DE29818721U1 - Injection device - Google Patents

Description

Medico Development Investment Company

ViadelleSchool 19

CH-6612 Ascona

19.10.1998

Injection device

The invention relates to an injection device. - DE 3 638 984 C2 discloses an injection device with a housing and a threaded rod which is provided with an external thread and serves to squeeze liquid out of a liquid container and which is arranged in the housing so that it can be moved axially but cannot be rotated. The threaded rod is used to first insert an injection needle during the injection process and then to inject liquid through this needle.

It is an object of the invention to provide a new injection device.

According to the invention, this object is achieved by an injection device according to claim 1. This makes it possible to rotate the actuator in the first position relative to the axially displaceable part, and thereby to influence the axially displaceable part in a certain way, and after completing this process, the actuator can be brought into the second position in which this rotation is blocked and the actuator is forced to follow the movements of the axially displaceable element, with the actuator being locked to the axially displaceable element in the second position in a particularly preferred manner. This enables two different operating modes of such an injection device, whereby, for example, the first operating mode can be reserved for medical professionals (doctor, nurse), and only the second operating mode is released to the patient, and the patient cannot, for example, return from the second operating mode to the first operating mode. This represents an important safety feature in order to prevent incorrect operation of such an injection device by the patient.

Another solution to the problem is provided by an injection device according to claim 7. Such an injection device has the advantage that a relative rotational movement between the external thread of the

Threaded rod and internal thread of the actuator allow movement of the threaded rod in the proximal direction and in the distal direction, as is necessary, for example, for the reconstitution of an injection liquid, while an axial displacement of the actuator relative to the threaded rod allows the teeth of the internal thread (of the actuator) to slide along the teeth of the external thread and thus enables simple and easily understandable handling by the patient during the injection.

Further details and advantageous developments emerge from the embodiments described below and shown in the drawing, which are in no way to be understood as a limitation of the invention, as well as from the remaining claims. It shows:

Fig. 1 is an external view of an injection device according to the invention in the condition in which it leaves the factory, i.e. before reconstitution of the lyophilisate,

Fig. 2 an external view of the injection device in the state after the device has been prepared for injections, i.e. after the reconstitution of the lyophilisate, and after setting an injection dose of approximately 20 units,

Fig. 3 is a longitudinal section through the injection device of Fig. 1,

Fig. 4 is a longitudinal section analogous to Fig. 3, but perpendicular to the plane of Fig. 3,

Fig. 5 is a longitudinal section through a threaded rod as used in the injection device, seen in the direction of arrows V-V in Fig. 7,

Fig. 6 is a plan view of the threaded rod of Fig. 5, seen in the direction of arrow VI of Fig. 7,

Fig. 7 is a plan view of the upper end of the threaded rod according to Fig.

Vi .if:. Q;-;

and 6,

Fig. 8 a detail VIII of Fig. 5,
Fig. 9 a detail IX of Fig. 5,

Fig. 10 is a three-dimensional representation of a trigger element with locking element used in the injection device according to Figs. 1 to 10,

Fig. 11 is a three-dimensional representation of an actuator used in the injection device,

Fig. 12 an enlarged section of Fig. 4,

Fig. 13 a representation analogous to Fig. 12, but in the position of the parts after completion of a reconstitution,

Fig. 14 is a section taken along the line XIV-XIV of Fig. 13, Fig. 15 is a section taken along the line XV-XV of Fig. 13,

Fig. 16 is a longitudinal section through a preferred connecting part according to the invention,

Fig. 17 is a section through the connecting part of Fig. 16, to which a container with a lyophilized drug is connected,

Fig. 18 is a view showing how a reconstitution begins, Fig. 19 is a view showing the processes during reconstitution, Fig. 20 is an enlarged view of detail XX of Fig. 19, Fig. 21 is an enlarged view of detail XXI of Fig. 19,

Fig. 22 is a diagram showing the suction of the reconstituted liquid back into the injection device,

Fig. 23 is an enlarged view of detail XXIII of Fig. 22,

Fig. 24 is a diagram explaining the dose setting after completion of reconstitution,

Fig. 25 is a diagram to explain the first section of the clamping process, in which the injection needle is displaced along the puncture path into the interior of the housing,

Fig. 26 is an enlarged view of detail XXVI of Fig. 25, Fig. 27 is a view to explain the second section of a tensioning process, in which the injection needle remains in the position shown in Fig. 25 and the actuating button is moved further in the distal direction - in accordance with the set dose,

Fig. 28 is an enlarged view of detail XXVIII of Fig. 27 with a signal button to indicate that reconstitution has taken place,

Fig. 29 is a representation analogous to Fig. 27, but in a plane perpendicular to Fig. 27,

Fig. 30 is an enlarged view of detail XXX of Fig. 29, Fig. 31 is a view of the injection process (after its completion),

Fig. 32 an enlarged view of the central parts of the injection device in the tensioned state before an injection,

Fig. 33 a representation analogous to Fig. 32 during the initial phase of an injection,

Fig. 34 a representation analogous to Fig. 33, with the injection needle fully inserted,

Fig. 35 a representation analogous to Fig. 32 to 34 after completion of an injection,

Fig. 36 is a view showing how the device is prepared for injections after reconstitution, in a longitudinal section analogous to Fig. 3, and

Fig. 37 is a representation in the same position as in Fig. 36, but in a cutting plane offset by 90°.

