Infusion medium delivery device and method with drive device for driving plunger in reservoir

A delivery device includes a durable housing portion and a separable disposable portion that selectively engage and disengage from each other. The disposable housing portion secures to the patient-user and may be disposed of after it has been in use for a prescribed period. Components that normally come into contact with a patient-user or with infusion medium are supported by the disposable housing portion, while the durable housing portion supports other components such as electronics and a drive device. A reservoir is supported by the disposable housing portion and has a moveable plunger that operatively couples to the drive device, when the disposable and durable housing portions are engaged.

FIELD OF THE INVENTION

Embodiments of the present invention relate to an infusion medium delivery device for delivering an infusion medium to a patient-user, where the delivery device includes a base portion and a durable portion connectable to the base portion, where the base portion is securable to a patient-user's skin and can be removed and disposed of after a specified number of uses.

BACKGROUND OF THE INVENTION

Certain chronic diseases may be treated, according to modern medical techniques, by delivering a medication or other substance to a patient's body, either in a continuous manner or at particular times or time intervals within an overall time period. For example, diabetes is a chronic disease that is commonly treated by delivering defined amounts of insulin to the patient at appropriate times. Some common modes of providing an insulin therapy to a patient include delivery of insulin through manually operated syringes and insulin pens. However, other modern systems employ programmable pumps to deliver controlled amounts of insulin to a patient.

Pump type delivery devices have been configured in external devices (that connect to a patient) or implantable devices (to be implanted inside of a patient's body). External pump type delivery devices include devices designed for use in a stationary location (for example, in a hospital or clinic), and further devices configured for ambulatory or portable use (to be carried by a patient). Examples of some external pump type delivery devices are described in Published PCT Application WO 01/70307 (PCT/US01/09139) titled “Exchangeable Electronic Cards For Infusion Devices” (which is owned by the assignee of the present invention), Published PCT Application WO 04/030716 (PCT/US2003/028769) titled “Components And Methods For Patient Infusion Device,” Published PCT Application WO 04/030717 (PCT/US2003/029019) titled “Dispenser Components And Methods For Infusion Device,” U.S. Patent Application Publication No. 2005/0065760 titled “Method For Advising Patients Concerning Doses Of Insulin,” and U.S. Pat. No. 6,589,229 titled “Wearable Self-Contained Drug Infusion Device,” each of which is incorporated herein by reference in its entirety.

External pump type delivery devices may be connected in fluid-flow communication to a patient-user, for example, through a suitable hollow tubing. The hollow tubing may be connected to a hollow needle designed to pierce the patient-user's skin and deliver an infusion medium there-through. Alternatively, the hollow tubing may be connected directly to the patient-user as or through a cannula or set of micro-needles.

In contexts in which the hollow tubing is connected to the patient-user through a hollow needle that pierces the patient-user's skin, a manual insertion of the needle into the patient-user can be somewhat traumatic to the patient-user. Accordingly, insertion tools have been made to assist the insertion of a needle into the patient-user, whereby a needle is forced by a spring to quickly move from a retracted position into an extended position. One example of such an insertion tool is described in U.S. Patent Application Publication No. 2002/0022855, titled “Insertion Device For An Insertion Set And Method Of Using The Same” (assigned to the assignee of the present invention), which is incorporated herein by reference in its entirety. As the needle is moved into the extended position, the needle is quickly forced through the patient-user's skin in a single, relatively abrupt motion that can be less traumatic to a patient-user as compared to a slower, manual insertion of a needle.

As compared to syringes and insulin pens, pump type delivery devices can be significantly more convenient to a patient-user, in that accurate doses of insulin may be calculated and delivered automatically to a patient-user at any time during the day or night. Furthermore, when used in conjunction with glucose sensors or monitors, insulin pumps may be automatically controlled to provide appropriate doses of infusion medium at appropriate times of need, based on sensed or monitored levels of blood glucose.

Pump type delivery devices have become an important aspect of modern medical treatments of various types of medical conditions, such as diabetes. As pump technologies improve and doctors and patient-users become more familiar with such devices, the popularity of external medical infusion pump treatment increases and is expected to increase substantially over the next decade.

DETAILED DESCRIPTION

The present invention relates, generally, to delivery devices, systems and methods for delivering an infusion medium, such as a drug, to a recipient, such as a medical patient-user. In particular embodiments, a delivery device includes a disposable portion that secures to the recipient and that may be readily disposed of after it has been in use for a period of time. Such embodiments may be configured to provide a reliable, user-friendly mechanism to secure the delivery device to a patient-user for delivery of a fluidic infusion medium to the patient-user.

While embodiments of the present invention are described herein with reference to an insulin delivery example for treating diabetes, other embodiments of the invention may be employed for delivering other infusion media to a patient-user for other purposes. For example, further embodiments of the invention may be employed for delivering other types of drugs to treat diseases or medical conditions other than diabetes, including, but not limited to drugs for treating pain or certain types of cancers, pulmonary disorders or HIV. Further embodiments may be employed for delivering media other than drugs, including, but not limited to, nutritional media including nutritional supplements, dyes or other tracing media, saline or other hydration media, or the like. Also, while embodiments of the present invention are described herein for delivering or infusing an infusion medium to a patient-user, other embodiments may be configured to draw a medium from a patient-user.

A generalized representation of an infusion medium delivery system10is shown inFIG. 1, wherein the system includes a delivery device12configured according to an embodiment of the invention described herein. The system10may also include other components coupled for communication with the delivery device12, including, but not limited to, a sensor or monitor14, a command control device (CCD)16and a computer18. Each of the CCD16, the computer18, the sensor or monitor14and the delivery device12may include receiver or transceiver electronics that allow communication with other components of the system. The delivery device12may include electronics and software for analyzing sensor data and for delivering an infusion medium according to sensed data and/or pre-programmed delivery routines. Some of the processing, delivery routine storage and control functions may be carried out by the CCD16and/or the computer18, to allow the delivery device12to be made with more simplified electronics. However, in other embodiments, the system10may include delivery device12that operates without any one or more of the other components of the system10shown inFIG. 1.

In the generalized system diagram ofFIG. 1, the delivery device12and sensor or monitor14are secured to a patient-user1. The locations at which those components are secured to the patient-user1inFIG. 1are provided only as a representative, non-limiting example. The delivery device12and sensor or monitor14may be secured at other locations on the patient-user1, and such locations may depend upon the type of treatment to be administered by the system10. Such other locations may include, but are not limited to, other locations on the patient-user's body, locations on the patient-user's clothing, belt, suspenders, straps, purse, tote or other structure that may be carried by the patient-user.

As described in further detail below, the delivery device12contains a reservoir of an infusion medium and delivers the infusion medium into the patient-user's body in a controlled manner. Control instructions and/or data may be communicated between the delivery device12, the sensor or monitor14, the CCD16and the computer18. The delivery device12may be configured to secure to the skin of a patient-user1, in the manner of a patch, at a desired location on the patient-user. In such embodiments, it is desirable that the delivery device12have relatively small dimensions for comfort and ability to conceal, for example, under a garment.

Examples of patch-like delivery devices are described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, which is incorporated herein, in its entirety. A further example of a patch-like delivery device12is shown inFIGS. 2-5herein. The delivery device12inFIG. 2includes a base housing portion20that, in some embodiments, may be disposable after one or a number of specified uses, and a durable housing portion22. The disposable housing portion20may support structural elements that ordinarily contact the patient-user's skin or the infusion medium, during operation of the delivery device12. On the other hand, the durable housing portion22may support elements (including electronics, motor components, linkage components, and the like) that do not ordinarily contact the patient-user or the infusion medium during operation of the delivery device12. Thus, elements in the durable portion22of the delivery device12are typically not contaminated from contact with the patient-user or the infusion medium during normal operation of the delivery device12.

In the illustrated embodiment, the disposable portion20of the delivery device12includes a base21that includes or otherwise supports a reservoir retaining portion24that houses a reservoir. The durable portion22may include a housing that secures onto the base21adjacent the reservoir retaining portion24. The durable portion22may house a suitable drive device, such as an electrically operated motor (not shown inFIG. 2), and drive linkage components (not shown inFIG. 2) for driving fluid out of the reservoir. The durable portion22also may house suitable control electronics (not shown inFIG. 2) for controlling the operation of the drive device to drive fluid from the reservoir in a controlled manner. Further embodiments may include communication electronics (not shown inFIG. 2) within the durable portion22, for communicating with the sensor or monitor14, the CCD16, the computer18and/or other components of the system10shown inFIG. 1.

The base21of the disposable housing portion20has a bottom surface (facing downward and into the page inFIGS. 2 and 3) that is configured to secure to a patient-user's skin at a desired location on the patient-user. A suitable adhesive may be employed at the interface between the bottom surface of the base21and the patient-user's skin, to adhere the base21to the patient-user's skin. The adhesive may be provided on the bottom surface of the base portion21, with a peelable cover layer23covering the adhesive material. In this manner, a patient-user may peel off the cover layer23to expose the adhesive material and then place the adhesive side of the base21against the patient-user's skin.

The disposable portion20may include a button or other operator25for operating a needle inserter device located within the reservoir retaining portion24. Alternatively, or in addition, reference number25may represent an opening, through which an external needle inserter device may operate. Alternatively, or in addition to an operator or opening25, the needle inserter device may be activated, through a wireless link, from an external controller, such as the CCD16, sensor or monitor14or computer18. For such embodiments, the CCD16, sensor or monitor14or computer18includes a wireless signal transmitter, while the delivery device includes a receiver for receiving a wireless actuation signal and an electronic actuator that is controlled to actuate the needle inserter device, upon receipt of an actuation signal from the CCD16, sensor or monitor14or computer18. Examples of suitable needle inserter device are described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, and U.S. Patent Application Ser. No. 60/839,840 , titled INFUSION MEDIUM DELIVERY SYSTEM, DEVICE AND METHOD WITH NEEDLE INSERTER AND NEEDLE INSERT DEVICE AND METHOD, filed Aug. 23, 2006, each of which is incorporated herein by reference in its entirety. Alternatively, the reservoir retaining portion may include a suitable opening or port for connecting one end of a hollow tube to the reservoir, while the other end of the hollow tube is connected to a hollow needle for piercing the patient-user's skin and conveying the infusion medium from the reservoir into the patient-user, for example, as described with reference toFIG. 2of U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005 and/or as described herein with reference toFIG. 21.

