Treatment device and control method

Abstract

To provide a treatment device, which is particularly suitable for coagulation and cutting of biological tissue of a human or animal patient.SOLUTION: The treatment device (10) comprises an instrument (11) connected to supplying apparatus (12). The instrument (11) and the apparatus (12) can control each other. By means of an activation device (24) provided on the instrument (11) or provided otherwise, a generator can be activated in a first or second operating type. The instrument (11) comprises an alterable switch to guide the electrical power provided by the generator to a first or a second electrode pair (20 / 21) or (22 / 21). The alterable switch is controlled by the generator (12). This offers the possibility to store treatment progresses in the generator and to carry them out with the instrument (11) without requiring the user to change operating types.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a treatment device that is particularly suitable for coagulating and cutting living tissue in a human or animal patient. [Background technology]

[0002] Treatment devices for coagulating and / or cutting tissue are known in a variety of configurations.

[0003] Patent document 1 describes such a treatment device consisting of a generator and an instrument, the generator generating a voltage sufficient for coagulation of living tissue. The instrument is provided with a transformer, which is connected to a cutting electrode and transforms a voltage sufficient for incision of tissue from a voltage configured for coagulation. An electric switch, which can be activated by a push button provided on the instrument, serves to activate the electrode portion. An activation signal for the generator is generated by means of this push button or an alternative second push button in order to switch the generator on and off.

[0004] A treatment device with a generator and an instrument is also known from US Pat. No. 5,399,633, the instrument including a switch for selectively connecting a first and a second electrode pair to the generator. The control of the activation of the generator and the instrument is performed by an activation device in the form of a hand or foot switch. The power factor of the generator is thus switched.

[0005] Further treatment devices are known from US Pat. No. 5,399,623, US Pat. No. 5,499,633, US Pat. No. 5,523,367, and US Pat. No. 5,523,674. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent Application Publication No. 3895642 [Patent Document 2] European Patent Application Publication No. 1287788 [Patent Document 3] European Patent Application Publication No. 1545360 [Patent Document 4] US Patent Application Publication No. 2010 / 0137854 [Patent Document 5] European Patent No. 1599146 [Patent Document 6] European Patent No. 1711116 Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide an improved treatment device. [Means for solving the problem]

[0008] The treatment device according to the invention comprises a generator and an instrument provided by the generator. The generator outputs a voltage in response to a generator control signal, the voltage being suitable for a first treatment mode, e.g. tissue coagulation, or a second treatment mode, e.g. tissue cutting. The generator is switchable between the two treatment modes. If required, the generator can also be switchable between other and / or multiple treatment modes.

[0009] The generator is controlled by a generator control signal that defines the treatment mode and further outputs a variable switch control signal that controls a variable switch, preferably located within the instrument, to supply the voltage output by the generator, and thus the current provided by the generator, to the electrodes (or respective electrode pairs) appropriate for each selected treatment mode.

[0010] In the present invention, a signal carrier is used for transmitting the generator control signal and the variable switch control signal. The generator supplies the signal carrier. The appliance is connected to the generator via a line and connected to the signal carrier, such that the signal carrier is transmitted from the generator to the appliance. The signal carrier is preferably an AC voltage in the sound frequency range of 20 Hz to 20 kHz, for example an AC voltage with a square waveform. The frequency of the signal carrier is preferably about 2 kHz. The signal carrier can be an AC current signal alternating at the above mentioned frequency, for example between positive and negative values. The absolute values ​​of the positive and negative values ​​can be the same.

[0011] The appliance can be assigned an activation device which generates a generator control signal. For this purpose, the activation device can apply this alternating current signal to different resistors for different desired operating modes. The resulting voltage then becomes the generator control signal, which is detected by the generator control device and used to control the generator.

[0012] Alternatively, the signal carrier can be an AC voltage signal having a suitable frequency, for example 20 Hz to 20 kHz, e.g. 2 kHz, again applied to a different resistor that can be activated via a push button in the instrument or activation device, in which case the resulting AC current becomes the generator control signal and the generator's control device controls the generator accordingly.

[0013] The activation device may be located within the instrument or may be located remote from the instrument in a separate operating portion.

