Cartridge insertion mechanism for a fluid delivery device

A fluid delivery device comprises a drive unit including an actuator and one or more first features and a cartridge filled with a fluid prior to being inserted into the housing. The cartridge having a fluid reservoir sealed at one end by a movable piston and sealed at another end by a pierceable septum. The cartridge includes one or more second features that are configured to align and mate with the one or more first features allowing the cartridge to be inserted into the drive unit. The piston is moveable by the actuator once the cartridge is inserted into the drive unit.

BACKGROUND OF THE INVENTION

The present invention generally relates to cartridge insertion mechanisms for fluid delivery devices and, more particularly, to cartridge insertion mechanisms for ambulatory fluid delivery pumps for delivering a medicament to a patient.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1-3B, an exemplary fluid delivery device110is shown. In one embodiment, fluid delivery device110is a discrete ambulatory insulin delivery pump. Fluid delivery device110may be single use, disposable and incapable of reuse. Fluid delivery device110may provide therapeutic capability in a small, single use, disposable package and can be produced using high volume manufacturing fabrication (e.g., injection molding) and assembly processes, allowing for low cost of goods. Devices of the invention can be used for a broad range of applications, including, but not limited to, clinical applications (e.g., administration of medicaments, etc.) and biomedical research (e.g., microinjection into cells, nuclear or organelle transplantation, isolation of single cells or hybridomas, etc.).

In one embodiment, fluid delivery device110is a device for dispensing, delivering, or administering the fluid or agent to the user or patient. The fluid may be a low viscosity gel agent and or a therapeutic agent. In one embodiment, the fluid is an analgesic agent. In one embodiment, the fluid is insulin of any type. In one embodiment, the fluid is a U100 insulin. In another embodiment the fluid is a U200 insulin. In another embodiment, the fluid is a U300 insulin. In another embodiment, the fluid is a U500 insulin. In another embodiment, the fluid is any insulin between U100 and U500. In other embodiments, the fluid may be, but is not limited to, opiates and/or other palliatives or analgesics, hormones, psychotropic therapeutic compositions, or any other drug or chemical whose continuous dosing is desirable or efficacious for use in treating patients. Single fluids and combinations of two or more fluids (admixed or co-administered) may be delivered using fluid delivery device110. As used herein “patients” or “user” can be human or non-human animals; the use of fluid delivery device110is not confined solely to human medicine, but can be equally applied to veterinarian medicine.

Fluid delivery device110may dispense the fluid over a sustained period of time (i.e., basal delivery). In one embodiment, the fluid delivery rate is continuously or near continuously delivered to the user over the sustained period of time. Fluid delivery device110may also be capable of dispensing a supplementary amount of fluid, in addition to the basal amount, on demand, under patient control (i.e., bolus delivery). In one embodiment, the bolus amount delivered in a single, selectable administration is pre-determined. In preferred embodiments, fluid delivery device110is hydraulically actuated and comprises one or more reservoirs or chambers containing hydraulic fluid of a suitable viscosity for transferring power from one or more actuators to the fluid and controlling the delivery rate as discussed further below.

Referring toFIG. 1, for example, the fluid delivery device110shown includes a housing112and an adhesive bottom surface114such as a foam pad.

Referring toFIG. 2, fluid delivery device110includes a cartridge222having a fluid reservoir220containing the medicament. The fluid delivery device110may include one or more actuators226(such as a basal actuator),228(such as a bolus actuator) that act on piston224within cartridge222.

Referring toFIGS. 3A and 3B, a needle330may be deployed to fluidly couple fluid reservoir220and the patient. Needle330may be coupled to a button332and the needle330may be bent such that a translation of button332toward the patient causes a fluid coupling end330ato be fluidly coupled to fluid reservoir220and a delivery end330bto extend from bottom surface114.

Liquid pharmaceuticals for subcutaneous delivery mendicants are commonly packaged in cartridge or vials having a fluid reservoir. It is desirable to be able to load these prefilled cartridges into a fluid delivery device for ease of handling rather than have to fill a reservoir already inside of the device.

