REQ: Need blood flow hearing device

[jopapadogr]

I had a health problem and my doctor has a device which had a speaker and when he touched my leg with a kind of "microphone", he could hear the blood flow through the speaker. I'm looking to build a similar device for my personal use. Any help would be appreciated.

 

[pranam77]

Coudnt guess what may be the device. May be it is an Electronic stethscope or may be a doppler. More inputs may facilitate better replies.

 

[jopapadogr]

As i could remember it was a box about 30X20X10 cm and has a speaker and a cable with a tip at the end. When he opens the device you can hear some parasitic noise like hush... from a untuned radio. When he puts the tip on my leg and he was searching for a blood flow. Sudenly when he was found a good blood flow you can here the noise of the flowing blood through the speaker. And in the end when you take a big breath the noise was stoping until normal breathing. Hope to help somehow

thanking for any reply

 

[pranam77]

It is then for sure it is a doppler. Dopplers are very difficult to construct by an average hobbyist, as it requires tunning just as in various secttions as in a radio. You may try get a readymade one which is available with pharmacuitcal diistributors or Surgical suppliers. But still getting accustomed to hear the heartbeat through the noise comes with practice. Good luck

 

[jopapadogr]

Yes it is. By a google search i found that this exactly what i need. An acoustic dopler vein finder. I'm proffesional electronic engineer and i have an 2 ch osciloscope for tests. Is it possible for anyone send such design? I will keep on looking on that. thank you all for help

 

[pranam77]

I personally do not have any doppler designs. But you may wait and see if any other friends come out with some designs for you. Good luck

 

[kender]

It's probably Doppler flow meter. The sensed signal is the variation of frequency shift of a an echo reflected from blood cells. I know an engineer who had designed such device (which literally had under 20 electronic components).

 

[jopapadogr]

Lets hope then that someone can send sutch designs. I like to tell me your opinion in my idea.
Lets assume that we have a ultrasonic radar device e.x. for parking
It works in the same prinsipal. Sends ultrosonic frequency and receives the feedback.
I was wondering if this kind of adapted circuit meet my needs. what do you think about it?
It's just a thought

 

[kender]

Lets assume that we have a ultrasonic radar device e.x. for parking
It works in the same prinsipal. Sends ultrosonic frequency and receives the feedback.
I was wondering if this kind of adapted circuit meet my needs. what do you think about it?

Majority of ultrasonic rangefinders work on the time of flight principle. The vascular device works on a Doppler principle. Echos reflected from moving blood cells (during systole) will have a different frequency than the echo reflected from stationary blood cells (during diastole).

 

[jopapadogr]

i found a way to walk now but i have a critical question. Where i can find a HF ultrasound transducer called PZT-5 or any equivalence desing. My need is to achive a resonate frequency about 2-3MHZ to build a probe. Any info would be helpfull.

 

[kender]

There could be blood vessel finders with disposable applicators. I saw such thing, but can't recall teh maker or the model. The transducer is in the cheap disposable applicator. It may or may have the frequency you want, though.

When it comes to hobby ultrasound usually one picks the transducer from what's available first. Then the transducer drives the rest of the design.

 

[obex]

hey jopapadogr, how is ur health. i dont know anything about vein finder. But u can see the design from "will0707". I think the different of ur doctor's device with blood flow meter is ur doctor device's can measure one vein than the other veins. It has some kind like the "settle button".

About the transducuer. if ur doctor's transducer is microphone,then it have to be a sensor transducer. I mean, not piezoelectric transducer.

Sorry, im new here. Forgive me if im wrong.

Best regards,

 

[karesz]

Hi jopapadogr,
What about progress, do youi found a PZT-5 transducer pls?
K.