Fig. 1 shows an injection device 40 in the condition in which it leaves the manufacturer's factory. It looks somewhat like an oversized fountain pen and has an elongated, tubular housing 42. At the top there is an actuating button 44, and at the bottom, where a cover cap 46 is shown, a needle is attached before use, see Fig. 24.

As is common in medicine, the terms distal and proximal are used as follows:

Proximal: The side facing the patient, i.e. the side with the needle

(in Fig. 1 below).
Distal: The side facing away from the patient, i.e. in Fig. 1 the side with the actuation button 44.

In the proximal part of the housing 42 there is a window 48 through which the patient can see how much liquid 49 remains in a cartridge 50 there (Fig. 3).

A dosing wheel 52 is arranged on the middle part of the housing 42 so that it can rotate but cannot move axially. It has an internal thread 54 (Fig. 3) which engages in an external thread (coarse thread) 56 (Fig. 2) of a dose setting part 58 which is guided in longitudinal grooves 59, 59' of the housing 42 so that it can move axially but cannot rotate, see Fig. 20. If the dosing wheel 52 is rotated,

the dose setting part 58 is axially displaced accordingly, as a comparison of Fig. 1 and 2 shows, i.e. Fig. 1 shows the dose setting "0", recognizable by the "0" shown at 60, and Fig. 2 shows the dose setting "20". The injection dose can therefore be set by turning the dosing wheel 52, and if this is not changed, this set dose is injected with each injection. This is called a "steady dose injector". However, the dosage can be changed before each injection if desired.

A spring-loaded clip 62 is arranged on the dose setting part 58 and is used to trigger an injection. At its free end it has a projection 64 which projects towards the device 40 and is located opposite a locking opening 66 of the dose setting part 58. As a comparison of Figs. 1 and 2 shows, this opening 66 is displaced in the distal direction when the dose is increased.

Fig. 1 shows a rotation arrow 68 at the distal end, i.e. at the top, to indicate that in the state according to Fig. 1 the actuating button 44 can be rotated in both directions. Alternatively, the button 44 can also be moved in the direction of an arrow 70 in the distal direction.

In Fig. 2, i.e. in the "prepared" state of the injection device 40 after reconstitution of the lyophilisate, it is no longer possible to turn the knob 44 and it can only be moved axially (Fig. 2: arrow 70).

Fig. 3 is a longitudinal section through the injection device 40 of Fig. 1, and Fig. 4 is an analogous longitudinal section, but in a plane perpendicular to Fig. 3.

In the proximal part of the housing 42 there is a transparent cartridge holder 74, which is composed of a proximal part 76 and a distal part 78 and holds the cartridge 50 in its interior. The parts 76, 78 are connected to one another by a micro-lock 77, which is shown on an enlarged scale in Fig. 30. It allows a simple and highly precise adjustment of the length of the cartridge holder 74 to adapt to the cartridge 50 and its filling quantity.

The part 78 has a radial projection 80 which is received in a longitudinal groove 82 of the

·■ ·

Housing 42 and is displaceable there between two stops 84, 86. As a result, the cartridge holder 74 cannot be rotated relative to the housing and can only be axially displaced to a limited extent. Fig. 21 shows the projection 80 on an enlarged scale.

In the state shown in Fig. 1, 3 and 4, the liquid 49 in the cartridge 50 is only a solvent. An active ingredient must be added to this solvent, which is usually present as a lyophilisate in a container, see the container 224 in Fig. 18 with the lyophilisate 226. How this happens is described in detail below. This is called the reconstitution of the liquid 49, or in other words: its conversion into a drug. For this, the injection device must be "prepared" accordingly before it can be used by the patient. The reason for storing the solvent and active ingredient separately is that the reconstituted liquid only has a limited shelf life, usually only two to three weeks. The reconstitution is usually carried out by specialist personnel (nurse, doctor), but can also be carried out by a trained patient.

The cartridge 50 has, in the usual way, a rubber membrane 88 at its proximal end, which can be pierced by a needle, see Fig. 25. At its distal end, it has a rubber piston 90, to which the proximal end of a threaded rod 92 is attached, which is shown enlarged in Figs. 5 to 9 and which - because of its dual function - can also be referred to as a rack. For this purpose, the proximal end of the threaded rod 92 is buttoned with a mushroom-like projection 94 into a complementary recess 96 of the rubber piston 90, see Figs. 5 and 6. This can be done with the help of the micro-latch 77.

Fig. 7 shows a plan view of the distal end 98 of the threaded rod 92. This has a substantially circular cross-section, with two opposite longitudinal grooves 100, 102 for axial longitudinal guidance. These are guided in radially inwardly projecting projections 104 (Fig. 3 and Fig. 15) of the distal part 78 of the cartridge holder 74, which itself is secured against rotation by its radial projection 80, so that the piston rod

·

92 cannot be rotated relative to the housing 42 but can only be moved axially.

