Monitoring Neuronal Activity in vivo with a Novel Implantable Battery-Free Wireless System

Authors

Carolina Moncion, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biomedical Engineering

First Advisor's Name

Jorge Riera Diaz

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

John L. Volakis

Second Advisor's Committee Title

Co-Committee Chair

Third Advisor's Name

Elias Alwan

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Armando Barreto

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Jacob McPherson

Fifth Advisor's Committee Title

Committee Member

Keywords

Biomedical Telemetry, Backscattering, Battery-Free, Electrocorticography, Implants, Neuroscience

Date of Defense

6-9-2022

Abstract

Intracranial neuronal recordings are essential for understanding neuronal function. They can be classified into levels like electrocorticography (ECoG)/local field potentials (LFP) and neuronal spiking activity. Typically, wired systems have been used to conduct these recordings; however, they have been linked to drawbacks, including infections, subdural hematomas, and are limited to a clinical setting, all of which can be detrimental to the patients’ quality of life. To address these issues, wireless biotelemetric devices have been increasingly adopted; nevertheless, they are coupled with their own drawbacks like bulky components and heat-generating batteries. Miniaturized battery-free systems have been developed for addressing these concerns, and while they are promising, they have not been successfully demonstrated in vivo.

To this end, we propose and validate a fully implantable battery-free alternative for remote monitoring of neuronal activity, namely the Wireless Neurosensing System (WiNS). In this dissertation, we address challenges that have previously prevented experimental testing and provide the first comprehensive in vivo evaluation of WiNS using rats. To ensure the reliability of the recordings, we also compare it with state-of-the-art technology. To achieve our goal, firstly, we identify and develop electrodes for WiNS to record activity ranging from evoked somatosensory responses of ~15 μV in amplitude to fully implanted recordings during movement. Secondly, we incorporate a passive impedance matching network, explore different electrode coating techniques for impedance reduction, and demonstrate an ability to successfully record LFP and spiking activity. Lastly, we design, fabricate, and evaluate an optical element for automated channel multiplexing, thereby expanding WiNS for multichannel recordings with an achievable sampling rate of ~10 kHz. Using recordings of activity elicited in different areas of the somatosensory cortex, we prove that WiNS can be used to record multichannel ECoG activity.

Overall, the analysis presented in this dissertation goes beyond previous demonstrations of this system, and other comparable devices, to, for the first time, establish WiNS as a battery-free system for monitoring neuronal activity. Our groundbreaking technology should have great potential upon its clinical translation for monitoring and understanding different neurological disorders such as epilepsy, Parkinson’s disease, and Alzheimer’s disease.

Identifier

FIDC010717

Previously Published In

Moncion, C., Balachandar, L., Bojja Venkatakrishnan, S., Riera, J. J., & Volakis, J. (2019). Fully-Passive Wireless Implant for Neuropotential Acquisition: An In Vivo Validation. IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology, 3(3), 199–205. https://doi.org/10.1109/jerm.2019.2895657

Moncion, C., Bojja-Venkatakrishnan, S., Diaz, J. R., & Volakis, J. L. (2020). Fully-Passive and Wireless Recording of Neural Activity in Freely Moving Animals. 2020 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting, IEEECONF 2020 - Proceedings, 1373–1374. https://doi.org/10.1109/IEEECONF35879.2020.9329887

Moncion, C., Bojja-Venkatakrishnan, S., Diaz, J. R., & Volakis, J. L. (2018). Low-Impedance Probes for Wireless Monitoring of Neural Activation. 2018 IEEE/MTT-S International Microwave Biomedical Conference, 76–78.

Recommended Citation

Moncion, Carolina, "Monitoring Neuronal Activity in vivo with a Novel Implantable Battery-Free Wireless System" (2022). FIU Electronic Theses and Dissertations. 5081.
https://digitalcommons.fiu.edu/etd/5081