CA2356614A1

CA2356614A1 - Method for reconstituting an injection fluid, and injection apparatus for implementing said method

Info

Publication number: CA2356614A1
Application number: CA 2356614
Authority: CA
Inventors: Jochen Gabriel; Ulf Polzin
Original assignee: Individual
Current assignee: B D Medico Sarl
Priority date: 1998-10-21
Filing date: 1999-10-09
Publication date: 2000-04-27
Also published as: JP2002527210A; DE19948988A1; EP1123124A2; DE29818721U1; WO2000023133A2; WO2000023133A3

Abstract

The invention relates to an injection apparatus comprising a housing (42) designed for receiving a container (50) containing a liquid. An axially sliding member (92) which is received in the housing (42) is used to act upon said container (50). An actuating member (174) is used to influence the position of the axially sliding member (92) relative to itself. An element (144) is placed in the housing (42) in such a way that it can slide axially but is substantially rotatively-blocked relatively to the housing (42). The actuating member (174) can take at least two different positions relatively to said element (144). In a first position (Fig. 12), it can rotate relatively to said element (144) and in a second position (Fig. 13), it is rotatively blocked relatively to said element (144). The invention also relates to a method for reconstituting an injection fluid and a method for performing an injection.

Description

METHOD FOR RECONSTITUTING AN INJECTION FLUID, AND INJECTION APPARATUS FOR IMPLEMENTING SAID METHOD
The invention concerns a method for reconstituting an injection fluid, and an injection apparatus for carrying out such a method.
DE 36 38 984-C2 has disclosed an injection apparatus having a housing and a threaded rod which is equipped with external threads for ejecting fluid from a fluid container, and which is arranged in the housing in axially displaceable but nonrotatable fashion. The threaded rod serves during the injection operation firstly to insert an injection needle, and then to inject fluid through that needle.
An object of the invention is to make available a new method for reconstituting an injection fluid, as well as an injection apparatus for carrying out such a method.
According to the invention, this object is achieved by an injection apparatus according to claim 1. The result is to create the possibility of rotating the adjusting member, in the first position, relative to the axially displaceable part, and thereby influencing the axially displaceable part in a specific fashion; and after completion of that operation, the adjusting member can be brought into the second position in which said rotation is blocked and the adjusting member is forced to follow the movements of the axially displaceable element; in particularly preferred fashion, in the second position the adjusting member is snap-locked to the axially displaceable element. This makes possible two different operating modes of an injection apparatus of this kind; for example, the first operating mode can be reserved for specialized medical personnel (physicians, nurses), and only the second operating mode is made available to the patient, and, for example, the patient cannot return from the second operating mode to the first operating mode. This represents an important safety feature to prevent improper operation by the patient of an injection apparatus of this kind.
The aforesaid object is achieved in a different fashion by an injection apparatus according to claim 7. An injection apparatus of this kind has the _2_ advantage that a relative rotary movement between the external threads of the threaded rod and the internal threads of the adjusting member makes possible a movement of the threaded rod in the proximal direction and the distal direction, as is necessary, for example, for reconstitution of an injection fluid;
whereas an axial displacement of the adjusting member relative to the threaded rod makes it possible for the teeth of the internal threads (of the adjusting member) to slide along the teeth of the external threads, thus allowing simple and easily understandable handling by the patient during injection.
A method according to the present invention for reconstituting an injection fluid is the subject matter of claim 38, and a method according to the present invention for carrying out an injection is the subject matter of claim 41.
In the method according to claim 38, the switchover to single injection results in a sensible and easily understandable procedure which eliminates operating errors. The method according to claim 41 has the advantage that the needle can be inserted by "mechanical drive," and that the pressure rise in the cartridge necessary for "hydraulic drive" need not be effected until the needle has already been inserted, so that little or no fluid loss can occur as a result of the pressure rise.
Further details and advantageous developments are evident from the exemplary embodiments, which are described below and depicted in the drawings and are in no way to be understood as limiting the invention, and from the other claims. In the drawings:
FIG. 1 shows an external view of an injection apparatus according to the present invention in the state in which it leaves the factory, i.e. before reconstitution of the lyophilisate;
FIG. 2 shows an external view of the injection apparatus after preparation of the apparatus for injections, i.e. after reconstitution of the lyophilisate, and after an injection dose of approx. 20 units has been set;
FIG. 3 shows a longitudinal section through the injection apparatus of FIG. 1;
FIG. 4 shows a longitudinal section analogous to FIG. 3 but perpendicular to the plane of FIG. 3;
FIG. 5 shows a longitudinal section through a threaded rod that is used in the injection apparatus, viewed in the direction of arrows V-V of FIG. 7;

