real time signal processing..moving window concept..

[rueter]

I am using labview 6.1 and wish to perform REAL TIME processing of biopotentials taken in a "moving window" ... where do I begin?...I have t done real time processing before and my assignment requires the waveform in the "window" to be subject to certain measurements, such as the time instant when the peak is highest..etc...What is the best approach for real time processing and what ways are there for implementing the moving window concept? I am using a DAQ for data capture..

[Robert_Jackson]

Reuter,
I assume you are using LabVIEW to perform this analysis. Peak detection, FFT, and hundreds of other analysis features exist with LabVIEW. You have a few options. First with LabVIEW 7.0 Express, there are several analysis express VIs that will allow you to select the type of analysis you want such as peak detection and generate the code necessary. In LabVIEW 6.1, a set of analysis VIs exist in Functions>>Analyze>>Signal Processing. Specifically the Time Domain palette inside of Signal processing includes a Peak Detection VI. These analysis VIs are not available in the LabVIEW Base package. If you have LabVIEW Base feel free to contact a Technical Representative and discuss options.

Regards,
Robert Jackson
Application Engineer
National Inst
ruments

[rueter]

Hello Robert, thank you for the response. I am using LabView 6.1 and 6062E DAQ. What I am trying to perform is capture the signal at an input port in REALTIME and display it (the vi is meant to act like an ocsilloscope) but I need to access each point point-by-point (I need control over every point that is captured - enabling me to subject it to more than one constraint. What I mean by constraint is if the point captured at any time instant (say y value at time instant 32 is 5volts) would need to be subject to parallel tests - one would be to determine it it crosses a certain threshold value, also if the signal comes into this loop then it may need to be subject to another test that determines the duration for which the incoming signal was above the thr
eshold value etc.

I realize "real" real time cannot be achieved with Windows OS and I have looked at the VI s you have mentioned, but my question is how can I perform realtime point-by-point signal capture without any buffering so that I capture a signal and let it run on a chart (like an ECG Monitor beside a patient bed)

I have attached a vi that is supposed to perform a threshold detection - and give out a beep if a spike is detected - but I dont have it right.
Thank you, Rueter.