Patent Description:
Conventional injection devices are often used to inject a medication into a patient. For example, injection pens that utilize disposable cartridges containing insulin are often used by diabetes patients. Such pens generally include an elongate rod that acts on a piston within the cartridge. As the rod advances the piston, the medication is dispensed through a needle into the patient.

The rod must project outwardly from the cartridge to engage a driving mechanism within the pen throughout the injection process including when the rod has reached the limit of forward advancement into the cartridge. The rod must also be accommodated within the pen when it is has been fully retracted so that the rod may be inserted into a fresh cartridge that is filled with medicament. As a result, conventional injection pens are generally elongate and thin with the length of the injection pen being more than twice the length of the cartridge barrel in which the medicament is contained. Similarly, for non-pen-shaped refillable injection devices, the length of the device is generally more than twice the length of the cartridge barrel in which the medicament is contained.

When such injection devices are used to self-administer the medicament at different times throughout the day, it is desirable for the injection device to be readily carried by the user. For example, diabetes patients often self-administer insulin using injection devices and carry the devices with them throughout the day. While conventional injection pens and similar devices are sufficiently small to be portable, the length of such devices often makes transport of the devices awkward.

<CIT> discloses a medical delivery device for use with a medicament container having a container body holding the medicament and defining an outlet, the medicament container further including a piston disposed within the container body, advancement of the piston in the container body expelling medicament through the outlet. The delivery device comprises: a support structure adapted to support the medicament container; and a drive assembly supported on the support structure and adapted to advance the piston within the container body. The drive assembly comprises:.

Aspects, embodiments and examples of the present disclosure which do not fall under the scope of the appended claims do not form part of the invention and are merely provided for illustrative purposes. Only drug cassettes in which the drive ribbon forms part of the cassette are in accordance with the present invention.

The above mentioned and other features of the present disclosure, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, wherein:.

Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplification set out herein illustrates embodiment of the present disclosure, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.

Examples of a medication delivery device are provided. One of the advantages may be that such delivery device may provide a configuration having a relatively short length and compact configuration. In some embodiments, the device is a disposable device, such as an autoinjector, with a syringe prefilled with a medication, such as, for example, insulin or other type drug for treatment of diabetes. In some embodiments, the device includes a disposable syringe cartridge that is removably coupled to a drive housing such that a patient may replace the used cartridge with another cartridge having a new and/or different medication. The drive housing may include electronics for sensing, indicating, displaying and/or communicating onboard and/or off board steps in drug delivery.

The illustrated devices utilize an axially expandable drive ribbon as part of the drive assembly for dispensing a medication. As can be seen with reference to <FIG>, the drive ribbons of the exemplary embodiments have a retracted configuration in which a retracted portion of the drive ribbon <NUM> defines a spiral and an extended configuration wherein an extended portion of the drive ribbon <NUM> defines a helix.

As used herein, the retracted portion <NUM> of the drive ribbon defines the proximal end and the opposite end of the extended portion <NUM> of the drive ribbon defines the distal end. The drive ribbon can be incrementally shifted between the retracted configuration and extended configuration to alter the length of the extended portion <NUM>. As the drive ribbon is shifted to the extended configuration, the ribbon is formed into a helix and the ribbon is secured to itself as a proximal edge region of the ribbon is engaged with a distal edge region of ribbon.

<FIG> illustrate several different manners in which the drive ribbon may function. <FIG> schematically depicts a drive ribbon <NUM> in which the extended portion <NUM> of the drive ribbon advances without rotation of the extended portion <NUM>. In such an embodiment, as the extended portion of the drive ribbon is advanced axially, the nearest retracted portion of the ribbon is drawn radially inward and upward such that distal edge of the ribbon being drawn in is engaged to the proximal edge of the ribbon at the bottom of the extended portion of the ribbon. The ribbon can be guided in this movement by the use of a camming ramp engaged with the proximal edge of the ribbon being drawn radially inward and upward.

One advantage of such a non-rotating drive ribbon is that a bearing member attached to the distal end of the ribbon will not rotate and, thus, can bear directly on the piston of a medication container without any relative rotational movement between the bearing member and the piston.

<FIG> schematically depict drive ribbons <NUM>, <NUM> which rotate as they are axially extended. The distinction between drive ribbon <NUM> shown in <FIG> and drive ribbon <NUM> shown in <FIG> is the manner in which the distal and proximal edges of the ribbons are engaged. Ribbon <NUM> shown in <FIG> has edges that project inwardly and outwardly to form projecting lips. Similar ribbons are shown in <FIG> and <FIG> which are discussed below.

Drive ribbon <NUM>, similar to ribbon <NUM>, forms a more cylindrical shape and the proximal and distal edges of the ribbon do not project or form a significant discontinuity in the inner and outer surfaces of the extended portion <NUM> of the ribbon. The drive ribbons shown in <FIG> and <FIG> have this type of engagement and are further discussed below.

The use of a rotating drive ribbon allows for a greater variety of drive ribbon configurations than that of a non-rotating drive ribbon. The rotation of the drive ribbon, however, will generally require that the bearing member be mounted to a secondary component on the drive ribbon to allow a bearing member engaged with the piston of the medication container to rotate relative to the drive ribbon. This will allow the bearing member to engage the piston of the medication container without any relative movement between the bearing member and piston. This arrangement may also increase the overall length of the drive ribbon assembly.

Because of the short axial length of the retracted portion of the drive ribbon, the use of such a drive ribbon allows an injection device or similar medication delivery device to have a relatively short and compact size. Various different drive assemblies for moving the drive ribbon and device architectures are disclosed herein and discussed below.

One example of a drive ribbon <NUM> that forms a generally cylindrical extended portion (similar to the ribbons of <FIG>) is shown in <FIG>. Ribbon <NUM> would not take the shape shown in <FIG> during use and is shown in this configuration merely to aid in understanding the structure of ribbon <NUM>. A foot member <NUM> is secured to the distal end of ribbon <NUM>. If ribbon <NUM> is used in a non-rotating application, foot <NUM> can bear directly against the piston of a medication container. Foot <NUM> also includes a central bore which may function as a rotatable bearing. For example, a bearing member having a projection that fits into the central bore of foot <NUM> could be rotatably mounted on foot <NUM> and bear directly on the piston instead of foot <NUM>. This arrangement would facilitate the use of ribbon <NUM> in an application where the drive ribbon rotates as it is axially advanced.

Ribbon <NUM> has a distal edge section <NUM> and a proximal edge section <NUM> which are engageable with each other and are shown in greater detail in <FIG>. Distal edge section <NUM> faces inwardly and includes a recess <NUM> disposed between an inwardly projecting lip <NUM> and inwardly projecting ledge <NUM>. Lip <NUM> also includes a series of notches <NUM>. The inwardly facing surface of ribbon <NUM> also includes a series of raised ribs <NUM>. Ribs <NUM> may be engaged by a gear or similar drive member mechanism to rotatably drive the movement of ribbon <NUM>.

Proximal edge section <NUM> can be seen in <FIG> and the outwardly facing surface of ribbon <NUM> includes a lip <NUM> and a recess <NUM> along the proximal edge of ribbon <NUM>. Axially extending ribs <NUM> are located within recess <NUM>. When the proximal and distal sections of ribbon <NUM> are engaged together, lip <NUM> fits within recess <NUM> with lip <NUM> and ledge <NUM> restraining its axial movement. Similarly, lip <NUM> fits within recess <NUM> and is axially restrained as a result. This axial engagement allows the extended portion of the ribbon <NUM> to exert axial compressive forces, such as when biasing a piston forward to expel medication, and resist axial tensile forces to thereby prevent the extended portion of the ribbon from becoming disengaged from itself due to being pulled apart axially. Ribs <NUM> fit within notches <NUM> to provide shear resistance and allow the extended portion of the ribbon to withstand torque that it may be subjected to when being rotated.

An example of a drive ribbon that has proximal and distal edges that form projecting lips when engaged (similar to the ribbon of <FIG>) and has sidewalls taking a slightly conical shape when in an extended position, is shown in <FIG>. Ribbon <NUM> is shown laying on a flat surface in <FIG>. <FIG> provide more detailed views of ribbon <NUM>.

Drive ribbon <NUM> includes a recessed area <NUM> along the proximal edge section of ribbon <NUM> that receives an adjacent portion of the distal edge section of ribbon <NUM> when ribbon <NUM> is extended and forms a helix. Recessed portion <NUM> does not, however, receive the full thickness of the distal edge section and a portion of both the distal and proximal edge sections project radially in opposite directions as a result.

A plurality of pegs <NUM> are located in recess <NUM> and engage a corresponding plurality of holes <NUM>. In the illustrated embodiment, pegs <NUM> are located on the proximal edge section with holes <NUM> being located on the distal edge section. These positions, however, in other examples, can be reversed. As drive ribbon <NUM> is extended and formed into a helix, the engagement of the proximal edge section with an adjacent portion of the distal edge section includes the engagement of pegs <NUM> with holes <NUM>. In the illustrated embodiment, pegs <NUM> have a chamfered tip surface that facilitates the entry and removal of pegs <NUM> from holes <NUM>.

The engagement of pegs <NUM> with holes <NUM> secures the adjacent portions of drive ribbon <NUM> together axially. The engagement of pegs <NUM> and holes <NUM> also provides for the transfer of torque between adjacent portions of the extended ribbon and maintains the stability of the column formed by the extended ribbon.

In the illustrated embodiment, drive ribbon <NUM> has a plurality of recesses <NUM> that provide a geared surface. Recesses <NUM> are engaged by a gear member or other suitable drive member whereby a drive assembly can rotate drive ribbon <NUM> by transmitting a rotational force to drive ribbon <NUM>. As can be seen in <FIG>, drive ribbon <NUM> includes a tapered section <NUM> that, when formed into a helix, defines the distal end of the drive ribbon and has a bearing member, such as foot <NUM>, mounted thereto.

The illustrated drive ribbons utilize a flexible polymeric ribbon that has been machined to define the various features of the ribbon. Nylon, polypropylene, acetal (polyoxymethylene or POM), and high density polyethylene are examples of suitable polymeric materials that may be used to form a drive ribbon. While the illustrated embodiments are machined, alternative embodiments could use a molding process to form a polymeric ribbon with all of its features. It is envisioned that molding the ribbon in a flat arrangement and then rolling the ribbon into a spiral configuration will be the most efficient manufacturing method of forming a ribbon.

