DE102015220905A1 - Fluid delivery device, method for operating a fluid delivery device and control device - Google Patents

Abstract

The invention relates to a fluid dispenser (100) for dispensing a fluid (108). The fluid delivery device (100) comprises a housing (102) for receiving a container (110) filled with the fluid (108) and a piston (104) displaceably arranged or arrangeable in the housing (102) for emptying the container (110). Furthermore, the fluid delivery device (100) comprises at least one coil element (114), which is designed to change its length in dependence on a movement of the piston (104), and a measuring unit (116), which is designed to provide an inductance and / or or to measure a change in the inductance of the coil element (114) during displacement of the piston (104) so as to determine an amount of fluid (108) evacuated from the receptacle (110).

Description

State of the art

The invention is based on a device or a method according to the preamble of the independent claims. The subject of the present invention is also a computer program.

The lack of endogenous insulin in a diabetes mellitus disease can be treated today by injecting an insulin preparation. Common methods of injection are, for example, disposable syringes, permanent insulin pumps or disposable and reusable pens. The pens may, for example, resemble a very thick ballpoint pen and be populated with insulin spools.

A survey of people suffering from diabetes has shown that those affected would see considerable added value if, for an insulin pen, the last dose of insulin at the appropriate injection time could be recorded continuously. Such detection can be done using a sensor that detects either the level of the ampoule or the injected dose and either displays directly on the device in a display or transmits to an additional device. Known sensor concepts are based, for example, on resistive measuring methods by means of spring contacts. Furthermore, optical methods are known in which one or more light sources and a CCD line scan camera can be arranged on opposite sides of a carpule. A spatially resolved intensity measurement can be used to determine the level and thus the last dose of insulin delivered.

Disclosure of the invention

Against this background, with the approach presented here, a fluid dispenser for dispensing a fluid, a method for operating a fluid dispenser, furthermore a control unit which uses this method, and finally a corresponding computer program according to the main claims are presented. The measures listed in the dependent claims advantageous refinements and improvements of the independent claim device are possible.

A fluid dispenser for dispensing a fluid is presented. The fluid dispensing device may comprise a housing for receiving a container filled with the fluid and a piston displaceably arranged or arrangeable in the housing for emptying the container. The fluid delivery device also has the following features:
at least one coil element configured to change its length in response to movement of the piston; and
a measuring unit configured to measure an inductance and / or a change in inductance of the coil element upon displacement of the piston to determine an amount of fluid evacuated from the receptacle.

By way of example, the fluid delivery device may in particular be an injection device for injecting a fluid, in particular a fluid, into a tissue, for example a so-called insulin pen. The container may be, for example, a capsule, an ampoule or a carpule. Under a carpule, a cylindrical ampoule can be understood, which may have on one side of a pierceable membrane, while another side may be closed with a sliding plug. Under a piston, a rod or rod-shaped element can be understood. In this case, one end of the piston may have a piston for moving the fluid, for example by compressing the container.

A coil element can be understood to mean a component in the form of a coil with an inductance variable as a function of a length of the coil. For example, the coil element can be realized as a spring or wire winding. For this purpose, the coil element can be mechanically coupled to the piston. For example, the coil element may be aligned in the longitudinal direction substantially parallel to a direction of movement of the piston. In particular, the coil element and the piston can be aligned coaxially with one another, wherein the piston can be displaceable within the coil element. The length or the change in the length of the coil element may be proportional to a volume of the amount of fluid evacuated from the container during displacement of the piston or a change in this volume.

Depending on the embodiment, the measuring unit may for example be designed to measure the inductance or the change of the inductance using an electrical resonant circuit, which may comprise the coil element as a coil, an L-integrator, a DC-DC converter or a bridge circuit.

The approach presented here is based on the recognition that a metering piston of a fluid delivery device can be mechanically coupled to a coil element in order to supply a quantity of fluid delivered upon actuation of the metering piston determine. By using the coil element, a sensor arrangement, in particular for example an integrated linear displacement sensor, can be realized for detecting an inductance of the coil element. This can be deduced on the inductance on a change in length of the coil element and thus on the delivered fluid quantity. Such a fluid delivery device offers the advantage of low mechanical wear, low manufacturing costs, low sensitivity to contamination and good reproducibility of measurement results with respect to the amount of fluid delivered.

