The invention relates to a flexible catheter with a bendable drive wave according to the general concept of the main claim as well as a blood pump arrangement with such a catheter.
The present catheters is typically used for generating or transmitting a rotational moment or a rotational movement within the body of a human being or an animal. The drive wave travels axially along the longitudinal extension of the catheter between a proximal end of the catheter and a distal end of the catheter. Typically, a proximal end of the drive wave is connected outside the body to a drive motor in order to generate the rotational moment or the rotational movement and to transmit it to the drive wave. At the distal end of the drive wave, a rotational element or functional element is typically rigidly connected to the drive wave, which is adapted to the respective application. For example, the functional element may be a drill, a rotor ablator, or a pump rotor for blood propulsion. For example, US 2012/178986 A1 describes a flexible catheter according to the generic concept of the main claim. Further examples of flexible catheters are described in US 5 569 275 A, US 2013/066140 A1, and EP 2 314 330 A1.
For many applications it is necessary to guide a catheter along a curved path through the body, e.g. along or within blood vessels, in order to position the distal end of the catheter at a desired location within the body, e.g. within a heart chamber, for the duration of the respective application. Apart from the required flexibility and curviness of the catheter, further criteria must also be fulfilled. For example, in some applications it is necessary that with the drive wave rotational movements with a very high rotational speed are generated or transmitted, e.g. the required rotational speed may be more than 10,000, more than 20,000 or even more than 30,000 rpm.000 Rotations per minute, as is the case with blood transport in the example already mentioned. In cases where rotation must be generated over a longer period of time, such as for several hours, days, or even weeks, as can also be the case with blood transport, especially high demands are placed on the mechanical and chemical loadability of the catheter, particularly on the driving wave. Material fatigue and damage processes in the driving wave and in other components of the catheter should progress as slowly as possible and, above all, in a foreseeable and controllable manner. In critical applications, such as blood transport, cracks and breaks in the driving wave must be eliminated as safely as possible during operation.这在硬壳中使用柔性的推进波时是有利的，该壳会磨损波浪。
Furthermore, in the case of an even occurring failure of the wave, it must be excluded with as high safety as possible that the typically grinding ends of the wave work with high rotation speed through the typically catheter sleeve made of plastics. In such a case, the ends of the wave would freely rotate in the blood vessel.
因此，本发明的任务是提出一种柔性的导管，其具有可弯曲的驱动波浪线，且尽可能安全，并且尤其适合高转速下的持续操作。此外，还提出一种血液泵布置，其也尽可能安全，并且尤其适合高转速下的持续操作。
The task is solved according to the main claim by a catheter, and according to the subclaims by a catheter and a blood pump arrangement. Preferred embodiments and further developments result from the dependent claims.
Aspects as detailed in the following, each of these aspects being realisable in an inventive catheter and in an inventive blood pump arrangement, provided also all features mentioned in the main claim or the subsidiary claim are realisable, respectively, though in principle each of these aspects can also be realised individually. However, a catheter or a blood pump arrangement falls under the claimed invention only if also all features mentioned in the main claim or the subsidiary claim are realisable, respectively. The aspects can thus be realisable independently of each other (and represent in each case special further developments of a generic catheter according to the overall concept of the main claim) and can also be combined in any way with each other to synergistically improve a generic catheter or a blood pump arrangement with a generic catheter. For example, a generic catheter according to one of these aspects may be provided and may simultaneously also be provided according to one (or more) further aspects. Then this catheter is a particularly advantageous embodiment of a catheter according to the first mentioned aspect. Each of the aspects also allows a further development of each of the other aspects.
The first aspect concerns the material and the material properties of the drive wave, the second aspect the geometric arrangement of the drive wave, the third aspect the arrangement of the casing, the fourth aspect the connection between the drive wave and the drive motor, the fifth aspect the storage of the drive wave, and the sixth aspect a lubricant for the drive wave. Each of these aspects contributes to improving the loadability and safety of the catheter or the blood pump arrangement.
一种类别的柔性导管包括驱动波，包围驱动波的护套和包围驱动波和护套的套筒，其中驱动波、护套和套筒是柔性的。驱动波的远端具有与驱动电机连接的连接元件或连接头。
Typically, the (axial) overall length of the catheter is between 50 cm and 200 cm, usually between 80 cm and 150 cm. Typically, the (axial) overall lengths of the drive wave, the sleeve and the shell also lie within these ranges. The flexibility or bending ability of the catheter, especially of the drive wave, the sleeve and the shell, should be sufficient to be able to elastically bend the catheter with a curvature radius in a range between 20 mm and 40 mm, preferably between 25 mm and 35 mm, especially from about 30 mm. With such a curvature, the drive wave and the sleeve should ideally only elastically deform at operating speed. There should also be no permanent (plastic) deformations or changes to the drive wave or the housing. Especially, an elastic curvature with the named curvature radius should also be possible for a roughly U-shaped curvature of the catheter by about 180°, when the catheter is, for example, continuously curved along an axial section of the catheter with a length of about (depending on the curvature radius) 80 mm to 150 mm, typically about 100 mm to 120 mm. Such curvatures of the catheter arise, for example, when the catheter runs through the aortic arch into the left heart chamber. Furthermore, it often occurs due to the rhythmic heart action to a rhythmic change of the described curvature radius.where the position of the curvature relative to the catheter can be rhythmically changed.
In many cases, it is not necessary for the catheter to exhibit such flexibility along its entire axial length. It is often sufficient that this flexibility is present in a certain axial section (or sections), for example, when a distal end of the catheter must be placed in a heart chamber in the case of blood flow, at least a distal end piece or a distal segment of the catheter may exhibit such flexibility. This distal end piece or segment may have an axial length in one of the above-mentioned length ranges, for example.
As described in more detail below, in some cases, the bendability and flexibility of the catheter or the drive wave may not be too high, especially in those axial sections of the drive wave that run distally or proximally outside the sheath or emerge from the sheath, so that it may be advantageous or even necessary in at least one of these sections to a certain extent to locally stiffen the drive wave. Such stiffening may allow a vibration minimization to be achieved in a more advantageous manner, thereby also reducing the risk of hemolysis.
As per the first aspect of the patent application, the catheter according to the invention comprises a propulsion wave in its entirety or at least partially in the form of an alloy, which contains, respectively, at least 10% by weight of chromium, nickel and cobalt. Preferably, the alloy contains at least 30% by weight of nickel, preferably not more than 40% by weight of nickel. Preferably, the alloy contains at least 30% by weight of cobalt, preferably not more than 40% by weight of cobalt. Preferably, the alloy contains 15% by weight of chromium, preferably not more than 25% by weight of chromium. The alloy preferably further comprises molybdenum, preferably at least 5% by weight, preferably not more than 15% by weight molybdenum.
