An auto-injector automatically dispenses a predetermined dose of medicament upon activation. The auto-injector includes a needle cover operative to engage an injection site and activate the injector. The needle cover is configured to move from a locked retracted position prior to a medicament dispensing operation to a locked extended position after the medicament dispensing operation. The non-removable needle cover prevents contact with the needle both before and after the medicament dispensing operation.
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This is a continuation-in-part of U.S. patent application Ser. No. 11/095,664, filed Apr. 1, 2005, now U.S. Pat. No. ______, which claims the benefit of U.S. Provisional Application No. 60/599,054, filed Aug. 6, 2004, the entire contents of each are expressly incorporated herein by reference thereto.FIELD OF THE INVENTION
The invention relates to an automatic injector or auto-injector for delivering medicament to an injection site. In particular, the invention is directed to an auto-injector having a needle cover mechanism to prevent a user from coming into contact with the needle of the auto-injector after use. The needle cover mechanism is held in a locked position prior to activation of the auto-injector. After injection, the needle cover mechanism is held in a locked deployed position such that the user cannot access the needle.
The invention is also directed to an auto-injector having a power pack containing a one-piece molded collet. The molded collet reduces the overall number of manufactured components while increasing versatility. The molded collet can be used with cartridges of varying sizes, different sized needles and can be used to vary the amount of the delivered dosage of medicament.BACKGROUND OF THE INVENTION
An automatic injector or auto-injector is a device designed to allow a user to self-administer a pre-measured dose of a medicament composition subcutaneously or intramuscularly, usually in an emergency situation. Automatic injectors are used, for example, to treat anaphylactic (severe allergic) reactions and to administer antidotes for certain poisons, such as chemical nerve agents and various drug compositions such as diazepan.
A typical auto-injector has a housing, inside of which is a cartridge. The cartridge has one or several chambers containing medicament compositions or components thereof and is adapted to be attached to a needle assembly. The cartridge can hold either a pre-mixed liquid medicament or a solid medicament and a liquid that are mixed prior to injection. The housing carries an actuation assembly with a stored energy source, for example, a compressed spring. Activation of the actuation assembly causes a sequence of movements, whereby the needle extends from the auto-injector into the user so that the medicament compound is then forced through the needle and into the user. After delivery of the dose of medicament into the injection site, the needle remains in an extended position. If the auto-injector is of the type designed to carry plural components of the medicament composition in separate, sealed compartments, structure may be included that forces the components to mix when the actuation assembly is activated.
There is a need for an auto-injector having a cover that provides adequate protection from the needle both prior to and after operation of the auto-injector. U.S. Pat. No. 5,295,965 to Wilmot et al. discloses an external cover member providing sharps protection for an auto-injector after use. The cover member is deployed after actuation of the auto-injector such that the user does not view the needle after use. The position of the cover member with respect to the auto-injector body is offset after use such that the needle cannot be redeployed through an opening in the needle cover.
U.S. Pat. No. 6,767,336 to Kaplan discloses a cover for an auto-injector. In an effort to reduce components, Kaplan eliminates an outer housing for the auto-injector. The cover is secured to the exterior of the cartridge holder sleeve. The cartridge holder sleeve includes several slots, which are sized to receive a latch on the cover. When the auto-injector is actuated, the cartridge within the cartridge holder sleeve causes the latch to be released from the recess such that the cover is free to travel under the bias of the spring. Since the cover disclosed by Kaplan is located on the exterior of the cartridge holder sleeve, it is possible for the user to grip the cover during operation of the auto-injector. As such, the user may prevent the latches from being released from the respective slots, which could prevent the cover from being properly deployed. This could impede the movement of the cartridge within the cartridge holder sleeve, which could result in the medicament being dispensed through the needle prior to the needle reaching the injection site. To overcome these deficiencies, higher trigger forces would be necessary. When the latches are released during the deployment of the cover, the latches are biased outwardly. It is possible for the user to be pinched or otherwise injured by this deployment.
If the cover deploys prior to delivery of the drug, a potentially life threatening event may arise because the user may not receive the proper dose of medicament. There is a need for a secured cover such that it cannot be displaced prior to use of the auto-injector. There is also a need for a cover that does not impede or adversely impact the operation of the auto-injector in the event it is contacted by the user. It is also desirable that the cover be locked in an extended position after use of the auto-injector so that the needle is not exposed such that a person cannot be accidentally pricked by the needle. It is also desirable to have a cover member having locking and deployment mechanisms that are protected against contact from the operator to prevent improper deployment of the cover.SUMMARY OF THE INVENTION
One aspect of the present invention relates to an auto-injector for dispensing a predetermined dosage of a medicament. The medicament may be either self administered or administered by a caregiver. The auto-injector includes a housing. The housing is preferably oval or elliptical in shape such that it is more ergonomic. The oval shape prevents the auto-injector from rolling off a table or flat surface, while providing a larger surface area for printing user instructions. A cartridge container is disposed within the housing. A cartridge is received within the cartridge container. The cartridge has at least one opening therein and contains a medicament. The medicament is rearwardly confined by a plunger. The cartridge includes a needle assembly to dispense the medicament therethrough. The cartridge is advanced within the cartridge container from a stored position to an operation position where the needle extends from the cartridge container such that the dose of medicament can be administered. An actuation assembly or power pack provides a stored energy source that is capable of being released to drive the plunger within the cartridge to dispense the medicament through the needle assembly into the user and allowing the needle to be accessible on activation.
