Research On Near Infrared Diffuse Correlation Spectroscopy And Tomography Technology Based On Non-contact Measurement

Near-infrared diffuse correlation spectroscopy/tomography(DCS/DCT)are emerging recently as noninvasive measurement/imaging technologies for tissue blood flow.In DCT studies,the high-dense collection of light temporal autocorrelation curve(g2(?))via fiber array are critical for image reconstruction of blood flow.Previously,the camera-based fiber array limits the field of view(FOV),precluding its applications on large-size human tissues.The line-shape fiber probe based on lens combination,which is dominantly used in current DCT studies,requires rotated-scanning over the surface of target tissue,substantially prolonging the measurement time and increasing the system instability.In this study,we design a DCT non-contact optical probe based on a collimating microlens fiber array.For each source/detector fiber,a single microlens is coupled to collimate a single optical path.In addition,the probe can quickly complete high-density optical signal data acquisition with the help of optical switches,and the cost is low.The system based on this collimated microlens fiber array is called FA-nc-DCT(Fiber Array Noncontact Diffuse Correlation Tomography).)System,which is very important for the high-density acquisition of optical signals in DCT technology.The main research work of this paper is as follows:(1)Firstly,a non-contact array near-infrared diffuse optical blood flow imaging system was built,which mainly included the selection of the collimating microlens fiber model and the design of the fiber array fixed probe.The use of collimated micro-lens fiber instead of the traditional lens combined lens system enables the entire photon emission and photon detection process to be carried out in a non-contact manner,and reduces the loss of light intensity and the volume of the instrument,so it is easier to achieve large-area array acquisition.More measurement data can further improve the quality of blood flow image reconstruction.(2)Secondly,the photon path simulation software is used to complete the Monte Carlo photon path simulation and the NL-DCT theory and algorithm are used to complete the image reconstruction under the set SD pair(light source-detector pair)array,through the variable speed simulation experiment Human experiments with cuff cuffs verified the non-contact array system.Finally,from the FA-nc-DCT system,the body's analog and ischemic muscle flow abnormalities were accurately reconstructed.These results prove the great potential of FA-nc-DCT technology for rapid and powerful imaging of various diseases(such as human breast cancer),and it is expected to provide high-quality,rapid and large-scale imaging for clinical cancer diagnosis and treatment.A complete non-invasive,low-cost blood flow imaging solution.