subject:(CMUT)

1. Jeanne, Edgard. Réalisation et caractérisations électromécaniques de transducteurs ultrasonores capacitifs micro-usines : No title available.

Degree: Docteur es, Electronique, 2008, Université François-Rabelais de Tours

URL: http://www.theses.fr/2008TOUR4041

►

Les transducteurs ultrasonores capacitifs micro-usinés peuvent s’adapter à la complexité et à la miniaturisation requise par l’évolution des techniques d’échographie vers l’imagerie intracardiaque ou l’imagerie… (more)

▼

Les transducteurs ultrasonores capacitifs micro-usinés peuvent s’adapter à la complexité et à la miniaturisation requise par l’évolution des techniques d’échographie vers l’imagerie intracardiaque ou l’imagerie 3D en temps réel. L’objectif de ce travail de thèse est la réalisation de démonstrateurs pouvant être intégrés dans une sonde cathéter 9Fr pour l’imagerie intracardiaque. Nous proposons, d’évaluer une technologie de micro-usinage de surface a?n de réaliser une architecture reposant sur un couple de membrane en nitrure de silicium faiblement contraint et de couche sacri?cielle en oxyde. Nous abordons la caractérisation électromécanique des transducteurs ultrasonores en proposant une approche mécanique pour la détermination de la tension de collapse et la fréquence de résonance. Di?érentes techniques nous ont permis d’extraire les propriétés mécaniques de la couche structurelle du microsystème. Nous ?nalisons ces travaux sur l’intégration des dispositifs dans la sonde avec un report de connectique sur la face arrière, basée sur des vias traversants et une couche de passivation en nitrure de silicium déposé par PECVD ou de parylène C.

Capacitive Micromachined Ultrasonic Transducers (cMUTs) based on MEMS technology may ?t the complexity and the miniaturization required by ultrasound probes evolution. The objective of this thesis work is to realize a technological test vehicle which can be easily and directly integrated in a 9Fr catheter probe. This document focuses on a surface micromachining process in order to realize a 450nm thick suspended membrane over a 200nm gap. The process lies on a LPCVD low stress silicon nitride membrane and an oxide sacri?cial layer. The electromechanical characterization of the membrane is performed through laser Doppler vibrometry and optical pro?lometry in order to determine the collapse voltage and the natural frequency of the membranes. Material’s mechanical properties being fundamental in any MEMS prediction behavior, dedicated mechanical test structures were characterized in order to extract silicon nitride mechanical properties. In an integration and a ?ip-chip scheme, a through wafer interconnect technology is proposed. Finally, this document ends on the investigation of PECVD silicon nitride and parylene C as a passivation layer.

Advisors/Committee Members: Alquier, Daniel (thesis director).

Subjects/Keywords: Cmut

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Jeanne, E. (2008). Réalisation et caractérisations électromécaniques de transducteurs ultrasonores capacitifs micro-usines : No title available. (Doctoral Dissertation). Université François-Rabelais de Tours. Retrieved from http://www.theses.fr/2008TOUR4041

Chicago Manual of Style (16^th Edition):

Jeanne, Edgard. “Réalisation et caractérisations électromécaniques de transducteurs ultrasonores capacitifs micro-usines : No title available.” 2008. Doctoral Dissertation, Université François-Rabelais de Tours. Accessed March 06, 2021. http://www.theses.fr/2008TOUR4041.

MLA Handbook (7^th Edition):

Jeanne, Edgard. “Réalisation et caractérisations électromécaniques de transducteurs ultrasonores capacitifs micro-usines : No title available.” 2008. Web. 06 Mar 2021.

Vancouver:

Jeanne E. Réalisation et caractérisations électromécaniques de transducteurs ultrasonores capacitifs micro-usines : No title available. [Internet] [Doctoral dissertation]. Université François-Rabelais de Tours; 2008. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2008TOUR4041.

Council of Science Editors:

Jeanne E. Réalisation et caractérisations électromécaniques de transducteurs ultrasonores capacitifs micro-usines : No title available. [Doctoral Dissertation]. Université François-Rabelais de Tours; 2008. Available from: http://www.theses.fr/2008TOUR4041

Georgia Tech

2. Pirouz, Amirabbas. Capacitive micromachined ultrasound transducer (CMUT) design and fabrication for intracardiac echocardiography.

Degree: PhD, Electrical and Computer Engineering, 2019, Georgia Tech

URL: http://hdl.handle.net/1853/62656

► The objective of this research is to develop capacitive micromachined ultrasonic transducer (CMUT) arrays with novel geometry for intracardiac echocardiography (ICE) imaging along with a… (more)

▼ The objective of this research is to develop capacitive micromachined ultrasonic transducer (CMUT) arrays with novel geometry for intracardiac echocardiography (ICE) imaging along with a novel reliable CMUT fabrication process to improve the system performance. We used custom CMOS electronics and monolithically integrated our CMUT arrays to CMOS chips. The arrays are designed for 9-Fr (<3mm) ICE catheters over a total area of about 2.6x11 mm2 at around 7MHz center frequency with ~80% fractional bandwidth in both 1-D and 2-D configurations. The 1-D array transducer includes 64 channels with beam-steering capabilities for cross sectional ICE imaging application at distance range of about 5-cm. The ICE image with 40dB dynamic range from 7 metal wires has been obtained. Several 2-D (sparse) arrays are designed based on signal-to-noise ratio (SNR) optimization capable of generating volumetric images. The CMUT-on-CMOS technique is used for arrays integration with our ASICs using vias for top and bottom electrode connections to the related electronics pads. A 60V pulse is optimized during transmit operation and 2MPa surface pressure has been achieved that is in agreement with our simulation results. We also developed an improved CMOS compatible low temperature sacrificial layer fabrication process for CMUTs. The process adds the fabrication step of silicon oxide evaporation which is followed by a lift-off step to define the membrane support area without a need for an extra mask. The parasitic capacitance is reduced about 15% and device long-term test demonstrates 72-hours stable output pressure showing no significant degradation on performance. We have also developed a new energy-based calculation method for CMUT performance evaluation that is valid during both small and large signal operation since well-known frequency and capacitance based coupling coefficients definitions are not valid for large signal and nonlinear operation regimes. The quantitative modeling results show that CMUTs do not need DC bias to achieve high efficiency large signal transduction: AC only signals at half the operation frequency with amplitudes beyond the collapse voltage can provide energy conversion ratio (ECR) above 0.9 with harmonic content below -25dB. The overall modeling approach is also qualitatively validated by experiments. Advisors/Committee Members: Degertekin, Levent (advisor), Bakir, Muhannad S. (committee member), Hesketh, Peter J. (committee member), Inan, Omer T. (committee member), Sarioglu, Ali F. (committee member).

Subjects/Keywords: CMUT coupling coefficient; CMUT efficiency; CMUT large signal operation; CMUT low temperature fabrication; Oxide lift-off; CMUT parasitic capacitance; Reliable CMUT; CMUT array design; CMUT noise; CMUT on CMOS; CMUT integration; CMUT pulse optimization; Intracardiac echocardiography; CMUT ICE; CMUT 2D array

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Pirouz, A. (2019). Capacitive micromachined ultrasound transducer (CMUT) design and fabrication for intracardiac echocardiography. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/62656

Chicago Manual of Style (16^th Edition):

Pirouz, Amirabbas. “Capacitive micromachined ultrasound transducer (CMUT) design and fabrication for intracardiac echocardiography.” 2019. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021. http://hdl.handle.net/1853/62656.

MLA Handbook (7^th Edition):

Pirouz, Amirabbas. “Capacitive micromachined ultrasound transducer (CMUT) design and fabrication for intracardiac echocardiography.” 2019. Web. 06 Mar 2021.

Vancouver:

Pirouz A. Capacitive micromachined ultrasound transducer (CMUT) design and fabrication for intracardiac echocardiography. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1853/62656.

Council of Science Editors:

Pirouz A. Capacitive micromachined ultrasound transducer (CMUT) design and fabrication for intracardiac echocardiography. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/62656

University of Waterloo

3. Owais, Tirad. Capacitive Micromachined Ultrasound Transducers for Non-Destructive Testing Applications.

Degree: 2020, University of Waterloo

URL: http://hdl.handle.net/10012/15920

► The need for using ultrasound non-destructive testing (NDT) to characterize, test and detect flaws within metals, led us to utilize Capacitive Micromachined Ultrasound Transducers (CMUTs)… (more)

Subjects/Keywords: CMUT; NDT ultrasound

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Owais, T. (2020). Capacitive Micromachined Ultrasound Transducers for Non-Destructive Testing Applications. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/15920

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Owais, Tirad. “Capacitive Micromachined Ultrasound Transducers for Non-Destructive Testing Applications.” 2020. Thesis, University of Waterloo. Accessed March 06, 2021. http://hdl.handle.net/10012/15920.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Owais, Tirad. “Capacitive Micromachined Ultrasound Transducers for Non-Destructive Testing Applications.” 2020. Web. 06 Mar 2021.

Vancouver:

Owais T. Capacitive Micromachined Ultrasound Transducers for Non-Destructive Testing Applications. [Internet] [Thesis]. University of Waterloo; 2020. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/10012/15920.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Owais T. Capacitive Micromachined Ultrasound Transducers for Non-Destructive Testing Applications. [Thesis]. University of Waterloo; 2020. Available from: http://hdl.handle.net/10012/15920

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Alberta

4. Sampaleanu, Alexander P. Top-Orthogonal-to-Bottom-Electrode Capacitive Micromachined Ultrasound Transducers for Low-Cost 3D Ultrasound Imaging.

Degree: MS, Department of Electrical and Computer Engineering, 2013, University of Alberta

URL: https://era.library.ualberta.ca/files/kw52j904w

► Capacitive micromachined ultrasound transducers (CMUTs) offer a promising solution for three-dimensional ultrasound imaging due to their ability to be easily fabricated in two-dimensional arrays. However,… (more)

Subjects/Keywords: MEMS; CMUT; Ultrasound; Imaging

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Sampaleanu, A. P. (2013). Top-Orthogonal-to-Bottom-Electrode Capacitive Micromachined Ultrasound Transducers for Low-Cost 3D Ultrasound Imaging. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/kw52j904w

Chicago Manual of Style (16^th Edition):

Sampaleanu, Alexander P. “Top-Orthogonal-to-Bottom-Electrode Capacitive Micromachined Ultrasound Transducers for Low-Cost 3D Ultrasound Imaging.” 2013. Masters Thesis, University of Alberta. Accessed March 06, 2021. https://era.library.ualberta.ca/files/kw52j904w.

MLA Handbook (7^th Edition):

Sampaleanu, Alexander P. “Top-Orthogonal-to-Bottom-Electrode Capacitive Micromachined Ultrasound Transducers for Low-Cost 3D Ultrasound Imaging.” 2013. Web. 06 Mar 2021.

Vancouver:

Sampaleanu AP. Top-Orthogonal-to-Bottom-Electrode Capacitive Micromachined Ultrasound Transducers for Low-Cost 3D Ultrasound Imaging. [Internet] [Masters thesis]. University of Alberta; 2013. [cited 2021 Mar 06]. Available from: https://era.library.ualberta.ca/files/kw52j904w.

Council of Science Editors:

Sampaleanu AP. Top-Orthogonal-to-Bottom-Electrode Capacitive Micromachined Ultrasound Transducers for Low-Cost 3D Ultrasound Imaging. [Masters Thesis]. University of Alberta; 2013. Available from: https://era.library.ualberta.ca/files/kw52j904w

Delft University of Technology

5. Saccher, Marta (author). MEMS ultrasound for active implantable devices.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:dcd6bbdb-668c-440c-ba9a-dc315e675a28

►

During the past decade, Implantable biomedical devices have emerged as an efficient treatment for neurological disorders. Among them, low-intensity focused ultrasound (LIFU) has recently gained… (more)

▼

During the past decade, Implantable biomedical devices have emerged as an efficient treatment for neurological disorders. Among them, low-intensity focused ultrasound (LIFU) has recently gained interest due to its focusing ability, depth of penetration and reversible effects. Although the exact biophysical mechanism that leads to the interaction between ultrasound and neurons is not clear yet, many successful applications have been reported both in vitro and in vivo in animals, raising prospects for clinical applications. Nevertheless, treatments were mainly delivered transcranially due to the lack of implantable technologies, constraining the frequency range to below 1 MHz. Thanks to the development of biocompatible capacitive micromachined ultrasound transducers (CMUTs), ultrasound has become implantable, opening the way for high frequency ultrasound neuromodulation. In addition, implantable biomedical devices are becoming smaller and smaller, requiring their power supply to follow this trend. Batteries can be a limiting factor for their miniaturisation and other powering methods have been investigated. Among them, ultrasound as a means to wirelessly transfer power represents the best trade-off between the amount of available power, implanted receiver size, and depth of penetration. Also in this case, biocompatible CMUTs could be used as transducers to power an implanted device. Yet they require a DC bias source in the order of tens of volts which is not practical for an implanted device. In this thesis the application of ultrasound for implantable biomedical devices is investigated. First, the modulation of the excitability of in vitro mice hippocampal brain slices (normal and epileptic) using high frequency sonication protocols is explored. Secondly, wireless power transfer using CMUT devices with charges trapped in the dielectric which do not require a DC bias voltage is investigated. The results indicate that high frequency ultrasound clearly affects the excitability of neurons, having an excitatory effect when delivered using a 5 MHz continuous wave sonication protocol, while it inhibits the neurons when they are exposed to pulsed wave ultrasound at 13 MHz. The intensities used were in line or much lower compared to values used by other groups of researchers. In addition, ultrasound power transfer with an efficiency higher than 48% was achieved using CMUT devices with charges permanently trapped in their Al2O3 layer. This efficiency was in line with values obtained by other groups using piezoelectric transducers. Based on these results, it is clear that ultrasound, specifically using implantable CMUT devices, has a great potential to be used in bioelectronic medicine applications for both the treatment of neurological disorders as well as a means of power transfer.

