Harmonics of the Human Cardiovascular System

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Xaborus

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Joined 2013
#1
I'm a college student who is studying to go into the medical profession. I was googling about looking for sources on damping factor, when I stumbled on this article.

Looks like in a parallel world they are talking about damping too... and they also have a (different) Dr. Geddes!

I stumbled upon this gem:
arterial%20waveform%20and%20component%20harmonics%20from%20Hansen%2C%201949.JPG

The original article is here. It's a fun read!

I really wonder what an audio amplifier would sound like with a distortion characteristic similar to the human cardiovascular system. :magnify:
 
#3
Any complicated waveform can be represented as combination of a sine wave of fundamental frequency (f) and a succession of harmonics (2f, 3f etc) of diminishing amplitude.

The same is obviously true of heartbeats!

It is the pressure transducer which must be damped so that the amplitude of its signal does not increase due to resonance with the fundamental frequency of the heartbeat waveform.

In audio, harmonic distortion occurs when an amplifier adds unwanted harmonics to a voltage signal.
 
#5
What say the professor about some external long wave length in the low audio frequency range at high quantity and spl in pressurised space or outdoor on armed hearth and hearth valves ? Are they know the frequency range that may be dangerous for some people ?


Do harmonics in that range reenforce the further fundamental in that range to arm even more ?
 
#6
@ diyiggy. I've found the following information for you. It may go some way towards answering your questions. 🙂

The sinus rhythm is typically 60bpm (1.0Hz) when resting. This fundamental frequency is well below the lower frequency limit (20Hz) of audible sound waves in a room.

The chest area of the human body functions as a resonance chamber at infrasound frequencies (< 20Hz) so exposure to high levels of infrasound are dangerous. From about 100 to 140 decibels, infrasound can resonate the internal organs causing death. Infrasound can also cause feelings of pressure in the chest and respiratory incapacitation.

High powered, low frequency sound from about 30 Hz to about 1000Hz can also cause chest wall vibration and respiratory impairment.
 
#8
Why then do people and monkeys, in general, beings of a completely different type, also love the sound of a purring cat? And even many find it useful? Although in nature, cats make this sound primarily for the kittens themselves and themselves.
 
#10
GUNFU said:
Why then do people ... also love the sound of a purring cat? And even many find it useful?
Click to expand...
Experts believe that the low frequency purrs cause vibrations within the cat's body that hasten healing, ease breathing and decrease pain and swelling.

These advantages may be transferred in some small way to the cat's owner who, as a result, becomes soothed and calmed by the purring.
 
#11
Galu said:
High powered, low frequency sound from about 30 Hz to about 1000Hz can also cause chest wall vibration and respiratory impairment.
Click to expand...
Oh yeah, I can attest to that. Standing in front of a bank of EAW 850 subs when my buddies at the console decided to blast me. Yikes. I thought my heart and lungs would stop and then explode. No fun.
 
#12
The nervous system has sympathetic frequencies where the muscles are forced to relax, and this can cause damage when those muscles are needed for support or control in a situation where safety is a factor.
This can happen to truck drivers, and is the real reason they have the floating seats.
Certain industrial hand tools can do that also.
 
#13
Pano said:
Oh yeah, I can attest to that. Standing in front of a bank of EAW 850 subs when my buddies at the console decided to blast me. Yikes. I thought my heart and lungs would stop and then explode. No fun.
Click to expand...

Yowza. Let me guess, they played with the EQ to make it even more chest-shattering.


As for the cat purring, sure it may "hasten healing" or whatever, but don't the claws offset that effect?
 
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