Patient movement detection system for a bed including a load cell mounting assembly

• US 6,822,571 B2
• Filed: 09/24/2002
• Issued: 11/23/2004
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Conway, Kevin P.
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): LAI, ANNE VIET NGA
• Application Number:
  US10/253,692
• Publication Number:
  US 20030090383A1
• Time in Patent Office: 791 Days
• Field of Search: 340/573.1, 340/573.4, 340/665, 177/144, 560/0, 561/1, 561/6, 562/0, 5 8/11.R, 5 8/31, 5 8/61
• US Class Current: 340/573.1
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/1115 Monitoring leaving of a patient support, e.g. a bed or a wheelchair
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/6891 Furniture
• CPC Class Codes: A61G 7/005 tiltable around transverse horizontal axis, e.g. for Trendelenburg position rocking beds for physical therapy A61H1/003; hanging patient inclined downwardly for drawing him out A61H2203/0493
• CPC Class Codes: G01G 19/445 in a horizontal position
• CPC Class Codes: G08B 21/0446 worn on the body to detect changes of posture, e.g. a fall, inclination, acceleration, gait
• CPC Class Codes: G08B 21/0461 integrated or attached to an item closely associated with the person but not worn by the person, e.g. chair, walking stick, bed sensor

Abstract

A load cell mounting assembly for a bed. The bed includes a base unit. Two pairs of lift arms are pivotally attached to the base unit. Extending between each pair of lift arms is a torque bar. A frame is secured to the torque bars by a plurality of torque bar mounting brackets. Coupled to each torque bar are a number of load cells. The load cells are electrically connected to a control unit that is configured to receive signals from the load cells and to determine patient information from the load cell signals. When the bed is in its lowest position, the load cells engage the floor and the bed is supported only by the load cells.

Claims

1. In a bed having a base unit, two pairs of lift arms pivotally attached to said base unit, a torque bar extending between each pair of lift arms, a frame secured to the torque bars and a traveling nut mechanism connected to each of the torque bars and configured to move the bed between upper and lower elevational positions, the improvement comprising a plurality of load cells attached to said frame, each said load cell including an indentation sized to receive said respective torque bar, said plurality of load cells being electrically connected to a control unit that is configured to receive signals from said plurality of load cells and to determine patient information, said plurality of load cells being configured so that the bed is supported only by said plurality of load cells when the bed is in the lower position.

2. The apparatus of claim 1, wherein each load cell includes a T-shaped member slidably received in a sleeve.

3. The apparatus of claim 1, wherein said patient information includes a center of gravity for a patient on the bed.

4. The apparatus of claim 3, wherein said bed is divided into plural zones and said patient information includes which of the zones corresponds to the center of gravity of a patient.

5. The apparatus of claim 1, wherein said load cells are positioned at first and second ends of said frame and each of the load cells at the first end of said frame are secured to a different element of said frame than each of the load cells at the second end of said frame.

6. The apparatus of claim 1, wherein said torque bar is oriented transverse to the length of said bed.

8. The apparatus of claim 2, wherein said patient information is determined based on relative movement between each said T-shaped member and each said respective sleeve.

7. In a bed having a base unit, two pairs of lift arms pivotally attached to said base unit, a torque bar extending between each pair of lift arms, torque bar brackets securing each of the torque bars to a frame, and a traveling nut mechanism connected to each of the torque bars and configured to move the bed between upper and lower elevational positions, the improvement comprising a plurality of load cells attached to said frame, said plurality of load cells being electrically connected to a control unit that is configured to receive signals from said plurality of load cells and to determine patient information, said plurality of load cells being configured so that the bed is supported only by said plurality of load cells when the bed is in the lower position;

wherein each load cell is aligned with and attached to a respective torque bar bracket.

9. The apparatus of claim 7, wherein said torque bar is oriented transverse to the length of said bed.

10. In a bed having a base unit, two pairs of lift arms pivotally attached to said base unit, a torque bar extending between each pair of lift arms, a frame secured to the torque bars and a traveling nut mechanism connected to each of the torque bars and configured to move the bed between upper and lower elevational positions, the improvement comprising a plurality of load cells retrofittingly attached to said frame, each said load cell includes an indentation sized to receive said respective torque bar, said plurality of load cells being electrically connected to a control unit that is configured to receive signals from said plurality of load cells and to determine patient information, said plurality of load cells being configured so that the bed is supported only by said plurality of load cells when the bed is in the lower position.

11. The apparatus of claim 10, wherein each load cell includes a T-shaped member slidably received in a sleeve.

12. The apparatus of claim 11, wherein said patient information is determined based on relative movement between each said T-shaped member and each said respective sleeve.

13. The apparatus of claim 10, wherein said patient information includes a center of gravity for a patient on the bed.

14. The apparatus of claim 13, wherein said bed is divided into plural zones and said patient information includes which of the zones corresponds to the center of gravity of a patient.

15. In a bed having a base unit, two pairs of lift arms pivotally attached to said base unit, a torque bar extending between each pair of lift arms, torque bar brackets securing each of the torque bars to a frame, and a traveling nut mechanism connected to each of the torque bars and configured to move the bed between upper and lower elevational positions, the improvement comprising a plurality of load cells retrofittingly attached to said frame, said plurality of load cells being electrically connected to a control unit that is configured to receive signals from said plurality of load cells and to determine patient information, said plurality of load cells being configured so that the bed is supported only by said plurality of load cells when the bed is in the lower position;

wherein each load cell is aligned with and attached to a respective torque bar bracket.