GB2593727A

GB2593727A - Argon plasma coagulation timer

Info

Publication number: GB2593727A
Application number: GB2004708.0A
Authority: GB
Inventors: Atwell Anthony
Original assignee: Gyrus Medical Ltd
Current assignee: Gyrus Medical Ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2021-10-06
Anticipated expiration: 2040-03-31
Also published as: GB202004708D0; GB2593727B

Abstract

A generator for use with an argon supply in fluid communication with a surgical instrument having a plasma providing component. The generator comprises a controller, a timer in communication with the controller, and a plasma initiation detector in communication with the controller. On receipt of the signal from the plasma initiation detector, the controller activates the timer to measure a preselected time period that may be selectable via a user-interface. At the end of the time period the controller signals the generator to stop argon flow to the surgical instrument. The controller may be coupled to a foot-pedal that may initiate argon flow on depression and may stop the flow of argon before the end of the time period if the foot pedal is released. The generator may operate in a mode that does not activate the timer. An argon plasma coagulation device and system comprising the aforementioned generator.

Description

ARGON PLASMA COAGULATION TIMER

The present invention relates to a timer for the control of plasma duration during argon plasma coagulation (APC) procedures.

BACKGROUND OF THE INVENTION

Argon plasma coagulation (APC) is the non-contact thermal method of haemostasis, coagulation and ablation of tissue using ionised argon gas.

Argon plasma coagulation (APC) uses argon gas to deliver plasma of evenly distributed thermal energy to a field of tissue adjacent to the surgical probe. A high voltage spark is delivered at the tip of the probe that ionizes the argon gas as it is sprayed from the probe tip 10 in the direction of the target tissue.

In addition to the probe, the equipment consists of an electrosurgical generator, a foot pedal, and an argon gas supply. Both the argon flow rate and the wattage delivered per pulse are easily adjusted by pressing buttons on the control panel of the generator.

During argon plasma coagulation procedures, it is sometimes necessary to activate the equipment for a very short period of time in order to avoid perforation in the lower gastrointestinal (GI) tract. This is normally achieved by the surgeon depressing the foot pedal for a very short period of time before releasing it again. However, this is problematic as the initiation of plasma delivery is not always instant on depression of the foot pedal. One solution to this is to depress the foot pedal until plasma initiation is observed, before immediate release of the foot pedal to immediately stop plasma activation. Obviously, the effectiveness of this approach depends on the reaction times of the surgeon and there is no consistency with respect to short-term plasma activation.

There is therefore a need for an alternative process that allows consistent and reliable plasma initiation over pre-selected short time periods on demand.

SUMMARY OF THE INVENTION

The present invention seeks to address the problems of the prior art.

According to a first aspect of the present invention, there is provided a generator for use with an argon supply in fluid communication with a surgical instrument, the generator comprising: a controller; a timer device in communication with the controller, the timer device being operable to measure a pre-selected time period on receipt of a signal from the controller; and a plasma initiation detector in communication with the controller and operable to send a signal to the controller in response to detection of plasma initiation, wherein on receipt of the signal from the plasma initiation detector, the controller is operable to activate the timer device to measure the preselected time period, and wherein on detection of the end of the pre-selected time period, the controller is operable to signal to the generator to stop argon flow to the surgical instrument.

In this way, the inaccuracies, such as those resulting from relying on the user's reaction times to stop coagulation on observation of plasma initiation, are avoided. Instead, on detection of plasma initiation, argon gas flow is permitted until the end of the pre-selected time period, at which point, the controller signals to the generator to stop argon flow to the surgical instruments, thereby halting coagulation. Thus, the period of time between plasma initiation and the halt of argon flow to the surgical instrument is both accurate and consistent over time.

Thus, the plasma duration and therefore the thermal effect on the tissue is controlled precisely without the user having to react quickly.

In one embodiment, the generator is configurated for communication with a foot pedal, and wherein argon flow is stopped on detection by the generator of the release of the foot pedal before the end of the pre-selected time period.

Thus, in situations where the user wishes to activate for a shorter amount of time that the pre-selected time period measured by the timer device or where, for whatever reason, the user wishes to stop plasma coagulation before the end of the pre-selected time period after plasma initiation has started, release of the foot pedal will immediately stop argon flow to the surgical instrument. However, if the foot pedal is not released by the end of the pre-selected time period, the argon gas flow to the surgical instrument will stop in any case. Thus, even if the foot pedal is held down beyond the end of the pre-selected time period, the argon gas flow to the surgical instrument will not continue.

Preferably, argon flow is initiated on depression of the foot pedal. However, it is to be appreciated that argon flow may be initiated by other methods, such as the pressing of a button, operation of a switch, on vocal command or any other suitable method known to the skilled person and suitable for function.

In a further embodiment, the generator further comprises a foot pedal in communication with the generator and moveable between a first active configuration wherein argon flow starts on depression of the foot pedal, and a second non-active configuration wherein argon flow stops on release of the foot pedal.

However, where the pre-selected time ends before the user has released the foot pedal, the argon flow will stop. Only where the foot pedal is release prior to the end of the pre-selected time period will the release of the foot pedal halt argon flow.

