+publisher:"Delft University of Technology" +contributor:("Serdijn, Wouter")

Delft University of Technology

1. Mul, Dieuwert (author). Stochastic Resonance Analog-to-Digital Conversion: 1-Bit Signal Acquisition Employing Noise.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:dcefcbc3-69d2-4a58-b73c-44d86c0f00f6

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Stochastic resonance (SR) is a phenomenon in which the presence of noise increases the performance of the system. The phenomenon has first been discovered in… (more)

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Stochastic resonance (SR) is a phenomenon in which the presence of noise increases the performance of the system. The phenomenon has first been discovered in a climate change model and is later observed in neuronal systems. In artificial, electronic, systems, stochastic resonance is observed in systems based on Schmitt-Triggers and comparators. The common property of all these systems is the threshold, which, when reached, causes a large transition in the system. The presence of noise in small signals can cause the system to reach the threshold or can increase the number of state transitions, increasing the quality of the output signal. Oversampling and integration are applied to reconstruct the original signal. Biomedical signals are typically affected relative high noise levels. The observations of stochastic resonance in nature, such as biological neural systems, combined with the observations of stochastic resonance in comparator-based circuits formed the inspiration and fundamental of this thesis research. The goal of this project is to investigate the potentials for using stochastic resonance in biomedical signal acquisition. In this thesis, an explorative study on the behavior, the performance, and the design of an analog-to-digital (ADC) converter fully based on stochastic resonance in a 1-bit quantizer is presented. The design and application focus on processing ECG measurements. A comprehensive analysis of the behavior, and an analytical method to determine the performance of 1-bit stochastic resonance analog-to-digital conversion in a comparator based circuit is presented. A novel technique using a negative hysteresis is found, showing a potential increase in SNDR up to 6.4 dB. Based on this analysis, a system level design is presented which implements a closed-loop operation of the stochastic resonance ADC. This design comprises a feedback loop to control the noise level, realizing the maximum performance over an input amplitude range from 1-10 mV, independent from noise present in the system. Furthermore, an offset compensation scheme is presented, which controls the threshold of the comparator, and a digital multi-rate filter is implemented to filter the high frequency noise, and to apply downsampling the highspeed bitstream. IC implementation of the comparator and the noise source is studied. A low-offset comparator, based on a strongARM latch, is proposed, with an offset calibration technique, reducing the offset to below 50 μV. The noise source creates a flat noise spectrum from 20 kHz to 4 MHz, using amplified thermal noise of a resistor combined with the amplifier noise. The proposed system can deliver a 27 dB SNDR in a signal bandwidth of 216 Hz, and an input amplitude range of 10×, using a sampling frequency of 2 MHz.

Electrical Engineering

Advisors/Committee Members: Serdijn, Wouter (mentor), Delft University of Technology (degree granting institution).

Subjects/Keywords: Stochastic Resonance; Analog-to-Digital; Noise; 1-bit processing; quantization; Signal Acquisition

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mul, D. (. (2018). Stochastic Resonance Analog-to-Digital Conversion: 1-Bit Signal Acquisition Employing Noise. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:dcefcbc3-69d2-4a58-b73c-44d86c0f00f6

Chicago Manual of Style (16^th Edition):

Mul, Dieuwert (author). “Stochastic Resonance Analog-to-Digital Conversion: 1-Bit Signal Acquisition Employing Noise.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:dcefcbc3-69d2-4a58-b73c-44d86c0f00f6.

MLA Handbook (7^th Edition):

Mul, Dieuwert (author). “Stochastic Resonance Analog-to-Digital Conversion: 1-Bit Signal Acquisition Employing Noise.” 2018. Web. 19 Jan 2021.

Vancouver:

Mul D(. Stochastic Resonance Analog-to-Digital Conversion: 1-Bit Signal Acquisition Employing Noise. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:dcefcbc3-69d2-4a58-b73c-44d86c0f00f6.

Council of Science Editors:

Mul D(. Stochastic Resonance Analog-to-Digital Conversion: 1-Bit Signal Acquisition Employing Noise. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:dcefcbc3-69d2-4a58-b73c-44d86c0f00f6

Delft University of Technology

2. Liu, Minghui (author). Passive Wireless ECoG Monitoring On Multiple Subjects.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:61b67578-6009-4538-858a-70302fe7fc68

► The neuroscience department of the Erasmus Medical Centre (EMC) has been working for many years to analyse the epilepsy and the treatments. It is a… (more)

▼ The neuroscience department of the Erasmus Medical Centre (EMC) has been working for many years to analyse the epilepsy and the treatments. It is a part of the neuro research in the collaborations between the Erasmus Medical Centre (EMC) neuroscience department and the section Bioelectronics at Delft University of Technology. The system is firstly tested by using discrete components and simulated, then the electronics schematic has been design and assembled. The approach for this wireless link system is using Frequency Division Multiple Access (FDMA) and Amplitude shift keying (ASK) modulation by backscattering method. Besides, the MCU is also used to generate the subcarriers for tests. In this work, a system level design for a wireless, multi-subject ElectroCorticoGram (ECoG) monitoring system for epilepsy research on mice is further optimized. The 915 MHz ISM band range is chosen and designed, where the GSM interference is detected and filtered out in the receiver. In this project, the receiver for downlink is further designed, which contains antennas, filters, oscillators and other commercial components. In uplink design, the MCU generates the subcarrier frequency and then this subcarrier is modulated on the main 915 MHz carrier by means of on-off-keying technique. The block prototype of the system is also simulated and tested to evaluate the general wireless link. In this wireless system, up to 3 objects can be simultaneously detected by using different subcarrier frequencies by designed analog receiver. The system experiments indicate different performance in terms of the power, interference and noise. According to these records, a schematic design with custom components guarantees the real time monitoring for multiple objects. The PCB design is completed including the power supply, transmitter and receiver. The receiver design is suitable for the scenario at 500 Hz sampling frequency of the ECoG signal and data bitrate below 100 KHz, with the demodulation of the subcarrier frequencies at 1.6 MHz, 2.6 MHz and 4 MHz. Advisors/Committee Members: Serdijn, Wouter (mentor), Delft University of Technology (degree granting institution).

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Liu, M. (. (2018). Passive Wireless ECoG Monitoring On Multiple Subjects. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:61b67578-6009-4538-858a-70302fe7fc68

Chicago Manual of Style (16^th Edition):

Liu, Minghui (author). “Passive Wireless ECoG Monitoring On Multiple Subjects.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:61b67578-6009-4538-858a-70302fe7fc68.

MLA Handbook (7^th Edition):

Liu, Minghui (author). “Passive Wireless ECoG Monitoring On Multiple Subjects.” 2018. Web. 19 Jan 2021.

Vancouver:

Liu M(. Passive Wireless ECoG Monitoring On Multiple Subjects. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:61b67578-6009-4538-858a-70302fe7fc68.

Council of Science Editors:

Liu M(. Passive Wireless ECoG Monitoring On Multiple Subjects. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:61b67578-6009-4538-858a-70302fe7fc68

Delft University of Technology

3. Baquer Gómez, Gerard (author). Optimal stimulation waveform for efficacious high-frequency block of the pudendal nerve with minimized electrochemical damage: A computer simulation optimization approach.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:5c875b14-08a3-4ef0-8e90-4fc997dc19d3

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"The use of high-frequency stimulation for conduction block of the pudendal nerve has potentially high benefits for patients suffering from non-neurogenic urinary retention. Special care… (more)

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"The use of high-frequency stimulation for conduction block of the pudendal nerve has potentially high benefits for patients suffering from non-neurogenic urinary retention. Special care has to be put in the design of stimulation parameters to ensure safe operation and prevent electrode and tissue damage. While high-frequency conduction block has been studied and used for many years, only standard waveforms, such as charge balanced sinewaves and square waves, have been utilized. Several studies have anticipated that the use of non-standard, non-symmetrical and slightly charge unbalanced waveforms may provide electrochemically safer stimulation protocols. In this computational simulation study, the MRG model is combined with an electrode-tissue interface (ETI) model based on in vivo experimental data to create a computational model capable of assessing both the efficacy and electrochemical safety of any given stimulation waveform. This model is coupled to a differential evolution algorithm to find the optimal waveform parameters that ensure a successful conduction block and a minimized charge injection through irreversible faradaic reactions. The classical DE algorithm is adapted to include several improvements such as evolutionary adaptive parametrization, elitism, and variable pattern to increase its performance. Additionally, acknowledging the fact that the axonal model is the main bottleneck in computational terms, an improvement baptized as "model down-sampling" is presented. Model down-sampling consists on only executing the axonal model to determine the effectiveness of the block once every N generations. This modification manages to double the execution speed without compromising accuracy. The results show that non-standard waveforms with a slight charge imbalance keep the ETI voltage well within the narrow electrochemical safe window of -0.25V and 0.55V, thus avoiding any irreversible charge injection process. The obtained waveforms show a 39.8% improvement on the safety margin with respect to the best performing standard stimulation waveform. The obtained results prove that well designed non-standard waveforms can lead to electrochemically safer high-frequency stimulation."

REValUE

Microelectronics

Advisors/Committee Members: Serdijn, Wouter (mentor), Delft University of Technology (degree granting institution).

Subjects/Keywords: High-frequency stimulation; modeling; optimization; safety; blocking; nerve conduction block; differential evolution; pudendal nerve

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Baquer Gómez, G. (. (2018). Optimal stimulation waveform for efficacious high-frequency block of the pudendal nerve with minimized electrochemical damage: A computer simulation optimization approach. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:5c875b14-08a3-4ef0-8e90-4fc997dc19d3

Chicago Manual of Style (16^th Edition):

Baquer Gómez, Gerard (author). “Optimal stimulation waveform for efficacious high-frequency block of the pudendal nerve with minimized electrochemical damage: A computer simulation optimization approach.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:5c875b14-08a3-4ef0-8e90-4fc997dc19d3.

MLA Handbook (7^th Edition):

Baquer Gómez, Gerard (author). “Optimal stimulation waveform for efficacious high-frequency block of the pudendal nerve with minimized electrochemical damage: A computer simulation optimization approach.” 2018. Web. 19 Jan 2021.

Vancouver:

Baquer Gómez G(. Optimal stimulation waveform for efficacious high-frequency block of the pudendal nerve with minimized electrochemical damage: A computer simulation optimization approach. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:5c875b14-08a3-4ef0-8e90-4fc997dc19d3.

Council of Science Editors:

Baquer Gómez G(. Optimal stimulation waveform for efficacious high-frequency block of the pudendal nerve with minimized electrochemical damage: A computer simulation optimization approach. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:5c875b14-08a3-4ef0-8e90-4fc997dc19d3

Delft University of Technology

4. Skrekas, Vassilis (author). Industry Compliant Wireless Power and Data Transfer Module Towards Ensuring Battery Denial of Service Protection.

