1. Patent Search
  2. Details

AUTO INJECTOR AND CASSETTE SYSTEM WITH INDEX RING IN THE CASSETTE

20240316276 ยท 2024-09-26

    Inventors

    Cpc classification

    International classification

    Abstract

    The invention relates to a system comprising a cassette and an auto injector for delivery of medicament. The cassette for containing the medicament comprises an index ring.

    Claims

    1. A cassette for use in an auto injector for administering a medicament, the cassette extending in a longitudinal direction (L) from a proximal end (102) to a distal end (104), the cassette (100) comprising: a syringe holder (300) for receiving a syringe (200) containing the medicament; a skin sensor (400) longitudinally movable relative to the syringe holder (300) between a plurality of longitudinal positions including at least: a proximal longitudinal position (LP); and a distal longitudinal position (LD); an index ring (500) rotatable relative to the skin sensor (400) between a plurality of rotational positions including at least: a first rotational position (R1) in which the skin sensor (400) is prevented from moving distally; and a second rotational position (R2) in which the skin sensor (400) is moveable between the distal longitudinal position and the proximal longitudinal position (LP); wherein the rotational position of the index ring (500) is configured to be controlled by one or more release members (1006) in the auto injector when the cassette (100) is secured in the auto injector (1000).

    2. The cassette according to any preceding claim, wherein when the skin sensor (400) is in the proximal longitudinal position (LP), and the index ring is in the first rotational position, the skin sensor (400) is prevented from moving distally from the proximal longitudinal position (LP) by the index ring.

    3. The cassette according to any preceding claim, wherein prior to use, the index ring is in the first rotational position (R1) and the skin sensor (400) is locked relative to the syringe holder (300) in an initial locked position (LP1).

    4. The cassette according to any preceding claim, wherein when the index ring (500) is in the second rotational position (R2), the skin sensor (400) is longitudinally movable relative to the index ring (500).

    5. The cassette according to any preceding claim, wherein when the index ring is in the second rotational position (R2), the skin sensor (400) is unlocked and able to move relative to the syringe holder (300) in a proximal direction and/or a distal direction.

    6. The cassette according to any preceding claim, wherein the index ring comprises a tubular index ring part (520) extending around a tubular skin sensor part (420).

    7. The cassette according to any preceding claim, wherein the index ring comprises a tubular index ring part (520) extending around the syringe holder (300).

    8. The cassette according to any preceding claim, wherein the skin sensor (400) comprises a protruding tab (408) on an outer surface of the skin sensor (400), and the index ring (500) comprises a first longitudinally extending part (506) with a first recess (508, 508) in which the protruding tab (408) is confined prior to use.

    9. The cassette according to any preceding claim, wherein the index ring (500) comprises a locking tab (507), and the skin sensor (400) comprises a first locking recess (412) in which locking tab (507) is confined prior to use.

    10. The cassette according to any preceding claim, wherein the index ring (500) is configured for moving between the plurality of rotational positions when the cassette (100) is inserted in the auto injector (1000) and a release member (1006) comprised in the auto injector travels proximally into in the cassette (100) and comes in contact with the index ring (500).

    11. The cassette according to any preceding claim, wherein the index ring comprises a track (530) extending from a first corner (532) to a second corner (534), wherein the index ring (500) is configured for rotating from the first rotational position (R1) to the second rotational position (R2) when the cassette (100) is inserted in the auto injector (1000) and a release member (1006) comprised in the auto injector travels proximally inside the track (530).

    12. The cassette according to claim 11 wherein the index ring comprises a first radially extending part (522) having a first surface area (528) extending between a first proximal surface (524) and a first distal surface (526), wherein the track (530) is positioned on the surface area (528).

    13. The cassette according to claim 11, wherein the track (530) is positioned on the first longitudinally extending part (506).

    14. The cassette according to any of the claims 11-13, wherein the index ring is configured for rotating to the first rotational position when the release member (1006) comprised in the auto injector travels distally inside the track (530).

    15. The cassette according to any of the claims 12-14, wherein the first radially extending part (522) is part of the tubular index ring part (520).

    16. The cassette according to any of the claims 11-15, wherein the track (530) extends from the first corner (532) in an angled direction towards the second corner (534), wherein the angled directions is between 20 and 70 degrees, such as between 30 and 60 degrees, such as between 35 and 55 degrees, such as between 40 and 50 degrees, such as approximately 45 degrees relative to the longitudinal direction of the cassette.

    17. The cassette according to claim 16, wherein the track (530) comprises a first track section (536), a second track section (538) and a third track section (540), wherein: the first track section (536) extends from the first corner (532) in a first angled direction towards a first middle point (542); the second track section (538) extends from the first middle point (542) to a second middle point (544) along the longitudinal direction of the cassette in a second angle direction; the third track section (540) extends from the second middle point (544) in a third angled direction towards the second corner (534), wherein the first and/or third angled directions are between 20 and 70 degrees, such as between 30 and 60 degrees, such as between 35 and 55 degrees, such as between 40 and 50 degrees, such as approximately 45 degrees relative to the longitudinal direction of the cassette, and wherein the second angled directions is between-20 and 20 degrees, such as between-10 and 10 degrees, such as approximately 0 degrees relative to the longitudinal direction of the cassette.

    18. The cassette according to any preceding claim, wherein prior to use, the skin sensor (400) is locked in a initial locked position (LP1), and after use, the skin sensor is in a final locked position (LP3), wherein the initial locked position (LP1) is positioned between the final locked position (LP3) and the distal longitudinal position (LD).

    19. The cassette according to any preceding claim, wherein the skin sensor (400) comprises a protruding tab (408) on an outer surface of the skin sensor (400), and the index ring (500) comprises a first longitudinally extending part (506) with a first recess (508, 508) in which the protruding tab (408) is confined prior to use.

    20. The cassette according to any preceding claim, wherein the index ring (500) comprises a locking tab (507), and the skin sensor (400) comprises a first locking recess (412) in which locking tab (507) is confined prior to use.

    21. The cassette according to any of the claims 19-20, wherein the first longitudinally extending part (506) extends proximally from the first proximal surface (524) on the first radially extending part (522).

    22. The cassette according to any of the claims 19-21, wherein the protruding tab (408) abuts the first proximal surface (524) when the skin sensor (400) is in the distal longitudinal position (LD) thereby preventing distal movement of the skin sensor (500) relative to the syringe holder (300).

    23. The cassette according to any of the claims 20-21, wherein the skin sensor (400) comprises a second distal surface (424), wherein the second distal surface (424) abuts the second proximal surface (514) of the second radially extending part (512) when the skin sensor (500) is in the distal longitudinal position (LD) thereby preventing distal movement of the skin sensor (500) relative to the syringe holder (300).

    24. The cassette according to any of the claims 19-22, wherein the index ring (500) further comprises a second radially extending part (512) having a second proximal surface (514) and a second distal surface (516, 516).

    25. The cassette according to claim 24, wherein the protruding tab (408) is abutting the second proximal surface (514) when the skin sensor is in the final locked position (LP3) and the index ring (500) is in the first rotational position (R1) thereby preventing distal movement of the skin sensor relative to the syringe holder.

    26. The cassette according to claim 24, wherein the distal surface (416) is abutting the second proximal surface (514) when the skin sensor is in the final locked position (LP3) and the index ring (500) is in the first rotational position (R1) thereby preventing distal movement of the skin sensor relative to the syringe holder.

    27. The cassette according to any of the claims 24-26, wherein the second radially extending part (512) is connected to a proximal end of the first longitudinally extending part (506).

    28. The cassette according to any of the claims 24-27, wherein the index ring (500) comprises a second longitudinally extending part (518) extending from the first proximal surface (524) of the first radially extending part (522) and connected to the second radially extending part (512) at a proximal end of the second longitudinally extending part (518).

    29. The cassette according to any of the claims 18-28, wherein the index ring (500) is configured for being rotated to a cap-release rotational position (Rcr) positioned between the first rotational position (R1) and a delivery rotational position (Rd), wherein in the cap-release rotational position (Rcr), the skin sensor is movable between the distal longitudinal position (LD) and an intermediate position (LP2), wherein the intermediate position (LP2) is positioned between the final locked position (LP3) and the initial locked position (LP1).

    30. The cassette according to claim 29, wherein the index ring (500) is in the cap-release rotational position (Rcr) when the track-guide protrusion (1008) comprised in the auto injector is in the second track section (538).

