Drug delivery devices, systems, and methods with force transfer elements

A wearable drug delivery device that can deliver a liquid drug stored in a container to a patient is provided. The container can be a prefilled cartridge that can be loaded into the drug delivery device by the patient or that can be preloaded within the drug delivery device when provided to the patient. A sealed end of the container is pierced to couple the stored liquid drug to a needle conduit that is coupled to a needle insertion component that provides access to the patient. A drive system of the drug delivery device can expel the liquid drug from the cartridge to the patient through the needle conduit. The drive system can include a spring coupled to a plurality of force transfer elements. The force transfer elements can have a variety of shapes and configurations.

TECHNICAL FIELD

Embodiments generally relate to medication delivery. More particularly, embodiments relate to force transfer elements used to actuate wearable drug delivery devices.

BACKGROUND

Many conventional drug delivery systems, such as handheld auto-injectors, are designed to rapidly delivery a drug to a patient. These conventional drug delivery systems are generally not suitable for delivering a drug to a user over relatively longer periods of time as may be required for many drugs.

As an alternative to conventional auto-injectors, many conventional drug delivery systems are designed to be wearable and to deliver a drug more slowly to the patient. However, these conventional wearable drug delivery systems often require a patient to transfer a drug or other medicine from a vial to a container within the drug delivery system. Transferring the drug can be a challenging task for many patients as it may require precise handling of the drug, a transfer mechanism (e.g., a syringe), and the drug delivery system. Some conventional wearable drug delivery systems use prefilled cartridges that contain the drug intended for the patient, obviating the need for such drug transfers. However, these conventional cartridge-based drug delivery systems are often bulky and cumbersome due to the included cartridge and can be uncomfortable when worn by the patient.

A need therefore exists for a more convenient and user-friendly wearable drug delivery device for providing a drug to a user.

SUMMARY

The present invention in various embodiments includes drug delivery devices, systems, and methods with force transfer elements. Fluids may be driving through and/or out of devices with force transfer elements and/or drive mechanisms of this disclosure.

In one aspect of the present invention, a drug delivery device may include a drug container for storing a liquid drug. A first end of the drug container may be sealed by a plunger. A needle conduit may be coupled to the plunger. A needle insertion component may be coupled to the needle conduit. A drive mechanism may be coupled to the plunger. The drive mechanism may include a drive spring and a plurality of linked force transfer elements. The plurality of linked force transfer elements may include a plurality of spherical body links. The spherical body may link each comprise partial spherical sections that may be coupled to adjacent body links via a ball and recess connection. The spherical body links may each include spherical sections coupled to connector links via a disc and recess connection. The linked force transfer elements may include partial spherical sections that may each having at least one roller coupled thereto. The plurality of linked force transfer element may include a plurality of chain links. Each of the plurality of chain links may include a depending portion that may be configured to be received in a recess portion of an adjacent chain link to enable adjacent links to pivot with respect to each other.

In another aspect, a drug delivery device may include a drug container for storing a liquid drug. A first end of the drug container may be sealed by a plunger. A needle conduit may be coupled to the plunger. A needle insertion component may be coupled to the needle conduit. A drive mechanism may be coupled to the plunger. The drive mechanism may include a drive spring and may include a plurality of non-spherical force transfer elements. The plurality of non-spherical force transfer elements may include a plurality of dog bone shaped links. Each of the plurality of non-spherical force transfer elements may comprise first and second shells biased apart by an elastic element. Each of the plurality of non-spherical force transfer elements may comprise a flexible rod and first and second guide rollers. Each of the plurality of non-spherical force transfer elements may include first and second roller elements and may include a reduced diameter section disposed therebetween. A bushed connecting rod may be coupled between adjacent one of said non-spherical force transfer elements. The bushed connecting rod may be rotatably coupled to the reduced diameter section of the non-spherical force transfer elements.

In another aspect, a drug delivery device may include a drug container for storing a liquid drug. A first end of the drug container may be sealed by a plunger. A needle conduit may be coupled to the plunger. A needle insertion component may be coupled to the needle conduit. A drive mechanism may be coupled to the plunger. The drive mechanism may include a drive spring and may include a plurality of substantially cylindrical force transfer elements. Each of the plurality of cylindrical force transfer elements may include a cylindrical portion having a groove and a protrusion. The groove and protrusion may be configured to engage a corresponding protrusion and a corresponding groove of an adjacent one of the plurality of cylindrical force transfer elements. The groove and the protrusion may be disposed adjacent each other at an upper end of each of said plurality of cylindrical force transfer elements. The groove and protrusion may be configured to engage the corresponding protrusion and the corresponding groove of said adjacent one of said plurality of cylindrical force transfer elements. The plurality of cylindrical force transfer elements may include a rail-engaging groove in the cylindrical portion, and may include a track-engaging portion configured to engage a rail disposed on a sidewall of a track of said drug delivery device. A substantially U-shaped track may have a straight track portion with walls spaced apart from each other a first distance, and a curved track portion with walls spaced apart from each other a second distance that may be smaller than the first distance. Each of the plurality of substantially cylindrical force transfer elements may include an hourglass shape having upper and lower portions that may be coupled by a reduced diameter portion. Each of the upper and lower portions may include a cylindrical portion that tapers to the reduced diameter portion to form upper and lower angled transition portions. The upper and lower angled portions may be straight angled portions. The upper and lower angled portions may each comprise curved portions.

