Drug cartridge-based infusion pump

An infusion pump includes a reusable housing unit, a disposable reservoir, and a cap fit on the reservoir, wherein the cap includes a conduit for fluid communication. An aseptic connector assembly includes first and second occlusions in the reservoir and the cap. A pull assembly extends from the aseptic connector assembly and forms the first and second occlusions. The pump has three states. In a storage state, the reservoir is separate from the housing unit and the first and second occlusions cooperate to occlude a wet path extending from the reservoir through the conduit in the cap. In a ready state, the reservoir is applied to the housing unit but the wet path is still occluded. In a use state, the reservoir is applied to the housing unit, the first and second occlusions are removed from the aseptic connector assembly, and the wet path is opened for communication.

FIELD OF THE INVENTION

The present invention relates generally to medical equipment, and more particularly to devices for dispensing drugs to a patient.

BACKGROUND OF THE INVENTION

Precise infusion of volumes of liquid drug or medicament through an administration line is usually accomplished by an infusion pump. Traditional infusion pumps make use of a flexible infusion bag suspended above the patient. For many medicaments and drugs, a pharmacist, nurse, doctor, or other medical professional is required to attach and couple the bag to the pump, making connections between the two which may be contaminated. This can involve wrapping a tubing line around a peristaltic pump, mixing or diluting drugs, connecting fittings, and other activities which are susceptible to medication errors and contamination risks. Other problems exist with conventional pumps. For example, periodic monitoring of the apparatus by a nurse, doctor, or other medical professional is required to detect malfunctions of the infusion pump.

Accordingly, over the years, infusion pumps developed into increasingly more complex devices of great expense and sophistication. Such devices include a large number of features, options, and programmability possibilities. While those capabilities can be advantageous in providing a range of customization to medicament administration, they also lead to user error and the possibility of patient harm, injury, or death.

Complicated infusion pumps also typically require many time-consuming steps for setup. Increased preparation requirements increase the risk of contaminating the pump, the medicament reservoir, the administration line, or other elements of the intravenous line system, posing a hazard to the patient. An improved system for providing a convenient, reliable, accurate, and sterile infusion of liquid medicament is needed.

SUMMARY OF THE INVENTION

An infusion pump includes a reusable housing unit, a disposable reservoir, and a cap fit on the reservoir, wherein the cap includes a conduit for fluid communication. An aseptic connector assembly includes first and second occlusions in the reservoir and the cap. A pull assembly extends from the aseptic connector assembly where it forms the first and second occlusions. The pump has three states. In a storage state, the reservoir is separate from the housing unit and the first and second occlusions cooperate to occlude a wet path extending from the reservoir through the conduit in the cap. In a ready state, the reservoir is applied to the housing unit but the wet path is still occluded. In a use state, the reservoir is applied to the housing unit, the first and second occlusions are removed from the aseptic connector assembly, and the wet path is opened for communication.

The above provides the reader with a very brief summary of some embodiments discussed below. Simplifications and omissions are made, and the summary is not intended to limit or define in any way the scope of the invention or key aspects thereof. Rather, this brief summary merely introduces the reader to some aspects of the invention in preparation for the detailed description that follows.

DETAILED DESCRIPTION

Reference now is made to the drawings, in which the same reference characters are used throughout the different figures to designate the same elements.FIGS. 1A and 1Bare front perspective views illustrating, respectively, a drug cartridge-based infusion pump10(hereinafter, “pump10”) in a ready state in which a drug cartridge11is applied to a housing unit12, and a storage state in which the cartridge11is separate from the housing unit12. The pump10is useful for holding and delivering a quantity of fluid medicament13to a patient via an administration line, and its structure and operation mitigate opportunities to introduce contamination into an intravenous line system. The pump10uniquely combines a reusable housing unit12with disposable cartridges11without sacrificing sterility concerns. The medicament13in the drug cartridge11may be any medicament in fluid form, including high-concentrate drugs, low-concentrate drugs, saline solution, and other liquids or fluids. The cartridge11is always fluidically isolated from the housing unit12, meaning that cartridge11is closed to fluid communication with the housing unit12, the fluid in the cartridge11never touches any part of the housing unit12, and no part of the housing unit12contacts the fluid in the cartridge11.

