Devices, systems, and methods for detecting blood clots

Abstract

In order to be able to detect blood clots in an extracorporeal blood circuit, a device for detecting blood clots in an extracorporeal blood circuit is proposed, which device optionally comprises: an actuator, which can create an adjustable constriction on the extracorporeal blood circuit, as the brake reduces the cross-section of a section of the blood line; at least one sensor that requires at least one parameter relating to a property of a liquid in the extracorporeal blood circulation; and a control unit configured to cause a measurement signal from the at least one sensor to be evaluated and, based on such evaluation of a parameter measured by the sensor, it is possible to detect passage of blood clots through the constriction and / or adhesion of blood clots in the constriction.

Description

Field of the Invention

[0001] The present invention relates to the field of extracorporeal blood circulation.

[0002] The present invention relates to a device for detecting blood clots in extracorporeal blood circulation. Background Art

[0003] Extracorporeal blood circulation occurs in the context of various therapeutic fields for medical treatment or for example for plasma donation. Blood in extracorporeal blood circulation may experience environmental conditions that are significantly different from those in endogenous blood circulation. Extravascular blood clots can form in extracorporeal blood circulation. Extravascular means that the clot is not located within endogenous blood vessels. A blood clot within an endogenous blood vessel is called a thrombus. A blood clot is a mass of blood and thus consists of red blood cells, white blood cells, and platelets, which form as blood begins to coagulate. A blood clot that reaches a certain size can trigger negative health consequences after entering the human blood circulation. Summary of the Invention

[0004] Accordingly, an object of the present invention is to provide a device, a system, and a method for detecting blood clots in extracorporeal blood circulation.

[0005] This object is achieved by a device for detecting blood clots in extracorporeal blood circulation according to the present invention, which device can be connected to an extracorporeal blood circulation having an adjustable constriction in a blood line, the device comprising:

[0006] - at least one sensor that acquires at least one parameter related to the properties of the liquid in the extracorporeal circulation, and

[0007] - a control unit that is configured such that a measurement signal from the at least one sensor is evaluated, and based on this evaluation of the parameter measured by the sensor, passage of a blood clot through the constriction and / or adhesion of a blood clot in the constriction can be detected,

[0008] - wherein the device is configured such that it can detect a blood clot at the adjustable constriction, which adjustable constriction has been adjusted by using an actuator or a mechanical clamp to constrict the blood line.

[0009] An advantage of this device is that blood clots can be reliably detected in a non-invasive manner. The device according to the present invention can not only detect the passage of a blood clot through the constriction, but also detect a partial blockage of the constriction caused by a blood clot adhering in the constriction.

[0010] The device according to the invention is provided and also configured for the purpose of being attached to an extracorporeal blood circulation or being part of an extracorporeal blood circulation system. The extracorporeal blood circulation typically includes blood lines or line segments, which are created, for example, using a set of tubing materials. Thus, the blood lines or blood tubes for extracorporeal blood circulation are usually elastic. According to the invention, the actuator of the device presented here can create an adjustable constriction on the extracorporeal blood circulation, as it reduces the cross-sectional area of a segment of the blood line. The constriction of the cross-section of the segment of the blood line is preferably achieved by compressing the blood line, and thus elastically deforming it. Thus, the deformation is reversible, and when the actuator releases the blood line, it will again assume the shape it had before the constriction was created. Due to hygiene requirements, the blood lines, blood tubes, and sets of tubing materials for extracorporeal blood circulation are usually for single use only and are discarded after the first use. In contrast, the blood treatment machines and other medical devices for extracorporeal blood circulation are typically used for hundreds or thousands of treatments. For blood treatment using extracorporeal blood circulation, a combination of a reusable treatment machine and blood tubes provided only for single use is therefore usually used in combination. The device for detecting blood clots presented here is intended for reuse and can be part of a treatment machine. However, the device can also be designed as a device separate from the treatment machine.

[0011] In the context of the present application, a constriction is a pipeline section on which the cross-section of the pipeline is smaller than the cross-section of the rest of the pipeline. The devices given here or the systems built thereon and the methods given here relate to an adjustable constriction, which can be created on or in an extracorporeal blood circulation. Generally, an adjustable constriction means that, on the one hand, the constriction can be said to be "additional", i.e., it can be formed by actuating an actuator. However, on the other hand, an adjustable constriction also means that the width - i.e., the remaining cross-section after constriction - can generally assume different values. This applies to various embodiments. The present invention relates to detecting the passage of a blood clot through a constriction in an extracorporeal blood circulation. That is to say, the constriction can have the property that the blood circulation through the adjustable constriction is not interrupted. Thus, in the sense of the present invention, the adjustable constriction can be a pipeline section having a smaller cross-section than the surrounding pipeline, but the pipeline is not completely clamped. In the sense of the present invention, when the adjustable constriction is adjusted, the blood pipeline cannot be sealed or closed at the adjustable constriction. On the contrary, in the sense of the present invention, liquid can flow through the adjustable constriction. For example, a pipeline section of a blood tube set completely clamped by a closed safety clamp is completely sealed / impermeable to the liquid in the extracorporeal blood circulation. It thus becomes clear that the last-mentioned example is clearly not an adjustable constriction in the sense of the present invention. In the context of the present invention, a completely closed valve in an extracorporeal blood circulation is also not an adjustable constriction. In the sense of the present invention, a mechanical device for forming an adjustable constriction on a section of a blood pipeline can be said to be in a partially open position with respect to the cross-section of that section of the blood pipeline in the mechanical device. Partially open means that, with respect to a section without a constriction, the pipeline section is reduced by the mechanical device, but at the same time is not completely squeezed, so that liquid can still flow through the constriction. In this case, the mechanical device can be an actuator, for example, an electrically controlled linear actuator, or an electric or electromagnetic safety clamp, or a manually actuated tube clamp, where, in the context of the present invention, all these devices reduce the tube cross-section by squeezing closed, thus achieving a semi-open position.

[0012] Manually actuated tube clamps can also be sold as disposable components for single use, which are integrated in an article such as a blood tube set.

[0013] In the context of the present invention, the detection of blood clots can be used to improve the level of patient safety. In an alternative refinement, protective measures can be initiated as a result of the detection of a blood clot. Such protective measures can be, for example, closing a safety tube clamp, stopping a blood pump, generally interrupting the delivery in the extracorporeal blood circulation, or also outputting an alarm or notifying the patient and / or the medical treatment personnel.

[0014] With respect to the present invention, generally, when referring to detecting the passage of a blood clot through a constriction, this alternatively or additionally means detecting the adhesion of a blood clot in the constriction.

[0015] Furthermore, this object is achieved by a method according to the invention for monitoring extracorporeal blood circulation to detect blood clots in the extracorporeal blood circulation, the method having at least the following steps:

[0016] - creating a constriction on the blood circulation, on a section of a blood tube, using an actuator or a mechanical device for manually creating a constriction,

[0017] - measuring, using a sensor, at least one parameter related to the properties of the liquid in the pipeline section having the constriction,

[0018] - evaluating, using a control unit, the measurement data of the sensor to detect the passage of a blood clot through the constriction and / or the adhesion of a blood clot in the constriction.

[0019] "Creating a constriction" on the blood circulation can be understood as synonymous with "generating a constriction". The constriction is created using an actuator. The blood circulation is typically formed using an elastic blood tube. The constriction can then be understood as a temporary constriction since it is created by the actuator and can also be eliminated again by the actuator and by resetting the blood tube. An advantage of this method is that blood clots can be reliably detected in a non-invasive manner.

[0020] In the context of the present disclosure, generating a constriction on the blood circulation mainly means creating a constriction on a section of a blood tube forming at least a part of the extracorporeal blood circulation, for example, because the cross-section of the blood tube in the constriction is smaller than the cross-section of the blood tube outside the constriction.

[0021] For the purpose of serving the above-mentioned aim of improving patient safety, the detection of blood clots on the extracorporeal blood circulation can preferably be carried out at a certain distance from the patient access, so that safety measures can be taken. Therefore, a constriction, i.e., an intubation, directly located at the return position of the patient's blood is not conducive to achieving this purpose: for example, if a blood clot is detected during the process of entering the patient's blood circulation from the extracorporeal blood circulation through the intubation, it is impossible to prevent the blood clot from reaching the patient's blood circulation by stopping the delivery in the extracorporeal blood circulation. This may be due to the inertia of the system. Due to the inertia of the system, a blood flow stop and / or a time delay in alarm processing may occur. Due to the inertia of the system, for example, although such detection is carried out, the clot may still reach the patient. However, for other reasons, in the context of the present application, the intubation is also not an adjustable constriction. On the one hand, the constriction is not adjustable but fixed - as part of the extracorporeal blood circulation. Compared with the context of the present application, a constriction of the intubation cannot be created / generated. On the other hand, the width of the intubation is not necessarily suitable for ensuring reliable detection of blood clots. The sensitivity of blood clot detection depends on the width of the constriction, and other factors such as flow rate, pressure, and viscosity also have an impact.

[0022] The device for detecting blood clots according to the present invention is configured to be able to detect not only the passage of blood clots but also the partial or complete blockage of the constriction by the blood clots. Using the method according to the present invention, it is also possible for the blood clots to partially or completely block the constriction. Adhesion can also be referred to as blockage. The detection of the passage of blood clots is the prospect of this application.

[0023] The present invention relates to a device for detecting blood clots in an extracorporeal blood circulation. The device has a control unit, which is configured to be able to detect blood clots at an adjustable constriction in the blood circulation, because a sensor acquires at least one parameter related to the properties of the liquid in the extracorporeal circulation. The control unit is configured here such that the measurement signals from the at least one sensor are evaluated, and based on this evaluation of the parameters measured by the sensor, the passage of blood clots through the constriction can be detected.

[0024] Furthermore, the present invention also relates to a method for monitoring an extracorporeal blood circulation to detect blood clots in the extracorporeal blood circulation, the method having at least the following steps:

[0025] - generating a constriction on the blood circulation using an actuator or a mechanical device for manually generating a constriction,

[0026] - measuring, using a sensor, at least one parameter related to the properties of the liquid in the pipeline section having the constriction,

[0027] - Evaluate the measurement data of the sensor to detect the passage of a blood clot through the constriction or the adhesion of a blood clot in the constriction.

