How can I catch heart beat signals?

[Nate Duong]

Dear everyone,

I am thinking about what know of machines in RF lab can catch heart beat signal,

In the RF lab with spectrum and network analyzers, also have Function generator and more.

They are just working on signal with high frequencies, but heart beats are very low frequencies about 1.17 to 10 Hz.

Any ideal, everyone?

Thank you.

Regards,

Nate Duong.

 

[Nidum]

(1) Using medical blood pressure / heart rate monitors . Detect actual pressure pulses . Either buy one or adapt well known technology .

(2) Using ECG . Detect electrical activity from heart beats . Again well known technology ,

 

[Nate Duong]

that is a good ideal, but in this case, I would like to collect signal with wireless, medical blood pressure / heart rate monitors are using cable to connect to body.

Do I need to amplify signals?

 

[Nidum]

You might find some interesting ideas here :

https://www.google.co.uk/search?q=r...&oe=utf-8&gws_rd=cr&ei=fh62VcLnL6i17gamq6TYBw

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1033047&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1033047

 

[berkeman]

in this case, I would like to collect signal with wireless,

You might find some interesting ideas here :

https://www.google.co.uk/search?q=r...&oe=utf-8&gws_rd=cr&ei=fh62VcLnL6i17gamq6TYBw

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1033047&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1033047

It looks like those sensors still need to be in contact with the body, and then they transmit their data wirelessly.

Check out this totally wireless, non-contact RF detection of heatbeat: http://www.omnevia.com/sega_node_lifedetector.php

It was invented by a company that has PF'ers working on it...

(BTW, their technology is very proprietary...)

 

[tech99]

Dear everyone,

I am thinking about what know of machines in RF lab can catch heart beat signal,

In the RF lab with spectrum and network analyzers, also have Function generator and more.

They are just working on signal with high frequencies, but heart beats are very low frequencies about 1.17 to 10 Hz.

Any ideal, everyone?

Thank you.

Regards,

Nate Duong.

The simple pulse monitors that you can buy seem to shine two wavelengths of IR through the blood vessels in the finger etc, one absorbed by haemoglobin and the other not. We use this system with a data logger.
If connecting any electronics to the body, there is an obvious safety issue because the connection might be low resistance and the electronics might generate fault currents or leakage currents. For this reason, I think it is only possible to use approved equipment.

 

[William White]

There is some very promising work that uses ultra-sensitive digital cameras to measure the change in colour of the face
Eulerian video magnification

 

[thankz]

did you ever consider a ni daq card with an op amp front end, I'm petty sure (but don't quote me) you can capture in labview and send your data to MATLAB for dsp processing of signals, I actually plan on doing this, got two books one on electrophysiology and one on the dsp processing of electrophysical signals/impulses.

 

[berkeman]

did you ever consider a ni daq card with an op amp front end, I'm petty sure (but don't quote me) you can capture in labview and send your data to MATLAB for dsp processing of signals, I actually plan on doing this, got two books one on electrophysiology and one on the dsp processing of electrophysical signals/impulses.

Do *not* connect a standard data Acq card to electrodes on a human body. That is just way too dangerous. Use the IR technique mentioned by tech99 so that you do not need electrode contact with the human skin. Before you can do anything with electrodes on humans, you better read and understand the electrical safety considerations that require special types of circuitry to be used. See UL 544, for example.

If connecting any electronics to the body, there is an obvious safety issue because the connection might be low resistance and the electronics might generate fault currents or leakage currents. For this reason, I think it is only possible to use approved equipment.

 

[thankz]

if I got a usb daq what do I need besides usb opto-isolation, crowbar circuit, current limiter, and gfi with transformer isolation. run the daq off a batt with ic regulator too. ?

 

[Nidum]

Pick up beats as sound with a microphone .

 

[thankz]

yea but I'm trying to measure electrical signals and later on nerve signals prob using live frogs anesthetized.

 

[berkeman]

if I got a usb daq what do I need besides usb opto-isolation, crowbar circuit, current limiter, and gfi with transformer isolation. run the daq off a batt with ic regulator too. ?

You need to read and understand biomedical electrical safety rules and regulations and best practices. What have you read about that so far? It looks like UL 544 has been superseded by UL 60601-1, which unfortunately is much bigger and more expensive ($500). You might check your local technical libraries to see if they have access to the UL safety standards.

I accidentally blasted myself pretty hard one time many years back, working on a biomedical device with electrodes. One small mistake and I almost killed myself. Do not take this lightly please.

 

[berkeman]

Well since the OP hasn't returned for several days, and we've gotten off-track from his original question, I'll go ahead and close the thread.