GB2597491A

GB2597491A - Medical gas treatment

Info

Publication number: GB2597491A
Application number: GB2011421.1A
Authority: GB
Inventors: Griffiths Dominic; Brewer Jason
Original assignee: Alesi Surgical Ltd
Current assignee: Alesi Surgical Ltd
Priority date: 2020-07-23
Filing date: 2020-07-23
Publication date: 2022-02-02
Also published as: GB202011421D0; WO2022018460A1

Abstract

A medical gas supply conditioning unit has an inlet for receiving a supply of a gas such as carbon dioxide, an electrostatic precipitator for removing particulate matter present in the gas, and an outlet for delivering treated gas from the unit. The unit may be an insufflation apparatus 10 for use in surgery, with an outlet 16 delivering gas to an intracorporeal cavity of a patient and a return port 22. A conditioning unit 20 contains the electrostatic precipitator 20a and optionally a heater 20b and a humidifier 20c. The flow of gas is regulated by a regulating assembly 28 and associated valves 28a-c, and an extractor unit 40 draws gas from the patient through the return port. Gas which has passed through the precipitator may be recirculated back to the patient or exhausted via a filter 44 through an exhaust port 32 to the environment. Sensors may measure parameters of the gas and/or patient to inform control of the apparatus.

Description

MEDICAL GAS TREATMENT

The present invention relates to treating medical gas to remove particulate matter using electrostatic precipitation. Specifically, an insufflation apparatus for use in surgical procedures, such as electrosurgical procedures where electrostatic precipitation is used to eliminate surgical smoke and provide a clear visual field during surgery.

Medical gas supply systems in hospitals and other healthcare facilities are utilized to supply specialized gases and gas mixtures to various parts of the facility and equipment. Medical gases are subject to quality requirements which necessitate filtration to remove particulate matter, including biological matter such as viruses, bacteria and other microorganisms. Filtration may occur; on input from the supply source; output from functions such as from an oxygen supply mask or evacuation from a surgical site; or during recycling and scavenging procedures.

Electrosurgical procedures which utilise electrostatic precipitation for smoke clearing, such as those described in W02011010148, are used to reduce particular matter generated by the procedure which may be a concern to the patient and healthcare workers, the presence of an electrode in the abdomen introduces an extra energy source which needs to be managed. Moreover, the performance of the electrostatic precipitation is significantly influenced by the positioning of the electrode relative to the site of surgery.

Smoke evacuators present an alternative method of clearing smoke from the site of the surgical procedure and include filters. These evacuators may be combined with an insufflator, however, removing the produced smoke via filtration requires the passing of the smoke through a filter with a very small pore size (typically 0.1 pm -ultrafiltration), which results in a back pressure that reduces the flow of gas through the filter and the efficiency of filtration. Also, it is found that these filters get wet which further reduces their efficiency. Finally, such filters are not typically rated to remove particles less than 120nm in diameter, which includes some viruses.

Additionally, exposing patients to excessive cold, dry CO2, as a result of using smoke evacuators to remove smoke and consequently having to replaced removed gas in order to maintain the operative environment, can result in adverse clinical consequences such as reduced body temperature and tissue adhesions for example. Heating and humidifying CO2 prior to its introduction into the abdomen has been used as a means of reducing the impact of these effects, and the use of electrostatic precipitation assists in maintaining a clear view throughout surgery whilst at the same time minimising CO2 exposure for the patient.

An embodiment of the present invention endeavours to integrate the functionality of insufflation and electrostatic precipitation techniques in order to achieve one or more of the following: - minimise CO2 volume delivered to the patient; - remove the electrostatic precipitation to outside of the body cavity, which improves ergonomics and minimise retained smoke within the patient; - provide efficient filtration of the gas, to include particles smaller than known viruses, prior to its release into the operating theatre environment; - provide heated and humidified CO2 to the patient; - rapidly and continuously clear the visual field of particulate matter throughout the procedure.

In a first aspect of the present invention there is provided an insufflation apparatus for use in surgery comprising: an inlet port for receiving insufflating gas from a source of insufflating gas into the apparatus; an outlet port for delivering insufflating gas from the apparatus to a intracorporeal cavity of a patient; a return port for receiving insufflating gas from the patient; a conditioning unit for conditioning the insufflating gas, the conditioning unit comprising an electrostatic precipitator for removing particulate matter present in the insufflation gas using electrostatic precipitation; a regulating assembly for regulating the flow of gas within the apparatus; and an extractor unit for extracting the insufflating gas from the cavity of the patient to the return port.

