Claims:
We claim:

1. A dose setting and correcting system for a dispensing device (102), comprising:
a dose dial knob (108) comprising a protrusion (412) positioned at a distal end (414) of the dose dial knob (108), wherein the dose dial knob (108) is adapted to be rotated in one or more directions for setting a desired dose of a material to be delivered from a cartridge (202) and for correcting an incorrectly set dose to the desired dose, wherein the incorrectly set dose is different from the desired dose; and
a plunger (205) comprising a plunger body (206) that is positioned within the dose dial knob (108), wherein the plunger body (206) comprises a set of stopper columns (608A-D), wherein each of the stopper columns (608A-D) comprises a set of non-flexible stoppers (610A-H, 614A-G, 618A-H, and 622A-H) and a set of flexible stoppers (612A-H, 616A-H, 620A-H, and 624A-I) that are positioned on an exterior surface (606) of the plunger body (206) such that each of the flexible stoppers (612A-H, 616A-H, 620A-H, and 624A-I) is successively followed by a non-flexible stopper and each of the non-flexible stoppers (610A-H, 614A-G, 618A-H, and 622A-H) is successively followed by a flexible stopper; and
wherein the protrusion (412) positioned at the distal end (414) of the dose dial knob (108) is adapted to slide over one or more designated flexible stoppers selected from the flexible stoppers (612A-H, 616A-H, 620A-H, and 624A-I) when setting the desired dose and when correcting the incorrectly set dose to the desired dose by rotating the dose dial knob (108) in the one or more directions, wherein sliding of the protrusion (412) over each of the designated flexible stoppers generates a corresponding non-visual feedback that indicates one of an increment and a decrement of a dose of the material by a designated unit.

2. The dose setting and correcting system as claimed in claim 1, wherein the one or more directions comprise a first direction and a second direction different from the first direction, wherein the dose dial knob (108) is adapted to be rotated in the first direction for incrementing a dose to be delivered and is adapted to be rotated in the second direction for decrementing the dose to be delivered, wherein the first direction corresponds to a clockwise direction and the second direction corresponds to an anti-clockwise direction, wherein the dose dial knob (108) is rotated in one or more of the first direction and the second direction for setting the desired dose of the material to be delivered from the cartridge (202), and wherein the dose dial knob (108) is rotated in one or more of the first direction and the second direction for correcting the incorrectly set dose to the desired dose.

3. The dose setting and correcting system as claimed in claim 2, wherein each of the stopper columns (608A-D) comprises a plurality of slots (626) disposed on the plunger body (206), wherein each of the plurality of slots (626) in a designated stopper column (608A) is disposed between a non-flexible stopper and a flexible stopper in the designated stopper column (608A).

4. The dose setting and correcting system as claimed in claim 3, wherein the set of non-flexible stoppers (610A-H, 614A-G, 618A-H, and 622A-H) and the set of flexible stoppers (612A-H, 616A-H, 620A-H, and 624A-I) are radially aligned to the plunger body (206) and are further aligned in parallel to a horizontal axis (920) of a plunger rod (208), and wherein each of the plurality of slots (626) is aligned in perpendicular to the horizontal axis (920) of the plunger rod (208).

5. The dose setting and correcting system as claimed in claim 4, wherein each of the set of flexible stoppers (612A-H, 616A-H, 620A-H, and 624A-I) comprises a corresponding first ramp (628) and a corresponding second ramp (630), wherein the first ramp (628) comprises a first elevated angle and the second ramp (630) comprises a second elevated angle different from the first elevated angle.

6. The dose setting and correcting system as claimed in claim 3, wherein the stopper columns (608A-D) comprises a first stopper column (608A), a second stopper column (608B), a third stopper column (608C), and a fourth stopper column (608D).

7. The dose setting and correcting system as claimed in claim 6, wherein the protrusion (412) is positioned at a first side (1002) of a designated flexible stopper (612A) selected from the first stopper column (608A) when the doses of the material set for delivery corresponds to zero.

8. The dose setting and correcting system as claimed in 7, wherein the protrusion (412) is positioned in an elevated state (1006) above the designated flexible stopper (612A) when the dose dial knob (108) is rotated in the first direction to set the desired dose, wherein the protrusion (412), positioned in the elevated state (1006), exerts a downward force on the designated flexible stopper (612A) and compresses the designated flexible stopper (612A) to position the designated flexible stopper (612A) in a compressed state (1008) into a slot (626) disposed on the plunger body (206).

9. The dose setting and correcting system as claimed in 8, wherein the protrusion (412) is adapted to be repositioned from above the designated flexible stopper (612A) to a second side (1010) of the designated flexible stopper (612A) when the dose dial knob (108) is further rotated in the first direction to set the desired dose, wherein repositioning of the protrusion (412) releases the downward force exerted on the designated flexible stopper (612A), thereby causing the designated flexible stopper (612A) to emerge out of the slot (626) and revert to a relaxed state (1012).

10. The dose setting and correcting system as claimed in 9, wherein the protrusion (412) is adapted to slide from the first side (1002) to the second side (1010) of the designated flexible stopper (612A) when the dose dial knob (108) is rotated in the first direction, thereby causing the designated flexible stopper (612A) to revert to the relaxed state (1012) from the compressed state (1008) and generating a first non-visual feedback that indicates an increment of the dose by a first designated unit from zero to a first intermediate dose.

11. The dose setting and correcting system as claimed in 10, wherein the dose dial knob (108) is adapted to be further rotated in the first direction when the first intermediate dose is not equivalent to the desired dose of the material to be delivered, wherein the rotation of the dose dial knob (108) in the first direction causes the protrusion (412) to move from a first side (1014) of a selected flexible stopper (616A) in the second stopper column (608B) and be positioned above the selected flexible stopper (616A), and wherein the protrusion (412) is further adapted to be repositioned from above the selected flexible stopper (616A) to a second side (1016) of the selected flexible stopper (616A), and wherein the protrusion (412) is adapted to slide from the first side (1014) to the second side (1016) of the selected flexible stopper (616A), the movement of the selected flexible stopper (616A) from the compressed state (1008) to the relaxed state (1012) generating a second non-visual feedback that indicates an increment of the dose by a second designated unit from the first intermediate dose to a second intermediate dose.

12. The dose setting and correcting system as claimed in 11, wherein the dose dial knob (108) is adapted to be rotated in the second direction when the first intermediate dose, equivalent to the desired dose, is inadvertently incremented to the second intermediate dose, wherein the rotation of the dose dial knob (108) in the second direction causes the protrusion (412) to move from the second side (1016) of the selected flexible stopper (6161A) and be positioned above the selected flexible stopper (616A), and wherein the protrusion (412) is further adapted to be repositioned from above the selected flexible stopper (616A) to the first side (1014) of the selected flexible stopper (616A) when the dose dial knob (108) is rotated in the second direction.

13. The dose setting and correcting system as claimed in 11, wherein the protrusion (412) is adapted to slide from the second side (1016) to the first side (1014) of the selected flexible stopper (616A) when the dose dial knob (108) is further rotated in the second direction, thereby causing the selected flexible stopper (616A) to revert to the relaxed state (1012) from the compressed state (1008) and generating a third non-visual feedback that indicates a decrement of the dose by the second designated unit from the second intermediate dose to the first intermediate dose.

14. The dose setting and correcting system as claimed in 12, wherein each of the first non-visual feedback, the second non-visual feedback, and the third non-visual feedback comprises one or more of an audible feedback and a tactile feedback.

15. The dose setting and correcting system as claimed in 2, comprising a selected non-flexible stopper (622A) in the set of non-flexible stoppers (610A-H, 614A-G, 618A-H, and 622A-H), wherein the protrusion (412) is adapted to move in a circular path while setting the desired dose for delivery, the circular movement causing the protrusion (412) to be placed in a locked state with respect to the selected non-flexible stopper (622A) when setting the desired dose equal to a designated maximum dose, thereby preventing further rotation of the dose dial knob (108) in the first direction and preventing setting of the desired dose above the designated maximum dose.

16. The dose setting and correcting system as claimed in 15, wherein the plunger body (206) comprises a particular non-flexible stopper (610H) disposed thereon and having an associated length that is longer than a corresponding length associated with each of other non-flexible stoppers (610A-G, 614A-G, 618A-H, and 622A-H) disposed on the plunger body (206), and wherein the particular non-flexible stopper (610H) is adapted to stop the circular movement of the protrusion (412) and to prevent setting a final dose that is more than a remaining dose of the material in a cartridge (202) of the dispensing device (102).

17. The dose setting and correcting system as claimed in 16, wherein the dispensing device (102) comprises:
a needle disposed at a distal end (118) of the dispensing device (102);
an outer body (106) that accommodates the cartridge (202) having the material to be delivered via the needle, wherein the outer body (106) is rotationally coupled to the dose dial knob (108) to set the desired dose to be delivered;
a dose sleeve (204) comprising a proximal end (502) that is coupled to the dose dial knob (108) and a distal end (508) that is coupled to the outer body (106), wherein the dose sleeve (204) rotates and moves linearly within the outer body (106) by a designated distance corresponding to a rotation of the dose dial knob (108) to set the desired dose;
a plunger ratchet (210) that is coupled to the plunger (205) and that comprises a plurality of teeth (906), wherein the plunger (205) extends out from a slot (514) of the dose sleeve (204);
a plunger rod (208) that is coupled to the plunger (205), wherein one end of the plunger rod (208) is disposed within the cartridge (202);
a locking device (214) that is coupled to the plunger ratchet (210) and that comprises a set of flexible pawls (712A-B) that are positioned in an engaged state with a tooth in the plurality of teeth (906) in the plunger ratchet (210) to hold the plunger (205) in a locked position while setting the desired dose;
an elastic member (212) disposed in a compressed state between the plunger body (206) and the locking device (214); and
an unlocking device (216) disposed partially within the locking device (214) and adapted to disengage the flexible pawls (712A-B) from the tooth in the plurality of teeth (906) in the plunger ratchet (210) when the unlocking device (216) is depressed, thereby releasing the plunger (205) from the locked position to an unlocked position, the release of the plunger (205) to the unlocked position causing an expansion of the elastic member (212), wherein the expansion of the elastic member (212) causes the plunger (205) to move only linearly by the designated distance to release the set desired dose from the cartridge (202).