As shown in Fig. 6, the teeth 104 of the threaded rod 92 are designed as external threads, but have the sawtooth shape characteristic of a rack, cf. Fig. 8, i.e. the proximal part 106 of a tooth 104 has a flat pitch, while the distal part 108 has a large pitch.

A proximal part 110 (Fig. 6) of the rack 92 is solid, and a distal part 112 has a cylindrical recess 114 on the inside, which does not extend radially to the longitudinal grooves 100, 102. A pin 116 (Fig. 5, 8, 9) is guided axially displaceably in the recess 114. This has two spring parts 118 at its proximal end, which protrude radially outwards through two diametrically opposed openings 120, 121 of the grooves 100, 102, see Fig. 9, which shows the exact shape of the projections 118 and the position of the openings 120, 121. These are located at the proximal end 122 of the recess 114.

The distal end of the pin 116 has a recess 124 (Fig. 8) in which a green signal body 126 is releasably locked with a spring pin 128. Furthermore, at the distal end of the pin 116 there are lateral barbs 130 which lock into corresponding recesses in the recess 114 and, after assembly, releasably hold the pin 116 in the position shown in Fig. 8. Furthermore, at the distal end 98 of the threaded rod there is a radially extending recess 132 which intersects the longitudinal grooves 100, 102, see Fig. 7, and into which the barbs 130 lock during reconstitution, see Fig. 22 and 23 below.

As Fig. 4 and 12 clearly show, at the distal end of the part 78 there are two resilient parts 136, 137 which are provided on their side facing the rack 92 with locking teeth 138 and 139 respectively for engaging with the teeth 104 of the rack 92.

In the state according to Fig. 1, as shown in Figs. 4 and 12, the locking teeth 138, 139 are not in engagement with the teeth 104, so that the rack 92 can be axially displaced unhindered by the parts 136, 137.

The resilient parts 136, 137 can, however, be moved radially inwards by means of a corresponding cam control to engage with the rack 92. Corresponding cams 140, 142 (Fig. 4) are located on the inside of the housing 42. An element 144 which can be moved axially in the housing 42 and which is shown in three-dimensional form in Fig. 10 has a hollow truncated cone-shaped section 146 at its proximal end, which also acts as a cam and, after completion of an injection, presses the resilient parts 136, 137 together and brings them into engagement with the rack 92, cf. Figs. 31 and 35, and also after completion of reconstitution, cf. Fig. 13.

The element 144, which can be moved axially in the housing 42, has on its outer side 148 two longitudinal grooves 150, 151, which are guided axially in corresponding projections 152, 153 of the housing 42. It also has a spring-loaded locking hook 156 with a radially outwardly projecting projection 158, which can engage in the recess 66 (Fig. 1) of the dose setting part 58, as shown, for example, in Fig. 36. In injection mode, i.e. after reconstitution, it serves as a tensioning and release element.

During the reconstitution, which is described below, the element 144 which is axially displaceable in the housing 42 is held in the position according to Figs. 3 and 4.

In its proximal region, the element 144 is penetrated by two diametrically opposed longitudinal grooves 162, 164 which, according to Fig. 4, are guided in the longitudinal direction on the cams 140 and 142 fixed to the housing and come into contact with these cams with their distal ends 162', 164' during injection, cf. Fig. 35.

Furthermore, the element 144 which is axially displaceable in the housing 42 has an inwardly projecting annular shoulder 166 in the central region of its inner side, see Figs. 12 and 13. In addition, it has radially inwardly projecting projections 170 in the distal end region of its inner side 168, one of which is shown in Fig. 10.

In the inner side 168 of the element 144 there is an adjusting member

174, which is shown in three-dimensional form in Fig. 11. Its distal section 176 has the shape of a cylindrical tube, which is locked to radial projections 180 of the actuating button 44 via radial recesses 178 at its distal end and therefore forms a unit with the latter in the assembled state. The threaded rod 92 is guided axially in this tube 176.

In the proximal direction, the tube 176 merges into a part 182 with two resilient latching hooks 184, 186, which are each provided on their inner side with latching teeth 184', 186' in the form of threaded sections of an internal thread, which are approximately complementary to the external thread in the form of the teeth 104 of the rack 92, as Fig. 11 clearly shows.

As can be seen from Fig. 11, the threaded rod 92 can be moved axially by rotating the actuator 174 (using the rotary knob 44). However, the actuator 174 can also be moved in the direction of the arrow 70 relative to the threaded rod 92, whereby the locking teeth 184', 186' slide resiliently over the teeth 104 of the threaded rod 92. Due to the shape of the teeth 104, this is only possible in the distal direction (arrow 70).

