IE881651L - Air sac for oscillating low air loss bed - Google Patents

Description

6 'I ■: 9 9 The present invention relates to an air sac for use on a . low air loss patient support system. More particularly, it relates to an air sac for use on a low air loss bed such as the bed disclosed in my co-pending application Serial No. 5 905,553 having integral means for retaining a patient on the air sac when the patient is moved toward the ends thereof. Such a bed can be used to advantage for the prevention of bed sores and the collection of fluid in the lungs of bedridden patients. % A number of patents, both U.S. and foreign,, disclose air mattresses or cushions comprised of sets of cells which are alternately inflated and deflated to support a patient first on one group of air cells and then the other group. Those patents include the following U.S. patents: 1,772,310, 15 2,245,909, 2,998,817, 3,390,674, 3,467,081, 3,587,568, 3,653,083, 4,068,334, 4,175,297, 4,193,149, 4,197,837, 4,225,989, 4,347,633, 4,391,009, and 4,472,847, and the following foreign patents: G.B. 959,103, Australia 401,767, and German 24 46 935, 29 19 438 and 28 0/ 038. None of the 20 devices disclosed in those patents rolls or alternately moves the patient supported thereon to further distribute the patient's body weight over additional air cushions or cells or to alternately relieve the pressure under portions of the patients body.

There are also a number of patents which disclose an inflatable device other than an air mattress or cushion but which involve alternately supplying air to a set of cells and then to another set of cells. Those patents include U.S. patent n os. 1,147, 560 , 3, 595, 223, and 3 , 867 ,132 ( and G.B. Patent No. 1,405,333. Of those patents, only the British patent discloses the movement of the body with changes in air pressure in the cells of the device. None of those 5 references disclose an apparatus which is adaptable for use in a low air loss patient support system.

British Patent No, 946,831 discloses an air mattress having inflatable elongated sacs which are placed side-by-side and. which are in fluid communication with each other. A-10 valve is provided in the conduit connecting the insides of the two sacs, Air is supplied to both sacs in an amount sufficient to support the patient, thereby raising the patient off the bed or other surface on which the air mattress rests. Any imbalance of the weight distribution of the patient causes the air to be driven from one sac to the other, allowing the patient to turn toward the direction of the now deflated sac*. An automatic changeover valve, the details of which are not shown, is said to then inflate the deflated sac while deflating the sac which was originally inflated, there-20 by rocking the patient in the other direction - The device disclosed in that patent is limited in its ability to prevent bed sores because when the patient rocks onto the deflated sac, there may be insufficient air to support the patient up off the bed or other surface on which the air mattress rests, resulting in pressure being exerted against the patient' s skin which is essentially the same as the pressure that would have been exerted fay the board or other surface without the air mattress. Even if there ware enough air left in the deflated sac to support the patient, if the air mattress were constructed in a low air loss configuration, the air remaining in the sac would be slowly lost from the sac until the patient rested directly on the bed or other surface with the -same result. Finally, that device is not adaptable for use on a bed having hinged sections corresponding to the parts of the patient's body lying on the bed so that the angle of inclination of th© various sections of the bed can be adjusted for tha patient's comfort or for therapeutic reasons.

The present invention is characterized bv a number of advantages over the prior art devices, including the ability to maintain air pressure,, the ability to quickly and easily replace one or more of the air sacs while the low air loss bed is in operation, and the ease of adjustment of the air pressure in the air sacs.

It is,, therefore,, an object of the present invention to provide a low air lossr water vapor permeable air sac which is comprised of a substantially rectangular enclosure constructed of a water vapor permeable material, means for connecting the inside of the enclosure with a source of gas for inflating the enclosure., means for releasably securing the enclosure to a low air loss bed? integral means for moving a patient resting on the top surface of the rectangular enclosure towards the end thereof when the enclosure is inflated, and integral means at the end of the rectangular enclosure toward which the patient is moved for retaining the patient on the top surface of the enclosure.

Another object of the present invention is to provide an air sac with a single opening which can be quickly and easily detached from an air bed to allow the easy replacement of the air sac, even while the bed is in operation.

