Systems and methods for preparing catheters prior to use

Abstract

To provide a system and method in the field of catheters for use in patients, particularly catheters of intravascular blood pumps.SOLUTION: There are provided systems and methods for properly purging and deairing catheters 1. A catheter 1 comprises an elongated tubular portion 11 and a connected device 230. The elongated tubular portion 11 is configured to be inserted into a patient's blood vessel and defines a lumen 12. The device 230 is connected to the elongated tubular portion 11 and has a cavity 13, where the cavity 13 may accommodate a drive unit 4 of a blood pump 10 and is in fluid communication with the lumen 12 of the elongated tubular portion 11. A sensor 15 such as an accelerometer is provided to detect orientation of the device 230, so as to ensure that the system 100 is deaired, and a user can be guided to correct the orientation of the connected device 230 for proper purging.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for preparing a catheter for use in a patient, in particular for purging and deairing, and further to a respective system including the catheter, which may be part of an intravascular blood pump for percutaneous insertion into a patient's blood vessel. [Background technology]

[0002] Before using a catheter in a patient, and more specifically, before inserting the catheter into a patient's blood vessel, the catheter must be properly prepared. In particular, the catheter must be purged and de-aired to prevent the introduction of air or other gas bubbles into the patient, which could result in serious complications such as infarction. Typically, a catheter comprises an elongated tubular body having a proximal end and a distal end, the distal end being the tip when inserted into a patient. The tubular body has a lumen extending through the catheter from the proximal end to the distal end and receiving functional structures, lines, or the like, depending on the application or for delivering fluids, including, for example, medicinal agents, to the patient. This lumen contains air prior to use and must be completely de-aired before the catheter is inserted into a patient. For de-airing and purging, fluid may be pumped through the catheter at a constant pressure.

[0003] Deairing the lumen of the elongated tubular body of a catheter is not a challenge due to its flat geometry and small diameter. Because the lumen typically lacks any convex surfaces and has a small diameter, capillary forces draw the purge fluid through the lumen itself, eliminating any air or other gas bubbles. However, the catheter may be in fluid communication with at least one connected device, such as a pump unit or handle, that may be held by a user to operate or otherwise control the catheter's functions. Depending on the application, the connected device may have at least one cavity in fluid communication with the lumen of the catheter and having a fluid inlet for receiving the purge fluid. Because this cavity of the connected device may have a complex geometry and may contain functional and possibly movable parts, it is possible that air bubbles may still be trapped within the cavity even if the purge fluid has already exited the catheter from the distal end. In particular, if the user does not hold the connected device correctly, for example, not in the correct air removal orientation, which may be an upright vertical orientation, it may be possible for air bubbles to become trapped inside the cavity. With current technology, determining when the catheter and connected device are fully evacuated relies heavily on the experience of the user, who may be, for example, a surgeon, cardiologist, general practitioner, or other medical staff.

[0004] The above-mentioned problem of catheter de-airing, and in particular connected device de-airing, is particularly relevant to intravascular blood pumps, which are configured for percutaneous insertion into a patient's blood vessel and include a pump unit having a rotatable impeller for conveying blood from a blood inlet to a blood outlet thereof, and a drive unit for causing rotation of the impeller is provided.

[0005] In one type of intravascular blood pump, the pump unit includes a drive unit directly coupled to the impeller and contained together with the pump unit in a common pump housing, which may be disposed at the distal end of the catheter. Evacuation of the catheter may be required prior to insertion into the patient.

[0006] In another type of intravascular blood pump, the drive unit may be coupled to the impeller by a flexible drive shaft extending through the lumen of the elongated tubular portion of the catheter, in which case the drive unit may be disposed in a cavity in the handle portion. In this type of intravascular blood pump, the pump unit with the impeller may be expandable. The drive unit may include an electric motor including a stator and a rotor, and additional electronic parts for controlling the rotation of the drive unit, which may create protrusions, undercuts, or cavities in which air bubbles may become trapped. Because the drive unit, such as the moving parts of the electric motor, may be submerged in the purge fluid, it may be even more difficult to properly remove all air bubbles from the cavity in the handle portion. Therefore, to avoid harm to the patient, it is important for the user to hold the catheter, particularly the handle portion, in the air removal orientation during purging and air removal. Summary of the Invention [Problem to be solved by the invention]

[0007] It is therefore an object of the present invention to provide a method for preparing, in particular purging, a catheter for use in a patient, and a respective system including the catheter, which makes it possible to reliably remove air from the catheter before insertion into the patient's body. In particular, the catheter may be part of an intravascular blood pump. [Means for solving the problem]

[0008] This object is achieved according to the present invention by a system and a method having the features of the independent claims. Preferred embodiments and further developments of the invention are specified in the claims dependent on the independent claims.

