Production and Use of Ultrasound problem 11

A transducer is placed in contact with the skin. Short pulses of ultrasound are transmitted into the body. These pulses are partly reflected from the boundary between media. The reflected pulses are received by the transducer and are converted into voltage pulses. The voltage pulses are amplified and processed to give a trace (series of spikes) on a cathode ray oscilloscope (C.R.O.) screen.

The intensity of the reflected pulse gives information about the nature of the boundary, while the time delay gives information about the depth of the boundary.

The linear attenuation (absorption) coefficient of the ultrasound in the layer of muscle is .