WO2007129324A2

WO2007129324A2 - A disposable injecting device with auto-retraction mechanism

Info

Publication number: WO2007129324A2
Application number: PCT/IL2007/000558
Authority: WO
Inventors: Gil Yigal
Original assignee: Gil Yigal
Priority date: 2006-05-09
Filing date: 2007-05-09
Publication date: 2007-11-15
Also published as: WO2007129324B1; WO2007129324A3

Abstract

A disposable auto-injector that facilitate full automation of injection process including auto retraction of the needle into the device at end of delivery without the associated drawbacks that currently exist. The disposable auto-injector comprises a syringe barrel which is opened distally with an outer finger's flange; a needle mounted in the hub of the barrel; a plug slidably located within the barrel; liquid medication delimited inside the barrel between the plug and the needle; and a plunger rod abuts the back of the plug. The injector device utilizes a reservoir containing liquid medication and a needle for delivering the medication that by releasing a safety catch and forcing the device against the injection sight, may automatically manipulate the reservoir and the needle to perform needle penetration into injection sight, drug delivery, and needle retraction at end of delivery.

Description

A DISPOSABLE INJECTING DEVICE WITH AUTO-RETRACTION MECHANISM

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 USC 119(e) from US provisional application

60/798,482 filed May 9^th, 2006, the disclosure of which is included herein by reference.

FIELD OF THE INVENTION

[Para 1 ] The present invention relates to injecting devices and in particular to disposable automatic injecting devices for injecting a predetermined dose of medication, including auto retraction of the needle after the injection of the dose of medication is terminated.

BACKGROUD AND PRIOR ART

[Para 2] Today, disposable auto injectors are mainly intended for use in acute illness such as rheumatoid arthritis (RA) and multiple sclerosis (MS), and in allergic or migraine attack, and in event of chemical warfare.

[Para 3] Auto injecting devices, being self used by patients with limited dexterity, should be very convenient and easy for use.

[Para 4] Auto injecting devices, being continuously carried by the user, should be compact and equipped with a safety catch.

[Para 5] Auto injecting devices, being intended for emergency situations and to be used by untrained patients, should facilitate instant unlocking capabilities, and intuitive injection activation with minimum operation steps.

[Para 6] Auto injecting devices, being disposable, should be of low cost and capable of utilizing standard pre-filled syringes or cartridges.

[Para 7] In general, all auto-injectors aim to automate the injection process to enable a user, spatially a self user, to perform injection in safety and convenience. The injection process includes the following steps: a) a needle penetrating into the tissue; b) delivering the dose; and c) retracting the needle back into the device.

[Para 8] Prior art auto-injectors facilitate auto penetration and auto delivery, but are having difficulties to auto retract the needle. Prior art auto-injectors fail to provide a reliable and accurate mechanism for instantly retracting the needle very close to end of the dosage delivery, such that only a minimal and repeatable residual volume of liquid is left in the injector, and prior art auto-injectors fail to provide such a mechanism that would be simple and cost effective. An attempt to overcome the problem of inaccuracy and reliability in facilitating auto retraction of the needle is described in application No. WO2005115512 ('512). Application '512 describes a two-part drive, incorporating a fluid-damped delay mechanism that is activated close to end of delivery, enabling the needle retraction to occur even after the plug has reached the bottom of the syringe barrel, thereby ensuring complete discharge of the syringe contents. The drawback of this method is in being complicated and expansive and the anxiety of contamination by involving of liquid. [Para 9] A common trend in prior art auto-injectors is to compromise on: a) A passive shielding of the needle upon removal of the injector from the injection site is provided by a spring biased sleeve (US Patents No. 5,137,516 and 6,932,793). But passive shielding of the needle does not provide an end of delivery indication, causing the user to hold the device attached to the body much longer than actually needed and still, the user removes the needle with some uncertainty with respect to the completion of the medication delivery. b) A needle retracting mechanism that is manually triggered by the user after the drug delivery has been completed is provided in US Patent No. 6,159,181. The user obtains indication that the drug delivery is completed by inspecting, through a window in the drug reservoir, that the syringe plug has reached the bottom of the reservoir. This indication is not definite, often inconvenient and depending on the location of the delivery site. One more disadvantage refers to safety issues resulted from the fact that the user might forget to activate the needle retraction, and thus leave the needle projected with the risk of injury by a possibly contaminated needle. Another disadvantage refers to the user's inconvenience as a result of applying activities and responsibilities on the user.

[Para 10] Auto retraction at the end of the medication delivery, however, facilitates an end of delivery indication, as the retraction of the drag reservoir and the needle back into the injecting device is typically heard and felt by the user. Another advantage of auto retraction is the increase in safety resulting from the independence of the user consciousness. One more advantage is the user's relief feeling, knowing that the needle is no longer in the user's body. [Para 11] However, prior art auto-injectors, such as described in US Pat. No. 6,387,078, do not maintain uniformity in drug delivery, during injection. The space and guidance appropriation for the driving source (typically a compressed spring) results in a very high liquid flow at the beginning of the delivery process and/or a very low liquid flow rate at the end of the delivery process. [Para 12] Thus, there is a need and it will be advantageous to have disposable auto- injectors that facilitate full automation of the injection process, including auto retraction of the needle into the device at end of delivery, wherein substantially all the pre-filled medication is repeatably delivered, while maintaining a low cost and simple device.

SUMMARY OF THE INVENTION

[Para 13] The injecting device of the present invention is an elongated device having a substantially tubular body, including a central axis. The components of the injecting device of the present invention are also generally elongated with a substantially tubular structure. The injecting device of the present invention is operatively directional, designed to inject liquid medication into a tissue at target injection site. The term "proximal end" of the injecting device, or an elongated component thereof, as used herein, refers to the end being proximal to the target injection site. The term "distal end" of the injecting device, or an elongated component thereof, as used herein, refers to the end being distal from the target injection site.

The term "distally", as used herein, refers to a direction of movement or direction of forces means a direction towards the distal end of the injecting device. The term "proximally", as used herein, refers to a direction of movement or direction of forces means a direction towards the proximal end of the injecting device.

[Para 14] The term "initial" state and/or position of the injecting device or a component thereof, as used herein, refers to the state and/or position of the injecting device before operation.

[Para 15] The term "potential energy stored" in a spring, as used herein, refers to the energy stored in a spring in a compressed state.