[0009] According to a first aspect of the present invention, there is provided a system comprising the catheter as described above, the catheter in particular comprising an elongated tubular portion and a connected device connected to the catheter. The elongated tubular portion has a lumen. The connected device has at least one cavity. As already explained, before the catheter is used in a patient, the lumen and the cavity should be deaerated, i.e., air bubbles should be completely removed. To monitor the orientation of the at least one connected device and the orientation of the elongated tubular portion, preferably one connected device, which will be described in further detail below, the system further comprises at least one sensor for detecting said orientation.

[0010] According to a second aspect of the present invention, there is provided a method of preparing a catheter for use in a patient. In particular, the catheter is constructed to have an elongated tubular portion and a connected device, as already described. In this method of preparing, and in particular purging, a catheter, fluid is supplied through a fluid inlet into at least one cavity of the connected device and thereby into the lumen of the elongated tubular portion to purge said cavity and lumen. The method further comprises the step of detecting the orientation of the at least one connected device and the orientation of the elongated tubular portion, preferably during fluid supply.

[0011] The systems and methods of the present invention are capable of detecting the orientation of at least one connected device and / or elongate tubular portion, preferably the connected device. Thus, the systems and methods of the present invention provide a means for monitoring the orientation of at least a portion of a catheter, particularly during the purging process, without relying on the user's experience to correctly orient the catheter, particularly the connected device. It will be understood that the term "connected device" may refer to any structure connected to an elongate tubular body that can be manipulated by a user, particularly held in the user's hand or rotated with a patient, and that has a cavity in fluid communication with the lumen of the elongate tubular body.

[0012] The term "orientation" refers to the orientation of each portion of the catheter in three-dimensional space, particularly relative to a fixed frame of reference such as gravity. In particular, orientation does not necessarily include the absolute position of each portion of the catheter in three-dimensional space, but rather may be considered a "relative position," for example, relative to a vertical or horizontal axis or plane in three-dimensional space or any other suitable reference point or frame. For example, orientation may refer to the inclination of each portion of the catheter, and may be expressed as an angle in degrees, for example, relative to a vertical axis or horizontal plane. The vertical axis may be oriented in the direction of gravity.

[0013] A control unit may be provided that can receive data from at least one sensor, the data including, inter alia, the detected orientation, i.e., the data representing the actual or current orientation of each portion of the catheter. The data may be transmitted by wire or wirelessly. It may be determined whether the detected orientation corresponds to an orientation that allows air removal of the cavity, which may be the cavity whose orientation is detected. The difference between the detected orientation and a predetermined orientation, i.e., a predefined orientation to be achieved by a user orienting the catheter, may be calculated. The predetermined target orientation is not necessarily a unique orientation, but may include a range of orientations suitable for proper purging, as will be explained in more detail below.

[0014] Based on the difference between the detected orientation and the predetermined orientation, the user may be guided to change, i.e., correct, the orientation of each portion of the catheter to approach the predetermined orientation. Each portion of the catheter may be moved to match the predetermined orientation or at least fall within the range defined by the predetermined orientation. It will be understood that tolerances may be allowed. A user interface, e.g., a display or similar, may be provided in the control unit, which may display the detected orientation and / or a representation indicating the difference between the detected orientation and the predetermined orientation. Alternatively or additionally, the user interface may display the correspondence between the detected orientation and the orientation in which the cavity may be deaerated, which may be the predetermined orientation. For example, an image of each portion of the catheter may be displayed showing its orientation in real time, or a simple graphic, such as a line or similar indicating the tilt angle. Additionally or alternatively, the difference between the detected orientation and the predetermined target orientation may be displayed. Any suitable graphic, e.g., a symbol, a color scale (e.g., red-yellow-green), or similar, may be displayed. Alternatively or additionally, this difference may be indicated by any suitable audio signal, thereby enabling the user to change orientation to approach the predetermined target orientation.

