829 Optical measurement of water content in tissue with near infrared light

Patients of kidney disease remove excess water by hemodialysis. In hemodialysis, blood pressure may fall and the patients may suffer from hypovolemic shock, because body fluid removal rate is normally larger than plasma refilling rate. The aim of our research is to measure water content in issue in order to prevent the hypovolemic shock and to know how much water has to be removed quantitatively. We employ a technique using near infrared spectroscopy for this purpose. It will have advantages of being real-time, noninvasive and continuous.