Device for controlling the flow rate of a medical liquid

Abstract

Such a device is known for controlling the flow rate of a medical liquid through a hose line of a transfer system, having a sensor device which is designed to detect at least one sensor signal that represents the flow rate of the medical liquid through the hose line, a controller which is designed to ascertain a control signal as a function of the detected sensor signal and a specified target flow rate of the medical liquid through the hose line, and an actuator which is designed to set the flow rate on the basis of the control signal, wherein the actuator device has a pressing element which is designed to apply a radial pressing force to the hose line, said pressing force varying on the basis of the control signal, whereby the diameter of the hose line can be varied in order to increase or reduce the flow rate. According to the invention, a housing is provided in which the sensor device, the controller, and the actuator device are arranged, said housing having a first housing half and a second housing half that can be moved relative to each other between an open state, in which the housing halves are moved away from each other in order to insert an axial hose section of the hose line between the housing halves, and a closed state, in which the housing halves are moved towards each other and are secured together in order to clamp the hose section between the housing halves and thus secure the housing to the hose line. The pressing element is arranged on the first housing half and can be moved relative to the second housing half in order to apply the pressing force. The invention also relates to a use of the device for infusion therapy.

Description

[0001] Device for controlling a flow rate of a medical fluid

[0002] The invention relates to a device for controlling a flow rate of a medical fluid through a hose line of a transfer system, comprising a sensor device configured to detect at least one sensor signal representing the flow rate of the medical fluid through the hose line, a control device configured to determine a control signal as a function of the detected sensor signal and a predetermined target flow rate of the medical fluid through the hose line, and an actuator device configured to adjust the flow rate depending on the control signal, wherein the actuator device has a pressing element configured to apply a radial pressing force to the hose line that is variable depending on the control signal, whereby a diameter of the hose line can be varied to increase and / or decrease the flow rate.

[0003] Such a device is known from EP 3 277 341 B1. The known device is intended for use in a transfer system that allows gravity-driven transfer of a medical fluid from a fluid container to a patient. The transfer system has a drip chamber and a hose line connected to an outlet of the drip chamber. The known device has a sensor device, a control device, and an actuator device. In the known device, the sensor device is an optical drop counter and is designed for attachment to the drip chamber of the transfer system. The control device of the known device is connected to the sensor device via a cable and determines a control signal for controlling the actuator device depending on the optical drop count and a predetermined target flow rate.In the known device, the actuator device is designed, for example, in the form of a motorized roller clamp with a movable pressing element in the form of a roller. Alternatively, the actuator device has a pressing element in the form of an adjustable eccentric cam, by means of which the hose line can be squeezed more or less tightly to increase or decrease the flow rate depending on the control signal, and its diameter can be changed accordingly. In the known device, the sensor device, the control device, and the actuator device are mounted separately from one another at different sections of the transfer system and are connected to each other via cables for signal transmission.

[0004] The object of the invention is to provide a device of the type mentioned above which offers advantages over the prior art and has a simplified structure.This object is achieved in that a housing is provided in which the sensor device, the control device and the actuator device are arranged, wherein the housing has a first housing half and a second housing half which are displaceable relative to one another between an open state in which the housing halves are moved away from one another for inserting an axial hose section of the hose line between the housing halves, and a closed state in which the housing halves are moved towards one another and fixed to one another for clamping the hose section between the housing halves and thus for attaching the housing to the hose line, wherein the pressing element is arranged on the first housing half and is movable relative to the second housing half for applying the pressing force. The solution according to the invention enables simplified attachment of the device to the transfer system.For installation, the housing and the devices contained therein can be easily fastened to the hose line of the transfer system. For this purpose, the housing has the two housing halves mentioned. The housing halves can be moved between the open and closed states to fasten the housing to the hose line. In the open state, the housing halves are moved away from each other such that the housing can be pushed laterally, i.e. radially, onto the hose line. In the closed state, the two housing halves are moved towards each other and secured to each other, whereby the hose section located between the two housing halves is clamped. The housing can thus be fastened to the hose line with a radial form-fitting fit and an axial friction fit. As a result, the device according to the invention is compatible with conventional transfer systems.In different embodiments, the two housing halves can be displaced relative to one another in different ways. In a preferred embodiment, a folding axis is provided around which the housing halves can be folded relative to one another between the open and closed states. In other embodiments, the housing halves are completely separated from one another in the open state and releasably fastened to one another in the open state by means of a latching, clamping, snap-in or other force-fitting and / or form-fitting connection. Preferably, the housing is subdivided along a radially and axially extending plane into the first housing half and the second housing half, with respect to an orientation of the hose section in the closed state.The term “housing half” does not necessarily imply that the first housing half and the second housing half have essentially the same dimensions, although this is advantageously the case. In different embodiments, the sensor device is set up to detect the flow rate using different measuring techniques. For example, the sensor device can be based on an optical, acoustic, inductive, capacitive or other measuring principle suitable for detecting flow rates. The pressing element of the actuator device is set up to apply the said pressing force to the hose line. The pressing element acts radially on the hose section located between the housing halves. Depending on the pressing force, the hose section is squeezed radially to varying degrees. To apply the pressing force, the pressing element is radially movable relative to the hose section.In a preferred embodiment, the pressing element is immovable relative to the first housing half, wherein the pressing force is variable by changing the relative position of the two housing halves in the closed state. In a further embodiment, the housing halves are immovable relative to one another in the closed state, and the pressing element is mounted on the first housing half so as to be relatively movable in order to apply the pressing force. It is understood that the hose line of the transfer system is not a component of the device. The device is particularly advantageously suitable for use on a transfer system designed for the gravity-driven transfer of a medical fluid from a fluid container, for example an infusion bag, to a patient.Such transfer systems typically comprise a drip chamber assembly and a hose connected to an outlet of the drip chamber assembly. The housing is designed to be attached to said hose. In one embodiment, the forces required to attach the housing are applied exclusively to the hose by the pressing element. In another embodiment, the housing has alternative or additional means for this purpose, for example, a groove into which the hose section is clamped, or the like.