For example, the alloy may contain alloy components such as nickel with about 35% weight fraction, cobalt with about 35% weight fraction, chromium with about 20% weight fraction, and molybdenum with about 10% weight fraction. The alloy components of the alloy may also vary by up to 3% weight fraction or by up to 2% weight fraction. The alloy components of these elements may correspond to the alloy components of these elements in the alloy MP35N® or the alloy 35NLT® or may deviate from them by up to 2% weight fraction or may deviate from them by up to 1% weight fraction. The alloy may also contain further alloy elements. These may be selected and adjusted according to those of the alloy MP35N® or those of the alloy 35NLT®.
The alloy is preferably MP35N® or 35NLT® or is produced in a corresponding (or equivalent) manner, i.e. with corresponding (or equivalent) process steps and with corresponding (or equivalent) process parameters, as MP35N® or as 35NLT®. For example, it may be provided that the alloy of the drive roller or the drive roller as a whole is cold hardened or produced or shaped by means of a (high-)cold forming or cold hardening. For example, the cold hardening degree of the material of the drive roller and/or the shell between 35% and 70% and/or between 40% and 60%. Therefrom may result a tensile strength of the material in a range between 1900 MPa and 2200 MPa.
Figures 16 and 17 show the connections between flow limit, tensile strength, fracture elongation, and cold hardening degree for the example of the material 35NLT (based on manufacturer Fort Wayne Metals). This example shows that different heat treatment states and cold hardening degrees of a material can lead to very different material properties in general. These often only become apparent as unsuitable for a flexible driving wave after the fact.
例如，过高或过低的冷硬可能会导致材料最大断裂韧性和韧性下降，进而影响驱动波的弯曲刚度和波的可弯曲半径。材料硬度相对较低和屈服强度相对较低也是一致的。较低的硬度直接影响波的磨损行为，进而影响其耐用性，可能导致操作过程中波的磨损加剧。这在滑动对，如柔性波的典型配置中尤其关键。较低的屈服强度会导致较低的弯曲刚度。
由于驱动波在不同的材料参数上也具有不同的优化目标，优化稳定且耐用的柔性驱动波非常复杂，因此没有常规的和有意义的优化方法，也没有显而易见的参数窗口。
Surprisingly, it has turned out that propulsion waves which are made up in whole or at least in part from a material having a tensile strength of 1800 N/mm2 to 2400 N/mm2, preferably from 2034 to 2241 N/mm2 (that is, from 295 KSI to 325 KSI), lead to good results. The material may in particular be one of the alloys described here, which forms at least in part the propulsion wave of the catheter according to the invention, which therefore contains at least 10% weight fraction of chromium, nickel and cobalt. However, other materials for the propulsion wave are also conceivable, such as metal and non-metallic materials, in particular also plastics and composite materials.
A drive wave that is complete or at least regionally based on such an alloy or such a material is also suitable for applications at very high rotational speeds and long operation times, so that it is possible with such a drive wave to maintain the above mentioned rotational speed ranges for a longer time period. Typically, the torques transmitted by the drive wave at such high rotational speeds are relatively low, especially in blood transport, where the torque for driving an expanded pump rotor is typically higher due to the larger diameter. While the use of MP35N® or similar alloys, such as 35NLT®, may be known for various medical instruments, such as a stylet, due to their load-bearing capacity and corrosion resistance, they are surprising for flexible drive waves due to the described specific requirements, especially at high speed, long operation time, and strong curvature, especially considering that for use as a blood pump, in extreme cases, more than 500,000,000 complete load changes may occur, and in some cases, more than 1,000,000,000 load changes
For many decades, in particular for blood pumps, alloys with a relatively high iron or titanium content have been used to achieve high load capacity. However, as has been found within the scope of the present invention, it is possible and should even be possible to do without an iron and/or titanium content as high as possible in order to allow continuous operation at high rotational speeds. The weight percentage of iron and/or titanium is preferably very low, preferably less than 2% by weight, or even less than 1% by weight. In principle, iron and/or titanium can be completely dispensed with as alloy components, corresponding to a weight percentage of less than 0.1% each.
According to the first aspect, the driving wave can be fully or at least regionally composed of an alloy with an iron weight fraction of less than 2% or preferably less than 1% or particularly preferably less than 0.1%. According to the first aspect, the driving wave can be fully or at least regionally composed of an alloy with a titanium weight fraction of less than 2% or preferably less than 1% or particularly preferably less than 0.1%.
优选地，驱动波、壳、外套以及/或者可能存在的储存部件由生物兼容材料构成；或者至少每个组件的外表面由生物兼容材料构成。
According to the second aspect of the invention, the drive wave may have a hollow space that extends axially within the drive wave. In this case, the drive wave may be a hollow wave. The hollow space may extend longitudinally along the entire length of the drive wave. The high flexibility of the drive wave can be achieved by the hollow space, while the relative large torsional rigidity is maintained. The flexibility can be further increased if the drive wave has a plurality of or multiple coaxial turns that encircle the hollow space of the drive wave helically. Furthermore, the turns of the drive wave can be arranged in two or more coaxial layers of the drive wave. Then, the turns within different coaxial layers have a preferred opposing winding directions. In this way, the tension and pressure stresses caused by torsion stresses between the layers can be fully or at least partially compensated or balanced. As a result, the bending stresses in the drive wave can also be reduced in general.
Typically, the winding of the drive wave concerns windings of a wound wire or several corresponding wound wires, within each position the drive wave can contain exactly one or several such wires, for example 1 to 8 wires, preferably 4 to 6 wires, particularly preferred 5 wires. The wire or the wires are typically made of the above-described alloy. The wire or the wires have typically diameters in the range of about 0.09 mm to about 0.21 mm, preferably about 0.135 mm to about 0.165 mm. The outer diameter of the drive wave typically lies in the range of about 0.53 mm to about 132 mm, preferably in a range of about 0.79 mm to about 0.97 mm. In particular, the outer diameter of the driving wave is preferably less than 1 mm. The inner diameter of the driving wave typically lies in a range of about 0.17 mm to about 0.39 mm, preferably in a range of about 0.25 mm to about 0.31 mm. In the case of two concentric layers, the axially adjacent turns of the inner layer touch each other, whereas the axially adjacent turns of the outer layer preferably do not touch each other (each in the case of a curvature-free alignment of the driving wave), but an axial distance in a range of about 0.018 mm to about 0.042 mm, preferably about 0show between 027 mm and approximately 0,033 mm.
The use of a small outer diameter of the drive wave allows a small outer diameter of the catheter to be realized, thus minimizing the tissue damage at the puncture site. Further advantages that can be achieved with a small outer diameter of the drive wave include reduced friction and wear problems due to a lower circumferential velocity of the drive wave, reduced vibration problems due to a lower mass of the drive wave, as well as reduced interference of motor current signals by vibrations and, for example, a reduced risk that potentially existing calcifications within the blood vessels may detach from the vessel wall and reach the patient's circulation with potentially life-threatening consequences.
Surprisingly, it has turned out that the transmission of sufficiently high torque, for example for the drive of an expandable pump rotor in the expanded state, is also possible with the here mentioned small outer diameters of the drive wave of less than 1 mm over a longer period of time. Here, it has also been proven particularly advantageous for the case of a wave constructeded from wires of the above mentioned kind, that the specified areas for the wire diameters are particularly advantageous, and it has also been proven that the optimal range for the diameters of the individual wires is not trivially related to the outer diameter of the drive wave.