[0015] Guiding the user to correct the orientation of each section of the catheter can improve the purging process and reduce or eliminate the risk of trapping air bubbles inside the cavity or lumen. In particular, complex geometries inside the cavity or lumen, such as protrusions, undercuts, or the like, may require the user to hold each section of the catheter in a specific orientation to allow air bubbles to escape.

[0016] Because air bubbles move vertically upward in the purge fluid, the predetermined orientation is preferably a vertical or substantially vertical orientation, or a conical range defined by a vertical axis and a predetermined angle. It will be understood that any other orientation is possible depending on the geometry of the cavity or lumen to be deaerated. For example, depending on the interior geometry, a 45-degree angle or any other angle may be necessary or appropriate to completely deaerate the cavity. As previously mentioned, the "predetermined orientation" may include a range of orientations, such as a range of angles within which the catheter cavity and lumen can be completely deaerated. For example, if the cavity has a flat, regular geometry, it may be sufficient for the user to hold the catheter, and in particular each part of the connected device, within a 45-degree or 30-degree range in either direction relative to the vertical axis. Preferably, the orientation can be detected in a range from 0 to 180 degrees, for example, to determine which end of the handle portion faces up and which end faces down. Generally, to ensure proper air removal, the fluid inlet of the handle portion should be positioned vertically below the outlet of the lumen of the elongated tubular portion. For example, the angle of orientation may point in the main longitudinal direction of the catheter or connected device.

[0017] It will be appreciated that the predetermined orientation, whether it refers to a single orientation or a range of orientations, may not refer to tilt, i.e., the angle of the respective catheter portion relative to an external reference frame, but may refer to any other degree of freedom, such as rotation about the longitudinal axis of the respective catheter portion. For example, it may be necessary to rotate, for example, the connected device about its longitudinal axis to the predetermined orientation in order to remove any air bubbles from the cavity, particularly if the predetermined orientation is other than vertical.

[0018] In certain embodiments, the user can initiate the purging process, and fluid, i.e., any suitable purging fluid, is supplied to the cavity of the connected device and thereby into the lumen of the tubular portion of the catheter. The purging fluid can be continuously supplied to the cavity and lumen of the catheter while the user is continuously guided to hold each portion of the catheter in the correct orientation, i.e., to change the orientation if necessary.

[0019] However, in a preferred embodiment, fluid delivery may be specifically activated only if the detected orientation matches a predetermined target orientation, i.e., if the user correctly orients the catheter and / or connected device relative to the respective catheter portions. Similarly, fluid delivery may be deactivated, i.e., stopped or interrupted, if the detected orientation differs from the predetermined target orientation, i.e., if the user does not correctly orient the respective catheter portions. In this particular embodiment, it may be advantageous to measure the volume of fluid delivered. Thus, if the measured volume of fluid delivered reaches the known volume of the cavities and lumens to be purged, a conclusion can be drawn that air removal is complete due to the fact that air bubbles can always escape from the cavities and lumens due to the correct orientation. At this point, the system may notify the user that purging is complete. It will be appreciated that a certain safety margin, i.e., additional volume of purge fluid, may be added until the system indicates that the purging process has been successfully completed. Furthermore, to complete the purging process, the user may be required to confirm that purge fluid is being expelled from the catheter at the distal end.

[0020] As already explained, even though purging at least one cavity of the connected device may be difficult, there may be no problem with purging the lumen of the elongated tubular portion of the catheter. In another preferred embodiment, at least one sensor is disposed in the connected device of the catheter to detect its orientation. It may not be necessary to detect the orientation of the elongated tubular portion of the catheter.

