ELECTROSURGICAL GENERATOR AND SYSTEM

Abstract

Electrosurgical high-frequency (HF) generator (1), comprising: an output socket (2) for supplying an RF output signal to an electrosurgical instrument (12) according to an operating mode of the generator (1); and an output port configured to output and return a loop signal for controlling a pump (10), wherein the generator (1) is designed to generate the loop signal based at least partially on the operating mode of the generator (1).

Description

Technical field

[0001] Embodiments of the present invention described herein relate to an electrosurgical RF generator and an electrosurgical RF system comprising an electrosurgical RF generator. Background of the invention and general state of the art

[0002] Electrosurgical instruments offer advantages over traditional surgical instruments in that they can be used for coagulation and tissue sealing. Electrosurgical instruments are frequently used with fluid management devices or systems, such as a pump or suction source.

[0003] A known arrangement is disclosed in US 2017 / 0 106 199 A1, which describes a system comprising a pump and surgical devices, such as a shear and a high-frequency (HF) device. The system has an inlet tube for conveying surgical wash fluid from the pump to a body cavity and an outlet tube for aspirating fluid from the body cavity to the pump. Various information from elements of the system can be used to modify the flow rate and / or pressure of the surgical fluid being delivered to or aspirated from the body cavity. If the surgical devices are manufactured by the same manufacturer as the pump system, two-way communication between the surgical devices and the pump is possible.Therefore, the power parameters of the surgical device can be communicated to a pump control processor to control the flow rate or pressure of the surgical fluid. When the pump is used with "external" surgical devices (e.g., surgical devices from a manufacturer other than the pump manufacturer), the surgical devices can be connected to power outlets located on the pump housing. The pump housing may include current and / or voltage sensing devices to detect a waveform of energy drawn by the unseen surgical devices when they are operating. Changes in the waveform can be used to differentiate between when the surgical device is on and off, and this information can be used to control the flow rate or pressure of the surgical fluid. Summary of the invention

[0004] The present disclosure provides an improved method for activating and controlling an external pump in an electrosurgical system. The system comprises an electrosurgical generator, a pump, and an electrosurgical instrument. The instrument is capable of performing various operations, such as electrosurgical coagulation, electrosurgical ablation, and / or mechanical cutting. The generator delivers the appropriate RF signal and / or other signals to the instrument via a signal cable. The pump is connected to the instrument via tubing to provide irrigation and suction to the instrument. The generator determines whether the pump should be activated or triggered, for example, by internally detecting whether the generator is delivering signals to the instrument via the signal cable. If it is determined that the pump should be activated, the generator generates a loop signal.The generator outputs the loop signal to a cable loop connected to the generator, with the cable loop being separate from the signal cable. A sensing device on the pump senses the loop signal passing through the cable loop. The pump detects the loop signal and triggers it to activate its irrigation and suction functionalities. The generator can control the pump's flow rate by generating a loop signal with an appropriate current level. The required pump flow rate may depend on the operations (e.g., coagulation, ablation, and / or mechanical cutting) being performed by the system. The generator generates the loop signal to have a current level proportional to the required pump flow rate. The sensing device senses the current level of the loop signal passing through the cable loop.The pump detects the current of the loop signal from the sensing device and controls the pump flow rate proportionally to the sensed current.

[0005] The system offers the advantage of improved control over the operation of the external pump. For example, in other configurations, the sensing device might attempt to sense the current through the signal cable that carries the RF signal to the electrosurgical instrument. However, sensing the current through the signal cable is difficult because the signal cable is heavily shielded or protected against emission interference. Furthermore, the signal cable may be too large a diameter to accommodate most external sensing devices. However, if a separate loop signal is output via a dedicated loop cable, it is easier for the sensing device to detect the current through the loop cable. In particular, the loop cable does not require as much shielding or protection as the signal cable, thus making it easier for the sensing device to detect the current through the loop cable and control the pump.Furthermore, the loop cable can have a smaller diameter than the signal cable and therefore accommodate a wider range of external sensing devices.

[0006] In light of the above, a first aspect of the present invention provides an electrosurgical high-frequency (HF) generator comprising: an output jack for supplying an HF output signal to an electrosurgical instrument according to an operating mode of the generator; and an output port configured to output and return a loop signal for controlling a pump. Furthermore, the generator is configured to generate the loop signal based at least partially on the operating mode of the generator. Advantageously, such an arrangement generates a separate loop signal for controlling the pump and outputs the loop signal from a separate output port. This provides improved control over external pumps because the current of the loop signal can be more easily detected.

