fig1 shows an inflatable thermal blanket 10 constructed in accordance with the present invention . as shown , the blanket provides access to the upper body of a patient 12 during medical treatment and includes a lower end 14 that is placed near the feet of the patient and an upper end rolled onto itself to form a gathered portion 16 and a primary portion 17 . thus , the torso of the patient 12 is not covered by the blanket in the gathered condition . an inlet port 18 of the blanket is connected by a hose 19 to a heater / blower assembly 20 that produces a thermally controlled inflating medium , such as heat and air . when the blanket 10 is inflated with the heater / blower assembly , the blanket erects itself into a structure having a quilted upper surface 22 . medical treatment can then be provided to the exposed torso of the patient while the remainder of the patient &# 39 ; s body is kept warm by the blanket . a closure 24 maintains the gathered portion 16 in a non - inflated condition . after the medical treatment has been completed , the closure is opened so as to release the gathered portion , permitting the inflating medium to enter the gathered portion , inflating it so that it assumes the configuration illustrated in fig2 . in this way , the same blanket can be used to keep an area of the patient &# 39 ; s body warm during medical treatment and then can be converted into a full body covering after completion of treatment . fig3 and fig4 illustrate some of the construction details of the thermal blanket 10 . a lower sheet 49 of the blanket is formed by bonding a layer 50 of flexible material to a layer 52 of heat - sealable plastic . in the preferred embodiment , the layers 50 and 52 respectively comprise a layer of non - woven polyester pre - laminated with a layer of heat sealable plastic such as a polypropylene extrusion . an upper layer 53 of the thermal blanket consists of a layer of extruded polypropylene film bonded to the plastic underside layer 52 by a heat - sealing process to form interrupted seams , one of which is indicated by the arrow 54 , and inflatable tubes , one of which is indicated by the arrow 55 . as can be seen in fig4 the seam 54 forms a passageway 56 between two adjacent tubes 55 and 57 . the thermal blanket 10 bathes a patient in the thermally controlled inflating medium by means of a plurality of apertures 62 illustrated in fig4 . the apertures extend through the blanket underside , which includes the layers 50 and 52 . the apertures 62 are provided in a pattern determined to produce a uniform flow of the inflating medium from the underside of the blanket . for example , the apertures are provided in a density that varies inversely with the distance of the aperture to the center tube having the inlet port 18 . thus , the ambient temperature beneath the inflated blanket is substantially uniform from edge to edge . fig5 illustrates the manner of attaching the closure 24 to the blanket in the gathered position . as illustrated in fig5 the closure comprises an elongated strip having a first edge 26 that is attached to the primary portion 17 of the thermal blanket and a second edge 28 attached to the gathered portion 16 of the blanket . in fig5 the closure 24 is shown in phantom , and therefore a strip of adhesive backing 30 applied along the underside of the first edge is indicated by shading , as is another strip of adhesive backing 32 applied along the underside of the second edge . thus , the elongated strip of the closure 24 bridges the primary portion 17 and the gathered portion 16 , thereby holding the gathered portion 16 in the rolled , non - inflated condition . in this way , when the inflating medium is admitted into the thermal blanket to inflate the primary portion 17 through the inlet 18 , the gathered portion does not inflate . fig5 also shows that a central tear strip 34 is defined between the first edge 26 and second edge 28 of the closure 24 by two parallel perforations 36 , 38 that extend along the length of the closure strip . it should be apparent that one end 40 of the tear strip can be grasped and pulled , tearing the perforations apart , thereby releasing the first edge from the second edge , permitting the gathered portion to be unfurled , and permitting the inflating medium to be admitted into the gathered portion to inflate the blanket and assume the condition illustrated in fig2 . the fig5 embodiment shows that the closure 24 also can include an attachment flap 70 that extends outwardly from the second edge 28 of the closure . a free edge 72 of the attachment flap is provided with a strip of adhesive 74 on its underside along its length . the adhesive is used to attach the flap to the patient &# 39 ; s body , thereby holding the gathered portion 16 in a fixed relative location . holding the gathered portion fixed assists the attending medical personnel in maintaining the thermal blanket 10 in a desired location while medical treatment is provided . the attachment flap 70 preferably also includes a perforation 76 that can be torn , thereby releasing the closure 24 ( and also the gathered portion 16 ) from the attachment flap . thus , the attachment flap can be released independently of , or along with , the elongated strip of the closure 24 . a thermal blanket in accordance with the present invention can be provided in a variety of configurations in addition to that illustrated in fig1 and 2 . for example , fig6 and fig7 illustrate a thermal blanket 100 