WO2008106810A1

WO2008106810A1 - Hydraulic occlusion detection in a medical administration device

Info

Publication number: WO2008106810A1
Application number: PCT/CH2008/000066
Authority: WO
Inventors: Edgar Hommann; Thomas Gurtner
Original assignee: Tecpharma Licensing Ag
Priority date: 2007-03-02
Filing date: 2008-02-15
Publication date: 2008-09-12

Abstract

The invention relates to an administration device for a fluid product, particularly a liquid medication, such as insulin, comprising a fluid reservoir (231), onto which pressure is applied for administering the product. The fluid reservoir is preferably a hydraulic reservoir of a device for the hydraulic transmission of force to a product container. The pressure in the fluid reservoir is monitored for occlusion detection. A corresponding unit (260) comprises a gate valve (261) that is disposed in a displaceable manner along a displacement direction (266) against an elastic force. Once a predetermined pressure in the fluid reservoir is exceeded, the gate valve is displaced in the displacement direction against the elastic force.

Description

Hydraulic occlusion detection in a medical

An administration device

Technical area

The present invention relates to a device for administering a fluid product, in particular a medicament in liquid form. Such a device is referred to below as an administering device.

State of the art

In various diseases, it may be necessary to give a patient a liquid-form medicament, e.g. to administer an insulin preparation or a blood-thinning medication such as heparin over a long period of time. For this compact portable administration devices are known, which are constantly carried by the patient close to the body. In such delivery devices, the drug is often present in a container in which a plug is advanced so as to expel the drug from the container.

For a reliable supply of the patient with the drug, it is essential that malfunctioning, which can lead to a deficiency of the drug or a complete interruption of the administration of the drug, be recognized effectively and safely and to trigger an alarm and / or to shut down the Device. Such a malfunction may arise, in particular, in that a blockage (occlusion) of a fluid-carrying line, eg of the infusion set, occurs, or that the plug is stuck in the container so that the driving force is not sufficient to advance the plug further, eg because of excessive friction.

To detect occlusions, various measures have been proposed in the prior art. Thus, in US 5,097,122 an optical motion sensor for monitoring the drive movement of an administering device is disclosed. In US 5,462,525 an inductive flow measurement at the drug outlet of the delivery device is proposed. In WO 03/045302, a pressure difference is monitored along a pressure reducing capillary, which is traversed by the drug to be administered. In US 2006/0184154, the drive current of an electromotive drive of an administration device is monitored and an alarm is triggered in the event of an unexpected increase in the drive current. In US Pat. No. 5,647,853, the counterforce which the plug in the medicament container opposes to its feed is measured and monitored. These procedures are sometimes relatively complicated and involve the risk of errors during calibration or actual monitoring. In some cases, these methods are based on the measurement of magnitudes, which only indirectly allow conclusions to be drawn on the administration of the drug.

Presentation of the invention

It is an object of the present invention to provide a device for administering a fluid product which safely and easily permits recognition of malfunctions due to occlusions or other obstructions of administration.

This object is achieved by a device according to claim 1 or 3. Advantageous embodiments are specified in the dependent claims.

A device according to the invention for administering a fluid product thus has: a fluid reservoir formed as a hydraulic reservoir with a fluid, which is pressurizable for administration of the product; a product container for the fluid product, wherein the pressure from the fluid reservoir is transferable to the product container.

The pressure in the product container serves to dispense the fluid product from the product container, either immediately when the product container is in direct communication with a conduit or catheter or cannula, or indirectly when in addition to the actual administration e.g. a valve must be opened. To detect occlusions, the device comprises a pressure monitoring device for monitoring the pressure in the fluid reservoir, that is to say in the hydraulic system.

The hydraulic system may in particular comprise a displacement reservoir, which is connected via a hydraulic connection to the fluid reservoir. The displacement reservoir is then designed and arranged such that a pressure increase in the displacement reservoir leads to an increase in pressure in the product container. When the product container is opened to dispense the product, the increase in pressure in the hydraulic reservoir leads to an increase in the volume of the dispenser reservoir, which in turn causes an ejection of the fluid product from the product container. The monitoring of the pressure is then preferably carried out on the hydraulic connection.