Degree: 2020, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:e85d9ca8-ffd1-48ad-a57b-1b4f95cfd80b

► The field of active implantable medical devices (IMDs) has made huge steps forward in the last years. IMDs are used today for the treatment of… (more)

▼ The field of active implantable medical devices (IMDs) has made huge steps forward in the last years. IMDs are used today for the treatment of previously untreatable conditions as well as the continuous monitoring of the health of patients. The field, where active IMDs have been the most successful, is the field of neurological conditions, on which traditional medicine such as the intake of pills has very limited effect. In order to take full advantage of the possibilities offered by the IMDs it is vital to have communication between them and the external world. In this way, the treatment method provided by the IMD can be configured and optimized for each separate individual, achieving the best possible results. Moreover, the state of the device itself can be assessed and therefore possible flaws in its operation can be detected and corrected. Finally, in case of monitoring the patient’s health condition communication is also vital. However, this communication between the external world and the implanted device also introduces the possibility for someone, that possesses the required expertise and skills, to hack the device. The hacker can possibly “eavesdrop” the communication channel in order to extract information regarding the patient or even act in order to change parameters of the device and the therapy it provides, possibly causing harm to the patient. One way for hackers to disrupt the normal operation of the IMD is to drain its power source, namely the battery of the device, an attack that is named battery denial of service (BDoS) attack. One of the easiest ways to achieve such an attack is to make the device commit valuable power resources in order to run the authentication protocols continuously, by non-stop requesting for access. In this thesis, we try to tackle this problem by creating an analog circuit module that can act as an add-on to commercial IMDs that will have the task of authenticating the user that is trying to communicate with the IMD by making use of harvested wireless energy that is required for the communication. In this way, we expect to relieve the IMDs from spending time and resources on the authentication process. To that end, we designed and created an analog experimental prototype that employs both wireless power transfer and data communication, by simply making use of off-the-shelf components. The goal of this experimental prototype is to identify further challenges that can arise in a so called zero power defence scenario. To that end we implement a system that makes use of near-field resonant inductive coupling as a wireless power transfer method and is able to provide some mW of power across distances of up to 2cm, an amount of power that is sufficient to drive a microcontroller that can execute a low power security protocol in order to authenticate the entity trying to access the receiver. In addition to that, it can achieve a downlink data rate of 200kbit/s using amplitude shift keying modulation and an uplink data rate of 1kbit/s by making use of passive load shift… Advisors/Committee Members: Serdijn, Wouter (mentor), Strydis, Christos (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Wireless power transfer; Wireless Communication; Energy Harvesting; Security; Analog design; PCB Design; RF design

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Skrekas, V. (. (2020). Industry Compliant Wireless Power and Data Transfer Module Towards Ensuring Battery Denial of Service Protection. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:e85d9ca8-ffd1-48ad-a57b-1b4f95cfd80b

Chicago Manual of Style (16^th Edition):

Skrekas, Vassilis (author). “Industry Compliant Wireless Power and Data Transfer Module Towards Ensuring Battery Denial of Service Protection.” 2020. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:e85d9ca8-ffd1-48ad-a57b-1b4f95cfd80b.

MLA Handbook (7^th Edition):

Skrekas, Vassilis (author). “Industry Compliant Wireless Power and Data Transfer Module Towards Ensuring Battery Denial of Service Protection.” 2020. Web. 19 Jan 2021.

Vancouver:

Skrekas V(. Industry Compliant Wireless Power and Data Transfer Module Towards Ensuring Battery Denial of Service Protection. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:e85d9ca8-ffd1-48ad-a57b-1b4f95cfd80b.

Council of Science Editors:

Skrekas V(. Industry Compliant Wireless Power and Data Transfer Module Towards Ensuring Battery Denial of Service Protection. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:e85d9ca8-ffd1-48ad-a57b-1b4f95cfd80b

Delft University of Technology

5. Veloso O Donell, Miguel (author). Noise correlations and template matching on neural recordings.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:4b3b8b14-d02d-437e-b681-b774b484ee3b

► Spike sorting is the gold standard algorithm to detect and classify neural spikes in extracellular electrophysiological data. The classical spike sorting algorithm is, however, not… (more)

▼ Spike sorting is the gold standard algorithm to detect and classify neural spikes in extracellular electrophysiological data. The classical spike sorting algorithm is, however, not scalable to process thousands of neurons, and not fast enough to be applied on real time. Alternatively other algorithms have been implemented that are not only scalable to thousands of neurons but also faster in the classification task. In this work we focus on one of these algorithms: the Bayes Optimal Template Matching (BOTM). The BOTM presents the advantage of using a template matching procedure to solve, at the same time, the spike detection and classification. Within the BOTM algorithm we need to compute the noise covariance matrix. This matrix contains spatial, temporal, and spatio-temporal noise correlations among the electrodes used for recording the data, and it is important since its inverse works as a spatio-temporal whitening transformation. However, the matrix becomes too large to be computed or handled when large number of electrodes are used. In this work we focused on how to compute the noise covariance matrix when large number of electrodes are used for recording. First we separated its structure in two simpler matrices: one containing the spatial noise correlations, and one containing the temporal noise correlations among electrodes. We computed their inverses and applied three different whitening: spatial whitening, temporal whitening, and spatial and temporal whitening, one after each other. We evaluated the BOTM's performance under the different whitening approaches. Additionally, we took into account a new covariance matrix containing signal correlations, i.e. considering the whole signal, and not only the noise when computing correlations among the electrodes. We also evaluated the BOTM's performance for the signal covariance matrix. We were able to demonstrate that the spatio-temporal noise covariance matrix can be split in two simpler matrices: a spatial noise covariance matrix and a temporal noise covariance matrix. And that their inverses work as a spatial and as a temporal whitening transformations respectively. We also discuss about a problem we found within the toy data created for our measures: high-frequency components on inserted footprints. This problem can affect not only the BOTM algorithm, but also any other template matching based algorithm used. Finally, we concluded that the BOTM could not need any whitening transformation thanks to the redundancy on the recorded data when a large number of electrodes is used. Advisors/Committee Members: Franke, Felix (mentor), Serdijn, Wouter (mentor), Delft University of Technology (degree granting institution).

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Veloso O Donell, M. (. (2018). Noise correlations and template matching on neural recordings. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:4b3b8b14-d02d-437e-b681-b774b484ee3b

Chicago Manual of Style (16^th Edition):

Veloso O Donell, Miguel (author). “Noise correlations and template matching on neural recordings.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:4b3b8b14-d02d-437e-b681-b774b484ee3b.

MLA Handbook (7^th Edition):

Veloso O Donell, Miguel (author). “Noise correlations and template matching on neural recordings.” 2018. Web. 19 Jan 2021.

Vancouver:

Veloso O Donell M(. Noise correlations and template matching on neural recordings. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:4b3b8b14-d02d-437e-b681-b774b484ee3b.

Council of Science Editors:

Veloso O Donell M(. Noise correlations and template matching on neural recordings. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:4b3b8b14-d02d-437e-b681-b774b484ee3b

Delft University of Technology

6. van Wietmarschen, Luc (author). Energy harvesting on the human body: Hybrid charge pump design for cold start compatibility and high efficiency harvesting with minimal footprint.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:03532d19-2f51-47d8-ad5c-46cd553e2b2d

► This work proposes a new charge pump design suitable for energy harvesting on small human wearable devices. By using only one system for both cold… (more)

▼ This work proposes a new charge pump design suitable for energy harvesting on small human wearable devices. By using only one system for both cold start and high efficiency harvesting, the required silicon area is heavily reduced. The most fitting energy transducer is determined to be a photovoltaic cell, based on aspects of voltage, power and size. Both indoor and outdoor lighting conditions are suitable. The literature on fully integrated voltage boosting with special attention to cold start shows that the capacitive charge pump is the best solution for high efficiency, low power and small size voltage boosting. For cold start applications, a Dickson charge pump with dynamic charge transfer switches is the best solution. For achieving high efficiency conversion, theMakowski charge pump is the best. The proposed design combines the advantages of the Dickson charge pump for cold start and the high efficiency aspects of aMakowski charge pump for normal operation in one system with minimal silicon area. Using capacitor splitting, the conversion ratio of the cold start charge pump can be orthogonally chosen from the conversion ratio of normal operation. Dynamic charge transfer switches are used for the cold start charge pump to increase the performance. An implementation of the proposed design is made in Cadence Virtuoso and is tested for cold start capability and efficiency across five process corners and three temperatures. The results prove that the proposed design can achieve high efficiency energy harvesting that is on average 5% below the efficiency of a normal Makowski charge pump. Cold start was achieved from 100mV that is boosted to a battery voltage of 1.8 V within the micro-watt power range. With these results, the proposed charge pump is suitable for photovoltaic energy harvesting in small devices. The required silicon area is reduced by 50%, compared to systems where cold start and high efficiency harvesting are provided by separate systems. The proposed design is made into a lay-out, which is currently being tested and will be manufactured in the coming months. Advisors/Committee Members: Serdijn, Wouter (mentor), Babaie, Masoud (graduation committee), Rodrigues Mansano, Andre (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: charge pump; Energy Harvesting; integrated circuits; analog circuit design; Photovoltaic; Makowski charge pump; Dickson charge pump; Low power; low voltage; Cold start

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

van Wietmarschen, L. (. (2019). Energy harvesting on the human body: Hybrid charge pump design for cold start compatibility and high efficiency harvesting with minimal footprint. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:03532d19-2f51-47d8-ad5c-46cd553e2b2d

Chicago Manual of Style (16^th Edition):

van Wietmarschen, Luc (author). “Energy harvesting on the human body: Hybrid charge pump design for cold start compatibility and high efficiency harvesting with minimal footprint.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:03532d19-2f51-47d8-ad5c-46cd553e2b2d.

MLA Handbook (7^th Edition):

van Wietmarschen, Luc (author). “Energy harvesting on the human body: Hybrid charge pump design for cold start compatibility and high efficiency harvesting with minimal footprint.” 2019. Web. 19 Jan 2021.

Vancouver:

van Wietmarschen L(. Energy harvesting on the human body: Hybrid charge pump design for cold start compatibility and high efficiency harvesting with minimal footprint. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:03532d19-2f51-47d8-ad5c-46cd553e2b2d.

Council of Science Editors:

van Wietmarschen L(. Energy harvesting on the human body: Hybrid charge pump design for cold start compatibility and high efficiency harvesting with minimal footprint. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:03532d19-2f51-47d8-ad5c-46cd553e2b2d

Delft University of Technology

7. Joosse, Corniël (author). Absence seizure prediction using recurrent neural networks.

Degree: 2020, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:e752232f-cd6b-47c4-ba70-899a020b7e6d

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Absence seizures have a real-life impact on epileptic subjects, as day-to-day tasks can by suddenly interrupted making for dangerous situations. Though a lot of work… (more)

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Absence seizures have a real-life impact on epileptic subjects, as day-to-day tasks can by suddenly interrupted making for dangerous situations. Though a lot of work has been done on seizure detection, to limit the impact on epileptic patients, the true necessity lies in timely prediction of seizures before they manifest. Various attempts have been made using conventional algorithms to accurately predict seizures however, so far, results are not that encouraging. In this work, we applied various machine-learning algorithms, in an attempt to identify complex, multi-dimensional epileptic precursors in brain recordings. Three types of neural networks are used in this feasibility study, namely Multi-Layer Perceptron (MLP) networks, Long Short-Term Memory (LSTM) networks and Gated Recurrent Unit (GRU) networks. The used input data was annotated Electrocorticography (ECoG) data, recorded in living mutant rodents, containing epileptic events at an interval of about one minute. The data was pre-processed for better learning performance by data normalisation and by generating distinctive training features. The neural networks were configured as three-class classifiers, distinguishing among inter-ictal, pre-ictal and ictal periods. A grid-search approach was applied to determine the best set of parameters for the neural networks. Despite our best efforts, the relation between the input data and output data could not be learned in a reliable way. The maximum reached Average Prediction Rate (APR) was 0.57 with a prediction time of 3.1s when using the normalised data as input and 0.65 with a prediction time of 6.1s when using the distinctive features as input. These results essentially signify good detection but virtually no prediction of upcoming seizures. The evaluation of the experimental findings has revealed that the employed ECoG recordings were ill-selected for training our various neural-network models. Also, a non-conclusive exploratory experiment is performed by applying a Weibull Time-To-Event Recurrent Neural Network (WTTE-RNN) on a sub-set of the normalised input data. The experiment has yielded some positive results, a short-notice prediction of the upcoming seizure in some cases, encouraging for further exploration of this approach. Despite the limited success of this work, however, through its extended forensics analysis, it has paved the crucial, initial steps in the direction of seizure prediction.

