EP3142727A1

EP3142727A1 - Spindle device for a piston of a reservoir with medicament fluid

Info

Publication number: EP3142727A1
Application number: EP14724430.5A
Authority: EP
Inventors: Alex Müri
Original assignee: Meamedical AG
Current assignee: Meamedical AG
Priority date: 2014-05-14
Filing date: 2014-05-14
Publication date: 2017-03-22
Also published as: US20170056579A1; WO2015172828A1

Abstract

A spindle device (S) for a piston (K), which is held in a reservoir (A) containing a medicament fluid, said spindle device (S) comprising: a first rotationally secured displacement stage (9) with a thread (22), a second rotationally secured displacement stage (16) with a thread (24), a drive stage (15) arranged between the displacement stages and having two threads (23, 25), wherein one thread (23) is in engagement with the thread of the first displacement stage (9) and thus forms a first spindle drive (20), and the second thread (25) is in engagement with the thread of the second displacement stage (16) and thus forms a second spindle drive (21), and in this way two contradirectional spindle drives (20, 21) are formed, and wherein the spindle device (S) is designed in such a way that the first displacement stage (9) and the drive stage (15) move simultaneously in the direction of advance. The first and second displacement stages (9, 16) are connected to each other in a rotationally fixed manner via an element axially surrounding the drive stage (15) for the rotational securing (26), and the drive stage (15) of the spindle device (S) can be coupled in a rotationally fixed manner, only from an end face (35) of the spindle device (S) directed away from the piston (A), to an entrainment rod (4) designed as coupling member of a drive device (M), wherein the entrainment rod (4) is insertable into an axial hole formed on the drive stage (15).

Description

Spindle device for a piston of a reservoir with medication fluid

Technical area

The invention relates to a spindle device for a piston according to the preamble of claim 1.

State of the art

For the administration of fluidic medicaments, in particular for insulin, portable injection and / or infusion devices are used. The medicament fluid is conveyed continuously or quasi-continuously by means of a metering device which contains a drive device for a piston and a reservoir with the fluid. The piston of the reservoir is displaced and the fluid contained in the reservoir is displaced and administered. Such devices are used as pump devices and manually operated pens in insulin treatment. An injection pen is known, for example, from WO93 / 16740. For both injection pens and insulin pumps, these devices must be as compact, reliable and safe as possible for the user.

An example of an insulin pump is the D-TRONplus pump from Roche Diabetes Care GmbH. This has a fixedly arranged in the pump spindle device, which is formed of three telescopic spindle stages. In this case, a first displacement stage, which is movable against the piston of the reservoir, only perform a feed. A second shift stage can perform both a feed and a rotation when driving through a drive stage. The drive stage performs only one rotation to produce the feed of the first or the second shift stage. The Drive device with its firmly connected spindle device of the D-TRONplus pump is described in DE 197 17 107 B4. In addition to the serial embodiment in which the first and second shift stages are arranged one behind the other and the drive stage drives the second shift stage as the third spindle element, a spindle arrangement is also described in which the drive stage is arranged between a first shift stage and a reaction stage. In this arrangement, moves the first shift stage and repels itself from the drive stage, as well as the drive stage pushes off from the solid, connected to a housing reaction stage. This arrangement is provided for spindle devices arranged permanently in the pump. It can be considered as a parallel embodiment, since both movable stages - the first shift stage and the drive stage - simultaneously move in the feed direction, while in the said serial embodiment moves only one spindle stage. Serial embodiments in which the extending drive stages extend in succession, as is the case with the D-TRONplus pump, have the disadvantage that, during the transition from the first extending stage to the second extending stage, an interruption in the conveyance occurs as a result of an unreleased thread clearance can. Concretely, this can lead to a lack of support, which means that the patient is under-supplied with medication fluid. This problem is known and in DE 100 15 175 A1 a resistance element is disclosed for this purpose, the task of which is to eliminate thread play of the spindle drives in the feed direction. This further resistance element necessary for the suspension of the game is disadvantageous in that it increases the axial length of the spindle device and thus of the insulin pump and increases the complexity of the drive device. In FIG. 1 of DE 100 15 175 A1 it can be seen that further elements such as sealing points located on the spindle device, a sealing point for the drive stage, stops for the spindle stages and a cover of the drive stage substantially increase the size of the spindle device in the axial direction. The drive device according to DE 100 15 175 A1 accordingly has a complex construction consisting of many components, which unfavorable effect on the life and reliability of the insulin pump. In addition, such a construction is expensive to manufacture and assemble.

For the embodiment of FIGS. 13 and 14 disclosed in DE 197 17 107 A1, the drive stage arranged between the first shift stage and the reaction stage is driven by an outer drive member. The drive member has an unfavorably large diameter, so that any storage, which is primarily formed via sealing points with O-rings, has large friction losses. In order for a motor for the embodiment of FIGS. 13 and 14 not to come into contact with water or another fluid substance, the drive member must be sealed both above and below a gear connection formed on the drive member. Such a seal located on a large diameter increases the frictional loss significantly and has an unfavorable effect on the energy consumption of the metering device. The embodiment according to FIGS. 13 and 14 is therefore difficult to seal. The disadvantages described are accepted in order to form a pump which is as compact as possible according to DE 197 17 107 A1 and which is intended to have a minimal extent, especially in the longitudinal axis of the spindle device. The minimization of the linear expansion along the spindle axis corresponds to the task originally described in DE 197 17 107 A1. In the granted patent claims of EP 0 991 440 B1, for which DE 197 17 107 A1 justifies the priority application, it can be seen that the minimization of the longitudinal axis represents the essential object of the invention. This is achieved in that an outer drive stage in the form of a drive sleeve receives the shift stages. In the embodiment of FIGS. 13 and 14 of DE 197 17 107 A1, therefore, the reaction stage of the spindle device is firmly connected to a housing and supported on a lower housing inner wall. So that the medicament pump has a minimal extent along the spindle axis, the drive element of the drive stage is driven from the side via the laterally arranged motor. Another disadvantage is the necessary axial overlap between the drive member and the drive stage with a driver, and the axial stops for the spindle stages, which should prevent a separation of the spindle stages during operation. Both the said overlap and the stops on the spindle stages extend the size of the pump along the spindle axis. Furthermore, the embodiment of FIGS. 13 and 14 has an anti-twist device for the first shift stage. This is designed as a sleeve and rotatably connected to a base part. Viewed in radial direction, the arrangement of Fig. 14, the three telescopic spindle stages, the drive member, a cylindrical formed on the base part receptacle for the drive member and the anti-rotation device for the first shift stage. The radial extent of this device is so large and unfavorable that this embodiment has found no application as a compact insulin pump in practice. It is also known that the drive device of the D-TRONplus, which is disclosed in DE 197 17 107 B4 in FIG. 24, is not protected against contamination. Especially the spindle drives and threads of the first and second shift stages are not protected against contamination with dust, insulin, cleaning agents and water. Such contamination can reduce the life of this permanently arranged on the housing Spindelvor- direction. The embodiment according to FIGS. 13 and 14 has high frictional losses and is therefore unfavorable in terms of energy, moreover the motor-gear arrangement is difficult to seal against the outside. The drive device of the D-TRONplus pump of FIG. 24 has a serial embodiment of the spindle device. The construction according to FIGS. 13 and 14, however, corresponds to the parallel embodiment discussed above.