    31. The cassette according to any of the claims 29-30, wherein when the index ring is in the cap-release rotational position (Rcr), the skin sensor (400) is prevented from moving from the intermediate position (LP2) to the final locked position (LP3).

    32. The cassette according to any of the claims 29-31, wherein when the index ring is in the cap-release rotational position (Rcr) and the skin sensor (400) is in the intermediate position (LP2), the protruding tab (408) abuts the second distal surface (516, 516) on the index ring.

    33. The cassette according to any of the claims 29-31, wherein when the index ring is in the cap-release rotational position (Rcr) and the skin sensor (400) is in the intermediate position (LP2), the locking tab (507) on the index ring (500) abuts a second locking tab (415) on the skin sensor (400).

    34. The cassette according to any of the claims 29-33, wherein the skin sensor (400) is configured for being moved to the distal longitudinal position (LD) by a user pushing the skin sensor (400) against an injection site when the index ring is: in the cap-release rotational position (Rcr), or between the cap-release rotational position (Rcr) and the delivery rotational position (Rd), or in the delivery rotational position (Rd).

    35. The cassette according to any of the claims 18-34, wherein the cassette further comprises a syringe (200) having: a syringe compartment (202) containing the medicament; an outlet (204) at a proximal end (202) of the syringe compartment; a stopper (210) positioned inside the syringe compartment, wherein the stopper is movable from a distal end (204) of the syringe compartment towards the proximal end of the syringe compartment for emptying the medicament in the syringe compartment through the outlet; wherein when the skin sensor (400) is in the final locked position (LP3) and the index ring (500) is in the first rotational position (R1), the skin sensor (400) covers the syringe outlet (204), and wherein when the skin sensor (400) is in the distal longitudinal position (LD) and the index ring (500) is in the second rotational position (R2), the syringe outlet (204) is exposed.

    36. The cassette according to claim 35, wherein medicament can be delivered by an auto injector induced proximal movement of the stopper (210) inside the syringe compartment (206) when the skin sensor (400) is in the distal longitudinal position (LD) and the index ring is in the delivery rotational position (Rd).

    37. The cassette according to any of the claims 29-36, wherein the first longitudinally extending part (506) comprising a second recess (510, 510) in which the protruding tab (408) is confined when the skin sensor is in the intermediate position (LP2) and the index ring is in the first rotational position (R1).

    38. The cassette according to any of the claims 29-36, wherein the protruding tab (507) on the first longitudinally extending part (506) is confined in a second locking recess (414) on the skin sensor when the skin sensor is in the intermediate position (LP2) and the index ring is in the first rotational position (R1).

    39. The cassette according to any preceding claim, wherein the index ring (500) is longitudinally locked relative to the syringe holder (300).

    40. The cassette according to any preceding claim, wherein the skin sensor (400) and the syringe holder (300) are rotationally locked.

    41. The cassette according to any preceding claim, wherein the cassette further comprises a cassette housing (600) and a removable cassette cap (700) positioned at a proximal end (602) of the cassette housing (600), wherein the cassette housing (600) at least partly encloses the syringe holder (300), the syringe (200) when positioned in the syringe holder (300), the skin sensor (400), and the index ring (500) at least prior to use.

    42. The cassette according to claim 41, wherein the cassette cap (700) comprises one or more cap locking parts (706) extending distally from a proximal end (702) of the cassette cap (700), wherein prior to use, a cassette cap locking protrusion (708) on each of the one or more cap locking parts (706) is secured inside the cassette housing (600).

    43. The cassette according to claim 42, wherein: the skin sensor (400) comprises a recess (406) and ramp (410) at the proximal end of the skin sensor (400), the recess (406) being positioned distally of the ramp (410); and the cassette housing (600) comprising a cap holding part (608) extending radially inwardly at the proximal end (602) of the cassette housing (600); wherein prior to removal of the cassette cap (700), an inwardly extending part (709) of the cassette cap locking protrusion (708) on each of the one or more cap locking parts (706) is secured between the recess (406) of the skin sensor and the cap holding part (608), and is further abutting the proximal protruding part (410) preventing proximal movement of the cassette cap (600).

    44. The cassette according to any of the claims 42-43, wherein upon proximal movement of the skin sensor from the initial locked position (LP1) to the intermediate position (LP2), the cassette cap locking protrusions (708) are moved to a position outside the cassette housing (600), and wherein when the skin sensor is in the intermediate position (LP2), removal of the cassette cap (700) is possible.

    45. The cassette according to any of the claims 41-44, wherein the syringe (200) comprises a removable needle shield (212) covering the syringe outlet (208) prior to use, and wherein the cassette cap comprises a second distally extending part (710) extending around and grapping the needle shield (212), thereby removing the needle shield (212) when the cassette cap (700) is removed from the cassette housing (600).

    46. The cassette according to any of the claims 35-45, wherein the syringe outlet is a hollow needle.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0164] Various examples are described hereinafter with reference to the figures. Like reference numerals refer to like elements throughout. Like elements will, thus, not be described in detail with respect to the description of each figure. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the claimed invention or as a limitation on the scope of the claimed invention. In addition, an illustrated example needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated, or if not so explicitly described.

    [0165] FIGS. 1a-b show exploded views of a first example of a cassette extending along a longitudinal direction L, and FIG. 1c show the cassette housing in a side view.

    [0166] FIGS. 2a-c show an auto injector configured for receiving a cassette as shown in FIGS. 1a-c, where FIG. 2a shows the assemble injector, FIG. 2b shows a view of the surface in the auto injector in contact with the cassette, and FIG. 2c shows an exploded view of the auto injector.

    [0167] FIG. 3a show the plurality of longitudinal positions which the skin sensor may move into relative to the syringe holder, and FIG. 3b shows the rotational positions which the index ring may be rotated between.

    [0168] FIGS. 4a-i show the syringe holder, the skin sensor, and the index ring of the cassette from FIGS. 1a-b, and the injector release member shown in FIGS. 2c and 11a-d in different skin sensor longitudinal positions and index ring rotational positions as the injector release member moves longitudinally in the index ring track.

    [0169] FIGS. 5a-c show the assembly of the syringe holder in the cassette as shown in the previous figures.

    [0170] FIGS. 6a-i show a second example of the syringe holder, the skin sensor, and the index ring, and the injector release member in different skin sensor longitudinal positions and index ring rotational positions as the injector release member moves longitudinally in the index ring track.

    [0171] FIGS. 7a-b show a third example of the syringe holder, the skin sensor, and the index ring and FIG. 7c shows the cassette housing in a third example.

    [0172] FIGS. 8a-g show the syringe holder, the skin sensor, and the index ring of FIGS. 7a-b, and the injector release member in different skin sensor longitudinal positions and index ring rotational positions as the injector release member moves longitudinally in the index ring track, and FIGS. 8h-i show a cut-through of the cassette housing and the skin sensor showing the skin sensor in non-locked position (FIG. 8h) and the final position LP3 (FIG. 8i).

    [0173] FIGS. 9a-d show the removal of the cassette cap from the cassette.

    [0174] FIGS. 10a-d show the clutch coupling parts in different configurations during medicament delivery.

    [0175] FIGS. 11a-d show a simplified version of FIGS. 10a-d.

    [0176] FIGS. 12a-b show the clutch ring, and FIGS. 12c-d show the injector chassis with the clutch interacting part.

    [0177] FIGS. 13a-e show the locking of the cassette in the auto injector.

    [0178] FIGS. 14a-e show an example of a syringe holder suitable for use with any of the above described examples of the cassette.

    [0179] FIGS. 15a-d show the syringe holder of FIGS. 14a-e with a syringe positioned inside the syringe holder.

    DESCRIPTION OF EXAMPLES

    [0180] Exemplary examples will now be described more fully hereinafter with reference to the accompanying drawings. In this regard, the present examples may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the examples are merely described below, by referring to the figures, to explain aspects. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items. Expressions such as at least one of, when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

    [0181] In the drawings, thicknesses of a plurality of layers and areas are illustrated in an enlarged manner for clarity and ease of description thereof. When a layer, area, element, or plate is referred to as being on another layer, area, element, or plate, it may be directly on the other layer, area, element, or plate, or intervening layers, areas, elements, or plates may be present therebetween. Conversely, when a layer, area, element, or plate is referred to as being directly on another layer, area, element, or plate, there are no intervening layers, areas, elements, or plates therebetween. Further when a layer, area, element, or plate is referred to as being below another layer, area, element, or plate, it may be directly below the other layer, area, element, or plate, or intervening layers, areas, elements, or plates may be present therebetween. Conversely, when a layer, area, element, or plate is referred to as being directly below another layer, area, element, or plate, there are no intervening layers, areas, elements, or plates therebetween.

