Semi-automated closed-circuit bladder wash-out pump.

write: A pump has been constructed as a possible solution to a problem posed by one of us (D.W.)-namely, to produce a device which would wash out the bladder after prostatectomy vwithout breaking the closed drainage system (which could result ia an infection) and which could be used by relatively unskilled staff. The pump with its associated valves is composed of only two parts-a piston and a cylinder (figs. 1 and 2). The piston has two functions, which are divided between its upper and lower halves. The lower half of the piston is grooved and the relation between this groove and the ports in the cylinder wall determines the source and destination of fluids entering and leaving the cylinder. A peg in the cylinder wall engages in another set of grooves cut in the upper half of the piston. This engagement allows only certain movements of the piston relative to the cylinder , so that the order of pumping movements and direction of fluid movement in and out of the cylinder are predetermined. The top of the piston is in the form of a combined handle and pointer to indicate the function of the pump in that particular position. 0 W FIG. 2-Right: Groove in piston is shown opposite two ports in cylinder. Left: Diagram of "gate" cut in upper half of piston which is engaged by peg in wail of cylinder, thus limiting its movement.