此外，可设想的是，传动波纹管通过应用(高)冷形成或冷硬化来制造或形成，以改善传动波纹管的弹性和耐用性。
It is possible that the hollow space is completely or within axial sections of the driving wave filled with a reinforcement material, in order to set the stiffness and stability of the driving wave in each axial section and (possibly regionally) to increase it. As already explained in connection with the first aspect of the invention, in addition to a sufficient bending stiffness of the driving wave, a sufficient stiffness of the driving wave is also required for a safe operation of the catheter, in particular at high revolutions and long operating time, for example, to allow a stable rotation of the driving wave, in particular in axial sections of the driving wave that run distally or proximally outside the casing (distal or proximal end piece of the driving wave).第一和第二发明特征以协同的方式补充。因此，优选实施方式包括这样一种方式：驱动波的远端部分和/或驱动波的近端部分和/或驱动波的远端和/或近端部分是固定的。固定的部分特别优选地具有长度在10mm和60mm之间，尤其优选地具有长度在20mm和50mm之间。特别优选地，在驱动波的固定部分区域中，驱动波的放置位置在壳体的轴向和/或径向，和/或在壳体的轴向和/或径向的位置，和/或驱动波的放置位置在壳体的轴向和/或径向，和/或壳体的轴向和/或径向的位置处，和/或在壳体的轴向和/或径向的位置处，和/或壳体的轴向和/或径向的位置处。It may be advantageous to stiffen the drive wave in the region where the drive wave is proximal to the sheath and does not enter or exit the sheath. It may also be advantageous to stiffen the drive wave in the region where the drive wave is distal to the sheath and does enter or exit the sheath. Just in these transition regions, by stiffening the drive wave, bending and other loads, such as for example vibration loads, on the drive wave can be reduced.
作为支撑材料，用于支撑传动波，材料一方面表现出较高的刚性，同时又具有相当高的弹性变形性。尤其是，支撑材料应能容忍植入过程中和操作期间，导管或导管头在使用过程中所受到的所有弯曲。例如，可以考虑不锈钢作为支撑材料，例如符合德国标准1.4310的不锈钢。
In addition to or instead of the described reinforcement material, a corresponding reinforcement can be achieved by welding (axial and/or radial) adjacent to the windings of the (cylindrical) drive wave. It is also possible that a certain (and under certain circumstances sufficient) reinforcement of the drive wave can be achieved by the distal functional module, which is typically rotatably attached to the outer circumference of the drive axis, for example, a pump rotor.
According to the third aspect of the invention, the casing may be designed as a rack spiral with a plurality of windings. The windings of the rack spiral circumnavigate the drive wave in axial direction in the manner of a helix. For example, the rack spiral may be a wound flat belt. The flat belt has preferably a factor of at least 3, preferably a factor of 6, a larger width (axially measured) than thickness (radially measured). Typically, the width of the windings is in the range of about 0.36 mm to about 0.84 mm, preferably in the range of about 0.54 mm to about 0.66 mm. The thickness of the windings typically lies in the range of about0,68 mm.77. In which the inner diameter of the housing corresponds with the outer diameter of the flexible drive wave, particularly so that the outer diameter of the drive wave is larger than the outer diameter of the housing.
Preferably, the winding is laid in such a way that, if the flat band is laid out as a coiled band, the winding is as little as possible inclined with respect to the longitudinal axis of the storage spiral when the storage spiral is straight (without bending of the storage spiral). Preferably, the winding inclination is less than 10°, particularly preferably less than 5°. Preferably, the inner surface of the housing or the winding of the storage spiral forms cylindrical parts of the surface instead of conical parts (winding inclination). A winding inclination with respect to the longitudinal axis leads to a reduction of the available storage surface and to a greater load on the driving wave. Preferably, the edges of the flat band are rounded as much as possible to avoid pressure peaks on the driving wave. Preferably, the radius of curvature of the edges is 0.04 mm or more.
In accordance with the invention, the casing is completely or at least regionally made of the same alloy as the drive wave. The description of the alloy of the drive wave can be accordingly also transferred to the alloy of the casing. The casing is therefore made in accordance with the invention completely or at least regionally of the same material as the drive wave.
Using the same material for the drive shaft and the casing, very good results were achieved in the laboratory test under different pulsatile loads and with bend radii below 50mm. This is somewhat surprising. For example, in order to ensure patient safety, it is recommended to design the flexible shaft in a comparatively hard, wear-resistant material in order to prevent the drive shaft from being rubbed by the casing and the still softer catheter layer, especially in the case of a shaft break, which usually leads to a break in the shaft area and then rotating freely in the blood vessel. Moreover, in conventional mechanical engineering, it is generally advised against using the same material as sliding partners or friction partners, as it can lead to so-called "eating" of the parts, which arises when individual molecules of the two sliding partners combine and can then be torn out of the molecular bond of one of the parts. It is considered particularly critical that it is difficult or even impossible to predict which of the two parts will wear out. The use of the same material for a fast rotating flexible shaft and the casing around it is therefore surprising for the specialist.
The fourth aspect of the possible design and development of the inventive catheter relates to the design of the proximal coupling element or coupling head of the drive wave, which can also substantially improve the safety of the catheter and its suitability for long-term use in a further manner, especially if this aspect is combined with one of the other aspects. The basic idea of the fourth aspect consists in the fact that axial pressure and tension forces in the drive wave are often significantly reduced, when the connection between the coupling element of the drive wave, which is as stiff as possible and rigidly connected with the drive wave, and a corresponding coupling element of the drive motor, which is rigidly connected with the drive motor in the axial direction, but axial movements between the coupling element of the drive wave and the coupling element of the drive motor are possible.The coupling elements of the drive wave and the drive motor may correspondingly have axial sliding surfaces, which typically run parallel to the (local) rotational axis or the longitudinal axis of the respective coupling element. The shape of these axial sliding surfaces or their outer or inner contour does not change in the axial direction (i.e., along the rotational axis or the longitudinal axis). For example, the coupling element of the drive shaft may have the shape of a square or another profile piece, which has a constant cross-sectional surface (defined perpendicular to the rotational axis or the longitudinal axis) or outer contour along its longitudinal extension or the rotational axis. The coupling element of the drive motor may accordingly be designed as a corresponding reception for the square or该段个人资料已经整理。
As already mentioned, the catheter may have, for example, a pump rotor at a distal end of the driving wave that is firmly connected to the driving wave, for example for blood pumping. The pump rotor may, depending on configuration, design and tilting angle of the rotor chamber of the pump rotor, for example for pumping the blood proximally (proximal pumping direction, i.e. in the direction of the proximal end of the catheter) or distally (distal pumping direction, i.e. in the direction of the distal end of the catheter) be arranged. The fifth aspect of the possible design and further development of the catheter according to the invention relates to an axial mounting of the pump rotor, wherein an axial bearing of the catheter is matched to the pumping direction of the pump rotor so that axial bearing forces are mainly or mainly directed in the direction of the pumping direction of the pump rotor, for example, and/or are directed substantially in a direction opposite to the pumping direction of the pump rotor.Act exclusively as axial thrust forces (and less or not as axial pressure forces) on the drive wave. Unexpectedly, this can lead to a significant reduction in the load on the drive wave, especially at high rotational speeds. Moreover, it has surprisingly been shown that with such a design of the blood pump, the blood damage caused by the pump operation is lower. In the event of a proximal pump direction, the axial bearing is arranged proximal to the pump rotor and designed to counteract an axial displacement of the drive wave in the opposite direction (caused by the proximal conveying effect of the pump rotor). In the event of a distal pump direction, the axial bearing is arranged distal to the pump rotor and designed to counteract an axial displacement of the drive wave in the opposite direction.
