GB1327332A - Surgical specula - Google Patents

Abstract

1327332 Specula WELCH ALLYN INC 28 May 1971 [21 Dec 1970] 17991/71 Heading A5R A surgical speculum 10 comprises a pair of transparent blades 11, 13, the first blade 13 being pivotally mounted for movement towards and from the second blade 11, a depending post 15 extending laterally from the second blade, a longitudinally curved elongate light guide 17 of substantially uniform cross-section extending within the second blade from the junction of the post with the second blade to a position in which the guide lies substantially parallel with the longitudinal axis of the second blade, the curvature of -the guide being such that in operation light rays entering the guide at the junction thereafter only exceed the critical angle for total internal reflection at the distal-end surface of the guide. After insertion of the speculum into a body cavity, the physician moves the slide 12 along the post 15 by pushing against the finger-piece end 25' of the pawl 25 to separate the proximal ends of the blades. Catch 27 is engaged with one of the ratchet teeth 28 and the catch is held in position by the resiliency of the bridging portion 26, latching the slide in relation to the fixed blade 11. Lever 35 is depressed via fingerpiece 41 thereby rotating the movable blade 13 on its pivot pins 34 and hence changing the angular relationship of the blades 11, 13. The tongue 30 is biased by its resiliency against latch 40 so that the ratchet teeth 32 are successively engaged by the catch as the distal ends of the blades open. Pressure on the finger-piece 41 can be relaxed when sufficient distention is accomplished and the blades remain latched in their angular position. The light required for illumination of the body cavity upon observation is provided by a light carrier 45 which fits into a socket of the light-source handle 50. The light carrier includes a bundle of glass fibres (52), Figs 10, 11 (not shown) for transmitting light from the source at the end 46 to the end (53) adjacent to the face 18 of an optical surface of the light guide 17. The light is further transmitted via the light guide to an optical surface 19 which is also provided in the fixed blade 11.