that provides access to the lower extremities of the patient 12 while covering the torso of the patient during treatment . in fig6 and the remaining drawings , the heater / blower assembly 20 and connected hose 19 are not shown for clarity of illustration , but it should be understood that these elements are included in any actual usage of the thermal blanket . fig6 illustrates the blanket 100 in the gathered condition and fig7 illustrates the blanket in the fully deployed condition . again , a gathered portion 116 and a primary portion 117 are provided by rolling one end of the thermal blanket onto itself while in a non - inflated condition and maintaining it in the non - inflated condition with a closure 124 . as before , an attachment flap 170 can be provided , if desired , with an adhesive strip backing 174 for attaching the gathered portion to the body of the patient . when deployed , the unfurled gathered portion ends in a lower edge 180 at the feet of the patient 12 . the primary edge 126 of the released closure remains attached to the surface 122 of the blanket , as illustrated in fig7 . fig8 and 9 illustrate an alternative embodiment of a blanket 200 for providing access to the lower extremities of the patient . fig8 shows that the blanket can be draped over a patient so that the longest dimension of the blanket extends across the body of the patient from arm to arm . two gathered portions 210 , 212 define a central area 214 of the blanket , which covers the torso of the patient and bridges a blanket lower end 216 and a blanket upper end 218 . the lower end and upper end are each provided with an inlet port 18 but communicate internally so that both ends are simultaneously inflated even if only one port is connected to an inflating medium . an optional head drape 220 can be provided to maintain the temperature of the patient &# 39 ; s head . the blanket 200 also includes , in its upper end 218 , a removeable section 219 defined by a u - shaped perforation 221 . the removeable section 219 can be removed by tearing along the perforation 221 to leave a u - shaped indentation in the upper end edge 223 . the indentation is indicated at 224 in fig9 . fig9 shows the blanket 200 after medical care has been provided and the gathered portions have been released . as can be seen in fig9 after the gathered portions are released , the blanket 200 is preferably rotated so that the longest dimension of the blanket is oriented over the length of the patient &# 39 ; s body with the patient &# 39 ; s head received in the u - shaped indentation 224 . thus , complete coverage of the patient is obtained . fig1 - 12 illustrate an embodiment 300 of the thermal blanket in which access is provided to the lower extremities of the patient 12 in general , and to the legs of the patient in particular . fig1 shows that the thermal blanket has an overall shape that includes a primary portion having a relatively large , generally rectangular upper body portion 310 placed over the upper body of the patient 12 and a relatively narrow , elongated central lower body extension 312 having a width substantially less than the width of the upper body portion . in the preferred embodiment of fig1 - 12 , the lower body extension 312 comprises a single inflatable tube of the type illustrated in fig3 and 4 that is used to cover at least one elongated member of the patient , such as a leg . whereas the upper body portion comprises a plurality of inflatable tubes that are arranged transversely of the upper end of the lower body extension and are used to cover the chest area of the patient . the elongated central extension 312 and the transverse upper body tubes 310 communicate internally so that a single inlet port 18 permits them to be simultaneously inflated . fig1 also shows that the lower end of the elongated lower body extension 312 is flanked by two gathered portions 314 , 316 . each gathered portion includes an attachment flap 322 with an adhesive backing along its underside , as described previously for the other embodiments . other attachment flaps can be provided at other blanket portions as desired , such as the attachment flaps 324 for securing edges of the upper body portion 310 to the patient 12 . a head drape 326 also can be provided . fig1 shows a first one 314 of the gathered portions in its deployed condition , while fig1 shows the thermal blanket with both gathered portions in their respective deployed conditions , wherein full coverage of the patient is provided . more particularly , fig1 shows both of the gathered portions 314 , 316 in their non - inflated condition and shows that they are coupled to the central extension 312 of the blanket 300 along the length of the central extension , on opposite sides . each gathered portion 314 , 316 has a closure 315 , 317 , respectively , that maintains the gathered portions in their non - inflated condition . fig1 shows the blanket 300 after the closure 315 of the first gathered portion 314 has been opened , or removed , thereby permitting the inflating medium to enter the first gathered portion and inflate the first gathered portion so that it deploys transversely of the central extension 312 . in fig1 , the closure 317 of the remaining second gathered portion 316 has not been removed and therefore that gathered portion remains in the non - inflated condition . fig1 shows the blanket 300 after the closure 317 of the second gathered portion 316 also has been opened and after the second