From WO 94/15660 and WO 97/00091 telescopic spindle devices of the serial type are known. These are always the same arrangement in their arrangement and have a first and second shift stage, wherein the first shift stage envelopingly receives the second shift stage and encloses the second shift stage enveloping a drive stage. In this arrangement drives the drive stage in each case one of the shift stages. As soon as the extending shift stage reaches its axial stop, the remaining shift stage moves. This arrangement has the already described adverse transition of the drive stages, in which a reduced funding of drug fluid is possible. In WO 97/00091 a two-stage anti-rotation is shown for the first shift stage, which is formed of a fixed and a movable sleeves. This arrangement with three stages for the spindle device, and two sleeves for the anti-rotation has an unfavorable radial extent and is therefore only for larger Ampulenvolumi- na used. There is an indication in WO 94/15660 that the spindle device is intended for standard ampoules with "5 cc, 10 cc, etc." In the device disclosed in WO 97/00091, the ampoule body is attached to an intermediate part and In a further handling step, the intermediate part coupled to the ampoule has to be connected to a drive device In this step, both the intermediate part and the drive device must be fastened to the drive device It will be appreciated that these embodiments are complicated in structure, include many components, and require multiple manipulations, and no means are provided for engaging the spindle apparatus and apparatus At drive device to protect against contamination. Furthermore, it is stated here that the telescopic spindle devices according to the embodiments of WO 94/15660 and WO 97/00091 can be reused by a user. Since the driven gear protrudes freely outward and so the drive stage is directly accessible to a user, this can bring the spindle device by turning the drive stage back to its original position. For consumables that are to be protected from contamination by bacteria and the like and that are to be used only once, such a solution is not safe for the user. Further devices for the administration of medicaments are also known from DE 28 09 990 C2, DE 34 32 152 C2 and DE 37 33 452 C2. Furthermore, a large number of single-stage spindle devices is known. These only move one step. Single-stage spindle devices are not optimal for very compact devices, since their extension along the longitudinal axis of the spindle device unfavorably large fails. Single-stage spindle devices are known from WO2009 / 125398 and EP0143895 and are mentioned here as examples of single-stage spindle device for the sake of completeness. From the prior art it can be seen that for compact insulin-administering devices, an arrangement of the spindle device has been established in which the axial length of the pump is minimized. In this arrangement, the drive stage is driven from the side via a gear connection. This arrangement is obvious to the person skilled in the art and is preferred because it allows the spindle to be moved starting from a rear wall of the housing, thereby minimizing the axial length of the spindle device and the reservoir for the device. This design is therefore found both in DE 197 17 107 A1 for telescopic spindle devices, as well as, for example, in WO2009 / 125398 and EP0143895 for one-stage spindle devices. By contrast, the embodiments in WO 94/15660 and WO 97/00091 have not been designed for compact insulin-administering devices, and their driving motor can therefore be arranged axially below the spindle device. Presentation of the invention

The purpose of the invention is to provide a spindle device for a piston of a reservoir, which is replaceable and easily coupled with a drive device and which is in the application for the patient si- rather and reliable. Likewise, the spindle device should be easy to manufacture and have few components. Next, the user should not be in be able to bring a used spindle device itself in an initial state and re-use.

The stated object is achieved by the spindle device defined in claim 1. This has two non-rotating displacement stages and arranged between the shift stage drive stage, wherein between the first shift stage and the drive stage, a first spindle drive is formed and between the drive stage and the second shift stage, a second counter-rotating spindle drive. In an initial state, the shift levels overlap at least partially. Due to the fact that a drive element axially enveloping element for the rotation lock rotatably connects the two shift stages and the drive stage of the spindle device is directly or indirectly rotatably coupled directly or indirectly from an end face of the spindle device facing away from the piston with a driver rod of a drive device designed as a coupling member, the Users do not return a used spindle device itself in an initial state, wherein the driving rod is insertable into an axial hole formed on the drive stage. On the other hand, the user can easily replace the used spindle device with a new one. These properties of the spindle device according to the invention increase the lifetime of the entire metering device, since the spindle device exposed to wear can be replaced by the user. As a result, the life of the pump is increased and the safety for the patient is improved due to increased reliability and life for the entire metering device. The inventive spindle device merely has an interface to the drive device. This interface between the drive device and spindle device is formed by the arranged on the drive device coupling member. The coupling member of the drive device can be easily sealed to a housing of the drive device, which can further increase the reliability and life of the drive device. In the coupled state, the arranged between the shift stages drive stage with the Coupling member connected and surrounded by the enveloping element for the rotation. In the uncoupled state, the user has no access to the drive stage, because radially the drive stage is surrounded by the element of the rotation and from below it is accessible and operable only with suitable tools. The spindle device according to the invention ensures that the user must use a new spindle device to avoid contamination for each new reservoir filled with medication fluid.

For the purposes of the present invention is meant by an indirect rotationally fixed coupling between the drive stage and driving rod, that an intermediate piece between the drive stage and driving rod or, for example, a two-part embodiment of the driving rod can be provided, for example by an additional guide.

Advantageous embodiments of the invention are defined in claims 2 to 14.

Preferably, the drive stage is formed of two cylindrical sleeves, with the sleeves at their upper end, i. on the side facing the piston, or on its lower end, i. on the side facing away from the piston, rotatably connected to each other. Preferably, the rotationally fixed connection is carried out at its upper end sides on the side facing the piston.