The fluid delivery device can be realized, for example, as an injection device, in particular as an insulin pen, with dose sensors. In this case, the fluid delivery device can have an integrated linear displacement sensor in the form of a spiral spring, via which it is possible to deduce an amount of injected insulin. In addition to the linear displacement sensor, the fluid delivery device can have, for example, a measuring unit in the form of a microcontroller for measuring data acquisition and optionally further electronic components for communication with external devices, such as a smartphone or other external device, or for displaying the current dose on an integrated display. The inductance of the spiral spring now allows a conclusion on its length and thus on a current injected insulin quantity.

Advantageously, user safety can be increased by means of such a fluid delivery device by avoiding incorrect dosages of the amount of insulin and the associated serious acute or long-term consequences.

If the fluid delivery device is used for injecting a medical active substance, this has the advantage that the administration costs for doctor and patient can be reduced, since, for example, manual protocol guidance by the patient can be dispensed with. Instead, for example, a dose value automatically detected by means of the fluid delivery device can be electronically documented, for example using a corresponding smartphone app. The dose value may be electronically transmitted to e.g. to be sent to the doctor.

Another advantage is that such a fluid delivery device can be integrated into already available insulin pens with only minor changes to an outer shape. By using existing components, the manufacturing costs can be kept low.

According to one embodiment, the coil element may be realized as a helical spring, also called a spiral spring. Such a coil element can be provided in a particularly cost-effective manner.

Furthermore, the coil element can be designed to change its length along a displacement axis of the piston. For this purpose, a longitudinal axis of the coil element can be aligned parallel to the displacement axis. In this case, for example, at least a partial section of the piston can be guided through the coil element. This allows a simple and correspondingly robust determination of the emptied fluid quantity.

It is advantageous if the coil element is designed to act on the piston with a restoring force. For example, the piston between a discharge position in which at least a portion of the fluid is forced out of the container by the piston, and a rest position in which no fluid is forced out of the container, be displaced. Accordingly, the coil element can be designed to act on the piston with a restoring force acting in the direction of the rest position. Thereby, the operation of the fluid delivery device can be simplified.

According to a further embodiment, the fluid delivery device may comprise a metering unit for metering the fluid. In particular, the metering unit can have a shaft which can be screwed to the housing for setting a displacement path of the piston and a rotary knob for rotating the shaft. By this embodiment, the amount of the discharged fluid can be accurately metered.

In this case, the coil element can be guided at least in sections in the shaft. This makes it possible to dispense with additional components for guiding the coil element when moving the piston. Furthermore, the fluid dispensing device can thereby be carried out as space-saving.

It is furthermore advantageous if the metering unit and, additionally or alternatively, the housing is at least partially passed through the coil element. As a result, the coil element can be combined easily and inexpensively with a predetermined housing or a predetermined metering unit.

Furthermore, the housing may have a housing stop. The coil element can be clamped or clamped between the housing stop and the rotary knob. In particular, the housing stop may be formed by a partition disposed in the housing with a partition wall opening for passing the piston. Additionally or alternatively, the Housing stop be formed by a arranged on a lateral surface of the housing ring. For example, the ring may have a circumferential groove for receiving one end of the coil element. Similarly, the knob can be formed with a corresponding knob stop, wherein the coil element between the turret stop and the housing stop can be clamped or clamped. The knob stop may be similar to the housing stop as an outboard ring, optionally with a circumferential groove for receiving a further end of the coil element realized. Also by this embodiment, the integration of the coil element can be carried out with low assembly and cost.

It is also advantageous if the measuring unit is arranged in and / or on the rotary knob. As a result, the measuring unit can be integrated to save space in the fluid dispenser. Furthermore, the measuring unit can be placed as close as possible to the coil element by this embodiment.

The fluid delivery device may also have a contacting spring and, additionally or alternatively, a contacting layer for producing an electrically conductive connection between the measuring unit and an end of the coil element facing away from the rotary knob. Under a Kontaktierungsfeder can be understood in particular, for example, a coil spring. For example, the contacting spring may have a smaller diameter than the coil element. In this case, the contacting spring can be guided at least in sections through the coil element, for example in order to connect the end of the coil element with a measuring unit arranged in or on the rotary knob in an electrically conductive manner. Depending on the embodiment, the contacting layer, for example a metal layer, may, for example, be applied to the housing, the shaft, the rotary knob or the coil element itself. In the latter case, an insulating layer for electrically insulating the contacting layer of the coil element can be applied between the contacting layer and the coil element. This embodiment enables a simple, robust and cost-effective electrical contacting of measuring unit and coil element.

