PATIENT WARMING BLANKET

Abstract

A patient warming blanket comprising at least two layers capable of forming a hollow air space between the two layers for receiving warm air from a heating unit via an inlet port at or near an end of the blanket. The two layers being arranged so that the hollow air space forms at least one tubular portion disposed longitudinally there within, and one of the two layers has at least a portion of its surface formed of porous material so that warmed air is delivered to said patient by diffusion through said porous material. The tubular portion has non-parallel sides such that the sides of the tubular portion are further apart from each other at a first end of the tubular portion closer to the inlet port than at a second end of the tubular portion remote from the inlet port.

Claims

1. A patient warming blanket comprising at least two layers capable of forming a hollow air space between said two layers for receiving warm air from a heating unit via an inlet port at or near an end of said blanket, said two layers being arranged so that said hollow air space forms at least one tubular portion disposed longitudinally within said blanket, and one of said two layers has at least a portion of its surface formed of porous material so that warmed air is delivered to said patient by diffusion through said porous material, wherein said tubular portion has non-parallel sides such that said sides of said tubular portion are further apart from each other at a first end of said tubular portion closer to said inlet port than at a second end of said tubular portion remote from said inlet port.

2. A patient warming blanket as claimed in claim 1, wherein said at least one tubular portion comprises a plurality of tubular portions fluidally in communication with each other.

3. A patient warming blanket as claimed in claim 2, wherein said plurality of tubular portions are disposed longitudinally adjacent to each other, and a manifold is disposed between said inlet port and said first ends of said tubular portions.

4. A patient warming blanket as claimed in claim 3 wherein said manifold has a length which is no less than twenty percent the total length of said blanket.

5. A patient warming blanket as claimed in claim 3, wherein said first ends of said tubular portions are staggered relative to each other.

6. A patient warming blanket as claimed in claim 5, wherein said staggered first ends of said tubular portions are staggered such that centrally disposed tubular portions have first ends longitudinally further away from said inlet port than adjacent tubular portions disposed on either side thereof.

7. A patient warming blanket as claimed in claim 3, wherein a gallery is disposed at a bottom end of said blanket near said second ends of said tubular portions and said gallery is in fluid communication with said gallery, and said gallery has a width between said bottom end and said second ends of said tubular portions which is no less than ten percent the total length of said blanket.

8. A patient warming blanket as claimed in claim 1, wherein at least one of the outermost tubular portions is about ten percent larger than an adjacent tubular portion.

9. A patient warming blanket as claimed in claim 1, wherein said two layers are welded together such that said hollow space is substantially surrounded by a peripheral weld.

10. A patient warming blanket as claimed in claim 9, wherein an external weld substantially surrounds said peripheral weld.

11. A patient warming blanket comprising at least two layers capable of forming a hollow air space between said two layers for receiving warm air from a heating unit via an inlet port at or near an end of said blanket, said two layers being arranged so that said hollow air space comprises a plurality of adjacent tubular portions disposed longitudinally within said blanket and fluidally in communication with each other via a manifold at said first ends of said tubular portions near said inlet port and a gallery at the opposed ends of said tubular portions, and one of said two layers has at least a portion of its surface formed of porous material so that warmed air is delivered to said patient by diffusion through said porous material, wherein said tubular portions have non-parallel sides such that said sides of said tubular portions are further apart from each other at their first ends nearer to said inlet port than at said opposed ends of said tubular portion near said gallery.

12. A patient warming blanket as claimed in claim 11 wherein said manifold has a length which is no less than twenty percent the total length of said blanket.

13. A patient warming blanket as claimed in claim 12, wherein said first ends of said tubular portions are staggered relative to each other such that centrally disposed tubular portions have first ends longitudinally further away from said inlet port than adjacent tubular portions disposed on either side thereof.

14. A patient warming blanket as claimed in claim 11, wherein said gallery has a width between said bottom end of said blanket and said opposed ends of said tubular portions which is no less than ten percent the total length of said blanket.