Each of the disposable housing portion20and the durable housing portion22includes a respective housing shell or housing structure (also referred to herein as an enclosure structure). The durable portion22of the delivery device12includes a housing shell configured to mate with and secure to the disposable portion20. The durable portion22and disposable portion20may be provided with correspondingly shaped grooves, notches, tabs or other suitable features that allow the two parts to easily snap together, by manually pressing the two portions together in a manner well known in the mechanical arts. In a similar manner, the durable portion22and disposable portion20may be separated from each other by manually applying sufficient force to unsnap the two parts from each other. In further embodiments, a suitable seal, such as an o-ring seal, may be placed along the peripheral edge of the disposable portion20and/or the durable portion22, so as to provide a seal against water between the disposable portion20and the durable portion22.

The durable portion22and disposable portion20may be made of suitably rigid materials that maintain their shape, yet provide sufficient flexibility and resilience to effectively snap together and apart, as described above. The base21material may be selected for suitable compatibility with the patient-user's skin. For example, the disposable portion20and the durable portion22of the delivery device12may be made of any suitable plastic, metal, composite material or the like. The disposable portion20may be made of the same type of material or a different material relative to the durable portion22. The disposable portion and durable portions may be manufactured by injection molding or other molding processes, machining processes or combinations thereof.

The base21of the disposable housing portion20may be made of a relatively flexible material, such as a flexible silicone, plastic, rubber, synthetic rubber or the like. By forming the base21of a material capable of flexing with the patient-user's skin, a greater level of patient-user comfort may be achieved when the base is secured to the patient-user's skin. Also, a flexible base21can result in an increase in the site options on the patient-user's body at which the base21may be secured.

The disposable portion20and/or the durable portion22may include an internal sensor (not shown inFIGS. 2 and 3) for connection to a patient-user, for example, through a needle (not shown inFIGS. 2 and 3) or a set of micro-needles for piercing a patient-user's skin when the disposable portion20is secured to a patient-user's skin. In such embodiments, a suitable aperture (not shown inFIGS. 2 and 3) may be formed in the base21, to allow the passage of the sensor needle or micro-needles, when the sensor needle to pierce a patient-user's skin. Alternatively, or in addition, micro-needles may be arranged on or through the adhesive material on the base21, to pass through the patient-user's skin, when the base21is adhered to the patient-user's skin. Alternatively, the durable portion20of the delivery device12may be connected to an external sensor14, through a sensor lead, as described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005. The sensor may include any suitable biological sensing device, depending upon the nature of the treatment to be administered by the delivery device12. For example, in the context of delivering insulin to a diabetes patient-user, the sensor14may include a blood glucose sensor. Alternatively, or in addition, one or more environmental sensing devices may be included in or on the delivery device12, for sensing one or more environmental conditions.

As described above, by separating disposable elements of the delivery device12from durable elements, the disposable elements may be arranged on the disposable portion20, while durable elements may be arranged within a separable durable portion22. In this regard, after one (or a prescribed number) of uses of the delivery device12, the disposable portion20may be separated from the durable portion22, so that the disposable portion20may be disposed of in a proper manner. The durable portion22may; then, be mated with a new (un-used, pre-filled, refurbished, refilled or re-manufactured) disposable portion20for further delivery operation with a patient-user.

A reservoir26may be supported by the reservoir retaining portion24of the disposable portion20in any suitable manner. The reservoir26may be a hollow internal volume of the reservoir retaining portion24, such as, but not limited to, a cylindrical-shaped volume as shown in broken lines inFIG. 3. Alternatively, the reservoir26may be a cartridge or generally cylindrical canister having a shape and size to be received within a hollow internal volume of the reservoir retaining portion. The reservoir26is configured for containing a fluidic infusion medium.

The reservoir26has a port and a septum. The septum is located in a position at which a hollow needle or cannula may pass through the septum and into a patient-user's skin, when the disposable housing portion20is secured to a patient-user's skin, as described below. In other embodiments, the port and septum of the reservoir26may be connectable to a patient-user, through an external needle or cannula, through a connector and external tubing, as shown inFIG. 2of U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, for providing a fluid flow path between the reservoir26and the patient-user, when the disposable housing portion20is secured to a patient-user's skin. In further embodiments, the port or septum may be used (alternatively or in addition to an outlet port) for filling or re-filling the reservoir26, for example, but not limited to, inserting a syringe through the septum and passing fluid from the syringe into the reservoir.

The durable portion22of the delivery device12may include a motor or other force-applying mechanism, for applying a force to the infusion medium within the reservoir26to force the fluidic infusion medium out of the reservoir26and into the hollow needle or cannula (not shown inFIGS. 2 and 3), for delivery to the patient-user. For example, an electrically driven motor may be mounted within the durable portion22with appropriate linkage for causing the motor to operably connect to (through the linkage) a piston plunger within the reservoir and drive the piston plunger in a direction to force the fluidic infusion medium out of the reservoir port and into the patient-user. The motor may be arranged within the durable portion22and the reservoir26may be correspondingly arranged on the disposable portion20, such that the operable connection of the motor with the reservoir piston (e.g., through appropriate linkage) occurs automatically upon the patient-user snap fitting the durable portion22onto the disposable portion20of the delivery device12.

One example of a motor and reservoir configuration is shown inFIG. 4. In the embodiment ofFIG. 4, the reservoir26(shown in cross-section) is a canister, for example, made of a suitable metal, plastic, ceramic, glass, composite material or the like, and having a hollow interior28for containing a fluidic infusion medium. For example, the canister may be formed of a plastic material referred to as TOPAS (trademark of Ticona, a subsidiary of Celanese Corporation), such as described in U.S. patent application Ser. No. 11/100,188, filed Apr. 5, 2005 (Publication No. 2005/0197626), the contents of which is incorporated herein in its entirety.

The canister reservoir26inFIG. 4may be configured to fit within and be removable from a correspondingly-shaped opening and volume in the reservoir retaining portion24shown inFIG. 3. In such embodiments, the canister reservoir26and reservoir retaining portion24may include one or more mating protrusions, grooves, indentations and/or non-circular cross-section that restrain the canister reservoir26from rotating about the axis A relative to the reservoir retaining portion24, once the canister reservoir26is fitted within the reservoir retaining portion24. In further embodiments, a canister reservoir26may be permanently fixed within the interior volume of the reservoir retaining portion24.

By supporting a canister reservoir26in a manner that allows the reservoir26(and piston plunger32) to be removed and replaced relative to the remainder of the disposable portion20, a user may replace a spent canister reservoir26with a new (un-used, pre-filled, refurbished, refilled or re-manufactured) canister reservoir26(and piston plunger32), while the disposable portion remains secured to the patient-user's skin. In this manner, the same disposable portion20may be used for multiple new reservoirs26and, then, disposed of after a prescribed number of new or re-filled reservoirs have been used on the disposable portion20, while the same durable portion22may be used for multiple disposable portion20replacements.

As described above, in yet further embodiments, the reservoir26may be formed unitarily with the reservoir retaining portion24, for example, as a shaped, hollow interior of the reservoir retaining portion24. In such embodiments, the hollow interior of the reservoir retaining portion24may be coated or otherwise lined with a suitable metal, plastic, plastic, TOPAS (trademark of Ticona, a subsidiary of Celanese Corporation), ceramic, glass, composite material or the like. Alternatively, or in addition, the retaining portion24, itself, may be made of a suitable metal, plastic, plastic, TOPAS (trademark of Ticona, a subsidiary of Celanese Corporation), ceramic, glass, composite material or the like.

The reservoir26includes a septum30that can be pierced by a hollow needle or cannula to provide a hollow flow path from the interior28of the reservoir26to the patient-user. Examples of mechanisms that may be used for moving a hollow needle through a septum of a reservoir are described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, and U.S. Patent Application Ser. No. 60/839,840, titled INFUSION MEDIUM DELIVERY SYSTEM, DEVICE AND METHOD WITH NEEDLE INSERTER AND NEEDLE INSERT DEVICE AND METHOD, filed Aug. 23, 2006. Alternatively, or in addition, the septum30may include a surface that is exposed through a wall of the reservoir retaining portion, for refilling the reservoir26or withdrawing infusion medium from the reservoir26, for example, by piercing the exposed surface of the septum with a syringe, hollow needle or cannula. The septum30may be formed of a suitable material, such as, but not limited to, rubber, silicone rubber, polyurethane or other materials that may be pierced by a needle and form a seal around the needle.

With reference toFIG. 5, the septum30may be configured such that a hollow needle or cannula100may be passed through the septum to create a fluid flow path between the interior28of the reservoir26and a patient-user1. In particular, when the hollow needle or cannula100is passed through the septum30, a side opening104in the hollow needle or cannula100may be aligned with a channel or indentation31in the septum30to form a fluid flow path between the hollow interior of the needle and the interior28of the reservoir26. The hollow needle or cannula100includes a patient-end opening106, to form a fluid flow path between the hollow interior of the needle or cannula100and a patient-user1, upon the sharp end of the needle or an open end of the cannula being inserted in a patient-user's skin. Alternatively, an injection site for inserting a hollow needle or cannula into a patient-user and coupling the needle or cannula in fluid flow communication with the reservoir, as described below with reference to the injection site132inFIG. 8, may be employed in the embodiment ofFIGS. 1-5. In further embodiments, the injection site may comprise a set of hollow micro-needles arranged to pierce a patient-user's skin, when the disposable housing portion20is secured to the patient-user's skin, wherein the micro-needles are connected in fluid-flow communication (for example, through a manifold structure) to the reservoir26.

A piston plunger32is moveable within the interior of the reservoir, for changing the volume of the fluid-containing portion of the interior28of the reservoir26. When a hollow needle or cannula is passed through the septum30(or a set of micro-needles are arranged in fluid flow communication with the reservoir) to form a fluid flow path from the reservoir to a patient-user, as described herein, infusion medium inside of the reservoir26may be expelled from the reservoir, to the patient-user, in response to a force applied by the piston plunger32.