Other materials may also be used to form a drive ribbon. For example, thin metal strip could be used to form the ribbon. Photo etching, laser etching or other suitable micro machining methods could be used to form the individual features of the ribbon. Alternatively, a metal ribbon could be formed by diffusion bonding two half-thickness layers instead of using a single metal strip.

Still other ribbon embodiments might take the form of an overmolded metal strip. The metal strip would be provided with the distal edge features and the overmolded plastic portion of the ribbon would form the various features of the ribbon. This approach combines the desirable stiffness, elasticity and creep resistance of metal with the low friction and manufacturing ease of forming small features in molded plastic. It will generally be desirable for the ribbon to be flexible so that the ribbon can be extended and retracted, and undergo concomitant elastic strains, without permanent deformation.

In this regard, it is noted that the various embodiments disclosed herein may be either single-use devices or multiple use devices with some of the devices being best suited for one or the other. A multiple-use device will have a drive ribbon that can be extended and retracted multiple times so that it may be re-used with a new medication container after depleting a medication container. A single use drive ribbon will be used with only a single medication container and, once extended, will be discarded. Such single use drive ribbons do not need to have the ability to be retracted after extension. The ability of drive ribbons to resist axial tension and thus resist axial separation in the extended portion of the drive ribbon is most important during the retraction of the drive ribbon and if the drive ribbon is exposed while extended. Such concerns are reduced, if not eliminated, for single-use drive ribbons and, for at least some applications, it may not be necessary for the extended portion of the drive ribbon to have the ability to resist axial separation forces.

<FIG> relate to devices having a drive ribbon that does not rotate as it is axially advanced. Such medication delivery devices are suitable for use with a container having a container body holding a medication and defining an outlet wherein the container includes a piston disposed within the container body and advancement of the piston within the container body expels medication through the outlet (e.g., a hollow needle). The delivery device includes a housing adapted to couple with the container and a drive assembly coupled with the housing and adapted to advance the piston within the container. The drive assembly includes a drive ribbon having a distal edge section and a proximal edge section. The drive ribbon has a retracted configuration and an extended configuration wherein a retracted portion of the drive ribbon in the retracted configuration defines a spiral and an extended portion of the drive ribbon in the extended configuration defines a helix. The drive ribbon is incrementally movable from the retracted configuration to the extended configuration. Movement of the drive ribbon from the retracted configuration to the extended configuration defines a drive axis and advances the piston within the container body. The drive ribbon moves from the retracted configuration to the extended configuration without rotating relative to the housing or the container. A thrust member is engaged with the drive ribbon. The thrust member is rotatable relative to both the drive ribbon and the housing. Rotation of the thrust member moves the drive ribbon from the retracted configuration to the extended configuration.

In some embodiments having such a non-rotating drive ribbon, the thrust member is axially stationary. Such an axially stationary thrust member may include a helical thread engageable with the drive ribbon and the device may further include a rotational restraint member wherein the rotational restraint member is rotationally fixed relative to the housing and engaged with the drive ribbon and the engagement of the drive ribbon and the rotational restraint member prevents relative rotation of the extended portion of the drive ribbon and the rotational restraint member.

In such devices having a rotational restraint member, one of the rotational restraint member and the extended portion of the drive ribbon may define an axially extending key with the other one of the rotational restraint member and extended portion of the drive ribbon defining an axially extending keyway.

The rotational restraint member may be disposed radially outside of the drive ribbon at an engagement location where the rotational restraint member engages the drive ribbon to prevent rotation. See, for example, the embodiment of <FIG>, the embodiment of <FIG>, and the embodiment of <FIG>.

Alternatively, the rotational restraint member may be disposed radially inside of the drive ribbon at the location where the rotational restraint member engages the drive ribbon to prevent rotation. See, for example, the embodiment of <FIG>.

For embodiments having an axially stationary thrust member with a helical thread, the helical thread may be disposed radially outside of the drive ribbon at the location where the helical thread engages the drive ribbon. See, for example, the embodiment of <FIG>, the embodiment of <FIG>, and the embodiment of <FIG>. Alternatively, the helical thread may be disposed radially inside of the drive ribbon at the location where the helical thread engages the drive ribbon. See, for example, the embodiment of <FIG>.

Turning now to the embodiment of <FIG>, this embodiment includes a rotational restraint member <NUM> that is disposed radially outside drive ribbon <NUM>. Tabs <NUM> on rotational restraint member <NUM> engage axially extending slots <NUM> defined within the extended portion of drive ribbon <NUM> to define an engagement location <NUM>. Restraint member <NUM> is fixed relative to the housing and the housing can also support a medication container without relative movement between the housing and the container. Thus, tabs <NUM> prevent rotation of the extended portion of drive ribbon <NUM> relative to the housing and the medication container. As a result, bearing member or foot <NUM> can be fixed to drive ribbon <NUM>.

Thrust member <NUM> includes at least one helical thread <NUM> that engages a groove <NUM> that forms a helical shape on the extended portion of drive ribbon <NUM>. As thrust member <NUM> and thread <NUM> rotate, they pull and guide drive ribbon <NUM> from its retracted configuration <NUM> into its extended configuration <NUM>. Thread <NUM> also exerts an axial force on ribbon <NUM> whereby ribbon <NUM> can exert a biasing force on a medication container piston via foot <NUM> to dispense medication.

Thrust member <NUM> is axially stationary and rotatably mounted to restraint member <NUM>. More specifically, thrust member <NUM> is rotatable relative to rotational restraint member <NUM> and axially captured by, and cannot move axially relative to, rotational restraint member <NUM>. This is best understood with reference to <FIG>. Thrust member <NUM> includes an axially extending cylindrical section <NUM> on which helical thread <NUM> is located. A radially extending flange <NUM> is located at one end of section <NUM>. Rotational restraint member <NUM> includes an annular groove <NUM> which receives flange <NUM> that, once inserted into groove <NUM> prevents thrust member <NUM> from being moved axially relative to restraint member <NUM>. The engagement of thrust member <NUM> with rotational restraint member <NUM> is a snap-fit type engagement that is facilitated by the inclined outer radial surface 79A of flange <NUM>. Surface <NUM> acts as a camming ramp biasing flange <NUM> radially inwardly during engagement of thrust member <NUM> with rotational restraint member <NUM>.

A drive gear or other suitable drive member engages thrust member <NUM>, such as on the outer radial surface 76A of thrust member <NUM>, to drivingly rotate thrust member <NUM>. For example, outer radial surface 76A could be a geared surface that engages a motor driven gear to thereby rotate thrust member <NUM>.

The embodiment of <FIG> has the same general structure as the embodiment of <FIG>. The embodiment of <FIG> differs, however, in that drive ribbon <NUM> has externally extending tabs or posts <NUM> which engage axially extending slots in rotational restraint member <NUM> to prevent rotation of drive ribbon <NUM>. The use of tabs <NUM> avoids the use of axially aligned slots on the drive ribbon which may be difficult to form using a roll forming process.

The embodiment of <FIG> has a drive ribbon <NUM> with a groove on its external surface that takes a helical shape on the extended portion of the drive ribbon <NUM>. Ribbon <NUM> also has grooves on its inner surface that extend axially in the extended portion of the ribbon.

Rotational restraint member <NUM> is disposed radially inside of drive ribbon <NUM> and includes axially extending ribs <NUM> that engage the grooves on the inner surface of ribbon <NUM> to define the engagement location <NUM> to prevent rotation of the extended portion of drive ribbon <NUM>.

An axially stationary thrust member <NUM> is disposed radially outside of drive ribbon <NUM> and includes a helical thread <NUM> that engages the groove on the external surface of ribbon <NUM> that takes a helical shape on the extended portion of rib <NUM>. As thrust member <NUM> rotates, it pulls ribbon <NUM> from its retracted configuration into its extended configuration and can exert an axial force on drive ribbon <NUM>.

The embodiment of <FIG> has a drive ribbon <NUM> having an internal groove <NUM> that defines a helical shape in the extended portion of the drive ribbon and external grooves that extend axially in the extended portion of the drive ribbon.

Rotational restraint member <NUM> is disposed radially outside ribbon <NUM> and includes ribs <NUM> that engage axially extending external slots on ribbon <NUM> to define the engagement location to prevent rotation of ribbon <NUM>. An axially stationary thrust member <NUM> is rotatably mounted on a shaft and includes a helical thread <NUM>. Thrust member <NUM> and thread <NUM> rotate and, as they rotate, pull ribbon <NUM> into the extended configuration. Thread <NUM> also exerts axial forces on ribbon <NUM>.

<FIG> schematically depict two drive ribbons <NUM>, <NUM> which include radially outward extending projections that engage slots in a rotational restraint member to prevent rotation of the ribbon. Drive ribbon <NUM> includes a plurality of outwardly extending tabs <NUM> that are separate both axially and circumferentially as can also be seen in <FIG>. Drive ribbon <NUM> of <FIG> has elongate ribs <NUM> that are separated circumferentially but which are substantially continuous in the axial direction for the extended portion of the drive ribbon.

In some embodiments having a non-rotating drive ribbon, the thrust member moves axially in a proximal direction P as it is rotated and a distal end of the drive ribbon remains axially stationary as the thrust member rotates. To advance the piston within the container body, the thrust member and an extended portion of the drive ribbon are axially moved in a distal direction D, opposite to the proximal direction. Examples of such devices shown in <FIG>. Orientation using proximal and distal is consistent throughout this disclosure.

The device may further include a drive spring which is tensioned as the thrust member is rotated to extend the drive ribbon. As the ribbon is extended, the thrust member moves axially in the proximal direction and the distal end of drive ribbon remains stationary. To initiate a dispensing of medication, the thrust member and drive spring are released and the drive spring axially advances the thrust member together with the extended portion of the drive ribbon. The drive ribbon thereby advances the piston in the medication container to dispense the medication.

The embodiment of <FIG> has an axially movable thrust member <NUM>, the thrust member <NUM> includes a helical thread <NUM> engageable with the drive ribbon <NUM> wherein the helical thread <NUM> is disposed radially inside of the drive ribbon <NUM> at the location where the helical thread engages the drive ribbon. Rotational restraint member <NUM> is rotationally fixed relative to the housing and engaged with the drive ribbon <NUM> such that the engagement of the drive ribbon and the rotational restraint member prevents relative rotation of the extended portion of the drive ribbon <NUM> and the rotational restraint member <NUM>.

