Abstract: An infusion system in which therapeutic substance from a reservoir is pumped by a bolus pump to an infusion port is disclosed. The therapeutic substance delivered by the bolus pump passes first through a passive check valve located downstream from the pump. The passive check valve opens in response to fluid pressure of the therapeutic substance. After passing through the passive check valve, the therapeutic substance passes through an active check valve located downstream from the passive check if the active check valve is actuated such that it is open. When not activated, the active check valve is closed and fluid flow through the active check valve in the downstream direction is prevented.

Abstract: Implantable drug infusion devices, systems and methods for delivering therapeutic substance to a subject that include a bulkhead and an attached reservoir formed by an elastic bladder are disclosed. When filled with therapeutic substance, the elastic bladder is elastically expanded such that the therapeutic substance is held at a pressure above ambient pressure. As the therapeutic substance is removed from the reservoir, the bladder collapses and may conform to the shape of the bulkhead surface over which it is located.

Abstract: A medical device and displacement-based over-pressurization mechanism (OPM) for use with the same. The OPM may be positioned in or along a refill passageway of the device. It may include a valve plunger having a portion in biased, abutting contact with a reservoir surface that moves as the reservoir volume changes. The reservoir surface may move between a full position and a refill position. The OPM is preferably configured to close and occlude the refill passageway when the reservoir and reservoir surface reach the full position, e.g., before reaching an overfill position. A sensor may also be provided to detect a position of the valve plunger.

Abstract: A conical depression for guiding a hypodermic needle into a desired location and having a hole at the center for limiting the maximum needle diameter that can be used to access that location. The diameter of the hole prevents access by needles having a diameter greater than the diameter of the hole. The conical depression has a smooth surface and an angle such that needles that are inserted into the conical depression misaligned with the hole will be guided to the hole without damaging the tip of the hypodermic needle.