DE102010036534A1 - Electrosurgical device - Google Patents

Abstract

The present application is concerned with the cutting of biological tissue. The device provided should enable large blood vessels (e.g. with a diameter of 2 mm) to be cut cleanly and sealed at the same time. It comprises: - at least one electrosurgical instrument with a first jaw part and a second jaw part, which are articulatedly connected to one another in such a way that the jaw parts can be brought from a receiving position into a closed position for grasping tissue, the jaw parts in each case application electrodes for applying an HF Have tension on the gripped tissue, the second jaw part comprising an insulation part which is arranged directly opposite the first application electrode, - a supply device for supplying the application electrodes with an RF voltage. The device is characterized in that the supply device comprises at least one control device which is designed such that a cutting voltage is applied over a period of application during a cutting interval and a coagulation voltage is applied by means of the application electrodes during a coagulation interval.

Description

The invention relates to an electrosurgical device according to the preamble of claim 1.

Electrosurgical devices have been used for many years in high frequency surgery (RF surgery) to coagulate or cut biological tissue. In HF surgery, a high-frequency current is passed through the tissue to be treated, so that this changes due to protein coagulation and dehydration. The tissue contracts in such a way that vessels are closed and bleeding is stopped. A high current density is required for a cutting process, so that explosive vaporization of the tissue fluid and rupture of the cell membranes completely disrupt the tissue.

An electrosurgical device can have a supply device with a high frequency generator that generates the corresponding alternating current, and an electrosurgical instrument, by means of which the alternating current is applied to the tissue. Commonly used electrosurgical instruments are electrosurgical scissors and electrosurgical clamps.

The electrosurgical instruments already mentioned belong mostly to the class of bipolar electrosurgical instruments. The tool heads of the corresponding instruments thus have two application electrodes, between which the alternating current flows. The circuit is closed by the tissue to be cut or coagulated between the application electrodes. A monopolar instrument has only a single application electrode that contacts the tissue to be treated. Another application electrode has a large area and is attached, for example, directly to the patient. A supply device for a monopolar instrument is from the WO 2006/050888 A1 known.

Bipolar instruments are particularly suitable for closing vessels and then severing them. However, it proves to be particularly problematic to cut through large vessels (for example with a diameter of more than 2 mm). Using conventional HF surgical bipolar scissors at this point, their performance is often insufficient to occlude these larger blood vessels. In an alternative method, bipolar clamps are used to coagulate the vessel in two places. This is followed by a mechanical severing by means of a pair of scissors. The instrument change is associated with a considerable amount of time. Furthermore, ultrasound instruments are known which solve the problem. For the treating physician, however, it is problematic to have to use an additional instrument only for the closure of larger vessels.

The EP 1 632 192 A1 and the WO 2004/032777 A1 describe electrosurgical devices that are explicitly designed to cut through and seal vessels. That's how it shows WO 2004/032777 A1 a supply device to which at least one electrosurgical instrument with a first jaw part and a second jaw part can be connected. The jaws are connected to each other in such an articulated manner that they can be brought from a receiving position into a closed position for grasping tissue. The electrosurgical instrument is thus designed in the form of a forceps. The jaws each have an application electrode to apply an RF voltage to captured tissue. The two application electrodes serve to coagulate the collected tissue. At the upper jaw part, a cutting electrode is centrally arranged, which can cut a coagulated tissue in conjunction with the application electrode at the lower jaw part. Immediately opposite the cutting electrode, an insulating part is provided, so that there is no short-circuit in the case of a direct contact between the cutting electrode and the lower jaw part. The WO 2004/032777 A1 it provides that the cutting electrode is activated after sufficient coagulation by means of the application electrodes. The in the WO 2004/032777 A1 described device has the disadvantage that it is very complex. Furthermore, coagulating the tissue prior to cutting makes electrosurgical cutting difficult. Thus, the application of the coagulation current by means of the opposing application electrodes dries the tissue so strongly that efficient electrosurgical cutting is only possible with difficulty. The treating physician must try to estimate the coagulation current and the time it is applied so that the tissue remains in a state that allows electrosurgical severing.

Starting from the WO 2004/032777 A1 It is an object of the present invention to provide an improved electrosurgical device. In particular, a device is to be presented, the larger vessels securely sealed and then severed efficiently. When cutting through the tissue carbonization should be avoided.

This object is achieved by the electrosurgical apparatus according to claim 1.