[0014] According to the invention, the instrument of the treatment device includes a variable switch circuit that connects either the electrode provided for the first treatment mode or the electrode provided for the second treatment mode to the line coming from the generator, so that both electrodes are provided with the same counter electrode that forms an electrode pair with the respective electrode of the selected treatment mode. The variable switch can also switch the electrode of the first treatment mode as an indifferent electrode for the second treatment mode.

[0015] The variable switch circuit is controlled by a variable switch control signal according to a selected treatment mode. The generator generates the variable switch control signal and applies the signal to the signal carrier. For example, the signal carrier can have a variable duty cycle such that an average value of the signal carrier, which alternates between positive and negative values, is either positive or negative. A first average value can then be assigned to a first treatment mode and a second average value can be assigned to a second treatment mode. The variable switch circuit can connect the first or second electrode, respectively, to the line and thus to the generator based on detection of the different average values ​​of the signal carrier. The average value of the signal carrier then becomes the variable switch signal.

[0016] The system according to the invention allows a generator to control a variable switch provided in the instrument, which is controlled by an activation device, which may be located in the instrument or in a separate element, for example a pedal.

[0017] In the present invention, treatment current is delivered in a controlled manner only to the electrodes designated for each treatment, whereby a variable switch provided within the instrument is controlled by a device including a generator, the variable switch connecting to the generator only one or more electrodes associated with the selected mode in which the device is to operate.

[0018] Since the variable switch controlled by the generator supplies current only to the activated electrodes and no current flows through the electrodes associated with different modes, the generator voltage and / or generator current can be detected particularly accurately and controlled in a closed loop with sensitivity. Based on the voltage and current output by the generator and the phase shift between them, the output power can be determined. Furthermore, tissue resistance can be calculated and adjusted as desired.

[0019] Rapid alternation of the variable switch and the respective induction of the generator voltage can trigger an activation in which current is supplied to both electrodes simultaneously. For example, it is possible to preseal a vessel or another tissue before performing the incision in a dissection situation with a coagulation-dissection instrument. If an artery or other vessel is held with a forceps-like instrument that also contains a cutting electrode, the current can be applied to the coagulation electrode first, and the incision can be performed with a delay or slowly. This increases the safety of the procedure, since it is avoided that the artery, which is not yet completely sealed, slips out of the closed forceps-like instrument.

[0020] Another advantage of the treatment device according to the invention is that the instrument does not require a transformer, which makes it possible to provide a particularly light and slim instrument with low engineering effort.

[0021] The generator is preferably a high frequency generator and outputs an AC voltage with a frequency between 100 kHz and 5 MHz. The generator frequency is preferably between 300 kHz and 600 kHz and can be varied in terms of peak-to-peak voltage as well as at different current and / or power limits, for example. Furthermore, the generator can supply a modulated voltage, for example a voltage that can be switched on and off, in order to obtain different desired crest factors.

[0022] The invention is particularly suitable for forceps-like instruments with fixed cutting electrodes, where the first treatment mode can be a coagulation mode. For coagulation, electrodes are provided on the two jaws of the forceps-like bifurcated part. One of the two electrodes can be considered as an indifferent electrode, and the other electrode on the other jaw is an assigned coagulation electrode. The indifferent electrode and the coagulation electrode form an electrode pair for tissue coagulation and / or tissue fusion.

[0023] The second treatment mode can be a cutting mode. In this mode, a fixed cutting electrode is activated. One of the two electrodes on the jaws can be an indifferent electrode. The variable switch circuit can also be configured such that both electrodes on the jaws are electrically connected to each other in the cutting mode. Then, in this mode, both electrodes on the jaws are indifferent electrodes.

[0024] Primarily, the present invention is also suitable for other instruments, such as instruments having incision and ablation functions.

[0025] Using the concept according to the invention, it can be ensured that the generator control signal is set to start in time after the variable switch control signal and to end in time before the variable switch control signal, whereby it can be ensured that the generator outputs a voltage supplied for one mode only if and only if the assigned electrode is connected to the generator.

[0026] Furthermore, the concept according to the invention allows for an automatic mode progression by controlling a variable switch provided in the instrument by the generator, during which the different modes are subsequently used according to a provided program. For example, in a sealing and incising instrument it can be ensured that first the sealing of the tube or tissue begins and only afterwards the incision (tissue incision) takes place. In this case it is sufficient for the activation device to output a simple on / off signal as generator control signal. The mode progression can then be controlled by the generator itself, which is also responsible for controlling the variable switch of the instrument.