18. The dose setting and correcting system as claimed in 17, wherein the unlocking device (216) comprises a thumb pad (802) that comprises a stem portion (804) disposed within the locking device (214), and wherein the flexible pawls (712A-B) are secured to a first tooth (906) of the plunger ratchet (210) to hold the plunger (205) in the locked position before releasing a set first dose from the dispensing device (102).

19. The dose setting and correcting system as claimed in 18, wherein a depression of the thumb pad (802) causes the stem portion (804) to flex the flexible pawls (712A-B) upwards to release the plunger (205) from the locked position to the unlocked position, and thereby causing the expansion of the elastic member (212), wherein the expansion of the elastic member (212) causes the plunger (205) to move linearly by a selected distance towards the distal end (118) of the dispensing device (102) to release the set first dose, wherein the selected distance corresponds to the distance by which the dose sleeve (204) moves while setting the first dose using the dose dial knob (108).

20. The dose setting and correcting system as claimed in 19, wherein the flexible pawls (712A-B) are secured to another tooth (1302) of the plunger ratchet (210) post-delivery of the set first dose from the dispensing device (102) due to the linear movement of the plunger (205).

21. The dose setting and correcting system as claimed in 20, wherein the dose sleeve (204) is configured to rotationally move within the outer body (106) during dose setting by a corresponding distance based on a rotational motion of the dose dial knob (108) and is further adapted to be seated against the cartridge (202) provided within a cartridge holder (104) after a final dose is delivered from the dispensing device (102).

22. The dose setting and correcting system as claimed in 1, wherein the dispensing device (102) is one of an auto-injector pen, a syringe, an injection device, and a needleless material delivery device, and wherein the material comprises one of a medicament, an injectable fluid for use in therapy, and an injectable fluid for use in building repair.

23. The dose setting and correcting system as claimed in 22, wherein the medicament or the injectable fluid for use in therapy comprises one or more of a vaccine, a hormone, an anti-venom, insulin, an antibody, a protein, a chemotherapy agent, and an immune-system suppressant.
, Description:DOSE SETTING AND CORRECTING SYSTEM FOR A DISPENSING DEVICE

BACKGROUND

[0001] Embodiments of the present specification relate generally to a dispensing device, and more particularly to a dispensing device that allows a user to set a desired dose for delivery and to correct an incorrectly set dose to the desired dose.
[0002] Auto-injectors or injector pens are medical devices designed to deliver the same or variable doses of one or more types of drugs to patients at designated intervals in a day or in a week for treating certain diseases or disorders. By design, the injector pens are intended for self-administration by patients, and therefore, are easy to use. Present-day injector pens are designed to allow the patients to set a variable dose of medicament and self-inject a desired dose accurately.
[0003] However, certain injector pen designs fail to provide any error correction mechanism in the event of a user setting an incorrect dose accidently, and thus, needing to adjust an incorrectly set dose. For example, a treatment plan may require a patient to inject 0.2 milliliter (ml) of a medicine thrice a week. However, while setting a dose of 0.2 ml, the user may set the dose to 0.3 ml unintentionally and later needs to correct the set dose of 0.3 ml to 0.2 ml. Certain injector pens include integrated mechanisms that allow the user to correct a previously incorrectly set dose in such scenarios.
[0004] For instance, European granted patent EP1804865B1 describes an injection device that includes a dial-down mechanism for adjusting an incorrectly set dose. Specifically, the injection device includes a dose-setting member, a dial-up cam, a dial-up key, a dial-down cam, a dial-down key, and a torsion spring. For setting a desired dose, a user has to rotate the dose-setting member in a first direction during which the dial-up cam cooperates with the dial-up key to strain the torsion spring. However, if the user has accidentally set a dose beyond the desired dose, the user has to rotate the dose-setting member in a second direction opposite to the first direction. Rotating the dose-setting member in the second direction causes the dial-down cam to cooperate with the dial-down key to release the strained torsion spring, which enables the user to decrement the set dose to the desired dose. However, such multiple cams, keys, and torsion spring based mechanisms are complex to manufacture.
[0005] Furthermore, confirming a set dose requires visually reviewing a small dose window. Accordingly, injection devices, such as described in the European granted patent EP1804865B1, often fail to allow the user such as an aged patient or the user with uneven visual acuity or cognitive impairment to verify the dose set by him or her easily and accurately. Failure to verify the set dose accurately may lead to incorrect administration of a medicament, which may hinder the health, or even cause fatality of the user in certain scenarios.
[0006] Accordingly, there remains a need for a dispensing device that includes a simple in-built mechanism that allows users to adjust incorrectly set doses and enables users with visual or cognitive impairments to verify doses set by them easily.

BRIEF DESCRIPTION

[0007] It is an objective of the present disclosure to provide a dose setting and correcting system for a dispensing device. The dose setting and correcting system includes a dose dial knob and a plunger. The dose dial knob includes a protrusion positioned at a distal end of the dose dial knob. The dose dial knob is adapted to be rotated in one or more directions for setting a desired dose of a material to be delivered from a cartridge and for correcting an incorrectly set dose to the desired dose. The incorrectly set dose is different from the desired dose. The plunger includes a plunger body that is positioned within the dose dial knob. The plunger body includes a set of stopper columns. Each of the stopper columns includes a set of non-flexible stoppers and a set of flexible stoppers that are positioned on an exterior surface of the plunger body such that each flexible stopper is successively followed by a non-flexible stopper and each non-flexible stopper is successively followed by a flexible stopper.
[0008] The protrusion positioned at the distal end of the dose dial knob is adapted to slide over one or more designated flexible stoppers selected from the flexible stoppers when setting the desired dose and when correcting the incorrectly set dose to the desired dose by rotating the dose dial knob in the one or more directions. Sliding of the protrusion over each of the designated flexible stoppers generates a corresponding non-visual feedback that indicates one of an increment and a decrement of a dose of the material by a designated unit. The one or more directions include a first direction and a second direction different from the first direction. The dose dial knob is adapted to be rotated in the first direction for incrementing a dose to be delivered and is adapted to be rotated in the second direction for decrementing the dose to be delivered. The first direction corresponds to a clockwise direction and the second direction corresponds to an anti-clockwise direction. The dose dial knob is rotated in one or more of the first direction and the second direction for setting the desired dose of the material to be delivered from the cartridge. The dose dial knob is rotated in one or more of the first direction and the second direction for correcting the incorrectly set dose to the desired dose.
[0009] Each of the stopper columns includes a plurality of slots disposed on the plunger body. Each of the plurality of slots in a designated stopper column is disposed between a non-flexible stopper and a flexible stopper in the designated stopper column. The set of non-flexible stoppers and the set of flexible stoppers are radially aligned to the plunger body and are further aligned in parallel to an axis of a plunger rod. Each of the plurality of slots is aligned in perpendicular to the horizontal axis of the plunger rod. Each of the set of flexible stoppers includes a corresponding first ramp and a corresponding second ramp. The first ramp includes a first elevated angle and the second ramp includes a second elevated angle different from the first elevated angle. The stopper columns include a first stopper column, a second stopper column, a third stopper column, and a fourth stopper column. The protrusion is positioned at a first side of a designated flexible stopper selected from the first stopper column when the doses of the material set for delivery corresponds to zero.
[0010] The protrusion is positioned in an elevated state above the designated flexible stopper when the dose dial knob is rotated in the first direction to set the desired dose. The protrusion positioned in the elevated state exerts a downward force that compresses the designated flexible stopper to position the designated flexible stopper in a compressed state into a slot disposed on the plunger body. The protrusion is adapted to be repositioned from above the designated flexible stopper to a second side of the designated flexible stopper when the dose dial knob is further rotated in the first direction to set the desired dose. Repositioning of the protrusion releases the downward force exerted on the designated flexible stopper, thereby causing the designated flexible stopper to emerge out of the slot and revert to a relaxed state.
[0011] The protrusion is adapted to slide from the first side to the second side of the designated flexible stopper when the dose dial knob is rotated in the first direction. The sliding of the protrusion from the first side to the second side causes the designated flexible stopper to revert to the relaxed state from the compressed state and to generate a first non-visual feedback that indicates an increment of the dose by a first designated unit from zero to a first intermediate dose. The dose dial knob is adapted to be further rotated in the first direction when the first intermediate dose is not equivalent to the desired dose of the material to be delivered. The rotation of the dose dial knob in the first direction causes the protrusion to move from a first side of a selected flexible stopper in the second stopper column and be positioned above the selected flexible stopper. The protrusion is further adapted to be repositioned from above the selected flexible stopper to a second side of the selected flexible stopper. Sliding movement of the protrusion from the first side to the second side of the selected flexible stopper and movement of the selected flexible stopper from the compressed state to the relaxed state generate a second non-visual feedback that indicates an increment of the dose by a second designated unit from the first intermediate dose to a second intermediate dose. The dose dial knob is adapted to be rotated in the second direction when the first intermediate dose is equivalent to the desired dose and is inadvertently incremented to the second intermediate dose. The rotation of the dose dial knob in the second direction causes the protrusion to move from the second side of the selected flexible stopper and be positioned above the selected flexible stopper. The protrusion is further adapted to be repositioned from above the selected flexible stopper to the first side of the selected flexible stopper when the dose dial knob is rotated in the second direction.
[0012] The protrusion is adapted to slide from the second side to the first side of the selected flexible stopper when the dose dial knob is further rotated in the second direction. The sliding of the protrusion from the second side to the first side causes the selected flexible stopper to revert to the relaxed state from the compressed state and to generate a third non-visual feedback that indicates a decrement of the dose by the second designated unit from the second intermediate dose to the first intermediate dose. Each of the first non-visual feedback, the second non-visual feedback, and the third non-visual feedback includes one or more of an audible feedback and a tactile feedback. The protrusion is adapted to move in a circular path while setting the desired dose for delivery. The circular movement causing the protrusion to be placed in a locked state with a selected non-flexible stopper in the set of non-flexible stoppers when setting the desired dose equal to a designated maximum dose, thereby preventing further rotation of the dose dial knob in the first direction and preventing setting of the desired dose above the designated maximum dose.
[0013] The plunger body includes a particular non-flexible stopper disposed thereon and having an associated length that is longer than a corresponding length associated with each of other non-flexible stoppers disposed on the plunger body. The particular non-flexible stopper is adapted to stop the circular movement of the protrusion and to prevent setting a final dose that is more than a remaining dose of the material in a cartridge of the dispensing device. The dispensing device includes a needle disposed at a distal end of the dispensing device. The dispensing device further includes an outer body that accommodates the cartridge having the material to be delivered via the needle. The outer body is rotationally coupled to the dose dial knob to set the desired dose to be delivered. Furthermore, the dispensing device includes a dose sleeve including a proximal end that is coupled to the dose dial knob and a distal end that is coupled to the outer body. The dose sleeve rotates and moves linearly within the outer body by a designated distance corresponding to a rotation of the dose dial knob to set the desired dose. In addition, the dispensing device includes a plunger ratchet that is coupled to the plunger and that includes a plurality of teeth. The plunger extends out from a slot of the dose sleeve. Additionally, the dispensing device includes a plunger rod that is coupled to the plunger. One end of the plunger rod is disposed within the cartridge.
[0014] Further, the dispensing device includes a locking device that is coupled to the plunger ratchet and that includes a set of flexible pawls that are positioned in an engaged state with a tooth in the plurality of teeth in the plunger ratchet to hold the plunger in a locked position while setting the desired dose. Furthermore, the dispensing device includes an elastic member disposed in a compressed state between the plunger body and the locking device. In addition, the dispensing device includes an unlocking device disposed partially within the locking device and adapted to disengage the flexible pawls from the tooth in the plurality of teeth in the plunger ratchet when the unlocking device is depressed, thereby releasing the plunger from the locked position to an unlocked position. The release of the plunger to the unlocked position causing an expansion of the elastic member. The expansion of the elastic member causes the plunger to move only linearly by the designated distance to release the set desired dose from the cartridge.
[0015] The unlocking device includes a thumb pad that includes a stem portion disposed within the locking device. The flexible pawls are secured to a first tooth of the plunger ratchet to hold the plunger in the locked position before releasing a set first dose from the dispensing device. A depression of the thumb pad causes the stem portion to flex the flexible pawls upwards to release the plunger from the locked position to the unlocked position, and thereby causing the expansion of the elastic member. The expansion of the elastic member causes the plunger to move linearly by a selected distance towards the distal end of the dispensing device to release the set first dose. The selected distance corresponds to the distance by which the dose sleeve moves while setting the first dose using the dose dial knob. The flexible pawls are secured to another tooth of the plunger ratchet post-delivery of the set first dose from the dispensing device due to the linear movement of the plunger. The dose sleeve is configured to rotationally move within the outer body during dose setting by a corresponding distance based on a rotational motion of the dose dial knob and is further adapted to be seated against the cartridge provided within a cartridge holder after a final dose is delivered from the dispensing device. The dispensing device is one of an auto-injector pen, a syringe, an injection device, and a needleless material delivery device. The material includes one of a medicament, an injectable fluid for use in therapy, and an injectable fluid for use in building repair. The medicament or the injectable fluid for use in therapy includes one or more of a vaccine, a hormone, an anti-venom, insulin, an antibody, a protein, a chemotherapy agent, and an immune-system suppressant.