[0007] In one embodiment, the electrosurgical RF generator includes a loop cable coupled to the output port. In another example, the loop cable comprises a first end coupled to an output side of the output port and a second end coupled to a feedback side of the output port. This allows the loop signal to be routed through the loop cable in a closed loop. Advantageously, the loop signal can be sensed by a pump sensing device without requiring a direct electrical connection between the pump and the generator. As such, it is simpler and safer to use the generator with a wide variety of external pumps.

[0008] In one embodiment, the electrosurgical RF generator is designed to generate the loop signal based at least partially on the energy level of the RF output signal and / or the mechanical shear signal. Advantageously, the loop signal can be used to dynamically control the pump so that the pump delivers an appropriate amount of irrigation and suction based on how the electrosurgical instrument is used.

[0009] In one embodiment, the electrosurgical RF generator is designed to receive a command signal indicating a user-requested change to the pump's operation and to generate the loop signal based at least partially on the command signal. Advantageously, this allows a user of the electrosurgical instrument to request specific changes or settings to the pump's operation.

[0010] In one embodiment, the electrosurgical RF generator is designed to receive a sensor output signal from a temperature sensor on the electrosurgical instrument and to generate the loop signal based at least partially on the sensor output signal. Advantageously, the generator can control the pump to adjust its operation appropriately based on the temperature of the instrument, for example, to provide cooling to the instrument when the temperature is too high.

[0011] In one embodiment, the electrosurgical RF generator determines whether the pump requires activation, based at least partially on the operating mode, and then generates the loop signal when the pump requires activation. Advantageously, the pump can be dynamically activated and deactivated based on whether the generator is active in an operating mode. As such, the pump can be controlled in such a way that it is not kept unnecessarily active, thereby reducing energy waste.

[0012] In one embodiment, the electrosurgical RF generator is designed to generate the loop signal such that the current level of the loop signal exceeds a threshold current level when it is determined that the pump requires activation. Advantageously, this ensures that the loop signal is of a sufficiently large magnitude to be detected by a current sensing device.

[0013] In one embodiment, the electrosurgical RF generator further includes user input means for setting the threshold current level. Different current sensing devices may have different threshold settings for sensing currents. Therefore, the user input means allow a user to select a suitable threshold setting, enabling the generator to be used with a wide variety of external current sensing devices.

[0014] In one embodiment, the electrosurgical RF generator generates the loop signal by first determining a pump flow rate based on one or more of the operating mode, energy levels, command signal, or sensor readout signal. The electrosurgical RF generator then generates the loop signal to have a current level corresponding to the pump flow rate. Advantageously, the pump flow rate can be dynamically adjusted by the generator via the loop signal, depending on the amount of suction and irrigation expected to be required at the instrument.

[0015] In one embodiment, the electrosurgical RF generator is designed to generate the loop signal based on information indicating the pump's current response characteristic. Advantageously, this ensures that the loop signal has a suitable current magnitude to instruct the pump to activate and deliver the required pump flow rate.

[0016] In one embodiment, the electrosurgical RF generator further comprises user input means for entering or selecting information that displays the current response characteristic. Different pumps can have different current response characteristics. In particular, different pumps can deliver different flow rates for a given current level of the loop signal, or increase the pump flow rate by different amounts per unit increase in the current level, or activate aspiration and irrigation at different threshold current levels. Therefore, the user input means allow a user to select a suitable current response characteristic that corresponds to the type of pump being used. This ensures that the loop signal has a suitable magnitude to instruct the pump to activate and deliver the required pump flow rate.Furthermore, the user input devices allow the generator to be used with a wide variety of external current sensing devices.

[0017] In a second aspect of the present invention, an electrosurgical system is provided, comprising: an electrosurgical RF generator according to the first aspect above, an electrosurgical instrument and a pump.