Another aspect of the auto-injector is the provision of a needle cover received within the housing. The needle cover shields the user from inadvertent exposure to the needle after use of the auto-injector providing sharps protection. Theoretically, the operation of the needle cover is fail safe because the cover will not deploy until after the needle penetrates the user. During operation, the needle of the cartridge extends through an opening in the needle cover to permit the dispensing of a dose of medicament. After use of the auto-injector, the needle cover is held in a locked position to prevent the cover from being retracted to expose the needle. According to another aspect of the invention, the needle cover has a locked retracted position prior to activation of the auto-injector, thus maintaining a compact configuration of the device prior to use. According to another aspect of the invention, the actuation forces associated with the auto-injector are not imparted on the needle cover.
In accordance with another aspect of the present invention, the auto-injector has a first locking assembly that holds the needle cover in the first locked position. The first locking assembly may be located on the cartridge container. The first locking assembly may include at least one locking tooth pivotally connected to the cartridge container or the needle cover. Each locking tooth releasably engages the needle cover and includes a locking surface constructed and arranged to contact a surface on the needle cover or the cartridge container. Each locking tooth may be formed as a separate component that is connected to the container or cover. It is contemplated that the locking teeth may be formed as integral parts of the needle cover or cartridge. A spring force of the locking tooth biases the locking surface into contact with the needle cover. The spring force may be provided by a spring portion of the locking tooth. The spring force may also be provided by a separate spring assembly biasing the locking surface into contact with the needle cover. Each locking tooth is preferably pivotally connected to the cartridge container. Each locking tooth pivots in response to movement of the cartridge within the cartridge container. It is also contemplated that the locking teeth can pivot in response to movement of the collet or the power pack. Typically, the locking surface pivots out of contact with the needle cover when the locking tooth pivots in response to the movement of the cartridge. The spring force and the force exerted by the locking teeth on the cartridge are controlled such that they negligibly or minimally impede the motion of the cartridge during the injection operation to avoid any premature rupturing of the diaphragm within the cartridge and premature administering of the medicament.
The needle cover is spring biased so that the cover is biased outwardly from the housing to cover the exposed needle after the first locking assembly is released. In accordance with another aspect of the present invention, the auto-injector has a second locking assembly that holds the needle cover in the second locked position. The second locking assembly may be located on the cartridge container, the outer body or the cover member. The second locking assembly may include at least one locking arm or wing preferably connected to the cartridge container. Each locking arm is spaced from the cartridge container such that the locking arm can be temporarily compressed against the cartridge container as the needle cover moves from the first locked position to the second locked position. Each locking arm has a locking surface to engage the needle cover when the needle cover is in the locked extended position. Each locking arm has a thick strut portion and a thin strut portion, wherein the thick strut portion is outwardly curved and the thin strut portion is inwardly curved. This construction maintains the locking arm in a normal uncompressed state to reduce stress on the cartridge container. This also permits a smooth deployment of the cover member. Furthermore, this arrangement ensures that the thick strut portion will buckle into a stable condition. This creates a stronger lock to prevent the cover member from being moved rearwardly to a retracted position. The inwardly curved nature of the thin strut portion allows the thick portion to buckle in a controlled manner to a stable condition. Additionally, the outwardly curved shape of the thick strut portion provides for fail safe locking of the cover member in the extended position. In the event that the thin strut breaks, the thick strut portion will still engage the cover member to maintain it in an extended locked position.
The cartridge container may further include at least one ledge extending outwardly therefrom. Each ledge is constructed and arranged to engage an edge of an opening in the needle cover to limit the travel of the needle cover with the respect to the cartridge container when the needle cover is in the extended position. When the ledge on the cartridge container engages the edge of the opening, the outward travel of the needle cover is limited. The second locking assembly limits the inward travel of the needle cover. The needle cover and the cartridge container contain openings formed therein. When the openings are aligned prior to activation of the auto-injector, user can view the contents of the cartridge through the housing and the openings. The housing may be transparent or opaque. When opaque, the housing may contain an opening that can be aligned with the openings in the needle cover and cartridge container so that the color of the medicament may be checked to determine whether or not the medicament is suitable for injection. If the medicament is discolored, the user will know not to administer the medicament. When the openings are not aligned after operation of the auto-injector, the user is no longer able to view the contents of the cartridge through the openings providing a visual indication to the user that the auto-injector has been used.
