Mattress for retarding development of decubitus ulcers

• US 5,325,551 A
• Filed: 06/16/1992
• Issued: 07/05/1994
• Est. Priority Date: 06/16/1992
• Status: Expired due to Term

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Tappel, James G., Travis, Stephen C., Hopper, Christopher J.
• Primary Examiner(s): TRETTEL, MICHAEL
• Application Number:
  US07/900,067
• Time in Patent Office: 749 Days
• Field of Search: 5/449, 5/450, 5/453, 5/468, 5/469, 5/481
• US Class Current: 5/709
• CPC Class Codes: A47C 27/082 with non-manual inflation, e.g. with electric pumps
• CPC Class Codes: A47C 27/083 with pressure control, e.g. with pressure sensors
• CPC Class Codes: A47C 27/088 incorporating elastic bodies, e.g. foam
• CPC Class Codes: A47C 27/148 of different resilience
• CPC Class Codes: A47C 27/18 in combination with inflatable bodies
• CPC Class Codes: A47C 31/008 Use of remote controls
• CPC Class Codes: A61G 2203/12 Remote controls
• CPC Class Codes: A61G 2203/34 for pressure
• CPC Class Codes: A61G 7/05715 with modular blocks, or inserts, with layers of different material
• CPC Class Codes: A61G 7/05769 with inflatable chambers

Abstract

A mattress unit for retarding the development of decubitus ulcers includes a fabric cover having therein a foam material, and includes an inflatable bladder and a control unit disposed within openings in the foam material. The inflatable bladder contains a foam material having spaced holes in it. The control unit includes a pump which can selectively supply pressurized air to the bladder, a valve which can selectively bleed air from the bladder, and a pressure sensor which can determine the current pressure in the bladder. The pressure sensor is coupled to an input of a control circuit which controls the pump and valve. The control circuit receives power from an AC/DC converter and is remotely controlled by a hand-held pendant, the converter and pendant each being physically separate from the mattress unit and being connected to the control circuit by respective cables.

Claims

1. An apparatus comprising:

a mattress unit having an inflatable bladder therein, and having selectively actuable means therein responsive to a gas pressure in said bladder for selectively supplying pressurized gas to and selectively removing gas from said inflatable bladder so as to automatically maintain said gas pressure in said bladder substantially at a specified pressure value, wherein said selectively actuable means is disposed in a foot support portion of said mattress unit, and wherein said bladder is disposed in an upper body support portion of said mattress unit.

2. An apparatus according to claim 1, wherein said selectively actuable means includes pressure sensor means for detecting a gas pressure within said bladder.

4. An apparatus according to claim 2, wherein said foam material includes a bottom sheet of foam, a top sheet of foam, and intermediate foam components which are disposed between said top and bottom sheets and which define a first opening corresponding in size and shape to said inflatable bladder and a second opening corresponding in size and shape to a housing containing said selectively actuable means, said inflatable bladder and said housing being respectively disposed in said first and second openings.

3. An apparatus comprising:

a mattress unit having an inflatable bladder therein and having selectively actuable means for selectively supplying pressurized gas to and removing gas from said inflatable bladder;

wherein said selectively actuable means is provided within said mattress unit; and

wherein said mattress unit contains a foam material, said inflatable bladder and said selectively actuable means being embedded in said foam material.

5. An apparatus according to claim 3, wherein portions of said foam material surrounding said periphery of said inflatable bladder have a horizontal thickness of at least six inches, and portions of said foam material extending over the top of said inflatable bladder have a vertical thickness of at least two inches.

6. An apparatus comprising:

a mattress unit having an inflatable bladder therein and having selectively actuable means for selectively supplying pressurized gas to and removing gas from said inflatable bladder;

wherein said selectively actuable means is provided within said mattress unit, includes selectively and electrically actuable first means for supplying pressurized gas to said inflatable bladder, includes selectively and electrically actuable second means for removing gas from said inflatable bladder, and includes control circuit means electrically coupled to said first means and said second means for electrically effecting said selective actuation of each of said first means and said second means; and

including an AC to DC converter which is external to and physically separate from said mattress, and which is coupled by a cable to said control circuit means disposed within said mattress for supplying power to said control circuit means through said cable.