Thread <NUM> of thrust member <NUM> engages a helical groove on the inward facing surface of drive ribbon <NUM>. Thrust member <NUM> has a hollow center which defines a central bore for receiving center shaft <NUM>. Thrust member <NUM> has a helical thread <NUM> facing its central bore that engages a helical groove on shaft <NUM>. As thrust member <NUM> is rotated to move proximally on shaft <NUM> it compresses drive spring <NUM>. <FIG> shows thrust member in its most proximal position.

Shaft <NUM> can extend proximally of the drive assembly further than that shown in <FIG> and engage a locking mechanism that prevents the axial movement of shaft <NUM>. After rotating thrust member <NUM> to move in the proximal direction and compress spring <NUM>, shaft <NUM> can be released thereby also releasing thrust member <NUM> and spring <NUM>. Spring <NUM> will then bias thrust member <NUM> distally and thread <NUM> on thrust member <NUM> will cause drive spring <NUM> to advance distally with thrust member <NUM>.

The embodiment of <FIG> includes an axially movable thrust member <NUM>, the thrust member includes a helical thread <NUM> engageable with the drive ribbon <NUM> wherein the helical thread <NUM> is disposed radially outside of the drive ribbon <NUM> at the location where the helical thread engages the drive ribbon. Rotational restraint member <NUM> is rotationally fixed relative to the housing and engaged with the drive ribbon <NUM> such that the engagement of the drive ribbon <NUM> and the rotational restraint member <NUM> prevents relative rotation of the extended portion of the drive ribbon <NUM> and the rotational restraint member <NUM>.

Thrust member <NUM> may extend radially outwardly to a greater extent than is shown in <FIG> such that it threadingly engages the housing in a releasable manner. As thrust member <NUM> is rotated relative to the housing, it will move in a proximal direction and compress drive spring <NUM>. Reference numeral <NUM> is used in <FIG> to identify the location of thrust member <NUM> after it has been rotated to proximally retract the thrust member. After retracting the thrust member <NUM>, it can be released, which will also release drive spring <NUM> whereby spring <NUM> will axially advance thrust member <NUM> in the distal direction. Thread <NUM> on thrust member <NUM> will cause drive ribbon <NUM> to axially advance in the distal direction with thrust member <NUM> and thereby advance a medication container piston to dispense medication.

<FIG> relate to drive ribbons that rotate as they are axially advanced. Such ribbons may be employed in a medication delivery device for use with a container having a container body holding a medication and defining an outlet wherein the container includes a piston disposed within the container body and advancement of the piston within the container body expels medication through the outlet. The delivery device includes a housing adapted to couple with the container and a drive assembly coupled with the housing and adapted to advance the piston within the container. The drive assembly includes a drive ribbon having a distal edge section and a proximal edge section. The drive ribbon has a retracted configuration and an extended configuration wherein a retracted portion of the drive ribbon in the retracted configuration defines a spiral and an extended portion of the drive ribbon in the extended configuration defines a helix. The drive ribbon is incrementally movable from the retracted configuration to the extended configuration and movement of the drive ribbon from the retracted configuration to the extended configuration defines a drive axis. The drive ribbon rotates as it is moved from the retracted configuration to the extended configuration.

<FIG> relate to devices wherein a drive member is disposed radially inside the drive ribbon to engage and rotate the drive ribbon and a fixed component having a helical thread is disposed radially outside the drive ribbon. The helical thread of the fixed component engages the drive ribbon and controls the movement of the drive ribbon between the retracted configuration and the extended configuration.

<FIG> illustrates an assembly wherein drive member <NUM> has a pair of keys <NUM> that engage grooves on the inner facing surface of drive ribbon <NUM> to drivingly rotate ribbon <NUM>. Collar <NUM> is fixed relative to the housing and includes a helical thread <NUM> that engages a helical groove on the outer facing surface of drive ribbon <NUM>.

<FIG> illustrate an assembly very similar to that shown in <FIG> but wherein the drive member <NUM> has a larger number of keys <NUM> to engage a corresponding larger number of grooves on the inner surface of drive ribbon <NUM> to define the engagement locations.

Because drive ribbon <NUM> rotates as it is axially advanced, a rotatable bearing assembly <NUM> having a first member <NUM> fixed to the drive ribbon <NUM> and a second member <NUM> that can rotate relative to member <NUM> and ribbon <NUM> is employed. Second member <NUM> can bear directly against the piston of a medication container without rotating relative to the piston while first member <NUM> and ribbon <NUM> both rotate relative to member <NUM> and the piston as the ribbon is advanced and biases member <NUM> against the piston to advance the piston.

<FIG> illustrate alternative drive arrangements that are disposed radially within the drive ribbon to engage and rotate the drive ribbon. <FIG> shows the use of a single gear member <NUM> while <FIG> shows the use of a plurality of gears <NUM>. Gears <NUM>, <NUM> would engage axially extending grooves or raised ribs (not shown) on the inner surface of the drive ribbon. Such grooves/ribs would be spaced apart by a distance corresponding to the distance between the gear teeth on the gears being used with the ribbon.

<FIG> relate to embodiments having a rotatable drive ribbon wherein a drive member disposed radially outside the drive ribbon engages and drivingly rotates the drive member.

<FIG> schematically depicts the use of a single ring gear <NUM> with a drive ribbon <NUM>. Ring gear <NUM> completely surrounds drive ribbon <NUM> and engages a portion of the outer surface of the drive ribbon <NUM>. The central opening of ring gear <NUM> is larger than the outer diameter of drive ribbon <NUM> and, thus, a portion of the outer circumference of the drive ribbon is not engaged by ring gear <NUM>. <FIG> schematically depict the use of a plurality of ring gears. In the illustrated embodiment, two ring gears <NUM> engage a drive ribbon <NUM>. The use of two ring gears <NUM> allows the full outer circumference of the drive ribbon <NUM> to be engaged by a ring gear. As can be seen in <FIG>, the ring gears <NUM> are axially offset. The device of <FIG> also includes a spindle member <NUM> having a helical thread <NUM> which engages a groove on the inner surface of drive ribbon <NUM>. Ring gears <NUM> are advantageously axially positioned such that the ring gears <NUM> engage the outer surface of the drive ribbon proximate to the location where thread <NUM> engages the inner surface of the drive ribbon.

Various other types of drive members may alternatively be employed to drivingly rotate a drive ribbon. <FIG> schematically depicts the use of a belt drive arrangement wherein a belt <NUM> engages the outer surface of a drive ribbon <NUM> to rotate the drive ribbon. A driven shaft <NUM>, or other suitable mechanism, drives belt <NUM>.

A plurality of planet gears may also be employed to rotate the drive ribbon. <FIG> depicts the use of planetary gears <NUM> that are also reducing gears while <FIG> depict a slightly different embodiment with planetary gears <NUM> that are not reducing gears. As can be seen in <FIG>, a helical thread <NUM> engages the inwardly projecting proximal edge of drive ribbon <NUM> while planetary gears <NUM> engage the outer surface of drive ribbon <NUM>. Similar to the drive ribbon of <FIG>, drive ribbon <NUM> has outwardly projecting edges where the drive ribbon engages with itself.

<FIG> depict alternative drive arrangements that employ worm gears to rotate the drive ribbon. In <FIG> a pair of worm gears <NUM> engage the outer surface of drive ribbon <NUM> to rotate ribbon <NUM>. <FIG> depicts a drive arrangement where a single worm gear <NUM> is used to rotate drive ribbon <NUM>. While the use of a single worm gear would reduce the complexity and number of parts compared to the use of two worm gears, the use of a pair of worm gears disposed on opposite sides of the drive ribbon provides a more balanced force distribution on the drive ribbon.

<FIG> relate to the use of a key drive to drivingly rotate the drive ribbon. <FIG> depicts a drive ribbon <NUM> having a plurality of keys or ribs <NUM> that extend axially when the drive ribbon <NUM> is in an extended configuration. Ribs <NUM> can be engaged by keyways or slots on a drive member to drivingly rotate ribbon <NUM>. <FIG> depicts a drive ribbon <NUM> having a plurality of keyways or slots <NUM> that extend axially when the drive ribbon <NUM> is in an extended configuration. Slots <NUM> can be engaged by keys or similar projections on a drive member to drivingly rotate ribbon <NUM>.

<FIG> depict an example of a key drive arrangement. In <FIG>, drive member <NUM> has a plurality of ribs or keys <NUM> that engage axially extending slots on the outer surface of drive ribbon <NUM>. As drive member <NUM> is rotated, drive ribbon <NUM> is also rotated. A stationary spindle member <NUM> has a helical thread <NUM> which engages a groove on the inner surface of drive ribbon <NUM>.

<FIG> depict another example of a key drive arrangement. In this arrangement drive member <NUM> includes a plurality of ribs or keys <NUM> that engage axially extending slots on the outer surface of drive ribbon <NUM> to drivingly rotate ribbon <NUM>. A stationary collar member <NUM> includes a helical thread <NUM> that engages a groove on the outer surface of drive ribbon <NUM>.

<FIG> relate to a medication delivery device for use with a container having a container body holding a medication and defining an outlet. The container includes a piston disposed within the container body wherein advancement of the piston within the container body expels medication through the outlet. The delivery device includes a housing adapted to couple with the container and a drive assembly coupled with the housing and adapted to advance the piston within the container. The drive assembly includes a drive ribbon having a distal edge section and a proximal edge section. The drive ribbon has a retracted configuration and an extended configuration wherein a retracted portion of the drive ribbon in the retracted configuration defines a spiral and an extended portion of the drive ribbon in the extended configuration defines a helix. The drive ribbon is incrementally movable from the retracted configuration to the extended configuration. Movement of the drive ribbon from the retracted configuration to the extended configuration defines a drive axis and advances the piston within the container body. The drive ribbon rotates as it is moved from the retracted configuration to the extended configuration. The drive ribbon also defines a transition portion disposed between the retracted portion and the extended portion wherein the distal edge section and proximal edge section of the drive ribbon are not engaged together in the transition portion. A drive member engages the drive ribbon and drivingly rotates the drive ribbon and the drive member is engaged with the retracted portion or the transition portion of the drive ribbon.

