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Northeastern University

1. Swaminathan, Meenupriya. Wireless intra-body communication for implantable and wearable body devices using galvanic coupling.

Degree: PhD, Department of Electrical and Computer Engineering, 2017, Northeastern University

Implantable body sensors and actuators (eg., drug delivery pumps and neural stimulators) are becoming commonplace promising unprecedented improvements in personalized medicine. These miniaturized devices need to communicate with each other (i) to share the real time health data for actuation purposes, (ii) to upload the physiological data to a remote monitoring entity, and (iii) to dynamically configure implant sensing tasks with new instructions. Over-the-air radio waves are largely absorbed in human tissues and also leak into the environment up to two meters from the body. In this thesis we design a low power galvanic coupling based intra-body communication network (GC-IBN) that involves transmitting electrical currents and leveraging the natural conduction of the body tissues.; We first derive and experimentally validate expressions for the gain of the body tissue channel by building (1) a three-dimensional multi-layered tissue equivalent circuit model, and (2) a two-port network model that adapts for different body parts by enabling rearrangement of the signal source and pickup locations flexibly. Our models are sensitive to nearly ten different parameters, including electrode separation and tissue thicknesses.; Towards safe deployment of GC-IBN, it is critical to verify that the power injected into the tissue and the amount of heat generated during the signal propagation are both within the permissible limits. We next estimate the bounds on induced current that can be safely coupled to tissue. This induced current density and the frequency dependent power dissipation are measured and quantified to verify the safe limits. We then analyze the best and worst case for the thermal energy distribution within tissues for varying transmission power levels, number of co-located transmitters and blood perfusion conditions through finite element simulation and experiments on a human tissue phantom.; We make the first contribution towards building an energy-efficient topology through optimal placement of data collection points/relays using measurement-driven tissue channel models for GC-IBN and the Weiszfeld algorithm. Further, we show that the energy consumption over the entire implant network is balanced in our approach, while also meeting the application needs.; Finally, we propose a new cross-layer protocol for GC-IBN to address the limited energy constraint and co-channel interference among implants. Initially, we devise a method that allows multiple implants to communicate individual sensed data to each other through CDMA code assign- ments, but delegate the computational burden of decoding only to the surface relays. Then, we devise a distributed beamforming approach that allows coordinated transmissions from the implants to the relays by considering the specific tissue path chosen and tissue heating-related safety constraints. This collision-free protocol prevents undue interference at neighboring implants, and is the first application of near-field distributed beamforming in human tissue.; In summary, this thesis…

Subjects/Keywords: beam forming in body - near field; human tissue channel model; implant communication; intra-body network; safe signal propagation through tissue; topology optimization inside body

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

APA (6th Edition):

Swaminathan, M. (2017). Wireless intra-body communication for implantable and wearable body devices using galvanic coupling. (Doctoral Dissertation). Northeastern University. Retrieved from http://hdl.handle.net/2047/D20250014

Chicago Manual of Style (16th Edition):

Swaminathan, Meenupriya. “Wireless intra-body communication for implantable and wearable body devices using galvanic coupling.” 2017. Doctoral Dissertation, Northeastern University. Accessed July 19, 2019. http://hdl.handle.net/2047/D20250014.

MLA Handbook (7th Edition):

Swaminathan, Meenupriya. “Wireless intra-body communication for implantable and wearable body devices using galvanic coupling.” 2017. Web. 19 Jul 2019.

Vancouver:

Swaminathan M. Wireless intra-body communication for implantable and wearable body devices using galvanic coupling. [Internet] [Doctoral dissertation]. Northeastern University; 2017. [cited 2019 Jul 19]. Available from: http://hdl.handle.net/2047/D20250014.

