Abstract: 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).

Abstract: 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 distal segment of the sensor extends within a protective cannula, a portion of which is slidably disposed within the insertion needle. 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.

Abstract: A subcutaneous injection set is disclosed of the type having an insertion needle for quick and easy subcutaneous placement of a soft cannula through which medication can be delivered to a patient. In one preferred form, the subcutaneous injection set comprises a base adapted for press-on attachment to the skin of a patient at a selected infusion site. The base includes a connector sleeve for connecting a length of infusion tubing to the soft cannula. The soft cannula is threaded through an eye formed near the distal end of the insertion needle which is mounted on a collapsible injector that is detachably mounted to the base. The base is positioned on the patient's skin, the injector is collapsed by pressing toward the patient's skin whereby the insertion needle pierces the skin for transcutaneous cannula placement. The press stroke of the insertion needle is sufficient to unthread the cannula therefrom, whereupon the injector can be retracted to withdraw the insertion needle from the patient.

Abstract: 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.

Abstract: 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.

Abstract: A quick-connect coupling is provided for use in a medication infusion system, to permit temporary disconnection and subsequent re-connection of a medication infusion pump relative to a patient without requiring removal of a transcutaneous infusion cannula. The coupling is mounted in-line with a length of infusion tubing and includes a female component with a needle recessed therein and adapted for slide-fit connection with a male component having a self-sealing septum. Radial tabs on the male component slide freely into longitudinally open slots formed in the female component, whereupon the male component is rotatable to displace the tabs with interference fit past undercut cam surfaces into alignment with radially open ports formed in the female component. When connected, the male and female components are effectively locked against longitudinal separation.

Abstract: An improved indwelling catheter adapted for long-term usage includes a stable enzyme coating to prevent occlusion of the catheter lumen. The enzyme coating includes a fibrinolytic and/or lipolytic enzyme incorporated in a catheter coating to resist or control proteolytic degradation, thereby maintaining the enzyme in an active state for dissolving clots and occlusions within the catheter lumen over an extended period of time.

Abstract: A medication infusion pump is provided of the type adapted for implantation into the body of a patient, and for programmable delivery of a selected medication through a catheter to the patient over an extended period of time. A side port assembly is mounted quickly and easily onto the pump and defines a flow path through which the medication is discharged to the catheter. The side port assembly includes an access port to permit transcutaneous needle access to the discharge flow path, in combination with a check valve to prevent backflow within the discharge flow path. The discharge side access port can be used to flush residue from the catheter, or in combination with a primary refill port on the pump to flush the pump and/or to determine actual pump stroke volume.

Abstract: An implantable medication infusion pump is provided of the type having a pressure reservoir with a selected pressure fluid therein for maintaining liquid medication in an adjacent medication chamber under a substantially constant pressure. The reservoir comprises a hollow structural enclosure defined by at least one movable wall and adapted to be filled with a selected quantity of the pressure fluid, particularly such as a selected fluorocarbon in a liquid-vapor state. The movable wall of the pressure reservoir is shared with and defines one side of the medication chamber, with the pressure fluid undergoing appropriate change of state to expand or contract the pressure reservoir in a manner maintaining the medication under substantially constant pressure. The improved pressure reservoir includes an internal spacer element to prevent contraction of the pressure reservoir beyond a minimum volume at least slightly greater than the liquid state volume of the pressure fluid therein.

Abstract: An improved medication infusion pump is provided of the type for receiving and supporting a medication-containing syringe, wherein the pump and syringe include matingly interfitted components to ensure use of the pump with a compatible and correctly installed syringe. The infusion pump comprises a pump housing defining a syringe compartment for receiving and supporting the syringe, in combination with a drive member for engaging and programmably displacing a syringe plunger to administer medication to a patient. In one preferred form, the drive member and plunger include a matingly interfitting tab and notch which are engaged when the syringe is fully and properly positioned within the syringe compartment. In another form, the tab and notch are formed on the syringe plunger and a portion of the pump housing.

Abstract: An improved indwelling catheter adapted for long-term usage includes a stable enzyme coating to prevent occlusion of the catheter lumen. The enzyme coating includes a fibrinolytic and/or lipolytic enzyme incorporated in a catheter coating to resist or control proteolytic degradation, thereby maintaining the enzyme in an active state for dissolving clots and occlusions within the catheter lumen over an extended period of time.

Abstract: 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.