The housing unit12is constructed from a durable, rigid plastic, either in a monolithic construction or from several pieces coupled together by snap tab fittings, adhesive, sonic welding, screws, or like fastening methods suitable for an assembled medical enclosure. The embodiment shown throughout these drawings is a preferred, yet not limiting embodiment, and it should be understood that variations in the design of various structural elements—such as the housing unit12—do not alter the principle operation of the pump10. The housing unit12is a generally hollow body having a top20, an opposed bottom21, opposed sides22and23, and a front and back24and25.

The housing unit12includes a dock30at the side22. The dock30is a receptacle for receipt of the cartridge11. At the bottom21, the dock30has a quasi-cylindrical laterally-projecting foot31. The top of the foot31is recessed and defines a seat32with a hollow bore34. A plunger rod35carried in the housing unit12at the foot31is coupled to a motor within the housing unit12and mounted for reciprocal movement through the bore34. The plunger rod35drives a plunger within the cartridge11to dispense medicament.

A hold40extends up from the foot31along the side22. The hold40is a semi-cylindrical recess into the housing unit12and is sized and shaped to closely receive the cartridge11when applied to the housing unit12. Capture mechanisms at the top of the dock30secure the cartridge11when applied to the housing unit12. There is a slot41in the hold40proximate the top20of the housing unit12that receives part of the cartridge11, and just below is a smaller slot42. Inside this smaller slot42is a tab43, shown best inFIG. 3B, which has an enlarged head for snapping into a catch extending from the cartridge11, as is described in more detail below.

Returning toFIGS. 1A and 1B, the housing unit12has a wide face44into which is set a display45and a plurality of control buttons46. The display45and buttons46are carried on and operatively coupled to a printed circuit board50(hereinafter, “PCB50”) within the housing unit12, as shown inFIG. 3A. Depressing the buttons46provides signals to the PCB50, which controls operation of the pump10.

FIGS. 1B and 2illustrate the cartridge11separate from the housing unit12and in an exploded format. The cartridge11includes a tamper-evident base60, a plunger61, a reservoir62, a seal assembly63, an aseptic connector assembly64, a cap65, and a pull assembly66. Also shown is an administration line above the cartridge11and the plunger rod35below the cartridge11, but these are not part of the cartridge11.

The reservoir62is a rigid cylinder, such as a syringe barrel. It has an open top70, an open bottom71, and a transparent cylindrical sidewall72extending therebetween. Proximate to the top70of the reservoir62, the sidewall narrows into a neck73which terminates in a mouth75. The sidewall has an annular flange at the mouth75defining a lip74which bounds the mouth75. The neck73and lip74are formed integrally and monolithically as part of the sidewall72.

The plunger61is mounted for movement within the reservoir62. The plunger61is constructed of a material or combination of materials having resilient material characteristic, and has an outer diameter just slightly greater than an inner diameter of the reservoir62, so that the plunger61is slightly radially compressed when disposed within the reservoir62. The plunger61forms an impermeable seal against the reservoir62, so that the medicament13contained within the reservoir62cannot and does not leak from the reservoir62. As seen inFIG. 3A, the plunger61includes a recessed socket80extending into the plunger61from the bottom.

Just below the plunger61is the tamper-evident base60(hereinafter, “base60”). Referring toFIG. 3A, the base60is a rigid outer ring81with a frangible central barrier82. The outer ring81is annular and projects upwardly to a top and downwardly to a bottom with respect to the central barrier82, disposed at an intermediate location between the top and bottom of the outer ring81. For purposes of clarity, words like “top,” “bottom,” “up,” “down,” “above,” “below,” “higher,” and “lower” are used to indicate location, orientation, or relative arrangement of parts of the pump10, considering the top20is preferably at the top and the bottom21is preferably at the bottom when the pump10is oriented in a preferred manner. The central barrier82spans within the outer ring81and is formed to the outer ring81continuously around the inside of the outer ring81with a thinned annulus. The central barrier82is thus frangible and can be torn or severed from the outer ring81when the plunger rod35advances through the base81. The outer diameter of the base60corresponds in size to the inner diameter of the reservoir62, so that the base60is snug fit inside the reservoir62at the bottom71of the reservoir62. Indeed, when the plunger rod35does advance through the base60, the central barrier82tears away from the outer ring81, which remains in place at the bottom71of the reservoir62.

