Development of clinical instruments for traumatic brain injury patients: design, realisation, and performance

Abstract

This thesis focuses on designing and developing both wired and wireless multimodal clinical monitoring electronic instruments for traumatic brain injury (TBI) patients. Potentiostats using both a transimpedance resistive design and a novel switched-capacitor based design have been developed to support amperometric sensors and biosensors in detecting concentrations of important biomolecules, such as glucose and lactate in the injured brain tissue. The performance and relevant advantages/disadvantages of these two potentiostat designs have been also discussed. A high-resolution low-noise bio-potential acquisition system has been developed, to monitor the electroencephalography and electrocorticography of TBI patients. To optimise the monitoring performance, the system has been separated into two functional parts: a battery-powered head-stage box that records, amplifies, and digitalises the biopotentials; a bed-side digital unit that integrates with a new patient monitoring instrument. A commercial device has been used as a comparison, and the new design shows better electrical interference elimination. I have also designed an intelligent multimodal TBI instrumentation box to simultaneously monitor chemical, electrical, and physical parameters from a TBI patient. The instrumentation box has been carefully designed and evaluated to meet IEC60601 (3rd edition) safety regulation and it has passed local hospital test for clinical uses. The thesis then concentrates on developing different wireless solutions for the TBI instruments, and aims at eliminating clinical cable congestion and practical issues in intensive care units. By integrating with TBI-related electronics, different wireless modules have been evaluated and compared. Finally, to enable the device to display real-time tissue concentrations to the clinical team, a wireless control of a sensor auto-calibration system has been developed. Relevant graphic user interfaces have been designed on both PC and android-based smart phones or tablets.