FIG. 6 shows a plan view of the threaded rod of FIG. 5, viewed in the direction of arrow VI of FIG. 7;
FIG. 7 shows a plan view of the upper end of the threaded rod shown in FIGS.
and 6;
5 FIG. 8 shows a detail VIII of FIG. 5;
FIG. 9 shows a detail IX of FIG. 5;
FIG. 10 is a three-dimensional depiction of a triggering member used in the injection apparatus of FIGS. 1 through 10;
FIG. 11 is a three-dimensional depiction of an adjusting member used in the injection apparatus;
FIG. 12 shows an enlarged portion of FIG. 4;
FIG. 13 is a depiction similar to FIG. 12, but with the parts in the positions after completion of a reconstitution;
FIG. 14 shows a section viewed along line XIV-XIV of FIG. 13;
FIG. 15 shows a section viewed along line XV-XV of FIG. 13;
FIG. 16 shows a longitudinal section through a preferred connecting part according to the invention;
FIG. 17 shows a section through the connecting part of FIG. 16, to which a container having a lyophilized drug is connected;
FIG. 18 is a depiction showing how a reconstitution begins;
FIG. 19 is a depiction showing the operations during the reconstitution;
FIG. 20 is an enlarged depiction of detail XX of FIG. 19;
FIG. 21 is an enlarged depiction of detail XXI of FIG. 19;
FIG. 22 is a depiction showing how the reconstituted fluid is drawn back into the injection apparatus;
FIG. 23 is an enlarged depiction of detail XXIII of FIG. 22;
FIG. 24 is a depiction to explain dose setting after reconstitution is complete;
FIG. 25 is a depiction to explain the first portion of the cocking operation, in which the injection needle is displaced into the interior of the housing a distance equivalent to the insertion travel;
FIG. 26 is an enlarged depiction of detail XXVI of FIG. 25;
FIG. 27 is a depiction to explain the second portion of a cocking operation, in which the injection needle remains in the position shown in FIG. 25 and the actuation knob is displaced, in accordance with the dose that is set, farther in the distal direction;
FIG. 28 is an enlarged depiction of detail XXVIII of FIG. 27, with a signal button to indicate that a reconstitution has taken place;
FIG. 29 is a depiction analogous to FIG. 27 but in a plane perpendicular to FIG.
27;
FIG. 30 is an enlarged depiction of detail XXX of FIG. 29;
FIG. 31 is a depiction of the injection operation (after its completion);
FIG. 32 is an enlarged depiction of the central parts of the injection apparatus in the cocked state prior to an injection;
FIG. 33 is a depiction analogous to FIG. 32 during the initial phase of an injection;
FIG. 34 is a depiction analogous to FIG. 33, the injection needle being inserted all the way;
FIG. 35 is a depiction analogous to FIGS. 32 through 34, after completion of an injection;
FIG. 36 is a depiction, in a longitudinal section analogous to FIG. 3, showing how the apparatus is prepared, after reconstitution, for injections; and FIG. 37 is a depiction in the same position as in FIG. 36, but in a section plane offset 90° from it.
FIG. 1 shows an injection apparatus 40 in the state in which it leaves the manufacturer's factory. It somewhat resembles an oversized fountain pen, and has an elongated, tube-like housing 42. An actuation knob 44 is located at the top, and at the bottom, where a cover cap 46 is depicted, a needle is attached before use (see FIG. 24).
As is usual in medicine, the terms "distal" and "proximal" are used as follows:
Proximal: The end toward the patient, i.e. the end having the needle (at the bottom in FIG. 1 ).
Distal: The end away from the patient, i.e. in FIG. 1, the end having actuation knob 44.

Located in the proximal part of housing 42 is a window 48 through which the patient can see how much fluid 49 remains in a cartridge (FIG. 3) present therein.
A dosage wheel 52 is arranged rotatably but axially nondisplaceably on the central part of housing 42. It has internal threads 54 (FIG. 3) which engage into external threads (coarse threads) 56 (FIG. 2) of a dose setting part 58 which is guided axially displaceably but nonrotatably in longitudinal grooves 59, 59' of housing 42 (see FIG. 20). When dosage wheel 52 is rotated, dose setting part 58 is correspondingly axially displaced, as shown by a comparison between FIGS. 1 and 2, i.e. FIG. 1 shows a dose setting of "0" (evident from the "0" depicted at 60), and FIG. 2 shows a dose setting of "20". The injection dose can thus be set by rotating dosage wheel 52, and if it is not changed, that set dose will be injected at each injection. The term for this is "steady dose injector." The dosage can, however, be changed before each injection if desired.
Arranged on dose setting part 58 is a resilient clip 62 which serves to trigger an injection. At its free end it has a projection 64, protruding toward apparatus 40, which lies opposite a click-stop opening 66 of dose setting part 58. As shown by a comparison between FIGS. 1 and 2, this opening 66 is displaced in the distal direction as 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 shown in FIG. 1, actuation knob 44 can be turned in both directions. Alternatively, knob 44 can also be displaced distally in the direction of an arrow 70.
In FIG. 2, i.e. when injection apparatus 40 is in the "prepared" state after reconstitution of the lyophilisate, the possibility of rotating knob 44 no longer exists, and it can now only be displaced axially (FIG. 2: arrow 70).
FIG. 3 is a longitudinal section through injection apparatus 40 of FIG. 1, and FIG. 4 is an analogous longitudinal section but in a plane perpendicular to FIG. 3.
Located in the proximal part of housing 42 is a transparent cartridge holder 74, which is assembled from a proximal part 76 and a distal part 78 and retains cartridge 50 in its interior. Parts 76, 78 are connected to one another by a micro-click-stop system 77 that is depicted in FIG. 30 at enlarged scale.
It permits easy but also highly precise adjustment of the length of cartridge holder 74 in order to adapt to cartridge 50 and its capacity.
Part 78 has a radial projection 80 that is guided in a longitudinal groove 82 of housing 42 and is displaceable therein between two stops 84, 86. As a result, cartridge holder 74 is nonrotatable relative to housing 42, and is axially displaceable to only a limited extent. FIG. 21 shows projection 80 at enlarged scale.
In the state shown in FIGS. 1, 3, and 4, fluid 49 in cartridge 50 is only a solvent. This solvent must still have added to it an active ingredient, which is usually present as a lyophilisate in a container, cf, container 224 in FIG.

