PPG input file (array) what information or data ?

[saranzeb]

i am really looking for some simple answers 1) what should be the form of our input data (arrays) which we are going upload to hp .load or hp.get_data. either its shoud be the BVP values with timing information ? the instananoes time of the bvp readings or the total time of BVP reading,i.e the total timing of video or window size ?,because from PPG signal we can have only these two Readings (information) BVP values and time right? they shoud be both in same file like two arrays of BVP and time 2) secondly i am not getting the sampling rate here it will be depending on what how we will choose it ?

[paulvangentcom]

Hi Saran,

1. The form of the input data should be BVP values. When processing the data with heartpy.process() you specify the sample_rate which encompasses the timing information. If you do now know the samplerate but have a timing array, you can compute that with the get_samplerate_mstimer() or get_samplerate_datetime() methods.

2. The sample rate is very important to specify correctly, as it reflects how the heart rate is spaced over time. Without this value the analysis is not possible. Refer to the above methods if you have timer data but no sample rate, for methods that can help you compute it.

-Paul

[saranzeb]

Thank you sir for detailed answer it will be great if you can provide some files (BVP and timing ) with code so I can try them first and then can relate to my files, as i will be able to check the values and format . in my case I am trying to give Just the BVP file from VIPL_HR dataset and a random sampling rate, to the heart.py process (BVP) as I have just the BVP file and want just have a try but its gives me this error

''Could not determine best fit for given signal. Please check the source signal. Probable causes:

• detected heart rate falls outside of bpmmin<->bpmmax constraints
• no detectable heart rate present in signal
• very noisy signal (consider filtering and scaling) If you're sure the signal contains heartrate data, consider filtering and/or scaling first''

my BVP file is a reading of just BVP values from VIPL_HR dataset and its just an array of 2084 values saved in excel file which is the BVP values of a sample. Along with it i also have a video of 41 seconds, and a heart rate of 37values taken per second for the same sample , as i am calculating the heart rate in (bpm) from video so for that I also need the heart rate from these BVP values which i can compare with heart rate from video and for video i have to calculate the heart rate in bmp too in the same way.

[paulvangentcom]

There's example files included, you can use the method load_exampledata() to load these

See the quickstart here

Or the api reference for the method here