[0028] This means here that an adjustable constriction is formed and the adjustable constriction is maintained at least during the measured time period. This can be regarded as an implicit step.

[0029] For the method and the device, the measurement for detecting a clot at the constriction takes place within a minimum pre-determined time period during which the adjustable constriction does not change. Thus, the width remains constant during this time period. In certain embodiments of the method and device of the present invention, the adjustable constriction is adjusted after its generation and maintained for at least a pre-determined time period, such as one second, so that the measurement can be carried out. Other time periods can be envisaged, as low as less than a few tens of milliseconds or as high as two-digit seconds or can also be continuous for several minutes, such as 15 minutes. Short-time measurements can be advantageously carried out intermittently to less interfere with the process. Long-time measurements are advantageous for certain operating states or modes of blood treatment so that if required, the entire operating phase can be fully monitored, such as in closed-loop reinfusion. It can also be clearly seen from here that the adjustable constriction does not mean an infinitesimal intermediate state, for example, such an infinitesimal intermediate state that occurs when a tube clamp is closed in an emergency and there are different widths within a fraction of a second during the closing. Such an accidental coincidence is not intentional.

[0030] The device according to the invention may have an actuator for production or may be implemented without an actuator. In the case of implementation without the actuator, the device is configured to be able to detect a blood clot at a manually generated constriction during operation. For example, such a constriction can be produced by applying a mechanical device for producing a constriction in a blood tube or a blood line. In a core improvement, the control unit is also configured to be able to change to an operation mode for detecting blood clots or to an operation mode for not detecting blood clots upon user input, or alternatively to detect when to activate or deactivate the mode for detecting blood clots based on other parameters of extracorporeal blood treatment, and to change independently between the operation modes of detecting blood clots and not detecting blood clots. This detection can be performed, for example, based on the detection of the reverse operation of the blood pump of the blood treatment device or based on the detection of an elevated pressure in the blood tube, which is caused by the setting of the constriction. The two detections (the running direction of the blood pump, assuming a relatively high base pressure in the blood tube) can be combined. The device according to the invention can be part of a blood treatment device or a separate device connectable to a blood treatment device. Furthermore, a system according to the invention is disclosed, which system includes a device for detecting blood clots, a blood tube or a blood line or a set of blood tubes, which are configured for connection to a patient and / or a blood treatment device. In addition to the device for detection and the blood tube, an improvement of the system further includes a mechanical device for producing a constriction in the blood circulation. According to one aspect of the invention, a system for use with a device or method for detecting a blood clot at a constriction in an extracorporeal blood circulation is disclosed, which system includes a blood tube or a blood line or a set of blood tubes configured for producing an extracorporeal blood circulation and a mechanical device for producing an adjustable constriction in a pipeline section of the blood tube or the blood line or the set of blood tubes. In an embodiment of the invention, a system is formed, which system consists of a blood treatment machine, a device for detecting blood clots, a blood tube or a blood line or a set of blood tubes, and a mechanical device for producing an adjustable constriction in a pipeline section. The set of blood tubes on the one hand and the device for detecting blood clots (which can be part of the blood treatment machine or separated from the blood treatment machine) on the other hand form - similar to a plug and a socket - in some embodiments, for example, a pair consisting of a consumable product and an evaluation device for detecting blood clots can optionally be used to perform the method according to the invention, for example, because the device, the set of blood tubes, the system including the device and / or the set of blood tubes, and the method are all aspects of the invention. Various improvements and embodiments of the aspects, methods, devices, and systems of the invention are discussed hereinafter. As long as they are not technically contradictory, the improvements, embodiments, and aspects described hereinafter always mean the device and the method and the concepts including them, as well as the system.

[0031] In an improvement of the device for detecting blood clots in an extracorporeal blood circulation according to the invention, the sensor is a flow sensor that measures the current flow rate of the liquid or a pressure sensor that measures the current pressure of the liquid. These two types of sensors particularly advantageously enable robust detection of blood clots.

[0032] Another improvement of the device for detecting blood clots in an extracorporeal blood circulation according to the invention has at least one flow sensor and at least one pressure sensor. Furthermore, in this improvement, the control unit of the device is configured such that the device jointly considers the measured values of the pressure sensor and the flow sensor to detect blood clots. Due to the combined evaluation of the measured values of pressure and flow, the sensitivity of blood clot detection can be particularly advantageously increased.

[0033] An embodiment of the device for detecting blood clots in an extracorporeal blood circulation according to the invention has an actuator that can create an adjustable constriction on the extracorporeal blood circulation, since the actuator reduces the cross-sectional area of a section of the blood line. Thus, the possibility is particularly advantageously provided that the device creates the constriction required for detection without user action.

[0034] In an improvement of the device for detecting blood clots in an extracorporeal blood circulation according to the invention and having an actuator, the device is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted. Tube clamps are widely used in many medical devices, for example, as a safety system to prevent patient blood loss in case of interference (such as a power failure) or operating error or accident (such as an unnoticed slippage from an intubation). Such tube clamps are typically designed such that a blood tube can be inserted into a defined container and the clamp remains open during normal operation. In case of a power failure, for example, due to spring pre-tensioning or magnetic pre-tensioning, the clamp closes within a fraction of a second. The embodiment of the device according to the invention as a tube clamp or part of a tube clamp offers the advantage of increased cost-effectiveness, since the elements of the clamp provided in any case are also used in the context of the invention. On the other hand, the solution is also very compact. In addition, the safety aspect can also be improved.

[0035] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the device is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted, and the actuator can assume at least three different positions. These positions are: a closed position, in which the extracorporeal blood circulation does not have a free pipeline cross-section at a point, i.e., is blocked or the tube is clamped by the clamp; an open position, in which the extracorporeal blood circulation does not have a constriction at the actuator; and a third, partially open position, which is between the closed position and the open position, in which an adjusted constriction can be created to detect blood clots on the inserted tube. In the first position, the tube is thus impermeable and is instead completely pressed together / clamped / squeezed. In this case, the effective cross-section for liquid transport in the constriction is zero. In the second position, the tube is not affected by the clamp in terms of cross-section and is thus at its maximum. In the third position, since the clamp is half-open, a defined constriction is formed on the tube. This defined constriction is designed for the detection of blood clots according to the present invention. The particular advantage of a clamp with three positions is that the clamp can thus also perform the function of a typical tube clamp, but in the half-open position, a device for detecting blood clots according to the present invention can be formed.

[0036] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, in which the actuator is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted, the actuator can assume at least three different positions. These positions are: a closed position, in which the extracorporeal blood circulation does not have a free pipeline cross-section at a point, i.e., is blocked or the tube is clamped by the clamp; an open position, in which the extracorporeal blood circulation does not have a constriction at the actuator; and a third, partially open position, which is between the closed position and the open position, in which an adjusted constriction can be created to detect blood clots on the inserted tube. In the first position, the tube is thus impermeable and is instead completely pressed together / clamped / squeezed. In this case, the effective cross-section for liquid transport in the constriction is zero. In the second position, the tube is not affected by the clamp in terms of cross-section and is thus at its maximum. In the third position, since the clamp is half-open, a defined constriction is formed on the tube. This defined constriction is designed for the detection of blood clots according to the present invention. The particular advantage of a clamp with three positions is that the clamp can thus also perform the function of a typical tube clamp, but in the half-open position, a device for detecting blood clots according to the present invention can be formed.

[0037] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the device is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted, and wherein the actuator can assume at least three different positions, and the tube clamp has a so-called multi-magnet. The multi-magnet has a large number of magnetized regions such that the clamp has at least three different positions. The multi-magnet is a disc-shaped magnet made of ferromagnetic material which can be variably magnetized in small portions perpendicular to the disc surface by applying an external magnetic field. By using such a very finely adjustable magnet, it is particularly advantageous to adapt the various clamping positions to the applications according to the present invention.

[0038] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, wherein the actuator is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted, and wherein the actuator can assume at least three different positions, and the tube clamp has a so-called multi-magnet. The multi-magnet has a large number of magnetized regions such that the clamp has at least three different positions. The multi-magnet is a disc-shaped magnet made of ferromagnetic material which can be variably magnetized in small portions perpendicular to the disc surface by applying an external magnetic field. By using such a very finely adjustable magnet, it is particularly advantageous to adapt the various clamping positions to the applications according to the present invention.

[0039] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the device is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted, and spacers can be arranged between the clamping elements of the clamp so as to thereby achieve a partially open clamping position at the constriction. It could be argued that such an arrangement contradicts the actual intended use of the tube clamp as a safety device. However, on the one hand, it is conceivable to design the tube clamp such that the clamp can still be fully closed while only being partially closed by the spacers. On the other hand, it is conceivable to retrofit a tube clamp for detecting blood clots by using specific spacers and the configuration of the control unit to detect blood clots based on sensor data. The device according to the present invention can thus be produced particularly advantageously at reduced cost by modifying existing machine elements and the development time can be shortened. Components that are highly identical to the prior art are also advantageous. A clamp retrofitted to create a constriction for detecting blood clots cannot easily be used as a conventional safety clamp. In some applications, such as hemodialysis, in addition to the clamp required for safety aspects, the clamp retrofitted in this way will also be visible. The device implemented according to this aspect optionally only has an actuator for generating the constriction. In a variant, there is no actuator: then the constriction is achieved only by means of the spacers. Other variants have an actuator such that the constriction can be achieved alternatively by using the actuator or by using the spacers. Here again it is possible that the constriction of a different width can be achieved by using the spacers than by using the actuator. The constriction can thus advantageously be adapted in a cost-effective manner to the various parameters of the blood treatment. It is conceivable that the retrofitted clamp includes spacers that are arranged such that they can be folded or moved in another way on the clamp so that, if required, the spacers can be inserted into the clamp in such a way as to form a constriction. On the other hand, it is conceivable to provide the clamp and a separate spacer as a kit. As an improvement thereof, it is conceivable to provide a kit having a plurality of different or identical spacers.

