I am trying to generate ecg waves in both glcd and cro. My glc part is over, can any1 tell how to generate ecg signal using dac which can be given to the cro.?
.. there is no safety issues
generate ecg signal using dac it this REALLY what you want to generate ECG waves e.g. to test a cardiac monitor? or do you want to read them.
YES, I can read, but generating ECG waves, as opposed to reading them sounds strange. Thus this request for confirmation. We have had threads that went on for days before it was resolved that there was a linguistic misunderstanding.
Erik
Yes to generate ECG signal to calibrate the equipment n to study it
You take a human. Most ages should work, but history has shown that humans younger than 5-7 years so often have excessive amounts of extra humans (called parents) around them. Humans older than 80 should also be avoided, since they so often produce unreliable results. Sometimes, they have a huge jitter in their produced data. And sometimes, they just stops working permanently.
Connect a couple of wires to the chest area (this is a situation where female humans may pose a problem because of excessive bulging). At least two wires should be used, and the cable should be twisted to reduce noise pickup. It might actually be a good idea to go for three cables to not only get a differential input put also get a good ground reference.
As long as water and food is supplied regularly, most humans should now be able to produce ECG waves for quite a long time. Tickling them, or placing them on some kind of belt with configurable speed, it should also be possible to adjust the frequency of the ECG. But please observe the absolute maximum ratings in the datasheets before doing this, since too high loads will result in a lot of huffing and puffing and might let out the magic smoke. At best, this will just generate irregular, substandard, signals, but can result in permanent damage to the signal generator or even prematurely end the signal generator.
It has, by experiments, been found that humans are quite sensitive to electricity. Even currents below 50mA may result in permanent failures. Since the electrodes used are eletrical in nature and normally mounted with some form of grease for lowest possible resistance, it is best to isolate the measurement system from external electrical components. Batteries works quite well for this. For more permanent solutions - especially for long-term data logging - opto-isolators are recommended. After a couple of accidental failures, the rumous tends to spread, making it very hard to get access to new test subjects. So always try to get as much mileage out of a test subject as is possible, by being careful.
A neat trick while testing the setup is to make use of a TV, and try different channels. It has been found that watching drying paint^H^H^H^H^H^H^H^H^H^H^H^H cultural movies will result in a lower ECG frequency, than channels showing more mature (XXX) material.