BioMedical Engineering

Advisors/Committee Members: Dekker, Ronald (mentor), Kawasaki, Shinnosuke (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Ultrasound; Neuromodulation; Power transfer; CMUT

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Saccher, M. (. (2019). MEMS ultrasound for active implantable devices. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:dcd6bbdb-668c-440c-ba9a-dc315e675a28

Chicago Manual of Style (16^th Edition):

Saccher, Marta (author). “MEMS ultrasound for active implantable devices.” 2019. Masters Thesis, Delft University of Technology. Accessed March 06, 2021. http://resolver.tudelft.nl/uuid:dcd6bbdb-668c-440c-ba9a-dc315e675a28.

MLA Handbook (7^th Edition):

Saccher, Marta (author). “MEMS ultrasound for active implantable devices.” 2019. Web. 06 Mar 2021.

Vancouver:

Saccher M(. MEMS ultrasound for active implantable devices. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Mar 06]. Available from: http://resolver.tudelft.nl/uuid:dcd6bbdb-668c-440c-ba9a-dc315e675a28.

Council of Science Editors:

Saccher M(. MEMS ultrasound for active implantable devices. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:dcd6bbdb-668c-440c-ba9a-dc315e675a28

6. Samarasekera, Champika. Variations on Acoustophoretic Microchannels: From the Facile to the Highly Capable.

Degree: 2018, University of Waterloo

URL: http://hdl.handle.net/10012/13367

► The lab-on-a-chip toolkit is replete with techniques for microparticle manipulation. The use of ultrasonic waves to impart forces on particles, referred to as acoustophoresis, is… (more)

▼ The lab-on-a-chip toolkit is replete with techniques for microparticle manipulation. The use of ultrasonic waves to impart forces on particles, referred to as acoustophoresis, is one particularly powerful yet gentle option. Traditionally, piezoelectric transducers have been coupled with acoustic resonators in order to sustain standing waves for aggregating, sorting, and sensing applications. However, there are several drawbacks to these setups. First, the construction techniques underpinning resonators tend to be expensive and laborious. Secondly, the acoustic impedance of piezoelectric transducers is much higher than the aqueous medium in which microparticles are suspended. This requires the use of impedance-matching layers to adequately couple acoustic energy into the medium. Finally, piezoelectric materials tend to be incompatible with traditional fabrication methods for microelectromechanical systems (MEMS). This can significantly impact the use of piezoelectric materials in more complex lab-on-a-chip type platforms where many processes beyond sample manipulation may be necessary. Over the past two decades, another type of transducer, known as the capacitive micromachined ultrasonic transducer (CMUT), has been challenging the dominance of the piezotransducer. However, this competition has been occurring primarily in the arenas of non-destructive testing and medical imaging. Given some of the unique attributes of CMUTs, it is surprising that they have yet to be fully realized in acoustophoresis, especially because acoustophoresis is popularly practiced within a microfluidic setting. We first present a highly cost-effective and cleanroom-free technique for prototyping piezo-equipped, transversal acoustophoretic resonators. Simple bifurcation and trifurcation microchannels suitable for acoustophoresis in microscopy applications are fabricated and demonstrated. The second focus of our research looks at the suitability of CMUT microarrays as platforms for acoustophoresis. We address the following: issues surrounding their implementation; modeling of potential resonator designs; and possibility of foregoing resonators altogether. Several CMUT devices are then fabricated and tested, using travelling-wave ultrasound to demonstrate aggregation within droplets as well as sequential capture and separation within flows. A unique phenomenon of bead aggregate palpation is encountered, the physical underpinnings of which are attributed to magnitude changes in lateral gradient forces with frequency. Finally, we attempt to perform standing wave manipulations of particles using the CMUT microarray, and describe the difficulties encountered in doing so.

Subjects/Keywords: MEMS; Acoustophoresis; Ultrasound; Microfluidics; CMUT

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Samarasekera, C. (2018). Variations on Acoustophoretic Microchannels: From the Facile to the Highly Capable. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/13367

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Samarasekera, Champika. “Variations on Acoustophoretic Microchannels: From the Facile to the Highly Capable.” 2018. Thesis, University of Waterloo. Accessed March 06, 2021. http://hdl.handle.net/10012/13367.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Samarasekera, Champika. “Variations on Acoustophoretic Microchannels: From the Facile to the Highly Capable.” 2018. Web. 06 Mar 2021.

Vancouver:

Samarasekera C. Variations on Acoustophoretic Microchannels: From the Facile to the Highly Capable. [Internet] [Thesis]. University of Waterloo; 2018. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/10012/13367.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Samarasekera C. Variations on Acoustophoretic Microchannels: From the Facile to the Highly Capable. [Thesis]. University of Waterloo; 2018. Available from: http://hdl.handle.net/10012/13367

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Delft University of Technology

7. Teye, J. (author). 3D Robotic Ultrasound System: A 3D Volumetric Ultrasound Imaging System using a CMUT Phased Array and a Robotic Arm.

Degree: 2020, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:ced96a5f-8174-473b-a20d-298804db712b

►

Diagnostic imaging is a fundamental requirement for the effective treatment of about 25 % of patients globally. Ultrasound imaging is considered the safest, least expensive… (more)

▼

Diagnostic imaging is a fundamental requirement for the effective treatment of about 25 % of patients globally. Ultrasound imaging is considered the safest, least expensive and most convenient diagnostic imaging modality. Its widespread adoption has been in the area of 2D imaging. However, the accuracy of diagnosis with 2D ultrasound imaging is highly dependent on the experience and expertise of the sonographer because the sonographer has to mentally create a 3D impression from multiple 2D images of the region of interest and this could lead to erroneous diagnosis. 3D ultrasound imaging addresses this concern, however, it drives up the cost of ultrasound imaging. Also, disadvantages such as difficulty in taking quality images, prolonged time in learning how to effectively take these images and human distress during the acquisition of these images have been reported. By leveraging the high level of precision, accuracy and maneuverability provided by robotic systems in conjunction with low-end ultrasound imaging platforms, 3D ultrasound images can be captured, the problem of human distress alleviated and subsequently reducing the cost of 3D ultrasound imaging. This project sought to explore the feasibility of designing a low-cost 3D ultrasound robotic system. The design followed a distributed system approach using ROS (Robotic Operating System) where the data acquisition decoupled from the processing and visualization unit. The performance of the design was tested by constructing 3D ultrasound images of custom made phantoms. These results were compared with 3D ultrasound images of the phantoms acquired using the Philips EPIQ 7 - a high-tier ultrasound machine. The results obtained with this design had a low resolution in comparison with those obtained with the Philips EPIQ 7 however, a 3D point cloud representation of the object embedded in the phantom can be seen. Also, a full 3D image of the phantom could not be acquired due the transducer movement limitations of the design. This design successfully demonstrates the feasibility of integrating low-end electronics with robotic systems to acquire 3D ultrasound images.

BioMedical Engineering

Advisors/Committee Members: van Heesch, Chris (mentor), Dekker, R. (mentor), Hendriks, B.H.W. (graduation committee), Theuwissen, A.J.P. (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Ultrasound; CMUT; Robotic; 3D

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Teye, J. (. (2020). 3D Robotic Ultrasound System: A 3D Volumetric Ultrasound Imaging System using a CMUT Phased Array and a Robotic Arm. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:ced96a5f-8174-473b-a20d-298804db712b

Chicago Manual of Style (16^th Edition):

Teye, J (author). “3D Robotic Ultrasound System: A 3D Volumetric Ultrasound Imaging System using a CMUT Phased Array and a Robotic Arm.” 2020. Masters Thesis, Delft University of Technology. Accessed March 06, 2021. http://resolver.tudelft.nl/uuid:ced96a5f-8174-473b-a20d-298804db712b.

MLA Handbook (7^th Edition):

Teye, J (author). “3D Robotic Ultrasound System: A 3D Volumetric Ultrasound Imaging System using a CMUT Phased Array and a Robotic Arm.” 2020. Web. 06 Mar 2021.

Vancouver:

Teye J(. 3D Robotic Ultrasound System: A 3D Volumetric Ultrasound Imaging System using a CMUT Phased Array and a Robotic Arm. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Mar 06]. Available from: http://resolver.tudelft.nl/uuid:ced96a5f-8174-473b-a20d-298804db712b.

Council of Science Editors:

Teye J(. 3D Robotic Ultrasound System: A 3D Volumetric Ultrasound Imaging System using a CMUT Phased Array and a Robotic Arm. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:ced96a5f-8174-473b-a20d-298804db712b

Delft University of Technology

8. Dijkema, Eric (author). Towards CMUT for Neurostimulation: The Development of an Experimental Model for the Validation of Ultrasound Neuromodulation and Back-side Vent Etching for Low-Frequency CMUT Devices.

Degree: 2020, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:d82602f5-4013-40d4-a1d5-cdd2f5307ce3

►

Ultrasound (US) neurostimulation, the non-pharmacological, reversible excitation or inhibition of the nervous system using ultrasonic waves, is emerging as a high interest topic in neurostimulation… (more)

▼

Ultrasound (US) neurostimulation, the non-pharmacological, reversible excitation or inhibition of the nervous system using ultrasonic waves, is emerging as a high interest topic in neurostimulation research. In the current project, an attempt was made to demonstrate US neuromodulation in a Lumbricus Terrestris model of evoked compound action potentials (eCAP). Hardware and software for the electrophysiological observation of local field potentials were designed and assembled. The resulting system was used to perform mechanical, electrical and both direct and indirect ultrasonic neurostimulation experiments. It was shown electrical stimulation could be performed reliably in-vivo and ex-vivo. Mechanical stimulation only functioned in-vivo. Additionally, power transfer experiments showed that deeply embedded CMUT devices can be used to harvest acoustic power and use this signal to stimulate an explanted Lumbricus Terrestris medial nerve cord. Direct ultrasound neurostimulation was however not observed, likely due to a combination of misalignment and incorrect acoustic pressure profiles. As an additional project, a microfabrication step was designed and performed for the etching of high aspect-ratio silicon bulk structures for the backside venting of low frequency CMUT devices. A two-step process deep reactive ion etch (DRIE) was attempted where smaller features were first introduced into the silicon (phase A) and then advanced using a larger etch frame (phase B). It was shown that phase A etching could be performed adequately, resulting in high quality deep silicon etch profiles with minimal tapering and an excellent etch rate. However, phase B etching resulted in the consumption of side-walls and removal of previously etched features. It is likely some slight adjustments to the passivation stage of the DRIE process would result in successful completion of this fabrication step. Acknowledgements

Biomedical Engineering | Bioelectronics

Advisors/Committee Members: Dekker, Ronald (mentor), Giagka, V. (graduation committee), French, P.J. (graduation committee), Mastrangeli, Massimo (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: Neurostimulation; Ultrasound; Dry-etching; CMUT

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Dijkema, E. (. (2020). Towards CMUT for Neurostimulation: The Development of an Experimental Model for the Validation of Ultrasound Neuromodulation and Back-side Vent Etching for Low-Frequency CMUT Devices. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:d82602f5-4013-40d4-a1d5-cdd2f5307ce3

Chicago Manual of Style (16^th Edition):

Dijkema, Eric (author). “Towards CMUT for Neurostimulation: The Development of an Experimental Model for the Validation of Ultrasound Neuromodulation and Back-side Vent Etching for Low-Frequency CMUT Devices.” 2020. Masters Thesis, Delft University of Technology. Accessed March 06, 2021. http://resolver.tudelft.nl/uuid:d82602f5-4013-40d4-a1d5-cdd2f5307ce3.

MLA Handbook (7^th Edition):

Dijkema, Eric (author). “Towards CMUT for Neurostimulation: The Development of an Experimental Model for the Validation of Ultrasound Neuromodulation and Back-side Vent Etching for Low-Frequency CMUT Devices.” 2020. Web. 06 Mar 2021.

