BLOOD TESTING DEVICE

Description

[0001] The invention relates to a blood testing device for direct coupling to a blood flow device, in particular a flow device of an extracorporeal blood circuit, and for recording blood parameters of the blood flowing through the flow device.

[0002] The invention also relates to a flow device which is designed and intended to be inserted into an extracorporeal blood circuit in such a way that blood flows through the flow device along a flow direction and which is designed for direct coupling to a blood testing device according to the invention.

[0003] The invention also relates to a system comprising such a blood testing device and such a flow device.

[0004] Blood testing devices, in particular, are known from the state of the art.

[0005] Furthermore, WO 00 / 47248 A1 discloses a mobile heart-lung machine with essentially two modules which can be joined together to form a functional unit, namely a blood-carrying disposable module which includes sensors for blood testing, and a non-blood-carrying reusable module which includes a battery for power supply and a pump drive.

[0006] From DE 10 2013 014 097 A1 a disposable article for use in dialysis treatment is known, wherein the disposable article has at least one sensor for determining at least one measured value relating to dialysis.

[0007] Furthermore, WO 201 7 / 068 081 A1 discloses an intermediate element for a medical extracorporeal fluid line, which is designed to convey a fluid such as blood. The intermediate element has a base body that extends between two connecting parts and is hydraulically connectable to the fluid line. The base body has a receptacle designed to accommodate a sensor. A perforation is arranged in the base body at the receptacle, which is fluid-tight towards the receptacle via an elastic element. The receptacle is also designed to accommodate a gas sensor of a sensor device for measuring at least one gas contained in the fluid. The elastic element is a diffusion element that is permeable to at least one gas. The diffusion element is bonded to an edge of the perforation in a connection area.

[0008] The object of the present invention is to provide an improved blood testing device.

[0009] The problem is solved by a blood testing device for recording blood parameters of blood in an extracorporeal blood circulation outside of a heart-lung machine, wherein the blood testing device has a receptacle for direct coupling to a blood flow device which can be connected to the extracorporeal blood circulation, wherein the blood testing device is wirelessly operable and is self-sufficient with regard to its power supply from other devices of a heart-lung machine, and wherein the blood testing device has a sensor and a display device for displaying blood parameters recorded by means of the sensor and transmitted to the display device.

[0010] It is also advantageous to specify a flow device that makes it possible to determine different blood parameters easily and quickly at the same time in different ways using a blood testing device that can be connected.

[0011] The problem is solved by a system comprising the flow device, which is designed and intended to be inserted into an extracorporeal blood circuit in such a way that blood flows through the flow device along a flow direction and which is designed for direct coupling to the blood testing device, wherein the flow device comprises at least one sensor coupling element and at least one flow device sensor, and comprising the present blood testing device.

[0012] The blood analysis device according to the invention is self-contained. A particular advantage of the blood analysis device according to the invention is that it can be deployed quickly and without requiring connection to a power supply network or other devices. The blood analysis device according to the invention operates wirelessly, thus achieving particularly good handling and preventing the obstruction of patient care staff by dangling cables or even the risk of cables being torn off by moving personnel. No connection to other devices for control, operation, power supply, or data display via a screen or alarms is required. Therefore, it can be used wherever the measurement of one or all of the specified parameters in a blood-carrying tube is to be determined.Possible applications include heart-lung machines, ECMO and ECLS (artificial lungs, heart, or cardiovascular support), organ perfusion and other organ replacement or support systems.

[0013] The device features a display for showing the desired measurement parameters and one or more control buttons for selecting or changing the display of measurement parameters and alarms. The device can also be activated only when needed via the control button to save energy.

[0014] Furthermore, the blood testing device, preferably a handheld unit, can be designed to be so compact that it can be easily transported and used by one person. The device will weigh less than 1 kg, in particular less than 0.5 kg, and have a housing smaller than 10 x 10 x 10 cm, in particular less than 10 x 6 x 6 cm. The device is designed in such a way that it requires no holder, but is simply attached to the blood-carrying tubing.

[0015] In an advantageous embodiment, the blood analysis device has a housing in or on which an electrical energy storage device and the display unit for showing the measured blood parameters are arranged. The internal power source can be charged, supported, or replaced via a cable, for example a USB cable, even during operation. This optional connection can also be used to transfer or read data. Charging via wireless power transfer is also possible.

