A novel biomedical sensor for early detection of organ ischemia

Measuring PCO2 (partial pressure of carbon dioxide) in an organ can enableearly detection of ischemia. However, there are few clinical applicablesolutions for measuringPCO2. Based upon the requirement for clinicalapplications, a conductivity based PCO2 sensor is proposed. A conductivitybased PCO2 sensor measures conductance in an aqueous solution separatedfrom the measured object by a gas-permeable membrane. A bridge designwith two cavities is favored for such a sensor. A planar and a cylindricalmacro prototype based upon the bridge design were studied. The designcriteria were based on the contribution from the electrode polarization, straycapacitances, contact area with the sample and design ability to miniaturizethe sensor. The cylindrical sensor is favored because of its large contactarea and advantages for miniaturization. Further investigation has to be doneto confirm the functionality of such a design in a miniaturized form and itsclinical performance.