Electrosurgical instrument comprising a light guide

The instrument according to the invention for electrosurgically impacting biological tissue comprises an electrode (18) as well as a light guide (21), which is connected to a light inlet window (19), which is formed by means of a fluid body (27). The light guide is connected to a light analysis device (13), so as to absorb the light, which is generated at the electrode (18) in response to the HF surgery and so as to supply it to the light analysis device (13). The light inlet window (19) is arranged at the point of origin of the light, namely immediately at the electrode, that is, at the spark, which is generated. An adulteration of the absorbed light by means of smoke or particle deposition on the light inlet window (19) can virtually be avoided.

This application claims the benefit of European Patent Application No. EP13173066.5 filed Jun. 20, 2013, the contents of which are incorporated herein by reference as if fully rewritten herein.

TECHNICAL FIELD

The invention relates to an instrument for electrosurgically impacting biological tissue and in particular to an instrument for HF surgery.

BACKGROUND

Electrosurgical instruments are known, which impact biological tissue by generating sparks and which supply the light generated thereby to an analysis device.

For this purpose, WO 2011/055369 A2 discloses a micro plasma head for medical applications. This micro plasma head is formed by means of an elongated flexible instrument, at the end of which provision is made for electrodes for generating plasma. A light guide, the open front surface of which forms a light inlet window, ends so as to be slightly recessed. A plasma, the light of which is absorbed by the light inlet window, forms in front of the light inlet window. The connected light analysis device examines the light spectrum of the light emanating from the plasma in particular for the presence of a characteristic phosphor line. This serves for the differentiation of living tissue of plaques in response to the use of the instrument for removing plaques in blood vessels.

A more subtle light examination is proposed by U.S. 2007/0213704 A1. The elongated instrument illustrated therein encompasses an optical fiber in the center, which ends in a spherical recess of a ceramic end piece. Two sharp-edged electrodes, which generate a plasma in this recess, are also arranged in this recess.

A successful spectral light analysis requires for the light to reach to the spectral analyzer.

SUMMARY

The instrument according to the invention encompasses at least one electrode, which can be connected or which is connected to an electric source via a line. The source can be an HF generator, e.g. The electrode can be monopolar and can consists of one or a plurality of parts. In this case, the counter electrode, which is required to close an electric circuit, is fastened to the patient as neutral electrode.

The instrument can be embodied as an instrument for the use in open surgeries or as instrument, which is provided for laparoscopic use. It is set up in particular for HF surgical procedures, in the case of which sparks, advantageously with a spectrum of between 200 nm and 1200 nm, are generated at the electrode. Preferably, provision is made in such cases for an HF generator as electric source.

The instrument according to the invention is provided for connection to a light analysis device, by means of which information relating to the biological tissue, which is seized by the spark, are obtained from features of the absorbed light. To absorb this light, provision is made for a light inlet window, which is formed by means of a fluid body. The latter is in contact with the light guide, so as to transfer the absorbed light into the light guide and via the latter to the light analysis device. The fluid body has a liquid surface, which does not get dirty or char from the deposition of smoke particles, even if it is located in the immediate vicinity of the spark. It is thus possible to absorb the light, which emanates from the spark, without spectral distortion.

In particular when the light inlet window is arranged in the immediate vicinity of the electrode, it can be ensured that the light, which emanates from the spark, is actually absorbed and is not covered by tissue parts located between the spark and the light inlet window, by smoke or the like. In the preferred case, the light inlet window can be arranged so as to touch the electrode, for example in that a fluid body is held by means of adhesion between the electrode and the light guide. For this purpose, it is advantageous, if the light inlet window and/or the electrode encompass a hydrophilic surface. A substantially resting fluid body can be held in this manner between a surface of the light guide and the electrode. In the preferred case, two hydrophilic electrode surface, which are located opposite one another and between which there is no potential difference, form a gap, the bottom of which is formed by a hydrophilic light guide surface. The gap width is preferably so small that the fluid body is held in the gap by means of capillary effect. The fluid, which forms the fluid body, can be rinsing fluid, which is present in the vicinity, lymph or also a fluid, which is supplied via a channel. The channel can extend through the light guide, for example.

The light inlet window can also be formed by means of a flowing fluid body, for example in that a transparent liquid jet escapes from the electrode. For example, the light guide can be arranged in a fluid channel, which leads fluid to the fluid outlet openings, from which fluid jets then escape. They form the light inlet windows and guide light, which originates from the spark, into the fluid channel, where it is further absorbed by the light guide.

Regardless of whether the fluid body, which forms the light inlet window, is provided so as to rest or flow, it is advantageous, when the electrode encompasses at least two areas, which are electrically connected to one another and between which the light inlet window is arranged. The fluid body can thus be arranged between the electrode surfaces, which have the same potential, in the most immediate vicinity of the spark, which is generated.