Computer Engineering

Advisors/Committee Members: Strydis, Christos (mentor), Serdijn, Wouter (graduation committee), Hunyadi, Bori (graduation committee), Gaydadjiev, Georgi (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Recurrent Neural Networks; Absence seizure; Seizure prediction; Machine learning

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Joosse, C. (. (2020). Absence seizure prediction using recurrent neural networks. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:e752232f-cd6b-47c4-ba70-899a020b7e6d

Chicago Manual of Style (16^th Edition):

Joosse, Corniël (author). “Absence seizure prediction using recurrent neural networks.” 2020. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:e752232f-cd6b-47c4-ba70-899a020b7e6d.

MLA Handbook (7^th Edition):

Joosse, Corniël (author). “Absence seizure prediction using recurrent neural networks.” 2020. Web. 19 Jan 2021.

Vancouver:

Joosse C(. Absence seizure prediction using recurrent neural networks. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:e752232f-cd6b-47c4-ba70-899a020b7e6d.

Council of Science Editors:

Joosse C(. Absence seizure prediction using recurrent neural networks. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:e752232f-cd6b-47c4-ba70-899a020b7e6d

Delft University of Technology

8. Tacchetti, Lucia (author). Ultrasonic Power Transfer for Ultra-High-Frequency Biphasic Electrical Neural Stimulation.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:be3f241c-96d8-4c9c-b0dc-92b6cdd330d5

► Neurostimulators have been developed over the past few decades to treat various diseases, such as Parkinson’s disease, chronic pain, epilepsy, migraine and bladder dysfunction. One… (more)

▼ Neurostimulators have been developed over the past few decades to treat various diseases, such as Parkinson’s disease, chronic pain, epilepsy, migraine and bladder dysfunction. One of the major design challenges is the selection of a powering method that could supply mW power levels to miniaturized implanted devices. Among several methods, wireless power transfer is often used to directly supply the electronics or to recharge an implanted battery. In particular, the interest in ultrasonic waves as source of power and data for implantable medical devices has recently grown, particularly due to the advantages over RF and inductive coupling power transfer. In fact, ultrasounds can deliver higher power to mm-sized and deeply (> 10 cm) implanted receivers than the other techniques. Moreover, acoustic waves do not interfere with electromagnetic fields.Conventionally, biphasic constant current or constant voltage pulses are selected for stimulating nerve tissue. The first (usually cathodic) phase has the purpose of activating the excitable nerve fibres, while the second (usually anodic) phase reverses the direction of the stimulation current to avoid long-term accumulation of charge. Alternatively, Ultra-High-Frequency stimulation can be employed. This consists of current or voltage pulses at a high frequency (≥ 1 MHz), which are obtained from a DC source and the operation of high-frequency switches. In both techniques, when a wireless supply is chosen, the received AC signal is rectified, stored and regulated to operate the usually low-voltage blocks of the rest of the system. Nonetheless, up-conversion of the signal is often required to provide enough voltage compliance to operate an output stage connected to the stimulating electrodes.Taking a more radical approach, it is possible to avoid the lossy conversion from AC to regulated DC and from that to high-frequency stimulation by eliminating the need of power storage, regulation and up-conversion. To this end, the aim of this work was to design a circuit topology that generates ultra-high-frequency pulses by rectifying the sinusoid obtained from an ultrasound transducer and using the obtained waveform to directly stimulate the tissue in a biphasic fashion. This could result in a highly efficient and miniature circuit, which has the potential to be used for stimulating small peripheral nerves. Simulations in LTSpice were conducted to analyse the performance of the proposed system. The operation was then verified by measurements with a fabricated prototype, which was capable of providing biphasic pulses by receiving a signal from ultrasound piezoelectric transducers and driving a pair of electrodes. Advisors/Committee Members: Giagka, Vasso (mentor), Serdijn, Wouter (graduation committee), Dekker, Ronald (graduation committee), Mastrangeli, Max (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: ultrasound; neurostimulator; biphasic electrical stimulation; ultra-high-frequency

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tacchetti, L. (. (2018). Ultrasonic Power Transfer for Ultra-High-Frequency Biphasic Electrical Neural Stimulation. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:be3f241c-96d8-4c9c-b0dc-92b6cdd330d5

Chicago Manual of Style (16^th Edition):

Tacchetti, Lucia (author). “Ultrasonic Power Transfer for Ultra-High-Frequency Biphasic Electrical Neural Stimulation.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:be3f241c-96d8-4c9c-b0dc-92b6cdd330d5.

MLA Handbook (7^th Edition):

Tacchetti, Lucia (author). “Ultrasonic Power Transfer for Ultra-High-Frequency Biphasic Electrical Neural Stimulation.” 2018. Web. 19 Jan 2021.

Vancouver:

Tacchetti L(. Ultrasonic Power Transfer for Ultra-High-Frequency Biphasic Electrical Neural Stimulation. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:be3f241c-96d8-4c9c-b0dc-92b6cdd330d5.

Council of Science Editors:

Tacchetti L(. Ultrasonic Power Transfer for Ultra-High-Frequency Biphasic Electrical Neural Stimulation. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:be3f241c-96d8-4c9c-b0dc-92b6cdd330d5

Delft University of Technology

9. Emmer, Koen (author). Analysing the performance of KHFAC nerve block stimulation parameters: Developing design considerations for blocking the pudendal nerve using a new gate-dependent block determination model.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:1b06eb83-e5cd-4786-a848-d981e48c6095

►

A major cause for voiding dysfunction is the inability to relax the urethral sphincter. KiloHertz Frequency Alternating Current (KHFAC) stimulation can block signals that are… (more)

▼

A major cause for voiding dysfunction is the inability to relax the urethral sphincter. KiloHertz Frequency Alternating Current (KHFAC) stimulation can block signals that are travelling through the body; applying this type of stimulation at the pudendal nerve could inhibit the pulses that lead to contraction of the urethral sphincter, and restore voiding ability. In order to design a successful KHFAC block therapy for the pudendal nerve, it is necessary to understand what impact different stimulation parameters have on efficacy, safety and power-efficiency. This thesis will therefore test earlier researched KHFAC stimulation parameters against a new quality measure, study the impact of new waveform alterations, and study how bipolar electrode design can improve KHFAC therapy. By utilizing the theory behind the mechanism of the KHFAC nerve block, a new block-determination model was developed that is over thirty times faster than the classic model. The McIntyre-Richardson-Grill model was chosen as the implementation of the axon model, and the bipolar electrode was modelled as an electric dipole. The simulation experiments revealed that the charge per phase of the KHFAC signal at block threshold could be reduced, without increasing the amplitude of the signal, by introducing interphase delays to the waveforms and by creating asymmetric charge-balanced waveforms. Triangular waveforms were shown to also require less charge per phase than a regular square wave to block, albeit with a higher amplitude. A correctly aligned bipolar electrode set-up with an interpolar distance that was about the same as the electrode-to-axon distance was shown to result in reduced block thresholds. Overall, this thesis has shown how stimulation parameters can be chosen to develop an effective KHFAC block therapy for the pudendal nerve.

REValUE

Electrical Engineering

Advisors/Committee Members: Serdijn, Wouter (mentor), Negrello, Mario (graduation committee), Remis, Rob (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: KHFAC; KiloHertz Frequency Alternating Current stimulation; High-frequency stimulation; nerve conduction block; pudendal nerve; interphase delays; charge-balance; asymmetrical charge-balanced wave; stimulation parameters; design considerations; urinary retention; MRG Model; bipolar stimulation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Emmer, K. (. (2019). Analysing the performance of KHFAC nerve block stimulation parameters: Developing design considerations for blocking the pudendal nerve using a new gate-dependent block determination model. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:1b06eb83-e5cd-4786-a848-d981e48c6095

Chicago Manual of Style (16^th Edition):

Emmer, Koen (author). “Analysing the performance of KHFAC nerve block stimulation parameters: Developing design considerations for blocking the pudendal nerve using a new gate-dependent block determination model.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:1b06eb83-e5cd-4786-a848-d981e48c6095.

MLA Handbook (7^th Edition):

Emmer, Koen (author). “Analysing the performance of KHFAC nerve block stimulation parameters: Developing design considerations for blocking the pudendal nerve using a new gate-dependent block determination model.” 2019. Web. 19 Jan 2021.

Vancouver:

Emmer K(. Analysing the performance of KHFAC nerve block stimulation parameters: Developing design considerations for blocking the pudendal nerve using a new gate-dependent block determination model. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:1b06eb83-e5cd-4786-a848-d981e48c6095.

Council of Science Editors:

Emmer K(. Analysing the performance of KHFAC nerve block stimulation parameters: Developing design considerations for blocking the pudendal nerve using a new gate-dependent block determination model. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:1b06eb83-e5cd-4786-a848-d981e48c6095

Delft University of Technology

10. van der Lingen, Elisabeth (author). Dielectric spectroscopy for hydration monitoring, from application to portable sensors.

Degree: 2020, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:ee234106-0cfe-4c3f-9a08-210894bdff07

►

Due to the earth’s population growth and the increased living age of a person, more and more people could deal with medical problems. Early detection… (more)

Subjects/Keywords: CMOS permittivity sensor,; Dielectric spectroscopy; Hydration monitoring

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

van der Lingen, E. (. (2020). Dielectric spectroscopy for hydration monitoring, from application to portable sensors. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:ee234106-0cfe-4c3f-9a08-210894bdff07

Chicago Manual of Style (16^th Edition):

van der Lingen, Elisabeth (author). “Dielectric spectroscopy for hydration monitoring, from application to portable sensors.” 2020. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:ee234106-0cfe-4c3f-9a08-210894bdff07.

MLA Handbook (7^th Edition):

van der Lingen, Elisabeth (author). “Dielectric spectroscopy for hydration monitoring, from application to portable sensors.” 2020. Web. 19 Jan 2021.

Vancouver:

van der Lingen E(. Dielectric spectroscopy for hydration monitoring, from application to portable sensors. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:ee234106-0cfe-4c3f-9a08-210894bdff07.

Council of Science Editors:

van der Lingen E(. Dielectric spectroscopy for hydration monitoring, from application to portable sensors. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:ee234106-0cfe-4c3f-9a08-210894bdff07

Delft University of Technology

11. Petridis, Ioannis (author). Nonlinearity in the Light Processing of the Human Visual System.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:c54901b8-3552-468e-b41d-71b462ef7f06

► Visual evoked potentials, i.e responses to visual stimulation as recorded using electroencephalography have indicated the existence of nonlinear behavior of the visual pathway. Nonlinearities and… (more)

▼ Visual evoked potentials, i.e responses to visual stimulation as recorded using electroencephalography have indicated the existence of nonlinear behavior of the visual pathway. Nonlinearities and time delay in the visual system play an important role in understanding the complex nature of the visual system. This study investigated the nonlinear interactions and time delay in the visual pathway, using several types of stimulation paradigms. Multisine (i.e sum of multiple sinusoidal signals) and sine light stimulation were presented to healthy participants in order to elicit steady-state visual evoked responses. The recorded signals were analyzed using multi-spectral phase coherence, a novel cross-frequency phase coupling metric, in order to quantify the nonlinear interactions, form a brain map and estimate time delay. Chirp light stimulation (signals with linearly increasing frequencies) was used to elicit visual responses inside a specific frequency range. Time delay was estimated using Fractional Fourier Transformation due to its ability to handle chirps’ non-stationary properties. Brain maps indicated that multisine paradigms elicit more localized nonlinear interactions than chirp paradigms. All sinusoidal stimulation provided clusters of similar time delays. Bisine presented the most distinctive groups, fact that suggests that bisine is able to be used as a distinction measure. Trisine time delay showed the lowest variance, fact that shows more accurate estimation. Chirp time delay presented also small variances but the mean time delay found to be very frequency dependent. To conclude, this study showed that multisine paradigms are suitable to be used to elicit nonlinear responses but time delay may not be sufficient measure to fully describe the visual system. Advisors/Committee Members: Perenboom, MJL (mentor), Schouten, Alfred (graduation committee), Yang, Yuan (graduation committee), Serdijn, Wouter (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Nonlinear; Visual System; Steady State Visual Evoked Potentials; Light Stimulation; Light Processing; EEG Analysis; Brain Dynamics; SInusoidal; Chirp; Multisine

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Petridis, I. (. (2017). Nonlinearity in the Light Processing of the Human Visual System. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:c54901b8-3552-468e-b41d-71b462ef7f06

Chicago Manual of Style (16^th Edition):

Petridis, Ioannis (author). “Nonlinearity in the Light Processing of the Human Visual System.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:c54901b8-3552-468e-b41d-71b462ef7f06.