Vancouver:

Dijkema E(. Towards CMUT for Neurostimulation: The Development of an Experimental Model for the Validation of Ultrasound Neuromodulation and Back-side Vent Etching for Low-Frequency CMUT Devices. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Mar 06]. Available from: http://resolver.tudelft.nl/uuid:d82602f5-4013-40d4-a1d5-cdd2f5307ce3.

Council of Science Editors:

Dijkema E(. Towards CMUT for Neurostimulation: The Development of an Experimental Model for the Validation of Ultrasound Neuromodulation and Back-side Vent Etching for Low-Frequency CMUT Devices. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:d82602f5-4013-40d4-a1d5-cdd2f5307ce3

University of Waterloo

9. Wong, Lawrence. Capacitive Micromachined Ultrasonic Transducers for Non-destructive Testing Applications.

Degree: 2014, University of Waterloo

URL: http://hdl.handle.net/10012/8608

► Ultrasound is a popular technique for industrial non-destructive testing (NDT) applications. By sending ultrasonic waves into an object and observing the amplitude and the delay… (more)

▼ Ultrasound is a popular technique for industrial non-destructive testing (NDT) applications. By sending ultrasonic waves into an object and observing the amplitude and the delay of the reflected or transmitted waves, one can characterize the material, measure the thickness of the object, and detect discontinuities (flaws) as well as the size, location, and orientation of the defects in the object. Traditionally, ultrasonic transducers for NDT are made with piezoelectric crystals. Meanwhile, another class of ultrasonic transducers known as capacitive micromachined ultrasonic transducers (CMUTs) have become popular in medical ultrasound research because of their large bandwidths and other attributes that allow them to be integrated into the tip of a catheter. However, CMUTs have not been widely adopted in ultrasonic NDT applications. In this thesis, three important CMUTs characteristics that could potentially make them attractive for NDT applications are introduced and demonstrated. First, CMUTs can be beneficial to NDT because the fabrication techniques of CMUTs can easily be used to implement high-frequency, high-density phased arrays, which are essential for high resolution scanning. Surface scanning using a 2-D row-column addressed CMUT array was demonstrated. Secondly, CMUTs can be integrated with supporting microelectronic circuits, thus one can implement a highly integrated transducer system, which can be useful in structural health monitoring NDT applications. Front-end microelectronic circuits that include a transmit pulser and a receive amplifier were designed, tested, and characterized. Thirdly, CMUTs are suitable for air-coupled applications because of their low acoustic impedance at resonance. Air-coupled CMUTs fabricated in a standard RF-MEMS process were characterized and tested. This thesis concludes with an analysis of the potential usefulness of CMUTs for ultrasonic NDT. While many ultrasonic NDT applications are better off being performed using conventional piezoelectric transducers, CMUTs can and should be used in certain NDT applications that can take advantage of the beneficial characteristics of this exciting transducer technology.

Subjects/Keywords: MEMS; CMUT; Ultrasound; Non-destructive Testing

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Wong, L. (2014). Capacitive Micromachined Ultrasonic Transducers for Non-destructive Testing Applications. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/8608

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Wong, Lawrence. “Capacitive Micromachined Ultrasonic Transducers for Non-destructive Testing Applications.” 2014. Thesis, University of Waterloo. Accessed March 06, 2021. http://hdl.handle.net/10012/8608.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Wong, Lawrence. “Capacitive Micromachined Ultrasonic Transducers for Non-destructive Testing Applications.” 2014. Web. 06 Mar 2021.

Vancouver:

Wong L. Capacitive Micromachined Ultrasonic Transducers for Non-destructive Testing Applications. [Internet] [Thesis]. University of Waterloo; 2014. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/10012/8608.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wong L. Capacitive Micromachined Ultrasonic Transducers for Non-destructive Testing Applications. [Thesis]. University of Waterloo; 2014. Available from: http://hdl.handle.net/10012/8608

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

10. Hery, Maxime. Conception et optimisation de transducteurs capacitifs micro-usinés appliqués à l'imagerie ultrasonore : Design and optimization of capacitive micro-machined transducers applied to ultrasound imaging.

Degree: Docteur es, Électronique, 2019, Université François-Rabelais de Tours

URL: http://www.theses.fr/2019TOUR4013

► Les Transducteurs Ultrasonores Capacitifs Micro-usinés (CMUT en anglais) sont étudiés par plusieurs laboratoires internationaux depuis les années 90. Se présentant comme une alternative aux transducteurs… (more)

▼ Les Transducteurs Ultrasonores Capacitifs Micro-usinés (CMUT en anglais) sont étudiés par plusieurs laboratoires internationaux depuis les années 90. Se présentant comme une alternative aux transducteurs traditionnels piézoélectriques, cette technologie inspirée des MEMS (MicroElectroMechanical Systems) a aujourd'hui atteint la maturité suffisante pour voir émerger sa commercialisation. Dans son application historique, l'imagerie médicale, de nombreux acteurs industriels proposent des sondes CMUTs, comme Hitachi, Kolo Medicals ou Butterfly Network pour n'en citer que quelques uns. La recherche autour de ces dispositifs continue néanmoins à travers des études sur la conception, la modélisation, la fabrication ou pour de nouvelles applications. À travers le projet collaboratif TUMAHI (Transducteurs capacitifs Ultrasonores Multi-Application Hautement Intégrés) entre le laboratoire GREMAN et la société VERMON S.A, deux axes d'optimisation ont été étudiés. Le premier objectif consistait à créer et valider expérimentalement une stratégie de conception d'éléments CMUTs pour optimiser la réponse électroacoustique sur la bande passante ou la sensibilité. La principale contrainte était de définir des degrés de liberté et des paramètres fixes pour fabriquer des barrettes CMUTs pour diverses applications et fréquences de travail sur un même wafer. Par l'intermédiaire d'un dispositif centré à 10 MHz pour de l'imagerie médicale, nous avons fait varier les tailles de membranes pour posséder une configuration Large Bande et une configuration Sensible. Une campagne de mesures de pression a été effectuée avec les sondes complètes et prêtes à l'emploi pour valider les critères de conception établis. L'analyse poussée a néanmoins souligné que la démarche de conception pour une sonde CMUT la plus efficace était d'optimiser la fréquence de résonance du premier mode de rayonnement pour qu'elle coïncide avec la fréquence de travail désirée. La seconde étude était focalisée sur la couche de passivation, couche de protection pour les éléments CMUTs traditionnellement conçue en polymère silicone, et visait à implémenter son impact dans les outils de modélisation avec un nouveau modèle de couplage CMUT / matériau viscoélastique. Une fonction de Green en trois dimensions a été utilisée en définissant des équivalences entre propriétés élastiques et viscoélastiques et validée théoriquement avec des problèmes de Lamb 2D et 3D complémentaires. Une confrontation avec des résultats expérimentaux a été engagée en créant une série d'huiles avec des viscosités variables et en excitant des colonnes CMUTs découplées électriquement pour viser un mode de rayonnement plus sensible aux propriétés de cisaillement du milieu. L'influence de la viscosité a été identifiée à travers la variation de la fréquence centrale et du facteur de qualité sur l'impédance électrique mesurée et simulée, posant la base d'une étude de viabilité de la technologie CMUT pour un capteur sensible viscoélastique. La considération de la couche de passivation a permis de retrouver un… Advisors/Committee Members: Certon, Dominique (thesis director).

Subjects/Keywords: Transducteurs CMUT; CMUT; Modal decomposition; Design strategy; Green function; Viscoelasticity; Passivation layer

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Hery, M. (2019). Conception et optimisation de transducteurs capacitifs micro-usinés appliqués à l'imagerie ultrasonore : Design and optimization of capacitive micro-machined transducers applied to ultrasound imaging. (Doctoral Dissertation). Université François-Rabelais de Tours. Retrieved from http://www.theses.fr/2019TOUR4013

Chicago Manual of Style (16^th Edition):

Hery, Maxime. “Conception et optimisation de transducteurs capacitifs micro-usinés appliqués à l'imagerie ultrasonore : Design and optimization of capacitive micro-machined transducers applied to ultrasound imaging.” 2019. Doctoral Dissertation, Université François-Rabelais de Tours. Accessed March 06, 2021. http://www.theses.fr/2019TOUR4013.

MLA Handbook (7^th Edition):

Hery, Maxime. “Conception et optimisation de transducteurs capacitifs micro-usinés appliqués à l'imagerie ultrasonore : Design and optimization of capacitive micro-machined transducers applied to ultrasound imaging.” 2019. Web. 06 Mar 2021.

Vancouver:

Hery M. Conception et optimisation de transducteurs capacitifs micro-usinés appliqués à l'imagerie ultrasonore : Design and optimization of capacitive micro-machined transducers applied to ultrasound imaging. [Internet] [Doctoral dissertation]. Université François-Rabelais de Tours; 2019. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2019TOUR4013.

Council of Science Editors:

Hery M. Conception et optimisation de transducteurs capacitifs micro-usinés appliqués à l'imagerie ultrasonore : Design and optimization of capacitive micro-machined transducers applied to ultrasound imaging. [Doctoral Dissertation]. Université François-Rabelais de Tours; 2019. Available from: http://www.theses.fr/2019TOUR4013

University of Manitoba

11. Islam, Md. Iftekharul. Characterization of multiple moving membrane capacitive micromachined ultrasonic transducer.

Degree: Electrical and Computer Engineering, 2019, University of Manitoba

URL: http://hdl.handle.net/1993/34075

► A newly developed multiple moving membrane capacitive micromachined ultrasonic transducer (M3-CMUT) is fabricated and characterized in this thesis. Unlike the single vibrating membrane in the… (more)

▼ A newly developed multiple moving membrane capacitive micromachined ultrasonic transducer (M3-CMUT) is fabricated and characterized in this thesis. Unlike the single vibrating membrane in the conventional capacitive micromachined ultrasonic transducer (CMUT), the novel design involves two deflectable membranes suspended over a fixed bottom electrode. In the presence of bias, both of the membranes deflect simultaneously, which results in a smaller cavity compared to a CMUT. To understand the basics of a capacitive transducer, an equivalent mass-spring-capacitor model of CMUT was reported. The results of this analytical model were used to develop the finite element models (FEM) of CMUT and more complex M3-CMUT in COMSOL Multiphysics software. The electromechanical analysis of these models was conducted to observe their operating conditions. Following the modeling and analysis, several single-cell, 1-D, and 2-D arrays of these devices were fabricated using PolyMUMPs technology, a sacrificial fabrication technique for the MEMS transducers. The electrical and acoustic characterizations of the fabricated devices were performed to measure the actual transducer properties. The measured data and the model results were found to be in good agreement. It was observed from the electrical impedance measurements that a higher membrane deflection was achieved in the double membrane device. The reduction in the cavity of M3-CMUT enhanced the sensitivity of the transducer. The acoustic characterization using a pitch-catch experimental setup demonstrated that the novel M3-CMUT could be used as an ultrasonic transducer. The velocity and attenuation of the acoustic waves, when the transducer used as both the transmitter and the receiver, were found to be very close to the theoretical value. Advisors/Committee Members: Buchanan, Douglas (Electrical and Computer Engineering) Emadi, Arezoo (Electrical and Computer Engineering) (supervisor), Oliver, Derek (Electrical and Computer Engineering).

Subjects/Keywords: Microelectromechanical System (MEMS); Capacitive Micromachined Ultrasonic Transducer (CMUT); Multiple Moving Membrane Capacitive Micromachined Ultrasonic Transducer (M3-CMUT)

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Islam, M. I. (2019). Characterization of multiple moving membrane capacitive micromachined ultrasonic transducer. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/34075

Chicago Manual of Style (16^th Edition):

Islam, Md Iftekharul. “Characterization of multiple moving membrane capacitive micromachined ultrasonic transducer.” 2019. Masters Thesis, University of Manitoba. Accessed March 06, 2021. http://hdl.handle.net/1993/34075.

MLA Handbook (7^th Edition):

Islam, Md Iftekharul. “Characterization of multiple moving membrane capacitive micromachined ultrasonic transducer.” 2019. Web. 06 Mar 2021.

Vancouver:

Islam MI. Characterization of multiple moving membrane capacitive micromachined ultrasonic transducer. [Internet] [Masters thesis]. University of Manitoba; 2019. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1993/34075.