For guidance in the inner side 168 of the element 144, the part 182 of the actuator 174 has two guide parts 188, 190 with a substantially circular-cylindrical outline. On them are stop parts 188' and 190", which serve to stop against the annular shoulder 166, see Fig. 3. Stop parts 192 with a locking recess 192' and 194' are offset by 90° to the stop parts 188', 190'. The stop parts 188', 190', 192, 194 also serve as abutments for the proximal end of an injection spring 200, the distal end of which rests against an end cap 202, which is locked into the distal end of the housing 42 in the manner shown and forms a guide for the distal end of the tube 176.

As long as the stop parts 188', 190', 192, 194 rest against the annular shoulder 166, as shown in Fig. 3 and 4, the actuator 174 can be freely rotated relative to the housing 42, as is necessary for reconstitution. Fig. 12 shows this state again on a greatly enlarged scale.

It can also be seen that the spring-loaded parts 136, 137 are spring-loaded radially outward because they neither rest against the cams 140, 142 of the housing 42 nor against the hollow truncated cone 146 of the element 144 which is axially displaceable in the housing 42.

After reconstitution, which is described below, the internal parts of the injection device 40 are brought into a position which is shown in Fig. 13. Comparison with Fig. 12 immediately shows the differences: the actuator 174 is in the same position as in Fig. 12, but the element 144 which is axially displaceable in the housing 42 is displaced in the proximal direction until it stops on the cams 140, 142, so that its hollow truncated cone 146 now rests against the inclined surfaces 136" and 137" of the resilient parts 136, 137 and presses the latter against the rack 92, thereby establishing a positive connection between the rack 92 and the part 78 of the cartridge holder 74.

The inner projections 170 of the element 144 which is axially displaceable in the housing 42 are now firmly engaged in the recesses 192', 194' of the stop parts 192, 194, so that the actuator 174 is permanently locked to the element 144 which is axially displaceable in the housing and can only move together with it. Since the element 144 is prevented from rotating by the cams 140, 142 which protrude into the grooves 162, 164, the actuator 174 can no longer be rotated in this position.

The position of the parts according to Fig. 13 is achieved by pulling the actuating button upwards in the direction of arrow 70 after reconstitution of the device according to Figs. 1, 3 and 4 until the projections engage in the locking recesses 192', 194'. The device is then triggered for the first time by pressing on the clip 62. This is described in more detail below with reference to Figs. 36 and 37.

For the reconstitution, an adapter 210 is used, which is shown in Fig. 16. It has an approximately cylindrical housing 212 in which a cannula container 214 is attached, e.g. by pressing, gluing, or

I *

··

Welding. This has an upper flange 215 that projects radially beyond the upper edge of the housing 212. A standard cannula carrier 216 with its cannula 218 is attached in a suitable manner in the cannula container 214. The cannula container 214 is sterilely sealed at the top in the manner shown with a peel-off film 220, which is detachably attached to the flange 215. As usual, an internal thread 217 is provided in the cannula carrier 216 for attachment to the injection device 40.

The cannula carrier 216 and the cannula 218 can therefore be a standard component as used in large quantities for injections, which reduces the cost of manufacturing the adapter 210. - The widened flange 215 ensures a secure connection with the peel film 220.

In the lower part of the housing 212 there is a movable rubber piston 222 which, when not in use, covers the lower end of the cannula 218, while the upper end is covered by the peel film 220. This enables sterile storage of the cannula 218.

As shown in Fig. 17, a conventional container 224 containing a lyophilisate 226 is pressed with its lid 227 into the lower recess 228 of the housing 212 and latches there on a latching projection 230. In doing so, it displaces the rubber piston 222 upwards, and this, as shown, is pierced at a thin central section 222' by the lower end of the cannula 218, which then pierces a rubber membrane 233 in the lid 227. The film 220 is then removed and the arrangement according to Fig. 17 can be screwed onto the injection device 40 by means of the internal thread 217, just like an injection needle, see Fig. 18. In this case, the upper end of the cannula 218 in Figs. 16 and 17 penetrates the rubber membrane 88 of the cartridge 50 and forms a connection from this to the container 224.

According to Fig. 19, the actuating button 44 is now turned in the direction of arrow 234, i.e. - if you look at the button 44 in the direction of arrow 236 - counterclockwise. This causes the threaded rod 92 to be displaced in the proximal direction to an end position which is shown in Fig. 19.

, thereby displacing the rubber piston 90 in the proximal direction, thus forcing the liquid 49 from the cartridge 50 through the cannula 218 into the container 224, where the lyophilisate 238 is reconstituted, as shown in Fig. 19.

During this displacement of the threaded rod 92, the pin 116 with its projections 118 strikes the parts 104 of the cartridge holder 74 and is thereby displaced in the distal direction, as also shown in Fig. 21. As a result, the upper end of the pin 116 is displaced in the manner shown in Fig. 20 and engages with its projections 130 in the groove 132, so that the pin 116 is locked in this position according to Figs. 20 and 21. The signal body 126 thus protrudes from the distal end of the threaded rod 92, see Fig. 20.

