SU1595489A1 - Device for ultrasonic surgery - Google Patents

Abstract

This invention relates to an ultrasound medical technique. The purpose of the invention is to increase the duration of the operative action by reducing the overheating of the piezotransducer. The device comprises a power supply unit 1 connected to an excitation generator 2 and a piezoelectric transducer 3, a detector 4 connected in series, a comparator 5, the first and second drivers 6 and 8, element 7 OR and electronic switch 9, pulse generator 10 connected to element 7 OR and the first shaper 6, excitation generator 2 comprising a power amplifier 11 with a transformer 12 and a feedback winding connected to a band amplifier 13, and a phase shifter 14. In operation, when there is no acoustic load, the device provides A discontinuous mode of operation due to the use of internal energy stored in the oscillatory system of the generator 2 of the excitation and piezotransducer 3. 2 Il.

Description

Sd

with

01

00

with

I The invention relates to ultrasound and medical technology and can be used in the processing of pathological bioganum.

 The purpose of the invention is to increase the operability of the operative effect by reducing the overheating of the piezoelectric transducer.

FIG. 1 shows the structural scheme of the device; in fig. 2 - time diagram of work.

The device comprises a power supply unit 1, an excitation generator 2, a piezoelectric transducer 3, a detector 4, a comparator 5, a first driver 6, an OR element 7, a second driver 8, an electronic switch 9 and a pulse generator 10, included in the excitation generator 2 power amplifier 11 transformer 12 with feedback winding, bandpass amplifier 13 and phase shifter 14.

The device works as follows.

The pulse generator 10, after turning on the power supply unit 1, produces a short rectangular voltage pulse U (see Fig. 2), which through the logic circuit OR 7 enters the input of the second driver 8 of duration. At the output of the latter, voltage pulses of a predetermined duration are produced. At the time of the arrival of the voltage pulse U, the electronic switch 9 is closed and the power amplifier 11, included in the generator 2 of the excitation, is applied to the power supply from the power supply 1.

The power amplifier 11, covered by a positive feedback through the circuit, the bandpass amplifier 13 and the phase shifter 14, is excited at the mechanical resonance frequency of the electroacoustic piezoelectric transducer 3. At its input, voltage fluctuations U.

U (t) (). where U (t) is the instantaneous value of voltage.

fluctuations;

Uo is the initial voltage; a is the coefficient determining the shape of the envelope; (1) - oscillation frequency; Ф - initial phase; / - time

The duration of the voltage pulse Us is selected from the condition of the required time to reach the set value of voltage 4 of self-excitation of excitation generator 2. After the voltage pulse ends (/ 3 the electronic key 9 opens, violating the condition of the amplitude balance, which leads to generation failure. However, the piezotransducer 3 continues to oscillate due to stored internal energy, and the voltage at its output after the end of the voltage pulse f / h has the form

U (t) U, (wt +),

where Ivu is the steady-state value of the voltage amplitude at the moment of termination of the voltage pulse; . b - i- - loss of electroacoustic piezoelectric converter 3.

The feedback signal, taken from the feedback winding of transformer 12, completely coincides with the voltage (74 piezotransducer 3 and is fed to the input of the amplitude detector 4. At its output, the voltage envelope and L s, which is fed to the input of the comparator 5. At the output of the latter, a high voltage level t / 6 is formed when the voltage is exceeded by the threshold value Unop voltage. At a decrease and the envelope of the voltage signal U5 is below the threshold voltage Unop at the output of the comparator 5 is formed low 0 level of voltage U &. The voltage signal UG is fed to the input of the first driver 6 pulses, which, by decreasing the voltage pulse Ne, forms short positive voltage pulses (/. gC output of the first driver b voltage pulses U- / arrive through the OR element at the input of the second forma- tion. –1 8 duration, which leads to the opening of the electronic key 9 and the increase in voltage on the piezoelectric transducer 3, i.e., the process repeats. The voltage pulses t / 7 also arrive at the installation input of the generator 10 pulses, each time driving it to its original state and not allowing it to generate another pulse. If a significant change occurs in external conditions, for example, when the working part of the piezoelectric transducer 3 is jammed, the voltage U may not fall into the sensitivity zone of the comparator 5, which leads to the absence of voltage drops at its output, and, consequently, from the impact of voltage pulses f / at the output of the second driver 8. Therefore, in the absence of discharge pulses, the voltage Uj at the installation input of the generator 10 pulses, a voltage pulse U is generated at its output 45, which leads to generation and repetition processes.

Claims (1)

 Invention Formula A device for ultrasonic surgery 50 containing a power supply unit connected to an excitation generator and a piezoelectric transducer, characterized in that, in order to increase the duration of the operative action by reducing the overheating of the piezoelectric transducer, the detector, comparator, the first driver, the element OR., the second driver and the electronic key connected to the second input of the generator excitation, and the second input - with the output of the power supply unit, the pulse generator, the output connected to the second input of the OR element, and the reset input - with the output of the first driver, the excitation generator contains a series-connected power amplifier, a transformer with a winding. pa na % and pore and, I which feedback bandpass amplifier with phase shifter connected to second power amplifier input, first input - which is connected to the power supply, the input 5 detector connected to the reverse winding connection, the output winding of the transformer connected to a piezoelectric transducer. l lCL FIG. 2