Council of Science Editors:

Islam MI. Characterization of multiple moving membrane capacitive micromachined ultrasonic transducer. [Masters Thesis]. University of Manitoba; 2019. Available from: http://hdl.handle.net/1993/34075

Georgia Tech

12. Rashid, Muhammad Wasequr. Electronics design for high density CMUT array based ultrasound imaging system.

Degree: PhD, Electrical and Computer Engineering, 2017, Georgia Tech

URL: http://hdl.handle.net/1853/60180

► In catheter based ultrasound imaging applications, gathering real-time imaging data from a large number of transducer array elements is extremely challenging with the standard interconnect… (more)

▼ In catheter based ultrasound imaging applications, gathering real-time imaging data from a large number of transducer array elements is extremely challenging with the standard interconnect and transducer technology as there is a restriction on cable count due to the diameter of the catheter. Intracardiac Echocardiography (ICE) imaging systems require many cables connecting the transducer array elements at the tip of the catheter to the backend imaging systems. Reducing the number of cables using highly integrated front-end electronics, is essential for 3-D ICE imaging systems with 2-D imaging arrays. Cable reduction would also reduce the cost of the current 2-D imaging ICE catheters with 1-D imaging arrays and can enable to ICE imaging under MRI by reducing the RF induced heating of the catheters. Current approaches to cable reduction tend to rely on area and power-hungry circuits to function, making them unsuitable for use in catheters. This research explores the design of the CMOS receiver circuitry which implements a Time Division Multiplexing (TDM) scheme to address the receive cable restrictions of the catheter. This approach, implemented in the form of a direct digital demultiplexing technique, allows for a reduction in the number of analog signal processing stages required. Receive multiplexing alone is not enough to reduce the cable count since the same elements in the arrays are used as transmitters. Therefore, the CMOS circuitry should integrate transmit beamforming as well. For this purpose, this study also explores an on-chip programmable transmit beamformer circuit for producing focused and steered transmit beams. In this thesis, a system which uses an e cient real-time programmable on-chip transmit beamformer circuitry to reduce the cable count on the transmit side and analog 8:1 Time Division Multiplexing with Direct Digital Demodulation to reduce the cable count on the receive side is described and initial imaging results are presented. Advisors/Committee Members: Ghovanloo, Maysam (advisor), Degertekin, Levent (advisor), Hasler, Jennifer (advisor), Inan, Omer (committee member), Sabra, Karim (committee member), Brand, Oliver (committee member), Freear, Steven (committee member).

Subjects/Keywords: Catheter; Ultrasound; Intracardiac echocardiography (ICE); FPGA; CMUT-on-CMOS; Transmit beamformer; Micro-coax cable; Time-division multiplexing (TDM); CMUT electronics

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Rashid, M. W. (2017). Electronics design for high density CMUT array based ultrasound imaging system. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60180

Chicago Manual of Style (16^th Edition):

Rashid, Muhammad Wasequr. “Electronics design for high density CMUT array based ultrasound imaging system.” 2017. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021. http://hdl.handle.net/1853/60180.

MLA Handbook (7^th Edition):

Rashid, Muhammad Wasequr. “Electronics design for high density CMUT array based ultrasound imaging system.” 2017. Web. 06 Mar 2021.

Vancouver:

Rashid MW. Electronics design for high density CMUT array based ultrasound imaging system. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1853/60180.

Council of Science Editors:

Rashid MW. Electronics design for high density CMUT array based ultrasound imaging system. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/60180

13. Gross, Dominique. Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore : Design and evaluation of ultrasound-guided focused ultrasound CMUT probe for targeted therapy.

Degree: Docteur es, Sciences de la Vie et de la Santé, 2015, Université François-Rabelais de Tours

URL: http://www.theses.fr/2015TOUR3313

►

Présentés pour la première fois en 1994, les transducteurs ultrasonores capacitifs micro- usinés, ou CMUTs (Capacitive Micromachined Ultrasonic Transducers), représentent une technologie alternative aux matériaux… (more)

Subjects/Keywords: CMUT; Ultrasons; Échographie; Thérapie ciblée; USgFUS; Wafer bonding

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Gross, D. (2015). Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore : Design and evaluation of ultrasound-guided focused ultrasound CMUT probe for targeted therapy. (Doctoral Dissertation). Université François-Rabelais de Tours. Retrieved from http://www.theses.fr/2015TOUR3313

Chicago Manual of Style (16^th Edition):

Gross, Dominique. “Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore : Design and evaluation of ultrasound-guided focused ultrasound CMUT probe for targeted therapy.” 2015. Doctoral Dissertation, Université François-Rabelais de Tours. Accessed March 06, 2021. http://www.theses.fr/2015TOUR3313.

MLA Handbook (7^th Edition):

Gross, Dominique. “Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore : Design and evaluation of ultrasound-guided focused ultrasound CMUT probe for targeted therapy.” 2015. Web. 06 Mar 2021.

Vancouver:

Gross D. Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore : Design and evaluation of ultrasound-guided focused ultrasound CMUT probe for targeted therapy. [Internet] [Doctoral dissertation]. Université François-Rabelais de Tours; 2015. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2015TOUR3313.

Council of Science Editors:

Gross D. Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore : Design and evaluation of ultrasound-guided focused ultrasound CMUT probe for targeted therapy. [Doctoral Dissertation]. Université François-Rabelais de Tours; 2015. Available from: http://www.theses.fr/2015TOUR3313

Erasmus University Rotterdam

14. M. Pekař (Martin). Agile and Bright Intracardiac Catheters.

Degree: 2017, Erasmus University Rotterdam

URL: http://hdl.handle.net/1765/100840

► markdownabstractIntracardiac imaging catheters represent unique instruments to diagnose and treat a diseased heart. While there are imminent advances in medical innovation, many of the commercially… (more)

▼ markdownabstractIntracardiac imaging catheters represent unique instruments to diagnose and treat a diseased heart. While there are imminent advances in medical innovation, many of the commercially available imaging catheters are outdated. Some of them have been designed more than 20 years and therefore they lack novel sensor technology, multi-functionality, and often require manual assembly process. Introduction chapter of this thesis discusses clinical needs and introduces new technological concepts that are needed to progress the functionality and clinical value of the intracardiac catheters along with efficient and simple designs to make the catheters affordable for the patients. The following chapters are grouped into two parts that explore complementary transducer technology and a novel optical fiber-link solution for catheter-based intracardiac imaging. _Part I_ focuses on developing a new intracardiac catheter that has an advanced functionality, which provides clinician with high penetration or close-up high resolution ultrasound imaging in a single device. This agile ultrasound visualization is enabled by a capacitive-micromachined ultrasound transducer (CMUT), operated in collapse-mode, of which the operating frequency can be tuned. Acoustic performance of a fabricated CMUT is modelled and measured. Imaging performance of the CMUT array is quantified on a tissue-mimicking phantom and demonstrated both ex vivo and in vivo experiments. It is found that the combination of the forward-looking design, frequency-tuning and agile deflectability of the catheter allow for visualizing intracardiac structures of various sizes at different distances relative to the catheter tip, providing both wide overviews and detailed close-ups. _Part II_ is devoted to a novel optical technology for transmitting signals and transferring power inside catheters. A novel concept of an all-optical fiber link is introduced. A key insight obtained is that a blue light-emitting diode (LED) may be used as a photo-voltaic converter. Used in reverse under illumination with violet light, it converts significant amount of photonic energy to electricity and at the same time it may emit blue light back, which makes it a unique miniature power and communication channel for catheters. A pressure-sensing catheter prototype is built to demonstrate the concept of transmitting signals and delivering power using a single optical fiber and an LED. The potential of the power and signal fiber link solution is exploited further for ultrasound imaging. A bench-top demonstrator scalable to catheter dimensions is built, in which electrical wires for ultrasound-sensor signal and power tran

Subjects/Keywords: ultrasound; intracardiac imaging; transducer; catheter; cmut; optical communication; power delivery

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

(Martin), M. P. (2017). Agile and Bright Intracardiac Catheters. (Thesis). Erasmus University Rotterdam. Retrieved from http://hdl.handle.net/1765/100840

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

(Martin), M. Pekař. “Agile and Bright Intracardiac Catheters.” 2017. Thesis, Erasmus University Rotterdam. Accessed March 06, 2021. http://hdl.handle.net/1765/100840.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

(Martin), M. Pekař. “Agile and Bright Intracardiac Catheters.” 2017. Web. 06 Mar 2021.

Vancouver:

(Martin) MP. Agile and Bright Intracardiac Catheters. [Internet] [Thesis]. Erasmus University Rotterdam; 2017. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1765/100840.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

(Martin) MP. Agile and Bright Intracardiac Catheters. [Thesis]. Erasmus University Rotterdam; 2017. Available from: http://hdl.handle.net/1765/100840

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

15. Jeba, Dilruba Zaman. Capacitive Micromachined Ultrasonic Transducers: Design, Fabrication and Characterization.

Degree: Electrical and Computer Engineering, 2014, University of Manitoba

URL: http://hdl.handle.net/1993/23928

► Capacitive micromachined ultrasonic transducers (CMUTs) have been developed as an alternative to piezoelectric transducers for ultrasonic imaging in non-destructive testing applications. These CMUTs offer substantial… (more)

▼ Capacitive micromachined ultrasonic transducers (CMUTs) have been developed as an alternative to piezoelectric transducers for ultrasonic imaging in non-destructive testing applications. These CMUTs offer substantial advantages over their piezoelectric counterparts, which include a highly miniaturized system, easy integration with electronic control circuitry, a wider bandwidth, and a higher sensitivity. In this thesis, the design, fabrication and characterization of several single and array CMUT devices are reported. Many sizes of CMUTs, aiming to operate at different resonant frequencies, were fabricated using a PolyMUMPs sacrificial technique. An analytical and finite element model was used to further understanding of the physical behaviour of the transducer. The basic functionality of the CMUT devices was investigated through capacitance and electrical impedance measurements. These devices showed greater change in the capacitance and impedance data while operating close to their collapse voltages. This higher change in both capacitance and impedance is a result of a larger membrane displacement. The acoustic output power is directly related to the magnitude of the membrane’s displacement. The transducers performance thus can be enhanced by operating close to their collapse voltage and obtained higher sensitivity. The optical characterization, performed on the single devices and on the 1-D arrays, provided a better understanding of the membrane vibration modes and displacement profiles at different resonant frequency modes. Acoustic measurements were performed to demonstrate the transmission capability of the CMUTs. The generated acoustic signals were detected using a commercial detector. These acoustic experiments demonstrated that these CMUTs can potentially be used as ultrasonic transducers alternative to piezoelectric transducers. Advisors/Committee Members: Buchanan, Douglas A. (Electrical and Computer Engineering) (supervisor), Oliver, Derek (Electrical and Computer Engineering) Morrison, Jason (Biosystems Engineering) (examiningcommittee).

Subjects/Keywords: CMUT; Transducers; MEMS; Ultrasonic

…micromachined ultrasonic transducer (CMUT). 8 Figure 2.3. CMUT as (a) a… …26 Figure 3.5. A schematic diagram of a CMUT, illustrating the membrane thickness gap… …37 Figure 3.9. Analytical and FEM static deflection of a single CMUT device (40 µm… …38 Figure 3.10. The simulated natural vibration modes of a 40 µm radius CMUT device with a… …40 Figure 3.12. Transient response of a CMUT membrane with 40 µm radius, excited by a 14 V…

15 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Jeba, D. Z. (2014). Capacitive Micromachined Ultrasonic Transducers: Design, Fabrication and Characterization. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/23928

Chicago Manual of Style (16^th Edition):

Jeba, Dilruba Zaman. “Capacitive Micromachined Ultrasonic Transducers: Design, Fabrication and Characterization.” 2014. Masters Thesis, University of Manitoba. Accessed March 06, 2021. http://hdl.handle.net/1993/23928.

MLA Handbook (7^th Edition):

Jeba, Dilruba Zaman. “Capacitive Micromachined Ultrasonic Transducers: Design, Fabrication and Characterization.” 2014. Web. 06 Mar 2021.

Vancouver:

Jeba DZ. Capacitive Micromachined Ultrasonic Transducers: Design, Fabrication and Characterization. [Internet] [Masters thesis]. University of Manitoba; 2014. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1993/23928.

Council of Science Editors:

Jeba DZ. Capacitive Micromachined Ultrasonic Transducers: Design, Fabrication and Characterization. [Masters Thesis]. University of Manitoba; 2014. Available from: http://hdl.handle.net/1993/23928

University of Windsor

16. Manwar, Rayyan. A BCB Diaphragm Based Adhesive Wafer Bonded CMUT Probe for Biomedical Application.

Degree: PhD, Electrical and Computer Engineering, 2017, University of Windsor

URL: https://scholar.uwindsor.ca/etd/5996

► This dissertation presents the design methodology, fabrication procedure, and key experimental characterization results of a linear array of capacitive micromachined ultrasonic transducers (CMUT) for possible… (more)

▼ This dissertation presents the design methodology, fabrication procedure, and key experimental characterization results of a linear array of capacitive micromachined ultrasonic transducers (CMUT) for possible ophthalmic anterior segment imaging application. The design methodology involves analytical, 3-D electromechanical finite element analysis, and Verasonics Vantage 128 ultrasonic research platform based diagnostic imaging simulations to develop a technique that minimizes electrical charging and center frequency drift while improving the transduction efficiency. In the design, Bisbenzocyclobutene (BCB), a low K polymer from Dow Chemical Company, has been innovatively used for the first time to fabricate the structural layer of the CMUT diaphragm, realize the interelectrode dielectric spacer, and to act as a low temperature adhesive bonding agent. Additionally, the top CMUT electrode has been placed at the bottom of the diaphragm to affect higher capacitance change that increases sensitivity and provides additional decoupling of the electrical charging effects. Several arrays with element count ranging from 8 to 128 elements and a center frequency range of 5 MHz to 40 MHz have been designed and fabricated. Due to an unforeseen adhesion issue during wirebonding, a 32 channel 40 MHz CMUT array has been packaged manually to validate the fabrication process and CMUT operation. Extensive SEM inspections of the CMUT cross-sections show good agreement with the design specifications. Static and dynamic measurements using a Polytec laser Doppler vibrometer, impedance measurement using an Agilent vector network analyzer, and LCR measurement results are in excellent agreement with analytical and FEA analysis using IntelliSuite. The frequency analysis exhibits high electromechanical coupling coefficient of 0.66 at a low bias voltage of 20 V and high uniformity. A successful measurement of the lower drift of the center frequency 0.32% and higher coupling coefficient verifies the hypothesis that the excellent electrical, structural, and processing characteristics of BCB is a viable option to mitigate the dielectric charging and improve the transduction efficiency of CMUTs. Advisors/Committee Members: Chowdhury, Sazzadur.

