Development Of pCO2 Analytic System Using Soft-Lithography Method

This study carried out development of non-invasive optical transcutaneous partial pressure of carbon dioxide, pCO₂, monitoring system by non-dispersive infrared method, NDIR. The purpose of this system is to detect CO₂ from outer skin, not from the arterial blood-gathering method. There are advantages about a reduction of analysis time and real-time monitoring that this system might be available. The measurement system is composed of the IR lamp, the pyroelectric sensor including a 4.26 mum optical filter, the optical gas reaction chamber and the signal processing circuit. The optical reaction length of chamber was reduced by 1 mm using the soft-lithography method which CO₂ is exhausted in human body as we considered. The fabricated pCO₂ monitoring system showed linear result of 6.50times 10^-6 absorbance/ppm sensitivity for CO₂ concentration from 0 ~ 5,000 ppm by MFC and about 2 seconds of fast response time. The proposed system can be used in the optical biosensor field for the medical diagnosis such as pCO₂ monitoring system and environment monitoring systems.