Abstract: A positive pressure one way medical valve contains an inlet (10), outlet (11), an internal flow path between the inlet and the outlet and a plunger (12) movable between a retraced sealing position, where backflow is reduced or prevented and an extended open position, where fluid can flow from the inlet to the outlet. The plunger is moved from the retraced to the extended position by insertion of a tip onto the inlet (10). A variable volume chamber (23) is defined partially by an elastomeric member (14) that is stretched, when plunger is in the extended position and reduced, when the plunger is in the retraced position so to increase or decrease the volume of the chamber respectively. A valve (50), which is movable between open and closed positions by the presence or absence of fluid passing through the inlet, immediately seals the flow pathway before the plunger is retraced.

Abstract: A one-way valve assembly can be fitted to the end of a syringe to allow fluid to flow from the syringe and into a body cavity but to prevent backflow. The valve assembly is opened by insertion of the luer tip of the syringe into the assembly inlet. The valve has an internal elastic member that forms a variable volume internal chamber. This chamber expands upon insertion of the luer tip into the inlet and shrinks when the luer tip is removed from the assembly. The shrinking action creates a positive pressure in the valve assembly to prevent backflow.

Abstract: A single use syringe including shoot back, or retraction, mechanism for biasing a needle, retained in needle holder, back into the interior of the syringe body after use. The needle holder is urged, by a spring in the front of the syringe body, to pass through a piercable seal formed in the front fact of the piston. The needle holder comprises an inner part containing the needle, an outer part engaging the interior wall of the syringe, and a frangible portion joining the inner and outer parts. A raised portion, or bump, is formed partially about the outer part of the needle holder, facing the seal in the piston. The raised portion provides an initial contact area with the plunger, to reduce the force required to break the frangible portion and trigger the shoot-back mechanism. The raised portion may consist of an uppermost portion for contact with the plunger, and a shoulder portion adjacent the uppermost portion to reduce dead space.

Abstract: A single use syringe including shoot back, or retraction, mechanism for biasing a needle, retained in needle holder, back into the interior of the syringe body after use. The needle holder is urged, by a spring in the front of the syringe body, to pass through a piercable seal formed in the front fact of the piston. The needle holder comprises an inner part containing the needle, an outer part engaging the interior wall of the syringe, and a frangible portion joining the inner and outer parts. A raised portion, or bump, is formed partially about the outer part of the needle holder, facing the seal in the piston. The raised portion provides an initial contact area with the plunger, to reduce the force required to break the frangible portion and trigger the shoot-back mechanism. The edge portion of the seal is thickened, and is relatively compressible, to reduce the dead space prior to triggering the shoot-back mechanism.

Abstract: A one-way valve assembly can be fitted to the end of a syringe to allow fluid to flow from the syringe and into a body cavity but to prevent backflow. The valve assembly is opened by insertion of the luer tip of the syringe into the assembly inlet. The valve has an internal elastic member that forms a variable volume internal chamber. This chamber expands upon insertion of the luer tip into the inlet and shrinks when the luer tip is removed from the assembly. The shrinking action creates a positive pressure in the valve assembly to prevent backflow.

Abstract: A safety scalpel blade assembly adapted for attachment to a handle (12), the assembly comprising a scalpel blade (10) and guard (11) which extends at least about the cutting edge of the blade (10), the guard (11) having attachment means to lock the blade to the guard as the assembly is being attached to the handle and which releases the blade from the guard when the blade is attached to the blade carrier on the handle. Improvements include a removable safety tab (60) on the guard (11), means (68,71) to prevent the blade guard (11) lifting relative to the handle (12), a safely catch (75) to prevent excessive retraction of the guard (11) and location means (80,82) to locate the guard (11) in the extended and retracted positions.