Abstract: A bone assessment apparatus for obtaining an assessment value E for a bone 12 with good repeatability by simple calculation using the waveform of a signal derived from received ultrasound which has passed through the bone. A transmitting transducer (20) transmits an ultrasound pulse. A receiving transducer (22) receives the ultrasound pulse which has passed through a test sample (10), and then converts the received ultrasound pulse to a signal. An A/D converter (30) digitizes the signal amplified in a receiving amplifier (28). The digitized signal is inputted to a calculator (32) via a transducer controller (26). The calculator (32) calculates the assessment value E for the bone (12) from characteristic values of the waveform of the signal, such as the half-value width of the first positive portion, which are derived from ultrasonic transmission characteristics of the bone (12).

Abstract: A paper feeding apparatus comprises a flexible vibrating body made of an elastic matter. The body is excited with a resonant frequency so as to produce a progressive wave. A driving vibrator is fixed to one end of the flexible vibrating body, and a receiving vibrator is fixed to the other end thereof. A mechanism is included for urging paper against the flexible vibrating body, so that when the vibrating body is excited, the paper is conveyed.