<FIG> depicts a device which includes a storage bobbin <NUM> which holds the retracted portion of drive ribbon <NUM>. That portion of the drive ribbon <NUM> disposed within storage bobbin <NUM> expands radially outward to engage storage bobbin <NUM>. Thus, as storage bobbin <NUM> is rotated, drive ribbon <NUM> is also rotated. This can be used to force drive ribbon <NUM> into engagement with collar member <NUM>. Collar member <NUM> includes a helical thread <NUM> which engages a groove on the outer surface of drive ribbon <NUM> to control and guide ribbon <NUM> into engagement with itself to thereby axially extend ribbon <NUM>. It is noted that rotation of bobbin <NUM> in the opposite direction can be used to retract ribbon <NUM>. Similarly, for nearly all of the drive member mechanisms disclosed herein, unless it is specifically stated otherwise, the drive member mechanisms can be operated in reverse to retract the drive ribbon as well as extend it.

<FIG> illustrates a reciprocating drive member <NUM> that engages drive ribbon <NUM> in a transition portion <NUM> of the drive ribbon between the retracted portion and the extended portion. As can be seen in <FIG>, reciprocating drive member <NUM> engages a radially inward facing surface of drive ribbon <NUM>. For some embodiments of drive member <NUM>, the cyclic motion of member <NUM> and the nature of its engagement will result in member <NUM> being able to drive the ribbon <NUM> into its extended position but unable to drive ribbon <NUM> into its retracted position.

<FIG> depicts an embodiment where a worm gear <NUM> engages a drive ribbon <NUM> in the retracted portion of the drive ribbon.

Referring now to <FIG>, for embodiments having a reciprocating drive member, the reciprocating drive member <NUM> may take the form of a drive member that moves in a first direction and an opposite second direction, as depicted by double headed arrow <NUM>. The drive member <NUM> is shown including at least one flexible ratchet member <NUM> engageable with the drive ribbon <NUM> configured to allow relative movement between the drive member <NUM> and the drive ribbon <NUM> in the first direction <NUM> and not allow relative movement between the drive member <NUM> and the drive ribbon <NUM> in the second direction <NUM> (or allow unidirectional movement). When moving in the second direction <NUM>, the drive member <NUM> will push the drive ribbon and thereby cause the drive ribbon <NUM> to move. When moving in the first direction <NUM>, the ratchet member <NUM> will be repositioned on the drive ribbon <NUM> whereby it can push the ribbon forward when once again moving in the second direction <NUM>. The illustrated embodiment also includes a stationary ratchet member <NUM> which does not move relative to the housing and which includes a plurality of ratchet members <NUM> engaging the radially outward facing surface of drive ribbon <NUM>. When the reciprocating drive member <NUM> is being moved in the first direction <NUM>, ratchet member <NUM> will ensure that drive ribbon <NUM> is not pulled rearwards with reciprocating ratchet member <NUM>. The ratchet drive depicted in <FIG> is well suited for use in a single-use device where the ribbon is extended but is not later retracted. If it was desired to use such a ratcheting drive in a multi-use device, ratchet members <NUM> and <NUM> would have to be movable out of engagement with the drive ribbon and a second driving mechanism employed to rotate the drive ribbon in the opposite direction. For generating the reciprocating movement of drive member <NUM>, as well as drive member <NUM> discussed above, an oscillating escapement drive can be employed.

The various ribbons and drive member mechanisms disclosed herein can be combined in numerous ways to provide a medication delivery device. Two general categories of such devices include those having an inline architecture and those having a dual axis architecture. These two basic architectures are depicted in <FIG>.

A device having an inline architecture is depicted in <FIG>. In this arrangement, the drive ribbon R and the drive member mechanism used to drive the extension of the drive ribbon both share a common axis <NUM>. As shown in <FIG>, the device includes a dialing knob DK that is used to set the dosage and an inject button B that initiates the extension of the drive ribbon. The device also holds a medication container <NUM>. The illustrated container <NUM> is a conventional syringe cartridge having a glass barrel that holds the medication, a piston <NUM> disposed within the barrel and an outlet defined by hollow injection needle <NUM>. As the drive ribbon R extends, a bearing member <NUM> disposed on the distal end of the ribbon R bears against piston <NUM> to advance piston <NUM> within container <NUM> and thereby expel medication through needle <NUM>.

<FIG> provide simplified depictions of a dual axis device. <FIG> provide more detailed schematic images of dual axis devices and the figures which follow <FIG> provide even further representations of dual axis devices. References to common components, such as the needle <NUM>, container <NUM>, the dialing knob DK, drive ribbon R and inject button B, will be used for different device configurations throughout the figures. As will become evident from the discussion which follows, dual axis devices include a primary drive axis defined by the drive ribbon and also include a drive member mechanism that defines a secondary axis that is parallel to and offset from the primary drive axis. One advantage of a dual axis device is that by offsetting part of the drive member mechanism from the primary axis, the drive member mechanism can be positioned to extend parallel to the primary axis in the distal direction. This allows such dual axis devices to have an overall shorter length than if the entirety of the drive member mechanism was located in alignment with the primary axis.

As can be seen in <FIG>, the dual axis architecture can increase the bulk of the device, referred to here as <NUM>, over part of the relatively shorter length of the device, which may be beneficial to patient users with dexterity or handling challenges due to a debilitating disease or condition. The device <NUM> depicted in <FIG> is used to dispense medication from a conventional <NUM> syringe cartridge and has a drive ribbon defining a first primary axis <NUM> and a drive member mechanism that defines a secondary parallel axis <NUM>. Similarly, the device, referred to here as <NUM>', depicted in <FIG> also dispenses medication from a conventional <NUM> syringe cartridge and has a drive ribbon defining the first primary axis <NUM> and a drive member mechanism that defines the secondary parallel axis <NUM>. The housings of the two components (cartridge/drive ribbon portion and drive member mechanism component portion) may have different housing configurations.

Both of these devices, as wells as the devices which are depicted in <FIG>, are a medication delivery device for use with a container having a container body holding a medication and defining an outlet. The container includes a piston disposed within the container body wherein advancement of the piston within the container body expels medication through the outlet. The delivery device includes a housing adapted to couple with the container and a drive assembly coupled with the housing and adapted to advance the piston within the container. The drive assembly includes a drive ribbon having a distal edge section and a proximal edge section. The drive ribbon has a retracted configuration and an extended configuration wherein a retracted portion of the drive ribbon in the retracted configuration defines a spiral and an extended portion of the drive ribbon in the extended configuration defines a helix. The drive ribbon is incrementally movable from the retracted configuration to the extended configuration. Movement of the drive ribbon from the retracted configuration to the extended configuration defines a drive axis and advances the piston within the container body. A drive member mechanism is operably coupled with the drive ribbon and defines a secondary axis parallel with the drive axis. The drive member mechanism generates a force that is transferred to the drive ribbon to move the drive ribbon from the retracted configuration to the extended configuration.

Several embodiments of such dual axis devices will now be discussed. The various embodiments include several illustrated examples, such as those depicted in <FIG> and <NUM>-<NUM>, which have a drive member mechanism that includes a spring S aligned with the secondary axis wherein setting a dose includes tensioning the spring S and releasing the tension from the spring S generates the force that is transferred to the drive ribbon R to move the drive ribbon from the retracted configuration to the extended configuration.

Several of the illustrated dual axis embodiments, such as those depicted in <FIG><NUM>, have a drive member mechanism includes that a plunger disposed along the secondary axis wherein linear translation of the plunger generates the force that is transferred to the drive ribbon R to move the drive ribbon from the retracted configuration to the extended configuration.

Still other ones of the illustrated dual axis embodiments, such as those depicted in <FIG>, have a drive member mechanism that includes an electric motor M drivingly coupled with an element disposed along the secondary axis, the electric motor M generating the force that is transferred to the drive ribbon R to move the drive ribbon from the retracted configuration to the extended configuration. In such embodiments, the element disposed along the secondary axis may be a drive shaft of the electric motor.

In some of the illustrated embodiments, such as the embodiments of <FIG> the drive ribbon R and the drive member mechanism are disposed within the housing and the container <NUM> is not removable from the housing whereby these devices form single-use or disposable pre-filled devices. Modification of such devices, however, could adapt them for multiple use applications. Alternatively, the device may have a more modular architecture such as those depicted in <FIG>.

Turning now to the device, now referred to as device <NUM>", depicted in <FIG>, this device includes the primary axis <NUM> and the secondary axis <NUM>. A dialing knob DK on the secondary axis is used to set the dosage and tensions a torsion spring S by means of a ratcheting mechanism (dialing ratchet) DR which rotates a sleeve SL and the torsion spring S. The sleeve SL is coupled with the inject button B and when the inject button is pressed, the sleeve shifts, releasing the spring. When the spring S is released, it rotates an output sleeve <NUM> that has an output ratchet O disposed thereon. The output ratchet O, in turn, rotates the drive ribbon R. The output ratchet O engages a drive member that, in turn, engages and rotates either the ribbon or, if a non-rotating ribbon is used, a thrust member, such as described previously. Rotation of the drive ribbon, or thrust member, extends the ribbon axially and thereby advancing the piston and dispensing medication from the cartridge. A threaded member IRD is a "Turns-counting IRD" that functions as an insufficient remaining dosage indicator and prevents further rotation of the sleeve SL and, thus, the dialing knob DK after the member IRD has travelled the threaded length of the sleeve SL which is dimensioned to correspond to the quantity of medication in a <NUM> cartridge. <FIG> illustrates the device <NUM>" when the dialing knob DK is being rotated to tension the torsion spring S, also referred to as a dialing configuration and set the dosage. Rotation of the dialing knob DK in turn rotates a dose indicator dial <NUM> which can be visible through a window W defined by the housing to provide indication of the amount dialed. <FIG> illustrates the device <NUM>" during an injection procedure after the button is depressed by a user to release the spring S that rotates the sleeve <NUM>.

The device 253A" depicted in <FIG> is similar to that depicted in <FIG> but the dialing knob DK of the embodiment of <FIG> is located on the proximal end of the device with the inject button B instead of the distal end. Rotation of the dialing knob DK rotates the internal sleeves SL by means of a dialing ratchet <NUM>. <FIG> illustrates the device 253A" being placed in the dialing configuration to set the dosage. <FIG> illustrates the device 253A" during the injection procedure after the button is depressed by a user.