[0040] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the invention, wherein the actuator is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted, a spacer can be arranged between the clamping elements of the clamp, so that a partially open clamping position is achieved at the constriction. It can be considered that such an arrangement contradicts the actual intended use of the tube clamp as a safety device. However, on the one hand, it is conceivable to design the tube clamp such that the clamp can still be fully closed, and only the spacer causes the clamp to be partially closed. On the other hand, it is conceivable to retrofit a tube clamp for detecting blood clots by using a specific spacer and the configuration of the control unit to detect blood clots based on sensor data. The device according to the invention can thus be produced particularly advantageously at reduced cost by modifying existing machine elements and the development time can be shortened. Parts that are highly identical to the prior art are also advantageous. A clamp retrofitted to create a constriction for detecting blood clots cannot easily be used as a conventional safety clamp. In some applications, such as hemodialysis, in addition to the clamp required for safety aspects, the clamp retrofitted in this way will also be visible. The device implemented according to this aspect optionally only has an actuator for generating the constriction. In a variant, there is no actuator: then the constriction is achieved only by means of the spacer. Other variants have an actuator such that the actuator or the spacer can be used alternatively to achieve the constriction. Here again it is possible that using the spacer can achieve a constriction of a different width than using the actuator. Thus, the constriction can advantageously be adapted to the various parameters of blood treatment in a cost-effective manner. It is conceivable that the retrofitted clamp includes a spacer that is arranged such that it can be folded or moved in another way on the clamp, so that if necessary, the spacer can be inserted into the clamp in a way that forms a constriction. On the other hand, it is conceivable to provide the clamp and a separate spacer as a kit. As an improvement thereof, it is conceivable to provide a kit having a plurality of different or identical spacers.

[0041] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the actuator and the control unit are configured such that the device can assume at least two different operating states, in each of which the actuator forms the constriction, wherein a predetermined width of the constriction is different in different operating states. Thus, the device here has at least two different predetermined operating states with a predetermined width at the constriction, wherein the predetermined width has the property that blood flow through the constriction does not completely stop, so the constriction is not a completely occluding constriction. This makes it possible to select the width of the constriction such that, taking into account the parameters of the extracorporeal blood circulation, the highest available sensitivity or reliability for blood clot detection is obtained. The parameters can be the volumetric flow rate of the blood. For example, in one embodiment, if there is a lower volumetric flow rate, a constriction with a smaller width is selected. The parameters can be the diameter or wall thickness of the blood line / the blood tube. The parameters can be the viscosity or hematocrit of the blood or the progress of the treatment over time. The parameters can be the set delivery rate of the blood pump. Another parameter can be the pressure in the blood tube when the constriction is still open. The parameter can be a value formed by the pressure in the tube and the volumetric flow rate in the tube. In addition to the pressure parameter, the pressure increase when creating an adjustable constriction in the case of a known blood volume flow rate can be another parameter. For example, in this way, the influence of patient connectors such as cannulas on pressure measurement can be advantageously compensated for.

[0042] In two different predetermined operating states with different predetermined widths at the constriction, in both cases the blood tube is not completely clamped in the region of the adjustable constriction, but blood in the extracorporeal blood circulation can flow through the constriction.

[0043] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the device is designed as a tube clamp or is designed as part of a tube clamp into which a medical tube can be inserted, and wherein the actuator can assume at least three different positions, and the actuator can assume at least one additional partially open fourth position for setting a predetermined constriction, wherein a predetermined width of the constriction is different in different partially open positions. The advantages described in the previous paragraph also apply to this case.

[0044] All aspects and embodiments of the present invention have the feature that an adjustable constriction is formed for detecting blood clots, wherein the actuator or mechanical means assumes a partially open position. The partially open also relates to the cross-section of the section of the blood tube located at the position of the adjustable constriction: the free cross-section of the blood tube is reduced here relative to the relaxed blood tube, as may exist on the sections before and / or after the adjustable constriction. The free cross-section is reduced here only to the extent that the flow of liquid through the constriction in the tube section remains possible.

[0045] In an improvement of the device for detecting blood clots in an extracorporeal blood circulation according to the present invention, the actuator and the control unit are configured such that the device can assume at least two different operating states, in each of which the actuator forms the constriction, wherein a predetermined width of the constriction is different in the different operating states, and the control unit is configured to select and set the width of the constriction on the actuator according to a predetermined scheme in order to detect blood clots taking into account the parameters of the extracorporeal blood circulation. By this additional configuration of the control unit, setting the width of the constriction taking into account the parameters can advantageously achieve the automation of the device. Furthermore, if the device can thus select in each case the setting most suitable for detection, the detection ability of blood clots is advantageously improved.

[0046] In an improvement of the device for detecting blood clots in an extracorporeal blood circulation according to the present invention, the device is designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted, and wherein the actuator can assume at least three different positions and at least one additional partially open fourth position for setting a predetermined constriction, wherein a predetermined width of the constriction is different in the different partially open positions, and for the operation of detecting blood clots taking into account the parameters of the extracorporeal blood circulation, the control unit is configured to be able to select and set the clamping position on the actuator according to a predetermined scheme. The advantages associated with the exemplary embodiments described in the previous paragraph also apply in this case.

[0047] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the width of the constriction is variable, and the control unit is configured to be able to set the constriction for the operation of detecting blood clots taking into account the parameters of the extracorporeal blood circulation, so that the sensitivity and / or robustness of the detection is optimized. One advantage of this improvement is that the sensitivity or robustness of the detection can even be better than in embodiments specifying one or more predetermined widths of the constriction. For example, it can be envisaged that the parameters of the extracorporeal blood circulation are in the middle between two values, which according to a scheme for optimal results require a specific width of the constriction. Here, the variable constriction of this embodiment can be used to assume a single width of the constriction, so that the detection can be improved relative to a set of fixed widths. In another embodiment, the control unit is configured to be able to variably select a corresponding optimized width of the constriction for a specific previously known blood tube or group of blood tubes. Alternatively or additionally, the control unit can be configured to be able to adapt the width of the constriction to different groups of tube-shaped materials or blood tubes or blood lines or groups of blood tubes. One advantage is that blood clots can be easily detected in the same device even when using different blood tubes - for example, for treating adults or designed for treating children with significantly thinner tubes (the inner diameter of the blood tube / the blood line is smaller and / or the wall thickness is smaller). For this purpose, for example, the control unit can be configured to be able to process parameters of the blood tube, such as wall thickness or inner diameter, as input values for the adaptation setting of the constriction. According to an embodiment, the control unit can be configured to be able to, for example, manually input such a value, or for example if the device is part of an extracorporeal blood treatment machine, the control unit can be configured to be able to have the value transmitted from another device or other components of the device.

[0048] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the roller pump is the actuator, and the constriction is created because the movable mechanical means for creating the constriction is arranged at or adjacent to the roller pump, so that in the case of reverse operation of the pump, the mechanical means moves, thereby creating the constriction.

[0049] In an improvement of the device for detecting blood clots in extracorporeal blood circulation according to the present invention, the width of the constriction is variable, and the control unit is configured to be able to adjust the constriction for the operation of detecting blood clots taking into account the parameters of the extracorporeal blood circulation, such that the sensitivity and / or robustness of the detection is optimized, and the control unit is configured to be able to calculate the optimal width of the constriction based on the parameters of the extracorporeal blood circulation and / or the parameters of the treatment, and to set the optimal width using the actuator during a medical treatment using the extracorporeal blood circulation. In this way, an automatically and individually improved detection of blood clots is advantageously achieved. By the automation of the device, human errors are reduced and the burden on medical staff is alleviated.

[0050] An embodiment of the present invention relates to a blood tube set configured for use with the device for detecting blood clots in extracorporeal blood circulation given herein, or with the method for detecting blood clots in extracorporeal blood circulation given herein, the blood tube set having a blood tube or blood pipeline and mechanical means, in particular a mechanical clamp, for adjusting a constriction on a pipeline section of the blood tube or the blood pipeline. The blood tube set suitable for detecting blood clots is advantageously provided to the user in this way.

[0051] One aspect of the present invention relates to an extracorporeal blood treatment device having a device for detecting blood clots according to the present invention, a tube clamp, and / or a device for outputting an alarm and / or a blood pump, wherein the control unit of the blood treatment device is configured to close the tube clamp and / or output an alarm and / or stop the blood pump if the device for detecting blood clots detects a blood clot. In other words, according to this aspect, the extracorporeal blood treatment device according to the present invention is equipped with a device for detecting blood clots according to the present invention. In addition, the extracorporeal blood treatment device has one or more of the active components in the following list: a tube clamp, a device for outputting an alarm, a blood pump. The control unit is configured here such that upon detection of a blood clot, at least one activation of a component occurs in response to the detection of the blood clot. This enables, in particular, a control-technical response to the detection of a blood clot to be obtained directly. Including its different variants. For example, including a variant of the present invention, wherein the extracorporeal blood treatment device has a device for detecting blood clots according to the present invention and a tube clamp, wherein the control unit is configured to be able to close the tube clamp when the device detects a blood clot. Alternatively or additionally, for example, including a variant of the present invention, wherein the extracorporeal blood treatment device has a device for detecting blood clots according to the present invention and a device for outputting an alarm, wherein the control unit is configured to be able to output an alarm when the device detects a blood clot. Alternatively or additionally, for example, including a variant of the present invention, wherein the extracorporeal blood treatment device has a device for detecting blood clots according to the present invention and a blood pump, wherein the control device is configured to be able to stop the blood pump when the device detects a blood clot. In addition, these three variants can be combined as needed. Thus, for example, in a variant having a tube clamp and a blood pump, the control device can be configured such that upon detection of a blood clot, the tube clamp is closed and the blood pump is stopped. In addition, for example, in a variant having a blood pump and a device for outputting an alarm, the control unit can be configured such that upon detection of a blood clot, the blood pump is stopped and an alarm is additionally output. In addition, in a variant having a device for outputting an alarm and a tube clamp, the control unit can be configured such that upon detection of a blood clot, an alarm is output and the tube clamp is additionally closed. Or, for example, in a variant having a device for outputting an alarm, a tube clamp, and a blood pump, the control unit can be configured to be able to output an alarm, close the tube clamp, and stop the blood pump upon detection of a blood clot. Other variants can be envisaged. Thus, variants having multiple active devices (i.e., multiple blood pumps, multiple tube pumps, or multiple devices for outputting an alarm) are also conceivable. The control unit can then be configured here to be able to perform the actions mentioned above in one or more of the active devices upon detection of a blood clot.Accordingly, one or more blood pumps can be stopped, one or more tube clamps can be closed, or an alarm can also be output on one or more devices for outputting an alarm. Additionally, it is conceivable to output multiple alarms by means of one device for outputting an alarm.

