Monitoring system for use in extracorporeal blood treatment

Abstract

The invention relates to a monitoring system for use in extracorporeal blood treatment, comprising a holding device designed for placement in the area of ​​a patient's venous access, a sensor device attached to the holding device and designed to detect a change in the position of a venous needle within the venous access and to generate a sensor signal representing the detected change in the position of the venous needle, a detection device connected to the sensor device and designed to determine a display signal depending on the sensor signal, and a display device connected to the detection device and designed to output the display signal optically and / or acoustically.

Description

[0001] The invention relates to a monitoring system for use in extracorporeal blood treatment.

[0002] Extracorporeal blood treatments typically occur as part of renal replacement therapy, for example, in the form of hemodialysis, hemofiltration, or hemodiafiltration. During this type of treatment, blood is withdrawn from the patient, treated extracorporeally, and then reinserted. The blood is withdrawn using an arterial needle connected to an arterial vascular access. The treated blood is then administered via a venous needle connected to a venous vascular access. Inadvertent disconnection of the venous needle during treatment can lead to severe blood loss and thus endanger the patient.

[0003] Methods and systems for monitoring in this regard are therefore known from the state of the art.

[0004] For example, EP 2 913 072 A1 discloses a monitoring system for use in extracorporeal blood treatment, in which a venous needle disconnection is to be detected by evaluating prevailing fluid pressures.

[0005] The object of the invention is to provide a monitoring system that offers advantages over the prior art.

[0006] This object is achieved by providing a monitoring system having the features of claim 1. Advantageous embodiments are the subject of the subclaims.

[0007] The monitoring system according to the invention is intended for use in extracorporeal blood treatment and comprises: a holding device configured for attachment in the region of a patient's venous vascular access; a sensor device attached to the holding device and configured to detect a change in the position of a venous needle within the venous vascular access and to generate a sensor signal representing the detected change in the position of the venous needle; a detection device connected to the sensor device and configured to detect an indication signal depending on the sensor signal; a display device connected to the detection device and configured to optically and / or acoustically output the indication signal. The solution according to the invention allows for simple and reliable monitoring of the position of the venous needle.This allows early detection of an impending needle disconnection, thus improving patient safety. The holding device is used to secure the sensor device and, if applicable, other components of the monitoring system. The holding device is designed for attachment in the region of the venous vascular access and can be configured in different ways for this purpose. In a preferred embodiment, the holding device is a wristband. In a further embodiment, the holding device is a cuff. In a further embodiment, the holding device is designed in the manner of a plaster or a wrap. When the monitoring system is in use, the holding device rests on the patient's skin in the region of the venous vascular access. The sensor device is used to measure the change in position of the venous needle.The change in position relative to the sensor device and / or the holding device is detected. In principle, all suitable measuring principles can be used to detect the change in position, in particular inductive, capacitive, and / or magnetoresistive measuring principles. These measuring principles require inductive, capacitive, and / or magnetic properties of the venous needle used. Such properties are usually present or can be ensured through simple measures, for example, through the use of electrically conductive and / or magnetic or magnetizable materials. The sensor device is also configured to generate the sensor signal. The latter represents the change in position of the venous needle. The display signal is determined and output depending on the sensor signal and thus the change in position.The detection device connected to the sensor device is provided for determining the indication signal. The display device is provided for outputting the indication signal, wherein the output can be optical and / or acoustic. Based on the optical and / or acoustic display signal, medical personnel or the patient themselves can easily and reliably detect whether the venous needle is moving within the vascular access. This provides an early warning of an impending needle disconnection. In a preferred embodiment, the detection device and the display device are attached to the holding device. In a further embodiment, the detection device and the display device are provided separately from the holding device, in particular as components of a device for extracorporeal blood treatment.

[0008] In one embodiment of the invention, the holding device is a wristband. When the monitoring system is in use, the wristband rests on the patient's skin in the area of ​​the venous access. The venous needle is located beneath the wristband in the direction of the skin thickness. In this embodiment of the invention, the sensor device is attached to the wristband, preferably integrated into a cross-section of the wristband.

[0009] In a further embodiment of the invention, the sensor device comprises at least one inductive sensor, one capacitive sensor, and / or one magnetoresistive sensor, in particular a Hall effect sensor. The sensor device thus operates according to an inductive, capacitive, and / or magnetoresistive measuring principle.

