AbstractsBiology & Animal Science

Efficient wireless powering and reliable biotelemetry of neural implants

by Ahmed Ibrahim Al-Kalbani




Institution: Monash University
Department: ECSE
Year: 2014
Keywords: Neural implants; Biomedical communication; Wireless powering; Inductive coupling; Capacitive coupling; Electromagnetic compatibility
Record ID: 1049466
Full text PDF: http://arrow.monash.edu.au/hdl/1959.1/1133803


Abstract

The development of safe implants is one of the key priorities of biomedical engineering. Healthcare professionals are trying to create new and sophisticated strategies to improve and support people with disabilities using implants. The research described in this thesis focuses on developing a power supply from a wireless source for implants that will also serve as a wireless data telemetry channel for communication purposes. The design analysis of inductive coupled biomedical implant is expanded. The proposed method of powering the implant is a Class-E amplifier. An analytic approach is given in relation to tuning the class-E amplifier to maximize power transfer. This thesis culminates in specific recommendations for system level design including coil design, miniaturisation, coupling distance, stability of power supplies, consistent energy transfer and the ensuing electromagnetic exposure. The telemetry system for data transfer between implants and outside world has been also studied. This bio-telemetry system setup should ensure an optimal data rate, proper energy levels, low error rates, and a reliable power source. The efficiency of the system is crucial for these implants, and the use of efficient and low power consumption amplifiers and modulation schemes has been discussed in detail. The advantages of Pulse Width Modulated – Amplitude Shift Keying (PWM-ASK for short) are presented in comparison to current modulation schemes used in nowadays implants. Beside inductive coupled implants, this thesis also introduces a study of designing a wireless powered biomedical implant using capacitive coupling. A comparison between inductive and capacitive coupling is presented, while considering biotelemetry and power efficiency. A capacitive coupled biomedical implant is demonstrated through mathematical terms and simulations.