15. A patient warming blanket as claimed in claim 11, wherein at least one of the outermost tubular portions is about ten percent larger than an adjacent tubular portion.

16. A patient warming blanket as claimed in claim 11, wherein said two layers are welded together such that said hollow space is substantially surrounded by a peripheral weld.

17. A patient warming blanket as claimed in claim 16, wherein an external weld substantially surrounds said peripheral weld.

18. A patient warming blanket comprising at least two layers capable of forming a hollow air space between said two layers for receiving warm air from a heating unit via an inlet port at or near an end of said blanket, said two layers being arranged so that said hollow air space is U-shaped and comprising first and second elongate tubular portions fluidally connected by a tubular bend portion, and one of said two layers has at least a portion of its surface formed of porous material so that warmed air is delivered to said patient by diffusion through said porous material, said first elongate tubular portion having an inlet and associated manifold at its free end, wherein said first tubular portion has non-parallel sides such that said sides of said first tubular portion are further apart from each other at a first end of said tubular portion closer to said inlet port than at a second end of said tubular portion near said tubular bend.

19. A patient warming blanket as claimed in claim 18, wherein said second tubular portion has non-parallel sides such that said sides of said second tubular portion are further closer together at an end of said second tubular portion closer to said tubular bend portion than at a second end of said second tubular portion near its closed free end.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0036] FIG. 1 is a plan view of a single cage animal patient blanket in a first embodiment of the present invention.

[0037] FIG. 2. is a cross-section through I-I on FIG. 1.

[0038] FIG. 3 is a plan view of a double cage animal patient blanket in a second embodiment of the present invention.

[0039] FIG. 4 is a plan view of an animal patient blanket in a third embodiment of the present invention.

[0040] FIG. 5 is a plan view of an animal patient blanket in a fourth embodiment of the present invention.

[0041] FIG. 6 is a plan view of a surgical animal patient blanket in a fifth embodiment of the present invention.

BEST MODE OF CARRYING OUT THE INVENTION

[0042] FIGS. 1 and 2 depict a first embodiment of a blanket 1 which is for use in veterinary medicine, and suited for being placed in a single animal cage for post operative warming of cat or small dog patient. Blanket 1 is in use connected to a blower heating unit (not shown), via an inlet 2.

[0043] Blanket 1 is made of two layers, a first layer 3 and a second layer 4, which form a hollow air space 5 between them. When blanket 1 is not being used it will lie substantially flat as no air is being introduced into air space 5. In, use however, when warm air is being blown into air space 5, blanket 1 inflates to give a profile shown in cross-section of FIG. 2.

[0044] First layer 3 is made of a substantially non-porous material, whilst second layer 4 is made of a porous material. Whilst blanket 1 may be made of any appropriate thin material, in this embodiment it is made of polyester, with upper layer 4 being of porous polyester.

[0045] The purpose of the porous second layer 4 is to allow warm air introduced into hollow space 5 to gently diffuse there through at low velocity for warming the patient (not shown).

[0046] In manufacture of blanket 1, layers 3,4 are heat welded together to form a periphery 6, and a plurality of elongate continuous welds 7 are disposed spaced apart to form a plurality of elongate tubular portions 8, 8a of hollow air space 5 adjacent to each other. Periphery 6 is the peripheral weld substantially surrounding the portion of blanket 1 to be inflated. Welds 7, also applied by heat do not extend the full length of blanket 1, and therefore in use air entering blanket 1 can enter tubular portions 8,8a from either end.