Preferably, the coupling member may be formed as a profiled driving rod. The profile can be chosen so that the user can not create a coupling with the drive stage with a screwdriver or other tool. In addition, it is advantageous if the driving rod protrudes as far as possible into the drive stage. The overlap should have in the initial state at least one path V of a shift stage. This ensures that the driving rod and the drive stage are engaged for the entire travel of the piston. Partially filled reservoirs can also be used thanks to the intersection of at least one travel path V between the drive stage and the drive rod. This is advantageous because not every user needs the same amount of medication fluid per day and therefore prefers to only partially fill the reservoir.

In a preferred embodiment, the enveloping element for the rotation can be formed as a sleeve. Since both drive stages are formed of cylindrical elements, it makes sense to form the enveloping element for a rotationally fixed connection between the two displacement stages of a cylindrical element. This makes it possible to form a spindle device which has all cylindrical elements and thus a circular cross section. For the ejection of cylindrical reservoirs, this arrangement is particularly advantageous since the radial extent of such a spindle device should be low. Such a spindle device is particularly suitable for the ejection of pre-filled ampoules with insulin.

Preferably, the spindle device can be arranged directly on the piston. In this case, the piston itself may be formed as a first displacement stage of the spindle device. If, in addition, the piston and thus also a wall of the reservoir have oval cross-sections, then the wall can be used as an element for preventing rotation of the piston. The reservoir and the spindle device arranged on the spindle device together form a particularly compact component. Such an embodiment allows a very flat and at the same time very short design for the reservoir. This is particularly advantageous for reservoirs of patch pumps. Such systems are directly on the skin of a User worn. Small dimensions are particularly advantageous for such applications. Likewise, the handling is simplified for the user, because now reservoir and spindle device are connected together and together form an exchangeable part. This embodiment has a simple design and few components, is easy to install and inexpensive to manufacture.

According to a preferred embodiment, it is particularly advantageous if the length ratio L / D, where L is a longitudinal axis of the oval cross section of the piston and D is a maximum distance between sealing points arranged on the piston, is greater than 0.5 and less than 2.5. For insulin pumps, common ampule volumes are 1 .5 cc to 3.5 cc. In general, it is the case for conventional metering devices that the sealing points on the piston are very close to one another in order to obtain a compact ampule with a minimum length extension. The aspect ratio L / D is therefore very large and for commercially available reservoirs greater than 3.0. It has been shown, however, that for the special case of pistons with oval cross-sections, a ratio of less than 2.5 is advantageous, because such an aspect ratio L / D prevents a walking of the plug when dispensing medicament fluid. The walking of the piston can adversely affect the delivery accuracy of drug fluid. In addition, for aspect ratios L / D less than 2.5, it is possible to place the spindle device directly on the piston. According to claim 4, a reservoir can be provided which is compact in size and has a piston device integrated in the piston. In addition, owing to the favorable aspect ratio of less than 2.5, it is possible to avoid necking of the plug. Although reservoirs with length ratios of less than 0.5 have good properties with respect to the rolling of the piston, but have an unfavorable length expansion. Reservoirs with an aspect ratio of less than 0.5 are not suitable for compact dispensers. Preferably, the second shift stage may have at its lower portion a locking member which prevents rotation of the second shift stage via the wall of the reservoir. Thus, the wall of the reservoir also acts for the second shift stage as an element for the rotation. Such a design further simplifies the construction of the spindle device, also simplifies handling for the user. According to this embodiment, the second shift stage no longer has to be brought into engagement with a fixed housing in order to prevent a rotation of the shifting stages. According to such a preferred embodiment, the second displacement stage is prevented from rotating by the wall of the reservoir; for this purpose, according to a further preferred embodiment, a wing is suitable as a blocking member. The user only has to make the coupling between the drive rod of the drive device and the drive stage of the spindle device and subsequently non-rotatably connect the reservoir to a housing. According to such a preferred embodiment, an axial stop for the second displacement stage is necessary, this is advantageously formed according to a further preferred embodiment of the driving rod. A partially filled reservoir is brought into engagement with the catch rod by the user in a handling step and the reservoir is fixed to a fixed housing, for example, bayonet connections are suitable. Now, if the drive stage is driven, the second displacement stage moves backwards against its arranged on the drive rod axial stop. An arranged on the drive device force sensor for the decrease of an axial force can thus ascertain an approach of the spindle device at the stop. The spindle device and reservoir are ready for priming a fluid path or dispensing drug fluid after start-up. With the arrangement defined in this preferred embodiment, the handling for the user is further simplified by the dosing device can be automatically brought into an initial state for a priming or a payout in interaction with an electronic control. Tedious alignment of drive spindle and piston for manually connecting the piston and drive spindle, as is known for conventional insulin pumps, is spared the user. The insulin pump Spirit Plus from Roche Diabetes Care GmbH, for example, has a permanent spindle device with a plug plate for connection to a piston of a reservoir. In the case of partially filled reservoirs, in a first handling step the user has to extend the spindle device by eye, so that in a second handling step he can connect the piston and the spindle to one another via a screw connection. The connection of piston and plug plate is time-consuming, cumbersome and leads to inaccurate alignment of the piston and plug plate to a suction of air or expulsion of drug fluid to the user. Further, it is advantageous according to a further preferred embodiment, when the wall of the reservoir is formed as a housing and is directly connectable to the fixed housing. As a result, a slim and compact metering device can be formed. This embodiment is particularly advantageous for patch pumps that are worn directly on the skin and therefore may not apply heavily to the body of a user. A user will hardly perceive such a pump designed with a slim contour as disturbing.

According to a preferred embodiment, it is advantageous if the receptacle of the reservoir on the housing and the axial stop for the second displacement stage are at the same height or directly the same height along a common longitudinal axis. In addition, both the housing and the spindle device should have a similar coefficient of linear expansion. This advantageous embodiment makes it possible to compensate for temperature fluctuations and thus to minimize increase or decrease due to temperature fluctuations. In conventional pumps, the spindle devices are mostly made of metal. On the other hand, the wall of the Re- Servoirs and the housing of the pump made of plastic. When the temperature changes between the plastic components and those made of metal length expansion differences. The different length expansions of the components can lead to more or less promotion. This preferred embodiment enables a minimization of the increased and reduced production by the spindle device from its stop to the piston and the wall of the reservoir from its fixation to the piston expand the same. It is therefore advantageous if the fixation of the reservoir and the stop formed on the driving rod for the spindle device lie at the same height as possible along its longitudinal axis.