[Para 16] A principal intention of the present invention is to provide disposable auto- injectors that facilitate full automation of injection process including auto retraction of the needle into the device at end of delivery without the drawbacks prior art automatic injectors. [Para 17] The injecting device of the present invention operates a reservoir containing liquid medication and a needle providing a passageway for delivering the medication from the reservoir into the tissue during injection. The medication reservoir includes: (i) a barrel, wherein the barrel is narrowed and closed at the barrel proximal end and opened at the barrel distal end; (ii) a plug, wherein the plug is slidably disposed inside the barrel; (iii) a plunger rod, wherein the proximal end of the plunger rod extends into the opening at the distal end of the barrel; and (iv) a liquid medication contained in a chamber formed inside the barrel between the proximal end of the barrel and the plug. The needle is arranged to deliver the medication from the reservoir into the injection site. By releasing a safety catch and forcing the device against an injection site, the injecting device automatically manipulates the reservoir and the needle to perform needle penetration into the injection site, medication dose delivery, and needle retraction at the end of the delivery. The needle is either affixed to the proximal narrowed end of the reservoir barrel or is part of a separate needle assembly, and is automatically connected to the reservoir at the beginning of injection process. [Para 18] According to the present invention there is provided a disposable iηj ection device for automatically extend the needle for penetrating the tissue of a user, deliver a predetermined dose of medication stored in the medication reservoir into the tissue, and automatically retracts from the injection site, leaving substantially no residual volume of medication in the reservoir. The injection device includes: a) a housing; b) an internal assembly including: an inner sleeve, a driving sleeve and a propelling spring located and acting between the inner sleeve and the driving sleeve. The inner sleeve is initially disposed with free peripheral space inside a bore of the driving sleeve. The propelling spring is disposed inside the free peripheral space. The driving sleeve and the inner sleeve are initially interlocked, thereby restraining the propelling spring in a compressed state inside the free peripheral space; and c) a return spring with a stored potential energy significantly smaller with respect to the residual energy of the propelling spring. The return spring is being compressed during an injection process, and performs automatic retraction of the medication reservoir and needle, upon termination of the injection process. The return spring is substantially uncompressed when the medication reservoir is in a retracted position.

[Para 19] The driving sleeve, upon unlocking the initial interlock of the inner sleeve with the driving sleeve, is being driven proximally by the propelling spring and the inner sleeve is axially disposed in a determined location with respect to the housing, at least during an injection.

[Para 20] The driving sleeve further includes at least one arm extending distally and operatively engaged with the distal end of the plunger rod. When the driving sleeve is driven proximally, the arm, being part of the driving sleeve, pulls the plunger rod proximally, and with the friction between the plug and the barrel of the reservoir and the resistance of the medication, moving the medication reservoir from the retracted position to the forward position, while compressing the return spring. The medication reservoir is stopped by the inner sleeve. Then, the plunger rod drives the plug proximally along the barrel of the reservoir, thereby expelling the liquid medication through the passageway in the needle. [Para 21 ] The distal end of the inner sleeve includes an outer flange, which contains at least one notch on the circumference of the flange, enabling the at least one arm to pass through the outer flange towards the distal ends of the plunger rod.

[Para 22] The arm is arranged to be disposed outwardly, at least during injection. When the distal end of the arm is engaged with the distal end of the plunger rod, the engagement is obtained by providing an inwardly projection at the distal end of the arm, wherein the inwardly projection abuts an outer face of the distal end of the plunger rod by an outwardly inclined face of the projection, and wherein the projection is disposed inwardly towards the device central axis, respective to a higher distance from the central axis of a vector of force pulling the arm being, thereby creating an outwardly moment on the arm, and thereby causing an outwardly disposition of the arm.

[Para 23 ] The medication reservoir is stopped by the inner sleeve, when the narrowed proximal end of the barrel of the medication reservoir encounters an inwardly peripheral extension, extending from the inner wall of the inner sleeve at the proximal end of the inner sleeve or a few millimeters distally from the proximal end of the inner sleeve. [Para 24] In embodiments of the present invention, the medication reservoir is stopped by the inner sleeve when a finger flange at the distal end of the medication reservoir encounters the distal end of the inner sleeve.

[Para 25] The housing includes a gripping barrel and a triggering barrel. The triggering barrel is slidably adopted inside the gripping barrel through and partially projected from the proximal opened end of the triggering barrel.

[Para 26] The triggering barrel is initially in a rest position. The triggering barrel is distally moved a small distance into the gripping barrel to reach a triggering position. An injection is triggered when an external force is applied to operate a distal movement of the triggering barrel from the rest position to the triggering position, thereby causing the internal assembly to unlock the initial interlock of the inner sleeve with the driving sleeve. [Para 27] The gripping barrel, having an inner wall, further includes a longitudinal supports for supporting the arms of the driving sleeve. The longitudinal supports holds against the outwardly disposition of the arms, thereby preventing the arm from being deformed outwardly and maintaining the engagement of the arm with the plunger rod, along the movement of the driving sleeve. The longitudinal support has a proximal end in a pre-designed location, where the longitudinal support stops supporting the arm. The location is designed such that substantially all of the medication is delivered. At that time, the outwardly moment on the arm causes an outwardly deformation of the arm, disengaging the arm from the plunger rod, and thus enabling the compressed return spring to force the medication reservoir back to the retracted position.

[Para 28] During injection, the inner sleeve is axially situated in a pre-determined location with respect to the housing. When the external force is applied to bias the triggering barrel distally, the distal end of the triggering barrel biases the proximal side of the outer flange of the inner sleeve, forcing the outer flange against an internal abutment on the inner wall of the gripping barrel, which abuts the distal side of the outer flange of the inner sleeve.

[Para 29] The unlocking of the initial interlock of the inner sleeve with the driving sleeve is obtained by a limited rotation of the inner sleeve respectively to the driving sleeve. The inner sleeve and the driving sleeve contain locking elements designed to be unlocked by the limited rotation.

[Para 30] When the triggering barrel is moved distally into the triggering position, the distal movement of the triggering barrel is translated to a limited rotation of the inner sleeve, wherein the driving sleeve is prevented from rotating by the at least one arm of the driving sleeve, guided by designated limiting ribs on the inner wall of the gripping barrel. [Para 31 ] The triggering barrel contains at least one inclined side wall at the distal end of the triggering barrel, and the inner sleeve contains at least one notch in the outer flange. When the triggering barrel moves distally, each of the inclined side walls of the triggering barrel biases an adjacent side wall of a notch in the outer flange of the inner sleeve, to rotate the inner sleeve, while the outer flange of the inner sleeve is abutted by an internal abutment on the inner wall of the gripping barrel, and thereby preventing a distal movement of the inner sleeve. [Para 32] The propelling spring, which is initially restrained inside the free peripheral space created by the interlocked driving sleeve and the inner sleeve, is supported at a first end by the outer flange of the inner sleeve and supported at a second end by an inwardly peripheral abutment at the proximal end of the driving sleeve.

