How to capture external signal with labview

[integralx2]

This is probably a noob question, which I cant find the answer too. But, I have an EMG signal, and I would like to filter it. How can i connect it to my computer so labview will capture the signal ? Should I use an RS-232 cable , or the audio port somehow? Any help would be great.

[Steve.J]

You need to figure out how (if) the EMG instrument that you are using has some kind of output compatible with a PC or an analog output that can be digitized by a PC DAQ card.  Many instruments have a "live" analog output that is isolated from the patient and ready to be connected to a recorder or DAQ card for monitoring on a different instrument, PC, or for saving and post-processing.  This is the simplest and most flexible way to get the data into LabVIEW.  A serial port (or some other digital port) is also common, but usually more complex since you then have to understand the protocol used to communicate with the instrument and parse the data.

[cirrusio]

integral,

Can you be more specific?  What kind of signal is EMG?  Is this related to a particular device?  What are the available outputs on the device?

Cheers, Matt 

[TCPlomp]

For such a task you will need some kind of digitizer.

(almost) Every computer has one, the mic input. However these are not very reliable and I suspect the EMG signal is very weak.

I would advise you to get a sensor/transducer that outputs a signal in the volts range and get a DAQ (Data AcQuistion device).

National Instruments has a wide range of these instruments, but they can be pricey, another option is Easydaq which are cheaper and come with a labview driver as well.

Ton

[integralx2]

What I plan to do is amplify the signal of the human using an AD620.  Then I will pass it through a high pass filter. I would like to then feed the signal of mybreadboard into the computer. The signal should be about 1V in amplitude. This is what I plan on doing, and how should I approach the problem ?

[Coq_Rouge]

What is the bandwidth of the signal you are interested in. You could perhaps use a sound card. If this is non commercial application. A good 24 bit sound card will work very well in the audio range. And cost far less than NI DAQ card.  

[cirrusio]

Depending on bandwidth and resolution requirements, there are some cheap options out there starting at around $160 (for a 12-bit USB DAQ) that you might consider if the mic input does not work out.

Cheers, Matt 

[integralx2]

The signal range is from 50hz up to 2k Hz.