AN AUTO INJECTOR WITH SEPERATE NEEDLE INJECTION

• US 20140207106A1
• Filed: 09/10/2012
• Published: 07/24/2014
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Inventors: Johansen, Esben W., Bechmann, Soeren, Madsen, Flemming
• Granted Patent: US 9,775,948 B2
• Time in Patent Office: Days
• US Class Current: 604/506
• CPC Class Codes: A61M 2005/2013 triggering of discharging means by contact of injector with patient body
• CPC Class Codes: A61M 2005/202 cocking means, e.g. to bias the main drive spring of an injector
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/3267 Biased sleeves where the needle is uncovered by insertion of the needle into a patient's body
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 5/002 Packages specially adapted therefor, e.g. for syringes or needles, kits for diabetics needle protection, e.g. caps, A61M5/3202; for sharps A61B50/3001
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• CPC Class Codes: A61M 5/3157 Means providing feedback signals when administration is completed A61M5/20 takes precedence
• CPC Class Codes: A61M 5/3204 Needle cap remover, i.e. devices to dislodge protection cover from needle or needle hub, e.g. deshielding devices
• CPC Class Codes: A61M 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user

Abstract

An auto injector having sequential control of needle insertion and dose injection is disclosed. A syringe with a needle is movably positioned in a housing between a first position in which the needle is accommodated inside the housing and a second position in which the needle protrudes outside the housing. A plunger rod tube has at least one locking member configured to normally lock a plunger rod to the plunger rod tube. A syringe driver applies a force to the syringe to move the syringe together with plunger rod tube, plunger rod and plunger rod driver from the first position to the second position. In the second position, the locking member is unlocked and releases the plunger rod to thereby activate the plunger rod driver to advance the plunger rod in the syringe for delivering of at least one dose of medicament.

Claims

1-54. -54. (canceled)

55. An auto injector having sequential control of needle insertion and dose injection, the auto injector having a housing for accommodation of

a syringe with a needle, the syringe being movably positioned in the housing between a first position in which position the needle is accommodated inside the housing and a second position in which position the needle protrudes outside the housing,

a plunger rod configured to be advanced in the syringe for delivering at least one dose of medicament,

a plunger rod tube having at least one locking member configured to interact with a plunger rod stop to normally lock the plunger rod to the plunger rod tube,

a syringe driver configured to apply a force to the syringe thereby moving the syringe from the first position to the second position, the syringe driver being further configured to advance the plunger rod tube with the plunger rod to the second position,

a plunger rod driver being configured to apply a force to the plunger rod to advance the plunger rod in the syringe for delivering at least one dose of medicament,

wherein the housing is configured to unlock the locking member and release the plunger rod from the plunger rod tube when the syringe and the plunger rod tube is advanced to the second position, thereby activating the plunger rod driver to advance the plunger rod in the syringe for delivering of at least one dose of medicament,

wherein the locking member comprises at least one deflectable member and wherein the housing is configured to allow for the at least one deflectable member to enable deflection away from the plunger rod when the syringe and the plunger rod tube is advanced to the second position.

56. An auto injector according to claim 55, wherein the plunger rod tube and the syringe are interconnected so that the plunger rod tube cannot move in a longitudinal direction with respect to the syringe and vice versa,

wherein the housing has an opening (such as a window) configured to be aligned with the at least one deflectable member when the plunger rod tube is advanced to the second position.

57. An auto injector according to claim 56, wherein the at least one deflectable member is configured to deflect upon being aligned with the opening in the housing.

58. An auto injector according to claim 55, wherein the plunger rod driver comprises a plunger rod spring,

wherein the plunger rod spring in one end is fixedly connected to the plunger rod tube.

59. An auto injector according to claim 55, wherein the plunger rod driver applies the driving force directly onto the plunger rod, such as onto a plunger rod flange.

60. An auto injector according to claim 55, wherein the housing further accommodates a syringe tube for holding the syringe, and wherein the syringe having a syringe flange is locked between the syringe tube and the plunger rod tube.

61. An auto injector according to claim 55, wherein the plunger rod driver is provided inside the plunger rod tube, and wherein the syringe driver is provided outside the plunger rod tube.

62. An auto injector according to claim 55, wherein an inner surface of the housing prevents the at least one deflectable locking member from deflecting,

wherein, upon release of the plunger rod, the plunger rod driver advances the plunger rod within the syringe in that the plunger rod stop is able to pass the deflected locking member.

63. An auto injector according claim 55, wherein plunger rod stop has an angled surface normally pressing against an angular surface of the deflectable locking member, wherein the at least one deflectable locking member is hinged to the plunger rod tube in a downward position with respect to the movement of the plunger rod.

64. An auto injector according to claim 55, wherein the auto injector is reloadable.

65. An auto injector according claim 55, wherein the plunger rod tube comprises at least a first and a second locking member (such as at least a first and a second deflectable member) configured to sequentially engage with the plunger rod stop,

wherein the housing comprises a first and a second opening configured to align with at least the first and second locking member, respectively, when the syringe is in the second position.

66. An auto injector according to claim 64, wherein the auto injector is configured to deliver two or more separate doses of medicament.

67. An auto injector according to claim 64, wherein the plunger rod driver is configured to move the plunger a first distance upon a first activation of the plunger rod driver, and a further distance upon a further activation of the plunger rod driver.

68. An auto injector according to claim 67, wherein the second activation of the plunger rod driver follows a reload of the auto injector, and a repeated movement of the syringe assembly from the first position to the second position.

