WO2012010449A1

WO2012010449A1 - Electrosurgical device

Info

Publication number: WO2012010449A1
Application number: PCT/EP2011/061712
Authority: WO
Inventors: Florian Schulz; Ralf Klein; Erich Werner
Original assignee: Erbe Elektromedizin Gmbh
Priority date: 2010-07-21
Filing date: 2011-07-11
Publication date: 2012-01-26
Also published as: DE102010036534B4; DE102010036534A1

Abstract

The invention relates to cutting through biological tissue. The provided device is intended to allow large blood vessels (such as those having a diameter of 2 mm) to be cleanly cut through and simultaneously closed off. Said device comprises: at least one electric surgical instrument having a first jaw part and a second jaw part that are hinged together such that the jaw parts can be brought from a receiving position into a closed position for capturing tissue. The jaw parts each have application electrodes for applying a HF voltage to the captured tissue, and the second jaw part comprises an insulating part, which is disposed directly opposite the first application electrode, and further comprising a supply unit for supplying a HF voltage to the application electrodes. The device is characterized in that the supply unit comprises at least one control unit that is designed such that a cutting voltage is applied over an application period during a cutting interval, and a coagulation voltage is applied during a coagulation interval, by means of the application electrodes.

Description

Electrosurgical device

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 through the treated

Guided tissue, 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 may be a supply device with a

High frequency generator that generates the corresponding alternating current, and have 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 about to be cut or closed

Coagulating tissue between the application electrodes closed. 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 AI 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 with a

associated with considerable time. Furthermore, ultrasound instruments are known which solve the problem. However, it is for the attending physician

problematic to have to use an additional instrument only for the closure of larger vessels.

EP 1 632 192 A1 and WO 2004/032777 Al describe electrosurgical devices which are designed explicitly for cutting through and sealing vessels. Thus, WO 2004/032777 AI shows 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 is in the middle one

Cutting electrode arranged in conjunction with the application electrode on the lower jaw part can cut through a coagulated tissue. 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. WO 2004/032777 AI provides that the cutting electrode is activated after sufficient coagulation by means of the application electrodes. The device described in WO 2004/032777 AI 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 attending physician must try to determine the coagulation current and the period in which this is applied to estimate such that the tissue remains in a state that allows electrosurgical severing.

Starting from WO 2004/032777 AI 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.

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 in an articulated manner 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 jaw part

Application electrode and the second jaw part at least a 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 during a cutting interval and a cutting voltage during a coagulation interval

Coagulation voltage can be applied by means of the application electrodes.

An essential aspect of the present invention is therefore that the same application electrodes are used to the cutting voltage and the

Apply coagulation voltage. The insulating part can serve to avoid a short circuit between the application electrodes. Furthermore, care the isolation part that the RF current is passed through the tissue in predetermined paths, so that a large-scale coagulation, especially during the coagulation interval takes place.

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 a cutting device with a the edge facing the insulator part, for example a cutting edge, for cutting through 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 formed such that an insulating part width of the insulator part is greater than or equal to a cutter width of the

Cutting device is. 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 can be a spark detection device for detecting a spark occurring at the application electrodes and / or a

Impedance measuring device for detecting a tissue impedance, wherein the length of the cutting interval in dependence on the

Spark detector / impedance measuring device output signals is determined. 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 device may comprise an adjusting device for setting an operating speed, wherein the control device is adapted to the length of the cutting interval in dependence on the set

To choose working 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 shows an electrosurgical device with a supply device and an electrosurgical instrument connected thereto;

Fig. 2 individual components of the supply device;

FIG. 3 shows a cross section through the electrosurgical instrument of FIG. 1; FIG.

Fig. 4 is a detailed side view of the jaws of the instrument of Fig. 1;

Fig. 5 is 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 (FIG. 1) and a bipolar electrosurgical instrument 30, wherein the

Instrument 30 is connected via a supply cable 21 to the supply device 20.

The instrument 30 has a first and a second branch, which are rotatably attached to each other by means of a hinge 33. The hinge 33 allows the instrument 30 to be opened to receive tissue and then closed to retain the tissue in a closed state. In this closed state, both a coagulation as well as a cutting operation can be performed.

The first branch has at its distal end a first jaw part 40 and at its proximal end a first handle 31 for actuating the first jaw part 40. The second branch has correspondingly at the distal end a second jaw part 50 and at the proximal end a second handle 3. The handles 31, 3 include finger holes, so that the instrument 30 can be conveniently held and operated by a physician. Fig. 4 shows a detail view of the distal portion of the instrument. As already described, the jaw parts 40, 50 are rotatably connected to each other via the rotary joint 33. The first jaw part 40 has on the side facing the second jaw part 50 (first clamping surfaces 47) a cutting device 45, which projects beyond a layer of a first application electrode insulator 43. Apart from the side facing the first jaw part 40 (second clamping surface 57), the second jaw part 50 is also completely encased by an application electrode insulator 53.

