Design Of High Reliability Detection System Integrated In Pacemaker

According to medical research,the number of deaths from cardiovascular and cerebrovascular diseases in the world is as high as 15 million every year,ranking first in various causes of death.Cardiovascular and cerebrovascular diseases have the characteristics of high prevalence,high disability rate and high mortality rate.The patients usually show bradycardia,arrhythmia and heart block.Some serious patients need to implant pacemakers to ensure that normal heart rate can alleviate the disease.Pacemaker is used to be the main mean of modern treatment of cardiovascular disease.Medical personnel pay close attention to the real-time tracking of its working status for safety reasons.The traditional detection method is to use electrocardiogram to observe human electrocardiogram(ECG)signal in real time for effective detection.But medical personnel will be very time-consuming and complex to detect signals.And it is not the first choice for ultra-low power micro-implant equipment because of its large volume and power consumption.Based on the shortcomings of the existing methods to detect the working state of the pacemaker and the physical characteristics of the measured cardiac resistance when the electrode wire is loosened or separated from the pacemaker,this paper proposes a system which can be integrated into the pacemaker to detect the working state of the pacemaker in real time by accurately measuring the cardiac resistance.The detection system is designed a tiny reference current to inject into the heart,accurately sampled with a switching capacitor circuit,and pre-set the normal cardiac resistance range in the processor.The system uses the linear relationship between voltage and current in Ohm’s law to judge the measured exact resistance value and realize effective detection.Because of the closed-loop design,the system enhances the stability of the system extraction signal,and obtains the accurate detection signal under the premise of reducing the input reference current and ADC resolution.This is undoubtedly to achieve high-precision measurement,while greatly reducing the complexity of the system design and power requirements.The system uses Multisim simulation platform to design and simulate,Altium Designer software platform to PCB design,complete circuit board level verification.The experimental results show that the detection accuracy is as high as 99% while operating voltage is 2.5V and low reference current is 50μA.The proposed design has lower complexity,lower power consumption and stronger safety and reliability,compared with the traditional detection method.The experimental results show that the proposed method is correct and effective of the system design.