How to count the analog input pulses,measure the pulse width, determine the mean value and the rms value of the pulses?

[Veronica]

Hi, i'm new user of LabVIEW. My concern is about how to count the analog varying pulses which generated by our muscle contraction? Besides, i want to measure the pulse width and determine the mean value and rms value of the pulses. Here i attach with my signal example. Is the counter function can be use? Is the counter only receive digital pulse? Anybody can help me? Give me some direction? Is there any example for me to refer? Need help urgently 😞

[TylerS]

Hello Veronica,

What kind of hardware are you using to acquire the signal? The counter functionality is only for digital pulses, so that won't be of use to you. I think the VIs you'll want to use are under All Functions>>Waveform>>Analog Waveform>>Waveform Measurements. Here they have VIs you can use to measure RMS, amplitude, and a number of other characteristics of a waveform. As for example programs, take a look at our example finder (Help>>Find Examples) and look under Analyzing and Processing Signals>>Time Domain Analysis and see if some of those might start you in the right direction.

TylerS

[AAABBB]

Proper EMG analysis depends on what information you wish to extract. A simple surface EMG analysis would go something like this:
1. Full wave rectification (Functions -> Absolute Value)
2. Create a linear envelope - for example by passing data through a low-pass filter with a low cuttoff (ie Butterworth 2-5 Hz) (Analyze -> Signal Processing -> Filters)
3. Integrating or finding max of each contraction.

Or perhaps you are actually looking to extract the frequency content from your EMG - in which case there areSpectrum VIs under Analyze -> Waveform Measurements.

John.