Study On Quantitative Monitoring Method Of Tissue Oxygenation Based On Near-infrared Multispectral Spatial Resolution Technique

Near Infrared Spectroscopy(NIRS)can non-invasively,continuously and continuously monitor tissue blood oxygen parameters,and has been widely used in clinical diagnosis and monitoring.Under the model of multi-layered biological tissue,a set of tissue oxygenation quantitative monitoring system based on three-wavelength(735nm,805nm,850nm)near-infrared spatial resolution algorithm was designed and completed.And the system we developed is applied in the field of drug correlation research and acute altitude sickness monitoring.The algorithm eliminates the background absorption and the interference of the outer layer structure by differential method,thereby improving the sensitivity and accuracy of the measurement system.After completing the system design and commissioning work,in order to evaluate the reliability and effectiveness of the system,a series of test experiments were carried out on the system.First,a series of basic performance tests were designed and completed,including:light source safety test,system dark noise test and long-term measurement stability test.Next,three in vitro biological tissue optical models were designed and fabricated:the Intralipid-Ink liquid model,the single-layer agar model,and the multi-layer agar model to verify the effectiveness of the system for biological tissue measurements.Then,in order to assess the accuracy of the system for tissue oxygen saturation,an optical integrating sphere model was used to achieve multi-point calibration of tissue oxygen saturation.Finally,the forearm arterial blockade experiment was designed and implemented to simulate the hypoxia state and physiological change process of human tissues,and then verify the effectiveness of the system in body measurement.This system was applied to the study of drug correlation of NIRS signals.During the induction of propofol,the local tissue oxygenation status of the patient's brain was monitored,and the dose and time of the drug bolus were recorded.The results showed that NIRS,as an auxiliary index,could provide additional information on patient status in a continuous and non-invasive manner.And NIRS technology can reliably measure the effects of propofol on cerebral hemodynamics and demonstrate the presence of propofol neuro hemodynamics to help further assess sedation.The system was applied to brain oxygenation monitoring in an acute high-altitude hypoxic environment.The data of local brain tissue blood oxygenation parameters,pulse oximetry and heart rate were monitored in low altitude and acute high-altitude hypoxic environment.By analyzing the acute effects of atmospheric pressure drop caused by altitude elevation on the human systemic circulatory system and local brain tissue,the short-term adaptation process of the human body in anoxic environment was discussed.It provides an objective basis for the prevention of acute high-altitude sickness and provides a reference for medical staff to carry out medical rescue work in the plateau area.