Abstract:
The present invention relates to a medicament delivery device. The medicament delivery device may include an operation member configured to act on a medicament container for expelling a medicament. The device may be configured to hold the operation member in a pre-tensioned state. The device may include an activation member configured to interact with the operation member to release it from the pre-tensioned state. The device may further comprise feedback. For example, the feedback may include generating an audible and/or tactile and/or visual signal indicating that the medicament has been completely expelled.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 13/636,241 filed Oct. 12, 2012, which is a U.S. National Phase Application pursuant to 35 U.S.C. §371 of International Application No. PCT/SE2011/050236 filed Mar. 23, 2011, which claims priority to Swedish Patent Application No. 1050307-6 filed on Mar. 31, 2010 and U.S. Patent Application No. 61/319,453 filed Mar. 31, 2010. The entire disclosure contents of these applications are herewith incorporated by reference into the present application. 
    
    
     FIELD OF INVENTION 
     The present invention relates to a medicament delivery device and in particular to an improved, more user-friendly, automatic medicament delivery device providing an audible, tactile or visual confirmation to a user when an injection has been made. 
     BACKGROUND 
     Many medicament delivery devices are developed for self-administration, i.e. a user performs the medicament delivery her-, or himself. This requires a medicament delivery device which is as safe to use and as easy to handle as possible. In order to meet these requirements, the risk of human errors must be minimized, the number of actions needed to be performed in order to receive a dose need to be reduced and the device must be intuitive and ergonomic to use. Thus, in order to minimize the risk of human errors, it is desirable to have the device as pre-assembled as possible. 
     Document EP 1349590 B describes an injector having a number of features that facilitate the handling of the injector. The penetration and injection is performed manually by simply pressing the proximal end of a needle shield against the delivery area, causing the shield to move in a distal direction, enabling the needle to penetrate the injection area and thereafter initialize the injection process. When the injection is performed the injector is withdrawn whereby a needle shield extracts around the needle in a locked way. 
     Other aspects of injectors are the human aspect of handling the injector regarding how it is held during operation. a general aim is to have the patient holding the injector in an ergonomic way that may permit the penetration and injection in different locations on the body, such as around the waist and also on the backside of the waist and/or in the buttocks of the patient. Sometimes the patient does not see the injector at those locations and need to be able to hold the injector without having to change grip. By removing the action of pushing a button or the like, the patient is free to hold the device as he desires and feels comfortable. 
     It is considered important for the patient to receive a confirmation that the injection has been made, in particular in instances when an injector is used where the patient does not see the injector, e.g. such as around the waist and also on the backside of the waist and/or in the buttocks of the patient. 
     SUMMARY 
     The object of the present invention is to provide a medicament delivery device that is reliable and easy to use when handling and activating, this is achieved by a medicament delivery device comprising a drive means configured to act on a medicament container for expelling a medicament; a holding means configured to hold said drive means in a pre-tensioned state; an activation means configured to interact with said holding means for releasing said drive means from the pre-tensioned state; wherein the device further comprises feedback means configured to interact both with said holding means and with said drive means for generating an audible and/or tactile and/or visual signal indicating that the medicament has been completely expelled. 
     According to another aspect of the invention the device further comprises a tubular housing having a proximal end and an opposite distal end. 
     According to a further aspect of the invention the activation means is a tubular activation member slidably and coaxially arranged in relation to the tubular housing. 
     According to yet another aspect of the invention the device further comprises a container holder coaxially arranged within the tubular activation member and fixedly attached to the tubular housing. 
     According to yet a further aspect of the invention the medicament container is arranged within said container holder and wherein said medicament container comprises a predetermined volume of medicament, a slidable stopper and a delivery member. 
     According to yet an aspect of the invention the drive means comprises a plunger rod and a first resilient member which is pre-tensioned arranged within the plunger rod and wherein said plunger rod is arranged to be in contact with the slidable stopper within the medicament container. 
     According to another aspect of the invention the holding means are a tubular extension part fixedly connected to the distal end of the tubular housing and a tubular operation member which is interactively connected both to the tubular extension part and to the tubular activation member, such that when said tubular activation member is pressed against a delivery site said tubular operation member is rotated in relation to said tubular extension part whereby said drive means are released from the pre-tensioned state for exerting a pressure on the slidable stopper and thereby expelling the medicament. 