[0005] In an embodiment of the invention, the housing has a folding axis around which the first housing half and the second housing half can be folded relative to one another between the open state and the closed state. To attach the housing to the hose line, the housing halves are moved away from one another about the folding axis - the housing is folded open. To fasten the housing to the hose line, the two housing halves are moved towards one another about the folding axis - the housing is folded closed. Preferably, the folding axis is parallel to the axial direction of the hose section with respect to the orientation of the hose section in the closed state. The folding axis is formed between the first housing half and the second housing half. For example, the folding axis can be formed by a hinge, a solid-state joint, or other articulated mechanical connecting means.In a further embodiment of the invention, the housing has a receiving groove which is formed between the first housing half and the second housing half and is designed to receive the hose section in a radially positive-fitting and axially frictional manner. The receiving groove allows improved positioning of the hose section between the two housing halves. The dimensions of the receiving groove are matched to the hose section to be received. As a result, the hose section is received in the receiving groove in a radially positive-fitting and axially frictional manner. The receiving groove enables the housing to be held on the hose section, even when the housing is in its open state. This prevents the housing from inadvertently slipping off the hose line during attachment and before the housing is closed.In one embodiment, the receiving groove is formed on the first housing half, for example, countersunk into it. In another embodiment, the receiving groove is alternatively or additionally formed on the second housing half, preferably countersunk into it. The receiving groove can be continuous along its longitudinal direction or formed by spaced-apart groove sections. In this embodiment, the pressing element is arranged radially on the receiving groove. To vary the pressing force, the pressing element can be displaced relative to the receiving groove.

[0006] In a further embodiment of the invention, the pressing element is arranged immovably relative to the first housing half, and the actuator device is configured for relative movement of the housing halves in order to change a distance between the housing halves and thus the pressing force of the pressing element. This eliminates the need for movable mounting of the pressing element on the first housing half, which allows a further simplified design of the device. Instead of just the pressing element, the entire first housing half (including the pressing element) is displaced relative to the second housing half. For this purpose, the actuator device is operatively connected to the first housing half and / or the second housing half in a force- and / or movement-transmitting manner. The relative movement of the housing halves occurs when the housing is in the closed state.This means that in this embodiment, the housing halves can be positioned more or less close to each other in the closed state by means of the actuator device.

[0007] In a further embodiment of the invention, the housing has a locking device with at least one first locking element arranged on the first housing half and at least one complementary second locking element arranged on the second housing half, wherein the first locking element and the second locking element are releasably locked to one another in the closed state of the housing, and wherein the actuator device acts on at least one of the locking elements and is configured to displace the respective locking element relative to the respective housing half. The locking device thus has a particularly advantageous multiple function. Firstly, the locking device allows a releasable locking of the housing halves in the closed state. This counteracts an unintentional displacement into the open state.Secondly, the locking device additionally serves to effect the relative movement of the housing halves in the closed state, with the drive force / movement required for this being provided by the actuator device. In one embodiment, the actuator device acts on the first locking element. In this case, the first locking element is mounted on the first housing half so that it can move relative to the same and can be displaced by the actuator device. In a further embodiment, the actuator device acts on the second locking element. In this case, the second locking element is mounted on the second housing half so that it can move relative to the same and can be displaced by the actuator device.

[0008] In a further embodiment of the invention, the actuator device comprises a piezoelectric actuator. The piezoelectric actuator generates the movement and / or force required to displace the pressing element based on known physical principles. When subjected to an electrical voltage, the piezoelectric actuator expands. If the voltage is removed / reduced, the piezoelectric actuator returns to its original state. By using the piezoelectric actuator, the actuator device can be designed with comparatively few moving components. This is particularly advantageous compared to prior art solutions based, for example, on an electric motor drive principle. Furthermore, installation space can be saved, and a particularly compact design can be achieved.In a preferred embodiment, the actuator device has a lever element for amplifying the force generated by the piezoelectric actuator.