Another aspect of the present invention is the construction and arrangement of the actuation assembly or power pack, which is mounted within the housing adjacent to an open end. A release pin or safe pin is removably attached to the actuation assembly to prevent inadvertent actuation of the auto-injector when the release pin is in place. A pin or stem on the release pin is received within an opening in the actuation assembly to prevent actuation of the auto-injector. This opening in the power pack is spaced from the open end of the housing such that the opening is less visible to a user prior to administering the drug. This arrangement is provided so that user will not orient the incorrect end of the auto-injector against the injection surface of the user. The power pack is recessed or spaced from the end of the housing, which provides an indication to the user that pressing the power pack will not operate the auto-injector. The recessed nature of the power pack serves to hide the release pin hole in the power pack when the user is viewing the instructions on the outer body such that the user does not confuse the release pin hole with the opening through which the needle passes for administering the medicament. The release pin includes at least one tab extending therefrom. The tab is compression fit into a complimentary recess formed in the actuation assembly to prevent the inadvertent removal of the release pin. The tabs also prevent rotation of the release pin such that the user easily recognizes that the release pin must be pulled in order to be removed.
The actuation assembly includes an outer body, which is configured to engage the release pin. The outer body is constructed to be connected to the housing. An inner body is operatively coupled to the outer body. At least one retention tab on the inner body secures the inner body to the outer body. The inner body is capable of limited movement with respect to the outer body. A collet is operatively coupled to the inner body. An energy source is operatively connected to the inner body and the collet. Unlike conventional collets, the collet in the present invention is molded as a single piece. No spacers or other components are provided between the collet and the plunger in the cartridge. This arrangement simplifies construction. Different sized collets can be produced and installed into the actuation assembly, such that only the collet needs to altered when different sized cartridges are used or a different sized dosage of medicament is to be administered.
An understanding of the various embodiments of the invention may be gained by virtue of the following figures, of which like elements in various figures will have common reference numbers, and wherein:
It should be appreciated that some of the components described herein are conventionally known in the broader aspects, as described in U.S. Pat. No. 4,031,893 (“the '893 patent”) hereby incorporated by reference in its entirety, and thus not described in unnecessary detail here. It should also be appreciated that known modifications or variations to the '893 patent can apply equally to the auto-injector of the present invention as will be described below. These modifications or variations include embodiments described in U.S. Pat. Nos. 4,226,235; 4,329,988; 4,394,863; 4,723,937; and U.S. Ser. Nos. 09/985,466; 10/285,692, each of which is incorporated by reference in its entirety for the full teachings therein.
An auto-injector 100 of the present invention will now be described in greater detail in connection with
The auto-injector 100 includes an outer body 110 shown in FIGS. 38 and 44-48. The outer body 110 has a generally oval or elliptical shape, which is more ergonomic sized to permit easy grasping and use by the user or caregiver in comparison with a cylindrical body. The generally oval shape of the outer body 110 prevents the auto-injector 100 from inadvertently rolling or sliding off a flat surface. Furthermore, the oval shape provides a larger print surface for labeling the auto-injector 100 with instructions. The outer body 110 is preferably formed from a synthetic material such that it can be easily molded. The outer body 110 can be transparent such that the interior components can be easily viewed through the outer body 110. With such a construction, the user can view the contents of the cartridge 160 through windows 141a and 141b in the cartridge container 140 and the needle cover 150 at predetermined times. It is also contemplated that the outer body 110 can be opaque such that the interior components are not visible through the outer body 110. It is also contemplated that the outer body 110 has a window or windows that permit viewing of the components within the outer body 110. The outer body 110 has an opening 111 formed in one end that is sized to receive a release pin 120. When in place, the release pin 120 prevents inadvertent use or activation of the auto-injector 100. The release pin 120 is illustrated in
The opening 111 includes side recesses 111a and 111b, which extend downwardly along opposing sides of the outer body 110, shown in
As shown in
An opening 114 is formed in the outer body 110 on an end opposite the opening 111. The opening 114 is configured such that a portion of the cartridge container 140, a portion of the needle cover 150 can extend therefrom. The step 112 limits the travel of the container 140 through opening 114. The end of the outer body 110 is intended to be orientated adjacent the injection surface of the user such that end portion of the cover 100 contacts the injection surface.
The power pack 130 will now be described in greater detail in connection with
While these ribs 232 are shown, it is contemplated additional ribs may be provided. The ribs 232 are provided to prevent distortion of the outer body 110 of the auto-injector 100. A plurality of outer longitudinal ribs 233a, 233b are spaced about the outer surface of the hollow body 231. The ribs 233 cooperate with the ribs 232 to further strengthen the auto-injector 100 and prevent distortion of the outer body 110 when gripped and used by a user.
