GB2515155A

GB2515155A - Apparatus for application of heat to aid vein location

Info

Publication number: GB2515155A
Application number: GB1405466.2A
Authority: GB
Inventors: Tanwir Mian; Lyndon Owen; Maurice Thompson
Original assignee: ANEURIN BEVAN LOCAL HEALTH BOARD
Current assignee: ANEURIN BEVAN LOCAL HEALTH BOARD
Priority date: 2013-03-27
Filing date: 2014-03-27
Publication date: 2014-12-17
Anticipated expiration: 2034-03-27
Also published as: GB201305550D0; GB201405466D0; GB2515155B

Abstract

A flexible sleeve 2 to be worn around an arm and/or a hand has a gas inlet and a gas outlet, with the gas flowing over a wearer's skin. The gas is warmed to promote vasodilation in order that a vein can be more easily located for venipuncture. Preferably apertures at each end of the sleeve can be closed by drawing inwards the sleeve edges. There may be an access portion 58 which can be opened and secured by a magnetic or hook-and-loop fastening; it may be transparent. The sleeve may have an inner gas-permeable wall 52a and an outer impermeable wall 52b, defining between them a chamber 62 through which the gas flows. The gas inlet and outlet may be ports 4 and 6 with a barrier 66 or baffle between them. The gas may be circulated by a portable blower, in a closed or open circuit.

Description

Apparatus For Application of Heat to Aid Vein Location the present invention relates to an apparatus that provides heat to a wearer in order that a blood containing conduit, particularly a vein, can be more easily located by a medical practitioner.

Ibis is a significant problem in the medical field when accessing veins. Tins may be for the purpose of extracting blood or injecting a liquid into a patient such as an anaesthetic.

This is particularly difficult for palients who may have fear of needles or in patients whose veins are not readily accessible for a variety of reasons. It is conanon for a medical practitioner to attempt to locate a vein through inserting a needle through the patient's skin and missing the intended vein. This causes a first problem in that the fear of the patient increases leading to further retraction of the vein into the patient's body and leads to anxiety on behalf of the medical practitioner. These factors then influence a subsequent attempt by the medical practitioner to locate the appropriate vein. This practice of non location of a vein is time consuming for the medical practitioner leading to associated cost waste in terms of time and in terms of components such as needles which may only be used on a single occasion.

It is known that providing warmth to the body aids in the location of veins, This is because the warmth reduces the effect of shrinkage or constriction of the vein into the hand/arm and maintains the vein in closer proximity to the skin meaning it is more usable.

wool 35878 for example discloses an arrangement for warming hands and arms for pre-treatment of veins in the ann region whose veins are difficult for a medical practitioner to find. Such an arrangement comprises a sleeve and a warming deviec incorporated into the sleeve incorpomting therein an electrical resistance heater.

US2002 128699 discloses a sleeve arrangement for receipt at a hand and arm where a gas or liquid is injected into a chamber where the heat from the gas or liquid from the chamber conducts to the patient's arm.

There are limitations associated with these prior art arrangements.

According to the present invention there is apparatus for forming a flexible sleeve around a wearer's arm and/or hand arranged to enable gas to be transferred to the skin of a wearer, wherein the sleeve includes a gas inlet and a gas outlet, the sleeve being arranged such that gas flow between the gas inlet and the gas outlet passes over a wearer's skin.

The gas is beneficially heated gas (preferably heated air).

There are significant benefits associated with the invention as defined in claim I for intravenous use. The first benefit is ihe simplicily of the apparatus meaning that, for example, it can be made single use and/or to a low cost. Secondly it is extremely important that there is airflow over a wearer's skin, and in particular that there is direct contact between the gas (preferably air) and the wearer's skin. Heating without airflow over a wearer's skin causes the wearer to sweat which by nature causes cooling down of the associated area of skin. This is detrimental as makes location of the vein more difficult. A flow of air over the skin allows warming of, for cxamplc, the wearer's arm whilst reducing the effect of sweating.

