Feed line for a pump unit of a heart assist system, heart assist system and method for producing a feed line for a pump unit of a heart assist system

Abstract

The present invention relates to a feed line (105) for a pump unit (110) of a heart assist system (100). The feed line (105) is embodied as guiding a fluid flow to the pump unit (110) of the heart assist system (100). The feed line (105) comprises: a feed head portion (130) having at least one introduction opening (140) for introducing the fluid flow into the feed line (105); and a profile portion (135) having an inner surface profile. The profile portion (135) is arranged adjacent to the feed head portion (130). The inner diameter of the profile portion (135) at a first position is greater than the inner diameter at a second position. In order to reduce the inner diameter, the inner surface profile is rounded at the second position.

Description

[0001] describe

[0002] The invention relates to a feed line for a pump unit of a heart support system, a heart support system and a method for producing a feed line for a pump unit of a heart support system of the type specified in the independent claims.

[0003] The heart pump may include a pump unit and an inlet hose for supplying blood flow to the pump unit. The heart pump may further include a structure for preventing or reducing blood damage (hemolysis) in the area of ​​the pump unit. US2017 / 087288A1 describes a pump unit having a trumpet-shaped enlargement of the length of the pump unit in order to reduce hemolysis and / or minimize pressure losses.

[0004] On this basis, a basic object of the present invention is to further improve the systems and methods known from the prior art while ensuring the highest possible pumping efficiency with a compact design.

[0005] With this in mind, the method presented herein introduces a feed line for a pump unit for a cardiac support system, a cardiac support system and a method for producing a feed line for a pump unit for a cardiac support system according to the main claim. Advantageous further developments and improvements of the device defined in the independent claim can be obtained using the measures listed in the dependent claims.

[0006] This method presents the design of a feed line for a pump unit of a heart support system, which sets the flow behavior of a fluid flow introduced into the feed line by means of an inner surface profile in a section close to the inlet of the feed line. With the help of rounded portions, for example a concave configuration of the cross section and additionally or alternatively a convex configuration of the inner surface profile, flow separation of the fluid flow can be advantageously reduced or completely avoided. When conducting the fluid flow in the feed line, pressure losses are reduced and flow separation is reduced or avoided at the same time, which is advantageous with regard to the power consumption of the pump unit and therefore with regard to the pump efficiency of the heart support system. Reducing or avoiding flow separation by means of the inner surface profile advantageously enables a compact design of the feed line, which is particularly advantageous for heart support systems for minimally invasive implantation, for example for transaortic or transfemoral implantation.

[0007] The present invention presents a feed line for a pump unit of a cardiac support system. The feed line is configured to direct a fluid flow to a pump unit of a cardiac support system. The feed line includes at least one feed head portion and a profile portion. The feed head portion includes at least one introduction opening for introducing the fluid flow into the feed line. The profile portion has an inner surface profile. The profile portion is disposed adjacent to the feed head portion. An inner diameter of the profile portion at a first position is greater than an inner diameter at a second position. The inner surface profile has a rounded portion at the second position for reducing the inner diameter.

[0008] The heart support system can be a heart pump, such as a left ventricle support system, a right ventricle support system or a biventricular support system. For example, the heart support system can be designed for minimally invasive implantation. The feed line can be configured as a flow channel for guiding a fluid flow. The feed line can also be configured as a hose. In the implanted state of the heart support system, the feed line can be configured to conduct blood flow as a fluid flow from the ventricle to the pump unit of the heart support system. For example, the pump unit can be a micro-axis pump. The feed head portion can be understood as a sub-section of the feed line between the head unit (such as a sensor assembly) of the heart support system and another sub-section of the feed line disposed adjacent to the pump unit. The introduction opening can be cut, for example, from the feed line. The introduction opening can be configured as a multi-part window opening, for example, by cutting into the feed line and rounding three windows in the direction of the pump unit. The contour portion can be understood as a section of the feed line disposed between the feed head portion and another sub-section of the feed line. The inner surface profile may be, for example, a cutout or an applied structure, or a predetermined material configuration, for example a cross-section with different wall thicknesses, or an inserted element with a specific shape or structure. The first position may be upstream of the second position with respect to the flow direction of the fluid stream. The rounded portion of the inner surface profile may be a convex protrusion. The inner surface profile may also have a further rounded portion, for example in the form of a concave recess, at the first position.