7. An apparatus according to claim 6, wherein said control circuit means includes means defining a pressure setpoint, and means for effecting said selective actuation of said first and second means so as to maintain the pressure in said bladder approximately at said pressure setpoint.

8. An apparatus according to claim 7, including a manual control unit disposed externally to said mattress unit, and means for providing communication between said manual control unit and said control circuit means to facilitate variation of said pressure setpoint in response to manual operation of said manual control unit.

9. An apparatus according to claim 6, wherein said first means includes selectively actuable pump means for supplying pressurized gas to said inflatable bladder and said second means includes selectively actuable valve means for selectively removing gas from said inflatable bladder.

10. An apparatus according to claim 6, including a manual control unit which is disposed externally to said mattress unit, and means for facilitating communication between said manual control unit and said control circuit means disposed within said mattress unit to facilitate variation, in response to manual operation of said manual control unit, of a control function carried out by said control circuit means.

11. An apparatus according to claim 10, wherein said manual control unit is a hand-held unit which is physically separate from said mattress unit, which has thereon at least one manually actuable push button and which has means for providing visually perceptible indication under control of said control unit means.

12. An apparatus according to claim 10, wherein said manual control unit is a hand-held unit physically separate from said mattress unit, and said means for facilitating communication includes a cable electrically coupling said manual control unit to said control circuit means.

13. An apparatus comprising:

a mattress unit, an inflatable bladder disposed within said mattress unit, manually actuable means for selectively varying a first pressure set point and for selecting one of first and second operational modes, and control means for controlling a gas pressure in said bladder, said control means including means responsive to selection of said second operational mode for automatically selectively supplying pressurized gas to and removing pressurized gas from said inflatable bladder so as to maintain the gas pressure in said bladder substantially at a second pressure set point, and means responsive to selection of said first operational mode for automatically selectively supplying pressurized gas to and removing pressurized gas from said inflatable bladder so as to maintain the gas pressure in said bladder substantially at said first pressure set point.

14. An apparatus according to claim 13, wherein said pressure set point is a predetermined constant.

15. An apparatus according to claim 13, wherein said control means includes means for effecting said supplying of pressurized gas to said inflatable bladder at a selected one of first and second rates, said first rate being greater than said second rate, said control means being responsive to changing of said first pressure set point to a value greater than the current pressure in said inflatable bladder for supplying said pressurized gas to said inflatable bladder at said first rate until the pressure in said bladder reaches said first pressure set point, and thereafter effecting said selective supplying of pressurized gas to said inflatable bladder at said second rate.

16. An apparatus according to claim 15, wherein during said second operational mode said control means effects said selective supplying of pressurized gas to said inflatable bladder at said second rate.

17. An apparatus comprising:

a mattress unit;

an inflatable bladder disposed within said mattress unit; and

control means disposed within said mattress unit for controlling a gas pressure within said inflatable bladder, said control means including selectively actuable supply means for supplying pressurized gas to said bladder at a selected one of first and second rates, said first rate being substantially greater than said second rate.

18. An apparatus according to claim 17, wherein said second rate is a predetermined rate sufficiently low so that a person sleeping on said mattress unit is substantially undisturbed by audible sound produced by said control means within said mattress unit, and wherein said first rate is a predetermined rate at which said control means produces sound which is clearly audible to a person on said mattress unit to indicate that the gas pressure in said bladder is being increased.

19. An apparatus according to claim 18, including a manually operable control unit, said control means having means for supplying gas to said bladder at said first predetermined rate in response to manual operation of said control unit.