It is preferred that the apparatus is pre-forined as a sleeve to fit over a wearer's arm in order to reduce manufacturing costs. However, it is envisaged that a sheet may be provided to be folded for use by a medical practitioner to form a sleeve around the wearer's arm.

The sleeve preferably comprises first and second openings at opposing first and second ends of the longitudinal length of the sleeve, The openings are preferably defined by first and second peripheral edges respectively, the first and second peripheral edges arranged to extend around a wearer's arm. In one embodiment the first opening comprises the gas inlet. Purthennore, the second opening optionally comprises the gas outlet. In an embodiment where the gas inlet comprises a first opening, a gas supply tube may he positioned between a weaier's skin and the peripheral edge of the opening to extend into the sleeve.

In a preferred embodiment it is beneficial that the gas inlet comprises a gas inlet port and preferably the gas outlet comprises a gas outlet port. It will however be appreciated that an embodiment may have a gas inlet port and the gas outlet may be an opening through which the wearer's arm!hand is received. In onc embodiment the gas inlet port and gas outlet port are beneficially configured to communicate with outlet and inlet connections of a gas blower arrangement where the gas blower arrangement is beneficially configured to transfer warm gas to the gas inlet port and receive gas from the gas outlet port. The gas inlet port and preferably the gas outlet port beneficially comprise an opening. The gas inlet port and the gas outlet port beneficially are each arranged to communicate with a nozzle provided by a gas blower arrangement.

The gas flow path between the gas inlet port and gas outlet port is beneficially in a first direction in a longitudinal axis of the sleeve and in a second reverse direction in the longitudinal direction of the sleeve. The gas inlet port and gas outlet port are beneficially separated by a bather element. This aids in dispersion of the heated gas through the sleeve.

The gas inlet purL and gas outlet port are beneficially generally a4jacent to each other.

Ibis improves access by the gas blower arrangement and improves comfort for a wearer, The sleeve is beneficially formed by a first sheet and a second sheet, the first and second sheet secured to each other in the longitudinal axis at two longitudinal lengths spaced apart transversely. It is beneficial that the first and second sheets are sealed generally adjacent peripheral edges in the longitudinal axis. Accordingly, a sleeve is thus defined between the first and second sheets.

At least part of the sleeve is beneficially inflatable. It is beneficial that an inflatable gas chamber is positioned between the gas inlet and the gas outlet. At least a portion of the gas chamber is beneficially dcfincd by an inner skin and an outer skin. The inner skin beneficially contacts the wearer. Heat via warmed air is transferred to the gas chamber between the inner and the outer skin. This beneficially causes inflation of the gas chamber thereby effectively securing the sleeve to the wearer with minimal compression. This means that once the gas chamber is inflated then the sleeve is lightly retained on the wearer's anm'hand. At least a portion of the inner skin is beneficially gas permeable. A plurality of apertures is beneficially provided in the inner skin. This enables gas to travel over the wearer's skin thereby warming the skin. However, the gas flow directly over the skin ensures that the skin does not sweat, The outer skin is beneficially substantially gas impermeable. There will be some losses of gas between the first and second openings at each end of the sleeve and the wearer however this is minimised. A majority of the gas transferred through the gas inlet will transfer to the gas outlet and the heat combined in the gas car therefore be recycled.

At least a portion of the sleeve beneficially comprises a viewing access portion. The viewing access portion is beneficially of a single skin and is also beneficially substantially gas impermeable. The viewing access portion enables the medical practitioner to view the veins for example and determine when the veins are suitable for accessing.

The apparatus preferably also includes an arrangement to change, and preferably reduce, the cross sectional area of the slccvc in the direction around a wearer's arm and/or hand.

Preferably there is a first and second arrangement to achicvc this, The first and second arrangements are preferably longitudinally spaced. Preferably, an arrangement is provided to change the cross sectional area of the first opening in the transverse direction. It is further beneficial that the apparatus farther comprises a second arrangement to change the cross sectional area of the second opening in the transverse direction. This enables tightening of the sleeve around the wearer's ann or hand.