The injection liquid 238 is now reconstituted and can be sucked back into the cartridge 50. This is shown in Fig. 22. To do this, the injection device 40 is turned upside down and the threaded rod 92 is screwed back by turning the actuating knob 44. In doing so, the rotary knob 44 is turned clockwise, as seen in the direction of arrow 236.

Since the rubber piston 90 is connected to the threaded rod 92, see Figs. 5 and 6, it moves in the distal direction, i.e. downwards in Fig. 22, and sucks the reconstituted liquid 238 from the container 224 through the cannula 218 back into the cartridge (carpule) 50.

At the end of this process, the signal body 126 (made of elastic plastic) is pressed through an opening 242 (Fig. 3) of the actuating button 44 and permanently engages there with its annular groove 246. This constantly reminds the user that this injection device contains reconstituted injection liquid 238 which is intended for immediate use. Fig. 23 shows the signal body 126 on a greatly enlarged scale. The connecting member 210 and container 224 are then unscrewed.

The injection device 40 is now brought into its injectable state according to Fig. 36 and 37 by turning in the direction of the arrow 70 on the

actuating button 44, the projection 158 is engaged in the recess 66 of the dose setting part 58, as shown in Fig. 36, so that the element 144 is immobilized in the housing 42.

In this case, the actuator 174 is displaced in the distal direction relative to the - stationary - element 144, whereby the inner projections 170 of the element 144 firmly engage in the recesses 192', 194' of the stop parts 192, 194, see Fig. 13.

According to Fig. 36, the cartridge holder 74 is pulled along by the piston 90, which is connected to the piston rod 92, coming to a stop against the projections 104 of the part 78 and thereby pulling the cartridge holder 74 in the distal direction. Alternatively, the projections 104 can also engage in a groove (not shown) of the piston rod 92 as long as the piston 90 is in the position according to Fig. 36.

After completion of the process according to Fig. 36 and 37, the parts 136, 137 are closed by the cams 140, 142, see Fig. 37, and connect the piston rod 92 to the cartridge holder 74.

After reaching the position according to Figs. 36 and 37, the device 40 is triggered by pressure on the clip 62, and the position according to Fig. 24 is then obtained, in which the parts 136, 137 are held closed by the hollow truncated cone 146 of the element 144.

Once this position is reached, injections are possible, as described below. For this purpose, a cannula 250 with its cannula carrier 252 is screwed onto the thread at the proximal end of the cartridge holder 74, see Fig. 24, and the desired injection dose is set by turning the dosing wheel 52, as shown by way of example in Fig. 2. The rotation of the dosing wheel 52 is symbolized in Fig. 24 by a rotation arrow 254.

Fig. 13 shows on an enlarged scale the position of the injection device 40 according to Fig. 24, and as described in detail therein, in this

In this position, the resilient members 136, 137 are held in contact against the threaded rod 92 by the hollow cone 146 at the proximal end of the element 144.

After pre-selecting the injection dose by turning the dosing wheel 52, see Fig. 2, the injection device 40 is tensioned, i.e. prepared for an injection. This is done by pulling the actuating button 44 in the distal direction, as indicated in Fig. 25 by an arrow 256.

Fig. 25 and 26 show the first part of the clamping process. As a comparison of Fig. 24 and 25 shows, the cannula 250 is pulled completely into the interior of the housing 42 so that it is no longer visible to the patient. The resilient parts 136, 137 with their sections 270, 272 (Fig. 33) slide between the cams 140, 142 on the inside of the housing 42 and are held closed by them. At the same time, the radial projection 80 of the cartridge holder comes into abutment against the distal end 84 of the groove 82, which prevents further displacement of the cartridge holder 74 in the distal direction.

According to Fig. 27 and 29, the actuating button 44 is pulled further in the distal direction until the element 144 which is axially displaceable in the housing 42 engages with its locking element 158 in the recess 66 of the dose setting part 58.

Since the cartridge holder 74 can no longer follow this distal movement, the spring-loaded locking hooks 184, 186 (Fig. 29, 30) with their locking teeth 184', 186' (Fig. 11) now slide linearly over the teeth 104 (Fig. 5 and 6) of the rack 92, whereby each tooth 104 represents a dosing unit X, cf. Fig. 6.

In the position shown in Fig. 27 to 30, the injection device 40 is therefore tensioned and the desired injection dose is set. Fig. 28 shows that the signal body 126 is pulled out of the recess 124 of the cylindrical pin 116 during this tensioning process and is held in the recess 242 of the actuating button 44. This leaves the user with the

Signal body 126 constantly visible.

According to Fig. 31, an injection is now triggered by pressing on the clip 62 (arrow 260 in Fig. 31). At 262, a body part is symbolically indicated into which the cannula 250 has already been inserted and the previously set dose 238 ¹ of the liquid 238 has been injected.

The injection processes are explained using Fig. 32 to 35. These concern

a) the insertion of the cannula 250, and

b) injecting through the inserted cannula 250. These processes may partially overlap.

Fig. 32 corresponds to the position according to Figs. 27 to 30, i.e. the injection device 40 is tensioned.

