Hospital bed obstacle detection device and method

1. A patient support apparatus comprising:

a first component;

a second component configured to move relative to said first component along a path of travel;

a detection unit comprising;

a single emitter supported by one of said first and second components and

a plurality of detectors supported by the other of said first and second components, said detectors configured to provide a control signal in response to an obstacle within said path of travel between the emitter and any one of the plurality of detectors; and

a control unit in communication with said detector; and

a lifting device configured to move said second component vertically relative to said first component and wherein said control unit deactivates said lifting device if any one of said plurality of detectors fails to detect a signal emitted by said single emitter.

2. The patient support apparatus of claim 1 , wherein said emitter generates an obstacle detection signal.

3. The patient support apparatus of claim 2 , wherein said obstacle detection signal includes a pulsed portion having a predefined frequency, and said detector is configured to detect said predefined frequency.

4. The patient support apparatus of claim 3 , wherein said predefined frequency is approximately 57 kHz.

5. The patient support apparatus of claim 3 , wherein said pulsed portion has a duration of approximately 600 microseconds followed by a delay of approximately 2 milliseconds.

6. The patient support apparatus of claim 2 wherein the obstacle detection signal is a wireless signal.

7. The patient support apparatus of claim 6 wherein the wireless signal is an electromagnetic curtain.

8. The patient support apparatus of claim 1 , wherein said emitter comprises an infrared source.

9. The patient support apparatus of claim 1 , further comprising an indicator configured to indicate failure of any one of said plurality of detectors to detect an obstacle detection signal emitted by said single emitter.

10. A method of preventing movement of a movable component of a bed upon detection of an obstacle within a path of travel of the component, said method comprising the steps of:

providing the bed having the movable component;

providing a detection unit comprising a single emitter and a plurality of detectors;

causing the emitter to emit an obstruction detection signal for detecting an obstacle within the path of travel between the emitter and any one of the detectors;

moving said component;

generating a stop signal if at least one of said detectors fails to detect said obstacle detection signal; and

preventing movement of said movable component in response to said stop signal wherein said movable component includes an elevating frame movable vertically relative to a base frame, and the moving step includes moving said elevating frame vertically relative to said base frame.

11. The method of claim 10 , wherein said step of generating a signal comprises the steps of providing a light source and emitting infrared light from said light source.

12. The method of claim 10 wherein the obstruction detection signal is a wireless signal.

13. The method of claim 10 wherein the obstruction detection signal is an infrared signal.

14. The method of claim 10 wherein the obstruction detection signal forms a curtain.

15. A patient support apparatus comprising:

a base frame;

an elevating frame configured to move relative to said base frame along a path of travel above said base frame;

a detection unit comprising:

a single emitter supported by one of said frames and

a plurality of detectors supported by the other of said frames, said detectors configured to provide a control signal in response to an obstacle within said path of travel between the emitter and any one of the plurality of detectors; and

a control unit in communication with said detector and configured to prevent relative movement of the frames in response to said control signal.

16. The patient support apparatus of claim 15 wherein the emitter is supported by the base frame and the detectors are supported by the elevating frame.

17. The patient support apparatus of claim 15 , wherein the prevented movement is movement of the elevating frame toward the base frame.

18. The patient support apparatus of claim 17 wherein the prevented movement is lowering of the elevating frame relative to the base frame.

19. A patient support apparatus, comprising:

first and second sides extending substantially parallel to each other;

third and fourth sides extending substantially parallel to each other and substantially perpendicular to the first and second sides, the first and second sides cooperating with the third and fourth sides to define corners,

first and second detection units associated respectively with the first and second sides, the first detection unit oriented to emit an obstacle detection signal away from the third side and toward the fourth side, the second detection unit oriented to emit a signal away from the fourth side and toward the third side.

20. The bed of claim 19 , comprising a third detection unit associated with the third side and an optional fourth detection unit associated with the fourth side, the first, second and third detection units and the fourth detection unit, if present, each comprising an emitter proximate one corner and a detector proximate another corner, the emitter of the third detection unit and the emitter of the fourth detection unit, if present, being oriented to not emit a signal toward a detector of the first or second detection unit.

21. The bed of claim 19 wherein the first side is a left side, the second side is a right side, the third side is a foot side and the fourth side is a head side.

22. The patient support apparatus of claim 19 wherein each of the detection units comprises a single emitter and a plurality of detectors.

23. The patient support apparatus of claim 20 wherein each of the detection units comprises a single emitter and a plurality of detectors.