It is beneficial that the first opening and second opening each define sufficient cross sectional area to enable a wearer's arm to be inserted through the sleeve, It is further beneficial that the spacing defined between the inner surface of the sleeve and the wearer's arm is sufficient to allow air flow however the first and second openings are beneficially not so wide that the heating effect is insignificant, Accordingly, the ability to enable reduction of the cross sectional area of the sleeve around a wearer's arm, preferably of the first and second openings is preferred. This maybe achieved by a variety of means such as in one embodiment the inflatable chamber and in another embodiment an elasticated band provided secured to the sleeve adjacent a peripheral edge of the first and preferably second openings. Alternative forms of reducing the cross sectional area adjacent the first and second openings are envisaged however as will be described herein and may comprise for example a releasable band that tightens around a wearer's arm which may be secured for example a hook and ioop type mechanism or a magnet.

It is beneficial that a tourniquet may be incorporated into the sleeve, This may be achieved in one embodiment by positioning appropriately and tightening of the arrangement to change the cross-sectional area of the first andlor second openings sufficiently. In another embodiment this may be achieved at least partially by inflation of the gas chamber, Beneficially, the first and/or second arrangement to change the cross sectional area of the first and/or second opening is arranged to draw inwardly the peripheral edge of the first and/or second opening.

The sleeve preferably comprises an access portion arranged to enable access to the conduit defined by the sleeve. This enables intravenous access whilst the wearer continues to wear the sleeve. The access portion may comprise a variety of forms however it has significant benefits for the medical practitioner. Warm air can be supplied to the gas inlet while access is gaincd through thc wearer's arm or hand via the access portion meaning that heat is continued to be supplied to the wearer whilst the medical practitioner monitors the wearer's arm or hand. Optionally and preferably the medical practitioner can insert the needle whilst the heated air is supplied to the sleeve and the wearer's arm/hand. This is significantly beneficial as a medical practitioner can insert the needle whilst the heat is supplied thereby maintaining tile benefit of heating to the adjacent area meaning the vein remains accessible even though the skin adjacent the access point of the vein is open to the atmosphere.

The access portion is preferably withdrawn relative to the sleeve between an open and a closed configuration. For example the access portion may he retracted, folded, hinged or creased relative to the remaining sleeve. The access portion may take a variety of shapes, for example, it could be rectangular, square or triangular. The access portion is beneficially in the form of a flap.

Tn one embodiment the access portion may be in the form of serrations that may be provided in the longitudinal length of the sleeve to enable tearing subsequent to heating such that thc slccvc can be partially or completely removed quickly and easily without affecting the access to the vein by the medical practitioner. The access portion may be configured and comprise means to enable removal of the sleeve without requiring withdrawal of the sleeve over a wearer's hand. Serrations arc a suitable means for enabling tearing of the sleeve to allow removal from a wearer's arm.

A first securing arrangement is preferably provided for seeming the access portion in the closed configuration. The securing arrangement may comprise a magnetic arrangement andlor a hook and loop type fastening mechanism.

The access portion preferably retracts relative to the sleeve in the longitudinal axis of the sleeve. Accordingly, a first peripheral edge of the first opening of the sleeve adjacent in usc to a wearer's hand or preferably fingers is split by retraction of the access portion enabling access for a medical practitioner.

The access portion preferably folds relative to the sleeve in the longitudinal axis of the sleeve. A second securing arrangement is preferably provided for securing the access portion in the open configuration. Again a second securing arrangement may take a variety of forms as will be apparent to the skilled addressee. In one embodiment the first securing arrangement is preferably arranged to secure the access portion in the open configuration.

In one embodiment the access portion is retracted tangentially to the longitudinal axis of the sleeve and may be retracted substantially helically.