    [0182] The spatially relative terms lower or bottom and upper or top, below, beneath, less, above, and the like, may be used herein for ease of description to describe the relationship between one element or component and another element or component as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device illustrated in the drawings is turned over, elements described as being on the lower side of other elements, or below or beneath another element would then be oriented on upper sides of the other elements, or above another element. Accordingly, the illustrative term below or beneath may include both the lower and upper orientation positions, depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as below or beneath other elements would then be oriented above the other elements. The exemplary terms below or beneath can, therefore, encompass both an orientation of above and below, and thus the spatially relative terms may be interpreted differently depending on the orientations described.

    [0183] Throughout the specification, when an element is referred to as being connected to another element, the element is directly connected to the other element, or electrically connected to the other element with one or more intervening elements interposed therebetween.

    [0184] The terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting. As used herein, the singular forms a, an, and the are intended to include the plural forms, including at least one, unless the content clearly indicates otherwise. At least one is not to be construed as limiting a or an. It will be further understood that the terms comprises, comprising, includes and/or including, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

    [0185] It will be understood that, although the terms first, second, third, and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element discussed below could be termed a second element or a third element, and a second element and a third element may be termed likewise without departing from the teachings herein.

    [0186] About or approximately as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, about may mean within one or more standard deviations, or within +30%, 20%, 10%, 5% of the stated value.

    [0187] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this invention pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined in the present specification.

    [0188] Exemplary examples are described herein with reference to cross track section illustrations that are schematic illustrations of idealized examples, wherein like reference numerals refer to like elements throughout the specification. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, examples described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims. Some of the parts which are not associated with the description may not be provided in order to specifically describe exemplary examples of the present disclosure.

    [0189] FIGS. 1a-b show exploded views of a cassette 100 extending along a longitudinal direction L, and a syringe 200 for being mounted in the cassette 100. The difference between FIG. 1a and FIG. 1b is in the size of the syringe 200, where the syringe 200 in FIG. 1a is larger than that shown in FIG. 1b. When a thin syringe 200 is to be included in the cassette 100, an additional syringe sleeve 250 is used for ensuring that the syringe 200 is sufficiently secured in the cassette 100 during use.

    [0190] The syringe 200 extends from a proximal end 202 to a distal end 204. At the distal end 202 of the syringe 200 is a flange 220, which assists in securing the syringe 200 inside the cassette 100. The medicament is contained inside a syringe compartment 206, which is in fluid connection with a syringe outlet 208. Inside the syringe compartment 206 is a stopper 210, which pushes medicament out of the syringe outlet 208 when moving in the proximal direction. Normally, the stopper 210 is pushed in the proximal direction by means of a plunger rod included in an auto injector into which the cassette 100 with the syringe 200 is mounted.

    [0191] In the shown examples, the syringe outlet 208 is a hollow needle attached to the syringe compartment 206. The needle 208 may be detachable to the syringe compartment by means or e.g. threaded connection or a Luer lock, or be an integral part of the syringe 200 as shown in FIGS. 1a-b. The syringe compartment 206 has a shoulder 218 at its proximal connecting to the syringe outlet 208. Positioned around the syringe shoulder 218 is a needle shield 212, e.g. a rigid needle shield. The needle shield 212 will normally be constructed from two parts; an inner part 214 and an outer part 216 as shown in FIG. 1b. The needle shield 212 protects the needle prior to use.

    [0192] The syringe holder 300 extends from a proximal end 302 to a distal end 304 and is has an opening 306, 315 at both of these ends. The syringe 200 is mounted in the syringe holder 300 through the opening 315 at the distal end 304 of the syringe holder 300. When mounted in the syringe holder 300, the syringe compartment 206 is contained in a syringe holder tubular part 310 having a syringe holder tubular part inspection opening 312 through which the syringe 200 can be inspected. At the distal end 304 of the syringe holder 300 is a distal tubular ring part 314 having a larger outer diameter than that of the syringe holder tubular part 310. At the most distal end, there is a hinged syringe holder lid 330 with a lid opening 332 having a diameter, which allows passage of a plunger rod included in the auto injector there through. The syringe holder lid 330 is closed during assembly when a syringe 200 has been inserted into the cassette 100, as shown in FIGS. 5a-c. A lid locking tab 334 on the syringe holder lid 330 locks inside a lid locking opening 318 on the distal tubular ring part 314, when the hinged syringe holder lid 330 is closed after assembly of a syringe 200 inside the syringe holder 300. Figure s 5a-c show the assembly of syringe holder 300 in the cassette 100 in FIGS. 5a-b. Between the views in FIGS. 5b and 5c, it is to be understood that a syringe 200 may be inserted in the syringe holder 300.

    [0193] The cassette 100 may be fully assembled apart from the closing of the syringe holder lid 330 for easy delivery to a user. Alternatively, the syringe holder lid 330 may be opened again after transport for mounting of a syringe 200. The user may then insert the syringe 200 and close the syringe holder lid 330. Other means for securing the syringe 200 inside the syringe holder 300 may also be imagined. For example, the syringe holder lid 330 may be substituted with flexible arms, which flex inwardly to secure the syringe 200 after mounting of the same in the syringe holder 300.

    [0194] The proximal opening 306 in the syringe holder 300 has a diameter, which allows the needle shield 212 to pass there through, but which prevents the syringe compartment 206 to pass there through. The proximal opening 207 has an inwardly extending support surface 308 for supporting the syringe shoulder 218.

    [0195] The syringe sleeve 250 shown in FIG. 1b is used when the syringe compartment 206 has a diameter, which is similar to the diameter of the proximal opening 306 in the syringe holder 300. In order to ensure that the syringe 200 does not pass through the proximal opening 306, when e.g. the needles shield is removed, the syringe 200 is mounted in the syringe sleeve 250 prior to been positioned inside the syringe holder 300. The syringe sleeve 250 shown in FIG. 1b has a C-shape with a longitudinal mounting opening 258, which allows for sideways mounting of the syringe 200 in the syringe sleeve 250. At the proximal end 252 of the syringe sleeve 250 is an inward protruding support surface 256 against which the syringe should 218 rests. The needle shield 212 will be positioned outside the syringe sleeve 250 such that the inward protruding support surface 256 is placed between the needle shield 212 and the syringe shoulder 218. When mounted in the syringe sleeve 250, the syringe flange 220 will normally rest on a distal syringe sleeve support surface 260 at the distal end 254 of the syringe holder 250. The syringe 200 mounted in a syringe sleeve 250, may be positioned in a syringe holder 300 through the opening 315 in at the distal end 304 of the syringe holder 300 in the same manner as a larger syringe 200 is mounted into the syringe holder 300. When mounted in the syringe holder 300, the proximal end 252 of the syringe sleeve 250 is resting on the inwardly extending support surface 308 with the needle shield 212 extending in the proximal direction outside the syringe holder 300.

    [0196] Apart for the syringe sleeve 250 and the diameter of the syringe 200, the remaining cassette parts shown in FIG. 1a and FIG. 1b are the same, and includes a cassette housing 600, a skin sensor 400, a cap 700, an index ring 500, and possibly a cassette housing cover 800. The cassette housing cover 800 may be formed as an integral part of the cassette housing 700.

    [0197] The cassette housing 600 extends from a proximal end 602 to a distal end 604 and has an opening 606 at the distal end 602 through which the index ring 500, the skin sensor 400, and the syringe holder 300 is mounted. When the cassette 100 is assembled, the cassette housing 600 at least partly if not fully encloses the syringe holder 300, the syringe 200 when positioned in the syringe holder 300, the skin sensor 400, and the index ring 500. The syringe holder 300 will normally be longitudinally and rotationally locked to the cassette housing 600. The cassette housing 600 has an inspection opening 610 on at least one surface side allowing the user to inspect the syringe compartment 206 containing the medicament when the syringe 200 is mounted inside the cassette 100. The cassette 100 may be symmetrically constructed such that it may be mounted in an auto injector in different orientations. At the distal end of the cassette housing, cassette securing tabs 612 are positioned. These are also visible in FIG. 1c showing the cassette housing 600 in a side-way view, where also the inspection opening 610 is clearly viewable. The locking mechanism is shown and described in FIGS. 13a-e.