DETAILED DESCRIPTION

The present disclosure is not limited to the particular embodiments described. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs.

Although embodiments of the present disclosure are described with specific reference to drug delivery, including insulin, it should be appreciated that such systems, methods, and devices may be used in a variety of configurations of fluid delivery, with a variety of instruments, a variety of fluids, and for a variety of organs and/or cavities, such as the vascular system, urogenital system, lymphatic system, neurological system, and the like.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises” and/or “comprising,” or “includes” and/or “including” when used herein, specify the presence of stated features, regions, steps elements and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and/or groups thereof. As used herein, the conjunction “and” includes each of the structures, components, features, or the like, which are so conjoined, unless the context clearly indicates otherwise, and the conjunction “or” includes one or the others of the structures, components, features, or the like, which are so conjoined, singly and in any combination and number, unless the context clearly indicates otherwise. The term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about”, in the context of numeric values, generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may include numbers that are rounded to the nearest significant figure. Other uses of the term “about” (i.e., in a context other than numeric values) may be assumed to have their ordinary and customary definition(s), as understood from and consistent with the context of the specification, unless otherwise specified.

The recitation of numerical ranges by endpoints includes all numbers within that range, including the endpoints (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

This disclosure presents various systems, components, and methods for delivering a liquid drug or medicine to a patient or user. Each of the systems, components, and methods disclosed herein provides one or more advantages over conventional systems, components, and methods.

Various embodiments include a wearable drug delivery device that can deliver a liquid drug stored in a container to a patient or user. The container can be a prefilled cartridge that can be loaded into the drug delivery device by the patient or that can be preloaded within the drug delivery device when provided to the patient. A sealed end of the container can be pierced to couple the stored liquid drug to a needle conduit. The needle conduit can be coupled to a needle insertion component that provides access to the patient. A drive system of the drug delivery device can expel the liquid drug from the container to the patient through the needle conduit. The drive system can include an energy storage component and one or more energy/force transfer components to enable the drug delivery device to maintain a small form factor. The result is enhanced patient's comfort when using the drug delivery device. Other embodiments are disclosed and described.

FIG.1illustrates an embodiment of a drug delivery device100with force transfer elements according to the present disclosure. The drug delivery device100can include a top portion or cover102and a lower portion or base104. The top portion102and the lower portion104can together form a housing of the drug delivery device100. The top portion102and the lower portion104can be coupled together to form an outside of the drug delivery device100. The top portion102and the lower portion104can be formed from any material including, for example, plastic, metal, rubber, or any combination thereof.

The drug delivery device100can be used to deliver a therapeutic agent (e.g., a drug) drug to a patient or user. In various embodiments, the drug delivery device100can include a container for retaining a liquid drug. The drug delivery device100can be used to deliver the liquid drug from the container to the patient. Any type of liquid drug can be stored by the drug delivery device100and delivered to a patient. In various embodiments, the container can contain any therapeutic agent such as, for example, a drug, a subcutaneous injectable, a medicine, or a biologic. A patient receiving a drug or other medicine (or any liquid) from the drug delivery device100can also be referred to as a user.

The drug delivery device100can operate as a bolus drug delivery device. In general, the drug delivery device100can provide any amount of the stored liquid drug to a patient over any period of time. In various embodiments, the drug delivery device100can provide the stored liquid drug to the patient in a single dose over a desired amount of time. In various embodiments, the drug delivery device100can provide the stored liquid drug to the patient over multiple doses.

As shown inFIG.1, the top portion102of the drug delivery device100can include a raised portion106. The raised portion106can be elongated and run along a side of the drug delivery device100. A liquid drug cartridge can be approximately positioned under the raised portion106such that the raised portion106accommodates the size and positioning of the liquid drug container within the drug delivery device102. The top portion102can also include a patient interaction element or component108. In various embodiments, the patient interaction element108can be a push button or other patient input device. The patient interaction element108can be used to activate the drug delivery device100.

The drug delivery device100can be a wearable drug delivery device100. As a wearable device, the drug delivery device100can be an on-body delivery system (OBDS). The drug delivery device100can be coupled to a patient in a number of ways. For example, the lower portion104of the drug delivery device100can include an adhesive for attaching to a patient. In various embodiments, the drug delivery device100can be attached to a secondary device attached or worn by the patient such that the drug delivery device100fits onto or can be coupled to the secondary device.