Turning now toFIG. 3B, which illustrates an enlarged portion ofFIG. 3A, the top70of the reservoir62, the seal assembly63, the aseptic connector assembly64, and the cap65are shown. The aseptic connector assembly64is snug fit over the mouth75of the reservoir62and is held there to define a pathway from the reservoir62in communication with a conduit formed internally in the cap65. The aseptic connector assembly64includes a first portion, or upper aseptic connector83, and an opposed separate second portion, or lower aseptic connector84.

Referring still toFIG. 3B, the upper aseptic connector83includes a wide, squat, cylindrical base90having a top and bottom, and a wide oval flange91extending radially outward from the base90. The flange91is shorter than the base90at approximately one-fourth the height of the base90. The base90and flange91cooperate to define a flat lower surface93of the upper aseptic connector83extending across both the base90and the flange91. Extending upward into the base90from the lower surface93is a seat94. The seat94is a cylindrical depression in the upper aseptic connector83and receives a first annular gasket95therein. The depth of the seat94is slightly less than the height of the gasket95so that the gasket95protrudes slightly beyond the lower surface93of the upper aseptic connector83when received in the seat94. The gasket95is constructed of a material or combination of materials having characteristics of inertness, low permeability, durability, and compressibility, such as rubber. The seat94is located in the upper aseptic connector83concentric to both the base90and the flange91. An axial bore96extends centrally and coaxially through the upper aseptic connector83from the seat94upward to the top of the upper aseptic connector83. The bore96provides a pathway for movement of fluid through the upper aseptic connector83.

The lower aseptic connector84is somewhat similar to the upper aseptic connector83. Referring toFIG. 3C, which is an identical view toFIG. 3Bpresented again to reduce the density of reference characters, the lower aseptic connector84includes a top100, a bottom101, and a perforated cylindrical sidewall102extending from the top100to the bottom101. The top100has a flat upper surface103, which is pressed toward the flat lower surface93of the upper aseptic connector83. A seat104extends downward into the top100of the lower aseptic connector84from upper face103; the seat104is a cylindrical depression which receives a second annular gasket105therein. The depth of the seat104is slightly less than the height of the gasket105so that the gasket105protrudes slightly beyond the upper surface103when the gasket105is received in the seat104. The gasket105is constructed of a material or combination of materials having characteristics of inertness, low permeability, durability, and compressibility, such as rubber. The seat104is concentric to the sidewall102. A post110extends downward from the top100and is formed integrally thereto. The post110surrounds a bore106which extends centrally and coaxially through the lower aseptic connector84from the seat104downward to the bottom of the post110disposed inside the neck73of the reservoir62. The bore106provides a pathway for movement of fluid through the lower aseptic connector84. This bore106provides a pathway for the movement of fluid out of the reservoir62through the lower aseptic connector84. A short, annular collar111surrounds the post110. The collar111is radially spaced apart from the post110and, as such, defines a small annular gap112therebetween.

The lower aseptic connector84caps the reservoir62. With continuing reference toFIG. 3C, the lower aseptic connector84is fit into the reservoir62at the mouth and is sealed to it by the seal assembly63of a washer120and a gasket121. The washer120has an annular structure, a central bore defining a constant inner diameter, and a stepped outer diameter. The outer diameter increases in discrete amounts from the top of the washer120to the bottom. This stepped outer diameter engages with a stepped inner diameter of the collar111surrounding the post110of the lower aseptic connector84. The washer120includes an annular channel122bound on the inside by the stepped outer diameter and bound on the outside by a low upstanding annular lip123at the periphery of the washer120. The annular channel122is open upward.