In one or more embodiments the access porticn may be secured via the first securing arrangement in a plurality of configurations in order to allow adjustment of tightening of the sleeve around a wearer's ann in order to affect the provide an improved seal around the wearer's arm or hand.

At least a portion of the apparatus is beneficially transparent. Preferably at least part of the access portion is transparent, This provides a significant benefit in that a medical practitioner can judge whether sufficient heat is being applied to the wearer for finding of the vein without retracting the sleeve or the access portion and thereby losing associated warmth. If it is deemed that there is insufficient heat at that time extra time can he given for heating or alternatively the heat supply of warm gas such as heated air can be increased. The increase may be in the temperature of the air or alternatively the air flow.

A baffle is beneficially provided configured to interrupt gas flow between the gas inlet and the gas outlet. The baffle preferably extends in the longitudinal length of the sleeve. The baffle may take the form of undulations on the inner surface of the sleeve, and/or pockets.

The baffles are beneficially arranged to slow the transfer of gas between the gas inlet and gas outlet.

There is further beneficially provided a gas (air) blower arrangement for heating and for subsequently transferring the air to the gas inlet. The gas blower arrangement is preferably portable. The gas blower arrangement may be powered by batteries and is preferably powered by rechargeable batteries. This means that the apparatus can be used during transportation of a wearer or in a number of different locations without a requirement of fixed supporting apparatus.

The gas inlet is preferably at or adjacent a first end of the sleeve and the gas outlet is preferably at or adjacent a second opposing end of the sleeve. In one embodiment openings at each end of the sleeve effectively provide the gas inlet and gas outlet, however ports may be provided as a gas inlet and/or gas outlet. In one embodiment gas flow is beneficially in a single direction along the longitudinal axis of the sleeve, In an alternative embodiment thc gas inlct and the gas outlet may be positioned at or adjacent a first end of thc sleeve. Accordingly, gas flow is in a first direction along the longitudinal axis and then in a return opposing direction along the longitudinal axis.

In an embodiment the sleeve preferably comprises a gas permeable inner sleeve element and a substantially gas impermeable outer sleeve element defining a channel of air between. The gas inlet is preferably arranged to direct gas into the channel between the inner and outer sleeve elements. The channel preferably defines a gas flow path between the gas inlet and thc gas outlct, In such an embodiment gas flow is maintained over the wearer's skin thereby minimising the cffcct of sweating. The channel is preferably defined by the inner and outer sleeve elements and is arranged to cxtcnd along the longitudinal axis of the sleeve from the inlet in a first direction and back in the longitudinal axis in a second opposing direction. This is particularly beneficial for a portable arrangcrncnt wherein the gas blower arrangement is arranged to receive gas from the gas outlet. This beneficially means that the heat From the gas exiting through the gas outlet can be reused and re-circulated therefore improving battery life for the gas blower arrangement and providing energy savings.

Also according to the present invention there is a method of supplying heat to a persons arm and/or hand to aid in vein location, the method comprising providing a sleeve around a wearer's ann and/or hand, the sleeve having a gas inlet and gas outlet, and supplying heated gas to the gas inlet such that heated gas passes the wearer's skin and exits the sleeve via the gas outlet.

The present invention will now be described by way of exarnpk only with reference to the accompanying drawings where: Figure 1 is a schematic representation of an exemplary embodiment of the present invention.

Figure 2 is a schematic representation of an alternative exemplary embodiment of the present invention.

Figure 3 is a schematic representation of an alternative exemplary embodiment of the present invention.

Figure 4a is a schematic representation of an alternative exemplary embodiment of the present invention, Figure 4b is a schematic view of cross section B-B, and Figure 4c is a schematic view of cross section A-A.

Figure 5a and Sb are schematic perspective views of an embodiment of the present invention, and Figure 5c isa schematic cross sectional view through A-A of Figure Sa.