[0021] The at least one sensor for detecting the orientation of each portion of the catheter, in particular the orientation of at least one connected device, may be at least one of a gravity sensor, an accelerometer, and a gyroscope. For convenience, any of these elements may refer to all of these elements. However, the term "sensor" in the sense of this disclosure may include any other type of active or passive sensor, means or system capable of detecting the orientation of each portion of the catheter in three-dimensional space. These may include sensors based on magnetic or electromagnetic fields, optical sensors, or the like. For example, in another embodiment, at least one sensor may be disposed at a distance from the catheter. The sensor may be formed by a camera system that records the orientation of each portion of the catheter, in particular the orientation of at least one connected device, and detects the orientation from the recorded images.

[0022] However, sensors that are easy to implement in existing systems and provide reliable results are preferred. For example, the advantage of gravity sensors or accelerometers is that they do not require any external infrastructure, such as external sensors or external electromagnetic field generators. Furthermore, accelerometers are not affected by external perturbations, such as magnetic fields that may be generated by the electric motor of an intravascular blood pump. The accelerometer may be designed as a MEMS device or nanodevice and can be disposed on a printed circuit board (PCB) or printed circuit assembly (PCA) already present in, for example, the drive unit of an intravascular blood pump.

[0023] The gravity sensor or accelerometer can detect the "downward" direction, and more specifically, the vertical direction. This "downward" direction, which represents the detected orientation, can be transferred to the control unit using memory-mapped register technology. This means that the sensor data, i.e., the detected orientation (downward), is stored in a memory, such as the memory of the blood pump. Each time the control unit reads a specific byte of the pump memory, it gets the detected orientation, e.g., tilt angle, instead of the memory content. This means that the accelerometer does not need an additional connection, e.g., a wire, to the control unit to transfer the sensor's data, but uses the existing communication connection to read the memory.

[0024] As described above, the systems and methods according to the present invention can be particularly advantageous when used with an intravascular blood pump, particularly an intravascular blood pump having a pump unit connected to an elongated portion of a catheter. In this type of intravascular blood pump, the interior of the catheter is in fluid communication with the environment and is purged during pump operation, but must be completely purged of air prior to use to prevent air bubbles from being introduced into the patient's vasculature. By detecting the orientation of at least one connected device and guiding the user to properly orient the catheter, particularly at least one of the connected devices, it is possible to ensure that each cavity is purged of air. As will be appreciated by those skilled in the art, the pump unit can be expandable, i.e., it can be compressed into a compressed configuration for insertion into a blood vessel and released and expanded once positioned at the target location.

[0025] The foregoing summary and the following detailed description of the preferred embodiments will be better understood when read in conjunction with the accompanying drawings. For purposes of illustrating the disclosure, reference will be made to the drawings, which should be understood as being schematic and may not reflect precise scale. These drawings are exemplary for illustrating the invention, and the scope of the disclosure is not limited to the specific embodiments disclosed in the drawings. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 illustrates a system according to one embodiment of the present invention, including an intravascular blood pump connected to a control unit. [Figure 2] FIG. 2 shows the blood pump of FIG. 1 in more detail. [Figure 3a] 10A-10C are diagrams illustrating schematically the handle portion or pump unit of a catheter in different orientations during a purging process. [Figure 3b] 10A-10C are diagrams illustrating schematically the handle portion or pump unit of a catheter in different orientations during a purging process. [Figure 3c] 10A-10C are diagrams illustrating schematically the handle portion or pump unit of a catheter in different orientations during a purging process. DETAILED DESCRIPTION OF THE INVENTION

[0027] FIG. 1 illustrates a system 100 according to one embodiment of the present invention. In particular, the system 100 includes an intravascular blood pump 10 connected to a control unit 5. The intravascular blood pump 10 includes a catheter 1 having a pump unit 2 connected to a distal end 22 of the catheter 1, more specifically, to an elongated tubular portion 11 of the catheter 1 (see FIG. 2). The pump unit 2 is also referred to as a connected device 230. A handle portion 3 is connected to a proximal end 21 of the elongated tubular portion 11. The handle portion 3 is also referred to as a connected device 230. The handle portion 3 can be grasped by a user to handle the catheter 1 and is not inserted into the patient's body. The intravascular blood pump 10 may be designed to act as a left ventricular assist device and may be inserted into a patient's aorta toward the heart, more specifically, toward the left ventricle of the patient's heart. In this case, the pump unit 2 would be positioned through the aortic valve to pump blood from the left ventricle into the aorta. However, it will be understood that the blood pump 10 may be designed for a different application, such as acting as a right ventricular assist device, or that the catheter may be designed for a different application than an intravascular blood pump.