Advantageously, the apparatus of the present invention obviates the requirement for a physical filter and provides for an increased extraction pressure and cleaning of the insufflation gas.

Further features of the invention are provided as set out in the Claims.

In a second aspect of the present invention there is provide a medical gas supply conditioning unit for use with a supply of medical gas comprising: an inlet for receiving medical gas from a source of gas into the unit; an electrostatic precipitator for removing particulate matter present in the gas within the unit; and, an outlet for delivering treated gas from the unit.

The invention may be performed in various ways and embodiments thereof will now be described, by way of example only, reference being made to the accompanying drawings, in which: Figure 1 is a schematic diagram of an insufflation apparatus according to an embodiment of the invention; and, Figure 2 is a flow diagram illustrating the operation of the apparatus.

With reference to Figure 1 of the drawings, there is provided a schematic illustration of an insufflator apparatus 10 according to an embodiment of the present invention. The insufflation apparatus is arranged to introduce an insufflation gas, such as carbon dioxide, CO2, or other gases, into a cavity C of a patient P from an external gas supply 14 via appropriate tubing and trocars (not shown) in order to insufflate the patient cavity C to present a suitable space for a surgeon to perform a surgical procedure.

The apparatus 10 comprises an inlet manifold (not shown) comprising at least one inlet port 12 for receiving CO2 from the external supply 14 and an outlet manifold (not shown) comprising at least one outlet port 16 through which the insufflation gas is delivered to the patient cavity C. The inlet port 12 is fluidly coupled with the outlet port 16 via a delivery path 18 which includes a conditioning unit 20 for conditioning the insufflation gas prior to exiting the outlet port 16.

The apparatus 10 further comprises a return manifold (not shown) comprising at least one return pod 22 for receiving insufflation gas from the patient P. The return pod 22 is fluidly coupled to a recirculation path 24 which is arranged to recirculate the insufflation gas from the return port 22 to the outlet port 16. The recirculation path 24 includes the conditioning unit 20, which is arranged to receive the recirculated gas and condition the gas prior to passing back into the patient P. In an embodiment, the conditioning unit 20 comprises an electrostatic precipitator 20a for removing particulate material, such as smoke particles, entrained within the insufflation gas, using electrostatic precipitation. This may be achieved by ionising the insufflation gas and principally the entrained particulates, using an ionisation electrode (not shown), and subsequently passing the electrostatically charged gas through an electrically grounded passage (not shown) so that the charged particulates become attracted to the passage wall (not shown), and thus separate from the insufflation gas. The passage walls may comprise attachably removable collector plates, which can be cleaned between usage.

In an embodiment, the conditioning unit 20a further comprises a heater 20b and a humidifier 20c for respectively heating the gas and varying a water content of the gas, so that the conditioned gas is better suited for the surgical procedure to reduce the side-effects experienced by the patient resulting from the insufflation process alone. In alternative embodiments it is envisaged that heating and humidifying the CO2 can be performed outside of the conditioning unit 20, for example heated wires may be ran down the tubing defining the flow path. Therefore, the features of the conditioning unit 20a, 20b, 20c may be separated and either internal or external of the unit 20, but between the gas supply and the patient.

The insufflation apparatus 10 further comprises a controller 26 and a regulating assembly 28 which are communicatively coupled. The regulating assembly 28 comprises a plurality of valves 28a-c for controlling the flow of insufflation gas within the apparatus. In an embodiment, the assembly 28 comprises an inlet valve 28a and an outlet valve 28b respectively disposed at the inlet 12 and outlet pod 16 for regulating the flow of insufflation gas into the apparatus 10, and separately, the flow of gas out from the apparatus 10 into the patient P. The apparatus 10 further comprises an exhaust path 30 which terminates at an exhaust manifold (not shown) comprising at least one exhaust port 32. The exhaust path 30 is fluidly coupled with the recirculation path 24 and comprises a re-direct valve 28c for separately directing a flow of insufflation gas from the recirculation path 24 either to the exhaust path 30 or the outlet port 16. The re-direct valve 28c forms part of the regulating assembly 28, and the operation of the inlet, outlet and re-direct valves 28a-c of the regulating assembly 28 is controlled by the controller 26 via a respective valve actuator (not shown), in dependence of signals output from a plurality of sensors 34 to the controller 26.

