Disposable CMOS catheter-tip pressure sensor for intracranial pressure measurement

Presents a highly cost-effective sensor for intermittent measurement of average intracranial pressure. The key to the sensor's cost-effectiveness is its design for commercial-foundry fabrication and simple packaging approach. Unlike most conventional pressure sensors that require custom fabrication, the transducer chip in this work was fabricated entirely through a commercial CMOS process. The number of process steps required to fabricate an array of transducers is thus reduced, decreasing overall fabrication cost. The package design is simple, requiring no electrical feedthroughs or pressure ports, thereby also reducing manufacturing cost. The sensor has an accuracy of 90% over the range of 0 to 10 mmHg gauge, sensitivity of 0.7mV/V/mmHg, and a resolution of 1.25 mmHg, which is sufficient to measure the cardiac effect on intracranial pressure. The sensor has been found to be suitable for short-term (up to 0.5 hours continuous) or intermittent use, such as during surgery. The unconventional low-cost approach to the development of this sensor makes it a better candidate than existing sensors for disposable applications.