[0010] In a further embodiment of the invention, the sensor device comprises a plurality of sensors that are mounted adjacent to one another along a longitudinal axis on the holding device, forming a sensor array. During use of the monitoring system, the holding device is preferably mounted such that the longitudinal axis is oriented as parallel as possible to a longitudinal extension of the venous needle. The sensor array offers an enlarged detection range, so that even larger position changes can be reliably detected.

[0011] In a further embodiment of the invention, the sensor device comprises several rows of sensors that are mounted adjacent to one another on the holding device along a transverse axis, forming a sensor grid. The transverse axis is oriented orthogonally to the said longitudinal axis. The sensor grid allows for the detection of two-dimensional position changes. This enables particularly precise monitoring.

[0012] In a further embodiment of the invention, the determination device comprises a memory unit and a processor unit, wherein at least one reference value is stored or storable in the memory unit, and wherein the processor unit is configured to compare the reference value with the sensor signal and to determine the display signal depending on the comparison. The comparison can, in particular, comprise an addition or subtraction of the reference value and the sensor signal. For example, in this embodiment of the invention, the display signal can be output when the sensor signal exceeds or falls below the reference value. The reference value forms a threshold or a threshold value above which the display signal is output.Preferably, several different reference values ​​are stored or can be stored in the memory unit, so that the display signal can be output differently according to type and / or extent as soon as the said different reference values ​​are exceeded or undershot.

[0013] In a further embodiment of the invention, an actuating unit is provided that is configured for manual actuation, wherein the determination device is configured to store the sensor signal as a reference value in the storage unit when the actuating unit is actuated. This embodiment of the invention allows for simple initialization and / or calibration of the monitoring system. After attaching the holding device and thus the sensor device, the currently detected sensor signal (actual sensor signal) can be stored as a reference value. During the further course of monitoring, the sensor signal is compared with the initially detected sensor signal stored as a reference value. The display signal is determined and output based on this comparison. The actuating device varies in different embodiments and can be designed, for example, as a depressible push button or as a touch-sensitive actuating surface.

[0014] In a further embodiment of the invention, the display device has at least one LED and / or a loudspeaker. The at least one LED serves to visually output the display signal. The loudspeaker serves to acoustically output the display signal. Changes in the display signal can be output, for example, by changing the brightness and / or light color of the at least one LED and / or the volume of the loudspeaker. In a preferred embodiment, several LEDs are present, whereby changes in the display signal—and thus the position of the venous needle—can be output by changing the number of illuminated LEDs.

[0015] In a further embodiment of the invention, the detection device is configured to transmit the sensor signal and / or the display signal to a higher-level information system. The higher-level information system can be, for example, a centralized or decentralized information system for personnel of a medical facility, an emergency call system for alerting a medical emergency or rescue service, or the like. The sensor signal and / or the display signal are preferably transmitted wirelessly, for example via radio, WLAN, or another signal transmission technology suitable for the purpose.

[0016] In a further embodiment of the invention, the detection device and the display device are attached to the holding device. In this embodiment, the monitoring system forms a stand-alone solution that does not necessarily require the exchange of signals and / or data with a device for extracorporeal blood treatment. If the holding device is a wristband according to the previously explained embodiment, the detection device and the display device are attached to the wristband.

[0017] The detection device is preferably integrated into a cross-section of the wristband. The display device is preferably arranged on an outer side of the wristband.

[0018] In a further embodiment of the invention, the determination device and / or the display device are components of a device for extracorporeal blood treatment. The monitoring system is therefore partially formed by components of said device. Preferably, the determination device is a central data processing device of the device. The display device is preferably a human-machine interface (HMI) of the device, which is preferably designed as a touch-sensitive screen. In one embodiment, the determination device is fastened to the holding device and the display device is a component of said device. In a further embodiment, the determination device is a component of said device and the display device is fastened to the holding device. In a further embodiment, the determination device and the display device are components of said device.

[0019] In a further embodiment of the invention, the venous needle is a component of the monitoring system. In particular, the venous needle has magnetic properties and / or electrically conductive properties. Magnetic properties are required, for example, when the sensor device is based on a magnetoresistive measuring principle. The magnetic properties of the needle can be achieved by magnetizing the needle or by attaching a magnetic section to the venous needle. Electrically conductive properties are required, for example, when the sensor device is based on an inductive and / or capacitive measuring principle. Venous needles for use in extracorporeal blood treatment are generally made of a metal material suitable for medical purposes. Such materials are usually electrically conductive.