    [0198] The cassette cap 700 is removably attached to the cassette housing 600 at the proximal end 602 of the cassette housing 600. The cassette cap 700 comprises an inner cassette cap part 714 with second distally extending part 710 in the form of a tubular cap part, which is configured for griping the needle shield 212 by means of e.g. a gripping portion 712 as shown in FIGS. 1a-b. When removing the cassette cap 700, the needle shield 212 is also removed allowing for medicament delivery. Enclosing the inner cassette cap part 714 is an outer cassette cap part 716, which the user can hold when removing the cassette cap 700. The inner and the outer cassette cap parts 714, 716 may also be formed as one integral item. On the inner cassette cap part 716 is also found a cap locking part 706 with a cassette cap locking protrusion 708. The cap locking part 706 with the cassette cap locking protrusion 708 ensures that the cassette cap 700 is firmly secured to the cassette housing 600 before enabling the cassette 100 for cassette cap removal.

    [0199] Positioned around the syringe holder 300 is a skin sensor 400, which extends from a proximal end 402 to a distal end 404. At the distal end 404 of the skin sensor 400 is a distal skin contact surface 405, which rest against the skin of the patient during medicament delivery. At the proximal end 404 is also a proximal recess 406 in which the cassette cap locking protrusion 708 of the cassette cap 700 is secured prior to assembling the cassette 100 in the auto injector 1000 and initiation release of the cassette cap 700 (see FIGS. 9a-d). The proximal recess 406 is adjacent to a protruding tab 408 connected by a proximal protruding ramp 410 as more clearly seen in FIGS. 9a-d.

    [0200] The skin sensor 400 has a tubular skin sensor part 420 from where cassette skin sensor pins 422 extends in the distal direction. The tubular skin sensor part 420 has an inspection opening 426 for inspection of the syringe 200. The skin sensor 400 is normally symmetrically with a cassette skin sensor pin 422 on both sides of the skin sensor 400 and inspection openings 426 on both sides as well.

    [0201] The skin sensor 400 is rotationally locked relative to the syringe holder 300. The skin sensor 400 is movable relative to the syringe holder 300 in the longitudinal direction L. The skin sensor 400 may move relative to the syringe holder 300 between a plurality of longitudinal positions including at least a proximal longitudinal position LP and a distal longitudinal position LD. As seen in FIG. 3a, three proximal positions LP are present apart from the distal position LD. The three proximal positions LP include an initial locked position LP1, an intermediate position LP2, and a final locked position LP3. The proximal positions LP are all positions, where the skin sensor 400 covers the syringe outlet 206 when a syringe 200 is mounted in the cassette 100, whereas the syringe outlet 206 is exposed when the skin sensor 400 is in the distal longitudinal position LD. The proximal positions LP1, LP2, LP3 may be positions in which the skin sensor 400 is locked relative to the syringe holder 300 in at least one longitudinal direction. Thus, in a locked position, proximal and/or distal movement of the skin sensor 400 relative to the syringe holder 300 is prevented. Whether the position is a locked position or not is determined by the rotational position of the index ring 500, as the skin sensor 400 and the index ring 500 are coupled such the rotation of the index ring 500 locks and releases the skin sensor 400 for longitudinal movement in either the proximal and/or the distal direction.

    [0202] The skin sensor 400 also has a first locking recess 412 and a second locking recess 414 for interacting and coupling with the index ring 500. Between the two locking recesses 412, 412 is a first locking tab 413 and distally of the second locking recess 414 is a second locking tab 415. The second locking tab 415 is longer than the first locking tab 413. The distally directed surface of the second locking tab 415 is referred to as the first distal surface 416. The skin sensor 400 also comprises a proximally directed surface referred to as the first proximal surface 418. The first proximal surface 418 is proximally of the first locking recess 412.

    [0203] The index ring 500 extends from a proximal end 502 to a distal end 504. The index ring 500 is positioned around the syringe holder 300 and is longitudinally locked to the syringe holder 300. The index ring 500 is rotationally movable relative to the skin sensor 400/syringe holder 300 between a plurality of rotational positions including at least a first rotational position R1 in which the skin sensor 400 is prevented from moving distally, and a second rotational position R2 in which the skin sensor 400 is moveable between the distal longitudinal position LD and the proximal longitudinal position LP. The rotational positions are illustrated in FIG. 3b, and as seen in FIG. 3b, the two rotational positions; the cap-release rotational position and the delivery rotational position both fall under the definition of a second rotational position R2 in which the skin sensor 400 is moveable between the distal longitudinal position LD and the proximal longitudinal position LP (see also the positions in FIGS. 4b-e)

    [0204] The index ring 500 has two first longitudinally extending part 506 positioned opposite each other on the index ring 500. A tubular index ring part 520 on the index ring 500 is extending around the syringe holder 300. The index ring 500 comprises a first radially extending part 522, which may be part of the first radially extending part 522 as shown most clearly in FIGS. 4a-i. The first radially extending part 522 has a first surface area 528 extending between a first proximal surface 524 and a first distal surface 526 (see e.g. FIG. 4h). The first surface area 528 comprises a track 530 extending from a first corner 532 of the surface area 528 to a second corner 534 of the surface area 528 as shown in FIG. 4a. The surface area 528 on the first radially extending part 522 need not cover the entire surface of the first radially extending part 522, but can instead be a smaller area, which is defined by the by the two corners 532, 534 between which the track 530 extends.

    [0205] The track 530 extends from the first corner 532 in an angled direction towards the second corner 534, wherein the angled directions is between 20 and 70 degrees, such as between 30 and 60 degrees, such as between 35 and 55 degrees, such as between 40 and 50 degrees, such as approximately 45 degrees relative to the longitudinal direction of the cassette. In the track 530m shown most clearly in FIGS. 4a-i, the track 530 comprises a first track section 536, a second track section 538 and a third track section 540. The first track section 536 extends from the first corner 532 in a first angled direction towards a first middle point 542, the second track section 538 extends from the first middle point 542 to a second middle point 544 along the longitudinal direction of the cassette in a second angle direction, and the third track section 540 extends from the second middle point 544 in a third angled direction towards the second corner 534, as shown most clearly in FIG. 4i.

    [0206] The first and/or third angled directions are normally sloping directions, with an angle between 20 and 70 degrees, such as between 30 and 60 degrees, such as between 35 and 55 degrees, such as between 40 and 50 degrees, such as approximately 45 degrees relative to the longitudinal direction of the cassette. The second track section 538 is normally a plateau track section with a second angled directions between-20 and 20 degrees, such as between ?10 and 10 degrees, such as approximately 0 degrees relative to the longitudinal direction of the cassette.

    [0207] On the first longitudinally extending part 506 of the index ring 500 is a second radially extending part 512. The second radially extending part 512 forms a locking tab 507, which is configured for fitting into the two locking recesses 412, 414 on the skin sensor 400. The locking tab 507 has a second proximal surface 514 and a second distal surface 516 of the second radially extending part 512.

    [0208] The position of the locking tab 507 and thereby the rotational position of the index ring 500 relative to the skin sensor 400 is controlled by one or more release members 1006 in the auto injector 1000 when the cassette 100 is secured in the auto injector 1000. More specifically, the index ring 500 is configured for rotating from the first rotational position R1 to a second rotational position R2 when the cassette 100 is inserted in the auto injector 1000 and a track-guide protrusion 1008 comprised in the auto injector travels proximally inside the track 530. When the track-guide protrusion 1008 travels distally again, the index ring 500 rotates back form the second rotational position R2 to the first rotational position R1. Thus, by retrieving the release member 1006/track-guide protrusion 1008 into the auto injector again, the index ring is rotated back to its initial position. As seen in FIG. 3b and FIG. 4b-e, the two rotational positions; the cap-release rotational position and the delivery rotational position both fall under the definition of a second rotational position R2 in which the skin sensor 400 is moveable between the distal longitudinal position LD and the proximal longitudinal position LP. Thus, the second rotational position R2 need not be a position from where the index ring 500 cannot rotate further. The second rotational position may also be an intermediate position in which the skin sensor 400 is unlocked, but in which the skin sensor 400 is still prevented from moving to the most proximal position and/or the most distal position possible.