[0052] According to one aspect of the invention, the above-mentioned extracorporeal blood treatment device having a device for detecting blood clots according to the invention is a hemodialysis machine. The device for detecting blood clots according to the invention can advantageously be used in conjunction with or as a component of the hemodialysis machine. This results in a specific synergy because some elements of a typical hemodialysis machine can also be used as elements of the device for detecting blood clots, or vice versa, so the elements of the device can also extend the hemodialysis machine beyond the detection of blood clots. For example, a pressure sensor or a blood volume flow sensor can be such elements. Additionally, the invention also has particular advantages in the context of hemodialysis because there is currently great interest in detecting blood clots.

[0053] According to one aspect of the invention, a system for extracorporeal blood treatment of a patient has an extracorporeal blood treatment machine, and the extracorporeal blood treatment machine has a device for detecting blood clots in the extracorporeal blood circulation according to the invention. The system additionally has a blood tube. The device for detecting blood clots is arranged on a section of the blood line at a distance of at least 30 cm upstream of the patient access. This advantageously enables the detection of blood clots by the device at a significant distance from the patient. This distance is slightly larger than the distance covered in a time period of 1.5 s at a blood volume flow rate of 200 ml / min with a tube inner diameter of 4.5 mm. This time span is sufficient for the reaction of a safety tube clamp. In one embodiment, the section of the blood line having the constriction is arranged according to the blood volume flow rate provided for an individual treatment and taking into account the inner diameter of the blood tube to be used such that the blood in a measurement operation for detecting blood clots will reach the patient at the earliest 1.5 seconds after passing through the constriction. This embodiment is mainly an alternative to the embodiment where the distance is at least 30 cm. However, since in this embodiment the distance is calculated using a formula, the formula can also give a distance of 30 cm or more, and thus these two embodiments have an overlapping parameter range. The distance x(Q, D, T) in [cm] is a function of the blood volume flow rate Q in [ml / s = cm3 / s], the tube inner diameter D in [cm], and the desired time period T in [s] between the detection of a clot in the extracorporeal blood circulation and the cessation of blood delivery, and can be calculated as follows:

[0054]

[0055] Here, Q = 200 cm 3 / s; D = 4.5 mm; T = 1.5 s, the value of the distance x is approximately 18.9 cm. Thus, at the above 30 cm, the said distance is greater than the volume of blood delivered from the constriction within 1.5 seconds under these conditions in any case. For all aspects of the present invention, it is conceivable to arrange the adjustable constriction at a certain distance from the patient access according to the formula mentioned above.

[0056] However, according to another aspect of the present invention, the distance of the adjustable constriction to the patient access can alternatively be determined according to the following formula. The device for detecting blood clots is arranged here on a section of the blood pipeline, and the section of the blood pipeline is determined according to the blood volume flow rate and the tube diameter as follows:

[0057]

[0058] In this case, x is the distance in cm, Q is the blood volume flow rate in [ml / min], D is the free inner diameter of the normal general diameter of the blood pipeline in [mm], where no adjustable constriction is formed. This advantageously enables the selection of the minimum value determined by the treatment parameters for the distance of the adjustable constriction, where blood delivery can still be safely stopped so that the clot detected in the adjustable constriction remains in the extracorporeal circulation. At a delivery rate of 300 ml / min and the inner diameter of the relaxed blood tube, a distance of 45 cm results. For all aspects of the present invention, it is conceivable to arrange the adjustable constriction at a certain distance from the patient access according to the formula mentioned above.

[0059] Therefore, an embodiment of the method given here additionally includes the step of determining the distance mentioned above. This step is placed upstream of creating the adjustable constriction. In addition, the spatial distance advantageously enables a longer reaction time or time for detecting blood clots and processing the detection. As an improvement, a greater safety distance can be envisaged, such as corresponding to 2 s or 3 s, or a fixed distance, such as 50 cm or 100 cm.

[0060] In an improvement of the method according to the invention, the method for monitoring extracorporeal blood circulation to detect blood clots is extended such that it also includes aspects of controlling the extracorporeal blood treatment device. The method for controlling the extracorporeal blood treatment device has, in addition to the step of detecting blood clots, the following steps: when the passage of a blood clot through the constriction is established, closing the tube clamp and / or outputting an alarm and / or stopping the blood pump. The above-mentioned aspect of the device according to the invention also applies to the sub-form of the method, which aspect includes closing the tube clamp and / or outputting an alarm and / or stopping the blood pump when the passage of a blood clot through the constriction or the adhesion of a blood clot in the constriction is established.

[0061] An object of the above-mentioned improvement alternative involving closing the tube clamp and / or stopping the blood pump is that when a blood clot is detected at the adjustable constriction, the clot does not reach the patient. Thus, the implicit condition is that the adjustable constriction is arranged at a certain distance from the two patient-side ends of the blood tube such that when the passage of the clot through the adjustable constriction is detected, there is still sufficient reaction time such that when the tube clamp is closed and / or the blood pump is stopped, the blood volume with the detected clot does not reach the patient. That is, the distance - along the blood tube - must be selected to be at least such that there is sufficient time to control the extracorporeal blood circulation and the reaction of the actuator - also taking into account the inertia of the corresponding system - in order to prevent the blood delivery of the blood volume with the detected clot to the patient.

[0062] The terms identification of a blood clot and detection of a blood clot can be used synonymously.

[0063] According to one aspect, the device according to the invention for detecting blood clots in extracorporeal blood circulation is connected to an extracorporeal blood treatment machine or a part of an extracorporeal blood treatment device, wherein the extracorporeal blood treatment device is configured to be able to, at the end of the extracorporeal blood treatment, reinfuse the blood located in the extracorporeal blood circulation back to the patient by means of closed-loop reinfusion. This particularly advantageously enables the safety level of the reinfusion, blood treatment, and the extracorporeal blood treatment device to be increased. For example, the extracorporeal blood treatment machine in this example can be a hemodialysis machine or a machine for therapeutic plasma separation.

[0064] According to one aspect, the device for detecting blood clots in extracorporeal blood circulation of the present invention is designed as a safety system for extracorporeal blood circulation, such that the device can be later added to an already existing extracorporeal blood treatment device or an existing extracorporeal blood circulation (so-called retrofit). The device is here implemented as a retrofit kit, such that for example - as needed - it can establish a wired or wireless data connection with a blood treatment machine, or be managed without a data connection, it has an independent electrical power supply (for example by means of a transformer without electrical potential isolation from the electrical grid or by means of a storage battery), or be powered by the blood treatment machine, and it can simply be clamped onto a blood tube using a clip. In a completely independent variant, the device optionally has a separate display device, a separate device for outputting an alarm, and / or a transmission device for transmitting measurement values and / or alarm signals. The method according to the present invention will also be considered transferred to this aspect.

[0065] According to one aspect of the present invention, the control unit is configured to be able to detect whether the actuator is in an open state or whether the actuator forms a constriction on the extracorporeal blood circulation.

[0066] According to an improvement of the above-mentioned aspect, the control unit is configured to be able to perform an evaluation of the sensor signal to detect a blood clot only when the actuator forms a constriction.

[0067] According to another improvement of the above-mentioned aspect, the control unit is further configured to be able to detect a quantitative parameter related to the size of the constriction. Examples of such a parameter are for example the distance between the two jaws of a tube clamp, the current cross-section of the liquid conductor in the constriction, or also a parameter related to the actuator. A parameter related to the actuator can also be those parameters that are not directly and explicitly the size of the constriction itself, but are explicitly related to the size of the constriction, thus allowing the size of the constriction to be derived. These parameters can be the position of a positioning motor, a clamping position, the position of a linear motor, or for example the angular position of a rotatably mounted actuator magnet.

[0068] Other parameters of the extracorporeal blood circulation, based on which the optimal width of the constriction is determined, for example, the set flow rate of the blood, the time course of the treatment, the wall thickness of the tube / the blood tube / the blood line, the position of the rollers of the tube roller pump (for example, the position of the rollers of the tube roller pump takes into account the pressure pulsation in the roller pump when detecting blood clots), the viscosity or hematocrit of the blood. Another parameter can be the pressure in the blood tube when the constriction is still open. The parameter can be a value formed by the pressure in the tube and the volumetric flow rate in the tube. In addition to the pressure parameter, the pressure increase when creating an adjustable constriction in the case of a known blood volume flow rate can be another parameter. In this way, for example, the influence of patient connectors such as cannulas on the pressure measurement can be advantageously compensated for.

[0069] In an advantageous refinement, the device according to the invention is used together with a pump that can generate a temporally constant blood flow - for example, an impeller pump. Such a pump generates a uniform blood flow, while for example roller pumps, diaphragm pumps and syringe pumps generate an oscillating blood flow. According to the invention, the sensitivity of the device when detecting blood clots can be particularly advantageously further increased by a temporally constant blood flow. This is because if the potential undisturbed blood flow is constant, the deviation therefrom can be determined particularly easily.

[0070] In many medical devices, tube clamps are used, with which the flow through a tube with a flexible wall can be clamped. These clamps are present in many medical application areas and are generally constructed such that the tube is inserted into the open clamp. These clamps are generally used as safety devices, especially for blood catheters. The clamp is intended to ensure, for example, that blood flow can be interrupted in the event of an emergency. For this purpose, the clamp must have an open position and a closed position and must be able to switch between the two operating states. For this purpose, such a clamp generally has means for clamping, means for mechanical reset (for example a spring) and an electrically controlled holding element. The reset device provides a force in order to close the clamp in the de-energized state of the holding element, by means of which the blood tube is clamped and the blood line is interrupted. In some areas of medicine or medical technology, such tube clamps are provided to ensure patient safety.