[0018] In one embodiment, the electrosurgical system comprises a sensing device configured to sense the loop signal and supply a signal indicating the loop signal to the pump. In a third aspect of the present invention, a method for controlling a pump in an electrosurgical system is also provided, comprising: generating a loop signal in an electrosurgical generator based at least partially on an operating mode of the generator; outputting the loop signal to a loop cable; sensing the loop signal from the loop cable using a sensing device; and controlling the pump based on the sensor output. Advantageously, the loop signal can be more easily detected from the loop cable, thus providing improved control over the pump. Brief description of the drawings

[0019] Embodiments of the invention will now be described in more detail by means of mere examples and with reference to the enclosed drawings, in which similar reference numerals denote similar parts and in which: Fig. 1A illustrates an electrosurgical system comprising an electrosurgical instrument according to an embodiment of the present invention; Fig. 1B is a schematic representation of the electrosurgical system of Fig. 1A shows; and Fig. 2 is a side view of an electrosurgical instrument according to an embodiment of the present invention. Description of embodiments

[0020] Referring to the drawings, it shows Fig. Figure 1A shows an electrosurgical system comprising an electrosurgical generator 1, an electrosurgical instrument 12, and an irrigation fluid and suction source 10. The irrigation fluid and suction source 10 is also referred to here as the "pump" 10. Furthermore, Figure 1A shows Fig. 1B a schematic representation of the electrosurgical system of Fig. 1A.

[0021] Generator 1 includes an output socket 2 for supplying output signals to the electrosurgical instrument 12 via a connecting cable 4. Generator 1 is designed to generate these output signals. Specifically, Generator 1 is designed to generate and supply an RF signal to the instrument 12 to enable electrosurgical functionalities within the instrument 12. More specifically, Generator 1 is designed to generate and supply an RF signal with suitable power to the instrument 12 to provide electrosurgical coagulation or electrosurgical ablation functionality within the instrument 12.

[0022] In coagulation mode, generator 1 generates an RF signal with a first energy level to provide electrosurgical coagulation functionalities in instrument 12. In ablation mode, generator 1 generates an RF signal with a second energy level to provide electrosurgical ablation functionalities in instrument 12. The first energy level is within a coagulation range of energy levels that allows electrodes on a distal end effector of instrument 12 to perform coagulation functionalities. The second energy level is within an ablation range of energy levels that allows the aforementioned electrodes to perform ablation functionalities. The ablation range of energy levels typically includes energy levels higher than those in the coagulation range.

[0023] Generator 1 is also designed to generate a mechanical cutting signal and deliver it to instrument 12 via connecting cable 4 to provide mechanical cutting functionalities in instrument 12. In coagulation and ablation mode, the RF signal and the mechanical cutting signal can be generated and supplied to instrument 12 simultaneously to provide concurrent electrosurgical and mechanical cutting functionalities. If necessary, in other operating modes, generator 1 can generate only one of the RF or mechanical cutting signals at a time to provide either the electrosurgical or mechanical cutting functionality in instrument 12.

[0024] Fig. Figure 2 shows the electrosurgical instrument 12 in more detail. The instrument 12 comprises a proximal handle section 22, a hollow shaft 24 extending distally from the proximal handle section, and a distal end-effector assembly 26 at the distal end of the outer shaft. The power connection cable 4 connects the instrument to the RF generator 1, while the tubes 14 connect the instrument to the irrigation and suction source 10. The instrument 12 may also be equipped with activation buttons (not shown) to allow the operating surgeon to activate either the mechanical cutting function of the end effector and / or the electrosurgical functions of the end effector. It is referenced in UK patent application no. GB ​​1903712.Reference is made to Section 6, which describes the end effector arrangement 26 in more detail, and how the aforementioned mechanical cutting and electrosurgical functionalities can be achieved simultaneously by the end effector arrangement 26.

[0025] In some embodiments, the electrosurgical instrument 12 may also include one or more instrument sensors (not shown). In one example, the instrument sensors include a first temperature sensor configured to sense the temperature at or near the location of the instrument 12. As such, when the instrument 12 is used at a surgical site, the first temperature sensor senses the temperature of the surgical site. Additionally or alternatively, the instrument sensors may include a second temperature sensor configured to sense the temperature of the instrument 12 itself, e.g., the temperature of the distal effector assembly 26. In such embodiments, the generator 1 is configured to receive output signals from the one or more instrument sensors via the connecting cable 4.

[0026] With renewed reference to Fig. 1. The activation of the generator 1 can be carried out from the instrument 12 via a hand switch (not shown) on the instrument 12 or by means of a foot switch unit 5, which is separately connected to the rear of the generator 1 by a foot switch connecting cable 6. In the illustrated embodiment of Fig. Foot switch unit 5 has two foot switches, 5a and 5b, for selecting or activating the coagulation mode or the cutting / vaporizing (ablation) mode of generator 1, respectively. For example, a first foot switch 5a can be pressed to select the coagulation mode, and a second foot switch 5b can be pressed to select the ablation mode. In some examples, foot switch unit 5 and generator 1 are configured such that only one of the coagulation or ablation modes can be selected at any given time.