The output of the product is thus effected via a hydraulic power transmission. This allows a great deal of flexibility in the arrangement of the product container and the drive components. Various variants of such a hydraulic power transmission are described in the application PCT / CH 2006/000258 of 15 May 2006, to which reference is made for the possible embodiments of the hydraulic power transmission, the product container and the hydraulic reservoir. The detection of occlusions is done in this arrangement by monitoring the pressure in the hydraulics. In this way, occlusions can be detected easily, safely and directly. A particularly simple and advantageous device for pressure monitoring comprises a slide, which is displaceably arranged along a displacement direction against an elastic counterforce. The pressure in the fluid reservoir acts on the slide, so that when the pressure exceeds a predetermined pressure in the fluid reservoir, the slide shifts against the elastic counterforce in the displacement direction. Such a device can also be used for occlusion detection independently of a hydraulic power transmission. Thus, for example, the pressure in the product container itself can be monitored. Generally speaking, the pressure in any fluid reservoir of an administering device can be monitored in this way and used for occlusion detection.

An advantage of this arrangement lies in its simple structure. The recognition of an occlusion takes place in a simple manner with hydraulic and mechanical components alone. No calibration required. As soon as, due to an occlusion or for some other reason, the fluid pressure exceeds a certain threshold, which is predetermined by the elastic counterforce, the slider shifts and thus makes the presence of the occlusion or a fault in the hydraulic recognizable. Because of its simple structure, this arrangement is particularly suitable for use in a disposable cartridge.

In a preferred embodiment, the slide is sealingly disposed in a cylindrical receiving space, and the receiving space is in fluid communication with the fluid reservoir / hydraulic reservoir such that fluid entering the receiving space from the fluid reservoir causes displacement of the slide in the shifting direction. The receiving space is thus hydraulically connected to the fluid reservoir ("communicates" with no significant pressure loss with the fluid reservoir), and the slide forms a piston which is sealingly displaceable in the receiving space. For this purpose, the slide may have at its end a sealing ring or a stopper made of an elastomeric material. The cross section of the receiving space may be circular, it is but also other cross-sectional shapes such as oval, square, etc. possible.

The fluid reservoir may be pressurized by a drive plug having a first effective cross-sectional area that is movable in a cylindrical wall area in a drive direction. The "effective cross-sectional area" is to be understood as that cross-sectional area which effects a pressure in the fluid reservoir, that is, mathematically speaking, the quotient of the pressure force which generates the pressure and the pressure generated thereby. The slider has a second effective cross-sectional area which is smaller than the first cross-sectional area. In this way results in an advantageous hydraulic ratio between the drive plug and slider: In an occlusion leads a drive movement of the drive plug by a first distance to a movement of the slider by a second distance, which is greater than the first distance. This allows a very sensitive detection of pressure changes.

For space-saving accommodation of the drive plug and the slider are preferably arranged such that the displacement direction of the slider is anti-parallel to the drive direction of the drive plug. In this case, the cylindrical receiving space for the slide is preferably laterally offset from the cylindrical, see wall portion, in which the drive plug is movable. The two "cylinders" for which the drive plug and the slide form corresponding "pistons" are therefore preferably arranged next to one another and antiparallel to each other. Of course, however, another arrangement is readily possible.

In addition, there is preferably provided an electrical or electronic detection device for detecting a displacement of the slider in the displacement direction, which emits an electrical signal indicative of the displacement in such a displacement. In the simplest case, this may be, for example, an electrical contact, which is closed or opened directly by the displacement. But there are also many other possibilities Possibilities, such as capacitive, inductive or optical proximity sensors.

The administering device is preferably modular. For this purpose, it comprises a reusable base unit (a "reusable" module) with a drive device and the detection device and an exchangeable cartridge (a "disposable" module), which is releasably connectable to the base unit and which at least the fluid reservoir and the pressure monitoring device, at Presence of a hydraulic power transmission also contains the product container and the hydraulic connection. In order to detect the displacement of the slide of the pressure monitoring device in the base unit, an opening may be formed in a wall of the cartridge, in which an actuating element movable or integrally connected to the slide is arranged which moves when the slide is displaced. In order to detect a displacement of the slide, the detection device interacts with the actuating element.

The elastic counterforce (restoring force) on the slider can be selectively generated in the cartridge and / or in the base unit. If the counter force is generated in the cartridge, this can be done in the cartridge e.g. a coil spring surrounding the slider may be provided, which is compressed in a displacement of the slider in the direction of displacement between the slide and the housing. In contrast, when the counter force is generated in the base unit, the base unit preferably comprises a relative to the housing of the base unit movable, preferably displaceable transmission element, which is spring loaded relative to the housing of the base unit and cooperates with the slider so that it upon displacement of the slider generates an elastic restoring force on the slide in the direction of displacement.

