基于心音香农能量包络的实时心率检测的研究和实现

心音信号通常用于获取心脏瓣膜的功能信息和节律活动信息,本研究提出一种利用心音信号来测量实时心率的方法。将采集到的心音信号做归一化处理,基于香农能量算法计算心音信号的能量,再将香农能量信号做移动平均滤波,提取能量信号包络。经过处理的心音信号衰减了其中的背景噪声和杂音信号,突出了第一心音(S1)信号。选择一个合适的时间窗口并在其范围内寻找心音峰值,根据相邻峰值之间的距离计算出心率。本方法在硬件平台上用C语言进行了实现,与心电图机测量的心率进行对照,准确率达到97%以上。

Study and implementation of a Shannon energy envelope of heart sound for detecting instantaneous heart rate

Heart sound is generally used for obtaining information about the heart rhythm and valve.We described a method for calculating the instantaneous heart rate using the Phonocardiogram(PCG).First of all,the heart sound signal was normalized after sampling,and then the energy of the signal was calculated base on the Shannon energy algorithm.Finally,the Shannon energy signal was filtered using the moving average filtering algorithm and the Shannon energy envelope was obtained.After the above processing,most of the low level murmurs and background noises got suppressed,and the first heart signal(S1)was detected.We selected appropriate time window to find S1 peak.The instantaneous heart rate was calculated according to the distance between the two adjacent S1 peaks.This method was implemented using C programming language on the hardware platform.Comparing with the heart rate measured by ECG machine,the accuracy rate reaches more than 97%.