Abstract
The electrode head includes two working surfaces in accordance with an actual bipolar electrode. These may be manufactured lithographically, exhibiting even more complicated outlines. Working surfaces are depicted, which are structured as annulus sector-shaped, concentrically arranged areas, when projected in a plane. Moreover, a further area is situated centrally, which is disc-shaped in a planar projection. Plasma is ignited alternately at both poles. If the individual concentric zones are situated close enough with respect to each other a continuous plasma layer will result.
Claims
1. Surgical vaporization electrode, comprising an electrode head with at least two electrically conductive working surfaces, arranged as to be electrically isolated from each other.
2. A surgical vaporization electrode according to claim 1, wherein each of the working surfaces has at least one substantially annulus-shaped, annulus sector-shaped, elliptical annulus-shaped or elliptical annulus sector-shaped surface portion, when projected in a plane, and the surface portions are arranged concentrically or approximately concentrically in relation to each other, when projected in a plane.
3. Surgical vaporization electrode according to claim 1, wherein the working surfaces are applied in layers to an insulating base member.
4. Surgical vaporization electrode according to claim 1, wherein the electrode head is composed of electrically conductive and electrically non-conductive members.
5. A surgical instrument comprising a surgical vaporization electrode according to claim 1 and an RF generator, wherein the RF generator is configured and connected to the surgical vaporization electrode as to allow for activation and deactivation of the working surfaces separately from each other.
6. The surgical instrument of claim 5, further comprising an electronic control for activating and deactivating the working surfaces.
7. Surgical instrument according to claim 6, further comprising movement detection means for detecting a relative movement of the electrode head with respect to a reference system, wherein the electronic control is adapted to activate and/or deactivate at least one of the working surfaces depending upon the relative movement of the electrode head.
8. Surgical instrument according to claim 7, wherein the electronic control is configured to activate at least one working surface leading with respect to the direction of movement of the electrode head and to deactivate at least one working surface trailing with respect to the direction of movement of the electrode head.
9. The surgical instrument of claim 6, further comprising means for measuring impedance, wherein the electronic control is configured to activate and/or deactivate at least one of the working surfaces depending upon the impedance measurements.
10. A surgical instrument comprising a surgical vaporization electrode according to claim 1 and an RF generator, wherein the RF generator is configured and connected to the surgical vaporization electrode such that two working surfaces operate as alternating poles in bipolar mode.
11. A surgical instrument according to claim 5, wherein the surgical instrument is configured such that for plasma ignition, a predetermined working surface is activated prior to the activation of one or more of the remaining working surfaces.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1a shows a cross-sectional view of an embodiment of the electrode head of a surgical vaporization electrode according to the invention.
[0021] FIG. 1b depicts the lower surface of the electrode head of the vaporization electrode from FIG. 1a in a plan view (from below), the sectional plane being indicated by line A-A.
[0022] In FIG. 2 shows a cross-sectional view, similar to that in FIG. 1a, of a further embodiment of the electrode head of a surgical vaporization electrode according to the invention is shown, the plan view of which resembles FIG. 1b.
[0023] FIG. 3 depicts a cross-sectional view, similar to those in FIGS. 1a and 2, of a further exemplary embodiment of the electrode head of a surgical vaporization electrode according to the invention, the plan view of which, again, resembles FIG. 1b.
[0024] In FIG. 4a shows an embodiment of the electrode head of another surgical vaporization electrode according to the invention is depicted in a cross-sectional view, and, furthermore, the connection of the working surfaces to further components of a surgical instrument according to the invention.
[0025] FIG. 4b shows the lower surface of the electrode head of the vaporization electrode of FIG. 4a in a plan view (from below), the sectional plane being indicated by the line A-A.
[0026] FIG. 5 shows the lower surface of the electrode head of a further vaporization electrode according to the invention in a top view (from below).
PREFERRED EMBODIMENT OF THE INVENTION
[0027] Corresponding elements are denoted by the same respective reference numerals in the figures.
[0028] FIG. 1a shows an embodiment of the electrode head 1 of a surgical vaporization electrode according to the invention. In FIG. 1b, in the plan view of the lower surface the sectional plane A-A is indicated as a dashed line. The electrode head 1 consists of three metallic electrode bodies 2, 3, 4 and an insulator body 5 divided into three insulating rings 5a, 5b, 5c. The outer surface of each of the electrode bodies 2, 3, 4 forms a corresponding working surface 12, 13, 14. Via a respective electrical supply line 22, 23, 24, each of the electrode bodies 2, 3, 4 and thus each of the corresponding working surfaces 12, 13, 14 may be supplied with high-frequency AC voltage (activated) or be switched to zero potential (deactivated). The electrical supply lines 22, 23, 24 pass through a common head support 6, which is insulating towards the exterior, but they are isolated from each other. This may e.g. be accomplished by way of a multi-core cable. The insulating head support 6 is able perform mechanical and insulating functions. It is, however, also possible for separate elements adopting those functions. For example, a wire may provide for mechanical stability and insulation may be attained using a PTFE tube.
