Research On Conditions Of Percutaneous Non-invasive Measurements Of Human Body Components

The various chemical components present in human body carry importantinformation on health status. Such chemical information also serves as an importantindicator to a number of clinical diagnostics and therapeutic effect. Therefore, timelyanalysis of these chemical concentrations has special meaning for modern health care.Invasive measurement is unfavorable when compared with non-invasive methods.Hence, Near-infrared spectroscopy receives global attention as a principalnon-invasive diagnostic means. But, during the measurement, there are many factors affecting the results such asthe optics system to bring the NIR, which belongs to the hardware conditions, and themeasuring temperature, the contact pressure, the mismatch of indexes and so on, all ofwhich will put impact on the final precision to some extent. In this paper, startingfrom the above factors, we will do some researches deeply about the percutaneousmeasurement conditions which will affect the measurement precision during thedetection of non-invasive spectral measurement using NIR. To obtain precise result, itis necessary, in the aspect of hardware, to set up one stable optics system with highSNR, only if so, can we do the measurement with the steady NIR. To do so, we designthe optics system using AOTF, and take some measures to increase the light energyand the system SNR, which includes the three layers structure of the light chamber,the equipments to cover the useless light, polarizing to reduce the influence of 0 gradelight and focalize the light with lens. Apart from the hardware aspect, according to theexperiments, we can see that the different temperatures between at setting up themodels and at predicting the results will affect the prediction results in a way, and theaffection extent will be increased along with the increase of the temperaturedifference. Moreover, the light energy that can be detected will be different with thecontact pressure, and the match of the refractive indexes between the tissue and thesurroundings will enhance the light transmission depth, which will take moreinformation of the tissue. So, during the measurement, we should ensure the sametemperature between measuring and predicting, the same contact pressure at everymeasurement and the match of the indexes between the tissue and the surroundings aspossible as we can. In this paper, the innovative points mainly include the design of the five-portoptic fibers to measure the diffusion light and the introduction of LDs as assistantlight sources to increase the energy and the system SNR.