The piston plunger32extends partially into the interior of the reservoir26from the opposite side of the canister relative to the septum30. The piston plunger32may be made of a suitably rigid material, such as but not limited to metal, plastic, ceramic, glass or composite material, and has a head34that has an outside diameter of slightly less than the inside diameter of the interior28of the reservoir26. Alternatively, the piston plunger32may be made of a compressible material (such as, but not limited to, an elastically compressible plastic, rubber, silicone, or the like) and may be slightly larger in diameter than the inside diameter of the interior28of the reservoir26, so as to be compressed sufficiently to fit within the interior28of the reservoir26. One or more seals, such as but not limited to o-ring type seals36, may be arranged within annular grooves provided on the piston plunger head34. The o-ring seals36may be made of any suitable material, including, but not limited to rubber, plastic, metal, composite material or the like, where such o-rings provide a sealing function for inhibiting the leakage of infusion medium from the piston-plunger end of the reservoir26. The materials from which the canister portion of the reservoir26, piston plunger32and seal(s)36are made are preferably selected for suitable strength and durability characteristics, as well as compatibility with the infusion medium.

The piston plunger32and the interior surface of the reservoir26may include an anti-rotation structure, such as, but not limited to, one or more mating protrusions, grooves, indentations similar to those described below with respect toFIG. 10and/or non-circular cross-section that restrain the piston plunger32from rotating about the axis A relative to the reservoir26. Alternatively, the anti-rotation feature may include one or more seals, such as the seal(s)36, provided that such seal(s) have sufficient frictional resistance with the interior surface of the reservoir26to inhibit rotation of the piston plunger32about the axis A, relative to the reservoir26. For embodiments in which one or more protrusions and mating grooves are provided on the piston plunger32and interior surface of the reservoir26, the protrusions and grooves may be formed with sufficiently slowly arched or curved surfaces (instead of abrupt angles or corners), to allow a seal to be readily placed over the surfaces and seal against the piston plunger32and interior surface of the reservoir26. In yet further embodiments, an anti-rotation structure may be provided on the piston shaft40and may include any suitable structure for engaging a surface of the durable housing portion22or disposable housing portion20(or other suitable surface structure supported by the durable housing portion22or the disposable housing portion20) and inhibiting rotation of the piston shaft40about the axis A.

The piston plunger32inFIG. 4includes an engagement portion38, located external to the interior28of the reservoir26and connected by a plunger shaft40to the plunger head34. The piston plunger32is configured to be moveable in the axial direction A of the reservoir26. The fluid-containing portion of the interior volume28of the reservoir26varies, with movement of the piston plunger32in the axial direction A of the reservoir26. The engagement portion38is provided with keys, key slots or threads39(hereinafter referred to as threads) that are configured to operatively engage corresponding key slots, keys or threads (hereinafter, referred to as threads) on a lead shaft42. As described in more detail below, when the engagement portion38is operatively engaged with the lead shaft42and a drive motor44rotates the lead shaft42, the piston plunger32will move axially within the reservoir26.

The anti-rotation structure described above inhibits the piston plunger32from rotating about the axis A. Accordingly, the piston plunger32may be arranged in, and inhibited from rotating away from, a position in which the threaded surface39of the engagement portion38faces a direction that allows the surface39to automatically align with and readily come into operable engagement with the lead shaft42when the durable portion22and the disposable portion20are arranged together for coupling.

The lead shaft42may be supported for rotation on the durable portion22of the delivery device12. For example, one or more bearings or other suitable structure may be fixed in the durable portion for supporting the lead shaft42for rotation about its longitudinal axis. In the embodiment ofFIG. 4, the lead shaft42is supported at two locations by two rotary bearings43aand43b. In other embodiments, the lead shaft42may be supported in more than two locations by more than two bearings or may be supported in a cantilevered fashion at one location by a single bearing43aor43b. A portion of the length of the lead shaft42may be exposed for engagement with the engagement portion38of the piston plunger32. The lead shaft42extends through an opening in the durable portion22such that a further portion of the lead shaft42is located within the enclosed interior54of the durable portion22, for engagement with drive linkage, as described below. One or more seals45may be located around the lead shaft42, between the exposed portion of the lead shaft and the further portion of the lead shaft located in the durable portion22. In this manner, the seal(s)45may inhibit fluid from entering the opening in the durable portion22through which the lead shaft42extends. The seal(s)45may be made of any suitable seal material, including, but not limited to silicone or other flexible plastic, metal, ceramic, composite material or the like. In further embodiments, the seal(s)45may comprise a material and/or seal configuration that provides a liquid-tight seal, but allows the passage of air to allow equalization of pressure between the interior54of the durable housing portion22and the environment exterior of the durable housing portion22. In yet other embodiments, a pressure equalization port opening may be provided in any suitable location of the durable housing portion, to provide air-flow communication between the interior54and exterior of the durable housing portion. In such embodiments, the air-flow communication port may be covered with a material that allows the passage of air, but inhibits the passage of water or other liquids.

A drive motor44is mechanically coupled to the lead shaft42, to drive the lead shaft in a rotary motion about its longitudinal axis, in a controlled manner. The motor44may be coupled to the lead shaft42through one or more suitable gears, belts, chains, drive shafts or other linkage structure. The linkage structure may be configured to provide a torque conversion, for example, to increase torque and decrease rotational speed at the lead shaft, relative to the torque and speed output of the motor44. Accordingly, the motor44may produce relatively high-speed rotational motion, which may be converted through the linkage structure to a lower speed of rotation, but higher torque applied to the lead shaft. In the embodiment illustrated inFIG. 4, the motor44includes a drive gear46, while the shaft42is provided with an engagement gear47. A linking gear48is arranged between the drive gear46and the engagement gear47, to convey rotary drive force from the motor44to the shaft42. The linking gear48inFIG. 4includes hub portion49for engaging the drive gear46, and a main portion50for engaging the engagement gear47. The hub portion49is fixed to the main portion50and has a smaller diameter than the main portion50. In other embodiments, a linking gear48may be arranged such that a smaller diameter hub portion engages the engagement gear47, while a larger diameter main portion engages the drive gear46. In yet further embodiments, additional gears may be interposed between some or each of the gears46,47and48, to convey rotational motion from the motor44to rotational motion of the lead shaft42. In yet further embodiments, the linking gear48may be eliminated and the drive gear46may be arranged to directly engage the engagement gear47. In yet further embodiments, other linkage structure may be employed to operatively link the motor44to the lead shaft42.

The drive gear46, the linking gear47and engagement gear48form a gear train for transferring motor drive force from the motor44to the lead shaft42. In this manner, as the motor rotatably drives the motor drive shaft, the gear train transfers the motor drive force to rotate the lead shaft42. When the piston plunger32is engaged with the lead shaft42, rotation of the lead shaft42causes the engagement portion38of the piston plunger32to ride along a portion of the threaded length of the lead shaft42. In this manner, the rotation of the lead shaft42is transferred to an axial movement of the piston plunger32, when the piston plunger is engaged with the lead shaft42. The available length of travel of piston plunger32is dependant upon the length of the threaded portion of the lead shaft42, the length of the piston plunger shaft40and the starting location of the engagement portion38of the piston plunger along the threaded length of the lead shaft42.

The lead shaft42inFIG. 4may be provided with threads along most or all of the length of the exposed portion of the shaft, to allow operable engagement of the threads on the engagement portion38to the corresponding threads on the lead shaft42at any location along the length of the exposed portion of the lead shaft42. To further assist the operable engagement of the threads on the engagement portion38to the corresponding threads on the lead shaft42, the engagement portion38may be provided with a arcuate surface on which the threads are arranged, as shown inFIG. 6a. The threaded arcuate surface of the engagement portion38may extend around one half or less (180 degrees or less) of the circumference of the lead shaft42, when the engagement portion38is engaged with the lead shaft42(i.e., when the durable housing portion and disposable housing portion are engaged as shown inFIG. 2). In further embodiments, the threaded arcuate surface of the engagement portion38may extend around a little more than one half (more than 180 degrees) of the circumference of the lead shaft42and may be composed of sufficiently resilient, flexible material to provide a snap-fit with the lead shaft, when the engagement portion38is engaged with the lead shaft42(i.e., when the durable housing portion and disposable housing portion are engaged as shown inFIG. 2).

In other embodiments as represented inFIG. 6, the piston plunger shaft40may be provided with teeth (or threads) along its length and the lead shaft42may have a disk-shaped threaded head portion41that may be relatively short in length in the axial direction A. The threaded head portion41has threads on its outer peripheral surface to engage the teeth (or threads) of the piston plunger shaft40, for example, in a rack and pinion type of an arrangement, wherein the piston plunger shaft40may include a toothed rack and the threaded head portion41may function as a pinion gear. In embodiments as shown inFIG. 6, the piston plunger shaft40may be provided with an arcuate surface51on which the teeth (or threads) are located. The arcuate surface51extends along the longitudinal dimension of the piston plunger shaft40, outside of the interior portion28of the reservoir26and arcs partially around the axis of the lead shaft42, to engage the head portion41, when the durable housing portion and the disposable housing portion are engaged as shown inFIG. 2. The radius of the arcuate surface51may approximate the radius of the disk-shaped head41, to allow the head41to readily, operatively engage the piston plunger shaft and to increase the surface area of engagement between those components, when the durable housing portion and disposable housing portion are engaged as shown inFIG. 2.

Similar to the arcuate surface of the engagement portion38inFIG. 4described above, the arcuate surface51of the piston plunger shaft40inFIG. 6may extend around one half or less (180 degrees or less) of the circumference of the lead shaft42, when the piston plunger shaft40is engaged with the lead shaft42(i.e., when the durable housing portion and disposable housing portion are engaged as shown inFIG. 2). In further embodiments, the arcuate surface51of the piston plunger shaft40may extend around a little more than one half (more than 180 degrees) of the circumference of the lead shaft42and may be composed of sufficiently resilient, flexible material to provide a snap-fit with the lead shaft, when the piston plunger shaft40is engaged with the lead shaft42(i.e., when the durable housing portion and disposable housing portion are engaged as shown inFIG. 2).

In the embodiments ofFIGS. 4 and 6, one of the lead shaft42or the piston plunger shaft40includes a threaded portion extending a length along the direction of axis A, beyond the length in the direction of axis A of the fluid containing portion28of the reservoir26. The piston plunger shaft40may be provided with threads along most or all of the length of the exposed portion of the shaft, to allow operable engagement with the lead shaft42or threaded head portion41, at any location along the length of the exposed portion of the piston plunger shaft40.