In the case of a particularly preferred embodiment, the instrument encompasses a light guide comprising a rigid section, which supports the electrode. The rigid section can merge into a tapering tip, for example, at which an electrode is arranged, which consists of one or of a plurality of wires, metal strips or the like. The angle of the tapering tip can be between 5 and 90 degrees, for example. The size of the angle is then determined as a function of the refraction index of the used light guide, e.g. in response to the use of glass with 1.46 and as a function of the refraction index of the surrounding medium of the light guide, such as air (1.0) or water (1.33).

Preferably, the electrode is formed by means of a wire, which envelopes the tapering tip in a plurality of windings. A fluid body can remain in the gaps between adjacent windings by means of adhesion and capillary effect, if applicable. Said fluid body forms the light inlet window and transfers light to the light guide. Regardless of the location, at which location of the cone-shaped wire windings a spark originates, a majority of the light, which is generated, is absorbed by the light guide and can thus be supplied to the analysis device in an unadulterated manner. For example, the light guide can be embodied by means of a light-guiding material, such as glass, plastic, e.g. The light guide can also consists of a suitable pipe or cannula, which is metal-coated on the inside and which, as an alternative, can be filled with standing or flowing fluid. Further details of advantageous embodiments of the invention are the subject matter of the drawing, of the description or of claims.

DETAILED DESCRIPTION

FIG. 1illustrates an electrosurgical device10, which includes an instrument11, which is to be guided by the user, a feeding device12and a light analysis device13. As illustrated, it can be embodied as a separate unit or also as a part of the device12. To connect the instrument11to the device12and to the light analysis device13, provision is made for corresponding lines14, which include at least one electric line15, a light guide16and optionally at least one fluid line17. The electric line15connects an electrode18of the instrument11to the feeding device12, which includes an HF generator, for example. The light guide16connects a light inlet window19, which is provided at the electrode18, to the light analysis device13.

The instrument11can be embodied as laparoscopic instrument or also, as illustrated symbolically inFIG. 1, as instrument for open surgical procedures. It encompasses an electrode support20, which is illustrated separately inFIG. 2. Said electrode support is formed, for example, by means of a rigid light guide21, which is connected to the light guide16of the line14. The connection can be realized within a handle22, which can also support one or a plurality of operating elements23, or which can be realized so as to be spaced apart from said handle. As is illustrated inFIG. 3, the electrode support, which is formed by the rigid light guide21, can be embodied so as to be tapered in a cone-shaped manner at one end24. At this end24, a one-start or multi-start spiral groove25can be embodied, the lead of which is larger than the width of a wire, which is to be accommodated by the spiral groove25.FIG. 4illustrates a wire26, which forms the electrode18and which is inserted into the spiral groove25so as to be wound in a helical manner. This wire26forms the actual electrode. It is connected to the line15via one or a plurality of wires, which extend along the rigid light guide21.

The relationships are illustrated one again separately inFIG. 5. A distance exists between adjacent windings26a,26bof the wire26, so that the light guide21or its end24, respectively, remains visible at that location. Preferably, the surface of the light guide is embodied in a hydrophilic manner. In addition, the surface of the wire26is preferably embodied in a hydrophilic manner, at least in the part, which adjoins the light guide21. This means that the part of the light guide21, which is exposed between the windings of the wire26, and the adjoining parts of the wires26are wetted slightly by water and hold a water body by means of adhesion.

It is illustrated inFIG. 5that a fluid body27is held between adjacent windings of the wire26by means of adhesion. If the gap between the windings26a,26bis sufficiently narrow, it can also be said that there is a capillary effect. Due to the circular cross section of the wire26, the gap also widens towards the light guide.

The hydrophilic characteristic of the surfaces, which are touched by the fluid body27, can be seen by means of the concave curve of its surface, which is directed outwardly. The fluid body27consists substantially of water, for example rinsing liquid, lymph or the like. Said fluid body forms the light inlet window19, via which the light of a spark, which emanates from the wire26, is absorbed and is transferred to the light guide21.

The case at hand pertains to a resting fluid body27, which is formed by means of liquid, which flows from the environment. Smoke or other solid matter particles cannot stay permanently on its liquid surface. During operation, it is thus ensured that the light, which emanates from a spark, reaches the light analysis device13in an unadulterated manner. “Light” thereby does not only refer to visible light, but, if desired, also to infrared light and/or ultraviolet light.

The electrosurgical device10, which was described in this respect, operates as follows:

The user uses the instrument11, so as to carry out electrosurgical, preferably HF electrosurgical procedures. A neutral electrode, which is not illustrated in detail, which is connected to the device12, is fastened to the patient. The user can now generate a spark to the tissue of a patient by means of the electrode18and can thus cause an effect, for example cutting, coagulating or the like. The light, which is generated by the spark, is influenced by the treated tissue in a subtle manner. Parts of the tissue, which are treated by the spark, molecules, molecule fragments, atoms, ions reach into the spark and generate a light emission. This light is absorbed via the light inlet window19and is supplied to the light analysis device13via the light guide21,16. Said light analysis device13carries out a spectral decomposition of the light and analyses the spectrum of the absorbed light, so as to determine the type of the treated tissue as precisely as possible. Corresponding signals, which can be seen, heard or felt by the practitioner, can then display the tissue type or a change of the tissue type.

