Abstract
An intravascular blood pump (100) comprises a tip (110), a first region (120) with at least one blood through-opening (121), a flow cannula (130), a second region (140) with at least one blood through-opening (141), a motor-operated pump mechanism (150) and a conducting cable (170). At least in the region of the flow cannula (130), at least one electrical conductor track is realized by a surface coating structure.
Claims
1. An intravascular blood pump comprising: a tip; a first region comprising at least one blood through-opening; a flow cannula; a second region comprising at least one blood through-opening; a motor-operated pump device; and a conducting cable, wherein at least one electrical conductor track comprising a surface coating structure in at least a region of the flow cannula; and wherein the at least one electrical conductor track extends about a spiral structure of the flow cannula.
2-13. (canceled)
14. The blood pump according to claim 1, further comprising at least one electronic component disposed in a region of the tip, wherein the at least one electrical conductor track provides an electrical connection for the at least one electronic component.
15. The blood pump according to claim 14, wherein the at least one electrical component comprises an ultrasonic element.
16. The blood pump according to claim 14, wherein the at least one electrical component comprises a pressure sensor.
17. The blood pump according to claim 14, wherein the at least one electrical component comprises a temperature sensor.
18. The blood pump according to claim 1, wherein one or more sensors are integrated into the surface coating structure.
19. The blood pump according to claim 18, wherein the one or more sensors comprise at least one of strain sensors, breakage sensors, and temperature sensors.
20. The blood pump according to claim 18, wherein the at least one electrical conductor track comprises one or more meandering conductor tracks forming one or more sensor regions of the one or more sensors.
21. The blood pump according to claim 20, wherein the one or more meandering conductor tracks forming the one or more sensor regions are at least partially formed of a different material than one or more conductor tracks outside the sensor regions.
22. The blood pump according to claim 20, wherein the one or more meandering conductor tracks forming the one or more sensor regions are formed of platinum.
23. The blood pump according to claim 1, wherein the flow cannula comprises a coatable material, wherein the surface coating structure is configured to be applied to the coatable material to form the electrical conductor tracks.
24. The blood pump according to claim 23, wherein the coatable material comprises at least one of: nickel-titanium alloys, titanium, stainless steel, glass, and ceramic.
25. The blood pump according to claim 1, wherein the surface coating structure comprises a multilayer structure.
26. The blood pump according to claim 1, wherein electrical connection of the conductor tracks is established by a frictional connection.
27. A method of manufacturing electrical conductor tracks in a region of an intravascular blood pump, the method comprising: applying an insulating base layer to a coatable material; applying a photoresist material; applying a conductor track structure, wherein the conductor track structure is applied by sputtering; removing the photoresist material; and applying an electrically insulating surface, wherein the electrical insulating surface is biocompatible.
28. The method according to claim 27, wherein the intravascular blood pump comprises: a tip; a first region comprising at least one blood through-opening; a flow cannula; a second region comprising at least one blood through-opening; a motor-operated pump device; and a conducting cable.
29. The method according to claim 28, further comprising at least one electronic component disposed in a region of the tip, wherein at least one electrical conductor track provides an electrical connection for the at least one electronic component.
30. A method of manufacturing electrical conductor tracks in a region of an intravascular blood pump, the method comprising: applying an insulating base layer to a coatable material; applying an initial metallic conductor layer, wherein the initial metallic conductor layer is applied by sputtering; applying a photoresist material; thickening exposed portions of the initial metallic conductor layer using a wet chemical electroplating process; removing the photoresist material; removing portions of the initial metallic conductor layer outside conductor tracks; applying an electrically insulating surface, wherein the electrically insulating surface is biocompatible.
31. The method according to claim 30, wherein the intravascular blood pump comprises: a tip; a first region comprising at least one blood through-opening; a flow cannula; a second region comprising at least one blood through-opening; a motor-operated pump device; and a conducting cable.
32. The method according to claim 31, further comprising at least one electronic component disposed in a region of the tip, wherein at least one electrical conductor track provides an electrical connection for the at least one electronic component.