According to a preferred embodiment, it is advantageous if the piston or one of the elements of the spindle device can be connected to a mounting rod. This is advantageous for the user, as this allows him to connect the piston with the mounting rod as in conventional ampoules, fill the reservoir and then connect the reservoir with the drive device. The filling of the reservoir can be carried out in the same way as the user already knows and is familiar from known systems. Thus, no new handling steps are required for the user when filling the reservoir.

Preferably, the spindle device and the reservoir may form a common replaceable part. This facilitates handling, because a connection of the spindle device with the piston of a reservoir is eliminated. Since the spindle device can be brought into an initial state only with the aid of special tools, the user can use a reservoir only once. This improves the life of the metering device, because with each new reservoir also a new spindle device is used. The spindle device according to this preferred embodiment is thus not exposed to wear. It is known that permanently with The spindle connected spindle devices conventional insulin pumps are exposed to heavy wear. Wear of any kind significantly reduces the life of such metering devices. Since the spindle device defined according to this embodiment can be used only once, the safety for the user increases. Repeated use of reservoirs may result in infection due to bacterial contamination. Likewise, repeated use may result in leaks in the reservoir. Leaks cause the user to a shortage of medication fluid. A particularly advantageous embodiment according to claim 12 is defined in claims 4 to 11.

According to a preferred embodiment, it is advantageous if the spindle device is designed alone as an exchangeable part. For example, the spindle device defined in claim 3 can be designed as a separate part with different paths of travel. Thereby, a modular design can be achieved by the same drive device can be combined with different spindle devices and different reservoirs. The design effort and development effort for new devices can be drastically reduced. Preferably, the spindle device may also be permanently coupled to a drive device. For the administration of drug fluid devices are known that are used only once. For such devices, it makes sense to permanently couple the drive device with the spindle device. It is noted here that embodiments are conceivable in which the drive device and the spindle device are permanently coupled together and the spindle device can be used multiple times. Brief description of the drawings

Exemplary embodiments of the invention will be described in greater detail below with reference to the drawings, in which:

1 shows a first exemplary embodiment of a spindle device according to the invention connected to a prefilled glass ampoule before coupling with a drive device in longitudinal section,

Fig. 2a, the system shown in Fig. 1 in the coupled state in one

Starting position in longitudinal section,

2b shows the system shown in Fig. 2a in an extended state in longitudinal section,

3 shows a second embodiment according to the invention with a piston device integrated into a piston for an oval reservoir before a coupling with a drive device in a starting position in longitudinal section, FIG.

Fig. 4a shows the system shown in Fig. 3 in the coupled state in a

Starting position in longitudinal section,

4b, the system shown in Fig. 4a in an extended state in longitudinal section,

5a shows the system shown in FIG. 3 in the coupled state with a partially filled reservoir in a starting position in longitudinal section, FIG.

5b shows the system shown in FIG. 5a in the coupled state after the second displacement stage has been driven onto a stop in longitudinal section, FIG.

Fig. 6a, a first embodiment of a locking member for the second

Displacement stage in a starting position in cross section to the longitudinal axis for the system of Fig. 3, 6b, the blocking member shown in FIG. 6a supported on a wall of the reservoir in cross section to the longitudinal axis,

Fig. 6c, a second embodiment of a locking member for the second

Displacement stage in a starting position in cross section to the longitudinal axis for the system of Fig. 3,

Fig. 6d, the locking member shown in Fig. 6c on a wall of the

Reservoirs supported in cross-section to the longitudinal axis,

Fig. 7, the reservoir shown in FIG. 3 in the coupled state with the

Drive device in cross section to the longitudinal axis,

8, the reservoir shown in Fig. 3, wherein the spindle device is connected to a Aufziehstange, in longitudinal section,

FIG. 9a shows the replaceable spindle device shown in FIG

Use,

FIG. 9b shows the replaceable spindle device shown in FIG

Use in longitudinal section, and

Fig. 9c, the reservoir shown in Fig. 3 with integrated spindle device after use in longitudinal section.