The gasket121surrounds the collar111, just above the lip123at the periphery of the washer120. The seal assembly63cooperates with the lower aseptic connector84to close and seal the reservoir62. During assembly of the pump10, the gasket121is placed around the collar111of the lower aseptic connector84, proximate to its bottom. The washer120is then introduced to the gap112defined between the post110and the collar111. Preferably, the lower aseptic connector84is disposed in the mouth75, and the gasket121is between the collar111and the inner surface of the reservoir62at the mouth75. Tabs107on the lower aseptic connector84are directed inwardly and latch under the lip at the top of the reservoir62, thereby holding the lower aseptic connector84in place with respect to the reservoir62. The washer120acts in part as a shim, and as it is introduced and advanced into the gap112, it forces the collar111radially outward. This compresses the gasket121between the collar111and the reservoir62, thereby forming a fluid impervious seal. The washer120is advanced into the gap112until the bottom edge of the collar111is seated in the channel122inboard of the lip123, as shown inFIG. 3C.

The lower aseptic connector84cooperates with the seal assembly63to seal the reservoir62. The cap65fits over the lower aseptic connector84to hold the upper and lower aseptic connectors83and84in compressive contact against each other, and to hold the cartridge11in the housing unit12.

Referring now toFIGS. 3A and 3B, the cap65has a cylindrical solid body130with a closed top131and an open bottom132. The open bottom132leads to an interior recess or cavity133extending upward into the cap65from the bottom132. The cavity133is defined by a cylindrical inner surface134and an upper surface135thereof. A short central depression136is recessed upwardly into the body130from the upper surface135; the depth of this depression136into the body130corresponds to the height of the base90above the flange91on the upper aseptic connector83. The base90of the upper aseptic connector83is snug fit and glued into this depression136.

An internal conduit140extends from an opening at the upper surface135of the cavity133to an outlet141at the top131of the cap65. The conduit140couples the bore96of the upper aseptic connector83with the outlet141. Typically, the outlet141will be connected to the administration line51for connection to a patient or to other parts of an intravenous line system.

The cap65also includes a catch142and a sensor143, each extending laterally from the side of the cap65. The catch142is an integral and rigid projection of the cap65to the side and is formed with a slot144extending transversely through the catch142. The slot144is sized to receive the tab43in the housing unit12; when the tab43slips into the slot144, the enlarged head of the tab43becomes latched on the catch142, thereby preventing inadvertent removal of the cartridge11from the housing unit12. The sensor143is an infrared, NFC, or other sensor type on the cap65, which is brought into proximity to a reader145on the PCB50when the cartridge11is applied to the housing unit12. The sensor143corresponds to the reservoir62; the sensor143carries information about the reservoir62and the medicament13it contains. The reader145is electrically coupled to a logic controller on the PCB50, so that the sensor143is coupled in data communication with the PCB50in the housing unit12when the pump10is in ready and use states. The sensor143conveys information to the reader145, allowing the PCB50to determine information about the cartridge11, such as medicament type, volume, date of creation, date of expiration, etc.

The pull assembly66is a two-ply ribbon structure fitted with a pull ring. With reference toFIGS. 3A and 3B, the pull assembly extends from within the aseptic connector assembly64, where it is disposed between the upper and lower aseptic connectors83and84, forms the first and occlusions, and occludes both the upper and lower aseptic connectors83and84, to outside the reservoir62and the cap65. The pull assembly66includes a first or upper ribbon150, a second or lower ribbon151, and a pull ring152secured on the free ends of the upper and lower ribbons150and151.

The upper ribbon150is a flexible, thin film, or is constructed from flexible, thin films. Within the aseptic connector assembly64, the upper ribbon150overlies the bore96, the gasket95, and a portion of the lower surface93surrounding the gasket95. The upper ribbon150has an upper surface and an opposed lower surface. In the aseptic connector assembly64, the upper ribbon150is folded over on itself: the upper and lower surfaces are against each other. A free end of the upper ribbon150then extends out away from the upper aseptic connector83to the pull ring152, outside the cartridge11. The upper surface of the upper ribbon150is adhered and sealed to the lower surface93of the upper aseptic connector83around the gasket95, thereby forming a continuous, annular seal between the upper ribbon150and the lower surface93to act as an occlusion and a barrier to fluid migration. The upper ribbon150thus occludes the upper aseptic connector83.

