Patent ID: 8866610

Claim:
A patient support apparatus comprising a base frame including an elongated base frame member having an upper surface, an elevating frame disposed in spaced relation to said base frame, a lifting device configured to move said elevating frame relative to said base frame, an emitter arranged to emit a light beam that is located above the upper surface of the base frame member and that is generally parallel with the upper surface of the base frame member, a receiver arranged to receive the light beam emitted from the emitter, wherein the lifting device is disabled if an obstacle blocks the light beam emitted by the emitter from being received by the receiver, and a second base frame member having a second upper surface, a second emitter arranged to emit a second light beam that is located above the second upper surface of the second base frame member and that is generally parallel with the second upper surface of the second base frame member, and a second receiver arranged to receive the light beam emitted from the second emitter, wherein the lifting device is disabled if an obstacle blocks the second light beam emitted by the second emitter from being received by the second receiver, wherein the second base frame member is parallel with and spaced from the first base frame member, wherein the first base frame member and the second base frame member each have first and second ends, the first emitter being coupled to the first end of the first base frame member and the second emitter being coupled to the second end of the second base frame member such that light is emitted in opposite directions from the first and second emitters.