3 shows a cross section through the jaw parts 40, 50. It can be seen that in this cross section the cutting device 45 runs out in a substantially wedge-shaped manner towards the bottom, wherein the first clamping surfaces 47 form the side regions of the wedge. The cutting device 45 has at its lower end - the portion facing the second jaw part 50 - an edge 46 which is adapted to mechanically separate tissue. The sides remote from the second jaw part 50 are encased at least in sections by the first application electrode insulator 43. In cross section, this is substantially U-shaped. The edge 46

immediately opposite is an anvil 55, which serves as an insulator

is trained. This is preferably a ceramic layer which, in the closed state of the jaw parts 40, 50, is contacted by the edge 46. The anvil 55 has a substantially rectangular shape in cross-section and is partially covered by a second application electrode 51. The second

Application electrode 51 is in turn encased in sections by the second application electrode insulator 53. The second jaw part 50 thus includes the anvil 55, the second application electrode 51 and the second application electrode insulator 53. These elements form upwards a second clamping surface 57, which extends in a planar manner along the longitudinal axis of the second jaw part 50. The second application electrode 51 is only externally accessible on the side facing the first jaw part 40. The other sides are electrically insulated by the application electrode insulator 53. The second application electrode 51 forms two mutually parallel surfaces mutually to the anvil 55, which are part of the second clamping surface 57. The cutting device 45 can not contact these surfaces of the second application electrode 51 directly. As soon as tissue is clamped between the cutting device 45 and the anvil 55, an HF voltage can be applied to the first application electrode 41 and thus to the cutting device 45 and to the second application electrode 51 by means of the supply device 20. Current paths are formed in the tissue, which run essentially obliquely to the second clamping surface 57. The current density is therefore directly bar below the cutting device 45, in particular 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 region.

Preferably, a cutting device width b _{s is} smaller than an insulating part width bi, so that the surface accessible from above of the anvil 55 projects laterally beyond the cutting device 45 in a plan view. Thus, a secure isolation of the application electrodes 41, 51 is ensured 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 be understood, for example, as the smallest distance between the application electrodes 41, 51 in the closed state.

The supply device 20 according to the invention (see Fig. 2) may comprise an RF generator 22 and a control device 23, which together in

communicative connection. The control device 23 in this case acts on the HF generator 22 such that it operates the electrosurgical instrument 30 with a predetermined RF voltage I _H F. Already by the control of the RF generator 22 of the control device 23 essential parameters are known. Other parameters may be provided by an optional existing RF sensor unit 24. This RF sensor unit 24 can be understood as a logical unit that summarizes some essential sensor units of the supply device 20. 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 to the

Application electrodes 41, 51 is present.

In one exemplary embodiment (see FIG. 5), after activation of the supply device 20, a cutting voltage U _{s is applied} to the application electrodes 41, 51 over a cutting interval t _s . 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 , a coagulation voltage U _{K is} applied by the control device 23 via a coagulation interval t _K. This coagulation voltage U _K can be significantly smaller than the cutting voltage U _s . After the expiry of the coagulation interval t _K , a cutting interval t _s can again take place. The individual intervals can be alternately traversed until the supply device 20 is deactivated. This results in a large number of cutting phase start times sl, 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) that occurs at the application electrodes 41, 51. Thereafter, it is possible to switch immediately from the cutting interval t _s into the coagulation interval t _K. Alternatively, this change can be done 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. abl terminated. In the graph shown in Fig. 5, fl indicates the spark signal timing, 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 can also be specified statically or dynamically by the control device 23. For example, the attending physician can set a working speed. The control device 23 sets this operating 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. Thus, it is readily possible to dispense with one or both of the application electrode insulators 43, 53. Furthermore, these application electrode insulators 43, 53 can only partially encase the associated application electrodes 41, 51.

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 rests directly on the anvil 55 in the closed state. On the other hand, a stop can also be provided on the instrument 30, so that the cutting device 45 also maintains a predefined distance from the anvil 55 in the closed state. The articulated connection between the jaws 40, 50 may be a hinge 33. On the other hand, any joint can be used here. Thus, it is possible that only one of the jaw parts 40, 50 pivotally relative to the other jaw part 40, 50 is pivotable. Theoretically, however, both jaw parts 40, 50 can also be pivoted relative to a base. Furthermore, it is conceivable that the pivoting of the jaw parts 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.