The device <NUM>‴ depicted in <FIG> has a drive ribbon R defining a primary axis <NUM> and a driving mechanism centered on a secondary axis <NUM>. The drive member mechanism includes a dialing knob DK that is rotated by the user to set the dosage. Rotation of the dialing knob DK rotates an internal sleeves SL by means of a dialing ratchet <NUM>. As the sleeve rotates SL, it tensions a torsion spring S. Depressing the inject button B moves a shift member <NUM> which shifts the sleeve and thereby releases the torsion spring. When the torsion spring is released, it rotates output sleeve <NUM>. Output sleeve <NUM> has an output ratchet O disposed thereon which drives the ribbon assembly as output sleeve <NUM> is rotated. The input sleeve includes a threaded section on which a threaded member IRD (insufficient remaining dosage) is located.

The device <NUM>′‴ depicted in <FIG> also includes a shift member <NUM> to initiate the dispensing of medication in an injection procedure but it is configured differently than that of the embodiment of <FIG>. The embodiment of <FIG> includes a dialing knob DK that is used to set the dosage. Rotation of the dialing knob DK rotates the sleeve SL by means of a dialing ratchet <NUM>. As the sleeve SL rotates, it tensions a torsion spring S. Shift member <NUM> also defines the inject button B and when shift member <NUM> is moved from the dialing dose setting position shown in <FIG> to the injection dose delivery position shown in <FIG>, it releases the torsion spring S. When released, the torsion spring S rotates output sleeve <NUM>. An output ratchet member O on the output sleeve <NUM> then drives the ribbon assembly to extend the drive ribbon R, advance the piston and dispense medication. A threaded member IRD (insufficient remaining dosage) is disposed on a threaded section of the sleeve rotated by the dialing knob.

The embodiments depicted in <FIG> do not experience a change in length when setting the dosage or when extending the drive ribbon with the limited exception that, when the inject button is disposed on one of the ends of the device and the button is depressed to actuate the injection procedure, the movement of the inject button alters the length an insignificant amount. In contrast, the devices depicted in <FIG>, and further described below, include plungers that are extended from the device and increase the length of the device when the dosage is being set and the subsequent manual depression of the plungers to return them to their original position provides the driving power to extend the drive ribbon, advance the piston within the medication container and dispense the medication.

The device <NUM> depicted in <FIG> has dialing knob DK for setting the dosage. As the dialing knob DK is rotated, a dialing clicker in the form of a one-way ratchet mechanism <NUM> rotates the sleeve SL. As the sleeve SL is rotated, the plunger PL is extended out of the housing in the proximal direction due to the threaded engagement of the sleeve and plunger to place the device in the dialing dose setting configuration as shown in <FIG>. When the plunger PL is manually depressed to force it back into the housing in the distal direction to place the device in the injecting dose delivery configuration shown in <FIG>, the sleeve SL rotates in the opposite direction and causes output sleeve <NUM> to rotate along with it. The plunger PL does not rotate when being extended or depressed. To prevent the plunger PL from rotating, the stem of the plunger can have a non-circular cross section that passes through a corresponding opening in the housing. The output ratchet O on the output sleeve then transmits that rotational force to a drive member that rotates either the drive ribbon R or a thrust member to axially advance the piston and discharge medication.

The device <NUM>' depicted in <FIG> is generally similar to that depicted in <FIG> but the dialing knob DK has been relocated to the proximal end of the housing. Each of these embodiments may also include a threaded member IRD (insufficient remaining dosage) that is disposed on the threaded section of the sleeve.

The device <NUM>" depicted in <FIG> has an extendable plunger wherein several components of the drive assembly centered on secondary axis <NUM> extend with the plunger when the dosage is being set and move with the plunger when it is being depressed. A dialing knob is used to set the dosage. When rotating the dialing knob DK, it rotates a dial sleeve <NUM> and plunger rod <NUM>. Plunger rod <NUM> is threaded and engaged with a threaded opening <NUM> disposed on an internal portion of the housing. Rotation of plunger rod <NUM> relative to opening <NUM> causes the plunger rod <NUM> to be extended out of the housing in the proximal direction when setting the dosage, as shown in <FIG>, while sleeve <NUM> is rotationally decoupled from plunger rod <NUM> but travels axially with dialing sleeve <NUM> and plunger rod <NUM>. Depressing the inject button B rotationally engages plunger rod <NUM> with sleeve <NUM>, which is rotationally engaged with output sleeve <NUM>. As the dialing assembly is pressed distally back into the housing, it rotates causing output sleeve <NUM> to also rotate, as shown in <FIG>. As output sleeve <NUM> rotates, the output ratchet O on output sleeve <NUM> rotates the output shaft. The output shaft, in turn, rotates a drive member or thrust member to extend the drive ribbon R, advance the piston and discharge medication.

The device <NUM> depicted in <FIG> has a modular architecture with a detachable electronic module having an inject button that can be attached to a cartridge unit having a medication container, a drive ribbon and a drive assembly. The electronic module can be re-used multiple times with different cartridge units having the same basic structure. Such cartridge units may also be disposable units.

The device depicted in <FIG> has a reusable electronic module <NUM> which can be detachably connected to a cartridge unit <NUM>. Cartridge unit <NUM> includes a medication container <NUM> holding a medication and having a piston wherein advancement of the piston dispenses medication through an injection needle <NUM>. A drive ribbon R is used to advance the piston and defines a primary drive axis <NUM>. The illustrated cartridge unit <NUM> also includes a drive member mechanism centered on secondary axis <NUM>. Illustrated cartridge unit <NUM> is a single use cartridge that is disposed of after depletion of the medication.

A dialing knob DK is used to set the dosage. Rotation of the dialing knob DK rotates the sleeve SL by means of a dialing ratchet <NUM>. Rotation of the sleeve SL tensions the torsion spring S. Moving the inject button B from the position shown in <FIG> to that shown in <FIG> an arm <NUM> of the button B engages the sleeve SL and allows the sleeve SL to shift axially and thereby releases the torsion spring S. Injection cannot be initiated when display is removed. When released, the torsion spring S rotates output sleeve <NUM>. Rotation of output sleeve <NUM> is communicated to the ribbon assembly and extends the drive ribbon R to thereby advance the piston and discharge medication. When the inject button B is in the position shown in <FIG>, the sleeve SL is in an axial position that prevents the communication of torque from the torsion spring S to the output sleeve <NUM> and thereby prevents the torsion spring S from advancing the drive ribbon R. When the electronic module <NUM> is removed from the cartridge unit <NUM>, the sleeve S remains in the position shown in <FIG> and, thus, the torsion spring S will not advance the drive ribbon R when the electronic module <NUM> is removed.

The embodiments of <FIG> also have a modular architecture. The reusable module of these embodiments, however, includes a drive member mechanism centered on the secondary axis thereby allowing a greater percentage of the total assembly to be reused. The drive member mechanism is disposed within the housing and the device further includes a cartridge housing wherein the drive ribbon is disposed within the cartridge housing and the container is mounted on the cartridge housing with the cartridge housing being detachably securable to the housing.

In the embodiments depicted in <FIG> and <FIG>, the devices have a drive member mechanism that includes a spring aligned with the secondary axis wherein setting a dose includes tensioning the spring and releasing the tension from the spring generates the force that is transferred to the drive ribbon to move the drive ribbon from the retracted configuration to the extended configuration.

More specifically, the device <NUM> depicted in <FIG> includes cassette <NUM> having a cartridge housing 286A and a reusable module <NUM> having a main housing 288A. As can be seen in <FIG>, the drive ribbon R is disposed within cartridge housing 286A and the cartridge <NUM> holding a medication is mounted on the cartridge housing 286A. As can also be seen in <FIG>, the drive member mechanism <NUM> which drives the axial advancement of the drive ribbon R is disposed in main housing 288A and is centered on secondary axis <NUM>.

The depicted device <NUM> includes a dialing knob DK that is used to set the dosage. Rotation of the dialing knob DK rotates the sleeve SL by means of the dialing ratchet <NUM>. As the sleeve SL is rotated, the torsion spring S is tensioned. When the inject button B is depressed, the sleeve SL is shifted and the torsion spring S is released. When released, the torsion spring S rotates output member <NUM> that, in turn, rotates a drive member <NUM> engaged with the drive ribbon R to thereby extend the drive ribbon. Dial <NUM> is provided between the sleeve SL and spring S and is used with the interlock <NUM> for dose tracking.

The reusable module <NUM> includes an electronic module (not shown) coupled with the display. An interlock <NUM> provides an electrical signal which the electronic module uses to determine if the reusable module <NUM> is attached to the cassette <NUM>. A sensor senses the rotational movement of the sleeve SL and provides the electronic module with data concerning the quantity of medication to be dispensed based upon the extent to which the sleeve has been rotated due to rotation of the dialing knob DK. The interlock may be configured to return device to zero when cassette is removed, by resetting the positon of the dial <NUM>. The cassette <NUM> may include a RFID (radio frequency identification) chip to identify the contents of the medication container. Advantageously, the RFID chip is read/write whereby the electronic module on the reusable module <NUM> can record data related to the quantity of medication dispensed from the cassette <NUM> after each injection procedure whereby the module will be able to determine the remaining quantity of medication in the cassette. Alternatively, the cassette <NUM> may have a read only RFID tag with another form of digital memory to record such data. By recording data concerning the type and remaining amount of medication on the cassette, the cassette <NUM> can be removed from the reusable module <NUM> before it is completely depleted and then later re-attached with the electronic module being able to read the data concerning the identification of medication and remaining amount when the cassette is reattached. This will allow the electronic module to accurately track the amount of remaining medicine and generate an IRD (insufficient remaining dose) message even when a cassette has been detached when partially empty and then subsequently reattached.

The device <NUM>" depicted in <FIG> is similar to that shown in <FIG><NUM> but has a different reusable module <NUM> wherein the dialing knob DK is located on the distal end instead of the proximal end of the reusable module <NUM>. The dialing knob DK is used to set the dosage and rotation of the knob rotates the sleeve SL by means of a dialing ratchet <NUM>. Rotation of the sleeve SL tensions a torsion spring S. Depression of the inject button B releases the spring S which then rotates output member <NUM>. Rotation of output member <NUM> drives the extension of the drive ribbon R. Similar to module <NUM>, module <NUM> includes an electronic module that is coupled with a display and which can communicate with the cassette to identify the contents of the cassette and remaining volume.