DRAWINGS

[0016] These and other features, aspects, and advantages of the claimed subject matter will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0017] FIG. 1 illustrates a side perspective view depicting an exemplary dispensing device that is configured to deliver variable amounts of materials based on corresponding doses set by a user;
[0018] FIG. 2 illustrates an exploded view of the exemplary dispensing device of FIG. 1;
[0019] FIGS. 3A-C illustrate perspective and cross-sectional views of an outer body of the exemplary dispensing device of FIG. 1;
[0020] FIG. 4 illustrates a top perspective view of a dose dial knob of the exemplary dispensing device of FIG. 1;
[0021] FIG. 5 illustrates a side perspective view of a dose sleeve of the exemplary dispensing device of FIG. 1;
[0022] FIGS. 6A and 6B illustrate a front view of a plunger body of the exemplary dispensing device of FIG. 1;
[0023] FIG. 7 illustrates a side perspective view of a locking device of the exemplary dispensing device of FIG. 1;
[0024] FIG. 8 illustrates a side perspective view of an unlocking device of the exemplary dispensing device of FIG. 1;
[0025] FIG. 9 illustrates a cross-sectional view of the exemplary dispensing device of FIG. 1 depicting arrangements of various components of the exemplary dispensing device before delivery of a first dose;
[0026] FIGS. 10A-E illustrate exploded views of the dose dial knob (108) of FIG. 4 having the protrusion (412) positioned at different positions with respect to a set of flexible and non-flexible stoppers disposed on the plunger body of FIGS. 6A-6B;
[0027] FIG. 11 illustrates another cross-sectional view of the exemplary dispensing device of FIG. 1 depicting the dose sleeve of FIG. 2 moved from an initial position to an intermediate position by a first distance;
[0028] FIG. 12 illustrates another cross-sectional view of the exemplary dispensing device of FIG. 1 depicting first and second flexible pawls of the locking device of FIG. 2 in a flexed up position;
[0029] FIG. 13 illustrates another cross-sectional view of the exemplary dispensing device of FIG. 1 depicting the plunger body of FIG. 2 moved by the first distance; and
[0030] FIG. 14 illustrates another cross-sectional view of the exemplary dispensing device of FIG. 1 depicting the dose sleeve of FIG. 2 when disposed in an engaged state with respect to a cartridge.

