SU797659A1 - Ultrasonic cardiolocator - Google Patents

Description

(54) ULTRASOUND CARDIOLOKATOR

one

The invention relates to medical technology and is intended for ultrasonic examination of internal biological structures.

An ultrasound cardiolator is known that has a series-connected master oscillator, a modulator, a sensor, which includes transmitting and receiving parts, an amplifier, an amplitude detector and a gated amplifier, a demodulator, phase and peak detectors, a strobe generator, and an indicator 1.

However, the known device does not provide simultaneous recording of changes in the phase characteristic and time of the selected echo pulse when there are several pulses at the output of the gated amplifier, which reduces the accuracy of measurements of the displacement of the anterior and posterior wall of the heart muscle.

The purpose of the invention is to improve the accuracy and uniqueness of measurements of the displacements of the anterior and posterior wall of the heart muscle.

This goal is achieved by the fact that the device has a synchronization circuit including a serially connected one-shot, trigger and amplitude selector, the one-shot input is connected to the output of the gated amplifier, the output of the trigger is connected to the input of the demodulator, and the amplitude selector is included between the phase detector and peak detector.

The drawing shows a block diagram of an ultrasonic cardiolator.

The device contains a series-connected master oscillator 1, a modulator 2, a sensor 3, including transmitting and receiving parts, an amplifier 4, an amplitude detector 5, a gated amplifier 6, a demodulator 7, a phase 8 and a peak 9 detectors, a strobe generator 10, an indicator 11, a synchronization circuit 12 comprising a serially connected one-shot 13, a trigger 14 and an amplitude selector 15, wherein the input of the one-shot 13 is connected to the output of the gated amplifier 6, the output of the trigger 14 is connected to the input of the demodulator 7, and the amplitude selector connected between phase detector 8 and peak detector 9.

The device works as follows

The output of master oscillator 1, which is a harmonic wave oscillator with a frequency of, for example, 2.5 MHz, the output voltage is fed to the first input of the phase detector 8 to provide synchronous and coherent demodulation of the phase response of the reflected signals and to the input of the modulator 2, s by means of which a short radio pulse with a filling frequency of the master oscillator 1 is formed to excite the radiating transducer of ultrasonic oscillations in the sensor 3, which emits a pulse in the direction of the studied structures. At the same time, the modulator 2 performs a synchronized start of the sweep of the indicator 11, which provides visual observation, and the strobe generator 10 with an adjustable time delay. The reflection from the biostructure is converted by the receiving part of sensor 3, amplified by amplifier 4 and fed simultaneously to the second input of the phase detector 8 and to the input of the amplitude detector 5.

From the output of the amplitude detector, video pulses corresponding to the reflected signals are fed to the input of the Indicator 11; The position of the video pulses and the time sweep of the electron-beam tube corresponds to the depth of the reflecting biological structures and the magnitude of their functional displacements.

The presence of the indicator allows the operator to isolate, using a gated amplifier 6 of all the signals detected by the amplitude detector 5, a set of video pulses corresponding to a biostructure of interest, for example, the myocardium, using a gated amplifier 6. At the same time, the width of the strobe pulse is selected from the condition of ensuring the passage of video pulses through the amplifier 6 for any changes in their temporal position relative to the beginning of the radiation due to functional spatial displacements of the locatable biostructure.

In the case of the echolocation of such moving biostructures as the myocardium, the amount of functional displacement during the cardiac cycle is more or comparable to the anatomical size of the cardioelement being located. Therefore, at the input of the gated amplifier 6, when the pulse width of the strobe generator 10 is selected, there are two pulses corresponding to the signals reflected from the anterior and posterior borders of the myocardium, whose temporal position and phase characteristic can take ambiguous and independent values. To eliminate one of them, the output pulses of the gated enhancer arrive at the input of a single vibrator 13, which is triggered, for example, by the first pulse corresponding to the signal reflected from the front border of the myocardium and produces a pulse whose duration is less than twice the passage of ultrasound of the biological structure of the myocardium in the direction of radiation . At the same time, the amplitude selector 15, controlled by a single vibrator, is open and for a time equal to the duration of the single-pulse output pulse, the voltage from the output of the phase detector 8 to the input of the peak detector 9 is proportional to the magnitude and sign of the phase shift of the selected pulse relative to the coherent source — master oscillator one.

Thus, the envelope of the output pulses of the amplitude selector 15 on the peak detector 9 (carries information about the Doppler frequency and, therefore, about the speed of movement of only one of the gated cardioelement (myocardium) pulses of the amplifier 6).

The trigger 14 triggered by the front edge of the pulse of the strobe of the generator 10 is tilted by the output pulse of the one-shot 13. Consequently, the pulse duration at the output of the trigger 14 changes in proportion to the time delay of the reflected echo pulse relative to the start of the strobe pulse, while the pulse-width modulation of the output pulse trigger triggering corresponds to the nature of the pulse wave of the locatable biostructure.

0 To measure and record the magnitude of the pulsation and the law of motion of the locatable structure, the output pulses are fed to the input of the demodulator 7, the output voltage of which is proportional to the duration of the pulses to its input. The use of a synchronization scheme made in the form of a one-shot, amplitude selector and trigger, improves the functionality of the proposed coherent-pulse ultrasonic cardio-echoer, as it can be used for ultrasound examination of various body systems, such as studying the internal organs by measuring their movement and change parameters size of the studied organs (displacement, speed). The proposed cardio-echoler ensures unambiguity of measurements and reduction of the error when registering the motion parameters of a located biostructure.

Claims (1)

Measurement formula An ultrasound cardiolator containing a series-connected master oscillator, a modulator, a sensor, which includes transmitting and receiving parts, an amplifier, an amplitude detector, and a gated amplifier, a demodulator, a phase and peak detectors, a strobe generator and an indicator, characterized in that, in order to improve the accuracy and uniqueness of measurements of the displacement of the anterior and posterior wall of the heart muscle, it has a synchronization circuit including a serially connected one-shot, trigger and amplitude selector, the input one-shot connected to the output gated usi The trigger output is connected to the input of the demodulator, and the amplitude selector is connected between the phase detector and the peak detector. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 234608, cl. A 61 B 5/02, 1967.