[0016] The blood analysis device according to the invention has a device for wireless data transmission, for example via Bluetooth or an RF link, for external monitors. When a patient arrives in a clinical environment after transport, the blood analysis device can thus be directly integrated into the clinical monitoring system.

[0017] In a particular embodiment, the blood analysis device includes a sensor. Specifically, the sensor can be designed and configured to interact with a sensor coupling element of a flow device. The sensor coupling element can be, for example, a window or a membrane, which will be explained in more detail below. Ideally, an interactive connection is established between the sensor of the blood analysis device and a sensor coupling element of a flow device to measure blood values. To establish this interactive connection, the blood analysis device and the flow device are preferably fixed to one another, particularly by a positive locking mechanism.Furthermore, the fixing is preferably carried out in such a way that the measuring parameter sensor is directly adjacent to the measuring parameter sensor coupling element or comes into direct contact with it.

[0018] A particularly advantageous embodiment includes at least one light source for illuminating the blood flowing through a flow device. This allows a specific amount of light to be introduced into the blood by the sensor, and the detection light emitted from the blood as a result of this illumination (e.g., reflected light, scattered light, or fluorescent light) can be detected by a light sensor of the sensor and, if necessary, analyzed, particularly with regard to light intensity and / or wavelength.

[0019] Alternatively or additionally, it can be advantageously provided that the sensor has at least one sound source for imparting sound to the blood flowing through a flow device. This allows a specific amount of sound to be introduced into the blood by means of the sensor. A sound sensor can also be present that receives sound reflected or scattered by the blood. Such a sensor can, in particular, be an ultrasonic sensor that operates on the basis of ultrasound and functions as a flow meter.

[0020] A particularly advantageous embodiment is one in which the sensor incorporates both a light source and a sound source. This allows for the simultaneous measurement of blood parameters that can be determined using a sensor with either a light source or a sound source.

[0021] Easy handling is achieved in one embodiment in which the blood testing device according to the invention has a sensor interface designed and intended to communicate with a flow-through sensor integrated into a flow-through device. This makes it possible to use the blood testing device together with a flow-through device that includes an integrated sensor, enabling uncomplicated and quick connection, in particular without additional cable connections.

[0022] In particular, the sensor interface can advantageously be configured to transfer energy from an electrical energy storage device of the blood analyzer to a flow-through sensor integrated into a flow-through device and / or to forward measurement signals from a flow-through sensor integrated into a flow-through device. In this way, the flow-through sensor integrated into the flow-through device can be put into operation immediately by simply connecting the blood analyzer according to the invention, without the need for additional cable connections for energy or signal transmission.

[0023] The sensor can advantageously comprise a pressure sensor, a flow sensor, or an optical sensor. It is also possible, in particular, to have multiple sensors, especially of different types. This allows for various technical investigations, particularly in combination.

[0024] In an easy-to-use embodiment of the blood analysis device, a receptacle is provided in or on which a flow device can be attached, particularly without damage and / or without tools. The receptacle enables quick and efficient, and especially non-destructive, attachment and detachment of a flow device. Furthermore, the receptacle provides the user with an immediately identifiable attachment point, thereby reducing the risk of operator error due to incorrect coupling. In particular, this ensures that the blood analysis device and the flow direction can be coupled correctly and without damage.

[0025] The receptacle can advantageously be designed such that, upon insertion of a flow device, an operative connection is automatically established between the sensor and the sensor coupling element and / or between the sensor interface and the flow device sensor. This advantageously results in an efficient coupling of the flow device to the blood analyzer. Alternatively or additionally, the receptacle can be designed such that, upon insertion of a flow device, an operative connection is automatically established between the sensor interface and the flow device sensor, thereby also advantageously enabling the transmission of data from a sensor located on or within the flow device to the blood analyzer.

[0026] In a particular embodiment, the receptacle has at least one fastening element for securing a flow device. This ensures a particularly reliable mounting of the flow device to the blood analysis instrument. Alternatively, the flow device can have a fastening element that establishes the mechanical connection to the receptacle. In another embodiment, the receptacle has a fastening element that interacts with a counter-fastening element of the flow device, resulting in a particularly stable attachment.

[0027] In an advantageous embodiment, the blood testing device is designed to detect at least one blood parameter. For this purpose, the blood testing device has a signal and data processing unit that processes the signals received by the sensors, such as sound reflected by blood cells, determines the corresponding blood parameters from them, and forwards them to the display device for output.