[Para 33] The inner sleeve and the driving sleeve contain locking elements designed to be unlocked by the limited rotation. The inner sleeve includes longitudinal grooves opened proximally and ending distally with notches extending radially from the distal ends. [Para 34] The driving sleeve further includes dowels extending inwardly from the proximal end, wherein the dowels extend closer to the central axis of the device respectively to the abutment for supporting the propelling spring. The interlock is obtained by engaging the dowels with the notches. Upon rotating the inner sleeve with respect to the driving sleeve, the dowels disengage from the notches and engage the longitudinal grooves, thereby enabling the driving sleeve to be driven proximally. [Para 35] In embodiments of the present invention, the medication reservoir is a pre-filled syringe ending proximally with a hub having an orifice, and with the needle initially coupled to the orifice of the hub. The syringe is in the forward position, and is initially sealed closed at the proximal end by a needle shield covering the needle. The distal end of the needle shield is abutted by the front face of the inwardly peripheral extension of the inner sleeve. The needle shield is encircled by a releaser, having a substantially cylindrical body. The releaser is arranged to release and remove the sealing coupling of the needle shield. The releaser further includes a small sectioned arms ending with small inwardly projections, arranged to release the sealing coupling and support the needle shield during removal. The release is obtained by distally pushing the releaser by an external force, thereby pushing the narrowed end of the syringe by the inwardly projections of the arms. The syringe moves distally to the retracted position, while the distal end of the needle shield is being abutted by the inwardly peripheral extensions of the inner sleeve, thereby preventing the needle shield from moving distally. The removal of the needle shield is obtained by the inner side of the inwardly projections abutting the distal end of the needle shield, thereby being removed together with the releaser, when the later is removed.

[Para 36] In embodiments of the present invention, the releaser serves as a safety catch. The releaser couples the inner sleeve to the triggering barrel, thereby preventing rotation of the inner sleeve with respect to the triggering barrel. The safety catch is canceled when the releaser is removed.

[Para 37] In embodiments of the present invention, the releaser includes longitudinal ribs, which are fitly inserted through notches in the opening at the proximal end of the triggering barrel, and through grooves in the inner sleeve, thereby preventing the rotation of the inner sleeve with respect to the triggering barrel.

[Para 38] In embodiments of the present invention, the medication reservoir is a cartridge closed proximally with a piercable stopper. The needle is part of a needle assembly including a cannula sharpen at both ends and a middle wall for initially holding the needle proximally to the cartridge with the distal end of the cannula adjacent to the stopper. [Para 39] In embodiments of the present invention, the injecting device includes a longitudinal window for inspecting the medication barrel. The window includes respective openings in the gripping barrel, the triggering barrel and the inner sleeve. [Para 40] In embodiments of the present invention, the triggering barrel includes a safety catch preventing distal movement of the triggering barrel, thereby preventing activation of an injection.

[P a ra 41 ] In embodiments of the present invention, the safety catch limits the rotation of the triggering barrel with respect to the gripping barrel. The safety catch is operable to free the blocking by a limited rotation of the triggering barrel with respect to the gripping barrel. [Para 42] In embodiments of the present invention, the safety catch is a blocking element, which prevents the triggering barrel from moving with respect to the gripping barrel. The safety catch is operable to free the blocking by removing of the blocking element. [Para 43] In embodiments of the present invention, the safety catch is a blocking element, which is engaged with the flange of the inner sleeve, thereby preventing the rotation of the inner sleeve with respect to the driving sleeve. The safety catch is operable to free the blocking by removing of the blocking element.

[Para 44] The present invention includes a method for automatically inject a predetermined dose of medication into a tissue at a target injection site, using an injecting device according to the present invention. The method includes distally moving the triggering barrel with respect to the gripping barrel, there releasing the interlock of the inner sleeve and the driving sleeve.

[Para 45] The present invention includes a method for removing a needle shield using a releaser including the steps of: a) forcing a releaser distally towards the injecting device, thereby disengaging the needle shield from the medication reservoir; and b) withdrawing the releaser together with the needle shield.

BRIEF DESCRIPTION OF THE DRAWINGS

[Para 46] The present invention will become fully understood from the detailed description given herein below and the accompanying drawings, which are given by way of illustration and example only and thus not limitative of the present invention, and wherein:

FIGs. Ia, Ib and Ic illustrate prospective views of an automatic injection device according to embodiments of the present invention, showing the device from the outside and from the inside through a section and semi section view;

FIG. 2 is a prospective view illustration of the main components of an automatic injection device according to embodiments of the present invention; FIG. 3 is a section view illustration of the automatic injection device shown in Figure 2;

FIG. 4 is a prospective and section views of the internal assembly of an automatic injection device according to embodiments of the present invention;

FIG. 5 defines by illustration cross sections A-A and B-B of an automatic injection device according to embodiments of the present invention.

FIG. 6a illustrates a B-B section view of an automatic injection device with the internal assembly in a locked position, according to embodiments of the present invention;

FIG. 6b illustrates a B-B section view of the device with the internal assembly shown in

Figure 6a, in an unlocked position;

FIG. 7 is a perspective view illustration of an automatic injection device according to embodiments of the present invention, secured with a safety catch;

FIG. 8 is a perspective view illustration of the device shown in Figure 7, with the safety catch released;

FIG. 9 is a perspective view illustration of the device shown in Figure 7, triggered for injecting;

FIG. 10 illustrates an A-A section view of an automatic injection device according to embodiments of the present invention, in the position shown in Figure 8;

FIG. 11 illustrates an A-A section view of an automatic injection device according to embodiments of the present invention, in the position shown in Figure 9;

FIG. 12 illustrates an A-A section view of the device shown in Figure 7, with the needle projected for tissue penetration;

FIG. 13 illustrates an A-A section view of the device shown in Figure 7, after the delivery of the medication;

FIG. 14 illustrates an A-A section view of the device shown in Figure 7, with the driving sleeve disengaged from the plunger rod;

FIG. 15 illustrates an A-A section view of the device shown in Figure 7, after the needle retracts into the device;