[0027] Mechanical cutting can be provided automatically by the instrument 12 upon activation of the coagulation or ablation mode. Additionally or alternatively, mechanical cutting can be provided separately by actuating a separate button or switch, either on the foot switch unit 5 or the hand switch (not shown). It is clear that embodiments in which the activation of the generator 1 is performed via a hand switch can achieve the same functionality as embodiments in which the generator 1 is activated via the foot switch unit 5.

[0028] The front of the generator includes pairs of pushbuttons 7a and 7b. The pair of pushbuttons 7a can be used to set the ablation power level within the ablation power range. The pair of pushbuttons 7b can be used to set the coagulation power level within the coagulation power range. The front of the generator 1 also includes a display 8, which shows the set ablation and coagulation power levels. In some embodiments, an additional pair of mode selection pushbuttons 9 may also be provided as an alternative means of selecting between the ablation and coagulation modes.

[0029] The electrosurgical system of Fig. Generator 1 further comprises a loop cable 90 coupled to the generator 1. In particular, the generator 1 comprises a loop signal output port (not shown), and the loop cable 90 is coupled to the generator 1 via the loop signal output port. The loop signal output port comprises an output or transmit side for outputting or transmitting a loop signal to the loop cable 90. The loop signal output also comprises a feedback side for returning the loop signal from the loop cable 90. The loop cable 90 has a first end and a second end. The first end is coupled to the output side of the loop signal output port to receive a loop signal, and the second end is coupled to the feedback side to return a loop signal. As such, the loop cable 90 is configured to carry a loop signal output from the generator 1 in a closed loop.

[0030] In some embodiments, the loop cable 90 is detachably coupled to the generator 1 via the loop output port, thus forming a separate component of the electrosurgical system. In other embodiments, the loop cable 90 is integrally attached to the generator 1, e.g., soldered or welded to the generator 1, thus forming part of the generator 1.

[0031] Generator 1 is designed to generate the loop signal when irrigation and suction functionalities of pump 10 are required in instrument 12. Furthermore, generator 1 is designed to generate the loop signal with a current level proportional to the required amount of irrigation and suction in instrument 12. The amount of irrigation refers to the flow rate of the irrigation fluid through the irrigation hose, and the amount of suction refers to the rate of fluid flow through the suction hose. The irrigation fluid flow rate and the fluid flow rate through the suction hose are more commonly referred to as the pump flow rate.

[0032] Generator 1 is designed to route the loop signal through loop cable 90. The loop signal can also be referred to as a control signal or pump control signal. Generator 1 outputs the loop signal to the output side of the loop signal output, so that the loop signal is routed through loop cable 90 and returns to Generator 1 on the return side of the loop signal output. Therefore, Generator 1 and loop cable 90 are configured such that the loop signal is routed through loop cable 90, for example, in a closed loop.

[0033] Although in Fig. Not shown in Figure 1, generator 1 may also include a power input port to receive electrical energy from a power supply. The power input port is configured to be coupled to a power supply via a power cable. Furthermore, the power input port and the power cable are separate from the loop signal output port and the loop cable.

[0034] Pump 10 is connected to instrument 12 via irrigation and suction tubing 14. Pump 10 is designed to introduce or pump surgical fluid into instrument 12 via the irrigation and suction tubing 14. Pump 10 is also designed to provide suction from instrument 12 via the irrigation and suction tubing 14. Therefore, when instrument 12 is used as a surgical site, the pump allows surgical fluid to be introduced into the surgical site via the tubing 14 and instrument 12, and provides a suction source at the surgical site via the tubing 14 and instrument 12. Introducing the surgical fluid into the surgical site can improve the surgeon's view and create more space at the surgical site.Furthermore, suction can allow the removal of surgical fluid as well as other fluids, tissue fragments, bubbles or other residues near the surgical site.