[0028] In particular, the blood testing device is designed to measure at least one of the following blood parameters: blood oxygen saturation, blood CO2 content, blood temperature, blood pressure, blood flow rate, blood flow velocity, and hemoglobin concentration. This allows for the advantageous, and especially continuous, monitoring of many blood parameters relevant to the patient's vital functions.

[0029] The flow device is designed and intended to be inserted into an extracorporeal blood circuit such that blood flows through the flow device along a flow direction and is suitable for direct coupling to a blood analysis device according to the invention. The flow device comprises at least one sensor coupling element and at least one flow device sensor.

[0030] The flow device thus makes it particularly easy to connect a blood testing device mechanically and to establish a coupling for the transmission of energy and data, both from the flow device to the blood testing device and from the blood testing device to the flow device.

[0031] In a particular embodiment, the flow device sensor has a pressure sensor to detect the pressure of the blood in the extracorporeal blood circulation.

[0032] In another embodiment, the flow device sensor includes a flow sensor. This advantageously allows the blood flow rate through the extracorporeal blood circulation to be measured per unit of time.

[0033] In another embodiment, the flow device sensor incorporates an optical sensor. Such an embodiment has the advantage that, for example, the oxygen saturation, CO2, or hemoglobin content of the blood can be determined.

[0034] The flow device can advantageously also have several integrated measuring sensors, in particular several of the measuring sensors mentioned above.

[0035] Alternatively or additionally, the sensor coupling element can be configured for coupling to a flow-device sensor of the blood analyzer, wherein the flow-device sensor comprises a pressure sensor, a flow sensor, or an optical sensor. This advantageously allows various sensors of a blood analyzer to be coupled to the flow-device in different combinations.

[0036] In a particular embodiment, the flow device sensor can have at least one light source for illuminating the blood flowing through the flow device. This allows a specific amount of light to be introduced into the blood by the sensor, and the detection light emitted from the blood as a result of this illumination (e.g., reflected light, scattered light, or fluorescent light) can be detected by a light sensor of the sensor and, if necessary, analyzed, particularly with regard to light intensity and / or wavelength.

[0037] Alternatively or additionally, it can be advantageously provided that the flow device sensor has at least one sound source for imparting sound to the blood flowing through the flow device. This allows sound to be introduced into the blood by means of the sensor, in particular an adjustable level. A sound sensor can also be provided that receives sound reflected or scattered by the blood. Such a sensor can, in particular, be an ultrasonic sensor that operates on the basis of ultrasound and functions as a flow meter.

[0038] A particularly advantageous embodiment is one in which the sensor incorporates both a light source and a sound source. This allows for the simultaneous measurement of multiple, especially different, blood parameters.

[0039] In particular, it can be advantageous for the sensor coupling element to have a window. This window allows visual contact with the blood flowing through the flow device, for example, before the blood analyzer is coupled to the flow device. This allows, for instance, medical personnel to directly observe color changes in the blood that indicate a change in the hemoglobin content.

[0040] Furthermore, efficient coupling of an optical sensor is possible, since light emitted from a light source of the optical sensor and / or light received by a sensor of the optical sensor can propagate through the window.

[0041] Alternatively or additionally, the sensor coupling element of the flow device can have a flexible membrane. The flexible membrane allows for movement and contact with the blood flowing through the flow device.

[0042] The mechanical flexibility of the membrane enables, for example, quick and uncomplicated coupling of a pressure sensor of the blood analysis device according to the invention. By means of such a membrane, for example, an increase in blood pressure in a flow device or in an extracorporeal blood circuit, which causes the membrane to bulge outwards, can be transmitted directly to the pressure sensor.

[0043] In a particularly advantageous and especially compact embodiment, both the sensor coupling element and the flow device sensor (and possibly other such elements) are arranged tangentially around the longitudinal axis of the flow device and / or axially spaced relative to each other. In particular, they can be arranged in a common plane perpendicular to the flow direction. This allows the flow device to be advantageously short and thus compact in terms of its length. This enables the device to be used even in areas with hose bends and does not impede flexible hose routing. Typically, sensors are arranged longitudinally in the flow direction or at different positions.

[0044] In another embodiment, the flow device has push-fit connectors for fluidic connection to hoses or hose sections of an extracorporeal blood circuit. The hoses can be pushed onto the connectors, in particular in a non-slip and form-fitting manner. This ensures, in particular, that the interface between the hose and the flow device is fluid-tight, so that no blood escapes from the extracorporeal blood circuit.