The cartridges commonly have a septum seal on one end and a piston or plunger inside at an opposite end. The medicament is delivered by fluidly connecting the material inside of the cartridge through the septum with the patient's body and then pressing on the piston.

In most fluid delivery systems, and especially in hydraulically driven fluid delivery devices, the accurate and effective delivery of the medicament requires that there be little, and preferably no, compressible gaps between the drive mechanism and the piston, little, and preferably no, pre-delivery pressure on the piston and that the needle be accurately inserted into the septum.

Inserting a cartridge in a delivery device can result in performance issues due to the length tolerance of the cartridge resulting in unacceptably large gaps that are compressible between the drive mechanism and the piston and a misaligned needle insertion system.

In addition, temperature changes in storage and transport may cause changes in component dimensions and liquid volumes. If there is a significant difference in the coefficients of thermal expansion between components, then there may be significant changes in the components positions which could exacerbate tolerance issues. This is especially significant in hydraulically driven systems where the fluid is likely to have much greater thermal expansion characteristics than the solid components of the device.

It is therefore desired to have a simple to use mechanism that allows a prefilled fluid reservoir or cartridge to be inserted in a delivery device, create a fluid seal to the device minimizing compressible gaps between the drive mechanism and the piston. In one embodiment, the length tolerance of the cartridge usable with the delivery device is at least +/−0.4 mm. The delivery device may allow for minimal pressure in the system due to insertion or the insertion mechanism. The delivery device may allow for proper alignment between the cartridge septum seal and the needle mechanism. It is also beneficial if the delivery device can compensate for thermal expansion effects.

Referring to the drawings in detail, wherein like reference numerals indicate like elements throughout, there is shown inFIGS. 4-12fluid delivery devices in accordance with exemplary embodiments of the present invention. Embodiments of the cartridge configuration may be used with various fluid delivery devices110(seeFIGS. 1-3B) such as the fluid delivery devices disclosed in U.S. Pat. Nos. 9,101,706, 8,740,847, and U.S. Pat. No. 7,481,792 that are hereby incorporated by reference in their entirety.

In some embodiments, the fluid delivery device110,400includes a housing and a bottom surface configured to be coupled to a skin surface in an engaged position. In one embodiment, a cartridge having a fluid reservoir is coupled to the housing and has a septum. In one embodiment, the septum seals one end of the fluid reservoir and a piston (seeFIG. 2) seals the other end. In one embodiment, the patient inserts a pre-filled cartridge into the fluid delivery device prior to use. The septum of the cartridge may have a pierceable portion, the portion of the septum pierced by the needle during use. In one embodiment, the cartridge is comprised of glass, or has an inner glass coating, though other materials for the cartridge such as plastic may be used.

In some embodiments, a needle assembly having a needle may be used to fluidly couple the septum with the skin surface with the desired motion by the user or be configured to automatically deploy upon use of the device. The needle may have a delivery end and a fluid coupling end. Initially, the fluid coupling end may be fluidly disengaged from the fluid reservoir, (e.g., an initial or pre-fluid delivery position). The delivery end of the needle may also be spaced above the bottom surface of the fluid delivery device such that both ends of needle are contained within the housing in the initial position. After the fluid delivery device is adhered to the skin surface in the engaged position, the delivery end of the needle may be extended through the bottom surface of the fluid delivery device and the fluid coupling end of the needle may be extended through the pierceable portion of the septum either simultaneously, at offset times or separately such that fluid reservoir is fluidly coupled with the patient during use (e.g., a deployed, in-use or fluid delivery position).

In some embodiments, where the system is driven by a fluid, the fluid must be contained securely in the device prior to the cartridge being installed. Once installed, the fluid or fluid driven element is operable to urge or push the cartridge piston with minimal and preferably no compressible space between the two.