FIG.2illustrates an arrangement of internal components of the drug delivery device100with force transfer elements according to the present disclosure. For example,FIG.2shows various internal components of the drug delivery device100when the top portion102of the drug delivery device100is removed. The drug delivery device100can include a drug container202. The drug container202can include a first end204and a second end206. The drug container202can be sealed at or near the first end204and the second end206. The first end204can include a neck and a cap as shown. The second end206can include a plunger208. A liquid drug210can be contained between a sealing arrangement provided at the first end204of the drug container202and the plunger208. As an example, the first end204of the drug container202can be sealed by a septum. The drug container202of the drug delivery device100can be a drug cartridge such as, for example, an ISO standardized drug cartridge.

The liquid drug210is accessed through the second end206of the drug container202. A drug container access mechanism or component212can be positioned at or near the second end206for accessing the liquid drug210. As shown, the drug container access mechanism212can access the liquid drug210through the plunger208. The drug container access mechanism212can include a needle or other component at an end of the needle conduit214to pierce the plunger208to access the liquid drug210. The access mechanism212can include an access spring213disposed between a first plate211and a second plate215. The first and second plates211,215can include a wall configured to contain the access spring213. One or more force transfer elements (e.g., force transmitting spheres220) can be at least partially disposed within and/or adjacent the second plate215. The access spring213can provide a force load against the force transmitting spheres220to keep them substantially stable within the device. The needle and/or the needle conduit214can extend over (but not in contact with) one or more force transmitting spheres220, bend at about 90° through the second plate215(e.g., through a wall of the second plate215), bend at about 90° such that the needle conduit extends substantially parallel through a central axis of the access spring213, through a central aperture of the first plate211, and at least partially through an end of the plunger208. Prior to piercing through a second end of the plunger208, the plunger208may have one or both ends remain unpierced and the liquid drug210inaccessible and sealed within the drug container202. The drug container access mechanism212can remain in an idle state prior to being activated to access the liquid drug210. After activation, the needle of the drug container access mechanism212can extend through the plunger208.

The drug container access mechanism212can couple the liquid drug210to a needle conduit214. The needle conduit214can include tubing (e.g., plastic tubing or metal tubing) and can provide a path for a portion of the liquid drug210that is expelled from the primary drug container202. The needle conduit214can route the liquid drug210from the primary drug container202to a needle insertion mechanism or component216. The needle insertion mechanism216can provide an entry point to a patient. The needle insertion mechanism216can include a hard needle and/or a soft needle or cannula that provides access to the patient such that the liquid drug210can be delivered to the patient.

As further shown inFIG.2, the drug delivery device100can also include a drive spring218and a plurality of force transfer elements (e.g., force transmitting spheres220), which in the illustrated embodiment are ball bearings. The force transmitting spheres220can be formed of any type of material including glass, metal (e.g., stainless steel), a polymer, other plastic, or the like.

The drive spring218and the force transmitting spheres220can be used to expel the liquid drug210from the primary drug container202. In particular, the drive spring218can apply a force that can be applied to the spheres220. The force transmitting spheres220can be arranged to transfer the force from the drive spring218to the plunger208. When the force from the drive spring218is applied to the plunger208, the plunger208can advance into the drug container202(toward the first end204). As the plunger208advances into the drug container202, the liquid drug210within the drug container202can be forced into the needle conduit214and on to the needle insertion mechanism216for delivery to the patient.

In the illustrated embodiment, the drive spring218is a coil spring, though it will be appreciated that it could be any appropriate type of spring, and may consist of multiple springs. A dead bolt222or other fixed element can be positioned at one end of the drive spring218to provide a stable reference for the drive spring218(e.g., a push off point). The dead bolt222can be coupled to the inner top surface of the lower portion104.

The bottom portion104of the drug delivery device100can include a track224for guiding the force transmitting spheres220as they are pushed by the drive spring218toward the plunger208. The track224can completely surround or cover the force transmitting spheres220, and can form any shape and can be arranged to take on any shape to guide the force transmitting spheres220from the drive spring218to the drug container202.

Prior to activation, the drive spring218can be in an idle state. While in an idle state, the drive spring218can be compressed (e.g., as shown inFIG.2). When activated, the drive spring218can be allowed to expand. For example, after activation, the drive spring218can be allowed to expand in a direction away from the dead bolt222. When initially activated, the drive spring218can apply a force against the force transmitting spheres220which, in turn, press the plunger208into the drug container access mechanism212to cause a needle coupled to the needle conduit214to pierce the plunger208.