• – mindestens ein elektrochirurgisches Instrument mit einem ersten Maulteil und einem zweiten Maulteil, die derart gelenkig miteinander verbunden sind, dass die Maulteile aus einer Aufnahmestellung in eine Schließstellung zum Fassen von Gewebe bringbar sind, wobei das erste Maulteil eine erste Applikationselektrode und das zweite Maulteil mindestens eine zweite Applikationselektrode zum Anlegen einer HF-Spannung an das gefasste Gewebe haben, wobei das zweite Maulteil ein Isolationsteil umfasst, das der ersten Applikationselektrode unmittelbar gegenüberliegend angeordnet ist,
• – eine Versorgungseinrichtung zur Versorgung der Applikationselektrode mit einer HF-Spannung.

In particular, the object is achieved by an electrosurgical device comprising:

• At least one electrosurgical instrument having a first jaw part and a second jaw part, which are connected to one another such that the jaw parts can be brought from a receiving position into a closed position for grasping tissue, wherein the first jaw part has a first application electrode and the second jaw part has at least one second application electrode for applying an RF voltage to the collected tissue, wherein the second jaw part comprises an insulating part, which is arranged directly opposite the first application electrode,
• - A supply device for supplying the application electrode with an RF voltage.

The electrosurgical device is characterized inter alia by the fact that the supply device comprises at least one control device which is designed such that a cutting voltage is applied during a cutting interval over a period of application and a coagulation voltage is applied by means of the application electrodes during a coagulation interval.

An essential aspect of the present invention is therefore that the same application electrodes are used to apply the cutting voltage and the coagulation voltage. The insulating part can serve to avoid a short circuit between the application electrodes. Furthermore, the isolation part ensures that the HF current is conducted through the tissue in predetermined paths, so that large-area coagulation takes place, in particular during the coagulation interval.

The insulating member may be a radio play resistant material, e.g. As ceramics include. Preferably, the insulating material used has a resistance greater than or equal to 50 ohms, which is resistant to sparking when cutting.

The application electrodes can be arranged on the jaw parts such that they are spaced apart from one another in the closed state. Preferably, these have a distance from each other, which is at least 0.1 mm and / or at most 5 mm in the closed state. This distance in the closed state ensures that a sufficient sealing of the collected tissue is ensured when applying the coagulation voltage.

The first jaw part may comprise an insulator layer, which is arranged on the sides of the first application electrode facing away from the second jaw part, in order to electrically isolate the first application electrode from the tissue. Preferably, an immediate contacting of the fabric is therefore possible only on the side facing the second jaw part. Thus, the RF current is concentrated to a predefined range. Leakage currents over tissue areas that should not be coagulated are avoided. Furthermore, the exact application of the HF current allows better monitoring of the processes. For example, a spark occurring between the application electrodes can be detected. Preferably, it is an insulation with a resistance greater than 300 ohms.

The second jaw part may comprise an insulator layer, which is arranged on the sides of the second application electrode facing away from the first jaw part in order to electrically insulate the second application electrode from the tissue. This insulating layer on the second jaw part can effectively electrically shield the second application electrode in such a way that the current flow is limited to the gap between the first and the second jaw part.

The second jaw part may comprise a substantially planar clamping surface for receiving the tissue. Likewise, the first jaw part may comprise a cutting device with an edge facing the insulator part, for example a cutting edge, for severing tissue. The flat clamping surface allows a planar arrangement of the applied there application electrode, so that the RF current is distributed over a larger area of the captured tissue and the tissue, in particular the vessels are sealed over a large area. The edge mechanically supports the separation process of the tissue. Furthermore, side surfaces of the edge may act as application electrodes and be inclined so as to advantageously introduce the RF current into the tissue.

The jaw parts may be configured such that an insulation part width of the insulator part is greater than or equal to a cutting device width of the cutting device. Preferably, the application electrodes are formed and arranged such that the current density in the gap between the jaw parts decreases in lateral directions (transverse to a longitudinal axis). This applies at least to the intermediate region which does not directly adjoin the insulator part.

The control device may be designed such that an application time comprises a plurality of, in particular regular, changes between the cutting voltage and the coagulation voltage. Preferably, the cutting current is a bipolar continuous RF current which is controlled for cutting control in pulses with a break.