[0047] Welds 7 together with the peripheral edges 6a,6b of hollow space 5 form sides of tubular portions 8, 8a. However, it should be pointed out that the sides defined by welds 7 and peripheral edges 6a,6b are non-parallel (or tapered), such that the tubular portions 8, 8a each have wider openings at location nearer inlet 2 than they do near the opposed closed end 9 of blanket 1. In this embodiment the centrally disposed weld (side) 7c is substantially parallel to the longitudinal axis of blanket 1. The peripheral edges 6a,6b are skewed at two and a half (2.5) degrees to side 7c, and side 7a is skewed at one and a half (1.5) degrees to the side 7c, whilst side 7b is skewed at about two degrees to the side 7c.

[0048] The two opposed outermost tubular portions 8a have a width W that is about ten percent wider than width W.sub.C of tubular portions 8, disposed between them.

[0049] By looking at the cross-section of FIG. 2 you will see the width of a tubular portion 8a indicated as dimension W. As the tubular portion 8a has sides that are non-parallel (tapered), the width dimension W.sub.L near the inlet end of blanket 1 is larger than W at the cross-section of FIG. 2, and near the opposed end of tubular portion 8 the width dimension W.sub.S is smaller than both dimensions W.sub.L and W.

[0050] The abovementioned dimensions W, W.sub.L and W.sub.S are described with a single tubular portion 8a, however preferably, each tubular portion 8,8a has a width larger towards the inlet end of blanket 1, rather than its width nearer to closed end 9 of blanket 1. Or stated otherwise, the sides of tubular portion 8,8a are further apart from each other at a first end of tubular portion 8,8a closer to inlet port 2 than at a second end of tubular portion 8,8a remote from inlet port 2.

[0051] Skewing the edges and sides by just a few degrees, so that the tubular portions 8,8a at the inlet end are slightly larger than at the opposed closed end, markedly improves air distribution along the tubular portions 8,8a.

[0052] It should be noted that the cross-section of the tubular portions 8,8a when inflated approximate an oval form as shown in FIG. 2. However it is customary to refer to the tubular portions as having a diameter, and a simplified way of correlating this oval form to a nominal calculated tube diameter, is to say that the width W of the oval form is ten percent greater than the calculated diameter, and height H is about ten percent smaller than the calculated diameter.

[0053] In an area disposed immediately between first ends of tubular portions 8,8a near the inlet end of the blanket towards inlet 2 is a manifold 10. The area of manifold 10 should be of a size sufficient to allow a portion of the warm air entering blanket 1 via inlet 2 on one side of blanket 1 to easily travel and reach across to the tubular portions 8,8a disposed furthest from inlet 2. The centrally disposed tubular portions 8 have first ends longitudinally further away from said inlet port than opposed tubular portions 8a disposed on either side thereof. The length L.sub.M of manifold 10 from inlet 2 to the open first ends of tubular portions 8 should preferably not be less than twenty percent of the length of the hollow space of blanket 1.

[0054] By providing manifold 10 and tubular portions 8,8a with non-parallel sides with wider openings near the inlet end of blanket 1, and the outermost tubular portions 8a being larger, at least a portion of warm air 1 being delivered to inlet 2 to inflate blanket 1 has a better opportunity to distribute evenly through tubular portions 8,8a and get to the opposed closed end 9. Whilst there will be heat loss as the warm air moves away from inlet 2 because of the porosity of upper layer, the abovementioned arrangement having tubular portions 8,8a with non-parallel sides and manifold 10 ameliorates the warm air distribution over that achievable by the prior art.

[0055] In an area disposed immediately between second ends of tubular portions 8,8a and the closed end 9 is a gallery 11. The area of gallery 11 should be of a size sufficient to allow a portion of the warm air passing through tubular portion 8a closest to inlet 2 on one side of blanket 1 to easily pass there through and travel and reach across to the second ends of tubular portions 8,8a disposed furthest from inlet 2. The length L.sub.G of gallery 11 between closed end 9 to the open second ends of tubular portions 8,8a should preferably not be less than ten percent the length of blanket 1. By doing this, along with providing a further external weld 15 disposed externally of periphery 6, minimises the possibility of kinking or other forms of restriction towards bottom end 9.