Once the plunger208is pierced, the primary drug container202can be drained of its contents and delivered to a patient. The drive spring218and the force transmitting spheres220can be sized and adjusted to help regulate a flow of the liquid drug210from the primary drug container202to the needle insertion mechanism216based on a variety factors including the viscosity of the liquid drug210and the diameter of the needle conduit214.

As shown inFIG.2, when the drive spring218is allowed to expand it applies a force in a direction230against the force transmitting spheres220. The direction230can correspond to a direction in which the drive spring218is allowed to expand, based on a positioning of the dead bolt222, which can provide a thrust point for the drive spring218. The force transmitting spheres220can translate or transfer the force from the drive spring218to the plunger208. The force transmitting spheres220allow the force to be translated to a different direction than the original direction of the force. Specifically, the force transmitting spheres220can apply the force along a curved path, and finally in a direction toward the first end204of the primary drug container202relative to the second end206of the primary drug container202. Consequently, the force transmitting spheres220enable the force provide by the drive spring218provided in a first direction to be applied to the plunger208in a second, approximately opposite direction, via, e.g., the second plate215, access spring213, and first plate211, as described above.

As shown inFIG.2, the direction230of the force provided by the drive spring218can cause the force transmitting spheres220to move in the direction232—that is, through the track224toward the second end206of the primary drug container202. The force transmitting spheres220can therefore transfer the force from the drive spring218to the plunger208, thereby causing the plunger208to move in a direction240. The movement of the plunger208in the direction240can force the liquid drug210out of the primary drug container202and into the needle conduit214.

Although the embodiment ofFIG.2includes a drug delivery device including a drive mechanism employing a plurality of force transmitting spheres220, force may be transferred from the drive spring218to the plunger208using force transmitting elements having a variety of other configurations. Such alternative configurations are described throughout this disclosure. It will be appreciated that each of the described alternative force transmitting elements can be implemented in various drug delivery devices such as the drug delivery device100described in relation toFIGS.1and2.

Referring toFIGS.3A and3B, a drive mechanism301with force transfer elements according to the present disclosure includes a plurality of spherical body links320disposed within a track324formed in or on the bottom104(FIG.1) of the drug delivery device100. Each spherical body link320includes a partial spherical portion320a, a neck portion320b, and a rounded head portion320c. The partial spherical portions320aeach have a recess320dtherein for receiving the head portion320cof an adjacent link. In some embodiments the recess320dmay receive the head portion320cof an adjacent link via a snap-fit. The recess320dis sized and shaped to enable the received head portion320cto pivot therein, thus allowing the individual links to pivot with respect to each other. This, in turn, enables the drive mechanism301to move through the curved section325of the track324. An advantage of this embodiment is that the spherical body links320can be shorter than a similarly sized sphere (e.g.,220), thus allowing for more individual links along the length of the drive mechanism301. Such an arrangement can be a benefit because it allows for greater articulation of the drive mechanism in the curved section325of the track324.

A first end301aof the drive mechanism301is configured to engage a drive spring (e.g., the spring218ofFIG.2), while the second end301bof the drive mechanism is configured to engage a plunger (e.g., the plunger208ofFIG.2). Activation and operation of the drug delivery device100including the drive mechanism301of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.4A and4Bshow a drive mechanism401with force transfer elements according to the present disclosure including a plurality of spherical rollers420disposed within a track424formed in or on the bottom104(FIG.1) of the drug delivery device100. Each spherical roller420includes first and second circumferential slots420a,420bfor receiving first and second arms421a,421bof a spacer421. The first and second circumferential slots420a,420bmay be parallel, and may slindingly receive the first and second arms421a,421bof the spacer421to enable the spherical rollers420to rotate with respect to the spacer421and with respect to adjacent spherical rollers. This, in turn, enables the drive mechanism401to move through the curved section425of the track424. An advantage of this embodiment is that the spacers421prevent the spherical roller420from touching each other on the large diameter, thus facilitating rolling movement of the rollers.

A first end401aof the drive mechanism401is configured to engage a drive spring218(FIG.2), while the second end401bof the drive mechanism is configured to engage a plunger208. Activation and operation of the drug delivery device100including the drive mechanism401of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.5A and5Bshow a rolling ball link520of a drive mechanism with force transfer elements according to the present disclosure. Each rolling ball link520includes a partial spherical portion520a, a neck portion520b, and a base portion520c. The base portions520cof each rolling ball link520has a recess520dtherein for receiving the head portion520aof an adjacent link. In some embodiments, the recess520dmay receive the head portion520aof an adjacent link via a snap-fit. The recess520dis sized and shaped to enable the received head portion520ato pivot therein, thus allowing the individual links to pivot with respect to each other. Each base portion520ccan have a triangular shape, and can have a roller520erotatably disposed at each apex of the triangle. This enables the rollers520eof each rolling ball link520to ride on the track and to spin. The rolling ball links520can be shorter than comparably sized spheres, thus allowing for more links in the curved section of the track. Such an arrangement can be a benefit because it allows for greater articulation of the drive mechanism in the curved section of the track.

