Development Of A Portable NIRS Instrument For Muscle Oxygen Monitoring Based On PDA

Blood oxygen is an important index to evaluate life activity. As a new optical measure technology, Near-infrared spectroscopy (NIRS) has been developed rapidly in recent decades. Compared with the traditional methods, NIRS method can monitor the oxygenation of local tissue and organ no invasively and in real time. The combine of the intelligent mobile devices with NIRS, can give more freedom to subjects. So we can use NIRS technology to measure the muscle oxygen in moving subjects.In this dissertation, a portable NIRS muscle oxygen monitor based on PDA is designed. The paper describes every subsystem including light driver of three wave length, detector, amplifier and filter, data acquisition, data receiving on PDA, data processing and visualization. The temporal resolution of the system is 340ms which is adequate to measure blood volume and hemodynamic changes in muscle. The probe is so flexible that is easy to belt on and made good attachment to skin. The main weight of system is about 400g, so the whole system is light and portable.By means of the performance test, cuff ischemia experiment and in-vivo experiment, the system property and accuracy of measurement was validated. Through the long time stability test, dark-noise detection and light power test, the stability, detecting ability and safety of system is insured. In cuff ischemia experiment, the change of Blood volume (BV), HbO2 and Hb measured by system is in accordance with the real physiology status. The in-vivo incremental load experiment at last shows the relationship between load and muscle oxygenation. The result demonstrates the validity of system used in human exercise physiology research.