69. An auto injector according to claim 64, further comprising a reload handle configured to reload the auto injector and wherein the user operation of the reload handle comprises a rotational movement,

wherein the reload handle is configured for a rotational movement, the auto injector further comprising an intermediate component (torsion ring) transferring the rotational movement of the reload handle to a (translational or lateral or) axial movement of at least the syringe assembly, wherein the intermediate component has a tap configured to move along an inclined surface of the reload handle upon operation of the reload handle,

wherein a complete operation of the reload handle forces the tap over an inclined surface top and into a second reload handle slot,

wherein the second reload handle slot has an inclined surface to allow for continuous reloading to the auto injector,

wherein the second reload handle slot allows for longitudinal movement only to thereby prevent further reload of the auto injector.

70. An auto injector according to claim 64, wherein the reload operation is configured to reverse the operation of the auto injector.

71. An auto injector according to claim 55, further comprising a syringe lock configured to lock the syringe in the first position, and a skin sensor configured to release the syringe lock upon engagement with the skin of a user wherein the skin sensor is activated by pressing the skin sensor onto a user'"'"'s skin,

wherein the activation of the skin sensor is configured to cause an upward movement of the skin sensor whereby a skin sensor angled surface is configured to engage with a syringe lock angled surface translating the lateral motion of the skin sensor into angular motion of the syringe lock.

72. An auto injector according to claim 71, wherein the syringe assembly rests on a ledge in the syringe lock to lock the syringe in the first position and wherein the angular motion of the syringe lock releases the syringe assembly.

73. An auto injector according to claim 55, wherein the plunger rod tube comprises a plunger rod tap, the plunger rod tap being configured to move in a syringe lock guide slot from a released position adjacent the ledge to a syringe lock end stop,

wherein the syringe is moved from the first position to the second position when the plunger rod tap travels in the syringe lock guide slot from the released position to the syringe lock end stop.

74. An auto injector according to claim 55, wherein forward motion of the syringe in the second position is restricted by the plunger rod tap engaging a syringe lock end stop,

wherein a skin sensor driver upon removal of the auto injector from a user'"'"'s skin is configured to push the skin sensor forward to shield the needle after each injection cycle.

75. An auto injector according to claim 55, wherein the syringe assembly comprises a syringe tube co-axially encompassing the syringe and a plunger rod tube co-axially encompassing the plunger rod, the syringe tube and the plunger rod tube being interconnected via syringe tube connectors engageable with plunger rod tube connectors,

wherein the syringe assembly is configured to rest on a syringe lock ledge when the intermediate component tap is provided in the first or second handle slot,

wherein the reload operation is configured to reverse syringe driver, syringe lock, skin sensor, etc.

76. An auto injector according to claim 55, wherein the auto injector housing further comprises an indicator for indicating a “

ready”

state and a “

not ready”

state,

wherein the “

ready”

state indicates a first rotational position of the syringe lock in which position the syringe assembly is locked in the first position.

77. An auto injector according to claim 55, wherein a skin sensor extends over the length of the needle when the syringe assembly is in the first position to hide the needle from a user'"'"'s view,

wherein the skin sensor is configured to extend over the length of the needle as the needle is withdrawn after a dose has been delivered,

wherein the skin sensor has a locked forward position and an unlocked forward position,

wherein the skin sensor is unlocked in the forward position upon operation of the reload handle.

78. An auto injector according to claim 55, wherein the auto injector further comprises a sound generator configured to emit a sound while dosing,

wherein the sound generator comprises a ratchet mechanism,

wherein the ratchet mechanism comprises flexible arms positioned with the syringe assembly for engaging sloped teeth on the plunger rod,

wherein the ratchet mechanism allows for forward movement only of the plunger rod.

79. An auto injector according to claim 55, wherein the syringe assembly further comprises an anti-tamper component,

wherein the anti-tamper component comprises a protection mechanism to ensure that backward movement of the plunger rod is prevented.

80. An auto injector according to claim 55, wherein the auto injector is re-usable,

wherein the syringe assembly is replaceable.

81. An auto injector having sequential control of needle insertion and dose injection, the auto injector having a housing for accommodation of

a syringe with a needle, the syringe being movably positioned in the housing between a first position in which position the needle is accommodated inside the housing and a second position in which position the needle protrudes outside the housing,

a plunger rod configured to be advanced in the syringe for delivering at least one dose of medicament,

a plunger rod tube having at least one locking member configured to interact with a plunger rod stop to normally lock the plunger rod to the plunger rod tube,

a first spring configured to apply a force to the syringe thereby moving the syringe from the first position to the second position, the first spring being further configured to advance the plunger rod tube with the plunger rod to the second position,

a second spring configured to apply a force to the plunger rod to advance the plunger rod in the syringe for delivering at least one dose of medicament,

wherein the at least one locking member is configured to be unlocked upon advancing the plunger rod tube with the plunger rod to the second position thereby unlocking the plunger rod from the plunger rod tube and allowing the second spring to advance the plunger rod in the syringe.

82. A method of delivering a dose of medicament using an auto injector, wherein the auto injector has a housing for accommodation of a syringe assembly, the syringe assembly comprising a syringe with a needle, the syringe being movably positioned in the housing between a first position in which position the needle is accommodated inside the housing and a second position in which position the needle protrudes outside the housing, a plunger rod configured to be advanced in the syringe for delivering at least one dose of medicament, a plunger rod tube having at least one locking member configured to interact with a plunger rod stop to normally lock the plunger rod to the plunger rod tube,

the method comprising the steps of

activating a syringe driver to apply a force to the syringe thereby moving the syringe from the first position to the second position, and further advancing the plunger rod tube with the plunger rod to the second position,

in the second position, unlocking the at least one locking member and activating a plunger rod driver to apply a force to the plunger rod to thereby advance the plunger rod in the syringe for delivering at least one dose of medicament,

wherein the syringe driver is a first spring and the plunger rod driver is a second spring.