[0009] In a further embodiment of the invention, the sensor device has at least one sensor integrated into the pressing element. By integrating the at least one sensor into the pressing element, the sensor signal can be detected in the immediate vicinity of the hose line / hose section. This results in metrological advantages on the one hand. On the other hand, by integrating the sensor into the pressing element, installation space can be saved. In different embodiments, the at least one sensor operates on the basis of different measuring principles. For example, the at least one sensor can be an optical sensor, an acoustic sensor, an inductive or capacitive sensor for optical, acoustic, inductive or capacitive detection of the flow rate. In a further embodiment of the invention, the sensor device has at least one acoustic sensor which is designed to detect pressure waves and / or structure-borne sound in the hose section.This embodiment is particularly advantageous when the transfer system has a drip chamber arrangement into which the medical fluid to be administered is introduced drop by drop from the fluid container, for example an infusion bag. In this case, the acoustic sensor allows the structure-borne sound generated when the fluid is dripped into the drip chamber arrangement to be recorded. This allows the number of drops per unit of time to be acoustically recorded, i.e., acoustic drop counting. Based on the number of drops per unit of time, the flow rate can be determined if the drop volume is known. It is particularly advantageous if the acoustic sensor is integrated into the pressing element according to the previous embodiment. This means that the acoustic sensor - together with the pressing element - lies firmly against the hose section, so that the pressure waves and / or the structure-borne sound can be recorded particularly reliably and without loss.

[0010] In a further embodiment of the invention, the sensor device comprises at least a first acoustic sensor, which—when the hose section is inserted between the housing halves—is arranged at a first position of the hose section and is configured to detect a first sensor signal, and a second acoustic sensor, which is arranged at an axially spaced second position of the hose section and is configured to detect a second sensor signal, wherein the control device is configured to determine the control signal as a function of the first sensor signal, the second sensor signal, and the predetermined target flow rate. The use of two acoustic sensors spaced axially along the hose section offers metrological advantages. For example, the two sensor signals can be compared with one another by means of the control device. Based on such a comparison, improved measurement accuracy can be achieved.Alternatively or additionally, such a comparison allows for the detection of faulty measurements. If the housing has a receiving groove, the two acoustic sensors are preferably spaced apart along the receiving groove. Preferably, the two acoustic sensors are integrated into the pressing element at a distance from each other.

[0011] In a further embodiment of the invention, the control device is configured to determine an axial propagation direction of the pressure waves and / or structure-borne sound based on the first sensor signal and the second sensor signal. Based on the propagation direction within the tubing, a position of the source of the pressure waves and / or structure-borne sound can be determined. This can prevent patient-induced noises from being mistakenly detected as "drops."

[0012] In a further embodiment of the invention, the control device is configured to determine an axial propagation velocity of the pressure waves and / or structure-borne sound as a function of the first sensor signal and the second sensor signal. The propagation velocity has a known physical relationship with a density of a propagation medium, i.e., the medium in which the pressure waves and / or structure-borne sound propagate. The propagation velocity is therefore dependent on the medium located in the hose line, or more precisely, on its density. In this embodiment, the density of the medical fluid located in the hose line can be deduced from the determined axial propagation velocity. This enables measurement error detection.For example, it can detect whether a medical fluid other than the one intended for administration is mistakenly flowing through the tubing. It can also detect whether and when the tubing is emptying, i.e., filling with air, or becoming blocked.

[0013] In a further embodiment of the invention, an input device is arranged on the housing and is configured at least for entering the target flow rate, and / or a display device is arranged on the housing and is configured at least for displaying the target flow rate and / or the flow rate, in particular wherein the input device and the display device are designed in the form of a touchscreen embedded in a flat side of the housing. The input device and / or the display device allow simplified operation of the device. This is particularly the case when they are combined to form a touchscreen. The touchscreen also offers hygienic advantages because it can be cleaned easily and reliably. In a preferred embodiment, the touchscreen takes up at least substantially the entire surface of the flat side.

[0014] In a further embodiment of the invention, the control device has a data transmission unit that is configured for the wireless transmission of at least the flow rate and / or the target flow rate. This allows the flow rate and / or the target flow rate to be wirelessly sent to an external receiving unit by means of the data transmission unit. A reverse transmission is also conceivable and possible. For example, said data can be transmitted to or received from a central database system of a hospital or other medical facility. In a further embodiment of the invention, a power supply device is provided that has a rechargeable battery arranged in the housing and an inductive power transmission device for inductively recharging the battery, wherein the power transmission device has an induction surface arranged on a further flat side of the housing.The rechargeable battery is designed to supply the sensor device, the control device, and the actuator device with electrical operating energy. If the device has an input device and / or a display device, these devices are also powered by the battery. The inductive energy transfer device enables wireless recharging of the battery and offers particular hygienic advantages over wired solutions. Compared to a charging socket and / or a cable, the induction surface located on the other flat side of the housing is easy to clean.

[0015] The invention further relates to an infusion arrangement. The infusion arrangement according to the invention comprises a device according to the preceding description and a transfer system. The transfer system is designed for the gravity-driven transfer of a medical fluid from a fluid container to a patient. The fluid container can be, for example, an infusion bag. The transfer system comprises a drip chamber arrangement and a tubing. The drip chamber arrangement has an inlet and an outlet. The inlet of the drip chamber arrangement is designed for fluid-conducting connection to said fluid container. In one embodiment, the inlet is formed by a piercing spike. The tubing is elongated between a first end and a second end. The first end of the tubing is fluid-conductingly connected to the outlet of the drip chamber arrangement.The second end of the tubing is configured to deliver the medical fluid to the patient. For this purpose, the second end can be provided with a fluid connector. In the infusion assembly according to the invention, the housing of the device is detachably attached to the tubing between the first end and the second end of the tubing.

