Minimed, Inc.

Pacesetter Infusion, Ltd.

Minimed Technologies, Ltd.

Peter C Lord

William P Van Antwerp

John Joseph Mastrototaro

Paul S Cheney, Ii

Nannette M Schnabel

Alfred E Mann

Susan M McConnell

Chad Srisathapat

John B Slate

April A Konopka

Fredric C Colman

Magdi F Habib

William P VanAntwerp

John R Schultz

David G Powell

Raymond D Clark

Fredric C Coleman

A medication infusion pump includes a housing, a medication chamber defined within the housing, a medication delivery device in fluid communication with the medication chamber, a propellant chamber defined within the housing and adapted to apply a predetermined positive pressure to a medication in the medication chamber, and a non-ozone depleting, non-toxic propellant within the propellant chamber. The propellant preferably has a vapor pressure between about 11 psig and about 50 psig at 37&deg; C.

Constant flow medication infusion pump

A medication infusion pump is provided for substantially constant flow delivery of a selected medication from a medication chamber through a catheter to a patient. The medication infusion pump comprises a compact housing adapted for implantation into the body of a patient, wherein the housing defines a hollow interior forming a medication chamber. An inlet port on the housing permits transcutaneous access to and filling of the medication chamber within the housing. A flexible propellant reservoir occupies a portion of the medication chamber volume and is filled with a selected fluid propellant to apply a substantially constant pressure to the medication for medication delivery with substantially constant flow through an elongated capillary tube and the catheter for administration to the patient. The capillary tube is spooled within the housing at the perimeter thereof in association with an annular filter of large surface area to prevent impurities and particulate from entering and potentially clogging the capillary tube. The inlet port also includes a click plate for providing a positive feedback indication of proper registration between the inlet port and a refill needle for refilling the medication chamber.

A medication infusion device such as a programmable infusion pump includes data input regarding a selected patient parameter such as a current blood glucose reading. The infusion device includes a controller responsive to this data input to develop a medication delivery protocol which can be implemented automatically, recommended via a display for subsequent approval or rejection upon manipulation of control switches, or otherwise overridden in favor of a different medication delivery protocol.

Medication infusion device with blood glucose data input

An improved glucose sensor adapted for in vivo implantation includes one or more optical fiber optrodes mounted within a semipermeable probe housing designed for differential diffusion of glucose and oxygen. In a preferred form, an enzyme optrode comprises an optical fiber with an enzyme coating such as glucose oxidase for catalyzing glucose in the presence of oxygen (O.sub.2) to produce gluconic acid and hydrogen peroxide. An oxygen sensitive coating such as a fluorescent dye is provided on the enzyme optrode in close proximity with the enzymatic reaction, and also on a reference optrode at a position spaced substantially from the enzymatic reaction. Optical monitoring of the fluorescent activity of the optrode coatings provides an indication of oxygen depletion as a result of the enzymatic reaction, and thus also indicates glucose concentration level. The semipermeable housing is designed to ensure that the reaction proceeds with a stoichiometric excess of oxygen (O.sub.2).

Optical glucose sensor

An infusion pump system includes a removable in vivo glucose sensor for monitoring glucose concentration level in a patient, and for signaling an infusion pump to deliver a selected medication such as insulin to a patient. The glucose sensor comprises a sensor cable for placement through a catheter to position a distal sensor tip at a selected in vivo sensor site. A proximal end of the sensor cable seats within a connector fitting mounted on the catheter at a convenient and accessible subcutaneous position. The connector fitting couples the sensor cable to an implanted control unit which signals the infusion pump to deliver the patient medication. In a preferred system, the infusion pump is also implanted and receives control signals via a direct or telemetric connection. The sensor cable is easily accessed at the connector fitting for periodic sensor removal and replacement, without requiring removal or replacement of other system components.

Closed loop infusion pump system with removable glucose sensor

An improved insertion set is provided for transcutaneous placement of a sensor such as a glucose sensor at a selected site within the body of a patient. The insertion set comprises an insertion needle extending through a mounting base adapted for mounting onto the patient's skin. A flexible thin film sensor includes a proximal segment carried by the mounting base and adapted for electrical connection to a suitable monitor or the like, and a distal segment protruding from the mounting base with sensor electrodes thereon for transcutaneous placement. The distal segment of the sensor and a distal segment of the insertion needle are positioned within a flexible cannula which extends from the mounting base, whereby placement of the mounting base onto the patient's skin causes the insertion needle to pierce the skin for transcutaneous placement of the cannula with the sensor therein. The insertion needle can then be withdrawn from the cannula and the mounting base to leave the sensor distal segment at the selected insertion position, with the sensor electrodes being exposed to patient blood or other extracellular fluid via a window formed in the cannula. The cannula is carried by the mounting base to insure alignment of the sensor electrodes with the cannula window.