with lyophilisate 226. The manner in which this occurs will be described in detail below. This is called the "reconstitution" of fluid 49, in other words, its conversion into a drug. For that purpose, the injection apparatus must be correspondingly "prepared" before it can be utilized by the patient. The reason for the separate storage of solvent and active ingredient is that the reconstituted fluid has only a limited shelf life, usually only two to three weeks.
Reconstitution is usually performed by specialized personnel (a nurse or physician), but can also be performed by a trained patient.
Cartridge 50 has at its proximal end, in the usual way, a rubber membrane 88 which can be pierced by a needle (cf. FIG. 25). At its distal end it has a rubber piston 90 to which is attached the proximal end of a threaded rod 92 that is depicted at larger scale in FIGS. 5 through 9 and that can also, because of its dual function, be referred to as a toothed rod. For that purpose, the proximal end of threaded rod 92 is snapped with a mushroom-shaped projection 94 into a recess 96, complementary thereto, of rubber piston 90 (cf.
FIGS. 5 and 6). This can be done with the aid of micro-click-stop system 77.
FIG. 7 shows a plan view of distal end 98 of threaded rod 92. The latter has a substantially circular cross section, with two opposing longitudinal grooves 100, 102 for axial longitudinal guidance. These are guided in radially inwardly protruding projections 104 (FIG. 3 and FIG. 15) of distal part 78 of cartridge holder 74, which itself is prevented from rotating by its radial _7_ projection 80, so that piston rod 92 is not rotatable relative to housing 42, but is only axially displaceable.
As FIG. 6 shows, teeth 104 of threaded rod 92 are configured as external threads, but also have the sawtooth shape characteristic of a toothed rod (cf. FIG. 8), i.e. proximal part 106 of a tooth 104 has a shallow slope, whereas distal part 108 has a steep slope.
A proximal part 1 10 (FIG. 6) of toothed rod 92 is of solid configuration, and a distal part 112 has internally a cylindrical recess 114 that does not, however, extend radially as far as longitudinal grooves 100, 102. A pin 1 16 (FIGS. 5, 8, 9) is guided in axially displaceable fashion in recess 1 14. Said pin has at its proximal end two resilient parts 1 18 which protrude radially outward through two diametrically opposite openings 120, 121 of grooves 100, 102;
cf. FIG. 9, which precisely indicates the shape of projections 118 and the location of openings 120, 121. The latter are located at proximal end 122 of recess 114.
The distal end of pin 116 has a recess 124 (FIG. 8) in which a green signal element 126 is releasably snap-mounted with a resilient stem 128. Also located at the distal end of pin 116 are lateral barbs 130 which snap into corresponding cutouts of recess 114 and, after assembly, retain pin 116 releasably in the position shown in FIG. 8. A radially extending cutout 132, which intersects longitudinal grooves 100, 102 Icf. FIG. 7) and into which barbs 130 snap upon reconstitution (cf. FIGS. 22 and 23 below), is also located at distal end 98 of threaded rod 92.
As FIGS. 4 and 12 clearly show, two resilient parts 136, 137, which are equipped on their sides facing toward toothed rod 92 with snap teeth 138 and 139, respectively, for engagement into teeth 104 of toothed rod 92, are located at the distal end of part 78.
In the state shown in FIG. 1, as depicted in FIGS. 4 and 12, snap teeth 138, 139 are not in engagement with teeth 104, so that toothed rod 92 can be axially displaced without interference by parts 136, 137. Resilient parts 136, 137 can, however, be moved radially inward by a corresponding cam control system for engagement with toothed rod 92. Corresponding cams 140, 142 (FIG. 4) are located on the inner side of housing 42. An element 144, _$_ axially displaceable in housing 42 and depicted in three dimensions in FIG.
10, has at its proximal end a segment 146 of hollow truncated conical shape that also acts as a cam and presses resilient parts 136, 137 together and brings them into engagement with toothed rod 92 after completion of an injection (cf.
FIGS. 31 and 35) and also after the completion of reconstitution (cf. FIG.
13).
Element 144 that is axially displaceable in housing 42 has on its outer side 148 two longitudinal grooves 150, 151 which are axially guided in corresponding projections 152, 153 of housing 42. It also has a resilient snap-lock hook 156 having a radially outwardly protruding projection 158 that can engage into recess 66 (FIG. 1 ) of dose setting part 58, as depicted, for example, in FIG. 36. In injection mode, i.e. after reconstitution, it serves as a cocking and triggering member.
During reconstitution, which is described below, element 144 that is axially displaceable in housing 42 is retained in the position shown in FIGS.