[0071] Although continuous pumping pumps such as impeller pumps, gear pumps or combinations consisting of multiple injection pumps would be advantageous, it is also conceivable to use cyclic operation pumps such as roller pumps or injection pumps. For a device or method for using a cyclic operation pump to transport the liquid in the extracorporeal blood circulation, a configuration with a pressure sensor is advantageous, the pressure sensor being arranged to determine the current pressure curve over time in the liquid transported by the pump in the current delivery cycle of the pump, to store a reference pressure curve in a memory, wherein the memory can be associated with the device according to the invention or with a more advanced blood treatment device. The device according to the invention or the possible more advanced blood treatment device then has an evaluation unit, which determines a pressure deviation by comparing the pressure curve from the current delivery cycle of the pump with the reference pressure curve, and detects the pressure deviation by the deviation. The reference pressure curve can be obtained, for example, by obtaining the pressure curve over time from one or more delivery cycles before the current delivery cycle of the pump or also from historical data or an average value. For higher accuracy, the reference pressure curve is preferably based on one or more delivery cycles of the same pump, which have occurred immediately or at least only a few pump delivery cycles earlier than the current delivery cycle.

[0072] According to an improvement of the invention, the device according to the invention is implemented such that the tube clamp provided for patient safety is extended in such a way that it has an actuator that can create an adjustable constriction. Thus, the tube clamp is extended in such a way that, in addition to the two typical operating states of "fully open" assumed during appropriate blood treatment and "fully closed" assumed, for example, in an emergency, such as in the case of a power failure, the tube clamp can assume a third operating state of "adjusted constriction for detecting blood clots", which is neither fully open nor fully closed. This particularly advantageously enables the integration of a device for detecting blood clots into a device that already exists in many application areas, such as a blood tube clamp. This enables a particularly compact, resource-saving and reliable integration.

[0073] According to an improvement of the above-mentioned improvement with the integration of the device according to the invention, the tube clamp is further improved relative to known tube clamps such that the tube clamp has two disc-shaped permanent magnets, which have more than two magnetic poles, which are generated by magnetization extending perpendicular to the surface of the disc, for example using an electromagnetic coil device in the manner of a hard disk drive write head (the so-called ). The implementation of a tube clamp with magnetizable magnets is particularly advantageous for achieving an efficient, compact and energy-saving device. This is because the various operating states can be configured by the adjustability of the magnetic regions, such that only little energy is required to maintain the corresponding operating states.

[0074] In a particularly advantageous refinement of the system according to the invention, this above-mentioned tube clamp is used in the system together with a blood pump with continuous flow, in particular an impeller pump. Thus, it is particularly advantageous that the sensitivity of the device for detecting blood clots according to the invention can be further increased. Corresponding advantages are also obtained if pumps or combinations of pumps and / or additional elements such as valves and throttle valves or connectors are interconnected such that a continuous blood flow is generated. Furthermore, corresponding advantages are also present if blood is transported in an extracorporeal blood circulation by a pump that is not itself arranged in the blood circulation but continuously transports a medium - for example, a dialysis fluid - such as a gear pump and a transport pump.

[0075] In the context of the present invention, an adjustable constriction means that the constriction does not fixedly and unchangeably exist in the blood circulation, but can be adjusted by means of an actuator. In the simplest case, an adjustable constriction means that the actuator of the device can create and remove the constriction, or the adjustable constriction can be recreated or removed on a blood tube set by applying, for example, a mechanical device for constricting the cross-section of the blood tube. In other words, the adjustable constriction does not simply mean a constriction that remains unchanged during the period of use (including treatment and preparation and follow-up of treatment) in an extracorporeal blood circulation. Thus, it does not simply mean, for example, the constriction used by a cannula for connecting the extracorporeal blood circulation to the blood vessels of a patient. Such a cannula usually has a smaller pipeline cross-section than the blood tube, which usually constitutes an important part of the extracorporeal blood circulation. Nor does it mean other elements fixedly and immutably arranged in the extracorporeal blood circulation, such as Luer connectors or time-invariant constrictions in the flow cross-section, such as those present in cartridge elements or at the transitions of various pipeline sections due to design. If the actuator simply does not create the constriction, the point in the blood circulation where the actuator can create the constriction is not constricted by the actuator. In other words, in the simplest case, the constriction can be increased by means of the actuator, or it can also be absent. Thus, it is ensured that the constriction is created only when clot detection is actively performed. If no blood clot is detected, the cross-section of the blood circulation is not reduced by the actuator to the constriction required for measurement. The width of the constriction can preferably be predetermined here and matched to the detection of blood clots according to the invention.

[0076] In the context of the present application, a device for detecting blood clots can include the following subgroups:

[0077] - An extracorporeal blood circulation having an adjustable constriction on a tube section,

[0078] - A device for detecting blood clots, the device comprising a sensor for detecting at least one parameter related to the properties of the fluid in the extracorporeal blood circulation, and wherein there is an open fluid connection between the section of the adjustable constriction and the section of the sensor such that the sensor can detect a change in the measured parameter caused by the passage of a clot through the adjustable constriction.

[0079] Conversely: If there is a complete blockage in the extracorporeal blood circulation between the sensor and the adjustable constriction, this would not be in accordance with the teachings of the present application, since in this way a change in the measured parameter caused by the passage of a clot through the adjustable constriction cannot be detected by the sensor.

[0080] The subgroups or components in the previous paragraph may be sold here as separate products. The device for detecting blood clots according to the present invention may be sold separately and is designed as a retrofit kit for an extracorporeal blood circulation device or may be sold as part of such a device. Such a device may in particular be an extracorporeal blood treatment device. The generation of the adjustable constriction for detecting blood clots may be carried out by means of an actuator of the device - for example an electromechanical tube clamp or a linear actuator. The blood tube set used in these embodiments may here be a typical blood tube set for a specific application (such as in dialysis, therapeutic plasma separation or cardiopulmonary support). The actuator of the device forms the constriction on the typical blood tube set. Alternatively, the generation of the adjustable constriction for detecting blood clots may be carried out by applying a manual clamp. The clamp may be sold separately or as part of a blood tube set for treatment. Compared with widely used manual blood tube clamps, the clamp according to the present invention must have the property that it forms the adjustable constriction on the blood tube for detecting blood clots as a partially open constriction, i.e., such that blood circulation does not stop but can continue. Such a clamp may be implemented as part of a single-use blood tube set or as a separate product.

[0081] In a preferred embodiment of the device or method according to the present invention, the adjustable constriction and the pressure sensor may be arranged adjacent to each other along the route of the blood tube, i.e., at most a few centimeters apart. A more direct measurement for detecting blood clots is particularly advantageously produced in this way, and moreover, it is less susceptible to interference effects than at greater distances.

[0082] According to a preferred embodiment, the device and method according to the invention are adapted to enable constriction to be performed on a blood tube for extracorporeal blood treatment, the blood tube having an inner diameter between 3 mm and 15 mm in the relaxed state. The free cross-sectional area in the adjustable constriction preferably corresponds here to 1% to 99% of the cross-sectional area in the relaxed state. Furthermore, the area preferably corresponds to 10% to 90% of the cross-sectional area in the relaxed state. In any case, the width of the adjustable constriction is chosen such that it can detect clots, preferably improving detection.

[0083] According to one aspect of the invention, the width of the adjustable constriction created by the actuator of the device on the blood circulation is predetermined and matched to the current blood clot detection.

[0084] According to another aspect of the method according to the invention for monitoring extracorporeal blood circulation to detect blood clots in the extracorporeal blood circulation, the method steps are for: using an actuator to create a constriction on the blood circulation, using a sensor to measure at least one parameter related to the properties of the liquid in the pipeline section having the constriction, evaluating the measurement data of the sensor to detect the passage of a blood clot through the constriction during the reinfusion method after hemodialysis treatment, wherein, during reinfusion, blood is returned to the patient simultaneously via two patient connectors, for example, via an arterial cannula and via a venous cannula. In this case, for example, in one of the two branches, a clot trap cannot be arranged along the blood pipeline.

[0085] In one embodiment, the method is extended by the following sequence of method steps for individually adjusting the width of the adjustable constriction:

[0086] - Set a defined blood volume flow

[0087] - Create the adjustable constriction

[0088] - Due to the creation of the constriction, the pressure and / or other parameters of the blood at the sensor change

[0089] - Adjust the width of the constriction until a predetermined target value of the pressure and / or other parameters is reached

[0090] - Detect clots

[0091] The control unit of the device having an actuator for creating a variable constriction can advantageously be constructed similarly to adjust the width of the constriction.

[0092] Thus, an optimal measurement range for parameters for detecting blood clots - such as pressure or flow and / or other parameters - can advantageously be achieved.

[0093] A blood volume flow rate sensor may also be referred to simply as a flow meter, a flow sensor, a volumetric flow sensor, or a volume flow rate sensor.

[0094] A blood tube and a blood line may be used synonymously. A blood tube form material set and a blood tube set may be used synonymously. A blood tube set has at least one blood tube and may optionally have connectors. A section of a blood tube may be synonymous with a segment of a blood tube. An adjustable constriction according to the teachings of the present application is located on a section of the blood tube, and during operation of extracorporeal blood circulation, the blood in circulation flows through the section. A segment of the blood tube may also have special properties, such as material properties, material quality, and tube cross-section.

[0095] One aspect of the present invention relates to a system for use with a device or method for detecting a blood clot at a constriction in extracorporeal blood circulation, the system including a blood tube, a blood line, or a blood tube set configured to produce extracorporeal blood circulation and a mechanical device for producing an adjustable constriction on a line section of the blood tube, the blood line, or the blood tube set. The blood tube, the blood line, or the blood tube set is configured to produce extracorporeal blood circulation and is configured to be connected to a human body. For this purpose, the blood tube, the blood line, or the blood tube set may have connection means. The blood tube, the blood line, or the blood tube set may be designed for single use. The blood tube, the blood line, or the blood tube set may have properties enabling the use of an extracorporeal blood treatment device to produce extracorporeal blood circulation.

