Abstract: The apparatus for diagnosing osteoporosis in the present invention radiates repeated ultrasonic pulses Ai toward cortical bone Mb in a subject and receives echoes Ae from the bone Mb. The received signal is converted to a digital echo signal by an A/D converter 8, and the echo level is detected by a CPU 11. The CPU 11 extracts the maximum echo level from the echo levels detected during the measurement period and calculates the acoustic impedance Zb of the cortical bone based on the maximum echo level which has been extracted. The bone density of the subject is calculated from the detected acoustic impedance Zb of the cortical bone using a predetermined recurrence formula. The acoustic impedance of bone is given by the square root of ?the elastic modulus.times.density! of bone, and since the elastic modulus of bone increases (or decreases) as bone density increases (or decreases), the elastic modulus of bone and bone density play a synergistic role in the acoustic impedance.

Abstract: The 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.

Abstract: An image recording apparatus has a first recording-sheet storing section for storing a first recording sheet, a second recording-sheet storing section for storing a second recording sheet, a serial recording head for effecting image recording on the first recording sheet while travelling with respect to the first recording sheet, a line recording head for effecting image recording on the second recording sheet when the second recording sheet is in a stationary state, a first conveying device for conveying the first recording sheet to the position of the serial recording head; and the second conveying device for conveying the second recording sheet to the position of the line recording head. With this arrangement, it is possible to selectively effect serial recording and line recording and, in addition, to effect recording from an original document as well as recording and reproduction of the thus-read original document.

Abstract: An access alarming method and apparatus for activating an alarm in the event of the access of a working vehicle, such as a road roller, to an object, such as a worker, in the same working area as the vehicle. An ultrasonic wave transmitted by a transmitter on the object is received by a receiver on the vehicle. The received signal is processed and used to determine the relative position of the vehicle with respect to the object. An alarm is activated, and/or the vehicle is braked when it is judged that the object is within a hazard area determined in relation to the position and course of the vehicle.