DETAILED DESCRIPTION

[0031] The following description presents an exemplary dispensing device that includes a set of components that allow a user to vary and set a desired dose of material for delivery and to deliver the desired dose of material accurately. Further, the dispensing device allows a user to adjust or correct an incorrectly set dose. For example, a treatment plan may require a patient to inject a desired dose of 0.2 ml of a medicine thrice a week. However, while setting the desired dose of 0.2 ml, the user may accidentally set the dose to 0.3 ml and later needs to correct the reset dose of 0.3 ml to 0.2 ml. In this example, the present dispensing device allows the user to correct the set dose from 0.3 ml to 0.2 ml. Additionally, the dispensing device prevents the user from setting a subsequent dose after a final dose is delivered, and limits a maximum amount of dose that can be delivered by a single actuation of the dispensing device. Furthermore, the dispensing device allows the user to set a final dose to be delivered according to an amount of material remaining in a cartridge.
[0032] The term “dose,” used in the various embodiments described herein, broadly refers to a unit such as a weight or volume of a material to be dispensed. Examples of the material include, but are not limited to, a medicament, a chemical substance, an injectable fluid for use in therapy, and an injectable fluid for use in building repair, and a composition of suitable substances. Examples of the medicament include vaccines, hormones such as gonadotropin and adrenaline, anti-venom, insulin used for treating diabetes, antibodies, proteins, chemotherapy agents, and immune-system suppressants. Certain exemplary configurations of the dispensing device that provides the aforementioned features and functions are described in greater detail with reference to FIGS. 1-14.
[0033] FIG. 1 illustrates a side perspective view (100) of an exemplary dispensing device (102) that is configured to deliver variable amounts of materials based on corresponding doses set by a user. Examples of the dispensing device (102) include one or more of an auto-injector pen, a syringe, an injection device, and a needleless material delivery device. In one embodiment, the dispensing device (102) is a medicament-dispensing device having an appearance of a pen. In certain embodiments, the dispensing device (102) is a disposable device that is configured so as not to be reused once a final dose of medicament is delivered from the dispensing device (102).
[0034] To that end, in certain embodiments, the dispensing device (102) includes a cartridge holder (104) that accommodates a cartridge (shown in FIG. 2), an outer body (106), and a dose dial knob (108) that is rotationally coupled to the outer body (106). In one embodiment, the dose dial knob (108) is rotationally coupled to the outer body (106) such that the dose dial knob (108) exhibits only rotational motion with respect to the outer body (106), and such that translational motion of the dose dial knob (108) is arrested in all directions.
[0035] In one embodiment, the dose dial knob (108) is used for setting a desired dose of material for delivery. The dose dial knob (108) is also used for correcting a dose that is incorrectly set for delivery. In certain embodiments, the rotation of the dose dial knob (108) in a first direction with respect to the outer body (106) increments a dose of the material to be delivered. An example of the first direction includes a clockwise direction. Similarly, the rotation of the dose dial knob (108) in a second direction opposite to the first direction decrements the dose of the material to be delivered. An example of the second direction includes an anticlockwise direction.
[0036] In certain embodiments, a user sets a desired dose of a material for delivery by rotating the dose dial knob (108) in the first and/or second directions. For example, a user sets a desired dose of 0.1 ml for delivery by incrementing a dose from zero to 0.1 ml by rotating the dose dial knob (108) in the first direction. In the previously noted example, if the user inadvertently sets a dose to 0.2 ml, the user later decrements the dose from 0.2 ml to the desired dose of 0.1 ml by rotating the dose dial knob (108) in the second direction. Thus, it is to be understood that setting a desired dose for delivery may include both incrementing and decrementing a material dose.
[0037] Similarly, a user adjusts or corrects an incorrectly set dose that is different from the desired dose by rotating the dose dial knob (108) in the first and/or second directions. For example, while setting a desired dose of 0.2 ml, a user may wrongly set a dose to 0.1 ml in lieu of 0.2 ml for delivery. In this example, the user later increments the dose from 0.1 ml to 0.2 ml by rotating the dose dial knob (108) in the first direction. In the same example, if the user inadvertently increments the dose to 0.3 ml, the user later decrements the dose from 0.3 ml to the desired dose of 0.2 ml by rotating the dose dial knob (108) in the second direction. Thus, it is to be understood that adjusting or correcting an incorrectly set dose may include both incrementing and decrementing a material dose. In one embodiment, the dose dial knob (108) includes a dose indicator window (110) that is disposed on an outer surface (112) of the dose dial knob (108) to visually indicate a dose set for delivery. In one embodiment, the dose indicator window (110) includes a cover (114) that is made up of a transparent material, for example a glass material or a plastic material, through which at least one dosage number corresponding to the set dose can be visually perceived by the user.
[0038] In certain embodiments, the cover (114) is made up of a material such as a simple lens, a compound lens, a non-spherical lens such as a Fresnel lens, a spherical lens, a concave lens, or a convex lens that magnifies the dosage number corresponding to the set dose. Magnification of the dosage number corresponding to the set dose enables the user to easily perceive and verify the set dose in a magnified view prior to dispensing the dose. In one embodiment, the dispensing device (102) includes a proximal end (116) having an actuation mechanism for dispensing the set dose and a distal end (118) for securing the needle that delivers the set dose of medicament to a patient. Various components of the dispensing device (102) for use in dispensing variable amounts of a material are depicted and described in greater detail with reference to FIGS. 2 through 14.
[0039] FIG. 2 illustrates an exploded view (200) of the exemplary dispensing device (102) of FIG. 1. In one embodiment, the dispensing device (102) further includes a cartridge (202) that carries a material to be dispensed out from the dispensing device (102), a dose sleeve (204), and a plunger (205) that includes a plunger body (206), a plunger rod (208), and a plunger ratchet (210). In addition, the dispensing device (102) includes a first elastic member (212), a locking device (214), an unlocking device (216), a second elastic member (218), and a dose knob screw (220). The various components of the dispensing device (102), except the first and elastic members (212 and 218), may be made of plastic materials such as polybutylene terephthalate, acrylonitrile butadiene styrene, polypropylene, polyoxymethylene, and/or polycarbonate. In one embodiment, the dose dial knob (108) and the plunger (205) along with other components, for example including the outer body (106), the dose sleeve (204), the first elastic member (212), the locking device (214), and the unlocking device (216) of the dispensing device (102) form a dose setting and correcting system of the dispensing device (102). Each of the aforementioned components of the dispensing device (102) is depicted and described in further detail with reference to one or more of FIGS. 3A to 14.
[0040] FIG. 3A, for example, illustrates a side perspective view (300) of the outer body (106) of the exemplary dispensing device (102) of FIG. 1. In one embodiment, the outer body (106) includes a proximal end (302) and a distal end (304). The distal end (304) of the outer body (106) includes a male threaded section (306) (shown in FIG. 3B), which engages with a corresponding female threaded section (not shown in FIGS) disposed at the cartridge holder (104) for coupling the outer body (106) with the cartridge holder (104).
[0041] In addition to the male threaded section (306), the distal end (304) of the outer body (106) includes a cutout portion (308) (depicted in FIG. 3C). The cutout portion (308) includes a circular portion (310) having a central cut (312) and a plurality of ribs (314A-D) that protrude out from an exterior surface (316) of the circular portion (310). The central cut (312) defines a slot through which the plunger rod (208) passes through when various components of the dispensing device (102) are assembled.
[0042] In certain embodiments, a profile of the central cut (312) is selected such that the selected profile of the central cut (312) corresponds to a profile of the plunger rod (208). For example, if the profile of the central cut (312) has a D-shape, then the profile of the plunger rod (208) is also D-shape. As a result, the plunger rod (208) fits exactly into the central cut (312) without leaving any gaps, thereby preventing the plunger (205) from exhibiting rotational motion due to lack of space. Hence, the plunger (205) can exhibit only a linear motion while delivering a set dose.
[0043] In one embodiment, in addition to the central cut (312) disposed at the distal end (304) of the outer body (106), the outer body (106) includes a threaded portion (318) disposed at the associated proximal end (302). The threaded portion (318) of the outer body (106) is coupled to a threaded portion (510) (shown in FIG. 5) associated with the dose sleeve (204) when various components of the dispensing device (102) depicted in FIG. 2 are in an assembled state.
[0044] In one embodiment, the threaded portion (318) of the outer body (106) enables the dose sleeve (204) to move within the outer body (106) towards the proximal end (116) of the dispensing device (102) while decrementing a dose by rotating the dose dial knob (108) in the second direction. The threaded portion (318) also enables the dose sleeve (204) to move within the outer body (106) towards the distal end (118) of the dispensing device while incrementing a dose by rotating the dose dial knob (108) in the first direction, as described in detail with reference to FIG. 4.
[0045] FIG. 4 illustrates a top perspective view (400) of the dose dial knob (108) of the exemplary dispensing device (102) of FIG. 1. In one embodiment, the dose dial knob (108) is a cylindrical-shaped body that can be rotated to set a dose and correct the set dose if required, as noted previously. In certain embodiments, the dose dial knob (108) includes a coupling mechanism, for example, a tongue and groove coupling mechanism that enables coupling of the dose dial knob (108) to the dose sleeve (204). In one embodiment, the coupling mechanism is disposed within an internal cylindrical body (402) of the dose dial knob (108) and includes one or more sets of elevated walls.
[0046] For example, FIG. 4 depicts the coupling mechanism having four sets of elevated walls including a first set of elevated walls (404A), a second set of elevated walls (404B), a third set of elevated walls (404C), and a fourth set of elevated walls (not visible in FIG. 4). Though FIG. 4 depicts the coupling mechanism having four such sets of elevated walls, the dose dial knob (108) may include any number of sets of elevated walls. Further, the coupling mechanism includes a corresponding groove disposed between each of the first set of elevated walls (404A), the second set of elevated walls (404B), the third set of elevated walls (404C), and the fourth set of elevated walls. While assembling various components of the dispensing device (102), the each corresponding groove receives a rib selected from a plurality of ribs (506A-D) (shown in FIG. 5) disposed on an exterior surface of the dose sleeve (204), thereby coupling the dose dial knob (108) to the dose sleeve (204). For example, a first groove (406A) is disposed between the first set of elevated walls (404A).
[0047] Similarly, it is to be understood that a second groove (406B), a third groove (406C), and a fourth groove (not visible in FIG. 4) are disposed between the second set of elevated walls (404B), the third set of elevated walls (404C), and the fourth set of elevated walls, respectively. While assembling various components of the dispensing device (102), the dose sleeve (204) is positioned within the internal cylindrical body (402) of the dose dial knob (108) and is secured to the dose dial knob (108) using a tongue and groove coupling mechanism, as described with reference to FIG. 5.
[0048] In one embodiment, the dose dial knob (108) and the dose sleeve (204) can be coupled to each other using intermediate components that are used to scale down or scale up the transfer of rotational motion of the dose dial knob (108). For example, if the dose dial knob (108) is rotated by 180 degrees, then the dose sleeve (204) can be configured to rotate by 90 degrees. In another example if the dose dial knob (108) is rotated by 180 degrees, then the dose sleeve (204) can be configured to rotate by 360 degrees based on specific requirements. In one embodiment, a manufacturer of the dispensing device (102) may select a degree of rotation of the dose sleeve (204) corresponding to a degree of rotation of the dose dial knob (108) based on a desired dose to be set. For example, a designer or the manufacturer of the dispensing device (102) may select the degree of rotation of the dose sleeve (204) as 90 degrees when the desired dose to be set is 0.05 ml with a 180 degrees rotation of the dose dial knob (108). In another example, the designer or the manufacturer of the dispensing device (102) may select the degree of rotation of the dose sleeve (204) as 360 degrees when the desired dose to be set is 0.2 ml with a 180 degrees rotation of the dose dial knob (108). Alternatively, a degree of rotation of the dose dial knob (108) corresponds to a degree of rotation of the dose sleeve (204). For example if the dose dial knob (108) is rotated by 90 degrees, then the dose sleeve (204) is also configured to rotate by 90 degrees.
[0049] In addition to the coupling mechanism disposed within the internal cylindrical body (402), a proximal end (410) of the dose dial knob (108) includes a threaded arrangement (408) for coupling the dose dial knob (108) to the dose knob screw (220) that acts as a top protection cover for the dispensing device (102). In another embodiment, the proximal end (410) of the dose dial knob (108) includes a locking mechanism such as a snap fit mechanism instead of the threaded arrangement (408) for locking the dose dial knob (108) to the dose knob screw (220).
[0050] Further, a distal end (414) of the dose dial knob (108) includes a protrusion (412). The protrusion (412), along with the plunger (205), produces an audible and/or tactile feedback when a user increments and decrements a dose by rotating the dose dial knob (108), and limits a maximum dose that can be delivered by a single actuation of the dispensing device (102), as described in greater detail with reference to FIGS. 10A-E. Examples of the non-visual feedback include one or more of audible feedbacks and tactile feedbacks. In one embodiment, rotation of the dose dial knob (108) for incrementing or decrementing the dose causes the dose sleeve (204), coupled to the dose dial knob (108), to move towards the distal end (118) and the proximal end (116), respectively, of the dispensing device (102), as described with reference to FIG. 5.
