Multi-parameter,Multi-site,Multi-channel Non-invasive Monitor In Critical Period

Severe symptoms,such as shock,vascular disease and edema,often accompany patients in critical period.If the patient's condition can be obtained in time,the patient in dangerous condition can be intervened effectively.In this paper,NIRS technology is used to develop a multi-parameter,multi-location and multi-channel non-invasive monitor,which integrates multi-wavelength near-infrared light sources on the probe of the non-invasive monitor,and achieves the purpose of real-time acquisition of many physiological indicators.Multi-parameter,multi-location and multi-channel integrated non-invasive monitor can provide real-time,continuous,multi-location and multi-parameter comprehensive physiological indicators for medical staff,which has important clinical value for ensuring patient's life safety.In this paper,the principle of near infrared spectroscopy and three detection methods of near infrared spectroscopy are analyzed and summarized,and then the existing commercial NIRS system is summarized.The current research status of NIR monitors in three aspects: multi-parameter,multi-location and multi-channel is introduced,and the multi-parameter,multi-location and multi-channel integration scheme adopted in this paper is proposed.In order to monitor multi-physiological parameters,based on the two-parameter monitoring algorithm,this paper determines the wavelength selection of multi-parameter monitoring at the same time through the absorption of near infrared spectra by key physiological parameters of human tissues,and deduces the monitoring algorithm of multi-physiological parameters at four wavelengths.In order to design a photoelectric probe module suitable for multiple locations,this chapter also obtains the optimum light source and photodetector distance by analyzing the space sensitivity of the monitoring signal obtained from the simulation of photon transmission characteristics in forehead,gastrocnemius and lumbar spine.Secondly,in order to realize the hardware design of multi-parameter,multi-position and multi-channel integration of non-invasive monitor,the scheme of MCU main control circuit module and photoelectric monitoring probe module is adopted.In the photoelectric probe part,the light source of multi-parameter probe is selected.In the control circuit part,the multi-parameter multi-probe monitoring and control circuit and the multi-channel data acquisition scheme are designed.Because the human signal we monitor is weak,the high integration of the system brings the challenge of reliability.In the layout and wiring of instrument PCB,various measures are introduced to reduce the crosstalk,oscillation and timing problems that may be encountered in the transmission of signals,and to improve the reliability of products.Then the software design of multi-parameter,multi-position and multi-channel integration of the monitor is carried out.The lower computer software of the integrated system controls the multi-parameter photoelectric probes placed in multiple parts,integrates the data of multiple channels in the microcontroller,and then transmits them to the upper computer with excellent human-computer interaction interface.The upper computer can integrate,save and display the detection results of multiple channels and multiple parameters in multiple parts.Finally,in order to give a complete performance description of the instrument after the completion of the instrument,on the basis of the conventional performance test,this paper also focuses on the cross-talk between channels,the cross-talk between parameters and the stability of the system caused by the integration of multi-parameters,multi-parts and multi-channels of the monitor.The test results show that the performance of the instrument meets the design requirements.