20. An apparatus comprising:

a mattress unit;

an inflatable bladder disposed within said mattress unit; and

control means for controlling a gas pressure within said inflatable bladder, said control means including selectively actuable supply means for supplying pressurized gas to said bladder at a selected one of first and second rates, said first rate being greater than said second rate, said control means further including means for supplying gas to said bladder at said second rate when the gas pressure in said bladder is below a pressure value, and means responsive to the gas pressure in said bladder being below said pressure value after gas has been supplied to said bladder at said second rate for a predetermined time period for thereafter supplying gas to said bladder at said first rate.

21. An apparatus according to claim 20, wherein said control means includes means responsive to the gas pressure in said bladder being below said pressure value after gas has been supplied to said bladder at said first rate for a predetermined time period for terminating the supply of gas to said bladder and for generating an operator perceptible indication that a problem has been detected.

22. An apparatus comprising:

a mattress unit;

an inflatable bladder disposed within said mattress unit; and

control means for controlling a gas pressure within said inflatable bladder, said control means including selectively actuable supply means for supplying pressurized gas to said bladder at a selected one of first and second rates, said first rate being greater than said second rate;

wherein said control means includes an electrical control circuit and is responsive to turning on of power to said control circuit for supplying gas to said bladder at said first rate until the pressure in said bladder reaches a pressure value, and thereafter selectively supplying gas to said bladder at said second rate when necessary to maintain the pressure in said bladder at a desired pressure.

23. An apparatus comprising:

a mattress unit;

an inflatable bladder disposed within said mattress unit;

control means for controlling a gas pressure within said inflatable bladder, said control means including selectively actuable supply means for supplying pressurized gas to said bladder at a selected one of first and second rates, said first rate being greater than said second rate; and

manually operable means for manually specifying a desired pressure within said inflatable bladder, said control means being responsive to manual actuation of said manually operable means in a manner specifying a desired pressure greater than a current actual pressure within said inflatable bladder for effecting said supply of pressurized gas to said bladder at said first rate in order to reach said desired pressure, and thereafter selectively supplying gas to said inflatable bladder at said second rate when necessary to maintain the pressure in said bladder at said desired pressure.

24. An apparatus according to claim 23, wherein said control means is operable in a selected one of first and second modes, said control means being responsive to said manually operable means in said first mode and ignoring said manually operable means in said second mode, wherein in said second mode said control means effects said selective supplying of gas to said inflatable bladder at said second rate to maintain the gas pressure in said bladder substantially at a further pressure.

25. An apparatus according to claim 24, including means responsive to initial actuation of said control means for causing said control means to initially operate in said second operational mode and to selectively supply pressurized gas to said bladder at said first rate until said further pressure is reached for the first time.

26. An apparatus according to claim 25, wherein said manually operable means includes means for manually effecting said selection of one of said first and second operational modes for said control means.

27. An apparatus comprising:

a mattress unit;

an inflatable bladder disposed within said mattress unit;

control means disposed within said mattress unit for selectively supplying pressurized gas to and removing gas from said inflatable bladder so at to maintain the gas pressure in said bladder at a specified pressure; and

a hand-held control unit separate from and external to said mattress unit and means facilitating communication between said control unit and said control means to effect manual variation of said specified pressure, wherein said hand-held control unit has a first push button which causes said control means to switch between first and second operational modes in which said control means respectively uses as said specified pressure a predetermined pressure value and a manually-entered pressure value, includes a second push button for manually increasing said manually-entered pressure value, and includes a third push button for manually decreasing said manually-entered pressure value;

wherein said hand-held control unit has first and second visual indicators which are respectively actuated by said control means when said control means is respectively operating in said first and second operational modes;

wherein said control means includes means for detecting a leakage of air from said inflatable bladder; and

wherein said hand-held control unit has a further visual indicator which is actuated by said control means in response to a detection of air leakage from said inflatable bladder.