[0027] Further details of advantageous embodiments of the invention are the subject of the claims, the drawings and the associated specification. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is an exemplary schematic diagram of an instrument and an associated generator. [Diagram 2] FIG. 2 is a block diagram of a treatment device according to the invention comprising a generator and an instrument. [Diagram 3] FIG. 3 is a block diagram of an instrument that is part of a treatment device according to the present invention. [Figure 4] FIG. 4 is a diagram of an electronic switch used in the device according to FIG. [Diagram 5] Figure 5a is a time diagram of the signal carrier, Figure 5b is a schematic diagram of the time progression of the variable switch control signal, Figure 5c is a schematic diagram of the high-frequency voltage output by the generator, and Figure 5d is a diagram of the variable switch control signal resulting from the duty cycle of the signal carrier according to Figure 5a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Fig. 1 shows a treatment device 10 comprising an instrument 11 and an apparatus 12 to which the instrument 11 is connected by a cable 13. The instrument 11 is illustrated in Fig. 1 as a laparoscopic instrument. For this purpose, the instrument 11 comprises a handle 14 provided on a housing 15 from which extends distally a shank 16 at the end of which a forceps-like tool 17 is held. The tool 17 serves for tissue coagulation and tissue dissection, i.e. for example sealing and dissection of vessels, e.g. blood vessels.

[0030] Tool 17 includes coagulation electrodes 20, 21 in jaws 18, 19 that can clamp and compress and hold tissue between jaws 18, 19. Electrical current passes between coagulation electrodes 20, 21, causing tissue to heat and coagulate, for example, thereby causing blood vessels and other hollow structures to fuse and thus seal.

[0031] At least one of the jaws 18, 19 is further provided with a cutting electrode 22 which serves to cut through tissue and which typically operates at a higher voltage and with a higher local current concentration than a coagulation electrode.

[0032] The instrument 11 is shown in this form by way of example only. The instrument 11 can also be configured as an open surgical or endoscopic instrument. Instead of the coagulation electrodes 20, 21 and the cutting electrode 22, other treatment electrodes can also be provided, such as ablation electrodes, which can be activated at different times and connected to the generator by a switching device for this purpose.

[0033] At least one operating element 23, for example in the form of a hand lever, is arranged in the housing 14 for opening and closing the jaws 18, 19. Furthermore, for activation of the electrodes 20, 21, 22 an activation device 24 can be provided having one or more switches or push buttons 25, 26 (see FIG. 2). The activation device 24 can be part of the instrument 11, as shown in FIG. 1. Alternatively, the activation device 24 can also be arranged in a separate housing and can be configured, for example, as a hand switch or a foot switch.

[0034] Furthermore, the device 12 may have an operating part 27 which may affect the operation of the tool 11. The operating part 27 may set operating parameters for the treatment modes coag, cut or make other adjustments.

[0035] In FIG. 2 the treatment device 10 is shown separately and in an abstract way. The apparatus 12 comprises a generator 28 which outputs a high-frequency voltage U suitable for performing different treatments on the living tissue. The voltage U is preferably a high-frequency voltage, the peak value of which can be varied within the range of about 100 V to several hundred V or even more. Furthermore, the generator 28 preferably modulates this high-frequency voltage. For example, the voltage U can be output as a continuous voltage or even an on / off switching voltage, the pulse / pause ratio being variable depending on the desired treatment mode. For example, the generator 28 can output a voltage Ucoag for a first treatment mode coag, for example a coagulation mode, in which a voltage must be effective between the two electrodes 20, 21. Furthermore, the generator 28 can output a voltage Ucut for a second treatment mode cut, for example a cut mode, in which a voltage is sufficient for tissue incision and must be effective between the electrodes 22, 21.

[0036] The generator is controlled according to a generator control signal sg. A control device 29 can be provided which evaluates the generator control signal sg and uses it to control the generator 28. The control device 29 can be part of the apparatus 12 or can be connected to the operating unit 27.

