I'm working on a 12 lead ECG device based on Wilson Network. I have made the filter(3-lead) circuit which is giving fine output. But when I integrate that with my wilson network+lead selection circuit and test the output there is a lot of noise and no clear curve. I cant understand where is the flaw in the entire system.I suppose it could be something related Right Leg drive so I wanted to be clear what exactly it is and also I'm giving WCT+RL to the negative terminal of filter along with precordial leads on the positive. Should I give a single WCT or is RL necessary to be added to WCT(wilson central terminal), which i once read somewhere that it is. Please Help.
I don't fully understand the background to the question but I gather that RL is the reference to each of the signals making up the WCT.
Presumably you have designed the filter network to load the leads equally or have used an amplifier to isolate the impedance networks from each other?
Have you designed notch filter to isolate power line interference??
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Without the RL driver, your interface is completely high-impedance. Which makes it susceptible to all kinds of noise including CM noise.
The 'trick' with the RL driver is to create a path of low(er) impedance. This path in effect results in a reduction of common mode voltage(s) - including any noise - while the 8nputs ar3 still h8gh-impedance.
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Hello,
Of course, this is difficult for people who are not familiar with electronics.
Wilsons' network is giving us only a reference point by using the sum of the three frontal limb leads
The driven right leg connection is a negative feedback reducing the noise and common-mode interference by providing a virtual ground potential. You may find a more adequate explanation in "Medical Instrumentation - Application and Design" by Webster on pages 316 - 320 (2nd ed. 1992). RL is needed for all leads.
@thomas peter dye, WCT is the reference point for measuring all the pre cordial leads(V1-V6) and RL is added to the WCT . My question is why do we need to add RL to WCT ?
@ manpreet kaur aneja, No i havent as i have kept my frequency range below 50 Hz( 0.5-44Hz).
@ MOHAMAD ARINAL BIN ABDUL HALIM ·, thankyou sir i appreciate the effort however I'm aware of how to connect the leads and what does each indicate. My question still remains unsolved.
@ U dreher, I'm afraid i did not fully understand the concept of impedence here
@ Roland X Stroobandt, Sir I know the what , I'm looking for the whys and hows. Thanks ery much for the reference text.
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