Similarly, the lower ribbon151is a flexible, thin film, or is constructed from flexible, thin films. Within the aseptic connector assembly64(shown more clearly inFIG. 3C), the lower ribbon151overlies the bore106, the gasket105, and a portion of the upper surface103surrounding the gasket105. The lower ribbon151has an upper surface and an opposed lower surface. In the aseptic connector assembly64, the lower ribbon151is folded over on itself: the upper and lower surfaces are against each other. A free end of the lower ribbon151then extends out away from the lower aseptic connector84to the pull ring152, outside the cartridge11. The lower surface of the lower ribbon151is adhered and sealed to the upper surface103of the lower aseptic connector84around the gasket105, thereby forming a continuous, annular seal between the lower ribbon151and the upper surface103to act as an occlusion and a barrier to fluid migration. The lower ribbon151thus occludes the lower aseptic connector84.

The upper ribbon150is characterized as a first occlusion of the aseptic connector assembly64, and the lower ribbon151is characterized as a second occlusion of the aseptic connector assembly64, meaning the upper and lower ribbons150and151prevent fluid communication through the aseptic connector assembly64. The upper ribbon150, being sealed only to the upper aseptic connector83, is only an occlusion to the upper aseptic connector83, and prevents fluid communication through the upper aseptic connector83. The lower ribbon151is only an occlusion to the lower aseptic connector84because it is sealed only to the lower aseptic connector84, and thus prevents fluid communication through the lower connector assembly84only. The occlusions are part of the aseptic connector assembly64.

The upper and lower ribbons150and151extend out of the aseptic connector assembly64. They are adhered, sonically welded, or otherwise fixed to each other at the pull ring152, which is a rigid ring on the free ends of the upper and lower ribbons150and151. The pull ring152allows a user to grasp and remove the pull assembly66from the cartridge11and from the aseptic connector assembly64.

The upper and lower ribbons150and151allow independent, separate sterilization of the cap65and reservoir62. During assembly of the cartridge11, the upper aseptic connector83is applied to the cap65. The base90of the upper aseptic connector83is registered with the depression136in the cap65and a small amount of adhesive is placed in the depression136before the base90is seated therein. The upper aseptic connector83is thus seated in the cap65with its bore96registered with the conduit140. The gasket95is seated in the seat94of the upper aseptic connector83, and the upper ribbon is placed over the gasket95and sealed to the lower surface93around it. The cap65is then sterilized, such as by Gamma- or ETO-sterilization or some other like medical sterilization process. The outlet141may be fitted with the administration line51or may be fitted with one later on.

The reservoir62is sterilized as well. As described above, the lower aseptic connector84is set into the mouth75of the reservoir62and sealed therein with the seal assembly63. The reservoir62is then filled with medicament13, and the plunger61is set into the reservoir62, thereby sealing the other end of the reservoir62. The medicament13is a fluid and is preferably one of the following fluids, but is not limited to acetaminophen, ketamine, propofol, dexmedetomidine, fentanyl, remifentanyl, etomidate, midazolam, foscarnet, ganciclovir, dopamine, dobutamine, milrinone, hemin, bupivacaine, ropivacaine, lidocaine, ciprofloxacin, cefazolin, fluconazole, cefmetazole, nafcillin, zoledronic acid, hetastarch, lactated ringers, hydroxyethyl startch, sodium chloride, dextrose, bendamustine, filgrastim, aztreonam, 5-fluorouracil, cetuximab, bortezomib, epirubicin, fludarabine, irinotecan, oxalaplatin, paclitaxel, carboplatin, cisplatin, cytarabine, methotrexate, vinblastine, vincristine, and ifosfamide. The base60is also fit over the bottom71of the reservoir62to indicate whether the reservoir62is or has been tampered. The lower ribbon151is then placed over the gasket105and sealed to the upper surface103around it. The reservoir62is then sterilized.

With the upper ribbon150occluding and sealing the upper aseptic connector83after sterilization and the lower ribbon151occluding and sealing the lower aseptic connector84after sterilization, the fluid-contacting portions of the cartridge11are maintained in a sterile state. The fluid-contacting portions of the cartridge11define a wet path160through the cartridge11. This wet path160, generally illustrated with an arrowed line inFIGS. 3A, 3B, and 3C, includes the plunger61, the reservoir62, the bore106and the gasket105in the lower aseptic connector84, the bore96and the gasket95in the upper aseptic connector83, and the conduit140in the cap65, and the path that medicament13takes when being dispensed from the reservoir62, pushed by the advancing plunger61. The constituent structures of the wet path160are the only elements of the cartridge11which are in contact with the medicament13. Indeed, the constituent structures of the wet path160are the only elements of the pump10which are ever in contact with the medicament13. Since those structures are entirely contained within the cartridge11, the cartridge11is always fluidically isolated from the housing unit12; no fluid in the cartridge11ever contacts the housing unit12.