[0051] FIG. 5 illustrates a side perspective view (500) of the dose sleeve (204) of the exemplary dispensing device of FIG. 1. In certain embodiments, the dose sleeve (204) is a hollow elongated body having a proximal end (502) that includes a plurality of ribs disposed at an outer surface (504) of the dose sleeve (204). While assembling various components of the dispensing device (102), the dose sleeve (204) is placed within the dose dial knob (108) and the plurality of ribs is fitted into the first, second, and third grooves (406A-C) and the fourth groove associated with the dose dial knob (108) to couple the dose dial knob (108) to the dose sleeve (204). For example, FIG. 5 depicts four such ribs including a first rib (506A), a second rib (506B), a third rib (506C), and a fourth rib (506D) that fit within the first groove (406A), the second groove (406B), the third groove (406C), and the fourth groove, respectively. Further, a distal end (508) of the dose sleeve (204) includes a threaded portion (510) that is secured against the threaded portion (318) associated with the outer body (106).
[0052] When a user sets a desired dose or corrects an incorrectly set dose by rotating the dose dial knob (108), the dose sleeve (204) rotates along with the dose dial knob (108) as the dose sleeve (204) and the dose dial knob (108) are coupled to each other. Further, the threaded portion (510) of the dose sleeve (204) slips against the threaded portion (318) of the outer body (106) such that the dose sleeve (204) exhibits trans-rotational motion. The trans-rotational motion causes the dose sleeve (204) to move within the outer body (106) towards the proximal end (116) or the distal end (118) based on a rotational direction of the dose dial knob (108). For example, in one embodiment, the dose sleeve (204) advances and moves towards the distal end (118) of the dispensing device (102) while incrementing a dose achieved by rotating the dose dial knob (108) in the first, that is, a clockwise direction.
[0053] In another embodiment, the dose sleeve (204) moves in a reverse direction towards the proximal end (116) of the dispensing device (102) while decrementing a dose achieved by rotating the dose dial knob (108) in the second, that is, an anti-clockwise direction. In one embodiment, the dose sleeve (204) includes a slot (514) through which the plunger rod (208) of the dispensing device (102) passes and moves towards the distal end (118) of the dispensing device (102) to deliver a set dose from the dispensing device (102).
[0054] FIGS. 6A and 6B illustrate a front view (600) of the plunger body (206) of the exemplary dispensing device (102) of FIG. 1. Although FIGS. 6A and 6B depict a shape of the plunger body (206) to be cylindrical, in other embodiments, the plunger body (206) can be of any desired shape. For example, the plunger body (206) can be of a rectangular shape instead of a cylindrical shape.
[0055] In one embodiment, the plunger body (206) includes a proximal end (602) and a distal end (604). The proximal end (602) of the plunger body (206) is secured to the plunger ratchet (210) and the distal end (604) of the plunger body (206) is secured to the plunger rod (208) when various components of the dispensing device (102) are in the assembled state.
[0056] In certain embodiments, the plunger body (206) includes one or more stopper columns (608A-D), each of which includes a set of stoppers disposed on an exterior or an annular surface (606) of the plunger body (206). In one embodiment, a number of stopper columns (608A-D) disposed on the exterior surface (606) varies with a maximum amount of dose that needs to be delivered by a single actuation of the dispensing device (102). For example, the plunger body (206) includes four stopper columns (608A-D) when the dispensing device (102) is designed to deliver a designated maximum dose of 0.3 ml by a single actuation of the unlocking device (216). In another example, the plunger body (206) includes only two stopper columns (608A-B) when the maximum amount of dose corresponds to 0.1 ml.
[0057] In addition, the number of stopper columns (608A-D) disposed on the exterior surface (606) varies with a minimum dose resolution of the dispensing device (102). The term “minimum dose resolution,” as used herein throughout various embodiments of the present disclosure, refers to a minimum dose that can be set for delivery and/or a dose by which a previously set dose can be incremented and decremented. For example, in one embodiment, the minimum dose resolution of the dispensing device (102) corresponds to 0.1 ml.
[0058] In the previously noted example, the minimum dose that can be set for delivery corresponds to 0.1 ml. Additionally, a user can either increment or decrement a previously set dose by 0.1 ml using the dose dial knob (108). For instance, rotation of the dose dial knob (108) in a clockwise direction increases a dose from zero to 0.1 ml. A further rotation of the dose dial knob (108) in the clockwise direction increments the dose from 0.1 ml to 0.2 ml. Similarly, the rotation of the dose dial knob (108) in an anticlockwise direction, for example, decreases the dose from 0.2 ml to 0.1 ml.
[0059] In one exemplary implementation, the plunger body (206) may include four stopper columns (608A-D) when the minimum dose resolution of the dispensing device (102) corresponds to 0.1 ml. In this implementation, increasing the number of stopper columns (608A-D) disposed on the exterior surface (606) of the plunger body (206) decreases the minimum dose resolution of the dispensing device (102). For instance, increasing the number of stopper columns (608A-D) from four to eight decreases the minimum dose resolution of the dispensing device (102) from 0.1 ml to 0.05 ml. Accordingly, a user can set 0.05 ml as a minimum dose for delivery and can either increment or decrement a previously set dose by 0.05 ml.
[0060] Similarly, decreasing the number of stopper columns (608A-D) disposed on the exterior surface (606) of the plunger body (206) increases the minimum dose resolution of the dispensing device (102). For instance, decreasing the number of stopper columns (608A-D) from four to two increases the minimum dose resolution of the dispensing device (102) from 0.1 ml to 0.2 ml. Accordingly, a user can set only 0.2 ml as a minimum dose for delivery and can either increment or decrement a previously set dose by 0.2 ml.
[0061] Thus, it is to be understood that the plunger body (206) can have any number of stopper columns (608A-D) selected based on specific requirements such as the maximum amount of dose that can be delivered by a single actuation of the dispensing device (102) and the minimum dose resolution of the dispensing device (102). For sake of simplicity, an exemplary embodiment of the dispensing device (102) is described in the following sections with the plunger body (206) having four stopper columns (608A-D). Additionally, the maximum amount of dose that can be delivered by a single actuation of the dispensing device (102) corresponds to 0.3 ml, and the minimum dose resolution of the dispensing device (102) corresponds to 0.1 ml.
[0062] As noted previously, the plunger body (206) includes four stopper columns (608A-D) including a first stopper column (608A) (shown in FIG. 6A), a second stopper column (608B) (shown in FIG. 6B), a third stopper column (608C) (shown in FIG. 6B), and a fourth stopper column (608D) (shown in FIG. 6A). Each of these stopper columns (608A-D) includes a set of non-flexible stoppers and a set of flexible stoppers that protrude out from the exterior surface (606) of the plunger body (206).
[0063] For example, the first stopper column (608A) includes a set of non-flexible stoppers (610A-H) and a set of flexible stoppers (612A-H). Similarly, the second stopper column (608B) includes a set of non-flexible stoppers (614A-G) and a set of flexible stoppers (616A-H). Likewise, the third stopper column (608C) includes a set of non-flexible stoppers (618A-H) and a set of flexible stoppers (620A-H). In addition, the fourth stopper column (608D) includes a set of non-flexible stoppers (622A-H) and a set of flexible stoppers (624A-I).
[0064] In one embodiment, the set of non-flexible stoppers (610A-H, 614A-G, 618A-H, and 622A-H) and the set of flexible stoppers (612A-H, 616A-H, 620A-H, and 624A-I), disposed in the stopper columns (608A-D), are radially aligned to the plunger body (206) and are further aligned in parallel to a horizontal axis (920) (shown in FIG. 9) of the plunger rod (208).
[0065] Further, each of the flexible stoppers (612A-H, 616A-H, 620A-H, and 624A-I) in the stopper columns (608A-D) includes a first ramp at a corresponding first side and a second ramp at a corresponding second side. In one embodiment, the first ramp oriented at a particular elevated angle that is different from an elevated angle associated with the second ramp. For example, the flexible stopper (616A) depicted in FIG. 10C includes a first ramp (628) on a first side (1014) and a second ramp (630) on a second side (1016). The first ramp (628) is oriented at 30 degrees with respect to a horizontal axis (632) of the plunger body (206). The second ramp (630) is oriented at a different elevated angle, for example, 45 degrees with respect to the horizontal axis (632) of the plunger body (206).
[0066] The difference in elevation angles of the first and second ramps (628, 630) provides different audio and/or tactile feedbacks while setting a desired dose and while correcting a dose towards the desired dose. For example, while rotating the dose dial knob (108) in the first direction, the protrusion (412) slides over the first ramp (628) of the flexible stopper (616A) and moves to the second side (1016) from the first side (1014) of the flexible stopper (616A), which generates one or more of first audible tactile feedback. Similarly, while rotating the dose dial knob (108) in the second direction, the protrusion (412) slides over the second ramp (630) of the flexible stopper (616A) and moves to the first side (1014) from the second side (1016) of the flexible stopper (616A), which generates one or more of second audible and tactile feedback different from the first audible and tactile feedback. The difference between first and second audible and/or tactile feedbacks generated during rotation of the knob (108) in the first direction and second direction, respectively enables users, even those with uneven visual acuity, to easily identify whether he or she has incremented or decremented a dose without needing to perceive the dose indicator window (110).
[0067] For simplicity, arrangements of only the non-flexible stoppers (610A-H) and the flexible stoppers (612A-H) in the first stopper column (608A) are described herein in detail. It is to be understood that the non-flexible stoppers (614A-G, 618A-H, and 622A-H) and the flexible stoppers (616A-H, 620A-H, and 624A-I) in other stopper columns (608B-C) are similarly arranged. In one embodiment, the non-flexible stoppers (610A-H) and flexible stoppers (612A-H) are positioned alternately in the first stopper column (608A) such that each of the flexible stoppers (612A-H) is successively followed by a non-flexible stopper and each of the non-flexible stoppers (610A-H) is successively followed by a flexible stopper. Furthermore, the non-flexible stoppers (610A-H) are designed to be shorter in length than the flexible stoppers (612A-H).
[0068] In certain embodiments, in addition to the flexible and non-flexible stoppers (610A-H and 612A-H), the first stopper column (608A) also includes a set of slots (626). Each of the slots (626) is disposed between a non-flexible stopper and a flexible stopper in the first stopper column (608A) such that the slots (626) separate the set of flexible stoppers (612A-H) from the set of non-flexible stoppers (610A-H). In the embodiment depicted in FIGS. 6A and 6B, the slots (626) are C-shaped slots aligned perpendicular to the horizontal axis (920) of the plunger rod (208). However, the slots (626) may have any shape such as a square or rectangle shape as long as the slots (626) separate the flexible stoppers (612A-H) from the non-flexible stoppers (610A-H).
[0069] In one embodiment, the non-flexible stoppers (610A-H) are solid or rigid blocks that protrude out from the exterior surface (606) of the plunger body (206). The non-flexible stoppers (610A-H) prevent a user from setting a dose greater than a maximum dose that can be delivered by a single actuation of the dispensing device (102), as described in detail with reference to FIG. 10E.
[0070] It may be noted that, a particular non-flexible stopper (610H) selected from the non-flexible stoppers (610A-H) and disposed at the proximal end (602) of the plunger body (206) is designed to be longer than other non-flexible stoppers (610A-G) in the first stopper column (608A). This proximal, non-flexible stopper (610H) allows a user to set a final dose based on an amount of material left in the cartridge (202). For example, in one scenario, the dispensing device (102) may have already delivered 2.8 ml of the material and a remaining volume of the material in the cartridge (202) may be 0.2 ml. The user may attempt to set a final dose that is equivalent to 0.3 ml. In this example, the particular non-flexible stopper (610H) engages with the protrusion (412) when the user completes setting the dose to 0.2 ml. Consequently, a user cannot rotate the dose dial knob (108) in the first direction to further increment the dose from 0.2 ml to 0.3 ml as the particular non-flexible stopper (610H) impedes a circular rotation path of the protrusion (412) and blocks the protrusion (412) from moving further.
[0071] In contrast to the non-flexible stoppers (610A-H) that are solid inelastic blocks, the flexible stoppers (612A-H) disposed on the exterior surface (606) of the plunger body (206) are elastic in nature and operate between a relaxed state and a compressed state. By default, the flexible stoppers (612A-H) are disposed in the relaxed state (depicted in FIGS. 6A and 6B) when no dose is set for delivery. However, when a user rotates the dose dial knob (108) to set or correct a dose, the protrusion (412) coupled to the dose dial knob (108) encounters one or more flexible stoppers (612A-H) and slides over the flexible stoppers (612A-H).
[0072] For example, the protrusion (412) may encounter a flexible stopper (612A) and slide over the flexible stopper (612A) when the user rotates the dose dial knob (108) to set a desired dose as 0.1 ml from zero. While sliding over the flexible stopper (612A), the protrusion (412) applies a downward force on the flexible stopper (612A), which compresses the flexible stopper (612A) into a slot (626), thus disposing the flexible stopper (612A) in the compressed state (shown in FIG. 10B). Upon continuing rotation of the dose dial knob (108) to set or correct the dose, the protrusion (412) eventually disengages from the flexible stopper (612A). The disengagement of the protrusion (412) from the flexible stopper (612A) releases the downward force exerted on the flexible stopper (612A), which causes the flexible stopper (612A) to emerge out of the slot (626) and revert to the relaxed state. It may be noted that the sliding movement of the protrusion (412) over the flexible stopper (612A) and disengagement of the protrusion (412) from the flexible stopper (612A) produce an audible and/or tactile feedback, as described in detail with reference to FIGS. 10A-B. The audible and/or tactile feedback is especially useful for a user such as an aged patient or the user with uneven visual acuity or cognitive impairment to verify that a dose is set accurately prior to safely dispensing the dose using the plunger (205).
[0073] In certain embodiments, safe operation of the plunger (205) in the dispensing device (102) includes preventing the plunger (205) from exhibiting linear and rotational motions while setting a desired dose of material for delivery and while correcting an incorrectly set dose. To that end, the dispensing device (102) includes a locking device (214) that is described in greater detail with reference to FIG. 7.
