Design of a low-power interface circuitry for a vestibular prosthesis system

The human vestibular system is responsible for maintaining balance and orientation, and stabilizing gaze during head motion. Head motion is sensed by vestibular sensors and encoded via the firing rate of vestibular neurons. Vestibular disorders can result in dizziness, imbalance, and disequilibrium. Currently there are no therapeutic options for individuals suffering from bilateral vestibular dysfunction. A potential solution is a vestibular prosthesis (VP). This device serves to replace peripheral vestibular organs by sensing angular motion, detected by semicircular canals (SCCs), and linear head motion, detected by the otolith organs, and selectively stimulating the corresponding vestibular afferents. An ideal VP will not only mimic the patient-dependent vestibular neural dynamics, but also consume low power. In this study, three energy-efficient ways to implement the motion encoding function required in a vestibular prosthesis are presented. Both analog and digital signal processing techniques to implement the vestibular signal processing functions are investigated.Ph.D

Models and Techniques for Temperature Robust Systems on a Reconfigurable Platform

This paper investigates the variability of various circuits and systems over temperature and presents several methods to improve their performance over temperature. The work demonstrates use of large scale reconfigurable System-On-Chip (SOC) for reducing the variability of circuits and systems compiled on a Floating Gate (FG) based Field Programmable Analog Array (FPAA). Temperature dependencies of circuits are modeled using an open-source simulator built in the Scilab/XCOS environment and the results are compared with measurement data obtained from the FPAA. This comparison gives further insight into the temperature dependence of various circuits and signal processing systems and allows us to compensate as well as predict their behavior. Also, the work presents several different current and voltage references that could help in reducing the variability caused due to changes in temperature. These references are standard blocks in the Scilab/Xcos environment that could be easily compiled on the FPAA. An FG based current reference is then used for biasing a 12 × 1 Vector Matrix Multiplication (VMM) circuit and a second order G m − C bandpass filter to demonstrate the compilation and usage of these voltage/current reference in a reconfigurable fabric. The large scale FG FPAA presented here is fabricated in a 350 nm CMOS process