Council of Science Editors:

Swaminathan M. Wireless intra-body communication for implantable and wearable body devices using galvanic coupling. [Doctoral Dissertation]. Northeastern University; 2017. Available from: http://hdl.handle.net/2047/D20250014


EPFL

2. Sarafijanovic, Slavisa. Artificial immune system for the Internet.

Degree: 2008, EPFL

We investigate the usability of the Artificial Immune Systems (AIS) approach for solving selected problems in computer networks. Artificial immune systems are created by using the concepts and algorithms inspired by the theory of how the Human Immune System (HIS) works. We consider two applications: detection of routing misbehavior in mobile ad hoc networks, and email spam filtering. In mobile ad hoc networks the multi-hop connectivity is provided by the collaboration of independent nodes. The nodes follow a common protocol in order to build their routing tables and forward the packets of other nodes. As there is no central control, some nodes may defect to follow the common protocol, which would have a negative impact on the overall connectivity in the network. We build an AIS for the detection of routing misbehavior by directly mapping the standard concepts and algorithms used for explaining how the HIS works. The implementation and evaluation in a simulator shows that the AIS mimics well most of the effects observed in the HIS, e.g. the faster secondary reaction to the already encountered misbehavior. However, its effectiveness and practical usability are very constrained, because some particularities of the problem cannot be accounted for by the approach, and because of the computational constrains (reported also in AIS literature) of the used negative selection algorithm. For the spam filtering problem, we apply the AIS concepts and algorithms much more selectively and in a less standard way, and we obtain much better results. We build the AIS for antispam on top of a standard technique for digest-based collaborative email spam filtering. We notice un advantageous and underemphasized technological difference between AISs and the HIS, and we exploit this difference to incorporate the negative selection in an innovative and computationally efficient way. We also improve the representation of the email digests used by the standard collaborative spam filtering scheme. We show that this new representation and the negative selection, when used together, improve significantly the filtering performance of the standard scheme on top of which we build our AIS. Our complete AIS for antispam integrates various innate and adaptive AIS mechanisms, including the mentioned specific use of the negative selection and the use of innate signalling mechanisms (PAMP and danger signals). In this way the AIS takes into account users' profiles, implicit or explicit feedback from the users, and the bulkiness of spam. We show by simulations that the overall AIS is very good both in detecting spam and in avoiding misdetection of good emails. Interestingly, both the innate and adaptive mechanisms prove to be crucial for achieving the good overall performance. We develop and test (within a simulator) our AIS for collaborative spam filtering in the case of email communications. The solution however seems to be well applicable to other types of Internet communications: Internet telephony, chat/sms, forum, news, blog, or web. In all these… Advisors/Committee Members: Le Boudec, Jean Yves.

Subjects/Keywords: Internet; communication; email; security; network; ad hoc; routing; evolution; self; resources; protection; collaborative; filtering; detection; spam; misbehavior; artificial immune system (AIS); innate AIS; adaptive AIS; self-nonself; evolving self; danger signal theory; danger signal; PAMP signal; safe signal; Internet; communication; sécurité; émail; courriel; réseau; ad hoc; évolution; self; authentification; identité; clef privée; clef publique; ressources; protection; collaboration; filtrage; détection; pourriel; spam; comportement inapproprié; système immunitaire artificiel (SIA); SIA inné; SIA adaptif; self-nonself; évolution de self; théorie des modèles de danger; signal de danger; PAMP signal; signal de sûreté

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

APA (6th Edition):

Sarafijanovic, S. (2008). Artificial immune system for the Internet. (Thesis). EPFL. Retrieved from http://infoscience.epfl.ch/record/118657

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

Chicago Manual of Style (16th Edition):

Sarafijanovic, Slavisa. “Artificial immune system for the Internet.” 2008. Thesis, EPFL. Accessed July 19, 2019. http://infoscience.epfl.ch/record/118657.

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

MLA Handbook (7th Edition):

Sarafijanovic, Slavisa. “Artificial immune system for the Internet.” 2008. Web. 19 Jul 2019.

Vancouver:

Sarafijanovic S. Artificial immune system for the Internet. [Internet] [Thesis]. EPFL; 2008. [cited 2019 Jul 19]. Available from: http://infoscience.epfl.ch/record/118657.

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

Council of Science Editors:

Sarafijanovic S. Artificial immune system for the Internet. [Thesis]. EPFL; 2008. Available from: http://infoscience.epfl.ch/record/118657

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

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