[0035] The electrosurgical system of Fig. 1 further comprises a current sensing device 95. In the illustrated embodiment of Fig. In embodiment 1, the current sensing device 95 is inductively coupled to the loop cable 90 between its first and second ends. In other words, there is no direct electrical contact between the current sensing device 95 and the loop cable 90. The current sensing device 95 is also coupled to the pump 10 via a sensor cable 97. In some embodiments, the current sensing device 95 is detachably coupled to the pump 10 and therefore forms a separate component of the electrosurgical system. In other embodiments, the current sensing device 95 is integrally attached to the pump 10, thus forming part of the pump 10.

[0036] The current sensing device 95 is designed to sense or detect the loop signal passing through the loop cable 90. Specifically, the current sensing device 95 detects the current level of the loop signal from the loop cable 90. The current sensing device 95 outputs the detected current level of the loop signal to the pump 10. The pump 10 is designed to activate its irrigation and suction functionalities in response to the detection of the presence of the loop signal via the current sensing device 95. Additionally, the pump 10 is designed to control its pump flow rate based on the detected current level of the loop signal. In particular, the pump 10 can control its flow rate to be proportional to the detected current level of the loop signal. For example, if a low current is sensed, the pump 10 can deliver a correspondingly low pump flow rate.If a higher current level is detected, pump 10 can deliver a correspondingly higher pump flow rate.

[0037] Accordingly, generator 1 is able to control the operation of pump 10 to provide an appropriate amount of suction and irrigation at the surgical site via instrument 12. During operation, generator 1 generates a loop signal when irrigation and suction functionalities are required in instrument 12. Specifically, generator 1 generates a loop signal with a current level that reflects the required operation of pump 10 (e.g., reflecting whether the pump should be activated / triggered and what the pump flow rate should be). Generator 1 outputs the loop signal to loop cable 90. Pump 10 detects the presence of the loop signal via current sensor 95 and activates its irrigation and suction functionalities. Pump 10 also controls its pump flow rate according to the detected current level of the loop signal.In particular, the pump 10 can adjust the speed or flow rate of the irrigation fluid and the fluid through the suction hose based on the detected current level.

[0038] As explained above, generator 1 generates the loop signal when irrigation and aspiration functionalities are required in instrument 12, i.e., when pump 10 requires activation or triggering. Pump 10 may require activation / triggering when the generator becomes active by entering an operating mode, such as electrosurgical coagulation mode, electrosurgical ablation mode, mechanical cutting mode, or any combination thereof. As such, generator 1 is designed to generate the loop signal when operating in any of these modes. In other words, generator 1 generates the loop signal when it supplies RF and / or mechanical cutting signals to instrument 12 via connecting cable 4. However, when generator 1 is not operating in any of the above modes (i.e., when it is not operating in any of the above modes), the loop signal is not generated.Since the generator does not supply RF and / or mechanical cutting signals to the instrument 12), no suction or irrigation may be required, and therefore the generator 1 cannot generate the loop signal.

[0039] The required pump flow rate may depend on the operating mode of generator 1. In particular, the required pump flow rate may depend on whether generator 1 is operating in electrosurgical coagulation mode, electrosurgical ablation mode, mechanical cutting mode, or any combination thereof. This is because some operating modes or combinations of operating modes may require a higher pump flow rate than others. For example, using ablation mode may result in more residue at the surgical site compared to using coagulation mode, thus requiring a higher pump flow rate. Furthermore, the required or optimal pump flow rate may also depend on the energy level of the RF signal supplied by generator 1 while operating in its current mode, which may be, for example,as set using the pairs of pushbuttons 7a and 7b. For example, a higher energy level may result in relatively more residue at the surgical site, thus requiring a higher pump flow rate. If necessary, the optimal pump flow rate may also depend on the energy level of the mechanical shear signal supplied to the instrument 12.

[0040] Since generator 1 has access to information regarding its current operating mode and the energy levels of the signals, it can generate a loop signal of a suitable current level that reflects the required pump flow rate. In some embodiments, generator 1 can first determine or calculate the required pump flow rate (e.g., as a unit of m). 3 / s), based on the current operating mode and the energy levels of the RF and / or mechanical shear signals. Generator 1 can be programmed using a suitable technique to determine a required or optimal pump flow rate based on the operating mode and the signal energy levels. For example, Generator 1 can include one or more lookup tables to determine a suitable pump flow rate from the set of operating modes and from the energy levels of the RF and mechanical shear signals within these operating modes. After determining the required pump flow rate, Generator 1 can generate the loop signal to provide a current level corresponding to the determined pump flow rate.