[0020] The invention also relates to a device for extracorporeal blood treatment with a monitoring system according to the invention.

[0021] In a further embodiment of the invention, the device comprises a control device connected to the monitoring system, wherein the control device is configured to control, in particular deactivate, at least one function of the device as a function of the sensor signal. In this embodiment of the invention, different functions and thus functional units of the device can be controlled, in particular deactivated, as a function of the change in position of the venous needle. In one embodiment, the device comprises a blood pump for pumping the treated blood through the venous needle. The control device is configured to control, in particular deactivate, the blood pump as a function of the sensor signal—and thus the change in position.

[0022] 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. Fig. 1 shows a cut-off schematic front view of an embodiment of a device according to the invention for extracorporeal blood treatment, which is equipped with an embodiment of a monitoring system according to the invention, Fig. 2 an enlarged detailed view of the monitoring system according to Fig. 1 in a state of use in which the monitoring system is attached to a venous vascular access, Fig. 3 a variant of the Fig. 2 shown monitoring system, Fig. 4 a schematically simplified representation to illustrate further features of the variant according to Fig. 3, Fig. 5 a cut-off schematic plan view of the variant according to Fig. 3 to clarify further features and Fig. 6 in a Fig. 2 and Fig. 3 shows a further embodiment of a monitoring system according to the invention.

[0023] According to Fig. 1, a device 200 for extracorporeal blood treatment is provided and designed in the form of a dialysis machine for hemodialysis. The device 200 is in Fig. 1 is shown only partially and schematically simplified.

[0024] In Fig. 1 shows essentially an entire extracorporeal blood circuit (without reference numerals) of the device 200.

[0025] The extracorporeal blood circuit comprises an arterial blood tubing 201, by means of which blood to be treated is conveyed from a patient to a fluid pumping system 202 of the device 200. An arterial pressure sensor 203 is provided upstream of the fluid pumping system 202 in relation to the blood flow direction. The arterial pressure sensor 203 can be used to measure the pressure in the arterial blood tubing 201 upstream of the fluid pumping system 202. This fluid pressure can also be referred to as the low-pressure side pressure. Downstream of the fluid pumping system 202 in the blood flow direction—and thus on the high-pressure side—a high-pressure blood tubing 204 leads to an arterial air trap 205. A fluid supply line 206, which is connected to a pump 207, is arranged at an outlet of the fluid pumping system 202. An additive, for example heparin for blood thinning, can be added via the fluid supply line 206.From the arterial air trap 205, a blood tubing transfer line 208 carries the blood to be treated to a dialyzer 209, to which dialysis fluid is supplied at the inlet via a dialysis fluid supply line 210. In the dialyzer 209, the blood is treated in a manner known to those skilled in the art by a diffusion process across a semipermeable membrane of the dialyzer 209. During this diffusion process, urinary substances are released from the blood into the dialysis fluid via the semipermeable membrane. Used dialysis fluid (dialysate) is drained from the dialyzer 209 via a dialysis fluid drain line 211 and sent for disposal or processing (not shown). The blood treated in this way is conveyed from the dialyzer 209 to a venous air trap 213 via another blood tubing line 212. The venous air trap 213 serves for (further) separation of air.An air bubble detector 215 is connected downstream of the venous air trap 213 and arranged on a venous blood tubing 216. The air bubble detector 215 is configured to detect air within the venous blood tubing 216. Furthermore, a venous pressure sensor 214, by means of which the venous pressure can be measured, is arranged on the venous air trap 213. The aforementioned components of the extracorporeal blood circuit are attached to a housing 217 of the device 200. The housing 217 has a housing front 218, which can also be referred to as a front panel. Furthermore, the device 200 in the present case has a human-machine interface 219, which can also be referred to as an interface for short. The interface 219 is designed as a touchscreen 220 and serves to input and output information.

[0026] The treated blood is supplied to the patient via the venous blood line 216. For this purpose, the venous blood line 216 is fluidically connected to a venous needle 100 arranged distally on the venous blood line 216.

[0027] In the Fig. In the usage situation shown in Figure 1, the venous needle 100 is attached to a venous vascular access Z (hereinafter referred to as access) of the patient P. The treated blood can thus be delivered via the venous needle 100 into the vein V of the patient P (shown purely as an example).