     According to a further aspect of the invention the feedback means is a longitudinally extending signal generating member interactively connected to said tubular extension part and to said drive means, such that when the plunger rod is completely released from the tubular extension part and the longitudinally extending signal generating member, the longitudinally extending signal generating member is released from said tubular extension part and displaced distally by a remaining force of the first resilient member for generating an audible and/or tactile and/or visual signal indicating that the medicament has been completely expelled. 
     According to a still further aspect of the invention, the tubular operation member comprises a first co-acting means interactively connected to a corresponding first co-acting means of the tubular activation member and a second co-acting means interactively connected to a corresponding second co-acting means of the tubular extension part; the plunger rod comprises a releasable engaging means interactively connected to the corresponding second co-acting means of the tubular extension part and a proximal end wall being in contact with the slidable stopper; the longitudinally extending signal generating member is releasable arranged on an inner surface of the tubular extension part; and wherein the first resilient member has a first end abutting the proximal end wall of the plunger rod and a second end abutting a transversal wall of the signal generating member. 
     According to another aspect of the invention, the second co-acting means comprises a groove on an inner surface of the tubular operation member and the corresponding second co-acting means of the tubular extension part comprises a resilient tongue, having a radial inward protrusion. 
     According to a yet another aspect of the invention, the releasable engaging means comprises a groove on an outer surface of the plunger rod releasable engaged to the radial inward protrusion of the resilient tongue adapted to hold the drive means in the pre-tensioned state. 
     According to a yet a further aspect of the invention, the first co-acting means comprise a groove on an outer surface of the tubular operation member and the first corresponding co-acting means comprise a radial inward extending protrusion on the distal end of the inner surface of the tubular activation member, such that the radial inward extending protrusion is adapted to be guided within the groove on an outer surface of the tubular operation member forcing the tubular operation member to rotate when the tubular activation member is distally moved, whereby the resilient tongue is flexed radial outward into a groove on the inner surface of the tubular operation member and the radial inward extended protrusion is disengaged from the groove on the outer surface of the plunger rod such that the drive means are released from the pre-tensioned state. 
     According to another aspect of the invention, the signal generating member is an elongated u-shaped bracket comprising a transversal wall and two longitudinally extending flexible arms provided with angled support members extending radially outward, and wherein said support members are adapted to rest on an annular proximal end of the tubular extension part when the drive means are in the pre-tensioned state. 
     According to a further aspect of the invention, the transversal wall of the U-bracket is arranged at a predetermined distance D from an inner distal surface of said tubular extension part when the drive means are in the pre-tensioned state. 
     According to yet another aspect of the invention, the audible signal is generated for confirming that a medicament delivery has been performed when the distal end of the plunger rod has passed the supporting members, such that the longitudinally extending flexible arms, with the support members, are released and allowed to move in a radial inward direction, enabling the U-bracket to move the predetermined distance D in the distal direction by a remaining force exerted by said first resilient member, whereby the transversal wall of the bracket hits the inner distal surface of said tubular extension part. 
     According to yet a further aspect of the invention, the transversal wall of the U-bracket comprises a distally extending protrusion and the distal surface of the tubular extension part comprises a through hole, such that when the transversal wall of the U-bracket hits the inner distal surface of said tubular extension part, the distally extending protrusion passes through the through hole and extends distally a predetermined distance over the outer surface of said tubular extension part for generating a tactile signal. 
     According to another aspect of the invention, the distally extending protrusion has a bright and/or different colour than the rest of the device for generating a visual signal. 
     By the term automatic medicament delivery device, is herein meant a medicament delivery device adapted to deliver a medicament without a user having to press a push button or activation member, but instead only by pressing the proximal end of the medicament delivery device against the delivery site. 
     In automatic medicament delivery device it is considered, as mentioned above, important for the patient to receive a confirmation that the delivery has been made, in particular when the medicament delivery device is used where the patient does not see the medicament delivery device, e.g. such as around the waist and also on the backside of the waist and/or in the buttocks of the patient. Therefore, a signal i.e. an audible sound, and/or a tactile signal, and/or a visual signal, or a combination thereof is generated in direct temporal relationship to the physical actuation of the medicament container, in order to expel the medicament from the medicament container. 
     The medicament delivery device according to the present invention presents a number of advantages. There is a high degree of functionality and automation, which remove unnecessary components and actions for delivering a medicament. 
     Also an important safety aspect is met since, during withdrawal, the tubular activation member is pushed out and covers the delivery member e.g. a needle, and also locks in the extended state, thereby preventing unintentional needle sticks. 