FIG. 16 illustrates an A-A section view of an automatic injection device, according to embodiments of the present invention, utilizing a pre-filled cartridge and a needle assembly, in rest position;

FIG. 17 illustrates an A-A section view of the device shown in Figure 16, after being triggered for injecting;

FIG. 18 illustrates an A-A section view of the device shown in Figures 16 and 17, with the needle projected for penetrating the tissue target injection site; FIG. 19a is a section view illustration of another embodiment of an automatic injection device according to embodiments of the present invention, with an extractor that facilitates removal of the needle shield when utilizing pre-filled syringes;

FIG. 19b is a section view illustration of the device shown in Figure 19a, after forcing the extractor distally inwards the device);

FIG. 19c is a section view illustration of the device shown in Figures 19a and 19b, after removing of the extractor with the needle shield from the device;

FIG. 20 is a semi section view illustration of the device shown in Figures 19a, 19b, and 19c, in the position shown in Figure 19a but with the syringe and the needle shield hidden; and

FIG. 21 is a prospective view illustration of the device shown in Figures 19, 20 and 21, in the position shown in Figure 19c.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION [Para 47] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided, so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[Para 48] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods and examples provided herein are illustrative only and not intended to be limiting.

[Para 49] The preferred embodiment of the invention will now be described with reference to Figures Ia-Ic, which illustrates prospective views of an automatic injection device 100 according to embodiments of the present invention, showing device 100 from the outside and from the inside through a section and semi section view. Injecting device 100 consists of an internal assembly 400, which is housed inside gripping barrel 50 and triggering barrel 60, and holds a standard pre-filled syringe 30.

[Para 50] Reference is also made to Figures 2 and 3, which illustrate prospective and section views of the main components of automatic injection device 100 and a standard pre- filled syringe 30. The standard pre-filled syringe 30 consists of: a) a syringe barrel 31 that is opened distally with an outer finger's flange 32 and narrowed to a neck ending with a hub 37 in syringe barrel 31 proximal end; b) a needle 33 is coupled to the orifice of hub 37 of syringe barrel 31 and extended proximally, initially housed with needle shield 39. Needle shield 39 includes an elastomeric cap, which covers needle 33 and is sealed fitted to the outer radii of hub 37 of syringe barrel 31. Needle shield 39 may also include a rigid plastic cap which covers the elastomeric cap; c) a plug 34, slidably located inside syringe barrel 31; d) liquid medication delimited inside syringe barrel 31 between plug 34 and needle 33; and e) a plunger rod 35 abuts the back of plug 34, extends distally out of syringe barrel 31 and ends with a disk 36.

[Para 51] Gripping barrel 50 is closed at the distal end and opened at a proximal end. Triggering barrel 60 is opened distally and closed with a head section 63 in the proximal end. Head section 63 has a small opening 64 at the center of the head to allow the projection of needle 33.

[Para 52] Reference is now made to Figure 4, which is a prospective and section views of the internal assembly 400 of automatic injection device 100, according to embodiments of the present invention. Internal assembly 400 consists of inner sleeve 410, driving sleeve 420, propelling spring 430 and return spring 440.

[Para 53 ] Inner sleeve 410 is initially disposed with free peripheral space within a bore of driving sleeve 420 and axially locked to driving sleeve 420 by designated locking elements 413 and 422. Propelling spring 430 is slidably cooperated within the free peripheral space, between the interior bore of driving sleeve 420, and the outer radial face of inner sleeve 410. Inner sleeve 410 contains an outer flange 411 at the distal end of inner sleeve 410, and inwardly peripheral extension 412 in the proximal end of inner sleeve 410. The interior bore of inner sleeve 410 includes a section with wider diameter 415 ending with inner step 416. Inner sleeve 410 further includes longitudinal grooves 414 opened proximally and ending distally with radial notches 413. Driving sleeve 420 contains at least one gripping arm 423 elongated distally operable to deform outwardly, whereby each of gripping arms 423 is ended with an inwardly projection 424.

[Para 54] Driving sleeve 420 further contains an inner rim 421 on the proximal end of driving sleeve 420, and dowels 422 extending inwardly from inner rim 421. Dowels 422 are initially interlocked with radial notches 413 to disable any axial movement between inner sleeve 410 and driving sleeve 420, while locking propelling spring 430 in a compressed position, biased between outer flange 411 of inner sleeve 410 and inner rim 421 of driving sleeve 420.

[Para 55] Figure 5 defines by illustration cross sections A-A and B-B of automatic injection device 100, according to embodiments of the present invention. Referring is also made to Figure 6a which illustrates a B-B section view of automatic injection device 100 with internal assembly 400 in a locked position, and to Figure 6b, which illustrates a B-B section view of automatic injection device 100 with internal assembly 400 in an unlocked position. Pre-filled syringe 30 is slidably cooperated within the interior bore of inner sleeve 410 of internal assembly 400, whereby the distal end with outer finger's flange 32 extends distally from inner sleeve 410. Return spring 440 is wrapped over barrel 31 of pre-filled syringe 30 with the first end of return spring 440 resting against interior step 416 of inner sleeve 410, and the other end of return spring 440 biases finger's flange 32 of syringe barrel 31. [Para 56] Referring now to Figure 7, which is a perspective view illustration of automatic injection device 100 according to embodiments of the present invention, secured with a safety catch. Gripping arms 423 of driving sleeve 420 elongated distally beyond the distal end of plunger rod 35 in a way that the inwardly projections 424 at end of arms 423 overlapping disc 36 from the outer side of plunger rod 35 (back support).

[Para 57] Referring back to Figures 6b and 7, internal assembly 400 containing pre-filled syringe 30 therein is arranged within gripping barrel 50 with gripping arms 423 of driving sleeve 420 disposed distally, each arm 423 is slidably located between two parallel limiting ribs 51, which are contained longitudinally along the inner wall of gripping barrel 50, to enable axial movement and to eliminate rotational movement of driving sleeve 420. [Para 58] Referring back to Figures 2 and 7, triggering barrel 60 is slidably fitted within the interior of gripping barrel 50 with head 63 projected proximally from gripping barrel 50. Triggering barrel 60 is axially locked with respect to gripping barrel 50 by dowels 65, which are located on leaves 68, interlacing the radial section of "L" shaped groove 51. [Para 59] Referring back to Figures 6-7, internal assembly 400 is longitudinally fixed within injector 100 by supporting outer flange 411 of inner sleeve 410 from the outside with the ends of the stopping ribs 52 (formed longitudinally along the inner wall of gripping barrel 50), and from the inside by abutment faces 66 at the distal end of triggering barrel 60. [Para 60] Reference is now made to Figure 8, which is a perspective view illustration of device 100 shown in Figure 7, with the safety catch released, and to Figure 9, which is a perspective view illustration of the device 100, triggered for injecting. For unlocking device 100, triggering barrel 60 is rotated with respect to the gripping barrel 50 until dowels 65 reach the routes of the axial section of the "L" shaped grooves 51, whereby abutment faces 66 no longer abut outer flange 411 and slants 67 of triggering barrel 60 (close to abutments 66) become tangent to a side wall 417 of the notch in outer flange 411.