For example, the axial housing may comprise a first axial housing element and a second axial housing element, wherein the first axial housing element is rotatably connected to the driving wave, and the second axial housing element is fixed to the housing or the mantle. The first axial housing element and the second axial housing element each comprise mutually opposed, preferably ring-shaped sliding surfaces (which can also be referred to as impact surfaces or front surfaces), which block an axial displacement of the driving wave when they touch each other in at least one direction. The mentioned sliding surfaces overlap each other in the radial direction. The first axial housing element may be designed as a radial extension of the driving wave, but also as a ring, which is attached to the driving wave, for example by crimping. The second axial housing element may simultaneously be a radial housing element, for example with a sliding surface directed towards the driving wave, preferably cylindrical and arranged coaxially to the driving wave's rotation axis.
At least one of the named glide or impact surfaces is prioritized, typically the glide surface of the first storage element of the axial storage, such that a profile is provided such that the two glide surfaces together with a (fluid) lubricating medium form a hydrodynamic storage. The lubricating medium is preferably the lubricating medium described further above. The profile has the function of generating wave patterns of the lubricating medium between the two glide surfaces, which in turn circulate the driving wave in the rotational operation. Surprisingly, the wear that arises in this area could be reduced by more than 50% by this design of the glide surfaces.
For example, profiling of each sliding surface may comprise several, preferably 6 to 24, elevations and/or depressions, which may preferably each have a height or depth of about 0.03 mm to about 0.1 mm. The elevations and/or depressions are typically arranged along a circumferential direction and/or periphery direction of each sliding surface over this sliding surface. The elevations may be the same, similarly the depressions may be the same. The elevations may abut the depressions laterally and vice versa. Especially, profiling may be arranged as a (along the periphery direction) alternating sequence of elevations and depressions. For example, the elevations and/or depressions may be arranged as ribs or as grooves, which typically start from an inner edge of the sliding surface facing the driving wave and extend in the direction of an outer edge of the sliding surface opposite the driving wave. Typically, the grooves or ribs run exactly from the inner edge to the outer edge and thus have a length corresponding to the radial measured width of the respective sliding surface.
Typically, the grooves or rills show a width (measured in circumferential direction) in the range of about 0.08 mm to about 0.5 mm. In the radial direction, the width of the grooves or rills can be constant or change. Typically, the profiling along the circumferential direction of the slide surface alternates depressions or rills and an elevation or ridge. If the grooves have a constant width, the ridges typically spread radially outward. Such implementations are often particularly easy to produce by milling. If the ridges have a constant width, the grooves typically spread radially outward. It is also possible that both the ridges and the grooves spread radially outward. The last implementation is often particularly easy to produce by laser cutting. The grooves or ridges can also be formed spirally in areas, so extending on a curved path (e.g., a circular path) from the inner edge to the outer edge of the slide surface.
The catheter may also comprise further storage elements for the radial and/or axial storage of the drive wave, which are also made of the materials mentioned.
As part of a possible embodiment and development of the invention, the space between the driving wave and the housing is filled with a lubricant which is biocompatible and preferably also physiological. For example, this lubricant may consist of distilled water or of a water-based solution, for example of a solution of cooking salt and/or of a glucose solution. The solution may have a concentration of cooking salt which is physiological, for example 0.9%. However, an isotonic solution of cooking salt or so-called Ringer solution may also be provided. Since the lubricant is biocompatible, on the one hand the construction of the catheter can be simplified, as the discharge of the lubricant into the body does not have to be avoided in any case. Provided that the driving wave, the housing and the storage elements are made of the materials proposed here, these components are chemically relatively stable with regard to corrosion by these (relatively corrosive) lubricants, so that the use of these lubricants does not practically impair the safety and suitability of the catheter for continuous operation. The use of a solution of cooking salt is particularly advantageous in this respect, since such solutions are usually very well tolerated by patients and without side effects, especially also in the case of a diabetes disease of the patient.
The present invention relates to a blood pump arrangement of the type comprising a catheter of the type described and an actuator motor for producing the rotational movement or torque, wherein a rotatably fixed and preferably axially displaceable connection exists between the actuator motor, or the coupling element of the actuator motor already mentioned, and the coupling element or coupling head of the actuator wave. With regard to the latter, reference is made to the description in connection with the fourth aspect. The actuator motor can be arranged to generate high revolutions, for example revolutions in the range of 10,000 to 40,000 revolutions per minute. The functional element which is connected to the distal end piece of the actuator wave in a rotatably fixed manner is designed as a pump rotor. The catheter has at its distal end a pump housing,The pump rotor is arranged in the pump housing. The pump housing may, for example, be designed in such a way that the pump housing (e.g. under pressure exerted in the proximal (or distal) end of the catheter) can be converted from an expanded (or compressed) state to a compressed (or expanded) state. For details, reference is made to the printed document EP2399639 A1. In the case of a use of the pump arrangement, for example, it may be provided that the catheter with its distal end is pushed in front through the femoral artery over the aortic arch into the left ventricle of the heart and the pump housing remains in the left ventricle. An outflow tube connected proximally to the pump housing,The catheter typically runs through the aortic valves, allowing the blood pushed by the pump rotor, which is flowing out of the pump housing, to enter the aorta. The proximal end of the catheter and the driving wave as well as the driving motor are arranged outside the body.
In applications of this kind, and similar, external force effects and bending effects are exerted on the driving wave and possibly on the catheter storage elements of the catheter or the blood pump arrangement. External force effects and bending effects can be transmitted to the catheter, for example, through the inner wall of the heart, where the catheter possibly lies or is supported (e.g. through so-called pigtail tips), through pulsatile pressure changes or flow changes in the blood within a heart chamber or a blood vessel, such as the left or right ventricle or the aorta, through a change in position or support of the body, in particular through a body movement or a (leg-)movement near a puncture site. Despite these effects, the proposed catheter and the proposed blood pump arrangement can still pump blood over longer periods of time, such as hours, days or even weeks, even at high rotor speeds of the pump, for example in the above mentioned speed range, as described, for example, in the above described use of the blood pump arrangement.
