need help

[Coq_Rouge]

here is some info http://www.bem.fi/ click on the red book icon Malmivuo and Plonsey: Bioelectromagnetism

[muskan]

one q. is... in 12 lead ecg. if we are considering the o/p of lead v1... then what about other leads... what happened with other voltages???????

[Fianlor]

Here's a good place to start on 12-lead ECG theory:

http://library.med.utah.edu/kw/ecg/ecg_outline/Lesson1/index.html

And here is an excellent textbook:

"Rapid ECG Interpretation" by M. Gabriel Khan, Humana Press, 2003, ISBN978-1-58829-979-6

[Fianlor]

My suggestion is to start your work with 2-lead ECG. You have simply one "+" and one "-" lead, which you can place in either the classic Lead I or Lead II positions. You can read about these at Wikipedia by searching on "ECG" at that web site. Once you have that working, you can start adding other leads. Each new lead simply gives you a different ECG waveform shape, as each lead is being placed at a different location on the body.

[Mindaugas]

12 lead EKG is rarely used for monitoring purposes. It is mostly used for a diagnostic "snapshot". Even then most EKG recorders record not more than 6 leads simultaneously. 12 leads refer not to electrodes but to their combinations- 6 limb leads I, II, III, AVF, AVL, AVR and 6 precordial leads (V1-V6). There are 10 electrodes- 3 limb (LA, RA, LL),  ground (RL) and 6 precordial (V1-6). You should revisit your application requirements/purposes. For monitoring we commonly use 3 electrodes (LA, RA, LL) or 5 (ground and one precordial- commonly V5). With 3 electrodes you can register all limb leads (I=RA-LA; II=RA-LL, III=LA-LL, AVL=(RA+LL)-LA and so far). With 5 electrodes fourth is used for ground and fifth- for precordial lead. Most of the monitors have one or two EKG channels with selectable lead. If your task is however to obtain 12 lead EKG remotely, then you will need transmit all 12 leads (6 at a time) for about 5 seconds each chanell. Please note that fidelity requirements are much different for monitoring and diagnostic purposes.

[Coq_Rouge]

I must admit I have problem to see what you will gain with a 12 lead system. As posters before me have said a 12 lead system is only used by trained cardiologists. 12 lead systems is not very common in the ICU, or during surgery. A 12 lead system will add a great deal of complexity to your project. And from your previous postings I do not think you have the needed skills or competence to do such a project yet.

[muskan]

i have to work with diagnostic ecg... i know its very complex and difficult... i cant work with 2 lead because of shortage of time and instrument, my teacher gave me 12lead ecg simulator... now i have to make a lead selector actually... my idea is to use a MUX ic, whose selection will be done by parallel port... and the programing of parallel port will do in labview... can i use mux?

any give me literature on stereo cable? as stereo cable has 3pt. 1is ground 1is positive and 1is negative potential... i want to know its working...

[muskan]

hello!

can v acquire triangular & square wave using sound card?

my mother board has built in sound card having D955XBK no.

[muskan]

hi..

v r giving a triangular wave signal thru sound card..does the ADC resolution  of sound card will affect the aquired signal? how?

can v improve the resolution in labview?.. it is to b noted that v r not using DAQ..

WAITING FOR RESPONSE

REGARDS

[Coq_Rouge]

First of all Muskan. Please use proper English. This is not SMS so you can write normal English. Then using sound card or any other A/D converter unit so is it important to use the full range of the AD converter. That will give the best result. A good thing with sound cards is that they have digital controlled amplifier so you can easy adapt the input signal to the range of the AD converter. Many modern sound card do also use AD converters with digital filters. A square wave with its steep flanks may cause artifacts in the filtering process even if the frequency is low. So a sound card and square wave is not a good match. It is in fact hard reproduce a proper square then sampling it with any DAQ equipment. Working with triangular and sine waves are much more easy. Another important factor is the signal frequency and the sample rate. Can you tell us which values you have for the latter mentioned signals. You should also post some screen shoots describing your problem, and your code. If not we can not help you.