One of the peripheral ribs 232a forms a top end surface 237 of the power pack outer body 230. A hole 234 is provided in end surface which is sized to receive the downwardly extending pin 125 of the release pin 120. Retention recesses 235a and 235b are formed on opposing sides of the hollow body 231 adjacent the top end surface. The recesses 235a and 235b are formed by walls 236a and 236b which extend outwardly from the hollow body 231 and upwardly from the top end surface 237 of the peripheral rib 232a. The recesses 235a and 235b are aligned with the side recesses 111a and 111b of the outer body 110 such that when the release pin 120 is secured to the auto-injector 100, the tabs 121a and 121b are received in both recesses 235a and 235b. The recesses 235a and 235b are sized to apply a compressive force on the tabs 121a and 121b to secure the release pin 120 in place to prevent inadvertent removal.
As shown in
A plurality of projections or teeth 238a, 238b, 238c are formed on the outer surface of the hollow body 231. The teeth 238a, 238b, 238c are sized to be snap fit into the openings 113a, 113b, 113c to secure the power pack 130 within the outer body 110. This construction permits these components 110 and 130 to be secured together without the need of an adhesive of other form of bonding. A corresponding set of teeth 238 may be provided on the opposite side of the hollow body 230 to match the corresponding openings in the outer body 110.
The interior of the hollow body 231 includes a recess 231a, which is sized to receive a retention tab 334 on the power pack inner body 330. The recess 231a may be a groove, which extends about the inner periphery of the hollow body 231. The recess 231a is positioned in the hollow body 231 near an end opposite the end surface 237. As seen in
The power pack inner body 330 is a generally cylindrical hollow inner body 331. The hollow inner body 331 has an opening 332 formed in one end. The opening 332 has a collet assembly lead-in surface 332a which is used to compress a portion of the collet assembly 430 during assembly of the auto-injector 100 such that is can be properly mounted within the power pack inner body 330. The opening 332 also has a collet retention surface 332b located on an opposite edge which support the opposing arrowheads 434 of the collet 430 prior to activation. The hollow inner body 331 has an opening 333 formed on an opposing end. Spaced from the opening 333 are a plurality of retention tabs 334 which are sized to be snapped into the retention recess 231a. The recess 231 and tabs 334 permit limited movement between the power pack inner body 330 and the power pack outer body 230. The arrangement is also beneficial for purposes of assembling the auto-injector 100. The inner body 330 and the outer body 230 can be preassembled. The recess 231 and tabs 334 maintain the inner body 330 and the outer body 230 in proper alignment for assembly. Furthermore, this arrangement prevents the subassembly of the inner body 330 and the outer body 230 from separating prior to the final assembly in the auto-injector 100. It is also contemplated that other means which permit limited movement between the outer power pack and the inner power pack, which secure the components together may be employed. A ledge 335 at least partially extends about the periphery of the opening 333. The ledge 335 is sized to engage the cartridge container 140 and the power pack outer body 230 at certain times during the operation of the auto-injector 100, described in greater detail below. A spacing exists between the inner power pack 330 and the cartridge container 140 after assembly and prior to activation of the auto-injector 100 to create a gap, which avoids permanently putting forces on the power pack and the spring 530.
A collet 430 is received within the hollow interior of the power pack inner body 330. The collet 430 preferably is a molded one piece construction. The collect 430 has an elongated body 431 having an opening 432 formed therein which forms a pair of side arms 433a and 433b. Each side arm 433a and 433b includes an arrowhead detail 434a and 434b respectively. One side of each arrowhead 434a and 434b is configured to contact and engage the collet retention surface 332b. An opposite side of each arrowhead 434a and 434b is configured to engage the collet assembly lead-in surface 332a, which permits the side arms 433a and 433b to be deflected inwardly to permit operation of the auto-injector 100. The end 435 of the collet 430 adjacent the arrowheads 434a and 434b includes an opening 435a sized to receive the pin 125 of the release pin 120. The pin 125 prevents the side arms 433 from being deflected inwardly towards each other. When secured in place, the pin 125 prevents activation of the auto-injector 100. The opening 432 has an arch 432a formed on one end, as shown in
The collet 430 is positioned within the power pack spring assembly 530. One end of the spring assembly 530 is supported on a flange 436 formed on the collet 430. The flange 436 extends outwardly from the elongated body 431. While the flange 436 supports one end of the spring assembly 530, the location of the flange 436 on the body 431 can also serve to define the delivered dose volume of medicament injected into the user. In certain applications it is desirable to control the amount of medicament delivered through the needle such that a portion of the medicament remains in cartridge 160. The flange 436 may limit the distance that the collet 430 can travel into the cartridge 160, which contains the liquid medicament. As such, the amount of medicament delivered is controlled. In this arrangement, the flange 436 is sized to contact the end of the cartridge 160. For larger diameter cartridges and for larger doses of medicament, it is contemplated that the flange 436 can travel within the cartridge 160. The collet 430 further includes a projection 437, which receives a plunger 438. The plunger 438 is slidably received within the, cartridge 160. In other applications, it is desirable to dispense all of the medicament from the container 160. A small residual amount of medicament remains in the needle 162 and the neck of the cartridge 160 adjacent the needle 162. In these applications, the flange 436 travels within the interior of the cartridge 160 so that the plunger 438 travels the length of the interior of the cartridge 160 to dispense all of the medicament (except for the residual amounts mentioned above) through the needle 162. It is contemplated that different sized collets 430 may be used in the present auto-injector 100. As such, the collet 430 can be changed based upon cartridge size and desired dose.
