Capture system

Abstract

A capture canister for an anaesthetic gas capture machine 10 (Figure 1) comprises a body for receiving filter material and through which gas containing anaesthetic agent can flow. The canister include

Description

27 12 24 The present invention relates to generally to the capture of halocarbons and more particularly, although not exclusively, to apparatus (systems and / or parts thereof) for use in the capture of 5 anaesthetic agents in medical environments. Examples of agents for which systems can be configured, adapted or provided include e.g. halogenated ethers (such as isoflurane, desflurane, and sevoflurane), halogenated hydrocarbons (such as halothane), nitrous oxide or xenon. 10 A halocarbon is an organic chemical molecule composed of at least one carbon atom bound covalently with one or more halogen elements. Halocarbons have many uses and are used in several industries as solvents, pesticides, refrigerants, fire-resistant oils, ingredients of elastomers, adhesives and sealants, electrically insulating coatings, plastics and anaesthetics. 15 An alternative term for halocarbons is “halogenated fluorocarbons” when halogen elements other than fluorine are included in the molecule. Volatile anaesthetic agents are typically halogenated fluorocarbons, examples of which include desflurane, isoflurane, sevoflurane and halothane. Volatile anaesthetic agents are liquid at room 20 temperature but evaporate easily to produce a vapour for inhalation by a patient to induce anaesthesia. Anaesthetic agents are used extensively in modern healthcare and represent a significant cost. They are also potent greenhouse gases due to their ability to absorb infrared light and their upper atmospheric persistence. Isoflurane and Halothane also contain Chlorine and Bromine groups that contribute to ozone depletion. 25 Examples of halocarbons which are used as anaesthetic agents typically include desflurane, isoflurane, sevoflurane, halothane and enflurane. These anaesthetics may be referred to as volatile anaesthetic agents because they are liquid at room temperature but evaporate easily to produce a vapour for inhalation by a patient to induce anaesthesia. These agents are 30 administered to patients using the breathing circuit of an ananaesthetic machine, also known as a Boyle’s machine. The primary function of the anaesthetic machine is to mix oxygen with volatile anaesthetic agent, at a clinician-specified concentration, for delivery to the patient via the breathing circuit. 35 The present invention seeks to provide improvements in or relating to the capture of anaesthetic agents from medical environments. An aspect of the present invention provides a capture canister for a medical gas capture device, the canister comprises a body containing adsorbant material and through which gas can flow, 40 the canister includes an inlet and an outlet, a valve is provided for the inlet and a valve is provided for the outlet, the inlet and outlet valves are normally closed to seal the body and open 1 when the canister is loaded into a device, in which the canister comprises a mesh plate at or towards the inlet and / or outlet. 27 12 24 The inlet valve and / or outlet valve may include a return spring. 5 The inlet valve and / or outlet valve may be formed as a poppet valve. The canister may comprises a mesh plate at or towards the inlet and / or outlet. The mesh plate / s may act as a diffuser. 10 Part of the valve may be positioned in the mesh. A further aspect provides medical gas capture device that can releasably receive one or more capture canisters as described herein. 15 The device may be configured to push exhausted gas through the or one or more of the canisters under positive pressure. 20 The device may comprise or may be connected to suction means for drawing gas exhausted from a machine to the device. The device may be pneumatically decoupled from an anaesthetic machine so that the device cannot apply vacuum pressure to the machine. 25 The device may comprise a sensor for sensing the presence of anaesthetic agent in gas flow from the machine, The sensor may be provided on an inlet side of the device, 30 The suction means may be provided upstream of the capture canister / s and downstream of the sensor. In some embodiment the sensor can activate the suction means when anaesthetic agent is 35 detected, whereupon the suction means pushes gas through the or one or more of the canisters under positive pressure. The device may be configured to receive one or more capture canisters as defined herein. 40 The device may also connected or connectable to a gas scavenging system. The device may be pneumatically decoupled from the scavenging system. 27 12 24 In some embodiments the or each canister can be removed / replaced during operation of the device (“hot-swap”). 5 The device may comprise means for determining the remaining capacity of a canister. The device may comprise means for detecting the presence of a canister. 10 The device / machine / appliance of the present invention may be formed as a mobile trolley. The device may be wall mountable. The present invention also provides a mobile anaesthetic gas scavenging device comprising a 15 device as described herein. The present invention is also described, by way of example, with reference to the accompanying drawings. 20 All orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention or its connection to a closure. 25 Example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein. 30 Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed and as well as individual embodiments the invention is intended to cover combinations of those embodiments as well. On the contrary, all modifications, equivalents, and alternatives falling 35 within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate. The terminology used herein to describe embodiments is not intended to limit the scope. The 40 articles “a,” “an,” and “the” are singular in that they have a single referent; however, the use of the singular form in the present document should not preclude the presence of more than one 3 27 12 24 referent. In other words, elements referred to in the singular can number one or more, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and / or “including,” when used herein, specify the presence of stated features, items, steps, operations, elements, and / or components, but do not preclude the 5 presence or addition of one or more other features, items, steps, operations, elements, components, and / or groups thereof. Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common 10 usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein. Figure 1 shows a capture rig 10 formed in accordance with an aspect of the present invention and comprising a main body 15. The body 15 has four (in this embodiment) pairs of top and 15 bottom canister valves 20, 25. Canister sensors 30 are provided to detect the presence / absence of a canister in each canister bay. A graphical user interface (GUI) is provided on the body. The anaesthetic gas capture rig 10 extracts anaesthetic gas from an anaesthesia machine. The 20 rig comprises or can be connected to suction means for drawing gas exhausted from a machine to the rig. The rig is pneumatically decoupled from the machine so that the rig cannot apply vacuum pressure to the machine. Figures 2, 3 and 4 show schematics for Active, Passive and Recovery configurations of 25 aneasthesia systems including capture rigs (“Sagetech Device”) formed in accordance with the present invention. In the schematics the rig has been shown with a vacuum source. This could be an external or internal vacuum source, venturi pump, or fans. The vacuum pressure may be between 10- 30 20kPa vacuum pressure with a flow rate between 50-80lpm, for example. These values could increase or decrease if there are changes to legislation. Either side of the device is an air break that effectively de-couples each of the systems so no over-pressure or vacuum condition can affect the patient. 35 The device is fitted with valves that allow canisters to be swapped while in operation. In a condition where all canisters have been removed, the system would move to a bypass condition so there is no interruption to gas flowthrough the systems. 27 12 24 Load cells and canister sensors work together to determine the presence and mass of individual canisters so that their capacity can be tracked and indication of when they need to be replaced can be provided. 5 Figures 5 to 8 show a schematic of a capture device formed in accordance with the present invention. An anaesthetic sensor (e.g. a VOC sensor) is provided at the inlet side of the device. 10 A vacuum source, in this embodiment a fan, is provided upstream of the canisters (and downstream of the sensor). The sensor activates the fan when the level of VOC (anesthetic) detected in gas flow pulled from the anaesthetic machine is high. 15 Because the fan is at the inlet side of the canister it pulls flow from the anaesthetic machine and pushes gas through the canister. This means the system is not pulling a vacuum across the canister. This results in more 20 efficient binding of anaeasthetic agent onto the canister filter, because binding is happening in a positive and not a negative pressure environment. This also reduces duty of the vacuum source because it is not having to fight airway resistance provided by the filter in the canister. Figures 9 to 13 illustrate further embodiments. 25 Figures 14 and 15 illustrate some of the principles underpinning some aspects and embodiments of the present invention. Figure 16A shows an extraction dock / machine / apparatus / appliance / device fitted with two 30 capture canisters. Figure 16B shows a capture canister (removed from the dock). Figure 17 shows the dock with a front panel closed. Figure 18 shows the dock with the panel ajar, revealing a capture canister bay and fitted with two capture canisters. 35 Figure 19 illustrates removal of a capture canister. Figure 20 shows a canister. Figure 21 illustrates a capture canister formed in accordance with an embodiment of the present invention. 40 Safety SID-Can 27 12 24 Benefits: 5 - safe and easy to handle, store and transport intraoperative canister exchange (“hot-swap”) lower number of changes Features: 10 lightweight valves at both ends hydrophobic adsorbent material made from coconut husks captures 675ml (equals 2.7 bottles of agent) 15 Figure 22 shows a canister formed in accordance with the present invention and fitted into a canister loading mount (that may be provided as part of a capture dock). Figure 23 is a section taken along line A-A of Figure 22. 20 Figure 24 shows the canister of Figures 22 and 23 being moved in the mount. Figure 25 is a section of Figure 24. Upper and lower canister actuators are provided by the mount. The upper and / or lower canister actuators may be spring loaded to facilitate entry / insertion of the canister. In this embodiment the upper actuator can be lifted “up” - see Figures 24 and 25 - and then released “down” - see Figure 26. This would move the lower end of the body down onto the 25 lower actuator (see Figures 27 and 28). Movement of the canister into the mount causes upper and lower valves at the end of the body to be opened. The valves may be described as inlet and outlet valves, depending on which direction air is flowing through the body. Similarly the inlet / outlet of the body may be described 30 as through flow openings e.g. upper and lower openings / apertures formed at or towards each end of the body. Figures 29Ato 29C illustrate a capture canister in unloaded and loaded configurations. 35 The valves are supported by mesh plates (which act as diffusers). The part of the valve which blocks / unblocks the final outlet at either end of the body may be spring loaded and move up and down in a valve carrier which itself is supported in the mesh. The moving part of the valve may be provided with a sealing gasket to seal against the respective body opening. The actuators from the mount move partially into the body openings to provide a sealed gas flow path through the body in use (see Figures 26 and 28). In this embodiment the actuators form part of and link into the dock. 5 Figures 30 to 33 illustrate a dock formed according to an embodiment of the present invention. Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected 10 therein by one skilled in the art without departing from the scope of the invention. 27 12 24

Claims

27 12 241. A capture canister for a medical gas capture device, the canister comprises a body containing adsorbant material and through which gas can flow, the canister includes an inlet5 and an outlet, a valve is provided for the inlet and a valve is provided for the outlet, the inlet and outlet valves are normally closed to seal the body and open when the canister is loaded into a device, in which the canister comprises a mesh plate at or towards the inlet and / or outlet.

2. A canister as claimed in claim 1, in which the inlet valve and / or outlet valve include a 10 return spring.

3. A canister as claimed in claim 1 or claim 2, in which the inlet valve and / or outlet valve is formed as a poppet valve.15 4. A canister as claimed in any preceding claim, in which part of the valve is positioned inthe mesh.

5. A canister as claimed in any preceding claim, in which the valve is supported by the mesh.

206. A medical gas capture device fitted with one or more canisters according to any preceding claim.25

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