MATLAB: Who can i plot like star or circle in plot ?

digital signal processingekgMATLABSignal Processing Toolbox

i have to detect S-wave in ECG and i need to put some thing to determined it is location in the figure how can i plot this ??

Best Answer

It looks like a normal Lead II EKG 10 second rhythm strip with a regular rhythm and a rate of about 66. The S-wave is near the end of the QRS complex, so the easiest way to detect the S-wave is to first identify the preceding R wave, get the index (since this is most likely a data vector), and look for the minimum in the next 5 milliseconds. (It’s easiest to do this in terms of data vector indices, but you have to know the sampling rate to do the conversion. The sampling rate isn’t stated.) In this tracing, that minimum should be the S-wave. Store the indices of the S-waves in a vector, then plot your markers at the time and EKG values corresponding to the vector of S-wave indices.
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