The control device may comprise a spark detection device for detecting a spark occurring at the application electrodes and / or an impedance measuring device for detecting a tissue impedance, the length of the cutting interval being determined as a function of signals output by the spark detection device / impedance measuring device. To brake the cut sufficiently, the individual cutting pulses or cutting intervals are interrupted. The interruption may occur depending on the detection of a spark or the change of the RF current (the tissue will become high impedance). In the intervening pauses, a coagulation voltage can be applied at least temporarily.

The electrosurgical apparatus may comprise an adjustment device for setting an operating speed, wherein the control device is designed to select the length of the cutting interval as a function of the set operating speed.

Further advantageous embodiments will be apparent from the dependent claims.

The invention will be described with reference to an embodiment which is explained in detail by means of several illustrations. Hereby show:

1 an electrosurgical device having a supply device and an electrosurgical instrument connected thereto;

2 individual components of the supply device;

3 a cross section through the electrosurgical instrument 1 ;

4 a detailed side view of the jaws of the instrument 1 ;

5 a diagram showing the applied RF voltage over time.

In the following description, the same reference numerals are used for the same and like parts.

The electrosurgical device according to the invention comprises a supply device 20 ( 1 ) and a bipolar electrosurgical instrument 30 , where the instrument 30 via a supply cable 21 to the utility 20 connected.

The instrument 30 has a first and a second industry, the rotatable by means of a rotary joint 33 attached to each other. The swivel joint 33 allows the instrument 30 open to receive tissue and then close to hold the tissue in a closed state. In this closed state, both a coagulation and a cutting process can be performed.

The first branch has a first jaw part at its distal end 40 and at its proximal end a first handle 31 for actuating the first jaw part 40 , The second branch has a corresponding second jaw part corresponding to the distal end 50 and at the proximal end a second handle 31 ' on. The handles 31 . 31 ' include finger holes, allowing the instrument 30 can be comfortably held and operated by a doctor.

The 4 shows a detailed view of the distal portion of the instrument. As already described, the jaw parts 40 . 50 rotatable about the hinge 33 connected with each other. The first jaw part 40 has at the second jaw part 50 facing side (first clamping surfaces 47 ) a cutting device 45 comprising a layer of a first application electrode insulator 43 surmounted. Except for the first jaw part 40 facing side (second clamping surface 57 ) is also the second jaw part 50 completely from an application electrode insulator 53 jacketed.

3 shows a cross section through the jaw parts 40 . 50 , It turns out that in this cross-section the cutting device 45 essentially wedge-shaped downwards expires, wherein the first clamping surfaces 47 forming the side portions of the wedge. The cutting device 45 has at its lower end - the second jaw part 50 facing section - an edge 46 , which is designed to mechanically separate tissue. The second jaw part 50 opposite sides are at least partially by the first application electrode insulator 43 jacketed. In cross section, this is substantially U-shaped. The edge 46 immediately opposite is an anvil 55 which is formed as an insulator. This is preferably a ceramic layer, which in the closed state of the jaw parts 40 . 50 through the edge 46 will be contacted. The anvil 55 has a substantially rectangular shape in cross-section and is of a second application electrode 51 in sections. The second application electrode 51 in turn is from the second application electrode insulator 53 sheathed in sections. The second jaw part 50 includes the anvil 55 , the second application electrode 51 and the second application electrode insulator 53 , These elements form a second clamping surface at the top 57 out, which is flat along the longitudinal axis of the second jaw part 50 extends. The second application electrode 51 is only on the first jaw part 40 facing side accessible from the outside. The other sides are through the application electrode insulator 53 electrically isolated. The second application electrode 51 forms two mutually parallel surfaces alternately to the anvil 55 made up of part of the second clamping surface 57 are. The cutting device 45 can these areas of the second application electrode 51 do not contact directly. Once tissue between the cutter 45 and the anvil 55 is clamped, can be by means of the supply device 20 an RF voltage to the first application electrode 41 and thus to the cutting device 45 and to the second application electrode 51 invest. It form current paths in the tissue, which are substantially oblique to the second clamping surface 57 run. The current density is therefore immediately below the cutting device 45 , especially below the edge 46 , relatively low, so that the tissue located there denatured until a relatively late time. Beyond the anvil 55 the current density increases and decreases towards the edge area.