[0028] Still referring to FIG. 1 , the handle portion 3 houses the drive unit 4 of the blood pump 10, which will be described in more detail below. An electrical connection cable 7 is provided connecting the intravascular blood pump 10 to a control unit 5 for controlling the drive unit 4. The control unit 5 has a user interface with a display 6. It will be understood that the control unit 5 may include various additional control elements, such as a touch screen, a control dial, buttons, or the like. The display 6 may be configured to display various operating parameters of the blood pump 10, such as pump flow rate, pump speed, motor current, etc. In particular, in the context of the present invention, the display 6 may display a representation of the orientation of a connected device 230, such as the handle portion 3, detected by the sensor 15 during the initial purging process. As shown in FIG. 1 , the current orientation 27 of the connected device 230 may be displayed relative to a predetermined target orientation 28 of the connected device (indicated by a dashed line in FIG. 1 ). Any other display options suitable for guiding a user may also be implemented. Additionally or alternatively, the orientation 27 of the pump unit 2 may be displayed.

[0029] In addition to the electrical connections, the blood pump 10 is further connected to a purge line 8 that is provided to supply a purge fluid to the blood pump 10 for the initial purging and air removal process and for purging and air removal during operation of the blood pump 10. The purge line 8 may be connected to a purge cassette 9, which may be provided to generate a specific purge pressure, which may be, for example, 500 mmHg. The purge fluid, which may be any suitable fluid such as water or preferably a glucose solution, may be provided in a container or bag 17 and supplied to the purge cassette 9 and further to the blood pump 10 via the purge line 8. Details regarding how to prepare the blood pump 10 are described in more detail below in connection with FIGS. 3a-3c.

[0030] Referring now to FIG. 2, the intravascular blood pump 10 of the system 100 of FIG. 1 is described in more detail. The blood pump 10 includes two connected devices 230: a handle portion 3 and a pump unit 2. Each of the connected devices 230 includes a cavity 13. Each of these cavities 13 is in fluid communication with the lumen 12 of the elongated tubular body 11. The blood pump 10 of the illustrated embodiment is an expandable catheter pump; in other words, the pump unit 2 is expandable from a compressed configuration (not shown) to an expanded configuration. More specifically, to insert the blood pump 10 into a patient's blood vessels through a small inlet, the pump unit 2 is compressed to the compressed configuration to reduce its diameter. Once positioned at a target location, such as the left ventricle and aorta, the pump unit 2 can expand. To this end, the pump unit 2 can include an expandable pump housing 23, which can be in the form of a cannula or formed as a mesh-like support structure covered by a thin polymer membrane. The support structure may be fabricated from a shape-memory material such as nitinol. The pump unit 2 may have an atraumatic tip 24, also known as a J-tip or pigtail, at its distal end. An impeller 18, which may be expandable and compressible, is disposed inside the pump housing 23. In particular, for the aforementioned application for left ventricular support, a blood inlet 19 may be formed in the distal portion of the pump housing 23, for example, in the enlarged diameter section. Blood enters the pump housing 23, is conveyed through the pump housing 23 by the impeller 18 rotating about its axis of rotation, and exits through a blood outlet 20 (indicated by arrow B).

[0031] Impeller 18 is coupled to a flexible drive shaft 16 that extends through catheter 1, and more particularly through lumen 12 of elongated tubular body 11 of catheter 1. Flexible drive shaft 16 is coupled to a drive unit 14 located within cavity 13 of handle portion 3. Drive unit 4, which is only diagrammatically illustrated in FIG. 2, may include an electric motor. Further electronics of drive unit 4, such as PCB 26, are connected to cable 7, which in turn is connected to control unit 5, as already described in connection with FIG. 1.

