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Need Working ECG circuit

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udhay_cit

udhay_cit

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Hello,
Please anybody provide me a proven and working circuit for ECG measurement. I want to see the ECG waveform using a DSO. I got lot of links from google search, but mostly theoretical or they points to another link.

Lot of INAMP datasheets are having ECG circuit but only partial. please provide me a working circuit including the filters & amp.

Thanks & regards
Udhay
 

:wink:
Take a look at the EEG amplifier channel:
modEEGamp-v1.0.png


http://openeeg.sourceforge.net/doc/modeeg/modeeg.html
 
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    elms

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    dselec

    dselec

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Hmm... great circuit.
anybody understand how it works ?
specially ic204 and whats expected to be at j201 ?
 

Hi my friends
Dear Udhay i hope there isn't any problem from your side that i have asked my question here in your thread .
In continue of dselec's question : what are the benefits of those transistors in that arrangement ?
By the way , a friend of mine told me , the right leg in our body can be considered as ground of our body . and we will have 12 leads of measurement . i designed a circuit ( subtracter amplifier with opamp and ( of course it was an active LPF too ! ) but i don't know why when i connected the electrodes into my right leg and my heart and the other leads , the waveform that i saw in my oscilloscope was awful ! it was alike with everything unless waveform of ECG ! where can be the problem ?
Best Regards
Goldsmith
 

Real-world ECG circuits, includes at input some circuitry protection devices ( i.e: Neon lamps ). The reason is the fact that ECG equipments are usually used toghether with External defibrilators at medical centers.


+++
 

Dear andre
Hi
Can you tell me , please why neon lamps in input ? and how ?
Thanks and Regards
Goldsmith
 

dselec said:
Hmm... great circuit.
anybody understand how it works ? specially ic204
Click to expand...
The input common-mode voltage is fed back via the IC204 amplifiers to the right leg of the patient for further 50/60 Hz noise rejection. This approach requires only a few micro amps of current. This current is used to significantly improve the common-mode rejection.
More details here:
https://www.ti.com/lit/an/sbaa188/sbaa188.pdf
 
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    dselec

    dselec

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Yes Texas show the cmrr output going to amp to compare with ref .
Now the circuit above show the leg output amp getting input from the wrong place.
 

There’s no connection error. The right leg drive amplifier provides a common electrode bias usually at Vref and feeds back the inverted common mode noise signal to reduce the overall noise seen at the inputs of the instrumentation amplifier gain stage.
c0886-figure1.gif
 
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    dselec

    dselec

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Hi, thank you for everyone. Please find the attachment & this is one i got from Texas Instrument Directly. I am seriously working on it & i will post the reply soon.

Regards
Udhay

- - - Updated - - -

Hi, thank you for everyone. Please find the attachment & this is one i got from Texas Instrument Directly. I am seriously working on it & i will post the reply soon.

Regards
Udhay
 

Attachments

  • Dry contact ECG.rar
    414.9 KB · Views: 137

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