Referring to Figure 1 there is a schematic exemplary embodimcnt of the present invention showing a sleeve (2) arranged to locate around a wearer's arm. In the embodiment shown die sleeve extends to partially cover a wearer's fingers and extend to nearly the top of the wearer's ann adjacent to the annpit. It will be appreciated, however, that the longitudinal length of the sleeve may be reduced to extend to a wearer's elbow orjust beyond a wearer's elbow.

The sleeve is beneficially lightweight and may be constructed from materials suitable for single use. A cheap lightweight material may be paper for example, or a flexible polymeric material. The sleeve may therefore be manufactured to be single use. The sleeve may alternatively be made from material such as a polymer for re-use allowing sterilization.

The sleeve comprises a gas inlet (4) and gas outlet (6). Tn the exemplary emhodiment shown in Figures 1-3 for example the gas inlet (4) comprises a port to which a conduit (8) is secured. The connection between the conduit (8) and the port is beneficially temporary meaning that the conduit (8) can be used with a number of different sleeves. In an alternative embodiment the gas inlet (4) may not comprise a specific port (4) hut instead a conduit may pass into and transfer heated gas directly into a first end (10) of the sleeve (2).

The gas is therefore effectively transferred between the peripheral edge of the first end (10) and the wearer's arm, In order to improve this operation a securing arrangement may be provided at the first end comprising for example a strap (12) extending at least partially around the circumferential edge of the sleeve (2) and comprising a securing arrangement such as a hook and loop type mcchanism or a maoict enabling tightening of the peripheral edge of the first end (10). In the event that the conduit (8) is positioned between the wearer's skin and the peripheral edge of the first end then the conduit (8) is better secured to improve gas flow into the sleeve (2).

The end of the conduit (8) connected to the gas inlet (4) may connect via a number of alternative arrangements such as a threaded arrangement for example or a snap-fit type arrangement having a push button release, The heated gas source may comprise a plurality of different foims. The gas source (14) is beneficially portable and may be permanently or temporarily secured to the conduit (8). In one embodiment it will be appreciated that the gas source (14) may be secured directly to the gas inlet (4). The gas source (14) preferably comprises a power source such as rechargeable batteries wherein the gas source (14) may be rechargeable via securing to a docking station (not shown). The gas source (14) preferably also comprises a fan arrangement and heater arrangement for drawing in air, heating the air and subsequently passing the heated air through the conduit (8). The heated air therefore travels through the gas inlet (4) into the area between the inner surface of the sleeve (2) and the wearer's arm.

The sleeve (2) has a longitudinal length and is provided in order to warm a wearer's arm in order to aid vein location. Veins suitable for needle access are typically found on the top or upper portion of the hand and as such warming the hand and the portion of the arm at least between the elbow and wrist provides warmth to those veins. This has the effect that these veins dilate and thus become more accessible to the medical practitioner.

A significantly advantageous feature of the present invention is the provision of an access portion (16) which may take a number of forms as shown in Figures 1-3. In the embodiment as shown in Figure 1 the access portion (16) is retractable and is moveable tangentially to the longitudinal axis of the sleeve (2). The access portion (16) thereby provides access to a wearer's veins whilst transfer of heated through the sleeve (2) is maintained. With respect of Figure 1 the access portion (16) is beneficially retracted tangentially and the medical practitioner can insert the needle accordingly whilst the sleeve (2) remains in position. A securing arrangemcnt is beneficially provided preferably along both edges (17) and (18) and the securing arrangement maybe for example a hook and loop type mechanism whereby one of the hook or ioop arrangement is located at the edge of the sleeve (2) adjacent the opening covered by access portion (16). Retraction of the access portion (16) in the direction indicated by arrow (20) thereby withdraws the access portion (16) and disconnects the hook and loop type securing arrangement. Alternatively, a magnet may be provided at the edge of the sleeve to defining the opening or may alternatively be provided on an overlapping portion of the access portion (16) thus enabling securing of the access portion (16) to the sleeve (2).