The motor44, lead shaft42and any linkage between the motor and lead shaft may be supported by the durable portion22of the delivery device in a location at which the threaded portion of the shaft42engages the threaded portion of the piston plunger32, as shown inFIGS. 4or6. In this manner, when the durable portion22is arranged to be snap fitted onto the disposable portion20, the threaded portion of the shaft42operatively engages the threaded portion of the piston plunger32without requiring further user manipulation of the elements.

While not shown inFIG. 4, the motor44may be provided with electrical terminals for connection to a motor control circuit52. The motor control circuit52may be mounted within the durable portion22of the delivery device, for controlling the operation of the motor according to a desired infusion delivery program or profile. A delivery program or profile may be stored within a suitable electronic storage medium (not shown) located within the durable portion22and/or may be communicated to the delivery device12from other sources, such as a CCD16or a computer18(as shown inFIG. 1). In such embodiments, the delivery program or profile may be employed by the motor control circuit52to control the operation of the motor44in accordance with the delivery program or profile. Alternatively or in addition, the motor control circuit52may control the motor44to deliver one or more discrete volumes of infusion medium in response to delivery demand control signals generated within the device12or communicated to the device12from other sources, such as a CCD16, sensor or monitor14or a computer18(as shown inFIG. 1).

The durable portion22may contain additional electronic circuitry (not shown) for communication with external devices such as the CCD16or computer18, for storage of sensor data or other data, for processing and control functions, or for other functions. The durable portion22may have a user interface (not shown) including one or more buttons, electronic display, or the like, to allow a user to access data and/or input data or instructions to control electronic circuitry within the durable portion22.

In some embodiments, the durable portion22may contain a battery, high energy capacitor or other electronic power source (not shown) for providing electrical power to the motor44, motor control circuit52and other electronic circuitry contained in the durable portion22. In such embodiments, the battery, high energy capacitor or other electronic power source may be rechargeable through a recharge connector (not shown) provided on the durable portion22. In other embodiments, a battery, capacitor or other electronic power source (not shown) may be supported on the disposable portion20and connectable to the motor44, motor control circuit52and other electronic circuitry in the durable housing portion, through electrical connectors that make an electrical connection upon the durable portion22being coupled to the disposable portion20, without additional manual manipulation. Such electrical connectors may include one or more pairs of conductive pads, where each pair of pads is connected to opposite poles of the power source and located on any suitable surface of the disposable portion20that engages a corresponding surface on the durable portion22, when the durable portion22is coupled to the disposable portion20. In such embodiments, the corresponding surface of the durable portion22includes one or more corresponding pairs of conductive pads that are electrically connected to the motor44, motor control circuit52and other electronic circuitry in the durable housing portion and are arranged to engage the conductive pads on the disposable portion, when the durable portion22is coupled to the disposable portion20.

The durable portion22includes an interior volume54that contains the motor44, gears46-48, motor control circuit52, other electronic circuitry and, in some embodiments described above, a power source. To protect those electrical and mechanical components from certain environmental conditions (such as, but not limited to, moisture, air, biological or medical fluids), the interior volume54of the durable portion22may be suitably sealed from the external environment by the housing structure55that forms the durable portion22and the seal(s)45for the opening through which the lead shaft42extends. Accordingly, the housing structure of the durable portion22and the seal(s)45may form a suitable moisture-tight seal, air-tight seal and/or hermetic seal, to protect the electronic components located in the interior volume54and/or separate those components from environmental, medical or biological materials to which the disposable portion20is exposed during normal operation. The gear train composed of gears46,47and48, may be included in the sealed interior volume54, to protect and/or separate those mechanical components from environmental or biological materials, as well.

As discussed above, in the arrangement illustrated inFIGS. 2,3,4and6, the durable portion22may be snap fitted onto the disposable portion20, where the threaded portion of the lead shaft42automatically engages the threaded portion of the piston plunger32without requiring further user manipulation of the elements. In the embodiment ofFIG. 4, the threaded surface39of an engagement portion38of the piston plunger32may have an arcuate surface that curves around a portion of the longitudinal axis of the lead shaft42. By providing the surface of the engagement portion38of the piston plunger32with an arcuate shape that curves around a portion of the longitudinal axis of the lead shaft42, the surface area of the surface39that engages the lead shaft42may be increased. In addition, the curvature of the surface39of the engagement portion38around a portion of the longitudinal axis of the lead shaft42can help to inhibit inadvertent separation of the engagement portion38and the lead shaft42, once the engagement portion38is engaged with the lead shaft42. The curvature of the surface39also may allow the engagement portion38to easily align with and operably engage the lead shaft42, by bringing the lead shaft42into contact with the engagement portion38as a consequence of the manual operation of coupling the durable portion22to the disposable portion20.

As described above, when the durable portion22and the disposable portion20are fitted together with the lead shaft42engaging the engagement portion38of the piston plunger32, the motor44may be controlled to rotatably drive the lead shaft42and, thus, move the piston plunger32in the axial direction A of the reservoir26. When the volume28of the reservoir26is filled with an infusion medium and a hollow needle or cannula is positioned in the septum30of the reservoir to form a fluid flow path between the reservoir26and a patient-user, the piston plunger32may be controlled to move in the axial direction A, toward the septum30end of the reservoir26, to force infusion medium from the reservoir volume28, through the hollow needle or cannula and to the patient-user.

Once the reservoir26has been sufficiently emptied or otherwise requires replacement, the patient-user may simply unsnap and remove the durable portion22from the disposable portion20of the delivery device12and replace the disposable portion20(including the reservoir) with a new disposable portion having a prefilled or re-filled reservoir26. The durable portion22may be snap fitted onto the new disposable portion and the delivery device (including the new disposable portion) may be secured to the patient-user's skin, as described above.

In further embodiments in which the reservoir26includes a reservoir canister that fits within a hollow interior of the reservoir retaining portion24, the canister may be removed from the retaining portion24and replaced with a new canister, to allow the disposable portion22to be remain in place on a patient-user for more than one reservoir depletion period. In such embodiments, the reservoir canister may be replaced one or more times during the operable life of the disposable portion20and the disposable portion20may be removed from the patient-user and replaced with a new or remanufactured disposable portion20, for example, after a predefined number of reservoir canister replacement operations.

The drive motor44inFIG. 4may include any suitable rotary drive device that converts electrical power to mechanical, rotary motion. Examples of a suitable rotary drive motor44include, but are not limited to, a DC motor, flat or pancake DC motor, servo motor, stepper motor, electronically commutated motor, rotary piezo-electrically actuated motor, and the like. In further embodiments, the drive motor44may include a bender or linear actuator in combination with an escapement wheel arrangement, to rotatably drive the lead shaft42. For example, a drive device for rotatably driving the lead shaft42may include a piezo-electrically actuated bender and escapement wheel arrangement, a thermally actuated bender and escapement wheel arrangement, a shape memory alloy wire and escapement wheel arrangement, an electronically actuated solenoid and escapement wheel arrangement, or the like.

Escapement wheel arrangements operable with bender or linear actuators in accordance with example embodiments of the present invention are described with reference toFIGS. 7a-7c. As shown inFIG. 7a, an escapement wheel60is supported for rotation around an axis Al (extending into the page), in the direction of arrow62. The escapement wheel60has an outer peripheral edge provided with serrations or teeth64. Each tooth64includes a sloped surface66arranged at an obtuse angle relative to an axial direction of the wheel60and a catch surface65in a substantially axial direction of the wheel. A drive pawl68is located adjacent to the escapement wheel60and at least partially between two of the teeth on the escapement wheel. The drive pawl68is supported for movement in a generally linear direction, as represented by the double arrow69, between a start position S and an end position E.

The drive pawl68has a drive surface70for engaging the catch surface65of an adjacent tooth64on the escapement wheel60, when the drive pawl68is moved in a direction from the start position S to the end position E. The drive pawl68has a further surface71facing away from the drive surface70and configured for riding over the sloping surface66of a tooth64on the escapement wheel60, when the drive pawl is moved in a return direction from the end position E to the start position S. The further surface71of the drive pawl68may be sloped at an angle relative to the radial direction of drive wheel, to assist the drive pawl68in riding over the sloping surface66of a tooth64of the escapement wheel.

As described in more detail below, the drive pawl68is coupled to a bender or linear motion actuator to selectively drive the drive pawl68from the start position S to the end position E. With each motion of the drive pawl68from the start position S to the end position E, the surface70engages the catch surface65of a tooth64on the escapement wheel and rotates the escapement wheel60a small distance. A bias member72is operably coupled to the drive pawl68, to bias the drive pawl68in a return direction, to return the drive pawl68to the start position. The bias member72may include a spring as shown inFIG. 7aor other suitable mechanism for providing a bias force to return the drive pawl68to the start position, including, but not limited to a permanent magnet, electromagnet, electronic or thermal linear actuator, shaped memory allow actuator, or the like. In the illustrated embodiment, the bias member72is a coil spring having one end coupled to the drive pawl68and another end coupled to a fixed surface, for example, a fixed surface of a wall or other fixed structure of or within the durable portion22of the drive mechanism12described above.

A further pawl74may be provided to inhibit back rotation of the escapement wheel60in the direction opposite to the direction of arrow62. For example, the further pawl74may be located adjacent the escapement wheel60and at least partially between two of the teeth on the escapement wheel. The further pawl74has a surface76for engaging the catch surface66of an adjacent tooth64on the escapement wheel60, to inhibit rotary motion of the escapement wheel60in the direction opposite to the direction of arrow62.

The pawl74has a further surface77facing opposite to the surface76, configured for riding over the sloping surface66of a tooth64on the escapement wheel60, when the escapement wheel is driven in the rotary direction of arrow62by action of the drive pawl68. The surface77of the pawl74may be angled relative to the radial direction of the drive wheel, to assist the pawl74in riding over the sloping surface66of a tooth64of the escapement wheel. The pawl74may be supported for pivotal motion about a pivot point78in the direction of double arrow79, to allow the surface77of the pawl74to pivot in a direction away from the escapement wheel, to further assist the pawl74in riding over the sloping surface66of a tooth64of the escapement wheel.

