Oscilloscope for EMG signals

[adrianvon]

Hi all,

I am looking for an inexpensive USB oscilloscope for analyzing EMG signals.
I found the Hantek 1008A which is an 8CH USB scope. Is this scope good for my application?
I know that this scope is used for vehicle testing, but since it is inexpensive and has 8CH (i.e can monitor multiple signals simultaneously) I thought it would by a good option.

Any kind of help would be highly appreciated.

 

[adrianvon]

Any suggestions please?

 

[JimB]

Excuse my ignorance, but what is an EMG signal ?

JimB

 

[Mikebits]

I was wondering the same thing.

 

[adrianvon]

Thanks for the replies.

Electromyography (EMG) is an electrodiagnostic medicine technique for evaluating and recording the electrical activity produced by skeletal muscles. (Wikipedia)

 

[adrianvon]

The typical EMG frequency around 20 to 2000Hz and the amplitude in the uV and mV range.

 

[Mikebits]

Well in that case, it sounds like you will need a very high quality scope. Many low cost scopes on the market today have internal noise that will be in the range that your scope needs to monitor. For measurements in the amplitude range you have mentioned will require a high quality scope, and it will be expensive. I have a Hantek bench scope and it has inherent noise that would make the measurements you require impossible. Your best bet is to purchase a used analog scope that will have very low noise in the amplitude range you need. I have seen good analog scopes as low as 50 dollars.

 

[JimB]

My thoughts are that you will need some kind of signal processing before the scope input.

An amplifier to amplify (obviously) the small signals from the muscles etc, and some filtering.
A lowpass filter to cut the HF noise above 2000Hz
A highpass filter to cut the LF noise below 20Hz ? Not sure. There maybe useful signal information way down there.
A notch filter to remove 50/60Hz mains supply noise.
Also, a reference input connected to reference electrode on the "patient" which can be used to subtract general noise from the wanted signal, as frequently used in ECG (ElectroCardioGram) type equipment.

How well the Hantek will perform with multiple inputs, I do not know, maybe it will be OK at the low frequencies that you will be measuring.
But without some processing between patient and scope ? ...
Probably no chance.

JimB