Generator and method for generating a treatment voltage - Patents.com

Abstract

To provide a generator that allows extended creation possibilities with regard to the produced oscillation and voltage shapes.SOLUTION: A generator 11 of the present invention includes a plurality of impulse generators Gn that are individually controlled by means of a control device 18 in a timely flexible manner. The RF voltage required for supply to a surgical instrument 12 is thus composed of individual impulses. The same applies for the current flowing at an electrode 14 of the instrument. Due to omitting resonance effects in the impulse generators and omitting energy storage in a system that is able to oscillate, a user can have an increased degree of control of the wave forms of the voltage supplied to the instrument and the wave forms of the current flowing to the instrument.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a generator for supplying treatment voltages and currents to medical instruments and to a method for generating such treatment voltages and currents. [Background technology]

[0002] Electrosurgical instruments, probes, and the like used in electrosurgery are typically supplied with high-frequency alternating current. The frequency of this alternating current or applied alternating voltage is typically above 100 kHz to avoid neuromuscular stimulation. The power of such generators is typically significantly greater than 1 W and can reach several hundred W.

[0003] To generate electrosurgical voltages in the range of several hundred kHz, externally controlled generators are commonly used, as is evident, for example, from US Pat. No. 5,623,999. Such generators comprise at least one oscillating circuit made to oscillate by an active transistor circuit, from which the electrosurgical energy is derived in a transformer-like manner. Various concepts are known for adjusting the generator voltage to obtain different tissue effects.

[0004] The oscillation variation of the oscillatory circuit is time limited, which also limits the type of adjustment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] German Patent Application Publication No. 102008039884 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a generator that allows for a wide range of production possibilities regarding the vibration and voltage shapes that can be generated. [Means for solving the problem]

[0007] This object is achieved by a generator according to claim 1 and a method according to claim 12.

[0008] The generator according to the present invention comprises a plurality of impulse generators, each having a control input and an impulse generator output. Each impulse generator is preferably configured to provide an output impulse upon receiving a control impulse at its control input. The impulse generator output is preferably connected to the generator output, at which the output impulses generated by the impulse generators arrive. A control device is connected to the control inputs of the impulse generators and regulates their impulse outputs. In this way, impulse sequences with impulses of equal or different magnitudes, periodically repeating impulses, or even impulse sequences with different, varying time intervals can be generated. Thus, many conceivable voltage and current shapes are possible at the generator output, which cannot be generated with parallel oscillatory circuits or can only be generated with excessive effort. Impulse sequences with symmetrical impulse shapes, but also impulse sequences with asymmetrical impulse shapes, can be generated.

[0009] The concept according to the invention distributes the generator output power to multiple impulse generators, each of which thus contributes its own power portion to the total power output by the generator, thereby minimizing stress on the individual components in the impulse generators, in particular their power switches, and reducing the need for cooling power. The power switches can then be constructed as an integral part, for example as a transistor array.

[0010] Preferably, the impulse generator is not a self-oscillating system, i.e., it does not include any resonant components, circuits, etc. connected to the impulse generator output (i.e., the output circuit is described by a differential equation, the order of which is less than two, and for solutions having frequencies at least within the magnitude range of the output frequency). For this reason, no resonant effects appear, and therefore the impulse generator can output impulses in a controlled manner without post-pulse oscillations. When these impulses are output, the impulse generator outputs all of its stored power as output impulses.

[0011] This gives the generator greater control over the voltage shape and power output to the instrument and therefore to the tissue.

[0012] The impulse generators are preferably identically configured relative to one another. Thus, the impulse generators are identical in structure and generate output impulses of equal magnitude. An output impulse sequence can be designed by timing the impulse outputs of the individual impulse generators. For example, the impulse generators can be fired simultaneously (send output impulses) so that the output impulses of the impulse generators are combined at the generator output. It is also possible to generate an impulse sequence with individual impulses delivered in a predetermined time scheme. Furthermore, it is also possible to provide impulse generators that send output impulses with different magnitudes, for example, to deliver output impulses with different magnitudes at the generator output by different combinations of the output impulses of the individual impulse generators.

