electronic stethoscope

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*Shima*

Joined Apr 22, 2010
7
But my father as I know him, doesnt have any problem with technology. He just thinks maybe there is more effective application that electronic can do for medicine and ofcourse there is. Our conversation was about replace electronic stethoscope with normal one and we didnt talk about special uses.

I think I have to do my project and he test that, then he'll can assessment better.
 

*Shima*

Joined Apr 22, 2010
7
One of the first use for the meditron electronic stethoscope was in veterinary medicine. The reason for this was part less rigid approval regime. But also the fact the working with large animals like horse you may want to use a long tube from the sensor to the ear. But for a conventional stethoscope this may cause reduced/poor sound quality. But with a electronic stethoscope this is not a problem
you're right, it even can use in veterinary medicine :)
 

Audioguru

Joined Dec 20, 2007
11,248
I had a heart attack one year ago. My doctor did a complete medical checkup two months before it happened including an ECG and a listen to my heart with an old style passive stethoscope. I told my doctor that I had a pain in my upper chest when shovelling snow and walking fast. My doctor said my heart is located lower and it is fine.

Two of the arteries that feed the heart muscle were completely blocked. Half of my heart was quickly dying.
The heart attack could have been prevented with a better diet (and a better doctor).
We are not talking about Birth Control but since it is mentioned then I admit that I had Vasectomy surgery about 28 years ago. I have 3 grown kids.

I wasn't fat like most people with poor health:
1) I ate too many hamburgers and sausages.
2) Too much Kentucky Fried Cholestrol (breaded chicken) and fried chicken wings.
3) Too much real cream in my coffee.
4) Too much ice cream.
5) Too much chocolate.
6) I smoked for most of my life but I quit about 8 years ago.

They gave me Angioplasty surgery and since it was done quick enough then I am better than new and there is no damage to my heart.
 

retched

Joined Dec 5, 2009
5,207
Congrats Audioguru on a good outcome. You have helped many (and ticked off a few) since your return from disaster. It is this kind of prevention I am talking about.

Preventing a heart attack, not preventing babies. But even though the stethoscope is often used on the heart, there are other functions.

Bowel sounds can tell alot about a persons health. Some high frequency sounds made by the bowel for tell of oncoming problems. (jokes a plenty) These sounds can be percieved as 'OK' by a human who thinks "Aww, thats not 18,000Hz, thats only 12,000Hz" Now some can do that, many cant. An electronic stethoscope can pick this up and tell immediately the frequency of the sound.

I think the signal processing is the most important part of the stethoscope sounds. blood through a narrowing artery makes a higher pitch noise during beats, these can be hard to distinguish by a human because there are other sounds happening at once, and the volume is low. An electronic stethoscope could have an "EQ" that boosts the signals that you want to hear and cut the ones you dont.

I see many reasons to go electronic. Sending a recording of an "iffy" heart sound to other doctors to see if they may recognize it. And banking of these sounds for student benefit.

Artery Doppler is an expensive marvelous machine used to SEE the blood flow in surface arteries. But it is not available to many doctors offices and hospitals in the world.

This could be a decent filler. The doctors, students, and researchers could even use a website that the scope could be hooked up to via usb and a PC to listen to body sounds to recognize these possible problems. Im thinking a good teaching tool that can record through the stethoscope and playback through it also. It would still have the personal "my-ears-and-your-heart" feel of the original scope that doctors know and love.

It would just help more.
 

Thread Starter

Cinek

Joined Jan 11, 2009
13
Hello everyone! :)

So this design of electronic stetoscope is working "almoust" great :) I mean almoust because (i think it is due to type of microphone) sometimes i can hear work of heart and lungs without problems, and sometimes it is just impossible (it depends on .. day, luck - i dont know :p ) But when I was talking with profesor , I encountered some difficulty with a question about this cut off frecuency. In this design we have about 100 Hz. Moreover all the modern elecotrnic stetoscope in heart beat mode also are listening for 20-100 Hz frecuencies; and my question is WHY is that? because normal beat of the heart is about 100 (from 60 up to 180 beats/minute) so it is about 2times/s so. 2 Hz, so why dont we use in case of "heart study" value of cut off frecuency, lets say 5Hz?

Kindest Regards,
Marcin
 

jpanhalt

Joined Jan 18, 2008
11,087
You seem to be confusing beats per minute with Hertz, cycles per second. Nevertheless, you need low frequency in a stethoscope to hear low frequency rumbles and such. Low-frequency response is not necessary just to hear the heart beat.

John
 

t06afre

Joined May 11, 2009
5,934
Hello everyone! :)

So this design of electronic stetoscope is working "almoust" great :) I mean almoust because (i think it is due to type of microphone) sometimes i can hear work of heart and lungs without problems, and sometimes it is just impossible (it depends on .. day, luck - i dont know :p ) But when I was talking with profesor , I encountered some difficulty with a question about this cut off frecuency. In this design we have about 100 Hz. Moreover all the modern elecotrnic stetoscope in heart beat mode also are listening for 20-100 Hz frecuencies; and my question is WHY is that? because normal beat of the heart is about 100 (from 60 up to 180 beats/minute) so it is about 2times/s so. 2 Hz, so why dont we use in case of "heart study" value of cut off frecuency, lets say 5Hz?

Kindest Regards,
Marcin
The human ear have bandwidth from 20Hz to 20Khz. At least this a thumb rule. Older people may in most cases have problem with the upper part of this range. and perhaps the lower part also. For more info use Google and search for human ear frequency range. Lots of good hits
 

Audioguru

Joined Dec 20, 2007
11,248
Heart beats are 40 to 200 beats per minute.
The sound made by each beat is about 16 to 20 cycles per second. You also want to hear the harmonics which extend up to about 100 cycles per second.

If the cutoff frequency of the lowpass filter is increased to 1khz then you will hear background noise, traffic noise, people talking and breathing noises.
 

retched

Joined Dec 5, 2009
5,207
However, listening for murmurs and other defects, will require other frequencies.

This is the type of thing I was talking about earlier in the thread.

Using DSP, you could filter out the norm, and listen to only the irregular. Or boost and cut the frequencies that fog or hide the sought after sound.
 
I know that this construction was discussed a long time ago, but can you give some information about the microphone used in this circuit? Thank you very much.
 
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