Another object of the present invention is to provide an air sac for use on a low air loss bed capable of rolling a patient back and forth on the bed while safely retaining the patient thereon.

Other objects and advantages will be apparent to those of skill in the art from the following disclosure.

SUMMARY OF THE INVENTION These objects and advantages are_ accomplished in the present invention by providing an air sac for use on a low air loss bed having a plurality of transversely mounted air sacs mounted thereon comprising an enclosure for supporting a patient and distributing pressure over the body of the patient to prevent pressure points and means for connecting the inside of the enclosure with a source of gas for inflating the enclosure with gas. The enclosure is provided with means for securing the enclosure to a low air loss bed and means for moving a patient supported thereon toward one end of the enclosure when the air sac is inflated. The air sac is also provided with integral means for retaining the pariant supported on the top surface of the enclosure when the patient is moved toward the end of the enclosure.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a low air loss bed having the presently preferred embodiments of the air sac of the present invention mounted thereto™ Figure 2 is a cross-sectional view of the bed of Fig. 1, showing an air sac with a second air sac therebehind taken along the lines 2-2 in Fig„ 1, the second air sac being shown in shadow lines for purposes of clarity- Figure 3 is an end view of a presently preferred embodiment of an air sac for use on the low air loss bed of Fig. 1.

Figure 4 is an end view of another presently preferred embodiment of an air sac for use on the low air loss bed of Fig. 1.

Figure 5 is an end view of another presently preferred embodiment of an air sac for use on the low air loss bed of Fig. I., Figure 6 is an end view of another presently preferred embodiment of an air sac for use on the low air loss bed of Fig. 1.

Figures 7A-7D are an end view of a patient supported upon the top surface of the air sacs of the low air loss bed of the present invention (7DJ * as that patient is rocked toward one side of the frame of the low air loss bed (7A), then toward the other side (7C) or supported on the air sacs when all air sacs are fully inflated (Fig. 7B).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Fig. 1, there is shown a bed 10 including a frame 12™ The frame 12 is comprised of a plurality of sections 14% 14s % 14' * ' and 14s 98 % hinged at the points 44% 4488 and 44®and end members 16. The frame 12 is provided with headboard-20 at one end and a foot board 21 at the other end.

The air sacs 58 are substantially rectangular in shape,, and are constructed of a coated fabric or similar material through which water vapor can move,, but which water and other liquids will not penetrate. The fabric sold under the trademark "GORE-TEX" is one such suitable material.

Referring to Figs. 1-6, air sacs of different configuration are shown for use according to the location at which they are mounted on the frame 12 of bed 10. For instance, some of the air sacs mounted to the feet baseboard 46 are of the configuration designated at reference numeral 328. Likewise, some of the air sacs mounted to the feet baseboard 46 are of the configuration designated at reference numeral 322, and all the air sacs mounted to leg baseboard 48 and seat baseboard 50 are of the configuration designated at reference numeral 322. Alternatively, some or all of the air sacs designated at reference numeral 322 can be replaced with air sacs of the configuration shown at reference numeral 325 (see Pig. 4) or 337 (see Fig- 6!. Some of the air sacs shown at reference numeral 322 are also mounted to head baseboard 52,,. as are air sacs of the configuration shown at reference numeral 58 Mr sacs 58, 322, 325, 328, and 337 are constructed in the form of a substantially rectangular enclosure, at least the top surface 323 of which is constructed of water vapor permeable material as described above. Air sacs 58, 322, 325, 328 and 337 are provided with means far connecting the inside of the air sac enclosure to a source of gas (not shown) to inflate the enclosure with gas in the form of the nipple 23 (see Figs. 2-6J which extends through the hole 54 in baseboard 50 into a gas manifold 80 mounted to baseboard 50 as shown in Fig. 2. An O-ring 68 is provided to seal nipple 23 in hole 54, and extension tab 15 fits under screw 13 to hold air sac 322 in place. Air sac 58, 322, 325, 328, or 337 is also provided with means for reieasably securing the air sac enclosure to the low air loss bed 10 in the form of a post 32, having retainer 34 on the end thereof, which extends through hole 54 to engage the underside of baseboard 50.