[0045] In particular, the connectors can each have a disc. The discs can each function as a stop element for the hose to be attached. Alternatively or additionally, the discs can be arranged such that they mechanically guide the flow device and a blood analysis device relative to each other during a coupling process, whereby the blood analysis device, guided between the discs, can be attached to the intermediate part of the flow device, in particular in a form-fitting manner.

[0046] In a particularly advantageous embodiment, the flow device is made of a flexible material, especially a plastic. This reduces the risk of breakage or destruction of the flow device in the event of a mechanical impact, since its flexibility allows it to change shape to a certain extent without damaging its structure. In particular, the flow device can have a flexible transparent tube or be designed in the form of a flexible transparent tube together with its technical components, with the blood flowing through the tube. In addition to the aforementioned advantage of flexibility, the transparent tube advantageously allows for direct observation of the blood.The blood testing device can also advantageously be designed in such a way that it can enter into an effective connection with a simple, in particular transparent, piece of tubing as a flow device (without an integrated sensor) in order to record blood parameters.

[0047] The flow device according to the invention can alternatively be designed as a cuvette made of polycarbonate or MABS.

[0048] A system comprising the present flow device and the blood testing device according to the invention is particularly advantageous. This enables medical personnel to quickly and easily measure and / or monitor blood parameters in the extracorporeal blood circulation of a patient, especially one connected to a heart-lung machine.

[0049] The invention is shown in the drawing in an exemplary and schematic manner and is described below with reference to the figures, whereby identical or similarly functioning elements are usually provided with the same reference numerals even in different embodiments. The figures show: Fig. 1 shows a first embodiment of a system according to the invention, comprising a first embodiment of a blood testing device and a first embodiment of a flow device, in a top view; Fig. 2 shows an extracorporeal blood circuit with the system according to the invention; Fig. 3 shows a second embodiment of a system according to the invention, comprising a second embodiment of the blood testing device according to the invention and a second embodiment of the flow device, in a sectional view; Fig. 4 shows a third embodiment of a system according to the invention, comprising a third embodiment of the blood testing device according to the invention and a third embodiment of the flow device, in a sectional view; Fig. 5 shows a fourth embodiment of the flow device in a perspective view; and Fig.6. A fifth embodiment of the flow device in a sectional view.

[0050] The Figure 1 and 2 Figure 1 shows an embodiment of a system according to the invention, comprising a blood analysis device 1 and a flow device 2, in a top view. The blood analysis device 1 is coupled to a flow device 2 of an extracorporeal blood circuit 3. The blood analysis device 1 is designed to detect blood parameters of the blood flowing through the flow device 2.

[0051] The flow device 2 has two plug connectors 4 which are connected to tubes 5 of an extracorporeal blood circuit 3. The flow direction 25 is in the Figure 1 and 2 Indicated by arrows.

[0052] The blood testing device 1 has a housing 6 in which a (in the Figure 1 and 2(not shown) electrical energy storage device 7 and a display device for displaying 8 the detected blood parameters are arranged.

[0053] The system's blood analyzer 1 can be deployed quickly and without requiring a connection to a power supply or other devices. Blood analyzer 1 operates wirelessly, ensuring excellent handling and preventing dangling cables from obstructing patient care or even causing accidental damage. Furthermore, blood analyzer 1 is designed as a particularly compact handheld device.

[0054] Figure 2Figure 1 shows an extracorporeal blood circuit 3 with the flow device 2, to which the blood analysis device 1 is connected. The extracorporeal blood circuit 3 also includes a pump 9 for pumping blood and an oxygenator 10. The devices are connected by means of tubes 5, with the connection to the patient's blood circuit also being made by means of tubes 5.

[0055] Fig. 3Figure 1 shows a second embodiment of a system according to the invention, comprising a second embodiment of a blood testing device and a second embodiment of a flow device, in a sectional view. The blood testing device 1 is self-contained and can be operated without a cable connection to other components of a heart-lung machine or an external power source. The blood testing device 1 has an electrical energy storage device 7, which in the illustrated embodiment is a battery 11, and which supplies the other components of the blood testing device 1 with electrical energy.

[0056] The blood testing device 1 has a receptacle 12 in which the flow device 2 is secured. The receptacle 12 has a flap 16 rotatably mounted on the housing 6, which can be opened to insert the flow device 2 and closed again after the flow device 2 has been inserted, so that the flow device 2 is positively locked to the blood testing device 1. The upper part of the flap 16 is elastic and has a locking lug 26 at its end.