In one embodiment the access portion (16) may be retractcd and may be secured to another portion of the sleeve during the time the medical practitioncr requires access to the wearer's arm or hand. It will be appreciated that the securing arrangement for securing the access portion (16) in the normal or closed configuration may also be utilised to secure the access portion (16) in an open configuration.

At least a portion of the access portion is preferably transparent. This aids the medical practitioner in viewing the wearer's veins to determine when they may be sufficiently warmed to enable access for a needle. This is particularly beneficial as withdrawal of the access portion (16) is not required which has the associated effect of losing heat.

Referring to the second end (22) of the sleeve out of which a wearer's fingers may project there may he provided a further securing arrangement (24) for tightening the sleeve (2) around a wearer's hand. This may take a number of forms and in one embodiment may comprise an elastieised band. Alternatively, an adjustable securing means may be provided such as a band extending circumferentially around at least a portion of the sleeve (2). This may be secured via a hook and loop type securing arrangement or a magnet and corresponding ferromagnetic material.

In the embodiment shown with respect to Figures 1-3 the second end (22) includes the gas outlet (6) whereby gas escapes from the gap provided between the wearer's hand and the second end of the sleeve (2). It will be appreciated. however, that one or more specific gas outlets may be provided such as a gas port (not shown) or perforations etc. It will also be appreciated that this end of the sleeve may be sealed meaning that gas escapes at the first end only or through the opening provided by the access portion (16) when in the open configuration.

Referring to Figure 4 there is a schematic representation of an alternative embodiment of S the present invention, In this embodiment again there is provided a sleeve (2) and access portion (16). Figure 4a is a schematic side view representation and shows the gas source (14) having an outlet (30) and an inlet (32). In this embodiment energy efficiency is improved as the air is re-circulated by what has previously been termed the gas source (14) hut effectively comprises a heater and fan anangcmcnt to circulate air from the sleeve (2) such that heated air is not all lost to the surrounding environment. Instead, a gas flow path is provided through the sleeve between the gas inlet (4) and gas outlet (6). I'he gas source (14) is connected to the gas inlet (4) via conduit (8) and the gas source (14) is connected to the gas outlet (6) via conduit (Ba). Accordingly, the gas source (14) providing heated air must only replace losses in the system following the circuit reaching operating temperature. The gas source may comprise monitoring means to ensure the correct temperature. The monitoring means may also be able to control gas flow rate, As shown in Figures 4b and 4c there is a flow path defincd between inner sleeve element (34) and outer sleeve element (36). The inner sleeve element is beneficially thermally conductive and air permeable cnsuring that there is airflow over the wearer's skin. The outer sleeve element (36) is beneficially thermally insulated and impermeable meaning that there is limited or no loss of warm air.

The arrangement as described with respect to Figure 4 defines an air flow path from the first end (10) of the sleeve to the second end (22) of the sleeve (2) and returns back to the first end to exit via outlet (6) and to return via conduit (8a) to the gas source (14). As represented in Figure 4c the channel defined between the inner and outer sleeve elements may be separated into two compartments via a separating wall (38) in order to define an inward and outward flow direction.

In an embodiment to the present invention a power source may be provided in communication with an electrical heating element which is located in the sleeve. In such an embodiment there is still provided an access portion providing the significant benefits of supplying heat to a wearer or at least maintaining warmth to a wearer on administering a needle.

Referring to Figures 5a to 5c there is shown a further embodiment of the present invention.

This embodiment comprises a sleeve (2) arranged to locate around a wearer's arm, Again the sleeve beneficially extends to partially cover a wearer's hand and extends to nearly the top of the wearers arm adjacent to the armpit. The sleeve is beneficially disposable and as such is single use. The sleeve comprises a gas inlet (4) and gas outlet (6) wherein the gas inlet and the gas outlet beneficially comprise ports configured to secure to the nozzle of a gas blower arrangement. Warmed air is therefore recycled therefore reducing operaLing cost associated with use of the apparatus. The sleeve (2) beneficially comprises a first sheet and a second sheet (52). The first sheet (50) and the second sheet (52) are beneficially secured along a longitudinal peripheral edge identified by reference numeral (56) and between each longitudinal edge is defined the opening for receipt of the wearer's hand and arm.