Fig. 33 shows the beginning of an injection, namely the so-called puncture phase, in which the cannula 250 is inserted into the body part 262. The resilient parts 136, 137 are initially held closed by the cams 140, 142 of the housing 42, since they have a longer section 270 or 272 parallel to the longitudinal axis of the device 40, which gradually slides out of the complementary straight section 140' or 142' of the cams 140, 142, so that the resilient parts 136, 137 are held closed for approximately the first third of the puncture path and transmit the force F from the rack 92 directly, i.e. mechanically, to the cartridge holder 74. (According to Fig. 31, the force F of the injection spring 200 is transmitted to the rack 92 via the actuator 174.)

As shown in Fig. 34, the spring-loaded parts 136, 137 finally slide out of the cams 140, 142 and spread apart due to their spring force, so that the force F from the rack 92 now acts directly on the rubber piston 90. This increases the pressure in the injection liquid 238, causing it to act similarly to a solid body and transmit the force F further to the cannula 250 until the projection 80 of the cartridge holder 74 is pushed against its proximal

Stop 86 hits, which ends the puncture phase, ie the cannula 250 then has the position according to Fig. 31. The resilient parts 136, 137 are open in the position of Fig. 34, so that the rack 92 can be displaced independently of the cartridge holder 74 relative to it.

The injection of the liquid 238 now follows according to Fig. 35. In this case, the rack 92 displaces the piston 90 in the (fixed) container 50 and presses the amount of liquid 238" set with the metering wheel 52 out of the container 50, see Fig. 31.

At the end of this pressing-out process, the element 144, which is axially displaceable in the housing 42, reaches its proximal end position according to Fig. 35, pressing with its hollow truncated cone 146 on the oblique sections 136", 137" of the spring parts 136, 137, and thereby bringing the latter back into engagement with the rack 92, so that a new clamping process can begin, as described in Fig. 25 ff.

During the injection process, the cannula 250 is initially inserted by a mechanical force transmission (via parts 136, 137) and then by a hydraulic force transmission, which results in a high dosing accuracy because no liquid can escape from the cannula 250 during the mechanical force transmission that leads to the insertion of the cannula. Any liquid that may escape from the cannula 250 during the subsequent hydraulic force transmission is injected into the body.

After completion of an injection (Fig. 31), the cannula 250 is withdrawn from the body part 262 and replaced by a new cannula which is covered with a sterile closure cap 46 (Fig. 2). This cap is only removed before the next injection.

The invention also relates to the following process sequences:

1. A method for reconstituting an injection liquid, comprising the following steps:

(a) By actuating an injection device, solvent is injected into a container containing a substance to be reconstituted.

lyophilisate transferred;

(b) the reconstituted lyophilisate is sucked back from the container into the injection device by actuating the injection device;

c) the injection device is switched to single injection mode in order to be able to inject the aspirated reconstituted lyophilisate.

2. Method according to claim 1, in which the injection device has a threaded rod which is provided with an external thread and is guided in the injection device so as to be axially displaceable but non-rotatable, and to which an actuator is assigned, the internal thread of which engages with the external thread of the threaded rod, wherein in step a) the transfer of the solvent and in step b) the suction of the reconstituted lyophilisate takes place by rotating the actuator relative to the threaded rod.

3. Method according to claim 2, in which the threaded rod has an external thread with a sawtooth-shaped cross section, and the actuator is designed to be radially resilient in order to be able to slide across the external thread,

and in step c) the actuator is immobilized against rotation.

4. Method for carrying out an injection, in which an injection cannula is first inserted by the effect of energy stored in a spring and injection liquid is injected after the insertion, wherein the insertion of the injection cannula by means of the stored energy takes place first by mechanical direct drive of the injection cannula and then by hydraulic power transmission by means of pressure increase in a displaceable liquid container storing the injection liquid.

Many modifications are possible with the present invention. For example, one of the spring parts 136, 137 would be sufficient for the mechanical force transmission to the cartridge holder 74. Except for the injection spring 150 and the cartridge 50, all parts can be made of a suitable plastic and can therefore be easily recycled.

Claims (37)

