▼ Despite intensive investigation, grinding and deburring have largely resisted attempts at automation over the past three decades. This thesis mainly addresses two primary difficulties associated with robotic surface finishing – the need for precision part fixturing and the difficulty of stable and responsive robotic control in a constrained environment. Through kinematic calibration, development of reliable and accurate robotic touch sensing, robust compliant motion control, and automated robotic registration of a workpiece with its CAD model, it is demonstrated that the traditional barriers to automated surface finishing can be overcome. Advisors/Committee Members: Newman, Wyatt.

▼ Two, dual-channel wireless neural recording and stimulation devices are presented. The basic version has a neural preamplifier in series with a second amplifier to provide a signal gain of 4000. A multiplexer selects the recording channel. An 8-bit ADC converts the analog neural data into a digital stream, which is Manchester-encoded and frequency-shift-key (FSK) modulated at 27.12 MHz, before being transmitted to the host transceiver. The device receives 125-kHz on-off-keyed (OOK) commands, allowing the user to change record channels, program stimulation parameters, and trigger stimulus. The electrical performance of the basic version has been measured and compared to theoretical results. In vitro and in vivo animal experiments are reported. A comparison of wired and wireless data is in good agreement. Commands are properly received. The advanced version has additional integration, circuit revisions, and provides support for on-board digital data processing. Basic functionality of the advanced prototype has been verified. Advisors/Committee Members: Garverick, Steven.

▼ Interface electronics for peripheral nerve recording and analog signal processing is developed in this work as part of sensing mechanism for a laryngeal pacemaker to reanimate the paralyzed larynx in subjects with bilateral vocal fold paralysis. The electronic system has been designed to record neural activity from the phrenic nerve, condition the neural signal, and provide activity-dependent triggering for stimulator control. The system has been implemented in discrete fashion with commercial off-the-shelf components as well as integrated on a single 2.2 × 2.2-mm2 chip fabricated using the AMI 1.5 μm 2P/2M n-well CMOS process. System architecture, circuit design and analysis, simulation results, and measurement data from benchtop experiments with pre-recorded neural activity are presented and discussed. Advisors/Committee Members: Mohseni, Pedram.

▼ Due to their large amplitudes, stimulus artifacts can easily saturate neural recording amplifiers and hamper neural signal analysis during recording. In this work, we present a prototype stimulus artifact rejection (SAR) system, which is based on the template subtraction technique. A reference template signal of the stimulus artifact is generated by a pseudo-higher sampling rate averaging method, which is then subtracted from the original contaminated signal to reveal the desired neural activity. Measurement results from a proof-of-concept discrete implementation of the SAR system indicate that it is highly effective in reducing the amplitude of the stimulus artifacts. The system exhibits a stimulus artifact rejection of ~10-15 dB at the rising and falling edges of the artifact (where it is changing rapidly with time) and successfully recovers microvolt-range neural action potentials from the slowly decaying tail of the artifact. Compared to the existing subtraction-based SAR algorithms, additional stimulus artifact suppression of ~5.5 dB is achieved in this work. Advisors/Committee Members: Mohseni, Pedram.