INFUSION ORDER FOR THE ADMINISTERATION OF A MEDICAL FLUID

Description

[0001] The invention relates to an infusion arrangement for administering a medical fluid, comprising a medical pump device with an elastomeric membrane that forms a pump volume for receiving and conveying the medical fluid, wherein the elastomeric membrane is elastically stretched in a filling state of the pump volume that is at least partially filled with the medical fluid and thus causes a delivery pressure on the pump volume, and comprising an infusion line operatively connected at one end to the pump volume, which is provided at the other end for a fluid-conducting connection to a patient access point and forms a main fluid channel for conveying the medical fluid from the pump volume to the patient access point, and comprising a mechanical control device operatively connected to the infusion line, which is configured for functional control of the pump device.

[0002] Such an infusion arrangement is known from WO 2015 / 110387 A1 and is intended for administering a medical fluid as part of infusion therapy. The known infusion arrangement comprises a medical pump device in the form of a medical elastomer pump with a balloon-like, elastically expandable membrane for receiving and pumping the medical fluid. The known infusion arrangement also includes an infusion line operatively connected to a pump volume of the membrane. The infusion line forms a main fluid channel for transferring the medical fluid from the pump volume to a patient access point. For functional monitoring of the pump device, the known infusion arrangement includes a mechanical control device. The control device has a measuring reservoir connected to the main fluid channel via a channel branch.For functional testing, the main fluid channel downstream of the channel branch is manually clamped using a clamp. If the pump is functioning correctly, this causes a pressure increase in the main fluid channel, resulting in a pressure-driven flow of medical fluid into the measuring reservoir. If the pump malfunctions or the main fluid channel is blocked upstream of the channel branch, no medical fluid enters the measuring reservoir. Depending on whether or not medical fluid flows into the measuring reservoir, a user can thus determine the functionality of the pump. With the known infusion setup, this functional test therefore always requires a temporary interruption of fluid administration. Furthermore, the functional test only provides purely qualitative information, namely whether or not the pump is dispensing fluid.

[0003] The object of the invention is to create an infusion arrangement of the type mentioned above which enables improved functional control of the pump device, in particular avoiding an interruption of the fluid administration and enabling quantitative information regarding the pumping function of the pump device.

[0004] This problem is solved by the control device having a differential pressure measuring element operatively connected to the main fluid channel and being designed such that a differential pressure formed along a channel section of the main fluid channel can be detected by means of the differential pressure measuring element, and a flow rate of the medical fluid along the main fluid channel can be displayed as a function of the differential pressure. The solution according to the invention enables differential pressure-dependent functional monitoring during the continuous operation of the pump device and thus uninterrupted, continuous fluid administration. This eliminates the need for temporary interruption of the main fluid channel and therefore of temporary interruption of the infusion therapy. The differential pressure measuring element serves to detect the differential pressure formed along the channel section.Such a differential pressure can arise due to unavoidable friction-related flow losses and / or due to a fluid throttling element located in the channel section. If the pump malfunctions or the channel section is blocked, however, no medical fluid flows through the channel section and consequently no such differential pressure develops. The control device is designed so that the flow rate of the medical fluid along the main fluid channel can be displayed as a function of the differential pressure determined by the differential pressure measuring element. The flow rate can also be referred to as volumetric flow rate, mass flow rate, or throughput rate. This allows the control device to provide qualitative information regarding the pumping function.As a result, in addition to basic pump function control, the user of the infusion set can also control the flow rate of the medical fluid. This prevents under- and / or overdosing of the medical fluid, ultimately leading to improved infusion therapy and increased patient safety. The mechanical control device is preferably designed to eliminate the need for an external power supply. The medical pump is preferably in the form of a medical elastomer pump, a type commonly known in medical technology and also referred to as an elastomeric infusion pump. The elastomeric membrane forms the pump volume, creating a kind of cavity. Therefore, the elastomeric membrane can also be described as an elastomeric hollow membrane.