MLA Handbook (7^th Edition):

Petridis, Ioannis (author). “Nonlinearity in the Light Processing of the Human Visual System.” 2017. Web. 19 Jan 2021.

Vancouver:

Petridis I(. Nonlinearity in the Light Processing of the Human Visual System. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:c54901b8-3552-468e-b41d-71b462ef7f06.

Council of Science Editors:

Petridis I(. Nonlinearity in the Light Processing of the Human Visual System. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:c54901b8-3552-468e-b41d-71b462ef7f06

Delft University of Technology

12. Beintema, Tim (author). Quantitative Analysis in Neonatal Healthcare: Detecting Delta Brushes with the Wavelet Transform.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:7a3d5163-be8a-4685-a47d-522b1853183e

► In the Netherlands the preterm birth rate is around 7%. The problematic part is that these preterm infants make up for 72% of all deaths… (more)

▼ In the Netherlands the preterm birth rate is around 7%. The problematic part is that these preterm infants make up for 72% of all deaths during or shortly after birth. To provide a way to aid these infants the following question was stated by the doctor: "turn on a light in the Neonatal Intensive Care Unit when the preterm infant’s development is not as expected". This question was interpreted as following: first of all, find an informative signal present for preterm infants which can provide knowledge on the state of development. Secondly, find a way to quantify this signal through measurement and provide a way to automate the detection. Based on literature the delta brush was selected as a promising waveform in the neonatal EEG, which can be used to follow the maturation of the brain. The spectral behavior of the EEG is used to identify the specific waveforms, but this analysis of the EEG is still mainly based on visual analysis, which is a subjective and time-consuming task. A way to quantify and automate this process was found in the Continuous Wavelet Transform (CWT). Using the Morlet mother wavelet, a time-frequency distribution of the EEG was calculated. The CWT’s redundant behavior was found to provide a finer sampling which could be used to reinforce specific waveform behavior. A third goal was to investigate the troubles that new innovations face in being accepted by the medical field. This was found to be related to the building of trust. The key elements for building trust in this work were identified as: interpretability of the results, transparency of the process, and ease of operation. These elements will be taken into account in the proposed solution. A set of high-density EEG measurements of preterm infants was acquired through collaboration with the the Academic Hospital Antwerp and the Erasmus Medical Center. This high-density consists of 19 electrode channels instead of the more commonly used 11 electrode channels. The measurement was done at 30 weeks postmenstrual age (PMA). These measurements were accompanied with annotation for the waveform of interest. An interactive application for visualization of the EEG data and wavelet coefficients was designed in MATLAB. This application can run standalone and can be used to visualize the detector’s results for the end user. Based on the inherent characteristics of the target waveform two detection features were chosen. The first feature is a measure of the ratio between peak in the high-frequency region (3.3-40 Hz) and the low-frequency region (0.1-3.3 Hz). The second feature is an energy calculation based on a windowed Squared Energy Operator (SEO). A triple-threshold multi-channel detector, based on these features, was initialized and performance was tested over the full threshold range. A Precision-Recall (PRC) curve was provided showing the total solution space for both feature thresholds. Based on the point closest to (100,100) in the training set PRC, a single threshold was selected for validation with the validation datasets. This has resulted in… Advisors/Committee Members: Serdijn, Wouter (mentor), Hunyadi, Bori (graduation committee), Goos, Tom (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: EEG; Delta Brush; continuous wavelet transform; Morlet

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Beintema, T. (. (2019). Quantitative Analysis in Neonatal Healthcare: Detecting Delta Brushes with the Wavelet Transform. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:7a3d5163-be8a-4685-a47d-522b1853183e

Chicago Manual of Style (16^th Edition):

Beintema, Tim (author). “Quantitative Analysis in Neonatal Healthcare: Detecting Delta Brushes with the Wavelet Transform.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:7a3d5163-be8a-4685-a47d-522b1853183e.

MLA Handbook (7^th Edition):

Beintema, Tim (author). “Quantitative Analysis in Neonatal Healthcare: Detecting Delta Brushes with the Wavelet Transform.” 2019. Web. 19 Jan 2021.

Vancouver:

Beintema T(. Quantitative Analysis in Neonatal Healthcare: Detecting Delta Brushes with the Wavelet Transform. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:7a3d5163-be8a-4685-a47d-522b1853183e.

Council of Science Editors:

Beintema T(. Quantitative Analysis in Neonatal Healthcare: Detecting Delta Brushes with the Wavelet Transform. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:7a3d5163-be8a-4685-a47d-522b1853183e

Delft University of Technology

13. Silos Viu, Maria (author). SOMNUS: An Ultra-Wideband Radar-Based Approach for Neonatal Sleep State Classification.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:e27b8f5f-7247-4474-9190-6105c64434b5

►

Recently, there has been an increasing awareness of the critical role of sleep for the brain development of young infants. During the early neonatal stages… (more)

▼

Recently, there has been an increasing awareness of the critical role of sleep for the brain development of young infants. During the early neonatal stages of human development, the basic activity of the brain is to develop itself during sleep. Prolonged sleep is required in infants for further development of the nervous system. Sleep also plays an important role in body temperature regulation and energy saving. Neonatal sleep is divided into two main different sleep stages: Rapid EyeMovement (REM) and Non-Rapid Eye Movement (NREM). As the infant develops, sleep stages vary in maturity, length and distribution, thus underlining the importance of the quantification of these stages, which could eventually lead to new biomarkers of neonatal brain development. Nowadays, the golden standard in sleep monitoring is Polysomnography (PSG), in which vital signs as well as EEG and muscle activity are recorded during a whole-night study and subsequently sleep stages are classified by an expert. However, the high obtrusiveness of the multiple electrodes involved in PSG and its high associated costs make it impossible to use PSG as a routine monitor system. The SOMNUS project had two main targets: (i) to accurately measure respiration signals from patients using an ultra-wideband radar module, and (ii) to detect differences in respiration between REM and NREM phases in order to unobtrusively and automatically score sleep states of infants without the need of any electrode attached to the patient. The system has been developed using a training dataset of 23 patients from 3 months to 14 years old. It is for the first time UWB radar technology is used to monitor sleep in young patients. Moreover, this work provides a new data analysis algorithm to suppress motion artifacts from radar signals and increase the robustness of respiration monitoring. The results from the breathing detection algorithm developed in the present work provided an average mean absolute error of 3.25 Respirations per Minute in respiration rate. Amount of movement was employed to estimate Sleep/Awake events, with an average error in percentage of Total Sleep Time of 7.48%. Regarding sleep-state classification, several classification analyses were performed in order to study the best classification variable to detect REM/NREM, along with analyses regarding the best classification technique. Respiration variability was the main feature determining REM/NREMstate, with an overall sleep classification accuracy of around 80% when using linear classifiers such as Support Vector Machines and Fisher Linear Discrimination.

SOMNUS

Biomedical Engineering

Advisors/Committee Members: Serdijn, Wouter (mentor), Bes, Cees-Jeroen (graduation committee), Schouten, Alfred (graduation committee), Dudink, Jeroen (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Ultra-Wideband Radar; Neonatal Sleep Monitoring; Sleep-state classification; Breathing detection

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Silos Viu, M. (. (2017). SOMNUS: An Ultra-Wideband Radar-Based Approach for Neonatal Sleep State Classification. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:e27b8f5f-7247-4474-9190-6105c64434b5

Chicago Manual of Style (16^th Edition):

Silos Viu, Maria (author). “SOMNUS: An Ultra-Wideband Radar-Based Approach for Neonatal Sleep State Classification.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:e27b8f5f-7247-4474-9190-6105c64434b5.

MLA Handbook (7^th Edition):

Silos Viu, Maria (author). “SOMNUS: An Ultra-Wideband Radar-Based Approach for Neonatal Sleep State Classification.” 2017. Web. 19 Jan 2021.

Vancouver:

Silos Viu M(. SOMNUS: An Ultra-Wideband Radar-Based Approach for Neonatal Sleep State Classification. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:e27b8f5f-7247-4474-9190-6105c64434b5.

Council of Science Editors:

Silos Viu M(. SOMNUS: An Ultra-Wideband Radar-Based Approach for Neonatal Sleep State Classification. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:e27b8f5f-7247-4474-9190-6105c64434b5

Delft University of Technology

14. Konsolakis, Kostas (author). Physical Activity Recognition using Wearable Accelerometers in Controlled and Free-Living Environments.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:af2e1786-ccc4-4592-afc8-b19819544f26

► Physical activity recognition through wearables has enabled the development of novel applications in healthcare. Most of the existing studies focus on predicting activities using wearable… (more)

Subjects/Keywords: Physical Activity; Activity Recognition; Wearables; Accelerometer; Wrist; Chest; Controlled Experiment; Uncontrolled Experiment

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Konsolakis, K. (. (2018). Physical Activity Recognition using Wearable Accelerometers in Controlled and Free-Living Environments. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:af2e1786-ccc4-4592-afc8-b19819544f26

Chicago Manual of Style (16^th Edition):

Konsolakis, Kostas (author). “Physical Activity Recognition using Wearable Accelerometers in Controlled and Free-Living Environments.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:af2e1786-ccc4-4592-afc8-b19819544f26.

MLA Handbook (7^th Edition):

Konsolakis, Kostas (author). “Physical Activity Recognition using Wearable Accelerometers in Controlled and Free-Living Environments.” 2018. Web. 19 Jan 2021.

Vancouver:

Konsolakis K(. Physical Activity Recognition using Wearable Accelerometers in Controlled and Free-Living Environments. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:af2e1786-ccc4-4592-afc8-b19819544f26.