[0013] The control device preferably outputs control impulses in a selectable scheme assigned to different operating modes. For example, a mode can be provided in which at least two of the impulse generator impulses are output in chronological order. In this way, an impulse sequence consisting of individual pulses can be generated at the generator output. Additionally or alternatively, the control device can simultaneously output control impulses to at least two of the impulse generators. These impulse generators then also simultaneously send output impulses at the impulse generator output so that the output impulses merge at the generator output. In this way, when adjusting the control device, output impulses that are higher than other output impulses can be generated at the generator output. Impulse sequences with impulses of varying impulse heights and / or varying impulse time gaps can be generated.

[0014] The controller can output control impulses at regular time intervals in selected operating modes, resulting in a regular sequence of output impulses at the generator output. To produce a particular surgical effect, the controller can also output control impulses after one or more predetermined time patterns in other operating modes. For example, a sequence of multiple, e.g., six, individual impulses may be followed by a longer pause, followed by a subsequent sequence of individual impulses.

[0015] The impulse generator of the generator includes at least one energy storage unit, which may be configured, in particular, as an inductor. The impulse generator output is preferably a coil coupled to the inductor in a transformer manner. The inductor is at least preferably not part of a system capable of oscillation, in particular not part of a parallel or series oscillating circuit. The impulse generator output is preferably formed by a coil coupled to the inductor in a transformer manner. The impulse generator is preferably configured as a flyback converter. The impulse generator includes an electronic switch that stores energy in the coil and then selectively connects the inductor to a voltage source to isolate the coil from the voltage source, in order to provide energy as a high-voltage impulse at the impulse generator output.

[0016] In a preferred embodiment of the generator, the outputs of the impulse generators are connected in series, so that they are all connected to the output of the generator, whereby the coils forming each impulse generator output are preferably connected in series in the same direction, so that the impulses output from the individual impulse generators arrive at the generator outputs with the same polarity.

[0017] However, if desired, one or more of the coils can be connected in series with the other coils in the opposite direction so as to provide positive and negative voltage impulses at the generator output. In this way, asymmetric as well as symmetric output impulse sequences can be generated at the generator output.

[0018] The method according to the invention is based on generating a series of current impulses by means of several impulse generators connected together on the output side. By using several impulse generators, each of which outputs only a single output impulse upon receiving a control impulse, the generated output voltage and the generator's supply current can be designed arbitrarily within a wide range, without having to take into account transient and post-impulse oscillations of the oscillatory circuit.

[0019] Details of the invention will become apparent from the embodiments set forth in the following description, with reference to the drawings, including the following figures: [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic block diagram of a generator according to the present invention. [Figure 2] FIG. 2 is an embodiment of an impulse generator for a generator according to FIG. [Figure 3] FIG. 3 is an embodiment of an impulse generator for the generator according to FIG. [Figure 4] FIG. 4 is a simplified circuit diagram of the generator according to FIG. [Figure 5] FIG. 5 is a control signal diagram in the operating mode of the generator according to FIGS. [Figure 6] FIG. 6 shows the output voltage diagram in the operating mode of the generator according to FIGS. [Figure 7] FIG. 7 shows control signal diagrams for different operating modes of the generator according to FIGS. [Figure 8] FIG. 8 shows output voltage diagrams for the generators according to FIGS. 1 and 4 in different operating modes. [Figure 9] FIG. 9 shows control signal diagrams for different operating modes of the generator according to FIGS. [Figure 10] FIG. 10 shows output voltage diagrams for the generators according to FIGS. 1 and 4 in different operating modes. DETAILED DESCRIPTION OF THE INVENTION

[0021] FIG. 1 shows a generator 11 useful for delivering a surgical instrument 12. As an example, FIG. 1 shows a surgical instrument 12 for open surgery having a handle 13 and an electrode 14. In this case, the surgical instrument 12 is a monopolar instrument. Like the instrument 12, a neutral electrode 15 is provided, connected to an output 16 of the generator 11 via a suitable line, to discharge the current flowing from the instrument 12 to the patient. FIG. 1 shows a monopolar instrument 12 as an example. However, the generator 11 is also suitable for delivering bipolar instruments. Furthermore, the generator 11 can also be provided for delivering laparoscopic or endoscopic instruments (probes), whether monopolar or bipolar.

