Multi-channel And FDM Emission Technique For FNIRS System

In neuroscience research,a very important research goal is to understand the neural mechanisms in the human brain under the movement and activities of executive cognitive tasks.Functional near-infrared spectral imaging technology,a means of detecting brain's activity,has been considerable development in the last decade.This technology is very suitable for continuous monitoring of the brain's dynamic activity.Near-infrared spectroscopy is a non-invasive,safe and portability technique for functional imaging of the brain.In the past decade,with the increase of interests in brain activity and cognitive task,this technology has been widely used.Oxy-hemoglobin and deoxy-hemoglobin concentration changes of the cortex can be detected using near-infrared light which contain two different wavelengths.Based on the functional near infrared spectroscopy detection technology,this paper discusses the multi-channel frequency division multiplexing transmission techniques of fNIRS.In this paper,research progress and results include:1)Based on continuous-wave functional near infrared spectroscopy detection equipment,this paper discusses the principle of the functional near-infrared imaging which include the pattern of near-infrared light propagation in the brain and Beer-Lambert Law.By the combination of these principles,we discuss the implantation scheme of the near-infrared light emission module which is applied to the functional near-infrared spectroscopy instrument.2)From the perspective of system requirements,this paper discusses each sub-module design and implementation scheme of the multi-channel frequency division multiplexing technique.These discussion include the signal generator module responsible for the occurrence of modulation signal of near-infrared light source,the election of the light source,the characteristics of the light source,the light source driving circuit,the coupling system of light source,the optical fiber and the channel expansion.