[0028] An unintentional detachment of the venous needle 100 from the access Z can have serious consequences for the patient P. To prevent such a needle disconnection, a monitoring system 1 is provided. Details of the monitoring system 1 are described in particular in Fig. 2 shown.

[0029] The monitoring system 1 comprises a holding device 10, a sensor device 20, a detection device 30 and a display device 40.

[0030] The holding device 10 is for attachment in the area of ​​the access Z. In the Fig. 1, Fig. In the usage situation shown in Figure 2, the holding device 10 is attached in a manner described in more detail.

[0031] The sensor device 20 is attached to the holding device 10 and is configured to detect a change in position (in short: position change) of the venous needle 100 within the access Z and to generate a sensor signal S that represents the detected position change.

[0032] The determination device 30 is connected to the sensor device 20 and is configured to determine an indication signal A as a function of the sensor signal S.

[0033] The display device 40 is connected to the detection device 30 and is configured to optically and / or acoustically output the display signal A.

[0034] Using the monitoring system 1, the patient P or medical personnel can detect, even before an actual needle disconnection, whether the venous needle 100 is moving within the access Z. The movement of the venous needle 100 can be indirectly detected by the optically and / or acoustically output display signal A.

[0035] At the Fig. 2, the detection device 30 and the display device 40 are also attached to the holding device 10. In this embodiment, the components of the monitoring system 1 are fundamentally separated from the device 200. In this embodiment, the monitoring system 1 forms a stand-alone solution. This is to be distinguished, for example, from the device shown in Fig. 6, which will be described in more detail below.

[0036] At the Fig. In the embodiment shown in Figure 2, the holding device 10 is a bracelet 11. The vein V shown as an example is therefore an arm vein of the patient P. The bracelet 11, more precisely: its inner side or inner circumference 111, rests on the skin H of the patient P. An outer circumference 112 (outside) of the bracelet 11 is facing away from the skin H.

[0037] In the embodiment shown, the sensor device 20 is arranged in the region of the inner circumference 111. The display device 40 is arranged in the region of the outer circumference 112. The detection device 30 is integrated into a cross-section (without reference numeral) of the bracelet 11.

[0038] The bracelet 11 can have any design suitable for the present purpose. For example, the bracelet 11 can be made of a textile material, a plastic material, or another suitable material. In one design, the bracelet is circumferentially closed and elastically variable in diameter. In another design, the bracelet has a clasp, similar to a wristwatch. In another design, the bracelet is circumferentially open and elastically flexible, similar to a bangle.

[0039] In the usage situation, the bracelet 11 is applied in the area of ​​the access Z. The bracelet 11 and thus also the sensor device 20 are located in the thickness direction of the skin H above a needle tip 101 of the venous needle 100.

[0040] In principle, any suitable measuring principle can be used to detect the change in position of the needle 100. The sensor device 20 is accordingly configured differently in different embodiments. In particular, an inductive, capacitive, and / or magnetoresistive measuring principle is suitable. The aforementioned measuring principles require electrically conductive properties E and / or magnetic properties M of the venous needle 100. In the embodiment shown, the venous needle 100 is made of an electrically conductive metal material suitable for medical purposes. The magnetic properties M can be achieved by selecting a magnetic material, magnetization, or an additional component made of a magnetic material that is attached to the venous needle 100. In the present case, such a component 102 is attached in the region of the needle tip 101.

[0041] Based on the Fig. 3 to 5 show a variant of the monitoring system 1 which has further features.

[0042] At in the in the Fig. 3 to 5, the sensor device 20 has a plurality of sensors 21 to 25. The plurality of sensors 21 to 25 are attached to the holding device 10 adjacent to one another along a longitudinal axis L and form a sensor row R. The sensor row R extends along the longitudinal axis L. In use, the longitudinal axis L extends approximately parallel to a longitudinal axis (without reference symbol) of the venous needle 100. In the event of an impending needle disconnection, the venous needle 100 moves along its longitudinal axis and thus along the longitudinal axis L beneath the sensor device 20, more precisely: the sensor row R. Due to the sensor row R, the sensor device 20 covers a larger measuring range than would be the case when using only a single sensor.