In particular, the detection device preferably comprises an electrical element, for example a switch or a variable resistor, which is arranged in such a way that when the slider is moved into the circuit Shifting direction an electrical property, eg its switching state or its resistance changes.

When the electrical element is a switch, it is preferably actuated by an actuator which is movably or integrally connected to the slider, e.g. in the form of a cam which projects through the opening in the cartridge wall. In this case, the switch and actuating element are preferably designed and arranged so that in operation of the device, the actuating element in an initial position of the slide, which occupies this falls below the predetermined threshold pressure in the fluid reservoir, the switch is actuated and upon displacement of the slider in the direction of the switch releases. The switch can serve at the same time for switching on the administering device when it is composed of a base unit and a cartridge.

In particular, when the electrical element comprises a variable resistor or other continuously variable electrical element such as a variable capacitor, this may be variable by rotation of a shaft and arranged so that displacement of the slider in the direction of displacement causes rotation of the shaft. Preferably, a rack is then connected to the slider, which cooperates with a gear connected to the shaft. The detection means then includes a monitoring circuit for monitoring the variable resistor or in an otherwise varying electric EIe- ment a corresponding electrical property, for example, the capacity at ¹ egg nem variable capacitor.

The elastic counterforce (restoring force) is preferably generated by an elastic element which is connected to the slider. Preferably, the elastic member is a pressure acting coil spring. While a coil spring is very compact and can be placed very easily in the receiving space, other types of elastic elements can also be used. ments such as an elastic foam element or another type of spring, for example a disc spring.

Preferably, the elastic element in a starting position of the slide, which occupies this falls below the predetermined threshold pressure biased with a predetermined force ("biasing"). In this way, the threshold pressure at which the occlusion detection starts to be preselected can be preselected.

In an advantageous further development, the elastic element (biasing element) can be designed and arranged such that it produces a greater biasing force on the guide element along the feed direction after connecting the cartridge to the base unit than in a state in which the cartridge is detached from the base unit is. As a result, a deflection of the slide is facilitated during storage, if it comes by an increase in temperature to an expansion of the fluid in the product container and / or hydraulic reservoir and thereby to an undesirable increase in pressure, which could lead to leaks in extreme cases. Specifically, this can be solved so that the biasing element is designed as a spring which is compressible between the slider and a displaceable along the feed direction spring rest, wherein the spring seat is designed such that it moves when connecting the cartridge to the base member in the direction of the guide member is compressed and so the biasing element.

The power transmission between the cartridge and base unit is preferably carried out via a pure rotary motion. The base unit has for this purpose a driver, which is displaceable by the drive device in a rotational movement about an axis of rotation. The cartridge has a transmission element, which is displaceable by the driver in a rotation and converts the rotational movement into a feed movement of a piston, for example by the transmission element is guided via a threaded connection in the cartridge, so that it rotates a screw movement with a translatory Kompo - nents. Thereby, the connection between the cartridge and the base unit can be done in a very simple way, since a coupling of two rotatable elements for transmitting a rotary motion is very easy to implement. In addition, the cartridge change is greatly simplified. When the cartridge is to be replaced, it can simply be removed from the base unit, and a new cartridge can be inserted without having to reset the drive unit beforehand. Such a structure is also very advantageous regardless of the proposed occlusion detection.

Brief description of the drawings

Preferred embodiments of the invention will now be described with reference to the drawings, in which:

Fig. 1 is an end view of a cartridge; 2 shows a longitudinal section through the cartridge of FIG. 1 in the plane II-

II;

FIG. 3 shows an enlarged detail from FIG. 2; FIG.

Fig. 4 is a plan view of a base unit;

5 shows a longitudinal section through the base unit of Figure 4 in the plane V-V in a highly schematic representation ..;

Fig. 6 is an end view of an administration device, which from the

Cartridge of Figures 1 to 3 and the base unit of Figures 4 and 5 is composed;

7 shows a longitudinal section through the administration device of FIG. 6 in the plane VII-VII, partly in a highly schematic representation;

8 is an enlarged view of the device for occlusion detection;

9 shows a functional sketch of the occlusion recognition according to a first embodiment; 10 is a functional diagram of the occlusion detection according to a second embodiment; such as

11 is a longitudinal section through an administration device according to a third embodiment in a highly schematic representation.

Detailed description of preferred embodiments

The drawings show an administration device according to the invention. The administering device comprises a replaceable cartridge 200, which is shown alone in FIGS. 1 to 3, and a complementary, reusable base unit 100, which is shown alone in FIGS. 4 and 5. Figures 6 to 8 show the administration device composed thereof.