Means is provided for moving a patient 348 (see Figs. IK-TO) supported on air sacs 322, 325, 328, or 337 toward one side of frame 12 when air sacs 322, 325, 328, or 337 are inflated and for retaining the patient 348 on the top surface 323 of air sacs 322, 325, 328, or 337 when patient 348 is rolled or rocked towards one side of frame 12 or the other -The means for moving patient 348 supported on air sacs 322,, 325# 328,« or 337 toward one side of frame 12 when the air sacs 322, 325, 328# or 337 are inflated comprises a cutout 324 in the top 323 of the substantially rectangular shape of each of the air sacs 322, 325, 328 or 337.

Each air sac 322, 325. 328, or 337 is also provided with means for retaining a patient 348 on the top surface 323 of the air sac 322# 325# 328# or 337 when patient 348 is rolled toward the side of frame 12 by the inflation of air sacs 322, 325, 328, or 337 in the form of a pillar 326 which is integral with each air sac 322, 325, 328, or 337 and which, when inflated# projects upwardly to form the end and corner of the substantially rectangular enclosure of air sac 322, 325, 328, or 337.

As shown in Fig® 1, a plurality of air sacs 58, 322„ 325, 323 and/or 337 is mounted transversely on the frame 12 of bed 10. The air sacs 322, 325328, or 337 are divided into a first set in which the pillar 326 and cutout 324 are closer to one side of bed frame 12 than the other and a second set of sir sacs 322, 325, 328, or 337 in which the pillar 326 and cutout 324 are closer to the second side of the bed frame 12. The air sacs 322, 325, 328,, or 337 of the first set and the air sacs 322 , 325, 328, or 337 of the second set alternate with each other along the length of baseboards 46, 48, 50, and 52„ As will be explained, the first set of air sacs 322, 325, 328# or 337 is inflated with air from a gas source (not shown) , thereby causing the patient 348 supported thereon to be rolled toward the first side of bed frame 12 and then deflated while the second set of air sacs 322, 325, 328, or 337 is inflated, thereby moving the patient 348 supported thereon toward the other side of bed frame 12 (see Fig„ 7A-7D). The air pressure in the sets of air sacs is monitored by gauges 241., The air sacs 58 which are mounted on head baseboard 52 are provided with a flat top surface 323 so that the head of patient 348 is retained in a relatively constant position while the body of patient 348 is alternately rolled first toward one side of the bed frame 12 and then back toward the other side of bed frame 12. Referring to Fig,. 3, an air sac 58 is shown for use under the head of patient 348. Air sac 58 is substantially rectangular in shape, but is provided with a slanted top surface 323 in the area 331 adjacent to corners 448. The total height of air sac 58 is less than the height of air sacs 322, 325, 328, and 337 because when patient 348 lies upon air sacs 322, 325, 328,, and/or 337, the heavier portions * i.e.,, the portions of the body other than the headj, sink into those air sacs 322, 325, 328, and/or 337 as shown in Fig. 7D. When the patient 348 sinks into air sacs 322, 325, 328, and/or 337, the head rests evenly on air sacs 58 because the head does not sink into air sacs 58 as far as the other portions of the patient's body sinks into the air sacs 322, 325, 328, or 337 on which the rest of the body is supported.

The air sacs 328 mounted on the foot baseboard 46 are also provided with a cutout 324 and pillar 326 as described for the air sa.cs 322. Additionally, air sacs 328 are provided with a hump 330 so that the legs of patient 34 8 are 5 relatively restrained from movement during the alternate back and forth movement of patient 348t thereby helping to retain the patient 343 on the top surface 323 of air sacs 58 , 322, 325, 328, and 337 as well as helping to distribute the pressure exerted against the skin of patient 348 over an 10 increased area <, Referring to Fig. 5, there is shown an and view of an air sac 328 having hump 330 formed in the top surface 323 thereof. As can be seen, when air sac 328 is inflated, hump 330 and pillar 326 project upwardly to help prevent the rolling of patient 348 too far to one side of air 15 sac 328 or the other.