and 4.
In its proximal region, element 144 is interrupted by two diametrically opposite longitudinal grooves 162, 164 which, as shown in FIG. 4, are guided in the longitudinal direction on housing-mounted cams 140 and 142, respectively, and during injection come into contact with their distal ends 162', 164' against those cams (cf. FIG. 35).
Element 144 that is axially displaceable in housing 42 also has, in the central region of its inner side, an inwardly protruding annular shoulder 166 (cf.
FIGS. 12 and 13). It additionally has, in the distal end region of its inner side 168, radially inwardly protruding projections 170, one of which is depicted in FIG. 10.
Arranged in interior 168 of element 144 is an adjusting member 174 that is depicted in three-dimensional form in FIG. 1 1. Its distal segment 176 has the shape of a cylindrical tube that is snap-locked, via radial recesses 178 on its distal end, to radial projections 180 of actuation knob 44, and therefore forms one unit with the latter in the assembled state. Threaded rod 92 is axially guided in this tube 176.
In the proximal direction, tube 176 transitions into a part 182 having two resilient snap-lock hooks 184, 186, which are each equipped on their inner _g_ sides with snap-lock teeth 184', 186' in the form of segments of internal threads which are configured in approximately complementary fashion to the external threads in the form of teeth 104 of toothed rod 92, as shown in FIG.
11.
~ As is evident from FIG. 1 1, threaded rod 92 can be axially displaced by rotating adjusting member 174 (with the aid of rotary knob 441. Adjusting member 174 can also, however, be displaced relative to threaded rod 92 in the direction of arrow 70, in which context snap-lock teeth 184', 186' slide along resiliently over teeth 104 of threaded rod 92. Because of the shape of teeth 104, this is possible only in the distal direction (arrow 70).
For guidance in interior 168 of element 144, part 182 of adjusting member 174 has two guidance parts 188, 190 with a substantially round cylindrical contour. Located on them are stop parts 188' and 190', respectively, which provide a stop against annular shoulder 166 (cf. FIG. 3).
Offset 90° from stop parts 188', 190' are stop parts 192, 194 having snap-lock recesses 192', 194', respectively. Stop parts 188', 190', 192, 194 also serve as abutments for the proximal end of an injection spring 200 whose distal end rests against a closure cap 202 that, as depicted, is snapped into the distal end of housing 42 and forms a guide for the distal end of tube 176.
As long as stop parts 188', 190', 192, 194 are in contact against annular shoulder 166, as depicted in FIGS. 3 and 4, adjusting member 174 is free to rotate relative to housing 42, as is necessary for reconstitution.
This state is shown in FIG. 12, once again at greatly enlarged scale. It is also evident that resilient parts 136, 137 are springing radially outward because they are not resting either against cams 140, 142 of housing 42, or against hollow truncated cone 146 of element 144 that is axially displaceable in housing 42.
After reconstitution, which is described below, the inner parts of injection apparatus 40 are brought into a position depicted in FIG. 13. A
comparison with FIG. 12 immediately reveals the differences: adjusting member 174 is in the same position as in FIG. 12, but element 144 that is axially displaceable in housing 42 has been displaced in the proximal direction until it stops against cams 140, 142, so that its hollow truncated cone 146 now rests against oblique surfaces 136" and 137" of parts 136, 137 and presses the latter against toothed rod 92, thereby creating a positively engaged connection between toothed rod 92 and part 78 of cartridge holder 74.
Inner projections 170 of element 144 that is axially displaceable in housing 42 are now immovably snapped into recesses 192', 194' of stop parts 192, 194, so that adjusting member 174 is permanently snap-locked to element 144 that is axially displaceable in housing 42 and can now be moved only together with it. Since element 144 is prevented from rotating by cams 140, 142 which protrude into grooves 162, 164, in this position adjusting member 174 also can no longer be rotated.
The position of the parts shown in FIG. 13 is achieved by the fact that after reconstitution, in the context of the apparatus as shown in FIGS. 1, 3, and 4, actuation knob 44 is pulled upward in the direction of arrow 70 until projections 170 snap into snap-lock recesses 192', 194'. The apparatus is then triggered for the first time by pressing on clip 62. This is described in more detail below with reference to FIGS. 36 and 37.
An adapter 210 that is depicted in FIG. 16 is used for reconstitution. It has an approximately cylindrical housing 212 in which a hollow needle container 214 is secured, for example by being pressed in, adhesively bonded, or welded. The latter has an upper flange 215 that projects radially beyond the upper rim of housing 212. A standard hollow needle support 216, with its hollow needle 218, is secured in hollow needle container 214 in suitable fashion. Hollow needle container 214 is sealed at the top in sterile fashion, as depicted, with a peel film 220 that is removably applied on flange 215. As is usual, internal threads 217 for attachment to injection apparatus 40 are provided in hollow needle support 216.
Hollow needle support 216 and hollow needle 218 can therefore, in this case, be a standard component such as is used in large quantities for injections, which reduces the cost of manufacturing adapter 210. The widened flange 215 ensures a secure bond to peel film 220.
Located in the lower part of housing 212 is a displaceable rubber piston 222 which, in the unused state, covers the lower end of hollow needle 218, while the upper end is covered by peel film 220. This allows sterile storage of hollow needle 218.
As FIG. 17 shows, a usual container 224 that contains a lyophilisate 226 is pressed with its cover 227 into lower recess 228 of housing 212, where it snap-locks onto a snap projection 230. In the process, it displaces rubber piston 222 upward, and the latter, as depicted, is pierced at a thin center portion 222' by the lower end of hollow needle 218, which then pierces a rubber membrane 233 in cover 227. Film 220 is then pulled off, and the arrangement shown in FIG. 17 can be threaded, just like an injection needle, by means of internal threads 217 onto injection apparatus 40 (cf. FIG. 18).
