| 摘要 |
PURPOSE: To diagnose the progressing condition of osteoporosis by estimating the bone density and the modulus of elasticity of the bone. CONSTITUTION: Ultrasonic impulses Ai are first shot without pressing a transducer 1 to a living body and at this time, the echoes returned from the front end face of the transducer 1 and the boundary with air are received and measurement data are extracted. Next, the transducer 1 is pressed to the living body and while the transducer is oscillated and moved within a prescribed angle range toward the bone Mb, the ultrasonic impulses Ai are shot and the surface echoes Ae1 returned from the surface of the living body and the bone echoes Ae2 returned from the surface of the bone Mb are received and the normal measurement data are extracted. The acoustic impedance of the bone of the testee M is thereafter calculated in accordance with the extracted preliminary measured data and the normal measurement data. 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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