[0032] A sensor 15 for detecting the orientation of the handle portion 3 is arranged on the PCB 26 so as to transmit data regarding the current orientation to the control unit 4. Prior to use on a patient, the cavity 13 of the handle portion 3 of the catheter 1, the lumen 12 of the elongated tubular portion 11, and also the pump unit 2 must be completely purged of air, which means that all cavities of the blood pump 10 must be completely purged of air to prevent the introduction of air into the patient's vasculature, which could result in serious complications such as infarction. To supply purge fluid to the blood pump 10, a purge line 8 is connected to a purge fluid inlet 25 of the handle portion 3. Those skilled in the art will understand that various connectors, such as Y-connectors, luer connectors, or the like, can be used to connect the various lines and cables. Additionally or alternatively, sensors may be arranged in the pump unit, either additionally or separately.

[0033] 3a-3c, a method for preparing a catheter according to an embodiment of the present invention will now be described. In particular, as already explained, air bubbles must be completely removed during preparation of the catheter 1 before it can be used on a patient. While there is virtually no risk of air bubbles being trapped in the lumen 12 of the elongated tubular body 11 of the catheter 1, air bubbles may be trapped inside the handle portion 3 and / or the cavity 13 of a connected device, such as the pump unit 2. In particular, there is a risk that the purge fluid exiting the catheter 1 (i.e., exiting the pump unit 2) at the distal end 22 may erroneously imply that the catheter 1 has been successfully purged. This is because, even if purge fluid has already flowed through the lumen 12 of the elongated tubular body 11 of the catheter 1, the cavity 13 of the handle portion 3 (or the pump unit, not shown) may still have interior walls or recesses or other geometric structures of originally incorporated components that can fill with air. In particular, the lumen 12 may have such a small diameter that capillary forces may draw the purge fluid into the lumen 12 even if air is still present in the handle portion 3 and / or the cavity 13 of the pump unit. Furthermore, the cavity or the original installed components may have an irregular structure which further increases the risk of trapped air bubbles.

[0034] The risk of air bubbles being trapped inside the handle portion 3 and / or pump unit 2 can be substantially reduced or eliminated if the handle portion 3 and / or pump unit 2 are kept in the correct orientation during the initial purging process for de-airing the catheter 1. Therefore, the system 100 of the present invention includes a sensor 15 for detecting the orientation of the handle portion 3 and / or pump unit 2. In other words, the current orientation of the handle portion 3 and / or pump unit 2 can be detected while supplying purge fluid through the line 8 (see arrow P) into the handle portion 3 or pump unit 2 via the tubular portion 11. In particular, the current orientation can be detected continuously or at specific time intervals, preferably very short time intervals, so that the orientation can be appropriately monitored.

[0035] The sensor 15 may be a gravity sensor, an accelerometer, a gyroscope or any other sensor capable of detecting orientation. In particular, it is sufficient to detect the orientation, and it may not be necessary to detect the absolute position in three-dimensional space of the handle portion 3 and / or the pump unit 2, in particular in relation to gravity. In particular, an accelerometer does not require any external infrastructure, such as an external electromagnetic field generator or the like, and is not affected by magnetic fields that may be generated by the drive unit 4. Therefore, the accelerometer can provide an accurate orientation.

[0036] In particular, the orientation can be represented by the tilt angle α between the common longitudinal axis L and / or the pump unit 2 and a vertical axis V, preferably aligned with gravity. As shown by the arrows in FIGS. 3a-3c, the accelerometer 15 typically detects a vertical downward direction. The sensor data can be used to calculate the tilt angle α relative to a specific downward direction. The detected orientation can be transmitted to the control unit 5. Preferably, the sensor data obtained by the sensor 15 is transmitted using memory mapping, which eliminates the need for additional connecting wires; however, it is also possible to use the existing connecting cable 7 to transmit the sensor data. The control unit 5 can display the detected orientation calculated from the sensor data on the display 6, as illustrated in FIG. 1. Furthermore, the control unit 5 can be configured to guide the user to change the orientation of the handle portion 3 or the pump unit 2 to approach a predetermined target orientation. As illustrated in FIGS. 3a-3c, the display 6 can also provide positive and negative indications 29 regarding whether the current orientation matches or does not match the predetermined target orientation, respectively.