1. Injection device with a housing ( 42 ),
which is designed to receive a container ( 50 ) with a liquid,
with a part ( 92 ) arranged axially displaceably in the housing ( 42 ) for acting on this container ( 50 ),
with an actuator ( 174 ) for influencing the position of the axially displaceable part ( 92 ) relative to this actuator ( 174 ),
further comprising an element ( 144 ) arranged axially displaceably in the housing ( 42 ) but essentially non-rotatably relative to the housing ( 42 ),
wherein the actuator ( 174 ) can assume at least two different positions relative to this element ( 144 ) and is rotatable relative to this element ( 144 ) in a first of these positions ( Fig. 12) and is non-rotatable relative to this element ( 144 ) in a second of these positions ( Fig. 13). 2. Injection device according to claim 1, wherein the actuator ( 174 ) in the second position ( Fig. 13) is locked to the axially displaceable element ( 144 ) so that it can only be moved together with the latter. 3. Injection device according to claim 1 or 2, in which the part arranged axially displaceably in the housing ( 42 ) is designed as a threaded rod ( 92 ) which is guided axially displaceably in the housing ( 42 ) but non-rotatably relative to the housing ( 42 ). 4. Injection device according to claim 3, wherein the external thread ( 104 ) of the threaded rod ( 92 ) engages with a corresponding internal thread ( Fig. 11: 184', 186') of the actuator ( 174 ). 5. Injection device according to claim 4, in which the external thread of the threaded rod ( 92 ) is designed in the manner of a rack, and the internal thread ( Fig. 11: 184', 186') of the actuator ( 174 ) is designed to be substantially complementary to this external thread ( 104 ). 6. Injection device according to claim 4 or 5, wherein the internal thread of the actuator ( 174 ) is designed as a partial thread ( Fig. 11: 184', 186') on at least one resilient element ( 184 , 186 ) of the actuator ( 174 ) in order to enable a movement of this resilient element ( 184 , 186 ) transversely to the teeth of the threaded rod ( 92 ). 7. Injection device with a housing ( 42 ),
which is designed to receive a container ( 50 ) with a liquid, in which container ( 50 ) a piston ( 90 ) is displaceably arranged,
with a threaded rod ( 92 ) for moving this piston ( 90 ), which threaded rod is provided with an external thread ( 104 ) and is arranged in the housing ( 42 ) so as to be axially displaceable but non-rotatable,
with an actuator ( 174 ) which is provided with an internal thread ( 184 ', 186 ') for engagement with the external thread ( 104 ) of the threaded rod ( 92 ) in order to enable an axial displacement of the threaded rod ( 92 ) by a relative rotation between the actuator ( 174 ) and the threaded rod ( 92 ),
wherein the external thread ( 104 ) of the threaded rod ( 92 ) has the shape of teeth of a rack, and the internal thread ( 184 ', 186 ') of the actuator ( 174 ) which is essentially complementary thereto is arranged on at least one resilient element ( 184 , 186 ) of the actuator ( 174 ),
to enable the teeth of this internal thread ( 184 ', 186 ') to slide transversely to the teeth of the external thread ( 104 ) of the threaded rod ( 92 ) by axial displacement of the actuator ( 174 ) relative to the threaded rod ( 92 ). 8. Injection device according to claim 7, wherein the threaded rod ( 92 ) is connected at its proximal end ( 96 ) to the piston ( 90 ) which is slidably arranged in the container ( 50 ). 9. Injection device according to claim 7 or 8, in which the teeth ( 104 ) of the threaded rod ( 92 ) are essentially sawtooth-shaped and, viewed in cross-section, each have a proximal section ( 106 ) with a small pitch and a distal section ( 108 ) with a large pitch in order to enable axial displacement between the threaded rod ( 92 ) and the actuator ( 174 ) in one direction only. 10. Injection device according to one or more of claims 7 to 9, in which the actuator ( 174 ) can assume at least two different positions relative to an element ( 144 ) which is arranged in the housing ( 42 ) so as to be axially displaceable but non-rotatable, wherein the actuator ( 174 ) is rotatable relative to this element ( 144 ) in one of these positions ( Fig. 12) and non-rotatable relative to this element ( 144 ) in another of these positions ( Fig. 13). 11. Injection device according to claim 10, in which at least one locking element ( 170 , 192 ', 194 ') is provided between the actuator ( 174 ) and the element ( 144 ) axially displaceable in the housing ( 42 ) in order to enable locking between the actuator ( 174 ) and this element ( 144 ) in at least one of the said positions. 12. Injection device according to claim 10 or 11, in which a locking member ( 170 , 192 ', 194 ') is provided for locking in the position in which the actuator ( 174 ) is not rotatable relative to the element ( 144 ) axially displaceable in the housing ( 42 ). 13. Injection device according to one or more of claims 7 to 12, in which the liquid container ( 50 ) is axially displaceable relative to the housing ( 42 ) in order to enable a piercing movement of a cannula ( 250 ) connected to the liquid container ( 50 ) into the skin of the patient by displacing the liquid container ( 50 ). 14. Injection device according to claim 13, wherein a mechanical connection ( 136 , 137 ) influenced by the axial position of the liquid container ( 50 ) is provided between the displaceable liquid container ( 50 ) and the threaded rod ( 92 ). 15. Injection device according to one or more of claims 7 to 14, which has an indicator ( 126 ) which is actuated when the threaded rod ( 92 ) has been displaced by rotating the actuator ( 174 ) first by a predetermined value in the proximal direction and then by a predetermined value in the distal direction. 