     These and other aspects of and advantages with the present invention will become apparent from the following detailed description and from the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following detailed description of the invention, reference will be made to the accompanying drawings, of which 
         FIG. 1   a - FIG. 1   c  shows perspective views of different components of the medicament delivery device. 
         FIGS. 2   a - FIG. 2   d  shows perspective views of different states of the medicament delivery device. 
         FIG. 3  illustrates a plunger rod and audio-tacit-visual signal generating member assembly. 
         FIG. 4   a - FIG. 4   c  illustrates the components of the audio-tacit-visual signal generating member-, and plunger rod assembly. 
         FIG. 5  shows a perspective view of a driving means comprised in the present invention. 
         FIG. 6   a - FIG. 6   c  shows a side view of the tubular housing and the audio-tacit-visual signal generating member in operation, 
         FIG. 7-FIG .  11  show side views along the longitudinal axis of the medicament delivery device according to an embodiment of the present invention, illustrating different states of an injection procedure. 
     
    
    
     DETAILED DESCRIPTION 
     In the present application, when the term “distal part/end” is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which is/are located the furthest away from the medicament delivery site of the patient. Correspondingly, when the term “proximal part/end” is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which, is/are located closest to the medicament delivery site of the patient. 
       FIG. 1   a  illustrates, in perspective, a tubular housing  20  of an exemplary medicament delivery device  1 . The tubular housing  20  having a proximal end  11  and an opposite distal end  12 . The tubular housing  20  further comprises a protrusion (not illustrated) on its inner wall. The protrusion is adapted for receiving a recess  36  of an activation means, such as a tubular activation member  30  (see  FIG. 1   b ). The recess  36  of the tubular activation member  30  is used for locking the tubular activation member  30 , inside the tubular housing  20 , when the tubular activation member  30  is in its most proximal position, after an injection has been made. In an exemplary embodiment there are two protrusions (not illustrated), one on each side of the inner wall of the tubular housing  20 , and correspondingly two recesses  36  of the tubular activation member  30 . The tubular housing  20  further comprises a container holder  50  which is coaxially arranged and fixedly attached within the tubular housing  20  for lodging a medicament container  80  (see  FIG. 1   c ). The medicament injection device  1  further comprises a tubular extension part  22 , being coaxially arranged and fixedly attached to the distal end  12  of the housing preferably by a flexible tongue  15  engaging with a corresponding ledge  23  (see  FIG. 5 ) of the tubular extension part  22 . 
       FIG. 1   b  illustrates the tubular activation member  30  of the medicament injection device  1 . The tubular activation member  30  having an annular contact member  31  and a corresponding first co-acting means  35 , which in an exemplary embodiment is a protrusion. In an exemplary embodiment of the invention there are two corresponding first co-acting means  35  which are used for activating the medicament delivery device  1  as will be described in detail below. In the figure is in particular illustrated a guiding means  34  which is adapted to cooperate with a corresponding guiding rod (not shown) at the interior of the tubular housing  20 , with the purpose to prevent that the tubular activation member  30  may rotate in relation to the tubular housing  20  and to allow the tubular activation member  30  to move in the axial direction in relation to the tubular housing  20 . In a preferred embodiment of the invention there are two guiding means  34  and correspondingly two guiding rods (not shown). According to an embodiment of the invention, a second resilient member  24  (see  FIG. 1   c ), which in an exemplary embodiment is a tension spring, is arranged at the proximal end of the tubular activation member  30  for moving it in a proximal direction. The cut-out/recess  36  is, when the medicament injection device  1  is positioned in its final position in order to prevent unintentional availability of a proximal needle end  61  (see  FIG. 1   c ), engaging with a corresponding protrusion (not illustrated) of the tubular housing  20 . 