    [0209] FIGS. 2a-b show the auto injector in an assembled view, and FIG. 2c shows an exploded view of the auto injector 1000 configured for receiving a cassette 100. The auto injector 1000 is extending from a proximal end 1002 to a distal end 1004 along a longitudinal axis L, and comprises an injector housing 1040 and a multiple of internal injector parts positioned inside the injector housing 1040.

    [0210] The cassette 100 is removable received in the auto injector 1000 along the longitudinal direction L. Normally, the cassette 1000 will be received at the proximal end 1002 of the auto injector 1000, thereby making it a front-loaded auto injector. In FIG. 2b, a view inside the injector 1000 showing the cassette abutting surface 1042 where against which the cassette 100 is resting when assembled in the injector 1000 is shown. This view in FIG. 1b also shows the openings in the cassette abutting surface 1042 through which internal injector parts extend during medicament delivery and the preparatory step leading to the medicament delivery. The openings include a cassette detection pin opening 1081 through which a cassette detection pin 1080 extends, a skin sensor pin opening 1028 through which an injector skin sensor pin 1024 extends, and a release member opening 1043 through which a release member 1006 extends. Cassette locking tabs 1086 on the inside of the injector housing 1040 for securing the cassette 100 inside the auto injector 1000 can also be seen in FIG. 1b.

    [0211] As seen most clearly in FIG. 1c, the internal injector parts includes a plunger rod 1018 configured for proximal movement for delivery of medicament. The plunger rod 1018 has an internal threaded surface, which is threadedly engaged with an outer threaded surface of a threaded rod 1014 positioned inside the plunger rod 1018. When the threaded rod 1014 inside the plunger rod 1018 rotates, the plunger rod 1018 is moved along the longitudinal axis L in the proximal or distal direction depending on which way the threaded rod 1014 rotates.

    [0212] The auto injector 1000 comprises a release member 1006, which has two release member pins 1007 with each a track-guide protrusion 1008 (see also FIG. 11a-d). The release member 1006 travels inside the index ring track 530 thereby rotating the index ring 500, when the auto injector is activated after a cassette 100 is mounted in the auto injector 1000. The release member pins 1007 are connected by a release member bridge 1010 with a plunger rod opening 1012 allowing the plunger rod 1018 to pass through for medicament delivery.

    [0213] The release member 1006 and the plunger rod 1018 are connected to a clutch 1030, which is configured for moving between a first clutch position where the plunger rod 1018 and the one or more release members 1006 are longitudinally coupled for proximal movement together; and a second clutch position where the plunger rod 1018 is decoupled from the one or more release members 1006 allowing the plunger rod 1018 to move longitudinally while the one or more release members 1006 are longitudinally stationary. This interaction is shown and discussed in more details in FIGS. 10-12.

    [0214] The auto injector 1000 further comprises an injector skin sensor pin 1024 and a skin sensor spring system 1026, which pushes the injector skin sensor pin 1024 proximally. When the cassette 100 is mounted in the auto injector 1000, the injector skin sensor pin 1024 will push the skin sensor 400 proximally when the skin sensor 400 is free to move proximally, and the user is not pressing the skin sensor in the distal direction simultaneously. Normally, the injector skin sensor pin 1024 will be abutting one of the cassette skin sensor pins 422 in the skin sensor 400.

    [0215] Inside the auto injector 1000 is further a cassette detection pin 1080 and a cassette detection spring 1082, which detects when a cassette 100 has been mounted in the auto injector 1000 by making contact with the other cassette skin sensor pin 422 in the skin sensor 400.

    [0216] As shown in FIG. 2a, the injector housing 1040 has a distal housing section 1044 and a cassette covering section 1046, where the distal housing section 1044 covers the internal injector parts and the proximal cassette covering section 1046 at least partly covers the cassette 100 when mounted in the auto injector 1000. The distal end 104 of the cassette 100 abuts a cassette abutting surface 1042 inside the auto injector 1000 when the cassette 100 is mounted in the auto injector 1000.

    [0217] The internal injector parts also includes a drive module adapted for moving the plunger rod 1018 proximately. The drive module may be constructed in a number of manners of which the solution shown in FIG. 2c is only one example. The drive module shown in FIG. 2c includes a motor 1076 and motor gear wheels 1078 for rotating the threaded rod 1014 inside the plunger rod 1018, a battery 1056 e.g. chargeable from a USB charger accessible via the USB gasket 1068, and a number chassis parts 1070, 1077, 1090, 1094, 1095 and screws 1079 for supporting the drive module parts.

    [0218] The auto injector 1000 further may include a processor controlling the drive module, the processor including a print circuit board (PCB) 1054. Visual indicating signals to the user may be included in the form of light emitting diodes (LEDs) 1064 possibly positioned on a PCB placeholder 1062 or similar. The LEDs are displayed via an LED window frame 1050, a light box placeholder 1058, and a light guide placeholder 1060.

    [0219] The auto injector may be activated by pressing an activation button 1052 positioned on a user interface housing part 1048. Normally, a protective foil 1049 is included to protect the electronic parts inside the injector 1000. For the other internal injector parts, reference is made to the reference list.

    [0220] FIGS. 4a-i show the syringe holder 300, the skin sensor 400, the index ring 500, and the injector release member 1006 in the different skin sensor longitudinal positions and index ring rotational positions as the injector release member 1006 moves longitudinally in the index ring track 530.

    [0221] FIG. 4a shows the initial locked position in which the cassette 100 is in prior to use. The locking tab 507 on the index ring 500 is secured in the first locking recess 412 on the skin sensor 400, which prevents longitudinal movement of the skin sensor 400 relative to the syringe holder 300. The skin sensor 400 is in the initial locked position LP1 and the index ring 500 is in the first rotational position R1. The first rotational position may also be seen as a locking rotational position, since this rotational position always locks the skin sensor 400 longitudinal in one of the proximal longitudinal positions.

    [0222] FIG. 4b shows the cap-release position in which the cassette cap 700 can be removed from the cassette 100 (see description of FIGS. 9a-d for further details). Between FIGS. 4a and 4b, the auto injector track-guide protrusion 1008 on the injector release member 1006 has moved into the index ring track 530 through the injector release member opening 322 and into and along the first track section 536 and is in the second plateau track section 538 in FIG. 4b. This has rotated the index ring 500 into the cap-release rotational position Rcr in which the locking tab 507 is released from the first locking recess 412 in the distal direction allowing the skin sensor to move proximally until the locking tab 507 abuts the second locking tab 415, which is longer than the first locking tab 413 securing the locking tab 507 inside the first locking recess 412 in FIG. 4a. FIG. 4b shows the position of the skin sensor 400 after release, but before the skin sensor 400 is moved from the initial locked position LP1 to the ready-to-remove-cap position LP2.

    [0223] In FIG. 4c, the skin sensor 400 has moved proximately to the intermediate position LP2, where the cassette cap 700 can be removed. The index ring 500 is still in the cap-release rotational position Rcr, and the locking tab 507 abuts the second locking tab 415, which ensures that the skin sensor 400 is prevented from moving further in the proximal direction during cassette cap removal. The skin sensor 400 can however be moved in the distal direction by a user. This is shown in FIG. 4d, where the skin sensor is pushed into the distal longitudinal position LD where the needle 208 is no longer covered by the skin sensor 400 but instead inserted into an injector site. A second proximal surface 514 on the second radially extending part 512/locking tab 507 abuts a second distal surface 424 on the skin sensor 400 therefore preventing further distal movement of the skin sensor 400.

    [0224] When the skin sensor 400 is pushed into the distal longitudinal position LD as shown in FIG. 4d, the auto injector track-guide protrusion 1008 is ready to moved further proximally in the index ring track 530. When moving along the third track section 540, the index ring 500 is rotated to the delivery rotational position Rd as shown in FIG. 4e. When the auto injector track-guide protrusion 1008 reaches this position inside the index ring track 530, the injector release member 1006 is decoupled from the plunger rod 1018 by the clutch 1030 in the auto injector 1000. The plunger rod 1018 is thereby enabled for further proximal movement for medicament delivery while the injector release member 1006 remains in the position as shown in FIG. 4a.