[0037] The cable 13 includes at least three lines NE, AE and AK leading to the instrument 11. The line AE provides a neutral potential and the generator 28 outputs a treatment voltage and a treatment current to the instrument 11 via the line NE.

[0038] The instrument 11 comprises an electric variable switch 30, by means of which the treatment voltage and the respective treatment current coming from the line NE are selectively directed to the electrode 20 provided for coagulation or to the electrode 22 provided for cutting. The variable switch 30 is so far a switching device which is switched by a variable switch control signal sw by a control device 29 which is part of the generator 28. The variable switch control signal sw is transmitted via a line AK. Similarly, the generator control signal sg is also transmitted via a line AK. In this respect reference is made to FIG. 3.

[0039] The variable switch comprises two electronic switches 31, 32, which may be constructed according to the example of FIG. 4. FIG. 4 exemplarily shows a switch 31 with two field effect transistors T1, T2 oriented in opposite polarity and switched in series for this purpose, the gate electrodes of which can be controlled in a potential-free manner via an optocoupler 33. The optocoupler 33 receives at its input a signal a provided by the activation device 24 (FIG. 3). The switch 31 can be connected to the electrode 22 via a coupling capacitor C1. Similarly, the second switch 32 can be connected to the electrode 22 via a coupling capacitor C2.

[0040] As an option, the variable switch 30 can further include a third switch 34 which connects the capacitor output of the switch 31 to the neutral line AE immediately after receiving the control signal b. This switch 34 can be used to leave the electrode 20 without voltage, while applying a current to the cutting electrode 22. In this case, both electrodes 20, 21 together form a neutral electrode for the cutting voltage generated by the cutting electrode 22.

[0041] Electrical switches 25, 26, for example in the form of push buttons, provided in or on the activation device 24 serve to switch on and toggle the generator 28. As is evident from FIG. 3, these switches 25, 26 are switched in series with resistors R1, R2 between the neutral potential of the line AE and a line AK. The line AK induces a signal carrier. For communication between the activation device 24 and the control device 29 and between the control device 29 and the variable switch 30, a generator control signal sg and a variable switch control signal sw can be applied to the signal carrier.

[0042] The resistors R1 and R2 can have different values ​​in order to influence the signal carrier on the line AK to generate the generator control signal sg in a different way. For example, the signal carrier on the line AK is a square wave alternating current symmetrical about zero, for example with a frequency of 2 kHz, at which the signal carrier alternates between two current values ​​of +25 mA and -25 mA. Depending on the value of the resistor R1 or R2 activated by the actuation of the switch 25 or 26, the control device 29 detects the resulting voltage as the generator control signal sg. The control device 29 thus activates the generator 28 either in the first or in the second operating mode, i.e. for example in the coagulation mode coag or in the cutting mode cut, and immediately thereafter the generator 28 outputs the required voltage Ucoag or Ucut.

[0043] The signal carrier on the line AK can also be a voltage signal alternating between positive and negative voltage values ​​with a defined frequency, for example 2 kHz. The control device 29 then detects the resulting current as a generator control signal sg and operates the generator 28 accordingly in a signaled manner.

[0044] The control device 29 further generates a variable switch control signal sw for controlling the variable switch 30 and outputs it via a line AK after detection of the generator control signal sg. The variable switch control signal sw is detected in the instrument 11 by a detector device 35, which may be configured as an average value detector 36 (Figure 3).

[0045] The control device 29 encodes the variable switch control signal sw in the duty cycle of the signal carrier. This is exemplarily shown in FIG. 5a. Here, duty cycle means the ratio of the duration of positive voltage to the duration of negative voltage or the ratio of the duration of positive current to the duration of negative current within one wave train shown in FIG. 5a. The duty cycle is low in the left part of the diagram of FIG. 5a, characterized by the term "cut", and high in the right phase, characterized by the term "coag". The detection of these ratios is aided by an average value detector 36, which can be configured, for example, in the form of an RC low pass. The output of the low pass can be connected, for example, to light-emitting diodes of an optocoupler and form the input of the respective electronic switches 31, 32 (and 34, if necessary). These light-emitting diodes are shown diagrammatically in the actuation device 24 in FIG. 3. However, they can also be arranged in the switches 31, 32, 34, as is clear from FIG. 4. Additionally, switching or amplifying components may be placed between the other inputs of the light emitting diodes or switches 30, 32, 34 and the average value detector 36, the preferably high ohmic inputs of which impose little or no stress on the average value detector 36 and thus the voltage on capacitor C.