According to another embodiment, the fluid delivery device may be implemented with a display unit for displaying the deflated amount. Additionally or alternatively, the fluid delivery device may include a transmission unit for wirelessly transmitting a signal representing the depleted amount to an external device, such as a mobile terminal or other external display device. Thereby, the deflated amount can be read directly at the fluid delivery device, whereby the operability of the fluid delivery device can be improved.

Furthermore, the approach presented here provides a method for operating a fluid delivery device according to one of the preceding embodiments, wherein the method comprises the following steps:
Reading the inductance and / or changing the inductance of the coil element; and
Determining the emptied during displacement of the piston from the container amount of fluid in dependence on the inductance and / or the change in inductance.

This method can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control unit.

The approach presented here also creates a control unit which is designed to execute, to control or to implement the steps of a variant of a method presented here in corresponding devices. Also by this embodiment of the invention in the form of a control device, the object underlying the invention can be achieved quickly and efficiently.

For this purpose, the control unit can have at least one arithmetic unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface to a sensor or an actuator for reading sensor signals from the sensor or for outputting control signals to the actuator and / or or at least a communication interface for reading or outputting data embedded in a communication protocol. The arithmetic unit may be, for example, a signal processor, a microcontroller or the like, wherein the memory unit may be a flash memory, an EPROM or a magnetic memory unit. The communication interface can be designed to read or output data wirelessly and / or by line, wherein a communication interface that can read or output line-bound data, for example, electrically or optically read this data from a corresponding data transmission line or output to a corresponding data transmission line.

In the present case, a control device can be understood as meaning an electrical device which processes sensor signals and outputs control and / or data signals in dependence thereon. The control unit may have an interface, which may be formed in hardware and / or software. At a In terms of hardware design, the interfaces can be part of a so-called system ASIC, for example, which contains various functions of the control unit. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules.

In the present case, the control unit can be used, for example, in connection with an evaluation of parameters in a medical device such as an insulin dosing unit.

Also of advantage is a computer program product or computer program with program code which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and for carrying out, implementing and / or controlling the steps of the method according to one of the embodiments described above is used, especially when the program product or program is executed on a computer or a device.

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. It shows:

1 a schematic representation of a fluid delivery device according to an embodiment;

2 a circuit diagram of an electrical resonant circuit for determining an inductance of a coil element according to an embodiment;

3 a schematic representation of a fluid delivery device according to an embodiment;

4 a schematic representation of a coil element according to an embodiment;

5 a schematic representation of a fluid delivery device according to an embodiment;

6 a schematic representation of a fluid delivery device according to an embodiment;

7 a schematic representation of a knob with integrated measuring unit according to an embodiment;

8th a schematic representation of a knob with integrated measuring unit according to an embodiment;

9 a flowchart of a method for operating a fluid delivery device according to an embodiment; and

10 a block diagram of a control device according to an embodiment.

In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and similar acting, wherein a repeated description of these elements is omitted.

1 shows a schematic representation of a fluid dispenser 100 according to an embodiment. The fluid delivery device 100 includes a housing 102 in which a piston 104 along a displacement axis 106 slidably arranged. The housing 102 further includes a fluid 108 filled container 110 For example, a capsule or carpule on. The piston 104 is designed to handle the fluid 108 when moving along the displacement axis 106 from the container 110 push out. A direction of displacement of the piston 104 is marked with a horizontal arrow. This is on a the container 110 facing the end of the piston 104 for example, one within the container 110 movable stamp 112 appropriate. Exemplary is the housing 102 according to 1 with one with the container 110 fluidically connected cannula 113 , such as a hypodermic needle, through which the fluid passes 108 when moving the piston 104 the fluid delivery device 100 leaves.

The fluid delivery device 100 is still with a coil element 114 realized that with the piston 104 is mechanically coupled. The coil element 114 is designed to change its length depending on a movement of the piston 104 along the displacement axis 106 to change. One with the coil element 114 Electrically conductive connected measuring unit 116 is designed to be an inductance of the coil element 114 or one by changing the length of the coil element 114 caused change in the inductance of the coil element 114 capture. Based on the inductance or the change of the inductance determines the measuring unit 116 the from the container 110 deflated amount of the fluid 108 ,

According to this embodiment, the coil element 114 realized as a coil spring. A longitudinal axis of the coil element 114 corresponds to the displacement axis 106 so that the change in the length of the coil element 114 essentially with the displacement of the piston 104 matches. The piston 104 is inside the coil element 114 slidably arranged.