To indicate directions within the delivery device, directional designations are defined as follows. The distal direction is to be understood in each case as the direction in which the respective movable elements of the administering device move in the course of the administration of the medicament. As will be described in more detail below, there is a deflection of this movement by 180 degrees in the interior of the administering device. The distal direction therefore corresponds to different absolute spatial directions for different parts of the administering device. The proximal direction is accordingly defined as the direction opposite to the distal direction. A lateral direction is a direction perpendicular thereto.

The cartridge 200 shown alone in FIGS. 1 to 3 comprises a cartridge housing 210, in the region of which is arranged at the bottom in FIG. 2 a product container 250 in the form of a carpule with cylindrical side wall portion 251 and product plug 252 displaceable therein. At its proximal end, the product container 250 is held in a sealing ring 242 while abutting an inner annular flange 214 of the housing 210 at its distal end. The product container is closed at its distal end by a septum closure 254 which is shown only schematically and delimits a product reservoir (medicament reservoir) 255. In the region of the product container 250, the housing for reading the fill level of the product container is preferably transparent. In the region of the cartridge arranged at the top in FIG. 2, a hydraulic reservoir 231 is formed which is bounded laterally by an inside cylindrical insert 235, which is held in the housing 210 and in which a hydraulic plug 230 is axially movable. The head of the hydraulic plug 230 is sealed against the insert 235 at its periphery by an elastic seal 232, which is preferably integrally molded on the head in a two-component injection molding process.

For the right side in FIG. 2, the housing 210 is open. In this open end of the housing 210, a closing element 240 is inserted, which defines together with the cartridge housing 210 a fluid channel 241, which adjoins the hydraulic reservoir 231. The fluid channel 241 terminates in a displacement reservoir 243, which is delimited in the distal direction by the product plug 252. From the fluid channel 241, a channel extension 244 branches off, which leads to an occlusion recognition device 260, which will be described in more detail below.

In the hydraulic reservoir 231 is a hydraulic fluid, e.g. stained, deionized water or a suitable oil, filled. The hydraulic fluid also completely fills the fluid channel 241, the shuttle reservoir 243 and the channel extension 244. Between product container 252 and housing wall, a narrow intermediate space 253 is formed in the present embodiment. If hydraulic fluid enters this space due to a leak, this can be recognized by the user.

An elongated, cylindrical hollow-spindle-like sleeve 233 adjoins the head of the hydraulic plug 230 in the proximal direction, on the outside of which an external thread is formed. Inside the sleeve 233, a plurality of longitudinal ribs 234 are formed, which run parallel to the longitudinal direction of the sleeve. The external thread of the sleeve 233 is in threaded engagement with an internal thread 216 of a guide sleeve 215 fixed to the housing. The basic unit 100, which is shown very schematically in FIGS. 4 and 5, has a housing 110 in which, inter alia, an electric battery, not shown, and control electronics are accommodated. In an outwardly open receiving area 120, a motor, also not shown, one of which is driven, arranged coaxially with the engine gear and one thereof arranged in a rotatable driver are arranged. The driver consists essentially of a wheel, on whose peripheral surface two diametrically opposite driver fingers are arranged. A correspondingly configured base unit is described in the international application PCT / CH 2007/000113 dated Mar. 2, 2007, to which reference is made for a possible closer design of the base unit and the transmission of power between the base unit and the cartridge.

To administer the drug in the product container 250, the cartridge 200 is first connected to the base unit 100. In this case, the region of the cartridge arranged at the top in FIG. 2 is accommodated in the receiving region 120 of the base unit. In Figs. 6 to 8, the thus-composed administering apparatus is shown. The engine, the transmission and the driver now protrude into the interior of the sleeve 233. In this case, the driver fingers of the driver engage in the space between each two longitudinal ribs 234 and thus cause a rotationally fixed, but longitudinally displaceable connection between the driver and the sleeve 233rd

A needle adapter is then placed on the cartridge, followed by a catheter of an infusion set. The needle adapter (not shown in the drawing) comprises a hollow needle which pierces the septum of the closure 254 and thus connects the product container 250 to the catheter. Cartridge and needle adapters are fixed to the base unit 100 by a sliding latch (not shown).