    [0225] After medicament delivery, the user removed the skin sensor from the skin and the injector skin sensor pin 1024 and skin sensor spring system 1026 ensures that the skin sensor is pushed first into the intermediate position LP2 as shown in FIG. 4f and finally into the final position LP3 as shown in FIG. 4g. When the skin sensor 400 is the final position LP3 as shown in FIG. 4g, the plunger rod 1018 moves distally and couples with the injector release member 1006 again when reaching the same coupling point as where it was decoupled during medicament delivery. The plunger rod 1018 and the injector release member 1006 moves together distally, which forces the index ring 500 to rotate from the delivery rotational position Rd into the first rotational position R1 again. When the index ring 500 is in the first rotational position R1 once more, the skin sensor 400 is locked longitudinally, this time in the final position LP3 as shown in FIG. 4h. The locking tab 507 now abuts a first distal surface 416 on the second locking tab 415.

    [0226] FIG. 4i shows the locked position, which the auto injector forces the cassette into if a user having removed the cassette cap when the cassette was in a configuration as shown in FIG. 4c, but for some reason have been prevented from continuing the medicament delivery process by inserting the needle into the injections site by pushing the skin sensor 400 distally. If this happens, the auto injector may be programmed to after a pre-determined time period move the injector release member 1006 distally, whereby the index ring 500 rotates into the first rotational position R1 thereby locking the skin sensor in the intermediate position LP2, where the locking tab 507 is secured in the second locking recess 414 on the skin sensor 400. The cassette 100 will be seen as being a used cassette if the user tries to mount it again the auto injector 1000, since the injection needle 208 may have been contaminated after removal of the needle shield 212 when removing the cassette cap 700.

    [0227] FIGS. 6i-a show a second example of the syringe holder 300, the skin sensor 400, the index ring 500, and the injector release member 1006 in the different skin sensor longitudinal positions and index ring rotational positions as the injector release member 1006 moves longitudinally in the index ring track 530. The positions which are shown are the same in the a-i figures for the examples shown in FIG. 4 and FIG. 6, i.e. FIG. 6a shows the initial locked position in which the cassette 100 is in prior to use; FIG. 6b shows the cap-release position; FIG. 6c shows the skin sensor in the intermediate position LP2, where the cassette cap 700 can be removed; FIG. 6d shows the position, where the skin sensor is pushed into the distal longitudinal position LD, but the index ring not completely rotated for delivery; FIG. 6e shows the delivery position; FIG. 6f shows an intermediate position after delivery; FIG. 6g shows the final position LP3 before locking; and FIG. 6h shows the locked final position. FIG. 6i shows the locked position, which the auto injector forces the cassette into if a user having removed the cassette cap when the cassette was in a configuration as shown in FIG. 6c, but for some reason have been prevented from continuing the medicament delivery process by inserting the needle into the injections site by pushing the skin sensor 400 distally.

    [0228] The differences between the 4a-i figures and the 6a-i figures are the design and form of the skin sensor 400 and the index ring 500. In FIGS. 6a-i, the index ring 500 has a second longitudinally extending part 518 such that the longitudinal extending parts 516, 518 and the radially extending parts 512, 522 form an rectangle. Inside the rectangle on the first longitudinally extending part 506 is a first recess 508 and a second recess 510. These recesses are configured for containing a protruding tab 408 on the skin sensor 400. In the initial locked position LP1 as shown in FIG. 6a, the protruding tab 408 is contained inside the first recess 508. When the skin sensor 400 is in the intermediate position LP2, the protruding tab 408 is either in the second recess 510 if the index ring is rotated to the first rotational position as shown in FIG. 6i, or above the second recess 510, but supported in the proximal direction by the second distal surface 516 of the second radially extending part 512 thereby preventing further proximal movement during cap removal as shown in FIG. 6c. When the delivery of medicament occurs, the index ring 500 is rotated such that the protruding tab 408 is aligned with an opening 513 in the second radially extending part 512 such that when the skin sensor 400 is removed from the injection site, the protruding tab 408 is allowed to pass through the opening 513 in the second radially extending part 512 to the most proximal position, i.e. the final position LP3. This alignment is shown in FIGS. 6e-g. When the index ring 500 is rotated back to the first rotational position R1, the protruding tab 408 is abutting the second proximal surface 514 of the second radially extending part 512 preventing the exposure of the needle 208 after medicament delivery as shown in FIG. 6h.

    [0229] FIGS. 7 and 8 show a third example of the cassette, where FIGS. 7a-b show the syringe holder 300, the skin sensor 400, the index ring 500, FIG. 7c shows the cassette housing 600, FIGS. 8a-g show the syringe holder 300, the skin sensor 400, the index ring 500, and the injector release member 1006 in the different skin sensor longitudinal positions and index ring rotational positions as the injector release member 1006 moves longitudinally in the index ring track 530, and FIGS. 8h-i show a cut-through of the cassette housing 600 and the skin sensor 400 showing the skin sensor 400 in non-locked position (FIG. 8h) and the final position LP3 (FIG. 8i).

    [0230] The differences between FIGS. 4a-i and 6a-i and FIGS. 7a-c and 8a-i, are the design and form of the skin sensor 400 and the index ring 500, the shape of the release member 1006 in the injector 1000, and the locking of the skin sensor 400 in the final locked position LP3. In the third example, the track 530 is positioned on the first longitudinally extending part 506, which is attached to the tubular index part 520 on its outside. The track 530 is an open track. On an inner surface of the longitudinally extending part 506 are a first recess 508, a second recess 510 and an index ring ramp 509 extending distally from the first recess 508. The skin sensor 400 has a protruding tab 408, which is confined in the first recess 508 prior to us as shown in FIG. 8a. After the index ring 500 is rotated to the cap-release rotational position Rcr position as shown in FIG. 8b, the skin sensor 400 moves to the cap-removal position shown in FIG. 8c. The cassette cap 700 and the needle shield 212 can be removed as shown in FIG. 8c. In the position shown in FIG. 8c, the protruding tab 408 rest against the second distal surface 516 of the second radially extending part 512. During distal movement of the skin sensor 400 by the user for insertion of the needle at the injection site, the index ring 500 is rotated to the delivery rotational position Rd as shown in FIG. 8d. Thus, in the third example shown in FIGS. 7a-b and 8a-g, the release member 1006 is not the item rotating the index ring from the cap-release rotational position Rcr to the delivery rotational position Rd, but instead the protruding tab 408 coming in contact with the index ring ramp 509 thereby forcing the index ring 500 to rotate. During medicament delivery as shown in FIG. 8e, the release member 1006 moves further into the cassette 100. After end medicament delivery, the skin sensor 400 moves to the final position LP3 due to the spring force from the skin sensor pin spring system 1024, 1026 in the injector 1000. This is shown in FIG. 8f. In the position shown in FIG. 8g, the skin sensor 400 is in final locked position. In the final locked position LP3, the skin-sensor 400 is pushed proximally by a spring system as described in the previous examples of the cassette and auto injector and locked into a locking position in the cassette housing 600. The locking is obtained by a cassette housing locking protrusion 428 on the skin sensor 400 fitting into a skin sensor locking opening 614 in the cassette housing 600 as shown in FIG. 8i. In the position shown in FIG. 8h, the skin sensor 400 is in non-locked position. The skin sensor locking opening 614 in the cassette housing 600 is visible most clearly in FIG. 7c.

    [0231] In FIG. 7a, an alternative securing of the syringe 200 inside the syringe holder 300 is also shown, where two flexible syringe securing tabs 320 moves from an open to a closed position securing the syringe 200 inside the syringe holder 300.

    [0232] FIGS. 9a-d show the removal of the cassette cap 600 from the cassette 100. The cassette cap 700 has locking cap parts 706 extending distally from a proximal end 702 of the cassette cap 700. Prior to use, a cassette cap locking protrusion 708 on each of the one or more locking cap parts 706 is secured inside the cassette housing 600 by a cap holding part 608, which is extending radially inwardly at the proximal end 602 of the cassette housing 600. At the proximal end 402 of the skin sensor 400, the skin sensor 400 has a ramp 410 and a recess 406 positioned distally of the ramp 410. The ramp 410 normally forms a protruding tab 408. An inwardly extending part 709 of the cassette cap locking protrusion on each of the locking parts 706 are secured between the recess 406 of the skin sensor 400 and a cap holding part 608, and is further abutting the proximal protruding ramp part 410 preventing proximal movement of the cassette cap 600 prior to use as shown in FIG. 9a. This locks the cassette cap 700 to the cassette 100 and prevents that the cassette cap 700 is removed from the cassette 100 before the cassette 100 is assembled inside the auto injector 1000.

