Valved catheters

Claim 1

A CATHETER COMPRISING A DRAINAGE TUBE HAVING AN INLET AT THE UPPER END FOR RECEIVING BODY FLUIDS AND AN OUTLET AT THE LOWER END FOR DISCHARGING SUCH BODY FLUIDS, SAID DRAINAGE TUBE BEING PROVIDED ALONG AN INTERMEDIATE PORTION OF ITS LENGTH WITH A PARALLEL DUCT FOR INFLATION FLUID, SAID INFLATION-FLUID DUCT BEING ISOLATED FROM COMMUNICATION WITH SAID DRAINAGE TUBE, SAID INFLATION-FLUID DUCT TERMINATING AT ITS UPPER END IN A THIN-WALLED JACKET ADAPTED TO BE EXPANDED BY APPLIED FLUID PRESSURE INTO A GENERALLY ROUND BULB ENCOMPASSING BUT ISOLATED FROM SAID DRAINAGE TUBE, SAID INFLATION-FLUID DUCT TERMINATING AT ITS LOWER END IN A BRANCH TUBE; A VALVE IN THE EXTREME LOWER TERMINAL PORTION OF SAID BRANCH TUBE, SAID VALVE COMPRISING A TUBULAR BODY HAVING A LARGER UPPER BORE AND A SMALLER BORE FORMING THEREBETWEEN AN ANNULAR VALVE SEAT, AND A MOVABLE CLOSURE ELEMENT IN SAID VALVE BODY HAVING A HEAD IN THE UPPER BORE AND A DEPENDENT STEM IN THE LOWER BORE, SAID HEAD HAVING AN ANNULAR UNDERSURFACE FORMING A SHOULDER ADAPTED NORMALLY TO SEAT ON SAID ANNULAR VALVE SEAT TO CLOSE SAID VALVE, SAID STEM EXTENDING SUFFICIENTLY INTO THE LOWER END OF SAID LOWER BORE TO BE ENGAGEABLE AND MOVABLE UPWARD BY THE TIP OF A SYRINGE INSERTED THEREINTO, WHEREBY SAID SHOULDER OF SAID HEAD MAY BE LIFTED OFF SAID SEAT TO OPEN SAID VALVE, THE CROSSSECTIONAL AREA OF SAID HEAD BEING LESS THAN THAT OF SAID UPPER BORE, THE CROSS-SECTIONAL AREA OF SAID STEM BEING SLIGHTLY LESS THAN THAT OF SAID LOWER BORE LEAVING A NARROW ANNULAR SPACE THEREBETWEEN FOR PASSAGE OF INFLATION FLUID, THE LOWER TIP OF SAID STEM HAVING A RADIALLY EXTENDING PASSAGE FOR PROVIDING COMMUNICATION BETWEEN SAID ANNULAR SPACE AND THE PASSAGE IN THE TUBULAR TIP OF A SYRINGE INSERTED INTO SAID LOWER BORE.