Hello,
I am acquiring a pulse signal using DAQ unit and filtering that using digital filter from here http://wwwp.cord.edu/faculty/jensen/LabVIEW/Simulations/Simulation%20Pages/DigitalFiltering.html . The filter cutoff frequencies are set as 1Hz and 11Hz , but here I don’t understand why the output of filter(image attached) shows the frequency of 0.9Hz (sometimes 1Hz) which(0.9Hz) should be actually filtered by the filter as the higher cutoff frequency is 1Hz(0.9Hz<1Hz).
In general, the heart rate (BeatsPerMinute) is calculated from pulse signals i.e., by calculating number of beats measured in 1 minute.
So, to calculate the heart rate
1) What values of lower and higher cutoff frequencies should be provided as input to the filter (currently using)
2) But the pulse signal will be having harmonic frequency components as shown in the attached image(multitone).which value of frequency from these frequency components(measured using multion tone) should be used to calculate heart rate form incoming pulse signal.
3)Is there any other filtering method other than the one currently used to get the heart rate.
Can someone help me with this.