Once the reservoir62and the cap65are sterilized separately, they can be brought together. The cap65is registered with the reservoir62, the cavity133of the cap65is directed toward the top70of the reservoir62and the lower aseptic connector84thereon, and the cavity133is moved over the top70of the aseptic connector84until the upper and lower aseptic connectors83and84come into contact. The lower aseptic connector84is held in place on the reservoir62by the engagement of its tabs107with the lip74of the reservoir62and by the compression of the seal assembly63against the mouth75of the reservoir62, and the upper aseptic connector assembly83is held in place by adherence to the upper surface135of the cap65. When the cap65and reservoir62are registered in this manner, the gaskets95and105and the bores96and106are registered with each other as well. The upper and lower ribbons150and151are disposed in contact between the gaskets95and105. The cap65is further advanced downward on the reservoir62, thereby compressing the gaskets95and105toward each other with the upper and lower ribbons150and151therebetween, until the cap65locks onto the reservoir62. The inner surface134of the cap65is formed with several inwardly-directed teeth146which pass into and catch just under the lower aseptic connector84. The teeth146, once engaged under the lower aseptic connector84, cannot be disengaged without breaking the cap65or the lower aseptic connector84. With the lower aseptic connector84secured on the reservoir62, and the cap65secured on the lower aseptic connector84, the upper and lower aseptic connectors83and84are thus held in compressive contact, maintained in coaxial alignment, so that when the pull assembly66is removed from the cartridge11, the bores96and106can be joined to each other in fluid communication and the wet path160opened.

With the cap65secured on the reservoir62, the free ends of the upper and lower ribbons150and151both loosely extend out of a slot147in the cap65. The pull ring152is fit to the free ends of the upper and lower ribbons150and151. The upper and lower ribbons150and151are straightened and flattened, so that the lower surface of the upper ribbon150is flat against the upper surface of the lower ribbon151, and the pull ring152is then adhered, sonically welded, or otherwise fixed to the free ends of the upper and lower ribbons150and151, thereby similarly fixing the upper and lower ribbons150and151to each other as well.

In this manner, the assembled cartridge11and the housing unit12are separate in a storage state of the pump10. The storage state is shown most clearly inFIGS. 1B and 1scharacterized in that the cartridge11is free of and fluidically isolated from the housing unit12. The upper and lower ribbons150and15are disposed between the first and second gaskets95and105. The occlusions of the upper and lower ribbons150and151, entirely encased by the reservoir62and the cap65, together cooperate to occlude the wet path160. The cartridge11is fluidically isolated from the housing unit12in the storage state. The storage state of the pump10is a stable state that the pump10can be kept in for long periods of time. Since the reservoir62is sterilized and the cap65is separately sterilized, the cartridge11can be usefully maintained in the storage state of the pump10as long as the medicament does not expire.

The pump10is delivered to a health worker in the storage state, and the health worker then must ready the pump10for use. To do so, the health worker must first assemble the pump10into the ready state. This is shown inFIGS. 1A, 3A, 3B, and 3C. It is simple to arrange the pump10into the ready state. The health worker merely needs to apply the cartridge11to the housing unit12. The worker registers the base60with the seat32at the top of the foot31of the housing unit12. The worker applies the base60into the seat32, seating it therein, and then pivots the rest of the cartridge11into the dock30of the housing unit12, inserting the sensor143on the cap65into the slot41and the catch142into the smaller slot42. The slot144in the catch142engages with the enlarged head of the tab43, and the cartridge11is secured to the housing unit12if necessary. A push button release161on the outside of the housing unit12releases the capture of the cartridge11from the housing unit12. Because the cartridge11is fluidically isolated from the housing unit12, the cartridge11can be released at any time and discarded or moved to another housing unit12if needed.