The collet 430 is preferably formed as a single piece from a suitable plastic material. The one piece collet 430 simplifies manufacturing and lowers costs by reducing the number of components needed to form a collet. In conventional collets, multiple brass components may be used. In addition in other auto-injectors, a spacer has been required for use in conjunction with the collet 430 to accommodate different amounts of medicament for different auto-injectors. The collet 430 in accordance with the present invention eliminates the multi component construction and also advantageously eliminates the need for a spacer. The length of the collet can be selected based upon the desired dosage. This construction further permits the elimination of a metal insert typically found in the plunger and a firing seat above the power pack inner body. It is contemplated that the size and shape of the collet 430 itself may be varied to accommodate different sized cartridges 160. When the flange 436 does not contact the cartridge 160, it is possible to dispense the entire contents of the cartridge 160 except for any residual amounts remaining in the needle or in the neck of the cartridge 160. It is contemplated that a nipple plunger, as disclosed in U.S. Pat. No. 5,713,866 to Wilmot, the disclosure of which is hereby incorporated specifically herein by reference, may be employed to prevent any buildup of residual amounts of medicament in the neck of the cartridge 160. The position of the flange 436 can be varied to control the amount of dosage injected into the user when the flange is positioned such that the collet and the plunger 438 travel a greater distance within the cartridge 160 before the flange 436 contacts the cartridge 160, a larger dose is dispensed. The length of the collet 430 and the diameter of the cartridge 160 can be selected to control the flow of fluid through the needle 162 of the cartridge 160 so that a desired flow rate is obtained. The auto-injector 100 in accordance with the present invention is configured such that collets 430 of varying sizes can be used within the same outer body 110 and the power pack 430.
An opposite end of the spring assembly 530 rests against an inner surface of the power pack inner body 330 against opening 332.
The cartridge container 140 will now be described in greater detail in connection with FIGS. 41 and 49-52. The cartridge container 140 has a generally elongated hollow body 141 sized to be received within the outer body 110. A ledge 142 is formed on one end of the elongated body 141. The ledge 142 contacts the retention step 112 formed on the inner surface of the outer body 110. The ledge 142 limits the downward movement of the cartridge container 140 within the outer body 110 such that it cannot be removed through opening 114. The ledge 142 is formed by peripheral ribs 142a and 142b, which extend outwardly similar to the ribs 232a, 232b and 232c on the power pack outer body 230. The ribs 142a and 142b also prevent distortion of the outer body 110.
The elongated hollow body 141 has a hollow interior sized to receive the cartridge 160 therein. The hollow body has an opening 143 such that the cartridge 160 can be located in the hollow interior and to permit the collet 430 to be slidably received within the cartridge 160. The cartridge container 140 and the locking teeth 340 thereof are designed to accommodate various sized cartridges 160, while maintaining full needle cover functionality. As such, a common design needle cover assembly (including the cartridge container and locking teeth) can be used for various different volumes of drugs and different sized needles. For longer and larger cartridges, it is desirable to provide additional support to prevent axial and radial movement, which could damage or fracture the cartridge 160. A pair of tabs 600 are formed on the hollow body 141 to apply a compressive force on the cartridge 160 to hold and align the cartridge 160 in a proper orientation to prevent such axial and radial movement. The tabs 600 provide friction to prevent movement of the cartridge 160 within the hollow body 141 during shock loading to prevent the cartridge from being dislodged or moved forward with the cartridge holder 140 prior to the medicament dispensing sequence. Typically, the smaller cartridges do not contact the tabs 600. The collet 430 and the needle and needle sheath provide sufficient support for the cartridge. The end of hollow body 141 has a tapered construction with an opening 144 sized to permit the passage therethrough of the needle 162 and protective sheath 165 of the cartridge 160. A plurality of ribs 145 are formed on the outer surface of the hollow body 141 on the tapered end. The ribs 145 help stabilize the needle cover spring 153 of the needle cover 150. The ribs 145 also serve as guides to aid in the assembly of the auto-injector 100.
The elongated hollow body 141 has at least one viewing window 141a and 141b formed therein. The viewing windows 141a and 141b permit the user to view the contents of the cartridge 160 before activation of the auto-injector 100 to insure that the medicament has not become contaminated or expired.