[0022] The generator 11 may be a suitable number, e.g., 4, 6, 12, or even a different number, of impulse generators G1, G2, G3, G4, ... G n Impulse generators G1 to G n are configured identically compared to each other and have an operating voltage U b and ground 17. Although not fundamentally necessary, the impulse generators G1 to G n may also be configured differently in terms of structure and / or dimensioning, for example, to deliver different amounts of output impulse.

[0023] Each impulse generator G1 to G n are the impulse generator output sections A1 to A2 connected to the output section 16 of the generator 11, respectively. n For this purpose, the impulse generator output sections A1 to A n are, for example, connected in series with one another as shown in FIG. 1. This is particularly possible if the impulse generator outputs A1 to A n This is because the impulse generator output sections A1 to A2 have low ohmic resistance, i.e., they can transmit the output impulses of other impulse generators in the series connection. nare highly ohmic resistors, they can be connected in parallel with each other and connected to the output 16.

[0024] Furthermore, the generator 11 includes impulse generators G1 to G n Control signal input section E1 to E n The control device 18 in turn comprises a control signal output connected to the control input S, via which the control device 18 can receive an activation signal which can be generated by an operating element, for example a foot switch, a hand switch, etc.

[0025] In the figure, the impulse generator G1 is connected to all other impulse generators G2 to G n The following description of the impulse generator G1 is intended to be representative of all other impulse generators G2 to G3 in terms of their structure and function. n are applied as appropriate.

[0026] The impulse generator G1 is preferably configured as a flyback converter. It is connected to an inductor L1, i.e., a transformer having an operating voltage U b The inductor L1 comprises a core-wound coil with only a few windings or an air-core coil, the other end of which is connected to an electronic switch T1, which selectively connects or disconnects the inductor L1 to ground 17. The electronic switch T1 can be assigned a protection capacitor C1 connected in parallel to the switchable path of the electronic switch. If the electronic switch T1 is a transistor, for example a field-effect transistor, the switchable path is the drain-source path.

[0027] The electronic switch T1 is assigned a control circuit V1, which is preferably effective between ground 17 and a control electrode 21 of the electronic switch T1. The control circuit V1 can be an active or passive control circuit. The control circuit V1 serves to open or close a controlled path of the electronic switch T1 by respectively supplying a signal at the control electrode 21. The control circuit V1 comprises an input E1 connected to the control device 18.

[0028] Operating voltage U b are supplied by a DC voltage source 22, preferably via decoupling diodes 23. The individual generators G1 to G n The diodes 23 are isolated from each other. b are the impulse generators G1 to G n The voltage is stored in a buffer capacitor 24.

[0029] The impulse generator G1 includes an output A1 realized by the end of a coil 26-1 coupled in a transformer manner to an inductor L1. In this embodiment, the inductor L1 and the coil 26-1 have the same polarity. However, they could also have opposite polarities.

[0030] The impulse generator G1 according to Fig. 3 is essentially identical to the impulse generator G1 according to Fig. 2. The description provided therefor applies accordingly, based on the same reference numerals. The particularity of the impulse generator G1 according to Fig. 3 is that a diode D is connected in parallel to the switchable path of the electronic switch T1 in the blocking direction. This protects the switch T1 and reduces the internal resistance of the impulse generator output part A1.