[0005] According to the invention, the control device has a bypass channel which is operatively connected to the main fluid channel at one end via a first channel branch and at the other end via a second channel branch, each transmitting fluid pressure. The differential pressure measuring element is arranged in the bypass channel. The bypass channel is preferably designed in the form of a hose. The channel branches can be integrally integrated into the infusion line or subsequently attached to it. The channel section preferably extends between the first and second channel branches. In simplified terms, the bypass channel serves to measure the differential pressure between the first and second channel branches. Preferably, the bypass channel serves exclusively to measure the differential pressure. The flow of the medical fluid along the bypass channel is preferably not provided.

[0006] According to the invention, the differential pressure measuring element comprises at least one mechanical measuring element that can be deflected by means of a differential pressure by means of a spring-like action. The mechanical measuring element is operatively connected to the main fluid channel in a fluid pressure-transmitting manner. If a bypass channel is provided, the mechanical measuring element is preferably operatively connected to the bypass channel in a fluid pressure-transmitting manner. The mechanical measuring element can, for example, be designed in the form of a hydraulically deflectable, spring-loaded piston, a diaphragm, or the like.

[0007] According to the invention, the mechanical measuring element comprises at least one spring-elastic diaphragm. This is a particularly robust and reliable embodiment of the invention.

[0008] According to the invention, the control device comprises a pointer element operatively connected to the differential pressure measuring element, which is configured to display the delivery rate as a function of the differential pressure. The pointer element can be operatively connected to the differential pressure measuring element by means of a mechanical linkage. In this way, a differential pressure-induced deflection of the differential pressure measuring element, in particular the spring-elastic deflection of the mechanical measuring element of the differential pressure measuring element, can be translated into a pointer movement of the pointer element. Preferably, a scale for reading the delivery rate is associated with the pointer element.

[0009] According to the invention, the control device comprises at least one fluid-filled fluid chamber, wherein the pointer element is arranged to float freely within the fluid chamber. The fluid chamber is preferably hydraulically connected to the main fluid channel. If a bypass channel is provided, the fluid chamber is preferably hydraulically connected to the bypass channel. The fluid chamber is preferably at least partially transparent, so that a user can observe the differential pressure-induced floating movement of the pointer element within the fluid chamber.

[0010] In a further embodiment of the invention, the indicator element is designed in the form of a float or a colored oil droplet. The coloring of the oil droplet serves to improve the visual perception of its respective floating position within the fluid chamber. This allows for improved readability of the control device.

[0011] In a further embodiment of the invention, the control device comprises a first fluid throttling element arranged between the first and second channel branches in the main fluid channel. The fluid throttling element is thus preferably located within the channel section. The fluid throttling element serves to influence the differential pressure. Compared to an unthrottled configuration, in which the differential pressure is generated within the channel section due to unavoidable flow losses, the fluid throttling element results in a comparatively higher differential pressure. This allows, in particular, a less sensitive design of the differential pressure measuring element. The fluid throttling element can be designed as a constriction of the channel section or as a separate fluidic component and inserted into the channel section.

[0012] In a further embodiment of the invention, a second fluid throttling element is arranged in the main fluid channel downstream of the second channel branch. This second fluid throttling element serves, in particular, to reduce the pressure of the medical fluid to be administered, so that it can be delivered from the infusion line into the patient access at a predetermined output pressure. "Downstream" here means that the second fluid throttling element is located downstream of the second channel branch, relative to the intended flow direction of the pump device. The second fluid throttling element can be designed as a constriction of the main fluid channel or arranged as a separate fluid-technical component within the main fluid channel.

[0013] In a further embodiment of the invention, the first fluid throttling element has a throttling effect that is preferably 1.5 to 15 times lower than that of the second fluid throttling element. Accordingly, the first fluid throttling element has a reduced, preferably significantly reduced, throttling effect compared to the second fluid throttling element. It has been shown that this embodiment of the invention enables particularly advantageous determination of the flow rate. In particular, it allows for the linearization of the flow rate determination with respect to pressure fluctuations in the medical pump device.