2 shows a circuit diagram of an electrical resonant circuit 200 for determining an inductance of a coil element according to an embodiment. The resonant circuit 200 For example, as a component of a preceding by means of 1 be implemented described measuring unit. The resonant circuit 200 comprises a variable inductance coil L and a capacitor C.

berechnet, wobei µ₀ die magnetische Feldkonstante, N die Windungszahl, A die Querschnittsfläche und l die Spulenlänge bezeichnen. Bis auf die Spulenlänge l bleiben beim Ein- bzw. Ausfedern alle Größen nahezu identisch. Durch die Stauchung bzw. Streckung des Spulenelements steigt bzw. sinkt die Induktivität. Bei typischen Spulenabmessungen (Länge der Feder im nicht eingefederten Zustand: 5 cm; Windungszahl: 15; Durchmesser: 1 cm) ergeben sich beispielsweise Induktivitätswerte von einigen Hundert Nanohenry bis wenigen Mikrohenry.The inductance of the coil element, such as a coil spring is, according to

where μ _{0 is} the magnetic field constant, N is the number of turns, A is the cross-sectional area, and l is the coil length. Except for the coil length l, all sizes remain virtually identical during compression and rebound. As a result of the compression or extension of the coil element, the inductance increases or decreases. For typical coil dimensions (length of the spring in the undamped state: 5 cm, winding number: 15, diameter: 1 cm), for example, inductance values of a few hundred Nanohenry to a few microhenries result.

eine Resonanzfrequenz, die von der Induktivität, also der Spiralfederlänge, abhängt. Wird beispielsweise ein Kondensator C mit einer Kapazität von 500 pF verwendet, so liegt die Resonanzfrequenz im Bereich einiger Megahertz. Die Sensitivität, d. h. die Frequenzänderung pro Längenänderung, liegt entsprechend bei über 1 MHz/cm und ist damit leicht detektierbar.Will the coil element in the electrical resonant circuit 200 interconnected, it follows

a resonant frequency, which depends on the inductance, so the coil spring length. For example, if a capacitor C with a capacitance of 500 pF is used, the resonance frequency is in the range of a few megahertz. The sensitivity, ie the frequency change per change in length, is correspondingly greater than 1 MHz / cm and is thus easily detectable.

As an alternative to determining the inductance via the above-described measurement of the resonant frequency by means of an electrical resonant circuit, other measuring principles are also conceivable.

According to one embodiment, the inductance is measured by means of an L-integrator. In this case, a DC voltage is applied to the coil element and the rising current is converted by an operational amplifier into a measuring voltage. This is measured and used to infer the inductance.

According to a further embodiment, a DC-DC converter is used for determining the inductance. In this case, an energy of the coil element is charged to a capacitor whose voltage serves as a measurement signal for measuring the inductance.

Alternatively or additionally, a parallel resistor is determined. For this purpose, a chip can be used, which is designed to determine an effective resonance parallel resistance and a resonant frequency of a resonant circuit. By selecting a suitable parallel capacitance, the resonance frequency can be adjusted.

Also conceivable is the use of a reactive voltage divider. In this case, a phase relationship between an exciting sinusoidal signal and a voltage across an LC resonant circuit is determined via a phase-locked loop, in short PLL. Based on the phase, the inductance is then determined.

According to a further embodiment, the coil element is integrated in a bridge circuit. The main task of the hardware here is the demodulation of a measurement signal. For this purpose, the bridge circuit is formed with at least one further reference coil.

3 shows a schematic representation of a fluid dispenser 100 according to an embodiment in cross section. In the fluid dispenser 100 For example, it is a preceding one based on 1 described fluid dispenser. According to this embodiment, the fluid dispenser is with an optional dosing unit 300 executed. The dosing unit 300 includes one with the housing 102 screw-on shaft 302 and one on the shaft 302 attached knob 304 for turning the shaft 302 around the displacement axis 106 , By turning the shaft 302 can be the displacement of the piston 104 be changed. According to this embodiment, the shaft 302 with an external thread 306 realized that in a corresponding internal thread 308 of the housing 102 intervenes.