[0009] According to one embodiment, the inner diameter of the profile portion at the third position may be larger than the inner diameter at the second position. For example, the second position may be located between the third position and the first position. Thus, the third position may be downstream of the second position with respect to the flow direction of the fluid flow. For example, the inner surface profile may also have a rounded portion in the form of an additional concave recess at the third position. This may advantageously change the flow behavior of the fluid flow, which reduces flow separation of the fluid flow. This is conducive to reducing pressure losses or friction of the fluid flow, which may improve the pump efficiency of the heart support system.

[0010] According to one embodiment, the first position may be arranged in the profile portion between the feed head portion and the second position. For example, the first position and the second position may be sections along the longitudinal axis of the profile portion. This arrangement advantageously allows the inner diameter of the profile portion to be varied along the longitudinal axis of the profile portion in order to set the flow behavior and thereby the flow separation of the fluid flow by optimizing the configuration.

[0011] According to one embodiment, the first position and the second position can be additionally or alternatively arranged along the circumference of the profile portion.Therefore, the cross section of the profile portion can also have at least one rounded portion, so that the flow behavior of the fluid flow can be advantageously set.

[0012] According to one embodiment, the length of the profile portion can correspond to up to twice the inner diameter of the profile portion. The length of the profile portion can correspond in particular within a tolerance range to the radius of the feed line. The feed line can have a constant radius. The tolerance range can be understood as, for example, a deviation from the radius of the feed line of no more than twenty percent. Thus, a local limit setting of the flow behavior is possible. Advantageously, further downstream of the feed line, i.e. in the subsection of the feed line between the profile portion and the pump unit, the pressure losses are also lower, since the suppression of separation leads to lower fluctuations of the fluid flow downstream.

[0013] According to one embodiment, the inner radius of the profile portion in the second position can be at most one fifth smaller than the inner radius in the first position. This advantageously enables the flow behavior to be set and also guides the flow of the fluid to be conveyed through the profile portion without increasing the installation space.

[0014] The inner surface contour can also be formed rotationally symmetrically. For example, in the case of a rotationally symmetrical inflow into a feed line, this is advantageous in order to minimize flow separations and thus reduce pressure losses.

[0015] According to one embodiment, the wall thickness of the profile portion at the first position may be smaller than the wall thickness at the second position. Alternatively or additionally, the inner surface profile may be configured as an insert element of the profile portion. These two embodiments advantageously enable a simple and cost-effective realization of the profile portion.

[0016] Furthermore, according to one embodiment, at least one inlet edge of the introduction opening of the feed head part may be rounded. This advantageously reduces pressure losses at the introduction opening.

[0017] According to one embodiment, the profile section may also have a constant outer diameter. This advantageously enables a compact design, which is particularly advantageous when the feed line is used in conjunction with a heart support system for minimally invasive implantation.

[0018] The present invention further presents a cardiac support system having the aforementioned embodiment of the feeding line.

[0019] A method for producing a feed line for a cardiac support system is also proposed. The feed line is configured to direct a fluid flow to a pump unit of the cardiac support system. The method comprises a forming step. In the forming step, a feed head portion having at least one introduction opening is formed, the at least one introduction opening being used to introduce the fluid flow into the feed line. Furthermore, in the forming step, a contour portion is formed, the contour portion having an inner surface contour, wherein the contour portion is disposed adjacent to the feed head portion, wherein an inner diameter of the contour portion at a first position is greater than an inner diameter at a second position, and wherein the inner surface contour has a rounded portion at the second position for reducing the inner diameter.

[0020] The feed line can be cut from a tube, for example, or the feed line can be constructed as a hose and comprise insert elements for configuring the profiled portion and the inner surface profile.The embodiments of the sliding bearing described above can advantageously be produced by carrying out the method.