After venting the catheter (priming) is now in normal operation in predetermined intervals (eg three times hourly) delivered a certain amount of product. For this purpose, the motor puts the driver in a rotary motion via the gearbox. This rotational movement is transmitted to the sleeve 233 and to the head of the hydraulic stopper 230 connected to it with the longitudinal ribs 234 on account of the engagement of the driver with the longitudinal ribs 234. Since the sleeve 233 is guided with its external thread in the guide sleeve 215, the rotational movement of the sleeve 233 also causes a feed movement in the axial direction. Overall, the hydraulic plug 230 thus carries out a screw movement. As a result, the volume of the hydraulic reservoir 231 decreases, so that hydraulic fluid is forced through the fluid channel 241 into the displacement reservoir 243 and here leads to a feed of the product plug 252 in the distal direction. In this way, finally, the fluid product through the hollow needle and the catheter from the now also decreasing product reservoir 255 ejected. Ultimately, therefore, a rotation of the sleeve 233 causes a feed of the hydraulic plug 230 and so indirectly via the hydraulic arrangement, an ejection of the fluid product from the product container 250th

The occlusion recognition device 260, which is shown enlarged in FIG. 3, will now be explained below. This device comprises a piston-like slide 261, which is displaceably guided in a cylindrical cavity (receiving space) open towards the channel extension 244. At its end facing channel extension 244, pusher 261 is sealed against the sidewalls of the lumen by means of a sealing plug 265 of elastomeric material which is slid onto the tapered proximal end of pusher 261. On the also tapered distal end of the slider 261 one end of an elastic element in the form of a coil spring 264 is pushed, the other end rests on a distal end wall of the cavity. The coil spring 264 acts on pressure and is already precompressed in the initial position, as shown in FIG. 3, so that it exerts a biasing force on the slider 261 in the proximal direction (to the right in FIG. 3). In a central taper 262 of the slider 261, an actuator in the form of a cam 263 is held. This cam protrudes through an elongated opening 212 in the direction of the base unit 100 facing housing wall to the outside. Its displacement range is limited both in the proximal and in the distal direction by the dimensions of the opening. As a result, the cam 263 in particular prevents the slider from being displaceable beyond the initial position shown in FIG. 3 by the biasing force of the spring 264 in the proximal direction.

The cavity 26 accommodating the slide 261 (receiving space) runs with its cylinder axis parallel to the cylinder axis of the hydraulic reservoir 231 or of the limiting insert 235. For reasons of space, the cavity is arranged laterally offset relative to a central longitudinal sectional plane of the cartridge, in particular from the course of the plane IMI in Fig. 1 can be seen.

In the initial position, when the infusion device is pushed together, the cam presses a pressure switch (pushbutton) 130 in the base unit, thus closing an electrical contact in the base unit. This can be seen particularly well in FIG. 7, which shows the composite infusion device in the starting position of the slide 261. To facilitate push-in of the switch, the distal end of the cam 263 is chamfered so that the switch 130 can slide on the cam as the cartridge and base unit are pushed together. For reasons that will become apparent below, the proximal end of the cam is also chamfered in this manner.

As long as the switch 130 is closed, this indicates a normal operating condition (no occlusion) and the device will periodically administer product doses as described above. By having to be closed (activated) to initiate administration, it is ensured that a malfunction of the switch itself or a faulty collapse of the base unit and the cartridge is detected, since in such cases the switch does not close at all. The switch can in particular serve to switch on the administration device altogether at all. With reference to Fig. 8 and Fig. 9, in which the operation of the Okklusionser- recognition device is illustrated in a simplified representation, it will be explained what happens if during the administration of the drug, the feed of the product plug 252 is obstructed. Such a disability can have various reasons. The most frequent reason in practice is a possible occlusion of the catheter, eg due to foreign bodies or kinking of the catheter. But other reasons are conceivable. For example, the cartridge could simply be completely emptied, so that no further feeding of the product plug is possible anymore. Also, a user may have failed to properly set up the needle adapter so that the septum of the product container is not yet pierced and therefore no product can escape. It is also conceivable jamming or due to excessive production tolerances increased plug friction of the product plug. In all these cases, it is essential that this malfunction is detected by the delivery device and that the user is warned accordingly.