16. Injection device according to claim 15, wherein a displaceable member ( 116 ) is arranged in a recess ( 114 ) of the threaded rod ( 92 ), to the distal end of which the indicator ( 126 ) is releasably attached. 17. Injection device according to claim 16, wherein the displaceable member ( 116 ) has a stop member ( 118 ) which, during a proximal movement of the threaded rod ( 92 ), abuts against a stop ( Fig. 21: 104) and thereby displaces the displaceable member ( 116 ) from a first locking position ( Fig. 5) in the distal direction into a second locking position ( Fig. 23) in which the indicator ( 126 ) is activated. 18. Injection device according to one or more of the preceding claims, with a spring ( 20 ) for storing energy for an injection, which spring ( 200 ) can be tensioned by displacing a tensioning member ( 144 ) in the distal direction, and with a locking member ( 156 , 158 ) for releasably locking the tensioning member ( 144 ) in this displaced position. 19. Injection device according to claim 18, in which cams ( 140 , 142 ) are provided in the housing ( 42 ), which, in the displaced position of the clamping member ( 144 ), activate a position-dependent mechanical connection ( 136 , 137 ) between the threaded rod ( 92 ) and the liquid container ( 50 ). 20. Injection device according to one or more of the preceding claims, in which the liquid container ( 50 ) is associated with a holder ( 74 ) which is axially displaceable in the housing ( 42 ) between a proximal and a distal end position and is designed to receive the liquid container ( 50 ). 21. Injection device according to claim 20, wherein the length of the holder ( 74 ) is variable. 22. Injection device according to claim 21, wherein the holder ( 74 ) has a proximal portion ( 76 ) and a distal portion ( 78 ) which are connected to one another by an adjustable connection ( 77 ) which enables a change in the overall length of the holder ( 74 ). 23. Injection device according to claim 22, wherein the adjustable connection comprises a micro-latch ( 77 ) which connects a proximal portion ( 76 ) and a distal portion ( 78 ) of the holder ( 74 ) in an adjustably manner. 24. Injection device according to one or more of claims 20 to 23, in which the holder ( 74 ) is provided in its distal region with stop means ( 80 ) which determine its proximal and/or distal end position relative to the housing ( 42 ), and in which the length adjustment of the holder ( 74 ) takes place relative to these stop means, so that when the length of the holder ( 74 ) changes, the position of the liquid container ( 50 ) relative to the threaded rod ( 92 ) is changed. 25. Injection device according to one or more of the preceding claims, in which a dose setting part ( 58 ) which is displaceable in the longitudinal direction relative to the housing ( 42 ) has locking means ( 66 ) for locking a locking member ( 158 ). 26. Injection device according to claim 25, wherein a member ( 62 ) for releasing the locking between the locking means ( 66 ) and the locking member ( 158 ) is provided on the displaceable dose setting part ( 58 ). 27. Injection device according to claim 25 or 26, in which a threaded sleeve ( 52 ) is provided on the housing ( 42 ) which is rotatable relative to the housing but not axially displaceable relative to the housing and which engages with a thread ( 56 ) on the displaceable dose setting part ( 58 ). 28. Injection device according to one or more of claims 25 to 27, in which the displaceable dose setting part ( 58 ) is not rotatable relative to the housing ( 42 ). 29. Adapter for attaching a container ( 224 ) provided with a rubber membrane ( 233 ) to an injection device,
with a housing ( 212 ),
with a cannula ( 218 ) arranged in this housing ( 212 ), which extends both in the direction of the injection device ( 40 ) and in the direction of the container ( 224 ) and is attached to a cannula carrier ( 216 ),
with an internal thread ( 217 ) provided at one end region of the cannula carrier ( 216 ) for attachment to an external thread of the injection device ( 40 ),
and with a receptacle ( 228 ) provided at the opposite end region of the housing ( 212 ) for the part ( 227 ) of the container which is provided with the rubber membrane ( 233 ) ( Fig. 16, 17). 30. Adapter according to claim 29, wherein the receptacle ( 228 ) provided at the opposite end region of the housing ( 212 ) is provided with a radially inwardly projecting locking projection ( 230 ) in order to be able to lock the container ( 224 ) in the housing ( 212 ) of the adapter. 31. Adapter according to claim 29 or 30, in which a part ( 222 ) which can be perforated by the cannula ( 218 ) is slidably arranged in the opposite end region. 32. Adapter according to claim 31, wherein the part ( 222 ) perforable by the cannula ( 218 ) covers the associated end of the cannula ( 218 ) in a sterile manner in the state before perforation ( Fig. 16). 33. Adapter according to one or more of the preceding claims, in which the one end region ( 217 ) of the housing ( 212 ) is covered in a sterile manner. 34. Adapter according to claim 33, wherein a holder ( 214 ) for the cannula carrier (216) is provided between the cannula carrier ( 216 ) and the tubular housing ( 212 ), and the sterile cover ( 220 ) is provided at one end of this holder ( 214 ). 35. Adapter according to claim 33 or 34, in which a peel film ( 220 ) or the like is provided for sterile covering. 36. Adapter according to one or more of claims 29 to 35, in which the housing ( 212 ) is divided by the cannula carrier ( 216 ) into partial regions which are in fluid communication with one another via the cannula ( 218 ). 37. Adapter according to one or more of claims 29 to 36, in which the cannula carrier ( 216 ) and the cannula ( 218 ) are essentially designed as a standard component as used for injections with conventional injection devices.