Council of Science Editors:

Konsolakis K(. Physical Activity Recognition using Wearable Accelerometers in Controlled and Free-Living Environments. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:af2e1786-ccc4-4592-afc8-b19819544f26

Delft University of Technology

15. Ólafsdóttir, Guðrún Erla (author). An Implantable Spinal Cord Stimulator with Adaptive Voltage Compliance for Freely Moving Rats.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:b42dd4d0-7dfc-4fb5-ba4d-e763718e0477

► When the neural pathway within the spinal cord gets damaged, a person’s ability to initiate loco- motion can be affected. Currently, no restorative treatments exist… (more)

▼ When the neural pathway within the spinal cord gets damaged, a person’s ability to initiate loco- motion can be affected. Currently, no restorative treatments exist for individuals that suffer from such an injury. However, recent studies have shown epidural spinal cord stimulation (ESCS) to be a potential option for re-establishing some voluntary control. Further research is required to increase our understanding and allow us to investigate the neuronal response to different stimulation parameters. For these purposes, experiments have been conducted in spinal cord injured rats but they suffer from limitations due to the difficult criteria that an electrical stimulation device has to fulfill. In order to investigate the effect of different stimulation parameters, the system needs to offer full programmability to the researcher. Furthermore, since it is desired to investigate the natural behavior patterns of the animal, they should not have to be tethered to a setup during experiments. Ideally such an experimental setup would be fully implantable, which greatly limits the acceptable size of the system. Moreover, an implantable device needs to operate on a minimum amount of power in order to extend the lifetime of the implant. Current controlled stimulation (CCS) devices are favored in electrical stimulation applications due to the accurate control that they offer over the injected charge. Nonetheless, they are known to suffer from poor power efficiency due to the highly variable and dynamic range of electrode-tissue impedance. A high voltage compliance is required to provide stimulation to high impedance loads and most devices include a system block to boost up the internal voltage. Therefore, during operation with lower loads, a lot of power is wasted within the system as the excess voltage is dissipated across its current source. Furthermore, high-voltage compliant devices often exhibit large current spikes at the output when driving lower loads, compromising the overall charge control. The aim of this work was to design and fabricate a fully programmable control unit for epidu- ral spinal cord stimulation in freely moving rodents. The control unit would provide rectangular current pulses to an active electrode array, that was previously designed to be implanted within the spinal canal of the rat. It proposes a novel approach that implements an adaptive voltage compliance in order to reduce the unnecessary power consumption of CCS. Instead of providing a fixed voltage value at its output, the boost converter can be controlled and adjusted to the required value across the load. Moreover, lowering the voltage compliance of the device both enhances the speed of the system and reduces the generated current spikes when operating on lower loads or generating smaller stimulation currents. Thus, it provides safe, charge-balanced stimulation pulses to the tissue. The fabricated version of the system is 13.5 cm3 and therefore fulfills the size restrictions of a system to be implanted in a rat. Because it is… Advisors/Committee Members: Giagka, Vasso (mentor), Serdijn, Wouter (graduation committee), French, Paddy (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: electrical stimulation; adaptive compliance; freely moving rat; spinal cord injury; implantable; stimulator

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Ólafsdóttir, G. E. (. (2017). An Implantable Spinal Cord Stimulator with Adaptive Voltage Compliance for Freely Moving Rats. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:b42dd4d0-7dfc-4fb5-ba4d-e763718e0477

Chicago Manual of Style (16^th Edition):

Ólafsdóttir, Guðrún Erla (author). “An Implantable Spinal Cord Stimulator with Adaptive Voltage Compliance for Freely Moving Rats.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:b42dd4d0-7dfc-4fb5-ba4d-e763718e0477.

MLA Handbook (7^th Edition):

Ólafsdóttir, Guðrún Erla (author). “An Implantable Spinal Cord Stimulator with Adaptive Voltage Compliance for Freely Moving Rats.” 2017. Web. 19 Jan 2021.

Vancouver:

Ólafsdóttir GE(. An Implantable Spinal Cord Stimulator with Adaptive Voltage Compliance for Freely Moving Rats. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:b42dd4d0-7dfc-4fb5-ba4d-e763718e0477.

Council of Science Editors:

Ólafsdóttir GE(. An Implantable Spinal Cord Stimulator with Adaptive Voltage Compliance for Freely Moving Rats. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:b42dd4d0-7dfc-4fb5-ba4d-e763718e0477

Delft University of Technology

16. Insani Abdi Bangsa, Abdi (author). System Building Blocks for Mathematical Operators Using Stochastic Resonance: Application in an Action Potential Detection System.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:4b87974d-a736-4d34-bd36-d4aafd25da9b

► Stochastic resonance (SR) is a phenomenon where the performance of a nonlinear system subjected to noise is better than it is without noise. This phenomenon… (more)

▼ Stochastic resonance (SR) is a phenomenon where the performance of a nonlinear system subjected to noise is better than it is without noise. This phenomenon can be found both in natural and artificial systems, especially in threshold-based systems such as comparators or a population of neurons. As noise always exists and interacts with the system, it is advantageous to design a system that purposefully uses SR to boost its performance. One possible use of SR is in the signal reconstruction. In this application, noise is added to the input signal and is processed by a comparator to produce a 1-bit output signal. This output can be averaged to recover the amplified input signal. In this thesis, three challenges regarding the use of SR in signal reconstruction are addressed. Firstly, to use SR not only to reconstruct the original signal, but also to implement mathematical operators, specifically a multiplier and an adder, that take two or more input signals. Secondly, to define the relevant metric(s) that can be used to measure the performance of the operators. Lastly, to build a system out of the proposed SR-based operators. The SR-based mathematical operators are implemented on the system level with a comparator as its fundamental building block. To analyze the behavior of the operators, formulas for noise and distortion power are derived. MATLAB simulation is then used to verify the theoretical analysis. Finally, these SR-based mathematical operators are used to build a Teager Energy Operator (TEO) for action potentials (APs) detection. An SR-based multiplier and adder can be implemented with the use of an XNOR logic gate and a binary half adder, respectively. The theoretical formulas are successful in predicting the noise and distortion behavior of the operators. In conclusion, it is possible to implement mathematical operators, specifically multipliers and adders, which use noise to boost their performance. The noise and distortion behavior of these operators can be predicted mathematically. Signal-to-noise ratio (SNR) and signal-to-noise-and-distortion ratio (SNDR) are used to measure the performance of the operators. Systems, specifically a TEO, can be built using the SR-based operators. Advisors/Committee Members: Serdijn, Wouter (mentor), Weber, Jos (graduation committee), Tax, David (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: stochastic resonance (SR); multiplier; adder; Teager Energy Operator (TEO); 1-bit processing

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Insani Abdi Bangsa, A. (. (2017). System Building Blocks for Mathematical Operators Using Stochastic Resonance: Application in an Action Potential Detection System. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:4b87974d-a736-4d34-bd36-d4aafd25da9b

Chicago Manual of Style (16^th Edition):

Insani Abdi Bangsa, Abdi (author). “System Building Blocks for Mathematical Operators Using Stochastic Resonance: Application in an Action Potential Detection System.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:4b87974d-a736-4d34-bd36-d4aafd25da9b.

MLA Handbook (7^th Edition):

Insani Abdi Bangsa, Abdi (author). “System Building Blocks for Mathematical Operators Using Stochastic Resonance: Application in an Action Potential Detection System.” 2017. Web. 19 Jan 2021.

Vancouver:

Insani Abdi Bangsa A(. System Building Blocks for Mathematical Operators Using Stochastic Resonance: Application in an Action Potential Detection System. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:4b87974d-a736-4d34-bd36-d4aafd25da9b.

Council of Science Editors:

Insani Abdi Bangsa A(. System Building Blocks for Mathematical Operators Using Stochastic Resonance: Application in an Action Potential Detection System. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:4b87974d-a736-4d34-bd36-d4aafd25da9b

Delft University of Technology

17. de Veij Mestdagh, Jurriaan (author). The effect of perturbation properties on system identification of human balance control during stance.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:6e4e8553-b215-489c-96ee-fa22dacd9c17

►

Introduction: System identification of the neuromuscular controller that regulates human balance, gives insight in the causes and effects of human balance disorders. The combination of… (more)

Subjects/Keywords: System Identification; human balance control; neuromuscular controller; perturbation; multisine; perturbation amplitude; averaging; repetitions; nonlinearity; single inverted pendulum

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

de Veij Mestdagh, J. (. (2017). The effect of perturbation properties on system identification of human balance control during stance. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:6e4e8553-b215-489c-96ee-fa22dacd9c17

Chicago Manual of Style (16^th Edition):

de Veij Mestdagh, Jurriaan (author). “The effect of perturbation properties on system identification of human balance control during stance.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:6e4e8553-b215-489c-96ee-fa22dacd9c17.

MLA Handbook (7^th Edition):

de Veij Mestdagh, Jurriaan (author). “The effect of perturbation properties on system identification of human balance control during stance.” 2017. Web. 19 Jan 2021.

Vancouver:

de Veij Mestdagh J(. The effect of perturbation properties on system identification of human balance control during stance. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:6e4e8553-b215-489c-96ee-fa22dacd9c17.

Council of Science Editors:

de Veij Mestdagh J(. The effect of perturbation properties on system identification of human balance control during stance. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:6e4e8553-b215-489c-96ee-fa22dacd9c17

Delft University of Technology

18. Bisschop, Marc (author). Resistive Matching using an AC Boost Converter for Efficient Ultrasonic Wireless Power Transfer.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:6d1b467a-7ac9-4758-988c-8d19bd0a360d

► Implantable Medical Devices (IMDs) could fulfill many different functions in the human body. Batteries have always been the main power source of these devices. Batteries… (more)

▼ Implantable Medical Devices (IMDs) could fulfill many different functions in the human body. Batteries have always been the main power source of these devices. Batteries have some drawbacks, the biggest one being the replacement of IMDs with fully discharged batteries. In this thesis a wireless power transfer system, with a receiving power conversion system with a maximum volume of 10 mm3, is proposed for IMDs implanted at more than 10 cm deep. Ultrasonic wireless power transfer to IMDs could enable scaling down the devices to dimensions less than 1 cm. Compared with the electromagnetic far-field and near-field wireless power transfer methods, the power throughput to the IMD is much higher. Piezo-electric elements could be used to perform the acoustic to electric energy conversion. With the Butterworth-Van Dyke modeling technique, the ultrasonic wireless power transfer link could be characterized. Maximum acoustic intensity at the receiving piezo-electric element is assumed because of the high efficiency and the possible methods to focus the waves from the transmitter at a certain point in the human body. An electrical storage element is assumed because of fluctuations both in received and used power. As the piezo-electric receiver outputs sinusoidal voltage and current waveforms, and the electrical storage element requires DC voltage, the signal requires significant processing for maximum power transfer. A perfect complex conjugate match between the piezo-electric receiver and the power conversion circuit is required for maximum power transfer as well. Two different methods which are used in prior art to achieve maximum power transfer are presented in this thesis, and one new method is developed. The standard method, which is used often in literature, does not include any special processing by means of impedance transformations and is therefore only efficient around one power level operating point. The varying frequency method varies the frequency so as to vary the piezo resistance and match it to the power conversion systems resistance. The piezo inductance varies with the varying piezo resistance, and is canceled out by tunable capacitor banks. A DC boost converter is required for high efficiency to the electric storage element. This method has many drawbacks, among which the continuous communication back to the transmitter to close the loop, which is consuming power and adding delay. The newly proposed method is the AC boost method. The AC voltage of the piezo-electric receiver is transformed into a pulse width modulated square wave voltage, so all power could go through the rectifier and into the storage element. A continuous resistive match is made between the AC boost converter and the piezo-electric element, ensuring maximum power transfer. This new method is validated by performing electric circuit simulations. Circuits are designed for the simulations that are comparable because of using the same piezo-electric element, rectifier, and storage element. The simulations show that it is the most… Advisors/Committee Members: Serdijn, Wouter (mentor), Pertijs, Michiel (graduation committee), Valente, Virgilio (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: impedance transformation; implantable medical devices (IMDs); maximum power transfer; resistor emulation; ultrasound; wireless power transfer; AC boost

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bisschop, M. (. (2019). Resistive Matching using an AC Boost Converter for Efficient Ultrasonic Wireless Power Transfer. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:6d1b467a-7ac9-4758-988c-8d19bd0a360d

Chicago Manual of Style (16^th Edition):

Bisschop, Marc (author). “Resistive Matching using an AC Boost Converter for Efficient Ultrasonic Wireless Power Transfer.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:6d1b467a-7ac9-4758-988c-8d19bd0a360d.

MLA Handbook (7^th Edition):

Bisschop, Marc (author). “Resistive Matching using an AC Boost Converter for Efficient Ultrasonic Wireless Power Transfer.” 2019. Web. 19 Jan 2021.

Vancouver:

Bisschop M(. Resistive Matching using an AC Boost Converter for Efficient Ultrasonic Wireless Power Transfer. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:6d1b467a-7ac9-4758-988c-8d19bd0a360d.