Instead of having a spring drive member mechanism, the reusable module may alternatively have an electric motor. For example, the embodiments depicted in <FIG>; <FIG>; and <FIG> each have a drive member mechanism that includes an electric motor drivingly coupled with an element disposed along the secondary axis, the electric motor generating the force that is transferred to the drive ribbon to move the drive ribbon from the retracted configuration to the extended configuration. For example, the motor shaft may be the element disposed along and defining the secondary axis.

The device <NUM> depicted in <FIG> includes a reusable module <NUM> having an electric motor M that can be coupled with a cassette <NUM>. The motor M includes a motor shaft <NUM> that rotates a drive element <NUM> which, in turn, rotates drive member <NUM> of the cassette to extend the drive ribbon R. In the embodiment of <FIG>, the drive ribbon R extends axially without rotation. Cassette housing member <NUM> functions as the rotational restraint member and includes axially extending tabs (not shown here but described previously) to prevent rotation of the drive ribbon R. Drive member <NUM> functions as a thrust member and includes a helical thread that engages and axially drives the drive ribbon R. Drive member <NUM> is axially captured by housing member <NUM> within an annular groove that allows drive member <NUM> to rotate but prevents axial movement of drive member <NUM>. The outer radial surface of drive member <NUM> projects outwardly from the cassette as can be seen in <FIG> and defines a geared surface. Drive element <NUM> defines a cooperating geared surface for engaging and rotatably driving the drive member <NUM>.

An electronic module can be used to control the operation of the motor. A dialing knob DK can be used to generate signals to the electronic module to define the dosage and an inject button B communicates with the electronic module to initiate the operation of the motor. As can be seen in <FIG>, the dialing knob DK is located on the distal end of module <NUM> while the inject button B is located on the side of the module <NUM> farthest from the cartridge <NUM> of cassette <NUM> and near the dialing knob DK. The electronic module may also communicate with the cassette <NUM> as described above to identify the contents of the cartridge <NUM> and determine the quantity of medication remaining in the cassette.

The device <NUM>' depicted in <FIG> has a reusable module <NUM> that can have a cassette <NUM> attached thereto. Module <NUM> has an electric motor M and the same general functionality of module <NUM>. A motor shaft <NUM> extends from the motor M and a drive element <NUM> is mounted on shaft <NUM>. Drive element <NUM> engages and rotates drive member <NUM> on the cassette <NUM> when the motor M is energized. Module <NUM> differs from module <NUM> in that it includes a proximal foot <NUM>. Foot <NUM> is positioned adjacent the proximal end of cassette <NUM> and has an inject button B mounted thereon. Foot <NUM> helps to prevent accidental dislodgement of the cassette <NUM> and provides a more secure attachment for the cassette <NUM>. It also allows the inject button B to be placed on the drive axis <NUM> defined by the drive ribbon. Some users may find this placement to be more intuitive and comfortable due to its similarity with a syringe having an inline manual plunger.

The device <NUM>" depicted in <FIG> has a reusable module <NUM> that is similar to module <NUM> with the only distinction being that module <NUM> uses input buttons <NUM> to set the dosage instead of a dialing knob. As shown, one of the input buttons <NUM> is for increasing the dosage and the other of the input buttons <NUM> is for reducing the dosage. The display may be used to indicate the change in dosage as a result the use of the input buttons.

In any of the reusable modules described herein having an electric motor M and/or electronic module, the reusable modules can include a single charge disposable battery or a rechargeable battery (shown in <FIG> as battery <NUM>) for powering the electric motor and the electronic module and/or cassette <NUM>'. Electronic modules described herein (shown representatively as electronic module <NUM> in <FIG>) that is electrical communication with the module and the cassette is configured to control operation of the module and cassette and may include a processor or similar microcontroller and a transceiver or alternative communication hardware.

Instead of a rechargeable battery, the reusable modules described herein may employ disposable batteries or, alternatively, a small disposable battery could be included in each cassette, rather than onboard on the module, which is sized to provide sufficient energy to the electric motor M to empty the contents of the cassette. In this regard, it is noted that <FIG> schematically depicts a cassette <NUM>' having a battery <NUM> for powering the reusable module. When positioning a battery or other electrical power source in the cassette <NUM>', electrical contacts <NUM> on the cassette and electrical contacts <NUM> on the module (<FIG>) will engage when the cassette and module are connected to thereby transfer electrical power from the cassette to the module. Such cooperating electrical contacts on any of the cassettes and reusable modules described herein may also be used to provide communication or power conduit between electronic circuits on the cassette and reusable module.

As best understood with reference to <FIG>, for embodiments having a reusable module and a cassette with a cartridge housing, the device may further include a plurality of cartridges, each cartridge including a cartridge housing with a drive ribbon being disposed within the cartridge housing and a container being mounted on the cartridge housing, each of the cartridges being interchangeably and detachably securable to the housing of the reusable module.

Moreover, as discussed above with regard to a single cassette, in those embodiments having a plurality of cartridges, an electronic module may be disposed on the housing of the reusable module and each of the plurality of cartridges may further include a digital memory device such as a read/write RFID or other form of digital memory (e.g., internal flash memory or on-board EEPROM). The electronic module of the reusable module will establish communication with the digital memory device of the cartridge coupled with the housing and, after completing an injection procedure, the electronic module records data on the digital memory device related to the injection procedure. In such an embodiment, the data recorded on the digital memory device may include data related to the volume of medication remaining in the container. In such embodiments, the plurality of cartridges may all contain the same medication or they may contain a plurality of different medications.

<FIG> illustrates a medication delivery system <NUM> including the cassette <NUM>, a second cassette <NUM>, and the reusable module <NUM> which can be detachably secured to cassette <NUM> whereby the module <NUM> can drive the extension of the drive ribbon within cassette <NUM> to dispense a medication. Second cassette <NUM> may be identical to cassette <NUM> except that it does not yet have a needle assembly secured to the distal end of the medication container. The ability to interchange cassettes <NUM> and <NUM> with a single reusable module <NUM> has several advantages. For example, if a patient potentially needs to inject two different medicines over the course of the day, cassettes <NUM> and <NUM> can hold the two different medicines and the patient only needs to carry the single module <NUM> to use with the two different cassettes providing a compact system. Moreover, the cassettes <NUM> and <NUM> can be provided with read/write RFIDs or read only RFIDs and a digital memory whereby the patient can interchange the cassettes as needed and the module will still be able to identify the medicine contained in the cassette which is attached and the amount remaining in the cassette as discussed above. Alternatively, if the patient only requires a single medication, they may still find it convenient to carry the module <NUM> and two cassettes <NUM> and <NUM> which hold the same medication with the second cassette functioning as a back-up supply in case the first cassette is depleted or needs to be replaced for some other reason.

<FIG> also illustrates how module <NUM> can be used with multiple cassettes of different medications in a medication delivery system <NUM>. In the embodiment of <FIG>, cassettes <NUM> and <NUM> all have the same structure as cassette <NUM>. The only difference between cassettes <NUM> and <NUM> is that cassette <NUM> contains a different medication than cassettes <NUM>. While the RFID of the cassettes will identify the medication contained within the cassette and such information can be displayed for the user to see it on the display of the reusable module <NUM>, the cassettes holding different medicines are also advantageously identifiable by visual inspection. For example, cassettes <NUM> which all hold the same type of medication may advantageously have the same color cartridge housing while cassette <NUM>, which holds a different medicine, has a cartridge housing of a different color. Printed labels identifying the contents of the cassettes may also be adhered to the cassettes.

In the embodiments of <FIG>, cassettes <NUM>, <NUM>, <NUM>, <NUM> each may have a digital memory device <NUM> which includes data on the type of medication contained within the cartridge and remaining volume of the medication. Still other data, such as date of manufacture, serial numbers may also be recorded on digital memory device <NUM>. Module <NUM> includes an electronic module <NUM> utilizing a controller which controls operation of the module and cassette. Electronic module <NUM> also communicates with the digital memory device <NUM> of the cassette engaged with the module <NUM> to acquire information about the type of medication and remaining amount of the medication in the cassette.

Also shown in <FIG> are electrical contacts <NUM> on cassettes <NUM>, <NUM>, <NUM>, <NUM> and cooperating electrical contacts <NUM> on module <NUM>. When a cassette is mounted on module <NUM>, the cooperating contacts <NUM>, <NUM> are engaged to provide electrical communication therebetween for data signal transmission and/or power. The use of contacts <NUM>, <NUM> allows the electronic module <NUM> of module <NUM> to communicate in a hard-wired manner with digital memory device <NUM>. Alternatively, electronic module <NUM> can communicate wirelessly with digital memory device <NUM> and contacts <NUM>, <NUM> can be used to confirm that a cassette has been successfully docked on module <NUM>. For example, when contacts <NUM>, <NUM> are not engaged, the circuit on module <NUM> with contacts <NUM> may be open. Then, when a cassette is mounted on module <NUM>, contacts <NUM> will engage with contacts <NUM> and close the circuit in which contacts <NUM> are located. Electronic module <NUM> can monitor whether or not the circuit having contacts <NUM> is open or closed to thereby determine whether or not a cassette has been mounted to module <NUM>.

<FIG> depict systems <NUM>, <NUM>, respectively, similar to systems <NUM>, <NUM> in <FIG> but have a reusable module <NUM> that differs from module <NUM> in that module <NUM> includes a foot <NUM> similar module <NUM>. Otherwise, reusable module <NUM> functions the same as module <NUM> and can be used with cassettes <NUM>, <NUM> and <NUM> and <NUM> in the same manner discussed above with regard to module <NUM>.

It is noted that the reusable modules and cassettes may track the remaining quantity of medication in the cassette in various manners. As mentioned, above, the remaining quantity can be tracked by having the reusable module monitor the set dosages and/or the mechanical output delivered to the cassette to determine the amount of medication dispensed during each injection procedure. The original quantity of medication held in the medication container is known and, thus, by substracting the dispensed amount, the remaining quantity can be tracked and monitored.