33. A method of manufacturing electrical conductor tracks in a region of an intravascular blood pump, the method comprising: applying a conductor track structure to a coatable material of a flow cannula, wherein the flow cannula comprises a spiral structure; electrically connecting a first portion of the conductor track structure to a sensor; electrically connecting a second portion of the conductor track structure to an electrical connection region; and closing the spiral structure using a flexible material, wherein the flexible material comprises silicone or polyurethane.
Description
[0018] The figures show:
[0019] FIG. 1 a sectional view of a human heart and lung with an inserted intravascular blood pump;
[0020] FIG. 2 components of an intravascular blood pump (LVAD system);
[0021] FIG. 3 an isometric illustration of a flexible hose guide of the flow cannula of an intravascular blood pump;
[0022] FIG. 4 a detail view of the hose guide of a flow cannula having a surface coating structure according to the invention for the formation of conductor tracks;
[0023] FIG. 5 a detail view of the hose guide of a flow cannula having a surface coating structure according to the invention with the configuration of sensor regions by the conductor tracks;
[0024] FIG. 6 a detail view of the hose guide of a flow cannula having a surface coating structure according to the invention showing electrical contact pads;
[0025] FIG. 7 a detail view of a cross-section through a flow cannula having a surface coating structure according to the invention;
[0026] FIG. 8 a further detail view of a cross-section through a flow cannula having a surface coating structure according to the invention with a two-layer structure;
[0027] FIG. 9 a further detail view of a cross-section through a surface coating structure with a multilayer structure; and
[0028] FIG. 10 a further detail view of a cross-section through a surface coating structure with a multilayer structure and shielding.
[0029] FIG. 1 shows a human heart 10 and the surrounding lungs 20, wherein an intravascular blood pump 100 is inserted in the left ventricle 11. Pumping the blood pump 100 supports the pumping function of the heart 10 by moving oxygen-rich blood coming into the left ventricle 11 from the pulmonary vein 12 into the aorta 13. The intravascular blood pump can be designed for continuous pumping, for example, or the pump is based on a pulsatile system, for example, in which the pump speed is modulated.
[0030] FIG. 2 schematically shows the components of an intravascular blood pump 100 that is equipped according to the invention with a surface coating structure for the formation of electrical conductor tracks. The blood pump 100 comprises a tip 110, wherein one or more electronic components 112, in particular sensors, can be provided in a region within the tip 110. The tip is closed by a slidable cap 111. A first region 120 (inlet cage) with blood through-openings 121 adjoins the tip 110. Blood can be drawn into the blood pump, for example from the left ventricle, through the blood through-openings 121. This is adjoined by a flow cannula 130 and a second region 140 (impeller cage) having further blood through-openings 141. This is adjoined by region 150 for a motor-operated pump device. Inside the region 140 there is a rotor (impeller), for example, that is operated via the pump device 150, so that the pumped blood can exit through the blood through-openings 141. The pump device 150 is adjoined by a back end 160, via which the electrical connection is made. A supply cable 170 is provided for electrical supply and control. The motor-operated pump device is preferably a rotary pump (flow machine), wherein a reversal of the conveying direction can also be provided if necessary.
[0031] The surface coating structure according to the invention allows sensors or sensor regions, for example breakage sensors or strain sensors or temperature sensors, to be realized, in particular in the region of the flow cannula. The surface coating structures can also be used to electrically connect any existing electronic components 112 of the tip 110 to the supply cable 170. This allows the length of the flow cannula 130 in particular, but also the regions 120 and 140 and the region with the motor-operated pump device 150, to be bridged. Different components can be combined and realized as one structural element. For example, the first region 120 can be combined with the flow cannula 130 to one structural element, which can then very advantageously be equipped with the surface coating structure according to the invention for the formation of conductor tracks.
