Ultrasonic sensor for body measurement

Hi,

I'm using a Arduino Mini Pro 5v/16MHz

I would like to use an ultrasonic sensor to calculate the speed propagation in a body which will enable me to know some factors like tension in a muscle etc. I've already tried with the HC-SR04 by putting it directly on my skin and get the echo time in microsecond with "sonar.ping()" (obviously) without success...

Do you know if this is something possible with an arduino and if a more specific sensor exist for this kind of use?

Thanks

Get a medical ultrasound head.
Expect to shell-out big bucks.

The thing is, it must be portable and small. I don't need a high accuracy sensor to start. I was thinking to combine an US transmitter and an US receiver and measure the time between the transmit and the receive signal?

I wouldn't use the standard Murata sensors - they ring badly. The typical rangefinder uses an eight cycle burst, which is about 68mm in air, but they may ring significantly for another four or five cycles, stretching the ping even further. Shorter bursts may not even get any significant energy out.

Living tissue is probably closer to water, so a higher speed of sound.

Medical heads operate in the MHz range

AWOL: Living tissue is probably closer to water, so a higher speed of sound.

Medical heads operate in the MHz range

Ok I understand the issue here...