Subjects/Keywords: Adhesive Wafer Bonded; BCB; CMUT; Coupling coefficient; Dielectric charging; Ophthalmic

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Manwar, R. (2017). A BCB Diaphragm Based Adhesive Wafer Bonded CMUT Probe for Biomedical Application. (Doctoral Dissertation). University of Windsor. Retrieved from https://scholar.uwindsor.ca/etd/5996

Chicago Manual of Style (16^th Edition):

Manwar, Rayyan. “A BCB Diaphragm Based Adhesive Wafer Bonded CMUT Probe for Biomedical Application.” 2017. Doctoral Dissertation, University of Windsor. Accessed March 06, 2021. https://scholar.uwindsor.ca/etd/5996.

MLA Handbook (7^th Edition):

Manwar, Rayyan. “A BCB Diaphragm Based Adhesive Wafer Bonded CMUT Probe for Biomedical Application.” 2017. Web. 06 Mar 2021.

Vancouver:

Manwar R. A BCB Diaphragm Based Adhesive Wafer Bonded CMUT Probe for Biomedical Application. [Internet] [Doctoral dissertation]. University of Windsor; 2017. [cited 2021 Mar 06]. Available from: https://scholar.uwindsor.ca/etd/5996.

Council of Science Editors:

Manwar R. A BCB Diaphragm Based Adhesive Wafer Bonded CMUT Probe for Biomedical Application. [Doctoral Dissertation]. University of Windsor; 2017. Available from: https://scholar.uwindsor.ca/etd/5996

17. Yashvanth, Varshitha. CMUT Crosstalk Reduction Using Crosslinked Silica Aerogel.

Degree: MA, Electrical and Computer Engineering, 2018, University of Windsor

URL: https://scholar.uwindsor.ca/etd/7427

► Inter-element acoustic crosstalk is one of the major concerns which restricts the potential deployment of Capacitive Micromachined Ultrasonic Transducers (CMUTs) in Nondestructive Evaluation (NDE) despite… (more)

Subjects/Keywords: CMUT; Scholte waves

…12 CMUT Operation Principle… …17 2.4 CMUT Array Design Methodology… …Contributors for Acoustic Crosstalk in CMUT Cells .................. 36 4.1.1 Effects of Inter-cell… …Material on CMUT Crosstalk ............... 39 4.1.3 Effects of Coupling Medium on Acoustic… …43 4.2 Scientific Approach to Mitigate CMUT Crosstalk…

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Yashvanth, V. (2018). CMUT Crosstalk Reduction Using Crosslinked Silica Aerogel. (Masters Thesis). University of Windsor. Retrieved from https://scholar.uwindsor.ca/etd/7427

Chicago Manual of Style (16^th Edition):

Yashvanth, Varshitha. “CMUT Crosstalk Reduction Using Crosslinked Silica Aerogel.” 2018. Masters Thesis, University of Windsor. Accessed March 06, 2021. https://scholar.uwindsor.ca/etd/7427.

MLA Handbook (7^th Edition):

Yashvanth, Varshitha. “CMUT Crosstalk Reduction Using Crosslinked Silica Aerogel.” 2018. Web. 06 Mar 2021.

Vancouver:

Yashvanth V. CMUT Crosstalk Reduction Using Crosslinked Silica Aerogel. [Internet] [Masters thesis]. University of Windsor; 2018. [cited 2021 Mar 06]. Available from: https://scholar.uwindsor.ca/etd/7427.

Council of Science Editors:

Yashvanth V. CMUT Crosstalk Reduction Using Crosslinked Silica Aerogel. [Masters Thesis]. University of Windsor; 2018. Available from: https://scholar.uwindsor.ca/etd/7427

University of Arizona

18. Montilla, Leonardo Gabriel. Advanced Devices for Photoacoustic Imaging to Improve Cancer and Cerebrovascular Medicine .

Degree: 2013, University of Arizona

URL: http://hdl.handle.net/10150/312510

► Recent clinical studies have demonstrated that photoacoustic imaging (PAI) provides important diagnostic information for breast cancer staging. Despite these promising studies, PAI remains an unfeasible… (more)

▼ Recent clinical studies have demonstrated that photoacoustic imaging (PAI) provides important diagnostic information for breast cancer staging. Despite these promising studies, PAI remains an unfeasible option for clinics due to the cost to implement, the required large modification in user conduct and the inflexibility of the hardware to accommodate other applications for the incremental enhancement in diagnostic information. The research described in this dissertation addresses these issues by designing attachments to clinical ultrasound probes and incorporating custom detectors into commercial ultrasound scanners. The ultimate benefit of these handheld devices is to expand the capability of current ultrasound systems and facilitate the translation of PAI to enhance cancer diagnostics and neurosurgical outcomes. Photoacoustic enabling devices (PEDs) were designed as attachments to two clinical ultrasound probes optimized for breast cancer diagnostics. PAI uses pulsed laser excitation to create transient heating (<1°C) and thermoelastic expansion that is detected as an ultrasonic emission. These ultrasonic emissions are remotely sensed to construct noninvasive images with optical contrast at depths much greater than other optical modalities. The PEDs are feasible in terms of cost, user familiarity and flexibility for various applications. Another possible application for PAI is in assisting neurosurgeons treating aneurysms. Aneurysms are often treated by placing a clip to prevent blood flow into the aneurysm. However, this procedure has risks associated with damaging nearby vessels. One of the developed PEDs demonstrated the feasibility to three-dimensionally image tiny microvasculature (<0.3mm) beyond large blood occlusions (>2.4mm) in a phantom model. The capability to use this during surgery would suggest decreasing the risks associated with these treatments. However, clinical ultrasound arrays are not clinically feasible for microsurgical applications due to their bulky size and linear scanning requirements for 3D. Therefore, capacitive micromachined ultrasound transducer (CMUT) two-dimensional arrays compatible with standard ultrasound scanners were used to generate real-time 3D photoacoustic images. Future probes, designed incorporating CMUT arrays, would be relatively simple to fabricate and a convenient upgrade to existing clinical ultrasound equipment. Eventually, a handheld tool with the ability to visualize, in real-time 3D, the desired microvasculature, would assist surgical procedures. The potential implications of PAI devices compatible with standard ultrasound equipment would be a streamlined cost efficient solution for translating photoacoustics into clinical practice. The practitioner could then explore the benefits of the enhanced contrast adjunctive to current ultrasound applications. Clinical availability of PAI could enhance breast cancer diagnostics and cerebrovascular surgical outcomes. Advisors/Committee Members: Witte, Russell S (advisor), Witte, Russell S. (committeemember), Gmitro, Art (committeemember), Pagel, Mark (committeemember), Unger, Evan (committeemember).

Subjects/Keywords: Imaging; Neurosurgery; Optoacoustic; Photoacoustic; Ultrasound; Optical Sciences; CMUT

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Montilla, L. G. (2013). Advanced Devices for Photoacoustic Imaging to Improve Cancer and Cerebrovascular Medicine . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/312510

Chicago Manual of Style (16^th Edition):

Montilla, Leonardo Gabriel. “Advanced Devices for Photoacoustic Imaging to Improve Cancer and Cerebrovascular Medicine .” 2013. Doctoral Dissertation, University of Arizona. Accessed March 06, 2021. http://hdl.handle.net/10150/312510.

MLA Handbook (7^th Edition):

Montilla, Leonardo Gabriel. “Advanced Devices for Photoacoustic Imaging to Improve Cancer and Cerebrovascular Medicine .” 2013. Web. 06 Mar 2021.

Vancouver:

Montilla LG. Advanced Devices for Photoacoustic Imaging to Improve Cancer and Cerebrovascular Medicine . [Internet] [Doctoral dissertation]. University of Arizona; 2013. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/10150/312510.

Council of Science Editors:

Montilla LG. Advanced Devices for Photoacoustic Imaging to Improve Cancer and Cerebrovascular Medicine . [Doctoral Dissertation]. University of Arizona; 2013. Available from: http://hdl.handle.net/10150/312510

Georgia Tech

19. Lim, Jaemyung. Reduced-wire readout systems-on-chip for high-frequency intravascular ultrasound imaging.

Degree: PhD, Electrical and Computer Engineering, 2017, Georgia Tech

URL: http://hdl.handle.net/1853/59800

► The objective of the proposed research is to minimize and integrate intravascular ultrasound imaging (IVUS) system on a guidewire and to develop wireless data communication… (more)

Subjects/Keywords: IVUS; Ultrasound imaging; Intravascular; Capacitive micromachined ultrasonic transducer; CMUT

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Lim, J. (2017). Reduced-wire readout systems-on-chip for high-frequency intravascular ultrasound imaging. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59800

Chicago Manual of Style (16^th Edition):

Lim, Jaemyung. “Reduced-wire readout systems-on-chip for high-frequency intravascular ultrasound imaging.” 2017. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021. http://hdl.handle.net/1853/59800.

MLA Handbook (7^th Edition):

Lim, Jaemyung. “Reduced-wire readout systems-on-chip for high-frequency intravascular ultrasound imaging.” 2017. Web. 06 Mar 2021.

Vancouver:

Lim J. Reduced-wire readout systems-on-chip for high-frequency intravascular ultrasound imaging. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1853/59800.

Council of Science Editors:

Lim J. Reduced-wire readout systems-on-chip for high-frequency intravascular ultrasound imaging. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/59800

University of Waterloo

20. CHEN, ALBERT I-HSIANG. Row-Column Capacitive Micromachined Ultrasonic Transducers for Medical Imaging.

Degree: 2016, University of Waterloo

URL: http://hdl.handle.net/10012/11105

► Ultrasound imaging plays an important role in modern medical diagnosis. Recent progress in real-time 3-D ultrasound imaging can offer critical information such as the accurate… (more)

▼ Ultrasound imaging plays an important role in modern medical diagnosis. Recent progress in real-time 3-D ultrasound imaging can offer critical information such as the accurate estimation of organ, cyst, or tumour volumes. However, compared to conventional 2-D ultrasound imaging, the large amount of data and circuit complexity found in 3-D ultrasound imaging results in very expensive systems. Therefore, a simplification scheme for 3-D ultrasound imaging technology is needed for a more wide-spread use and to advance clinical development of volumetric ultrasound. Row-column addressing 2-D array is one particular simplification scheme that requires only N + N addressing lines to activate each element in an N × N array. As a result, the fabrication, circuit, and processing complexity dramatically decrease. Capacitive micromachined ultrasonic transducer (CMUT) technology was chosen to fabricate the array as it offers micro-precision fabrication and a wide bandwidth, which make it an attractive transducer technology. The objective of this thesis is to investigate and demonstrate the imaging potential of row-column CMUT arrays for RT3D imaging. First, the motivation, physics, and modelling of both CMUTs and row-column arrays are described, followed by the demonstration of a customized row-column CMUT pseudo-real-time 3-D imaging system. One particular limitation about row-column arrays discovered as part of this dissertation work is the limited field-of-view of the row-column arrays’ imaging performance. A curved row-column CMUT array was proposed to improve the field-of-view, and the resulting modelling of the acoustic field and simulated reconstructed image are presented. Furthermore, a new fabrication process was proposed to construct a curved row-column CMUT array. The resulting device was tested to demonstrate its flexibility to achieve the necessary curvature. Finally, a new wafer bonding process is introduced to tackle the next generation of RC-CMUT fabrication. Many of the new fabrication techniques reported in this work are useful for CMUT fabrication engineers. The analysis on row-column array also provides additional insights for 2-D array simplification research.

Subjects/Keywords: mems; cmut; flexible ultrasonic transducer array; row-column addressing ultrasound

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

CHEN, A. I. (2016). Row-Column Capacitive Micromachined Ultrasonic Transducers for Medical Imaging. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/11105

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

CHEN, ALBERT I-HSIANG. “Row-Column Capacitive Micromachined Ultrasonic Transducers for Medical Imaging.” 2016. Thesis, University of Waterloo. Accessed March 06, 2021. http://hdl.handle.net/10012/11105.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

CHEN, ALBERT I-HSIANG. “Row-Column Capacitive Micromachined Ultrasonic Transducers for Medical Imaging.” 2016. Web. 06 Mar 2021.