The coil element 114 is between one inside the case 102 located housing stop in the form of a partition 310 with a partition opening 311 , also called fixed passage, and the knob 304 clamped. Here is a knob 304 facing portion of the coil element 114 in the shaft 302 arranged so that the shaft 304 as a guide for the coil element 114 serves.

According to one embodiment, the knob is used 304 as a dose button to set an amount of insulin by turning. The larger a set angle of rotation, the farther the knob will turn 304 over the threads 306 . 308 out of the case 102 unscrewed. A distance between rotary knob 304 and housing 102 then corresponds to the path length to the container, here an insulin cartridge, when pressing the knob 304 is emptied, possibly scaled with a certain translation factor. For emptying pushes the stamp 113 on the container. The Stamp 113 For example, at the end of a threaded rod, which is part of the piston 104 can be arranged.

For example, it is ensured by means of a corresponding locking mechanism that the threaded rod can only rotate in one direction. Through an optional mechanical component 312 , such as a driver, also ensures that the knob 304 can be maximally rotated by a path length corresponding to a remaining level of the container.

According to the in 3 the embodiment shown is the fluid dispenser 100 realized as Injektionspen. Contains the fluid dispenser 100 , as in 3 already shown, a coil spring for applying the piston 104 or the dosing unit 300 with a restoring force during an injection, this can be used directly as a measuring coil. The fluid delivery device 100 is for example structured as follows.

The knob 304 is at the end of the shaft 302 attached, the external thread 306 having. The counterpart of the external thread 306 in the form of the internal thread 308 is located on the housing 102 , The mechanical component 312 is between the knob 304 and partition 310 arranged. The partition 310 is designed to prevent a higher dose can be set, as there is still fluid in the container. The piston 104 is through the partition opening 311 passed. Here is the stamp 113 at one of the dosing unit 300 opposite end of the piston 104 appropriate. The Stamp 113 For example, has direct contact with a stopper of the container, which may be about a carpule.

The coil element 114 in the form of the spiral spring is fixed on one side with the dividing wall 310 and on the other side with the knob 304 connected. The length of the coil element 114 thus corresponds to a sum of a certain constant value and a horizontal distance between rotary knob 304 and housing 102 , where the horizontal distance is equivalent to the dose.

According to one embodiment, the measuring unit 116 with electronics for measuring a spring length of the coil element 114 executed on the inductance and in the knob 304 arranged. For this purpose, the two ends of the coil element 114 each electrically conductive with the measuring unit 110 connected. While a the knob 304 facing end of the coil element 114 , as already mentioned, directly with the knob 304 can be connected, provide for electrical contacting of one of the partition 310 facing the end of the coil element 114 several possibilities.

For example, the fluid delivery device 100 with an electrically conductive contacting layer 314 for making an electrically conductive connection between the housing 102 facing the end of the coil element 114 and the measurement unit 116 realized. Depending on the embodiment, the contacting layer 314 on the partition wall 310 , the case 102 , the internal thread 308 or the shaft 302 applied. As a result, the return conductor is practically through the housing 102 and the dosing unit 300 realized.

Alternatively, the contacting layer 314 on the coil element 114 applied. Here is the contacting layer 314 by an insulating layer, such as a lacquer layer, of the coil element 114 electrically isolated. Thus, the return conductor becomes a coating on the coil element 114 applied. This has the advantage that no modifications of plastic parts of the fluid dispenser 100 are required because only the coil element 114 is modified.

Another way of contacting the coil element 114 is below based on 4 described.

4 shows a schematic representation of a coil element 114 according to an embodiment. In the coil element 114 For example, it is a coil element, as previously described with reference to 1 to 3 is described. Shown is the contacting of the coil element 114 in the form of a coil spring via a Kontaktierungsfeder 400 in the form of another spiral spring. According to this embodiment, the contacting spring 400 within the coil element 114 arranged. In this case, the contact spring 400 a smaller diameter than the coil element 114 on. The contact spring 400 is on one of the dividing wall 310 facing side electrically conductive with the coil element 114 connected. Alternatively, the partition 310 made of an electrically conductive material, wherein the coil element 114 and the contact spring 400 over the partition 310 electrically conductive interconnected.

The measuring unit is connected via a connection point x1 with the contacting spring 400 and via a second connection point x2 with the coil element 114 contactable.

