Does anyone know a cheap, simple way to detect the presence of bone under skin using electronics (ie. sternum)

Question

I need a simple electronic circuit or technique that could tell if the sternum or any bone was located directly under the skin. Ultrasonic sensors are generally very expensive. Is there any other cheap way?

Answer 1

It shouldn't be too hard. The density of the material has a lot to do with how quickly sound waves and/or electricity pass through the object. Infact, you could easily map using a type of resonance imaging. (That's the basic principle behind the MRI.) One thing on the market that works VERY similarly to what I'm explaining to you is what some call a "Stud Finder". It's the tool you purchase at a hardware store to find wall studs when you hang shelving on your walls, etc.

Answer 2

A microphone and a small hammer will work. Place the microphone near the patient's mouth and strike the sternum with the small hammer. A large signal from the microphone will indicate the presence of a bone.