35. An apparatus according to claim 27, including a foam material which is disposed within said mattress unit and which extends around the entire periphery of said inflatable bladder and covers the entire top of said inflatable bladder, wherein portions of said foam material surrounding said periphery of said inflatable bladder have a horizontal thickness of at least six inches, and portions of said foam material extending over the top of said inflatable bladder have a vertical thickness of at least two inches.

36. An apparatus according to claim 35, wherein said foam material includes a bottom sheet of foam material extending the full length and width of said mattress, a top sheet of foam material spaced above said bottom sheet and extending the full length and width of said mattress, and intermediate elements of foam material disposed between said top and bottom sheets and defining an opening corresponding in size and shape to said inflatable bladder, said inflatable bladder being disposed between said top and bottom sheets within said opening.

28. An apparatus comprising:

a mattress unit having therein an inflatable bladder, and having therein a foam material which extends around the entire periphery of said inflatable bladder and covers the entire top of said inflatable bladder, wherein portions of said foam material surrounding said periphery of said inflatable bladder have a horizontal thickness of at least six inches, and portions of said foam material extending over the top of said inflatable bladder have a vertical thickness of at least two inches, wherein said inflatable bladder has a foam material therein, and wherein said foam material in said bladder has a plurality of openings provided at spaced locations therein.

29. An apparatus comprising:

a mattress unit having therein an inflatable bladder, and having therein a foam material which extends around the entire periphery of said inflatable bladder and covers the entire top of said inflatable bladder, wherein portions of said foam material surrounding said periphery of said inflatable bladder have a horizontal thickness of at least six inches, and portions of said foam material extending over the top of said inflatable bladder have a vertical thickness of at least two inches, wherein said foam material includes a bottom sheet of foam material extending the full length and width of said mattress, a top sheet of foam material spaced above said bottom sheet and extending the full length and width of said mattress, and intermediate elements of foam material disposed between said top and bottom sheets and defining an opening corresponding in size and shape to said inflatable bladder, said inflatable bladder being disposed between said top and bottom sheets within said opening, and wherein said intermediate elements include first and second side elements disposed on opposite sides of said inflatable bladder and each extending from a head end of said mattress unit approximately three-quarters of the distance to a foot end of said mattress, a head element extending between said side elements at said head end of said mattress, and at least one foot element extending between the sides of said mattress and from said foot end to the adjacent ends of said side elements, said side elements and said further element each having inner surfaces which face peripheral edges of said inflatable bladder and which are concave.

30. An apparatus according to claim 29, wherein said mattress unit includes a fabric cover having said inflatable bladder and all of said foam elements therein, said foam elements being free of physical interconnections to other said foam elements, said bladder and said cover.

31. An apparatus comprising:

a mattress unit;

an inflatable bladder disposed within said mattress unit; and

selectively actuable control means disposed within said mattress unit for selectively supplying pressurized gas to and removing gas from said bladder;

wherein said inflatable bladder includes a gas impermeable cover having therein a foam material, said foam material in said bladder having a plurality of openings provided at spaced locations therein.

32. An apparatus according to claim 31, wherein a first pair of adjacent said openings are spaced by a distance which is different from the distance between a second pair of adjacent said openings.

33. An apparatus according to claim 32, wherein each said opening is a cylindrical hole extending completely through said foam material in a horizontal direction transversely of said mattress unit, said holes being provided at locations which are spaced from each other in a direction lengthwise of said mattress unit, each end of said bladder having a group of holes which are uniformly spaced from each other by substantially a first distance, and a central portion of said bladder having a further group of said holes which are spaced by a second distance greater than said first distance.

34. An apparatus according to claim 31, wherein two of said holes are of different size.

37. An apparatus, comprising:

a mattress unit having therein an inflatable bladder and having therein selectively and electrically actuable pressure control means for changing a gas pressure within said bladder, and a control unit physically separate from said mattress unit and electrically coupled by a cable to said pressure control means in said mattress unit, wherein said cable enters said mattress unit through an opening which is in a bottom surface of said mattress unit and which is spaced a substantial distance inwardly from each edge of said bottom surface of said mattress unit.