[Para 61] When injector 100 is pressed against a target injection site, triggering barrel 60 is forced to slide distally towards gripping barrel 50 while dowels 65 slide along the axial section of the "L" shaped grooves 51, thus eliminating rotational movement of triggering barrel 60.

[Para 62] Referring back to Figures 6, reference is also made to Figure 10, which illustrates an A-A section view of injection device 100 according to embodiments of the present invention, in the position shown in Figure 8, and to Figure 11, which illustrates an A- A section view of injection device 100 according to embodiments of the present invention, in the position shown in Figure 9. The distally movement of triggering barrel 60 cause slants 67 to bias side wall 417 in outer flange 411, causing inner sleeve 410 to rotate with respect to driving sleeve 420, whereas the driving sleeve 420 is rotationally limited by limit ribs 51. Inner sleeve 410, when biased by slants 67 of triggering barrel 60, is abutted by the ends of stopping ribs 52 of gripping barrel 50 for preventing distal movement of inner sleeve 410. The proportional rotation of inner sleeve 410 with respect to driving sleeve 420, causes the disengagement of dowels 422 in driving sleeve 420 from notches 413 in inner sleeve 410, thereby eliminating the axial lock and enabling propelling spring 430 to propel driving sleeve 420 proximally, while inner sleeve 410 is fixed to the gripping barrel 50 by outer flange 411 being clamped between the proximal ends of stopping ribs 52 of gripping barrel 50 and the distal end of triggering barrel 60.

[Para 63] Reference is now made to Figure 12, which illustrates an A-A section view of device 100 shown in Figure 7, with needle 33 projected for tissue penetration. Driving sleeve 420, propelled by propelling spring 430, drives plunger rod 35 through the back support of the inwardly projections 424 of gripping arms 423. The ends of gripping arms 423 are supported along their travel by supporting ribs 53, thereby preventing arms 423 from being opened outwardly and thus maintaining the engagement of gripping arms 423 with plunger rod 35. [Para 64] The force for compressing return spring 440 is less then the force needed to start moving elastomeric plug 34 inside syringe barrel 31 of pre-filled syringe 30, and significantly less then the force of propelling spring 430. Hence, plunger rod 35, by moving proximally, biases plug 34 to drive syringe barrel 31 and to project needle 33 out of injector 100 through opening 64, while compressing return spring 440.

[Para 65] Reference is now made to Figure 13, which illustrates an A-A section view of device 100 shown in Figure 7, after the delivery of the medication. After the narrowed end of syringe barrel 31 is stopped by inwardly peripheral extension 412 of inner sleeve 410, plunger rod 35 further drives plug 34 causing plug 34 to slide inside syringe barrel 31 and to expel the liquid medication through needle 33 out of syringe 30. Supporting ribs 53 of gripping barrel 50 are arranged such that when plug 34 reaches close to proximal end 38 of barrel 31, the ends of gripping arms 423 pass the ends of support ribs 53. [Para 66] Reference is also made to Figure 14, which illustrates an A-A section view of device 100 shown in Figure 7, with driving sleeve 420 disengaged from plunger rod 35. The contact point of the slopes of inwardly projections 424 with disk 36 at the distal end of plunger rod 35, together with the contact point being disposed inwardly with respect to the routes of gripping arms 423, generate a bending moment acting on arms 423 outwardly, so that when supporting ribs 53 no longer support the ends of gripping arms 423, the arms are deformed outwardly towards the inner wall of gripping barrel 50, while disengaging disc 36 at the end of plunger rod 35.

[Para 67] Reference is also made to Figure 15, which illustrates an A-A section view of device 100 shown in Figure 7, after needle 33 retracts into device lOO.The disengagement of driving sleeve 420 from plunger rod 35 enables return spring 440 to force pre-fϊlled syringe 30 distally, while retracting needle 33 back into the injector housing.

[Para 68] Reference is now made to Figures 16 and 17. Figure 16 illustrates an A-A section view of an automatic injection device 200, according to embodiments of the present invention, utilizing a pre-fϊlled cartridge 70 and a needle assembly 80, in rest position. Figure 17 illustrates an A-A section view of device 200 shown in Figure 16, after being triggered for injecting. In embodiments of the present invention, Injecting device 200 utilizes a pre-filled cartridge 70 and a needle assembly 80 instead of syringe assembly 30, utilized by injecting device 100. Cartridge 70 consist of a barrel 71 proximally ended with a neck 72, caped with a piercable stopper 73 that is tighten to cartridge 70 by cover 74. Piercable stopper 73 is made, for example, from rubber. Cover 74 is made, for example, from aluminum. [Para 69] Inner sleeve 210 of injecting device 200 differs with respect to injecting device 100, by having at -the proximal end of inner sleeve 210, a tubular extension 418 ending with inner rim 419. Inwardly peripheral extension 412 of injector 100 remains in the transition to extension 418. Extension 418 houses return spring 440 that acts between the proximal end of cartridge 70 and the inner rim 419 at the proximal end of inner sleeve 210 to urge cartridge 70 distally. Injecting device 200 further includes a needle assembly 80 that is disposed within the interior of return spring 440 (distally and separately to cartridge 70). Needle assembly 80 includes a cannula 81 sharpened at both ends, a fixed middle wall 82 and a slidable wall 83, which is frictionally mounted to cannula 81 and initially disposed proximally, supported by the inner facing shoulder 419.