[0032] FIG. 3 shows a combined configuration of the first region with blood through-openings 221, which is directly adjoined by the flow cannula 230. The flow cannula 230 is advantageously realized as a flexible inlet hose or as a flexible hose guide. In this example, the flexible flow cannula 230 is realized by a spiral-shaped structure formed by circumferential windowed webs 300. A laser-structured tube made of NiTiNol material, for example, can be provided as the coatable material for this purpose. On the right side of the laser structured tube there is an elongated opening, which is provided for the passage of a guide wire in a per se known manner during the implantation process. The skeleton or web structures 300 of the NiTiNol material are electrically functionalized by surface coating for the formation of the conductor tracks, whereby the conductor tracks can in particular be used for electrically connecting electronic components and/or for the formation of sensors. The spiral structure of the NiTiNol tube can be produced by laser structuring. The exposed windows of the laser structured form can be closed by flexible materials, for example by silicone or polyurethane. The flexibility of the hose guide can also be achieved with other structures, for example by zigzag or wave patterns. The surface coating structure as such can be applied according to the method already described above. In this context, reference is also made to an article by Bechtold et al. (Biomed Microdevices, 2016 December; 18(6): 106) and an article by Lima de Miranda et al. (Rev. Sci. Instrum., 2009 January; 80(1): 015103), whereby these articles deal with surface structuring in general. Bechtold et al. describe the coating of thin films made of a nickel-titanium alloy to form insulated electrodes on the outer surface. Lima de Miranda et al. describe a rotational UV lithography for cylindrical geometries. The laser structuring of the NiTiNol tube to form the spiral structure, for example, can take place before or after the electrical functionalization.
[0033] FIG. 4 shows a detail view of the resulting exemplary conductor track structures on the flow cannula 230. The webs 300 of the laser-structured spiral structure (see FIG. 3), which to a certain extent form the framework of the flexible flow cannula 230, leave windows 301 open. The windows 301 are preferably closed in a flexible manner, for example using silicone or polyurethane. The webs 300 together with the closed windows 301 form the hose guide of the flow cannula 230. According to the invention, electrical conductor track structures 302, 303 are applied to the webs 300 using lithography and coating technologies.
[0034] For the actual production of the electrical conductor tracks, a lithography mask comprising the corresponding coating structures (electrical conductor track structures) is applied for each layer. The lithography mask can be a chrome-coated quartz substrate, for example. Non-conductors such as photoresist or polyimide can be applied over a large area by dipping, for example. Non-conductors such as parylene C can be deposited in a vacuum, for example. Initial metallic layers are in particular applied by sputtering, thicker layers by electrodeposition.
[0035] There are two main approaches that can be used in the production process: According to Method 1, the tube material (for example NiTiNol) is first provided with the electrical surface coating for the formation of the conductor tracks. In the next step, the flexible structure is produced, for example, by laser cutting (laser structuring), whereby the coating structure and the laser cutting contour are geometrically aligned to one another. In the last step, the windows of the flexible structure are closed, for example by dipping or overmolding. According to Method 2, the pipe material is structured first. The surface functionalization for the formation of the conductor tracks is then produced using the lithographic processes. Lastly, the windows of the flexible structure are closed as in Method 1. Method 1 has the advantage that the lithography process is simplified. Method 2 has the advantage that shape embossments in the NiTiNol material are possible directly after the structuring of the pipe material; for example to “save” bends or cross-sectional changes to the cross-section of the starting material (e.g. widenings of the cross-section). Because of the process temperatures needed for the shape embossment, it is generally advantageous to perform this step before the lithographic surface coating.
[0036] FIG. 5 shows particularly preferred configurations of the conductor tracks, in which the conductor track structure is designed as a sensor (left) or as an electrical connection and additionally as a sensor (right). As in FIG. 4, the flow cannula 230 is equipped with conductor tracks 302,303, which are formed by surface structuring of the webs 300 of the flow cannula 230 (right part of the illustration). Meandering conductor tracks are provided as well, which form the sensor regions 304 (left) or the additional sensor region 305 (right). Straight sections of the conductor tracks can be provided between individual sensor regions 304, or the sensor region 305 is formed by a continuously meandering conductor track. The input and output lines 306, 307 of the sensor regions 304 can be made of a different material than the sensor regions themselves. A plurality of sensor regions can be implemented via separate input lines or even with a common return channel line 308, for example.
