SU1175435A1 - Apparatus for investigating the bone tissue - Google Patents

Abstract

A DEVICE FOR STUDYING BONE TISSUE, containing a generator connected in series, an emitter structurally integrated with piezo receivers, as well as a time interval meter and indicator, characterized in that, in order to improve the measurement accuracy by eliminating the effect of the thickness of soft tissues on the measurement results, it is equipped counter and serially connected switch and shaper, as well as serially connected shift register, adder and digital-analog converter, out d is connected to the first input of the indicator, the second input of which is connected to the generator output and the first input of the counter, the second input of which is connected via a measuring time intervals to the input shift register, and an output - through to the outputs of the piezoelectric switch. S (L yot pemy. / / Pnag SP 4 00 ate

Description

The invention relates to medical technology, in particular to ultrasound devices for determining bone tissue parameters by measuring the speed of ultrasound in it.

The purpose of the invention is to improve the measurement accuracy by eliminating the influence of the thickness of soft tissues on the measurement results.

FIG. 1 shows a block diagram of the device; in fig. 2 - diagrams for the operation of the device.

The device contains a series-connected generator 1, emitter 2, structurally combined with a multi-element equidistant lattice 3 of piezo receivers 4, switch 5, driver 6, time meter 7, shift register 8, adder 9, digital-to-analog converter 10 and indicator 11, the output of driver 6 additionally connected to the counter 12, the output of which is connected to the control input of the switch 5, and the control input connected to the second input of the indicator 11 and the output of the generator 1.

Gate 3 contains linearly equidistant piezoelectric receivers 4, the distances between which satisfy the condition of equality of the thickness of soft tissues under adjacent piezo receivers.

The device works as follows.

The generator 1 generates clock pulses 13 (Fig. 2), which periodically excite the emitter 2 of the ultrasonic probe pulses and reset the counter 12 to the zero state. In this case, the switch 5 connects the piezoelectric device 4 closest to the emitter 2 to the input of the imaging device 6. The ultrasonic signal excites a longitudinal wave into the bone, propagating at a speed determined by the bone density, and is perceived by the first piezoelectric receiver 4 of the grid 3 connected to the imaging unit 6. The piezo receiver 4 converts ultrasonic oscillations into an electrical signal 14, which is amplified, limited and normalized by the duration in the imaging unit 6. This impulse (plot at output 15) contents

the counter 12 is converted to a unit and, accordingly, the switch 5 connects the second piezo-receiver 4 of the grid 3 to the former 6. At the time the ultrasonic signal is received by the second piezoelectric receiver 4, a second pulse 15 of a constant duration is formed at the output of the former 6, which is separated from the first pulse 15 signal in the bone at a distance from the first to the second piezo receiver 4

the grids 3. The contents of the counter 12 is increased by one more diagram of the plot 16. Thus, the switch 5 sequentially connects to the shaper b all piezo receivers 4 grids 3, at the output of which a sequence of pulses is formed, the follow-up period of which is equal to the difference of the transit time of the ultrasonic signal along adjacent piezo receivers 4 lattices 3 Since the tongue of the grating 3 is chosen sufficiently small compared with the possible change in the thickness of the soft tissues under the adjacent piezoelectric receivers 4, the pulse following period is formed at the output 15 shaper 6 can be regarded as equal to the propagation time of the ultrasonic pulse in the bone tissue. Next, the sequence of pulses 13 is fed to the input of the meter 7 time intervals, where the time interval between adjacent pulses of the sequence at the output 15 is converted into a digital code, which

0 is successively entered into the shift register 8 and at the adder 9, where the meter readings are sequentially averaged at 7 time intervals over a group of measurements, for example, four adjacent sequence measurements, which avoid accidental errors and improve measurement accuracy. The code of the averaged value of the measurement result is removed from the output of the adder 9 and through the digital-to-analog converter 10 is fed to an indicator 11, for example, of an oscillographic type. In turn, the sweep of the indicator 11 is synchronized with the clock pulses of the generator 1, therefore, curve 17 is formed on its screen, representing the dependence of the ultrasound velocity in the bone

5 along the direction of scanning with a grid of 3 piezo receivers 4.

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Claims (1)

DEVICE FOR RESEARCHING BONE TISSUE, containing a series-connected generator, emitter, structurally combined with piezoelectric receivers, as well as a time interval meter and indicator, characterized in that, in order to increase the accuracy of measurements by eliminating the influence of the thickness of soft tissues on the measurement results, it is equipped counter and serially connected by a switch and a shaper, as well as serially connected by a shift register, adder and digital-to-analog converter, cat output cerned is connected to the first input of the indicator, the second input of which is connected to the generator output and the first input of the counter, the second input of which is connected via a measuring time intervals to the input shift register, and an output - through to the outputs of the piezoelectric switch. <o Fig! SU, 1175435