Preferably, a cutting device width b _{S is} smaller than an insulating part width b _I , so that the surface accessible from above of the anvil 55 in a plan view laterally over the cutter 45 protrudes. Thus, a secure isolation of the application electrodes 41 . 51 guaranteed against each other. An electrode distance b _E amounts to approx. 5 mm. In another embodiment, this distance may be any value between 0.1 mm and 5 mm. The electrode spacing b _E can, for example, be the smallest distance between the application electrodes 41 . 51 be understood in the closed state.

The supply device according to the invention 20 (see. 2 ) can be a rf generator 22 and a controller 23 include communicating with each other. The control device 23 acts in this way on the RF generator 22 one that this is the electrosurgical instrument 30 operates at a predetermined RF voltage I _HF . Already by the control of the HF generator 22 are the controller 23 essential parameters known. Other parameters may be from an optional existing RF sensor unit 24 to be delivered. This HF sensor unit 24 can be understood as a logical unit containing some essential sensor units of the supply device 20 summarizes. This may include, for example, a spark sensor, an RF voltage sensor and an RF current sensor, which provide information regarding the applied current or the applied voltage and indicate whether a spark is present at the application electrodes 41 . 51 is present.

In one embodiment (cf. 5 ) is activated after activation of the supply device 20 over a cutting interval t _S a cutting voltage U _S to the application electrodes 41 . 51 created. This cutting voltage U _S is such that it comes to a separation of the captured tissue. After the expiry of the cutting interval T _S is from the controller 23 a coagulation voltage U _{K is} applied via a coagulation interval t _K. This coagulation voltage U _K can be significantly smaller than the cutting voltage U _S. After the expiration of the coagulation interval t _K , a cutting interval t _S can again take place. The individual intervals can be run alternately until the supply device 20 is deactivated. This results in a large number of cutting phase start times s1, s2.

Preferably, the incision is braked to ensure sufficient coagulation of the tissue. The control device 23 can be designed for this purpose so that it determines the individual cutting intervals t _S dynamic. For example, a spark may be detected (eg, by means of a spark detection device) at the application electrodes 41 . 51 occurs. Thereafter, it is possible to switch immediately from the cutting interval t _S into the coagulation interval t _K. Alternatively, this change can take place with a delay t _V. The delay t _V may be, for example, between 0 and 25 ms. After the expiration of the delay t _V so the cutting process at a termination time z. B. ab1 ended. In the in 5 f1 shows the spark signal time, ie the time at which a corresponding spark occurs. Alternatively, this point in time may indicate the change in the applied HF current-due to a tissue change. For example, the tissue may become highly resistive due to dehydration. The coagulation interval t _K may also be static or dynamic by the control device 23 be specified. For example, the attending physician can set a working speed. The control device 23 sets this working speed by setting a certain length for the coagulation interval t _K.

Numerous variations of the embodiment described should be conceivable for the person working here. So it is readily possible to one or both of the application electrode insulators 43 . 53 to renounce. Furthermore, these application electrode insulators 43 . 53 the associated application electrodes 41 . 51 only partially encase.

Furthermore, it is conceivable to vary the coagulation voltage U _K as a function of the tissue state or other parameters (eg the course of the separation process).

It is possible that the cutting device 45 in the closed state directly on the anvil 55 rests. On the other hand, on the instrument 30 also be provided a stop, so that the cutting device 45 also in the closed state a predefined distance to the anvil 55 comply.

The articulated connection between the jaw parts 40 . 50 can be a swivel 33 be. On the other hand, any joint can be used here. So it is possible that only one of the jaw parts 40 . 50 articulated against the other jaw part 40 . 50 is pivotable. Theoretically, however, both jaws can 40 . 50 to pivot against a base. Furthermore, it is conceivable that the pivoting of the jaws 40 . 50 takes place by a parallel displacement or by a rotational movement.

An electrosurgical version was described in advance. However, it is also possible to use the teaching according to the invention in an endoscopic instrument.