Ways to carry out the invention

In Fig. 1, a first embodiment of an inventive spindle device S is shown. Fig. 1 shows an arrangement, as occurs for example in an insulin pump. In such a pump, a metering device comprises a drive device M, a replaceable spindle device S and a reservoir A with drug fluid. A fluid path F, which connects the pump with the user, is only partially shown here. At her- conventional insulin pumps, the spindle device S with the drive device M is directly connected and not interchangeable. Examples of this type are the D-TRONplus and Accu-Chek pumps from Roche Diabetes Care GmbH. The drive device M shown in FIG. 1 has a motor 1, a planetary gear 2, a reduction spur gear 3, which rotatably drives a driving rod 4 serving as a coupling member, and a housing 5. The driver rod 4 serves as an interface element between the drive device M and the spindle device S. The driver rod 4 having a circular cross-section at its sealing point can thus be sealed against the housing 5 by means of an O-ring. The slender cross-section of the driving rod 4 allows an efficient, with low friction losses associated with sealing on the housing inner wall 6. An intrusion of foreign fluid in the gear housing is thus avoided. The drive rod 4 is supported axially on a housing rear wall via a force sensor 7 arranged therebetween. The force sensor 7 has the task to measure an axial, acting on the driving rod 4 force. An axial stop 8 formed on the driving rod 4 serves as a stop for the spindle device S. An axial force acting on the spindle device S is thus guided via the driving rod 4 to the force sensor 7. The measurement of the spindle force is used to detect an approach of the spindle device S to its stop, to detect an occlusion in the fluid path and to monitor other conditions of the pump. The inventive spindle device S of FIG. 1 has a first displacement stage 9, which is connected to a piston K of a reservoir A. The reservoir A comprises for the illustrated embodiment a pre-filled glass ampoule 10 with a septum 1 1 for a connection with a liquid path F, a round glass body 12 and a rubber piston K, the latter having an internal thread 13, so that the glass ampoule 10 and the Spindle device S can be connected to each other. For the threaded connection with the piston K, the spindle device S has at its first displacement stage 9 an external thread 14 engaging in the internal thread 13 of the piston K. In a first handling step the user connects the spindle device S with the piston K, by screwing the two elements together. In a second handling step, the system formed from glass ampoule 10 and spindle device S is brought axially into an ampoule compartment for accommodation in a housing. This results in a coupling operation between the drive device M and the spindle device S, in which the drive rod 4 is coupled to a drive stage 15 of the spindle device S. At the same time a second shift stage 16 of the spindle device S is rotatably connected to the fixed housing. After the coupling of the drive device M with the spindle device S, the pump is ready for a connection with a fluid path F. The fluid path F is shown in Fig. 1 only partially. This has the task of ensuring the fluidic connection between the ampule A and the user. In general, the fluid path F can have an adapter which can be connected to the ampule A for connecting the ampule A to the fluid path F, a catheter tube and a port located at the end of the catheter tube with a cannula for connection to the user. If the motor 1 rotates, then the carrier rod 4 executes a reduced rotational movement and thereby drives the drive stage 15 in rotation. So that the displacement stages 9 and 16 merely shift axially, the first displacement stage 9 and second displacement stage 16 are connected to one another in a rotationally fixed manner via a concentrically arranged, cylindrical sleeve 17. The sleeve 17 has radial catches 18, which engage in corresponding longitudinal grooves 19 on the displacement stages. In the arrangement according to FIG. 1, the first displacement stage 9, the second displacement stage 16 and the sleeve 17 are connected to each other in a rotationally fixed manner. There is also a first spindle drive 20 formed by threads between the first shift stage 9 and the drive stage 15. Likewise, there is a second spindle drive 21 formed from threads between the second shift stage 16 and the drive stage 15. The two spindle drives 20 and 21 are formed in opposite directions, so that the one spindle drive is formed of right-hand threads and the other of left-hand threads. In a first step, an axial longitudinal clearance between the spindle device S and the drive device M must be moved, doing the second shift stage 16 backwards against their arranged on the drive rod 4 stop 8. With the driving of the second shift stage 16 at its axial stop 8, the longitudinal clearance between the spindle device S and the drive device M is repealed. The pump is now in an initial state for a drug delivery. This initial state is shown in FIG. 2a. If the drive stage 15 is further driven to rotate, the first displacement stage 9 of the drive stage 15 and the drive stage 15 of the second, located at its stop 8 shift stage 16 repel. Since both spindle drives 20 and 21 are driven simultaneously, any possible thread play in the two spindle drives is simultaneously canceled. Means for the game suspension are therefore not necessary. The threads can, for example, have a pitch of 0.4 mm per revolution. In one revolution of the drive stage 15 thus move the spindle device S and so the piston K by 0.8 mm per revolution. The spindle device of the D-TRONplus pump, for example, has a pitch of 1 .2 mm per revolution and has spindle drives in the same direction. The inventive embodiment of the spindle device S shown in FIG. 1 is compact and its radial extent is so small that it is particularly suitable for the ejection of prefilled glass ampoules with insulin. These have generally slim ampoule bodies, wherein the inner diameters can only be 8 to 10 mm. By further rotation of the drive stage 15, the spindle device S pushes the piston K in the feed direction and displaces medicament fluid. This is handed over to the user. For administration, any release profiles are conceivable. In insulin pump therapy, the delivery is divided into a basal delivery and a bolus delivery. When the piston K reaches an upper position, the ampoule A is emptied. In Fig. 2b this fully extended state of the spindle device S is shown. In this state, the engagement between the drive rod 4 and the drive stage 15 is minimal. In a simple way, the user can remove the ampoule A and the spindle device S connected to it via the piston K from the ampoule compartment. Afterwards, he can start the pump with a new loaded ampule A and a new spindle device S. Since the first displacement stage 9, the sleeve 17 and the second displacement stage 16 are rotatably connected to each other and the sleeve 17 surrounds the drive stage 15 enveloping, the user can no longer bring a used spindle device S in its initial state. He is thereby forced to use a new spindle device S. Using a new spindle device S for each ampule A to be used increases patient safety and extends the life of the drive device M. The drive devices coupled to permanent spindle devices of conventional systems, such as those of the D-TRONplus and Accu-Chek pumps , have to reliably perform several hundred strokes over their lifetime. The spindle devices of conventional systems permanently connected to the pump are exposed to high wear and often fail before the end of a guaranteed service life.

FIGS. 3 to 8 show a second exemplary embodiment according to the invention. This is particularly advantageous for the user in handling, because the spindle device S is integrated directly on a piston K of a reservoir A. FIG. 3 shows the spindle device S arranged on the piston K and the oval reservoir A in front of a coupling with a drive device M. The piston K serves as a first displacement stage 9 of the spindle device S and also has an oval cross-section. Such a designed reservoir A is advantageous for applications in which a flat pump contour is required. An internal thread 22 arranged on the first displacement stage 9 forms a first spindle drive 20 with an external thread 23 formed on a drive stage 15. The drive stage 15 in turn is connected to a second displacement stage 16 via a further spindle drive 21 formed from threads 24 and 25. Also for this embodiment, the two spindle drives 20 and 21 are in opposite directions. The oval reservoir A serves as an element for preventing rotation 26 of the piston K. A spindle drive torque acting on the first displacement stage 9 and thus also on the piston K is discharged from the reservoir A added. The second displacement stage 16 has a radial locking member 27 in the form of a wing 28 at a lower end. Embodiments of the locking member 27 in an initial position and in a locking position are shown in Figs. 6a, 6b, 6c and 6d. The locking member 27 of Fig. 6a and 6c has a radial extent which is greater than the smallest distance between opposing walls of the reservoir A. A at the second shift stage 16 attacking spindle drive torque is transmitted via the locking member 27 to the reservoir A, as this is shown in Figs. 6b and 6d. The second displacement stage 16 is thus prevented from rotating, wherein for both displacement stages 9 and 16, a wall 29 of the reservoir A serves as a reaction member for the spindle drive moments formed in the spindle drives 20 and 21. The wall 29 of the reservoir A thus corresponds to the element for the anti-rotation device 26. The user can easily couple the reservoir A having the integrated spindle device S with the drive device M. He leads a arranged on the drive device M profiled drive rod 4 in a formed on the drive stage 15, axial hole 30. For the profiling of the drive rod 4 and the hole 30 are, for example, square or star-shaped cross-sections. The reservoir A, on the other hand, is non-rotatably connected to a housing 5 of the drive device M via a bayonet connection 31. The wall 29 of the reservoir A is here itself designed as an outer housing, whereby the pump has a very flat pump contour. If the drive rod 4 driven by the engine 1 rotates and thus drives the drive stage 15, then the piston K pushes off the drive stage 15 as the first shift stage 9. At the same time, the drive stage 15 pushes itself off from the second displacement stage 16 located at its axial stop 8. The feed thus generated is for the drive stage 15 a pitch per revolution and for the piston K two pitches per revolution. The piston K moves thereby a thread pitch per revolution relative to the drive stage 15. In Fig. 4a, the system is in an initial state. The second displacement stage 16 is located according to FIG. 4a at its stop 8 formed on the driving rod 4. In FIG. 4b, the piston K is thus in an upper position and the spindle device S in an extended position. The drive device M will not be described again here, because their structure is the same as that of the first embodiment. It is precisely this property that different spindle devices S can be combined with a same drive device M in a simple manner and thus results in a modular design, is a significant advantage.