It is pointed out that numerous modifications are possible. For example, the light analysis device13can be a part of the instrument11. It can be installed in the handle22thereof, for example. Further modifications can relate to the electrode18, the electrode support20and the fluid body27. For this purpose,FIG. 6illustrates an electrode support20. The latter is preferably made of a light-guiding material. It thus forms the rigid light guide21. In the rigid light guide21, provision is made here for a fluid channel28, through which a suitable fluid, for example a physiological salt solution, is guided to the end24. Provision can be made at that location for one or preferably for a plurality of fluid outlet openings29, which are connected to the fluid channel28. The fluid outlet openings29are preferably arranged such that they empty between the windings26a,26bof the wire26, which are spaced apart from one another, that is, such that they are located between the spiral groove25, as is shown inFIG. 7.

In the case of such an instrument, the fluid body27can be renewed continuously via the fluid outlet openings29during the operation. It can also be effected as a function of the fluid pressure that fluid jets, which then act as light inlet window19, escape from the fluid outlet openings29. They are then connected directly to the sparks, which originate at the wire26and thus absorb the light thereof. In the case of this embodiment, it is also possible to use optically opaque material instead of the rigid light guide21, and to arrange the light guide in the fluid channel28, so as to absorb light from the fluid at that location.

It is pointed out that the rigid light guide21can also be embodied as flexible light guide in the case of all of the above-described embodiments according toFIGS. 1 to 7. This applies in particular for instruments11, which are to be used laparoscopically.

A further embodiment of the instrument11according to the invention follows fromFIG. 8. As a small thin-walled tube, the electrode18is embodied so as to be electroconductive or by means of partially applied electroconductive metal layers, at the end24of which fluid outlet openings29are embodied. Fluid, for example a physiological salt solution or another fluid, which is based on water, is guided to the fluid outlet openings29via the fluid channel28. The fluid jets27a, which escape at that location, form the light inlet windows19. The fluid in the fluid channel28can form the light guide21. In the event that the fluid pressure is less, so that the fluid only drips or seeps from the fluid outlet openings29, the liquid-filled fluid outlet openings29form the light inlet windows19.

The light guide21, which preferably extends to the end24, is arranged in the channel28. It acts as light collector so as to capture the light, which reaches into the channel28via the fluid outlet openings29, and to supply it to the light analysis device13.

As is illustrated, the end24of the electrode18as well as the end of the light guide21can be formed in a cone-shaped manner, or also otherwise, if necessary, for example so as to be ball-shaped, spatulate or the like.

The light emission detection can be improved, when the spark is generated in the area of the light inlet windows19. For this purpose, the exemplary embodiment according toFIG. 8can encompass an electrically insulating layer, as is illustrated inFIG. 8b. The application of this electrically insulating layer, for example a plastic layer, onto the electrode18comprising openings, which form the light inlet windows19, leads to different thicknesses of the insulation layer. In the edge area of the openings of the light inlet windows, an insulation layer comprising a smaller thickness is generated. These locations, which are covered with a thin layer, are preferably penetrated when applying a HF voltage in the range of between 1000 to 10000 Volts, whereby the spark between the tissue and the electrode is generated directly at the light inlet windows19. It is thus possible to define the point of origin of the spark and thus of the light emission immediately at the edge in the area of the light inlet window19. The path to the light guide29is as small as possible. The light emission determination can thus take place virtually without any losses.

FIG. 9shows a further modified embodiment. The electrode18encompasses an electroconductive small flat plate30, which is connected to the electric source. Light guides21a,21b, which consist of plastic, for example, and which are connected to the light analysis device13, are arranged on at least one, preferably on both flat sides of the small plate30. The light guide is visible on the narrow sides31of the light guides21a,21b, which tower above the small plate30. The narrow sides31, as well as the flat sides of the small plate30, are preferably embodied so as to be hydrophilic, so that fluid bodies27, which are held at the light guide21a,21band the small plate30by means of adhesion and which form the light inlet windows19, form during operation from lymph, rinsing liquid or the like. Provision can also be made for fluid supply agents, so as to generate the fluid body27specifically or so as to supplement and renew it continuously.

The instrument11according to the invention for electrosurgically impacting biological tissue comprises an electrode18as well as a light guide21, which is connected to a light inlet window19, which is formed by means of a fluid body27. The light guide is connected to a light analysis device13, so as to absorb the light, which is generated in response to HF surgery at the electrode18, and so as to supply it to the light analysis device13. The light inlet window19is arranged at the point of origin of the light, namely immediately at the electrode, that is, at the spark, which is generated. An adulteration of the absorbed light caused by smoke or particle deposition on the light inlet window19can virtually be avoided.

LIST OF REFERENCE NUMERALS

12light analysis device

19light inlet window

21rigid light guide

24end of the light guide21

26a, bwire windings, which form areas of the electrode18

32insulating material, for example plastic