A pair of locking arms or wings 240 extend from the ledge 142 and are connected to a mid-portion of the hollow body 141, as shown in
A thinner strut 242 extends from the free end of the strut 241 and is connected to the body 141 of the cartridge container 140. A locking surface 243 is formed at the intersection of struts 241 and 242. The locking surface 243 engages a surface on the cover 150 to limit the inward travel of the cover 150 after operation of the auto-injector 100, as shown in
As shown in
An elongated slot 146 is formed on each side of the elongated body 141. The slot 146 extends from the ends of the strut 242, as shown in
Each locking tooth 340 is capable of pivoting about the bearing axle 341 within the axle slot 147. Multiple axle slots may be provided such that the position of the tooth 340 may be adjusted. As shown in
Formed below the spring tail 343 is a v-shaped notch 347. The notch 347 has a locking surface 347a on one side which holds the needle cover 150 before activation of the auto-injector 100. Another surface 347b limits the travel of the tooth 340 within the cartridge container 140 to limit its rotation. The notch 347 is formed as part of a tab 348, which extends on either side of the spring tail 343. The locking teeth 340 increase the flexibility of the auto-injector 100. Numerous cartridges of various lengths and diameters can be used without modifying the auto-injector 100. The spring action of the tails 343 adjust the position of the locking teeth 340 such that the surface 342a contacts the cartridge 160.
The cartridge container 140 further includes a pair of openings 141a and 141b, which are formed on opposing sides of the body 141. The openings 141a and 141b permit viewing of the contents of the cartridge 160 such that the user can visually inspect the medicament prior to operation of the auto-injector 100. Prior to use the openings 141a and 141b are aligned with corresponding openings in the needle cover 150 such that the user can view the contents of cartridge 160 through the outer body 110. A ledge 149 having a plurality of reinforcing ribs 149a is formed adjacent one end of the opening 141. The ledge 149 contacts the edge 154a of the opening 154 in the needle cover 150 to prevent the needle cover 150 from moving any further forward relative to the cartridge container 140 so that the needle cover 150 cannot be pulled out of the outer body 110. When in this position, the locking surface 243 of the locking wings 240 engages the end of needle cover 150 to prevent the needle cover 150 from being inserted back into the outer body 110. When the ledge 149 is in contact with the edge of the opening in the needle cover 150, the openings in the cartridge container and the needle cover are no longer aligned such that the user cannot view the cartridge 160 through the outer body 110. This provides a visual guide indicator to the user that the auto-injector 100 has been used.
The needle cover 150 will now be described in greater detail in connection with FIGS. 12-15,38,42,43 and 53-54. The needle cover 150 has a generally elongated hollow body 151 having a shape that is complementary to the shape of outer body 110. The elongated body 151 is slidably received within the outer body 100. One end of the hollow body 151 is tapered having an enclosed end surface 152. End surface 152 prevents a human finger (e.g., a child's finger) from entering the needle cover and contacting the needle. End surface 152 has an opening 152a sized to permit the passage of the needle of the cartridge 160 there through during an injection operation, as shown in
The hollow body 151 further includes a pair of openings 154 formed thereon. As discusses above, the openings 154 align with the openings 141a and 141b in the cartridge container 140 prior to activation to allow visibility of the medicament within the cartridge 160. Edge surface 154a of the opening 154 is designed to contact ledge 149 to prohibit further advancement of the needle cover 150.
Slots 155 are provided on opposing sides of the needle cover 150. The slots 155 are positioned to be aligned with the locking wings 240 and the locking teeth 340. The slots 155 guide and support the locking wings 240 prior to deployment of the needle cover 150. A cross slot 155a may be provided to aid in the assembly of the auto-injector 100 such that the locking teeth 340 can be inserted in place on the cartridge container 140 through slot 155 in the needle cover 150. Bearing surface 344 can be placed through the slot 155a. Locking projections 156 extend inwardly into the slot 155. The locking projections 156 are configured to engage the locking surface 347a on the locking teeth 340. Multiple projections 156 are provided to correspond to the multiple axle slots 147 in the cartridge container 140 for the bearing axle 341.
An interior groove 157 is provided within the interior of the hollow body 151. The interior groove 157 is axially aligned with the slots 155. A portion of the strut 241 is aligned in the groove 157 when the cover member 150 is in the position shown in
The cartridge 160 includes a generally elongated glass tube having an opening 161 at one end sized to receive the plunger 438 and collet 430. The flange 436 on the collet 430 is designed to contact the end of the cartridge 160 to limit the inward travel of the plunger and collet into the cartridge 160 to control the dosage dispensed through the needle 162. The needle 162 is attached to a hub assembly 163 which is secured to another end of the cartridge 160. The hub assembly 163 may include a diaphragm 164 to prevent the passage of liquid medicament through the needle 162 prior to activation of the auto-injector. The needle 162 is encased in a protective sheath 165. The sheath 165 is secured to the hub assembly 163. The needle 162 pierces the sheath 165 during operation, when the needle 162 projects through the needle cover 150. The cartridge 160, as illustrated, provides a container for a dose of liquid medicament. It is not intended that the auto-injector 100 be limited solely to the use of a single liquid, rather, it is contemplated that one or more liquids may be stored in cartridge 160 that mix upon activation of the auto-injector 100. Furthermore, a solid medicament and a liquid can be separately stored in the cartridge 160 whereby the solid is dissolved in the liquid prior to dispensing.
