Showing papers by "Henry Buchwald published in 1987"

Spring driven infusion pump

Abstract: An implantable infusion pump (20) for infusing drugs or other chemicals or solutions into the body. A flexible spring diaphragm (25) forms an outer back wall portion (26) of a housing (22) of the infusion pump (20). The spring diaphragm (25) applies substantially constant force over a range of displacement and communicating internal body pressure to the drug chamber (30) so as to maintain a substantially uniform pressure difference between the drug chamber (30) and the internal body pressure.

Pressure regulated implantable infusion pump

Abstract: An implantable infusion pump (20) for infusing drugs or other chemical or solutions into the body. A movable diaphragm (26) forming a variable volume drug chamber (22). A fluid piston (32) opposing the force exerted by the diaphragm (26) on the drug solution in the drug chamber (22). The pressure of the fluid piston (32) being controlled by a regulator (33) providing a reference pressure and in fluid communication with the fluid piston (32). The regulator (33) reducing the fluid pressure of the piston fluid (32) as drug solution is expelled from the drug chamber (22) so as to maintain a constant pressure differential between the drug chamber (22) and an infusion site in the body. The implantable infusion pump (20) being readily adaptable to variable or electronic flow control.

A rabbit model for implanting continuous drug infusion pumps.

Abstract: This paper describes a surgical technique for implanting a readily available, human-sized drug infusion pump in rabbits. We developed this technique in order to expand uses of implantable infusion pump technology in the laboratory. The dog, which has been the research animal of choice in previous studies using implantable pumps, can now be replaced by smaller, less expensive animals for similar or other laboratory purposes. This technique can be of particular importance in the study of atherosclerosis where the dog is a poor model and the rabbit an excellent one. In 18 rabbits with inferior vena cava cannulations, we were able to obtain 100% survival and constant solution delivery for up to and greater than 6 months. This technique is safe and reproducible. By employing a simple catheter modification and using special pump anchoring precautions, we found that we could successfully use a human-sized device in rabbit studies. Commentary is also made concerning the relative contributions to patency and vein sclerosis of catheter diameter and the infusate media.