Council of Science Editors:

Bisschop M(. Resistive Matching using an AC Boost Converter for Efficient Ultrasonic Wireless Power Transfer. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:6d1b467a-7ac9-4758-988c-8d19bd0a360d

Delft University of Technology

19. Huang, Chengyu (author). Design and MEMS Microfabrication of an Optrode for Combined Optogenetics and Electrophysiology Studies.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:36c6fef5-3eef-4472-a4b2-c2fc4f4d3bba

► Optogenetics is a biological technique that uses light to control cells in living tissues, typically neurons, that have been genetically modified to express light-sensitive ion… (more)

▼ Optogenetics is a biological technique that uses light to control cells in living tissues, typically neurons, that have been genetically modified to express light-sensitive ion channels. Using this technique, neuroscientists can investigate the neural circuits underlying neurological diseases with a higher spatio-temporal resolution when compared to other known neuromodulation methods. As employed today, optogenetics requires methods for guiding sufficiently strong and precisely timed light to specific brain regions, while the experimental subject carries out behaviors of interest. For this role, miniaturized devices (namely optrodes) shall be properly engineered to hold the required components (e.g. light source, recording electrodes, etc) whilst complying with some surgical and biocompatibility issues. In this work, an optrode was designed and fabricated using an in-house MEMS microfabrication technology. The custom-made device featured (a) low impedance level with TiN-coated microelectrodes, (b) sufficient optical power delivery through on-chip-uLEDs, and (c) miniaturized dimensions with tolerable tissue damage during long-term animal experiments. In addition, different optrodes were fabricated to allow different experiment conditions (i.e. chronic or acute implantation, multi-site or multi-layer studies). A MEMS cavity for the on-chip-uLED was engineered on the optrode's shaft in order to further minimize the induced tissue damage during the surgical implantation. Last but not least, this customized optrode is also compatible with our in-house CMOS technology and can be further upgraded with additional electronic functionalities, as well as with the deposition of novel materials. After the microfabrication and system integration, in-vitro experiments on three different designs were performed to characterize electrically the electrode impedance, the control of uLED's light intensity and pulse frequency. Advisors/Committee Members: Serdijn, Wouter (mentor), Martins da Ponte, Ronaldo (mentor), French, Paddy (graduation committee), Giagka, Vasso (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Optrode; Optogenetics; Electrophysiology; MEMS technology; Micro-LED; Microelectrodes; Microfabrication

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Huang, C. (. (2018). Design and MEMS Microfabrication of an Optrode for Combined Optogenetics and Electrophysiology Studies. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:36c6fef5-3eef-4472-a4b2-c2fc4f4d3bba

Chicago Manual of Style (16^th Edition):

Huang, Chengyu (author). “Design and MEMS Microfabrication of an Optrode for Combined Optogenetics and Electrophysiology Studies.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:36c6fef5-3eef-4472-a4b2-c2fc4f4d3bba.

MLA Handbook (7^th Edition):

Huang, Chengyu (author). “Design and MEMS Microfabrication of an Optrode for Combined Optogenetics and Electrophysiology Studies.” 2018. Web. 19 Jan 2021.

Vancouver:

Huang C(. Design and MEMS Microfabrication of an Optrode for Combined Optogenetics and Electrophysiology Studies. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:36c6fef5-3eef-4472-a4b2-c2fc4f4d3bba.

Council of Science Editors:

Huang C(. Design and MEMS Microfabrication of an Optrode for Combined Optogenetics and Electrophysiology Studies. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:36c6fef5-3eef-4472-a4b2-c2fc4f4d3bba

Delft University of Technology

20. Geelen, Jinne (author). Terahertz Torching: Towards closed-loop neurostimulation of group-housed freely moving rodents.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:e3260861-ae33-4356-a240-cf8341546f6a

► Close collaboration between the Bioelectronics department at Delft University of Technology and the Neuroscience department at the Erasmus Medical Centre has resulted in a successful… (more)

▼ Close collaboration between the Bioelectronics department at Delft University of Technology and the Neuroscience department at the Erasmus Medical Centre has resulted in a successful tethered design for a real-time epileptic seizure detection and suppression method for mice. The goal of the Neuromate project is to develop this method into a wireless setup containing group-housed freely moving and interacting mice for use in behavioural studies. The system will include continuous monitoring and stimulation at set points in time. The Neuromate project comprises three links, two of which have previously been established. The main goal of this study was to find and evaluate a technique to complement the current Neuromate project with a wireless downlink, channelling the communication from the researchers towards the mice. This new downlink should fit in the ongoing project and meet particular specifications. The most critical requirements are that it should be lightweight and small-scale and should allow simultaneous multi-user communication. Also crucial are the prevention of interference with the two other links, reliability and low power consumption. The three most promising techniques, power source keying, optical wireless transmission and terahertz torching are elaborated. Terahertz (THz) torching, covering the high thermal part of the THz band (10 to 100 THz), was chosen as the technique to be developed in this thesis. This decision was based on the fundamental limitations of power source keying and optical wireless transmission, which appear in the weighted criteria evaluation of the requirements. The challenges of THz torching are mainly practical, while fundamentally it provides the opportunity to form a reliable non-interfering wireless link. The feasibility of THz torching for our specific application was tested by creating a proof-of-principle and conducting five different experiments. The prototype includes two components. The first is a thermal source, which in the final design will be placed above the cage, and the second is a pyroelectric detector, which will later be positioned on top of the head module of each of the mice. During the experiments, communication with the recently developed THz torch was proven to be feasible. Experiment 1 resulted in an optimum data rate of 35.71 bps, allowing for the simultaneous stimulation of the mice. And the divergence of the source was sufficient to cover the entire cage, as it was found in experiment 3 that an angle of 50° was the maximum misalignment still allowing reliable transfer of the data. However, the prototype did fail to reach the required distance. In experiment 2 only 8 cm could reliably be bridged. The source was not strong enough to overcome the attenuation in the air. A more powerful source will allow an increased reachable distance, making sure the entire cage is covered. In this work, an innovative and promising proof-of-concept has been realized for the wireless downlink of the Neuromate… Advisors/Committee Members: Serdijn, Wouter (mentor), Hoebeek, Freek E. (mentor), Schouten, Alfred (graduation committee), Giagka, Vasso (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: terahertz torching; wireless communication; neuromate; downlink; thermal terahertz

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Geelen, J. (. (2017). Terahertz Torching: Towards closed-loop neurostimulation of group-housed freely moving rodents. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:e3260861-ae33-4356-a240-cf8341546f6a

Chicago Manual of Style (16^th Edition):

Geelen, Jinne (author). “Terahertz Torching: Towards closed-loop neurostimulation of group-housed freely moving rodents.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:e3260861-ae33-4356-a240-cf8341546f6a.

MLA Handbook (7^th Edition):

Geelen, Jinne (author). “Terahertz Torching: Towards closed-loop neurostimulation of group-housed freely moving rodents.” 2017. Web. 19 Jan 2021.

Vancouver:

Geelen J(. Terahertz Torching: Towards closed-loop neurostimulation of group-housed freely moving rodents. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:e3260861-ae33-4356-a240-cf8341546f6a.

Council of Science Editors:

Geelen J(. Terahertz Torching: Towards closed-loop neurostimulation of group-housed freely moving rodents. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:e3260861-ae33-4356-a240-cf8341546f6a

Delft University of Technology

21. Das, Aurojyoti (author). Multichannel LC ADC: to Record Atrial Electrograms.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:ca77d0f7-0ea7-4782-a42a-c878c5204956

►

Biosignals such as electoencephalogram (EEG), electrocorticogram (ECoG), atrial electrogram (AEG) etc. are being recorded from multiple channels simultaneously to improve the spatial resolution of the… (more)

Subjects/Keywords: Biosignals; atrial fibrillation; ADC; level crossing ADC; multichannel ADC

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Das, A. (. (2019). Multichannel LC ADC: to Record Atrial Electrograms. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:ca77d0f7-0ea7-4782-a42a-c878c5204956

Chicago Manual of Style (16^th Edition):

Das, Aurojyoti (author). “Multichannel LC ADC: to Record Atrial Electrograms.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:ca77d0f7-0ea7-4782-a42a-c878c5204956.

MLA Handbook (7^th Edition):

Das, Aurojyoti (author). “Multichannel LC ADC: to Record Atrial Electrograms.” 2019. Web. 19 Jan 2021.

Vancouver:

Das A(. Multichannel LC ADC: to Record Atrial Electrograms. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:ca77d0f7-0ea7-4782-a42a-c878c5204956.

Council of Science Editors:

Das A(. Multichannel LC ADC: to Record Atrial Electrograms. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:ca77d0f7-0ea7-4782-a42a-c878c5204956

Delft University of Technology

22. Velea, Andrada (author). Flexible Graphene-Based Passive and Active Spinal Cord Implants.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:13f3c500-4edd-4cf3-80ea-a4464279a78e

► The spinal cord, considered to be the most important path of the human body, when injured induces severe motor dysfunction. Therefore, patients affected by lesions… (more)

▼ The spinal cord, considered to be the most important path of the human body, when injured induces severe motor dysfunction. Therefore, patients affected by lesions on the spinal cord, are most of the time unable to walk, stand or perform motor activities that are trivial for healthy people. To provide a better quality of life for these patients, extensive research and effort have been put by both neuroscientists and engineers to provide clinical therapies for pain relief and locomotion restoration together with dedicated platforms that could deliver these therapies. Currently, for these purposes, epidural spinal cord stimulation is widely used. Apart from being used as a method to reduce pain, it has also been proven to promote locomotion recovery. Apart from clinical trials, it is of great importance to understand the mechanisms that occur while delivering specific therapies. To this end, more exploratory research is mostly conducted in rodents. However, the availability of tailored neurotechnologies, for experiments conducted in small animals, is limited mostly due to size constraints. Moreover, when developing implantable devices that would target the spinal cord, careful selection of the materials used is equally important. However, understanding the underlying mechanism leading to a specific behaviour or motor outputs requires exploring and quantifying new methods of stimulation. For instance, optogenetics has been gaining a lot of popularity in the field of neural stimulation as it is a more specific technique that could help neuroscientists map the neuronal circuitry within the human body. Thus, apart from developing spinal cord implants that resemble best the anatomy of the body, while inducing as little stress as possible on the spinal cord, for exploratory reasons the developed implants must provide optogenetic compatibility. Therefore, this thesis reports the development as well as the characterization of both passive and active spinal cord implants with optogenetic compatibility. To achieve the desired goal of having a fully implantable, flexible spinal cord implant with optogenetic compatibility, a scalable and reproducible microfabrication process has been developed. Materials such as graphene, for transparency, flexibility and conductivity were used to develop the microelectrode arrays. Moreover, soft, polymeric encapsulation was employed to sustain the high flexibility and transparency of the implant. The end result of the microfabrication process would lead to a device consisting of a multi-layered graphene structure between two polymeric-based encapsulation layers and metal test pads for interconnection to the outside world. However, towards achieving this final structure, several challenges were encountered. Suspension of the implants after developing them on a rigid substrate, yet ensuring high quality for the graphene layer leads to several iterations of the fabrication process. Despite the challenges encountered, several prototypes were successfully developed. However, having prototypes that… Advisors/Committee Members: Giagka, Vasiliki (mentor), Vollebregt, Sten (mentor), Serdijn, Wouter (graduation committee), Steeneken, Peter (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Graphene; Passive; Active; Spinal Cord Implants

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Velea, A. (. (2019). Flexible Graphene-Based Passive and Active Spinal Cord Implants. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:13f3c500-4edd-4cf3-80ea-a4464279a78e

Chicago Manual of Style (16^th Edition):

Velea, Andrada (author). “Flexible Graphene-Based Passive and Active Spinal Cord Implants.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:13f3c500-4edd-4cf3-80ea-a4464279a78e.

MLA Handbook (7^th Edition):

Velea, Andrada (author). “Flexible Graphene-Based Passive and Active Spinal Cord Implants.” 2019. Web. 19 Jan 2021.

Vancouver:

Velea A(. Flexible Graphene-Based Passive and Active Spinal Cord Implants. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:13f3c500-4edd-4cf3-80ea-a4464279a78e.

