A catheter for administering medical therapy to a remote site in a body

Description

1 / 25 A catheter for administering medical therapy to a remote site in a body.

[001] The invention relates to a catheter for administering medical therapy to a remote site in the body.

[002] In the aforementioned medical therapy, such as, for example, an interventional cardiovascular or neurovascular application, such a catheter must be angled through the tortuous curves and folds of a (vascular) passage to reach the target anatomy. Such a catheter requires sufficient flexibility, particularly closer to its distal end, to navigate such tortuous pathways. However, other design aspects must also be considered. For example, the catheter must also be able to provide sufficient torqueability (i.e., the ability to transmit torque applied at the proximal end to the distal end), pushability (i.e., the ability to transmit axial thrust to the distal end), and structural integrity to perform the intended medical functions.

[003] For example, with regard to the aforementioned torquibability, it often happens in interventional cardiovascular or neurovascular applications that catheters have a preferred orientation in a particular arterial tree. This is due to the interactions between the catheter configuration and the arterial tree. As a result, it is sometimes very difficult or impossible for the medical professional to twist the catheter from outside the patient's body at the proximal end of the catheter in such a way that the catheter tip is rotated and directed towards the origin of the target branching passage. The reason is that the preferred orientation of the catheter in relation to a certain Petition 870250095131, dated 10 / 17 / 2025, page 24 / 60 2 / 25 The blood vessel structure, combined with the phenomenon known as whiplash, often causes catheter twisting to result in one or more precise 360-degree rotations of the distal tip. In this way, the distal tip almost always ends up in its initial erroneous orientation, which is not directed towards the origin of the target branching passage. In such cases, the aforementioned whiplash phenomenon is usually caused by twisting the catheter from outside the patient's body, which is far from the distal tip. As the torque increases during twisting, energy is stored in the catheter. And when the catheter finally and suddenly rotates, this rotation is caused by the fact that a certain uncontrollable amount of stored energy is suddenly released. In fact, the catheter does not use all the stored energy to automatically return to its preferred orientation relative to the blood vessel structure.Instead, the remaining unused portion of the stored energy is insufficient to overcome the resistance of stable catheter support within the blood vessel structure in the catheter's preferred orientation, where the distal tip of the catheter is not directed toward the origin of the target branching passage. Clearly, this is a frustrating experience for medical professionals.

[004] It is an objective of the present invention to provide a new catheter design that not only offers additional design freedom but also improves the torqueability of the catheter, among other aspects, providing a preventive effect on the occurrence of the whiplash phenomenon mentioned above during twisting.

[005] To this end, the invention provides a catheter according to the attached independent claim 1. Embodiments Petition 870250095131, dated 10 / 17 / 2025, page 25 / 60 3 / 25 preferable aspects of the invention are provided by the appended dependent claims 2-9.

[006] Thus, the invention provides a catheter for administering medical therapy to a remote site in a body, wherein: The catheter has a proximal end, a distal end, and a longitudinal direction that extends from the proximal end to the distal end; The catheter comprises a tubular catheter wall, which encloses a catheter lumen structure and extends from the distal end, proximally along the longitudinal direction, to at least 100 mm proximal from the distal end; The catheter wall comprises a randomized skeleton wall section, which extends in a randomized skeleton band along the longitudinal direction, wherein said randomized skeleton band extends at least between 10 mm proximal to the distal end and 100 mm proximal to the distal end; The randomized skeleton wall section comprises: — a randomized skeleton, extending at least along said randomized skeleton strip, and providing catheter wall reinforcement in the longitudinal direction as well as in a circumferential direction around the longitudinal direction, wherein the randomized skeleton is an interrupted tubular reinforcement wall obtained by microfabrication of a cut pattern in a fully uninterrupted tubular reinforcement wall made of a reinforcing material, — an inner lining, which is coaxially surrounded by said randomized skeleton with respect to a catheter wall centerline, and Petition 870250095131, dated 10 / 17 / 2025, page 26 / 60 4 / 25 — an outer laminate, which coaxially surrounds the aforementioned randomized skeleton in relation to the midline of the catheter wall; The randomized skeleton comprises a plurality of interconnected rods, wherein, as seen in radial view in the randomized skeleton, said radial view being radially in a cylindrical coordinate system relative to the centerline: — each of said rods has a corresponding pair of two mutually opposite longitudinal rod edges side by side, which determine a corresponding distribution of tangential thickness of a rod in question longitudinally along the rod in question, said tangential thickness being tangentially in a cylindrical coordinate system relative to the centerline, — said longitudinal rod edges are boundary to said cutting pattern, and — each of said longitudinal rod edges has randomized folds and / or randomized cusps; A general ratio of skeletal shear of a longitudinal section of the catheter wall in a longitudinal strip along the longitudinal direction is defined as the percentage of: — the volume of all parts, within the aforementioned longitudinal strip, of the aforementioned reinforcing material being cut from the aforementioned completely uninterrupted tubular reinforcing wall according to the aforementioned microfabricated cutting pattern, in relation to — the volume of all parts, within the aforementioned strip Petition 870250095131, dated 10 / 17 / 2025, page 27 / 60 5 / 25 longitudinal, of said reinforcement material of said fully uninterrupted tubular reinforcement wall; and the overall skeleton shear ratio of the randomized skeleton wall section in said randomized skeleton strip is between 40% and 90%.

[007] In the above-mentioned features of the present invention, the main features of the invention are: i. the randomized folds and / or randomized cusps of each of the two mutually opposed longitudinal stem edges of each stem of the plurality of interconnected stems of the randomized catheter wall skeleton; and ii. the overall shear ratio of the randomized skeleton wall section being between 40% and 90%.

