EMG/NCV amplifier

Thread Starter

ajapyy

Joined Apr 27, 2013
6
hi everybody ;)
I want to design an EMG/NCV amplifier and search for it's circuit in internet.
anybody has data about my issue ?
EMG amplifier or NCV(nerve conduction velocity) amplifier ?
if possible for you, please send help for me ;)
with best regards ..
 

HadMatter

Joined Aug 16, 2009
11
Hey Jappy. I'm currently working on an EMG circuit for school, and have been spring boarding off of this design: http://m.instructables.com/id/Muscle-EMG-Sensor-for-a-Microcontroller/
It's pretty clear on how to assemble the circuit, although I wish it explained a little better about what was going on in each stage of the design. I'll go ahead and pass on some advice a grad student gave me, to replace the TL072 op amps with TLC2272(s) because they put less noise in the circuit. Also, full disclosure, my project is still a work in progress. something about the final filtering stage isn't working quite right, but it seems to be working up to that point . The people who wrote this instructable also sell ready made kits of this schematic on Mouser, so it's a reasonable assumption I've got something hooked up wrong or something.
 

HadMatter

Joined Aug 16, 2009
11
Update: Got this sucker working. I'm not certain what's going on with the low pass filter in the circuit in this instructable, but according to my calculations the resistor/capacitor pairing sets the cutoff frequency at 1.9Hz which seems decidedly low as it's my understanding muscle impulses fire at 7-20Hz. Maybe the TL072 chips have some characteristic that shifts that cutoff into a more appropriate range. Just be mindful of that one discrepancy and this should work just fine for you.
 

Thread Starter

ajapyy

Joined Apr 27, 2013
6
thank you for your feedback,
in first stage we are a pre-amplifier, then a filter and finally an amplifier.
have u schematic for stages which in understand how circuit work or can draw circuit in simulation programs such proteus and run it ?
 
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