Real-time filtering adaptive algorithms for non-stationary noise in electrocardiograms

The computer programs implement the adaptive algorithms for real-time ECG signal filtering and numerical simulation for evaluation of filter effectiveness. The adaptive algorithms with complex use Hampel identifiers and Z-parameter are an author’s development.
To launch a program, enter the name of the program and the ECG model signal in the command line. For example: ahzmthp.exe clean.txt. The test signal parameters (its length) and parameters of the filtering algorithms are read from the text file named as “filters.txt”. The program requests the additive and multiplicative noise variance, the probability and the amplitude of the spikes, and the number of realizations for statistical averaging of the calculated filter performance indicators. For example, via the “space” key enter: 0.0001 0 0 0 200, then press “Enter”. To apply filtering to a test signal which is read from a text file, select the menu item "Load from file" by pressing the key "6". The filter results are put in the “RESULT” subfolder. The filter efficiency estimates are written to the "MSE.res" and "SNR.res" output text files. The input signal has an extension “.x” (no noise), “.xn” (with simulated noise), “.xns” (with noise and spikes). The signals from filter algorithms outputs have the extension “.yf”. Also, files with functions of identifiers used to adapt the algorithm parameters to the local signal behavior and to the changes in the noise level and with adaptable filter parameters, and other intermediate signals are put to the “RESULT” subfolder. Input and output signals are presented in text format in the form of two columns, where the first column is the numbering of the samples, the second one is the corresponding values of the discrete signal. The first number in the first line is the signal length. To apply filtering to signals of different lengths, the first number that indicates signal length in the second line in the "filters.txt" file has to be changed accordingly.
Correction of the filter parameters (in the "filters.txt" ) for ECGs with another sampling rate is recommended.
The program was compiled by Free Pascal.

该计算机程序实现了实时心电图信号滤波的自适应算法，并进行了数值模拟以评估滤波器有效性。所采用的自适应算法，其复杂运用涉及汉普尔识别符和Z参数，乃作者之独创。启动程序时，需在命令行中输入程序名称及心电图模型信号。例如：ahzmthp.exe clean.txt。测试信号参数（其长度）及滤波算法参数将从名为“filters.txt”的文本文件中读取。程序请求添加性和乘性噪声方差、尖峰的概率和幅度，以及用于计算滤波器性能指标统计平均的实现次数。例如，通过“空格”键输入：0.0001 0 0 0 200，然后按“Enter”键。要对从文本文件读取的测试信号进行滤波，请通过按“6”键选择“从文件加载”菜单项。滤波结果将置于“RESULT”子文件夹中。滤波效率估计值将写入“MSE.res”和“SNR.res”输出文本文件。输入信号具有“.x”扩展名（无噪声）、“.xn”扩展名（模拟噪声）、“.xns”扩展名（噪声和尖峰）。滤波算法输出的信号具有“.yf”扩展名。此外，用于将算法参数适应于局部信号行为以及噪声水平变化的标识符函数、可适应滤波参数以及其他中间信号，均放置于“RESULT”子文件夹中。输入和输出信号以文本格式呈现，形式为两列，其中第一列是样本编号，第二列是对应的离散信号值。第一行中的第一个数字是信号长度。若要对不同长度的信号进行滤波，需相应更改“filters.txt”文件中第二行指示信号长度的第一个数字。建议对具有不同采样率的心电图，对“filters.txt”中的滤波器参数进行校正。该程序由Free Pascal编译而成。