Thus, it can be appreciated that, in use, a user will carry out coagulation in the normal manner and, when a very short period of coagulation time is required, for example in order to avoid perforation in the lower gastrointestinal (GI) tract, the user can opt to use the setting within the generator, allowing the generator to operate in accordance with the present invention and limit the agon flow to the expiry of the pre-selected time period after argon initiation is detected. The additional option to use a foot pedal such that release of the foot pedal stops argon flow in the event that the foot pedal is released prior to expiry of the pre-selected time period allows the user the option of early termination of argon flow should it be required for any reason.

One advantage of the present invention is that if the ARC probe is too far from the tissue surface on depression of the foot pedal, provided the user keeps the foot pedal depressed so as not to stop argon flow, the probe can be moved towards the tissue until plasma activation takes place, at which time the timer device will accurately control the activation time, provided the foot pedal is not released before termination of the pre-selected time period.

In one embodiment, the generator further comprises a manual mode selection which is operable by a user to select a first mode where the timer is activated on detection of argon plasma initiation and a second mode where the timer is deactivated. This allows the user to select when to use the controlled short time activation using the timer device and preselected time period for argon flow after plasma activation is detected, and when to manually operate the surgical instrument, for example when longer periods of coagulation are required.

In one embodiment, when the first mode is selected, the timer may be reset by release and subsequent depression of the foot pedal. Thus, in the first mode, a user can repeat the process of plasma detection and timed argon flow to the surgical instrument. Should manual control over the coagulation time be required, the user can simply select the second mode where the timer is inactivated.

In one embodiment, the generator further comprises a user-interface, wherein the preselected time period is adjustable by a user via the generator user interface. Thus, different 5 pre-selected time periods may be applied depending on the requirements of the specific surgical procedure being undertaken.

The user-interface may comprise a touchscreen, digital screen and keyboard combination, physical switches or any other suitable user-interface known to the skilled person and suitable for function.

However, it is to be appreciated that the user may operate the mode selection using foot pedal switch controls. Such foot pedal switch control of the mode selection may be in addition to or instead of mode selection control via the user interface of the generator.

For longer plasma applications, the timer device will be of limited benefit and will be deactivated (second mode). Where there is a risk of coagulation through the full thickness of the tissue being treated, (for example when treating the lower GI tract) and therefore a risk of delayed perforation, the user may apply very short bursts of energy at a lower power level. These bursts of energy can be less than 0.5 seconds in duration, and it is for this type of application that the first mode of operation i.e. where the time device is activated, would be most useful.

A second aspect of the present invention provides an argon plasma coagulation device comprising a generator according to a first aspect of the present invention, and a surgical instrument in communication with the generator, wherein the surgical instrument is in fluid communication with the argon supply and is operable to receive argon flow from the argon supply.

A third aspect of the present invention provides an argon plasma coagulation system comprising an argon plasma coagulation device according to a second aspect of the present invention and an argon supply in communication with the surgical instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an illustration of an embodiment of an argon plasma coagulation system 30 in accordance with a third aspect of the present invention, incorporating a generator

S

according to a first aspect of the present invention and a surgical instrument in communication with the generator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 shows a generator 10 in fluid communication with a surgical instrument 12.

Generator 10 comprises a controller 14. Generator 10 further comprises a timer device 16, a plasma initiation detector 18, both of which are in communication with generator 14.

Plasma initiation detector 18 is operable to signal to controller 14 immediately on detection of plasma initiation, and timer device 16 is operable to measure a pre-selected time period on receipt of a signal from controller 14. There are several ways in which plasma initiation can be detected with which the skilled man would be familiar. In the embodiment shown, plasma initiation detector 18 operates by measuring the d.c. offset voltage resulting from arc rectification. Further details are provided in European Patent Application EP1053719.

Generator 10 is further provided with a user-interface 20 via which a user can input instructions to the controller 14. The user-interface of the present invention may comprise any suitable arrangement to facilitate the receipt of user commands by the controller, such as but not limited to a touch screen and/or audio input and/or one or more switches or buttons. Use-interface 20 may be used by a user to change between a first mode in which the time device is active and a second mode in which the timer device is inactive. Thus, a user can switch from timed coagulation to manual coagulation where the coagulation time is controlled by the user.

Argon gas supply 24 is in fluid communication with surgical instrument 12 and, in use, provides argon gas flow to surgical instrument 12 on receipt of a signal from controller 14.

Foot pedal 22 is also provided for use by an operator when instructing the controller 14 with respect to argon flow from argon gas supply 24 Generator 10 is in communication with argon gas supply 24 and is operable to initiate argon flow on detection of the depression of foot pedal 22 by a user and to cease argon flow on detection of the release of foot pedal 22. Generator 10 is further operable to cease argon flow on receipt of a signal from the timer device 16 that the pre-selected time period has ended.

Operation in First Mode In the first mode, the timer device 16 is active.

In use, a user would bring the surgical instrument adjacent a tissue whilst depressing foot pedal 22. The depression of foot pedal 22 is communicated to controller 14 of generator 10, 5 which signals to the argon gas supply 24 to initiate argon flow to surgical instrument 12.