Abstract: An implantable infusion port is provided to facilitate delivery of medication to a patient, wherein the infusion port has a substantially reduced internal volume to minimize the quantity of residual medication therein. The infusion port comprises a cup-shaped housing with a self-sealing septurn mounted thereon to define an internal chamber for receiving medication infused through the patient's skin and the septurn via a hypodermic needle or the like. A catheter mounted on the housing communicates with the internal chamber to deliver the medication to a selected site within the patient. A substantial portion of the chamber volume is occupied by inert beads which minimize the open volume of the chamber and thereby maximize medication delivery to the patient.

Abstract: A mounting clip is provided for removable mounting of a medication infusion pump of the type used to deliver a selected medication such as insulin to a patient. In the preferred form, the mounting clip comprises a belt clip with a pair of pivotally interconnected and spring-loaded legs adapted for mounting onto a belt or other item of clothing worn by a patient. One leg of the belt clip includes a dovetail key for slide-fit reception into a mating dovetail slot formed in the housing of a medication infusion pump. A detent button is carried on the belt clip at the distal end of a spring arm for snap-fit reception into a detent seat formed in the pump housing, to lock the pump onto the belt clip. The spring arm is manually accessible to permit fingertip retraction of the detent button from the seat, and thereby permit easy sliding removal of the pump housing from the belt clip.

Abstract: A medication infusion pump is provided of the type adapted for implantation into the body of a patient, and for programmable delivery of a selected medication through a catheter to the patient over an extended period of time. A side port assembly is mounted quickly and easily onto the pump and defines a flow path through which the medication is discharged to the catheter. The side port assembly includes an access port to permit transcutaneous needle access to the discharge flow path, in combination with a check valve to prevent backflow within the discharge flow path. The discharge side access port can be used to flush residue from the catheter, or in combination with a primary refill port on the pump to flush the pump and/or to determine actual pump stroke volume.

Abstract: An infusion pump for delivering a selected medication to a patient is provided with an inductance flow sensor for monitoring and verifying delivery of medication in response to pump operation. The flow sensor comprises a compact inductor coil wrapped about a pump discharge conduit, in combination with a magnetically attractable core pin disposed within the discharge conduit for movement to a position within the inductor coil in response to pump outflow. A control circuit operates with minimal power requirements to monitor coil inductance changes as a result of core pin displacement to confirm medication delivery to the patient in response to pump operation. A magnet mounted at one end of the inductor coil draws and retains the core pin at a position retracted from the coil in the absence of pump outflow.

Abstract: An improved side slit catheter is provided for use in long term delivery of a selected medication to a patient, wherein the catheter has a distal end tip shaped to permit expulsion of an occlusive deposit. The catheter includes an elongated lumen for passage of medication such as insulin to the distal end tip for administration to the patient at a selected infusion site. The tip includes a cylindrical wall segment defining a tapered bore which expands in cross section to a delivery port, with at least one and preferably a plurality of longitudinal side slits formed in said wall segment. In the event of delivery port occlusion, medication delivery at normal pressure will continue through the side slits. The occlusion can be expelled from the catheter tip by delivering a selected fluid through the catheter at elevated pressure, whereupon the slitted catheter tip deformably responds to detach from and thus permit expulsion of the occlusion.

Abstract: A system and related method are provided for lubricating an interior surface of a device, such as the inner diameter surface of a syringe barrel. A fixture is provided for receiving and supporting the syringe barrel with an open rear end in alignment with a lubricant spray nozzle and an open front end in alignment with a counterflow air nozzle. Lubricant is sprayed via the lubricant spray nozzle into the syringe barrel in counterflow relation to an air flow discharged through the air nozzle, resulting in turbulent lubricant atomization and dispersal as a substantially uniform surface coating of interior surfaces of the syringe barrel.

Abstract: A medication infusion pump is provided for use in the programmable delivery of a selected medication to a patient, wherein the pump includes a fluoropolymer valve seat engageable with a nonmetallic valve member. The fluoropolymer valve seat defines a substantially inert and nonadherent surface to prevent accumulation of medication deposits thereon. Such deposits are believed to occur as a result of shear denaturation and/or precipitation in the vicinity of the valve seat, in response to relatively high compression forces applied to the medication as the valve member opens and closes. The fluoropolymer valve seat provides a surface which is particularly nonadherent to protein based medications, such as insulin.