       FIG. 1   c  illustrates the interior of the medicament delivery device  1  further comprising the second resilient member  24  arranged in relation to the tubular activation member  30  for moving it in a proximal direction from a non-activated position to an activated position whereby the annular contact member  31  is in contact with the proximal end of the housing  20  when the medicament injection device  1  is in non-activated state and whereby the annular contact member  31  is at a predetermined distance from the proximal end of the housing when the medicament injection device  1  is in activated state. The medicament container  80  is arranged within the container holder  50  and has a predetermined volume of medicament, a slidable stopper  83  and a delivery member. In an exemplary embodiment of the invention the medicament container  80  is a syringe provided with a needle  61  as the delivery member, however the invention should not be limited to this, other embodiments could include a medicament cartridge having a membrane  82 , or the like where a delivery member can be adapted. In the medicament delivery device  1  is also included a tubular operation member  100  (see  FIG. 5 ) comprising a second co-acting means  101 ,  102  interactively connected to a corresponding first co-acting means  35  of the tubular activation member  30  (see  FIG. 1   b ), drive means comprising a plunger rod  90  and a first resilient member  91  arranged within the plunger rod. The plunger rod comprises a releasable engaging means  94  as a cut-out/recess (see  FIG. 4   c ) interactively connected to a corresponding second co-acting means  121  (see  FIG. 5 ) of the tubular extension part  22 . The first resilient member  91  is in an exemplary embodiment of the invention a tension spring. The proximal end  92  of the plunger rod  90  is in contact with the slidable stopper  83 . The tubular operation member  100  (see  FIG. 5 ) is rotatably and coaxially arranged on a proximal part of the tubular extension part  22  between the container holder  50  and an annular ledge of the tubular extension part  22  at the distal end of the tubular housing  20 . 
     Together, the tubular extension part  22  and the tubular operation member  100  form a holding means, for holding the drive means in a pre-tensioned state prior to penetration. Upon actuation of the activation means a feedback means interacts with the holding means and the drive means to signal that a medicament has been completely expelled. 
       FIG. 2   a - FIG. 2   d  show simplified perspective views of the medicament delivery device  1 , where  FIG. 2   a  illustrates an initial, non-activated, state of the medicament delivery device  1  having a cap  10 .  FIG. 1   b  shows an activated state of the medicament delivery device  1 , where the cap  10  is removed.  FIG. 2   c  shows the penetration and injection state of the medicament delivery device  1  and finally  FIG. 2   d  shows the medicament delivery device  1  in a final locked state. With references to  FIG. 2   a , the medicament delivery device  1  comprises the tubular housing  20 , having a proximal end and an opposite distal end. The medicament injection device  1  further comprises the tubular activation member  30  which is slidably and coaxially arranged inside the tubular housing  20  and comprises the proximal annular contact member  31 . The cap  10  comprises a distal end surface, abutting with the proximal end surface of the annular contact member  31  of the tubular activation member  30  such that when the cap  10  is manually operated and detached, it allows the tubular activation member  30  to be moved by the force from the second resilient member  24  ( FIG. 1   c ) from its non-activated position to its activated position. 
       FIG. 2   b  show the medicament delivery device  1  when it is ready for use. When a user is about to perform a medicament delivery e.g. an injection he/she presses the proximal end, i.e. the annular contact member  31 , against the delivery site e.g. an injection site. The tubular activation member  30  is then moved in the distal direction, in relation to the tubular housing  20 , and during the relative movement when having a medicament delivery device as an injection device, then a needle  61  manually penetrates the skin. When the tubular activation member  30  is about to reach its most distal position in relation to the tubular housing  20  the medicament delivery is performed. A medicament delivery is automatically performed when the tubular activation member  30 , being in an activated position, is moved in a distal direction in relation to the tubular housing  20 , to a delivery state position, where the annular contact member  31  is close to the proximal end  11  of the tubular housing  20 . 
       FIG. 2   c  illustrates when the delivery is made, then the user removes the medicament delivery device  1  from the delivery site, thereby allowing the tubular activation member  30  to move in the proximal direction in relation to the tubular housing  20 , by the force exerted by the second resilient member  24  and finally reaches a final state; the locked state. 
       FIG. 2   d  illustrates the medicament delivery device  1  in its final and locked state, wherein the tubular activation member  30  once more is in its most proximal position, as illustrated. in this state the proximal part of the tubular activation member  30  fully protects the delivery member  61  and the tubular activation member  30  is also locked, by the cut-out/recesses  36  (see  FIG. 1   b ) in the distal end of the tubular activation member  30 , engaging with the protrusions (not illustrated) of the tubular housing  20 , in the final position in order to prevent unintentional availability of the delivery member  61 . 
       FIG. 3  illustrates various aspects of the feedback means, such as a signal generating member  110  and its implementations (see also  FIG. 4   a - FIG. 4   c ). In  FIG. 3  is illustrated an embodiment of the invention comprising the signal generating member  110  adapted to generate an audible and/or tactile and/or visible injection confirmation signal upon a performed medicament delivery, wherein the medicament delivery confirmation signal is generated when the drive means changes state from a pre-tensioned state wherein the first resilient member is pretensioned arranged within the plunger rod and the plunger rod is engaged to the tubular extension part, to a released state wherein the plunger rod is completely released from the tubular extension part and is no longer in contact with the signal generating member. 