The reservoir A shown in FIGS. 3 to 8 may also be only partially filled, wherein the filling may be 50 to 100% of the maximum volume. A 50% filled reservoir A is shown in FIG. 5a. The drive rod 4 here has a minimal overlap with the drive stage 15. Between the arranged on the driving rod 4 stop 8 for the second shift stage 16 and the second shift stage 16, an axial longitudinal distance is present. In the starting position shown in Fig. 5a, a rotational movement of the drive stage 15 leads to a backward process of the second shift stage 16. In this process, the piston K does not act as a result of acting between the piston K and the reservoir A stiction. If the second displacement stage 16 then moves towards its stop 8, then a force sensor 7 for measuring an axial force occurring on the driving rod 4 can detect the approach of the spindle device S and stop the driving device M. For this purpose, the force sensor 7 is arranged on the drive device M, wherein the drive rod 4 is supported on the housing via the force sensor 7 arranged between the drive rod 4 and a housing rear wall 32. After driving up the second displacement stage 16 at its axial stop 8, the system is in the position shown in Fig. 5b. In a further step, the user performs a priming of the liquid path F. In this process, the user ensures that the drive device M and the reservoir A are properly connected to each other and the spindle device S is supported on its stop. If these conditions are met, the priming leads to a filling of the liquid path F. For safety reasons, the User not connected to the pump during priming. The user performs priming until he observes a first delivery of drug fluid in the form of drops. The user then stops priming the fluid path and connects the pump to his body via a port. The port has a cannula for administering the IV drug fluid into the body.

The exemplary embodiment illustrated in FIGS. 3 to 8 is very advantageous in terms of handling, size and safety. The advantages thus achieved are listed and discussed again here.

The reservoir A connected to the spindle device S shown in FIGS. 3 to 8 is particularly suitable for use in a patch pump in insulin pump therapy. The reservoir A of FIGS. 3 to 8 has a fluid volume of 2 cc. Its outer diameter is only 1 1 to 14 mm. By integrating the spindle device S in the piston K, the axial length of the reservoir A is very advantageous. The axial length of the patch pump shown in FIGS. 3 to 8 can be significantly reduced and can be 45 to 50 mm for the embodiment. This length measure is comparable to that of conventional insulin pumps, which have lengths of 70 to 120 mm and depths of 18 to 22 mm. However, commercially available patch pumps have lengths of 52 to 62 mm and depths of 14 to 18 mm. The reservoir A shown in FIGS. 3 to 8 further has an oval cross-sectional area of 125 m ^A 2, a stroke of 16 mm and a travel path V per step of 8 mm. The thread pitch per step is 0.4 mm per revolution.

The exemplary embodiment illustrated in FIG. 3 also has an aspect ratio L / D of 1.32, where L is the longitudinal axis of the piston cross section and, for the exemplary embodiment, is 13.9 mm. D is the largest distance between see sealing points 33 of the piston K and is for the embodiment 10.5 mm. With such a length ratio L / D, it is possible to form a particularly compact piston K with an integrated spindle device S. In addition, the piston K in the reservoir A has a good guide formed by seals. The seals can be designed as O-rings 33 and have two or more sealing points. It is also conceivable to connect the sealing points directly to the piston K by means of an injection molding process. Especially for an oval piston, the ratio L / D is important for good guidance and accurate dosing. For particularly favorable length ratios L / D, no piston K travel in the reservoir A occurs. A walking of the piston occurs when the greatest distance between the sealing points 33 is not sufficiently large and therefore the ratio L / D exceeds a limit. The limit value for the embodiment illustrated in FIG. 3 is 2.5. If the ratio L / D is less than 0.5, the greatest distance between the sealing points 33 becomes so great that the reservoir A becomes unfavorably long. For a reservoir with an integrated spindle device S and a volume of 2 to 3.5 ml, it is particularly favorable if the aspect ratio L / D is in a range of 0.5 to 2.5. In the preferred range, the reservoir A with an integrated spindle device S has a short design, and the piston K in the reservoir A is well guided. A walking in the process is thereby avoided and the delivery of drug fluid can be accurately metered.

Another advantage is the simplicity of construction, because the spindle device is formed of only three parts. Because the first displacement stage 9 is formed directly on the piston K, a first component is saved for the embodiment of FIGS. 3 to 8. The oval reservoir A also takes over the function of the rotation for the first shift stage 9 and second shift stage 16. This reduces the construction by a second component. In the embodiment of FIGS. 3 to 8, the wall 29 of the reservoir A serves as an element for the anti-rotation device 26. The embodiment illustrated in FIGS. 3 to 8 therefore comprises only four components for the reuse. Servoir A and the spindle device S. These are the wall 29, the piston K, the drive stage 15 and the second shift stage 16. The embodiment shown in FIGS. 3 to 8 is both easy to produce and assemble and also inexpensive to manufacture. The assembly takes place by simply screwing together the two threaded connections on the piston K, then the piston with its preassembled spindle device S is moved into the reservoir A.