A bias member80may be arranged to bias the surface76of the pawl74toward the escapement wheel, to return the pawl74to a position in which the surface76engages the catch surface65of a tooth64, after the pawl74has ridden over the sloping surface66of an adjacent tooth64of the escapement wheel. The bias member80may include a spring as shown inFIG. 7aor other suitable mechanism for providing a bias force to return the pawl74to the position in which the pawl surface76engages the catch surface65of a tooth64, including, but not limited to a permanent magnet, electromagnet, electronic or thermal linear actuator, shaped memory allow actuator, or the like. In the illustrated embodiment, the bias member80includes a coil spring having one end coupled to the pawl74and another end coupled to a fixed surface, for example, a fixed surface of a wall or other fixed structure of or within the durable portion22of the drive mechanism12described above. In further embodiments, a leaf spring or other suitable spring structure may be employed, instead of a coil spring. For example, a spring may be located around or within the pivot point78of the pawl74for effecting the bias force described above.

As described above, the drive pawl68is coupled to a bender or linear motion actuator to selectively drive the drive pawl68and cause the escapement wheel to rotate a small distance with each motion of the drive pawl68from the start position S to the end position E. A bender or linear actuator may include a piezoelectric bender or piezoelectric actuator, a thermally actuated bender, a shape memory alloy wire, an electronically actuated solenoid, or the like. Such actuators for providing small, generally linear movements in response to the application of an electrical power signal are known.

As shown inFIG. 7b, a bender actuator82may be configured to include a connector end84that is provided with a lateral motion represented by arrow86relative to a major axis A2of the actuator body, when a power signal is applied to the actuator. Alternatively, as shown inFIG. 7c, a linear actuator88may be configured to include a connector end90that is provided with a longitudinal motion represented by arrow92relative to a major axis A3of the actuator body, when a power signal is applied to the actuator. A bender actuator as shown inFIG. 7b, for providing lateral motion, may be coupled to the drive pawl68at a connection location96. The connection location96for a bender actuator may be on a surface of the drive pawl68that is substantially perpendicular to the drive surface70. Alternatively, a linear actuator as shown inFIG. 7c, for providing longitudinal motion, may be coupled to the drive pawl68at a connection location98. The connection location98for a linear actuator may be on a surface of the drive pawl68that is substantially parallel to the drive surface70. In that manner, a bender or a linear actuator as shown inFIGS. 7band7cmay be employed to selectively move the drive pawl68from the start position S to the end position E and, thus drive the escapement wheel60in a rotary manner. In yet further embodiments, the drive pawl68may be eliminated and the bender or linear actuator may be arranged to directly engage the catch surfaces of the teeth on the escapement wheel60.

The escapement wheel60may be configured to rotate the rotary distance of one tooth for each movement of the drive pawl68from the start position S to the end position E. In further embodiments, the drive pawl68may be configured to cause the escapement wheel60to rotate a rotary distance of a pre-defined number of teeth greater than one tooth, for each movement of the drive pawl68from the start position S to the end position E. The escapement wheel60may be coupled to the lead shaft42, to rotate the lead shaft42with rotation of the escapement wheel60. In one embodiment, the lead shaft42may be connected in axial alignment directly to the escapement wheel60, such that the rotary axis A1of the escapement wheel is in alignment with the longitudinal axis of the lead shaft42. In other embodiments, the escapement wheel60may be coupled, in axial alignment, with any one of the drive gear46, engagement gear47or linking gear48shown inFIG. 4, to transfer rotary motion of the escapement wheel60to the lead shaft42. In yet further embodiments, other suitable gear and linkage arrangements may be employed for transferring rotary motion of the escapement wheel60to the lead shaft42.

The use of bender or linear actuators with escapement wheel arrangements as described above may provide certain advantages over electric motor and linkage arrangements, in that the bender or linear actuators can provide a repeatable, controlled, step-like response to an electrical power signal. In the context of driving a delivery device for delivering a medication to a patient-user, the ability to accurately control the drive response can provide significant advantages, for example, in administering accurate quantities, small quantities at accurate levels and accurate recording of delivered quantities of the medication. In addition, bender or linear actuators with escapement wheel arrangements can be made relatively small and flat and can, therefore, improve the ability to form the delivery device12with a relatively small and flat shape. In addition, bender or linear actuators with escapement wheel arrangements can operate with relatively low power requirements, thus prolonging the operational life of the power source and allowing smaller power sources to be employed, thus, allowing further reductions in the size of the delivery device.

Other types of drive devices may be coupled to an escapement wheel60, as shown inFIG. 7d, to provide a controlled, step-like response. For example, in the embodiment shown inFIG. 7d, the escapement wheel60has one tooth and is coupled to the lead shaft42as described above, while a second toothed wheel99is operatively coupled to the lead shaft27, for example, through a suitable linkage structure as described herein. The escapement wheel60may be driven by any suitable rotary drive source, including, but not limited to a DC motor, flat or pancake DC motor, servo motor, stepper motor, electronically commutated motor, rotary piezo-electrically actuated motor, and the like. While the escapement wheel60inFIG. 7dis provided with a single tooth to effect a rotation of the second wheel99a rotary distance of a single tooth for each complete rotation of the escapement wheel60, other embodiments may employ an escapement wheel60having two teeth (or another pre-defined number of teeth) for effecting a rotation of the second wheel99a rotary distance of two teeth (or the pre-defined number of teeth) for each complete rotation of the escapement wheel60.

The above embodiments involve various manners of conveying a drive force to the lead shaft42, to rotate the lead shaft42and drive a piston plunger32within the reservoir26. Further embodiments may employ other mechanisms for driving a plunger within a reservoir, to selectively deliver infusion medium from the reservoir.

For example,FIGS. 8-12show a further embodiment of a delivery device, which includes a disposable portion120and a durable portion122. The disposable portion has a reservoir retaining portion124in which a reservoir126is located. The disposable portion120, durable portion122, reservoir retaining portion124and reservoir126may be similar to the disposable portion20, durable portion22, reservoir retaining portion24and reservoir26described above with respect toFIGS. 2-6. However, the reservoir126inFIGS. 8-12employs a rotatable plunger shaft127located within the reservoir interior128, instead of the arrangement shown inFIGS. 2-6that employs a piston plunger shaft40that extends, lengthwise, a distance beyond the medium-containing portion of the interior28of the reservoir26by a distance at least as great as the distance that the piston head34moves over the full period of use of the reservoir. Accordingly, the overall length of the reservoir and internal shaft ofFIGS. 8-12may be smaller relative to the overall length of the reservoir and external shaft ofFIGS. 2-6, for a given reservoir volume.

The reservoir126inFIGS. 8 and 9may include a septum130, similar to the septum30described above with respect toFIG. 5. The septum130may include a surface131that is exposed through a wall of the reservoir retaining portion124, for refilling the reservoir126or withdrawing infusion medium from the reservoir26, for example, by piercing the exposed surface of the septum with a syringe.

An injection site132may be located within the disposable portion120, adjacent the reservoir126and connected in fluid flow communication to the interior of the reservoir126. The injection site132may employ a mechanism for inserting a hollow needle or cannula into a patient-user, after the disposable portion120is secured to the patient-user and coupling the needle or cannula in fluid flow communication to the interior of the reservoir126. Examples of mechanisms that may be used for inserting a hollow needle or cannula into a patient-user and coupling the needle and cannula in fluid flow communication with a reservoir are described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, and U.S. Patent Application Ser. No. 60/839,840, titled INFUSION MEDIUM DELIVERY SYSTEM, DEVICE AND METHOD WITH NEEDLE INSERTER AND NEEDLE INSERT DEVICE AND METHOD, filed Aug. 23, 2006.

The rotatable shaft127is threaded along its length within the interior of the reservoir126. A moveable plunger head134is located within the interior of the reservoir126and is threaded and engaged with the rotatable shaft127. In particular, the plunger head134has a threaded channel that has threads of a pitch and diameter to engage and mate with the threads of the rotatable shaft127. By rotating the shaft127without rotating the plunger head134, the plunger head is moved along the length of the shaft127, within the interior of the reservoir126. In this manner, the shaft127may be rotated to drive the plunger head134and force the infusion medium from the reservoir126to a patient-user, through a hollow needle or cannula connected in fluid flow communication with the reservoir. While the threaded channel in the plunger head134may be located at the center of the diameter of the plunger head134, other embodiments may employ a plunger head134with an off-center channel (a channel that is laterally spaced relative to the longitudinal axis A of the reservoir). An off-center location of the channel in the plunger head134allows the transfer of linear motion (with the rotational motion of the lead shaft127) to the plunger head134, while inhibiting rotation of the plunger head134relative to the lead shaft127.

One or more seals136may be provided around the outer peripheral surface of the plunger head134, to inhibit the passage of infusion medium across the plunger head134, from the medium-retaining interior portion128of the reservoir to the external side129of the plunger head134. One or more annular grooves may be provided in the outer peripheral surface of the plunger head134for retaining the seal(s)136. The seal(s)136may include one or more o-ring seals or other suitable seal structure and may be made of any suitable seal material, including, but not limited to, rubber, silicone rubber, polyurethane or other plastic material, metal, composite material or the like. The seal(s)136may provide sufficient frictional force between the plunger head134and the interior surface of the reservoir126to inhibit rotation of the plunger head134with the rotation of the shaft127. However, in further embodiments, additional structure may be provided to inhibit rotation of the plunger head with the rotation of the shaft127, including, but not limited to, one or more projections or shaped portions138on the plunger head134that fit within corresponding one or more shaped grooves along the length of the interior wall of the reservoir126, as shown in the cross-section view ofFIG. 10(taken along the cross-section10-10ofFIG. 9). The shaped projection(s)138may have generally curved configurations, with slow curvatures (as compared to an abrupt step), to allow one or more seals136to be placed around the plunger head. In alternative embodiments, the interior wall of the reservoir126may include a projecting portion extending along the length of the reservoir, for engaging a corresponding groove in the plunger head134, similar to, but reverse of the projection and groove arrangement shown inFIG. 10. In yet further alternative embodiments, the cross-sectional shape of the plunger head134and the reservoir126(in the cross-sectional direction shown inFIG. 10) may be non-circular, to inhibit rotation of the plunger head134with rotation of the shaft127. Such non-circular cross-section shapes may include, but are not limited to, an oval or partially oval shape, a polygonal or partially polygonal shape, or the like.

