Study On Technologies And Experimental Devices For The Combined Electrical And Optical Neural Stimulation

The nervous system plays a leading role in the human body.All kinds of information in the internal and external environment are transferred to the central nerves for integration after received by the receptors,and then returned to the peripheral nerves to control and regulate the activities of various systems and organs of the body so as to maintain the relative balance of the internal and external environment of the body.Nerves are an important part of human activities.Once the nerve is damaged,human movements will not be able to proceed.The potential change of nerve fibers is an important characteristic of nerve conduction and all nerve conduction is produced by the change of potential.In the neurology department,patients with hemi paralysis caused by nerve dysdunction are increasing every year.Rehabilitative treatment is a more effective method now,such as electrical stimulation,infrared laser stimulation and chemical dressing.And many products have come out.However,chemical methods may cause unrecoverable damage to nerve tissue,and chemical agents are not suitable for patients with long-term pain due to that uncertain latency of injury to the human body.Electrical stimulation can cause electrical damage to the tissues around the electrodes,and point-to-point stimulation cannot be executed.Power supply is also a problem during long-term implantation.The other method is the infrared pulse laser stimulation of nerve tissue,whose advantage is in no contact with tissue and high spatial resolution.However the laser energy is hard to control and it is easy to cause burns to the surrounding tissue.In order to solve this problem,many scientists have begun to study the innovative combination of stimulation methods,such as any two combination stimulation methods from light stimulation,chemical stimulation and electrical stimulation.Based on the above research background,this paper proposes a neural regulation technique using combined electrical and optical stimulation based on the enhancement of carbon nanoparticles,and also designs and builds an experimental device for combined electrical and optical stimulation of frog sciatic nerve.The specific research work is as follows:1.An experimental device for combined electrical and optical stimulation of frog sciatic nerve is designed and built,which includes a laser,an electrical stimulator,the synchronous control circuit of laser stimulus,cuff electrodes,a multi-channel physiological signal acquisition instrument,a computer,a magnetic base 3D thruster,and so on.2.The cuff electrode based on flexible circuit board(FPC)is designed and fabricated.The cuff electrode is used as stimulating and recording electrode for electrical stimulation to reduce the nerve injury and maximize the collection of the electrical signal of all nerve bundles.3.The synchronous control circuit of photoelectric stimulation is designed.In this experiment,the frog sciatic nerve is stimulated by the photoelectric synchronous stimulation,so a pulse signal circuit that synchronously outputs a control laser according to the electrical stimulation signal is designed.The synchronization control circuit is based on the PWM signal of STC89C52 microcontroller.4.This study establishes a theoretical model of combined electrical and optical neural stimulation.The electrical stimulation of nerves around the distribution of the electric field is solved by the finite element analysis software COMSOL,the propagation of laser and the temperature distribution of the biological tissue is calculated by the Monte Carlo algorithm.Finally the relevant electric signal and temperature information are transmitted to the NEURON software to simulate the electrical behavior of the sciatic nerve.5.This research carries out an experimental study of combined electrical and optical stimulation under nanoparticle enhancement,including test of the enhancement of nanoparticles,the influence of laser on electrical stimulation,the influence of electrical stimulation on the laser energy needed to block nerve action potential,and the influence of ambient temperature on electrical stimulation.In this paper,neural functional electrical stimulation and near infrared laser combined stimulation on nerve repair was studied.A cuff electrode was designed to protect the nerve tissue and carbon nanoparticles were used to enhance the impact of photoelectric stimulation.The effect of combined electrical and optical stimulation was studied both in theory and experiment.Result of this paper provides a theoretical reference for the application of photoelectrical stimulation to the repair of clinical nerve function,and accelerates the application process of optical stimulation of nerve repair.