It is important to bear in mind that the initiation of argon flow to surgical instrument 12 does not correspond to plasma initiation. The time from depression of foot pedal 22 to plasma initiation is dependent on a number of factors including the distance of the probe tip 26 of the surgical instrument from the tissue surface, the medium through which the plasma is being generated (which is initially air then argon as the gas flow catches up), any inbuilt delay in the generator (with the intention of delivering argon gas ahead of R.F. application at probe tip 26, and whether the probe tip 26 is wet or dry.

When the foot pedal 22 is depressed, argon gas flow and the high voltage R.F. pulses used to initiate the plasma are applied. Usually the first pulse results in no plasma or an air plasma because argon gas flow is not fully developed. The plasma will initiate on the second, third or subsequent pulses. Such a delay between the depressing of the foot pedal 22 and plasma initiation may typically be up to 0.5 seconds, but could be longer, particularly if the probe tip to tissue distance is excessive or the probe tip is wet.

Therefore, to time coagulation from the moment of depression of the foot pedal 22 would result in an inaccurate control of activation time, which is of particular concern when a short activation time is required.

Once plasma initiation occurs, this is detected by plasma initiation detector 18 which signals to controller 14 that plasma initiation has been detected. Controller 14 then signals timer device 16 to begin measuring the pre-selected time period.

Argon flow then continues until either: The user releases foot pedal 22 thereby signalling to controller 14 to halt plasma flow from the argon gas supply 24 to surgical instrument 12; or The timer device signals to the controller that the pre-selected time period has expired. The controller then halts argon flow from the argon gas supply 24 to surgical instrument 12.

Thus, argon flow is halted on expiry of the pre-selected time period after detection of plasma initiation or on release of foot pedal 22 if this occurs before the end of the pre-selected time period.

The pre-selected time period may be selected and instructed to the controller 14 by a user 5 via user-interface 20. Further, the pre-selected time period is adjustable by a user via user-interface 20 of generator 10.

Operation in Second Mode In the second mode, the timer device 16 is deactivated.

In use, a user would bring the surgical instrument adjacent a tissue whilst depressing foot pedal 22. The depression of foot pedal 22 is communicated to controller 14 of generator 10, which signals to the argon gas supply 24 to initiate argon flow to surgical instrument 12. Once argon flow is initiated to surgical instrument 12, plasma initiation will begin when the probe tip 26 is close enough to the tissue and all other required conditions are met. Argon flow will continue until such time as the use releases the foot pedal 22, thereby signalling to the controller 14 to halt argon flow to the surgical instrument 12.

As the timer device 16 is deactivated, there is no activation of the timer device to begin measuring the pre-selected time period on detection of plasma initiation. Instead, the user is in full manual control of the delivery of argon gas to the surgical instrument 12 and argon flow ceases only when the user releases foot pedal 22.

There may be a safety feature built into the system in mode 2, whereby argon flow is halted after a period of time (longer than the pre-selected period of time) should no release of the foot pedal take place. This prevents accidental over coagulation at the tissue surface in the event that the foot-pedal sticks in the depressed position.

Claims

CLAIMS: 1. A generator for use with an argon supply in fluid communication with a surgical instrument, the generator comprising: a controller; a timer device in communication with the controller, the timer device being operable to measure a preselected time period on receipt of a signal from the controller; and a plasma initiation detector in communication with the controller and operable to send a signal to the controller in response to detection of plasma initiation, wherein on receipt of the signal from the plasma initiation detector, the controller is operable to activate the timer device to measure the preselected time period, and wherein on detection of the end of the preselected time period, the controller is operable to signal to the generator to stop argon flow to the surgical instrument.
2 A generator as claimed in claim 1, wherein the controller is configurated for communication with a foot pedal, and wherein argon flow is stopped on detection by the controller of the release of the foot pedal before the end of the pre-selected time period.
3. A generator as claimed in claim 2, wherein argon flow is initiated on depression of the foot pedal.
4 A generator as claimed in claim 1, further comprising a foot pedal in communication with the controller and moveable between a first active configuration wherein argon flow starts on depression of the foot pedal, and a second non-active configuration wherein argon flow stops on release of the foot pedal.
A generator as claimed in any one of claims 2 to 4, wherein the generator further comprises a user interface, wherein a manual mode selection which is operable via the user interface by a user to select a first mode where the timer is activated on detection of argon plasma initiation and a second mode where the timer is deactivated.
6 An argon plasma coagulation device as claimed in claim 5, wherein when the first mode is selected, the timer is reset by release and subsequent depression of the foot pedal.
7 An argon plasma coagulation device as claimed in claim 5 or claim 6, wherein the generator further comprises a user-interface, and wherein the pre-selected time period is adjustable by a user via the generator user interface.
8 An argon plasma coagulation device comprising a generator as claimed in any preceding claim, and a surgical instrument in communication with the generator, wherein the surgical instrument is in fluid communication with the argon supply and is operable to receive argon flow from the argon supply.
9. An argon plasma coagulation system comprising an argon plasma coagulation device as claimed in claim 8 and an argon supply in communication with the surgical instrument.