Each of the first and second sheets beneficially comprises an inner and outer skin. The first sheet has a single outer skin area to provide a viewing access portion (58). However, it will be appreciated that in use as shown in the Figures a double skin is provided in the areas of the first sheet which are inflated. The viewing access portion (58) is beneficially impermeable. The second sheet represented by reference numeral (52) and including inner skin (52a) and outer skin (521,) further defines a gas chamber (62) extending between the inlet port (4) and outlet port (6). Arrows shown in Figures Sb and Sc identified by reference numeral (60) identify the gas flow from die gas chamber (62) provided between the inner skin (52a) and outer skin (52b) to the wearer's skin. This also occurs from the gas chamber inside the inflated portions of the first sheet (50) clearly identified in Figures Sa and Sb. A partial barrier (66) reduces gas flow directly from the gas inlet (6) to the gas outlet (8) ensuring gas flow as indicated by arrow (68).

The sleeve is beneficially provided on a paper type backing naterial and is withdrawn from the backing material ready for use. The first and second sheets are separated by the medical practitioner such that a wearer's hand passes through the sleeve. The gas supply is then turned on thus causing inflation of the gas chamber (62) and effectively sealing the sleeve around the wearers arm, The viewing access portion (58) ensures that the medical practitioner can see when sufficient wannth has been supplied to the arm in order that the veins can be located.

A weakened area may be provided, preferably in the first shcct (50) not shown in the figures. This may take the form of perforations for example enabling the medical practitioner to quickly withdraw at least a portion of the sleeve to allow access to the wearer's veins. Perforations may be provided aLong a seam for example between first and second sheets, and may extend part way along the longithdinal length, or even more beneficially extend along (he entire longitudinal length meaning that the sleeve can be removed quickly and easily without affecting access to the vein.

Aspects of the present invention have been described by way of example only and it will be appreciated by the skilled addressee that modifications and variations may be made without departing from the scope of protection afforded by the appended claims,