[0056] In the abovementioned first embodiment whilst the nominal calculated diameter of the tubes varies it can be estimated that tubular portions 8 when inflated are about 145 mm diameter. The blanket in this embodiment having a length (from inlet end to closed end) of about 850 mm, and a width of about 875 mm.

[0057] The manifold 10 and gallery 11 also have an oval like shape if viewed in cross section transversely rather than longitudinally ie at right angles to the longitudinal extent of the blanket. Like that of the tubular portions 8,8a the oval form can be expressed as a nominal calculated diameter. In this embodiment the calculated nominal diameter of manifold 10 is about 110 mm at the outlet side and expands to about 120 mm in the centre. Thus manifold 10 has a nominal diameter that varies between fifteen to twenty-five percent (about twenty percent) the nominal diameter of tubular portions 8,8a. Also in this embodiment the calculated nominal diameter of gallery 11 is about 65 mm.

[0058] FIG. 3 depicts a second embodiment of a blanket 21 which also is for use in veterinary medicine, and suited for being placed in a double animal cage for post operative warming of a medium to small dog patient. Blanket 21, like blanket 1 of the first embodiment, is provided with a hollow space which in use is connected to a blower heating unit (not shown), via either inlet 22, 22a.

[0059] Also like blanket 1, blanket 21 is manufactured by heat welding two layers together, with the second layer being made of porous material. The periphery 26 and continuous heat welds 27 define sides of a plurality of tubular portions 28, 28a, and 28c. The sides defined by welds 27 and peripheral edges 26a,26b are non-parallel (or tapered), such that the tubular portions 28,28a, and 28c each have wider openings at a location nearer inlets 22,22a than they do near the opposed closed end 29 of blanket 21. In this embodiment the centrally disposed weld (side) 27c is substantially parallel to the longitudinal axis L.sub.B of blanket 21. Peripheral edge 26b is skewed at about two and a half (2.5) degrees to longitudinal axis L.sub.B and the closest side 27a to inlet 22 is skewed two (2) degrees to the longitudinal axis L.sub.B. Side 27b is skewed at one and a half (1.5) degrees to the longitudinal.

[0060] Blanket 21 is also provided with a manifold 30. The centrally disposed tubular portions 28c have first ends longitudinally further away from inlet ports 22,22a than adjacent tubular portions 28 disposed on either side thereof. This provides a larger manifold area near the longitudinal axis L.sub.B of blanket 21. The length L.sub.M2 of manifold 30 between the central open first ends of tubular portions 28 preferably should not be less than twenty percent of the length of blanket 21.

[0061] Near the inlet end of blanket 21 a chevron shaped weld 37 is centrally disposed. Weld 37 is shaped such that a portion of the air entering either inlet 22,22a is channeled towards the central portion of blanket 21, and in particular tubular portions 28c, thus assisting in air distribution.

[0062] In an area disposed immediately between second ends of tubular portions 28 and the closed end 29 is a gallery 31. The length L.sub.G2 of gallery 31 between closed end 29 to the open second ends of tubular portions 28 should preferably not be less than ten percent of the length of blanket 21. Again like in the first embodiment, by doing this, along with providing a further external weld 35 disposed externally of periphery 26, this minimises the possibility of kinking or other forms of restriction towards bottom end 29, and therefore improves the distribution of warm air.

[0063] Manifold 30 and gallery 31 also have an oval like shape if viewed in cross section transversely rather than longitudinally ie at right angles to the longitudinal extent of the blanket. The calculated (or average) nominal diameter of manifold 30 is about 180 mm. Thus manifold 30 has a nominal diameter is one hundred percent larger (or double the size) of that of the tubular portions 28. In effect it expands over 90% between the outlet side to the centre.

[0064] The two opposed outermost tubular portions 28a have a nominal width W that is about ten percent wider than width W.sub.C2 of tubular portions 8, disposed between them.