       FIG. 4   a - FIG. 4   c  illustrates a side view and perspective views, respectively, of the signal generating member  110  according to an exemplary embodiment of the invention. In the illustrated embodiment, the signal generating member  110  is an elongated u-shaped bracket, provided with at least two elongated arms  111 , directed in the proximal direction, and a lower part, a distal transversal end wall,  112  directed in the distal direction of the medicament delivery device, when arranged within the tubular extension part  22 . The signal generating member  110  may be made from metal, plastic, or any combination of these materials. 
       FIG. 4   c  is a perspective, and partly exploded, view of the signal generating member  110  in relation to the plunger rod  90  and the first resilient member  91 . The upper parts of the arms  111  are provided with angled support members  113  extending in essentially radial outward directions with regard to a longitudinal axis of the u-bracket  110 . The u-bracket  110  is adapted to enclose at least a part of the plunger rod  90  and the first resilient member  91 , and the support members  113  are adapted to rest on an annular surface on the proximal end of the tubular extension part  22  when the drive means are in a pre-tensioned state, i.e. the opening  94  of the plunger rod  90  is engage with a radial inward projected protrusion (not shown) of a flexible tongue  121  of the tubular extension part  22 . 
     When the drive means is in the pre-tensioned state, the distal end of the u-bracket  110  is arranged at a predetermined distance “D” (see  FIG. 6   a ) from an inner distal surface of said tubular extension part  22  and when the drive means are in the released state, the distal end of the u-bracket  110  is in contact with the inner distal surface of said tubular extension part  22 . The audible and/or tactile and/or visible confirmation signal is generated when the distal end of the u-bracket  110  hits and contacts the inner distal surface of the tubular extension part  22  by a remaining force exerted by said first resilient member  91 . Thus, during the delivery procedure, when the distal end of the plunger rod  90  passes by the supporting members  113 , the arms  111  with the support members  113  are released and allowed to move in a radial inward direction, due to a pre-tension of the arms  111 , enabling the u-bracket  110  to move in the distal direction and the signal, typically an audible sound and/or a visual signal and/or a tactile signal is generated, when the u-bracket  110  hits the distal end of the tubular extension part  22 . In the pre-injection state the u-bracket  110  is arranged such that the arms  111  are positioned in a space along the plunger rod  90  between the plunger rod  90  and the tubular extension part  22  enclosing the plunger rod  90 . The support members  113  must have an extension in the radial outward direction that exceeds the radial extension of the space between the plunger rod  90  and the inner wall of the tubular extension part  22  to secure that the signal generating member  110  is not released prior the plunger rod  90  has moved away from between the arms  111 . the outer distal surface of the distal transversal end wall  112  may further have a protrusion (not illustrated), adapted to be guided through an opening, typically a through hole (also not illustrated) of the distal end wall of the tubular extension part  22  and extends distally a predetermined distance over the outer surface of said tubular extension part  22 . In an exemplary embodiment of the invention, the distally extending protrusion has a bright and/or different colour than the rest of the device for generating a visual signal. Thus, said protrusion will enable both a tactile and a visual signal when the u-bracket  110  hits the distal end of the tubular extension part  22 . 
       FIG. 5  illustrates the drive means as well as the holding means, wherein the holding means comprises the tubular operation member  100  and the tubular extension part  22 . The above-mentioned first corresponding co-acting means  35  are at least one inwards extending protrusion (see  FIG. 1   b ) on the distal end of the inner surface of the tubular activation member  30  and the first co-acting means are at least one groove  101 ,  102 ,  103  on an outer surface of the tubular operation member  100 , such that said radial inwards extending protrusion  35  is adapted to be guided within the at least one groove  101 ,  102 ,  103 , forcing the tubular operation member  100  to rotate when the tubular activation member  30  is axially moved. A second co-acting means  105  for holding the plunger rod  90  and the first resilient member  91  in the pre-tensioned state comprises at least one groove  105  of the tubular operation member  100  and engages with a flexible tongue  121  on the tubular extension part  22 , which locks the plunger rod  90  by the radial inwards extending protrusion (not shown) of the flexible tongue  121  and engaging with the opening  94  of the plunger rod  90 . When the tubular operation member  100  is rotated, at least one groove  105  of the tubular operation member  100  allows the radial inwards extending protrusion of the flexible tongue  121  to radial extension, thereby releasing the engagement between the protrusion and the opening  94  of the plunger rod  90 , thus releasing the plunger rod  90 , exerted by the force of the first resilient member  91 , in a proximal direction. 