As a result of the fact that the spindle device S can not be manually brought into an initial state by a user, the reservoir A with integrated spindle device S shown in FIGS. 3 to 8 can be used only once. In insulin pump therapy it is recommended to use a reservoir only once. However, conventional reservoirs have the disadvantage that they can be used several times. Repeated use may lead to contamination and, in the worst case, infections to the user. Likewise, problems with the tightness of the reservoir can occur, which lead to reduced production. In addition, with the replacement of the reservoir A and thus with the spindle device S, the life of the drive unit M is increased. The drive unit M must apply the spindle drive torque for the delivery of medication fluid, which corresponds to the two spindle drive torques. As a result of the fact that a new spindle device S integrated on the piston K is used for each reservoir A used, the spindle drive torque remains constant over the life of the metering device. In addition, the drive unit M, as shown in FIGS. 3 to 8, are well sealed, which also contributes to increasing the life of the metering device.

The spindle device S shown in FIGS. 3 to 8 also requires no means for game suspension, since both spindle drives 20 and 21 are driven simultaneously, wherein the one spindle drive from left-hand threads and the other are formed from right-hand threads. By this arrangement, both Wind games eliminated by turning the drive stage 15 at the same time. Means for game suspension are therefore not necessary in the embodiments of FIGS. 3 to 8, whereby the axial length of the spindle device S is further reduced. For the exemplary embodiments illustrated in FIGS. 3 to 8, both the drive stage 15 and the first displacement stage 9 with defined feeds proceed simultaneously in the dispensing of medicament. Due to this synchronized method of both stages, no stops to prevent separation of the spindle stages are necessary between the stages. Such attacks are essential for the state of the art. The spindle device of the D-TRONplus pump has such stops because their stages do not extend at the same time but in succession. The stops prevent a complete extension of the steps, which would lead to a separation of the spindle stages. Since both means for the game suspension and no attacks on the shift stages 9 and 16 and drive stage 15 are necessary, the axial length is considerably reduced.

Further advantages for the embodiment shown in FIGS. 3 to 8 will be briefly discussed here. A retraction of the spindle device S is omitted when changing the reservoir A, which facilitates handling for the user. Retracting the spindle device of the D-TRONplus pump as a reference takes several minutes. The filling of the reservoir A takes place in the same way as the user of the current state of the art knows. This is advantageous for the user because he does not have to learn any new handling steps. The user uses a Aufzieh- rod 34 for filling the reservoir A. This is directly or indirectly coupled with the piston K. In Fig. 8, the reservoir A of Fig. 3 is connected to a Aufziehstange 34. In this case, the Aufziehstange 34 has an external thread, which connects the user with a formed on the second shift stage 16 internal thread. The retracting rod 34 and the piston K of the reservoir A are now connected to each other and the user can perform the filling of the reservoir A. The steps for filling Reservoir A are listed here and are: the Aufziehstange 34 with the piston K, fluidly connecting a reservoir of drug fluid with the reservoir A by means of a connection adapter, moving the piston K in an upper position and displacement of the air in the reservoir A in the reservoir and backward process of the piston K. in its initial position, whereby the drug fluid from the reservoir flows into the reservoir A and the reservoir A fills. The reservoir A shown in FIGS. 3 to 8 can be connected to the fluid path F in various ways. The reservoir A may, for example, have a septum and be connected with a needle of an adapter, or it may itself have a needle for the connection arranged on its housing. It is also conceivable that a Luer connection is provided to connect a catheter tube directly to the reservoir A.

FIGS. 9a, 9b and 9c show the spindle devices S of the embodiments of FIGS. 1 to 8 after use. The spindle devices are fully extended after use. In FIGS. 9a and 9b, the spindle device S of the embodiment of FIGS. 1 and 2 is shown. This spindle device S can be separated both from the drive device M and from the reservoir A. FIG. 9c shows the spindle device S of FIGS. 3 to 8 firmly connected to the reservoir A. The reservoir A and the spindle device S of FIG. 9c can only be separated from the drive device M. Clearly it can be seen that the user can not reuse the embodiments shown in Figs. 9a, 9b and 9c after use. The drive stage 15 is always radially surrounded by the element of the anti-rotation device 26 and is accessible to the user only from the side 35 facing away from the piston K by means of auxiliary means. The shift stages 9 and 16 in turn are rotatably connected to the element of rotation 26. For the spindle devices S of FIGS. 9a, 9b and 9c shown after use, the user has no options for bringing the spindle devices S into an initial state and for reusing them. This improves the safety for the user and increases the life of the metering device, because for each new reservoir A, a new spindle device S is used.

It can be seen from FIGS. 9a, 9b and 9c that the two displacement stages 9 and 16 are connected to one another in a rotationally fixed manner via the enveloping element of the anti-twist device 26. For the embodiment of Figs. 9a and 9b, the rotationally fixed connection is formed by the driver 18 and longitudinal grooves 19, for the embodiment of FIG. 9c, the rotation of the shift stages 9 and 16 through the oval configured wall 29 of the container A. It is therefore sufficient in that, for the spindle device S, one of the three elements 9, 16 or 26 is non-rotatably connected to the housing. For the embodiment of FIGS. 9a and 9b, this is done via the second shift stage 16, for the embodiment of FIG. 9c via the element 26th

For the two embodiments shown in FIGS. 1 to 9, the drive stage 15 is formed from two cylindrical sleeves. The cylindrical sleeves are rotatably connected to each other at their upper end sides on the piston K side facing. In addition, the drive sleeve 15 has the two external threads 23 and 25 for the spindle drives 20 and 21. The inner sleeve has the hole 30 for the coupling with the drive device M. The embodiments of FIGS. 1 to 9 illustrate parallel embodiments of the spindle device S. In the case of parallel embodiments according to FIGS. 1 to 9, two spindle stages of the spindle device S travel simultaneously, whereas in the case of serial embodiments only one spindle stage can be moved. For the examples of FIGS. 1 to 9, the drive stage 15 and one of the two shift stage 9 or 16 proceed simultaneously. After loading the metering device with a fully filled or partially filled reservoir A, the axial longitudinal play between the spindle device S and the drive device M must first be canceled. For the repeal of the axial longitudinal play between see the spindle device S and the stop of the drive device M the spindle device S initially moves backwards. Both the drive stage 15 and the second shift stage 16 move backwards against the stop 8. After the removal of the longitudinal clearance, the metering device for the priming of the fluid path F is ready. When priming and subsequent drug delivery process the drive stage 15 and the first shift stage 9 in the feed direction simultaneously. The second shift stage 16 is supported on its fixed stop 8 and now serves as a reaction stage. In this case, it absorbs the torque formed in the spindle drive 21 and directs the axially acting force of the spindle device S to the stop 8. Because the spindle device S can be moved backwards both for the cancellation of a longitudinal clearance, as well as for the drug delivery in the feed direction is movable makes handling much easier for the user. The control of the pump can take over and carry out the cancellation of the longitudinal play automatically.