[0057] The flow device 2 can be attached to the receptacle 12 without damage or tools. The receptacle 12 enables quick and efficient connection and disconnection of the flow device 2. Furthermore, the receptacle 12 provides the user with an immediately identifiable attachment point, thus reducing the risk of operator error due to incorrect coupling. In particular, this ensures that the blood analyzer 1 and the flow device 2 are correctly and securely connected.

[0058] The flow device 2 has a sensor coupling element 17, and the blood analysis device 1 has a sensor 18. The sensor 18 is an optical sensor 19. The sensor coupling element 17 is formed by the transparent wall of the flow device 2, through which light can pass to detect an optical measurement signal.

[0059] When the flow device 2 is inserted, a functional connection is automatically established between the sensor 18 of the blood analyzer 1 and the sensor coupling element 17 of the flow device 2, and a functional connection is automatically established between the sensor interface 23 and the flow device sensor 13 of the flow device 2. This advantageously results in an efficient coupling of the flow device 2 to the blood analyzer 1. Data can also be advantageously transmitted from the sensor 13 to the blood analyzer 1 via the sensor interface 23.

[0060] The flow device 2 has a flow device measuring parameter 13, which is located in the Figure 3In the illustrated embodiment, a pressure sensor 14 is used. The pressure sensor 14 is connected to the interior 15 of the flow device 2, through which the blood flows, by means of a sensor coupling element 17, so that the pressure of the blood occurring in the interior is transmitted to the pressure sensor 14. The sensor coupling element 17 has a diaphragm by means of which the pressure of the blood is transmitted to the pressure sensor 14.

[0061] The measuring parameter coupling element 17 can alternatively be formed, for example, by a pressure piston that acts on the pressure measuring parameter 14.

[0062] The blood testing device 1 also includes an electronic device 20, such as a programmable logic controller (PCL), and a display device for displaying 8 the recorded blood parameters.

[0063] Furthermore, the blood testing device 1 has a transmission and receiving device 21 for sending and receiving measurement signals, wherein the transmission and receiving device 21 in this embodiment is designed for wireless transmission.

[0064] Figure 4 Figure 1 shows a third embodiment of a blood testing device 1 according to the invention in a sectional view. The blood testing device 1 has an optical sensor 19 as a measuring parameter 18, which is arranged opposite the pressure sensor 14 of the flow device 2.

[0065] The battery 11 of the blood analyzer 1 supplies electrical energy to both the optical sensor 19 of the blood analyzer 1 and the pressure sensor 14 of the flow device 2. The battery 11 is connected to the sensor 19 by means of a cable and to the pressure sensor 14 by means of the sensor interface 23 shown schematically.

[0066] Figure 5 Figure 1 shows a fourth embodiment of a flow device 2 according to the invention in a perspective view.

[0067] The flow device 2 has two push-in connectors 4 for fluidic connection to tubing 5 (not shown in this figure) of an extracorporeal blood circuit 3 (not shown in this figure). Each push-in connector 4 has a disc 22. The discs 22 act as a stop for the tubing 5 to be connected. The discs 22 simultaneously perform a dual function, namely guiding a blood analysis device 1 to be connected to the flow device 2 as soon as it is connected to the flow device 2. Furthermore, the discs 22 are arranged such that they ensure a positive-locking connection of the blood analysis device 1.

[0068] The discs are arranged in such a way that they guide a blood testing device 1 to be attached to the flow device 2, the blood testing device 1 being guided between the discs 5 and positively fitted onto the intermediate part of the flow device 2.

[0069] The flow device 2 also includes a pressure sensor 14 and a sensor coupling element 17 for automatically coupling a sensor 18 (not shown in this figure) of a blood testing device 1. The sensor coupling element 17 and the pressure sensor 14 are arranged in a common plane (shown schematically as dashed lines) perpendicular to the flow direction 25. This makes the flow device 2 short and therefore compact in terms of its length.

[0070] Fig. 6A fifth embodiment of a flow device 2 according to the invention is shown in a sectional view.

