ultrasonic transceiver small size

[JayLau]

Hi,

I'm trying to find a company where I can buy
small low power ultrasonic transceivers (to use in distance measurement) small as in < 10 mm
- measurement of short distances

tried google, but can't find anything

Anybody can help me

Thx in advance

Jay

 

[buzzp]

Hmm try just ultrasonic sensors. I have seen several because looking for one myself (complete unit though). If the distances are small, depending on the targets material, a capacitive or inductive prox sensor might be better.

 

[efp]

Try

http://www.digikey.com

Search for "ultrasonic transducer"

 

[JayLau]

to buzzp:

the sensor i want to use is actually for inside the body.
CO2-gas environment, and soft tissue

are capacitive or inductive prox sensors also suitable for that? and where can i find them.

to Efp:

I'm really trying to search for sensors smallers than 10 mm
low power

thx
jay

 

[buzzp]

This sensor is to go in a human? or is "body" meaning some other body?
Capacitive or inductive sensors can be used on certain non-conductive materials. This may present some problems as the medium between the plates is not air any more but human juices. I am sure they would still be feasible. I assume your going to design this from scratch. I can't help you with a company that has products for use in a human body. Some of the common mfgs of these products, for industrial uses, are Banner Engineering or Turck. I generally use the Thomas Register (online) to find specialty parts like it appears you need. Its free.

 

[JayLau]

yes, it needs to go inside the human body (abdominal region)

sorry but what is MFGS?

Thank you for your info, I will try Thomas Register

thx

Jay

 

[buzzp]

mfgs - my abbreviation for manufacturer, sorry

 

[TurboXS]

It also depends on the frequency you want to operate at and how much money you want to spend.

I have one I bought from commercial company which is 16mm diameter by 10mm long for example.

http://www1.jaycar.com.au/products_uploaded/AU5550.pdf

As the case is much larger than the ceramic/piezo I have also bought commercial sensors and removed the ceramic/piezo element from the case. In general the diameter is not much smaller but the depth may only be <2mm.

At the other end of the scale I have worked for a company that manufactured ceramics and I have seen transducers as small as 1mm in diameter, however the frequency of operation was quite high. So a company can manufacture a custom one for you, or may have one in their inventory. Obviously cost and leadtime will be an issue if you take this approach. (No the company I worked for won't do it.)

Remember that the frequency that you want to operate at will affect the resolution and range. I am also not sure what are "safe" frequencies you can apply to the human body.

regards
Pete
(TurboXS)

 

[JayLau]

Hi

the frequency that I want to use is around 40 kHz purely for distance measuring, so no harm to the human body,
Low power also only a small range max of 10 cm

so how big can this be? because I really want to come close about 5 mm or less in diameter.

but if I use piezo? can I use it inside a body? moist etc?

Thank you for your time

Jay

 

[Comcokid]

For your application you will need a high-frequency piezo. Max measurement distance is inversly porporational to the frequency used. A 30 to 40 kHz piezo is what might be used to measure ocean depths of up to a thousand feet or more. Piezos used for pregancy ultrasound (a typical abdominal application) are typically in the 3 to 7 MHz range.

 

[JayLau]

hmmm I purely want to measure distance during a laparoscopic surgery (CO2-gas in the abdominal area). So that is why I can't use 3-7 MHz, I really need to be in the kHz range.

so it is NOT ultrasonic imaging

Jay

 

[Comcokid]

So, this is through the air (CO2 in this case) and not a water medium.

Will the transducer be outside the abdomen making measurements through the abdomenal wall, or inside?

 

[JayLau]

it will be inside the body just distance measurement