The upper (in FIGS. 16 and 17) end of hollow needle 218 thereby penetrates rubber membrane 88 of cartridge 50 and forms a connection from it to container 224.
As shown in FIG. 19, actuation knob 44 is then turned in the direction of arrow 234, i.e. counterclockwise when knob 44 is viewed in the direction of arrow 236. As a result, threaded rod 92 is displaced in the proximal direction to an end position that is depicted in FIG. 19; in the process it displaces rubber piston 90 in the proximal direction, and pushes fluid 49 out of cartridge 50 through hollow needle 218 into container 224, where lyophilisate 238 is reconstituted, as depicted in FIG. 19.
In the course of this displacement of threaded rod 92, pin 1 16 pushes with its projections 118 against parts 104 of cartridge holder 74 and is displaced in the distal direction, as also depicted in FIG. 21. As a result, the upper end of pin 1 16 is displaced in the manner depicted in FIG. 20 and snaps with its projections 130 into groove 132, so that pin 1 16 is snap-locked in this position shown in FIGS. 20 and 21. As a consequence, signal element 126 protrudes out of the distal end of threaded rod 92 (cf. FIG. 201.
Injection fluid 238 is now reconstituted and can be drawn back into cartridge 50. This is shown in FIG. 22. For this purpose, injection apparatus is turned upside down, and threaded rod 92 is screwed back out by turning actuation knob 44. Rotary knob 44 is turned clockwise in this context as viewed in the direction of arrow 236.
Since rubber piston 90 is connected to threaded rod 92 (cf. FIGS. 5 and 6), it moves in the distal direction, i.e. downward in FIG. 22, thereby drawing the reconstituted fluid 238 out of container 224 through hollow needle 218 back into cartridge 50.
At the end of this operation, signal element 126 (made of flexible plastic) is pushed through an opening 242 (FIG. 3) of actuation knob 44, where it permanently snaps in with its annular groove 246. The user is thereby constantly reminded that this injection apparatus contains reconstituted injection fluid 238 which is intended for prompt use. FIG. 23 shows signal element 126 at greatly enlarged scale. Connecting member 210 and container 224 are then unscrewed.
Injection apparatus 40 is then brought, as shown in FIGS. 36 and 37, into its injection-capable state by pulling actuation knob 44 in the direction of arrow 70; projection 158 is thereby snap-locked into recess 66 of dose setting part 58, as depicted in FIG. 36, so that element 144 is immobilized in housing 42.
In this process, adjustment member 174 is displaced in the distal direction relative to (stationary) element 144, and inner projections 170 of element 144 snap immovably into recesses 192', 194' of stop parts 192, 194 (cf. FIG. 13).
As shown in FIG. 36, cartridge holder 74 is pulled along by the fact that piston 90, which is connected to piston (sic) rod 92, comes to a stop against projections 104 of part 78 and thereby pulls cartridge holder 74 in the distal direction. Alternatively, projections 104 can also snap into a groove (not depicted) of piston rod 92, as long as piston 90 is in the position shown in FIG.
36.
After completion of the operation shown in FIGS. 36 and 37, parts 136, 137 are closed by cams 140, 142 (cf. FIG. 37), and connect piston rod 92 to cartridge holder 74.
Once the position shown in FIGS. 36 and 37 has been reached, apparatus 40 is triggered by pressure on clip 62, and the position obtained is then as shown in FIG. 24, in which parts 136, 137 are held closed by hollow truncated cone 146 of element 144.
Once this position has been reached, injections are possible as described below. For this purpose, a hollow needle 250 is screwed with its hollow needle carrier 252 onto the threads at the proximal end of cartridge holder 74 (cf.
FIG.
24), and the desired injection dose is set by rotating dosage wheel 52, as depicted by way of example in FIG. 2. The rotation of dosage wheel 52 is symbolized in FIG. 24 by a rotary arrow 254.
FIG. 13 shows at enlarged scale the position of injection apparatus 40 as shown in FIG. 24; and as described there in detail, in this position the resilient parts 136, 137 are held in contact against threaded rod 92 by hollow cone 146 at the proximal end of element 144.
Once the injection dose has been preselected by turning dosage wheel 52 (cf. FIG. 2), injection apparatus 40 is cocked, i.e. prepared for an injection.
This is done by pulling actuation knob 44 in the distal direction, as indicated in FIG. 25 by an arrow 256.
FIGS. 25 and 26 show the first part of the cocking operation. As a comparison of FIGS. 24 and 25 shows, hollow needle 250 is pulled completely into the interior of housing 42, so that it is no longer visible to the patient. In the process, parts 136, 137 slide with their segments 270, 272 (FIG. 33) between cams 140, 142 on the inner side of housing 42 and are held closed by them. Simultaneously, radial projection 80 of the cartridge holder comes to a stop against distal end 84 of groove 82, preventing further displacement of cartridge holder 74 in the distal direction.
As shown in FIGS. 27 and 29, actuation knob 44 is pulled farther in the distal direction until element 144 that is axially displaceable in housing 42 snaps with its snap element 158 into recess 66 of dose setting part 58.
Since cartridge holder 74 can no longer participate in this distal movement, resilient snap-lock hooks 184, 186 (FIGS. 29, 30) now slide with their snap-lock teeth 184', 186' (FIG. 1 1 ) linearly over teeth 104 (FIGS. 5 and 6) of toothed rod 92, each tooth 104 denoting one dosage unit X (cf. FIG. 6).
In the position as shown in FIGS. 27 through 30, injection apparatus 40 is therefore cocked and the desired injection dose is set. FIG. 28 shows that signal element 126 is pulled during this cocking operation out of recess 124 of cylindrical pin 116, and is retained in recess 242 of actuation knob 44.
Signal element 126 is thus constantly visible to the user.