Council of Science Editors:

Velea A(. Flexible Graphene-Based Passive and Active Spinal Cord Implants. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:13f3c500-4edd-4cf3-80ea-a4464279a78e

Delft University of Technology

23. Stijnman, Peter (author). Transceive Phase Corrected Contrast Source Inversion-Electrical Properties Tomography.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:cca2d3a8-d02e-4481-a16b-e78e745c6b80

►

Electrical properties tomography is the quantification of the conductivity and permittivity of different materials. In an MRI setting this can be used to map the… (more)

▼

Electrical properties tomography is the quantification of the conductivity and permittivity of different materials. In an MRI setting this can be used to map the electrical properties of tissue. These values can be used as a different contrast mechanism, for hyperthermia treatment or the improvement of antenna design for specific applications. There are different methods used to obtain these electrical properties, however these often use differential operators on measured data. This leads to reconstructions corrupted by noise, thus in this thesis the work on contrast source inversion based electrical properties tomography is continued. This method uses an integral approach and is therefore more robust with respect to noise. The work presented continues from the two-dimensional Matlab based simulations and extends these to a more realistic measurement setup. The RF-shield is numerically implemented and an extension is made to the existing algorithm to handle the transceive phase based on Maxwell's equations. This is done by implementing a forward problem into the inverse problem of getting the contrast from the measured radiofrequency field. After this the algorithm was tested with three-dimensional FDTD simulations and finally a phantom study was done to test with an MRI scanner. From the results of the two-dimensional simulations it was seen that this method is indeed very robust when it comes to a realistic measurement setup. In the three-dimensional simulations it was observed that the electrical properties are underestimated. Nonetheless CSI-EPT is more precise than the standard Helmholtz based methods. Plus the improvement made to the algorithm makes it possible to map all the RF fields inside the scanner which has not been done before. The same underestimation was seen with the reconstruction of the measured data from the phantom study.

Circuits and Systems

Advisors/Committee Members: Remis, Rob (mentor), van den Berg, Cornelis A.T. (mentor), Mandija, S. (graduation committee), Serdijn, Wouter (graduation committee), Brink, W. (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: CSI; EPT; contrast source inversion; electrical properties tomography; MRI; transceive phase; in vivo; FDTD

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APA (6^th Edition):

Stijnman, P. (. (2017). Transceive Phase Corrected Contrast Source Inversion-Electrical Properties Tomography. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:cca2d3a8-d02e-4481-a16b-e78e745c6b80

Chicago Manual of Style (16^th Edition):

Stijnman, Peter (author). “Transceive Phase Corrected Contrast Source Inversion-Electrical Properties Tomography.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:cca2d3a8-d02e-4481-a16b-e78e745c6b80.

MLA Handbook (7^th Edition):

Stijnman, Peter (author). “Transceive Phase Corrected Contrast Source Inversion-Electrical Properties Tomography.” 2017. Web. 19 Jan 2021.

Vancouver:

Stijnman P(. Transceive Phase Corrected Contrast Source Inversion-Electrical Properties Tomography. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:cca2d3a8-d02e-4481-a16b-e78e745c6b80.

Council of Science Editors:

Stijnman P(. Transceive Phase Corrected Contrast Source Inversion-Electrical Properties Tomography. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:cca2d3a8-d02e-4481-a16b-e78e745c6b80

Delft University of Technology

24. Kaichouhi, Ali (author). IQ offset and gain mismatch compensation for phase-domain ADC.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:508d8a90-40c1-46b4-9a32-c4a3f4a83946

► A phase-domain analog-to-digital converter (PhADC) is a promising alternative to a pair of amplitude-domain in-phase and quadrature (IQ) ADCs for low power FSK/PSK demodulation, but… (more)

▼ A phase-domain analog-to-digital converter (PhADC) is a promising alternative to a pair of amplitude-domain in-phase and quadrature (IQ) ADCs for low power FSK/PSK demodulation, but due to the nonlinear amplitude-to-phase conversion, IQ offsets and gain mismatch can produce nonlinear phase distortions which that can lead to phase errors and an increase in bit-error rate (BER). An IQ offset and gain mismatch detection technique is developed for PhADCs and verified. The offset and gain mismatch is estimated by detecting the phase vector distribution imbalance among the four phase quadrants after the analog-to-phase conversion. A feedback path has been constructed between the PhADC output and the offset/mismatch compensation interface. The closed loop will help the compensation interface to settle to the proper compensation values of the offset and mismatch. Incorporating this cancellation loop in a receiver system can improve its sensitivity and robustness. In a conventional IQ ADC receiver we have two quantizations, i.e., one for I and one for Q, and then process the information to extract the phase. By contrast, the PhADC, due to its embedded demodulation attribute, performs only phase quantization. So only one quantization is needed. Because of its compactness, the hardware is simpler and thereby consumes less energy. Moreover the PhADC is immune to magnitude variations, because in an IQ ADC, amplitude quantization noise produces larger phase quantization noise at small vector magnitudes, while in a PhADC a larger vector has the same phase quantization error as a small vector. Because of these advantages the PhADC is a very good candidate for low power communication. A detection algorithm has been developed that detects the phase vector distribution imbalance between the left and right IQ complex half plane in case of I offset and between the top and bottom of IQ complex half plane in case of Q offset. Using this imbalance we can determine the sign and size of IQ offset. A similar approach has been done for IQ gain mismatch, where the phase vector distribution imbalance is detected between the four phase quadrants in the IQ complex plane. A mixed-signal approach, i.e., detecting the offset and mismatch in the digital domain and compensate in the analog domain. It is well known that in the IQ ADC receiver the offset and mismatch can be detected and calibrated if necessary before the amplitude is converted into phase in the digital domain, but in the PhADC receiver the offset and mismatch cannot be determined directly due to the absence of amplitude information. Here, we use phase information rather than amplitude information for detection and compensation. For this reason, we have created a direct mismatch and offset detection technique using the output phase signal of the PhADC. The relation between signal-to-noise power ratio (SNR) and its digital counter parts bit-energy-to-noise density (E_b/N_o) and symbol-energy-to-noise density (E_s/N_o) is established… Advisors/Committee Members: Serdijn, Wouter (mentor), Mc Cune Jr, E.W. (graduation committee), Janssen, G.J.M. (graduation committee), Liu, Y. (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Phase Domain ADC; IQ offset; IQ gain mismatch; compensation system; Low power; Short range communication

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Kaichouhi, A. (. (2018). IQ offset and gain mismatch compensation for phase-domain ADC. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:508d8a90-40c1-46b4-9a32-c4a3f4a83946

Chicago Manual of Style (16^th Edition):

Kaichouhi, Ali (author). “IQ offset and gain mismatch compensation for phase-domain ADC.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:508d8a90-40c1-46b4-9a32-c4a3f4a83946.

MLA Handbook (7^th Edition):

Kaichouhi, Ali (author). “IQ offset and gain mismatch compensation for phase-domain ADC.” 2018. Web. 19 Jan 2021.

Vancouver:

Kaichouhi A(. IQ offset and gain mismatch compensation for phase-domain ADC. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:508d8a90-40c1-46b4-9a32-c4a3f4a83946.

Council of Science Editors:

Kaichouhi A(. IQ offset and gain mismatch compensation for phase-domain ADC. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:508d8a90-40c1-46b4-9a32-c4a3f4a83946

Delft University of Technology

25. Suriani, Irene (author). Unobtrusive Monitoring of Fluid Accumulation in the Body Using Ballistocardiography: A Feasibility Study.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:709e05de-f6f3-4073-aea0-a9a5a4972fcb

► Fluid accumulation in the human body is, in many cases, a symptom of some underlying pathological condition. Most common examples include edema, ascites, pleural effusion,… (more)

▼ Fluid accumulation in the human body is, in many cases, a symptom of some underlying pathological condition. Most common examples include edema, ascites, pleural effusion, and internal bleeding. Currently available non-invasive methods to assess fluid accumulation in the body are mainly imaging-based (i.e. ultrasound, computed tomography). This means that monitoring is limited to spot-checks and is only performed when the presence of a particular condition is already suspected from prior clinical evaluation of the patient. There is high clinical interest in the development of a system allowing such monitoring to be performed automatically, continuously over a prolonged period of time, and independently of prior clinical evaluation. For instance, in the case of internal bleeding, hemorrhage indicators such as variation in heart rate and blood pressure are only observable after significant blood loss (up to more than 1 liter) has already taken place, therefore an early warning system can save lives, decrease hospital stay length and significantly reduce complication-related costs. In this thesis, a pioneer solution is proposed for development of such a monitoring system. The hypothesized solution is based on the observation of specific energy-describing features of the Ballistocardiogram (BCG) signal, a measure of the periodic displacements generated on the body as a result of ballistic forces produced by the heart during each cardiac cycle. Because of additional damping generated by the presence of internally accumulated fluid, the energy of this signal is expected to decrease compared to its baseline value. The BCG can be recorded unobtrusively with different sensing modalities on the surface of the body. In order to validate the research hypothesis and assess the feasibility of this novel technique, a custom experimental set-up exploiting several different BCG sensing options has been used to carry out a study on 15 human volunteers. Localized fluid accumulation along the GI tract was induced in a controlled, safe and simple fashion, by means of water intake by the participants, and the BCG signal was recorded before and after intake. Signal feature exploration and performance analysis has been used to develop an optimized feature able to accurately capture the decrease in signal energy due to fluid accumulation, as well as to identify the most suitable sensor type and monitoring body location for the present application. The developed energy-describing feature shows a significant decrease in energy value from baseline to after-intake condition with a p-value<0.001. Moreover, the selected feature was able to correctly identify presence of fluid accumulation with high sensitivity (90% in bed-based, and 100% in standing-position monitoring). Given the promising results of the present study, further research towards improvement and development of the proposed technique is highly encouraged. Advisors/Committee Members: French, Paddy (mentor), Serdijn, Wouter (graduation committee), Hunyadi, Bori (graduation committee), Janssen, Gerard (graduation committee), Dellimore, Kiran (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: ballistocardiography; unobtrusive monitoring; accelerometers; signal processing; feature design; intra-abdominal fluid accumulation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Suriani, I. (. (2019). Unobtrusive Monitoring of Fluid Accumulation in the Body Using Ballistocardiography: A Feasibility Study. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:709e05de-f6f3-4073-aea0-a9a5a4972fcb

Chicago Manual of Style (16^th Edition):

Suriani, Irene (author). “Unobtrusive Monitoring of Fluid Accumulation in the Body Using Ballistocardiography: A Feasibility Study.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:709e05de-f6f3-4073-aea0-a9a5a4972fcb.

MLA Handbook (7^th Edition):

Suriani, Irene (author). “Unobtrusive Monitoring of Fluid Accumulation in the Body Using Ballistocardiography: A Feasibility Study.” 2019. Web. 19 Jan 2021.

Vancouver:

Suriani I(. Unobtrusive Monitoring of Fluid Accumulation in the Body Using Ballistocardiography: A Feasibility Study. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:709e05de-f6f3-4073-aea0-a9a5a4972fcb.

Council of Science Editors:

Suriani I(. Unobtrusive Monitoring of Fluid Accumulation in the Body Using Ballistocardiography: A Feasibility Study. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:709e05de-f6f3-4073-aea0-a9a5a4972fcb

Delft University of Technology

26. Vyza, Yashwanth (author). Novel microelectrode arrays for in-vitro analysis of neural activity.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:df36a2dd-caa3-455b-84a7-77f99511d4b6

► Microelectrode arrays (MEAs) are extensively used for measuring neural activity in-vitro given their ability to monitor several neurons simultaneously unlike techniques such as patch clamp.… (more)

Subjects/Keywords: Microelectrode arrays; Neural interface; In-vitro analysis

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Vyza, Y. (. (2019). Novel microelectrode arrays for in-vitro analysis of neural activity. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:df36a2dd-caa3-455b-84a7-77f99511d4b6

Chicago Manual of Style (16^th Edition):

Vyza, Yashwanth (author). “Novel microelectrode arrays for in-vitro analysis of neural activity.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:df36a2dd-caa3-455b-84a7-77f99511d4b6.