[0096] A preferred embodiment of the present invention relates to a manual mechanical tube clamp for generating an adjustable constriction on a section of a blood tube in an extracorporeal blood circulation to detect blood clots in the extracorporeal blood circulation. The clamp has the property that it can assume and maintain a partially open position, in which the clamp can partially compress the section of the blood tube. By means of the clamp, on the one hand, a constriction is formed on the blood tube, and on the other hand, due to the constriction, the blood tube remains liquid-permeable at the constriction. However, known clamps cannot achieve the partially open position required for detecting blood clots. An advantage of the manual mechanical tube clamp for generating an adjustable constriction for detecting blood clots is that blood clots can be detected without the actuator of a treatment machine, and a conventional blood tube set can also be used. The hygiene required in the medical field can be achieved, for example, by the clamp being made of plastic and intended for single use, being sterilized and packaged in a sterile manner, or, for example, the clamp can be autoclaved and made of medical steel. "Assumed position" means that the clamp remains in a partially open state and is thus locked until the clamp is released again from the partially open state. Thus, the defined state means the clamping position that the clamp can assume. This does not mean, for example, that household scissors available on the market can not only be fully opened but also fully closed, and there is a partially open position in between: this does not correspond to the defined state, such as the specific clamping position referred to here.

[0097] One aspect of the present invention relates to a blood tube set for extracorporeal blood treatment to detect blood clots in an extracorporeal blood circulation, the blood tube set including a manual mechanical tube clamp as described in the previous paragraph and a blood tube having an arterial end for connection to a patient access. Thus, it is particularly advantageously ensured that the tube and the clamp match each other such that an adjustable constriction in the sense of this teaching can be formed using the clamp on the tube.

[0098] According to an improvement of the blood tube set for detecting blood clots in extracorporeal blood circulation described in the previous paragraph, the blood tube set includes a manual mechanical tube clamp that can assume a partially open position. The blood tube set additionally includes at least one mechanical manual tube clamp that completely blocks the tube in the clamping position. However, the additional tube clamp does not have a partially open position. This means that for a typical manual tube clamp, the blood tube can be completely blocked by pressing down using the typical manual tube clamp. Thus, the blood tube set advantageously includes at least two different clamps for different tasks. However, the improved embodiment can also include two, three, or more typical manual tube clamps that completely block the tube position in the clamping position. In one improvement, the clamps are equipped with identifiers, thus reducing the risk of confusion.

[0099] According to an improvement of the blood tube set for detecting blood clots in extracorporeal blood circulation, the blood tube set includes a manual mechanical tube clamp that can assume a partially open position, as described in one of the previous two paragraphs, with another additional mechanical clamp once and without another additional mechanical clamp once. The another additional mechanical clamp can completely interrupt blood flow because the another additional mechanical clamp completely clamps the tube in the clamping position. The blood tube set has the property that by arranging the clamp that can assume a partially open position and by converting the clamp to the partially open state, an adjustable constriction can be formed in one of the following regions on a section of the blood line:

[0100] [Alternative AA] Between the arterial end of the blood line, thus the access to the patient (H), and the pump tube section, where the pump tube section is the section of the blood tube that can be inserted into the blood pump, and the blood tube set includes the pump tube section; or

[0101] [Alternative BB] Between the manual mechanical tube clamp and the pump tube section, where the manual mechanical tube clamp does not have a partially open position but completely presses down the blood tube in its clamping position, and the pump tube section is the section of the blood tube that can be inserted into the blood pump, and the blood tube set includes the pump tube section; or

[0102] [Alternative CC] Between the manual mechanical tube clamp and the device for arterial pressure measurement of the blood tube set, where the manual mechanical tube clamp does not have a partially open position but completely presses down the blood tube in its clamping position, and the blood tube set includes the device for arterial pressure measurement; or

[0103] [Alternative DD] Between the device for measuring arterial pressure for the blood tube set and the pump tube section, the pump tube section being the section of the blood tube that can be inserted into the blood pump, where the blood tube set includes the pump tube section, where - if there are multiple blood pumps and / or pump tube sections - the pump tube section refers to the pump tube section closest to the arterial end of the blood pipeline, where the blood tube set includes the device for arterial pressure measurement and the pump tube section; or

[0104] [Alternative EE] Between the fluid interface configured for administering an infusion and the pump tube section of the blood tube set, the pump tube section being the section of the blood tube that can be inserted into the blood pump, where

[0105] the blood tube set includes the interface for administering an infusion, the blood pump, and the pump tube section; or

[0106] [Alternative FF] Arranged upstream of the patient (H)'s access, at least 30 cm upstream of the arterial end of the blood pipeline, thus at least 30 cm upstream of the patient (H)'s access; or

[0107] [Alternative GG] According to the following formula for determining the distance x, at least at the distance x upstream of the arterial end of the blood pipeline, thus at the distance x upstream of the patient (H)'s access

[0108] :

[0109] Or

[0110] [Alternative HH] According to the following formula for calculating the distance x, at least at the distance x upstream of the arterial end of the blood pipeline, thus at the distance x upstream of the patient (H)'s access:

[0111]

[0112] In the alternative embodiments AA to HH of this improvement, it is particularly advantageous that the blood tube set and the clamp are designed such that the arrangement of the adjustable constriction can be used to facilitate the detection of the position of a blood clot. The alternative embodiments AA to HH here have the property that they are not mutually exclusive: depending on the parameter values and configuration of the blood tube set, etc., and thus the calculations according to alternative embodiments GG and HH can provide the same value or a value corresponding to alternative embodiment FF. Thus, two or three of these alternative embodiments may have been implemented simultaneously. Furthermore, for a given set of tube materials, one of the alternative embodiments AA to EE can be implemented simultaneously, such that one or more of the alternative embodiments FF to HH and at least one of the alternative embodiments AA to EE can be implemented simultaneously. For a known set of tube materials, the scope of alternative embodiment AA can include the scope of alternative embodiments BB to EE, the scope of alternative embodiment BB can include the scope of alternative embodiments CC and alternative embodiment EE. The scope of alternative embodiment CC can include the scope of alternative embodiment EE. A known set of tube materials can have the property that the scope of alternative embodiment DD and the scope of alternative embodiment CC are not provided in an overlapping manner. A known set of tube materials can have the property that the scope of alternative embodiment DD and the scope of alternative embodiment EE overlap. The term tube set / tube material set can be used synonymously with the term blood tube set / blood tube material set. For alternative embodiments EE to HH, it may be particularly advantageous that, due to the adjustable constriction being at a certain distance from the patient access, sufficient reaction time of the system is ensured such that a detected blood clot can be prevented from being delivered to the patient.

[0113] One aspect of the present invention relates to an extracorporeal blood treatment device, the extracorporeal blood treatment device comprising means for detecting a blood clot according to the present invention, an electromagnetic safety tube clamp for pressing down on the blood tube in the event of an impending risk and / or means for outputting an alarm and / or a blood pump, wherein the control unit of the blood treatment device is configured to close the safety tube clamp and / or output an alarm and / or stop the blood pump if the means for detecting a blood clot detects a blood clot. In other words, according to this aspect, the extracorporeal blood treatment device according to the present invention is equipped with means for detecting a blood clot according to the present invention, and furthermore, the extracorporeal blood treatment device includes one or more of the active components in the following list: an electromagnetic safety tube clamp, means for outputting an alarm, a blood pump. The statement elsewhere in this document also applies, where an extracorporeal blood treatment device according to the present invention is discussed, the extracorporeal blood treatment device having active components such as a tube clamp, means for outputting an alarm, and a blood pump. Since active components of the device are involved here, the "tube clamp" does not refer to a manual mechanical tube clamp, but to an electrical or electromagnetic or otherwise actuated tube clamp.

[0114] One aspect of the present invention relates to a system for extracorporeal blood treatment of a patient, the system comprising an extracorporeal blood treatment device having means for detecting blood clots in the extracorporeal blood circulation according to the present invention. The extracorporeal blood treatment device further comprises an electromagnetic safety tube clamp for pressing down on the blood tube in the event of an impending risk and / or means for outputting an alarm and / or a blood pump, wherein the control unit of the blood treatment device is configured to close the safety tube clamp and / or output an alarm and / or stop the blood pump if the means for detecting blood clots detects a blood clot. The extracorporeal blood treatment device typically has a control unit. The means for detecting blood clots and the extracorporeal blood treatment device may have separate control units. However, the two functions may also be combined in one control unit. The control unit of the extracorporeal blood treatment device will then also have the functions of the control unit of the means for detecting blood clots. In addition, the system comprises a blood tube set. In this embodiment of the present invention, the means for detecting blood clots is arranged on a section of the blood pipeline, this section of the blood pipeline being at a distance of at least 30 cm upstream of the patient's access, or is calculated according to one of two alternative formulas for determining the distance x:

[0115]

[0116] Or

[0117]

[0118] This advantageously enables blood clots to be detected by the device at a significant distance from the patient. Embodiments described elsewhere in this document for arranging the adjustable constriction at a specific distance also apply to this embodiment, if not contradictory.