[Para 70] Injection activation of injecting device 200 is triggered in the same manner as described for injecting device 100, utilizing pre filled syringe 30, by forcing triggering barrel 60 inwardly, while attaching device 200 against the body tissue of the target injection site. [Para 71] Referring now to Figure 18, which illustrates an A-A section view of device 200 shown in Figures 16 and 17, with needle 81 projected for penetrating the tissue at the target injection site. During the injection process, when cartridge 70 is driven proximally by driving sleeve 420, needle assembly 80 is urged by piercable stopper 73 to partially project out of device 200 for penetrating the tissue while slidable wall 83 slides towards and into contact with fixed wall 82, and thereafter, cartridge 70 is forced towards needle assembly 80 causing the distal end of cannula 81 to penetrate piercable stopper 73 of cartridge 70, thereby providing a fluid path for delivering the medication. When cartridge 70 is retracted back into device 200 after end of delivery, needle 81 is retracted together with the cartridge, because the holding forces between cannula 81 and stopper 73 are higher then the holding forces between cannula 81 and the tissue at the injection site.

[Para 72] Reference is now made to Figures 19, 20 and 21, illustrating another embodiment of the present invention. Figure 19a is a section view illustration of an automatic injection device 300, according to embodiments of the present invention, with an extractor 90 that facilitates removal of the needle shield 39 when utilizing a pre-filled syringe 30. Figure 19b is a section view illustration of injecting device 300 shown in Figure 19a, after forcing extractor 90 distally inwards device 300. Figure 19c is a section view illustration of injecting device 300 shown in Figures 19a and 19b, after removing of extractor 90 with needle shield 39 from injecting device 300. Figure 20 is a semi section view illustration of injecting device 300 shown in Figure 19, in the position shown in Figure 19a, but with syringe 30 and needle shield 39 hidden. Figure 21 is a prospective view illustration of injecting device 300 shown in Figures 19, 20 and 21, in the position shown in Figure 19c.

[Para 73] Injecting device 300 differs with respect to injecting device 100, by further containing an extractor 90 for locking injecting device 300 before injecting and for easy removal of needle shield 39. Injecting device 300 also includes means for housing and communicating with extractor 90.

[Para 74] Referring to Figure 20 and 21, extractor 90 has a cylindrical body with longitudinal ribs 91 along the outer radial face, and arms 92 which extend distally as continuation of ribs 91 and ended with inwardly extensions 93. [Para 75] Referring now to Figure 19a, inner sleeve 310 of injecting device 300 is generally similar to inner sleeve 410 of injecting device 100. But inner sleeve 310 of injecting device 300 has an extension 418 at the proximal end, with a wider bore size. Inwardly peripheral extension 412 in the transition to the wider bore size is preserved as in inner sleeve 410 of injecting device 100. Extractor 90 is housed within the wider bore size of extension 418, covers needle shield 39 and abuts the narrowed end of syringe 30 by inwardly extensions 93 at the ends of arms 92.

[Para 76] Referring also to Figures 19b and 19c, the removal of needle shield 39 by extractor 90 is obtained by firstly pushing extractor 90 distally inwards device 300 to disconnect the sealed fitting of the needle shield 39 on the outer radii of hub 37 of syringe 30, and thereafter removing extractor 90 out of device 300, with needle shield 39 contained inside extractor 90 and abutted by the inner side of inwardly extensions 93. The disconnecting of needle shield 39 from syringe 30, while inserting extractor 90, is obtained by inwardly extensions 93 of arms 92, which abut the narrowed end of syringe 30 and force syringe 30 distally, while needle shield 39 is stopped by inwardly peripheral extension 412 of inner sleeve 310.

[Para 77] Referring to Figures 19c and 20, extractor 90 couples inner sleeve 310 to triggering barrel 60 for preventing the rotation of inner sleeve 310, which activates the injection. The coupling arranged by ribs 91 which pass through notches 69 around opening 64 in head 63 of triggering barrel 60 and through longitudinal grooves 414 and extra local grooves 418 along inner sleeve 310. The coupling is canceled after extractor 90 is removed. [Para 78] For assembling device 300, grooves 418 partially split inner sleeve 310 together with inwardly peripheral extension 412. In assembly process, syringe 30, ended with needle shield 39, is inserted into inner sleeve 310 and in this variation, is forced proximally while compressing return spring 440. The two medians (half s) of inner sleeve 310 are forced and deformed outwardly to let needle shield 39 pass through inwardly peripheral extension 412 of inner sleeve 310, and to facilitate the insertion of extractor 90. Inner sleeve 310 is then released and thereby eliminating the outwardly deformation, letting inwardly peripheral extension 412 to be disposed in the space between the narrowed end of syringe 30 and the distal end of needle 70.

[Para 79] During injection, outer flange 411 of inner sleeves 410, 310 or 210 is clamped between gripping barrel 50 and triggering barrel 60. The sleeve portion of inner sleeves 410, 310 or 210 houses syringe 30 while abutting the bottom of barrel 31 of syringe 30. The disengagement of driving sleeve 420 from plunger rod 35 is triggered by the end of longitudinal supporting ribs 53 on the inner wall of gripping barrel 50. The disengagement occurs when the distal end of plunger rod 35 has passed the end of longitudinal supporting ribs 53 in a distance of the width of the inwardly projections 424 at the ends of arms 423 of driving sleeve 420. [Para 80] Injecting devices 100, 200 and 300 repeatably deliver substantially all the pre- filled medication, which is achieved by providing a short tolerances chain, while ignoring the inaccuracy in the length of syringes 30 or cartridges 70, typically made of glass, and by substantially eliminating any freedom between participating parts, resulted from a typical syringe structure.

[ P a r a 81 ] In embodiments of the present invention, medication reservoir 31 proximal drive, during an injection process, is stopped by inner sleeves 410, 310 or 210, when outer finger flange 32 at the distal end of medication reservoir 31 encounters the distal end of inner sleeves 410, 310 or 210.

[Para 82] In embodiments of the present invention, injecting devices 100, 200 or 300 include a longitudinal window for inspecting medication barrel 31. The window includes respective openings in gripping barrel 50, triggering barrel 60 and inner sleeves 410, 310 or 210.

[Para 83] In embodiments of the present invention, triggering barrel 60 includes a safety catch preventing distal movement of triggering barrel 60, thereby preventing activation of an injection. The safety catch includes dowels 65, which are located on leaves 68, interlacing the radial section of an "L" shaped groove 51.

[Para 84] In embodiments of the present invention, the safety catch limits the rotation of triggering barrel 60 with respect to gripping barrel 50. The safety catch is operable to free the blocking by a limited rotation of triggering barrel 60 with respect to gripping barrel 50. [Para 85] In embodiments of the present invention, the safety catch is a blocking element, which prevents triggering barrel 60 from moving with respect to gripping barrel 50. The safety catch is operable to free the blocking by removing of the blocking element. [Para 86] In embodiments of the present invention, the safety catch is a blocking element, which is engaged with outer flange 411 at the distal end of inner sleeves 410, 310 or 210, thereby preventing the rotation of inner sleeves 410, 310 or 210, with respect to driving sleeve 420. The safety catch is operable to free the blocking by removing of the blocking element.

