Im familiar with the idea of capacitive coupling to human body acting as antenna to ambient 50Hz or 60Hz AC electric field only. When you are using an ECG. There is a third electrode that cancels the common mode noises such as 60 Hz AC from capacitive coupling to your body which acts like antenna. Id like to know up to what frequency does it hold true if the source is artificially made on purpose for transmitting to body?

And how can you create source of capacitive coupling via some kind of transducer where audio is converted into it so you can use ECG modified for audio frequency to receive it via electrodes to body

I know at some frequency, the magnetic field and electric field couple into narrow beam electromagnetic field, and you can't separately measure the magnetic field (say using an EMF meter). In capacitive coupling, what frequency before the electric field can no longer couple to the body acting like antenna. 5kHz? 3kHz? what?

Is it really possible for the body to get this 5kHz (etc) capacitive coupling frequency? If yes, then we can easily build a circuit similar to ECG/EKG (with isolator and worn like watch) where electrode with differential inputs will measure the capacitive coupling and convert it back to music.

Has this experiment been tried before?

 

What would be the sense organ for demodulation to sound for this injection of electrical energy?

 

What would be the sense organ for demodulation to sound for this injection of electrical energy?

The skin or all part of the body just like you can put ECG probe anywhere and where you dont use the Right Leg Drive electrode, you get 60Hz interference.

 

The skin or all part of the body just like you can put ECG probe anywhere and where you dont use the Right Leg Drive electrode, you get 60Hz interference.

Why do you think that skin can 'hear'.

 

is it not when you put ECG electrodes on the skin, you can measure the 60Hz ac electric field where the body acts like an antennae if you dont use 60 Hz filtering?

 

is it not when you put ECG electrodes on the skin, you can measure the 60Hz ac electric field where the body acts like an antennae if you dont use 60 Hz filtering?

A block of pure carbon has the same electrical properties. Yes, you can detect the electric field if you inject it into skin but why would you do that at some audio frequency in this experiment?

 

Welcome to AAC.

Im familiar with the idea of capacitive coupling to human body acting as antenna to ambient 50Hz or 60Hz AC electric field only.

This is mistaken. Capacitive (and inductive coupling) are distinct from the sort of electromagnetic radiation that involves an antenna.

It would be very helpful if you would clearly state your goal. The description is very muddled. You don't want to eliminate common mode interference for example, so just don't mention it. What does and EEG have to do with your question other than suffering from interference from stray fields?

Drop all the stuff that inspired the question and ask it directly. "Is it possible to build a device that..." or something that doesn't require mind reading and untangling. It is much more likely to get you an answer.

On the mind reading front:

...measure the capacitive coupling and convert it back to music.

If you are hoping to make some sort of odd wireless headphones then 5kHz is a useless frequency, that's barely able to cover HD voice. There are other problems with this idea as well. But, this is pure speculation. Please make this more clear.

 

Usually ECG/EMG has frequency limit of 100 Hz or 250 Hz. So i'll increase the frequency limit to 20kHz. So it can measure the capacitive coupling of 1 of 20,000 kHz that will be send out by another device to the person. After the 1 to 20 kHz ECG-EMG like device has received the signal. It would be played in Audacity where you can hear the sound back, or after conversion.

The above is just to understand the concept if it can work. I won't actually build it if the capacitive coupling source of 1 to 20kHz needs to be big and dangerous. I know there would be no practical application.

 

I'm also unclear what you are trying to do, but in theory any AC frequency can be capacitively coupled from one node to another. In ECG equipment, low-pass filtering is used to severely limit or eliminate unwanted frequencies.

 

Usually ECG/EMG has frequency limit of 100 Hz or 250 Hz. So i'll increase the frequency limit to 20kHz. So it can measure the capacitive coupling of 1 of 20,000 kHz that will be send out by another device to the person. After the 1 to 20 kHz ECG-EMG like device has received the signal. It would be played in Audacity where you can hear the sound back, or after conversion.

The above is just to understand the concept if it can work. I won't actually build it if the capacitive coupling source of 1 to 20kHz needs to be big and dangerous. I know there would be no practical application.

What will you do about the 50/60Hz noise that is ubiquitous and often quite powerful?

Aside from this, there are far too many questions that aren't answered. What would you do with this arrangement, chief among them. Asking "in principle" questions can be useful if there is otherwise a framework understood by the questioner—but you don't seem to have that.

A lot of questions are answered/answerable if there is an actual goal (e.g.: what distance does the transmission have to go?, what will be done with the signal after it is received?, &c) that have no answers here, and—so far as I can tell—could only be answered with arbitrary placeholders because there is either no real plan for a practical implementation, or it is being purposely obscured.