Referring toFIGS. 4-11, a first exemplary embodiment of a fluid delivery device400is shown. The fluid delivery device400may comprise two main components, the hydraulic drive unit401and the insertable prefilled cartridge420. In one embodiment, the cartridge420includes a fluid reservoir415, containing a medicament, sealed at one end with a piercable element416such as a septum held in place by a crimp cover417and sealed at the other end by an internally movable piston419(seeFIG. 9). The cartridge420also may also include a keyed feature418at one end. In other embodiments, the keyed feature418is proximate the middle and/or other end of the cartridge420. In one embodiment, the keyed feature418is part of a sleeve as shown inFIGS. 4-11, at the piston end of the fluid reservoir415that is attached to the outer surface of the cartridge420and is configured to mate with the hydraulic drive unit401upon insertion of the cartridge420into the hydraulic drive unit401. In one embodiment, the keyed feature418has one or more features418asuch as radially protecting indentations and/or protrusions that are unique to the model of the cartridge that mate with one or more corresponding features of the hydraulic drive unit401. This keyed configuration between the cartridge420and the drive unit401may help to prevent a cartridge420not intended for the specific drive unit401, such as a cartridge containing an undesirable type or volume of medicament, from being inserted into the specific drive unit401.

In the embodiment shown inFIGS. 4-11, the features418aof the cartridge420include one or more groves that correspond with features421such as protrusions of the drive unit401. In other embodiments, the features418aof the cartridge420also or alternatively include protrusions that correspond with the features421of the drive unit401such as indentations. In one embodiment, the one or more features418aof the keyed feature418project radially inwardly and/or outwardly relative to a longitudinal axis A of the cartridge420and extend around the entire circumference of the keyed feature418such that the cartridge420may be inserted into the hydraulic drive unit401in any radial position about axis A. In other embodiments, the one or more features418a,421extend only partially around the circumference of the keyed feature418and/or the drive unit such that the cartridge420may only be inserted into the drive unit401in one or more discrete radial positions about axis A.

In one embodiment, the features421of the drive unit401are proximate the seal receptacle408within the hydraulic drive unit. The drive unit401may include an actuator that drives a hydraulic fluid configured to drive the piston419. The drive unit401may be positioned within a housing402.

Referring toFIG. 8A, in one embodiment, the keyed feature418is a separate part that is joined to the cartridge420with sufficient strength to resist the maximum force applied to the reservoir by the hydraulic system. In one embodiment the keyed feature418is secured to the cartridge420using an adhesive. In one embodiment, the keyed feature418is secured to the cartridge420by a press fit. In one embodiment, the keyed feature418is secured to the cartridge420by a swage of two pieces where an outer annular piece compresses an inner annular part around the reservoir when they the inner piece is pressed axially into the outer annular piece. In one embodiment, the keyed feature418is secured to the cartridge420by welding. In one embodiment, the keyed feature418is secured to a preparatory surface on the cartridge420such as a thin film, an etched surface or an adherent label. In one embodiment, the keyed feature418is secured to the cartridge420by a sleeve that slips over the end of the cartridge420and at least partially over a portion of the seal418b. In one embodiment, the keyed feature418is integrally formed into the cartridge420.

FIG. 5shows the fluid delivery device400with the housing removed to expose the seal receptacle space408.FIG. 6show the cartridge420inserted into the available space within the hydraulic drive unit401. In one embodiment, a door406is coupled to the housing402and configured to be closed over the cartridge420to retain the cartridge420in the drive unit401once the cartridge420is in place. The door406may be configured to force the cartridge420into its fully seated position when the user closes the door406as shown inFIG. 7. In one embodiment, there is an interlock that prevents the door406from closing without a cartridge420being at least partially inserted.