In a general embodiment of the electrosurgical device according to the invention, this comprises:

- At least one electrosurgical instrument (30) having a first jaw part (40) and a second jaw part (50) which are hinged together so that the jaws (40, 50) can be brought from a receiving position into a closed position for grasping tissue .

wherein the first jaw part (40) has a first application electrode (41) and the second jaw part (50) has at least one second application electrode (51) for applying an HF voltage to the collected tissue, wherein the second jaw part (50) comprises an insulation part (55 ), that of the first application electrode (41)

is arranged opposite one another,

a supply device (20) for supplying the application electrodes (41, 51) with an HF voltage,

in which

the supply device (20) comprises at least one control device (23), which is designed such that over an application period during a

Cutting interval (t _s ) a cutting voltage (U _s ) and during a

Koagulationsintervalls (t _K ) a coagulation voltage (U _K ) by means of

Application electrodes (41, 51) are applied. LIST OF REFERENCE NUMBERS

20 supply device

21 supply cable

22 H F generator

23 control device

24 H F sensors

30 instrument

31, 31 'handle

33 swivel joint

40 first jaw part

41 first application electrode

43 first application electrode insulator

45 cutting device

46 edge

47 first clamping surface

50 second jaw part

51 second application electrode

53 second application electrode isolatoi

55 anvil

57 second clamping surface

abl termination date

b _s cutter width

bi isolation section

b _E Electrode distance

fl radio signal time

sl, s2 cutting phase start time

tv delay

ts cutting interval

t _K coagulation interval

U _s cutting voltage

U _K coagulation voltage

UHF H F voltage

Claims

claims

An electrosurgical device comprising:

wherein the first jaw part (40) has a first application electrode (41) and the second jaw part (50) has at least one second application electrode (51) for applying an HF voltage to the collected tissue, wherein the second jaw part (50) comprises an insulation part (55 ), that of the first

Application electrode (41) is arranged opposite,

characterized in that

the supply means (20) comprises at least one control device (23), which is designed such that over a period of application during a cutting interval (t _s) a cutting voltage (U _s) and during a Koagulationsintervalls (t _K) a coagulation stress (U _K) by means of the application electrodes (41, 51) are applied, wherein the control device (23) is designed such that an application period a plurality of alternations between the cutting voltage (U _s ) and the coagulation voltage (U _K ) and between the coagulation voltage (U _k ) and the cutting voltage (Us) includes.

2. Electrosurgical device according to claim 1,

d a d u r c h e c e n c i n e s that

the insulating member (55) is a spark-resistant material, e.g. As ceramic, includes.

3. Electrosurgical device according to one of the preceding claims,

d a d u r c h e c e n c i n e s that

the application electrodes (41, 51) are arranged on the jaw parts (40, 50) such that the application electrodes (41, 51) are spaced apart from one another in the closed state.

4. Electrosurgical device according to one of the preceding claims, in particular according to claim 3,

d a d u rc h e ke n ze i c h n et that

the application electrodes (41, 51) are arranged on the jaw parts (40, 50) 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.

5. Electrosurgical device according to one of the preceding claims,

d a d u rc h e ke n ze i c h n et that

the first jaw part (40) comprises an insulator layer (43) which is arranged on the sides of the first application electrode (41) remote from the second jaw part (50) in order to electrically isolate the first application electrode (41) from the tissue.

6. Electrosurgical device according to one of the preceding claims,

d a d u rc h e ke n ze i c h n et that

the second jaw part (50) comprises an insulator layer (43) which is arranged on the sides of the second application electrode (51) facing away from the first jaw part (50) in order to electrically isolate the second application electrode (51) from the tissue.

7. Electrosurgical device according to one of the preceding claims,

d a d u rc h e ke n ze i c h n et that

the second jaw part (50) has 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 cutting through tissue.

8. Electrosurgical device according to one of the preceding claims,

in particular according to claim 7,

d a d u rc h e ke n ze i c h n et that

the jaw members (40, 50) are formed such that an insulating member width (bi) of the insulator member (55) is greater than or equal to a cutter width (b _s ) of the cutter (45).

9. Electrosurgical device according to one of the preceding claims, characterized in that the change between the cutting voltage (U _s ) and the coagulation voltage (U _K ) takes place regularly.

10. Electrosurgical device according to one of the preceding claims,

d a d u rch e ke n ze i c h n et that

the control device (23) comprises a spark detection device for detecting a spark occurring at the application electrodes (41, 51) and / or an impedance measuring device for detecting a tissue impedance, the length of the cutting interval being dependent on the

Spark detector / impedance measuring device output signals is determined.

11. Electrosurgical device according to one of the preceding claims,

in particular according to claim 10,

d a d u rc h e ke n ze ze ch n et 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 point in time (fl) at which the spark occurs and / or a tissue impedance exceeds a predetermined value, and

Cutting interval (t _s ) after a predetermined delay interval (t _v ) interrupts.

12. Electrosurgical device according to one of the preceding claims,

marked by

an adjusting device for setting an operating speed, wherein the control device (23) is adapted to select the length of the cutting interval (t _s ), in particular the delay interval (t _v ), in dependence on the set operating speed.

13. Electrosurgical device according to one of the preceding claims,

d a d u rc h e ke n ze i c h n et that

the device comprises exactly two application electrodes (41, 51).