[0016] Further advantages and features of the invention emerge from the claims and from the following description of preferred embodiments of the invention, which are illustrated with reference to the drawings.

[0017] Fig. 1 shows a schematic perspective view of an embodiment of an infusion arrangement according to the invention with a transfer system and an embodiment of a device according to the invention for controlling a flow rate of a medical fluid through the transfer system, Fig. 2 shows a schematic perspective view of the device according to Fig. 1, wherein its housing assumes an opened state, together with a hose section of a hose line of the transfer system,

[0018] Fig. 3 shows the device according to Figs. 1 and 2 in a folded closed state of the housing and looking towards a front flat side of the housing,

[0019] Fig. 4 shows the device according to Figs. 1 to 3 in a further schematic perspective view looking towards a rear flat side of the housing,

[0020] Fig. 5 is a schematically simplified block diagram of the device according to Figs. 1 to 4 and

[0021] Fig. 6 is a schematic detailed view of the device according to Figs. 1 to 5 together with a section of a hose line of the transfer system.

[0022] According to Fig. 1, an infusion arrangement 1000 is provided for use in infusion therapy and comprises a transfer system 100 and a device 1.

[0023] The transfer system 100 serves for a gravity-driven transfer of a medical fluid from a fluid container, for example an infusion bottle or an infusion bag, to a patient and can also be referred to as a fluid transfer system or infusion system, in particular an intravenous one.

[0024] The transfer system 100 has a design generally known to those skilled in the art, comprising a drip chamber arrangement 200 and a tubing 300.

[0025] The drip chamber arrangement 200 has an inlet 201, an outlet 202, a drip chamber 203 arranged between the inlet 201 and the outlet 202, and a piercing spike 204, which in the present case is hidden under a removable protective cap 205.

[0026] The tubing 300 has a first end 301 and a second end 302. The first end 301 of the tubing 300 is fluidly connected to the outlet 202 of the drip chamber assembly 200. The second end 302 is only schematically indicated in Fig. 1 and is configured to deliver the said medical fluid to the patient. For example, the second end 302 can have a patient connector or the like.

[0027] To use the transfer system 100, the protective cap 205 is first removed from the piercing spike 204. The piercing spike 204 can then be inserted, in a manner known to those skilled in the art, into a section provided for this purpose in the fluid container, which is usually suspended from a frame. The medical fluid contained in the fluid container then flows, due to gravity, through the piercing spike 204 to the inlet 201 and drips from there into the drip chamber 203. From the drip chamber 203, the medical fluid flows via the outlet 202 into the tubing 300 and can be delivered to the patient via its second end 302. This establishes a flow rate F of the medical fluid. The flow rate F can also be referred to as the volume flow and indicates the amount of fluid flowing through the tubing 300 per unit of time.

[0028] Roller clamps are typically used to adjust the flow rate in conventional infusion systems. Such roller clamps are attached to the tubing and have a design and function familiar to those skilled in the art for manually adjusting the flow rate. The roller clamp is manually adjusted by medical personnel depending on the number of drops entering the drip chamber per unit of time. The number of drops is typically recorded visually and by a stopwatch. All of this is error-prone and, in particular, does not allow for automatic control of the flow rate.

[0029] The device 1 is designed to automatically control the flow rate F. The term "control" or "control" in this context expressly also includes "regulation" or "regulation".

[0030] The device 1 comprises a housing 2, a sensor device 3, a control device 4, and an actuator device 5. The housing 2 is attached to the hose line 300 in a manner described in more detail below. The sensor device 3, the control device 4, and the actuator device 5 are arranged in the housing 2.

[0031] The sensor device 3 is configured for the metrological detection of the flow rate F. Specifically, the sensor device 3 detects at least one sensor signal representing the flow rate F. In the embodiment shown, a first sensor signal S1 and a second sensor signal S2 (see Figs. 5, 6) are detected. These two signals S1, S2 are detected in a manner described in more detail below. Regardless of the embodiment shown, different measuring principles for detecting the flow rate F are conceivable and possible, such as optical, acoustic, inductive, or capacitive measurement of the flow rate F.

[0032] The control device 4 serves to control, in particular, the actuator device 5. The control device 4 is configured to determine a control signal S3 (see Fig. 5). The control signal S3 is determined in the present case as a function of the detected sensor signals S1, S2 and a predetermined target flow rate F'. The sensor signals S1, S2 are provided by the sensor device 3. The target flow rate F' can, for example, be stored in the control device 4, made available via data transmission or otherwise as a signal and / or data-based. The target flow rate F' defines a flow rate of the medical fluid through the hose line 300 that is required or desirable from a therapeutic point of view. In the simplest case, the said control signal S3 can be determined by comparing the (current) flow rate F represented by the sensor signals S1, S2 and the predetermined target flow rate F', for example by simple subtraction.In this case, the control signal S3 represents a deviation between the flow rate F and the target flow rate F'.

