Electrode arrangement and electrosurgical gripping instrument

Abstract

The invention relates to an electrode arrangement for an electrosurgical gripping instrument with an electrode, a heating element and a resilient insulator arranged between the electrode and the heating element to insulate them from one another, wherein the insulator is soft relative to bending. The invention further relates to an electrosurgical gripping instrument with an electrode arrangement according to the invention.

Claims

1. An electrode arrangement for an electrosurgical gripping instrument with an electrode, a heating element having feed lines for supplying the heating element with electrical current, and an electrically insulating thermally conductive insulator being arranged between the electrode and the heating element and electrically insulating them from one another, wherein the insulator is resilient; the insulator is a foil made from insulating, resilient plastic material, glass, ceramic or silicon on which the heating element and the feed lines for supplying the heating element with electrical current are applied; and the foil and the feed lines jointly form a contact tab which protrudes laterally from a surface which is covered by the heating element.

2. The electrode arrangement according to claim 1, wherein the insulator is configured flat.

3. The electrode arrangement according to claim 1, wherein the insulator is wholly or partially made of a flexible plastic material, glass, ceramic or silicon.

4. The electrode arrangement according to claim 3, wherein the plastic material is polyimide.

5. The electrode arrangement according to claim 3, wherein the plastic material is poly(4,4′-oxydiphenylene-pyromellitimide).

6. The electrode arrangement according to claim 1, wherein the heating element is at least two times as thick as the insulator.

7. The electrode arrangement according to claim 1 wherein the heating element covers more than 80% of a surface of the insulator, and wherein the insulator covers more than 80% of the surface of the electrode.

8. The electrode arrangement according to claim 1, wherein heating element has one or multiple recesses for temperature sensors.

9. The electrode arrangement according to claim 1, wherein the electrode, in comparison to the insulator, is inflexible.

10. The electrode arrangement according to claim 1, wherein the electrode is configured flat.

11. The electrode arrangement according to claim 1, wherein the heating element, the insulator and the electrode form a layer stack.

12. The electrode arrangement according to claim 1, wherein the heating element is four times as thick as the insulator.

13. An electrosurgical instrument including a stiff jaw, wherein the jaw supports an electrode arrangement with an electrode, a heating element having feed lines for supplying the heating element with electrical current, and an electrically insulating thermally conductive insulator being arranged between the electrode and the heating element and electrically insulating them from one another, wherein the insulator is resilient, the heating element is facing towards the jaw; the insulator is a foil made from insulating, resilient plastic material, glass, ceramic or silicon on which the heating element and the feed lines for supplying the heating element with electrical current are applied; and the foil and the feed lines jointly form a contact tab which protrudes laterally from a surface which is covered by the heating element.

Description

(1) Additional features, advantages and embodiments of the invention are described with reference to the accompanying figures.

(2) FIG. 1 illustrates an electrosurgical gripping instrument according to the second aspect of the invention;

(3) FIG. 2 illustrates a first embodiment of an electrode arrangement according to the first aspect of the invention;

(4) FIG. 3a illustrates a second embodiment of an electrode arrangement according to the first aspect of the invention;

(5) FIG. 3b illustrates a modification of the embodiment of FIG. 3a;

(6) FIG. 4 illustrates a third embodiment according to an electrode arrangement according to the first aspect of the invention;

(7) FIG. 5 illustrates the embodiment of FIG. 4 in an installed condition.

(8) FIG. 1 illustrates an electrosurgical gripping instrument 10 according to the second aspect of the invention with a first handle part 20 and a second handle part 25, a first jaw 30 and a second jaw 35. The first handle part 20 is inflexibly connected with the first jaw 30. Likewise, the first handle part 25 is inflexibly connected with the second jaw 35. At a respective transition between handle part and jaw, the first handle part 20 and the second handle part 25 are rotatably connected with one another by means of a swivel joint 40.

(9) When the first handle part 20 is pushed towards the second handle part 25, the first jaw 30 and the second jaw 35 jointly perform a plier-like gripping movement.

(10) The first jaw 30 carries a first electrode arrangement 100 which is facing towards the second jaw 35. Likewise, the second jaw 35 carries a second electrode arrangement 105 which is facing towards the first jaw 30. If the first jaw 30 and the second jaw 35 jointly perform a plier-like gripping movement, the first electrode arrangement 100 and the second electrode arrangement 105 move towards one another.

(11) The electrosurgical gripping instrument 10 further includes connecting lines 180, 185, 190, 195 through which heating elements and electrodes of electrode arrangements can be energized. These are described infra.

(12) Suitable electrode arrangements 100, 105 are respectively described as electrode arrangements 100 in FIGS. 2-4.

(13) FIG. 2 illustrates a first embodiment of an electrode arrangement 100 according to the first aspect of the invention. The electrode arrangement 100 includes an electrode 200 which is suitable for electrode-tissue contact. The electrode 200 is connectable with an HF energy source through a connecting line 190. An insulator 110 configured as a foil made from poly (4,4′-oxydiphenylenepyromellitimide) is applied onto the electrode 200.

(14) The insulator requires more than 90% of the surface area of the electrode on one side. On the insulator 100, a heating element 120 in form of a heating wire is applied. This heating wire is partially configured in meandering shape in order to achieve an as far as possible even heating over a surface of the insulator 110 or the electrode 200, respectively.

