Finding ECG Local Maximums using Threshold/Loops

Hi, I am trying to figure out how to use a threshold to isolate data from an ECG signal and then find the maximums for each spike that has data above the threshold. I feel that I have to use a loop to analyze the data. I know that if I start with: threshold = 8.5 y > threshold I get values of 0 or 1 that tell me if the threshold has been passed, but then I get lost. Any help would be appreciated :)

Answer 1

[Image Analyst]

If you have the Signal Processing Toolbox, use findpeaks(). If you have the Image Processing Toolbox, use imregionalmax(). If you don't have either of those, check the File Exchange or here: http://billauer.co.il/peakdet.html

[Image Analyst]

Bob said in his "Answer" below: "Thanks! but findpeaks gives me many peaks instead of just the ones above the threshold. Any help on how to do that?"

[Image Analyst]

Bob, look at the help. See the option for 'MINPEAKHEIGHT'? I think that if you adjust that you can get what you want. Perhaps you might also need to specify 'MINPEAKDISTANCE' and 'THRESHOLD' also.

Answer 2

[Bob]

Thanks! but findpeaks gives me many peaks instead of just the ones above the threshold. Any help on how to do that?