Abstract: A surgically implantable flow control device positionable over a burr-hole through a patient's skull is provided for use in shunt systems for controlling the release of entrapped body fluids. The device includes a rigid base including an inlet port and a valve seat which surrounds the inlet port, and a flow control member secured to the base. The flow control member has an asymmetric membrane which is resiliently biased to contact the valve seat in a manner forming a releasible seal therebetween, to provide controlled resistance to proximal-to-distal fluid flow through the device. The membrane includes a septum portion overlying the inlet port and a relatively thin portion responsive to fluid pressure differentials on inlet and outlet sides thereof. A membrane shield overlies an outlet side of the membrane and includes a needle guide aperture in alignment with the septum portion of the membrane and the inlet port.

Abstract: A subcutaneously implantable and percutaneously adjustable fluid flow control device includes a magnetically adjustable valve for controlling fluid flow from an inlet to an outlet. The valve includes a housing having a fluid passageway therethrough, a valve element designed to bear upon a valve seat to close the passageway to fluid flow, and a spring which biases the valve element against the valve seat so as to keep the passageway closed until a fluid pressure differential between the inlet and the outlet exceeds a selected valve opening pressure. A fixed dual concentric stair-step array and an overlying rotor assembly permit the amount of bias applied to the valve element by the spring to be adjusted. The rotor assembly is adapted to rotate in response to an external or percutaneously-applied magnetic field. In one embodiment, the rotor assembly may be locked into one of several possible rotational positions relative to the stair-step array to prevent rotation thereof.

Abstract: In a cerebrospinal fluid shunt including a flow control device forming a portion of a fluid conduit, a capacitive element is provided for reducing overdrainage of cerebrospinal fluid due to the pulsatile nature of cerebrospinal fluid flow. The capacitive element includes a reservoir having a base and a housing for the base which cooperatively define a fluid flow pathway through the reservoir. A pair of spaced, substantially parallel, flexible diaphragms form opposite sides of the housing such that each flexible diaphragm has an outer surface which forms an exterior surface of the reservoir, and an inner surface in contact with and subject to pressure variations of cerebrospinal fluid within the reservoir. A raised ring surrounds each diaphragm and forms a recess in which the respective diaphragm is positioned. The capacitive element accommodates the pulsatile nature of cerebrospinal fluid flow between a cerebrospinal fluid source and the flow control valve by varying the fluid capacity of the reservoir.

Abstract: An implantable shunt device useful in treating glaucoma includes an episcleral plate and a catheter having a first end adapted for insertion into the anterior chamber of the eye, and a second end mounted adjacent to the episcleral plate. A slit valve is provided in a wall of the catheter between the first end and the second end, and the opposing, generally planar surfaces of the episcleral plate are textured to interrupt the formation of a dense fibrous capsule and to promote vascularization around the episcleral plate. In order to restrict the flow of fluid through the catheter to the episcleral plate until a fibrous capsule forms around the episcleral plate, the catheter is temporarily occluded utilizing a biodegradable ligation tied between the slit valve and the second end of the catheter. In the immediate post-operative period, excess aqueous humor is forced to flow through the slit valve, which provides a significant pressure drop.

Abstract: An implantable fluid flow control device is assembled in a process wherein a first base is provided having a snap-fit barbed connector which defines a fluid passageway and a spline offset from the barbed connector, and a second base having a connector receptacle which defines another passageway and a spline receiving slot. The barbed connector is inserted into the receptacle, and simultaneously the spline is slidably received within the spline receiving slot in a manner preventing tensile and torsional movement between the bases. The coupled bases are placed in a holding fixture, and brought into close proximity with a heated element to fuse the first and second bases together. A pair of housing bodies are placed over, respectively, the first and second bases such that the bases and the housing bodies cooperatively define a fluid flow path through the flow control device.

Abstract: A flow control device for use in a subcutaneously implanted physiological shunt system includes a relatively rigid base and a resiliently flexible encasement which defines a fluid flow path therethrough from an inlet to an outlet. Two valves for controlling the flow of fluid through the device are situated within the fluid flow path between the inlet and the outlet. The fluid flow path includes a first fluid conduit which directs fluid through both valves, and a second fluid conduit which bypasses the first valve and directs fluid only through the second valve. The first valve is constructed to provide a greater resistance to flow through the device than the second valve, and when the second fluid conduit is unobstructed, fluid will tend to flow through the second fluid conduit and bypass the first valve. A pivotable plug is provided within the encasement for selectively occluding a portion of the second fluid conduit.