[0014] Further advantages and features of the invention will become apparent from the claims and from the following description of a preferred embodiment of the invention, which is illustrated with reference to the drawings. Fig. 1 shows a schematic, partially cutaway representation of an embodiment of an infusion arrangement according to the invention, and Fig. 2 shows the infusion arrangement according to Fig. 1 in a highly simplified schematic representation.

[0015] An infusion order A according to the Fig. 1 and 2 is intended for the administration of a medical fluid 4 as part of outpatient and / or inpatient infusion therapy. The infusion set A includes a medical pump device 1, which can also be referred to as an elastomeric infusion pump or medical elastomer pump. The medical pump device 1 has an elastomeric membrane 2 that forms a pumping volume 3 for receiving and delivering the medical fluid 4. Based on Fig. 1 The medical pump device 1 is shown in a state at least partially filled with the medical fluid 4. In this state, the elastomeric membrane 2 is stretched in a soft, balloon-like elastic manner as a result of the action of the medical fluid 4. The membrane 2 is shown based on Fig. 1 For graphical reasons, the wall thickness is shown exaggerated. In contrast, when not filled with medical fluid 4, the membrane 2 is slack or at least less elastically stretched. A resealable filling nozzle 5 is provided for filling the pump volume 3 or the membrane 2 with medical fluid 4. This nozzle is connected to the membrane 2 in a fluid-tight manner in a generally known way.

[0016] The elastically stretched membrane 2 exerts a delivery pressure p on the pump volume 3. By means of this delivery pressure p, the medical fluid 4 can be pumped from the pump volume 3 into an infusion line 8, which is fluid-conducting and connected to the pump volume 3 at one end, via an outlet nozzle 6 that is fluid-tight to the membrane 2. For this purpose, the infusion line 8 is permanently connected at one end, facing the pump volume 3, to the outlet nozzle 6. At its opposite end, the infusion line 8 has a connection 9, which in this case is a Luer connector. In an embodiment not shown, the connection is an NRFit connector. The Luer connector 9 is provided for connection to a patient access port 7. The patient access port 7 is connected by means of Fig. 1 The diagram is shown only in a highly simplified schematic and partially truncated form. In this way, the infusion line 8 forms a main fluid channel 11 for transferring the medical fluid 4 from the pump volume 3 to the patient access point 7. The main fluid channel 11 is shown based on Fig. 1 schematically represented by dashed lines.

[0017] The pump device 1 is designed to be easily worn by a patient and used without an external power supply in outpatient therapy. Accordingly, the pump device 1 is lightweight and compact, with a nominal pump volume 3 of 400 ml. It is understood that the pump volume 3 can also be adjusted, for example, from 50 ml to 750 ml.

[0018] What next based on Fig. 1 As can be seen, the infusion set A has a mechanical control device 10 connected to the infusion line 8. The control device 10 is designed to monitor the function of the medical pump device 1 and is connected to the infusion line 8 for this purpose. Based on Fig. 1 The control device 10 is only shown schematically. Further design and functional features of the control device 10 are described below. Fig. 2 visible.

[0019] The control device 10 has a differential pressure measuring element 12 operatively connected to the main fluid channel 11 and is designed such that a differential pressure Δp formed along a channel section 13 of the main fluid channel 11 can be detected by means of the differential pressure measuring element 12 and a flow rate v of the medical fluid 4 along the main fluid channel 11 can be displayed as a function of the differential pressure Δp.

[0020] In this case, the mechanical control device 10 has a bypass channel 14 for this purpose. The bypass channel 14 is operatively connected to the main fluid channel 11 at one end by means of a first channel branch 15 and at the other end by means of a second channel branch 16, each transmitting fluid pressure. The differential pressure measuring element 12 is arranged in the bypass channel 14. The bypass channel is designed in the form of a hose 14, which has a first line section 17 and a second line section 18. The first line section 17 establishes a fluid pressure-transmitting operative connection between the first channel branch 15 and the differential pressure measuring element 12. The second line section establishes a fluid pressure-transmitting operative connection between the second channel branch 16 and the differential pressure measuring element 12. The channel section 13 extends between the first channel branch 15 and the second channel branch 16 on the fluid flow side.