Similar to other embodiments, a plurality of rolling ball links520can be coupled together to form a drive mechanism, which is configured to engage a drive spring218(FIG.2) at one end, and to engage a plunger208at an opposite end. Activation and operation of the drug delivery device100including the plurality of rolling ball links520of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.6A and6Bshow a drive mechanism601with force transfer elements according to the present disclosure including a plurality of partial spherical rollers620disposed within a track624formed in or on the bottom104(FIG.1) of the drug delivery device100. Each partial spherical roller620includes a recess620afor receiving the spherical portion620bof an adjacent partial spherical roller620in the manner of a caterpillar. The nested arrangement of partial spherical rollers620allows the partial spherical rollers to rotate with respect to adjacent partial spherical rollers620.

The nesting arrangement also means that the partial spherical rollers620can be shorter than comparably sized spheres, thus allowing for more links in the curved section625of the track. Such an arrangement can be a benefit because it allows for greater articulation of the drive mechanism601in the curved section625of the track624.

In some embodiments, a plurality of bearings621can be disposed between the associated nested partial spherical rollers620to reduce friction between the recess620aof one partial spherical roller and the spherical portion620bof an adjacent roller.

A first end601aof the drive mechanism601is configured to engage a drive spring218(FIG.2), while the second end601bof the drive mechanism is configured to engage a plunger208. Activation and operation of the drug delivery device100including the drive mechanism601of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.7A and7Bshow a roller bearing link720for a drive mechanism with force transfer elements according to the present disclosure where each link720includes a plurality of roller bearings721. When viewed from the side/end, such asFIG.7B, each of the roller bearings721may be disposed on or in a separate face722of the roller bearing link. In the illustrated embodiment, the faces are disposed 120-degrees apart from each other such that the roller bearing link720is supported at three points (i.e., at the three bearings). Each roller bearing link720may have a recess for receiving a pivot connector723to enable adjacent roller bearing links to pivot with respect to each other. The track724of this embodiment may include separately spaced rails726upon which the roller bearings721may run. In some embodiments, the rails726are disposed only in the curved section of the track, while in other embodiments the rails are employed along the entire length of the track.

Similar to other embodiments, a plurality of roller bearing links720can be coupled together to form a drive mechanism that is configured to engage a drive spring218(FIG.2) at one end, and to engage a plunger208at an opposite end. Activation and operation of the drug delivery device100including the plurality of roller bearing link720of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.8A and8Bshow a drive mechanism801with force transfer elements according to the present disclosure including a plurality of spherical rollers820disposed within a track824formed in or on the bottom104(FIG.1) of the drug delivery device100. Each spherical roller820includes a central circumferential slot820afor receiving a portion of a disc spacer821. The circumferential slot820amay slindingly receive the disc spacer821to enable the spherical rollers820to rotate with respect to the disc spacer821and with respect to adjacent spherical rollers. This, in turn, enables the drive mechanism801to move through the curved section825of the track824. An advantage of this embodiment is that the disc spacers821prevent the spherical rollers820from touching each other on the large diameter, thus facilitating rolling movement of the rollers. Another advantage is that the disc spacers821prevent the spherical rollers820from rotating in directions other than that which facilitates movement of the drive mechanism801along the track824.

A first end801aof the drive mechanism801is configured to engage a drive spring218(FIG.2), while the second end801bof the drive mechanism is configured to engage a plunger208. Activation and operation of the drug delivery device100including the drive mechanism801of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.9A and9Bshow a drive mechanism901with force transfer elements according to the present disclosure comprising a roller chain having individual chain links920disposed within a track924formed in or on the bottom104(FIG.1) of the drug delivery device100. Each chain link920is rotatably coupled to an adjacent chain link920via a pin921, which enables the chain links920to rotate with respect to the pin921and with respect to adjacent chain links920. Each pin921includes a cylindrical hollow body roller923about the pin921and between the chain links920. The rollers923make contact with the track924and may spin about their respective pin921while the chain links920separate the pins921and keep the rollers923from contacting each other and allow the rollers923to roll. This, in turn, enables the drive mechanism901to move through the curved section925of the track924.

A first end901aof the drive mechanism901is configured to engage a drive spring218(FIG.2), while the second end901bof the drive mechanism is configured to engage a plunger208. Activation and operation of the drug delivery device100including the drive mechanism901of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIG.10shows a drive mechanism1001with force transfer elements according to the present disclosure including a plurality of split sphere elements1020disposed within a track1024formed in or on the bottom104(FIG.1) of the drug delivery device100. Each split sphere element1020includes first and second shells1020a,1020bwith an expanding element1021, such as a spring, disposed therebetween biasing the first and second shells apart. This arrangement enables the entire track1024to be filled with expanding split sphere elements1020, as opposed to a single long spring (such as might be used with a single-spring arrangement). The disclosed arrangement of split sphere elements1020can make the drive mechanism1001compliant through the curved section1025of the track1024.