As shown in FIG. 31, an injection is then triggered by pressure on clip 62 (arrow 260 in FIG. 31 ). The number 262 symbolically indicates a body part into which hollow needle 250 has already been inserted, and into which the previously set dose 238' of fluid 238 has been injected.
The sequences during injection are explained with reference to FIGS. 32 through 35. These involve a) insertion of hollow needle 250; and b) injection through inserted hollow needle 250.
These operations may partially overlap.
FIG. 32 corresponds to the position as shown in FIGS. 27 through 30, i.e. injection apparatus 40 is cocked.
FIG. 33 shows the beginning of an injection, namely the so-called insertion phase in which hollow needle 250 is inserted into body part 262.
Resilient parts 136, 137 are initially held closed by cams 140, 142 of housing 42, since they have a longer segment 270, 272, parallel to the longitudinal axis of apparatus 40, that gradually slides out of straight segment 140', 142', complementary thereto, of cams 140, 142, so that resilient parts 136, 137 are held closed during approximately the first third of the insertion travel, and force F is transferred from toothed rod 92 directly (i.e. mechanically) to cartridge holder 74. (As shown in FIG. 31, force F of injection spring 200 is transferred via adjusting member 174 to toothed rod 92.) As FIG. 34 shows, resilient parts 136, 137 finally slide out of cams 140, 142 and spread apart as a result of their spring force, so that force F now acts directly from toothed rod 92 on rubber piston 90. This raises the pressure in injection fluid 238 so that the latter acts similarly to a solid object and transfers force F in turn to hollow needle 250 until projection 80 of cartridge holder strikes against its proximal stop 86, which terminates the insertion phase, i.e.
hollow needle 250 is now in the position shown in FIG. 31. In the position of FIG. 34, resilient parts 136, 137 are open, so that toothed rod 92 can be displaced relative to cartridge holder 74 independently thereof.
Injection of fluid 238 then follows, as shown in FIG. 35. In this process, toothed rod 92 displaces piston 90 in the (now stationary) container 50, thereby ejecting from container 50 the fluid quantity 238' that was set with dosage wheel 52 (cf. FIG. 31 ).
At the end of this ejection operation, element 144 that is axially displaceable in housing 42 arrives at its proximal end position as shown in FIG.
35, pushes with its hollow truncated cone 146 on oblique segments 136", 137" of resilient parts 136, 137, and thereby brings the latter once again into engagement with toothed rod 92, so that a new cocking operation can begin as described with reference to FIGS. -25 and following.
In the injection operation, hollow needle 250 is therefore inserted at first by means of a mechanical force transfer (via parts 136, 1371 and then by means of a hydraulic force transfer; this results in a high level of dosage accuracy, since during the mechanical force transfer which results in insertion of hollow needle 250, no fluid can emerge from it. Fluid that may possibly emerge from hollow needle 250 during the subsequent hydraulic force transfer is injected into the body.
After completion of an injection (FIG. 31 ), hollow needle 250 is pulled out of body part 262 and replaced v~iith a new hollow needle which is covered in sterile fashion with a closure cap 46 (FIG. 2). This cap is only removed prior to the next injection.
Many modifications of the present invention are possible. For example, one of resilient parts 136, 137 would suffice for the mechanical force transfer to cartridge holder 74. All parts except for injection spring 200 and cartridge 50 can be made of suitable plastic, and the apparatus can therefore easily be recycled.