LIST OF REFERENCE NUMBERS

20

supply

21

power cable

22

RF generator

23

control device

24

RF sensors

30

instrument

31, 31 '

handle

33

swivel

40

first jaw part

41

first application electrode

43

first application electrode insulator

45

cutter

46

edge

47

first clamping surface

50

second jaw part

51

second application electrode

53

second application electrode insulator

55

anvil

57

second clamping surface

ab1

Demolition time

b _s

Cutter width

b _i

Insulation part width

b _E

electrode distance

f1

Radio signal timing

s1, s2

Cutting phase start time

t _V

delay

t _s

cutting interval

t _K

Koagulationsintervall

U _S

cutting power

U _K

coagulation stress

U _HF

RF voltage

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2006/050888 A1 [0004]
• EP 1632192 A1 [0006]
• WO 2004/032777 A1 [0006, 0006, 0006, 0006, 0007]

Claims (13)

An electrosurgical device comprising: - at least one electrosurgical instrument ( 30 ) with a first jaw part ( 40 ) and a second jaw part ( 50 ), which are connected so articulated that the jaws ( 40 . 50 ) are brought from a receiving position into a closed position for grasping tissue, wherein the first jaw part ( 40 ) a first application electrode ( 41 ) and the second jaw part ( 50 ) at least one second application electrode ( 51 ) for applying an RF voltage to the collected tissue, wherein the second jaw part ( 50 ) an isolation part ( 55 ), that of the first application electrode ( 41 ) is arranged opposite, - a supply device ( 20 ) for the supply of the application electrodes ( 41 . 51 ) with an RF voltage, characterized in that the supply device ( 20 ) at least one control device ( 23 ), which is designed in such a way that a cutting voltage (U _S ) and during a coagulation interval (t) a coagulation voltage (U _K ) by means of the application electrodes (U _S ) over an application period during a cutting interval (t _S ) 41 . 51 ). Electrosurgical device according to claim 1, characterized in that the insulating part ( 55 ) a material resistant to spark play, e.g. As ceramic, includes. Electrosurgical device according to one of the preceding claims, characterized in that the application electrodes ( 41 . 51 ) so on the jaw parts ( 40 . 50 ) are arranged such that the application electrodes ( 41 . 51 ) are spaced apart in the closed state. Electrosurgical device according to one of the preceding claims, in particular according to claim 3, characterized in that the application electrodes ( 41 . 51 ) so on the jaw parts ( 40 . 50 ) are arranged such that a distance between the application electrodes ( 41 . 51 ) in the closed state is at least 0.1 millimeters and / or at most 5 millimeters. Electrosurgical device according to one of the preceding claims, characterized in that the first jaw part ( 40 ) an insulator layer ( 43 ), which are connected to those of the second jaw part ( 50 ) facing away from the first application electrode ( 41 ) is arranged around the first application electrode ( 41 ) to electrically isolate from the tissue. Electrosurgical device according to one of the preceding claims, characterized in that the second jaw part ( 50 ) an insulator layer ( 43 ), which are connected to those of the first jaw part ( 50 ) facing away from the second application electrode ( 51 ) is arranged around the second application electrode ( 51 ) to electrically isolate from the tissue. Electrosurgical device according to one of the preceding claims, characterized in that the second jaw part ( 50 ) a substantially planar clamping surface for receiving the tissue and / or the first jaw part ( 40 ) a cutting device ( 45 ) with an insulator part ( 55 ) facing edge ( 46 ) for severing tissue. Electrosurgical device according to one of the preceding claims, in particular according to claim 7, characterized in that the jaw parts ( 40 . 50 ) are formed such that an insulation part width (b _I ) of the insulator part ( 55 ) greater than or equal to a cutter width (b _S ) of the cutter ( 45 ). Electrosurgical device according to one of the preceding claims, characterized in that the control device ( 23 ) is designed such that an application time comprises a plurality of, in particular regular, changes between the cutting voltage (U _S ) and the coagulation voltage (U _K ). Electrosurgical device according to one of the preceding claims, characterized in that the control device ( 23 ) a spark detection device for detecting a at the application electrodes ( 41 . 51 ) and / or an impedance measuring device for detecting a tissue impedance, wherein the length of the cutting interval is determined as a function of signals output by the spark detection device / impedance measuring device. Electrosurgical device according to one of the preceding claims, in particular according to claim 10, characterized in that the control device ( 23 ) is designed such that the control device ( 23 ) determines, by means of the spark detection device / impedance measuring device, a time (f1) at which the spark occurs and / or a tissue impedance exceeds a predetermined value, and interrupts a cutting interval (t _S ) after a predetermined delay interval (t _V ). Electrosurgical device according to one of the preceding claims, characterized by an adjusting device for setting an operating speed, wherein the control device ( 23 ) to is designed to select the length of the cutting interval (t _S ), in particular the delay interval (t _V ), depending on the set operating speed. Electrosurgical device according to one of the preceding claims, characterized in that the device exactly two application electrodes ( 41 . 51 ).

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