[0033] The actuator device 5 serves to set / change the flow rate F as a function of the control signal S3. For this purpose, the actuator device 5 has a pressing element 51 which is provided for pressing, i.e. squeezing or compressing, the hose line 300. The pressing element 51 applies a variable pressing force P to the hose line 300 as a function of the control signal S3, so that its diameter (without reference symbol) varies as a function of the pressing force P. The flow rate F therefore also changes as a function of the diameter of the hose line 300 in the region of the pressing element 51. With a comparatively strong pressing force P, the hose line 300 is comparatively strongly radially pressed / squeezed in the region of the pressing element 51, as a result of which the flow rate F decreases.Starting from such a squeezed state, the pressing force P can be reduced depending on the control signal S3, whereby the hose line 300 is pressed / squeezed less strongly and the flow rate F is consequently increased in relation. The pressing force P is generated in a manner described in more detail below. The pressing force P acts in the radial direction R of the hose line 300.

[0034] To simplify the attachment of the device 1 to the hose line 300, the housing 2 has a first housing half 21 and a second housing half 22. The two housing halves 21, 22 are displaceable relative to one another between an open state (Fig. 2) and a closed state (see Figs. 1, 3, 4).

[0035] In the open state, the housing halves 21, 22 are moved away from each other—the housing 2 is open. When the housing 2 is open, a hose section 303 of the hose line 300 can be inserted between the housing halves 21, 22 (see Fig. 2).

[0036] In the closed state, the housing halves 21, 22 are moved toward each other and secured to one another—the housing 2 is closed. In the closed state of the housing 2, the hose section 303 previously inserted between the housing halves 21, 22 is clamped between the housing halves 21, 22, whereby the device 1 is fastened to the hose section 300. Alternatively, it can also be said that the housing 2, or more precisely its housing halves 21, 22, is clamped to the hose section 303 in order to fasten the device 1 to the hose line 300. The hose section 303 is held between the housing halves 21, 22 in a form-fitting manner in the radial direction R and with axial frictional engagement.

[0037] In the embodiment shown, the housing 2 has a cuboid shape with a first end 23 and a second end 24. The first end 23 and the second end 24 lie opposite one another along a longitudinal axis (without reference symbol) of the housing 2. When the hose section 303 is inserted, its axial direction A is parallel to the longitudinal axis of the housing 2. The housing 2 also has a first flat side, which can also be referred to as the front side 25. A second flat side of the housing 2, which can also be referred to as the rear side 26, lies opposite the front side 25 orthogonal to the longitudinal axis of the housing 2.

[0038] In the embodiment shown, the housing 2 is divided along a central longitudinal plane (without reference numeral) into the first housing half 21 and the second housing half 22. Said central longitudinal plane is defined by the longitudinal axis of the housing and an axis orthogonal thereto.

[0039] In the embodiment shown, the housing halves 21, 22 are movable relative to one another about a folding axis K. The folding axis K is parallel to the longitudinal axis of the housing 2 and thus also to the axial direction A of the hose section 303. The folding axis K is arranged laterally, orthogonal to the longitudinal axis of the housing 2, between the two housing halves 21, 22 and has a design not shown in detail. For example, the folding axis K can be formed by a hinge or joint arranged between the housing halves 21, 22. If a joint is present, it is preferably designed as a solid-state joint. The housing halves 21, 22 can be folded open about the folding axis K into the open state and, starting from this, folded closed into the closed state.

[0040] In the embodiment shown, the housing halves 21, 22 are securely mounted on one another even in the open state, namely by means of the folding axis K. In embodiments not shown in the figures, the housing halves 21, 22 are completely detached from one another in the open state and are only connected to one another in the closed state.

[0041] In the embodiment shown, the housing 2 has a receiving groove 27. The receiving groove 27 is formed between the first housing half 21 and the second housing half 22 and is designed to receive the said hose section 303. When inserted into the receiving groove 27, the hose section 303 is held in the receiving groove 27 with a radial positive fit and an axial friction fit. For this purpose, the receiving groove 27 is dimensionally matched, in particular with regard to its diameter, to the hose section 303 to be received. A diameter of the receiving groove 27 (not specified in more detail) is therefore slightly smaller than an outer diameter of the hose line 300, which in particular creates the axial frictional connection. This prevents the housing 2 from moving unintentionally along the hose line 300.In the embodiment shown, the receiving groove 27 is dimensioned such that the aforementioned axial frictional engagement is also present in the open state of the housing 2. This allows the housing 2 to be secured against unintentional slipping when attached to the hose line 300, even before the housing halves 21, 22 are folded together.

[0042] In the present case, the receiving groove 27 extends continuously over the entire length of the housing 2 and has a first groove end 271 and an axially opposite second groove end 272. The first groove end 271 is arranged at the first end 23 of the housing 2. The second groove end 272 is arranged at the second end 24 of the housing 2. The receiving groove 27 extends continuously between the two groove ends 271, 272. In an embodiment not shown in the figures, the receiving groove is interrupted between its groove ends, for example by radial recesses or the like. In the present case, the receiving groove 27 is parallel to the folding axis K. The pressing element 51 is arranged in the present case on the first housing half 21 and is adjustable relative to the second housing half 22 (by means of the actuator device 5) in order to apply the pressing force P. Within the scope of the invention, different mobility of the pressing element 51 is conceivable and possible.For example, the housing halves 21, 22 can be releasably and immovably fastened to one another in the closed state. In this case, the pressing element is displaced relative to both housing halves to apply the pressing force. In the present case, however, the pressing element 51 is firmly connected to the housing half 21. In other words, the pressing element 51 is arranged immovably relative to the first housing half 21. Consequently, to apply the pressing force P, not only the pressing element 51 is displaced on its own. Instead, a relative movement of the housing halves 21, 22 occurs. This relative movement occurs in the closed state of the housing 2 and is effected by the actuator device 5.