Abstract: A subcutaneously implantable medication infusion device includes a variable capacity reservoir for receiving and storing fluid medication for delivery to a catheter which directs the medication to a specific infusion location in the body. A control assembly is interposed between the reservoir and the catheter to facilitate and control the transfer of the medication from the reservoir to the catheter in a safe and efficient manner. The control assembly includes a self-recharging pump and a normally closed valve, both of which are manually actuable by percutaneous pressure when subcutaneously implanted, and defines a portion of a fluid flow conduit between the reservoir and the catheter. The control assembly is constructed to permit the infusion of a measured bolus of medication on demand through manual percutaneous manipulation of the control assembly.

Abstract: A subcutaneously implantable injection port includes an elastomeric outer housing which encloses an easily assemblage multi-piece rigid base structure. An injection chamber is defined between an upper septum, formed integrally with the elastomeric outer housing, and the underlying base structure. The outer housing includes an upper dome and a lower reinforced sheet. The septum, which is formed integrally with the upper dome, includes a septum flange which is compressed, interiorly of the outer housing, between two base members. A filter extends across the injection chamber dividing it into upper and lower portions. A needle guard, provided by one of the base components, prevents contact between a needle inserted into the injection chamber and the filter. An outlet connector integrally formed with one of the base components extends through the outer housing for connecting a catheter or the like, with the lower portion of the injection chamber.

Abstract: A method for delivering a medication into a body cavity includes the steps of inflating a flexible bag within the body cavity such that the flexible bag expands to fill most of the void of the body cavity, and injecting medication into the space between an exterior surface of the flexible bag and the cavity wall such that the medication substantially surrounds the flexible bag and fills the remaining void. The steps of inflating the flexible bag and injecting medication are accomplished through subcutaneous injection at a site remote from the body cavity. To accomplish this, a surgically implantable tumor access device includes co-located first and second injection ports, for respectively, receiving a sterile fluid and a fluid medication. A flexible fluid conduit, which includes two coaxial tubes, directs the injected fluids, in a manner providing separate fluid flow paths, to a point adjacent to an inlet for the flexible bag. An inner tube fluidly connects the flexible bag with the first injection port.

Abstract: A stylet assembly is provided for inserting a catheter into a brain ventricle and providing a cerebrospinal fluid flashback indicia of proper catheter positioning. The stylet assembly includes an elongated, generally cylindrical rigid hollow stylet having an open distal end, a rounded blunt proximal end, and an internal fluid passageway extending the length of the stylet. A relatively large single aperture is provided through the stylet adjacent to its proximal end, for permitting fluid flow into the internal fluid passageway. The aperture is configured to underlie a plurality of catheter inlet apertures and has a width generally corresponding with the diameter of the internal fluid passageway. An elastomeric hub surrounds a portion of the stylet adjacent to the distal end.

Abstract: A subcutaneously implantable medication infusion device includes a variable capacity reservoir for receiving and storing fluid medication for delivery to a catheter which directs the medication to a specific infusion location in the body. A control assembly is interposed between the reservoir and the catheter to facilitate and control the transfer of the medication from the reservoir to the catheter in a safe and efficient manner. The control assembly includes a self-recharging pump and a normally closed valve, both of which are manually actuable by percutaneous pressure when subcutaneously implanted, and a one-way valve positioned within a primary fluid conduit between the pump and the normally closed valve. The control assembly is constructed to permit the infusion of a measured bolus of medication on demand through manual percutaneous manipulation of the control assembly.

Abstract: A ventriculostomy reservoir includes a rigid base and an elastomeric cap which is positioned over the base to enclose a reservoir well. A rigid cap insert is captured by the lower portion of the cap and is positioned for engagement with the base. The cap insert and the base are configured so that the cap may be snap-fit onto the base in a manner forming a fluid-tight seal therebetween. In one form of the invention, the cap insert includes a cylindrical portion which extends downwardly from a flange-like portion captured within the cap, to fit within an upwardly extending wall portion of the base. The cylindrical portion includes an encircling protrusion on an exterior surface thereof which engages and fits within an encircling detent provided on the interior surface of the wall portion to snap-fit the cap to the base. In a second embodiment of the invention the cap insert exteriorly surrounds an upper end of the base, and a similar protrusion and detent arrangement is utilized to snap-fit the cap to the base.

Abstract: A subcutaneously implantable siphon control device is provided for use in a physiological shunt system including a proximal catheter, a flow control valve and a distal catheter. The siphon control device limits fluid flow through the shunt system due to the siphoning effect of hydrostatic pressure created by the elevation of the proximal catheter inlet with respect to the distal catheter outlet. The siphon control device includes, generally, a base having an inlet typically placed in fluid communication with an outlet of the flow control valve, and an outlet typically placed in fluid communication with the distal catheter, and a housing for the base which, in connection with the base, defines a fluid flow pathway between the inlet and the outlet. The base provides a wall having substantially parallel upper and lower seating surfaces, which separates the inlet from the outlet.