Microprocessor controller and method of initializing and controlling low air loss floatation mattress

• US 5,815,864 A
• Filed: 04/02/1996
• Issued: 10/06/1998
• Est. Priority Date: 04/02/1996
• Status: Expired due to Term

• Current Assignee: Sytron Corp (Arcada Software, Inc.)
• Original Assignee: Sytron Corp (Arcada Software, Inc.)
• Inventors: Sloop, David J.
• Primary Examiner(s): Meyers, Steven N.
• Assistant Examiner(s): LUU, TUYET PHUONG PHAM
• Application Number:
  US08/626,361
• Time in Patent Office: 917 Days
• Field of Search: 5/706, 5/709, 5/710, 5/713, 5/714, 5/914, 324/661, 324/662, 324/669
• US Class Current: 5/706
• CPC Class Codes: A61G 2203/34 for pressure
• CPC Class Codes: A61G 2203/40 for distance
• CPC Class Codes: A61G 7/05769 with inflatable chambers
• CPC Class Codes: A61G 7/05784 with ventilating means, e.g. mattress or cushion with ventilating holes or ventilators

Abstract

An air pressurization and control system for a low air loss air floatation mattress or cushion is disclosed. The control system controls air supplied to the air floatation mattress within a range of pressures and flowrates so as to inflate all of the cells of the mattress and to maintain a flow of air to all of the cells over an extended period of time while maintaining all of the cells at a desired level of inflation for the air floatation support of the patient without any of the cells exerting decubitus pressures above the maximum desired decubitus pressure and so as to prevent collapse of any of the cells. A sensor is provided for sensing the pressure of the air within the common supply. The controller includes a microprocessor for initializing the controller to a particular patient to be supported by the mattress and for the air floatation support of the patient over an extended period of time without exceeding a maximum decubitus pressure on any portion of the person'"'"'s body in contact with the mattress and without permitting any of the cells to collapse. The initializing procedure comprises inflating the mattress with the person supported thereon and determining when at least one of the cells becomes fully inflated thereby determining a maximum inflation pressure not to be exceeded during the course of treatment and then deflating the mattress and determining the pressure at which at least one of the cells collapses thereby determining a lower pressure level above which pressure within the mattress is to be maintained during the course of treatment. The controller monitors the pressure of the air supplied to the common source and regulates operation of the source of pressurized air so as to be at a predetermined pressure between the minimum and the maximum pressure.

Claims

1. A method of initializing and controlling the inflation of a low air loss air floatation mattress or other pad for supporting a person'"'"'s body with a decubitus pressure maintained below a desired maximum decubitus pressure level during an extended period of use and for insuring that no portion of the mattress collapses during said extended period of use, an air supply system which continuously supplies air to said mattress, said mattress having an air inlet and a multiplicity of air discharge opening such that air must be continuously supplied to said mattress at a flowrate and pressure to maintain the mattress at a desired inflation pressure, said method comprising the steps of:

placing the person to be supported by said mattress on said mattress;

inflating said mattress;

measuring the pressure of the air supplied to said mattress by said air supply system;

monitoring the rate of the change of the inflation pressure of said mattress;

determining the pressure at which at least a portion of said mattress becomes fully inflated;

deflating said mattress;

determining the pressure at which at least a portion of said mattress attains at least a partially collapsed condition; and

controlling operation of said source of pressurized air over an extended period of time when the person is supported by said mattress so as to maintain a pressure within said mattress intermediate said full inflation pressure and said collapse pressure whereby said person is supported by said mattress with a decubitus pressure less than a desired maximum decubitus pressure.

2. The method of claim 1 wherein said step of determining the pressure at which at least a portion of said mattress becomes fully inflated comprises determining the pressure at which the rate of change of the pressure sharply increases.

3. The method of claim 1 wherein said step of determining the pressure at which at least a portion of said mattress attains at least a partially collapsed condition comprises determining the pressure at which the rate of change of the inflation pressure during deflation decreases substantially.

4. The method of claim 1 wherein said step of determining the pressure at which at least a portion of said mattress attains at least a partially collapsed condition comprises sensing when at least one of said cells at least partially collapses and generating a signal in response to such partial collapse.