5 shows a schematic representation of a fluid dispenser 100 according to an embodiment in cross section. In contrast to 3 the coil element extends 114 according to 5 around the dosing unit 300 and the case 102 ie, the dosing unit 300 and the case 102 are through the coil element 114 passed.

At the in 5 shown coil element 114 For example, it is a spring that subsequently enters the fluid delivery device 100 has been integrated, so that a modification of an internal structure of the fluid dispenser 100 could advantageously be omitted.

For fixing the coil element 114 is according to this embodiment on a lateral surface of the knob 304 a knob ring 500 and on a lateral surface of the housing 102 a housing ring 502 applied as housing stop. The coil element 114 is between the knob ring 500 and the case rings 502 clamped. At the two rings 500 . 502 These are, for example, circular rings each with a circumferential groove for receiving one end of the coil element 114 , As in 5 To recognize, are the two grooves of the rings 500 . 502 arranged opposite each other. By means of the two rings 500 . 502 becomes the coil element 114 fixed over his own spring force. Alternatively, the coil element can also be non-positively connected, for example via an adhesive connection with the rings 500 . 502 be connected.

The electrical contacting of the coil element 114 takes place, for example, analogous to the basis of 3 and 4 described contacting.

6 shows a schematic representation of a fluid dispenser 100 according to an embodiment. The fluid delivery device 100 essentially corresponds to the basis of 5 described fluid dispenser, with the difference that the electrical contact of the housing 102 facing the end of the coil element 114 via the contact spring 400 he follows. For this purpose, the contact spring 400 between the coil element 114 and the dosing unit 300 or the housing 102 arranged.

7 shows a schematic representation of a knob 304 with integrated measuring unit 116 according to an embodiment. At the knob 304 For example, it is a knob, as previously described by the 3 to 6 is described. The knob 304 has a recess 700 on, in which the measurement unit 116 is arranged.

The measuring unit 116 According to this embodiment, all electronic components for detecting the inductance, for calculating the empty amount of the fluid as well as for transmitting corresponding data. Here are the electronic components on a in the recess 700 placed substrate 702 arranged. It is also conceivable housing in the housing. 7 shows the arrangement of the electronic components in the knob 304 ,

Schematically illustrated are the two connection points x1, x2 for connecting the coil element, a capacitor 704 for measuring the inductance across the resonant frequency of a resonant circuit, a power supply unit 706 , about a button cell, and other components. The further components include, for example, at least one microcontroller 708 for measuring the resonant frequency and calculating the amount of fluid drained and a transmission unit 710 for the wireless transmission of a value representing the deflated fluid quantity, for example via Bluetooth or NFC. For example, the transmission unit 710 designed to pass the value to an external display device 712 , in particular, for example, to a smartphone or a tablet PC to transfer.

8th shows a schematic representation of a knob 304 with integrated measuring unit 116 according to an embodiment. Shown is the optional integration of a display unit 800 in the knob 304 out 7 , The display unit 800 is configured to indicate the value representing the deflated amount. According to this embodiment, the display unit 800 on one of the recess 700 opposite surface of the knob 304 arranged.

The display unit 800 is realized, for example, as an e-ink display. This allows a low-energy, permanent display of the value.

In addition, the measuring unit 116 be formed to detect the time at which the amount of fluid was emptied. Such time detection takes place, for example, by means of a preceding by means of 7 described microcontroller. For example, the time detection can be initialized at a first radio contact.

9 shows a flowchart of a method 900 for operating a fluid delivery device according to an embodiment. The procedure 900 For example, in connection with a preceding on the basis of 1 to 9 described fluid dispenser are performed. This is done in one step 910 the inductance and, additionally or alternatively, read the change in the inductance of the coil element. In a further step 920 the amount of fluid emptied when the piston is displaced from the container is determined as a function of the inductance or the change in the inductance.

10 shows a block diagram of a controller 116 according to an embodiment. The control unit 116 , previously also referred to as a measuring unit, is designed, for example, to provide a method as described above with reference to FIG 9 is described, perform or control. This includes the control unit 116 a read-in unit 1010 for reading in an inductance signal representing the inductance or the change of the inductance 1015 and a discovery unit 1020 , which is adapted to the amount of fluid drained using the inductance signal 1015 to determine and a fluid volume signal representing the amount of fluid emptied 1025 provide.

