Patent ID: 7537566

Claim:
In a bone strength measuring instrument, which transmits/receives an ultrasonic wave to/from part of a human body in a state where the part of the human body is held between a pair of ultrasonic probes each containing an ultrasonic transmission/reception transducer and an acoustic impedance matching liquid, and processes signals generated upon transmission/reception of the ultrasonic wave, thereby measuring a bone strength in the part of the human body, the improvement comprising: a calculating unit for determining, a first wave obtained from the ultrasonic wave probe and is high in speed upon passing through a cancellous bone and a second wave obtained from the ultrasonic wave probe and is low in speed thereupon, where in an acoustic speed Vs of the second wave in the cancellous bone has a constant value, an operation is performed using the constant value of acoustic speed Vs and arrival times Ts of the second wave to the ultrasonic wave probe, respective thickness values of a soft tissue, a cortical bone and the cancellous bone in the part of a human body.