As noted above, some of the air sacs mounted to foot baseboard 46 „ and preferably all the air sacs mounted to legs baseboard 48 and seat baseboard SO,, are of the configuration shown in Fig. 2 at reference numeral 322. Alternatively,,, air 20 sac 322 is constructed in the configuration shown at reference numeral 325 of Fig. 4 or reference numeral 337 of Fig. 6. Air sac 325 is provided with cutout 324 of approximately the same depth as the cutout 324 of air sacs 322, 328 and 337, but the top surface 323 of air sac 32S in the area 25 329 is less than the slope of the top surface 323 in the area 329 of air sacs 322, 328, and 337. Air sac 325 is also provided with an area, indicated by reference numeral 327 ^ in which the slope of the wall of cutout 324 is reversed. The corner 335 of air sac 325 acts as a balance point as shown in 30 Figs- 7A and 7C as the patient 348 is alternately rolled from one end of the air sac 325 to the other such that the body-weight ©f patient 348 is used to assist in the rolling of patient 348 towards each end af air sac 325. To further distribute the pressure exerted by air" sac 325 against the 35 shoulder and hip of patient 348 when the patient is rolled to the position shown in Figs- 7A and 7C, the cutout 324 is provided with a sloped portion, indicated at reference numeral 339,, of the vail of pillar 326. Air sac 325 , in conjunction with the adjustment of the air pressure in the air sacs 58, 322, 328, and/or 337, is used under different 5 portions of the body of patient 348 to increase or decrease the extent and speed with which patient 348 is rolled from one side of bed frame 12 to the other. For instance, air sac 325 is particularly well-suited for use under the shoulders of a patient 348,.

It will be understood by those skilled in the art who have the benefit of this disclosure that, although patient 348 is shown supported on air sacs having the configuration shorn at reference numeral 325 in Figs, 7A-7D, the patient 348 can also be alternately rolled back and forth when 15 supported on any of the air sacs 322 , 328, or 337.

Regardless of the configuration utilized, when one set of air sacs 322, 325, 328 or 337 is inflated, one side of patient 348 drops into cutout 324, causing the patient 348 to roll toward one end of the air sac 322„ 328, 328, or 337. As that 20 set of air sacs 322, 325, 328, and/or 337 is deflated and the second set of air sacs 322, 325, 328, and/or 337 is inflated, patient 328 is first returned to the horizontal position shown in Fig. 7D and then rolled toward the other end of air sacs 322, 325, 328, and/or 337.

As noted above, each of the air sacs 58, 322, 325, 328, and 337 forms a substantially rectangular enclosure, the dimensions of the rectangle being approximately 18 x 39 inches when uninflated- When inflated, the enclosure measures approximately 16 x 36 inches. Each is provided with 30 a baffle 460 attached to the inside of side walls SI (see Pics., 1 and. 2) which holds the side walls 61 against bowing when the air sac 58, 322, 325, 323, or 337 is inflated- Each of the corners 448 has a radius of curvature of approximately three inches,, and the depth of cutout 324 in the direction 35 shown by line 451 ranges from approximate ly eight to approximately thirteen inches, the presently preferred dimension being about ten inches,, The dimension of pillar 326 of air sacs 325, 328,, and 337 in the direction shown by line 450 ranges from approximately five to approximately twelve inches, the presently preferred dimensions being from 5 about seven to about twelve inches,, That range of dimensions along line 450 gives pillar 325 sufficient bulk, and therefor® sufficient rigidity when inflated, to prevent, in conjunction with baffle 460, the forcing of the pillars 326 outwardly fro®, the sides of the bed frame 12 when both sets 10 ox the air sacs 58, 322, 325, 328, and 337 are inflated either partially, i.e., when patient 348 is in the position shown in Fig„ 7D, or fully inflated# as when patient 328 is in the position shown in Fig. 70. The configuration of air sac 325 (se® Pig. 45 is even more effective at preventing 15 that outward movement of pillar 326 because of the sloped portion 339 of the wall of pillar 326 toward the bottom of cutout 324, and it will be understood by those skilled in the art who have the benefit of this disclosure that any or all of the pillars 326 of air sacs 322, 328 or 337 can be 20 provided with a similarly sloped portion 339 - Referring to Fig„ 2, the dimension of the top surface 323 of air sac 322 along line 459 is approximately nineteen inches- Top surface 323 then drops off into cut out 324 in a curve 464 of approximately a three inch radius along surface 25 329. The dimension of cutout 324 in the direction shown by line 462 ranges from about five to about ten inches, depending upon the dimension of pillar 326 in the direction of line 450, the presently preferred dimension being approximately seven inches.