Transcutaneous sensor insertion set

A connector is provided for electrical connection to a flex circuit in a hermetically sealed manner. The flex circuit comprises thin film conductors encased between layers of insulative material, and including a proximal end with conductive contact pads exposed through one of the insulative layers. In a preferred form, the proximal ends of the two flex circuits are assembled in face-to-face relation and compressed by a clamp fixture against opposite side faces of a compressible terminal block. The terminal block is formed from a resilient insulative elastomer such as silicone rubber with embedded conductive strips having opposite edges exposed at the opposite side faces of the terminal block for electrically connecting aligned pairs of the contact pads on the two flex circuits. The exposed edges of the conductive strips are circumscribed by the insulative elastomer which engages the flex circuits with a footprint circumscribing the exposed contact pads, whereby the terminal block hermetically seals the interface between the conductive strips and the contact pads.

Flex circuit connector

An insertion set is provided for transcutaneous placement of a sensor such as a glucose sensor at a selected site within the body of a patient. The insertion set comprises a slotted insertion needle extending through a mounting base adapted for mounting onto the patient's skin. A flexible thin film sensor includes a proximal segment carried by the mounting base and defining conductive contacts adapted for electrical connection to a suitable monitor, and a distal segment protruding from the mounting base with sensor electrodes for transcutaneous placement. The proximal and distal segments of the sensor are linearly offset or misaligned, with the distal segment fitted within the insertion needle for transcutaneous sensor placement with the needle as the mounting base is pressed onto the patient's skin. The insertion needle can then be withdrawn to leave the sensor distal segment at the selected insertion position with the sensor electrodes in contact with patient blood or other extracellular fluid.

Apparatus located in an implantable medication infusion pump for quickly and easily detecting a condition adversely affecting medication delivery in the implantable medication infusion pump is disclosed which can reliably detect occurrences including an occluded catheter, the presence of air in the pumping mechanism, and the failure of the pumping mechanism. The system uses the amplitude of an acoustic signal generated by operation of the pumping mechanism as compared with a baseline signal to detect an encapsulated or occluded catheter or air in the fluid line. In addition, the system can detect a partially encapsulated or occluded catheter by detecting repeated downward slope patterns during repetitive, closely spaced pumping cycles.

Implantable medication infusion pump including self-contained acoustic

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.

Recondition process for a medication infusion pump

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. The improved reservoir can be provided in a variety of structural shapes and/or utilized in pump housings of various size and shape to permit the pump size to be reduced, or, in the alternative, to increase pump medication capacity without increasing pump housing size.

Medication infusion pump with improved liquid-vapor pressure reservoir

An improved and simplified pressure reservoir is provided for use with an implantable medication infusion pump to maintain a selected medication in liquid form with a pump housing under a substantially constant pressure. The pressure reservoir comprises a hollow structural enclousre 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 contact the reservoir in a manner maintaining the medication under a substantially constant pressure. The improved reservoir can be provided in a variety of structural shapes and/or utilized in pump housings of various size and shape to permit the pump size to be reduced, or, in the alternative, to increase pump medication capacity without increasing pump housing size.

Liquid-vapor pressure reservoir for medication infusion pump

An injection set for delivering a fluid to a subcutaneous injection location in a patient is disclosed which has a soft cannula projecting from a bottom surface of a holding pad. An insertion needle is initially inserted through a septum located between a catheter hub and a retaining cap mounted on the holding pad. The insertion needle extends through a fluid chamber defined by the septum and the catheter hub and then through a lumen of the soft cannula, with the sharpened tip of the insertion needle extending beyond the end of the soft cannula when the insertion needle is fully inserted. The insertion needle, which allows priming of the injection set, may be removed following installation of the injection set without kinking of the soft catheter, and fluid may be supplied to the injection set for delivery to the patient.

Growing community of inventors

Santa Clarita, CA, United States of America

Peter C Lord