The Application Of The Electromyographic Signal In The Ventilator Based On FPGA

Ventilator plays an important role in the rescue of patients, but traditional mechanicalventilation still can’t solve the problem of patient-ventilator synchronization, primarilybecause the delay of using flow or pressure to trigger the ventilator. When using the pressureas the trigger signal, the patient will pay more efforts coping with the airway resistance totrigger the ventilator.People mostly use their diaphragm muscle to breath, and the diaphragmatic signal isearlier than the flow and pressure signal. At the same time, diaphragmatic signal can wellreflect the inspiratory time and respiratory effort of the respiratory center better than flow andwon’t be affected by other lung disease and the airway resistance. Such ventilator will havebright future and improve people’s lives.This paper develop a platform based on the trigger mode of diaphragmatic signal,including multichannel collecting system(the diaphragmatic signal, flow and pressure signal),signal processing system. This device can also adjust the fan’s speed according thediaphragmatic signal, than help the patients to breath.The surface diaphragmatic signal has many noise that made by the heart and50Hz powerfrequency disturbance. So that it need to develop some filters to reduce the noise. This paperexplore the feature of diaphragmatic signal and use IIR filter, comb filter, mathematicalmorphological method as the core algorithms to remove the disturbances. Finally to get thepatient’s breathing time and the effort they make. About the hardware, this device choseFPGA as the core controller, and some circuits were developed to collect the flow andpressure. In the software, I used VHDL language to realize the AD/DA controller, IIR filter,comb filter and mathematical morphological method in real time. I also used Visual C++towrite the program which can display the collected signals and save it at the same time.