The invention being thus described in terms of the embodiments and examples, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. An injecting device for automatically inject a predetermined dose of liquid medication into a tissue at a target injection site, the injection device has a distal end and a proximal end, and houses a medication reservoir having a proximal end and a distal end, wherein the medication reservoir includes: (i) a barrel, wherein the barrel is narrowed and initially closed at the barrel proximal end and opened at the barrel distal end; (ii) a plug, wherein the plug is slidably disposed inside the barrel; (iii) a plunger rod, wherein the proximal end of the plunger rod extends into the opening at the distal end of the barrel; and (iv) a liquid medication contained in a chamber formed in the barrel between the proximal end of the barrel and the plug, and wherein the injection device further houses a needle, wherein the needle is disposed in front of the proximal narrowed end of the barrel, either affixed to the proximal narrowed end of the barrel or part of a separate needle assembly, arranged to provide a passageway for delivering the medication from the reservoir into the tissue during injection, wherein the medication reservoir is operable to move between a retracted position, wherein the needle is fully secured inside the housing of the device, and a forward position, wherein the needle is partially projected out of an opening at the proximal end of the device, the injection device comprising: a) a housing; b) an internal assembly comprising: (i) an inner sleeve ending proximally with an outer flange and having a bore; (ii) a driving sleeve having a bore, and (iii) a propelling spring, wherein said inner sleeve is slidably disposed with free peripheral space inside said bore of said driving sleeve, wherein said driving sleeve and said inner sleeve are initially interlocked, and wherein said propelling spring is initially restrained in a compressed state inside said free peripheral space; and c) a return spring having a stored potential energy significantly smaller with respect to said propelling spring residual energy in released state of said propelling spring, wherein said return spring is arranged to bias said medication reservoir distally, said return spring is in substantially uncompressed when said medication reservoir is in said retracted position, whereas said internal assembly is axially disposed inside said housing; whereas said medication reservoir is slidably mounted inside said bore of said inner sleeve with said needle disposed proximally to the medication reservoir; whereas said return spring is axially disposed within said internal assembly, acting between said inner sleeve and said medication reservoir; and whereas said return spring performs automatic retraction of said needle, upon termination of an injection of said medication into said tissue.

2. The device of claim 1 , wherein said driving sleeve, upon said unlocking of said initial interlock of said inner sleeve with said driving sleeve, is being driven proximally by said propelling spring, and wherein said inner sleeve is axially situated in a determined location with respect to said housing at least during said injection.

3. The device of claim 2, wherein said driving sleeve further comprising at least one arm extended distally and operatively engaged with said distal end of said plunger rod, wherein when said driving sleeve is driven proximally, said at least one arm is being pulled, thereby pulling said plunger rod proximally to firstly move said medication reservoir from said retracted position to said forward position while compressing said return spring, whereas said medication reservoir is stopped by said inner sleeve, and thereafter, driving proximally said plug along said barrel of said reservoir, thereby expelling said liquid medication through said passageway of said needle.

4. The device of claim 3, wherein said at least one arm extended distally, said outer flange of said inner sleeve contains at least one notch on the circumference of said outer flange, enabling said arms to pass through said outer flange towards said distal ends of said plunger rod.

5. The device of claim 3, wherein said at least one arm is arranged to be disposed outwardly at least during injection.

6. The device of claim 5, wherein said engagement of said distal end of said at least one arm with said distal end of said plunger rod is obtained by providing an inwardly projection (424) at said distal end of said at least one arm, wherein said inwardly projection abuts an outer face of said distal end of said plunger rod by an outwardly inclined face of said projection (424), and wherein said engagement of said projection with said plunger rod being disposed inwardly towards said device central axis respectively to a higher distance from said central axis of a vector offeree of said at least one arm being pulled, thereby creating an outwardly moment on said at least one arm, and thereby causing said outwardly disposition of said arm.

7. The device of claim 3, wherein said medication reservoir is stopped by said inner sleeve when said narrowed proximal end of the barrel of said medication reservoir encounters an inwardly peripheral extension extending from the inner wall of said inner sleeve at said proximal end of said inner sleeve or a few millimeters distally from said proximal end of said inner sleeve.

8. The device of claim 3, wherein said medication reservoir is stopped by said inner sleeve when a finger flange at said distal end of said medication reservoir encounters said distal end of said inner sleeve.

9. The device of claims 1 and 5, wherein said housing comprising a gripping barrel, having a proximal opened end and a distal end, and a triggering barrel, having a proximal end and a distal end, wherein said triggering barrel is slidably adopted inside said gripping barrel through said proximal opened end and partially projected from said proximal opened end.

10. The device of claim 9, wherein said triggering barrel is initially in rest position operable to further move a small distance into said gripping barrel to reach a triggering position, wherein an injection is triggered when an external force is applied to operate said movement of said triggering barrel from said initial rest position to said triggering position, thereby causing said internal assembly to unlock said initial interlock of said inner sleeve with said driving sleeve.

11. The device of claim 10, wherein said gripping barrel, having an inner wall, further comprising at least one longitudinal support (53) for supporting said at least one arm of said driving sleeve, thereby holding said outwardly disposition of said at least one arm, thereby preventing said arm from being deformed outwardly and maintaining said engagement of said at least one arm with said plunger rod along said movement of said driving sleeve, wherein said at least one longitudinal support (53) has a proximal end in a location where said at least one longitudinal support stops supporting said at least one arm when substantially all of said medication is delivered, causing by said outwardly disposition moment of said arm, causing an outwardly deformation of said at least one arm, thereby disengaging from said plunger rod, enabling said compressed return spring to force said medication reservoir back to said retracted position,

12. The device of claims 10, wherein said inner sleeve is axially situated in a determined location with respect to said housing at least during injection by said external force being further applied during injection to bias said triggering barrel distally, thereby said distal end of said triggering barrel forces the proximal side of said outer flange of said inner sleeve against an internal abutment (52) on the inner wall of said gripping barrel, which abuts the distal side of said outer flange of said inner sleeve.

13. The device of claims 1 , wherein said unlocking of said initial interlock of said inner sleeve with said driving sleeve is obtain by a limited rotation of said inner sleeve respectively to said driving sleeve, whereas said inner sleeve and said driving sleeve contain locking elements designed to be unlocked by said limited rotation.