[0041] In some embodiments of the electrosurgical system, a user can issue separate commands to further control the operation of pump 10. In such embodiments, the instrument 12 and / or the foot switch unit 5 include additional buttons (not shown). A user can press one of the additional buttons to request a temporary change in the operation of pump 10. The generator 1 can then receive a corresponding command signal from the instrument 12 via cable 4 or from the foot switch unit 5 via connecting cable 6. The command signal indicates the change in the operation of pump 10 requested by the user. The generator 1 can store a predetermined response to the command signal, such as increasing or decreasing the required pump flow rate and loop signal current by a predetermined amount.In one example, the command signal can indicate a request for a temporary increase in the pump flow rate (e.g., a "Flow+" command) to remove fluid and debris from the surgical site. Generator 1 can appropriately increase the current level of the loop signal to reflect the newly required pump flow rate. Alternatively, if the loop signal is not already being generated, Generator 1 can begin generating the loop signal in response to the command signal to activate the pump. As such, Generator 1 is further designed to generate the loop signal based on the command signal indicating a user-requested change in the operation of Pump 10. The Instrument 12, Generator 1, and / or Footswitch Unit 5 can include any number of additional buttons for the user to request any other change in the operation of Pump 10.

[0042] In embodiments where the instrument 12 includes one or more instrument sensors, the generator can also be configured to generate the loop signal based on the outputs of the instrument sensors. For example, if the output of one of the first or second temperature sensors on the instrument 12 is higher than a respective temperature threshold, this may indicate that a higher pump flow rate is required to provide cooling for the surgical site or the instrument 12. If the generator 1 does not already generate the loop signal, it can therefore generate the loop signal after determining that the temperature sensor output is higher than the temperature threshold. If the generator 1 already generates the loop signal (e.g.,(Generator 1 is operating in an operating mode), generator 1 can increase the current level of the loop signal when determining that the temperature sensor output is higher than the temperature threshold.

[0043] In view of the above, the generator 1 can be designed to generate the loop signal based on one or more of the operating mode, energy level, command signals or sensor readout signals, such that the current level of the loop signal reflects the required operation of the pump 10.

[0044] Different types of current sensors (95) can have different current sensing thresholds. For example, a current sensor type X may only be able to sensing a current above a threshold of 0.05 mA. A current sensor type Y may only be able to sensing a current above a threshold of 0.01 mA.

[0045] Therefore, in some embodiments, generator 1 includes a sensor threshold button (not shown) on the generator housing. The sensor threshold button can be used by a user to program the current sensing threshold of the current sensor 95 into generator 1. For example, if the current sensor 95 is sensor type X, a user can select a current sensing threshold of 0.05 mA using the sensor threshold button. Under this setting, if generator 1 determines that suction and irrigation are required, generator 1 will generate a loop signal with a current level of at least 0.05 mA. Accordingly, the current sensor 95 will be able to sense the loop signal and output the detected current level of the loop signal to pump 10, thus activating / triggering pump 10.Although an example is given above, it is clear that any other suitable current sensor threshold can be programmed into generator 1 to enable generator 1 to be operated with any other suitable type of current sensor. It is also clear that the sensor threshold knob can be replaced by any other suitable means for programming the current sensor threshold into generator 1 (for example, a pair of pushbuttons). Furthermore, the sensor threshold programmed into the generator can be displayed on the display 8.

[0046] Different types of pump 10 can have different pump activation thresholds. For example, pump type A can only activate suction and irrigation functionalities when the detected current level from sensor 95 exceeds a pump activation threshold of 0.1 mA, while pump type B can only activate suction and irrigation when the detected current level from current sensor 95 exceeds a pump activation threshold of 0.2 mA.

[0047] Therefore, in some embodiments, generator 1 includes a pump threshold button (not shown) on the generator housing. The pump threshold button can be used by a user to program the pump activation threshold of pump 10 into generator 1. For example, if pump 10 is pump type A, a user can select a pump activation threshold of 0.1 mA using the threshold button. Under this setting, when generator 1 determines that priming and irrigation are required, generator 1 will generate the loop signal, which has a current level of at least 0.1 mA. Accordingly, current sensor 95 will output the detected current level of the loop signal to pump 10, which is a sufficiently high level to allow pump 10 to be activated.Although an example is given above, it is clear that any other suitable activation threshold can be programmed into generator 1 to enable generator 1 to be operated with any other suitable type of pump 10. It is also clear that the pump threshold button can be replaced by any other suitable means of programming the pump activation threshold into generator 1 (for example, a pair of pushbuttons). Furthermore, the pump activation threshold programmed into the generator can be displayed on the display 8.