[0119] One aspect of the present invention relates to a system for extracorporeal blood treatment of a patient, the system comprising an extracorporeal blood treatment device having means for detecting blood clots in the extracorporeal blood circulation according to the present invention. The extracorporeal blood treatment device further comprises an electromagnetic safety tube clamp for pressing down the blood tube in case of an impending risk and / or means for outputting an alarm and / or a blood pump, wherein the control unit of the blood treatment device is configured to close the safety tube clamp and / or output an alarm and / or stop the blood pump if the means for detecting blood clots detects a blood clot. The extracorporeal blood treatment device typically has a control unit. The means for detecting blood clots and the extracorporeal blood treatment device may have separate control units. However, the two functions may also be combined in one control unit. The control unit of the extracorporeal blood treatment device will then also have the function of the control unit of the means for detecting blood clots. In addition, the system comprises a blood tube set. In the system according to the present embodiment, the blood tube set and the blood treatment device are arranged relative to each other such that an adjustable constriction for detecting blood clots is formed on a section of the blood pipeline in one of the following areas by means of an actuator or by means of a mechanical clamp:

[0120] [Alternative 21AA] Between the arterial end of the blood pipeline, thus the access to the patient, and the pump tube section, which is the section of the blood tube that can be inserted into the blood pump,

[0121] wherein the blood tube set comprises the pump tube section;

[0122] [Alternative 21BB] Between the manual mechanical tube clamp and the pump tube section, the manual mechanical tube clamp not having a partially open position but fully pressing down the blood tube in its clamping position, the pump tube section being the section of the blood tube that can be inserted into the blood pump, wherein the blood tube

[0123] set comprises the pump tube section;

[0124] [Alternative 21CC] Between the manual mechanical tube clamp and the means for arterial pressure measurement of the blood tube set, the manual mechanical tube clamp not having a partially open position but fully pressing down the blood tube in its clamping position, wherein the blood tube set comprises the means for

[0125] arterial pressure measurement;

[0126] [Alternative 21DD] Between the device for arterial pressure measurement for the blood tube set and the pump tube section, the pump tube section being the section of the blood tube that can be inserted into the blood pump, where the blood tube set includes the pump tube section, where, - if there are multiple blood pumps and / or pump tube sections - the pump tube section means the pump tube section closest to the arterial end of the blood pipeline, where the blood tube set includes the device for arterial pressure measurement and the pump tube section;

[0127] [Alternative 21EE] Between the fluid interface configured for administering an infusion and the pump tube section of the blood tube set, the pump tube section being the section of the blood tube that can be inserted into the blood pump, where,

[0128] The blood tube set includes the interface for administering an infusion, the blood pump, and the pump tube section.

[0129] The statements made above regarding the position of the adjustable constriction described in Alternatives AA to EE (including its advantages) apply to Alternatives 21AA to 21EE.

[0130] When "pressing down on the tube" (in whole or in part) is mentioned in this document, this means "occluding". That is, it does not matter whether the adjustable constriction is created by pressing down or by another means of reducing the cross-section. Thus, "pressing down" can also be interpreted as "occluding". This can also be understood as the position of a partially open adjustable constriction.

[0131] An embodiment of a method according to the invention for monitoring extracorporeal blood circulation to detect blood clots in the extracorporeal blood circulation at least includes the following steps:

[0132] - Using an actuator or by setting or applying a manual mechanical clamp, creating an adjustable constriction on the blood circulation by compressing a section of the blood tube, where the adjustable constriction has a width such that blood can continue to flow through the constriction, where the manual clamp presents a partially open position,

[0133] - Using a sensor to measure at least one parameter related to the properties of the liquid in the pipeline section having the constriction,

[0134] - Using a control unit to evaluate the measurement data of the sensor to detect the passage of a blood clot through the constriction.

[0135] The statements made above regarding the method according to the invention, including the advantages, apply to this embodiment of the method. Description of the Drawings

[0136] In the drawings:

[0137] Figure 1Shows a schematic diagram of an extracorporeal blood circulation having a device according to the present invention, the extracorporeal blood circulation being connected to the blood circulation of a human body;

[0138] Figure 2 Shows two graphs of liquid pressure and volume flow velocity on the same time axis;

[0139] Figure 3 Shows a schematic diagram of an extracorporeal blood circulation having a device according to the present invention, the extracorporeal blood circulation being configured for hemodialysis treatment;

[0140] Figure 4 Shows a modification of the schematic diagram of the extracorporeal blood circulation, the extracorporeal blood circulation being Figure 1 similar and having a device according to the present invention, but with the pump in a different position, the extracorporeal blood circulation being connectable to the blood circulation of a human body. Detailed Description

[0141] Figure 1An extracorporeal blood circulation 300 with a device 100 for detecting blood clots in an extracorporeal blood circulation, as presented here, is schematically shown. In the schematic illustration, a human body H is shown on the left side, and in the example shown, the extracorporeal blood circulation is connected to the human body H. The upper branch of the blood circulation 300 leads away from the human body H via a blood pump 10 to an adjustable constriction 20 of a blood line. The actuator D of the device can create the adjustable constriction 20 as it reduces the cross-section of the blood line in section 25. Downstream of the constriction 20, a pressure sensor P for measuring the liquid pressure in the extracorporeal blood circulation 300 and a volumetric flow velocity sensor Q for measuring the flow velocity of the extracorporeal blood circulation 300 are arranged. However, in a basic variant, only one of these two sensors P, Q is required. The second sensor is optional. After passing through the sensors, the blood flows back to the human body H via the lower branch of the extracorporeal blood circulation 300. An elastic blood tube is typically located at the position of the constriction 20. The actuator D itself can create the constriction, or as shown here, the actuator D can be connected to another element E, which compresses a section of the blood tube, thereby forming the constriction. The constriction 20 can be adjusted by means of the actuator D. An exemplary structure is shown in which the constriction 20 is formed and the blood tube is deformed accordingly in section 25 such that the cross-section is reduced. The control unit CU of the device 100 presented here is connected to the actuator D of the adjustable constriction and one or more sensors P, Q. The order of the flow directions of the pump 10, the constriction 20, and the sensors P, Q shown here is merely exemplary. Other arrangements, such as arranging one or more sensors P, Q between the pump 10 and the constriction 20, are also conceivable. In the exemplary embodiment shown, it is possible that a blood clot further transported through the extracorporeal blood circulation 300 starting from the blood pump P then reaches the constriction 20. The presence of a blood clot in the constriction 20 will cause changes in the flow rate Q and the pressure P. The control unit CU acquires the measurement values of one or more sensors, thereby enabling the detection of blood clots in the constriction.

[0142] Figure 2 shows where is drawn in Figure 1A graph of measurement data recorded by the device 100 according to the invention is used in the arrangement. Two separate curves O, U are shown in the graph. The upper curve O shows the measurement data of the volume flow rate measured using the volume flow sensor Q, while the lower curve U shows the measurement data of the pressure measurement measured using the pressure sensor P. The measurement data are recorded simultaneously on the same device 100 and share a common horizontal axis, on which the time "time" is plotted in seconds s. The two curves have different value ranges and units on the vertical axis: the upper curve O shows the volume flow rate "flow" in ml / min, where many values are in the range of approximately 140 - 150 ml / min. The lower curve U shows the pressure (in mbar) relative to the reference pressure, where these values are initially in the single-digit positive range and then also drop to almost about -20 mbar. Although the variables plotted in the ordinates in the two different curves are different, it is advantageous to plot them on a shared axis. The arrow on the left side of the graph, approximately at "Time" = 22 seconds on the horizontal axis, marks a short-term drop a in the flow rate and pressure caused by the passage of a blood clot through the constriction 20. The short-term drop in the flow rate and / or pressure is an example of a feature in the measurement signal based on which the device 100 according to the invention detects the passage of a blood clot through the adjustable constriction 20. On the right side of the graph, approximately at "Time" = 44 seconds, the arrow indicates a further sudden drop b in the flow rate and pressure, however, where the flow rate and pressure remain at a low level after the drop b. This is a feature where the clot has become stuck in the constriction 20 of a device having a continuous pumping pump such as an impeller pump. In the case where the order of the elements of the pump 10, the constriction 20, and the pressure gauge P and / or the volume flow rate sensor Q is different, the passage of the clot through the constriction 20 may be accompanied by an increase in pressure and flow rate. However, depending on the arrangement, the flow rate value may also drop when the pressure rises.

[0143] Figure 3Fig. 0 shows a device 100 according to the present invention in an exemplary embodiment, the device 100 being configured for hemodialysis treatment using a dialyzer D in an extracorporeal blood circulation 300. The arm of the patient H with two connectors shown as arterial and venous blood cannulas is indicated on the right side of the image. During the dialysis treatment, in the lower branch, blood flows from the patient H to the dialyzer DZ, and here it first passes through an optional first flowmeter Q', then through an actuator D which can create an adjustable constriction 20 on the line section 25 of the blood line, then through a second flowmeter Q and a pressure gauge P and a blood pump 10, where the blood pump 10 is optionally represented here as a roller pump. Instead of the roller pump P, other blood pumps P such as an impeller pump P can also be used. During the reinfusion phase, the blood present in the extracorporeal blood circulation is reinfused into the patient's body. In the so-called closed-loop reinfusion, in the Figure 3 arrangement, the blood in the lower branch is transported back to the patient H from the dialyzer DZ via the blood pump 10 and the constriction 20. If only one sensor, i.e., a blood volume flow rate sensor Q or a pressure gauge P, is arranged in this branch of the extracorporeal blood circulation, the detection of blood clots according to the present invention is already possible. Additional sensors are optional. However, the arrangement of both the pressure sensor P and the flow sensor Q and their combined evaluation are advantageous because higher sensitivity can be achieved. In the Figure 3 arrangement, depending on the optionally arranged sensors in the section, the passage of a blood clot will have a different signature from that Figure 2 shown: In an exemplary embodiment according to Figure 3 , there is only one pressure sensor P and one volume flow rate sensor Q between the adjustable constriction 20 and the blood pump, and the resulting characteristics of measuring blood clots are as described below. During the treatment operation, a blood clot in the constriction 20 will cause a decrease in the pressure and flow rate in the sensors. In the case of reinfusion, a clot in the constriction 20 will cause an increase in the measured pressure and a decrease in the measured volume flow rate.

[0144] Figure 4 Fig. 12 schematically shows the extracorporeal blood circulation 300 of the device 100 for detecting blood clots in the extracorporeal blood circulation as presented here as Figure 1 shown, with the only difference being that the pump is arranged upstream of the sensors and the constriction. In this case, in the presence of a blood clot, a representation similar to the Figure 2 data graph will have different signatures. The arrangement shown here has a pressure sensor arranged upstream of the constriction in the flow direction. Therefore, a high level of sensitivity for pressure measurement for clots in the constriction is particularly advantageously achieved.

