Design Of Multi-channel Micro-electronic Neural Bridge Stimulator Based On Wireless Power Supply

Limb paralysis caused by spinal cord injury will bring heavy burden to the patients,their family and the society.Reconstruction of motor function for the paralyzed limbs has great impact to improve the life quality of patients,helping them to return to society,and reduce the burden of all parties.Our team proposed a method to reconstruct the motor function of the paralyzed limbs,which has been named as the "Micro-Electronic Neural Bridge"(MENB).The research content of this paper mainly includes: 1.Design of the multi-channel microelectronic neural bridge stimulator based on wireless power supply: The design of stimulator is composed of three parts.The first part is the implantable stimulator.The second part is the epidural stimulation electrode and stimulator.The third part is the external wireless charging module for the implantable stimulator.The stimulator can be implanted into the organism for a long term to stimulate the spinal cord and ensure a stable power supply.2.Design of the stimulate signal control algorithm based on spontaneous neural signal: Firstly,through the cooperation with the students of our research group,we carried out animal experiments to explore the influence of spinal epidural stimulation on lower limb muscle movement,and tested the influence of epidural stimulation area,stimulation current amplitude and frequency on lower limb muscle movement.Then,according to the experimental results,combined with the common method of action potential detection,the control algorithm of stimulation signal based on spontaneous nerve signal is designed,which can separate the action potential from the collected nerve signal,and appropriately amplify the detected action potential as the stimulation signal output to realize the nerve signal bridging.3.Design of the implantable microelectronic nerve bridge stimulator: First,a prototype of a microelectronic neural bridge stimulator was designed,the stimulation circuit based on complementary current source and time division multiplexing method proposed by Dr.Wang,which can be used for epidural stimulation experiments.Then,a Bluetooth communication circuit and a wireless energy receiving circuit are added along with the stimulator,and the form factor is significantly reduced.The stimulator is designed to implant into the animal body,and to receive the nerve signal from the detection module in the MENB system and convert it into stimulating current output.4.Design of the epidural stimulation electrode and the external wireless charging module: Three versions of epidural stimulation electrodes array and three metal wire electrodes with skull joints are designed,which can be used in different animal experiment scenarios.The external wireless charging module provides the power supply of implantable stimulator,and the wearable package is designed according to the shape of the module.5.Experimental Research: First,the prototype of the stimulator was used to carry out the piggyback stimulation experiment and an acute epidural stimulation experiment in pigs.The small-size implantable stimulator was used to carry out the implantation stimulation experiment in rats.The experiment verified the function of the stimulator.The muscles of the animals' paralyzed lower limbs isactivated by epidural stimulation.Then,on the basis of epidural stimulation experiment,we combined the stimulator with the microelectronic nerve bridge detection module designed by our team to form the MENB system,and carried out the spinal nerve bridge experiment on the rat model,which successfully bridged the spinal nerve signal,and evaluated the function of the system.