RU139710U1 - BIPOLAR ELECTRODE FOR DESTRUCTION OF BIOLOGICAL FABRIC - Google Patents

Abstract

The bipolar electrode for destroying biological tissue is made in the form of coaxial electrodes isolated from each other with a partial dielectric coating, the internal electrode having the form of a hollow metal needle without insulation at the end part, and the external electrode has openings for supplying the coolant to the biological tissue, a thermal sensor, and a coolant supply system characterized in that the external electrode is installed with a gap relative to the internal electrode and is made in the form of a hollow metal needle that does not have insulation on the tip and girdle the end part near the holes located at the tip, the temperature sensor is built into the needle cavity of the internal electrode, and the external electrode is equipped with a tee to supply the coolant to the gap from the coolant supply system.

Description

This device relates to the field of medicine and veterinary medicine, mainly to surgery, and can be used to destroy biological tissues of various organs affected by the pathological process of various origins, including oncological origin.

Devices that carry out thermocoagulation of biological tissue and its destruction at a temperature of 50-100 ° C are widely used in clinical practice (see, for example, Dolgushin B.I. et al. Radio-frequency thermoablation of liver tumors / Edited by M.I. Davydov. - M: Practical Medicine, 2007). The energy from the generators in these devices is transferred to the biological tissue using fairly thin electrodes, emitters or optical fibers.

To implement the destruction of biological tissue by high-frequency current, a number of devices are known that contain a high-frequency current generator, a large neutral flat electrode mounted on the surface of the body, and an active electrode with a small working surface, introduced into the destroyed biological tissue. The high-frequency current flowing between the electrodes heats the biological tissue near the active electrode, where the current density is highest. To prevent drying of the biological tissue, which leads to an increase in its resistance and, as a consequence, carbonization of the biological tissue, in the known device (US patent No. 5599346), the active electrode is made in the form of a hollow needle with holes in the end part for the introduction of physiological saline, which maintains the normal humidity of the biological tissue adjacent to the surface of the electrode. The main disadvantage of such devices is the small amount of biodegradable tissue, usually not exceeding 2.5 cm in diameter, due to a significant decrease in current density with distance from the active electrode.

Closest to the proposed one is a device for destroying biological tissue containing a high-frequency current generator connected through a flange to a bipolar electrode made in the form of coaxial electrodes isolated from each other, having a partial coating of a dielectric, the inner electrode is made in the form of a hollow metal needle and does not have insulation on the end part, the external electrode has openings for supplying the coolant to the biological tissue, a thermal sensor, and a coolant supply system (CA 2238395, 04/02/1998). When using a device of this design, the volume of destructible biological tissue is small, since the heating of biological tissue is carried out mainly due to heat during the flow of current between two electrodes with a large distance between them.

The objective of the proposed device is to increase the volume of coagulated biological tissue.

For this, in the known device for destroying biological tissue, the bipolar electrode for destroying biological tissue is made in the form of coaxial electrodes isolated from each other with a partial coating of a dielectric, the inner electrode having the form of a hollow metal needle without insulation at the end part, and the outer electrode has openings for supplying coolant in biological tissue, a temperature sensor and a coolant supply system, characterized in that the external electrode is installed with a gap relative to the internal electrode and is made in the form of a hollow m a metal needle that does not have insulation on the tip and girdle of the end part near the holes located at the tip, the temperature sensor is built into the needle cavity of the internal electrode, and the external electrode is equipped with a tee to supply the coolant to the gap from the coolant supply system.

The essence of the proposed utility model can be understood from the following description. As shown in figure 1, the device (1), which is a bipolar electrode, consists of two electrodes. The inner electrode (2) is made in the form of a hollow metal needle coated with a dielectric (3) with the insulation removed at the end part, and with a temperature sensor (4) built into the needle cavity. The external electrode (5) is also made in the form of a dielectric coated hollow metal needle of a larger diameter, which is fixed coaxially outside the internal electrode with a gap (6) so that the electrodes do not have electrical contact with each other and together form a bipolar structure. In the end part of the external electrode near the tip there are holes (7) for supplying the coolant to the area of the biological tissue to be destroyed through the gap (6) between the electrodes. Insulation from the surface of the end part of the external electrode is removed in the form of a girdle (8) with a width of 3-5 mm in the immediate vicinity of the holes and from the tip of the electrode. The external electrode (5) has a tee (9) for supplying the coolant from the coolant supply system to the gap and a flange (10) connecting the device (1) to the high-frequency generator.

The coolant is supplied to the area of destruction of the biological tissue by means of an infusion pump (not shown in FIG. 1) through a tee (9) into the gap (6) between the inner surface of the electrode (5) and the outer insulated surface of the electrode (2) and is introduced into the biological tissue through openings (7 ) The centering of the electrodes between themselves is carried out using dielectric bushings located inside the electrode (5) near its ends. One of the bushings (11) is shown in FIG.

Testing of the device was carried out on pig liver. Under general anesthesia, the animal was fixed on the operating table and a bipolar electrode was inserted into various lobes of the liver using an ultrasound scanner. The test results showed that using the proposed device achieves an almost spherical coagulation volume with a diameter of up to 5 cm, which is almost 2 times larger in volume of the coagulated tissue than in the prototype. Histological analysis of the samples showed that heterogeneity in the volume of coagulated tissue was not observed.

Claims (1)

The bipolar electrode for destruction of biological tissue is made in the form of coaxial electrodes isolated from each other with a partial dielectric coating, the internal electrode having the form of a hollow metal needle without insulation at the end part, and the external electrode has openings for supplying the heat carrier to the biological tissue, a temperature sensor, and a coolant supply system characterized in that the external electrode is installed with a gap relative to the internal electrode and is made in the form of a hollow metal needle that does not have insulation on the tip and girdle the end part near the holes located at the tip, the temperature sensor is built into the needle cavity of the internal electrode, and the external electrode is equipped with a tee to supply the coolant to the gap from the coolant supply system.

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