[0037] The air removal process will be described by way of example using the handle in Figures 3a-3c, which can be similarly applied to the pump unit 2. That is, a predetermined target orientation can be selected that ensures the escape of air bubbles from the cavity 13 of the handle portion 3 into the lumen 12 of the elongated tubular portion 11 of the catheter 1, depending on the internal geometry of the handle portion 3. This predetermined target orientation can be vertical, as shown in Figure 3a, but in this case, the purge fluid line 8 is positioned vertically further below the proximal end 21 of the tubular portion 11, i.e., at an angle α of zero degrees; in other words, the vertical axis V is coincident with the longitudinal axis L. In this orientation, the purge fluid 30 is introduced from below and can reliably push all air 31 vertically upward, ensuring that the cavity 13 and lumen 12 are deaerated. It will be understood that any angle α greater than zero, or any range of angles, can be selected to define the predetermined target orientation.

[0038] As shown in Figure 3b, if the handle portion 3 is held at an oblique angle, for example, where angle α is greater than 0 degrees but less than 90 degrees, such as 45 degrees, air 31 may be trapped in the corners of the cavity 13 of the handle portion 3 even though purge fluid 30 is already present in the lumen 12. Similarly, as shown in Figure 3c, if the handle portion 3 is held in an orientation where the fluid inlet into the handle portion 3 is positioned vertically above the outlet into the lumen 12, for example, where angle α is greater than 90 degrees but less than 180 degrees, air 31 may be trapped in the corners of the cavity 13 of the handle portion 3. However, purge fluid may continuously be expelled from the catheter 1 at the distal end 22, thereby causing the user to mistakenly believe that they have successfully purged the catheter 1.

[0039] The user is thus guided on how to hold the handle portion 3, in other words, how to change the orientation of the handle portion 3 to match the predetermined target orientation. The detected orientation, by which we mean the current orientation detected by the sensor 15, is compared with the predetermined target orientation, and an appropriate indication, for example at least one of the above-described indications 27, 28, and 29, is displayed on the display 6. It will be understood that any indication representing the difference between the current detected orientation and the predetermined target orientation appropriate for guiding the user to select the correct orientation may be envisaged, such as a graphical illustration, a color scale, an arrow, or the like. Similarly, additionally or instead, an audio signal may be used to guide the user to change their current orientation to approach and match the predetermined target orientation, which is necessary for complete air purging of the system.

[0040] During the above-described purging and air removal process, purge fluid may be continuously supplied into cavity 13 and lumen 12 by fluid line 8, although it may be advantageous to activate the flow of purge fluid only if the user holds handle portion 3 in the correct orientation. Conversely, the flow of purge fluid may be stopped or paused if the user does not hold handle portion 3 correctly. This may reduce or eliminate the risk of purge fluid being drawn into lumen 12 prematurely while air is still present in handle portion 3. The volume of purge fluid supplied may be measured such that an indication may be displayed once the purging and air removal process is complete based on the known volumes of all cavities in catheter 1. For safety reasons, control unit 5 may prompt the user to confirm that purge fluid exits blood pump 10 at the distal end, which may add a safety margin to the amount of purge fluid.

[0041] The disclosed methods and systems allow for proper and reliable preparation of a catheter for use with a patient, and in particular, proper purging and de-airing of the catheter to prevent air bubbles from being introduced into the patient's vasculature. It will be appreciated that while the present invention is particularly useful in the field of intravascular blood pumps, it may be implemented with any catheter that requires proper de-airing before use with a patient.

Claims

1. 1. A system (100) comprising a catheter (1), the catheter (1) comprising an elongated tubular portion (11) configured for insertion into a patient's blood vessel, the elongated tubular portion (11) having a proximal end (21) and a distal end (22) and a lumen (12) extending from the proximal end (21) to the distal end (22), each connected device (230) being connected to the elongated tubular portion (11) and having at least one cavity (13) in fluid communication with the lumen (12) of the elongated tubular portion (11); The system (100) further comprises at least one sensor (15) for detecting an orientation of at least one of the elongated tubular portion (11) and the at least one connected device (230).

2. 2. The system of claim 1, further comprising a control unit (5) configured to receive data from the at least one sensor (15) including the orientation detected by the at least one sensor (15) and to determine whether the detected orientation corresponds to an orientation in which air can be released from the cavity (13).

