how do I detect onset in PPG data?

I am working on queensland vital sign database. I have divided the pleth data into one minute segments for each case. Now for each minute I need to do onset detection however I am unable to do so.

[Ram Krishnan]

I am also looking for a way to do this (for PPG-to-blood pressure algorithms). Here's an algorithm from Harvard that might be useful:

"An open-source algorithm to detect onset of arterial blood pressure pulses" by Zong, et al

It's written for arterial BP which has a much bigger amplititude than PPG but that should be a matter of scaling. The fundamental ideas should still be applicable.

Answer 1

[Star Strider]

Without knowing the details, there are several functions and approaches that can be used to detect the onset of each pulse (assuming a flat, detrended baseline).

Using findpeaks on the negated (‘inverted’) PPG signal is one option.

The findchangepts and islocalmin functions may also be appropriate.

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