Research On Near Infrared Brain Function Imaging Of Pain

The brain is the most complex organ of the human body. It is a difficult task todecrypt the operation mode of the brain and explore the mystery of life. And there aremany scientists studying this topic. J bsis first observed near-infrared light canpenetrate human tissue in1977.Since then, People began to use NIRS technique tostudy brain activity. Anatomy of Pain shows that some regions of brain exhibitsignificant neural activity and its local blood volume accordingly increases whensome areas of human suffers painful stimuli. Because oxygenated hemoglobin (HbO2)and deoxygenated blood hemoglobin (Hb) have different absorption coefficients inthe near-infrared (600-1300nm wavelength), the intensity of the emitted light mayreflect changes physiologically.In this paper, a set of NIRS blood oxygen measure system has been designedwhich using dual-wavelength near-infrared LED as its light source and having eightdetection channels. The principle of the system is based on the interaction betweentwo wavelengths760nm and850nm near-infrared light with biological tissue andrevising Lambert-Beer law. The equipment uses microcontroller as its core to controlthe entire circuit. The main function of the microcontroller is controlling the lightsource driver chip to light source in the order and controlling8-channel A/Dacquisition, data processing. The optical detector uses OPT101with low-noise,high-gain in the700nm~850nm wavelength range. The host computer control systemis constructed on Visual C++6.0platform for serial communication, data storage,display of blood oxygenation content. A series of experiments and tests for the systemhas been carried out, and it is mainly including the basic performance test of thesystem and experiment in in vivo. These test verify the ability of the system to detectthe such weak oxygen content and it can be used to detect brain functional activity.In this paper, the NIRS blood oxygen measure system is be used to detectorbitofrontal cortex function imaging of20tester randomly. The test detectedorbitofrontal cortex is activated under the pain stimuli and brain activity is increasedin the region.