Vancouver:

CHEN AI. Row-Column Capacitive Micromachined Ultrasonic Transducers for Medical Imaging. [Internet] [Thesis]. University of Waterloo; 2016. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/10012/11105.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

CHEN AI. Row-Column Capacitive Micromachined Ultrasonic Transducers for Medical Imaging. [Thesis]. University of Waterloo; 2016. Available from: http://hdl.handle.net/10012/11105

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

21. Hord, Samuel Kay. A novel fabrication process for CMUTs in air.

Degree: MSin Engineering, Mechanical Engineering, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/69092

► A novel fabrication method for producing capacitive micromachined ultrasonic transducers (CMUTs) is presented. The process uses conductive silicon on insulator (SOI) substrates to produce an… (more)

Subjects/Keywords: CMUT; Ultrasonic transducers; Transducers; Semiconductor fabrication; Acoustics; Acoustical MEMS; MEMS

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Hord, S. K. (2018). A novel fabrication process for CMUTs in air. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/69092

Chicago Manual of Style (16^th Edition):

Hord, Samuel Kay. “A novel fabrication process for CMUTs in air.” 2018. Masters Thesis, University of Texas – Austin. Accessed March 06, 2021. http://hdl.handle.net/2152/69092.

MLA Handbook (7^th Edition):

Hord, Samuel Kay. “A novel fabrication process for CMUTs in air.” 2018. Web. 06 Mar 2021.

Vancouver:

Hord SK. A novel fabrication process for CMUTs in air. [Internet] [Masters thesis]. University of Texas – Austin; 2018. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/2152/69092.

Council of Science Editors:

Hord SK. A novel fabrication process for CMUTs in air. [Masters Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/69092

22. Oliveira, Victor Inacio de. Estudo de dispositivos CMUTS fabricados com métodos e materiais alternativos para aplicação potencial em ensaios não destrutivos.

Degree: PhD, Engenharia de Controle e Automação Mecânica, 2014, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/3/3152/tde-11082015-160035/ ;

►

O presente trabalho propõe o estudo de dispositivos CMUTs fabricados através de métodos e materiais alternativos com potencial aplicação em ensaios não destrutivos. O CMUT… (more)

▼

O presente trabalho propõe o estudo de dispositivos CMUTs fabricados através de métodos e materiais alternativos com potencial aplicação em ensaios não destrutivos. O CMUT é constituído por uma membrana condutiva colocada sobre uma cavidade com o fundo metalizado, formando uma estrutura capacitiva. Ondas acústicas incidentes criam uma vibração na membrana que modifica de forma detectável a capacitância do dispositivo (modo de detecção). De modo inverso, é possível aplicar tensão alternada sobre a estrutura do CMUT fazendo com que a membrana vibre gerando ondas acústicas (modo de emissão). Hoje as principais tecnologias utilizadas para detecção e emissão de ondas acústicas utilizam materiais piezelétricos que são de difícil obtenção, possuem baixa integrabilidade e restrições em aplicações em altas temperaturas. O transdutor proposto baseia-se na tecnologia MEMS onde efeitos elétricos e mecânicos são combinados de forma a atender uma determinada aplicação. Os dispositivos MEMS são fabricados por técnicas de microfabricação, o que diminui o custo de produção e possibilita o uso de diversos tipos de materiais. Antes da fabricação dos CMUTs, foram feitas modelagens analíticas e computacionais visando determinar as dimensões ideais dos dispositivos a serem fabricados e também quais materiais seriam melhores se aplicados como membrana. A partir dos resultados da modelagem foi possível determinar que CMUTs com membrana de cobre fossem fabricados. Com os resultados da modelagem foram propostos métodos de fabricação baseados em técnicas de wafer-bonding. Dois materiais foram utilizados para produzir as cavidades, um deles foi o fotorresiste SU-8 e outro uma resina adesiva de secagem rápida, material este não convencional para produção de CMUTs. No primeiro caso, as cavidades foram abertas por processo de fotolitografia, já no segundo foi utilizado um método de corrosão a laser, também não convencional. Diferentes métodos foram utilizados na colagem das membranas, sendo que membranas coladas com resina adesiva e membranas deixadas suspensas sobre as cavidades apresentaram melhores resultados. As caracterizações elétricas e acústicas realizadas nos dispositivos fabricados mostraram que os CMUTs obtidos possuem características capacitivas e podem emitir e receber, comprovando assim seu funcionamento. Isto indica que os roteiros de fabricação propostos são eficientes e que os materiais e métodos utilizados se mostraram adequados. Além disso, a partir das caracterizações acústicas é possível dizer que os CMUTs fabricados podem ser potencialmente aplicados em ensaios não destrutivos, principalmente em análise de vibrações.

This thesis proposes the study of CMUT devices produced using alternative methods and materials with potential application in non-destructive analysis. CMUT is composed of a metallized substrate covered with an insulator cavity structure and a conductive membrane on its top, forming a capacitive structure. Incident acoustic waves cause vibration in the membrane modifying their capacitance (detection mode). AC…

Advisors/Committee Members: Barros, Ettore Apolonio de.

Subjects/Keywords: Análise de vibrações; Analyses of vibrations; CMUT; CMUT; Ensaios não destrutivos; Finite elements method; MEMS; MEMS; Método dos elementos finitos; Nondestructive analyses; Ultrasound; Ultrassom

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Oliveira, V. I. d. (2014). Estudo de dispositivos CMUTS fabricados com métodos e materiais alternativos para aplicação potencial em ensaios não destrutivos. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/3/3152/tde-11082015-160035/ ;

Chicago Manual of Style (16^th Edition):

Oliveira, Victor Inacio de. “Estudo de dispositivos CMUTS fabricados com métodos e materiais alternativos para aplicação potencial em ensaios não destrutivos.” 2014. Doctoral Dissertation, University of São Paulo. Accessed March 06, 2021. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-11082015-160035/ ;.

MLA Handbook (7^th Edition):

Oliveira, Victor Inacio de. “Estudo de dispositivos CMUTS fabricados com métodos e materiais alternativos para aplicação potencial em ensaios não destrutivos.” 2014. Web. 06 Mar 2021.

Vancouver:

Oliveira VId. Estudo de dispositivos CMUTS fabricados com métodos e materiais alternativos para aplicação potencial em ensaios não destrutivos. [Internet] [Doctoral dissertation]. University of São Paulo; 2014. [cited 2021 Mar 06]. Available from: http://www.teses.usp.br/teses/disponiveis/3/3152/tde-11082015-160035/ ;.

Council of Science Editors:

Oliveira VId. Estudo de dispositivos CMUTS fabricados com métodos e materiais alternativos para aplicação potencial em ensaios não destrutivos. [Doctoral Dissertation]. University of São Paulo; 2014. Available from: http://www.teses.usp.br/teses/disponiveis/3/3152/tde-11082015-160035/ ;

23. Novell, Anthony. Imagerie de contraste ultrasonore avec transducteurs capacitifs micro-usinés : Contrast agent imaging with capacitive micromachined ultrasonic transducers.

Degree: Docteur es, Sciences de la Vie et de la Santé, 2011, Université François-Rabelais de Tours

URL: http://www.theses.fr/2011TOUR3316

►

Les produits de contraste ultrasonore constituent un véritable apport pour l’imagerie échographique et sont aujourd’hui utilisés en clinique pour l’évaluation de la perfusion cardiaque ou… (more)

▼

Les produits de contraste ultrasonore constituent un véritable apport pour l’imagerie échographique et sont aujourd’hui utilisés en clinique pour l’évaluation de la perfusion cardiaque ou encore la détection de tumeurs. Depuis quelques années, les transducteurs capacitifs micro-usinés (cMUTs) se présentent comme une alternative intéressante aux transducteurs piézoélectriques classiques et offrent certains avantages comme une large bande passante. Nous proposons dans cette thèse d’évaluer le potentiel de cette technologie pour l’imagerie de contraste. Dans un premier temps, notre étude s’est orientée vers l’adaptation des cMUTs à l’imagerie non linéaire. Ensuite, de nouvelles méthodes de détection de contraste, basées sur le comportement spécifique des microbulles, ont été développées pour exploiter les avantages de la technologie cMUT. Comparés aux méthodes conventionnelles, les résultats obtenus montrent une meilleure visualisation des agents de contraste par rapport aux tissus environnants. L’utilisation de cMUTs améliore l’efficacité de ces méthodes démontrant, ainsi, leur intérêt pour l’imagerie de contraste.

Using ultrasound contrast agents, many clinical diagnoses have now been improved thanks to new contrast dedicated imaging techniques. Contrast agents are now used routinely in cardiology and in radiology to improve the detection and visualization of blood perfusion in various organs (e.g. tumors). Since a few years, Capacitive Micromachined Ultrasonic Transducers (cMUTs) have emerged as a good alternative to traditional piezoelectric transducer. cMUTs provide several advantages such as wide frequency bandwidth which could be further developed for nonlinear imaging. In this dissertation, we propose to exploit cMUT for contrast agent imaging. Firstly, the excitation signal was adapted to suppress the inherent nonlinear behavior of cMUT. Then, new detection methods based on specific acoustic properties of microbubbles have been developed and evaluated with a cMUT probe. Results show a good suppression from tissue responses whereas echoes from microbubbles are enhanced. Furthermore, the efficiency of each method is improved by the use of cMUT revealing the potential of this new transducer technology for contrast agent detection.

Advisors/Committee Members: Bouakaz, Ayache (thesis director).

Subjects/Keywords: Echographie de contraste; CMUT; Imagerie non linéaire; Microbulle; Compensation; Harmoniques; CTR; Chirps; Contrast agent imaging; Microbubble; Nonlinear imaging; Chirp; Contrast to tissue ratio; CMUT; Compensation; Harmonic components

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Novell, A. (2011). Imagerie de contraste ultrasonore avec transducteurs capacitifs micro-usinés : Contrast agent imaging with capacitive micromachined ultrasonic transducers. (Doctoral Dissertation). Université François-Rabelais de Tours. Retrieved from http://www.theses.fr/2011TOUR3316

Chicago Manual of Style (16^th Edition):

Novell, Anthony. “Imagerie de contraste ultrasonore avec transducteurs capacitifs micro-usinés : Contrast agent imaging with capacitive micromachined ultrasonic transducers.” 2011. Doctoral Dissertation, Université François-Rabelais de Tours. Accessed March 06, 2021. http://www.theses.fr/2011TOUR3316.

MLA Handbook (7^th Edition):

Novell, Anthony. “Imagerie de contraste ultrasonore avec transducteurs capacitifs micro-usinés : Contrast agent imaging with capacitive micromachined ultrasonic transducers.” 2011. Web. 06 Mar 2021.

Vancouver:

Novell A. Imagerie de contraste ultrasonore avec transducteurs capacitifs micro-usinés : Contrast agent imaging with capacitive micromachined ultrasonic transducers. [Internet] [Doctoral dissertation]. Université François-Rabelais de Tours; 2011. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2011TOUR3316.

Council of Science Editors:

Novell A. Imagerie de contraste ultrasonore avec transducteurs capacitifs micro-usinés : Contrast agent imaging with capacitive micromachined ultrasonic transducers. [Doctoral Dissertation]. Université François-Rabelais de Tours; 2011. Available from: http://www.theses.fr/2011TOUR3316

24. Meynier, Cyril. Modélisation, conception et caractérisation de transducteurs ultrasonores capacitifs micro-usinés : Modelling, design and characterization of micromachined ultrasonic transducers.

Degree: Docteur es, Sciences de la Vie et de la Santé, 2012, Université François-Rabelais de Tours

URL: http://www.theses.fr/2012TOUR3308

►

La transduction électrostatique est utilisée depuis plusieurs décennies dans les fréquences du domaine audible, principalement sous la forme de microphones membranaires. La transposition du même… (more)

▼

La transduction électrostatique est utilisée depuis plusieurs décennies dans les fréquences du domaine audible, principalement sous la forme de microphones membranaires. La transposition du même principe de transduction, mais dans un domaine de fréquence au-dessus du MHz, et par l’utilisation de dispositifs micro-usinés, c'est-à-dire produits à l’aide de technologies de photolithographie, a été proposée à partir de la fin des années 1990. Ces transducteurs, désignés sous l’acronyme cMUT (capacitive micromachine ultrasonic transducers), se composent d’un assemblage de transducteurs élémentaires, chacun possédant une partie mobile conventionnellement appelée diaphragme ou membrane, actionnée par la pression électrostatique. Cette thèse s’inscrit dans le développement de transducteurs de ce type destinés au domaine de l’imagerie médicale ultrasonore. Ce secteur d’application utilise actuellement des transducteurs basés sur des céramiques (ou, dans certains cas précis, des polymères) piézoélectriques. Le cMUT est intéressant dans certains sous-domaines d’application des ultrasons médicaux en raison de sa bonne adaptation à une production en grande série, de son intégration plus facile avec des éléments électroniques, de son faible échauffement et de l’absence de matériaux toxiques dans son processus de fabrication. La partie théorique de cette thèse repose sur une approche de modélisation par différences finies. Un modèle basé sur la théorie des plaques minces est développé pour prendre en compte la mécanique du transducteur élémentaire cMUT (c'est-à-dire d’un seul diaphragme). Ce modèle est ensuite complété par l’intégration de l’effet d’un chargement acoustique par un fluide. De façon à modéliser un transducteur entier, il est nécessaire de prendre en compte le couplage acoustique existant entre les différentes membranes. Pour rendre cela possible, un circuit équivalent, permettant de réduire chaque membrane à un système à un seul degré de liberté, est développé. Il est validé en le comparant au modèle de différences finies dans des cas où celui-ci peut être utilisé. Les travaux expérimentaux ont fait appel principalement aux deux techniques de caractérisation suivantes : les mesures d’impédance électrique, et les mesures de déplacement effectuées par interférométrie laser. Ces mesures ont été utilisées dans une double optique. D’une part, dans un objectif de caractérisation, ils ont permis de vérifier la fonctionnalité des dispositifs fabriqués et d’évaluer leurs performances. D’autre part, en comparant différentes configurations entre elles, ils ont rendu possible une validation expérimentale du modèle qui a été mis au point.

