Brain Microdevice For Stroke Treatment Based On The Combination Of Microfluidic And Microelectrode

Stroke is an acute cerebrovascular disease that seriously threatens human health.It has the characteristics of high morbidity,high recurrence rate,high disability rate and high mortality rate,and has become the world’s first roughly disability rate disease.It will cause part of the neurons to die at the time of onset,resulting in many patients having language disorders,limb paralysis or other functional disorders after stroke.How to recover stroke patients is the most difficult problem facing researchers at present.The theory of neuroplasticity provides a theoretical basis for rehabilitation treatment of stroke.As long as the damaged neurons are regenerated or there are new neurons to replace the previously damaged neurons,then the patient has the possibility of recovery.Electrical stimulation is a widely used effective treatment for stroke rehabilitation.Stem cell transplantation therapy is also an emerging treatment.If these two technologies are combined,there is a new method of stroke rehabilitation.A microdevice system could achieve this goal,through the combination of microelectrode technology and microfluidic technology.The entire microdevice system is mainly divided into two parts: the implant part and the circuit part.The implanted part is composed of an electrode part having a tapered electrode structure and a microfluidic part having a microfluidic channel and a chamber.Its overall size is 2.5 × 2.5 × 2mm,and the base material is PDMS.These structures were prepared by molding.Therefore,the fineness of the template determines the quality of the implanted part.The mold of the electrode part was completed by laser processing.The specific method was to prepare conical micropores on acrylic by the excimer laser rotation method.The part of the tapered electrode was the core of the device,so this process was studied deeply.The influence of different factors on the depth and taper of the tapered micropores was explored.Suitable parameters were found,and the preparation of tapered micropores was completed.The mold of the microfluidic profile is processed by 3D printing technology.After pouring the model into the 3D printing,the preparation of the mold can be completed.The device structure was prepared through the moldover experiment.A metal film was plated on the tapered electrode to make it conductive.Perforation was made in the microfluidic outer profile so that it could communicate with the outside world.Finally,the two parts were combined to complete the preparation of the implanted part.This study successfully developed an electrical stimulation system that could output an adjustable dual-phase symmetrical square waveform.The electronic design conducted by the automation software and integrated development environment.A microprocessor was used to control the whole system,combining PCF8591 chip and voltage regulator.The system has human-computer interaction function,which can realize real-time observation and control of the system.Through testing,the ideal waveform can be observed on the oscilloscope to meet the requirements of the microdevice system.The micro-flow control pump is connected to the implanted part through a capillary tube.The circuit part was connected with the implant part through the lead wire output from the output terminal,and finally forms a complete micro device treatment system.The function of electrical stimulation is detected by oscilloscope.It is functional and can be tested on animals in the future.