Alternatively, the extent to which the drive ribbon has been axially extended can be monitored to determine the remaining quantity. For example, the drive ribbon may be provided with markings that can be read by an optical sensor. The optical sensor is positioned to sense the markings on the extended portion of the drive ribbon and, for devices having a modular architecture, may be positioned on the cassette or on the reusable module with a window in the housings allowing the optical sensor to view the extended portion of the drive ribbon. The sensor could count the passage of identical markings or be able to recognize distinct markings to determine the extent to which the drive ribbon has been axially extended. By tracking the length to which the drive ribbon has been axially extended and knowing the dimensions of the medication container, the quantity of remaining medication can be determined. In this regard, it may be necessary to initially determine the length to which the drive ribbon is extended to initially engage the piston without dispensing medication. The extension of the drive ribbon after reaching its initial point of contact can be readily converted to an amount of medication dispensed for a conventional medication container having known dimensions.

<FIG> illustrate an example of a reusable drive member mechanism module and a cassette having a cartridge housing and a drive ribbon disposed therein. <FIG> also illustrate an example of a reusable drive member mechanism module and a cassette. One difference between the embodiment of <FIG> and the embodiment of <FIG> is that the size of the electric motor in the embodiment of <FIG> and of the gear attached to the motor shaft are larger than those of the embodiment of <FIG>. Where the parts of the two embodiments are the same and function in the same manner, the same reference number will be used in each embodiment.

Device <NUM>, which is shown in <FIG>, includes a reusable module <NUM> and a cassette <NUM>. A needle assembly <NUM> is securable to the threaded distal end of a holding member for medication container <NUM>. Module <NUM> includes a housing <NUM> within which an electric motor <NUM> is mounted. Gear <NUM> is coupled to and driven by the output shaft of motor <NUM>. A portion of gear <NUM> projects outwardly from housing <NUM> whereby it can engage a gear member <NUM> within cassette <NUM> when cassette <NUM> is attached to module <NUM>.

Cassette <NUM> includes a housing <NUM> that defines a projection <NUM> having a T-shaped cross section. Module housing <NUM> defines a corresponding T-shaped slot <NUM> which receives projection <NUM>. Cassette <NUM> also defines a second T-shaped projection <NUM> which is received by a second T-shaped slot <NUM> on housing <NUM>. When the T-shaped projections are slid into the T-shaped slots, a spring biased, pivoting latch member <NUM> on module <NUM> engages a projecting lip on the cassette to prevent the cassette from sliding out of engagement. Button <NUM> is depressed to disengage latch member <NUM>.

Device <NUM> is shown in <FIG> and includes a reusable module <NUM> and a cassette <NUM>. Cassette <NUM> is detachably secured to module <NUM> in the same way that it is secured to module <NUM>. Module <NUM> has a slimmer electric motor <NUM> and a smaller output gear <NUM> coupled to the motor shaft than module <NUM> but otherwise has the same construction.

<FIG> provides an exploded view of cassette <NUM>. Cassette <NUM> includes a base member <NUM> and a holding member <NUM> which together define the cartridge housing. A drive ribbon <NUM> is disposed within the cartridge housing and a thrust member <NUM>, ring <NUM> and collar <NUM> control the axial extension of drive ribbon <NUM>. A bearing member <NUM> is secured to the distal end of drive ribbon <NUM> and engages piston <NUM> within medication container <NUM>. Ribbon <NUM> extends without rotation and bearing member <NUM> is fixed directly to ribbon <NUM>. A conventional <NUM> medication container <NUM> is held within holding member <NUM>. Holding member <NUM> has a bayonet type engagement for attaching member <NUM> to the cassette although other suitable means such as permanent adhesive may alternatively be used.

Cassette base <NUM> is shown in <FIG>. Base <NUM> houses the proximal components of the cassette and includes a window <NUM> that allows gear member <NUM> to mesh with gear <NUM> which is formed on thrust member <NUM>. Base <NUM> also defines T-shaped projection <NUM> and a pair of smaller projections <NUM>, <NUM>. Projection <NUM> is engaged by latch <NUM> when cassette <NUM> is engaged with a reusable module and projection <NUM> prevents the inadvertent external disengagement of latch <NUM>.

Cassette collar <NUM> is shown in <FIG>. Collar <NUM> defines a central cylindrical opening <NUM>. Disposed within the central opening <NUM> are a plurality of axially extending ribs <NUM>. As further discussed below, ribs <NUM> engage axially extending grooves <NUM> in drive ribbon <NUM> to prevent the rotation of the extended portion of drive ribbon <NUM>. Collar <NUM> has a first section <NUM> with a non-circular cross section that fits within base member <NUM> and thereby prevents collar <NUM> from rotating relative to base <NUM>. Ribs <NUM> thereby prevent the extended portion of drive ribbon <NUM> from rotating relative to base <NUM>. A second section <NUM> is disposed distally of the end of base <NUM> and receives the bayonet projections of holder <NUM> to thereby attach holder <NUM> to cassette <NUM>. Section <NUM> has a central opening which is cylindrical in shape with two projections <NUM> that fit between the bayonet fittings of holder <NUM>. Collar <NUM> also includes a cylindrical projection <NUM> that extends proximally and defines a portion of the central bore <NUM>. Cylindrical section <NUM> also defines an annular recess <NUM> on its outer surface.

Cassette ring <NUM> is shown in <FIG>. Ring <NUM> encircles cylindrical section <NUM> and properly positions collar <NUM> relative to thrust member <NUM>. Ring <NUM> also functions as a bearing between the rotatable thrust member <NUM> and the rotationally fixed collar <NUM>. An annular projection <NUM> on ring <NUM> fits within on annular recess <NUM> on projection <NUM> and a threaded section <NUM> on ring <NUM> secures ring <NUM> to thrust member <NUM>. Ring <NUM> thereby prevents the axial separation of collar <NUM> from thrust member <NUM> while still permitting the rotation of thrust member <NUM> and attached ring <NUM> relative to collar <NUM>.

Distal bearing member <NUM> is shown in <FIG>. Member <NUM> includes a distal bearing flange <NUM> that engages piston <NUM> and a mounting stem <NUM> that is disposed radially inwardly of the most distal portion of drive ribbon <NUM>. Mounting posts <NUM> on stem <NUM> are engaged with holes on drive ribbon <NUM> to mount bearing member <NUM> to drive ribbon <NUM>.

Thrust member <NUM> is shown in <FIG>. Thrust member <NUM> has gear <NUM> formed on its outer perimeter. In another embodiment, a gear component may be fixedly coupled to the thrust member. Gear <NUM> engages gear <NUM> and thrust member <NUM> is rotated when motor <NUM> is energized and rotating gear <NUM>. Thrust member <NUM> has a generally cylindrical shape and rotates within and relative to base <NUM>. The proximal end of thrust member <NUM> forms a cylindrical skirt <NUM> that functions as a storage bobbin for the retracted portion of drive ribbon <NUM>. Threads <NUM> at the distal end of thrust member <NUM> engage threads <NUM> on ring <NUM> to secure ring <NUM> to thrust member <NUM>. As discussed above, this also axially secures collar <NUM> to thrust member <NUM> while still permitting the rotation of thrust member <NUM> and ring <NUM> relative to collar <NUM>.

An inner partition <NUM> extends inwardly and defines a central opening <NUM> within thrust member <NUM>. Partition <NUM> also defines a pair of generally helical threads <NUM> that act as camming ramps. Threads <NUM> engage grooves <NUM> in drive ribbon <NUM> that extend helically on the extended portion of drive ribbon <NUM>. When initially assembling cassette <NUM>, a portion of the drive ribbon <NUM> is placed in the extended configuration and threads <NUM> are engaged with grooves <NUM>. When thrust member <NUM> is subsequently rotated, threads <NUM> will force ribbon <NUM> from the retracted configuration to the extended configuration thereby extending the axial length of the extended configuration, or, depending on the direction of rotation, force ribbon from the extended configuration to the retracted configuration thereby reducing the axial length of the extended portion of the drive ribbon. If module <NUM> is designed to work with only disposable cassettes <NUM>, it will not be necessary to retract drive ribbon <NUM> after emptying the contents of container <NUM> and module <NUM> may be configured such that motor <NUM> will rotate in only one direction when energized with that direction corresponding to the axial extension of drive ribbon <NUM>. It is noted that as threads <NUM> engage helical grooves <NUM> and move drive ribbon <NUM> axially, ribs <NUM> located on collar <NUM> will engage the axially extending grooves <NUM> on drive ribbon <NUM> and prevent rotation of ribbon <NUM>. The adjacent edges of ribbon <NUM> will also become engaged with each other as the ribbon moves into collar <NUM>.

Holding member <NUM> is shown in <FIG>. Holding member <NUM> defines T-shaped projection <NUM> for engaging the reusable module. Holding member <NUM> also includes a pair of bayonet fittings <NUM> that are inserted into the bore defined by section <NUM> of collar <NUM> and tightly fit between projections <NUM> to thereby mount holding member <NUM> to cassette <NUM>. Alternative attachment means such as permanent adhesive may be used to attach holding member <NUM> to cassette <NUM>. A medication container <NUM> is placed within holder <NUM> before mounting the holding member <NUM> to cassette <NUM>. A threaded distal end <NUM> on holding member <NUM> is used to attach needle assembly <NUM>. When attaching needle assembly <NUM> to threaded distal end <NUM>, the needle of assembly <NUM> will pierce a septum on medication container <NUM> whereby it will be possible to dispense medication through the needle. Cut outs in member <NUM> form windows <NUM> that allow a user to view medication container <NUM> whereby the quantity of medication remaining in the container can be determined by a visual inspection.

Drive ribbon <NUM> is shown in <FIG>. In <FIG>, drive ribbon <NUM> is shown in a configuration that it will take within cassette <NUM>. In this arrangement, an extended portion <NUM> of ribbon <NUM> defines a helix while a retracted portion <NUM> of ribbon <NUM> defines a spiral. As can be seen in <FIG>, the distal section of ribbon <NUM> defines a pair of holes <NUM> that receive posts <NUM> to thereby mount bearing member <NUM> to ribbon <NUM>. The outer surface of ribbon <NUM> includes a plurality of regularly spaced projections <NUM> that define grooves <NUM>, <NUM> therebetween. It is noted projections <NUM> and grooves <NUM>, <NUM> will face outwardly on the retracted portion <NUM> of ribbon <NUM> just like they do on the extended portion <NUM>, however, <FIG> do not show projections <NUM> or grooves <NUM>, <NUM> for reasons of graphical simplification and clarity.

