Bed latch position detector and method

• US 20020013965A1
• Filed: 02/23/2001
• Published: 02/07/2002
• Est. Priority Date: 02/23/2000
• Status: Active Grant

• Current Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Original Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Inventors: Wilson, Scott K., Brooks, Jack, Calcutta, Richard, York, Fred, Hand, Barry
• Granted Patent: US 6,662,391 B2
• Time in Patent Office: Days
• US Class Current: 5/600
• CPC Class Codes: A61B 6/0487 Motor-assisted positioning
• CPC Class Codes: G01L 1/245 using microbending

Abstract

A bed is provided for supporting a patient thereon. The bed includes a first bed component that is movable relative to a second bed component. The bed further includes a position detector configured to detect the position of the second bed component relative to the first bed component.

Claims

1. A bed comprising

a support surface configured to support a person,

a bedframe configured to support the support surface, the bedframe including a first component and a second component configured to move relative to the first component between first and second position, and

a position detector including a conductor and a sensor, the conductor having a property changeable between first and second states, the second component of the bedframe being positioned to change the property of the conductor from the first state to the second state upon movement of the second component from the first position to the second position, the sensor being coupled to the conductor to detect the state of the property of the conductor to determine the position of the second component relative to the first component.

2. The bed of claim 1, wherein the conductor is a fiber optic cable.

3. The bed of claim 2, wherein the property is the shape of the fiber optic cable.

4. The bed of claim 3, wherein the conductor has a bend that has a first bend radius small enough to create a reflective region in the fiber optic cable when in the second state and the conductor has a second bend radius larger than the first bend radius when in the first state.

5. The bed of claim 2, wherein the sensor includes a time domain reflectometer configured to generate an energy pulse and to detect a portion of the energy pulse received from the fiber optic cable.

6. The bed of claim 5, wherein the sensor further includes a power meter coupled to the conductor to receive a portion of the energy pulse transmitted through the fiber optic cable.

7. The bed of claim 5, wherein the sensor further includes a microprocessor coupled to the time domain reflectometer to generate a component position signal indicative of the position of the second component relative to the first component.

8. The bed of claim 5, wherein the sensor further includes a microprocessor configured to detect a defect in the fiber optic cable by comparing an expected value of the portion of the energy pulse received from the conductor to an actual value based on the portion of the energy pulse received from the conductor.

9. The bed of claim 8, wherein the expected value is a predicted magnitude of the portion of the energy pulse and the actual value is the magnitude of the portion of the energy pulse received from the conductor.

10. The bed of claim 8, wherein the expected value is a predicted time delay of the portion of the energy pulse received from the conductor and the actual value is the actual time delay of the portion of the energy pulse from the conductor.

11. The bed of claim 8, wherein the sensor further includes a power meter coupled to the conductor to generate a power reading, the power meter is coupled to the microprocessor, the expected value is a predicted power reading from the power meter, the actual value is the power reading generated by the power meter, and the microprocessor is configured to generate an error message based on a comparison of the actual and expected values.

12. The bed of claim 1, wherein the conductor is coaxial cable.

13. The bed of claim 12, wherein the property is the impedance of a region of the coaxial cable changed by the movement of the second frame component of the bedframe.

14. The bed of claim 1, wherein the position detector is configured to send a signal into the conductor and the sensor receives the signal from the conductor to determine the position of the second component based on the signal received from the conductor.

15. The bed of claim 14, wherein the signal is electromagnetic.

16. The bed of claim 14, wherein the signal is electric.

17. The bed of claim 14, wherein the signal is pneumatic.

18. The bed of claim 14, wherein the sensor is configured to generate an error message when a defect is detected in the conductor based on the signal received from the conductor.

19. The bed of claim 1, wherein the position detector further includes a contact element positioned between the second component and the conductor to transfer movement of the second component to the conductor.

20. The bed of claim 19, wherein the position detector further includes a conductor bend apparatus configured to cooperate with the contact element to bend the conductor as the second component moves between the first and second positions.

21. The bed of claim 20, wherein the conductor bend apparatus includes a first pulley and a second pulley and the contact element is positioned to move between a deactuated position and an actuated position pushing the conductor between the first and second pulleys to urge the conductor into a bent position.

22. The bed of claim 21, wherein the conductor bend apparatus further includes a spring coupled to the conductor to bias the conductor away from the bent position.