For example, as indicated in “The Sternotomy Hemopump. A second generation intraarterial ventricular assist device”, Wampler RK et al., ASAIO J. 1993 Jul-Sep;39(3):M218-23, in the laboratory, undulating ruptures can only be simulated under pulsatile loads and bend radii of less than 2 inches (less than 50.8 mm) realistically. This is particularly indicative of the importance of multiple loading of the undulation. So far, it is not known to the applicant any flexible wave pumps that have been successfully used under pulsatile loads in the aortic arch for a longer period of time. This can be attributed to the problem of flexible waves not being successfully treated. So far, it has also been especially in the above-mentioned publication by Wampler et al., the use of a three-ply wave instead of a two-ply wave as essential for the improvement of the life span of the flexible wave was considered. The proposed drive undulations, however, also in a two-ply implementation, and thus also in versions with much smaller diameters than conventional drive undulations, show a comparable longevity or even significantly longer durability and loadability under small bend radii (less than 50 mm) and pulsatile loading than conventional drive undulations.
The outer surface of the driving wave may exhibit a surprisingly large roughness RZ. For example, the roughness RZ may be located in the range of 0.01 µm to 1 µm, preferably in the range of 0.1 µm to 0.8 µm. For example, the roughness RZ may amount to approximately 0.6 µm. It is surprising that very good results could be achieved in the endurance test with relatively large surface roughness of the driving wave, since, according to theoretical considerations, a perfectlyly smooth surface would be preferable to minimize wear by friction, especially if, as proposed here, a relatively corrosive substance, such as physiological cooking salt solution or glucose solution, is used as a lubricant, which does not come close to industry-standard lubricants in terms of lubrication effect, so that the commonly used design principles in classic mechanical engineering are apparently not directly transferable in this respect.
正如所描述的，这种可灵活的导管包括一个动力波浪，一个包围动力波浪的壳体和一个包围动力波浪和壳体的外套，其中动力波浪，壳体和外套是可弯曲的，其中动力波浪在动力波浪的近端具有一个接合元件以连接动力波浪和动力电机。
Furthermore, the driving wave may have an outer diameter of less than 1 mm. Preferably, the driving wave and/or the sheath are at least partially made of a material having a tensile strength between 1800 N/mm2 and 2400 N/mm2, preferably between 2034 N/mm2 and 2241 N/mm2. The driving wave and/or the sheath may be at least partially made of a non-metallic or metallic material. In the case of a metallic material, this is preferably an alloy as described above, which contains at least 10% by weight of chrome, nickel and cobalt. This such alloy may have the features described above. The driving wave and the sheath may be made of the same material fully or at least partially. Furthermore, the surface of the driving wave may have a roughness between 0.01 µm and 1 µm, preferably between 0.1 µm and 0.8 µm. Of course, the catheter may have all the features and feature combinations described above and below.
The aspects mentioned above are explained in the following by means of a schematic depiction of a specific embodiment of the catheter and of the blood pump arrangement proposed herein. It shows:Fig. 1 a catheter of the proposed type in a side view,Fig. 2 a blood pump arrangement with the catheter of Fig. 1 in an implanted state,Fig. 3 axial sections of parts of the drive wave of the catheter depicted in Fig. 1 in a side view,Fig. 4 a cross-section through the drive wave depicted in Fig. 3 at the place marked AA,Fig. 5 a distal end piece of the drive wave reinforced with a reinforcement material in a side view,Fig. 6 a longitudinal section through the end piece depicted in Fig. 5 at the place marked AA.Fig. 7 One casing of the catheter in Fig. 1, side view, Fig. 8 one cross section through a region in Fig. 7 marked with A, Fig. 9 one longitudinal section through the catheter in Fig. 1, the marked axial section marked with Y, Fig. 10 the distal end piece of Fig. 5 and 6 with a pump rotor fixed to the axis, Fig. 11 one longitudinal section through the catheter in Fig. 1, the marked axial section marked with Z, Fig. 12 one longitudinal section through a coupling module of the catheter in Fig. 1, and Fig. 13 an example of an axial rack element of Fig. 9 in a perspective view.Fig. 14a further example of the storage element shown in Fig. 13 also in a perspective representation,Fig. 15measured values of flow limit, tensile strength and fracture deformation for various cold hardening degrees for the material 35NLT, and Fig. 16graphical representation of the measured values of tensile strength and fracture deformation as functions of cold hardening degree for the material 35NLT.
在人物中，有回环的或对应的特性标记有相同的参照符号。
In Figur 1 ist eine spezielle Ausführungsform eines flexiblen catheters 1 hier vorgeschlagener Art schematisch dargestellt. The catheter 1 includes a flexible driving wave 2, from which in this figure a proximal end piece 3 is visible, which protrudes from a proximal coupling module 4 (freely carried) and has a driving wave element 5 at its proximal end for connecting the driving wave 2 with a driving motor, see Figur 2. The catheter 1 also includes a flexible sheath 6 surrounding and radially accommodating the driving wave 2 (not shown in this figure, but see Figures 7 to 9), and a flexible sleeve 7 surrounding the driving wave 1 and the sheath 6.When the coupling module 4 and the proximal end section 3 of the driving wave 2 are arranged at one proximal end 8 of the catheter 1, the catheter 1 comprises at one distal end 9 a pump head 10 with a pump housing 11, a housing 13 for the driving wave 2 arranged distally of the pump housing 11, and a proximal flow outlet 12 which is adjacent to the pump housing 11 (in figure 1, elements which are flowing within the flow outlet 12 are depicted in dashed lines). At the housing 13, a support element 14 in the form of a so-called pigtail tip is arranged distally. Moreover, the catheter 1 comprises a valve 15.Their function is that, when the pump head 10 is pulled into the sluice 15, the pump head 10 is radially compressed. In this compressed state, the pump head 10 may, for example, be guided through a guide sluice (not shown in the figures) and implanted through this. The guide sluice may, for example, be fixed at a puncture site on or in a patient's body, so that the catheter 1 can also be supported at this site in this way. In this context, reference is also made to the printed document EP2399639 A1.
Figure 2 shows this catheter as part of a blood pump arrangement 16 in an implanted state, schematically and in a highly simplified way. It shows a use or application of the catheter 1 and the blood pump arrangement 16, in which the driving wave 2 of the catheter 1 is connected via the coupling element 5 to a corresponding coupling element 17 of an electric motor 18 of the blood pump arrangement 1. The electric motor 18 is designed to produce high revolutions in the range of 10,000 to 40,000 revolutions per minute.
As shown in Figure 10, a driving wave 2 with a distal end piece 19 is connected to a function element 20, which is configured as a pump rotor. The pump rotor 20 is arranged inside the pump housing 11. The pump housing 11 can be switched from a radially expanded state to a radially compressed state. This can be achieved, for example, by means of the valve 15 or the previously mentioned admission valve, preferably by the pump housing 11 being pulled into one of the valves and compressed along a radial direction transverse to the longitudinal direction. By an opposing force, the pump housing 11 can be correspondingly switched from the compressed to the expanded state. Reference is also made to the pressure drawing EP2399639 A1 at this point.