The operation of the auto-injector 100 will now be described in greater detail. The auto-injector 100 is shown in an unactivated state in
When operation of the auto-injector 100 is desired, the release pin 120 is grasped by the peripheral ledge 124 and pulled to remove the release pin 120 from the end of the auto-injector 100. This readies the auto-injector 100 for operation, as shown in
As shown in
The spring 530 and collet 430 simultaneously force the cartridge 160 and the cartridge container 140 forward toward the open front end of the outer body 110. Once the needle 162 has been extended through the needle cover 150, pressure of the medicament within the cartridge 160 causes the diaphragm 164 to burst permitting the flow of medicament into the user. The drug is forced through the needle 162 allowing the plunger 438 and collet 430 to move further into the cartridge 160. The cartridge container 140 retains the sheath 165 and also prevents the spring force of the spring 530 from being transferred through the cartridge 140 onto the needle cover 150 and the injection site. That is, the force from spring 530 that drives the cartridge 160 forward is opposed by the front end of the cartridge container 140, with the sheath 165 compressed there between, rather than force being received directly by the needle cover 150. In addition, the needle cover spring force is less than the activation force required to collapse the collet to release the collet during actuation. Preferably, the needle cover spring force is about 0.25 to 0.75 of the minimum activation force. The power pack residual spring force after activation is contained within the cartridge container 140, cartridge 160, the outer body 110 and the power pack outer body 230. This arrangement advantageously prevents a kickback effect from occurring. As such, the auto-injector is not pushed away from the injection site during activation to ensure that the proper dose of medicament is administered and the proper needle extended length or proper needle penetration is maintained. This effect would occur if the spring force from the spring 530 were transferred to the needle cover 150 and the injection site, whereby the auto-injector 100 could be pushed away from the injection site and alter the location of the needle 162 within the injection site. This has several negative impacts including startling the patient; changing the injection from an intramuscular to subcutaneous injection, which will affect pk levels. At the same time, the cartridge 160 is advanced within cartridge container 140 (i.e., when the needle 160 goes from a retracted position to extended position). The advancement of the cartridge 160 causes the locking tooth 340 to pivot about the axle 341. This is in response to cartridge 160 contacting bearing surface 342a and pushing the bearing surface 342a away from the main longitudinal axis of the needle 162. This rotation of the locking tooth 340 causes the locking surface 347a to disengage the locking projections 156. The surface 347b limits the rotation of the locking tooth 340. At this point, the needle cover 150 is in an unlocked position such that it can move with respect to the cartridge container 140. The release of the collet 430 from the collet retention surface 332b forces the end of the power pack inner body 330 into contact with the power pack outer body 230.
Once the dose has been injected into the user, the user removes the auto-injector 100 from the injection surface. Since the needle cover 150 is not locked with respect to the cartridge container 140, the spring 153 forces the needle cover 150 out of the outer body 110 to cover the exposed needle 162, as shown in
Safe user operation of the auto-injector is of paramount importance. Various features were tested and studied in user trials to improve safety and usability. One feature in particular, color coding of some injector parts with certain colors, was shown to minimize, if not eliminate, the potential for accidental injection caused by incorrectly orienting the auto-injector. That is, after removing release pin 120, some users mistakenly placed the auto-injector upside down against an injection site, which would have likely resulted in the accidental injection of a thumb or other finger. The user trials indicated that, surprisingly, a blue release pin 120 and an orange needle cover 150 (as opposed to other colors, such as, for example, a green release pin and a red needle cover) best reduced the number of incorrect injector orientations and accidental injections. User trials also indicated that labeling of the needle cover improved injector handling, safety, and usability. For example, needle covers with “NEEDLE END” printed near the tip of the cover, as shown in
The invention having been disclosed in connection with the foregoing embodiment and examples, additional variations will now be apparent to persons skilled in the art. Various modifications and variations to the above described auto-injector can be made without departing from the scope of the invention. The invention is not intended to be limited to the embodiment specifically mentioned and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred embodiments and examples to assess the spirit and scope of the invention in which exclusive rights are claimed.