The plunger head134includes one or more seals140arranged to provide a fluid-tight seal between the plunger head134and the lead shaft127, to inhibit the passage of infusion medium through the central channel of the plunger head134, from the infusion medium-retaining interior portion128of the reservoir to the external side129of the plunger head134, as the plunger head134is moved toward the septum end of the reservoir126. The seal(s)140may include an annular structure disposed on one side (such as the infusion-medium-contacting side) of the plunger head134and made of any suitable seal material, including, but not limited to, rubber, silicone rubber, polyurethane or other plastic material, metal, composite material or the like. Alternatively, or in addition, the seal(s)140may be located within the central channel of the plunger head134, between the plunger head134and the lead shaft127.

Alternatively, or in addition, the lead shaft127may include seal structure to provide or enhance the seal between the plunger head134and the lead shaft127. For example, as shown inFIG. 11, the lead shaft127may include one or more seals142arranged around the shaft127, to contact the inner surface of the threaded channel of the plunger head134. The seal(s)142may include a plurality of o-ring seals disposed around the shaft127at predetermined intervals along the length of the shaft127. Alternatively, the seal(s)142may include one or more spiral runs of a seal material, spirally wound around the shaft127. The seal(s)142may be made of any suitable seal material, including, but not limited to, rubber, silicone rubber, polyurethane or other plastic material, or the like. The shaft127may include one or more annular or spiral grooves in which the seal(s)142may reside, to help retain the seal(s)142in place on the shaft127. Alternatively, or in addition, the lead shaft127may be coated or wrapped with one or more layers143of a seal material, as shown inFIG. 12. The seal material layer143may include, but is not limited to rubber, silicone rubber, polyurethane or other plastic material, or other material having suitable elasticity and flexibility to allow the threads of the plunger head134to operatively engage the coated or wrapped threads of the lead shaft127. In yet further embodiments, the inner surface of the central channel in the plunger head may be provided with seals142or sealing material143, in addition to or as an alternative to seals or sealing material on the shaft127.

The shaft127has a connection end150, for connection to a mating connection end152of a drive linkage154. The drive linkage154may be a direct connection to the drive shaft of a motor144, such that the connection end152of the drive linkage154rotates with the rotary drive motion of the drive shaft of the motor144. In other embodiments, the drive linkage154may include one or more gears, belts, chains, drive shafts or other linkage structure (not shown) for transferring drive force from a motor144to rotational motion of the connection end152of the drive linkage. The motor144may be any suitable drive device for rotatably driving the connection end152of the drive linkage (either directly or through one or more gears, belts, chains, drive shafts or other linkage structure), including, but not limited to the example drive devices described above with respect to the motor44inFIG. 4and escapement wheel arrangements inFIGS. 7a-7d.

The motor144and any gears, belts, chains, drive shafts or other linkage structure for coupling the motor144to the drive linkage154may be contained within the interior of the housing structure of the durable portion122. The drive linkage or the drive shaft of the motor144may extend through an aperture in a wall160of the housing structure of the durable portion122. A seal162may be provided within or adjacent the aperture in the wall160, to inhibit the passage of one or more of moisture, air, biological materials or infusion media into the interior of the housing structure of the durable portion122. The seal162may include, but is not limited to, one or more o-ring seals disposed around the aperture in the wall160or around the portion of the drive linkage or drive shaft that extends through the aperture in the wall160. The seal162may be made of any suitable sealing material, including, but not limited to rubber, silicone rubber, polyurethane or other plastic material, metal, composite material or the like.

The connection end152of the drive linkage154and the connection end150of the lead shaft127are configured to connect to each other when the durable portion122is coupled to the disposable portion120and to disconnect from each other when the durable portion122is separated from the disposable portion120. For example, the connection ends150and152of the lead-shaft127and the drive linkage154, respectively, may include mating features that are configured to easily engage with each other when the connection ends150and152are brought together and disengage from each other when the connection ends150and152are moved apart. In addition, the mating features allow the transfer of rotational motion from the drive linkage154to the lead shaft127, when the connection ends150and152are engaged.

In one example embodiment as shown inFIG. 13, the mating features may include a slot164formed on the connection end150of the lead shaft127and a tab166extending from the connection end152of the drive linkage154, where the tab166is shaped to fit within the slot164to connect the lead shaft127in rotational communication with the drive linkage154. Alternatively, the slot164may be formed on the connection end152of the drive linkage154and the tab166may extend from the connection end150of the lead shaft127. The shape of the tab166and the slot164inFIG. 13have a generally rectangular cross-sectional dimension (in the cross-section plane perpendicular to the longitudinal dimension of the lead shaft127). Other embodiments may employ a tab and slot arrangement with other non-circular cross-sectional shapes(in the cross-section plane perpendicular to the longitudinal dimension of the lead shaft127) to allow commutation of rotational motion from the drive linkage154gto the lead shaft127. In further alternative embodiments, the mating features may be other shapes that can be readily engaged together to commute rotational motion from the drive linkage to the lead shaft127and readily separated to allow the durable portion122to be removed from the disposable portion120of the delivery device. Such other shapes include, but are not limited to, mating star-shaped structures, cross-shaped structures, non-circular mating shapes (e.g., oval, partially oval, polygonal or partially polygonal), a mating pattern of projections and recesses, or the like, on the connection ends150and152.

In the delivery device embodiments described above, a plunger head34or134is driven within a reservoir26or126to drive the infusion medium from the reservoir. Further embodiments of mechanisms for driving a plunger head within a reservoir of a delivery device are described with reference toFIGS. 14-18.

In the embodiment ofFIG. 14, a reservoir226employs a moveable plunger head234. The reservoir226and the plunger head234may be similar to the reservoir126and plunger head134described above with respect toFIG. 9, except that the plunger head234need not include a threaded central channel. The plunger head234includes seals236similar to the seals136on the plunger head134described above with respect toFIG. 9. The plunger head234and reservoir226may include further structure to inhibit rotation of the plunger head within the reservoir226, for example, as described above with respect to example structure for inhibiting rotation of the plunger head134, including, but not limited to, structure described above with respect toFIG. 10. The reservoir226may include a septum230, similar to the septa30and130described above. The septum230may be used for refilling the reservoir226and/or for receiving a hollow needle or cannula to provide a fluid flow path to a patient-user, as described above with respect to the septa30and130.

A slide tube240is configured to engage the plunger head234. The slide tube240includes a generally hollow, cylindrical tube made of a suitably rigid material, such as, but not limited to, metal, plastic, ceramic, composite material or the like. One end of the cylindrical slide tube240is provided with a mating feature242for mating with a corresponding mating feature244on the plunger head234. In the embodiment ofFIG. 13, the mating feature242includes a projection that extends from the end of the slide tube240in the axial direction of the cylindrical shape of the slide tube, while the mating feature244includes a recess in the exterior-facing side of the plunger head234. The recess244has a shape adapted to receive the projection242, when the end of the slide tube240is brought into engagement with the exterior-facing side of the plunger head234. The recess244and projection242may have corresponding, mating shapes having non-circular cross-sectional dimensions (in the cross-section plane perpendicular to the axis A5) that inhibit relative rotation between the slide tube240and the plunger head234. In another embodiment (as shown inFIG. 15), the plunger head234may be connected to (or unitary with) a sleeve240that has a hollow interior. The sleeve240inFIG. 15may have a slot-like opening along its longitudinal dimension through which a rotary drive screw248may be received. The slot-like opening in the sleeve240may be smaller than the diameter of the rotary drive screw248and the sleeve240may be made of a suitably elastically flexible material to allow the dive screw248to be snap fit into the hollow interior of the sleeve240, through the slot-like opening in the sleeve240.

The slide tube240(in either of the embodiments ofFIGS. 14 and 15) has a generally hollow interior and an interior surface246that is threaded along at least a portion of its length. The rotary drive screw248includes a shaft that extends coaxially with the slide tube240. The drive screw248shaft extends through one end (opposite to the end connected to the plunger head) of the slide tube240. One end of the drive screw248shaft extends into the interior of the slide tube240and an opposite end of the drive screw248shaft extends outside of the slide tube240. The drive screw248may be threaded along its length (as shown inFIG. 15) or may have a threaded head249coupled to the drive screw shaft (as shown inFIG. 14). The threads along the length of the drive screw248or the threaded head249has threads of a pitch and diameter for engaging and mating with the threads on the threaded interior surface246of the slide tube240. In that arrangement, rotation of the drive screw248results in a linear movement of the slide tube240along the direction of the axis A5of the slide tube240. By rotating the drive screw with a rotary drive device in the appropriate direction, the slide tube pushes the plunger head234toward the septum end of the reservoir226, to force infusion medium through a hollow needle or cannula, to a patient-user.

The end of the drive screw248shaft that is external to the slide tube240is coupled to a drive device, through suitable drive linkage, to rotate the drive screw248in a controlled manner. In the embodiment shown inFIG. 14, the drive device includes a linear actuator250, such as a piezoelectric actuator device that expands in a linear direction, upon the application of a suitable electrical drive signal. The actuator250is arranged to frictionally engage and rotate a rotary wheel252a small amount in the direction of arrow256with each linear expansion of the actuator250. The actuator250may be selectively controlled to drive the rotary wheel252in the direction of arrow256for dispensing infusion medium from the reservoir226, and in the direction opposite to the direction of arrow256, to retract the plunger head234and allow replacement of the reservoir226. A spring254or other suitable structure may be provided to force the actuator250against the rotary wheel252during expansion of the actuator. The rotational motion of the rotary wheel252is transferred to rotational motion of the drive screw248, through suitable transfer gearing258. According to the arrangement shown inFIG. 14, the linear actuator250may be selectively energized to rotate the wheel252, which rotates the drive screw248, which causes the slide tube240to move axially and push the plunger head234toward the septum end of the reservoir226, in a controlled, step-like manner.

WhileFIG. 14shows a linear drive device that includes a linear actuator for rotatably driving the drive screw248, other embodiments may employ other drive devices operatively coupled to drive the drive screw248. For example,FIG. 15shows an embodiment in which the drive device includes a DC pancake motor260that is operatively coupled to the external end of the drive screw248, through any suitable interface gear arrangement262. In further embodiments, the drive screw248may be operatively coupled to any suitable drive device for rotatably driving the drive screw248in a controlled manner, including, but not limited to the example drive devices described above with respect to the motor44inFIG. 4and escapement wheel arrangements inFIGS. 7a-7d.