Claims

Claims: 1. Apparatus for forming a flexible sleeve around a wearer's arm and/or hand an'anged to enable gas to be transferred to the skin of a wearer, wherein the sleeve includes a gas inlet and a gas outlet, the sleeve being arranged such that gas flow between the gas inlet and the gas outlet passes over a wearer's skin.
2. Apparatus according to claim I, comprising a flexible sleeve for positioning around a wearer's arm and/or hand.
3. Apparatus according to any preceding claim, wherein the sleeve comprises first and second openings at opposing first and second ends of the longitudinal length of the sleeve, wherein the first and second openings are arranged to enable drawing of the sleeve over a wearer's hand.
4. Apparatus according to any preceding claim, wherein at least a portion of the sleeve comprises a viewing access portion.
5. Apparatus according to any preceding claim, comprising an arrangement to change the cross sectional area of the sleeve in the transverse direction around a wearer's arm and/or hand.
6. Apparatus according to claim 5, comprising first and second longitudinally spaced arrangements for changing the cross sectional area of the sleeve in the transverse direction around a wearer's arm and/or hand.
7. Apparatus according to any of claims 5 to 6, wherein the first and/or second arrangement to change the cross sectional area of the sleeve is arranged to draw inwardly the peripheral edges defining the first and/or second opening.
8. Apparatus according to any preceding claim, wherein the sleeve comprises an access portion arranged to enable access to the conduit defined by the sleeve.
9. Apparatus according to claim 8, wherein the access portion is capable of being withdrawn relative to the sleeve between a closed and an open configuration.
10. Apparatus according to claim 9, further comprising a first securing arrangement for securing the access portion iii the closed configuration.
11. Apparatus according to any of claims 8 to 10, wherein the access portion is configured to enable removal of the sleeve from a user without requiring withdrawal of the sleeve over a wearer' hand.
12. Apparatus according to claim Ii, wherein the securing arrangement comprises a magnetic arrangement and/or a hook and loop type fastening mechanism.
13. Apparatus according to claims 9 to 12, whcrcin the access portion rctracts rclativc to the sleeve in the longitudinal axis of the sleeve.
14. Apparatus according to claims 13, wherein the access portion folds relative to the sleeve in the longitudinal axis of the sleeve.
15. Apparatus according to any of claims 8 to 14, comprising a second securing arrangement for securing the access portion in the open configuration.
16. Apparatus according to any of claims 9 to 15, wherein the first securing arrangement is arranged to secure the access portion in the open configuration.
17. Apparatus according to any preceding claim comprising a baffle configured to interrupt gas flow between the gas inlet and the gas outlet.
18. Apparatus according to any preceding claim, wherein at least a portion of the sleeve is transparcnt.
19. Apparatus according to claim 18 and any of claims 8 to 16, wherein at least part of the access portion is transparent.
20. Apparatus according to any preceding claim, further comprising a gas blower arrangement for heating and subsequently transferring air to the gas inlet.
21. Apparatus according to claim 20, wherein the gas blower arrangement is portable.
22. Apparatus according to any of claims 20 to 21 whcrcin the gas blower arrangement is configured to receive gas from thc gas outlet.
23. Apparatus according to any preceding claim, wherein the gas inlet is defined by the opening at a first end of the sleeve.
24. Apparatus according to any preceding claims, wherein the gas outlet is defined by an opening at the second end of the sleeve.
25. Apparatus according to any preceding claim, wherein the sleeve comprises a gas permeable inner sleeve element and an outer sleeve element defining a channel therebctwccn and the gas inlet is arranged to direct gas into the channel between the inner and outer sleeve elements.
26. Apparatus according to claim 25, wherein the channel defines a gas flow path between the gas inlet and the gas outlet.
27. Apparatus according to any of claims 25 to 26, wherein the channel defined by the inner and outer sleeve elements extends along the longitudinal axis of the sleeve from the inlet in a first direction and back in the longitudinal axis in a second opposing direction.
28. Apparatus according to any preceding claim, wherein the gas inlet comprises a gas inlet port, and preferably the gas outlet comprises a gas outlet port.
29, Apparatus according to claim 28, wherein the gas flow path between the gas inlet port and the gas outlet port is in a first direction in a longitudinal axis of the sleeve and a second reverse direction in the longitudinal axis of the sleeve.
30. Apparatus according to claim 29, wherein the gas inlet port and gas outlet port are separated by a barrier element.
31. Apparatus according to any of claims 29 to 30, wherein thc gas inlet port and gas outlet port are generally adjacent to each other.
32. Apparatus according to any preceding claim, wherein the sleeve is formed by a first sheet and a second sheet, the first and second sheet secured to each other in the longitudinal axis and at two longitudinal lengths spaced apart transversely.
33. Apparatus according to any preceding claim, wherein at least part of the sleeve isinflatable.
34. Apparatus according to claim 33, comprising an inflatable gas chamber positioned between the gas inlet and the gas outlet.
35. Apparatus according to claim 34. wherein at least a portion of the gas chamber is defined by an inner skin and an outer skin.
36, Apparatus according to claim 35, wherein at least a portion of the inner skin is gas permeable.
37. Apparatus according to any of claims 35 to 36, wherein the outer skin is substantially gas impermeable.
38. A method of supplying heating to a person's arm and/or hand to aid in vein location, the method comprising providing a sleeve around a wearer's aim and/or hand, the sleeve having a gas inlet and a gas outlet, and supplying heated gas to the gas inlet such that heated gas passes over the wearer's skin and exits the sleeve via the gas outlet.
39. Appantus as hereinbefore described with reference to the accompanying drawings.