If such a disturbance exists, the pressure in the hydraulic reservoir rises sharply when the motor continues to rotate the sleeve 233, since the hydraulic fluid can no longer flow away through the hydraulic channel 241. This pressure p builds up not only in the hydraulic reservoir 231, but equally in the hydraulic channel 240 and its extension 244. As a result, a pressure force in the distal direction acts on the stopper 265 of the slide 261, the amount of which corresponds to the product of pressure p and cross-sectional area of the stopper 265. When this compressive force now exceeds the proximally acting biasing force generated by the spring 264 plus the unavoidable frictional forces, the slider 261 deflects the pressure by moving in the distal direction or displacement direction 266 (to the left in FIGS. 8 and 9). shifts. The displacement takes place until the counterforce by the spring again substantially corresponds to the compressive force, so that these two forces balance with deduction of the friction forces. The resulting displaced position of the slider 261 is illustrated in FIG. The slider has now moved so far in the direction of displacement 266 that the switch 130 has slid down over the proximal chamfer of the cam 263 and the cam has thus released the switch 130. The switch 130 is thereby opened. This will cause the drive to shut down and trigger an alarm warning the user that a malfunction has occurred.

By the switch 130 is arranged in the base unit 100 and in the Kartu- see 200 only a purely hydraulic-mechanical arrangement is provided, the cartridge can be manufactured inexpensively. In addition, no electrical connections between the cartridge and the base unit are necessary. In addition, the hydraulic occlusion detection works very directly and reliably, since it detects a direct consequence of an occlusion, namely the pressure increase in the hydraulic reservoir, as the measured variable. In addition, this size is measurable not only during the actual administration, which occurs only periodically at predetermined time intervals (unlike, for example, the motor current or a flow rate at the outlet of the drug reservoir), but also between the individual administration times.

Another advantage of the proposed occlusion detection is the large translation that occurs in the presence of an occlusion between a displacement of the hydraulic plug and the resulting displacement of the slider. This translation is hydraulic: displacement of the hydraulic plug by a predetermined distance results in displacement of a volume corresponding to the product of travel and cross-sectional area of the hydraulic plug. If the receiving space with its much smaller cross-sectional area receives this volume, a displacement of the slider results in a path corresponding to the path of the hydraulic stopper multiplied by the quotient of the cross-sectional areas of the hydraulic stopper and the slide. The hydraulic ratio realized in this way can easily exceed a factor of 20. climb. In this way, a very high sensitivity of occlusion detection is achieved.

The switch 130 in the present embodiment is a simple electromechanical switch (push button). Instead, however, a suitable type of proximity sensor may also be used, e.g. operates on a capacitive or inductive path, as a pressure sensor or optically. The switch is preferably formed liquid-tight, so that a

Penetration of water or other liquids into the base unit is avoided.

An alternative embodiment for occlusion detection is shown very schematically in FIG. Instead of displacing a cam 263, the slider 261 is now connected to a rack 268. In the base unit 100, a rotary potentiometer (variable-resistance resistor) 140 is arranged, on the shaft of which a gear is mounted, which engages in the rack 268. A displacement of the slider 261 is transmitted via the rack 268 and the gear in a rotation of the shaft of the potentiometer. The thus changing resistance of the potentiometer is monitored by a monitoring circuit, and when a certain resistance value is exceeded, an occlusion alarm is triggered as in the first-mentioned embodiment.

This embodiment offers the advantage that the pressure in the hydraulic reservoir can be measured and monitored very finely in a range predetermined by the counterforce of the spring 264. The counterforce of the spring 264 may in particular be selected so that the slide 261 in the normal operation of

Device about halfway between its starting position, which he at

Below a threshold pressure occupies, and its end position, which it occupies when reaching a maximum pressure is located. Pressure fluctuations in the

Hydraulic reservoir are in this way directly in shifts of

Schieber's 261 translated. In this way not only a pressure increase, but also a pressure drop in the hydraulic reservoir can be detected.

In such an embodiment, it is advantageous if the pressure monitoring is calibrated appropriately. This can e.g. during venting of the infusion set (priming) or during the first administration steps after priming, by determining a normal value of the resistance of the potentiometer 240, which serves as the set point in the monitoring, and the resistance after each administration step Setpoint is compared. Of course, more complicated methods for determining the desired value and deviations from the desired value of the resistor can be used, as they are known from the prior art in connection with a force monitoring for occlusion detection.

In addition, the potentiometer 140 preferably has a switch which is actuated (in particular closed) during a first rotation from a zero position of the potentiometer. Such switched potentiometers have long been known and have e.g. Previously often found in radios to turn on and adjust the volume using a single knob. The potentiometer is then arranged in such a way that when the base unit 100 and cartridge 200 are pushed together, the switch is first actuated. This indicates that the cartridge and base unit are correctly assembled. The switch may in turn be used to turn on the delivery device as a whole, as described above for the switch 130.