A first end1001aof the drive mechanism1001is configured to engage a drive spring218(FIG.2), while the second end1001bof the drive mechanism is configured to engage a plunger208. Activation and operation of the drug delivery device100including the drive mechanism1001of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2. Alternatively, the drive mechanism1001may partially or completely replace the need for a drive spring (such as drive spring218ofFIG.2). Replacing the drive spring may lower the spring constant (often the “k” variable in the art) or average spring constant needed for the springs of the device.

FIG.11shows a drive mechanism1101with force transfer elements according to the present disclosure including a plurality of dog bone shaped (i.e., wider ends than a thinner middle section connecting the wider ends) elements1120disposed within a track1124formed in or on the bottom104(FIG.1) of the drug delivery device100. Each dog bone shaped elements1120include first and second ends1120a,1120bconnected by a neck portion1120c. The diameter of the first and second ends1120a,1120bcan be sized to slide within the track1124. The diameter of the neck portion1120cmay be smaller than the diameter of the first and second ends1120a,1120b. The disclosed arrangement of dog bone shaped elements1120can reduce the total number of individual parts making up the drive mechanism1101, while enabling the mechanism to be highly compliant through the curved section1125of the track1124.

A first end1101aof the drive mechanism1101is configured to engage a drive spring218(FIG.2), while the second end1101bof the drive mechanism is configured to engage a plunger208. Activation and operation of the drug delivery device100including the drive mechanism1101of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIG.12shows a drive mechanism1201with force transfer elements according to the present disclosure comprising a plurality of inter-engaged custom link members1220. Each custom link members1220includes a first end having a depending portion1220aand a second end having a recess1220b. The depending portion1220aof one custom link member1220is configured to be received in the recess1220bof a directly adjacent custom link member1220. The depending portions1220amay be rounded or spherical while the recesses1220bmay be sized and shaped to enable the received depending portion1220ato pivot therein, thus allowing the individual links to pivot with respect to each other. The disclosed arrangement allows the drive mechanism1201to pivot the custom link members1220and articulate around the curved portion225of a guide track224(FIG.2). The arrangement also enables the use of single-piece links1220that have the column strength of a chain, without the complexity and part count.

Similar to other embodiments, the drive mechanism1201can be disposed within an appropriate track224(FIG.2), and can have first and second ends for engaging a drive spring218at one end, and to engage a plunger208at an opposite end. Activation and operation of the drug delivery device100including the plurality of custom link members1220of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIG.13shows a drive mechanism1301with force transfer elements according to the present disclosure including a plurality of spherical rollers1320engaged with a track1324formed in or on the bottom104(FIG.1) of the drug delivery device100. First and second spherical rollers1321,1322oppose associated ones of the plurality of spherical rollers1320at each end of the curved portion1325of the track1324. A flexible guide rod1326is guided through the track1324via the plurality of spherical rollers1320. The flexible guide rod1326is constrained and guided into/out of the track1324via the first and second spherical rollers1321,1322.

The flexible guide rod1326can be sufficiently flexible to move through the curved section1325of the track1324while still maintaining a desired column strength to move the plunger208(FIG.2). A first end1301aof the drive mechanism1301is configured to engage a drive spring218(FIG.2), while the second end1301bof the drive mechanism is configured to engage a plunger208. Activation and operation of the drug delivery device100including the drive mechanism1301of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.14A and14Bshow a drive mechanism1401with force transfer elements according to the present disclosure comprising a roller chain having a plurality individual chain links1420, where adjacent chain links1420are coupled together by a bushed connecting link1421. Each chain link1420can have first and second roller portions1422connected via a reduced-diameter portion1423. The first and second roller portions1422can be sized to conform to the inner dimension of an associated guide track224(FIG.2) so that they can ride on the walls of the guide track. The bushed connecting link1421can engage the reduced-diameter portions1423of adjacent chain links1420. The bushed connecting link1421can couple to each of the reduced-diameter portions1423of adjacent chain links1420via a collar1421athat allows the individual chain links1420to rotate with respect to the bushed connecting link1421. The bushed connecting link1421may be stiff enough to transmit the spring force from the drive spring218(FIG.2) to the plunger208, while enabling the individual chain links1420to pivot with respect to each other. This, in turn, enables the drive mechanism1401to move through the curved section225(FIG.2) of the track224.