The sensors 34 are arranged to monitor at least one gas parameter including gas temperature, gas humidity, gas flow rate, gas pressure and/or gas volume, and the operation of the valves 28a-c by the controller 26 is dependent on the signals received by the controller 26 from the various sensors 34. The apparatus 10 further comprises a display screen 36 and a user interface 38, such as a keyboard, for enabling a user to set a preferred gas parameter, such as a preferred gas humidity and pressure, and to display the real-time gas parameters on the screen, for example.

The sensors 34 may further comprise a patient sensor 38 for measuring and regulating the pressure within the patient's abdominal cavity C, to a pre-set value throughout the surgical procedure.

The apparatus 10 further comprises an extractor unit 40 for extracting insufflation gas from within the patient to encourage a recirculation or flow of gas through the conditioning unit 20 and patient cavity C, to ensure that particulates generated from the surgical procedure, such as smoke particles generated by cauterising tissue using an electrosurgical tool 42, can be removed from within the patient and the insufflation gas using the electrostatic precipitator 20a. The extractor unit 40 may comprise an impellor (not shown) for example disposed downstream of the return port 22 for drawing the insufflation gas into the return port 22 from the patient cavity C. The extractor unit can vary the flow speed of the gas, this may become relevant to enable sufficient operation of the electrostatic precipitation, for example allowing a longer duration in which particulate matter can be precipitated.

The apparatus 10 further comprises a filter 44, such as a charcoal filter disposed in the exhaust path 30 for removing any volatile, not particulate species that are present in the extracted insufflation gas, prior to exhausting or venting the gas to the environment, namely the surgical theatre, once the procedure is complete. Alternatively or additionally a filter 44 may be located on the recirculation path 30 and/or delivery path 18.

With reference to figure 2 of the drawings, which illustrates a flow chart sequencing the steps associated with a method 100 of use the insufflation apparatus, during use, with the insufflator apparatus 10 suitably positioned and fluidly coupled with a intracorporeal cavity C of a patient P, the apparatus 10 is fluidly coupled with a source 14 of insufflation gas, such as a pressurised cylinder of CO2 gas, via the inlet port 12 at step 111. The user, such as a surgeon, subsequently sets the pre-defined gas parameters, such as gas pressure within the cavity C, temperature, humidity, flow rate, etc. via the interface and once the parameters are set, the controller 20 is arranged to open the inlet and outlet valves 28a, 28b to allow the insufflation gas to flow through the apparatus 10. As the gas passes along the delivery path 18, it becomes suitably conditioned, namely heated, humidified and cleaned for example, prior to passing into the patient cavity C, at step 112.

During this process, the impeller (not shown) of the extractor unit 40 is activated to generate a flow of gas from the outlet port 16 to the return port 22, via the patient cavity C at step 113, and then subsequently back to the outlet port 18 via the conditioning unit 20 and recirculation path 24. At the same time, the re-direct valve 28c is orientated to close the exhaust path 30 to re-direct the gas toward the outlet port 18.

The recirculation of the insufflation gas enables any smoke particulates that become generated within the patient cavity C during the surgical procedure, become entrained within the insufflation gas and can thus be removed therefrom by the electrostatic precipitator 20a, at step 114. The processed gas can then be fed back to the outlet port 16 maintaining a recirculation system which reduces the requirements of reheating and pressurising. If however, one or more of the sensors 34 indicates to the controller 26 that the gas pressure or temperature for example, falls outside of the preferred range, then the controller 26 instructs the conditioning unit 20 and/or the regulating assembly 28 to suitably adjust the pressure for example, via the respective valves 28a-c, and/or heat the gas using the heater 20b.

At the end of the procedure, the user, such as the surgeon, enters the required instruction to the insufflation apparatus 10 via the interface 38, and this instruction causes the controller 20 to instruct the respective actuator (not shown) to re-orientate the redirect valve 28c to cause close the recirculation path to the outlet port 16 and to cause the insufflation gas to instead pass to the exhaust path 30. As the gas passes along the exhaust path 30, it is arranged to pass through the filter 44 such as a charcoal filter to further remove any residual contaminants. The filtered gas is the vented from the apparats via the exhaust port 32.