The individual features of drive ribbon <NUM> are best seen in <FIG> which show a drive ribbon <NUM> unrolled and laying on a flat surface. <FIG> and detail view <FIG> show the outward facing surface of drive ribbon <NUM> while <FIG> and detail view <FIG> show the inward facing surface of drive ribbon <NUM>. <FIG> shows an edge of ribbon <NUM>.

As best seen in <FIG>, projections <NUM> on the radially outward facing surface of ribbon <NUM> define two sets of parallel grooves, <NUM>, <NUM> between the projections <NUM>. Grooves <NUM> extend in a helical shape on the extended portion <NUM> of ribbon <NUM>. Grooves <NUM> are engaged by threads <NUM> on thrust member <NUM> to form drive ribbon <NUM> into helical shape. The engagement of threads <NUM> with grooves <NUM> also allows axially directed forces to be transferred between ribbon <NUM> and thrust member <NUM>. Grooves <NUM> extend in an axial direction on the extended portion <NUM> of ribbon <NUM> and, as explained above, engage ribs <NUM> on collar <NUM> to prevent rotation of extended portion <NUM>.

As best seen in <FIG>, one of the edges (shown as the distal edge <NUM>) of ribbon <NUM> defines a plurality of projections <NUM> while the other edge (shown as the proximal edge <NUM>) defines a corresponding plurality of openings <NUM>. As can be seen in <FIG>, projections <NUM> and projections <NUM> overlap along the distal edge <NUM>. When the distal <NUM> and proximal <NUM> edges of ribbon <NUM> are being engaged, the proximal edge <NUM> will be positioned radially inward of the distal edge <NUM>. As the distal edge <NUM> moves radially inward to engage the proximal edge <NUM>, openings <NUM> and projections <NUM> will mesh to interlock the two edges and the overlapping projections <NUM> will prevent the projections <NUM> from being pushed completely through openings <NUM>. The engagement of projections <NUM> and openings <NUM> provides shear resistance along the edges and the shape of projections <NUM> with openings <NUM> with projections <NUM> having an enlarged head on a narrower neck also resist axial separation of the two interlocked edges.

When using a drive ribbon <NUM>, only a single ribbon <NUM> will be employed with each cassette <NUM> and the distal and proximal edges of the individual ribbon will be interlocked together in the extended portion of the ribbon. In <FIG>, two ribbons <NUM> are shown laying flat with their distal and proximal edges interlocked to provide a better understanding of the interlocking of the two edges and graphical clarity. In use, two separate drive ribbons <NUM> would not joined together as shown in <FIG> (with the possible exception of doing so to create a single larger ribbon).

<FIG> illustrate several additional embodiments which use various types of control to enhance the control and precision of the individual doses delivered by the device.

<FIG> schematically illustrates an embodiment which uses an encoder to enhance control and precision of the dosage amount delivered by the device, such as, for example, the device in <FIG>. In the illustrated embodiment, a rotating drive ribbon <NUM> includes a set of gear teeth <NUM> along its proximal edge. An electric motor <NUM> drives a gear <NUM> that, in turn, engages gear teeth <NUM> and thereby drives rotation of drive ribbon <NUM>. Drive ribbon <NUM> also includes a series of encoder targets <NUM> such as dark rectangles that are distinguishable from the drive ribbon <NUM> by optical sensor <NUM>. Optical sensor <NUM> generates signals that are received by processor <NUM>. By counting the number of encoder targets that pass by sensor <NUM>, processor <NUM> can determine drive ribbon parameters (for example, angular position, length or extension position, speed of extension and/or retraction, stoppage) such as the length by which drive ribbon <NUM> has been axially extended. Processor <NUM> uses this information to control the operation of motor <NUM> and thereby also control the dosage amount delivered by the device.

<FIG> schematically illustrate a device that uses a mechanical control to enhance the control and precision of the dosage amount. The embodiment of <FIG> includes a rotating drive ribbon <NUM> which is driven by a pretensioned spring <NUM>. Spring <NUM> is provided with sufficient pretensioning during manufacture to rotate drive ribbon <NUM> through its full extension. Drive ribbon <NUM> also includes a series of projections <NUM> that project radially outwardly from ribbon <NUM>. The distance between each of the projections <NUM> corresponds to a predefined dosage of medication such as the amount of an individual dosage or a whole fraction thereof.

An actuator <NUM> is mounted on housing <NUM> and includes a camming surface <NUM>. When actuator <NUM> is depressed radially inwardly, camming surface <NUM> interacts with control member <NUM>. Control member <NUM> is disposed adjacent the extended portion of drive ribbon <NUM> and is biased by a spring (not shown) or other biasing member into the position shown in <FIG>. In this position, it blocks the passage of projections <NUM>. Control member <NUM> also includes teeth that define camming surfaces <NUM> that are engageable with camming surface <NUM> on actuator <NUM>.

When actuator <NUM> is depressed, camming surfaces <NUM> and <NUM> interact to bias control member <NUM> upwards whereby opening <NUM> is aligned with a projection <NUM> engaged with the side of control member <NUM>. This allows projection <NUM> to pass through opening <NUM> and drive ribbon <NUM> to be extended under the influence of pretensioned spring <NUM>. Actuator <NUM> also includes a spring (not shown) that biases it out of engagement with control member <NUM>. Thus, when actuator <NUM> is depressed and then released, it will move control member <NUM> into a position where a projection <NUM> can pass through opening <NUM> and then return control member <NUM> to a position where it blocks the passage of a projection <NUM>. This allows a user to easily dispense a predefined dosage amount simply by depressing and releasing actuator <NUM>.

<FIG> illustrates a device that utilizes an image sensor <NUM> to read codes <NUM> on rotating drive ribbon <NUM>. Codes <NUM> are located at predefined intervals on drive ribbon <NUM> and read by image sensor <NUM> to facilitate control of individual dosage deliveries. Signals generated by image sensor <NUM> are communicated to processer <NUM> and may be stored in a digital memory. Processor <NUM>, in turn, controls an electric motor or other suitable mechanism for rotating drive ribbon <NUM> based upon the signals generated by image sensor <NUM>. Codes <NUM> may take various forms, for example, they may be QR codes, bar codes, encoder strip codes. Codes <NUM> may also take the form of different colors whereby a particular color change corresponds to a predefined distance along ribbon <NUM>. Codes <NUM> may formed by screen printing graphics on the drive ribbon and may also include other information readable by image sensor <NUM> such as the type of drug, original quantity of the drug, and other forms of information.

For the embodiments of <FIG> and <FIG>, the sensor may be a part of the cassette. Alternatively, it could be a part of the reusable module with cooperating windows on the cassette and reusable module allowing the sensor to view the drive ribbon. <FIG> illustrates a device having an alternative configuration that facilitates the use of a sensor on the reusable module and may otherwise use a control system similar to that of the embodiments of <FIG> and <FIG>.

In the embodiment of <FIG>, cassette <NUM> holds a rotatable drive ribbon <NUM> having codes <NUM> located on the inward facing surface of drive ribbon <NUM>. Reusable module <NUM> includes a proximal foot <NUM> similar to the embodiments of <FIG>, <FIG>, <FIG>. Extending from proximal foot <NUM> is a stem <NUM> having a sensor <NUM> mounted on its free end to read the codes <NUM> on the inward facing surface of drive ribbon <NUM>.

Any of the devices described herein may includes a controller (also referred to herein as an electronic module) and/or an electronic display. The display may include any one of or any combination of two or more light emitting diodes, e-ink technology, or liquid crystal technology. The display is circuited to and controlled by the electronic controller or computing assembly mounted within the housing. The controller includes conventional components such as, for example, a processor, power supply, memory, etc. The controller is programmed to achieve the electronic features of any one of the devices described herein, including causing the display of set doses. The set dose displayed in the display may be determined by the interaction of the dose setting and/or dose delivery drive mechanism and any one or more of the sensing systems electrically circuited or wirelessly communicated with the controller. The controller includes control logic operative to perform the operations described herein, including detecting a dose delivered by the medication delivery device based on a detected rotation or linear extension of the drive ribbon member relative to the actuator. The controller is operable to determine the dose setting by the drive ribbon parameter(s), such as, position based on rotational and/or linear position of respective components, which is determined by associating the electrical characteristic (such as voltage or resistance) from the respective sensors and the number of rotations to an exact and/or absolute position from a database, look up table, or other data stored in memory. The controller is operable to determine the dose delivery by determining the drive ribbon position based on rotational and/or linear position of respective components, which is determined by associating the electrical characteristic (such as voltage or resistance) from the respective sensor bands and the number of rotations to an exact and/or absolute position from a database, look up table, or other data stored in memory. The controller is operative to store the detected dose in local memory (e.g., internal flash memory or on-board EEPROM). The controller is further operative to wirelessly transmit a signal representative of the detected dose to a paired remote electronic device, such as a user's smartphone, over a Bluetooth low energy (BLE) or other suitable short or long-range wireless communication protocol. Illustratively, the BLE control logic and controller are integrated on a same circuit.

Claim 1:
A drug cassette (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for removable attachment to a drive module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to define a medication delivery device (<NUM>, <NUM>'', <NUM>, <NUM>', <NUM>‴), the cassette comprising:
a cassette housing (286A, <NUM>, <NUM>, <NUM>, <NUM>) configured to be attached to and detached from the drive module;
a container body (<NUM>, <NUM>) to hold a medication and defining an outlet;
a piston (<NUM>) disposed within the container body;
a drive ribbon (R, <NUM>) disposed within the cassette housing to advance the piston within the container body, wherein the drive ribbon includes a distal edge section and a proximal edge section, the drive ribbon being incrementally movable between a retracted configuration and an extended configuration about a drive axis, wherein a retracted portion of the drive ribbon in the retracted configuration defines a spiral and an extended portion of the drive ribbon in the extended configuration defines a helix; and
a driven member (<NUM>, <NUM>, <NUM>) engaged with the drive ribbon, wherein in response to a rotation of the driven member the drive ribbon is axially extended and the piston is advanced within the container body to expel the medication through the outlet.