Osteoporosis diagnosing apparatus and method

摘要

PCT No. PCT/JP95/02569 Sec. 371 Date Oct. 21, 1996 Sec. 102(e) Date Oct. 21, 1996 PCT Filed Dec. 14, 1995 PCT Pub. No. WO96/18342 PCT Pub. Date Jun. 20, 1996The osteoporosis diagnosing apparatus of the invention radiates repeatedly an ultrasonic impulse Ai toward the bone Mb of an examinee and receives an echo Ae from the bone Mb. The received signal is converted into a digital echo signal through an A/D converter (8), and the echo level is detected by a CPU (11). The CPU (11) extracts maximum echo level from among the echo levels detected in a given period of measurement to thereby calculate a bone acoustic impedance Zb based on the extracted maximum echo level, and then calculate the bone density of the examinee based on the calculated acoustic impedance Zb. As the impedance Zb is expressed in the square root of the product of modulus of elasticity and density of a bone, decreased in both the modulus of elasticity and the density synergistically affect the impedance to remarkably decrease the same. Thus the bone acoustic impedance serves as a good index in judging the bone density