[0029] Two of the electrode bodies 2, 3 are configured as rings, such that the electrical supply lines 22, 23, 24 may be conducted from the inside to the electrode body 2, 3, 4. The electrode head 1 may be manufactured by assembling the insulating and electrode rings 5a, 5b, 5c, 2, 3 and the third electrode body 4, which covers the body like a cap.
[0030] Due to the separate supply lines, it is possible e.g. to activate exclusively the intermediate working surface 14 for plasma ignition. By additional activation of one of the other working surfaces 12 or 13, the total working surface may be increased, respectively.
[0031] In case of the electrode shown in FIGS. 1a, 1b, the quasi-bipolar technique is continued to be used. Instead of a static active electrode, however, several areas (working surfaces 12, 13, 14) are utilized, which may be supplied dynamically with the active potential. Thus, as described above, only the central area 14 may be employed for initial plasma ignition, while the outer areas may be switched on later. To achieve this, automated control via the RF generator (not shown in FIGS. 1a, 1b) may be employed. Depending upon impedance measurements via suitable sensors, known per se from the prior art, the generator may switch individual areas 12, 13, 14 on and off. Thus, e.g. only the areas contacting tissue are ignited. Thus, the input of heat into the saline solution is reduced significantly.
[0032] The electrode heads depicted in FIGS. 2 and 3 are of similar construction as shown in FIG. 1a and comprise substantially the same arrangement of the working surfaces 12, 13, 14 as shown in FIG. 1b. There is provided, however, a solid base member as insulating member 5. The variant as shown in FIG. 2 may be manufactured, e.g. by casting the electrode bodies 2, 3, 4 with a high-temperature-resistant plastic, by inserting electrode bodies 2, 3, which are divided inherently, into a ceramic base member (followed by attaching the cap-like electrode body 4) or by casting the metallic electrode bodies 2, 3, 4 into a mold comprising as a core insulating member 5. In the variant depicted in FIG. 3, the working surfaces 12, 13, 14 are applied to the base member 5 electrochemically, by deposit welding or another coating method.
[0033] FIG. 4a shows an exemplary embodiment of the electrode head 1 of another surgical vaporization electrode according to the invention. The sectional plane A-A is indicated in as a dashed line the plan view in FIG. 1b. The electrode head 1 consists of three metallic electrode bodies 2, 3, 4 inserted into insulator body 5, which in turn is held by a head support 6, which is insulating towards the exterior. The respective electrical supply lines 22, 23, 24 of the electrode bodies 2, 3, 4 are conducted to control- and switching-device 9 via head support 6 and the electrode shaft 7 rigidly connected thereto (connection not shown). The control- and switching-device 9 may separately connect to the RF voltage source or switch to zero potential each of the respective supply lines 22, 23, 24.
[0034] The electrode shaft 7 is guided within a transporter 10. Via the capacitive sensor device 11, the control and switching device 9 may detect the movement of the electrode shaft 7 and thus of the electrode head 1 relative to the transporter 10.
[0035] In this exemplary embodiment, the working surfaces 12, 13, 14 formed by electrode bodies 2, 3, 4 are situated next to each other or one behind the other, respectively. Thus, working surface 13, leading in the direction of movement, may be activated (indicated as an arrow in FIG. 4a), while trailing working surface 12 may remain at zero potential, such that no thermal energy is introduced into the free saline solution there. The intermediate working surface 14 may either be connected to the respective leading working surface 13 (or, respectively, 12 in the opposite direction of movement), or else remain at zero potential. Obviously, such an electrode may also be implemented with only two working surfaces. Alternatively and differently from what is shown, the intermediate working surface 14 is implemented being considerably smaller than the remaining working surfaces 12, 13 and is used for plasma ignition.
[0036] In general, all of the described exemplary embodiments are may be implemented in a similar or modified form having either more or fewer than three working surfaces 12, 13, 14.
[0037] The electrode head 1, depicted in FIG. 5 in a plan view from the bottom, comprises two working surfaces 12, 13 in accordance with an actual bipolar electrode. These may be manufactured, e.g. lithographically, exhibiting more complicated outlines. Working surfaces 12, 13 are depicted, which are structured as annulus sector-shaped, concentrically arranged areas, when projected in a plane. A further area is situated centrally, which is disc-shaped in a planar projection. Spatially, the side of the electrode head 1 depicted is either hemispherical or curved, in correspondence to an alternative part of a spherical surface. Therein, plasma is ignited alternately at both poles 12, 13. If the individual concentric zones are situated close enough with respect to each other a continuous plasma layer will result.