31. An auto-injector comprising:
- a housing having a needle end and a release pin end;
- at least one cartridge container disposed within the housing;
- a cartridge received within the cartridge container, the cartridge comprising at least one opening and a medicament stored therein;
- a needle assembly to dispense the medicament there through, the needle assembly having a needle, wherein the cartridge is connected to the needle assembly through an assembly or carrier;
- a protective element for the needle, wherein the protective element is pierced by the needle during a medicament dispensing operation;
- an actuation assembly having a first stored energy source capable of driving the needle to permit injection of the medicament into a user, the actuation assembly positioned in the housing, recessed from the release pin end, and operatively coupled to the cartridge;
- a release pin removably attached to the actuation assembly at the release pin end of the housing to prevent inadvertent activation of the auto-injector while the release pin is attached to the actuation assembly, removal of the release pin allowing the auto-injector to be activated;
- a needle cover received and supported within the housing and partially disposed outside of the housing, the needle cover having an end surface for placement against an injection site prior to activation of the auto-injector, the end surface having an area to permit passage of the needle there through after the needle pierces the protective element during the medicament dispensing operation;
- a second stored energy source associated with the needle cover, or operatively connected thereto, that can be displaced from a non-active storage position to an injection position, and further to a post-medicament dispensing position;
- a damping element that prevents a force of the first stored energy source from being transferred through the cartridge onto the needle cover and the injection site; and
- a locking mechanism that locks the needle cover in a first locked position in which the needle cover is in a locked refracted position prior to activation of the auto-injector, and a second locked position in which the needle cover is in a locked extended position after the medicament dispensing operation,
- wherein the needle cover surrounds the needle on all sides outside of the housing to prevent contact with the needle before and after the medicament dispensing operation,
- wherein during the medicament dispensing operation in the injection position, a user holds the auto-injector against the injection site, and continues to hold the auto-injector on the injection site without change during the entire medicament dispensing operation, and
- wherein the auto-injector may be positioned in the non-active storage position, the injection position, and the post-medicament dispensing position, wherein automated actuating or displacement processes take place between the positions and the medicament dispersing operation takes place.
32. The auto-injector of claim 1 wherein the needle cover is operable to be pressed against the injection site to start the medicament dispensing operation.
33. The auto-injector of claim 2 wherein the pressing of the needle cover against the injection site with a predetermined force causes the needle cover to press against the cartridge container, which causes relative linear movement of the cartridge container toward the release pin end, which causes relative movement of the actuation assembly, which activates the medicament dispersing operation.
34. The auto-injector of claim 1 wherein the first and second stored energy sources are springs.
35. The auto-injector of claim 1 wherein the auto-injector has indicia printed thereon to indicate the location of the needle.
36. The auto-injector of claim 5 wherein the indicia comprises the words “needle end.”
37. The auto-injector of claim 1 wherein the auto-injector has indicia printed thereon to indicate that the auto-injector has been used.
38. The auto-injector of claim 7 wherein the indicia comprises the words “used,” “replace,” or a combination of “used” and “replace.”
39. The auto-injector of claim 1 further comprising a diaphragm, wherein relative movement between the diaphragm and an end of the needle allows a communication between the cartridge and the needle, which allows the needle to dispense the medicament.
40. The auto-injector of claim 1 wherein pressing the needle cover toward the release pin end unlocks the locking mechanism.
41. The auto-injector of claim 10 wherein pressing the needle cover causes a communication between the needle cover and the cartridge container that unlocks the locking mechanism.
42. The auto-injector of claim 10 wherein the unlocking of the locking mechanism involves a rotation of locking teeth.
43. The auto-injector of claim 1 wherein the second stored energy source is a spring, wherein the spring urges the needle cover toward the post-medicament dispensing position, and wherein the needle cover is locked when it reaches the post-medicament dispensing position.
44. The auto-injector of claim 1 wherein the locking mechanism comprises locking surfaces on at least the needle cover and the cartridge container.
45. The auto-injector of claim 1 wherein the protective element is attached to the cartridge container.
46. The auto-injector of claim 1 wherein the protective element is a rubber septum.
47. The auto-injector of claim 1 wherein the needle cover requires sufficient linear movement to reach the locked extended position after the medicament dispensing operation.
Filed: Oct 31, 2011
Publication Date: Feb 23, 2012
Applicant: Meridian Medical Technologies, Inc. (Columbia, MD)
Inventors: C. Michael Mesa (Boyds, MD), Sarah Jane Cors (Reston, VA), Melinda Fischer Penney (Providence, RI), Dalita Rosemarie Tomellini (Rehoboth, MA), Mark Bumb Bremley (Edwardsville, IL), John Glyndwr Wilmot (Mount Airy, MD), Matthew Egerton Young (Over Cambs), Sophie Rebecca Raven (Swavesey Cambs), Martin Joseph Murphy (Letchworth Garden City), Christopher John Hurlstone (Newport), Joseph William Daintrey (Royston Herts), Craig Malcolm Rochford (Andover Hants), Stephen Philip Kirkwood (Haynes Beds), Colin James Mathews (Huntingdon), Robert L. Hill (Abingdon, MD)
Application Number: 13/285,820
International Classification: A61M 5/50 (20060101); A61M 5/32 (20060101);