The pump unit 2 is arranged such that the catheter 1 is inserted into the patient's femoral artery 22 throughrough a puncture site 21 and along the aortic arch 23 into the left ventricle 24 of the heart 25. The pump casing 11 is positioned in the left ventricle such that it is supported by the support element 14 at an inner wall 26 of the left ventricle 24 and the outflow hose 12 runs through the aortic valves 27 into the aorta 28. The blood driven by the pump rotor 20 and discharged from the pump casing 11 is led through the outflow hose 12 into the aorta 28. The proximal end 8 of the catheter 1, the proximal piece 3 of the driving wave 2 and the driving motor 18 are arranged outside the body.
To enable this use, in this embodiment the (axial) overall length of the catheter and the (axial) overall length of the drive wave 2 are each approximately 150 cm (corresponding to an implantable length of about 140 cm), the (axial) overall length of the distal end 9 of the catheter (including pump head 12 and support element 14) is about 13.5 cm. The flexibility or bending stiffness of the catheter 1, in particular of the drive wave 2, the sleeve 6 and the jacket 7 is so large that the catheter 1, as described above, can be implanted and operated. For this purpose, these components must be at least within the distal end 9 of the catheter 1 with the typical curvature radius R of about 30 mm elastically bent by 180°, as shown in Figure 2, without any plastic deformation in particular of the drive wave 2 occurring.
为了实现传动波2较高的柔韧性，如图4和6所示，该传动波2被设计为空心波，且在传动波2的轴向方向上设置有空腔29。该空腔29沿传动波2的全长延伸。然而，至少在传动波2的远端部分19约4.5cm的范围内，该空腔29完全填充有增强材料30，如图6，9和10所示，以实现传动波2或传动波2的远端部分19足够的刚度和振动稳定性。
The driving wave 2 indicates a number of coaxial windings 31, 32, which wind coaxially around the hollow space 29 of the driving wave 2, to transform torsional and bending stresses into axial tensile stresses or into compressive stresses. The windings 31, 32 are arranged in two coaxial layers 33, 34 respectively of the driving wave 2, with the windings 31 arranged radially within the inner layer 33 (with the same winding radius) and the windings 32 arranged radially within the outer layer. The windings of the inner layer 33 have an opposite winding direction in relation to the windings of the outer layer 34, so that tensile and compressive stresses between the layers can compensate each other.In the shown example, the driving wave covers the inner position 33 four coaxial and coradial around the hollow 29 wound cables 35 and in the outer position 34 five coaxial and coradial around the hollow wound cables, so that the axially adjacent coils 31 of the inner position touch each other, but the axially adjacent coils (cable packages from five cables each) 32 of the outer position do not touch each other (each at curvature-free orientation of the driving wave), but an axial distance of about 0.03 mm is shown. The outer diameter of the driving wave in the example amounts to about 0.88 mm and an inner diameter to about 0.28 mm. The cables have a circular cross section with a diameter of about15 mm. In the following example, the winding direction of winding 36 of the outer position 34 is opposite to the (proximal) blood flow, according to the specified rotation direction of the driving wave 2.
The present invention relates to a drive wave with a first and a second winding direction (as defined for a wave traveling from the proximal to the distal end) and to a drive system having such a drive wave. The first winding direction and the second winding direction are opposed to each other.
The Drähte 35, 36 of the drive wave 2 consist completely of an alloy, which as alloy components contains approximately 35% weight component nickel, approximately 35% weight component cobalt, approximately 20% weight component chromium and approximately 10% weight component molybdenum. The alloy components of the alloy may also each be up to 3% weight components greater or smaller or each be up to 2% greater or smaller. In particular, in this example, the alloy is 35NLT®, it could however also be MP35N®. The weight component of iron in the wires is thus less than 1% weight component and the weight component of titanium is less than 0.1% weight percentage. The alloy and the windings 31, 32 of the drive wave are produced or shaped by means of high cold forming and cold hardening. As a reinforcement material 30 for the reinforcement of the drive wave 2 in this example a non-rusting austenitic steel according to material number DIN 1.4310 (X10CrNi18-8) is chosen. Alternately, any other material could also be chosen as a reinforcement material that fulfills the requirements above in this context.
Figures 7 and 8 show the shell 6, which is designed as a storage spiral with a large number of spirals 37, in which the spirals 37 of the storage spiral revolve in the axial direction around the driving wave 2 like a screw. The storage spiral is given by a wound flat band 38 in the example. The flat band 38 has a width B (measured axially) about 6 times larger than the thickness D (measured radially). In the example, the width B of the spirals 37 is 0.6 mm and the thickness D of the spirals 37 is 0.1 mm. The spirals 37 are also slightly angular relative to the longitudinal axis L of the storage spiral (in a straight state without bending of the storage spiral).tilted, preferably by less than 5°, so that an inner surface 39 formed by the windings 37 of the shell 6 is preferably cylindrical or cylindrical parts are formed. Furthermore, the side edges 54 of the flat band are preferably rounded with a curvature radius rk of about 0.04 mm. Preferably, the curvature radius rk of the edges 54 is greater than 0.04 mm. Furthermore, the inner diameter Di of the shell 6 is about 1 mm and the outer diameter DA of the shell 6 is about 1.2 mm and an inclination of about 0.7. The shell 6 or the flat band 38 is made of the same alloy as the wires 35 in this example.36号动力波浪2，当前位于35NL-T®，但也可以由所指材料的其他产品制成。
第二传动波因此从同样的材料生产。另外，第二传动波的表面可以达到约RZ 0.6的粗糙度，这种令人惊讶的粗糙度导致了特别好的磨损耐性。通过这些相对容易实施的措施，可以达到令人惊讶的磨损特性，并因此获得高运行安全性。
Figure 9 schematically shows a longitudinal section through the axial section of the catheter 1 as shown in Figure 1 with Y. In this section, the catheter 1, arranged proximally to the pump rotor 20, comprises the bearing elements 40, 41, 42 for radial and axial bearing of the drive wave 2.
The arrangement and design of storage elements 40, 41, 42 is aligned with the pump rotor 20 of the catheter 1 as shown in figure 10. Thise pump rotor 20 has a conveying chamber 43 with a configuration, design and installation angle for conveying the blood proximally (proximal conveying direction, i.e. towards the proximal end of the catheter) is installed. Storage elements 40 and 41 form a proximally arranged axial storage 44 with the pump rotor 20. (Storage element 41 is the first axial storage element of axial storage 44 and storage element 40 is the second axial storage element of axial storage 44.) The axial storage 44 is arranged due to the design and arrangement of these (axial) storage elements 40, 41, to counteract the axial displacement (triggered by the proximal conveying effect of pump rotor 20) in the direction of the driving wave 2. Thus, in operation of the blood pump arrangement, axial storage forces mainly act as pull forces on the driving wave 2.