[0043] In the closed state, the pressing element 51 rests radially against the hose section 303. This is shown schematically in FIGS. 5 and 6. FIGS. 5 and 6 show an exemplary situation in which the pressing force P causes no deformation of the hose section 303, or at least no deformation that is practically significant. To increase the pressing force P, the housing halves 21, 22 are moved further towards one another about the folding axis K in the closed state. In other words, the housing halves 21, 22 are folded together “more closely”. As a result, the pressing element 51 is pressed radially against the hose section 303, whereby the pressing force P is increased.

[0044] In the embodiment shown, the housing 2 also has a locking device 28. The locking device 28 is designed to releasably lock the housing halves 21, 22 in the closed state. For this purpose, the locking device 28 has a first locking element 281 and a second locking element 282. The first locking element 281 is arranged on the first housing half 21. The second locking element 282 is arranged on the second housing half 22 and is complementary to the first locking element 281. In the closed state, the first locking element 281 and the second locking element 282 can be releasably locked to one another. The locking prevents the housing halves 21, 22 from accidentally opening into the open state.

[0045] In the present case, the actuator device 5 acts on the locking elements 28. In particular, the actuator device 5 acts on the second locking element 282. The actuator device 5 allows a relative movement of the second locking element 282 with respect to the second housing half 22. For this purpose, the second locking element 282 is mounted on the second housing half 22 in a manner not shown in detail along a movement axis B relative to the latter (see Fig. 2). The actuator device 5 is configured to move the second locking element 282 along the movement axis B. The first locking element 281 is immovable relative to the first housing half—at least in the closed state and with respect to the movement axis B.A movement of the second locking element 282 along the movement axis B, driven by the actuator device 5, consequently causes the first locking element 281, and thus the entire first housing half 21, to be displaced relative to the second housing half 22. In this case, the displacement takes place about the folding axis K, wherein the movement axis B is oriented orthogonally to the latter at a radial distance not specified in more detail. The force applied by the pressing element 51 to the hose section 303 is closer to the folding axis K than the movement axis B and thus the force applied between the locking elements 281, 282. This results in an advantageous leverage effect, by means of which the force of the actuator device 5 acting on the second locking element 282 is translated into a pressing force P that is greater in relation to the distances.

[0046] In the embodiment shown, the first locking element 281 is designed as a pin 284. The second locking element 282 has a pin receptacle 285 for receiving the pin 284. In the locked state, the pin 284 is held radially in the pin receptacle 285 with a positive fit. Furthermore, an actuating element 283 is present, which is connected to the first locking element 281 and can be manually actuated to unlock the locking device 28.

[0047] For displacing the pressing element 51, i.e. in this case the relative displacement of the housing halves 21, 22, the actuator device 5 in the embodiment shown has a piezoelectric actuator 52. This is indicated schematically in Fig. 5. In the embodiment shown, the piezoelectric actuator 5 acts at least indirectly to transmit force and / or movement to the second locking element 282. The piezoelectric actuator 52 operates according to a fundamentally known physical principle. When an electrical voltage is applied, the piezoelectric actuator 52 expands. When the voltage is removed, the piezoelectric actuator 52 returns to its original state. This fundamentally known principle allows the generation of an actuating movement and thus also an actuating force.The movement and / or force of the piezoelectric actuator 52 can act directly on the second locking element 282 or via a transmission device configured for this purpose, for example, a lever transmission or the like. In the embodiment shown, the flow rate F is determined based on an acoustic measuring principle. For this purpose, the sensor device 3 in this case has two acoustic sensors 31, 32, which can also be referred to as the first acoustic sensor 31 and the second acoustic sensor 32. Such a design is optional. In embodiments not shown in the figures, the sensor device has only one acoustic sensor.

[0048] The two acoustic sensors 31, 32 are configured to detect pressure waves and / or structure-borne sound and thus allow acoustic "drop counting." This is based on the assumption that drops of the medical fluid to be administered entering the drip chamber 203 generate pressure waves in the fluid column located in the tubing 300 and / or structure-borne sound in the tubing 300 itself. These pressure waves or structure-borne sound can be detected by the acoustic sensors 31, 32 and allow a conclusion to be drawn about the number of drops per unit of time and thus the flow rate F.

