JPH0134063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolithotomy device that inserts electrodes into a body cavity and destroys stones in the body cavity by electric discharge between the electrodes.

Electrolithotomy devices are widely used because they can crush stones in the bile duct or ureter without opening the abdomen. However, as disclosed in Japanese Patent Publication No. 55-40257, a circuit configuration is adopted in which a capacitor is charged with a high voltage and this high voltage is directly applied to the discharge electrode, so a high voltage cannot be applied. In other words, the circuit components themselves are required to have high withstand voltage characteristics, and there is a problem in that the device itself becomes larger and more expensive.

An object of the present invention is to provide a small and inexpensive electrolithotomy device. According to the present invention, a circuit configuration that generates a high voltage only during discharge can be adopted, and the voltage specification can be made to withstand high voltages that are instantaneously generated.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the electrolith crusher of the present invention, in which a capacitor 8 is connected to an AC power source 2 via a resistor 4 and a switch 6. A primary side 12-1 of a transformer 12 is connected to this capacitor 8 via a discharge gap 10, and a discharge electrode 14 to be inserted into a body cavity is connected to a secondary side 12-2 of this transformer 12. has been done.

In such an electrolithotomy device, when the discharge electrode 14 is inserted into the body cavity and the switch 6 is closed, an AC voltage as shown in FIG. is applied to the capacitor 8, and the voltage across the capacitor 8 begins to rise as shown in FIG. 2b. When the voltage across the capacitor 8 reaches a predetermined voltage, a discharge occurs in the discharge gap 10, and a large current momentarily flows through the primary side of the transformer 12 as shown in FIG. The voltage is rapidly lowered to a predetermined voltage, and the discharge in the discharge gap 10 is stopped. Thereafter, the capacitor 8 starts to be charged again, and when a predetermined voltage is reached, discharge occurs again in the discharge gap 10, and a discharge current flows to the primary side of the transformer 12. As shown in FIG. 2c, each time a discharge current flows to the primary side of the transformer 12, a high voltage is generated on the secondary side of the transformer 12 as shown in FIG. 2d, and is applied between the discharge electrodes 14. be done. As a result, a discharge occurs between the discharge electrodes 14, and a shock wave is irradiated onto the calculus, leading to its destruction.

As described above, in this invention, only an AC voltage of about 100 to 200 V is applied to the capacitor 8, whereas conventional devices that apply a high voltage of about 2000 V have a withstand voltage of several thousand V. A withstand voltage specification of several 100V is sufficient for the required voltage. Furthermore,
A high voltage of several thousand volts is generated on the secondary side of the transformer 12, but only during discharge, the high voltage of several thousand volts momentarily flows between the secondary side of the transformer 12 and between the secondary side and the discharge electrode. However, since it is a momentary application of high voltage, the withstand voltage characteristics are not required to be even several thousand volts, but may be sufficiently lower than this value, so low withstand voltage specifications should be used. I can do it.

In addition, in the circuit shown in Fig. 1, the AC power supply 2
may be a commercial power supply connected via a transformer or an oscillation circuit, and the output voltage from the secondary side 12-2 of the transformer 12 is determined by the capacitance of the capacitor 8 and the transformer 12. It can be determined by appropriately selecting the winding ratio.

Next, another embodiment of the present invention will be described with reference to FIGS. 3 and 4.

In the embodiment of FIG. 3, an oscillator 16 connects a switch 6 to the bases of a pair of transistors 18, 20.
and a transistor 1 connected via a resistor 4.
Collectors 8 and 20 are connected to DC power supplies 22 and 24, respectively.
The emitters of the transistors 18 and 20 are connected to the oscillator 12 via the primary side 12-1 of the transformer 12. The secondary side 12-2 of the transformer 12 is connected to the discharge electrode 14 as in the previously described embodiments.