Claims

1. A device (100) for detecting blood clots in an extracorporeal blood circulation (300), the device (100) being connectable to an extracorporeal blood circulation (300) having an adjustable constriction, the device (100) comprising: at least one sensor (P, Q) that acquires at least one parameter related to the properties of the liquid in the extracorporeal blood circulation (300), a control unit (CU) configured such that measurement signals from the at least one sensor (P, Q) are evaluated and, based on this evaluation of the parameters measured by the sensor (P, Q), the passage of a blood clot through the constriction (20) and / or the adhesion of a blood clot in the constriction (20) can be detected, wherein the device (100) is configured such that it can detect a blood clot at an adjustable constriction that has been adjusted by shrinking a blood tube using an actuator or a mechanical clamp.

2. The device (100) according to claim 1, wherein, The sensor is a flow sensor (Q) that measures the current flow rate of the liquid or a pressure sensor (P) that measures the current pressure of the liquid.

3. The device (100) according to claim 1, wherein, The device (100) has at least one flow sensor (Q) and at least one pressure sensor (P), wherein the control unit (CU) is configured such that it jointly considers the measured values of at least one flow sensor (Q) and at least one pressure sensor (P) to detect a blood clot.

4. The device (100) according to any one of claims 1 to 3, wherein, The device (100) comprises: an actuator (D) that can create an adjustable constriction (20) in the extracorporeal blood circulation, since the actuator (D) reduces the cross-section of a section of the blood line (25).

5. The device (100) according to claim 4, the device (100) being designed as a tube clamp or as part of a tube clamp into which a medical tube can be inserted.

6. The device (100) according to claim 5, wherein, The actuator (D) can assume at least three different positions, namely: a closed position in which the extracorporeal blood circulation (300) does not have a free line cross-section at a point and is thus blocked; an open position in which the extracorporeal blood circulation (300) does not have a constriction (20) at the actuator (D); and (c) a third, partially open position that lies between the closed position and the open position, in which an adjusted constriction (20) can be created to detect a blood clot on the inserted tube (25).

7. The device (100) according to claim 6, wherein, The tube clamp has a so-called multi-magnet that includes a plurality of magnetized regions such that the tube clamp has at least three different positions.

8. The device (100) according to claim 5, wherein, Spacers can be arranged between the clamping elements of the clamp such that a partially open clamping position is achieved at the constriction, and wherein the device (100) only optionally includes an actuator (D) that can create an adjustable constriction (20) in the extracorporeal circulation.

9. The apparatus (100) according to any one of claims 4 to 8, wherein, The actuator (D) and the control unit (CU) are configured such that the device (100) is capable of assuming at least two different operating states, in each of which the actuator (D) forms the constriction (20), wherein a predetermined width of the constriction (20) is different in different operating states.

10. The device (100) according to claim 9, wherein, The control unit (CU) is configured to be able to select the width of the constriction (20) according to a predetermined scheme and to adjust the width of the constriction (20) at the actuator (D) taking into account the parameters of the extracorporeal blood circulation to detect blood clots.

11. The device (100) according to any one of claims 4 to 7, 9 or 10, wherein, The width of the constriction (20) is variable, and the control unit (CU) is configured to be able to adjust the constriction (20) for the operation of detecting blood clots taking into account the parameters of the extracorporeal blood circulation (300) such that the sensitivity and / or robustness of the detection is optimized.

12. The device (100) according to claim 11, wherein, The control unit (CU) is configured to be able to calculate the optimal width of the constriction (20) during a medical treatment using the extracorporeal blood circulation (300) according to the parameters of the extracorporeal blood circulation (300) and / or the parameters of the treatment, and to adjust the optimal width of the constriction (20) using the actuator (D).

13. A blood tube set configured for use with the device according to any one of claims 1 to 3 or the method according to any one of claims 18 or 19, the blood tube set comprising a blood tube or blood pipeline and a mechanical means, in particular a mechanical clamp, for adjusting a constriction on a pipeline section of the blood tube or the blood pipeline.

14. A manual mechanical tube clamp for creating an adjustable constriction on a section of a blood tube in an extracorporeal blood circulation to detect blood clots in the extracorporeal blood circulation, wherein, The clamp has the property that it can assume and hold a partially open position, wherein the clamp can partially compress a section of the blood tube in the partially open position, and by means of the clamp, on the one hand, a constriction is formed on the blood tube, and on the other hand, due to the constriction, the blood tube remains liquid permeable at the constriction.

15. A blood tube set for extracorporeal blood treatment to detect blood clots in extracorporeal blood circulation, the blood tube set comprising the manual mechanical tube clamp according to claim 14 and a blood tube having an arterial end for connection to a patient access.

16. A blood tube set for detecting blood clots in extracorporeal blood circulation according to claim 15, wherein, The blood tube set further comprises a mechanical manual tube clamp that completely blocks the tube in the clamping position but does not have a partially open position.

17. A blood tube set for detecting blood clots in extracorporeal blood circulation according to claim 15 or 16, wherein, The blood tube set has the property that by using the clamp that can assume a partially open position, by arranging the clamp and by transferring the clamp to the partially open position, an adjustable constriction can be formed on a section of the blood pipeline located in one of the following regions: - between the arterial end of the blood pipeline, thus the access to the patient (H), and the pump tube section, which is the section of the blood tube that can be inserted into the blood pump, wherein, the blood tube set comprises the pump tube section; or - between the manual mechanical tube clamp and the pump tube section, the manual mechanical tube clamp does not have a partially open position, but fully presses down the blood tube in its clamping position, the pump tube section being the section of the blood tube that can be inserted into the blood pump, wherein the blood tube set includes the pump tube section; or - between the manual mechanical tube clamp and the device for arterial pressure measurement of the blood tube set, the manual mechanical tube clamp does not have a partially open position, but fully presses down the blood tube in its clamping position, wherein the blood tube set includes the device for arterial pressure measurement; or - between the device for arterial pressure measurement of the blood tube set and the pump tube section, the pump tube section being the section of the blood tube that can be inserted into the blood pump, wherein the blood tube set includes the pump tube section, and wherein - if there are multiple blood pumps and / or pump tube sections - the pump tube section refers to the pump tube section closest to the arterial end of the blood pipeline, wherein the blood tube set includes the device for arterial pressure measurement and the pump tube section; or - between the fluid interface configured to administer an infusion and the pump tube section of the blood tube set, the pump tube section being the section of the blood tube that can be inserted into the blood pump, wherein the blood tube set includes the interface for administering an infusion, the blood pump, and the pump tube section; or - arranged upstream of the patient (H)'s access, at least 30 cm upstream of the arterial end of the blood pipeline, thus at least 30 cm upstream of the patient (H)'s access; or - at least at the distance x upstream of the arterial end of the blood pipeline, thus at the distance x upstream of the patient (H)'s access, according to the following formula for determining the distance x; or - at least at the distance x upstream of the arterial end of the blood pipeline, thus at the distance x upstream of the patient (H)'s access, according to the following formula for determining the distance x:

18. An extracorporeal blood treatment device, comprising: The device (100) according to any one of claims 1 to 12; An electromagnetic safety tube clamp for pressing down the blood tube in the event of an impending risk; and / or a device for outputting an alarm; and / or a blood pump (10), wherein the control unit of the blood treatment device is configured to be able to close the safety tube clamp and / or output an alarm and / or stop the blood pump (10) when a device (100) for detecting a blood clot detects a blood clot.

19. The extracorporeal blood treatment device according to claim 18, wherein, The blood treatment device is a hemodialysis machine.

20. A system for extracorporeal blood treatment of a patient, comprising the extracorporeal blood treatment device according to claim 18 or 19 and a blood tube, wherein, An adjustable constriction for detecting a blood clot (100) is formed on a section of the blood pipeline such that the constriction is arranged at least 30 cm upstream of the patient (H)'s access or such that, according to one of two alternative formulas for determining the distance x, the constriction is arranged at least the distance x upstream of the patient (H)'s access; or 21. A system for extracorporeal blood treatment of a patient, comprising the extracorporeal blood treatment device according to claim 18 or 19 and a blood tube set, wherein, The blood tube set and the blood treatment device are arranged relative to each other such that an adjustable constriction for detecting a blood clot (100) is formed on a section of the blood pipeline in one of the following regions by means of an actuator or by means of a mechanical clamp: - between the arterial end of the blood line, thus the access to the patient (H), and the pump tube section, which is the section of the blood tube that can be inserted into the blood pump, wherein, the blood tube set includes the pump tube section; - between the manual mechanical tube clamp and the pump tube section, the manual mechanical tube clamp does not have a partially open position, but completely presses down the blood tube in its clamping position, the pump tube section is the section of the blood tube that can be inserted into the blood pump, wherein the blood tube set includes the pump tube section; - between the manual mechanical tube clamp and the device for measuring the arterial pressure of the blood tube set, the manual mechanical tube clamp does not have a partially open position, but completely presses down the blood tube in its clamping position, wherein the blood tube set includes the device for measuring the arterial pressure; - between the device for measuring the arterial pressure of the blood tube set and the pump tube section, the pump tube section is the section of the blood tube that can be inserted into the blood pump, wherein the blood tube set includes the pump tube section, wherein, - if there are multiple blood pumps and / or pump tube sections - the pump tube section refers to the pump tube section closest to the arterial end of the blood line, wherein the blood tube set includes the device for measuring the arterial pressure and the pump tube section; - between the fluid interface configured for administering infusions and the pump tube section of the blood tube set, the pump tube section is the section of the blood tube that can be inserted into the blood pump, wherein the blood tube set includes the interface for administering infusions, the blood pump, and the pump tube section.

22. A method for monitoring extracorporeal blood circulation to detect blood clots in the extracorporeal blood circulation, wherein, The method at least includes the following steps: - using an actuator or by setting or applying a manual mechanical clamp, generating an adjustable constriction (20) on the blood circulation (300) by compressing a section of the blood tube, wherein the adjustable constriction has a width that allows blood to continue flowing through the constriction, wherein the manual clamp presents a partially open position, - using sensors (P, Q) to measure at least one parameter related to the properties of the liquid in the pipeline section with the constriction (20), - using a control unit to evaluate the measurement data of the sensors (P, Q) to detect the passage of a blood clot through the constriction.

23. A method for controlling an extracorporeal blood treatment device, including the method according to claim 22, and additionally including the following steps: - when the passage of a blood clot through the constriction (20) is established, closing the tube clamp and / or outputting an alarm and / or stopping the blood pump (10).

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