[0071] The flow device 2 is fixed to a blood testing device 1 according to the invention, wherein, for the sake of simplicity, only the measuring sensors 18 of the blood testing device 1 are shown. The blood testing device 1 has a measuring sensor 18, which, as an ultrasonic measuring sensor 24, records the blood flow per unit time. The ultrasonic measuring sensor 24 has an ultrasonic transmitter and a reflector for reflecting the ultrasonic waves. Furthermore, the blood testing device 1 (not fully shown) has an optical measuring sensor 19 for determining the oxygen content and / or CO2 content in the blood.

[0072] Because several different types of measuring sensors are available, various technical investigation options, including combinations, can be implemented. Reference symbol list:

[0073] 1 Blood analyzer 2 Flow device 3 Blood circulation 4 Plug connector 5 Hose 6 Housing 7 Energy storage 8 Display device 9 Pump 10 Oxygenator 11 Battery 12 Mount 13 Flow device sensor 14 Pressure sensor 15 Interior 16 Flap 17 Sensor coupling element 18 Sensor 19 Optical sensor 20 Programmable logic controller 21 Transducer 22 Disc 23 Sensor interface 24 Ultrasonic sensor 25 Flow direction 26 Detent

Claims

1. Blood testing device (1) for detecting blood parameters of blood in an extracorporeal blood circuit (3) outside a heart-lung machine, wherein the blood testing device (1) has a holder (12) for direct coupling to a throughflow apparatus (2), which can be connected to the extracorporeal blood circuit (3), characterised in that the blood testing device (1) is designed to be autonomous and can be operated without a cable connection to other devices of a heart-lung machine, wherein the blood testing device (1) has a transducer (18) and a display apparatus (8) for displaying blood parameters detected by means of the transducer (18) and forwarded to the display apparatus (8).

2. Blood testing device (1) according to claim 1, characterised in that the blood testing device (1) has a housing (6) in or on which the display apparatus (8) is arranged for displaying the detected blood parameters.

3. Blood testing device (1) according to claim 1 or 2, characterised in that the transducer (18) a. has at least one light source for applying light to the throughflow apparatus (2) and / or b. has a sound source for applying sound to the throughflow apparatus (2) and / or c. has a pressure transducer and / or d. has a flow rate transducer and / or e. has an optical transducer (19).

4. Blood testing device (1) according to one of claims 1 to 3, characterised by at least one transducer interface (23).

5. Blood testing device (1) according to claim 4, characterised in that the transducer interface (23) is designed to a. transfer energy from the electrical energy store (7) to a throughflow apparatus transducer (13) integrated into a throughflow apparatus (2) and / or b. forward measurement signals from a throughflow apparatus transducer (13) integrated into a throughflow apparatus (2).

6. Blood testing device (1) according to claim 4 or 5, characterised in that the transducer interface (23) is designed for coupling to a throughflow apparatus transducer (13) which has a pressure transducer (14) or a flow rate transducer or an optical transducer (19).

7. Blood testing device (1) according to one of claims 1 to 6, characterised by a receptacle (12), in or on which a throughflow apparatus (2) can be fixed.

8. Blood testing device (1) according to one of claims 1 to 7, characterised in that the blood testing device (1) is designed to detect at least one of the following blood parameters: a. Oxygen saturation of the blood, b. CO2 content of the blood, c. Temperature of the blood, d. Pressure of the blood, e. Flow quantity of the blood per unit of time, f. Flow speed of the blood, g. Haemoglobin level in the blood.

9. System having a throughflow apparatus (2), which is designed and intended to be inserted into an extracorporeal blood circuit (3) in such a way that blood flows through the throughflow apparatus (2) along a flow direction (25) and which is designed for direct coupling to a blood testing device (1), wherein the throughflow apparatus (2) comprises at least one transducer coupling element (17) and at least one throughflow apparatus transducer (13), and having a blood testing device (1) according to one of the preceding claims.

10. System according to claim 9, characterised in that a. the throughflow apparatus transducer (13) has a pressure transducer (14) or a flow rate transducer or an optical transducer and / or b. the throughflow apparatus transducer (13) has at least one light source and / or one sound source for applying light and / or sound to the throughflow apparatus (2) and / or c. the transducer coupling element (17) is designed for coupling to a transducer (18) of a blood testing device (1) which has a pressure transducer (14) or a flow rate transducer or an optical transducer and / or d. the transducer coupling element (17 has a window or a flexible membrane.

11. System according to claim 9 or 10, characterised in that both the transducer coupling element (17) and the throughflow apparatus transducer (13) are arranged tangentially around the longitudinal axis of the throughflow apparatus (2) and / or at an axial distance relative to one another.