For reasons of space, the gearwheel is preferably arranged in the base unit such that its shaft runs parallel to the viewing direction or perpendicular to the plane of the drawing in FIG. 4. In the illustration of FIG. 7, therefore, the shaft preferably runs parallel to the plane of the drawing, ie parallel to a plane containing the cylinder axes of the product container 250 and the hydraulic reservoir 131, and perpendicular to these cylinder axes. In this way, a relatively large gear can be used, so that the potentiometer allows a large shift range of the rack. Instead of a rotary potentiometer, for example, a variable capacitor can be used, whose capacity is determined for example by the natural frequency of a resonant circuit containing the capacitor.

Another embodiment is illustrated schematically in FIG. 11. In this embodiment, the housing 110 of the base unit 100 in a region facing the cartridge 200 has a step 112 extending transversely to the direction of displacement of the slider 261. In the region of this step, the housing wall has an opening through which a transmission element 150 which can be moved longitudinally along the displacement direction of the slide 261 extends. The transmission element 150 has a support flange 151 at its proximal end, which faces the slider 261. When the pressure in the hydraulic reservoir 231 increases, the slide 261 shifts in the distal direction and thereby pushes against the support flange 151. Upon a further increase in pressure, the slide 261 pushes the transmission element 150 along the displacement direction against the restoring force of a tensioned return spring 152 in the direction of displacement Base unit 100. At this time, the transmission member 150 operates an electric switch 153, e.g. in the form of a microswitch or the position of the transmitting element is detected by a proximity sensor or otherwise, e.g. determined by means of a potentiometer as described above.

In this embodiment, the motion is thus transmitted purely in the direction of movement of the slider 161. By the frontal motion transmission a particularly high reliability is achieved. Particularly advantageous in this embodiment is that a return spring in the disposable cartridge 200 can be omitted. The return spring is instead in the reusable base unit 100 in this embodiment. Since the cartridge is manufactured in much larger numbers than the base unit, this allows a significant cost savings. In addition, the recycling of the cartridge is facilitated since the usually made of metal- de spring in the utilization no longer needs to be separated from the plastic material of the cartridge.

Of course, many other possibilities are conceivable in order to detect the displacement of the slide 261. Thus, e.g. directly detecting a displacement by electrical means by placing in the cartridge an electrical contact which is closed when the slider shifts beyond a certain amount. In this case, however, an electrical connection between the cartridge and the base unit is necessary, e.g. via a contact pair. Also conceivable is a proximity sensor, e.g. a capacitive, inductive or optical sensor housed directly in the cartridge.

In the embodiments described above, a hydraulic power transmission between the transmission element, which is driven by the driver of the base unit, and the product container takes place. The hydraulic section does not serve to control the administration rate, but only serves for space-saving, cost-effective and safe deflection of the driving force. Various variants of such a hydraulic power transmission are described in the already mentioned application PCT / CH 2006/000258 of 15 May 2006. In particular, this application discloses further advantages and design details of the hydraulic power transmission and various variants for the design of the product container and the hydraulic reservoir, which can also be used in connection with the present invention.

Thus, in particular, instead of as a carpule, the product container can also be designed as a container which is compressible as a whole. The container may, for example, have a bellows-like side wall or simply be formed as a bag. The same applies to the hydraulic reservoir. It is also conceivable that the transmission of the rotational movement to the hydraulic reservoir is effected simply by virtually "wrung out" a flexible hydraulic container by its proximal end is twisted relative to the distal end.

Finally, in a further variant, a hydraulic power transmission completely eliminated. For example, the product plug may take the place of the hydraulic plug of the embodiment shown above, i.e. the product plug is then advanced directly through the sleeve 233 and the pressure in the product container is immediately monitored.

LIST OF REFERENCE NUMBERS

100 base unit

110 housing

111 frontal wall

112 level

120 receiving area with drive components

130 Occlusion detection switch

140 rotary potentiometer with gear

150 transmission element

151 support flange

152 return spring

153 switches

200 cartridge

210 housing

211 outer wall

212 opening

214 ring flange

215 guide sleeve

216 internal thread

230 hydraulic plugs

231 hydraulic reservoir

232 sealing ring

233 sleeve

234 longitudinal rib 235 use

240 end element

241 fluid channel

242 sealing ring

243 displacement reservoir

244 canal extension

250 product containers

251 cylindrical side wall area

252 product plugs

254 closure

255 product reservoir

260 occlusion detection

261 sliders

262 rejuvenation

263 cams

264 coil spring

265 plugs

266 shift direction

267 recording room

268 rack

Claims

claims

1. A device for administering a fluid product, in particular a fluid medicament, comprising a fluid reservoir (231) in the form of a hydraulic reservoir, which is acted upon by a pressure; and a product container (250) for the fluid product, the pressure being transferable from the fluid reservoir (231) to the product container (250), characterized in that the occlusion detection device comprises pressure monitoring means (260) for monitoring the pressure in the fluid reservoir (231).