Similar to other embodiments, a plurality of chain links1420can be coupled together to form a drive mechanism1401that is configured to engage a drive spring218(FIG.2) at one end, and to engage a plunger208at an opposite end. Activation and operation of the drug delivery device100including the plurality of chain links1420of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIG.14Bshows an example embodiment of how the individual chain links1420can be assembled from upper and lower portions1420a,1420b. The upper and lower portions1420a,1420bcan have first and second reduced diameter portions1423a,1423b. In the illustrated embodiment the first reduced diameter portion1423aincludes a projection1424areceived within a recess1424bin the second reduced diameter portion1423b. The projection1424acan be fixed within the recess1424busing any of a variety of appropriate technologies, including press-fit, adhesives, threads, and the like. During assembly, the first and second reduced diameter portions would be engaged with each other within a collar1421aof bushed connecting link1421.

FIG.15shows an embodiment in which the force transfer elements according to the present disclosure comprise cylindrical elements1500. In one embodiment the cylinders1500may be roller pins, which can maximize the transfer of loads, while minimizing deformation of the pin or its opposing surfaces. Input forces (from the drive spring218(FIG.2)) will not equal output forces, due to losses in friction around the curved portion225of the track224. Minimizing point loading and deformation, however, will tend to provide the highest output forces (i.e., highest efficiency). Providing the force transfer elements as cylindrically shaped elements1500allows for a plurality of elements to transfer the maximum force vector while minimizing losses and conforming to the track224within the drug delivery device100without buckling.

FIG.16shows an exemplary cylindrical force transfer element1620for a drive mechanism with force transfer elements according to the present disclosure. The force transfer element1620may have top and bottom portions1620a,1620band a central portion1620c. First and second reduced diameter portions1620d,1620emay be located between the top and central portions1620a,1620cand the bottom and central portions1620b,1620c, respectively. The top and bottom portions1620a,1620bmay include beveled upper/lower surfaces1620f,1620gto reduce the surface area that will contact surfaces of the track224(FIG.2). The first and second reduced diameter portions1620d,1620emay receive rail or other protruding features of the track224to guide and support the cylindrical force transfer elements1620within the straight portions of the track (e.g., where the spring218extends).

Similar to other embodiments, a plurality of cylindrical force transfer elements1620can be coupled together to form a drive mechanism that is configured to engage a drive spring218(FIG.2) at one end, and to engage a plunger208at an opposite end. Activation and operation of the drug delivery device100including the plurality of cylindrical force transfer elements1620of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIG.17shows a pair of exemplary cylindrical force transfer elements1720a,1720bfor a drive mechanism with force transfer elements according to the present disclosure which include keying features that allow the elements1720a,1720bto couple together while also allowing them to rotate with respect to each other (e.g., when traversing the curved portion225of the track224(FIG.2). As can be seen, the cylindrical force transfer elements1720a,1720bare 180-degree rotated images of each other. Each of the force transfer elements1720a,1720bincludes a circumferential recess1721and a circumferential projection1722. The recess1721and projection1722are sized and positioned so that the projection is received within the recess1721when the force transfer elements1720a,1720bare coupled together.

The projection1722may be loosely received within the recess1721to enable the force transfer elements1720a,1720bto rotate about their respective longitudinal axes A-A, B-B and to rotate with respect to each other about axes parallel to their longitudinal axes. This will enable the force transfer elements1720a,1720bto traverse the curved portion225of the track224of the drug delivery device100. The interaction of the projection1722and recess1721may, however, prevent rotation of the force transfer elements1720a,1720babout other axes. Thus, the cylindrical force transfer elements1720a,1720bof this embodiment will not randomly “fan-out” or twist within the track224of the drug delivery device100. Rather, they will be rotationally constrained from the cylinders that remain in the track.

FIG.18shows an embodiment of a drive mechanism1801for a drive mechanism with force transfer elements according to the present disclosure including a plurality of cylindrical force transfer elements1820disposed within a track1824formed in or on the bottom104(FIG.1) of the drug delivery device100. Each cylindrical force transfer elements1820includes a cylindrical body portion1820a, and offset top and bottom portions1820b. Adjacent the offset top and bottom portions1820bare recess portions1820c. The recess portions1820care configured to slidingly engage respective offset top and bottom portions1820bof an adjacent cylindrical force transfer element1820. This overlapping engagement allows adjacent cylindrical force transfer element1820to move with respect to each other as the drive mechanism1801traverses the curved portion1825of the track1824, while preventing them from “fanning-out,” over-rotating with respect to each other, or twisting within the track1824of the drug delivery device100.

Each of the plurality of cylindrical force transfer elements1820may also include one or more grooves1820ddisposed in the cylindrical body portion1820a. These grooves1820dmay be oriented so that they are parallel to the bottom104of the drug delivery device.100. The grooves1820dmay be sized and shaped to interface with guide rails1826disposed on one or more surfaces of the track1824. In the illustrated embodiment, the guide rails1826are disposed in a straight portion of the track1824adjacent to the drive spring1818. In other embodiments, the rails may be disposed in the curved portion of the track in addition to the straight portion.

