可集成在心脏起搏器中的高可靠性检测系统设计

Design of high reliability detection system integrated in cardiac pacemaker

心脏起搏器的传统检测方法是利用心电图仪观察人体心电信号,但存在十分耗时和复杂等问题,且体积和功耗较大,导致其并不是超低功耗微型植入设备的首要之选。基于传统方法的不足以及电极导线松开或与心脏起搏器分离时会导致测量的心脏阻值异常大的物理特性,文章提出一种可集成在心脏起搏器中,通过精确测量心脏阻力,从而实时检测起搏器工作状态的系统。该检测系统通过设计微小参考电流注入心脏,用开关电容电路精确采样,利用软件算法将系统中检测到的数字电压信号有效转化为心脏阻力,并与预先在处理器中设置的正常心脏阻力比较,从而实现有效检测。测试结果表明,在工作电压5 V、参考电流50μA下,检测精度高达99.0%,与传统检测方法相比设计的复杂性降低,应用更加方便。测试结果验证了系统设计的正确性与有效性。

The traditional detection method for cardiac pacemaker is to use electrocardiograph to observe human electrocardiogram(ECG)signal,but it is time-consuming and complex.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 and the physical characteristics of the abnormal large 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,by designing a tiny reference current to inject into the heart,accurately sampling with a switching capacitor circuit,effectively converts the digital voltage signal detected in the system into cardiac resistance by software algorithm.And it is compared with the normal cardiac resistance set in advance in the processor to achieve effective detection.The experimental results show that the detection accuracy is as high as 99.0%when the operating voltage is 5 V and the reference current is 50μA.The proposed design has lower complexity and is more convenient,compared with the traditional detection method.The experimental results show that the proposed design is correct and effective.