As shown inFIG. 14, the slide tube240may be supported within a portion of a housing structure266, such as the housing structure of a durable portion of a delivery device. The slide tube240extends through an opening in the housing structure266to engage the plunger head234. One or more seals268may be disposed around the opening in the housing structure266and/or the slide tube240, to protect the drive device from, for example, moisture, air, biological material or infusion media. The seal(s)268may be o-ring seals or other suitable seals made of any suitable seal material, including, but not limited to, the seal materials described above with respect to the seal(s)45. In addition, an anti-rotation structure may be provided, to inhibit rotation of the slide tube240about the axis A5, relative to the housing structure266. In one embodiment, the anti-rotation structure may include a projection241extending from the slide tube240, for engaging a stop surface243that is fixed relative to the housing structure266. In other embodiments, the seal(s)268may provide sufficient frictional engagement with the slide tube and/or the housing structure266, to inhibit rotation of the slide tube240about the axis A5, relative to the housing structure266.

The reservoir226may be located within a disposable housing portion, while the slide tube240, drive screw248and drive device250or260may be located within a durable housing portion that can selectively couple to or separate from the disposable housing portion, as described above with respect to embodiments ofFIGS. 1-13. In a further embodiment, as shown inFIG. 16, a delivery device includes a disposable housing portion320having a reservoir retaining portion324for containing multiple reservoirs326(two inFIG. 16). A piston plunger head334is located in each reservoir326and may be operated by a slide tube arrangement similar to that shown in either ofFIGS. 14or15or other suitable piston moving structure. The delivery device inFIG. 16includes a durable housing portion322for containing one or more drive devices344and linkage362(which may include, for example bevel gears pinion gears or other suitable gear arrangements) for coupling the drive device(s) to the reservoirs326. For example, a drive device, slide tube and drive screw arrangement as described with respect toFIGS. 14 and 15may be included in the durable housing portion322.

The embodiment ofFIG. 17employs a reservoir326, plunger head334, seals336and seals368, similar to the reservoir226, plunger head234, seals236and seals268described above with respect toFIG. 14. The embodiment ofFIG. 17also includes a slide tube340, similar to the slide tub240ofFIG. 14, except that the slide tube340need not include a threaded interior surface. Instead, the slide tube340inFIG. 17is operatively coupled to a drive device344in the form of a linear motor comprising one or more (two inFIG. 17) piezoelectric stacks346compressed on a drive shaft348. The drive shaft348may be fixed to a durable portion366of delivery device, similar to the durable portion266described above.

The linear motor drive device344maybe selectively energized by selectively applying electrical control signals to the piezoelectric stacks to cause the slide tube340to move toward the septum end of the reservoir326, to selectively force infusion medium out of the reservoir, as described above with respect to the reservoir226inFIG. 14. However, the linear motor drive device344ofFIG. 17may be considerably smaller and may consume less power than some of the drive devices and linkages described above for creating rotary motion to drive the slide tube240ofFIG. 14.

A further embodiment of a delivery device shown inFIG. 18includes a reservoir426and a moveable plunger head434within the interior of the reservoir426. The reservoir426and plunger head434may be similar to the reservoir326and plunger head334ofFIG. 17, except that the plunger head434need not have a mating feature for engaging a slide tube. Instead, the plunger head434is configured to abut an expandable bellows436and move along the direction of the longitudinal axis A6of the reservoir426with the expansion of the bellows436.

The bellows436is any suitable expandable structure that includes an interior volume that is expandable and that is capable of containing a hydraulic fluid. The delivery device inFIG. 18includes a second reservoir438for containing hydraulic fluid, a conduit or tube440connected to the hydraulic fluid reservoir438and the bellows436, for providing a fluid-flow communication path between the hydraulic fluid reservoir438and the interior volume of the bellows436. A pumping mechanism444is provided to selectively pump hydraulic fluid into the bellows436.

In the embodiment shown inFIG. 18, the pumping mechanism444is a peristaltic pump device including a rotor446mounted for rotation about an axis R. The rotor446has a plurality of rollers or pads arranged to engage a portion of the conduit440and roll or slide along a length of the conduit440. The conduit440may be elastically flexible, at least along the length engaged by the rotor446rollers or pads. The length of the conduit440engaged by the rotor446may be arranged along an arcuate surface448, where the arc of the surface448corresponds to the diameter of the rotor446. The arcuate surface448may be a surface of a wall or other structure formed within the durable housing portion422.

By rolling across the conduit440on the arcuate surface448, the rotor rollers or pads may engage and squeeze the conduit440during the period of motion of the rollers or pads along the length of the arcuate surface448. The rolling or sliding motion of the rotor rollers or pads along the arcuate length of the flexible conduit440creates a sufficient pressure differential to drive hydraulic fluid from the hydraulic fluid reservoir438to the interior of the bellows436, in a manner controlled by the controllable rotary motion of the rotor444. Any suitable rotary drive device or arrangement, such as, but not limited to those described herein, may be employed to drive the rotor444in a controlled manner.

As hydraulic fluid is pumped into the bellows436by the pumping mechanism442, the hydraulic fluid creates a fluid pressure within the bellows sufficient to cause the bellows to expand an amount dependent upon the amount of hydraulic fluid pumped into the bellows. As the bellows436expands, the end of the bellows that abuts the plunger head434is moved toward the septum end of the reservoir426and pushes the plunger head434toward the septum end of the reservoir426. As the plunger head434is moved toward the septum end of the reservoir426, the plunger head forces infusion medium within the reservoir426out through a suitable hollow needle or cannula, to a patient-user.

While the embodiment ofFIG. 18employs a peristaltic pump device444to drive hydraulic fluid from the hydraulic fluid reservoir438to the bellows436in a controlled manner, other embodiments may employ other suitable pump devices for performing that function, including, but not limited to, conventional piston pumps, impeller pumps, membrane pumps, or the like.

In the embodiment shown inFIG. 18the reservoir426may be located in a disposable portion420of the delivery device, while the hydraulic fluid reservoir438, hydraulic fluid pump device444, pump drive motor (not shown) and bellows436may be located in a durable portion422of the delivery device. The disposable portion420and durable portion422may be configured to be coupled together for operation, or separated for servicing, as described above with respect to disposable portion20and durable portion22inFIGS. 2 and 3. The disposable portion420may be provided with a needle insertion mechanism, for inserting a hollow needle or cannula into a patient-user's skin and connecting the hollow needle or cannula in fluid flow communication with the interior of the reservoir426, when the disposable portion420is secured to a patient-user's skin, as described above with respect to the disposable portion20ofFIGS. 2 and 3. Examples of mechanisms that may be used for inserting a hollow needle or cannula into a patient-user and coupling the needle and cannula in fluid flow communication with a reservoir are described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, and U.S. Patent Application Ser. No. 60/839,840, titled INFUSION MEDIUM DELIVERY SYSTEM, DEVICE AND METHOD WITH NEEDLE INSERTER AND NEEDLE INSERT DEVICE AND METHOD, filed Aug. 23, 2006.

In embodiments described above, the disposable housing portion (e.g.,20inFIG. 3) is provided with a base portion21that may be secured to the patient-user's skin by, for example, but not limited to, an adhesive material provided on the bottom surface of the base portion21. That arrangement is generally represented, in side view, inFIG. 19, wherein an adhesive material101is provided on the bottom surface (skin-facing surface) of the base21of the disposable housing portion20. As shown inFIGS. 2,3and19, the durable housing portion22may be configure to be arranged on the base21of the disposable housing portion20to engage and connect to the disposable housing portion22. In such an arrangement, the base21may be disposed between the durable housing portion22and the patient-user's skin, during operation, such that only the base21of the disposable housing portion remains in contact with the patient-user's skin, during operation.

However, in other embodiments, the durable housing portion22and the disposable housing portion20may be configured to engage each other in a side-by-side arrangement, for example, as represented inFIG. 20. In the side-by-side arrangement inFIG. 20, either one or both of the durable housing portion22and the disposable housing portion20may be provided with a base having an adhesive material101(and a peelable cover layer23as shown inFIG. 3).

In yet further embodiments, as represented byFIG. 21, one or both of the durable housing portion22nd the disposable housing portion20may be attachable and detachable from a separate base member21′. Suitable connecting structure, such as described above for connecting the durable housing portion and the disposable housing portion together, may be employed for connecting the durable housing portion and the disposable housing portion to the base member21′. The separate base member21′ may include a generally flat, plate-like structure made of any suitably rigid material including, but not limited to, plastic, metal, ceramic, composite material or the like. The base member21′ has a surface (the upper-facing surface inFIG. 21) to which the disposable housing portion20and the durable housing portion22may be attached. The base member21′ has a second surface (the lower-facing surface inFIG. 21) to which an adhesive material and a peelable cover film may be applied, as described above, to allow the base member21′ to be secured to a patient-user's skin.

The base member21′ may include a needle inserter device25, as described above. Examples of suitable needle inserter devices are described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, and U.S. Patent Application Ser. No 60/839,840, titled INFUSION MEDIUM DELIVERY SYSTEM, DEVICE AND METHOD WITH NEEDLE INSERTER AND NEEDLE INSERT DEVICE AND METHOD, filed Aug. 23, 2006, each of which is incorporated herein by reference in its entirety. In such embodiments, the base member21′ may be secured to a patient-user's skin. Then, the needle inserter25may be activated to insert a hollow needle or cannula into the patient-user's skin. Then, after the hollow needle or cannula is inserted, the durable housing portion22and the disposable housing portion20may be attached to the base member21′, to connect the reservoir within the disposable housing portion20in fluid flow communication with the hollow needle or cannula. In one embodiment, the durable housing portion22and the disposable housing portion20may be connected together (for example, in the manner described above) before attaching those housing portions to the base member21′. In a further embodiment, one of the durable and disposable housing portion is attached to the base member21′ before the durable and disposable housing portions are connected together. In such further embodiment, the needle inserter device may be activated to insert a hollow needle or cannula into the patient-user's skin after the disposable housing portion is attached to the base member21′ (either before or after the durable and disposable housing portions are connected together).

Alternatively, reference number25may represent an opening in the base member21′ that aligns with a needle inserter device (or aligns with a further opening) located in the disposable housing portion20, when the disposable housing portion20is attached to the base member21′. In such embodiments, the base member21′ may be secured to the patient-user's skin. Then the disposable housing portion20is attached to the base member21′ (either before or after the durable and disposable housing portions are connected together). Once the disposable housing portion20is attached to the base member21′, the needle inserter device25may be activated to insert a hollow needle or cannula into a patient-user's skin (either before or after the durable and disposable housing portions are connected together).

