CONTROL FOR PRESSURIZED BLADDER IN A PATIENT SUPPORT APPARATUS

• US 20120174322A1
• Filed: 12/22/2011
• Published: 07/12/2012
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: Andrew F. Skinner, Aziz A. Bhai, David P. Lubbers, Richard B. Stacy, Sandy M. Richards, Steven A. Dixon
• Original Assignee: Andrew F. Skinner, Aziz A. Bhai, David P. Lubbers, Richard B. Stacy, Sandy M. Richards, Steven A. Dixon
• Inventors: Skinner, Andrew F., Richards, Sandy M., Dixon, Steven A., Stacy, Richard B., Bhai, Aziz A., Lubbers, David P.
• Granted Patent: US 8,620,477 B2
• Time in Patent Office: Days
• US Class Current: 5/713
• CPC Class Codes: A47C 27/08 Fluid mattresses or cushions connecting valves to inflatable elastic bodies B60C29/00
• CPC Class Codes: A61G 2203/34 for pressure
• CPC Class Codes: A61G 2203/42 for inclination
• CPC Class Codes: A61G 7/05769 with inflatable chambers
• CPC Class Codes: Y10T 137/86035 Combined with fluid receiver
• CPC Class Codes: Y10T 137/86389 Programmer or timer

Abstract

An apparatus for supporting a patient, such as a hospital bed, is provided. The apparatus includes a patient support surface and at least one fluid containing bladder. A pressure control assembly is operably coupled with the bladder. When the fluid pressure within the bladder falls outside of an acceptable range of pressure values, the active adjustment of the pressure within the bladder is initiated by the pressure control assembly if the pressure does not return to the acceptable range of pressure values within a time period, e.g., a time delay, that has a variable length.

Claims

1-37. -37. (canceled)

38. A method of supporting a patient, the method comprising:

providing at least one fluid containing bladder to support at least a portion of the weight of the patient;

monitoring the fluid pressure within the at least one bladder; and

regulating the fluid pressure within the at least one bladder by defining an acceptable range of fluid pressures and adjusting the fluid pressure within the at least one bladder only when a fluid pressure value has been detected outside the acceptable range of fluid pressures and a time period following the detection of the fluid pressure value has elapsed without the fluid pressure within the at least one bladder returning to the acceptable range of fluid pressure values, the time period having a variable length.

51. The patient support of claim 38 wherein the acceptable range of fluid pressure values is variable and the acceptable range of fluid pressure values is a function of the weight of the patient.

52. The patient support of claim 38 wherein the patient is supported on an articulating surface having a plurality of configurations, the acceptable range of fluid pressure values is variable and the acceptable range of fluid pressures values is a function of the configuration of the articulating surface.

55. The method of claim 38, wherein the providing step includes providing first and second bladders, and the regulating step includes adjusting the fluid pressure within the first and second bladders at substantially spaced-apart times.

56. A pressure control assembly to regulate a fluid pressure in a bladder of a patient support, the pressure control assembly comprising:

a sensor operable to sense fluid pressure within a bladder over time, and

a programmable controller programmed to;

monitor the sensed pressure,

determine whether sensed pressure is outside an acceptable range of pressure, the acceptable range having an upper boundary and a lower boundary,

initiate adjustment of the fluid pressure within the bladder after a desired time period following the sensing of sensed pressure has elapsed without the fluid pressure within the bladder returning to the acceptable range of pressure,

change at least one of the upper boundary and the lower boundary of the acceptable range of pressure based on at least one of;

a mode of operation of the patient support, a configuration of the patient support, and a characteristic of a person to be at least partially supported by the bladder, and

determine the desired time period based on at least one of;

a difference between sensed pressure and the acceptable range of pressure, and an algorithm selected based on the difference between sensed pressure and the acceptable range of pressure.

57. The pressure control assembly of claim 56, wherein a second algorithm is selected when the difference between the sensed pressure and the acceptable range of pressure exceeds the first window value;

and wherein the time periods determined by the first algorithm have a first maximum value and the time periods determined by the second algorithm have a second maximum value, the first maximum value being greater than the second maximum value.

58. The pressure control assembly of claim 57, wherein the time periods determined by the first algorithm have a variable length and the time periods determined by the second algorithm have a substantially invariable length.

59. The pressure control assembly of claim 55, wherein the time periods comprise time periods that are a function of the stability of the sensed pressure values.

60. The pressure control assembly of claim 59, wherein the stability of the sensed pressure values is a function of a difference between a first variable representative of a current sensed pressure value and a second variable representative of a moving average of a most recent set of the sensed pressure values.

39-50. -50. (canceled)

53-54. -54. (canceled)

56-1. The pressure control assembly of claim 55, wherein a first algorithm is selected when the difference between the sensed pressure and the acceptable range of pressure does not exceed a first window value.

61-64. -64. (canceled)

65. An air delivery system for a patient support including an inflatable support zone, the air delivery system comprising:

an air supply,

a valve coupled to the air supply,

a pressure sensor operable to produce pressure signals indicative of air pressure with the support zone and an air system controller programmed to;

determine a target pressure for the support zone,

receive the pressure signals,

determine whether pressure in the support zone deviates from the target pressure based on the pressure signals,

determine a time period to elapse before adjusting pressure in the support zone, and

adjust the pressure in the support zone after the time period has elapsed.

66. The air delivery system of claim 65, wherein the target pressure includes an acceptable tolerance.

67. The air delivery system of claim 66, wherein the target pressure is determined based at least in part on a weight of a patient.

68. The air delivery system of claim 66, further comprising an angle sensor operable to produce an angle signal indicative of a value of an angle of the support zone relative to a longitudinal axis of the support zone, wherein the target pressure is determined based at least in part on the angle signal.

69. The air delivery system of claim 68, wherein the controller is further programmed to determine, based on at least one of the pressure signals and the angle signal, whether a person being at least partially supported by the support zone has changed positions.

70. (canceled)