     The medicament delivery device  1  further comprises a locking means interactively connected to the tubular activation member  30 . The locking means is preferably at least one ledge  106  on an annular surface of the tubular operation member  100  and a corresponding locking means are at least one protrusion  95  on an outer surface of the tubular extension part  22 , such that said at least one protrusion  95  is abutting said at least one ledge  106  holding the tubular operation member  100  rotable fixated to the tubular extension part  22 . 
       FIG. 6   a - FIG. 6   c  illustrates simplified side views of the distal part of the medicament delivery device  1  according to the present invention. The purpose of these figures is to briefly describe and illustrate the important features required to achieve the stated objects. In the figures are shown the tubular extension part  22  that partly encloses the drive means, i.e. the plunger rod  90  and the first resilient member  91 , and the signal generating member  110 . 
     In  FIG. 6   a  the medicament delivery device  1  is ready for use, wherein the signal generating member  110  is at a predetermined distance “D” from the inner distal surface of the tubular extension part  22 . 
     In  FIG. 6   b  the delivery procedure is initiated and the plunger rod  90  moves in the proximal direction forcing the slidable stopper  83  (not shown) to expel the medicament via the delivery member  61 . When the distal end of the plunger rod  90  has passed the proximal part of the signal generating member  110  the arms  111  of the signal generating member  110  flexes inwards allowing the signal generating member  110  to move in the distal direction, resulting in that a sound, and/or a tactile signal and/or a visual signal is generated when the signal generating member  110  contacts the inner distal surface of the tubular extension part  22 . This is illustrated by  FIG. 6   c.    
       FIG. 7-FIG .  11  show side views along the longitudinal axis of the medical delivery device  1 . For sake of simplicity only features relevant for describing the signal generation are indicated; in addition some main parts of the medical delivery device  1  are indicated in  FIG. 7-FIG .  11 . 
       FIG. 7  shows the medicament delivery device in an initial state where the cap  10  is still attached to the medicament delivery device. The container  80  is arranged within the medicament delivery device having a predetermined volume of medicament and also provided with a delivery member  61  and a slidable stopper  83  at its distal end. The second resilient member  34  is arranged in the proximal end of the medicament delivery device applying a force to the tubular activation member  30  in the proximal direction. The plunger rod  90  has a proximal end in contact with the slidable stopper  83  and encloses, at least partly, the first resilient member  91  which is adapted to apply a force to the plunger rod  90  in the proximal direction. The distal part of the plunger rod  90  is arranged in the tubular extension part  22  in combination with the signal generating member  110 . In the most distal part of the medicament delivery device  100  is indicated the distance “D”, i.e. the “sound-generating” distance between the distal part of the signal generating member  110  and the inner distal surface of the tubular extension part  22 . 
       FIG. 8  shows the medicament delivery device in the final locked state, where the tubular activation member  30  is locked in its proximal position, protecting the delivery member  61 . 
       FIG. 9  shows the medicament delivery device where the cap  10  has been removed from the medicament delivery device resulting in that the tubular activation member  30  is moved forward due to the forces exerted by the second resilient member  24 . In the figure is shown in greater scale the proximal part of the signal generating member  110  and its support members  113 . 
       FIG. 10  shows the medicament delivery device where the tubular activation member  30  is forced in the distal direction resulting in that the plunger rod  90  is released to be able to apply forces to the slidable stopper  83  resulting in that the medicament is delivered. In the figure is shown in greater scale the proximal part of the signal generating member  110  and its support members  113  and also the most distal part of the medicament delivery device. 
       FIG. 11  shows the medicament delivery device where the delivery has been made. The plunger rod  90  has now forced the slidable stopper  83  to expel all medicament from the container  80  through the delivery member  61 . When the distal part of the plunger rod  90  passes by the distal part of the signal generating member  110  the arms  111  are allowed to move inwards due to the pre-tension of the arms (illustrated by the upper in-zoomed part) and the signal generating member  110  is released and moves thereby in the distal direction generating a signal, when reaching the distal end surface of the tubular extension part  22  (illustrated by the lower in-zoomed part). 