A first end1801aof the drive mechanism1801is configured to engage a drive spring1818, while the second end1801bof the drive mechanism is configured to engage a plunger1808. Activation and operation of the drug delivery device100including the drive mechanism1801of this embodiment may be substantially the same as described in relation to the embodiment ofFIG.2.

FIGS.19A-23show a drive mechanism with force transfer elements according to the present disclosure in which the force transfer elements are designed as constant angular velocity force transfer rollers1920. The force transfer rollers1920have an hourglass shape in profile, and include upper and lower portions1920a,1920bcoupled by a reduced diameter portion1920c. Each of the upper and lower portions1920a,1920bhas a cylindrical portion1920d, which tapers to the reduced diameter portion1920cresulting in upper and lower angled transition portions1920e,1920fThe top and/or bottom surfaces of the cylindrical portions1920dinclude an array of radial etching markers even spaced about a center point of the cylindrical portions1920d. The etchings provide visual indication of motion of the rollers1920that may be measurable (e.g., a number of marks rotating and/or translating along a track).

FIGS.20A and20Bshow a track2024for use with the force transfer rollers1920. The track2024may be generally U-shaped, comprising a pair of straight track portions2024a,2024band an intermediate curved track portion2025. The inner walls of the straight track portions2024a,2024band the outer track wall of the curved track portion2025may be flat. The inner track wall of the curved track portion2025may have an expanded radius “R” and a tapered cross-section that produces a reduced-thickness portion2025aat the perimeter of the inner track wall of the curved track portion. The substantially U-shaped track2024includes the straight track portions2024a,2024bwith walls spaced apart from each other a first distance, and a curved track portion2025with walls spaced apart from each other a second distance that is smaller than the first distance.

FIG.21shows the configuration of the force transfer rollers1920while they are in the straight portion2024b(or2024a) of the track2024. While the force transfer rollers1920are in the straight portion of the track they all roll on the largest radius portions (i.e., upper and lower portions1920a,1920b). As can be seen, the upper and lower portions1920a,1920bhave diameters “D” that are smaller than a width “W” of the track2024. The force transfer rollers1920thus adjust their relative positions to fit within the track2024, creating a double stack arrangement. In the straight portion of the track, both stacks of rollers are rolling on equal radii. The ability to roll comes from the double stack design and avoids forced sliding that can occur in a single stack arrangement.

FIG.22shows the positions of the force transfer rollers1920in a transition region between the straight portion2024a/2024band the curved portion2025. The rollers in the inside stack (1920-1) will roll on a non-constant radius surface2025ato maintain contact with the rollers in the outside stack (1920-2,1920-3). While the rollers are going through the transition area they will roll on the angled transition portion1920f(FIG.19A), bringing the radius down from to the final size before rolling in the curved section2025.

In order to transition from the known straight configuration to the known curved section2025there must be a transition where the radius of the force transfer rollers1920changes with angular distance travelled until the rollers reach the curved section of the track. Entering the curved section2025may cause the force transfer rollers1920to slip instead of roll if the geometry between rollers changes. As can be seen, the angle between rollers is smaller when they are travelling in the straight portion than when they are in the curved portion. The transition curve may need both the inner and outer stacks to have different, changing radii at the same time to maintain 100% rolling. In some embodiments, the angled transition portion1920f(FIG.19A) may not be a straight line, but rather may be a radius change as defined by a curve.

FIG.23shows the rollers1920in the curved portion of the track2025. As can be seen, the inner stack (1920-1) rolls on the smallest radius to maintain a constant linear velocity relative to the rollers in the outside stack (1920-2,1920-3). There is a known but different configuration in the curved part of the track2025where the inside stack is rolling on the smallest radius (i.e., the reduced diameter portion1920-c(FIG.19A) and the outside stack rolls on the largest radii (cylindrical portions1920d). The ratio between radii is equal to the ratio between track radii.

With the embodiment ofFIGS.19A-23, the force transfer rollers1920in both stacks should satisfy v=ωr (with v being tangential linear velocity, co being angular velocity, and r being the radius), where v is constant and equal for both stacks. In the straight sections (2024a,2024b) this is achieved by having equal radii and an equal linear distance. In the curved portion2025, the outside track has a larger linear distance, so the rollers must change radius to compensate. Either the outer stack of rollers (1920-2,1920-3) need a larger rolling radius (i.e., UFO shape) or the inner stack of rollers (1920-1) needs a smaller rolling radius (i.e., hourglass). The track2024should include a variable radius portion (2025a) to meet the roller and facilitate rolling at the appropriate radius for that point in the transition.