Electro-acoustic transduction based on electrostatic force has a long history in the range of audible frequencies, mainly as membrane-based microphones. Starting in the late 1990’s, it has been proposed to use the same principle in the multi-MHz frequency domain, thanks to micro-machined devices – meaning they’re produced through lithography technology. Such transducers, known as cMUT for…

Advisors/Committee Members: Certon, Dominique (thesis director).

Subjects/Keywords: CMUT; Microsystème; Caractérisation; Transduction; Différences finies; Modélisation; Échographie; Actionnement électrostatique; Ultrasons; CMUT; Microsystem; Characterisation; Transducer; Finite difference model; Modelling; Echography; Electrostatic actuation; Ultrasound

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Meynier, C. (2012). Modélisation, conception et caractérisation de transducteurs ultrasonores capacitifs micro-usinés : Modelling, design and characterization of micromachined ultrasonic transducers. (Doctoral Dissertation). Université François-Rabelais de Tours. Retrieved from http://www.theses.fr/2012TOUR3308

Chicago Manual of Style (16^th Edition):

Meynier, Cyril. “Modélisation, conception et caractérisation de transducteurs ultrasonores capacitifs micro-usinés : Modelling, design and characterization of micromachined ultrasonic transducers.” 2012. Doctoral Dissertation, Université François-Rabelais de Tours. Accessed March 06, 2021. http://www.theses.fr/2012TOUR3308.

MLA Handbook (7^th Edition):

Meynier, Cyril. “Modélisation, conception et caractérisation de transducteurs ultrasonores capacitifs micro-usinés : Modelling, design and characterization of micromachined ultrasonic transducers.” 2012. Web. 06 Mar 2021.

Vancouver:

Meynier C. Modélisation, conception et caractérisation de transducteurs ultrasonores capacitifs micro-usinés : Modelling, design and characterization of micromachined ultrasonic transducers. [Internet] [Doctoral dissertation]. Université François-Rabelais de Tours; 2012. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2012TOUR3308.

Council of Science Editors:

Meynier C. Modélisation, conception et caractérisation de transducteurs ultrasonores capacitifs micro-usinés : Modelling, design and characterization of micromachined ultrasonic transducers. [Doctoral Dissertation]. Université François-Rabelais de Tours; 2012. Available from: http://www.theses.fr/2012TOUR3308

25. Lascaud, Julie. Elaboration de couches minces atténuantes en silicium poreux : Application aux transducteurs ultrasonores capacitifs micro-usinés : Development of thin attenuating porous silicon layers : application to the capacitive micromachine ultrasonic.

Degree: Docteur es, Electronique, 2017, Université François-Rabelais de Tours

URL: http://www.theses.fr/2017TOUR4026

►

Les transducteurs ultrasonores capacitifs micro-usinés (CMUT) représentent aujourd’hui une réelle alternative aux technologies piézoélectriques dans le domaine de l’imagerie échographique médicale. Au cours des années,… (more)

▼

Les transducteurs ultrasonores capacitifs micro-usinés (CMUT) représentent aujourd’hui une réelle alternative aux technologies piézoélectriques dans le domaine de l’imagerie échographique médicale. Au cours des années, les procédés de fabrication des transducteurs se sont enrichis en vue d’améliorer leurs performances. A contrario le choix du substrat, généralement en silicium, a été peu étudié. Il est cependant reconnu que le support contribue à la signature acoustique du dispositif ultrasonore. L’objectif de ces travaux de thèse a été d’intégrer une couche de silicium poreux afin d’absorber une partie des ondes élastiques qui se propagent dans le substrat et interfèrent avec le signal acoustique émis. Nous montrons alors qu’il été possible de réaliser une couche de silicium poreux en face arrière de composants, sur plaquettes 6 pouces, sans dégrader leurs performances. Finalement, par l’intermédiaire de caractérisations acoustiques et des signatures impulsionnelles des transducteurs, nous révélons le potentiel prometteur de ce matériaux pour la réalisation de milieu arrière atténuant dédié à la transduction ultrasonore.

Capacitive micromachined ultrasonic transducers (CMUT) have emerged as a potential alternative to traditional piezoelectric transducers for ultrasound imaging. Along the years, CMUT processes have been evolved to enhance the device performances. In the meantime, no particular attention was paid on the silicon substrate, even if it is well-known that it could contribute to the transducer efficiency. The aim of this PhD thesis was to use porous silicon as a backing material for ultrasonic transducers to absorb a piece of the acoustic wave propagating in the substrate and which induce crosstalks in the acoustic signal. We show that porous silicon layer can be obtained on the rear side of already processed wafers without any damage on the performances of capacitive micromachined ultrasonic transducers. Finally, by means of acoustic characterizations and the transducer electroacoustic responses, we reveal the potential interest of porous silicon as backing material for ultrasonic transducers.

Advisors/Committee Members: Gautier, Gaël (thesis director), Certon, Dominique (thesis director).

Subjects/Keywords: Couche atténuante; Silicium poreux; Transducteurs ultrasonores; Gravure électrochimique; Caractérisations acoustiques; CMUT; Backing layer; Porous silicon; Ultrasonic transducers; Electrochemical etching; Acoustic characterizations; CMUT

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Lascaud, J. (2017). Elaboration de couches minces atténuantes en silicium poreux : Application aux transducteurs ultrasonores capacitifs micro-usinés : Development of thin attenuating porous silicon layers : application to the capacitive micromachine ultrasonic. (Doctoral Dissertation). Université François-Rabelais de Tours. Retrieved from http://www.theses.fr/2017TOUR4026

Chicago Manual of Style (16^th Edition):

Lascaud, Julie. “Elaboration de couches minces atténuantes en silicium poreux : Application aux transducteurs ultrasonores capacitifs micro-usinés : Development of thin attenuating porous silicon layers : application to the capacitive micromachine ultrasonic.” 2017. Doctoral Dissertation, Université François-Rabelais de Tours. Accessed March 06, 2021. http://www.theses.fr/2017TOUR4026.

MLA Handbook (7^th Edition):

Lascaud, Julie. “Elaboration de couches minces atténuantes en silicium poreux : Application aux transducteurs ultrasonores capacitifs micro-usinés : Development of thin attenuating porous silicon layers : application to the capacitive micromachine ultrasonic.” 2017. Web. 06 Mar 2021.

Vancouver:

Lascaud J. Elaboration de couches minces atténuantes en silicium poreux : Application aux transducteurs ultrasonores capacitifs micro-usinés : Development of thin attenuating porous silicon layers : application to the capacitive micromachine ultrasonic. [Internet] [Doctoral dissertation]. Université François-Rabelais de Tours; 2017. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2017TOUR4026.

Council of Science Editors:

Lascaud J. Elaboration de couches minces atténuantes en silicium poreux : Application aux transducteurs ultrasonores capacitifs micro-usinés : Development of thin attenuating porous silicon layers : application to the capacitive micromachine ultrasonic. [Doctoral Dissertation]. Université François-Rabelais de Tours; 2017. Available from: http://www.theses.fr/2017TOUR4026

26. Vallet, Maëva. Développement d’un système d’imagerie photoacoustique : Validation sur fantômes et application à l’athérosclérose : Development of a photoacoustic imaging system : Phantom validation and application to atherosclerosis.

Degree: Docteur es, Physique, 2015, INSA Lyon

URL: http://www.theses.fr/2015ISAL0086

►

L’imagerie photoacoustique est une nouvelle modalité couplant imagerie optique et échographie. Non invasive, elle permet d’imager des absorbeurs optiques à quelques centimètres de profondeur et… (more)

▼

L’imagerie photoacoustique est une nouvelle modalité couplant imagerie optique et échographie. Non invasive, elle permet d’imager des absorbeurs optiques à quelques centimètres de profondeur et avec la résolution de l’échographie. La réception des signaux photoacoustiques se faisant à l’aide d’un échographe clinique, cette modalité hybride vient compléter idéalement l’imagerie ultrasonore en apportant des informations fonctionnelles aux informations structurelles de l’échographie. Ces atouts en font une technique d’imagerie très prometteuse pour la clinique, notamment comme outil de diagnostic précoce. Ce travail de thèse a pour objectif principal la mise en place des outils nécessaires au développement de cette thématique de recherche d’un point de vue expérimental, à des fins cliniques. En particulier, l’apport de l’imagerie photoacoustique pour le diagnostic de plaques d’athérome vulnérables est investigué sur fantômes, grâce à un protocole original. Pour cela un système d’imagerie photoacoustique a été développé et caractérisé à l’aide de fantômes bimodalités élaborés spécifiquement pour les différentes études présentées. Gardant à l’esprit le transfert de cette technique en clinique, un échographe clinique de recherche est utilisé et différentes spécificités du banc nécessaires à l’imagerie in vivo et au diagnostic médical ont été investiguées. Cela implique une amélioration des performances de détection du signal photoacoustique, notamment en termes de sensibilité et de contraste. Pour cela, une nouvelle technologie de sondes ultrasonores est évaluée en la comparant aux sondes actuellement utilisées. De plus, une excitation multispectrale permet l’identification de différents éléments présents dans les tissus. L’aspect temps-réel de l’échographie fait de cette modalité une des plus utilisées pour le diagnostic clinique. Par conséquent, une imagerie photoacoustique voire bimodale en temps réel présente un réel atout pour son transfert clinique. Cette possibilité est investiguée sur le système mis en place au cours de la thèse grâce à un échographe de recherche et une étude sur fantômes. Enfin, une autre contribution de ce travail concerne l’apport de l’imagerie photoacoustique à la caractérisation de la vulnérabilité de la plaque d’athérome. Cette indication de vulnérabilité est obtenue en déterminant la composition de la plaque, en particulier en termes de lipides. L’imagerie photoacoustique, couplée à l’échographie, peut permettre cette identification. Pour étudier cette possibilité, nous nous sommes intéressés à l’artère carotide pour son accessibilité et la place qu’elle occupe dans le diagnostic de la plaque d’athérome en échographie et échographie Doppler. Un protocole original a été élaboré afin d’apporter l’excitation optique au plus près de la carotide. La faisabilité de cette approche est investiguée sur un fantôme conçu spécifiquement pour cette étude et les résultats préliminaires sont présentés.

Photoacoustic (PA) imaging is a new imaging modality coupling ultrasound and optical imaging. This…

Advisors/Committee Members: Vray, Didier (thesis director).

Subjects/Keywords: Imagerie médicale; Imagerie photoacoustique; Imagerie optique; Echographie; CMUT - Capacitive micromachined ultrasonic transducers; Athérosclérose; Photoacoustic imaging; CMUT - Capacitive micromachined ultrasonic transducers; Atherosclerosis; 616.075 450 72

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Vallet, M. (2015). Développement d’un système d’imagerie photoacoustique : Validation sur fantômes et application à l’athérosclérose : Development of a photoacoustic imaging system : Phantom validation and application to atherosclerosis. (Doctoral Dissertation). INSA Lyon. Retrieved from http://www.theses.fr/2015ISAL0086

Chicago Manual of Style (16^th Edition):

Vallet, Maëva. “Développement d’un système d’imagerie photoacoustique : Validation sur fantômes et application à l’athérosclérose : Development of a photoacoustic imaging system : Phantom validation and application to atherosclerosis.” 2015. Doctoral Dissertation, INSA Lyon. Accessed March 06, 2021. http://www.theses.fr/2015ISAL0086.

MLA Handbook (7^th Edition):

Vallet, Maëva. “Développement d’un système d’imagerie photoacoustique : Validation sur fantômes et application à l’athérosclérose : Development of a photoacoustic imaging system : Phantom validation and application to atherosclerosis.” 2015. Web. 06 Mar 2021.