[0037] For a temperature sensor, for example, it can be provided that the conductor tracks of the sensor regions 304 or 305 are made of platinum, because platinum has a very linear resistance-temperature relationship. The input and output tracks 306, 307, 308 expediently have the lowest possible resistance in order to have little influence on the sensor signal. The conductor track structures can also be used as strain or breakage sensors, for example. They can also be used as capacitive sensors, electrode surfaces or contact pads for further sensors, for example.
[0038] FIG. 6 shows a preferred electrical contacting of the conductor tracks 302, 303 via electrical contact pads 310, 311, 312, 313. This electrical contacting can take place, for example, at the end of the flow cannula 230, i.e. in the direction toward the second region 140. However, it is also possible for the conductor tracks to also be guided over other components of the blood pump, for example over the region 140, 150 to the electrical connection region 160. The electrical connection can be established by conductive gluing, soldering, bonding or frictional connection, for example. The connection can be made directly from NiTiNol component to NiTiNol component, for example, or from NiTiNol component directly to a cable or a thin-film substrate, depending on the configuration of the blood pump.
[0039] FIG. 7 shows a cross-section through the resulting layer structure that realizes the electrical conductor tracks. 710 represents the underlying NiTiNol structure or another coatable material as the support structure of the flow cannula. 720 represents an insulating base layer, for example made of silicon oxide or polyimide. 730 shows the metallic conductor track structures, for example made of gold. 740 represents an insulating cover layer, for example made of silicon oxide, polyimide or parylene. A multilayer structure, for example a two-layer structure as illustrated in FIG. 8, can be created by repeating the surface coating several times (surface lithography). 710, 720, 730 and 740 represent the coatable structure, the insulating base layer, the first layer of the conductor track structures or the insulating cover layer, as in FIG. 7. A further conductor track 750 disposed at a slightly higher level is additionally provided in the spaces between the conductor track structures 730. During production, the space (empty space) between the conductor track structures 730 on the lower layer is used for the metallization of the upper layer by disposing the metallic conductor layer in this space. This offset arrangement of the conductor tracks on different levels prevents the formation of larger protrusions or roughnesses of the surface structure in the regions in which metallic conductor tracks would be on top of one another. This can occur in particular in higher multilayer structures having six or more layers. In this respect, this embodiment with an offset arrangement has the advantage over a purely coaxial embodiment that the resulting layer thickness of the conductor structure as a whole is reduced. This embodiment is also particularly advantageous compared to a coplanar design, because the overall conductor width is reduced. If an offset arrangement of the conductor tracks is not desired or possible, it is alternatively also possible to compensate any unevenness that may occur due to superimposed conductor tracks, for example with a silicone layer or the like.
[0040] FIG. 9 shows a further structure of a multilayered conductor track structure. Four narrow conductor tracks 910 and two wide conductor tracks 920 are disposed one above the other on the coatable material (not shown in detail). The narrow conductor tracks 910 serve as a communication bus for a pressure sensor and a temperature sensor in the tip of the blood pump, for example. The wide conductor tracks 920 have a lower resistance (electrical power) and are used, for example, to connect an ultrasonic element in the tip of the blood pump. To produce such a structure, a total of seven layers are required for the surface coating. FIG. 10 shows a similar example of a 5 multilayered structure having four narrow conductor tracks 1010 and two wide conductor tracks 1020. Metallizations, which shield the conductor tracks 1010 and 1020 against one another and to the outside, are additionally provided as a shielding 1030, so that a defined line impedance and less high-frequency radiation are achieved along with a shielded routing of the signals. A total of 11 layers are required to produce such a structure. In the contact pad region, the up to 11 layers can expediently be widened accordingly and, for example, passed into the top metal layer through a vertical through-connection.
