So far as I know, a 12-lead ECG system is able to generate waveforms on Lead I, II, III, aVR, aVL, and aVF. A 5-lead ECG system is also able to provide all these information.
So what is the difference between a 12-lead and a 5-lead ECG system?
What are Lead I, II, III, aVR, aVL and aVF for?
For heart rate estimation, is it feasible to analyze Lead II only?
Thank you guys.

 

may be of some help http://www.bem.fi/book/ For HR only a 3 lead system is enough

 

may be of some help http://www.bem.fi/book/ For HR only a 3 lead system is enough

thanks, buddy...i will go through book......and still open for other suggestions.....thanks

 

S
For heart rate estimation, is it feasible to analyze Lead II only?

Yes. Are you looking for a circuit?

Ken

 

Yes. Are you looking for a circuit?

Ken

ummmm..... thanks for your reply...Im currently not looking for a circuit. I just wanna figure out how thing's working?

 

may be of some help http://www.bem.fi/book/ For HR only a 3 lead system is enough

Actually a three "wire" ECG input is needed...RA, LA, and LL. "3 Lead" is the clinical term for an ECG that reads "Leads" I, II, and III.

Ken

 

Actually a three "wire" ECG input is needed...RA, LA, and LL. "3 Lead" is the clinical term for an ECG that reads "Leads" I, II, and III.

Ken

True, but just looking at Lead II requires only two wires - RA and LL.

 

True, but just looking at Lead II requires only two wires - RA and LL.

Sort of true, but in the normal ECGs, a RL driver is included to reduce offset and environmental noise. They are a differential amps after all and need a reference. Not that you couldn't get by with just a ground and a signal input.

Ken

 

There's something confusing me. The output from a ecg monitor is just one waveform showing P,Q,R,S,T. But for a 3 "wire" system, there are 3 different waveforms for leads I, II, III. How do these 3 different waveforms add up together to produce a single waveform? And what about aVR, aVL and aVF in a 12-lead system?

 

ECG monitors can have one ECG tracing or multiple traces.
The different "leads" are just signals from different combinations of electrodes on the body connected to the three differential amplifier wires.

Google: differential amplifier

This is done by having multiple differential amplifiers, or one amplifier and switching in different electrode combinations:

Lead I: RA>LA referenced to RL
Lead II: RA>LL referenced to RL
Lead III: LA>LL referenced to RL
aVR: (LA+LL)>RA referenced to RL
aVL: (RA+LA)>LA referenced to RL
aVF: (RA+LA)>LL referenced to RL

Did you read chapter 15 in the link that t06afre posted earlier? If so, was it too complex to grasp?

Ken

 

You may also try Google for more information. But as far as I know the link I gave you is one of the best free (and legal) Ebook on this topic.

 

Thank you guys. I will do some more research on my own. With your help, I have a better understanding now.