Light directing control system, particularly for medical operating and diagnostic use

Light directing control and positioning system comprising

• a hollow light guide (4) having an opaque, flexible tube (40) and a light transmitting liquid (41) within said tube;
• light generating means (2, 3) positioned at one end of the tube in light transmitting relation to the liquid therein;
• a light emitting terminal (12) located at the end of the tube;
• a positioning system (20, 21) having a positionable element capable of movement between terminal positions;
• controllable fluid pressure generating means (19, 20) in fluid communication with the light transmitting fluid (41) in said tube (40);
• and pressure-mechanical movement sensing and transducing means (18, 18', 18a) in fluid communication with the light transmitting fluid in the tube and mechanically linked to the element to be positioned, and transducing changes in pressure of the light transmitting fluid, as commanded by the controllable fluid pressure generating means into mechanical movement to position the element in dependence on the pressure being applied to said light transmitting liquid.