| 摘要 |
PURPOSE:To enable measurement of elasticity of a bone from the surface of a human body by making a leak surface pseudo longitudinal ultrasonic wave propagating near the surface of the bone-excite and propagate to measure sound velocity by a propagating distance and time when it propagates by a specified distance. CONSTITUTION:When a pulse excitation is performed with an ultrasonic transducer, a plane wave of an ultrasonic pulsethetac is excited and a beam alone impinged at a critical angle among the waves excites a wave of LSSC. The wave propagating by a distance 19 near the surface of a bone is refracted on a cylindrically curved surface 11 and grains to return to the transducer 13. When the wave is observed with an oscilloscope, a reflected pulse 21 on the cylindrically curved surface 11, a reflected pulse 24 on the surface 23 of the bone as produced by a wave 22 impinging vertically into the bone and a pulse produced by the wave propagating near the surface of the bone appear in succession following a leak pulse 20 during a transmission. Here, a time difference is determined between the reflected pulses 24 and 25 on the surface of the bone detector to obtained a distance between the electrically curved surface 11 and the surface of the bone from a lid difference between the reflected pulse 21 and 24, thereby enabling the calculating of sound velocity of the bone. |
