| 摘要 |
PURPOSE: To diagnose the progressing condition of osteoporosis by estimating the bone density and the modulus of elasticity of the bone. CONSTITUTION: A transducer 1 constituted by joining an ultrasonic delay spacer to the wave transmission, and reception surface of an ultrasonic vibrator transducer is pressed to organism and while this transmission and reception surface is oscillated and moved within a prescribed angle range toward the bone Mb, ultrasonic impulses Ai are intermittently shot and the surface echoes Ae1 from the skin surface and the bone echoes Ae2 from the bone surface are successively received. The CPU in an apparatus body 2 extracts the max. level from the received bone echoes Ae2 and thereafter, calculates the acoustic impedance of the bone Mb taking the attenuation rate of the ultrasonic waves into consideration in accordance with the max. bone echo level, the surface echo level making a pair therewith and the difference in the echo arrival time of this time. The acoustic impedance of the bone Mb is expressed by the square root of the [modulus of elasticity×density] of the bone Mb. The modulus of elasticity (increases) decreases as well when the bone density increases (decreases) and, therefore, a good index in judging the bone density and the modulus of elasticity of the bone are obtd.
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