(15) The layers of the stack comprising electrode, insulator and heating element are interconnected in a good thermal conductive manner. This can be achieved for example through a suitable glue or also through laminating, printing or sputtering.

(16) Furthermore, a first feed line 130 and a second feed line 135 for the heating element 120 are configured on the insulator 110. These are connected with a first contact pad 140 and a second contact pad 145. The heating element 120 can be electrically contacted by means of the contact pads 140, 145.

(17) With its largest flat portion, the insulator 110 defines a plane. A small portion of the insulator 110 and the feed lines 130, 135 attached thereto, however, are bent together out of this plane to form a contact tab 115. Here it is configured in U-shaped form. Thereby, the contact pads 140, 145 can be contacted through connecting lines 180, 185 without occurring of any mechanical loading of the electrode arrangement 100. Further, on the contact pads 140, 145, are cover 160 made from epoxy resin is applied which protects the contact pads 140, 145 against mechanical or chemical damage.

(18) FIG. 3a illustrates a second embodiment of an electrode arrangement 100 according to the first aspect of the invention in a sectional view. The view of FIG. 3a is not true to scale but only schematically. The insulator 110, the heating element 120 and the electrode 200, which are illustrated in FIG. 3a, have already been described with reference to FIG. 2.

(19) The electrode arrangement in FIG. 3a illustrates a further insulator 110b, so that the heating element 120 is enveloped on both sides by an insulator 110, 110b. The insulator 110, 110b protrudes laterally beyond the heating element 120. In reality, the thicknesses of the insulators 110, 110b are only a few tenths or hundredths of a millimeter, e.g. 0.025 mm. The heating element has a thickness of 0.1 to 0.2 mm and the electrode has a thickness of approximately 1 mm.

(20) A modification of the embodiment of FIG. 3a is illustrated in FIG. 3b. Herein, the heating element 120 is enclosed between the insulators 110, 110b, which together continue outside of the heating element 120 like a foil.

(21) The insulator 110, 110b on both sides of the heating element 120 has the advantage that the heating element 120 is insulated from the material of the jaw 30, 35.

(22) During a tissue fusion, the gripping element 10 with the electrode arrangements 100, 105 according to the invention is used as follows. The tissue layers to be fused are superimposedly engaged between the two jaws 30, 25. The two electrodes 200 of the electrode arrangement 100, 105 are connected through connecting lines 190, 195 to different poles of a bipolar output of a HF generator (not illustrated). The heating elements 120 are respectively connected through connecting lines 180, 185 to a further bipolar output of a HF generator. Alternatively, also the same bipolar output at the HF generator can be used, namely together with a switching device which can alternatively connect heating devices or electrodes.

(23) Now, initially the supply of HF energy to the electrodes 200 is activated, for example through a handswitch or foot switch. As a result, a HF current flows between the electrodes 200 of the electrode arrangements 100, 105 through the tissue layers to be fused. The tissue is heated by the HF energy and tissue fusion starts.

(24) Through the HF current, the tissue starts to dehydrate and the tissue resistance increases. Before it occurs that too little current flows to further heat and fuse the tissue, the heating elements 120 of the electrode arrangements 100, 105 are activated.

(25) The HF electrodes 200 are deactivated, i.e. it is switched from one output to another output of the HF generator. By means of the heating elements 120, thermal energy is generated and transmitted through the electrodes 200 and passed to the tissue. Due to the supply of thermal energy, tissue fusion is sustained. When the tissue layers are sufficiently sealed, the heating elements are deactivated and the tissue fusion is completed. During tissue fusion, permanent pressure is exerted onto the tissue layers through the jaws 30, 35 which has an advantageous effect on the tissue fusion.

(26) The heating elements 120 can, as an alternative to the alternating current of the HF generator, of course also be heated by direct current. However, alternating current is more advantageous.

(27) FIG. 4 illustrates a third embodiment of an electrode arrangement 100 according to the first aspect of the invention.

(28) This includes a flat electrode 200a, on which a flat insulator 110a is applied. On the insulator 110a, a heating element 120 is applied, which, in contrast to the heating element 120 of FIG. 2, is configured flat. Thereby, a particularly even heating of the electrode 200a is achieved.

(29) Furthermore, the heating element 120a, the insulator 110a and the electrode 200a have three recesses 170 for temperature sensors, of which two of them are shown in FIG. 4. Thus, the recesses 170 are passages in the electrode arrangement. Temperature sensors, preferably optical temperature sensors, can be inserted into these recesses 170. In order not to influence the temperature measurement, the heating element 120a is configured radially offset from the circular recesses 170. Therewith, an insulation offset is provided.

(30) Feed lines and connecting lines are not explicitly illustrated in FIG. 4. However, it is to be comprehended that the heating element 120a illustrated in FIG. 4 must to be supplied with electrical energy like the heating element 120 in FIG. 2. For this purpose, suitable feed lines are provided in a contact tab 115a, which is illustrated in FIG. 4.

(31) FIG. 5 illustrates the embodiment of FIG. 4 in installed condition. Therein, the electrode arrangement 100 is applied on a support block 220. The electrode 200a is clearly visible in this illustration, also the three recesses 170 for temperature sensors. The contact tab 115a, in comparison to FIG. 4, is bent differently; however, it has the same function.