The above steps describe the process for placing the pump10into the ready state from the storage state. The ready state is still stable for long-term storage, but is distinguished from the storage state because the cartridge11is now applied the housing unit12. However, the upper and lower ribbons150and15are still disposed between the first and second gaskets95and105. The occlusions of the upper and lower ribbons150and151, still entirely encased by the reservoir62and the cap65, still cooperate to occlude the wet path160. The cartridge11is still fluidically isolated from the housing unit12in the ready state.

To arrange the pump10from the ready state to a use state, shown inFIGS. 4A and 4B, the health worker merely needs to remove the pull assembly66. Removal of the pull assembly66removes the upper and lower ribbons150and151from the aseptic connector assembly64, thereby removing the occlusions of the wet path160in the aseptic connector assembly64. The gaskets95and105, under the compressive force of the upper aseptic connector83against the lower aseptic connector84, are now compressed directly against each other in continuous sealing contact, without the occlusions of the upper and lower ribbons150and151between. Since the gaskets95and105are maintained in coaxial alignment, they register with each other to form a fluid-impermeable seal and prevent any liquid from leaking between the gaskets, thus ensuring that the wet path160is fluidically isolated and protected from both leaking and ingress contamination. The wet path160is thus opened for communication of fluid medicament from the reservoir62to the conduit140in the cap65. The cartridge11is still fluidically isolated from the housing unit12in the use state, however.

Though medicament can flow from the reservoir62to the conduit140, it does not flow until the pump10is energized and the plunger rod35is advanced. The health worker must first connect the pump10to the patient. The health worker may arrange the pump10for use, such as by hanging it from a hook on a stand proximate to the patient. The health worker couples the fitting on the administration line51to the outlet141and then removes the cap on the other end of the administration line51. The administration line51may be connected to a catheter, an intravenous line, a port connected to the patient, or some other part of an intravenous line system. The health worker next activates the pump10on and inputs dosing information. The health worker uses the control buttons46to do this, depressing the control buttons46until the desired settings are selected, as confirmed on the display45. In some circumstances, the pump10may be primed to remove any air from the wet path160.

The health worker then starts the pump10to dispense the fluid medicament13by depressing one of the control buttons46. Logic controllers on the PCB50transmit power, supplied by a battery behind the PCB50, to a motor52, which is electrically coupled to the PCB50. The motor has a shaft53(seen inFIG. 5) on which a pinion gear54is mounted. The pinion gear54is engaged with teeth55formed along one side of the plunger rod35. When the motor52receives power, the pinion gear54rotates and advances the plunger rod35upward. The plunger rod35moves upward and encounters the central barrier82of the base60. The central barrier82is formed integrally to the outer ring81, but at its periphery, the central barrier82is thinned (as seen best inFIG. 5) to provide a stress point. Once the plunger rod35encounters the central barrier82and continues to advance, the plunger rod35moves through the central barrier82, severing it from the outer ring81. The plunger rod35tampers the reservoir62, as severing of the central barrier82indicates that some of the medicament13may have been dispensed or something may have interfered with the medicament13. The central barrier82is thus torn from the outer ring and is carried upward atop the plunger rod35, as seen inFIG. 4A. However, because the plunger rod35has not yet reached the bottom of the plunger61, medicament has yet to begin to flow from the reservoir62through the conduit140and into the administration line51.

The plunger rod35advances into the socket80of the plunger61. The central barrier82becomes disposed between the top of the plunger rod35and the underside of the socket80. The motor52drives the plunger rod35upward at a predetermined rate corresponding to the appropriate dosage for the patient, displacing the medicament13from the reservoir62, through the wet path160, and out through the administration line51. This continues until the reservoir62is emptied or the health worker discontinues administration of the medicament. The cartridge11is then ejected from the housing unit by depressing the push button release161, which releases the catch142, and the cartridge11is disposed. The housing unit12is available to be re-used with a new cartridge11.

A preferred embodiment is fully and clearly described above so as to enable one having skill in the art to understand, make, and use the same. Those skilled in the art will recognize that modifications may be made to the description above without departing from the spirit of the invention, and that some embodiments include only those elements and features described, or a subset thereof. To the extent that modifications do not depart from the spirit of the invention, they are intended to be included within the scope thereof.