[0046] The treatment device 10 thus far described operates as follows.

[0047] As shown in Figures 1 and 2, the tool 11 is connected to the device 12 after starting. Now, for example, if a living tissue (for example a blood vessel or another tube) has to be sealed and cut open, the living tissue is grasped with the jaws 18, 19, which are closed by the operating device 23 and the tissue is compressed. By the activation device 24, in particular by activation of the switch 25, for example the generator 28 is now activated. This occurs because the switch 25 is closed, whereby a current flows through the resistor R1 via the line AK. This is detected by the control device 29 as a generator control signal sg.

[0048] The generator control device 29 interprets the generator control signal sg as a command to assume the coagulation mode and applies the modulation shown in the right side of FIG. 5a to the signal carrier on the line AK. The duty cycle is high, so that after low-pass filtering, the positive variable switch control signal sw according to the right side of FIG. 5b is detected by the average value detector 26 as the control signal a and is supplied to the switch 31. The switch 31 is closed, i.e. the variable switch 30 connects the electrode 20 to the line NE and thus to the high-frequency generating part of the generator 28. The other switches 32, 34 remain open (not conducting). The coagulation voltage Ucoag is then applied to the electrode 20, which allows the coagulation current to flow from the electrode 20 to the electrode 21. If it is necessary to change to the cut mode, the user operates the other switch 26. Now the second resistor R2 is switched between the neutral potential on line AE and the signal carrier on line AK. This is interpreted by the control device 29 as a generator control signal sg for the cut mode. The control device 29 therefore changes the modulation of the signal carrier (line AK) according to the left side of Fig. 5a.

[0049] Due to the generator control signal sg, the generator voltage U now has a value Ucut (left) which is different from the coagulation mode Ucoag (right), as shown in Fig. 5c. The mean value of the signal carrier is now negative, which is why the detector 35 opens the switch 31 and closes the switches 32, 34. If this happens, the radio-frequency voltage U is now applied to the output 22 as a cutting voltage Ucut with a respective higher amplitude, as shown in the left side of Fig. 5c. The cutting voltage Ucut is induced to the electrode 22 via the variable switch 30 while the switch 34 is closed. The two electrodes 20, 21 are thus connected in parallel and together form a neutral electrode for the cutting electrode 22.

[0050] As is evident from figure 5d, the changeover switching of the variable switches and the switching on and off of the high voltage part of the generator 28 are time-shifted. The closing of the switches 31, 32, 34 always takes place before the start-up of the high voltage part of the generator 28. And vice versa: the generator 28 is always switched off before the respective switch of the variable switch 30 opens. This is evident from the time series of the generator control signal sg and the variable switch control signal sw shown in figures 5b and 5c.

[0051] The described changeover switching process can be performed one or more times sequentially, even in quick succession, for example to realize a virtual simultaneous cut and coagulation. During a first operating mode, e.g., during coagulation, and during a second operating mode, e.g., during cutting, it is possible to precisely monitor the generator current and voltage, the power output by the generator, or the tissue condition, and control the generator accordingly. Furthermore, the current and voltage are individually adjustable in the device 12 for each operating mode, coag, cut.

[0052] In addition to the manual changeover between the different operating modes described above, different treatment progressions can also be stored and retrieved within the generator 28. In this case, the generator 28 controls the variable switch 30 according to a predetermined treatment progression after a start signal is output from the activation device 24, and outputs the respective voltage and current to the activated electrode 20 or 22 according to the variable switch position.