23. The bed of claim 1, wherein the first component of the bedframe is a frame member and the second component is a latch positioned to couple the support surface to the frame member when in the first position and to permit the support surface to be removed from the frame member when in the second position.

24. The bed of claim 23, wherein the bedframe further includes a mover coupled to the frame member, the mover is configured to move the frame member and the support surface, and the position detector is in communication with the mover to disable the mover from moving the frame member and the support surface when the position detector senses that the latch is in the second position.

26. The position detector of claim 25, wherein the conductor is a fiber optic cable.

27. The position detector of claim 26, wherein the property is the shape of the fiber optic cable.

28. The position detector of claim 27, wherein the conductor has a bend that has a first bend radius small enough to create a reflective region in the fiber optic cable when in the second state and the conductor has a second bend radius larger than the first bend radius when in the first state.

29. The position detector of claim 26, wherein the sensor includes a time domain reflectometer coupled to the conductor and configured to transmit an energy pulse into the conductor and to detect a portion of the energy pulse received from the fiber optic cable.

30. The position detector of claim 29, wherein the sensor further includes a power meter coupled to the conductor to receive a portion of the energy pulse transmitted through the fiber optic cable from the time domain reflectometer.

31. The position detector of claim 29, wherein the sensor further includes a microprocessor coupled to the time domain reflectometer to generate a component position signal indicative of the position of the second component of the bedframe based on the portion of the energy pulse received from the conductor.

32. The position detector of claim 31, wherein the microprocessor is configured to detect a defect in the fiber optic cable by comparing an expected value of the portion of the energy pulse received from the conductor to an actual value provided by the time domain reflectometer.

33. The position detector of claim 32, wherein the expected value is a predicted magnitude of the portion of the energy pulse and the actual value is a magnitude of the portion of the energy pulse received from the conductor.

34. The position detector of claim 32, wherein the expected value is a predicted time delay of the portion of the energy pulse received from the conductor and the actual value is an actual time delay between the transmitting of the energy pulse and the receipt of the portion of the energy pulse.

35. The position detector of claim 31, wherein the sensor further includes a power meter coupled to the microprocessor and the microprocessor is configured to generate an error message based on a comparison of a predicted power reading from the power meter and an actual power reading generated by the power meter.

36. The position detector of claim 25, wherein the conductor is coaxial cable.

37. The position detector of claim 36, wherein the property is the impedance of a region of the coaxial cable changed by the movement of the second component of the bedframe.

38. The position detector of claim 25, wherein the position detector is configured to send a signal into the conductor and the sensor receives the signal from the conductor to determine the position of the second component based on the signal received from the conductor.

39. The position detector of claim 38, wherein the signal is electromagnetic.

40. The position detector of claim 38, wherein the signal is electric.

41. The position detector of claim 38, wherein the signal is pneumatic.

42. The position detector of claim 38, wherein the sensor is configured to generate an error message when a defect is detected in the conductor based on the signal received from the conductor.

43. The position detector of claim 25, wherein the position detector further includes a contact element positioned between the second component and the conductor to transfer movement of the second component to the conductor.

44. The position detector of claim 43, wherein the position detector further includes a conductor bend apparatus configured to cooperate with the contact element to bend the conductor as the second component moves between the first and second positions.

45. The position detector of claim 44, wherein the conductor bend apparatus includes a first pulley and a second pulley, the contact element is positioned to move between a deactuated position and an actuated position pushing the conductor between the first and second pulleys to urge the conductor into a bent position.

46. The position detector of claim 45, wherein the conductor bend apparatus further includes a spring coupled to the conductor to bias the conductor away from the bent position.

48. The position detector of claim 47, further comprising a board defining the support surface, the multiple components are latches positioned to move between the first position latching the board to the frame member and the second position permitting the board to be removed from the frame member.

49. The position detector of claim 48, wherein the bedframe further includes a mover coupled to the frame member and configured to move the frame member and the board and the sensor is coupled to the mover to disable movement of the mover if any of the latches are in the second position.

25. A position detector for use with a bed including first and second components, the second component being movable between first and second positions relative to the first component, the position detector comprising

a conductor having a property changeable between a first state and a second state upon movement of the second frame component of the bed from the first position to the second position and

a sensor coupled to the conductor to detect the change in state of the property of the conductor to determine the position of the second component of the bed based on the detected change in state of the property of the conductor.