[0021] Design examples of the method presented here are shown in the accompanying drawings and explained in more detail in the following description. These figures show:

[0022] Figure 1 is a schematic diagram of a cardiac support system with feeding lines;

[0023] Figure 2 is a schematic diagram of a portion of a profile portion of a feed line according to a design example;

[0024] Figure 3 is a schematic diagram of a portion of a feed line according to a design example;

[0025] Figure 4 is a schematic diagram of a portion of a feed line according to a design example;

[0026] Figure 5 is a visualization of the effect of the implemented rounded section compared to a hose with a constant inner diameter;

[0027] Figure 6 is a visualization of the effect of the implemented rounded section compared to a hose with a constant inner diameter;

[0028] Figure 7 is a schematic diagram of a portion of a profile portion of a feed line according to a design example;

[0029] Figure 8 is a schematic diagram of a portion of an inner surface profile of a profile portion of a feed line according to a design example; and

[0030] Fig. 9 is a flow chart of a method for producing a feed line for a cardiac support system according to one design example.

[0031] In the following description of advantageous embodiments of the invention, identical or similar reference numerals are used for those elements which are shown in the individual figures and function in a similar manner, so that a repeated description of these elements is omitted.

[0032] Figure 1A schematic diagram of a heart support system 100 with a close feed line 105 according to one design example is shown. The figure shows a perspective view of the heart support system 100, which is illustrated as a left ventricular heart support system, a left ventricular assist device (LVAD) for use in the aortic valve position. The elongated axial design of the heart support system 100 shown here with a substantially constant outer diameter enables transfemoral or transaortic implantation of the heart support system 100 with the aid of a catheter for simple implantation in a blood vessel, such as the aorta.

[0033] Corresponding to the configuration of the aortic valve position, the feed line 105 has, for example, an inclination or curvature of the longitudinal axis and thus has a slightly curved shape. In addition to the feed line 105, the cardiac support system comprises a pump unit 110. A head unit 115 as well as a housing segment 120 and an anchoring frame 125 are also shown as examples. The feed line 105 is arranged between the head unit 115 and the pump unit 110. The pump unit 110 is connected to the housing segment 120 to which the anchoring frame 125 is attached at the end facing away from the feed line 105.

[0034] According to one design example, the feed line 105 is configured to guide a fluid flow to the pump unit 110 of the cardiac support system 100. The feed line includes a feed head portion 130 and a contour portion 135. The feed head portion 130 includes at least one introduction opening 140 for introducing a fluid flow into the feed line 105. The contour portion 135 has an inner surface contour. The contour portion 135 is disposed adjacent to the feed head portion 130. As viewed in the flow direction, the inner diameter of the contour portion 135 at a first position is greater than the inner diameter at a second position. The inner surface contour has a rounded portion at the second position for reducing the inner diameter. A design example of the configuration of the contour portion 135 is referred to below Figures 2 to 9 Give a description.

[0035] The feed head portion 130 and the profile portion 135 are outlined in the design example shown herein as an example. The profile portion 135 in particular optionally covers a smaller or larger portion of the feed line 105 than shown here. In the implanted state of the heart support system 100, the feed head portion 130 and the profile portion 135 are arranged in the left ventricle. Another section of the feed line 105 is guided through the aortic valve, and the section of the heart support system 100 with the pump unit 110 is arranged in the section of the aorta. The pump outlet 145 in the area of ​​the pump unit 110 guides the fluid flow conveyed by the feed line 105 into the aorta. For example, the label 150 shows the position of a heart valve, such as the aortic valve, through which the feed line 105 passes in order to position the heart support system 100.

[0036] According to the design example shown here, at least one inlet edge of the introduction opening 140 of the feed head part 130 is rounded. For example, the introduction opening 140 is configured here as a window-shaped inlet cut into the feed head part 103.

[0037] According to the design example shown here, the length of the profile section 135 corresponds within a tolerance range to the radius of the feed line 105. A tolerance range is to be understood as a deviation from the radius of the feed line of no more than 20 percent.