[0021] When the medical fluid 4 is pumped by the medical pump device 1, a pressure gradient forms along the main fluid channel 11. This pressure gradient can be caused, at least in part, by the unavoidable flow resistance of the infusion line 8. Furthermore, the control device 10 includes a fluid throttling element 19 located between the first channel branch 15 and the second channel branch 16 in the main fluid channel 11. The fluid throttling element 19 contributes to and / or significantly influences the aforementioned pressure gradient. In this case, the fluid throttling element 19 is designed as a fluidic control element. In an embodiment not shown, the fluid throttling element can be integrally formed on the infusion line 8 as a constriction of the flow cross-section.

[0022] In simplified terms, the fluid pressure upstream and downstream of the fluid throttling element 19 is measured via the bypass channel 14. Upstream of the fluid throttling element 19, the delivery pressure p is present – ​​at least approximately. Downstream of the fluid throttling element, in the region of the second channel branch 16, a fluid pressure p1 is present. The differential pressure Δp is thus determined from the difference between the two aforementioned pressures p and p1.

[0023] The differential pressure measuring element 12 comprises at least one mechanical measuring element 20, 21, which can be deflected by means of a differential pressure by means of a spring-like elasticity. A first measuring element 20 and a second measuring element 21 are provided. The first measuring element 20 is arranged at the end face of the first line section 17. The second measuring element 21 is arranged at the end face of the second line section 18. The measuring elements 20, 21 are each operatively connected to the bypass channel 14 by means of fluid pressure transmission and are each designed in the form of a spring-like deflectable diaphragm 20, 21. Furthermore, the control device 10 has a fluid-filled fluid chamber 22. The two diaphragms 20, 21 are each hydraulically coupled to the fluid chamber 22. A pointer element 23 is arranged to float freely in the fluid chamber 22.The indicator element is designed in the form of a float 23 and is configured to indicate the flow rate v as a function of the differential pressure Δp. In an embodiment not shown, the indicator element can be designed in the form of a colored oil droplet. The fluid chamber 22 is hydraulically connected to the diaphragms 20, 21 such that the differential pressure Δp detected by the diaphragms 20, 21 can be transmitted to the fluid (not otherwise specified) located in the fluid chamber 22. A fluid-conducting connection from the first channel branch 15 via the bypass channel 14 to the second channel branch 16 is not established by the differential pressure measuring element 12 and, in particular, by the fluid chamber 22. The fluid chamber 22 is at least partially transparent. For this purpose, the fluid chamber 22 can, for example, be made of a transparent plastic.This allows a user of the infusion setup A to clearly see the differential pressure-induced movement of the float 23 within the fluid chamber 22 for functional testing of the pump device 1. A scale 25 is assigned to the fluid chamber 22 and / or the pointer element 23. The control device 10 is configured such that the float 23 is movable along the scale 25 depending on the differential pressure Δp transmitted to the fluid chamber 22 via the diaphragms 20, 21, with the position of the float 23 relative to the scale 25 being in a fixed ratio to the flow rate v.

[0024] In this arrangement, a second fluid throttling element 24 is arranged downstream of the second channel branch 16 in the main fluid channel 11. The throttling effect of the first fluid throttling element 19 is significantly less than that of the second fluid throttling element 24. Preferably, the throttling effect of the first fluid throttling element 19 is 1.5 to 15 times less than that of the second fluid throttling element 24. Downstream of the second fluid throttling element 24, a fluid pressure p2 is present in the main fluid channel 11. This pressure corresponds to the pressure at which the medical fluid 4 is delivered from the infusion line 8 into the patient access 7.

[0025] For the administration of the medical fluid 4, it enters the infusion line 8 at the delivery pressure p from the pump volume 3, which is pressurized by means of the elastically stretched membrane 2, and flows along the main fluid channel 11 into the patient access 7. In doing so, the medical fluid 4 first passes through the first channel branch 15 from the pump volume 3, enters the channel section 13, flows through the first fluid throttling element 19, passes through the second channel branch 16, and finally flows through the second fluid throttling element 24 and the Luer-lock connection 9.