     Thus is illustrated a signal generating member  110  provided with two arms  111 . As indicated above, a higher number of arms is naturally possible within the scope of the present invention as defined by the appended claims. If a higher number of arms is considered, e.g. three or four, it is important that they all are pre-tensioned such that they exert radially inward directed forces and also that they are evenly distributed in a cross-sectional plane of the signal generating member  110  in order to securely hold drive means in the pre-tensioned state. 
     With references mainly to  FIG. 7  to  FIG. 11  the operation of the medicament delivery device  1  will now be described in more detail. In the pre-tensioned state, the at least one protrusion  95  is abutting the ledge  106  and the groove  105  is not aligned with the flexible tongue  121  that is preventing release of the plunger rod  90 . When the cap  10  is removed the medicament delivery device  1  is ready for use. The tubular activation member  30  is now in its most proximal position and the medicament delivery device  1  is ready for use. The tubular activation member  30  is forced in the distal direction by the user and the protrusion  35  is moved along the groove from position  101  to position  102  achieving an anticlockwise rotation of the tubular operation member  100 , seen from the distal end. During the rotation of the tubular operation member  100  the protrusion  95  is moved along the ledge  106  and finally comes off the ledge  106 . Alignment of groove  105  with flexible tongue  121  enables the release of the pre-tensioned plunger rod  90  to move in the proximal direction, by the force exerted by the first resilient member  91 , and to apply forces to the slidable stopper  83  that is forced to move in the proximal direction and the medicament is thus delivered. When the medicament has been delivered and the medicament delivery device is removed from the delivery site, the tubular activation member  30  is forced in the proximal direction, by means of the second resilient member  34  and the locking means, e.g. a flexible tongue  104  (see  FIG. 5 ), on the at least one groove of the tubular operation member  100  which locks the radially inwards extending protrusion  35  when the radially inwards extending protrusion  35  is moved over the tongue  104 . The medicament delivery device  1  further comprises a locking means interactively connected to the tubular activation member  30 . The locking means is a flexible tongue  104  on the at least one groove of the tubular operation member  100  which locks the radially inwards extending protrusion  35  when said radially inwards extending protrusion  35  is moved over the tongue  104 . 
     The generation of the signal functions as follows. When the drive means is in the pre-tensioned state, the distal end of the u-bracket  110  is arranged at a predetermined distance “D” (see  FIG. 6   a ) from an inner distal surface of said tubular extension part  22  and when the drive means are in the released state, the distal end of the u-bracket  110  is in contact with the inner distal surface of said tubular extension part  22 . The audible and/or tactile and/or visible confirmation signal is generated when the distal end of the u-bracket  110  hits and contacts the inner distal surface of the tubular extension part  22  by a remaining force exerted by said first resilient member  91 . Thus, during the delivery procedure, when the distal end of the plunger rod  90  passes by the supporting members  113 , the arms  111  with the support members  113  are released and allowed to move in a radial inward direction, due to a pre-tension of the arms  111 , enabling the u-bracket  110  to move in the distal direction and the signal, typically an audible sound and/or a visual signal and/or a tactile signal is generated, when the u-bracket  110  hits the distal end of the tubular extension part  22 . In the pre-injection state the u-bracket  110  is arranged such that the arms  111  are positioned in a space along the plunger rod  90  between the plunger rod  90  and the tubular extension part  22  enclosing the plunger rod  90 . The support members  113  must have an extension in the radial outward direction that exceeds the radial extension of the space between the plunger rod  90  and the inner wall of the tubular extension part  22  to secure that the signal generating member  110  is not released prior the plunger rod  90  has moved away from between the arms  111 . the outer distal surface of the distal transversal end wall  112  may further have a protrusion (not illustrated), adapted to be guided through an opening, typically a through hole (also not illustrated) of the distal end wall of the tubular extension part  22  and extends distally a predetermined distance over the outer surface of said tubular extension part  22 . In an exemplary embodiment of the invention, the distally extending protrusion has a bright and/or different colour than the rest of the device for generating a visual signal. Thus, said protrusion will enable both a tactile and a visual signal when the u-bracket  110  hits the distal end of the tubular extension part  22 . 
     It is however to be understood that embodiments described above and shown in the drawings are to be regarded only as non-limiting examples of the present invention and that may be modified within the scope of the appended patent claims.