Design And Validation Of A Newly Device Based On Near-infrared Spectroscopy For Monitoring Spine Cord Lesions

Spinal cord is an important nerve center.Spinal lesions can cause a series of serious complications which may lead to paralysis in serious condition.Therefore,spinal lesions are with a high mortality and thus early diagnosis and treatment are of tremendous significance.Traditional spinal lesion detection techniques rely mainly on Bone Marrow Aspiration for biopsy,which is a dangerous and invasive method.Worse still,it is often difficult for many patients to undergo repeated surgical procedures because of the fact that the extracted samples do not meet the requirements.With the development of medical imaging technology,MRI,CT and other technologies have been adopted.However,these technologies are expensive and have some degree of radiation.Therefore,it is urgent to have a non-invasive,safe,cheap and real-time continuous detector.Near Infrared Spectroscopy(NIRS)is an emerging noninvasive human hemodynamic detection technique with non-ionizing radiation,portable,inexpensive and other strongpoints.This paper develops a noninvasive spinal lesion detector based on NIRS technology.In this paper,the background and significance of the research,as well as the existing detection methods were compared and analyzed.Besides,the detection principle and research status of NIRS were described.After verifying the feasibility of NIRS technology to detect spinal lesions,we developed the research and performance test of spinal lesion detector based on NIRS technology.Firstly,based on the Visualization of Chinese Human data set(VCH),we established a three-dimensional voxelized spinal cord model and used MCVM simulation to determine the transmission characteristics of near infrared light in the actual human spinal cord.The results of absorption distribution showed that the feasibility of using near infrared light to detect spinal lesions.In addition,in order to obtain the optimal distance between the light source and detectors,the system simulation and data processing analysis of different distances were carried out and finally,the range of optimal distance was shortened to 2.8 ~ 3.2cm.Secondly,the instrument was developed,including the design and implementation of hardware circuits,the program and test of software.In the aspect of hardware circuit,the distribution structure of the cross probe,using light dense material and packaged with embedded type,was designed according to the simulation result of MCVM.The system power supply module was designed,particularly using high-precision LDO to provide ADC with reference voltage to ensure the accuracy.Then,we used SPI bus control mode to drive the light source with the light source driver chip.We chose an ARM chip for system control because of its powerful function and rich interface.Next,the data processing module were designed including channel selection and A/D conversion.The way of data transmission was serial mode.For the software system,it contains two parts.One is lower computer software and the other is host computer software.The lower computer software was programmed by Keil,which is a software,to make the hardware system drive the peripheral equipment and collect data according to the predetermined timing.Host computer software was programmed by Qt.The date transmission was mainly dependent on qextserialport class and the curve drawing relied on QPainterPath class.We used dual threads to ensure the simultaneous implementation of data acquisition and curve drawing.Moreover,we defined the corresponding communication protocol between upper and lower computer for data communication.Finally,we verified the stability,consistency and sensitivity of the system.At the same time,the clinical performance of the system was tested and the test results were analyzed.The results show that the system is able to detect the signal of spinal cord,which indicates that our spinal lesion detector based on NIRS technology has the potential to detect the spinal lesions.