Pulse wave analysis

[acheung]

Hi, I'm having a little trouble with this VI that I'm working on and I'm hoping someone could help me. What I'm trying to do is detect the two peaks from a pulse wave measurement file. Each pulse cycle has two peaks and I want to get the times of the peaks. I can get the first higher peak, but I can't seem to get the time for the second peak, which you can see in waveform chart 2. That is the only thing I need to get and I appreciate whoever can help me. Thanks.

[aeastet]

I have a few questions before I can help.

First

Second

I see a significat difference between the raw data and the filtered data. It seems to me that there would be a big difference in the result if you use filtered data. Is this the intention?

[acheung]

To your first question, yes I am looking for those two peaks.

And I don't mean to use the filtered data to get the numbers, I was filtering it to get the data leveled and to look nicer. But the numbers of the peak should come from that graph. Hope that helps!

[aeastet]

Here is something that is finding what you are looking for. I can explain it if you have questions.

[acheung]

Ah I wasn't able to open it cause I have labview version 2009

[aeastet]

here is 2009

[acheung]

Thank you! I've been looking at it and I'm glad it does what I need it to do. So I understand that the locations it gives out corresponds to the peak values, if you wanted to change the scaling to time (since the data file is for 25 seconds long) how would that work?

[aeastet]

You would have to change the dt in the wave for to the sample rate or you would have to plot on XY graph with the time intervals.

I added an XY graph see attached.

[acheung]

Oh alright I got it. For the array displaying the locations of the peak then, is there a way to make them correspond with those values on that graph.

[aeastet]

is this what you are looking to do?