A novel optically-based approach to intracranial pressure measurement

Abstract

The objective of this research was to develop and test a closed-loop telemetric intracranial pressure (ICP) sensor system based on a transmissive optical approach. The system was composed of a pressure sensing membrane, an optical source, a detector, electronics, an electronically operated valve to provide flow control, and a telemetric transport mechanism. A temperature sensor was added to allow temperature compensation to be carried out at the receiver. A novel approach, using a reference sensor, was introduced to compensate for any drift. Once the system was designed and built, in vitro testing was performed using air to simulate the changes in ICP across the physiologic range of 0 to 300 mmHg. The prototype sensor showed a dynamic pressure range of -250 mmHg to 250 mmHg with an accuracy of 0.5 mmHg and a sensitivity of 10 mV/mmHg.