The first storage element 41 is preferably arranged in a ring shape and rotatably connected to the drive wave 22. The second storage element 40 is, similarly to the storage element 42, firmly connected to the shell 6 and the mantle 7. The storage elements 40, 41 have each other facing, ring-shaped sliding surfaces 45, 46, which block an axial displacement of the drive wave 2 in the distal direction when touching each other. The sliding surface 46 of the first storage element 41 has a profile, see figures 13 and 14 and the corresponding description below, so that the formation of a stable lubricating film between the two sliding surfaces 45, 46 is facilitated and an arrangement of the axial storage 44 as a hydrodynamic storage is in principle enabled. The lubricating film or the hydrodynamic storage is formed in this example with the lubricating medium described above. The storage element 40 is also arranged as a radial storage element with a sliding surface 45 that is directed to the drive wave 2, cylindrical arranged and coaxial to the drive axis of the drive wave 2.
As shown in Fig. 9, the driving wave 2 is supported in the axial sections, where it exits the sleeve 6 or is supported by the store elements 40, 41, 42, by the reinforcement material 30.
Figure 11 schematically illustrates a longitudinal section through the in Figure 1 with the reference number Z designated axial section of the catheter 1, which in particular comprises the distal sealing chamber 13 adjacent to the pump housing 11. The sealing chamber 13 is tubularly designed and includes a distal storage channel 47 and a corresponding storage element 47 for the distal end piece 19 of the drive wave. The cavity 47 is in particular sized in such a way that axial balancing movements of the drive wave 2 are allowed.
Figure 12 schematically shows a longitudinal section throughproximal coupling module 4, which shows a proximal storage channel 49 for the proximal end piece 3 of the driving wave 2, wherein the proximal end piece 3 of the driving wave 2 runs axially through the storage channel 49 and projects axially out of the proximal coupling module 4. A storage element 50 is arranged in the storage channel 49 for radial stabilization or storage of the proximal end piece 3 of the driving wave 2. The housing 6 extends axially through this storage element 50 up to its proximal end. The storage element 50 in this embodiment has the function of stabilizing the housing 6 radially from the outside and supporting it.In an alternative embodiment, the housing does not pass through the storage element 50, but ends (coming from distal) at the distal end of the storage element 50. In this case, the storage element 50 may be arranged as a sliding bearing or as a rolling bearing. Similarly, the proximal end piece 3 of the drive wave can also be stiffened by the reinforcement material 30, in particular in the axial sections, in which the drive wave exits from the storage channel 49 or is stored in the storage element 50. The storage elements 40, 41, 42, 48, and 50 are preferably made of zirconium oxide, preferably in the yttrium stabilized form, and aluminum oxide.来自陶瓷或者与驱动波2的导线35,36同样的材料。
Furthermore, the coupling housing 4 indicates channels 51 for the input and output of a lubricant, wherein the channels are fluidically coupled with the storage channel 49 as well as with a space between the shell 6 and the drive wave 2. According to the sixth aspect, a space or a gap between the drive wave and the shell is filled with a lubricant that is biocompatible and preferably also physiological. The lubricant is biocompatible and in this example is distilled water, but it could also be a physiological salt solution or a glucose solution.
The coupling element 5 of the drive wave 2 is as rigid as possible and coupled in a torsion-proof, pull-proof and push-proof manner with the proximal end piece 3 of the drive wave 2. The coupling element 5 of the drive wave as well as the coupling element 17 of the drive motor 18, which in this example is provided for the coupling element 5 as an accommodation, have corresponding axial sliding surfaces 52 or 53 for the formation of a torsion-proof but axially shiftable connection to each other. These run parallel to the longitudinal axis of each coupling element 5 or 17 and do not change their shape along the longitudinal axis of each coupling element 5 or 17. In this example, the coupling element 5 of the drive shaft 2 is a square.
外套7可以完全或至少部分由塑料制成，例如由聚氨酯制成，特别是由碳黑或聚氨酯制成。优选地，外套具有金属增强，例如由驱动波纹提出的合金组成，例如MP35N®。
Figures 13 and 14 each show a schematic perspective representation of an implementation example of the first storage element 41 of the axial storage 44 shown in Figure 9. The sliding surface 46 of each storage element 41 has a profile 55, so that the two sliding surfaces 45, 46 in cooperation with the lubricating medium form a hydrodynamic sliding surface, which allows a considerable reduction of the sliding surface volume 45, 46 respectively of the two storage elements 40, 41. In the implementation forms shown here, the profile 55 of each sliding surface 46 comprises several elevations 56 and depressions 57. In the example shown in Figure 13, it is exactly 12 elevations and 12 depressions, in the example shown in Figure 14 it is exactly 8 elevations and 8 depressions, wherein the elevations 56 and depressions 57 are each evenly distributed along a circumferential direction or circumference direction (in the figures indicated by an arrow U) of the respective sliding surface 46 and arranged in an alternating sequence of ribs and grooves.
这些波纹和凹槽延伸到每个滑动表面46的内部边缘58和驱动波纹2的外缘59。在图13所示的实例中，波纹具有约0.06mm的高度（与邻近的凹槽深度相同）和约0.2mm的中等宽度（在U方向测量）。在图13所示的实例中，作为波纹构造的隆起55具有约0.1mm的最大高度，每个隆起具有前侧60和后侧61，前侧60在U方向旋转存储元件41时，沿U方向（在向远端9的透视方向时，U方向是逆时针方向）前进至后侧61。
This test surface 60 is opposed to the longitudinal axis of storage element 41 in a slanted or offset manner so that the bulge 56 is narrowed or thinned upwards (i.e. in the direction of the opposite gliding surface 45 of the second storage element 40, i.e. in the distal direction in the present example). With such slanted or offset test surfaces 60, a more uniform ridge wave formation of the lubricant medium can be achieved in principle, and thus a more stable lubricating film can be formed. On each of the bulges 56, each bulge has a middle width (measured in circumferential direction U) of about 0.3 mm, where the width of the bulge 56 is increased radially. The width (measured in circumferential direction U) of the grooves 57 in this example is about 0.1 mm, where the width of the grooves is also increased radially outward. The examples shown in figures 13 and 14 can be manufactured, for example, using a (laser) cutter.
In figures 15 and 17 the dependence between the material properties flow limit, tensile strength, fracture toughness and cold hardening degree of the material 35NLT is presented on the example of Fort Wayne Metals. It is shown that different heat treatment conditions and cold hardening degrees of a material in general can lead to very different material properties.
For example, in the case of the embodiment shown in figures 1 to 15, the driving wave 2 and/or the shell 6 are made of 35NLT, so the cold hardening grade of this material is preferably at about 35 to 70%, especially preferably at about 50% to 60%, so here a tensile strength of about 2000 to 2200 MPa, for example 2068 MPa, is achieved and a fracture elongation of 3.5% is not exceeded.