[0038] Heart support systems that are limited in terms of installation space, such as the heart support system 100 shown here as an example and which can be implanted in a minimally invasive manner, have relatively low power consumption at a given pump efficiency. The efficiency is limited by the friction in the pump of the pump unit 110. When the fluid flow is guided in the ventricle from the introduction opening 140 of the feed head part 130 to the pump unit 110, the pressure loss or friction in the feed line 105 can be adjusted via the configuration of the feed line 105. To this end, the inlet edge of the inlet opening 140 is rounded in order to reduce pressure losses. This alone cannot prevent flow separation. An inlet inner surface profile in the form of a contoured portion 135 constructed according to the method presented herein inhibits flow separation and thereby reduces pressure losses. Design examples of correspondingly constructed inlet inner surface profiles are discussed below.

[0039] Figure 2 A schematic diagram of a portion of a profile portion 135 of a feed line according to one design example is shown. The figure shows an example of the dimensional relationship of the profile portion 135 and the inner surface profile 205. The figure shows an axial section of half of the profile portion 135. The inner diameter 210 of the profile portion 135 at a first position 215 is greater than the inner diameter 210 at a second position 220. In order to reduce the inner diameter 210, the inner surface profile 205 has a rounded portion 225 in the form of an axially arcuate inner wall profile at the second position 220. According to the design example shown here, the first position 215 indicates a position on the profile portion 135 along the longitudinal axis of the profile portion 135, and the second position 215 indicates another position on the profile portion 135 along the longitudinal axis. In the design example shown here, the longitudinal axis corresponds to the rotation axis 230 of the profile portion 135.

[0040] According to the design example shown here, the first location 215 is arranged in the profile section 135 between the feed head section and the second location 220. With respect to the flow direction of a fluid flow introduced through the feed head section and guided through the feed line and thus through the profile section 135 in the direction of the pump unit, the first location 215 is arranged upstream of the second location 220.

[0041] Furthermore, according to the design example shown here, the inner diameter of the contour portion 135 at the third position 235 is larger than the inner diameter at the second position 220 .

[0042] According to the design example shown here, the inner radius of the contour portion 135 at the second position 220 is at most one fifth smaller than the inner radius at the first position 215. Figure 2 In FIG. 2 , this is shown with reference 240 , which indicates one fifth of the inner radius. The rounded portion 225 of the inner surface contour 205 is correspondingly configured as a convex protrusion at most within a range of up to one fifth of the inner radius, which is further visualized by reference 240 .

[0043] According to one design example, the inner surface profile 205 is configured rotationally symmetrically. The portion of the profile portion 135 that is opposite to the portion of the inner surface profile 205 shown here with respect to the rotation axis 230 accordingly has an inner surface profile 205 that is configured rotationally symmetrically.

[0044] The configuration of the profile portion 135 and the inner surface profile 205 shown here makes it possible to reduce or suppress the flow separation of the fluid flow in the feed line, which would otherwise develop downstream of the inlet edge. The outer diameter 245 of the profile portion 135 remains constant, and advantageously avoids the expansion of the installation space of the feed line. The design example using the profile portion 135 and the inner surface profile 205 shown here reduces the pressure loss of the fluid flow to be transported. The inlet flow and therefore the flow behavior of the fluid flow are only guided locally by the profile portion 135. The profile portion 135 optionally has a length, which corresponds to at most twice the inner diameter of the feed line in this design example. Due to the configuration of the profile portion 135, the pressure loss of the fluid flow further downstream is lower than the pressure loss of the feed line with a constant inner diameter without an inner surface profile, because the suppression or reduction of the separation leads to less turbulence downstream. The inner surface profile 205 is configured so that the flow separation is largely suppressed over a length of up to four times the radius of the feed line. The local outer diameter 245 of the feed line is limited by the specified wall thickness. Adjacent to the inlet opening of the feed head section, the inlet edge is convexly rounded to reduce flow separation. The configuration optimization of the inner surface profile 205, such as the configuration shown here, can be rotationally symmetric, or alternatively independent of the rotation angle, as shown in reference Figure 8 According to the design example shown here, independently of the described inlet edge rounding, as shown herein, by means of the first position 215, the second position 220, the third position 235 and the rounding 225, the profile of the inner surface profile 205 has two concave and one convex configuration optimizations and a constant wall thickness. For this purpose, the wall inner profile is optionally configured so that a local wall inner radius of up to four fifths relative to the wall inner radius is achieved at a constant wall thickness of the profile portion 135.