3. 3. The system according to claim 1 or 2, characterized in that the difference between the detected orientation and a predetermined orientation can be calculated to guide the user to change the orientation to approach the predetermined orientation.

4. 4. The system according to claim 1, wherein the control unit (5) is configured to display at least one of a coincidence indicator representing a coincidence between the detected orientation and an orientation in which air is releasable from the cavity (13), and a representation showing the detected orientation and a difference between the detected orientation and the predetermined orientation.

5. 5. The system of claim 3 or 4, wherein the predetermined orientation is a vertical orientation or a conical range around a vertical axis defined by a predetermined angle.

6. 6. The system according to claim 1, wherein the at least one sensor (15) is disposed on the connected device (230) and configured to detect an orientation of the connected device (230).

7. 7. The system according to any one of claims 1 to 6, wherein the at least one sensor (15) comprises at least one of a gravity sensor, an accelerometer, and a gyroscope.

8. 8. The system according to any one of claims 1 to 7, further comprising a pump unit (2) and a drive unit (4) providing an intravascular blood pump (10) for percutaneous insertion into a patient's blood vessel, the pump unit (2) being one of the at least one connected device (230), the pump unit (2) being disposed at the distal end (22) of the elongated tubular portion (11) of the catheter (1) and comprising a cavity (13), the pump unit (2) being rotatable about a rotation axis to convey blood from a blood inlet (19) to a blood outlet (20) of the pump unit (2). the pump unit (2) is preferably an expandable pump unit, the impeller (18) is coupled to a flexible drive shaft (16) extending through the lumen (12) of the elongated tubular portion (11) of the catheter (1), and the drive unit (4) is another one of the at least one connected device (230) and is disposed in the at least one cavity (13) of a handle portion (3) coupled to the flexible drive shaft (16) to cause rotation of the impeller (18).

9. 1. A method for preparing a catheter (1) for use in a patient, the catheter (1) comprising an elongated tubular portion (11) configured to be inserted into a blood vessel of a patient and having a proximal end (21) and a distal end (22) and a lumen (12) extending from the proximal end (21) to the distal end (22), each of the at least one connected device (230) connected to the elongated tubular portion (11) and having at least one cavity (13) in fluid communication with the lumen (12) of the elongated tubular portion (11), supplying a fluid (30) into at least one of: (a) the at least one cavity (13) of at least one of the at least one connected device (230) and (b) the lumen (12) of the elongated tubular portion (11) to purge at least one of the at least one cavity (13) and the lumen (12); detecting the orientation of at least one of the elongated tubular portion (11) and the at least one connected device (230); A method comprising:

10. 10. The method of claim 9, further comprising the step of determining whether the detected orientation corresponds to an orientation in which air can be released from the cavity (13).

11. 11. The method according to claim 9 or 10, characterized in that the difference between the detected orientation and a predetermined orientation is calculated to guide the user to change the orientation to approach the predetermined orientation.

12. 12. The method according to any one of claims 9 to 11, further comprising the step of displaying at least one of a coincidence indicator representing a coincidence between the detected orientation and an orientation in which air is releasable from the cavity (13), and a representation showing the detected orientation and a difference between the detected orientation and the predetermined orientation.

13. 13. The method of claim 11 or 12, wherein the predetermined orientation is a vertical orientation or a conical range around a vertical axis defined by a predetermined angle.

14. 14. A method according to any one of claims 11 to 13, characterized in that the supply of fluid is energized when the detected orientation coincides with the predetermined orientation, and the supply of fluid is de-energized when the detected orientation differs from the predetermined orientation.

15. 15. The method according to any one of claims 9 to 14, further comprising the step of measuring the volume of the supplied fluid (30).

16. 16. The method according to any one of claims 9 to 15, wherein the orientation is detected by at least one sensor (15), the at least one sensor (15) comprising at least one of a gravity sensor, an accelerometer and a gyroscope, the at least one sensor (15) being preferably arranged on at least one of the handle portion (3), the pump unit (2) and the elongated tubular portion (11), the handle portion (3) being one of the at least one connected devices (230) and the pump unit (2) being another of the at least one connected devices (230), and the sensor preferably comprising a camera preferably arranged externally of the handle portion (3), the pump unit (2) and the elongated tubular portion (11).

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