[0048] Different types of pump 10 can also have different pump flow rates for the same level of a sensed stream. For example, pump type A can have a pump flow rate of 0.2 m³ / h. 3 / s at its pump activation threshold of 0.1 mA. Pump type A can then linearly increase the pump flow rate at a rate of 0.2 m³ / s.3 The current level increases by 0.1 mA per second. Pump type B, on the other hand, can achieve a pump flow rate of 0.3 m³ / s. 3 / s at the pump activation threshold of 0.2 mA. Pump type B can then linearly increase the pump flow rate at a rate of 0.3 m³ / s. 3 / s increase per 0.1 mA increase in the sensed current level.

[0049] Therefore, in some embodiments, generator 1 further includes a pump sensitivity knob (not shown) on the generator housing. The pump sensitivity knob allows a user to select by how much pump 10 increases its flow rate per unit of current (e.g., per 0.1 mA). For example, if pump 10 is type A, a user can set the flow rate to "0.2 m³ / h". 3 Select " / s" using the pump sensitivity knob. A pump sensitivity setting of 0.2 m 3 / s indicates to generator 1 that pump 10 should increase its flow rate by 0.2 m 3 The current is increased per unit current level (e.g., per 0.1 mA), starting at the pump activation threshold level of 0.1 mA. If, under this setting, generator 1 determines that suction and irrigation are required, it will generate a loop signal of an appropriate current so that pump 10 delivers the required pump flow rate. For example, generator 1 might determine that a flow rate of 1.2 m³ / s is required. 3 / s is required. Under the above pump sensitivity setting according to pump type A (as well as the appropriate pump activation threshold setting), generator 1 can generate the loop signal so that a current of 0.6 mA passes through loop cable 90. Accordingly, pump 10 can detect a current of 0.6 mA and a pump flow rate of 1.2 m 3 / s supply. Although an example is given above, it is clear that any other suitable pump activation level can be programmed into generator 1 to enable generator 1 to be operated with any other suitable type of pump 10. It is also clear that the pump sensitivity knob can be replaced by any other suitable means of programming the pump activation threshold into generator 1 (for example, a pair of pushbuttons). Furthermore, the current pump sensitivity programmed into the generator can be displayed on display 8.

[0050] In some embodiments, the current-response characteristics of a discrete set of pump types can be programmed into generator 1. The current-response characteristic is the relationship between the sensed current and the amount of irrigation and suction delivered by the pump, which includes the pump activation threshold and pump sensitivity. In these embodiments, generator 1 may include a knob or pushbuttons to allow a user to select the pump type. In such embodiments, the pump activation threshold knob and the pump sensitivity knob may be omitted.

[0051] Advantageously, generator 1 can generate a loop signal of a suitable magnitude to allow current sensor 95 to detect the loop current and to enable pump 10 to deliver the required pump flow rate. This allows generator 1 and instrument 12 to be used with a wide range of current sensor and pump types from various manufacturers, which may exhibit different current response characteristics.

[0052] The arrangements of the electrosurgical system described above by Fig. 1 offers several advantages over other arrangements. For example, in another arrangement, the current sensing device may be configured to detect current passing through the connecting cable 4. The current sensing device can derive a required amount of extraction from the detected current through the cable 4. This is because the current passing through the connecting cable 4 may depend on the amount of energy supplied to the instrument 12, which in turn provides an estimate of the required amount of irrigation or extraction.

[0053] However, cable 4 may be heavily insulated or shielded to prevent emission interference between the RF signal and the mechanical cutting signals simultaneously transmitted through cable 4. An undesirable effect of this insulation may be a reduction in the accuracy of the current measurement by the current sensing device. In particular, the current sensing device may be prevented from detecting properly when the mechanical shearing and / or electrosurgical RF functions are used, and therefore it may be difficult to determine whether the pump needs activation and the required pump flow rate from the current sensor output.

[0054] Since cable 4 serves to propagate both RF and mechanical shear signals, its diameter can also be relatively large. As such, cable 4 may have a diameter that is too large to accommodate coupling with many current-sensing devices.

