電流誘導型磁気変調分光法による土砂中のヒト心肺活動検出法の基礎検討

抄録

We have suggested the current-induced magnetic modulation spectroscopy (CIMMS) to detect human cardiopulmonary activity in sediment for lifesaving. Initially, a Finite Element (FE) model of human in sediment was developed to simulate impedance change by human cardiopulmonary activity and an optimal electrode arrangement was estimated to detect the activity at burial distance of 47mm, 97mm and 147mm. The estimated electrode arrangement was 427mm apart for current injection and 305mm apart for voltage difference detection. The impedance changes at burial distance of 47mm, 97mm and 147mm were 0.0635%, 0.0432% and 0.0278% caused by respiration and were 0.0006%, 0.0004% and 0.0003% caused by pulsation respectively. Secondly, cardiopulmonary activity of a normal male subject was measured with an electrode contactless electrical impedance spectroscopy (EIS) device using the estimated optimal electrode arrangement. Respiration and pulsation at the distance of 50mm had shown good agreement between a medical equipment and impedance measurement device. However, the accuracy was worse significantly at the distance of 100mm and 150mm gradually. Finally, we calculated the sensitivity difference between EIS and CIMMS and concluded that it would be possible to detect human cardiopulmonary activity in sediment when we use the CIMMS.