Also, while embodiments described above may include an on-board needle or cannula injector device that may be activated through the operator or opening25, other embodiments may employ an injection site module103that is external to the disposable housing portion20, but connected to the disposable housing portion20, through a suitable conduit102, as shown inFIG. 22. The external injection site module103may include a needle or cannula injector device structure and an operator or opening (similar to the operator or opening25described above) through which the injector device may be activated. Alternatively or in addition, the external injection site module103may include an infusion set such as, but not limited to an infusion set as described or referenced in U.S. patent application Ser. No. 10/705,686, filed Nov. 10, 2003, titled “Subcutaneous Infusion Set” (Publication No. 2005/0101910) and/or U.S. patent application Ser. No. 11/004,594, filed Dec. 3, 2004, titled “Multi-Position Infusion Set Device And Process” (Publication No. 2006/0129090), each of which is assigned to the assignee of the present invention and each of which is incorporated herein by reference, in its entirety.

The conduit102that connects the module103with the disposable housing portion20may be any suitable tubing structure having a fluid flow passage, such as, but not limited to, a flexible tube made of plastic, silicone or the like. An adhesive material may be provided on the tubing structure (or between the tubing structure and the patient-user's skin) to secure the tubing to the patient-user's skin. By locating the injection site module103external to the disposable housing portion20, the disposable housing portion20and the durable housing portion22may be clipped to a patient-user's clothing, belt, suspender or other article of apparel or may be held in a pocket of an article of apparel or carried in a purse or the like.

In one embodiment, the conduit102may be fixed at one end to the disposable housing portion20, in fluid-flow communication with the reservoir within the disposable housing portion20, and fixed at a second end to an external injection site module103, for connection in fluid-flow communication with a hollow needle or cannula, as described above. In further embodiments, one or both of the ends of the conduit102may include suitable connection structures that allow the conduit ends to be selectively connected in fluid-flow communication with, and selectively disconnected from the disposable housing portion20and/or the injection site module103. Such connectors may comprise a hollow needle and septum, a Luer connector, or other suitable fluid-communication connectors. In such embodiments, the disposable housing portion20and the durable housing portion22may be disconnected from the module103, for example, by disconnecting one of the ends of the conduit102from the module103or the disposable housing portion20, while leaving the module103in place (without requiring the patient-user to withdraw the needle or cannula and, later, insert a needle or cannula to resume operation). In this manner, a patient-user may readily disconnect and remove the disposable housing portion20and durable housing portion22, for example, to allow the patient-user to shower, bath, swim or conduct other activities, yet also allow the patient-user to readily re-connect the disposable housing portion20to the module103, for example, upon completion of such activities.

In yet further embodiments, the conduit102may be eliminated and an injection site module103may be directly connected with the disposable housing portion20, as shown inFIG. 23. In such an embodiment, one or more suitable fluid flow passages are provided through the disposable housing portion20and into the injection site module103, for fluid-flow communication between the reservoir in the disposable housing portion20and a hollow needle or cannula, as described above. Also, in such embodiments, the injection site module103and the disposable housing portion20may include mating connection structures to allow the injection site module103and the disposable housing portion20to be selectively connected and disconnected from each other.

Various examples of mating arrangements, for directly connecting an injection site module103to a disposable housing portion are described with reference toFIGS. 24-29.FIGS. 24 and 25show an example arrangement, in which an injection site module103includes at least one (two inFIG. 23) protruding engagement pawl174that are configured to be received in a corresponding number of receptacles on the disposable housing portion20(similar to the pawls74and receptacles76described in U.S. Patent Application Ser. No. 60/839,741, titled INFUSION PUMPS AND METHODS AND DELIVERY DEVICES AND METHODS WITH SAME, filed Aug. 23, 2006, which has been incorporated herein by reference. In other embodiments, the pawl(s)174may be located on the disposable housing portion20, while the corresponding receptacles may be located on the module103. In yet other embodiments, each of the disposable housing portion20and the module103may include one or more pawls and one or more receptacles.

The pawls174and receptacles may be configured to allow a patient-user to manually slide the pawls into the receptacles as the disposable housing portion20and the module103are brought together. When the pawls174are received in the corresponding receptacles, the module103is secured to the disposable housing portion20. The pawls174may include a shaped portion or head to provide a snap-fit with the receptacles, when the pawls174are fully received within the receptacles. The pawls174may be configured with sufficient flexibility to allow the patient-user to separate the disposable housing portion20from the module103, by applying a sufficient force to full those two parts away from each other and unsnap the pawls174from the receptacles. In the embodiment ofFIGS. 23 and 24, the module103may be attached to or may include a base portion450that may be secured to a patient-user's skin during operation, in lieu of the extended base21of the disposable housing portion20described above. The base portion450may include an adhesive material as described above with respect to the base21of the disposable housing portion20.

Another example of a connection structure is described with reference toFIGS. 26 and 27, wherein the module103includes a shaped head452configured to be received within a correspondingly shaped opening or receptacle in the disposable housing portion20. The shaped head452may be configured with a shape that allows the head to be received in the receptacle when the disposable housing portion20is aligned relative to the module103in a first alignment position, as shown inFIG. 26, and further allows the disposable housing portion20to be rotated relative to the module103while the head452is received within the receptacle to a second alignment position as shown inFIG. 27. The receptacle in the disposable housing portion20may be shaped to allow the head452to be freely received or removed from the receptacle, when the disposable housing portion20is in the first alignment position (FIG. 26), yet abut the head452and inhibit separation of the head452from the receptacle (and, thus, inhibit separation of the disposable housing portion20from the module103), when the disposable housing portion is in the second alignment position (FIG. 27).

A further example of a connection structure is described with reference toFIGS. 28 and 29, wherein the module103includes a shaped receptacle454configured to receive a correspondingly shaped connector member in the disposable housing portion20. The shaped receptacle454may be configured with a shape that allows the connector member of the disposable housing portion to be engaged with the receptacle454when the disposable housing portion20is aligned relative to the module103in a first alignment position, as shown inFIG. 28, and further allows the disposable housing portion20to be rotated relative to the module103, while the receptacle454is engaged within the connector member, to a second alignment position as shown inFIG. 28. The receptacle454and the connector member in the disposable housing portion20may be shaped to allow the connector member to be freely engage the receptacle454, when the disposable housing portion20is in the first alignment position (FIG. 28), yet lock with the receptacle454and inhibit separation of the connector member from the receptacle (and, thus, inhibit separation of the disposable housing portion20from the module103), when the disposable housing portion is in the second alignment position (FIG. 29). The receptacle454and connection member may include any suitable known rotary connection structures for connecting two structures together upon engagement and relative rotation of the two structures in one direction, yet allow the two structures to be disengaged and separated from an engaged arrangement, by relative rotation of the two structures in the second, opposite direction.

In yet further embodiments, the injection site module may be formed as a unitary structure with the disposable housing portion20. Also, in any of the embodiments described above, one or more sensors may be located in the disposable housing portion20, the injection site module103or the durable housing portion22, for sensing a biological condition, including, but not limited to, blood glucose level, level of infusion medium in the patient-user's blood and/or other conditions. Such sensor(s) may include a hollow needle or cannula and/or a set of micro-needles, as described above, for piercing the patient-user's skin to convey fluid from the patient to the sensor.

Various aspects of the multiple embodiments described above may be employed independently or in combinations thereof. Significant advantages can be obtained from various embodiments and combinations described herein, wherein an at-site delivery system may be made of two parts, including a disposable portion and a non-disposable portion. The disposable portion may contain all materials that are in direct contact with the infusion medium, such as reservoir body, reservoir piston, septum systems and injection needle. The non-disposable portion could contain substantially the materials that are not in contact with the medication including the drive system, pressure or force sensing system, battery, electronics, display, and non-disposable housing. The pump could be designed such that the disposable portion (user filled or pre-filled cartridge) is inserted into the non-disposable portion. By simplifying the manner in which the disposable portion of the delivery device can be replaced and by simplifying the manner in which the delivery device can be re-activated after replacing a disposable portion, a greater number of patient-users will be able to use and benefit from such delivery devices.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that the invention is not limited to the particular embodiments shown and described and that changes and modifications may be made without departing from the spirit and scope of the claimed invention. For example, while embodiments described above may include an adhesive material and a cover film23(FIGS. 2 and 3), further embodiments may include a plurality of adhesive material layers alternating with a corresponding plurality of cover film layers23, to allow the delivery device to be secured, removed and re-secured to the patient-user's skin one or more times.

In such embodiments, a first cover film layer located at the end of the stack of alternating layers of adhesive material and cover film, may be removed to expose a first layer of adhesive material. With the first layer of adhesive material exposed, the delivery device (or component thereof) may be adhered to a patient-user's skin, as described above. After a suitable period of usage, the delivery device (or component having the adhesive) may be removed from the patient-user's skin, for example, for servicing, re-filling, replacement of one or more components, or the like. After removal of the delivery device (or component) from the patient-user's skin, a second cover film layer on the delivery device (or component) may be removed to expose a second layer of adhesive material. With the second layer of adhesive material exposed, the delivery device (or component) may be secured to the same patient-user or, in certain contexts, to a different patient-user, for further operation. The process may be repeated a number of times up to the number of adhesive material and cover film layer pairs are included in the plural alternating layers of adhesive material and cover film.

In addition, while embodiments described above include an injection site located on the disposable housing portion20or in an external injection site module103, other embodiments may employ an injection site located in the durable housing portion22and connected, through suitable fluid-flow passages, to the reservoir in the disposable housing portion20, when the durable housing portion and disposable housing portion are engaged. Also, while embodiments are described above in the context of delivery devices for delivering an infusion medium from a reservoir to a patient-user, other embodiments may be operated to withdraw a fluidic medium from a patient-user (or other source) and transfer the fluidic medium to the reservoir. Such other embodiments may be operated by operating the drive device to selectively move the piston plunger away from the septum-end of the reservoir (to increase the fluid-retaining volume of the reservoir) to create a negative pressure sufficient to draw fluid from the patient-user (or other source) to which the hollow needle or cannula is secured.