    [0233] The cap locking parts 706 and/or the cassette cap locking protrusion 708 on each of the one or more cap locking part 706 are flexible. Upon proximal movement of the skin sensor 400 from the initial locked position LP1 to the intermediate position LP2, the cap locking parts 706 and/or the cassette cap locking protrusion 708 on the locking part 706 first flex slightly radially inwards in the recess 406 of the skin sensor 400 thereby enabling the cassette cap locking protrusion locking protrusions 708 to move proximally pass the cap holding part 608. When the skin sensor 400 is moved from the initial locked position LP1 to the intermediate position LP2, the distal locking ends 708 thereby move outside the cassette housing 600 as shown in FIG. 9b. Since the locking parts 706 and/or the cassette cap locking protrusion 708 on the locking part 706 are configured to flex, they now flex radially outwardly and slide up the ramp 410 as the user removes the cassette cap 700 from the cassette 100. This is shown in FIG. 9c. The cassette cap 700 with the needle shield 212 inside may be positioned on the skin sensor 400 after use to provide an additional security preventing access to the used needle. This is shown in FIG. 9d. The cassette cap 700 is not non-removably connected to the cassette 100 again, but it will stay in position unless pulled off again by a user.

    [0234] FIGS. 10a-d and 11a-d show the clutch coupling and decoupling in the injector 1000, FIGS. 12a-b show the clutch 1030 in detail, and FIGS. 12c-d show the proximal chassis part 1070 in details.

    [0235] The clutch 1030 is positioned around the plunger rod 1018 and next to the release member 1006 such that in the first clutch position shown in FIGS. 10a-b and 11a-b, the plunger rod 1018 and the release members 1006 are longitudinally coupled and move proximally together. The clutch 1030 is a tubular clutch having two clutch tabs 1032 each having a first rotation surface 1034 and a second rotation surface 1036. The proximal chassis part 1070 has a clutch coupling part 1071 with first coupling surfaces 1072 and second coupling surfaces 1073 on each of the small distally extending parts 1075.

    [0236] When the second rotation surface 1036 on the clutch 1030 comes in contact with the second coupling surfaces 1073 on the clutch coupling part 1071, the clutch is rotated from the first clutch position and into the second clutch position as shown in FIGS. 10c-d and 11c-d. In the second clutch position, the plunger rod 1018 is decoupled from the release members 1006 allowing the plunger rod 1018 to move longitudinally while the release members 1006 are longitudinally stationary. When the second rotation surface 1036 on the clutch is not in contact with the second coupling surfaces 1073 on the clutch coupling part 1071, the clutch is in the first clutch position. The clutch 1030 moves proximally with the release members 1006 before the second rotation surface 1036 comes into contact with the second coupling surfaces 1073, and axial rotates when the second rotation surface 1036 comes into contact with the second coupling surfaces 1073, thereby moving from the first clutch position to the second clutch position.

    [0237] The clutch coupling part 1071 also comprises a clutch stopping surface 1074 abutting the clutch 1030 when the clutch 1030 is in the second clutch position thereby preventing the clutch 1030 and the release members 1006 positioned distally of the clutch 1030 from moving proximally with the plunger rod 1018.

    [0238] The plunger rod 1018 comprises a stopping clutch tab 1019, and a distal surface of the stopping clutch tab 1019 is abutting a proximal surface of the release members 1006 when the clutch 1030 is in the first clutch position as shown in FIGS. 10a-b and 11a-b. The stopping clutch tab 1019 rotates the clutch 1030 from the second clutch position to the first clutch position upon distal movement of the plunger rod 1018 after medicament delivery bringing the distal surface of the stopping clutch tab 1019 in contact with the proximal surface of the members 1006 again.

    [0239] The clutch 1030 may be configured for moving from the first clutch position to the second clutch position when the plunger rod 1018 moves distally after medicament delivery. The clutch 1030 is in the first clutch position prior to use and normally moves to the second clutch position when the index ring 500 is also rotated to the delivery rotational position Rd by proximal movement of the one or more release members 1006.

    [0240] When assembling the cassette 100 and the auto injector 1000, the cassette 100 is first loaded into the auto injector 1000. Upon loading of the cassette 100 in the auto injector 1000, cassette securing tabs 612 at the distal end 604 of the cassette housing 600 snap behind corresponding cassette securing openings 1028 in the injector housing 1040. By forward movement of the release member 1006, the cassette securing tabs 612 are prevented from deflecting and exiting the cassette securing openings 1028 in the injector housing 1040 thereby locking the cassette 100 to the auto injector 1000. As the cassette 100 is now firmly locked inside the auto injector 1000. When the cassette release member 1006 moves distally again, the cassette 100 is unlocked. The locking process is shown in FIGS. 13a-e, where FIGS. 13a-c show the cassette being inserted into the injector 1000 and engaging into a snap fit connection. FIGS. 13d-e show the movement of the release member 1006 into the cassette 100 thereby locking the cassette 100 to the injector 1000. Thus, the injector comprises one or more cassette interacting parts 1086 configured for engaging in a snap-fit connection with corresponding one or more cassette securing tabs 612 on the cassette 100 when the cassette is inserted into the injector, and wherein proximal movement of the release member 1006 prevents a disengagement of the snap-fit connection thereby securing the cassette inside the auto injector. The locking mechanism shown in FIGS. 13a-e could alternatively be substituted with the similar locking turned 90 degrees.

    [0241] FIGS. 14a-e show an example of a syringe holder 300 suitable for use with any of the above described examples of the cassette 100. FIGS. 15a-d show the syringe holder 300 of FIGS. 14a-e with a syringe 200 positioned inside the syringe holder 300. The syringe holder 300 is extending in a longitudinal direction L from a proximal end 302 to a distal end 304 as shown in FIGS. 1a-b. The syringe holder 300 comprises the syringe holder tubular part 310 for receiving a syringe 200 and a syringe holder lid 330, which has a slightly different shape compared to that shown in the previous examples.

    [0242] The holder lid 330 has a substantially C-shaped lid part 336 comprising an inner surface 340. The C-shaped lid part 336 may also be referred to as an open circle or a circle with a cut-through opening 337 in the circumference. The cut-through opening 337 may span an area of at least 10%, such as at least 20%, such as at least 30% of a full circular circumference. The substantially C-shaped lid part 336 is hingedly connected to the distal end of the syringe holder tubular part 310. By hingedly connected is meant that the substantially C-shaped lid part 336 can be in at least two positions as shown in FIG. 14a compared to FIGS. 14c-e and FIGS. 15a-d.

    [0243] In FIG. 14a, the syringe holder lid 330 is in an open position allowing for a syringe 200 to be positioned in the syringe holder 300 through the opening 315 in the distal end of the syringe holder tubular part 310.

    [0244] In FIGS. 14c-e and FIGS. 15a-d, the syringe holder lid 330 is in a closed position, where the syringe holder lid 330 prevents the syringe 200 from exiting the syringe holder 300 through the opening in the distal end of the syringe holder tubular part 310. This is also seen in FIGS. 15a-d.

    [0245] Extending radially outward from the substantially C-shaped lid part 336 are a plurality of lid locking tabs 334. These locking tabs 334 are positioned in corresponding syringe holder lid locking openings 318 in the syringe holder tubular part 310 when the substantially C-shaped lid part 336 is in the closed position as shown in FIG. 14b-e. Normally, each of the plurality of lid locking tabs 334 fits into a separate one of the syringe holder lid locking openings 318.

    [0246] The inner surface 340 of the substantially C-shaped lid part 336 seen most clearly in FIG. 14a is oriented towards the syringe 200 when the syringe 200 is positioned in the syringe holder 300. Extending from the inner surface 340 is a plurality of support lid parts 338. In the example shown in FIGS. 14-15, there are four support lid parts 338, but both more or less can be imagined. Compared to the entire inner surface 340 surface area, the support lid parts 338 cover an area of less than 50%, such as less than 40%, such as less than 30%, such as less than 20%, such as less than 10%. Having a broken surface structure on the surface, which the syringe may come in contact with ensures that if the user pushes on the syringe 200 unevenly from a proximal direction, not all of the support lid parts 338 will come in contact with the syringe. This ensures the pushing forces are not transferred around in the entire substantially C-shaped lid part 336. If a user should succeed in pushing so hard on the syringe 200 that one of the locking tabs 334 are pushed out of the syringe holder lid locking opening 318, there is an increased change that the other locking tabs 334 will remain in position thereby providing an increased security preventing the syringe 200 from being pushed out of the distal end of the syringe holder.