[0053] The treatment device 10 according to the invention comprises an instrument 11 connected to a supplying device 12. The instrument 11 and the device 12 can control each other. By means of an activation device 24 provided on the instrument 11 or otherwise, the generator can be activated in a first or second operating type. The instrument 11 includes a variable switch 30 to direct the power provided by the generator to the first electrode pair 20 / 21 or to the second electrode pair 22 / 21. The variable switch 30 is controlled by the generator 12. This allows a treatment progression to be stored in the generator and performed by the instrument 11 without the user having to change the operating type. [Explanation of symbols]

[0054] 10 Treatment Device 11. Equipment 12 Equipment 13 Cable 14 Handle 15. Cabinet 16 Shank 17 Tools 18 Upper jaw 19 Mandible 20 Upper electrode 21 Lower electrode 22 Cutting electrode 23 Operation Device 24 Boot Device 25, 26 Switch 27 Control section 28 Generator 29 Control Devices NE Line for process current and process voltage AE Neutral potential line AK signal carrier line 30 Variable Switch sw Variable switch control signal sg Generator control signal 31, 32 Electronic switch 33 Optocoupler a, b control signal C1, C2 Coupling capacitors 34 Electronic Switch 35 Detector Devices 36 Average Value Detector R resistor C Capacitor U Voltage Ucoag coagulation voltage Ucut Cutting voltage

Claims

1. A treatment device (10), in particular for coagulating and cutting biological tissue of a human or animal patient, comprising: a generator (28) for selectively outputting a voltage (U) having a first value (Ucoag) for a first treatment mode (coag) and a voltage (U) having a second value (Ucut) for a second treatment mode (cut) in response to a generator control signal (sg), and for outputting a variable switch control signal (sw) according to the treatment mode in a first state or a second state different from the first state; an instrument (11) including two electrodes (20, 22) connected to said generator (28) via an electric line (NE), an electric variable switch (30) is disposed between the electrodes (20, 22) and the line (NE), and the electric variable switch (30) connects one or the other of the electrodes (20, 22) to the electric line (NE) in response to the variable switch control signal (sw); The treatment device comprises an activation device (24) for generating the generator control signal (sg). Treatment device.

2. The generator (28) is a high frequency generator that outputs a voltage having a frequency between 100 kHz and 5 MHz. The treatment device of claim 1 .

3. The first treatment mode (coag) is a mode for tissue coagulation. A treatment device according to claim 1 or 2.

4. The second treatment mode (cut) is a mode for tissue incision. A treatment device according to claim 1 or 2.

5. The first value (Ucoag) of the voltage (U) is a peak-to-peak voltage measured from a positive peak to a negative peak, and the second value (Ucut) of the voltage (U) is a peak-to-peak voltage measured from a positive peak to a negative peak, and the first value (Ucoag) of the voltage (U) is smaller than the second value (Ucut) of the voltage (U). A treatment device according to claim 1 or 2.

6. The generator (28) includes a control device (29) that transmits a signal carrier to the activation device (24) via a line (AK). The treatment device of claim 1 .

7. The activation device (24) generates the generator control signal (sg) from the signal carrier in response to a user input. The treatment device of claim 6.

8. The activation device (24) includes at least two switches (25, 26) connected to different electrical resistors (R1, R2). A treatment device according to claim 1 or 2.

9. The activation device (24) is disposed in the instrument (11). A treatment device according to claim 1 or 2.

10. The signal carrier includes the variable switch control signal (sw). The treatment device of claim 6.

11. The signal carrier is an AC signal with a variable duty cycle. The treatment device of claim 6.

12. The variable switch control signal (sw) is determined by the duty ratio of the signal carrier. The treatment device of claim 6.

13. An average value detector (36) is provided for extracting the variable switch control signal (sw). A treatment device according to claim 11 or 12.

14. The generator control signal (sg) is defined to start in time after the variable switch control signal (sw) and to end in time before the variable switch control signal (sw). A treatment device according to claim 1 or 2.

15. 2. A method for controlling a treatment device (10) according to claim 1, comprising: A signal carrier output from the generator (28) is supplied to the activation device (24); A generator control signal (sg) corresponding to a desired treatment mode (coag, cut) is generated from the signal carrier by the activation device (24) and supplied to the generator (28); Immediately thereafter, the generator (28) varies the signal carrier to generate the variable switch control signal (sw); The variable switch control signal (sw) is determined from the signal carrier in the instrument (11) and is supplied to the variable switch (30); The variable switch (30) then connects the electrodes (20, 22) appropriate for the desired treatment mode (coag, cut) to the line (NE); Thereafter, the generator (28) generates voltages (Ucoag, Ucut) for the desired treatment mode (coag, cut) and supplies them to the electrodes (20, 22). method.

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