[0074] FIG. 7 illustrates a side perspective view (700) of the locking device (214) of the exemplary dispensing device (102) of FIG. 1. In one embodiment, the locking device (214) includes a collar (702), an elongated body (704) that extends from the collar (702), and an opening (not visible in FIG. 7) at one end (708) of the elongated body (704). In one embodiment, the locking device (214) is secured between the dose sleeve (204) and the dose knob screw (220) and is rotatable with respect to the dose dial knob (108). In certain embodiments, the locking device (214) is adapted to hold the plunger (205) in a locked position while setting a desired dose to be delivered and while correcting an incorrectly set dose to prevent the plunger (205) from exhibiting motion. To that end, the locking device (214) is provided with at least one flexible pawl that is disposed at another end (710) of the elongated body (704).
[0075] FIG. 7 depicts an embodiment of the locking device (214) including four flexible pawls, out of which only two flexible pawls are visible, namely a first flexible pawl (712A) and a second flexible pawl (712B) that are disposed at the end (710) of the elongated body (704). As noted previously, the locking device (214) can have any number of flexible pawls. However, for the sake of simplicity, the following embodiments will be described with respect to only two flexible pawls (712A-B). The first and second flexible pawls (712A-B) are configured to be positioned in an engaged state with at least one teeth (906) (shown in FIG. 9) in the plunger ratchet (210) to hold the plunger (205) in the locked position while setting the desired dose and while correcting an incorrectly set dose using the dose dial knob (108).
[0076] In one embodiment, the first and second flexible pawls (712A-B) that are placed in the engaged state with at least one teeth in the plunger ratchet (210) need to be disengaged, once the desired dose is set or an incorrectly set dose is corrected, to deliver the set dose from the dispensing device (102). To that end, the unlocking device (216), which is operatively coupled to the locking device (214), disengages the first and second flexible pawls (712A-B) from the plunger ratchet (210) and releases the plunger (205) from the locked position to an unlocked position. An embodiment of the unlocking device (216) is described in greater detail with reference to FIG. 8.
[0077] FIG. 8 illustrates a side perspective view (800) of the unlocking device (216) of the dispensing device (102) of FIG. 1. In one embodiment, the unlocking device (216) includes a thumb pad (802) positioned at the distal end (118) of the dispensing device (102) for dispensing the set dose by depressing the thumb pad (802). The unlocking device (216) further includes a stem portion (804) that is positioned within the opening of the locking device (214) to flex up the first and second flexible pawls (712A-B) associated with the locking device (214). When a user depresses the thumb pad (802) to dispense the set dose, the stem portion (804) moves linearly within the opening and flexes up and disengages the first and second flexible pawls (712A-B) from the plunger ratchet (210). Disengaging the first and second flexible pawls (712A-B) releases the plunger (205) from the locked position to the unlocked position, thereby freeing the plunger (205) to move linearly towards the distal end (118) of the dispensing device (102) to release the set dose.
[0078] As noted previously, the dispensing device (102) includes an integrated dose setting and dispensing mechanism including the plunger (205) that allows a user to set and release the set dose of material from the cartridge (202). An embodiment of the integrated dose setting and dispensing mechanism that enables the user to set and deliver a desired dose of 0.3 ml is described in detail with reference to FIGS. 9-14.
[0079] FIG. 9 illustrates a cross-sectional view (900) of the dispensing device (102) of FIG. 1 depicting an exemplary arrangement of various components of the dispensing device (102) before setting a first dose of a medicament for delivery. In one embodiment, the plunger body (206) is positioned within the slot (514) in the dose sleeve (204) such that the distal end (604) of the plunger body (206) is seated against the distal end (508) of the dose sleeve (204). Further, a distal portion (902) of the plunger rod (208) rests against a rubber stopper (904) that is placed inside the cartridge (202). Alternatively, the distal portion (902) of the plunger rod (208) may be coupled to the rubber stopper (904) via a butt joint.
[0080] The plunger ratchet (210) is disposed, opposite to the distal portion (902) and towards a proximal portion (903) of the plunger rod (208), within the opening provided in the elongated body (704) of the locking device (214). The locking device (214), in turn, is disposed within the dose dial knob (108) such that the collar (702) of the locking device (214) is placed in proximity to the proximal end (502) of the dose sleeve (204). Further, the locking device (214), having the first and second flexible pawls (712A-B), is placed in an engaged state with respect to a set of first tooth (906) of the plunger ratchet (210), as depicted in FIG. 9, before delivering the first desired dose of 0.3 ml of the medicament from the dispensing device (102).
[0081] In one embodiment, the first elastic member (212) is disposed between the plunger body (206) and the locking device (214) for linearly moving the plunger body (206) and the plunger rod (208) towards the distal end (118) of the dispensing device (102). More particularly, a first end (908) of the first elastic member (212) is seated on the distal end (604) of the plunger body (206) and a second end (910) of the first elastic member (212) rests against the collar (702) of the locking device (214). In certain embodiments, the first elastic member (212) is a high-tension spring that is placed in a compressed state between the plunger body (206) and the locking device (214) before delivering the first desired dose of the medicament from the dispensing device (102). The first elastic member (212) stores energy required to dispense an entire volume of a material from the cartridge (202), for example, over the lifetime of the dispensing device (102). Further, the first elastic member (212) pushes the plunger (205) towards the distal end (118) of the dispensing device (102) for delivering the first desired dose of 0.3 ml, as described in greater detail with reference to FIGS. 10A-13.
[0082] FIG. 10A illustrates an exploded view (1000) of the dose dial knob (108) having the protrusion (412) positioned in contact with a first side (1002) of a flexible stopper (612A) in the first stopper column (608A) of the plunger body (206) before setting the first desired dose of the medicament for delivery. In one embodiment, a user sees a set dose as zero via the dose indicator window (110) when the protrusion (412) is positioned at the first side (1002) of the flexible stopper (612A). When the user intends to set the first desired dose as 0.3 ml for delivery, the user rotates the dose dial knob (108) in the first direction such that the protrusion (412) slides over the flexible stopper (612A) in the first stopper column (608A).
[0083] Specifically, the protrusion (412) moves and climbs over the flexible stopper (612A) from the first side (1002) of the flexible stopper (612A) and is positioned in an elevated state above the flexible stopper (612A) when the user rotates the dose dial knob (108) in the first direction for incrementing the dose to 0.3 ml. For example, FIG. 10B illustrates an exploded view (1004) of the dose dial knob (108) having the protrusion (412) positioned in an elevated state (1006) above the flexible stopper (612A) during the process of incrementing the dose towards the first desired dose of 0.3 ml. The protrusion (412), thus positioned above the flexible stopper (612A), exerts a downward force on the flexible stopper (612A), thus compressing and disposing the flexible stopper (612A) in a compressed state (1008), further positioning the flexible stopper (612A) completely or at least partially inside the slot (626) disposed on the plunger body (206). A further rotation of the dose dial knob (108) in the first direction causes the protrusion (412) to climb down and reposition from above the flexible stopper (612A) to a second side (1010) (shown in FIG. 10A) of the flexible stopper (612A). The protrusion (412), thus repositioned at the second side (1010) of the flexible stopper (612A), releases the downward force exerted on the flexible stopper (612A) such that the flexible stopper (612A) emerges out of the slot (626) and reverts to a relaxed state (1012) (shown in FIG. 10A).
[0084] It may be noted that the movement of the protrusion (412) from the first side (1002) to the elevated state (1006) and from the elevated state (1006) to the second side (1010), and the movement of the flexible stopper (612A) from the compressed state (1008) to the relaxed state (1012) generates one or more of a first audible and a tactile feedback. The first audible and/or tactile feedback indicates to the user that he or she has incremented a dose, for example, by a first designated unit of 0.1 ml from zero to a first intermediate dose of 0.1 ml. Continuing rotation of the dose dial knob (108) in the first direction causes the protrusion (412) to move away from the second side (1010) of the flexible stopper (612A) and to come in contact with a first side (1014) of another flexible stopper (616A) (shown in FIG. 10C) in the second stopper column (608B). While the protrusion (412) is in contact with the first side (1014) of the flexible stopper (616A) in the second stopper column (608B), the user can recognize a set dose as 0.1 ml by either visually reading the dose indicator window (110) and/or based on the first audible and/or tactile feedback generated previously.
[0085] Further, at this stage, when the user completes setting the dose to 0.1 ml, the dose sleeve (204) would have moved towards the distal end (118) of the dispensing device (102) by a designated distance from an associated initial position (912) to a first intermediate position (914) (shown in FIG. 9). Referring back to FIG. 10C, a user further rotates the dose dial knob (108) in the first direction for incrementing the dose from 0.1 ml to the first desired dose of 0.3 ml. As the user rotates the dose dial knob (108) in the first direction, the protrusion (412) moves and climbs from the first side (1014) of the flexible stopper (616A) in the second stopper column (608B) and is positioned in the elevated state (1006) above the flexible stopper (616A). The protrusion (412), thus, positioned above the flexible stopper (616A), exerts a downward force on the flexible stopper (612A) and compresses the flexible stopper (616A) to be disposed in a compressed state (1008) into another slot (626) disposed on the plunger body (206). Subsequently, the protrusion (412) climbs down from above the flexible stopper (616A) and is repositioned to a second side (1016) of the flexible stopper (616A), which causes the flexible stopper (616A) to emerge out of the slot (626), and to revert to a relaxed state (1012) from the compressed state (1008).
[0086] The sliding movement of the protrusion (412) from the first side (1014) to the elevated state (1006) and subsequently to the second side (1016) of the flexible stopper (616A), and the movement of the flexible stopper (616A) from the compressed state (1008) to the relaxed state (1012) generates a second audible and/or tactile feedback. The second audible and/or tactile feedback indicates to the user that he or she has incremented the dose, for example, by a second designated unit of 0.1 ml from the first intermediate dose of 0.1 ml to a second intermediate dose of 0.2 ml.
[0087] Continuing rotation of the dose dial knob (108) in the first direction causes the protrusion (412) to move away from the second side (1016) of the flexible stopper (616A) and to come in contact with a first side (1018) of another flexible stopper (620A) (shown in FIG. 10D) in the third stopper column (608C). While the protrusion (412) is engaged with the first side (1018) of the flexible stopper (620A) in the third stopper column (608C), the user can recognize a set dose as 0.2 ml by either visually reading the dose indicator window (110) and/or based on the second audible and/or tactile feedback generated previously. Further, at this stage, when the user completes setting the dose to 0.2 ml, the dose sleeve (204) would have moved towards the distal end (118) of the dispensing device (102) by another designated distance from the first intermediate position (914) to a second intermediate position (916) (shown in FIG. 9).
[0088] Referring back to FIG. 10D, the user further rotates the dose dial knob (108) in the first direction for incrementing the dose from 0.2 ml to the first desired dose of 0.3 ml. As the user rotates the dose dial knob (108) in the first direction, the protrusion (412) moves from the first side (1018) to the elevated state (1006) above the flexible stopper (620A), which compresses and disposes the flexible stopper (620A) in a compressed state (1008) inside another slot (626), as described previously. Subsequently, the continuing rotation of the dose dial knob (108) repositions the protrusion (412) from above the flexible stopper (620A) to a second side (1020) of the flexible stopper (620A), which releases the flexible stopper (620A) to a relaxed state (1012), as described previously. The sliding movement of the protrusion (412) from the first side (1018) to the elevated state (1006) and from the elevated state (1006) to the second side (1020), and the movement of the flexible stopper (620A) from the compressed state (1008) to the relaxed state (1012) generates a third audible and/or tactile feedback. The third audible and/or tactile feedback indicates the user that he or she has incremented the dose, for example, by a third designated unit of 0.1 ml from 0.2 ml to the first desired dose of 0.3 ml.
[0089] Continuing further rotation of the dose dial knob (108) in the first direction causes the protrusion (412) to move away from the second side (1020) of the flexible stopper (620A) and to engage with a non-flexible stopper (622A) (shown in FIG. 10E) in the fourth stopper column (608D). While the protrusion (412) is engaged with the non-flexible stopper (622A) in the fourth stopper column (608D), the user can recognize a set dose as 0.3 ml by either visually reading the dose indicator window (110) and/or based on the third audible and/or tactile feedback. Further, the dose sleeve (204) moves trans-rotationally within the outer body (106) from the second intermediate position (916) and is positioned at a third intermediate position (918) (shown in FIG. 9) when the user completes incrementing the dose to 0.3 ml.
[0090] In one embodiment, the user cannot further rotate the dose dial knob (108) in the first direction after setting dose, for example to 0.3 ml, which is designed to be equivalent to a maximum dose that can be set and delivered at once from the dispensing device (102). Specifically, the non-flexible stopper (622A), disposed in an engaged or locked state with the protrusion (412), serves as an obstacle in a rotational path of the protrusion (412) and blocks the protrusion (412) from undergoing further rotational motion, which ensures that the dose dial knob (108) cannot be further rotated in the first direction to increment the dose to greater than 0.3 ml.