[0031] As is clear from FIG. 4, impulse generators G1 to G n are connected in parallel to the DC voltage. n , inductor L1...L n , control circuit V1...V n , capacitors C1...C n, and the coils 26-1 to 26-n are respectively provided with impulse generators G1...G n However, the impulse generator outputs A1...A n That is, the coils 26-1 to 26-n are connected in series in the same direction. n The coil start ends of the coils 26-1 to 26-n are marked with dots. The series connection of the coils 26-1 to 26-n in the same direction means that the coil start ends are connected to the coil end ends of the adjacent coils. This is particularly true for the inductors L1 to L2. n When all the coil start ends are connected in the same direction, that is, when all the coil start ends are connected to the electronic switches T1 to T n and all coil ends are connected to the operating voltage U b This is true when connected to a

[0032] Impulse generator output section A1...A n The series connection of may be connected to the generator output 16 via one or more coupling capacitors 27, 28. The coupling capacitors 27, 28 may be located at another position in the series connection or may alternatively be omitted. If coupling capacitors 27, 28 are provided, they eliminate the DC component of the current output from the generator 11. If such a DC component of the current is acceptable, the coupling capacitors 27, 28 may be omitted or they may be provided with a controlled or uncontrolled bridge circuit.

[0033] The generator 11 described so far operates as follows.

[0034] The control device 18 controls the impulse generators G1 to G nThe control impulses for the impulse generators G1 to G6 are generated in a timely and coordinated manner. FIG. 5 shows, as an example of an operating mode (first mode) with regular time intervals, such control impulses I1 to I6 for a generator 11 having six impulse generators G1 to G6. As shown in FIG. 5, the control impulse I2 for the impulse generator G2 can be output a predetermined period, for example, 5 μs, after the control impulse I1 for the impulse generator G1 is output. This also applies to the other control impulses I3, I4, I5, and I6, as appropriate. I3 can be output with a time delay, for example, 5 μs later than I2, and I4 can be output 5 μs later than I3, etc. In the example according to FIG. 5, there is always a time interval of 5 μs. Therefore, the impulse generators G1 to G n are their control impulses I1 to I n are obtained at a time interval of 30 μs (multiplying the six impulse generators G1 to G6 by 5 μs). Within this period, all other impulse generators G1 to G6 generate their control impulses I1...I n at constant time intervals, in this case 5 μs intervals. Therefore, the individual impulse generators G1 to G6 output their output impulses sequentially at 5 μs intervals. The output impulse sequence shown diagrammatically in FIG. 6 is generated at the output 16 of the generator 11. n The individual impulses of I1...I2 are largely of the same magnitude and together form an impulse sequence with a fundamental frequency of 333 kHz. The voltage supplied at output 16 is an asymmetrical high-frequency voltage. The control impulses I1...I2 n Other fundamental frequencies may be obtained at other time intervals in between.

[0035] Control impulse I1...I n is the electronic switch T1...T n However, as a control impulse, the impulse generators G1...G n Any other signal shape suitable for causing the to output an output impulse or even a sequence of output impulses may also be used.

[0036] Figure 7 shows another control pattern in which control signals, i.e., control impulses I1, I2, and I3 for impulse generators G1, G2, and G3, are simultaneously supplied to the respective impulse generators for the second operating mode (mode 2), while control impulses I4, I5, and I6 are sequentially supplied to impulse generators G4, G5, and G6 in a timed sequence. According to Figure 8, an impulse sequence is generated at the output 16 of generator 11, with a high first output impulse 29 generated by superimposing the output impulses of the three simultaneously operating generators G1, G2, and G3. Further output impulses 30, 31, and 32 are each a single output impulse of an individual impulse generator. The output of the last output impulse 32 can be followed by a pause of any duration, e.g., 15 μs in this case.

[0037] Another example illustrating the flexibility of the signal configuration can be seen from Figures 9 and 10, which show the third operating mode (mode 3). According to Figure 9, generators G1 and G2 are supplied with control impulses I1 and I2 synchronously, which results in the generation of a doubled output impulse 33. The output impulse 33 is followed by a control impulse I3 for generator G3, which generates a single (1x) output impulse 34. Impulse generators G4, G5 and G6 then receive their control impulses I4, I5, I6 simultaneously, which results in the generation of a tripled output impulse 35.

[0038] As is evident from the timing of the control impulses I1 to I6, different output voltage shapes can be generated that would not have been possible with a resonant generator. In this regard, the presented circuit principle offers the possibility of generating voltage shapes with physiological effects that would not have been possible with previous generators. Apart from the modes explicitly shown here, the control impulses I1...I n The timing of the impulse generators G1 to G n Output impulse A1...A n Timing and / or impulse generators G1 to G nThe number and / or number of coils 26-1...26-n may be varied to generate additional modes.