According to one embodiment, the determination unit 1020 optionally configured to the fluid quantity signal 1025 via suitable interfaces to a display unit of the fluid delivery device or, in particular via a wireless radio link to transmit to an external display device.

If an exemplary embodiment comprises a "and / or" link between a first feature and a second feature, then this is to be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment either only first feature or only the second feature.

Claims (15)

Fluid delivery device ( 100 ) for dispensing a fluid ( 108 ), wherein the fluid delivery device ( 100 ) a housing ( 102 ) for receiving one with the fluid ( 108 ) filled container ( 110 ) and one in the housing ( 102 ) displaceably arranged or arranged piston ( 104 ) for emptying the container ( 110 ), wherein the fluid delivery device ( 100 ) has the following features: at least one coil element ( 114 ), which is adapted to its length in dependence on a movement of the piston ( 104 ) to change; and a measuring unit ( 116 ), which is designed to be an inductance and / or a change in the inductance of the coil element ( 114 ) when moving the piston ( 104 ) to remove one from the container ( 110 ) emptied amount of the fluid ( 108 ). Fluid delivery device ( 100 ) according to claim 1, characterized in that the coil element ( 114 ) is realized as a coil spring. Fluid delivery device ( 100 ) according to one of the preceding claims, characterized in that the coil element ( 114 ) is formed to its length along a displacement axis ( 106 ) of the piston ( 104 ) to change. Fluid delivery device ( 100 ) according to one of the preceding claims, characterized in that the coil element ( 114 ) is adapted to the piston ( 104 ) to apply a restoring force. Fluid delivery device ( 100 ) according to one of the preceding claims, characterized by a metering unit ( 300 ) for metering the fluid ( 108 ), in particular wherein the dosing unit ( 300 ) one with the housing ( 102 ) screwable shaft ( 302 ) for adjusting a displacement path of the piston ( 104 ) and a rotary knob ( 304 ) for rotating the shaft ( 302 ) having. Fluid delivery device ( 100 ) according to claim 5, characterized in that the coil element ( 114 ) at least in sections in the shaft ( 302 ) is guided. Fluid delivery device ( 100 ) according to claim 5 or 6, characterized in that the dosing unit ( 300 ) and / or the housing ( 102 ) at least in sections through the coil element ( 114 ) is passed. Fluid delivery device ( 100 ) according to one of claims 5 to 7, characterized in that the housing ( 102 ) a housing stop ( 310 . 502 ), wherein the coil element ( 114 ) between the housing stop ( 310 . 502 ) and the rotary knob ( 304 ) is clamped or clamped, in particular wherein the housing stop ( 310 . 502 ) by a in the housing ( 102 ) arranged partition ( 310 ) with a partition opening ( 311 ) for passing the piston ( 104 ) and / or by a on a lateral surface of the housing ( 102 ) arranged ring ( 502 ) is formed. Fluid delivery device ( 100 ) according to one of claims 5 to 8, characterized in that the measuring unit ( 116 ) in and / or on the rotary knob ( 304 ) is arranged. Fluid delivery device ( 100 ) according to one of claims 5 to 9, characterized by a contacting spring ( 400 ) and / or a contacting layer ( 314 ) for establishing an electrically conductive connection between the measuring unit ( 116 ) and one of the rotary knob ( 304 ) facing away from the end of the coil element ( 114 ). Fluid delivery device ( 100 ) according to one of the preceding claims, characterized by a display unit ( 800 ) for displaying the deflated quantity and / or a transfer unit ( 710 ) for wirelessly transmitting a signal representing the depleted amount ( 1025 ) to an external device ( 712 ). Procedure ( 900 ) for operating a fluid delivery device ( 100 ) according to any one of the preceding claims, wherein the method ( 900 ) includes the following steps: reading in ( 910 ) of the inductance and / or the change of the inductance of the coil element ( 114 ); and determining ( 920 ) when moving the piston ( 104 ) from the container ( 110 ) emptied amount of the fluid ( 108 ) as a function of the inductance and / or the change in the inductance. Control unit ( 116 ) with units ( 1010 . 1020 ), which are adapted to the steps of a method ( 900 ) according to claim 12 execute and / or to control. Computer program that is adapted to the procedure ( 900 ) according to claim 12 execute and / or to control. A machine readable storage medium storing the computer program of claim 14.

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