How do you determine the distance between the QRS interval, as well as the time over that distance, in order to calculate a heart rate

[bmeecg]

Hi!

I have a continuous sample data acquistion VI created.  I collected an ECG signal from electrodes connected to an ELVIS unit.  Once I viewed my signal, I am curious to determine the heart rate.  I need to know how I can find the R-R interval, as well as the time over than span, so I can roughly determine the heart rate, continuously.  Each time a new ECG wave occurs, the heart rate should be modified automatically.  Some algorithm is required. 

Thanks!

[Neal M]

Hello bmeecg,

Welcome to the NI forums!  If I understand your question correctly, you wish to calculate the instantaneous heart rate from your ECG (the inverse of your R-R interval).  I would recommend using the Peak Detection vi (Functions Palette»Signal Processing»Signal Operation) to determine the location of the R wave (since it is the largest magnitude, you could set a threshold above your P and T waves so that it only picks up the R wave).  The calculation for time is in the detailed help for the Peak Detection vi (Ctrl+H»Hover over the VI»Detailed Help).

I also found this forum which has a VI that reads an ECG and then does a lot of analysis. Maybe this would help you out as well.

And just FYI, the Counter/Timer forum is oriented toward our counter/timer boards (e.g. the PCI-6602),  the Multifunction DAQ forum probably would have more of the type of people that could help with this issue.

However, please post back here if you have more questions about this.