It is noted here that further embodiments of the invention are conceivable and the embodiments shown here are not exhaustive. For example, the drive stage 15 has an external thread for the threaded connection with the second displacement stage 16. It is quite conceivable to provide the drive stage 15 with an internal thread and the second displacement stage 16 with an external thread for the second spindle drive 21. Such changes do not lead to new and inventive solutions. Likewise, a reversal of the spindle device S is not a novel and inventive solution of the invention, in which the second displacement stage are directed against the piston and the first displacement stage against the drive device M. Since the three elements - the first drive stage 9, the second drive stage 16 and the anti-rotation element 15 - are rotatably connected to each other, it is sufficient to connect one of the three elements, 9, 16 or 15 with a solid housing to the Securing against rotation of the elements 9, 16 and 15 to achieve. In Figs. 1 to 9, only the essential features of the metering device are shown. These are the drive device M, the spindle direction S and the reservoir A. Other components and components such as batteries, displays, housings, fluid paths and the like, which are not essential to the invention have not been shown. The embodiments illustrated in FIGS. 1 to 9 are advantageous for patch pumps, conventional medication delivery systems such as insulin pumps and pens. The invention is particularly advantageous for compact devices for dispensing medicament fluid. Telescopic spindle devices are always more compact compared to single-stage spindle devices and thus have a favorable linear expansion. Other applications and devices for which accurate delivery of drug fluid is important are conceivable.

LIST OF REFERENCES

S spindle device

M drive device

A reservoir

K piston

F fluid path

1 engine

2 planetary gears

3 reduction gear units

4 driving rod

5 housing

6 housing inner wall

7 force sensor

8 stop

9 First shift level 10 glass ampule

1 1 septum

12 glass body

13 internal thread

14 external thread

15 drive stage

16 Second shift level

17 sleeve

18 drivers

19 longitudinal groove

20 First spindle drive

21 Second spindle drive

22 internal thread

23 external thread

24 threads

25 threads

26 Anti-rotation element

27 locking member

28 wings

29 wall

30 holes

31 bayonet connection

32 rear panel

33 sealing point

34 pull-up bar

35 Facing away from the side

Claims

claims

1 . Spindle device for a piston (K), which is held in a reservoir (A) containing a medicament fluid, the spindle device (S) comprising:

a) a first rotationally secured displacement stage (9) with a thread (22),

b) a second rotationally secured displacement stage (16) with a thread (24),

c) a drive stage (15) with two threads (23, 25) arranged between the first and second shifting stages (9, 16), one thread (23) being in engagement with the thread (22) of the first shifting stage (9) and thus forms a first spindle drive (20) and the second thread (25) is in engagement with the thread (24) of the second displacement stage (16) and thus forms a second spindle drive (21), and the threads (22,24) of first and second shift stages (9,16) are in opposite directions, and wherein the spindle device is configured such that the first shift stage (9) and the drive stage (15) simultaneously move in the feed direction,

wherein a drive element (15) axially enveloping element for the rotation (26) rotatably connects the first and second shift stage (9,16) with each other and the drive stage (15) of the spindle device (S) facing away from the piston (K) end face ( 35) of the spindle device (S) with a designed as a coupling member driving rod (4) of a drive device (M) is rotatably coupled, wherein the driving rod (4) in an on the drive stage (15) formed, axial hole (30) can be inserted.

Spindle device according to claim 1, characterized in that a projecting into the drive stage profiled driver rod (4) is designed as a coupling member for the drive stage (15), wherein the drive rod (4) and the drive stage (15) in an initial state, an overlap of at least one Travel path V have a shift stage (9,16).

Spindle device according to claim 1 or 2, characterized in that a cylindrical sleeve (17) is designed as an element for the anti-rotation (26) and the second displacement stage (16) directly or indirectly on a fixed housing (5) is rotatably receivable.

Spindle device according to claim 1 or 2, characterized in that the spindle device (S) for the piston (K) on the piston (K) itself is arranged and the piston (K) as the first displacement stage (9) is formed, wherein the piston ( K) and the reservoir (A) have oval cross sections and a wall (29) of the reservoir (A) is designed as an element for the anti-rotation device (26).

Spindle device according to claim 4, characterized in that the length ratio L / D of a longitudinal axis L of the oval piston cross section to a maximum distance D between sealing points (33) on the piston (K) is more than 0.5 and less than 2.5.

Spindle device according to claim 4 or 5, characterized in that the second displacement stage (16) has at its lower portion a locking member (27) whose maximum radial extent is greater than the smallest distance of opposite inner surfaces of the wall (29) of the reservoir (A). in that the wall (29) of the reservoir (A) serves as an element for the anti-twist device (26) of the second displacement stage (16).

Spindle device according to claim 6, characterized in that the wall (29) of the reservoir (A) as a reaction member for a wing (28) formed as a locking member (27) of the second shift stage (16) is formed and the second shift stage (16) to a axial stop (8) is movable.

Spindle device according to claim 7, characterized in that the axial stop (8) for the second displacement stage (16) on the rotationally driven driving rod (4) is formed.

Spindle device according to one of claims 4 to 8, characterized in that the wall (29) of the reservoir (A) itself is designed as a housing and the reservoir (A) with the housing (5) is connectable and axially fixable.

Spindle device according to claim 9, characterized in that the fixation of the reservoir (A) on the housing (5) and the axial stop (8) for the second displacement stage (16) are at the same height or directly the same height along the common longitudinal axis and the drive stage (15) and displacement stages (9,16) made of plastic with a similar temperature expansion coefficient as the reservoir (A) are formed.

Spindle device according to one of claims 4 to 10, characterized in that the piston (K) or one of the elements of the spindle device (S) with a mounting rod (34) can be coupled.

Spindle device according to one of claims 4 to 1 1, characterized in that the spindle device (S) and the reservoir (A) form a common exchangeable part.

13. Spindle device according to one of claims 1 to 3, characterized in that the spindle device (S) is formed alone as an exchangeable part of a metering device.

14. Spindle device according to one of claims 1 to 1 1, characterized in that the spindle device (S) is permanently connected to the drive device (M) coupled.