The invention is defined by the claims. The following examples are given to aid in the explanation of the invention:An example relates to a flexible catheter 1 with a drive wave 2, a casing 6 surrounding the drive wave 2 and a cover 7 surrounding the drive wave 2 and the casing 6, wherein the drive wave, the casing 6 and the cover 7 are bendable, wherein the drive wave 2 has a coupling element 5 at a proximal end of the drive wave 2 for connecting the drive wave 2 to a drive motor 18, wherein the drive wave 2 comprises at least regionally an alloy which comprises at least 10% by weight of chromium, nickel and cobalt.
According to a further example, the alloy contains nickel by 30%-40% by weight, cobalt by 30%-40% by weight, and/or chromium by 15%-25% by weight.
根据另一例子，合金至少在镍、钴和铬的重量比上与MP35N®或35NLT®或比其重量比偏离不超过3%。
根据另一项例子，合金具有1800N/mm2至2400N/mm2的抗拉强度，优选地为2034N/mm2至2241N/mm2。
根据另一个例子，驱动波浪面2的粗糙度在0.01μm和1μm之间，优选地在0.1μm和0.8μm之间。
根据另一示例，驱动波的外直径位于约0.53mm至约1.32mm之间，优选约0.79mm至约0.97mm之间。
根据另一个例子，动力波2使得轴向延伸于动力波2内的空腔29。
According to a further embodiment, the driving wave 2 is provided with a plurality of coaxial windings 31, 32 which wind helically around the hollow space 29 of the driving wave 2.
根据另一示例，驱动波浪2中的线圈31,32被安排在两个或多个轴向层33,34中，其中线圈31,32在不同的轴向层33,34中呈现相反的缠绕方向。
根据另一例子，缠绕线圈31、32由驱动波纹管2的至少一根波纹管构成，其中，至少一根波纹管的直径在大约0.09mm至大约0.21mm之间，优选地在大约0.135mm至大约0.165mm之间。
According to a further embodiment, the hollow space 29 of the drive wave 2 is filled with reinforcement material 30 in the axial section in order to stiffen the drive wave 2 in each axial section, preferably with a stainless austenitic steel.
根据另一个示例，驱动波纹管2的远端19部分是加强的，优选地，远端19部分的长度在10mm至60mm之间，特别优选在20mm至50mm之间。
根据另一个例子，导管1在驱动波2的远端端部指向与驱动波2固定连接的泵子转子20。
按照另一个示例，泵转子20被设计为产生从泵转子20的近端流向泵转子20的远端的轴向流，其中，导管1包括轴向轴承44，轴向轴承44被设计为与泵转子20的驱动波纹2的轴向移动方向相反；或者泵转子20被设计为产生从泵转子20的远端流向泵转子20的近端的轴向流，其中，导管1包括轴向轴承44，轴向轴承44被设计为与泵转子20的驱动波纹2的轴向移动方向相反。
根据另一示例，轴向存储器44至少包括第一存储单元41和第二存储单元40，其中第一存储单元41与动力波2固连，第二存储单元40与外壳6或外壳7固连，其中第一存储单元41和第二存储单元40彼此面对的滑动面45、46，这些滑动面在至少一个方向上阻止动力波2在彼此接触时的轴向移动。
根据另一个例子，滑动面46至少将第一存放元件41的轮廓55用于培养水动力滑动层。
按照另一示例，横截面55包括46号滑面的多个凸起56和/或凹槽57，优选地，凸起56和/或凹槽57的高度或深度大致为0.03mm至0.1mm。
根据另一个例子，凸起56和/或凹陷57设计成肋或沟，从滑动面46的内边缘58朝着相反于驱动波浪2的方向延伸，直到滑动面46的外边缘59，优选地，在大约0.08mm至大约0.5mm的范围内，肋或沟具有宽度。
按照进一步的例子，导管1包括至少一个存储元件40、41、42、48、50以径向和/或轴向存储驱动波2，其中至少一个的至少一个存储元件40、41、42、48、50优选地至少部分由锆氧化物，尤其是钇稳定锆氧化物，由氧化铝，由陶瓷和/或由在方面1、2或3中所指的合金组成。
根据另一个例子，外壳6以多层螺旋状构造，其中，螺旋状构造37沿轴向绕驱动波纹2螺旋运动，且螺旋状构造37优选地为缠绕带38。
根据另一个例子，壳6至少在区域上由与驱动波2相同的材料制成，或者由上文提到的合金制成。
根据另一个示例，从驱动波2到壳体6之间填充有生物兼容的润滑介质，优选为蒸馏水、煮盐水或葡萄糖溶液。
As an additional example, the proximal coupling element 5 of the drive wave 2 axially gliding surfaces 52 are arranged along a longitudinal axis of the coupling element 5 for a rotationally fixed and axially displaceable connection with the drive motor 18.
另一例是可挠曲导管1，具有驱动波形2，环绕驱动波形2的壳体6和包围驱动波形2和壳体6的外壳7，其中驱动波形2、壳体6和外壳7可挠曲，其中驱动波形2在驱动波形2的近端具有耦合元件5以将驱动波形2连接到驱动电机18，其中驱动波形2的外径小于1mm，至少部分由具有在1800 N/mm2和2400 N/mm2之间的拉伸强度的材料制成，优选在2034 N/mm2和2241 N/mm2之间。
根据另一个例子，驱动波浪面2的粗糙度为0.01到1µm，优选0.1到0.8µm。
根据另一个示例，传动波2和/或护管6至少部分由金属材料制成，其中金属材料优选为合金，其含有的铬、镍和钴的重量百分比至少为10%。
根据另一例，第2传动波和第6壳体至少部分由相同材料制成。
Another example is a blood pump arrangement 16 with a catheter 1 as per one of the preceding examples.
根据另一个示例，血液泵装置16还包括一个驱动电机18，其中驱动电机18和驱动轴5之间的传动轴2之间形成固定的和优选轴向可移动的连接。
参考清单1. Catheter2. Drive wave3. proximal end piece of the drive wave4. coupling module5. coupling element of the drive wave6. Hülse7. Mantel8. proximal end of the catheter9. distal end of the catheter10. Pump head11. Pump casing12. Abströmschlauch13. Abschlussgehäuse14. Stützelement15. Schleuse16. Blood pump arrangement17. coupling element of the drive motor18. Drive motor19. distal end piece of the drive wave20. Pumpenrotor21. Punktionsstelle22. Femoralarterie23. Aortenbogen24. linkes Ventrikel25. Herz26. Innenwand27. Aortenklappe28. Aorta29. Hohlraum30. Verstärkungsmaterial31. Windung der Antriebsswelle32. Windung der Antriebsswelle33. coaxial position of the Antriebsswelle34. coaxial position of the Antriebsswelle35. Wire of the Antriebsswelle36. Wire of the Antriebsswelle37. Windung der Hülse38. Flat band39. Inner surface of the Hülse40. Storage element41. Storage element42. Storage element43. Tip44. Axial bearing45. Gliding surface46. Gliding surface47. Storage channel of the closure housing48. Storage element49. Storage channel of the coupling module50. Storage element51. Channel for lubricating medium52. Gliding surface53. Gliding surface54. Edge55. Profile56. Rise57. Dipping58. Inner rim59. Outer rim60. Pre-running surface61. Post-running surface