Vancouver:

Vallet M. Développement d’un système d’imagerie photoacoustique : Validation sur fantômes et application à l’athérosclérose : Development of a photoacoustic imaging system : Phantom validation and application to atherosclerosis. [Internet] [Doctoral dissertation]. INSA Lyon; 2015. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2015ISAL0086.

Council of Science Editors:

Vallet M. Développement d’un système d’imagerie photoacoustique : Validation sur fantômes et application à l’athérosclérose : Development of a photoacoustic imaging system : Phantom validation and application to atherosclerosis. [Doctoral Dissertation]. INSA Lyon; 2015. Available from: http://www.theses.fr/2015ISAL0086

27. Heller, Jacques. Modélisation et caractérisation de transducteurs ultrasonores capacitifs micro-usinés appliqués à la réalisation de transformateurs pour l'isolation galvanique : Modelling and caracterization of capacitive micromachined ultrasonic transducers for the conception of galvanically isolated transformers.

Degree: Docteur es, Sciences de l'Ingénieur, 2018, Université François-Rabelais de Tours

URL: http://www.theses.fr/2018TOUR4009

►

Ces travaux présentent l'étude de transformateurs par voie acoustique, basés sur la technologie CMUT (Capacitive Micromachined Ultrasonic Transducer ), visant à développer des composants monolithiques… (more)

▼

Ces travaux présentent l'étude de transformateurs par voie acoustique, basés sur la technologie CMUT (Capacitive Micromachined Ultrasonic Transducer ), visant à développer des composants monolithiques assurant l'isolation électrique au sein de la commande des interrupteurs à semi-conducteurs. S'agissant de microsystèmes électromécaniques, les CMUTs offrent des perspectives intéressantes en terme d'intégrabilité monolithique avec les interrupteurs à semi-conducteurs. L'architecture proposée est constituée de deux transducteurs CMUTs de part et d'autre d'un substrat en silicium. Un outil de modélisation a été développé dans le but de prédire le comportement du transformateur. Des protocoles de mesure du rendement des dispositifs fabriqués ont été mis en place permettant une évaluation quantitative des performances des prototypes (un rendement de 32 % est atteint avec une marge de progression à 60 %). L'exploitation du modèle développé, et validé par les résultats de caractérisation, a permis de mettre en évidence les limites et perspectives d'amélioration de ces dispositifs.

This work is a study of CMUT (Capacitive Micromachined Ultrasonic Transduer)based acoustical transformers as a step in the development of insulating components in semiconductor switches control chain. CMUT transducers being electromechanical systems (MEMS), their monolithic integration with semiconductor switches is full of interesting perspectives . The proposed architecture consists of two CMUTs layered on each side of a silicon substrate. A computational tool was designed to predict the behaviour of the transformer. Measurement protocols of the power efficiency of the constructed transformers were set up and allowed to quantify the prototypes' performances (A 32 % efficiency is currently reached, with improvements attainable up to 60 %). Exploring the results of the developed model, validated by bench measurements, allowed to determine the current limits of the transformers as well as perspectives of improvement.

Advisors/Committee Members: Certon, Dominique (thesis director).

Subjects/Keywords: CMUT; Transformateur acoustique; Isolation galvanique; Éléments finis; FEM; Couplage au substrat; Caractérisation du rendement; CMUT; Acoustic transformer; Galvanic isolation; Finite elements; FEM; Substrate coupling; Power efficiency assessment

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Heller, J. (2018). Modélisation et caractérisation de transducteurs ultrasonores capacitifs micro-usinés appliqués à la réalisation de transformateurs pour l'isolation galvanique : Modelling and caracterization of capacitive micromachined ultrasonic transducers for the conception of galvanically isolated transformers. (Doctoral Dissertation). Université François-Rabelais de Tours. Retrieved from http://www.theses.fr/2018TOUR4009

Chicago Manual of Style (16^th Edition):

Heller, Jacques. “Modélisation et caractérisation de transducteurs ultrasonores capacitifs micro-usinés appliqués à la réalisation de transformateurs pour l'isolation galvanique : Modelling and caracterization of capacitive micromachined ultrasonic transducers for the conception of galvanically isolated transformers.” 2018. Doctoral Dissertation, Université François-Rabelais de Tours. Accessed March 06, 2021. http://www.theses.fr/2018TOUR4009.

MLA Handbook (7^th Edition):

Heller, Jacques. “Modélisation et caractérisation de transducteurs ultrasonores capacitifs micro-usinés appliqués à la réalisation de transformateurs pour l'isolation galvanique : Modelling and caracterization of capacitive micromachined ultrasonic transducers for the conception of galvanically isolated transformers.” 2018. Web. 06 Mar 2021.

Vancouver:

Heller J. Modélisation et caractérisation de transducteurs ultrasonores capacitifs micro-usinés appliqués à la réalisation de transformateurs pour l'isolation galvanique : Modelling and caracterization of capacitive micromachined ultrasonic transducers for the conception of galvanically isolated transformers. [Internet] [Doctoral dissertation]. Université François-Rabelais de Tours; 2018. [cited 2021 Mar 06]. Available from: http://www.theses.fr/2018TOUR4009.

Council of Science Editors:

Heller J. Modélisation et caractérisation de transducteurs ultrasonores capacitifs micro-usinés appliqués à la réalisation de transformateurs pour l'isolation galvanique : Modelling and caracterization of capacitive micromachined ultrasonic transducers for the conception of galvanically isolated transformers. [Doctoral Dissertation]. Université François-Rabelais de Tours; 2018. Available from: http://www.theses.fr/2018TOUR4009

UCLA

28. Eaimkhong, Sarayoot. Application of Nanotechnology in Biological Research: Diagnostics and Physical Manipulation.

Degree: Chemistry, 2013, UCLA

URL: http://www.escholarship.org/uc/item/5ds636hb

► Nanotechnology has been around for several decades and been adopted by many researchers in biological science and medicine. It has transformed and changed the way… (more)

Subjects/Keywords: Chemistry; Nanotechnology; Biosensors; Cell mechanic; Chemical sensors; CMUT; Live cell interferometry; Stem cells

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Eaimkhong, S. (2013). Application of Nanotechnology in Biological Research: Diagnostics and Physical Manipulation. (Thesis). UCLA. Retrieved from http://www.escholarship.org/uc/item/5ds636hb

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Eaimkhong, Sarayoot. “Application of Nanotechnology in Biological Research: Diagnostics and Physical Manipulation.” 2013. Thesis, UCLA. Accessed March 06, 2021. http://www.escholarship.org/uc/item/5ds636hb.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Eaimkhong, Sarayoot. “Application of Nanotechnology in Biological Research: Diagnostics and Physical Manipulation.” 2013. Web. 06 Mar 2021.

Vancouver:

Eaimkhong S. Application of Nanotechnology in Biological Research: Diagnostics and Physical Manipulation. [Internet] [Thesis]. UCLA; 2013. [cited 2021 Mar 06]. Available from: http://www.escholarship.org/uc/item/5ds636hb.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Eaimkhong S. Application of Nanotechnology in Biological Research: Diagnostics and Physical Manipulation. [Thesis]. UCLA; 2013. Available from: http://www.escholarship.org/uc/item/5ds636hb

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Windsor

29. Nazemi, Haleh. A Miniaturized Chemical Vapor Detector Using MEMS Flexible Platform.

Degree: MA, Electrical and Computer Engineering, 2019, University of Windsor

URL: https://scholar.uwindsor.ca/etd/8174

► According to the Canadian Cancer Society, lung cancer is the one of the leading causes of cancer death. It has been shown that cancer survival… (more)

Subjects/Keywords: Analytical Modeling; Bi-Layer CMUT; Capacitive Micromachined Ultrasonic Transducer; MEMS; Microelectromechanical Systems; VOC Sensor

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Nazemi, H. (2019). A Miniaturized Chemical Vapor Detector Using MEMS Flexible Platform. (Masters Thesis). University of Windsor. Retrieved from https://scholar.uwindsor.ca/etd/8174

Chicago Manual of Style (16^th Edition):

Nazemi, Haleh. “A Miniaturized Chemical Vapor Detector Using MEMS Flexible Platform.” 2019. Masters Thesis, University of Windsor. Accessed March 06, 2021. https://scholar.uwindsor.ca/etd/8174.

MLA Handbook (7^th Edition):

Nazemi, Haleh. “A Miniaturized Chemical Vapor Detector Using MEMS Flexible Platform.” 2019. Web. 06 Mar 2021.

Vancouver:

Nazemi H. A Miniaturized Chemical Vapor Detector Using MEMS Flexible Platform. [Internet] [Masters thesis]. University of Windsor; 2019. [cited 2021 Mar 06]. Available from: https://scholar.uwindsor.ca/etd/8174.

Council of Science Editors:

Nazemi H. A Miniaturized Chemical Vapor Detector Using MEMS Flexible Platform. [Masters Thesis]. University of Windsor; 2019. Available from: https://scholar.uwindsor.ca/etd/8174

Georgia Tech

30. Hochman, Michael. Investigation of acoustic crosstalk effects in CMUT arrays.

Degree: MS, Mechanical Engineering, 2011, Georgia Tech

URL: http://hdl.handle.net/1853/42782

► Capacitive Micromachined Ultrasonic Transducers (CMUTs) have demonstrated significant potential to advance the state of medical ultrasound imaging beyond the capabilities of the currently employed piezoelectric… (more)

▼ Capacitive Micromachined Ultrasonic Transducers (CMUTs) have demonstrated significant potential to advance the state of medical ultrasound imaging beyond the capabilities of the currently employed piezoelectric technology. Because they rely on well-established micro-fabrication techniques, they can achieve complex geometries, densely populated arrays, and tight integration with electronics, all of which are required for advanced intravascular ultrasound (IVUS) applications such as high-frequency or forward-looking catheters. Moreover, they also offer higher bandwidth than their piezoelectric counterparts. Before CMUTs can be effectively used, they must be fully characterized and optimized through experimentation and modeling. Unfortunately, immersed transducer arrays are inherently difficult to simulate due to a phenomenon known as acoustic crosstalk, which refers to the fact that every membrane in an array affects the dynamic behavior of every other membrane in an array as their respective pressure fields interact with one another. In essence, it implies that modeling a single CMUT membrane is not sufficient; the entire array must be modeled for complete accuracy. Finite element models (FEMs) are the most accurate technique for simulating CMUT behavior, but they can become extremely large considering that most CMUT arrays contain hundreds of membranes. This thesis focuses on the development and application of a more efficient model for transducer arrays first introduced by Meynier et al. [1], which provides accuracy comparable to FEM, but with greatly decreased computation time. It models the stiffness of each membrane using a finite difference approximation of thin plate equations. This stiffness is incorporated into a force balance which accounts for effects from the electrostatic actuation, pressure forces from the fluid environment, mass and damping from the membrane, etc. For fluid coupling effects, a Boundary Element Matrix (BEM) is employed that is based on the Green's function for a baffled point source in a semi-infinite fluid. The BEM utilizes the nodal mesh created for the finite difference method, and relates the dynamic displacement of each node to the pressure at every node in the array. Use of the thin plate equations and the BEM implies that the entire CMUT array can be reduced to a 2D nodal mesh, allowing for a drastic improvement in computation time compared with FEM. After the model was developed, it was then validated through comparison with FEM. From these tests, it demonstrated a capability to accurately predict collapse voltage, center frequency, bandwidth, and pressure magnitudes to within 5% difference of FEM simulations. Further validation with experimental results revealed a close correlation with predicted impedance/admittance plots, radiation patterns, frequency responses, and noise current spectrums. More specifically, it accurately predicted how acoustic crosstalk would create sharp peaks and notches in the frequency responses, and enhance side lobes and nulls in the angular… Advisors/Committee Members: Dr. F. Levent Degertekin (Committee Chair), Dr. Karim Sabra (Committee Member), Dr. Suresh Sitaraman (Committee Member).

Subjects/Keywords: Analytical model; Acoustic crosstalk; CMUT; Ultrasonic transducers; Crosstalk; Finite element method; Computer simulation

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Hochman, M. (2011). Investigation of acoustic crosstalk effects in CMUT arrays. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/42782

Chicago Manual of Style (16^th Edition):

Hochman, Michael. “Investigation of acoustic crosstalk effects in CMUT arrays.” 2011. Masters Thesis, Georgia Tech. Accessed March 06, 2021. http://hdl.handle.net/1853/42782.

MLA Handbook (7^th Edition):

Hochman, Michael. “Investigation of acoustic crosstalk effects in CMUT arrays.” 2011. Web. 06 Mar 2021.

Vancouver:

Hochman M. Investigation of acoustic crosstalk effects in CMUT arrays. [Internet] [Masters thesis]. Georgia Tech; 2011. [cited 2021 Mar 06]. Available from: http://hdl.handle.net/1853/42782.

Council of Science Editors:

Hochman M. Investigation of acoustic crosstalk effects in CMUT arrays. [Masters Thesis]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/42782

		in
And / Or
		in
And / Or
		in
And / Or
		in

Open Access Theses and Dissertations