gathered portion has been inflated and deployed transversely of the central extension . fig1 and 14 illustrate a blanket 400 similar to that shown in fig1 - 12 , except that the blanket 400 leaves the arms of the patient 12 exposed and covers the lower extremities of the patient . thus , the lower end 412 of the blanket covers the patient &# 39 ; s lower extremities and the upper end 414 includes the gathered portions . again , the primary portion of the blanket includes a relatively large portion 416 and a central extension 418 that is flanked by two gathered portions 420 , 422 . the gathered portions typically are deployed after medical care has been provided ( fig1 ) and it is desired to obtain full coverage of the patient . lateral drapes 424 can be provided for supplemental coverage , if desired . the closure 24 of a thermal blanket constructed in accordance with the present invention can assume a variety of structures in addition to the pull strip described above . in fig1 , the closure comprises a tear string 510 that is embedded in the elongated strip 524 of the closure . once again , the elongated closure strip includes a first edge 526 attached to the primary portion 14 of the blanket 10 and a second edge 528 attached to the gathered portion 16 . the tear string includes an enlarged release tab 512 that can be grasped and pulled , tearing the string out from the elongated strip and thereby separating the edge of the elongated strip attached to the primary portion of the blanket from the edge of the elongated strip attached to the gathered portion . as before , an optional attachment flap 70 can be provided , having a free end 72 with an adhesive backing 74 applied to the underside and having a central perforation 76 for easy removal . fig1 shows a closure 24 comprising a hook and loop fastening system 610 , such as commonly sold , for example , under the trademark &# 34 ; velcro .&# 34 ; the hook and loop fastening system includes a hook strip 612 having loops or coils 613 of a plastic material and a loop strip 614 having a loose , or fuzzy , pile of material . the hook strip can be engaged with the loop strip and then released by forcibly pulling them apart . although relatively modest forces will not separate the two strips , more deliberate pulling actions can be used to easily separate the hook strip from the loop strip . when engaged , the hook and loop fastening system provides a unitary strip that can be attached to the thermal blanket so as to maintain the gathered portion in the non - inflated condition . in fig1 , the looped plastic material is attached to the underside of a first edge 616 of the hook strap , which then is attached to the gathered portion 16 along a second edge 618 . preferably , the attachment is by an adhesive backing . the loop strip 614 is attached to the primary portion 14 of the thermal blanket . it should be noted that the hook strip and loop strip can be mounted on the opposite blanket portions . to hold the gathered portion 16 in the non - inflated condition , the bottom of the first edge 616 is pressed into engagement with the loop strip 614 . when it is desired to unfurl the gathered portion , the hook and loop fastening system is simply separated by pulling on the two respective strips in opposite directions . this releases the hook strip from the loop strip and permits the gathered portion to be unfurled , admitting the inflating medium into the gathered portion . as before , an attachment flap 70 can be included with the closure 610 . thus , all of the embodiments described above provide an inflatable thermal blanket that can be used to permit access to a site of interest while controlling a patient &# 39 ; s body temperature during surgery and then can be converted to a full - body covering that completely covers the patient . the present invention has been described above in terms of presently preferred embodiments so that an understanding of the present invention can be conveyed . there are , however , many configurations for inflatable thermal blankets not specifically described herein but with which the present invention is applicable . for example , the closure can be provided by a light tackiness adhesive backing . the present invention should therefore not be seen as limited to the particular embodiments described herein , but rather , it should be understood that the present invention has wide applicability with respect to inflatable thermal blankets generally . all modifications , variations , or equivalent arrangements that are within the scope of the attached claims should therefore be considered to be within the scope of the invention .
one or more portions of an inflatable thermal blanket that is sized sufficiently to fully cover a patient are gathered and maintained in a non - inflated condition by a closure such that a thermally - controlled inflating medium admitted into the blanket is prevented from being admitted into the gathered portion , thereby leaving a primary part of the patient covered and exposing a part of the patient for medical attention . thereafter the closure can be released to permit the inflating medium to be admitted into the gathered portion such that the gathered portion self - erects and assumes an inflated condition . the released thermal blanket covers the entire patient and bathes the patient in the inflating medium . the closure can be provided as an elongated tape strip with a central perforation that can be separated .