In an alternative embodiment, apparatus 10 may employ a non-recirculating arrangement of insufflation gas, whereby the insufflation gas is simply provided to the patient cavity C to suitably inflate the cavity to a desired pressure, and removed therefrom via the extractor unit 40, cleaned via the electrostatic precipitator 20a and vented direct to the environment via the exhaust path 30, and filter 44. In this manner, the patient cavity C is continuously provided with a flow of fresh insufflation gas.

One or more elements of the electrostatic precipitation station 20a may be either reusable or single-use.

The charcoal filter 44 may be used throughout the procedure or alternatively only used prior to purging the insufflation gas to the atmosphere at the end of the procedure.

In an embodiment, the components of the apparatus can be housed within a common housing 46 to form a compact device. Alternatively, the various component of the device may be separately coupled together.

The heater 20b and humidifier 20c of the conditioning unit 20 can be arranged in any order or combined into a single unit.

It will be appreciated that the apparatus and method of conditioning insufflation gas in surgery in accordance with the present invention can be suitably modified to suit the required surgery.

Claims

Claims 1. Insufflation apparatus for use in surgery comprising: an inlet port for receiving insufflating gas from a source of insufflating gas into the apparatus; an outlet port for delivering insufflating gas from the apparatus to a intracorporeal cavity of a patient; a return port for receiving insufflating gas from the patient; a conditioning unit for conditioning the insufflating gas, the conditioning unit comprising an electrostatic precipitator for removing particulate matter present in the extracted insufflation gas using electrostatic precipitation; a regulating assembly for regulating the flow of gas within the apparatus; and, an extractor unit for extracting the insufflating gas from the cavity of the patient to the return port.
2 The insufflation apparatus according to Claim 1, wherein the conditioning unit comprises heating means for heating the insufflating gas and humidifying means for varying a water content of the insufflating gas.
3. The insufflation apparatus according to claim 1 or 2, further comprising a delivery path for delivering insufflation gas from the inlet to the outlet port.
4 The insufflation apparatus according to any preceding claim, further comprising a recirculation path for recirculating insufflation gas from the return port to the outlet port.
The insufflation apparatus according to claim 3 and 4, wherein the conditioning unit is arranged within the delivery path and recirculation path for conditioning the insufflation gas prior to passing the conditioned gas to the outlet port.
6. The insufflation apparatus according to any previous claim, further comprising filtering means.
7. The insufflation apparatus according to any preceding claim, further comprising an exhaust path which terminates at an exhaust port.
8 The insufflation apparatus according to claims 6 and 7, wherein the filtering means is disposed in the exhaust path for filtering the insufflation gas prior to exhausting the insufflation gas to the environment.
9. The insufflation apparatus according to claim 7 as appended to claim 4 wherein the exhaust path is fluidly coupled with the recirculation path.
The insufflation apparatus according to any preceding claim, wherein the regulating assembly comprises at least one valve for controlling the flow of gas within the apparatus.
11. The insufflation apparatus according to claim 10 as appended to claim 9, wherein the regulating assembly comprises a re-direct valve for selectively directing the flow of insufflating gas from the recirculation path to either the outlet pod or the exhaust path.
12. The insufflation apparatus according to claim 10, wherein the regulating assembly comprises an inlet valve disposed at the inlet port and an outlet valve disposed at the outlet port for controlling the flow of insufflating gas into and out from the apparatus.
13. The insufflation apparatus according to any preceding claim, further comprising a controller and at least one sensor, the at least one sensor being arranged to output at least one signal to the controller, the at least one signal being representative of at least one insufflation gas parameter.
14. The insufflation apparatus according to claim 13, wherein the at least one gas parameter comprises at least one of gas temperature, gas humidity, gas flow rate, gas pressure and/or gas volume.
15. The insufflation apparatus according to claim 13 or 14, wherein the controller is configured to control the regulating assembly, for controlling the flow of insufflating gas within the apparatus and patient cavity, in dependence of the signals outlet from the at least one sensor.
16. The insufflation apparatus according to any preceding claim, further comprising a user interface and display, the user interface enabling a user to interface with the apparatus, the display being arranged to display operating characteristics and parameters of the apparatus
17.A medical gas supply conditioning unit for use with a supply of medical gas comprising: an inlet for receiving medical gas from a source of gas into the unit; an electrostatic precipitator for removing particulate matter present in the gas within the unit; and, an outlet for delivering treated gas from the unit.