| 摘要 |
PURPOSE: To diagnose the progressing condition of osteoporosis by estimating the bone density and the modulus of elasticity of the bone. CONSTITUTION: An ultrasonic transducer 1 is pressed to the skin and while this transducer is oscillated toward the bone Mb and within a prescribed range with respect to the normal of the bone Mb, ultrasonic impulses Ai are intermittently shot. The bone echoes Ae returning from bone Mb are successively received. The echo level and the echo arrival time after the emission of the ultrasonic impulses before the bone echoes Ae return are measured. The max. echo level and the echo arrival time of this time are extracted from the echo information obtd. by the measurement. The CPU in the main body 2 of the apparatus calculates the impedance of the bone in accordance with the extracted max. echo level and 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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