SU1631409A1 - Method of testing ultrasonic echo-pulse instruments - Google Patents

Abstract

The invention relates to ultrasound (US) diagnostics and is intended to verify the characteristics of ultrasonic measuring devices, both medical and general technical, which are used to determine dimensions or distances in a controlled object. The goal is to improve the accuracy of verification and expand the range of parameters to be tested by eliminating the need for creating reference measures. The formation of a time interval by an electromagnetic device makes it possible to eliminate its dependence on the physical parameters of the medium, and the interval value can be set to any range depending on the delay in generating the second pulse. 1 il.

Description

The invention relates to ultrasound (US) diagnostics and is intended to verify the characteristics of ultrasonic measuring instruments, both medical and general technical, for determining the dimensions or distances in a controlled object.

The purpose of the invention is to improve the accuracy of verification and expand the range of parameters to be checked by eliminating the need to create reference measures.

The drawing shows a flowchart that implements a method for calibrating an ultrasonic pulse echo device.

The scheme contains a scanned device 1 with an ultrasound probe 2 connected to the instrument to be tested, a source 3 of a reference signal with an ultrasound probe 4 connected to its outputs and a meter of 5 time intervals. Ultrasound

probes 2 and 4 are coupled through acoustically conducting medium 6.

The method of calibration of ultrasonic echo-pulse devices is carried out as follows.

A pulse triggering delay on the second channel relative to the first one, corresponding to the measurement range in the device under test 1, is installed on the source 3 of the reference signal using a discrete switch. The source 3 of the reference signal is included in the external trigger mode. Using a 5 time interval meter, the amount of delay of the reference time interval between the electrical pulses generated by the source 3 of the reference signal is measured. Then, the source 3 of the reference signal from the test instrument 1 is synchronized.

Formed in the source 3 of the reference signal two electrical impulses

Yo

J

OS

§

:

In the ultrasound probe 4, two consecutive acoustic pulses are excited, which propagate in the acoustically conducting medium 6 and are received by the probe 2. The ultrasonic pulses received by the ultrasound probe 2 are converted in the testable device 1 into electrical ones and by the magnitude of the time interval between they determine the distance I, corresponding to half of the product of the time interval by a factor C - the speediest propagation of ultrasound in the material, for the measurement of which this ultrasonic device is intended

t

C-t

(one)

where C is the calibration speed of the propagation of ultrasonic vibrations;

t is the measured time interval between acoustic pulses (the propagation time of ultrasonic vibrations over the material under study),

The value is syndicated in a calibrated instrument. The error in measuring the distance measured by the measuring instrument is determined by comparing the value E measured by the measuring instrument to the value of the reference time interval obtained on the meter 5 timeslots, using the formula

From 10

&.

(2)

where b is the measurement error of the device being tested, mm;

t is the reference time delay between a pair of pulses of the source 3 of the reference signal;

С is the calibration value of the velocity of propagation of ultrasonic vibrations, embedded in the test instrument 1, m / s.

By varying the pulse delay in the source channels 3 of the reference signal, the required value is set to calibrate measurement errors in different measurement ranges.

With this method of verification by forming a time interval by an electronic device in the form of two electrical pulses and converting them into

the acoustic pulses applied to the t input of the device being checked, the reference time interval between pulses is determined only by the parameters of the source of the reference signal 3 (electric pulse generator) and does not depend on the physical parameters of the medium through which the converted pulses are transmitted to the calibrated device. Since the environmental factors affecting time

the propagation of ultrasonic vibrations will equally affect both successive acoustic pulses, forming the beginning and the end of the measured time interval, and will be mutually

compensated, the differences in the measured time interval from the reference one will be caused only by the spread of the readings of the device being tested (its error), as well as the measurement error of the meter 5

time intervals.

Claims (1)

The invention The method of calibration of ultrasonic echo-pulse devices, which consists in generating an electrical impulse, converting it into an acoustic impulse, transmitting it through an acoustically conducting medium, transforming it with an verifiable instrument into an electrical impulse, determining the time interval and matching it with a reference time interval, characterized in that, in order to improve the accuracy of the calibration and expand the range of the measured values, the time interval is determined between two pulses applied to the instrument being checked, and the second impulse is generated with a predetermined delay and is converted into the same impulse as the first impulse, the sequences and the same medium.