Claims

-16-

1. An injection apparatus having a housing (42) which is configured to receive a container (50) having a fluid;
having a part (92), arranged axially displaceably in the housing (42), for acting on said container (50);
having an adjusting member (174) for influencing the position of the axially displaceable part (92) relative to said adjusting member (174);
further having an element (144) arranged axially displaceably in the housing (42) but substantially nonrotatably relative to the housing (42);
wherein the adjusting member (174) can assume at least two different positions relative to said element (144), and in a first of said positions (FIG. 12) is rotatable relative to said element (144) and in a second of said positions (FIG. 13) is nonrotatable relative to said element (144).

2. The injection apparatus according to claim 1, in which in the second position (FIG. 13), the adjusting member (174) is snap-locked to the axially displaceable element (144) so that it can be moved only together with it.

3. The injection apparatus according to claim 1 or 2, in which the part arranged axially displaceably in the housing (42) is configured as a threaded rod (92) which is guided axially displaceably in the housing (42) but nonrotatably relative to the housing (42).

4. The injection apparatus according to claim 3, in which the external threads (104) of the threaded rod (92) are in engagement with corresponding internal threads (FIG. 11: 184', 186') of the adjusting member (174).

5. The injection apparatus according to claim 4, in which the external threads of the threaded rod (92) are configured in the manner of a toothed rod;
and the internal threads (FIG. 11: 184', 186') of the adjusting member (174) are configured in substantially complementary fashion to said external threads (104).

6. The injection apparatus according to claim 4 or 5, in which the internal threads of the adjusting member (174) are configured as partial threads (FIG.
11: 184', 186') on at least one resilient element (184, 186) of the adjusting member (174) in order to make possible a movement of said resilient element (184, 186) perpendicular to the teeth of the threaded rod (92).

7. An injection apparatus having a housing (42) which is configured to receive a container (50) having a fluid, in which container (50) a piston (90) is displaceably arranged;
having a threaded rod (92) for moving said piston (90), said threaded rod being equipped with external threads (104) and being arranged axially displaceably but nonrotatably in the housing (42);
having an adjusting member (174) which is equipped with internal threads (184', 186') for engagement with the external threads (104) of the threaded rod (92) in order to make possible, by means of a relative rotation between the adjusting member (174) and threaded rod (92), an axial displacement of the threaded rod (92);
wherein the external threads (104) of the threaded rod (92) have the shape of teeth of a toothed rod; and the internal threads (184', 186'), substantially complementary thereto, of the adjusting member (174) are arranged on at least one resilient element (184, 186) of the adjusting member (174), in order to make it possible, by means of an axial displacement of the adjusting member (174) relative to the threaded rod (92), for the teeth of said internal threads (184', 186') to slide perpendicular to the teeth of the external threads (104) of the threaded rod (92).

8. The injection apparatus according to claim 7, in which the threaded rod (92) is connected at its proximal end (96) to the piston (90) which is arranged displaceably in the container (50).

9. The injection apparatus according to claim 7 or 8, in which the teeth (104) of the threaded rod (92) are of substantially sawtooth-shaped configuration, and when viewed in cross section each have a proximal segment (106) with a shallow slope and a distal segment (108) with a steep slope, in order to make possible an axial displacement between the threaded rod (92) and adjusting member (174) in only one direction.

10. The injection apparatus according to any of claims 7 through 9, in which the adjusting member (174) can assume at least two different positions relative to an element (144) which is arranged axially displaceably but nonrotatably in the housing (42), the adjusting member (174) being rotatable relative to said element (144) in one of said positions (FIG. 12), and being nonrotatable relative to said element (144) in the other of said positions (FIG. 13).

11. The injection apparatus according to claim 10, in which at least one snap-lock member (170, 192', 194') is provided between the adjusting member (174) and the element (144) that is axially displaceable in the housing (42), in order to make possible a snap lock between the adjusting member (174) and said element (144) in at least one of said positions.

12. The injection apparatus according to claim 10 or 11, in which a snap-lock member (170, 192', 194') is provided for snap-locking in the position in which the adjusting member (174) is not rotatable relative to the element (144) that is axially displaceable in the housing (42).

13. The injection apparatus according to any of claims 7 through 12, in which the fluid container (50) is axially displaceable relative to the housing (42) in order to make possible, by displacement of the fluid container (50), an insertion movement into the patient's skin of a hollow needle (250) connected to the fluid container (50).

14. The injection apparatus according to claim 13, in which a mechanical connection (136, 137) influenced by the axial position of the fluid container (50) is provided between the displaceable fluid container (50) and the threaded rod (92).

15. The injection apparatus according to any of claims 7 through 14, which has an indicator (126) that is actuated when the threaded rod (92) has been displaced, by rotation of the adjusting member (174), firstly a predefined amount in the proximal direction and then a predefined amount in the distal direction.

16. The injection apparatus according to claim 15, in which a displaceable member (116), at whose distal end the indicator (126) is releasably mounted, is arranged in a recess (114) of the threaded rod (92).

17. The injection apparatus according to claim 16, in which the displaceable member (116) has a stop member (118) that, upon a proximal movement of the threaded rod (92), strikes against a stop (FIG. 21: 104) and thereby displaces the displaceable member (116) in the distal direction out of a first snap-locked position (FIG. 5) into a second snap-locked position (FIG.
23) in which the indicator (126) is activated.

18. The injection apparatus according to one or more of the foregoing claims, having a spring (20) [sic] to store energy for an injection, which spring (200) can be cocked by displacing a cocking member (144) in the distal direction;
and having a snap-lock member (156, 158) for releasable snap-locking of the cocking member (144) in said displaced position.

19. The injection apparatus according to claim 18, in which there are provided in the housing (42) cams (140, 142) which, with the cocking member (144) in the displaced position, activate a position-dependent mechanical connection (136, 137) between the threaded rod (92) and fluid container (50).

20. The injection apparatus according to one or more of the foregoing claims, in which the fluid container (50) has associated with it a holder (74) which is displaceable axially in the housing (42) between a proximal and a distal end position, and is configured to receive the fluid container (50).

21. The injection apparatus according to claim 20, in which the length of the holder (74) is changeable.

22. The injection apparatus according to claim 21, in which the holder (74) has a proximal segment (76) and a distal segment (78) which are connected to one another by means of an adjustable connection (77) which makes possible a change in the total length of the holder (74).

23. The injection apparatus according to claim 22, in which the adjustable connection has a micro-click-stop system (77) which connects a proximal segment (76) and a distal segment (78) of the holder (74) to one another in adjustable fashion.