[0065] In the abovementioned second embodiment whilst the nominal calculated diameter of the tubes varies it can be estimated that tubular portions 28 when inflated are about 140 mm nominal diameter. The blanket in this embodiment having a length (from inlet end to closed end) of about 1200 mm, and a width (at inlet end) of about 1180 mm.

[0066] In approximately rectangular blankets such as those shown in FIGS. 1 and 3 you have at least one air inlet feeding a short, high flow reservoir, namely a manifold that distributes warm air substantially evenly to the higher resistance plurality of substantially longitudinally disposed tubular portions which feed into an end gallery, or alternatively a blind end. The manifold acts as a pressure regulator and configured to distribute the warm air as evenly as possible across the openings of the tubular portions, with the openings of some centrally disposed tubular portions being further distant from those closer to the outlet end. The nominal calculated diameter of the manifold should be no less than and preferably greater than the nominal calculated tube diameter, sufficient to accommodate airflow for all the longitudinally disposed tubular portions. In the abovementioned embodiments the average nominal calculated diameter of the manifolds 10, 30 is a minimum of about twenty percent of the length. The manifold is larger in the centrally disposed area than at the sides, thus providing a funnel or tapered shape to encourage even distribution of warm air flow to more distant openings of longitudinal tubular portions.

[0067] FIG. 4 depicts a third embodiment of a blanket 41 which also is for veterinary medicine, and suited for surgery or recovery of a medium to large dog. Blanket 41 like that of blanket 1 is provided with a hollow space which in use is connected to a blower heating unit (not shown).

[0068] Also like blanket 1, blanket 41 is manufactured by heat welding two layers together, the second layer being made of porous material. Blanket 61 has a centrally disposed inlet 42.

[0069] The periphery 46 and heat welds 47 define sides of a plurality of tubular portions 48,48a,48c. The sides defined by welds 47 and peripheral edges 46a,46b are non-parallel (or tapered), such that the tubular portions 48,48a,48c each have wider openings at location nearer inlet 42 than they do near the opposed closed end 29 of blanket 21. In this embodiment the centrally disposed weld (side) 47c is substantially parallel to the longitudinal axis of blanket 41. Peripheral edge 46a is skewed at about two and a half (2.5) degrees to weld (side) 47c and side 47a is skewed two (2) degrees to weld (side) 47c. Side 47b is skewed at one and a half (1.5) degrees to weld (side) 47c.

[0070] Furthermore the two opposed outermost tubular portions 48a have a width W.sub.3 that is about ten percent wider than the width W.sub.C3 of tubular portions 48, disposed between them.

[0071] Blanket 41 is also provided with a manifold 50. The length L.sub.M3 of manifold 30 between the central open first ends of tubular portions 28 preferably should not be less than 20% the length of blanket 20.

[0072] In an area disposed immediately between second ends of tubular portions 48 and the closed end 49 is a gallery 51. The length L.sub.G3 of gallery 51 between closed end 49 to the open second ends of tubular portions 48 should preferably not be less than ten percent the length of blanket 41. Again like in the first embodiment, by doing this, along with providing a further external weld 55 disposed externally of periphery 26, minimises the possibility of kinking or other forms of restriction towards the bottom end 49, and therefore improves the distribution of warm air.

[0073] In the abovementioned third embodiment whilst the nominal calculated diameter of the tubes varies it can be estimated that tubular portions 48 when inflated are about 153 mm diameter. The blanket in this embodiment having a length of about 1320 mm, and a width of about 950 mm.

[0074] FIG. 5 depicts a fourth embodiment of a blanket 81 which also is for use in veterinary medicine, and suited for being used for surgery of an exotic/small animal patient. This blanket 81 is a half size version of blanket 1 of the first embodiment.