    [0247] When the syringe 200 is correctly positioned inside the syringe holder tubular part 310 as shown in FIGS. 15a-d, the syringe 200 is not in direct contact with the syringe holder lid 330. The syringe 200 only comes in contact with the syringe holder lid 330 if it is pushed distally during use. The syringe holder lid 330 therefore has a safety function and not a syringe fixation or syringe holding function. In FIG. 15c, the empty space between the distal end 204 of the syringe 200, i.e. the syringe flange, and the support lid parts 338 is seen most clearly.

    [0248] The substantially C-shaped lid part 336 also has a throughgoing channel 342 in the dividing the substantially C-shaped lid part into two lid sections. The channel 342 does not divide the C-shaped lid part 336 into two completely separate parts, but instead the two sections are connected by a bridge portion 344 also forming the hinged connecting to the distal end of the syringe holder tubular part 310. This is seen most clearly in FIG. 14a-c. The first lid section and the second lid section are at least partly displaceable in relation to each other along the longitudinal axis. By this is meant that one section may be twisted or pushed distally or proximally without moving the other section to the same extend. The flexibility in the substantially C-shaped lid part 336 further ensures that if the user pushes on the syringe 200 unevenly from a proximal direction, only part of the substantially C-shaped lid part 336 is affected since the forces are not easily transferred around in the substantially C-shaped lid part 336.

    REFERENCES

    [0249] 100 cassette [0250] 102 proximal end of the cassette [0251] 104 distal end of the cassette [0252] 200 syringe [0253] 202 proximal end of the syringe/proximal end of the syringe compartment [0254] 204 distal end of the syringe/distal end of the syringe compartment [0255] 206 syringe compartment [0256] 208 hollow needle/syringe outlet [0257] 210 stopper [0258] 212 needle shield/RNS [0259] 214 inner part of the needle shield [0260] 216 outer part of the needle shield [0261] 218 syringe flange [0262] 220 syringe shoulder [0263] 250 syringe sleeve [0264] 252 proximal end of the syringe sleeve [0265] 254 distal end of the syringe sleeve [0266] 256 syringe sleeve inward protruding support surface [0267] 258 C-shaped longitudinal mounting opening [0268] 260 distal syringe sleeve support surface [0269] 300 syringe holder [0270] 302 proximal end of the syringe holder [0271] 304 distal end of the syringe holder [0272] 306 proximal opening in the syringe holder [0273] 308 syringe support surface [0274] 310 syringe holder tubular part [0275] 312 syringe holder tubular part inspection opening [0276] 314 distal tubular ring part [0277] 315 opening in the distal end of the syringe holder [0278] 316 proximal index ring support surface [0279] 318 syringe holder lid locking opening [0280] 320 syringe securing flexible tab at the distal end of the syringe holder [0281] 322 injection release member opening [0282] 330 syringe holder lid [0283] 332 syringe holder lid opening [0284] 334 lid locking tab [0285] 336 C-shaped lid part [0286] 337 opening in the C-shaped lid part [0287] 338 support lid part [0288] 340 inner surface on the C-shaped lid part [0289] 342 C-shaped lid part channel [0290] 344 bridge portion [0291] 400 skin sensor [0292] 402 proximal end of the skin sensor [0293] 404 distal end of the skin sensor [0294] 405 distal skin contact surface of the skin sensor [0295] 406 proximal recess [0296] 408 protruding tab [0297] 410 proximal protruding ramp [0298] 412 first locking recess on the skin sensor [0299] 413 first locking tab [0300] 414 second locking recess on the skin sensor [0301] 415 second locking tab [0302] 416 first distal surface [0303] 418 first proximal surface [0304] 420 tubular skin sensor part [0305] 422 cassette skin sensor pin [0306] 424 second distal surface [0307] 426 inspection opening in the skin sensor [0308] 428 cassette housing locking protrusion [0309] 500 index ring [0310] 502 proximal end of the index ring [0311] 504 distal end of the index ring [0312] 506 first longitudinally extending part [0313] 507 locking tab [0314] 508, 508 first recess on the index ring [0315] 509 index ring ramp [0316] 510, 510 second recess on the index ring [0317] 512 second radially extending part [0318] 513 opening in the second radially extending part [0319] 514 second proximal surface of the second radially extending part [0320] 516, 516 second distal surface of the second radially extending part [0321] 518 second longitudinally extending part [0322] 520 tubular index ring part [0323] 522 first radially extending part [0324] 524 first proximal surface of the first radially extending part [0325] 526 first distal surface of the first radially extending part [0326] 528 first surface area of the first radially extending part [0327] 530 track in the first radially extending part [0328] 532 first corner of the first radially extending part [0329] 534 second corner of the first radially extending part [0330] 536 first section of the track [0331] 538 second section of the track [0332] 540 third section of the track [0333] 542 first middle point of the track [0334] 544 second middle point of the track [0335] 600 cassette housing [0336] 602 proximal end of the cassette housing [0337] 604 distal end of the cassette housing [0338] 606 opening at the distal end of the cassette housing [0339] 608 cap holding part [0340] 610 inspection opening [0341] 612 cassette securing tabs [0342] 614 skin sensor locking opening [0343] 700 cassette cap [0344] 702 proximal end of the cassette cap [0345] 704 distal end of the cassette cap [0346] 706 cap locking part [0347] 708 cassette cap track-guide protrusion/cassette cap locking protrusion [0348] 709 inwardly extending part of the cassette cap locking protrusion [0349] 710 second distally extending part/tubular cap part [0350] 712 gripping portion [0351] 714 inner cassette cap part [0352] 716 outer cassette cap part [0353] 800 cassette housing cover [0354] 1000 auto injector [0355] 1002 proximal end of the auto injector [0356] 1004 distal end of the auto injector [0357] 1006 release member [0358] 1007 release member pin [0359] 1008 track-guide protrusion [0360] 1010 release member bridge [0361] 1012 plunger rod opening [0362] 1014 threaded rod [0363] 1016 motor and threaded rod connector [0364] 1018 plunger rod [0365] 1019 stopping clutch tab [0366] 1020 first plunger rod plug part [0367] 1022 second plunger rod plug part engaging the stopper [0368] 1024 injector skin sensor pin [0369] 1026 skin sensor spring system [0370] 1028 skin sensor pin opening in the cassette abutting surface [0371] 1030 clutch [0372] 1032 clutch tab [0373] 1034 first rotation surface on the clutch tab [0374] 1036 second rotation surface on the clutch tab [0375] 1040 injector housing [0376] 1042 cassette abutting surface [0377] 1043 release member opening in the cassette abutting surface [0378] 1044 distal housing section [0379] 1046 cassette covering section [0380] 1048 first user interface housing part [0381] 1049 protective foil [0382] 1050 LED window frame [0383] 1052 activation button [0384] 1054 Print circuit board (PCB) [0385] 1055 RCT battery [0386] 1056 battery [0387] 1057 adhesive [0388] 1058 light box placeholder [0389] 1060 light guide placeholder [0390] 1062 PCB placeholder [0391] 1064 LED placeholder with an LED [0392] 1066 content management system (CMS) [0393] 1068 USB gasket [0394] 1070 proximal chassis part [0395] 1071 clutch coupling part [0396] 1072 first coupling surface on the clutch coupling part [0397] 1073 second coupling surface on the clutch coupling part [0398] 1074 clutch stopping surface on the clutch coupling part [0399] 1076 motor [0400] 1077 motor flange [0401] 1078 motor gear [0402] 1079 screw [0403] 1080 cassette detection pin [0404] 1081 cassette detection pin opening in the cassette abutting surface [0405] 1082 cassette detection spring [0406] 1084 cassette detect holder [0407] 1086 cassette locking tab in the injector housing [0408] 1088 NFC antenna for detection of the RFID chip on the cassette [0409] 1090 distal end part connecting to the housing [0410] 1092 bearing [0411] 1094 middle chassis part [0412] 1095 distal chassis part [0413] L longitudinal direction [0414] LD distal longitudinal position/delivery position [0415] LP proximal longitudinal position [0416] LP1 initial locked position [0417] LP2 intermediate position/ready-to-remove-cap position [0418] LP3 final locked position [0419] R1 first rotational position/locking rotational position [0420] R2 second rotational position [0421] Rcr cap-release rotational position [0422] Rd delivery rotational position