Recent content by Photo1234

I do not know that. I have never read physiology literature and frequency in that regard. And if this sine waves from ECG are only mathematical process how can we get rid of them with filters? Makes no sense to me.

Yes of curse I know the rhythm and basic physiology behind it. I was not asking abaut physical meaning of classical ECG, but about the frequency "spectrum". So following this logic without Fourier transform we could not "know" frequency of ECG?

But ECG is technically is not spectrum(doesn't measure EM waves). When we have waves is easy to know what frequency means. With Fourier analysis, we can write any function as a sum of sin waves, if I understand that correctly, so ECG can be as well. Is the frequency of these waves the frequency...

I am undergraduate biologist, I think I know the basics of bioelectricity, I do not know much about signals and I know Fourier series very superficially, I just know some basic ideas, almost no concrete math.

But which events? Atrial contraction and ventricular contraction happen with the frequency of the heartbeat. Maybe on cellular level?

Yes, that is what I was asking about. But what is a physiological source that of an ECG that has frequency? Heartbeats have a frequency, but that is not the frequency of ECG. I look a bit more and it seems to me that the frequency is the frequency of ECG analyzed with Fourier transform. So is...

Example:

Yes but this is EEG, not ECG.(I am asking for ECG which measures heart, EEG measures electrical activity of the brain)

I was studying ECG measurements and come across the frequency of ECG. I couldn't find for sure the frequency of what this is? Is it the frequency of sampling(times of measurement) or is it something else?

I found the video where guy mesures electric field with oscilloscope(start at 1.45) of the plasma ball. So is this possible because plasma has AC current or would it work with Van Den Graaf also?

I do know the exact procedure that you do, but if I undestand correctly you say that if we have a charge on Van de Graffs generator of let say 1nC and we measure the potential using votlmeter at 1 and 5 m voltmeter would show 7V?

So will they? Do you have voltmer and can test that?

I am asking this from theoretical point of view. And the quetion I had was basicaly does oscciloscope or volmeter meassure voltage created from static charge at two diffrend distances of this card ,(Calculated V=Q/4*pi*e0*r) and the answer in as I understand pretty much no.

So technicaly osciloscope or voltmeter measure only voltage where current is possible? If we try to measure 12 V battery with either one we get result, but if we have have for example Van de Graaffs generator with a lot of voltage, than the metters wouldn show anything or very little, altrught...

If we have a point charge of significant value, would osciloscope measure voltage if we just point the electrodes in two diffrent point in space?