[0043] How to continue in Fig. 5, several sensor rows R, R', R'' are provided here. The sensor rows R, R', R'' are arranged spaced apart from one another along a transverse axis Q and form a sensor grid G. The sensor row R can also be referred to as the first sensor row and has the plurality of sensors 21 to 25. The sensor row R' can also be referred to as the second sensor row and has a plurality of sensors 21' to 25'. The sensor row R'' can also be referred to as the third sensor row and has a plurality of sensors 21" to 25'. It is understood that the sensor rows R, R', R'' are arranged at a distance from one another along a transverse axis Q and form a sensor grid G. The sensor row R can also be referred to as the first sensor row and has the plurality of sensors 21 ...' to 25'. It is understood that the sensor rows R, R', R'' are arranged as Fig. The number of three sensor rows shown in Figure 5 is purely exemplary. The same applies, mutatis mutandis, to the number of multiple sensors shown.

[0044] The transverse axis Q extends orthogonally to the longitudinal axis L. The longitudinal axis L can also be referred to as the axial axis of the wristband 11. In this case, the transverse axis Q defines a circumferential direction of the wristband 11. The sensor rows R, R', R'' are thus arranged spaced apart from one another in the circumferential direction of the wristband 11 on its inner circumference 111. The sensor grid G ​​achieves a sufficiently large measuring range of the sensor device 20 in the circumferential direction. If the wristband 11 slips somewhat in the circumferential direction, it is ensured that the venous needle 100 remains within the measuring range of the sensor device 20.

[0045] As already explained, the sensor device 20 can operate according to different measuring principles in different configurations. The plurality of sensors 21 to 25 (as well as 21' to 25' and 21" to 25") can therefore be of different designs in different configurations. This is shown in Fig. 4 is shown schematically and exemplarily for the sensor 21. This can be designed, in particular, as an inductive sensor 21a, a capacitive sensor 21b, or a magnetoresistive sensor 21c, in particular as a Hall effect sensor. The same applies to all other sensors of the sensor device 20.

[0046] The display device 40 has a plurality of light-emitting diodes (LEDs) 41 to 45. The number of LEDs 41 to 45 shown is purely exemplary. In one embodiment, the display device 40 has only one light-emitting diode (LED). Instead of or in addition to the plurality of LEDs 41 to 45, at least one loudspeaker 46 can be provided. The loudspeaker 46 is Fig. 3 is shown schematically as an alternative to the light-emitting diode 45, the reference symbol being accordingly placed in round brackets.

[0047] In the present case, the detection device 30 has a memory unit 31 and a processor unit 32 (see Fig. 3). At least one reference value R is stored or storable in the memory unit 31. The processor unit 32 is configured to compare the sensor signal S with the reference value R and to determine the display signal A based on the comparison. The reference value R can, for example, define a threshold value below or above which the display signal A is to be generated and output via the display device 40.

[0048] In Fig. 3, only a single reference value R is specified by way of example. It is understood that multiple reference values ​​can also be stored or storable in the memory unit 31. The multiple (different) reference values ​​can define different threshold values. For example, a first, second, third, fourth, and fifth threshold value. Upon reaching the respective threshold value, a corresponding number of the multiple LEDs 41 can light up. Alternatively or additionally, the multiple LEDs 41 to 45 can light up with different brightness or in a different light color upon reaching the different threshold values. This makes it easy to determine whether the current position change is merely slight or already critical. The same applies to an acoustic output of the display signal A via the loudspeaker 46.When the different threshold values ​​are reached, the display signal A can be output at different volume and / or pitch.

[0049] In the present case, the monitoring system 1 also has an actuating device 50 configured for manual actuation. The actuating device 50 is connected to the determining device 30. The determining device 30 is configured to store the sensor signal S as a reference value R in the storage unit 31 when the actuating device 50 is actuated. This allows for simple initialization or calibration of the monitoring system 1. For initialization / calibration, it must first be ensured that the venous needle 100 is correctly positioned within the access Z. The holding device 10 must be attached in a suitable position relative to the venous needle 100. If this is the case, the monitoring system 1 can be initialized by actuating the actuating unit 50. The reference value then stored represents a correct needle position.Deviations of the detected sensor signal S from the reference value R indicate a change in position.

[0050] In Fig. Figure 6 shows a further embodiment of a monitoring system 1a according to the invention. The structure and function of the monitoring system 1a are essentially identical to the monitoring system 1. To avoid repetition, only essential differences between the monitoring system 1a and the monitoring system 1 will be explained.

[0051] A key difference in monitoring system 1a is that the detection device 30a and the display device 40a are arranged apart from the holding device 10a. Specifically, the detection device 30a and the display device 40a are components of the device 200. In the present case, the detection device 30a is a central data processing device 220 of the device 200. The display device 40a is formed by the interface 219.