[0075] The periphery 86 and heat welds 87 define sides of a plurality of tubular portions 88,88a. The sides defined by welds 47 and peripheral edges 86a,86b are non-parallel (or tapered), such that the tubular portions 88,88a each have wider openings at location nearer inlet 82 than they do near the opposed closed end 89 of blanket 81. In this embodiment the periphery edge 86b is substantially parallel to the longitudinal axis of blanket 1. The peripheral edge 86a is skewed at two and a half (2.5) degrees to periphery edge 86b, and side 87b is skewed at one and a half (1.5) degrees to periphery edge 86b, whilst side 87a is skewed at about two degrees to periphery 86b.

[0076] Tubular portion 88a has a width W.sub.4 that is about ten percent wider than the width W.sub.C4 of tubular portions 88.

[0077] Blanket 81 is also provided with a manifold 90. The length L.sub.M4 of manifold 90 between the central open first ends of tubular portions 88 preferably should not be less than 20% the length of blanket 20.

[0078] In the abovementioned fourth embodiment whilst the nominal calculated diameter of the tubes varies it can be estimated that tubular portions 8 when inflated are about 145 mm diameter. The blanket in this embodiment having a length (from inlet end to closed end) of about 850 mm, and a width of about 438 mm.

[0079] FIG. 6 depicts a fifth embodiment of a blanket 81 which also is for use in veterinary medicine, and suited being used for surgery of cat or small dog patient. Blanket 61 is substantially U-shaped and has an inlet 62 at a free end thereof. Blanket 61, like blanket 1 of the first embodiment, is provided with a hollow space which in use is connected to a blower heating unit (not shown), via inlet 62.

[0080] Also like blanket 1, blanket 61 is manufactured by heat welding two layers together, the second layer being made of porous material. The U-shape of blanket 61 made up of two elongate tubular portions 68a,68b fluidally interconnected by tubular bend portion 69. The peripheral sides 66a, 66c and 66b, 66d make up the sides of the respective elongate tubular portions 48a,48b.

[0081] Disposed immediately adjacent said inlet 62 is flared manifold 70 which transitions from said inlet 62 to first tubular portion 48a.

[0082] The respective sides 66a,66c are non-parallel (or tapered), such that first tubular portion 68a has a wider opening at location nearer manifold 50 and inlet 62 than it does near the opposed tubular bend portion 69. This means the width dimension W.sub.L1 of first tubular portion 68a near the inlet/manifold end of blanket 61 is larger than the width dimension W.sub.S1 near tubular bend 69. In this embodiment peripheral edge 66a,66b are each skewed 2 degrees to the longitudinal.

[0083] In this embodiment the tubular bend (or gallery) 69 has a diameter same as that of the tubular portions 68a,68b at W.sub.S1.

[0084] The length L.sub.MB of manifold 70 between the end of first tubular portion 68a and inlet 62 should preferably not be less than 20% the length of blanket 61.

[0085] In the abovementioned embodiment whilst the nominal calculated diameter of the tubular portion 68a varies it can be estimated to be about 150 mm diameter, whilst the inlet manifold at W.sub.L1 is about 190 mm, its nominal calculated diameter is about 171 mm, thus making it about 14% greater than the nominal calculated diameter of the tube 68a.

[0086] The width of tubular bend 69 has a radius sufficient to reduce kinking and its diameter remains substantially constant from tubular portion 68a to tubular portion 68b.

[0087] Second tubular portion 68b, like that of tubular portion also has non-parallel (or tapered) sides with the width closer to tubular bend 69 smaller than the width as it approaches flared portion 71 (similar to manifold 70).

[0088] Please note that all five abovementioned embodiments are described with reference to blankets for use in veterinary applications, however it should be understood the invention is also applicable for blankets used with human patients. It is also be understood that the sizes and dimensions may differ from those shown for different sized animals, such as for example large dogs and humans.

[0089] The terms comprising and including (and their grammatical variations) as used herein are used in an inclusive sense and not in the exclusive sense of consisting only of.