MIT-BIH ECG 心电数据+matlab绘图详解

%% usage: plotATM('RECORDm') % This function reads a pair of files (RECORDm.mat and RECORDm.info) generated % by 'wfdb2mat' from a PhysioBank record, baseline-corrects and scales the time % series contained in the .mat file, and plots them. The baseline-corrected % and scaled time series are the rows of matrix 'val', and each % column contains simultaneous samples of each time series. % % 'wfdb2mat' is part of the open-source WFDB Software Package available at % http://physionet.org/physiotools/wfdb.shtml % If you have installed a working copy of 'wfdb2mat', run a shell command % such as % wfdb2mat -r 100s -f 0 -t 10 >100sm.info % to create a pair of files ('100sm.mat', '100sm.info') that can be read % by this function. % % The files needed by this function can also be produced by the % PhysioBank ATM, at % http://physionet.org/cgi-bin/ATM % function h = plotATM(Name) if nargin == 0 Name = '100m'; end %% 读取数据 infoName = strcat(Name, '.info'); matName = strcat(Name, '.mat'); Octave = exist('OCTAVE_VERSION'); load(matName); % 采样值变量的名字为val fid = fopen(infoName, 'rt'); fgetl(fid); % 第一行 fgetl(fid); % 第二行 fgetl(fid); % 第三行 [freqint] = sscanf(fgetl(fid), 'Sampling frequency: %f Hz Sampling interval: %f sec'); % 得到采样频率和采样间隔 interval = freqint(2); % 取采样间隔 fgetl(fid); % 第五行 if(Octave) % 一种软件：http://blog.csdn.net/Forlogen/article/details/54425766 for i = 1:size(val, 1) R = strsplit(fgetl(fid), char(9)); signal{i} = R{2}; gain(i) = str2num(R{3}); base(i) = str2num(R{4}); units{i} = R{5}; end else for i = 1:size(val, 1) Infor = textscan(fgetl(fid),'%d%s%f%f%s','delimiter','\t'); row = Infor{1}; signal{i} = Infor{2}; % 导联名称 gain(i) = Infor{3}; % 增益 base(i) = Infor{4}; % base units{i} = Infor{5}; % 单位 end end fclose(fid); %% 数据处理并作图 val(val==-32768) = NaN; for i = 1:size(val, 1) val(i, :) = (val(i, :) - base(i)) / gain(i); % 转化为mV end x = (1:size(val, 2)) * interval; % 采样时间 plot(x', val'); for i = 1:length(signal) labels{i} = strcat(signal{i},'(', units{i},')'); end if length(signal) == 1 legend(labels{1}); else legend(labels); end xlabel('Time (sec)'); xlim([min(x) max(x)]); % 设置横坐标 end