[0039] The generator 11 according to the present invention comprises a plurality of impulse generators G1 to G2 that are individually controlled by a control device 18 in a timely and flexible manner. n The RF voltage required to provide the surgical instrument 12 is therefore composed of individual impulses. The same applies to the current flowing through the electrodes 14 of the instrument 12. The impulse generators G1 to G n By eliminating the resonance effects of the secondary system and eliminating the energy storage in the vibrating system (secondary system), the user has a greater degree of control over the waveform of the voltage supplied to the instrument 12 and the waveform of the current flowing through the instrument 12. [Explanation of symbols]

[0040] 11 Generator 12 Equipment 13 Handle 14 electrodes 15 Neutral electrode 16 Output section G1…G n Impulse generator U b Operating voltage 17 Grounding A1…A n Impulse generator output section 18 Control Device L1…L n inductor E1…E2 impulse generators G1…G n Control signal input section I1…I n Impulse generator G1...G n Control impulse for S Control input section T1…T n Electronic Switch C1…C n Protection Capacitor V1…V n Control circuit 21 Control electrode 22 DC voltage source 23 Decoupling diode 24 Buffer capacitor 26-1...26-n coil 27, 28 Coupling capacitor 29...35 Output Impulse

Claims

1. A generator (11), an output (16) to which a medical device can be connected; Control input section (E １ …E ｎ ) and a plurality of impulse generators (G) each including an impulse generator output section (26-1...26-n). １ …G ｎ )and, The impulse generator (G １ …G ｎ ) to output output impulses (29...35). １ …G ｎ ) to the control impulse (I １ …I ｎ ) to provide the control input (E １ …E ｎ a control device (18) connected to the All impulse generators (G １ …G ｎ ) the impulse generator output section (A １ …A ｎ ) is connected to the output (16) of the generator (11), The impulse generator outputs (A 1 ...A n ) are electrically connected in series. generator.

2. All impulse generators (G １ …G ｎ ) are constructed identically when compared with each other The generator of claim 1 .

3. Each impulse generator (G １ …G ｎ ) is its control input (E １ …E ｎ ) control impulse (I １ …I ｎ ) in response to receiving the impulse generator output (A １ …A ｎ ) outputs an output impulse (29...35) A generator according to claim 1 or 2.

4. The control device (18) controls the impulse generator (G １ …G ｎ ) at least two of the control impulses (I １ …I ｎ ) are output sequentially. A generator according to claim 1 or 2.

5. The control device (18) controls the impulse generator (G １ …G ｎ ) at least two of the control impulses (I １ …I ｎ ) are output at the same time. The generator of claim 1 .

6. The control device (18) generates control impulses (I) according to different time patterns. １ …I ｎ ) The generator of claim 1 .

7. Each impulse generator (G １ …G ｎ ) includes an energy storage unit The generator of claim 1 .

8. The energy storage unit is an inductor (L １ …L ｎ ) The generator of claim 7.

9. The impulse generator output unit (A １ …A ｎ ) is a transformer type inductor (L １ …L ｎ ) are coils (26-1...26-n) that are coupled to The generator of claim 8.

10. The impulse generator (G １ …G ｎ ) is a flyback converter The generator of claim 1 .

11. 1. A method for generating a voltage for supplying a sequence of current impulses (29...35) to an electrosurgical instrument (12), said method comprising: a plurality of impulse generators (G) connected together at their outputs; １ …G ｎ ) to generate a sequence of current impulses (29...35), The impulse generator outputs (A 1 ...A n ) of all the impulse generators (G 1 ...G n ) are electrically connected in series. method.

12. The impulse generator (G １ …G ｎ ) simultaneously outputting current impulses (29, 33, 35) to at least two of the The method of claim 11.

13. The impulse generator (G １ …G ｎ ) to sequentially output current impulses (30, 31, 32) to at least two of the 13. The method of claim 11 or 12.

Images