MLA Handbook (7^th Edition):

Vyza, Yashwanth (author). “Novel microelectrode arrays for in-vitro analysis of neural activity.” 2019. Web. 19 Jan 2021.

Vancouver:

Vyza Y(. Novel microelectrode arrays for in-vitro analysis of neural activity. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:df36a2dd-caa3-455b-84a7-77f99511d4b6.

Council of Science Editors:

Vyza Y(. Novel microelectrode arrays for in-vitro analysis of neural activity. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:df36a2dd-caa3-455b-84a7-77f99511d4b6

Delft University of Technology

27. van der Molen, Hessel (author). Development of a Low-Cost, Solid-State, Line-Laser Distance Sensor: An Integrated Approach.

Degree: 2017, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:509d12ba-7224-4e24-adff-d15059422319

► Many robotic systems rely on laser ranging sensors to navigate and map their environment. As robots are getting more advanced, smaller and cheaper, their sensors… (more)

Subjects/Keywords: Triangulation; Distance Measurement; Solid-State Sensor; Line-Laser; Modelling; Optimisation; Low-Cost; LiDAR

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APA (6^th Edition):

van der Molen, H. (. (2017). Development of a Low-Cost, Solid-State, Line-Laser Distance Sensor: An Integrated Approach. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:509d12ba-7224-4e24-adff-d15059422319

Chicago Manual of Style (16^th Edition):

van der Molen, Hessel (author). “Development of a Low-Cost, Solid-State, Line-Laser Distance Sensor: An Integrated Approach.” 2017. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:509d12ba-7224-4e24-adff-d15059422319.

MLA Handbook (7^th Edition):

van der Molen, Hessel (author). “Development of a Low-Cost, Solid-State, Line-Laser Distance Sensor: An Integrated Approach.” 2017. Web. 19 Jan 2021.

Vancouver:

van der Molen H(. Development of a Low-Cost, Solid-State, Line-Laser Distance Sensor: An Integrated Approach. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:509d12ba-7224-4e24-adff-d15059422319.

Council of Science Editors:

van der Molen H(. Development of a Low-Cost, Solid-State, Line-Laser Distance Sensor: An Integrated Approach. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:509d12ba-7224-4e24-adff-d15059422319

Delft University of Technology

28. Parag, Anirudh Kumar (author). ENMOS: Energy Module for Self-Sustainable Wearable Sensors.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:b64fdbc9-64cb-44bf-9b17-3c57dcfa9c0a

►

This work focuses on addressing the fundamental limitation on the minimum cold start-up voltage that could be harvested from a thermoelectric element (TEG) for human-body… (more)

▼

This work focuses on addressing the fundamental limitation on the minimum cold start-up voltage that could be harvested from a thermoelectric element (TEG) for human-body wearable applications. For ultra-low DC voltages, the challenge translates to generating a timed-signal to amplify it up to a value that could be used to drive, say, a boost converter which can then start-up the entire energy module. Contemporary works have, thus, strived to accomplish this using a charge-pump-based or a transformer-based approach, which in turn imposes a limit on the minimum TEG voltage that can be harvested. The solution this work proposes is to decouple the Cold Start-up system from the TEG altogether and instead, use a piezoelectric element (PEH). This element being capable of producing a well-timed (AC) signal for free, based on human body vibrations, can potentially drive a boost converter. To this end, an integrated circuit (IC) is designed that can utilize the voltage from the PEH, amplifying it up to generate a well-controlled signal that could operate the boost converter. At the heart of this IC, is a self-reconfigurable charge pump that arranges its stages in different boosting ratios (without any complex logic or DSP) based on the input voltage, to allow for a maximum harvested power. The proposed self-reconfigurable architecture can potentially lead the charge pump to be load-variation-resistant. It achieves this by providing an almost constant voltage while increasing the power for higher load demands, at the same time maintaining a constant efficiency. Thus, the fully on-chip implementation in TSMC 0.18 um CMOS, can cold start-up the system from 25 mV of thermoelectric voltage to deliver an output voltage of 1 V at 56.5 % converter efficiency, consuming only 240.5 pW of dynamic power (simulation). The minimum Cold Start-up voltage and dynamic power were found to be 18 mV (ΔT = 0.1 K) and 231.6 pW respectively, to supply 1 V at 44 % converter efficiency. Moreover, in order to prove that the fundamental limitation on the Cold Start-up voltage has been addressed successfully, the IC was also simulated to check whether it can further be lowered. In this case, by providing a piezoelectric excitation voltage 73.3 mVRMS higher, the Cold Start-up voltage was found to be reduced to 15 mV to supply a constant 1 V at the load. It was also found that increasing the inductor value in this case, can also allow the energy module to support even lower Cold Start-up voltages.

Electrical Engineering

Advisors/Committee Members: Serdijn, Wouter (mentor), French, Paddy (graduation committee), Fan, Qinwen (graduation committee), Urso, Alessandro (graduation committee), Rodrigues Mansano, Andre (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Energy Harvesting; Cold Start-up; Thermoelectric energy generator (TEG); Piezoelectric energy harvester (PEH); Self-Reconfigurable charge pump; Dickson charge pump; Ultra-low power; Ultra-low voltage; Power module; Analog integrated circuit design

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Parag, A. K. (. (2019). ENMOS: Energy Module for Self-Sustainable Wearable Sensors. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:b64fdbc9-64cb-44bf-9b17-3c57dcfa9c0a

Chicago Manual of Style (16^th Edition):

Parag, Anirudh Kumar (author). “ENMOS: Energy Module for Self-Sustainable Wearable Sensors.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:b64fdbc9-64cb-44bf-9b17-3c57dcfa9c0a.

MLA Handbook (7^th Edition):

Parag, Anirudh Kumar (author). “ENMOS: Energy Module for Self-Sustainable Wearable Sensors.” 2019. Web. 19 Jan 2021.

Vancouver:

Parag AK(. ENMOS: Energy Module for Self-Sustainable Wearable Sensors. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:b64fdbc9-64cb-44bf-9b17-3c57dcfa9c0a.

Council of Science Editors:

Parag AK(. ENMOS: Energy Module for Self-Sustainable Wearable Sensors. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:b64fdbc9-64cb-44bf-9b17-3c57dcfa9c0a

Delft University of Technology

29. Lekkas, Konstantinos (author). A Power Efficient Multichannel Neurostimulator Based on the Ultra High Frequency Technique for Transcranial Direct Current Stimulation Applications.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:24036fca-c87d-472d-8285-3f4f84356dd2

► Transcranial direct current stimulation (tDCS) is a noninvasive technique, allowing for the reversible modulation of activity in particular brain regions. TDCS has obtained much scientific… (more)

▼ Transcranial direct current stimulation (tDCS) is a noninvasive technique, allowing for the reversible modulation of activity in particular brain regions. TDCS has obtained much scientific interest and it promises many potential benefits to the patients. However, tDCS that is performed today is almost the same with the method that was used 20 years ago (applying 2 mA current, during a 20 min session, using two large surface sponge electrodes). The tDCS module of the future must be characterized by increased portability, battery life and focality. Many commercially available devices have very low power efficiency, leaving space for the design of low power consumption tDCS devices. Power efficient tDCS modules will also need lower battery capacity and thus lighter batteries, increasing the portability of the system. Regarding focality, there is increased interest from the researchers and physicians for multichannel devices that use small diameter electrodes. These devices can increase the focality and the accuracy of the delivered currents offering more targeted therapies. In this thesis, the realization of a novel, low power, multichannel stimulation module, made with discrete components, which uses the ultra high frequency (UHF) technique for tDCS applications is implemented. With this approach, the technological benefits of the UHF stimulation technique, regarding increased multichannel power efficiency, are derived, combined with a cost effective, low scale production method. Moreover, contrary to previous integrated circuit (IC) realizations, current control feedback is added to the system. In this thesis, three prototypes are fabricated, with the last one being an eight channel module that can be supplied from a 3.5 V battery and has a very linear relationship between the selected DAC’s codes and the output delivered current and, at the same time, being able to stimulate a wide range of loads (0.148 - 10.11 kΩ) up to 2 mA. Furthermore, the employed novel boost technique shows 40.57% maximum improvement of the power efficiency, compared to the use of a conventional buck-boost converter. Moreover, the feedback system shows significant robustness, achieving only 7.6% output current divergence for 6731% change of the output load’s impedance. The module has 4 μΑ resolution, which is translated to 0.2% of the maximum delivered current. Except from the high resolution, the system also has a fast transient response, which is less than 2.1 ms. Additionally, when one channel is active, the stimulator shows 43.84% maximum power efficiency. The aforementioned power efficiency is 23.49% higher than the maximum efficiency of state of the art adaptive voltage current source implementations. Additionally, the multichannel system was tested in real life scenarios and its efficiency was compared to a fixed voltage current source module. The system achieved 37.57%, 45.47% and 11.59% power efficiency improvements for two, four and eight channels respectively. Hence, a novel, multichannel… Advisors/Committee Members: Serdijn, Wouter (mentor), French, Paddy (graduation committee), Giagka, Vasso (graduation committee), Dankelman, Jenny (graduation committee), Peuscher, Jan (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: stimulator; tDCS; multichannel

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Lekkas, K. (. (2019). A Power Efficient Multichannel Neurostimulator Based on the Ultra High Frequency Technique for Transcranial Direct Current Stimulation Applications. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:24036fca-c87d-472d-8285-3f4f84356dd2

Chicago Manual of Style (16^th Edition):

Lekkas, Konstantinos (author). “A Power Efficient Multichannel Neurostimulator Based on the Ultra High Frequency Technique for Transcranial Direct Current Stimulation Applications.” 2019. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:24036fca-c87d-472d-8285-3f4f84356dd2.

MLA Handbook (7^th Edition):

Lekkas, Konstantinos (author). “A Power Efficient Multichannel Neurostimulator Based on the Ultra High Frequency Technique for Transcranial Direct Current Stimulation Applications.” 2019. Web. 19 Jan 2021.

Vancouver:

Lekkas K(. A Power Efficient Multichannel Neurostimulator Based on the Ultra High Frequency Technique for Transcranial Direct Current Stimulation Applications. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:24036fca-c87d-472d-8285-3f4f84356dd2.

Council of Science Editors:

Lekkas K(. A Power Efficient Multichannel Neurostimulator Based on the Ultra High Frequency Technique for Transcranial Direct Current Stimulation Applications. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:24036fca-c87d-472d-8285-3f4f84356dd2

Delft University of Technology

30. Bisht, Anirudh (author). Motion artefact reference sensor study for ECG signals.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:509415da-bc97-4553-8545-03a08763835a

► ECG signals captured almost always have motion artefact noise. This noise arises due to relative motion between the ECG electrode and skin. To remove this… (more)

Subjects/Keywords: Motion artefacts; ECG; Embedded Systems; connected health; non-contact ecg; dry-contact ecg

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bisht, A. (. (2018). Motion artefact reference sensor study for ECG signals. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:509415da-bc97-4553-8545-03a08763835a

Chicago Manual of Style (16^th Edition):

Bisht, Anirudh (author). “Motion artefact reference sensor study for ECG signals.” 2018. Masters Thesis, Delft University of Technology. Accessed January 19, 2021. http://resolver.tudelft.nl/uuid:509415da-bc97-4553-8545-03a08763835a.

MLA Handbook (7^th Edition):

Bisht, Anirudh (author). “Motion artefact reference sensor study for ECG signals.” 2018. Web. 19 Jan 2021.

Vancouver:

Bisht A(. Motion artefact reference sensor study for ECG signals. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Jan 19]. Available from: http://resolver.tudelft.nl/uuid:509415da-bc97-4553-8545-03a08763835a.

Council of Science Editors:

Bisht A(. Motion artefact reference sensor study for ECG signals. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:509415da-bc97-4553-8545-03a08763835a

Open Access Theses and Dissertations