14. The device of claims 13, 3 and 10, wherein said triggering barrel is being moved distally into said triggering position, thereby causing said internal assembly to perform said unlocking of said initial interlock of said inner sleeve from said driving sleeve, wherein said distal movement is translated to a limited rotation of said inner sleeve, wherein said driving sleeve is prevented from rotating by said at least one arm of said driving sleeve, guided by limiting ribs (51) on said inner wall of said gripping barrel.

15. The device of claim 14 and 12, wherein said triggering barrel contains at least one inclined side wall at said distal end of said triggering barrel, and wherein said inner sleeve contains at least one notch in said outer flange, and wherein each of said inclined side walls of said triggering barrel biases an adjacent side wall of said notch of said inner sleeve when said triggering barrel is being moved distally into said triggering position to rotate said inner sleeve while said outer flange of said inner sleeve is abutted by said internal abutment (52) on said inner wall of said gripping barrel, thereby preventing distal movement of said inner sleeve.

16. The device of claim 1, wherein said restrained propelling spring is supported at a first end by said outer flange of said inner sleeve and supported at a second end by inwardly peripheral abutment at said proximal end of said driving sleeve.

17. The device of claim 13 , wherein said inner sleeve and said driving sleeve contain locking elements designed to be unlocked by said limited rotation wherein said inner sleeve further comprises longitudinal grooves (414) opened proximally and ending distally with notches (413) extending radially from said distal ends.

18. The device of claims 17 and 16, wherein said driving sleeve further comprises dowels (422) extending inwardly from said proximal end, wherein said dowels extend closer to said central axis respectively to said abutment for supporting said propelling spring.

19. The device of claims 18 and 2, wherein said interlock is obtained by said dowels engaged with said notches, and wherein upon said rotating of said inner sleeve with respect to said driving sleeve, said dowels disengage from said notches and engage said longitudinal grooves, thereby enabling said driving sleeve to be driven proximally.

20. The device of claim 1 , wherein said medication reservoir is a pre-filled syringe ending proximally with a hub having an orifice, and wherein said needle is initially coupled to said orifice of said hub.

21. The device of claims 20 and 7, wherein said syringe is in said forward position initially closed at the proximal end by a needle shield covering said needle and releasably sealed to said hub, whereas the distal end of said needle shield is abutted by a front face of said inwardly peripheral extension of said inner sleeve.

22. The device of claim 21, wherein said needle shield is encircled by a releaser (90), having a substantially cylindrical body, and wherein said releaser, is arranged to release said sealing coupling of said needle shield and thereafter to remove said needle shield.

23. The device of claim 22, wherein said releaser further comprising a small sectioned arms ended with small inwardly projections arranged to release said sealing coupling, wherein said release is obtained by said releaser being pushed distally, thereby the inwardly projections of the arms push said narrowed end of said syringe and force said syringe distally to said retracted position, while the distal end of said needle shield is being abutted by said inwardly peripheral extensions of said inner sleeve, thereby preventing said needle shield from moving distally, and wherein said removal of said needle shield is obtained by the inner side of said inwardly projections abut the distal end of said needle shield, thereby being removed together with said releaser, when said releaser is removed.

24. The device of claims 1 and 23, wherein said releaser (90) couples said inner sleeve to said triggering barrel, thereby said releaser serves as a safety catch, preventing said inner sleeve from rotating with respect to said triggering barrel, wherein said safety catch is canceled when said releaser (90) is removed.

25. The device of claim 24, wherein said releaser (90) comprises longitudinal ribs, wherein said longitudinal ribs fitly inserted through notches in said opening at said proximal end of said triggering barrel, and through grooves in said inner sleeve.

26. The device of claim 1 , wherein said medication reservoir is a cartridge closed proximally with a piercable stopper, and wherein said needle is part of a needle assembly comprising a cannula sharpen at both ends and having a proximal end and a distal end, and a middle wall for initially holding said needle proximally to said cartridge with said distal end of said cannula adjacent to said piercable stopper.

27. The device of claim 1, further comprising a longitudinal window for inspecting said medication barrel, wherein said window comprises respective openings in said gripping barrel, said triggering barrel and said inner sleeve.

28. The device of claim 1, further comprising a safety catch, said safety catch preventing distal movement of said triggering barrel, thereby preventing activation of an injection.

29. The device of claim 28, wherein said gripping barrel contains an "L" shaped groove, having an axial portion and radial portion, wherein said triggering barrel contains a dowel, wherein said dowel is a safety catch disposed inside the radial portion of said gripping barrel, and wherein said safety catch is operable to free said blocking by a limited rotation of said triggering barrel with respect to said gripping barrel, thereby moving said dowel into said axial portion.

30. The device of claim 28, wherein said safety catch is an annular clip, wherein said annular clip is located between a head portion at a proximal side of said triggering barrel and said proximal end of said gripping barrel, thereby preventing said triggering barrel from moving with respect to the gripping barrel, and wherein said safety catch is operable to free said blocking by removing of said blocking element.

31. The device of claim 1 , further comprising a safety catch, said safety catch preventing rotation of said inner sleeve from rotating with respect to said driving sleeve, thereby preventing activation of an injection.

32. The device of claim 31 , wherein said safety catch is a blocking element, wherein said blocking element engaged with said flange of said inner sleeve, thereby preventing rotation of said inner sleeve with respect to said driving sleeve, and wherein said safety catch is operable to free said blocking by removing of said blocking element.

33. The device of claim 31 , wherein said safety catch is a member slidably mounted on a side wall of said gripping barrel, having an internal portion and an external portion, wherein said internal portion is arranged to engage with notches on said outer flange of said inner sleeve, thereby preventing rotation of said inner sleeve with respect to said driving sleeve, and wherein said safety catch is operable to free said blocking by manually pushing said member through the external portion and remove said member out of engagement with said inner sleeve.

34. A method for automatically inject a predetermined dose of medication into a tissue at a target injection site, using an injecting device as in claim 1, the method comprising distally moving said triggering barrel with respect to said gripping barrel, thereby releasing said interlock of said inner sleeve and said driving sleeve.

35. The method of claim 34, further comprising releasing a safety catch prior to said moving of said triggering barrel with respect to said gripping barrel.

36. In a device as in claim 1 , a method for removing a needle shield, using a releaser (90), the method comprising the steps of: a) forcing said releaser distally towards said device, thereby disengaging said needle shield from said medication reservoir; and b) withdrawing said releaser together with said needle shield.