FIGS. 9 and 9Ashow a cross section of one embodiment in which the substantially keyed feature418is pressed into the seal receptacle space408on insertion of the cartridge420. In this embodiment, there is a compliant portion or seal418bthat slides along the rear surface408aof the seal receptacle space408. There are shoulders408bon the opposite end of the seal receptacle space408that fit with the corresponding end of the keyed feature418to force the keyed feature418and thus the seal418bagainst the rear surface408aeffecting a seal between the rear surface408aand the piston end of the cartridge420. In one embodiment, the rear surface408aand the front surface shoulders408bof the seal receptacle space408are spaced a distance approximately equal to the distance between the front and rear of the keyed feature418. In one embodiment, the rear surface408aand the front surface shoulders408bof the seal receptacle space408are spaced a distance less than the distance between the front and rear of the keyed feature418such that the seal418bis compressed against the rear surface408aonce the cartridge is inserted in the drive unit.

In one embodiment, the features421are spaced from the rear surface408aa distance approximately equal to the distance the features418aare spaced from the end of the seal418b. In one embodiment, the features421are spaced from the rear surface408aa distance less than the distance the features418aare spaced from the end of the seal418bsuch that the seal418bis compressed against the rear surface408aonce the cartridge is inserted in the drive unit. By creating the seal force through the fit of the keyed features418,421the length of the cartridge420is not relevant to the creation of the hydraulic fluid seal. In one embodiment, the seal418bis continuous with the keyed feature418and the compliance is a result of a thin feature on the end of the keyed feature418. In one embodiment, the seal418bis an o-ring. In one embodiment, the seal418bis a second shot of compliant material that is co-molded or over-molded with the keyed feature418. In one embodiment, the seal418bis a second part that is placed in a feature of the keyed feature418. In one embodiment, the seal418bis integral with the rear surface408aof the seal receptacle space. In one embodiment, there is no compliant material and the fit and surface quality of the keyed feature418and the surface408aof the seal receptacle space408are sufficient to affect a seal for the hydraulic fluid.

In one embodiment, the keyed feature418is comprised of a material that is less compliant than the seal418b. In one embodiment, the keyed feature418is comprised of polycarbonate. In other embodiments, the keyed feature418is comprised of plastics such as acrylonitrile butadiene styrene (ABS), polypropelene, polysulphone, polyether ether ketone (PEEK), nylon, polyethylene, acrylic, PVC and polystyrene. In one embodiment, the seal418bis comprised of a thermoplastic elastomer (TPE) such as Pebax® with a durometer of less than Shore A70. In other embodiments, the seal418bis comprised of rubbers including butyl, nitrile and silicone.

In one embodiment, as shown inFIG. 9, the hydraulic fluid is not yet in contact with the rear end of the piston419. The fluid is still contained within the hydraulic fluid manifold404by the hydraulic fluid valve407. In one embodiment, to bring pressurized hydraulic fluid in contact with the rear of the piston419the hydraulic valve407is opened by aligning the fluid path through the valve stem407awith the fluid path to the cartridge seal receptacle seal as shown inFIG. 10.

In one embodiment, to connect the medicament delivery path to the patient, the supply end of the needle430is pressed through the piercable element416as shown inFIG. 11making the fluidic connection between the inside of the cartridge420and the delivery needle430.

Referring toFIG. 12, a second exemplary embodiment of the fluid delivery device1200is shown. In one embodiment, the door1206is secured to the keyed feature1218and is part of the cartridge assembly1220. In one embodiment, the door1206and the keyed feature1218are integrally connected. In one embodiment, the door1206and the keyed feature1218are two parts but coupled together prior to insertion into the hydraulic drive unit1201.

In an alternative embodiment, the needle430and the needle support system are secured to the door1206and the door to the keyed feature1218prior to insertion into the hydraulic drive unit1201.

It will be appreciated by those skilled in the art that changes could be made to the exemplary embodiments shown and described above without departing from the broad inventive concepts thereof. It is understood, therefore, that this invention is not limited to the exemplary embodiments shown and described, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the claims. For example, specific features of the exemplary embodiments may or may not be part of the claimed invention and various features of the disclosed embodiments may be combined. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”.

Further, to the extent that the methods of the present invention do not rely on the particular order of steps set forth herein, the particular order of the steps should not be construed as a limitation on the claims. Any claims directed to the methods of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the steps may be varied and still remain within the spirit and scope of the present invention.