24. The injection apparatus according to any of claims 20 through 23, in which the holder (74) is equipped in its distal region with stop means (80) which define its proximal and/or its distal end position relative to the housing (42);
and in which the length adjustment of the holder (74) is accomplished relative to said stop means, so that upon a change in the length of the holder (74), the position of the fluid container (50) relative to the threaded rod (92) is changed.

25. The injection apparatus according to one or more of the foregoing claims, in which a dose setting part (58) that is displaceable in the longitudinal direction relative to the housing (42) has snap-lock means (66) for snap-locking a snap-locking element (158).

26. The injection apparatus according to claim 25, in which a member (62) for releasing the snap lock between the snap-locking means (66) and the snap-locking element (158) is provided on the displaceable dose setting part (58).

27. The injection apparatus according to claim 25 or 26, in which there is provided on the housing (42) a threaded sleeve (52) which is rotatable with respect thereto but not axially displaceable with respect thereto, and which is in engagement with threads (56) on the displaceable dose setting part (58).

28. The injection apparatus according to any of claims 25 through 27, in which the displaceable dose setting part (58) is not rotatable relative to the housing (42).

29. An adapter for attaching a container (224), equipped with a rubber membrane (233), to an injection apparatus, having a housing (212);
having a hollow needle (218), arranged in said housing (212), which extends both toward the injection apparatus (40) and toward the container (224) and is attached to a hollow needle carrier (216);
having internal threads (217), provided at the one end region of the hollow needle carrier (216), for attachment to external threads of the injection apparatus (40); and having a receptacle (228), provided at the opposite end region of the housing (212), for the part (227) of the container that is equipped with the rubber membrane (233) (FIGS. 16, 17).

30. The adapter according to claim 29, in which the receptacle (228) provided at the opposite end region of the housing (212) is equipped with a radially inwardly protruding snap-lock projection (230) to allow the container (224) to be snap-locked into the housing (212) of the adapter.

31. The adapter according to claim 29 or 30, in which a part (222) that can be perforated by the hollow needle (218) is displaceably arranged in the opposite end region.

32. The adapter according to claim 31, in which, in the state prior to perforation (FIG. 16), the part (222) that can be perforated by the hollow needle (218) covers the associated end of the hollow needle (218) in sterile fashion.

33. The adapter according to one or more of the foregoing claims, in which the one end region (217) of the housing (212) is covered in sterile fashion.

34. The adapter according to claim 33, in which a holder (214) for the hollow needle carrier (216) is provided between the hollow needle carrier (216) and the tubular housing (212); and the sterile covering (220) is provided at one end of said holder (214).

35. The adapter according to claim 33 or 34, in which a peel film (220) or the like is provided for sterile covering.

36. The adapter according to any of claims 29 through 35, in which the housing (212) is divided by the hollow needle carrier (216) into subregions which are in liquid communication with one another via the hollow needle (218).

37. The adapter according to any of claims 29 through 36, in which the hollow needle carrier (216) and the hollow needle (218) are configured substantially as a standard component such as is used for injections with ordinary injection apparatuses.

38. A method for reconstituting an injection fluid, having the following steps:
a) solvent is transferred out of an injection apparatus, by actuation of said injection apparatus, into a container having a lyophilisate that is to be reconstituted;
b) the reconstituted lyophilisate is drawn back out of the container into the injection apparatus by actuation of the injection apparatus;
c) the injection apparatus is switched over to operation with single injections so that the drawn-in reconstituted lyophilisate can be injected.

39. The method according to claim 38, in which the injection apparatus has a threaded rod which is equipped with external threads and is guided axially displaceably but nonrotatably in the injection apparatus, and with which is associated an adjusting member whose internal threads are in engagement with the external threads of the threaded rod, wherein in step a) the solvent is transferred, and in step b) the reconstituted lyophilisate is drawn in by rotating the adjusting member relative to the threaded rod.

40. The method according to claim 39, in which the threaded rod has external threads with a sawtooth-shaped cross section, and the adjusting member is of radially resilient configuration in order to slide along perpendicularly over the external threads;
and in step c) the adjusting member is immobilized in terms of rotation.

41. A method for displacing a hollow needle in the context of a fully automatic injection apparatus, in which firstly said hollow needle is displaced in the direction of its tip by the action of energy stored in a spring, and then a fluid is transported out of a fluid container through said hollow needle, movement of the hollow needle by means of the stored energy being accomplished firstly by mechanical direct drive of the hollow needle, and then by hydraulic force transfer to the hollow needle by means of a pressure rise in the displaceable fluid container which stores the fluid.

42. An adapter for attaching a container (224), equipped with a rubber membrane (233), to an injection apparatus, having a housing (212);
having a hollow needle (218), arranged in said housing (212), which extends both toward the injection apparatus (40) and toward the container (224) and is attached to a hollow needle carrier (216);
having internal threads (217), provided at the one end region of the hollow needle carrier (216), for attachment to external threads of the injection apparatus (40), said end region being covered in sterile fashion by a peel film (220) or the like; and having a receptacle (228), provided at the opposite end region of the housing (212), for the part (227) of the container that is equipped with the rubber membrane (233) (FIGS. 16, 17), in which receptacle is displaceably arranged a part (222) which can be perforated by the hollow needle (218) and which, in the state before perforation (FIG. 16), covers the associated end of the hollow needle (218) in sterile fashion.