[0049] As shown schematically in Fig. 6, the two acoustic sensors 31, 32 are spaced apart from one another in the axial direction A of the hose section 303. When the housing 2 is closed, both acoustic sensors 31, 32 rest against an unspecified outer circumference of the hose section 303. The first acoustic sensor 31 detects a first sensor signal S1, and the second acoustic sensor 32 detects a second sensor signal S2. Fig. 6 also shows exemplary pressure waves W1, W2 that propagate in the hose line 300 and can alternatively be understood as structure-borne sound. The pressure waves W1, W2 can also be referred to as first pressure waves W1 and second pressure waves W2. The first pressure waves W1 propagate along a first propagation direction d1 with a first propagation velocity v-.The second pressure waves W2 propagate along an opposite second propagation direction d2 at a second propagation velocity v2. Both propagation directions d^ d2 are parallel to the axial direction A of the tube section 303. The first propagation direction d! runs from the first end 301 and thus also the drip chamber 203 toward the second end 302 of the tube line 300. The second propagation direction d2 runs opposite to this and consequently starts from the second end 302 and thus also the patient.

[0050] By appropriately evaluating the first sensor signals S1 and the second sensor signals S2, conclusions can be drawn about the propagation direction and the propagation speed of the measured pressure waves. For example, the first pressure waves W1 are initially detected by the first acoustic sensor 31 and, with a time offset, by the second acoustic sensor 32. A measured time offset allows the propagation direction and the propagation speed to be determined. Pressure waves that originate from the drip chamber 203, i.e., in the first propagation direction d-, , represent a drop and thus indirectly the flow rate F. If, on the other hand, an opposite propagation direction is registered, this could be patient noise or other background noise, for example.By appropriately evaluating signals S1, S2 using the control device 4, erroneous measurements and thus an incorrect flow rate setting can be prevented. Furthermore, by determining the propagation velocity, the density of the propagation medium can be indirectly determined. This allows, in particular, a conclusion to be drawn as to whether the tubing section 303 is filled with air. Furthermore, by determining the density, it can be determined whether or not the medical fluid actually intended for administration is present.

[0051] In the embodiment shown, the two acoustic sensors 31, 32 are integrated into the pressing element 51. This is shown schematically in FIGS. 5 and 6. Further details can be seen in FIG. 2. The pressing element 51 in this case has a cuboid basic shape and protrudes in the direction of the second housing half 22 from an unspecified inner side of the first housing half 21. The two acoustic sensors 31, 32 are arranged on an inner side of the pressing element 51 facing the second housing half 22. The integration of the acoustic sensors 31, 32 into the pressing element 51 ensures that the acoustic sensors 31, 32 are always positioned on the hose section 303 in accordance with requirements.

[0052] In the embodiment shown, the device additionally has an input device 61 and a display device 62. The input device is configured to input at least the target flow rate F'. The display device 62 is configured to display the entered target flow rate F' and / or the measured flow rate F. The display can be graphical and / or text-based. In the present case, the input device 61 and the display device 62 are designed in the form of a touchscreen 6. This can also be referred to as a touchscreen and is flush-mounted in the front side 25 of the housing 2. In the present case, the touchscreen 6 essentially occupies the entire front side 25. In the situation shown in Figs. 1 and 3, the touchscreen 6 displays a target flow rate F' of 50 ml / h. Furthermore, key symbols are graphically displayed on the touchscreen 6.These key symbols (without reference numerals) allow the target flow rate F' to be increased or decreased. In the embodiment shown, a data transmission unit 41 is also present. The data transmission unit 41 is configured for wireless data transmission. For example, the measured flow rate F can be sent to an external receiver by means of the data transmission unit 41. The external receiver can be a database system of a medical facility, a smartphone, or the like. Alternatively or additionally, the target flow rate F' can be received by means of the data transmission unit 41. This allows the target flow rate F' to be specified externally, for example, from the aforementioned database system or the smartphone. In the present case, the data transmission unit 41 is assigned to the control device 4, although this is not necessarily the case. The data transmission unit 41 allows data transmission via WLAN.Alternatively, transmission can be done via Bluetooth or similar.

[0053] A power supply device 7 is provided to supply power to the device 1. The power supply device 7 is arranged in the housing 2 and has a rechargeable battery 71 and a power transmission device 72. The power transmission device 72 allows inductive recharging of the battery 71 and, in the embodiment shown, has an induction surface 73. The induction surface 73 is arranged on the rear side 26 of the housing 2. In the embodiment shown, the battery 71 supplies the entire device 1 with electrical operating power, in particular the sensor device 3, the control device 4, the actuator device 5, and the touchscreen 6. The power transmission device 72 allows simple inductive charging of the battery 71. For this purpose, the induction surface 73 is positioned on a suitable inductive bearing device.The inductive charging option also offers hygienic advantages, as the housing 2 remains easy to wipe clean in the absence of charging sockets or the like. Furthermore, complete encapsulation of the housing 2 is possible. In the embodiment shown, the device 1 has no components located outside / apart from the housing 2.