[0045] Figure 3 A schematic diagram of a portion of a feed line 105 according to one design example is shown. The figure shows a visualization of a flow separation 305 at an inlet edge in an inlet region 310 based on the flow velocity of a fluid flow conveyed through the feed line 105. The inlet region 310 shown here corresponds to a section of a portion of the feed line adjacent to an introduction opening. A scale 315 shows the flow velocity of the fluid flow. The flow separation 305 is also shown by the line indicated by the mark 320, at which the flow velocity is equal to zero. The section in the inlet region 310 indicated by the mark 320 can therefore also be referred to as a "zero velocity line". The flow separation 305 of the fluid flow shown here can be reduced using design examples of inner surface profiles and profile portions, as described with reference to the aforementioned and following figures.

[0046] Figure 4 A schematic diagram of a portion of a feed line 105 according to one design example is shown. The figure shows a cross section of a feed line 105 which is similar or identical to the feed lines described with reference to the previous figures. Figure 4 Optimization of the configuration in the inlet region of the feed line 105 is shown. The cross section of the feed line 105 shown here shows the inlet region 405 of the profile portion adjacent to the introduction opening of the feed head section. The region 410 adjacent to the inlet edge is rounded accordingly. The figure also shows the inner surface profile 205. The rounded portion in the region 410 and the configuration of the inner surface profile 205 can also be referred to as a local topological adaptation in the inlet region in terms of reducing flow separation.

[0047] Figure 5 A schematic diagram of a portion of a feed line 105 according to a design example is shown. The figure shows two scenarios of the flow behavior of a fluid flow based on flow separation in the feed line 105, which can be detected by the flow velocity. A scale 315 shows the flow velocity of the fluid flow. The feed line 105 at the top shows an example of the flow velocity of the fluid flow in the feed line 105 with flow separation in the inlet region, which can be seen in reference Figure 3 The bottom feed line 105 scenario shows an example of a flow velocity of the fluid stream, wherein flow separation in the inlet region is prevented, as indicated by reference numeral 505. The bottom scenario is similar to or corresponds to reference numeral 506. Figure 2 The configuration of the profiled portion and inner surface profile of the feed line 105 is described.

[0048] Figure 6A schematic diagram of a portion of a feed line 105 according to one design example is shown. The figure shows two scenarios of the flow behavior of a fluid flow visualized by a scale 605 based on the apparent viscosity of the turbulent flow (eddy viscosity). The illustration of the viscosity of the turbulent flow also shows the friction of the fluid flow in the inlet region of the feed line 105. The feed line 105 at the top shows an example of the eddy viscosity of the fluid flow in the feed line 105 with flow separation in the inlet region. The scenario of the bottom feed line 105 shows an example of friction reduction also in the region downstream of the inlet zone of the feed line 105. The bottom scenario is similar to or corresponds to the reference scenario. Figure 2 The configuration of the profiled portion and inner surface profile of the feed line 105 is described.

[0049] Figure 7 A schematic diagram of a portion of a profile portion 135 of a feed line according to one design example is shown. The figure shows a cross section of the profile portion 135. The profile portion 135 shown here is similar to or similar to the reference Figure 2 The outlines described are partly identical. Figure 7 Examples are also shown where the rounded portion is not rotationally symmetrical.

[0050] Figure 8 A schematic diagram of a portion of an inner surface profile 205 of a profile section of a feed line according to one design example is shown. According to the design example shown here, the inner surface profile 205 is constructed as an insert element of the profile section. For example, the inner surface profile 205 here is configured as a two-part insert element, which has two non-rotationally symmetrical inner surface profile sections 805, 810, which together form the inner surface profile 205 of the profile section. The two-part insert element can be an example of the case in which the inlet opening 140 has two open windows and one closed window. The illustration here shows different views of the inner surface profile 205 as an insert element: the top view shows a cross section through the inner surface profile section 805. The middle view shows the two inner surface profile sections 805 and 810 in a side view, and the bottom view shows a cross section through the inner surface profile section 810. The inner surface profile sections 805 and 810 shown here individually or together form the inner surface profile 205 of the profile section of the feed line. Therefore, they can be referred to as non-rotationally symmetrical optimizations of the feed line for reducing flow separation.

