Abstract: A method is provided for reconditioning a medication infusion pump by removal of accumulated medication deposits and the like to restore pump performance without requiring surgical removal of an implanted pump from a patient. The reconditioning process comprises sequential delivery of a buffer solution and a rinse solution to internal pump flow passages. The rinse solution is effective to dissolve medication deposits and the like within narrow pump flow passages before the rinse solution is neutralized by intermixing with the buffer solution. Dissolution of accumulated medication deposits results in restoration of pump performance substantially to original product specifications.

Abstract: A device for use as a subcutaneous injection set is disclosed which has a soft cannula through which a selected medication can be administered to a patient, wherein the soft cannula is adapted for transcutaneous placement by an insertion needle substantially without crimping or kinking. The cannula is supported by and protrudes outwardly from a housing adapted to receive the selected medication. The insertion needle is initially inserted through a septum on the housing and further through the cannula to provide a rigid structure to insert the soft cannula through the patient's skin. The insertion needle and cannula are constructed to prevent longitudinal slippage of the cannula on the needle during the insertion process, thereby preventing undesired crimping or kinking of the soft cannula. After insertion, the needle is withdrawn from the cannula and housing to permit medication delivery to the patient.

Abstract: A kit is provided for use in refilling a medication infusion pump of the type adapted for implantation into the body of a patient. The kit comprises a syringe having a plunger mounted for reciprocation within a syringe barrel having a manually operable control valve mounted at a nose end thereof. The syringe further includes a lock for retaining the plunger subsequent to retraction motion with the control valve closed to pull and maintain a vacuum within the syringe barrel. With this construction, the syringe can be connected transcutaneously with a medication reservoir within an implanted infusion pump to aspirate residual medication from the pump. Alternately, the syringe can be used to degas medication within the barrel preparatory to transcutaneous delivery to the pump reservoir. In either case, the syringe is designed for facilitated and safe manipulation to permit rapid pump aspiration and refill at periodic intervals according to patient requirements.

Abstract: An improved process and related apparatus are provided for filling a pressure reservoir of an implantable medication infusion pump with a selected pressure fluid, wherein the pressure reservoir is separated by a movable wall from an adjacent medication chamber. The improved filling process includes vacuum-draw filling of the pressure reservoir with relatively purified pressure fluid in liquid state. The specific quantity of pressure fluid within the pressure reservoir is thereafter calibrated by filling the adjacent medication chamber with a calibration fluid at a predetermined positive pressure, thereby expelling excess pressure fluid from the pressure reservoir. The pressure reservoir is then sealed and the performance characteristics thereof are tested under simulated implantation conditions to confirm the capability of the pressure reservoir to maintain medication within the medication chamber under substantially constant pressure conditions.

Abstract: An implantable medication infusion pump is provided which utilizes an improved and simplified pressure reservoir to maintain a selected medication in liquid form within a pump housing under a substantially constant pressure. The pressure reservoir comprises a hollow structural enclosure having at least one flexible resilient wall and is adapted to be filled with a selected quantity of a pressure fluid, such as a selected fluorocarbon in a liquid-vapor state, prior to mounting of the reservoir as a structural unit into the infusion pump housing. Within the pump housing, the flexible reservoir wall defines one side of a medication chamber, with the pressure fluid undergoing appropriate change of state to expand or contract the reservoir in a manner maintaining the medication under a substantially constant pressure.

Abstract: An improved subcutaneous injection set is disclosed which has a soft cannula for subcataneous delivery of a selected medication to a patient. The cannula is supported by and protrudes outwardly from a cylindrical support hub of a housing adapted to receive the selected medication. A flanged base end of the cannula is disposed within the housing and is captured by a swaged lock rim to retain a sealing gasket under compression against an annular seat within the support hub, thereby preventing leakage of the medication through the hub and about the exterior of the cannula.

Abstract: A pressure diaphragm installed in a disposable cassette for use on a main pump unit is disclosed which allows pressure downstream of a fluid pump to be measured with a high degree of accuracy. The pressure diaphragm is located over a raised cylindrical pressure plateau, and is spaced away from the plateau on the top and on the sides thereof to allow for a free movement of the pressure diaphragm. Fluid flow is from one side of the pressure plateau to the opposite side, with fluid flowing between the pressure diaphragm and the top and sides of the pressure plateau, as well as through a channel disposed in the pressure plateau.