Referring to Fig„ 4, the dimension of cutout 324 in the direction shown by line 452 is approximately five to ten inches. The slope of the reversed portion 327 of the top surface 323 of air sac 325 is determined by the dimension of line 461, which in a presently preferred embodiment is 35 between two and five inches, depending upon the dimension of lines 450 and 452, all of which can be varied depending upon the particular operating mode desired and the weight and size of patient 348 „ The dimensions of air sac 328 (Fig- 5) are as follows. As noted above, the dimension of pillar 326 in the direction 5 of line 4.50 can be varied from about five to about twelve inches, as can the dimension of cutout 324 in the direction of line 452, depending upon the dimension of line 450. The dimension of hump 330 on air sac 328 in the direction shown by line 454 -is approximately five inches, and in the 10 direction shown by line 456 e> the dimension is approximately two inches. The dimension of surface 333, as shown by line 458 is approximately fourteen inches.

Referring now to air sac 337 CFig. 6), the dimension of the surface 329 in the direction shown by line 453 is 15 approximately twenty inches, and that surface 329 drops off into cutout 324 in a curve 455 of approximately a three inch radius along a surface 466 having a steeper slope than the surface 329. The dimension of pillar 326 and cutout 324 can be varied as described above with reference to air sacs 322 , 20 325 and 328.

The use of individual air sacs 58, 322, 325, 328, or 337 rather than a single air cushion which runs the length of bed frame 12 allows the replacement of individual sacs should one develop a leak, need cleaning or otherwise need attention. 25 Whan it is desired to remove an individual air sac 58, 322, 325, 328, or 337 from its respective baseboard 46, 48, 50, or 52, post 32 and retainer .34 are removed from hole 54. (see Fig. 21 . Nipple 23 is then rotated until extension tab 15 rotates out of engagement with screw 13 and nipple 23 is then 30 pulled firmly to remove it from hole 54.

The hump 330 is air sacs 328 provides a longitudinal barrier along the top surface of the air sacs 328 such that one of the legs of patient 348 i's retained on either side of that longitudinal barrier even during the alternating in-35 flat ion and deflation of the air sacs 328. In this manner, the hump 330 prevents patient 348 from rolling too far to one end of air sac 328 or the other. Further, the legs of patient 348 do not slide and/or rub together while patient 348 is being alternately rolled from one side of the bed frame 12 to the other. It <« i 11 be understood by those 5 skilled, in the art that the air sacs 328 having the humps 330 therein can be replaced by air sacs 322, 325, or 337 depending upon the type of therapy and the extent of motion desired for a particular patient.

Although the present invention has been described in 10 terms of the foregoing preferred embodiments, this description has been provided by way of explanation only and is not to be construed, as a limitation of the invention, the scope of which is limited only by the following claiais.

Claims (1)