[0091] FIG. 11 illustrates another cross-sectional view (1100) of the exemplary dispensing device (102) depicting the dose sleeve (204) post moving by a first distance from the initial position (912) to the third intermediate position (918) towards the distal end (118) of the dispensing device (102), as a result of setting of the first desired dose to 0.3 ml. In one embodiment, a manufacturer of the dispensing device (102) defines a distance by which the dose sleeve (204) should move for setting a desired dose to be delivered by selecting an appropriate corresponding pitch for the threaded portion (318) of the outer body (106) and/or the threaded portion (510) of the dose sleeve (204).
[0092] After setting the first desired dose as 0.3 ml for delivery, the dose delivery includes a user piercing a needle disposed at the distal end (118) of the dispensing device (102) into his/her skin and pressing the unlocking device (216) downwards towards the distal end (118). More particularly, the thumb pad (802) that is part of the unlocking device (216) and is projected out of the dispensing device (102) is depressed downwards towards the distal end (118). Upon depressing the thumb pad (802), the stem portion (804) that is placed within the opening in between the plunger ratchet (210) and the elongated body (704) flexes the first and second flexible pawls (712A-B) that are placed in an engaged state with respect to the first tooth (906) of the plunger ratchet (210) upwards. Consequently, the first and second flexible pawls (712A-B) are disengaged from the first tooth (906), thereby releasing the plunger body (206) from the locked position to the unlocked position.
[0093] FIG. 12 illustrates another cross-sectional view (1200) of the exemplary dispensing device (102) of FIG. 1 depicting the first and second flexible pawls (712A-B) in a flexed-up position following actuation of the unlocking device (216) towards the distal end (118) of the dispensing device (102). Further, FIG. 12 depicts the first and second flexible pawls (712A-B) placed in a disengaged state with respect to the first tooth (906) of the plunger ratchet (210). Once the first and second flexible pawls (712A-B) are placed in the disengaged state, the first elastic member (212) that is placed within the plunger body (206) expands towards the distal end (118) and exerts a force on the plunger body (206) to push the plunger body (206) towards the distal end (118). In one embodiment, the expansion of the first elastic member (212) causes the plunger body (206) and the plunger rod (208) coupled to the plunger body (206) to move by a distance, which is same as the first distance by which the dose sleeve (204) had moved earlier while setting the first desired dose.
[0094] FIG. 13 illustrates another cross-sectional view (1300) of the exemplary dispensing device (102) of FIG. 1 depicting the plunger body (206) and the plunger rod (208) at corresponding positions post moving by the first distance towards the distal end (118). The movement of the plunger rod (208) by the first distance causes the rubber stopper (904) to move by the same distance, resulting in injecting the first desired dose of 0.3 ml of the medicament into the user. In certain embodiments, the plunger body (206) is configured such that the end (604) of the plunger body (206) is seated again against the distal end (508) of the dose sleeve (204) once the plunger body (206) completes its movement by the first distance.
[0095] In certain embodiments, the plunger body (206) includes a label (not shown in FIGS) affixed on the associated exterior surface (606). In one embodiment, the label includes a plurality of dosage numbers that are helically printed in a selected international unit of volume. In the previously noted example of setting and delivering the desired dose of 0.3 ml, the user initially perceives that the desired dose set for delivery as 0.3 ml printed on the label through the dose indicator window (110). When the user depresses the thumb pad (802) for delivering the desired dose of 0.3 ml, the plunger body (206) moves downward towards the distal end (118) of the dispensing device (102), as noted previously. The downward movement of the plunger body (206) leads to a change in a dosage number visible through the dose indicator window (110). In one embodiment, the distance between the plurality of dosage numbers printed on the label are pre-selected such that the downward movement of the plunger body (206) by the first distance causes a change in the dosage number visible through the dose indicator window (110) from 0.3 ml to 0 ml after delivering the desired dose. Thus, next dosage number that the user sees via the dose indicator window (110) is zero once the first desired dose of the medicament is delivered from the dispensing device (102).
[0096] Subsequent to delivery of the first desired dose from the dispensing device (102), the user needs to release the downward force exerted on the thumb pad (802) such that the unlocking device (216) moves back towards the proximal end (116) of the dispensing device (102) due to force exerted by the second elastic member (218). The movement of the unlocking device (216) towards the proximal end (116) also causes the stem portion (804) to disengage from the first and second flexible pawls (712A-B) and to move up towards the proximal end (116). Consequently, the first and second flexible pawls (712A-B) automatically flex downwards due to disengagement of the stem portion (804) from the first and second flexible pawl (712A-B). Further, the first and second flexible pawls (712A-B) are placed back in an engaged state with respect to another tooth, for example, a third tooth (1302) of the plunger ratchet (210) after the first desired dose is delivered from the dispensing device (102). Further, after delivering the first desired dose of 0.3 ml, the protrusion (412) is repositioned to a first side of a flexible stopper (624B) (shown in FIGS. 6A-6B) in the fourth stopper column (608D) due to a downward movement of the plunger body (206) towards the distal end (118) of the dispensing device (102) during a dose delivery process.
[0097] Though the dose setting and delivering processes for subsequent doses such as a second and a third dose are not explained herein in detail, it is to be understood that the dose setting and delivering processes are similar to the first dose setting and delivering process described previously. For example, the dose dial knob (108) is again rotated in the first direction to set 0.1 ml as a second desired dose to be delivered. In this example, the protrusion (412) slides over the flexible stopper (624B), generating an audible and/or tactile feedback, as noted previously. The audible and/or tactile feedback indicates that the user has incremented the dose from 0 ml to the second desired dose of 0.1 ml. The rotation of the dose dial knob (108) also causes the dose sleeve (204) to move by a second distance corresponding to the set dose of 0.1 ml.
[0098] Subsequent to setting the dose to 0.1 ml, the thumb pad (802) is depressed towards the distal end (118) of the dispensing device (102) such that the first and second flexible pawls (712A-B) are disengaged from the third tooth (1302) of the plunger ratchet (210). Further, the plunger body (206) and the plunger rod (208) move by the second distance by which the dose sleeve (204) had moved earlier due to force exerted by the first elastic member (212) to release the set second desired dose of 0.1 ml from the dispensing device (102). Upon releasing the downward force exerted on the thumb pad (802), the first and second flexible pawls (712A-B) flex downwards and are placed in an engaged state with respect to another tooth of the plunger ratchet (210).
[0099] In certain embodiments, in addition to allowing the user to set a desired dose for delivery, the dispensing device (102) also allows the user to adjust or correct an incorrectly set dose to the desired dose. For example, while setting a first desired dose of 0.2 ml, the user may accidentally set the dose to 0.3 ml and later needs to correct the set dose of 0.3 ml to 0.2 ml. In the previously noted example, the user rotates the dose dial knob (108) in the second direction opposite to the first direction for decrementing a currently set dose of 0.3 ml to the first desired dose of 0.2 ml. When the user rotates the dose dial knob (108) in the second direction, the protrusion (412) that is currently positioned in an engaged state with respect to the non-flexible stopper (622A) (shown in FIG. 10E) rotates in a reverse circular path. Specifically, the protrusion (412) disengages and moves away from the non-flexible stopper (622A) and is positioned at the second side (1020) of the flexible stopper (620A) (shown in FIG. 10D) as the user continues to rotate the dose dial knob (108) in the second direction.
[00100] Continuing rotation of the dose dial knob (108) in the second direction causes the protrusion (412) to move and climb from the second side (1020) of the flexible stopper (620A) and be positioned in the elevated state (1006) above the flexible stopper (620A), which compresses and disposes the flexible stopper (620A) in a compressed state (1008) into the slot (626). Subsequently, the continuing rotation causes the protrusion (412) to climb down and reposition to the first side (1018) of the flexible stopper (620A) such that the flexible stopper (620A) emerges out of the slot (626) and reverts to a relaxed state (1012).
[00101] The sliding movement of the protrusion (412) from the second side (1020) to the elevated state (1006) and subsequently to the first side (1018) of the flexible stopper (620A), and the movement of the flexible stopper (620A) from the compressed state (1008) to the relaxed state (1012) generates an audible and/or tactile feedback. The audible and/or tactile feedback indicates to the user that he or she has decremented the dose, for example, by 0.1 ml from 0.3 ml to 0.2 ml. In one embodiment, decrement of the dose from 0.3 ml to 0.2 ml causes the dose sleeve (204) to move back by a specific distance from the third intermediate position (918) to the second intermediate position (916) towards the proximal end (116) of the dispensing device (102).
[00102] After correcting the first desired dose from 0.3 ml to 0.2 ml, a user depresses the thumb pad (802) towards the distal end (118) of the dispensing device (102) for dispensing the first desired dose of 0.2 ml. The depression of the thumb pad (802) causes the first and second flexible pawls (712A-B) to disengage from the first tooth (906) of the plunger ratchet (210). Further, the plunger body (206) and the plunger rod (208) move by a particular distance by which the dose sleeve (204) had moved earlier from the initial position (912) to the second intermediate position (916) due to force exerted by the first elastic member (212). The movement of the plunger body (206) and the plunger rod (208) by the particular distance releases the corrected dose of 0.2 ml from the dispensing device (102).
[00103] FIG. 14 illustrates yet another cross-sectional view (1400) of the exemplary dispensing device (102) of FIG. 1 depicting the dose sleeve (204) placed in an engaged state with respect to the cartridge (202) after a final dose is delivered from the dispensing device (102). In certain embodiments, the dispensing device (102) allows the user to set and deliver variable doses for multiple injections such that the dose sleeve (204) is configured to move by a corresponding distance each time a desired dose to be delivered is set. Once a final dose is set and is delivered from the dispensing device (102), the dose sleeve (204) is placed in an engaged state with respect to the cartridge (202). Consequently, the dose dial knob (108) cannot be rotated further to set a new dose as a further movement of the dose sleeve (204) towards the distal end (118) is prevented by the presence of the cartridge (202). The inability to rotate the dose dial knob (108) any further indicates an end of life for the dispensing device (102).
[00104] Embodiments of the exemplary dispensing device (102) described herein allow a user to set a desired amount of material for dose delivery and to vary a dose according to a specific need of the user. Further, the dispensing device (102) allows the user to adjust or correct an incorrectly set dose. Furthermore, the dispensing device (102) generates audible and/or tactile feedbacks when the user rotates the dose dial knob (108) in first and second directions to set or correct a dose.
[00105] For example, a dose that is currently set for delivery corresponds to zero. Upon rotating the dose dial knob (108) in the first direction, the dispensing device (102) generates a first audible and/or tactile feedback due to a sliding movement of the protrusion (412) from the first side (1002) to the second side (1010) of the flexible stopper (612A). The generation of the first audible and/or tactile feedback upon rotating the dose dial knob (108) in the first direction indicates to the user that he or she has incremented the dose from zero to 0.1 ml. In another example, upon subsequently rotating the dose dial knob (108) in the second direction different from the first direction, the dispensing device (102) generates a second audible and/or tactile feedback due to a sliding movement of the protrusion (412) from the second side (1010) to the first side (1002) of the flexible stopper (612A). The generation of the second audible and/or tactile feedback upon rotating the dose dial knob (108) in the second direction indicates to the user that he or she has decremented the dose from 0.1 ml to zero. Therefore, the audible and/or tactile feedbacks generated by the dispensing device (102) enable the user to easily track the progress of dose setting and correction processes. Further, the audible and/or tactile feedbacks enables the user, such as an aged patient or a person with uneven visual acuity or cognitive impairment to identify and verify a dose set by him or her easily and accurately without needing to visually review a dosage displayed in the dose indicator window (110).
[00106] In addition, the dispensing device (102) is capable of accurately delivering the set desired dose by a pressing or pushing action of the thumb pad (802) towards the distal end (118) of the dispensing device (102). The pressing action of the thumb pad (802) releases the plunger body (206) from a locked position to an unlocked position to enable the movement of the plunger body (206) and the plunger rod (208) due to the force exerted by the first elastic member (212) to release the set desired dose. The locking device (214) ensures the plunger body (206) is placed in the locked position while setting a dose, and hence, the plunger body (206) is not disturbed during a dose-setting process, thus preventing any accidental delivery of dose during dose setting.
[00107] Further, the thumb pad (802) is designed so as not to protrude out of the proximal end (116) of the dispensing device (102) during a dose-setting process. Hence, the user can conveniently press the thumb pad (802) using a single arm once a desired dose is set for delivery. Moreover, the dispensing device (102) provides a variety of safety features to the user. The plunger (205) along with the dose dial knob (108) prevents the user from setting and delivering a dose that is more than a set threshold limit at once. Further, the non-flexible stopper (610H) on the plunger body (206) allows the user to set a final dose according to an amount of the material remaining in the cartridge (202). Hence, the dispensing device (102) ensures that the user is injected with an appropriate amount of material during the final dose delivery.
[00108] Although specific features of various embodiments of the present systems and methods may be shown in and/or described with respect to some drawings and not in others, this is for convenience only. It is to be understood that the described features, structures, and/or characteristics may be combined and/or used interchangeably in any suitable manner in the various embodiments shown in the different figures.
[00109] While only certain features of the present systems and methods have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes.