2. Apparatus according to claim 1, wherein the pressure monitoring device (260) comprises a slide (261) which is displaceably arranged along a displacement direction (266) counter to an elastic force such that the slide, when a predetermined pressure in the fluid reservoir (231) is exceeded. against the elastic force in the displacement direction (266) shifts.

3. A device for administering a fluid product, in particular a fluid medicament, comprising a fluid reservoir (231) with a fluid, which is acted upon in conjunction with the administration of the product with a pressure; a pressure monitoring device (260) for monitoring the pressure in the fluid reservoir (231), which comprises a slide (261) which is displaceable along a displacement direction (266) counter to an elastic force so that the slide at

Exceeding a predetermined pressure in the fluid reservoir (231) against the elastic force in the displacement direction (266) shifts.

4. Apparatus according to claim 2 or 3, wherein the slide (261) sealingly in a cylindrical receiving space (267) is arranged, and wherein the receiving space (267) in such a manner with the fluid reservoir (231) in fluid communication, that of the fluid reservoir in the fluid entering the receiving space (267) causes a displacement of the slide (261) in the displacement direction (266).

5. The apparatus of claim 4, wherein the fluid reservoir (231) by a nen in a cylindrical wall portion (235) in a drive direction movable drive plug (230) with a first effective cross-sectional area is pressurizable, and wherein the slide (261) a second effective cross-sectional area which is smaller than the first cross-sectional area such that upon occlusion drive movement of the drive plug (231) by a first distance results in movement of the spool (261) a second distance greater than the first distance ,

6. Apparatus according to claim 5, wherein the drive plug (230) and the slider (261) are arranged such that the displacement direction

(266) of the slider (261) is anti-parallel to the drive direction of the drive plug (230).

7. The apparatus of claim 5 or 6, wherein the cylindrical receiving cavities (267) laterally offset from the cylindrical wall portion is arranged, in which the drive plug (230) is movable.

8. Device according to one of the preceding claims, which comprises a detection device (130, 140) for detecting a displacement of the slider (261) in the displacement direction (266).

9. Apparatus according to claim 8, which comprises a reusable base unit (100) having drive means (120) and the detection means (130; 140); and an exchangeable cartridge (200) which is releasably connectable to the base unit (100) and which comprises at least the fluid reservoir (231) and the pressure monitoring device (260), wherein in an area of the cartridge (200) an opening (212) is formed in which an actuating element (263; 266) which is movable or integrally connected to the slide (161) is arranged, and wherein the detection device (130; 140) cooperates with the actuating element (263; 266) for detecting displacement of the slide.

A device according to claim 8 or 9, wherein the detection means (130; 140) comprises an electrical element arranged to change an electrical characteristic upon displacement of the slider (261) in the direction of displacement.

11. Device according to claim 10, wherein the electrical element comprises a switch (130) which can be actuated by an actuating element (263) which is movable or integrally connected to the slide (261).

12. The apparatus of claim 11, wherein the actuating element (263) in an initial position of the slide (261), which this falls below the predetermined pressure in the fluid reservoir (231) occupies, the switch (130) is actuated and a displacement of the slider

(261) releases the switch in the direction of displacement.

13. The device according to claim 9, wherein the electrical element comprises a variable by a displacement of the slider (261) resistance.

14. The apparatus of claim 13, wherein the variable resistor is variable by a rotation of a shaft, and wherein a displacement of the slider in the direction of displacement causes a rotation of the shaft.

15. The apparatus of claim 14, wherein the rack is connected to a rack, which cooperates with a gear connected to the shaft.

16. Device according to one of claims 13 to 15, wherein the detection device comprises a monitoring circuit for monitoring the variable resistor.

17. Device according to one of the preceding claims, wherein the elastic force is generated by an elastic element (264) which is cooperatively connected to the slider (260).

18. The apparatus of claim 17, wherein the elastic member (264) is a pressure acting coil spring.

19. The apparatus of claim 17 or 18, wherein the elastic element (264) is biased in a starting position of the slide (261) which it falls below the predetermined pressure in the fluid reservoir (231) is biased with a predetermined force.