47. A bed comprising

a support surface configured to support a person,

a bedframe configured to support the support surface, the bedframe including a frame member and multiple components configured to move relative to the frame member between first and second positions, and

a position detector including a conductor and a sensor, each of the multiple components being positioned to communicate a change in position of said component to the conductor, the sensor being coupled to the conductor to detect the change in position of each of the multiple components to determine the positions of the components.

50. A method of detecting the position of a first bed component relative to a second bed component, the first bed component being movable between first and second positions relative to the second bed component, the method comprising the steps of

providing a conductor positioned to be acted upon by the first bed component,

moving the first bed component from the first position to the second position,

changing a property of the conductor from a first state to a second state during movement of the first bed component from the first position to the second position,

detecting the state of the property of the conductor, and

correlating the state of the property of the conductor with the position of the first bed component to determine the position of the first bed component.

51. The method of claim 50, wherein the detecting step includes the steps of transmitting an energy pulse into the conductor, receiving a reflected portion of the energy pulse, and analyzing the reflected portion to determine the state of the property.

52. The method of claim 51, wherein the analyzing step includes measuring the magnitude of the reflected portion and comparing the measurement to a predetermined magnitude.

53. The method of claim 51, wherein the analyzing step includes measuring a time delay between transmitting the energy pulse and receiving the reflected portion of the energy pulse and comparing the measured time delay with a predetermined time delay to determine the state of the property of the conductor.

54. The method of claim 53, wherein the energy pulse in electromagnetic.

55. The method of claim 53, wherein the energy pulse is pneumatic.

56. The method of claim 53, wherein the energy pulse is electric.

57. The method of claim 50, wherein the conductor is bent during the changing step.

58. The method of claim 57, further comprising the step of straightening the conductor during movement of the first bed component from the second position to the first position.

59. The method of claim 50, further comprising the step of testing the integrity of the conductor.

60. The method of claim 59, wherein the testing step includes transmitting an energy pulse into a first end of the conductor, measuring the energy pulse at a second end of the conductor, and comparing the measurement to a predetermined value.

61. A method of detecting the position of multiple bed components movable between first and second positions relative to a bedframe, the method comprising the steps of

providing a conductor having a region associated with each of the multiple bed components, each region of the conductor being positioned to be manipulated by one of the multiple bed components,

moving at least one of the multiple bed components from the first position to the second position,

changing a property of the region of the conductor associated with at least one of the multiple bed components moved to the second position,

detecting the state of the property of each region of the conductor, and

correlating the state of the property of each region of the conductor with the position of each associated bed component to determine the position of each associated bed component.

62. The method of claim 61, wherein the changing step includes bending the conductor during movement of at least one of the multiple bed components from the first position to the second position.

63. The method of claim 62, further comprising the step of moving at least one multiple bed components back to the first position and removing the bend in the conductor during movement of at least one multiple bed components back to the first position.

64. The method of claim 61, further comprising the steps of moving at least one multiple bed components from the second position to the first position, changing the property of the region of the conductor associated with at least one multiple bed components moved back to the first position, detecting the state of the property of each region of the conductor, and correlating the state of the property of each region of the conductor with the position of each bed component to determine the position of each bed component.

65. The method of claim 61, wherein the detecting step includes the steps of transmitting an energy pulse into the conductor, receiving portions of the energy pulse, and measuring the time delay between transmitting the energy pulse and receiving the portions of the energy pulse.

66. The method of claim 65, wherein the correlating step includes associating each measured time delay to a corresponding region of the conductor and determining the position of each bed component based on the time delays measured for each portion of the energy pulse received.

67. The method of claim 61, wherein the detecting step includes the steps of transmitting an energy pulse into the conductor, receiving portions of the energy pulse, and measuring the magnitude of each portion of the energy pulse received.

68. The method of claim 61, further comprising the step of determining whether a failure exists in the conductor.

69. The method of claim 68, wherein the determining step includes transmitting an energy pulse into the conductor, receiving a portion of the energy pulse, and determining if the received portion of the energy pulse is not associated with one of the multiple bed components.

70. The method of claim 68, wherein the determining step includes transmitting an energy pulse into the conductor, receiving a portion of the energy pulse, detecting the magnitude of the portion of the energy pulse, and comparing the detected magnitude with a predetermined value.