[0052] The Fig. 6 The connection between the sensor device 20a and the detection device 30a for transmitting the sensor signal S can be wireless or wired. The same applies to all other Fig. 2, Fig. 3 and Fig. 6 shown connections for signal and / or data transmission.

[0053] In this case, the device 200 also has a control device 221 connected to the monitoring system 1a. Specifically, the control device 221 is connected to the detection device 30a (the central data processing device 220). The control device 221 is configured to control at least one function of the device 200 as a function of the display signal A—and thus indirectly as a function of the sensor signal S. For example, the control device 221 can control an emergency shutdown of the blood flow within the extracorporeal blood circuit as soon as a needle disconnection is detected. For this purpose, for example, the fluid pump system 202 can be shut down. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 913 072 A1

[0004]

Claims

[1] Monitoring system (1, 1a) for use in extracorporeal blood treatment, comprising a holding device (10, 10a) which is designed to be attached in the region of a venous vascular access (Z) of a patient (P), a sensor device (20, 20a) which is attached to the holding device (10, 10a) and is arranged to detect a change in the position of a venous needle (100) within the venous vascular access (Z) and to generate a sensor signal (S) which represents the detected change in the position of the venous needle (100), a detection device (30, 30a) connected to the sensor device (20, 20a) and configured to detect an indication signal (A) as a function of the sensor signal (S), and a display device (40, 40a) which is connected to the determination device (30, 30a) and is arranged to optically and / or acoustically output the display signal (A). [2] Monitoring system (1, 1a) according to claim 1, characterized by that the holding device (10, 10a) is a bracelet (11, 11a). [3] Monitoring system (1, 1a) according to claim 1 or 2, characterized by that the sensor device (20, 20a) has at least one inductive sensor (21a), a capacitive sensor (21b) and / or a magnetoresistive sensor (21c), in particular a Hall effect sensor. [4] Monitoring system (1, 1a) according to one of the preceding claims, characterized by that the sensor device (20, 20a) has a plurality of sensors (21 to 25) which are attached to the holding device (10, 10a) adjacent to one another along a longitudinal axis (L) and form a sensor row (R). [5] Monitoring system (1, 1a) according to claim 4, characterized bythat the sensor device (20, 20a) has a plurality of rows of sensors (R, R', R'') which are attached to the holding device (10, 10a) adjacent to one another along a transverse axis (Q) and form a sensor grid (G). [6] Monitoring system (1, 1a) according to one of the preceding claims, characterized by in that the determination device (30, 30a) has a memory unit (31) and a processor unit (32), wherein at least one reference value (R) is stored or storable in the memory unit (31), and wherein the processor unit (32) is set up to compare the sensor signal (S) with the reference value (R) and to determine the display signal (A) as a function of the comparison. [7] Monitoring system (1, 1a) according to claim 6, characterized bythat an actuating device (50) is present and is configured for manual actuation, wherein the determining device (30, 30a) is configured to store the sensor signal (S) as a reference value (R) in the memory unit (31) when the actuating device (50) is actuated. [8] Monitoring system (1, 1a) according to one of the preceding claims, characterized by that the display device (40, 40a) has at least one LED (41 to 45) and / or a loudspeaker (46). [9] Monitoring system (1, 1a) according to one of the preceding claims, characterized by that the determination device (30) is arranged to transmit the sensor signal (S) and / or the display signal (A) to a higher-level information system. [10] Monitoring system (1) according to one of the preceding claims, characterized by that the detection device (30) and the display device (40) are attached to the holding device (10). [11] Monitoring system (1a) according to one of claims 1 to 9, characterized by that the detection device (30a) and / or the display device (40a) are components (220, 219) of a device (200) for extracorporeal blood treatment. [12] Monitoring system (1, 1a) according to one of the preceding claims, characterized by that the venous needle (100) is a component of the monitoring system, in particular wherein the venous needle (100) has magnetic properties (M) and / or electrically conductive properties (E). [13] Device (200) for extracorporeal blood treatment with a monitoring system (1, 1a) according to one of the preceding claims. [14] Device (200) according to claim 13, characterized bythat a control device (221) is present and connected to the monitoring system (1, 1a), wherein the control device (221) is designed to control, in particular switch off, at least one function of the device (200) as a function of the sensor signal (200).

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