1. CLAIMSe 1- An Inflatable air sac for use on a patient support system including air sacs for supporting a patient, comprising; an inflatable enclosure having: a gas inlet for connecting the inside of said enclosure with a source of gas to inflate said enclosure with the gas; a first portion formed with said enclosure for rolling a patient by allowing one side of the patient to lower relative to the other side of the patient? and a second portion formed with said enclosure for retaining the patient on said enclosure when the patient is rolled. 2» An inflatable air sac as in claim 1, wherein: the first inflatable portion formed integral with said enclosure has a wall shaped, to allow lowering of one side of the patient relative to the other side of the patient when said enclosure is inflated, thereby rolling the patient toward one end of said enclosure when said enclosure is inflated. 3. An inflatable air sac as in claim 1, wherein the patient support system is a low air loss system. 4. An Inflatable air sac as in claim 1, wherein: the inflatable enclosure is elongate im plan view| and said retaining means is formed in said enclosure in such manner as to provide an abutment at the other side of the enclosure 5. The inflatable air sac of claim 1 wherein: said first inflatable portion has a first surface shaped to allow lowering of one side of the -14- patient relative to the other side of the patient when said first portion is inflated, thereby rolling the patient toward one end of said enclosure when said enclosure is inflated and said second inflatable portion is formed in said enclosure for retaining the patient on said enclosure when the patient is rolled toward the one end of said enclosure by inflation of said first inflatable portion™ 6. The inflatable air sac of claim 1 or claim 5 wherein: said first inflatable portion is in open communication with said second inflatable portion to enable equalisation of the gas pressure in each. 7. The inflatable air sac of claim 5 or claim 6, wherein: said first surface comprises a wall section sloping .downwardly from an upper end to a lower end thereof, the lower end of said wall section being eccentric relative to said, enclosure. 8. The inflatable air sac of claim 5 wherein: said first surface is positioned between first and second opposed end walls of said enclosure; and said second inflatable portion is positioned between said first surface and said second end wall; and said first surface is sloped downwardly toward said second portion for rolling the patient towards said second portion. 9- The inflatable air sac of claim 8 wherein: said second portion is formed integral with said enclosure adjacent the second end wall thereof. -15- iO» The inflatable air sac of any one of claims 5 to 9 wherein: the first surface of said first portion is asymmetrically sloped such that a space partially bounded by said first portion and said second portion is asymmetrical relative to said enclosure, into which space one side of the patient is allowed to roll when said first portion is inflated- 11. The inflatable air sac of any one of claims 8 to 10, further including a first side wall adjoining both the first end wall second end wall; a second side wall opposing the first side wall and adjoining both the first end wall and the second end wall; and a bottom wall adjoining each of the first end wall, the second end wall, the first side wall and the second side wall. 1.2» The inflatable air sac of any one of claims 8 to 11 wherein: said second inflatable portion includes a substantially vertical wall positioned between the first end wall and the second end wall. 13. The inflatable air sac of claim 11 or claim 12 further comprising: a baffle attached to and spanning between an interior surface of the first side wall and an interior surface of the second side wall. 14. The inflatable air sac of claim 12 and claim 13 wherein: said first surface is connected along opposed edges thereof to the first and second side walls? and said vertical wall is positioned between the first surface and the second end wall, the vertical wall being connected along opposed edges thereof to the first and second side wall. 15. The inflatable air sac of any one of claims 12 to 14, further including: a first generally horizontal upper wall extending from the first end wall towards the second end wall? and a second generally horizontal upper wall extending from the second end wall toward the first end wall. the first surface being connected to the first upper wall and extending downwardly therefrom; and the substantially vertical wall being connected to the second upper wall and extending downwardly therefrom; the first upper wall being connected at a first end to an upper end of the first end wall and at a second end to an upper end of the first surfacei the second upper wall being connected at a first end to an upper end of the; second end wall and at a second end to an upper end of the substantially vertical wall? the bottom wall being connected to each of the first and second end walls and the first and second side walls at lower ends thereof? a lower end of the substantially vertical wall is connected to a lower end of the first surface? the first end wall and the second end wall being generally vertical? and the bottom wall being generally horizontal. 16. The inflatable air sac of any one of claims 13 to 15,, wherein: said baffle is positioned between the first surfaces and the first end wall. 5 I/. The inflatable air sac of any one of claims 11 to 16 wherein: the gas inlet is integral with the bottom wall. 18. The inflatable air sac of any one of claims 15 to 10 17 wherein the first upper wall includes a hump. 19. The inflatable air sac of any one of claims 15 to 18 wherein at least said first upper wall is comprised of a water vapour permeable material. 20. The inflatable air sac of any one of claims 1 to 19 15 wherein said gas inlet comprises a nipple having an elongate shaft extending into said enclosure and a flange by which the shank of said nipple is retained inside said enclosure. 21. The inflatable air sac of claim 20 wherein said 20 securing means comprises the shank of said nipple. 22. The inflatable air sac of any one. of claims 1 to 21 wherein said securing means is releasable. 23. The inflatable air sac is claim 1 substantially as herein described with reference to any one of the 25 embodiments shown in the accompanying drawings™ F. R. KELLY _& CO. , AGENTS FOR THE APPLICANTS. -18-