LIST OF NUMERAL REFERENCES:

102 Dispensing device
104 Cartridge holder
106 Outer body
108 Dose dial knob
110 Dose indicator window
112 Outer surface
114 Cover
116 Device proximal end
118 Device distal end
200 Device exploded view
202 Cartridge
204 Dose sleeve
205 Plunger
206 Plunger body
208 Plunger rod
210 Plunger ratchet
212, 218 Elastic members
214 Locking device
216 Unlocking device
220 Dose knob screw
300 Perspective view of outer body
302 Outer body proximal end
304 Outer body distal end
306 Male threaded section
308 Cutout portion
310 Circular portion
312 Central cut
314A-D Ribs
316 Exterior surface
318 Threaded portion
400 Perspective view of dose dial knob
402 Internal cylindrical body
404A-C Elevated walls
406A-C Grooves
408 Threaded arrangement
410 Proximal end of dose dial knob
412 Protrusion
414 Distal end of dose dial knob
500 Perspective view of dose sleeve
502 Proximal end of dose sleeve
504 Outer surface
506A-D Ribs
508 Distal end of dose sleeve
510 Threaded portion of dose sleeve
514 Slot
600 Front view of plunger body
602 Proximal end of plunger body
604 Distal end of plunger body
606 Exterior surface of plunger body
608A-D Stopper columns
918 Third intermediate position
610A-H, 614A-G, 618A-H, and 622A-H Non-flexible stoppers
612A-H, 616A-H, 620A-H, and 624A-I Flexible stoppers
626 Slots
628, 630 Ramps
632 Horizontal axis of plunger body
700 Locking device perspective view
702 Collar
704 Elongated body
708 One end of elongated body
710 Another end of elongated body
712A-B Flexible pawls
800 Unlocking device perspective view
802 Thumb pad
804 Stem portion
900, 1100, 1200, 1300, 1400 Device cross-sectional view
902 Distal portion of plunger rod
904 Rubber stopper
906 First tooth
908 First end of first elastic member
910 Second end of first elastic member
912 Initial position of dose sleeve
914 First intermediate position
916 Second intermediate position
920 Horizontal Axis of plunger rod
1000 Dose dial knob exploded view
1002, 1014, 1018 First side of flexible stoppers
1004 Exploded view of dose dial knob
1006 Elevated state
1008 Compressed state
1010, 1016, 1020 Second side of flexible stoppers
1012 Relaxed state
1302 Tooth of plunger ratchet