[0051] Fig. 9A flow chart of a method 900 for producing a feed line for a pump unit of a cardiac support system according to a design example is shown. The feed line is configured to direct a fluid flow to a pump unit of a cardiac support system. Method 900 includes a forming step 901. In a forming step 905, a feed head portion having at least one introduction opening is formed, wherein the at least one introduction opening is used to introduce the fluid flow into the feed line. In addition, a profile portion having an inner surface profile is formed, wherein the profile portion is disposed adjacent to the feed head portion. An inner diameter of the profile portion at a first position is greater than an inner diameter at a second position. The inner surface profile has a rounded portion at the second position for reducing the inner diameter.

[0052] In a forming step 901, a feed head portion and a profile portion are cut from a tube. Additionally or alternatively, the inner surface profile of the profile portion is configured as an insert element of a feed line.

Claims

1. A cardiac support system, comprising: Pump unit; and a feed line configured to direct a fluid flow to the pump unit, wherein the feed line comprises: a feed head portion comprising at least one inlet opening for receiving the fluid flow into the feed line; and a contoured portion disposed adjacent the feed head portion and comprising an inner surface contour, wherein the inner surface contour comprises a first inner diameter at a first position, a second inner diameter at a second position, and a third inner diameter at a third position, wherein the first inner diameter is greater than the second inner diameter, wherein the third inner diameter is greater than the second inner diameter, wherein the second inner diameter comprises a minimum inner diameter of the contoured portion, wherein the inner surface contour comprises a rounded portion at the second position, wherein the contoured portion comprises a first inner radius at the first position and a second inner radius at the second position, wherein the second inner radius is at most one fifth smaller than the first inner radius, and wherein the second position is located between the third position and the first position; in: The inner surface profile includes an insert element insertable into the feed line; and The length of the insert element is greater than the radius of the feed line and is at most twice the inner diameter of the profile portion.

2. A cardiac support system as described in claim 1, wherein the first position is located in the contour portion between the feed head portion and the second position.

3. A cardiac support system as described in claim 1, wherein the interior of the contour portion is rotationally symmetric about the central axis of the contour portion.

4. A cardiac support system as described in claim 1, wherein the contour portion includes a first wall thickness at the first position and a second wall thickness at the second position, wherein the first wall thickness is less than the second wall thickness.

5. A cardiac support system as described in claim 1, wherein at least one entrance edge of the introduction opening of the feed head portion is rounded.

6. The cardiac support system of claim 1 wherein the contoured portion comprises a constant outer diameter.

7. A method for producing a feed line for a pump unit of a cardiac support system, comprising: forming a feed head portion having at least one inlet opening for receiving a fluid flow into a feed line, wherein the feed line is configured to direct the fluid flow to the pump unit; and forming a contoured portion adjacent to the feed head portion and comprising an inner surface contour, wherein the inner surface contour comprises a first inner diameter at a first location, a second inner diameter at a second location, and a third inner diameter at a third location, wherein the first inner diameter is greater than the second inner diameter, wherein the third inner diameter is greater than the second inner diameter, wherein the second inner diameter comprises a minimum inner diameter of the contoured portion, wherein the inner surface contour comprises a rounded portion at the second location, wherein the contoured portion comprises a first inner radius at the first location and a second inner radius at the second location, wherein the second inner radius is at most one fifth smaller than the first inner radius, and wherein the second location is located between the third location and the first location; in: The inner surface profile includes an insert element insertable into the feed line; and The length of the insert element is greater than the radius of the feed line and is at most twice the inner diameter of the profile portion.

8. The method of claim 7, wherein the first position is located at a portion of the profile between the feed head portion and the second position.

9. The method of claim 7, wherein an interior of the contour portion is rotationally symmetric about a central axis of the contour portion.

10. The method of claim 7, wherein the contoured portion comprises a first wall thickness at the first location and a second wall thickness at the second location, wherein the first wall thickness is less than the second wall thickness.

11. The method of claim 7, wherein at least one entrance edge of the introduction opening of the feed head portion is rounded.

12. The method of claim 7, wherein the contoured portion comprises a constant outer diameter.

Images