In this embodiment, when switch 6 is closed, transistors 18 and 20 are alternately conductive;
1 of the transformer 12 alternately from the DC power supplies 22 and 24.
A current is supplied to the secondary side 12-1, and a high voltage is periodically generated from the secondary side 12-2 of the transformer 12. Also in this embodiment, since high voltage is instantaneously generated on the secondary side of the transformer 12, the transformer 12
The secondary side of the transformer 12 can have a relatively low withstand voltage, and the primary side of the transformer 12 can have a sufficiently low withstand voltage because the withstand voltage characteristics determined by the DC power supplies 22 and 24 are sufficient.

In the embodiment shown in FIG. 4, a triple voltage is applied between the discharge electrodes 14. That is, the DC power supply 26 is connected to the first capacitor 3 via the resistor 28 and the first diode 30.
2 is connected to the first capacitor 32, and the second capacitor 32 is connected to the first capacitor 32.
A second capacitor 38 is connected via third diodes 34 and 36. A third capacitor 44 is also connected to the second capacitor 38 via fourth and fifth diodes 40 and 42, and the negative side of the first capacitor 32 and the second
A switch 48, which is closed by a switch drive circuit 46, is connected between the positive side of the capacitor 38 and the positive side of the capacitor 38.
is connected. A switch 52, which is similarly closed by a switch drive circuit 50, is connected between the minus side of the second capacitor 38 and the plus side of the third capacitor 44. A control circuit 54 for controlling the switch drive circuits 46 and 50 is connected thereto. This control circuit 54 is provided with a switch 56, and the discharge electrode 14 is connected to the first capacitor 32.
and the negative side of the third capacitor 44.

In this embodiment, the capacitors 32, 3
8 and 44 are connected to the diode 3 from the power supply 26, respectively.
0, 34, 36, 40, and 42. When the switch 56 is closed, a drive signal is transmitted from the control circuit 54 to the drive circuit 4.
6, 50, and switches 48, 52 are periodically closed in synchronization with each other. switch 48,
52 are closed simultaneously, the first, second and third
capacitors 32, 38, 44 are connected in series,
A voltage three times the power supply voltage is applied to the discharge electrode 14. When the switches 48, 52 are opened and the capacitors 32, 38, 44 are charged again to a predetermined voltage, the switches 48, 52 are closed again and a high voltage is applied to the discharge electrode 14.

Also in this embodiment, since a high voltage is applied to the discharge electrode 14 only during discharge, the withstand voltage of the line can be lowered. Note that the present invention is not limited to the triple voltage circuit, and any voltage doubler circuit may be used.

As described above, according to the present invention, the withstand voltage specifications of the device can be lowered, so the device can be made smaller and cheaper.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of the electrolith crusher of the present invention, FIG. 2 is a waveform diagram for each part of FIG. 1, and FIGS. 3 and 4 show other embodiments, respectively. It is a circuit diagram. 2... AC power supply, 6... Switch, 8... Capacitor, 10... Discharge gap, 12... Transformer, 14... Discharge electrode, 16... Oscillator, 18,
20...Transistor, 22,24,26...DC power supply, 30,34,36,40,42...Diode, 32,38,44...Capacitor, 4
6, 50...Switch drive circuit, 54...Control circuit.

Claims (1)

[Scope of Claims] 1. In an electrolithotomy device that destroys intracanal stones by inserting electrodes into the body and applying a high voltage between the electrodes to generate electric discharge, the device is connected to the electrodes and at the time of discharge operation. An electrolith crusher characterized in that it is equipped with a means for generating high voltage only in the 2. The high voltage generating means includes a step-up transformer, a current is intermittently supplied to the primary side of the step-up transformer, and a high voltage is intermittently generated to the secondary side of the step-up transformer. 1. The electrolithotomy device according to 1. 3. The electrolith crusher according to claim 1, wherein the high voltage generating means includes a switch that connects a plurality of capacitors connected in parallel to a power source in series, and a series high voltage is applied to the discharge electrode. .