Design Of Cerebral Oxygenation Monitor For The Newborns

HIE (hypoxia-ischemic encephalopathy) is a cerebropathy for the newbornsbecause of lacking oxygen during the perinatal period and it always cause greatharmful to the newborns. Because now there are few objective ways to determine theHIE correctly and in time, the best change to cure the disease will be disappeared. Soit is necessary to develop an instrument to monitor the rScO2 (regional cerebral O2saturation) of the newborns continuously and non-invasively. The monitor candetermine if the neonate is lacking of oxygen and blood or if the sick recovers well.The work is very useful to increase the quality of neonates.With the development of the NIRS technology in recent years, the measurementof the rScO2 by NIRS is more and more applied in the medical field. The monitorprovides a portable, real time, non-invasive and cheap measurement in clinic and itcan be applied in many situations such as ICU, NICU, CCU and etc.This paper puts forward a multi-layer simulation model, taking into account theconcrete structures of newborn brain. By the Mont-Carlo simulations, the detectedlight transporting within the tissues of a newborn brain is studied on the SpaceSensitivity Picture, Effectively Penetrate Depth, and Average Optical Length ofphotos. Based on the simulation results, a new kind of measurement design ispresented for the noninvasive monitoring of newborn brain oxygenation.A cerebral oxygenation monitor for the newborn is presented in this paper. It ismade up by sensor, analog circuit, digital circuit and computer. For the sake ofprecious data-acquisition and stability, many new devices are applied in the monitorsuch as integrated photodiode and amplifier, multi-channel lock-in amplifier,high-accuracy A/D converter and color LCD module. The monitor could transferdata with the computer to analyze if necessary.A serial of experiments are done to validate the performance of the monitor. Theexperiments of measure the dark noise and the stability show that the system is ofvery low dark noise and can work steadily. The experiment of blood blocked in theforearm show that the system could monitor the change of the oxygenation in tissueand give a reasonable explanation. Finally some clinic experiments are made toensure that if the system could specify the different between the health newborn andthe sick.