[0026] When the medical pump device 1 is functioning correctly, the medical fluid 4 is pumped at the flow rate v, creating a pressure gradient along the main fluid channel 11, and specifically a differential pressure Δp between the channel branches 15 and 16. The differential pressure Δp is hydraulically transmitted to the fluid chamber 22 via the bypass channel 14 and the diaphragms 20 and 21.

[0027] The float 23 moves along the scale 25 depending on the differential pressure Δp. Due to the physical relationship between the differential pressure Δp and the flow rate v, the control device 10 not only allows a statement as to whether or not there is a flow, but also quantifies it in the form of the flow rate v that can be read on the scale 25.

[0028] If, on the other hand, the pump device 1 malfunctions and does not produce a delivery pressure p, consequently no delivery of the medical fluid 4 occurs along the infusion line 8. Instead, the medical fluid 4 remains stationary within the main fluid channel 11. Accordingly, the differential pressure Δp is zero. This is reflected in the position of the float 23 relative to the scale 25. A malfunction of the pump device 1 and / or an inadequate delivery rate is therefore easily recognizable by a user of the infusion set A.

Claims

1. Infusion arrangement (A) for administering a medical fluid (4), having a medical pump apparatus (1) with an elastomeric membrane (2) which forms a pump volume (3) for receiving and delivering the medical fluid (4), wherein the elastomeric membrane (2) is elastically extended in a fill state, filled at least partially with the medical fluid (4), of the pump volume (3) and thereby produces a delivery pressure (p) on the pump volume (3), and having an infusion line (8) which, at one end, is operatively connected to the pump volume (3) and which, at the other end, is provided with a patient access means (7) for fluid-conducting connection and which forms a main fluid channel (11) for transferring the medical fluid (4) from the pump volume (3) to the patient access means (7), and having a mechanical monitoring device (10) which is operatively connected to the infusion line (8) and which is configured for monitoring the functioning of the pump apparatus (1), characterized in that the monitoring device (10) has a differential pressure-measuring element (12) operatively connected to the main fluid channel (11) and is designed such that a differential pressure (Δp) formed along a channel portion (13) of the main fluid channel (11) is able to be detected by means of the differential pressure-measuring element (12) and, in a manner dependent on the differential pressure (Δp), a delivery rate (v) of the medical fluid (4) along the main fluid channel (11) is able to be indicated, wherein the monitoring device (10) has a bypass channel (14), in which the differential pressure-measuring element (12) is arranged, and which is operatively connected at one end by means of a first channel branch (15), and at the other end by means of a second channel branch (16), to the main fluid channel (11), in each case in fluid pressure-transmitting fashion, wherein the differential pressure-measuring element (12) has a first membrane (20) and a second membrane (21), which are each able to be deflected in resiliently elastic fashion by means of application of differential pressure, and wherein the monitoring device (10) has at least one fluid-filled fluid chamber (22), which is pressurized with the differential pressure by means of the elastic membranes (20, 21) and in which an indicator element (23) is arranged so as to be movable in a floating manner, the indicator element (23) being configured for indicating the delivery rate (v) in a manner dependent on the differential pressure (Δp).

2. Infusion arrangement (A) according to Claim 1, characterized in that the indicator element is in the form of a float (23) or of a dyed oil drop.

3. Infusion arrangement (A) according to one of Claims 1 or 2, characterized in that the monitoring device (10) has a first fluid-throttling element (19) arranged in the main fluid channel between the first channel branch (15) and the second channel branch (16).

4. Infusion arrangement (A) according to Claim 3, characterized in that a second fluid-throttling element (24) is arranged in the main fluid channel (11) downstream of the second channel branch (16).

5. Infusion arrangement (A) according to Claims 3 and 4, characterized in that the first fluid-throttling element (19) has a throttling action which is lower, preferably 1.5 to 15 times lower, in comparison with the second fluid-throttling element (24).