PRESSURE DETECTION AND MEASUREMENT SENSOR INCORPORATING AT LEAST ONE RESISTIVE FORCE-DETECTOR CELL

• US 20090056020A1
• Filed: 08/28/2008
• Published: 03/05/2009
• Est. Priority Date: 08/30/2007
• Status: Active Grant

• Current Assignee: Hill - Rom Industries SA (Baxter International Inc.)
• Original Assignee: Hill - Rom Industries SA (Baxter International Inc.)
• Inventors: Basilio, Jean-Marie, Coupard, Olivier, Caminade, Jean-Luc
• Granted Patent: US 7,752,926 B2
• Time in Patent Office: Days
• US Class Current: 5/600
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/447 specially adapted for aiding the prevention of ulcer or pressure sore development, i.e. before the ulcer or sore has developed
• CPC Class Codes: A61G 2203/34 for pressure
• CPC Class Codes: A61G 7/05769 with inflatable chambers
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G01L 1/205 using distributed sensing elements

Abstract

The present disclosure relates to a pressure sensor, in particular for detecting and measuring at least one bearing pressure applied to a support device, in which said pressure sensor comprises at least one resistive force-detector cell placed between at least two protective plates suitable for avoiding any pressure bearing at a point or along a line directly against a surface of the resistive cell and for converting such a pressure into uniform pressure over the entire area of the resistive cell. The present disclosure also relates to a support device including such a pressure sensor and to a method of measuring pressures applied to such a support device by an object to be supported such as the body of a patient.

Claims

1. A pressure sensor, in particular for detecting and measuring at least one bearing pressure applied against a support device, wherein said pressure sensor comprises at least one resistive force-detector cell applied against a rigid backing plate, said backing plate being received in a recess formed in a first compressible intermediate layer, which recess has a shape complementary to the outline of said backing plate, said first intermediate layer being placed between at least two rigid or semi-rigid protective plates.

2. The pressure sensor according to claim 1, further comprising at least one second intermediate layer made of a compressible material, and disposed between one of said protective plates and said resistive cell, and in contact with said protective plate and with said resistive cell.

3. The pressure sensor according to claim 1, wherein said protective plates are made of a metal or synthetic rigid material.

4. The pressure sensor according to claim 3, wherein said protective plates are made of a plastics material chosen from PVC, PP, PE, or ABS.

5. The pressure sensor according to claim 1, wherein said protective plates are made of an expanded or cellular synthetic material.

6. The pressure sensor according to claim 1 or 2, wherein said intermediate layer is formed of at least one compressible material suitable for undergoing a reduction in thickness of 40% under a pressure lying in the range 100 N/cm² to 250 N/cm².

7. The pressure sensor according to claim 1 or 2, wherein said intermediate layer is made of a cellular material, and preferably of a polyurethane foam, and is of a thickness lying in the range 3 mm to 30 mm.

8. The pressure sensor according to claim 1 or 2, wherein said intermediate layer comprises a material structured in three dimensions, preferably a material based on woven polyester.

9. The pressure sensor according to claim 1, wherein said rigid backing plate of at least said resistive cell is constituted by a metal plate, in particular based on aluminum.

10. The pressure sensor according to claim 1, wherein said rigid backing plate of at least said resistive cell is constituted by a plate of resin, in particular of epoxy resin.

11. The pressure sensor according to claim 1, wherein, at least, said resistive cell is constituted by a printed circuit on a rigid plate, in particular on a plate of epoxy resin.

12. The sensor according to claim 1, comprising a plurality of said resistive cells.

13. The pressure sensor according to claim 12, further comprising a plurality of said resistive cells placed in an array and uniformly distributed between said protective plates, in a plurality of said recesses in a said intermediate layer, said resistive cells being connected together in series or in parallel.

14. A support device for supporting an element to be supported, in particular the body of a patient, said device comprising at least one upper layer resting on at least one lower layer for supporting said upper layer, said upper and lower layers being, preferably, encased in a preferably removable cover, in which said support device further comprises a pressure sensor, the pressure sensor comprises at least one resistive force-detector cell applied against a rigid backing plate, said backing plate being received in a recess formed in a first compressible intermediate layer, which recess has a shape complementary to the outline of said backing plate, said first intermediate layer being placed between at least two rigid or semi-rigid protective plates, which sensor is placed under said upper layer and/or under said lower layer, and is connected to a control and regulation device for detecting the pressures applied by said element to be supported on said upper layer of the support device and for determining the values of said pressures and optionally the locations thereof.

15. The support device according to claim 14, wherein said upper layer is made up of cells that are inflatable with a fluid, in particular air, and said cells communicate fluidly with one another and with inflation means suitable for being operated by said control device for the purpose of filling or of emptying said inflatable cells of said upper layer of the mattress, as a function of the pressures detected and measured by said sensor on said upper layer.

16. The support device according to claim 15, wherein said lower layer is also made up of cells that are inflatable with a fluid, in particular air, and that communicate with said inflation means connected to and suitable for being operated by said control device for the purpose of filling or emptying said cells of the lower layer, as a function of the pressures detected and measured by said sensor and/or of the inflation pressures of the inflatable cells of the upper layer of the support device.

17. The support device according to claim 15, wherein said upper layer and said lower layer communicate fluidly with each other in a manner such that they are at substantially the same pressure.

18. A method of measuring pressures applied to a support device by an object to be supported, in particular the body of a patient, in which method said pressures applied by the object to be supported on the support device are detected and measured and optionally located by means of a sensor comprising at least one resistive force-detector cell applied against a rigid backing plate, said backing plate being received in a recess formed in a first compressible intermediate layer, which recess has a shape complementary to the outline of said backing plate, said first intermediate layer being placed between at least two rigid or semi-rigid protective plates, said sensor being placed in said support device or under said support device.

19. The method according to claim 18, in which method said support device comprises cells inflatable with a fluid, in particular air, fluidly communicating with one another and with inflation means for inflating said cells, which means are operated by a control device, and in which method said control device is connected electrically to said pressure sensor in such a manner as to inflate or deflate said inflatable cells of the support device, as a function of the pressures detected and measured by said sensor.

20. The method according to claim 18, in which said sensor comprises a plurality of said resistive cells that are uniformly distributed in or under said support device.

21. The method according to claim 20, in which said control device is connected electrically to said resistive cells of said sensor, said resistive cells being connected together in series or in parallel.