Claims

Patent claims 1. A device (1) for controlling a flow rate (F) of a medical fluid through a hose line (300) of a transfer system (100), comprising a sensor device (3) configured to detect at least one sensor signal (S1, S2) representing the flow rate (F) of the medical fluid through the hose line (300), a control device (4) configured to determine a control signal (S3) as a function of the detected sensor signal (S1, S2) and a predetermined target flow rate (F') of the medical fluid through the hose line (300), and an actuator device (5) configured to adjust the flow rate (F) as a function of the control signal (S3), wherein the actuator device (5) comprises a pressing element (51) configured to apply a radial pressing force (P) to the hose line (300) that can be varied as a function of the control signal (S3).whereby a diameter of the hose line (300) is variable to increase and / or decrease the flow rate (F), characterized in that a housing (2) is provided in which the sensor device (2), the control device (4), and the actuator device (5) are arranged, wherein the housing (2) has a first housing half (21) and a second housing half (22), which are displaceable relative to one another between an open state in which the housing halves (21, 22) are moved away from one another for inserting an axial hose section (303) of the hose line (300) between the housing halves (21, 22), and a closed state in which the housing halves (21, 22) are moved towards one another and secured to one another for clamping the hose section (303) between the housing halves (21, 22) and thus for attaching the housing (2) to the hose line (300),and wherein the pressing element (51) is arranged on the first housing half (21) and is movable relative to the second housing half (22) to apply the pressing force (P).

2. Device (1) according to claim 1, characterized in that the housing (2) has a folding axis (K) about which the first housing half (21) and the second housing half (22) can be folded relative to one another between the open state and the closed state.

3. Device (1) according to claim 1 or 2, characterized in that the housing (2) has a receiving groove (27) which is formed between the first housing half (21) and the second housing half (22) and is designed for radially positive-locking and axially frictionally locking receiving of the hose section (303).

4. Device (1) according to one of the preceding claims, characterized in that the pressing element (51) is arranged immovably relative to the first housing half (21) on the same, and in that the actuator device (5) is designed for a relative movement of the housing halves (21, 22) in order to change a distance between the housing halves (21, 22) and thus the pressing force (P) of the pressing element (51).

5. Device (1) according to claim 4, characterized in that the housing (2) has a locking device (28) with at least one first locking element (281) arranged on the first housing half (21) and at least one complementary second locking element (282) arranged on the second housing half (22), wherein the first locking element (281) and the second locking element (282) - in the closed state of the housing (2) - are releasably locked to one another, and wherein the actuator device (5) acts on at least one of the locking elements (281, 282) and is designed for the relative displacement of the respective locking element (281, 282) with respect to the respective housing half (21, 22).

6. Device (1) according to one of the preceding claims, characterized in that the actuator device comprises a piezoelectric actuator (52).

7. Device (1) according to one of the preceding claims, characterized in that the sensor device (3) has at least one sensor (31, 32) integrated into the pressing element (51).

8. Device (1) according to one of the preceding claims, characterized in that the sensor device has at least one acoustic sensor (31, 32) which is designed to detect pressure waves (W1, W2) and / or structure-borne sound (303).

9. Device (1) according to claim 8, characterized in that the sensor device (3) at least one first acoustic sensor (31) which - in a state of the hose section (303) inserted between the housing halves (21, 21) - is arranged at a first position of the hose section (303) and is configured to detect a first sensor signal (S1), and a second acoustic sensor (32) which is arranged at an axially spaced second position of the hose section (303) and is configured to detect a second sensor signal (S2), wherein the control device (4) is configured to determine the control signal (S3) as a function of the first sensor signal (S1), the second sensor signal (S2) and the predetermined target flow rate (F').

10. Device (1) according to claim 9, characterized in that the control device (4) is arranged to determine an axial propagation direction (d^ d2) of the pressure waves (W1, W2) and / or the structure-borne sound as a function of the first sensor signal (S1) and the second sensor signal (S2).

11. Device (1) according to claim 9 or 10, characterized in that the control device (4) is arranged to determine an axial propagation speed (v^ v2) of the pressure waves (W1, W2) and / or the structure-borne sound as a function of the first sensor signal (S1) and the second sensor signal (S2).

12. Device (1) according to one of the preceding claims, characterized in that an input device (61) is provided on the housing (2), which is designed at least for inputting the target flow rate (F'), and / or that a display device (62) is provided on the housing (2), which is designed at least for displaying the target flow rate (F') and / or the flow rate (F), in particular wherein the input device (61) and the display device (62) are designed in the form of a touchscreen (6) embedded in a flat side (25) of the housing (2).

13. Device (1) according to one of the preceding claims, characterized in that the control device (4) has a data transmission unit (41) which is designed for the wireless transmission of at least the flow rate (F) and / or the target flow rate (F').

14. Device (1) according to one of the preceding claims, characterized in that an energy supply device (7) is provided which has a rechargeable battery (71) arranged in the housing (2) and an inductive energy transmission device (72) for inductively recharging the battery (71), wherein the energy transmission device (72) has an induction surface (73) arranged on a further flat side (26) of the housing (2).

15. An infusion arrangement (1000) comprising a transfer system (100) configured for the gravity-driven transfer of a medical fluid from a fluid container to a patient, said infusion system comprising a drip chamber arrangement (200) and a tubing (300), said drip chamber arrangement (200) having an inlet (201) configured for fluid-conducting connection to the fluid container and an outlet (202), said tubing (300) being elongated between a first end (301) fluid-conductingly connected to the outlet (202) of the drip chamber arrangement (200), and a second end (302) configured for delivering the medical fluid to the patient, and a device (1) according to any one of claims 1 to 14, said housing (2) being detachably attached to said tubing (300) between said first end (301) and said second end (302).

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