I would suggest you take a look at IEEE 802.15.6 and WBANs, along with medical HBC for a place to get some information that might be relevant. But the current question is just not answerable in any way that is useful.

 

I'm also unclear what you are trying to do, but in theory any AC frequency can be capacitively coupled from one node to another. In ECG equipment, low-pass filtering is used to severely limit or eliminate unwanted frequencies.

Completely true—of course, there are issues of passband based on what it is being coupled to. But in the sub 1MHz range, the human body is probably not a frequency response issue.

I would expect that if you want the 20-20KHz audio band you'd be best off modulating a carrier of three or four times that to avoid the low frequency noise that would otherwise fall into that range.

On the other hand, "why do it?" looms large...

 

I just want to understand what unique noises can occur. I know someone who has adjusted the ECG/EMG to get higher frequency like 10kHz. And she claimed to measure signal above those possible from muscles and heart. So I figured she must be ignorant and instead measuring noises. So I want to know if an ECG/EMG can pickup say 800 Hz noises from capacative coupling that is 800 Hz. I know 60 Hz noises are all around. But can you actually create a capacitive coupling to human body of 800 Hz? How just a rough idea? And if so, can an ECG/EMG that is set to higher frequency can measure it? If yes. I can understand how she made the mistake.

 

I just want to understand what unique noises can occur. I know someone who has adjusted the ECG/EMG to get higher frequency like 10kHz. And she claimed to measure signal above those possible from muscles and heart. So I figured she must be ignorant and instead measuring noises. So I want to know if an ECG/EMG can pickup say 800 Hz noises from capacative coupling that is 800 Hz. I know 60 Hz noises are all around. But can you actually create a capacitive coupling to human body of 800 Hz? How just a rough idea? And if so, can an ECG/EMG that is set to higher frequency can measure it? If yes. I can understand how she made the mistake.

This doesn't comport with your question, which specifies music, nor does it make any sense considering that you've ask this same question on an audio forum titled "Capacitive coupling music" where you said "my company is thinking of this innovation". Based on this, I am going to retire from this thread as I don't very much like being lied to, and it was already of extremely marginal value.

 

Well. I'm not lying to you. I mean. Soundonsound is a music website. When I asked electronics questions there. People kept asking what is my goal. So I have to say my company is thinking of the innovation.

My real goal is to understand if you can capacitive couple higher frequencies into the body. If yes. Then it explains how someone I know got duped. And of course if it is possible. It is intriguing if music can be made to transfer via the body. So asking about music can be a good punchline esp if you are in the music forum.

Look. When you touch your cellphone touchscreen. You use capactive couple. I heard this is called intra-communication.
Anyway. Someone just please answer this direct question.

Can the body be capacitively coupled in the audio frequences of 1 to 20 kHz?

If yes. Then if the ECG/EMG is set for audio range. Then it can decode it from the body, right?

If yes. then I can understand how someone got duped into thinking she was getting high frequency signal right from the body. Please let me know. Thanks!

 

If you want to split hairs and call what you told us obfuscation (I will still call it lying in context), you just told me you outright lied to them. Why should it matter to me whether the lie was to me or someone else? When a person chooses to manipulate others with falsehoods, I have found, I have no reason to expect they won't do the same to me.

Your question was already a familiar tarpit of tooth-pulling interaction.

Sorry, I'm done with it. No personal enmity involved, just practical self defense and, of course, I get to choose which threads I will participate in. If others want to continue, that's their choice, just as this is mine.

 

im not lying to them either. if a product is novel and has potential like the first capactive screen ipod, then marketing in future is part of anyone idea.

 

The AC line frequency is coupled to the body because the body is surrounded by wiring carrying high currents at that frequency.

Sure, could do the same with audio frequencies by surrounding the body with wiring carrying large currents at audio frequencies.

You could also pick this signal up by attaching an electrode to the skin. You would need a ground reference as well to get a good signal.

As a method of wirelessly transmitting audio programming to a person walking around the room, though, it would be far inferior to methods already in use, notably radio.

 

cant any low current source or configuration cause it too? I think Science Center should have something to demonstrate it.

 

hi Fz,
Have you seen this link?
E
https://www.google.com/search?clien...AHZdSAzIQzmd6BAggEAY&biw=1135&bih=637&dpr=1.4

 

cant any low current source or configuration cause it too? I think Science Center should have something to demonstrate it.

Yes, but with a much lower and noisier output.