[0055] Furthermore, if a user requests temporary changes to the pump flow rate, for example by selecting the “Flow+” function using the additional buttons on the instrument 12, the current signals received in the cable 4 may be too small to be detected by the current sensing device.

[0056] Advantageously, generator 1 uses the arrangement of Fig.1. A separate loop cable 90 is used to output a loop signal. The loop signal has a current level that indicates the required pump flow rate. The loop cable 90 is separate from cable 4 and does not carry the RF signal or the mechanical cutting signal. Therefore, the loop cable 90 does not require the same level of emission shielding as cable 4, thus allowing the loop signal and its current to be more easily detected by the current sensing device.

[0057] Since loop cable 90 does not carry the RF signal and the mechanical cutting signal, its diameter can be relatively smaller than that of cable 4, thus enabling the use of a wider variety of current sensing devices. Furthermore, because RF generator 1 generates a separate loop signal, user-requested changes in the required pump flow rate can be detected more easily. Since RF generator 1 generates a separate loop signal for pump control, it can also be programmed to operate more effectively with a wider variety of pump and current sensor types.

[0058] It is clear that the embodiments described above can be implemented using any known hardware, software, and implementation techniques known to those skilled in the art. For example, the electrosurgical generator 1 can comprise any number of processors and signal generator circuits designed to operate as described above.

[0059] Various modifications, whether by adding, omitting or replacing features, can be made to the embodiment described above in order to provide further embodiments, all of which are to be covered by the attached claims.

Claims

[1] Electrosurgical high-frequency (HF) generator (1), comprising: an output socket (2) for supplying an RF output signal to an electrosurgical instrument (12) according to an operating mode of the generator (1); and an output port configured to output and return a loop signal for controlling a pump (10), wherein the generator (1) is designed to generate the loop signal based at least partially on the operating mode of the generator (1). [2] Electrosurgical RF generator (1) according to claim 1, further comprising a loop cable (90) coupled to the output port. [3] Electrosurgical RF generator (1) according to claim 2, wherein the loop cable (90) comprises a first end coupled to an output side of the output port and a second end coupled to a feedback side of the output port. [4] Electrosurgical RF generator (1) according to one of the preceding claims, further designed to generate the loop signal based at least partially on an energy level of the RF output signal and / or the mechanical shear signal. [5] Electrosurgical RF generator (1) according to one of the preceding claims, further designed to receive a command signal indicating a change in the operation of the pump (10) requested by a user, and to generate the loop signal based at least partially on the command signal. [6] Electrosurgical RF generator (1) according to one of the preceding claims, further designed to receive a sensor output signal from a temperature sensor on the electrosurgical instrument (12) and to generate the loop signal based at least partially on the sensor output signal. [7] Electrosurgical RF generator (1) according to any one of the preceding claims, comprising generating the loop signal: Determine whether the pump (10) requires activation, based at least partially on the operating mode; and Generating the loop signal when the pump (10) requires activation. [8] Electrosurgical RF generator (1) according to any of the preceding claims, wherein the electrosurgical RF generator (1) is designed to generate a loop signal such that an actual level of the loop signal exceeds a threshold current level when it is determined that the pump (10) requires activation. [9] Electrosurgical RF generator (1) according to claim 8, further comprising user input means for entering the threshold current level. [10] Electrosurgical RF generator (1) according to any one of the preceding claims, comprising generating the loop signal: Determining a pump flow rate based on one or more of the operating mode, energy levels, command signal, or sensor readout signal; and Generating the loop signal to have a current level that corresponds to the pump flow rate. [11] Electrosurgical RF generator (1) according to one of the preceding claims, further designed to generate the loop signal based on information indicating a current response characteristic of the pump (10). [12] Electrosurgical RF generator according to claim 11, further comprising user input means for entering or selecting the information which indicates the current response characteristic. [13] Electrosurgical system, comprising: an electrosurgical RF generator (1) according to any one of claims 1 to 12; the electrosurgical instrument (12); and a pump (10). [14] Electrosurgical system according to claim 13, further comprising a sensing device (95) configured to sense the loop signal and to supply a signal indicating the loop signal to the pump (10). [15] Method for controlling a pump (10) in an electrosurgical system, the method comprising: Generating a loop signal in an electrosurgical generator (1) based at least partially on an operating mode of the generator (1); Outputting the loop signal to a loop cable (90); Sensing, using a discharge device (95), of the loop signal from the loop cable (90); and Control of the pump (10) based on an output of the sensing device (95).

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