topic Re: heart rate in Life Science

heart rate

brian1 — Fri, 16 Feb 2007 04:41:44 GMT

Hi,
I implemented a circuit which shows up heart beats using the electret microphone on the Oscilloscope, My point is that I want to show the heart beat using labview which i can do but I want to calculate the number of beats per minute, is there anyone who can help me out in this issue.
Brian

Re: heart rate

devchander — Fri, 16 Feb 2007 12:18:27 GMT

would not peak detection do??

what sort of a waveform does the voltages given by the "electret microphone" make on the scope??

Re: heart rate

brian5 — Fri, 16 Feb 2007 15:30:42 GMT

The waveform given are the PQRS wave form.

Re: heart rate

devchander — Sat, 17 Feb 2007 06:33:43 GMT

Ok then, detecting the Peak in QRS comlpex should do.

Depending on what rate you want to update the heart rate display, acquire samples in that time span and perform a peak detection on those samples.

Re: heart rate

brian4 — Wed, 07 Mar 2007 23:43:10 GMT

Hi Dev,

I am not able to figure out how to do the code using the peak detector circuit, can you please send me the simple and basic code for the heart rate calculation.

Re: heart rate

devchander — Thu, 08 Mar 2007 09:40:30 GMT

In the Examples shipped with LabVIEW, you will find an example vi called 'Advanced peak detector'

Go to Find examples>> search and find this vi

Additionally LabVEW has a function called 'Threshold peak detector' you could use it as demonstrated in the attached vi, to detect peaks in an acquired waveform and determine the heart rate

Acquire waveforms every second at a suitable sampling rate and find the numper of peaks in each second's data and determine the heart rate

Re: heart rate

Pawz — Mon, 04 Feb 2008 16:16:34 GMT

hi.., is this thread still active? I have same issue. I 've connected my microphone and labview acquire the sound from the mcirophone jack on my soundcard.. But firstly my vi's that i designed, is for recorded heart signal. The sound that i record comes from stethoscope that connect with electret microphone. Vi's can count the peak. but i cant count them as bpm.
Is there anybody can solve my problem?

Re: heart rate

stanthetiger — Tue, 05 Feb 2008 21:53:04 GMT

Hi Paws,

The Threshold Peak Detector VI also returns an array indices where the peak occurs. You should be able to do some sort of computation on the array indices to calculate bpm.

Regards,
Stanley Hu
National Instruments
Applications Engineering
http://www.ni.com/support

Re: heart rate

marp84 — Mon, 30 Jun 2008 22:13:39 GMT

hi bro can you give some theory of ecg, maybe in the formulas or the flowcharts of the processing signal ecg ?
tanx before