Abstract: An accumulator for an implantable infusion system employs a pair of separated diaphragms movable in unison by a transfer fluid disposed therebetween. A first chamber receives infusate in metered amounts and dispenses the contents as a function of toggled valve operation. During filling, the first diaphragm deflects upward and by pressure transfer causes a corresponding deflection in the second diaphragm. The second diaphragm is biased by springs, gas under pressure or the like. Hence, when the outlet valve opens, the pressure differential across the diaphragm causes downward deflection. No mechanical stops are needed in the infusate chamber for the first diaphragm since its movement is controlled by the pressure differential across the second diaphragm.

Abstract: A fluid metering device useful in implantable drug delivery systems is coupled between a pressurized fluid source and an outlet conduit to provide discrete flow pulses at a predetermined rate. The metering device consists of a first movable member constrained within a housing and a second movable member retained in a cavity by the first. Alternate positioning of the first member simultaneously fills and empties the cavity in which the second resides, discharging fluid through the conduit. The first movable member can be a planar slider, an axially translatable cylinder or a rotatable cylinder. The second movable member may be a flat shuttle, a sliding bar or a diaphragm.

Abstract: An implantable infusion reservoir having a resilient foam member in a rigid housing to urge fluid to an implantation site. The foam member compresses upon charging and then expands to maintain a predetermined pressure characteristic within the fluid. The foam replaces the previously used two-phase propellent and eliminates the need for a hermetic metal bellows. The foam may be either closed celled or open celled, with or without a barrier skin. The device can be conformal to any desired shape and employ various metering techniques to deliver accurate quantities of fluid.

Abstract: An implantable pump system employing a flow regulator isolates the regulator sensing chamber from the path of drug flow. This is accomplished by establishing either an independent sensing chamber in the regulator or coupling it to the propellant chamber of the pump. Additionally, a downstream restrictor may be used to provide an additional pressure drop between the regulator and the outlet catheter.

Abstract: An implantable pump system employing a flow regulator isolates the regulator sensing chamber from the path of drug flow. This is accomplished by establishing either an independent sensing chamber in the regulator or coupling it to the propellant chamber of the pump. Additionally, a downstream restrictor may be used to provide an additional pressure drop between the regulator and the outlet catheter.

Abstract: A drug delivery system for implantation into a living body having a pressure actuated infusion pump and an adjustable flow regulator. The regulator comprises a body having a regulator cavity divided by a diaphragm into two chambers. One chamber serves as a pressure sensor and the other as a conduit through which fluid flows. The outlet from the conduit chamber can be sealed by diaphragm movement as a function of pressure increase or the flow restricted. The outlet itself is mounted on an adjustable fitting that is movable relative to the diaphragm. The distance between the outlet and the diaphragm may be set as a calibration of the regulator.

Abstract: An implantable valve accumulator pump for the delivery of medication is disclosed. The implantable pump comprises a drug reservoir maintained at constant pressure vapor. The medication metering assembly comprises a fixed volume accumulator positioned between a pair of valves. The valves alternately open and close to admit medication from the reservoir into the accumulator and to dispense a precise volume spike to an outlet catheter. In order to minimize dead volume and insure complete discharge, the accumulator employs a titanium diaphragm seated in one position by a recessed stop and in the discharge position by a spacer plate having a concentric groove pattern. The grooves are in fluid communication with the inlet and outlet. Also, a wide groove extending between inlet and outlet provides fluid communication between the grooves. The unit is externally programmed.

Abstract: An implantable device uses shape memory alloy (SMA) as the driver to compress a reservoir thereby providing a constant pressure source fluid delivery device. The SMA may form either the reservoir itself by appropriate shaped sheets or it may form bands around a flexible reservoir member. The reservoir may also be formed of rigid members pivoted or clamped using SMA actuators to bias the rigid members together.