[008] The aforementioned key feature (i) refers to the randomized folds and / or randomized cusps of the randomized skeleton in the randomized skeleton strip along the longitudinal direction. Compared to known skeleton rods, which have skeleton rod edges in the form of repeating patterns of regular lines or regular curves, the randomly shaped skeleton rod edges of the present invention provide improved mutual contact surfaces and therefore improved mutual bonds between the skeleton material, the inner sheath material and the outer laminate material. Said improved mutual bonds provide additional design freedom to make catheters more sophisticated to meet the growing design challenges to enable more advanced medical therapies. For example, compared to known skeleton catheters, said improved mutual bonds provided by the randomized skeleton of a Petition 870250095131, dated 10 / 17 / 2025, page 28 / 60 6 / 25 catheters according to the invention allow for the design of a randomized skeleton wall section with reduced radial thickness without compromising catheter strength.

[009] Furthermore, the randomly shaped skeleton rod edges of the present invention have a preventive effect on the occurrence of the aforementioned whiplash phenomenon, which occurs when a catheter assumes preferred orientations in certain arterial trees. Thanks to the randomized shapes incorporated in a catheter according to the invention, the internal stress distribution within the randomized skeleton wall section of the catheter changes more randomly, in fact more like in natural structures, in response to the movement and twisting of the catheter by a physician within an arterial tree, compared to a known catheter with skeleton rod edges that are shaped with repeated patterns of curves or regular lines, which is in fact not natural. In fact, each randomized skeleton rod of a catheter according to the invention has a unique shape.It should be noted that the natural vessels of a body, in fact, also have randomly shaped structures, that is, naturally grown structures. When a physician is moving and twisting a catheter according to the invention within a natural vessel structure, the more randomly changing internal stress distribution within the randomized skeletal wall section of the catheter results in a more gradual rotational adaptation behavior of the catheter to the randomized characteristics of the natural vessel structure and thus contributes to preventing the occurrence of said preferred orientations of a catheter in the natural vessel structure. In other words, the invention provides a more natural interaction between the catheter and the structures. Petition 870250095131, dated 10 / 17 / 2025, page 29 / 60 7 / 25 of a body vessel when the catheter is moved and twisted within said vessel structures.

[0010] The aforementioned key feature (ii) related to the overall skeleton cut ratio of the randomized skeleton wall section being between 40% and 90%, allows for good catheter flexibility in the randomized skeleton range, which allows navigation through challenging tortuous paths.

[0011] Furthermore, it will be readily observed that the randomized skeleton provides the randomized skeleton wall section with good pushability and lumen structure integrity. Other longitudinal sections of the catheter can be designed in many different ways and be firmly or integrally connected to the randomized skeleton wall section having the randomized skeleton. Thus, the invention allows the catheter to be reliably and efficiently manufactured and designed with favorable properties regarding flexibility, torqueability, pushability, and lumen structure integrity.

[0012] It should be noted that manufacturing the aforementioned high overall skeleton shear ratio (at least 40%) of the randomized skeleton wall section according to the invention requires inventive measures to solve several problems. The reason is that the inner lining of a skeletonized catheter for many applications is typically a tube made of, for example, PTFE (polytetrafluoroethylene, e.g., Teflon®), PVDF (polyvinylidene fluoride, e.g., Kynar®) or HDPE (high-density polyethylene), which during catheter manufacturing is inserted axially into the skeleton and is then expanded against the skeleton by inflation and Petition 870250095131, dated 10 / 17 / 2025, p. 30 / 60 8 / 25 heat. For the aforementioned high shear ratios, problems arise whereby the tube made of, for example, PTFE, PVDF or HDPE being inflated against the frame may protrude from the large cuts in the frame material and / or break under the inflation pressure. Another problem, especially for frames made of less strong material, is that the frame may severely deform and / or crack and / or break under the inflation pressure due to the fact that the frame is severely weakened by the large cuts in the frame material.

[0013] In connection therewith, the present invention, among other things, is based on the novel understandings, as described herein, that said problems can be solved by temporarily introducing, during the manufacture of a catheter according to the invention, a heat-shrinkable outer tube over the outer side of the randomized skeleton, such that the heat-shrinkable outer tube temporarily closes the cutouts in the skeleton material during said expansion of the inner sheath by inflation and heat, while at the same time the heat-shrinkable outer tube temporarily reinforces the skeleton during said expansion of the inner sheath by inflation and heat. After the inner sheath has been successfully expanded against the skeleton and after the catheter under construction has been cooled, the temporary heat-shrinkable outer tube can be removed from the outer side of the skeleton and replaced by the final outer laminate over the outer side of the skeleton.

[0014] Alternatively, another new insight, as described in this document, is that the aforementioned problems can be solved by performing the following manufacturing steps to assemble the inner lining and the laminate. Petition 870250095131, dated 10 / 17 / 2025, page 31 / 60 9 / 25 external to the skeleton in the case of the aforementioned high overall skeleton shear ratio (at least 40%) of the randomized skeleton wall section of the catheter wall of a catheter according to the invention. First, a tubular base layer of fluorinated ethylene propylene (FEP) is extruded and the inner sheath is extruded over the base layer. Then, the FEP base layer together with the inner sheath is inserted axially into the skeleton. Next, the outer laminate is slid over the outer side of the skeleton. Subsequently, a temporary heat-shrinkable outer FEP tube is slid over the outer laminate and the entire assembly is heated. During heating, the temporary heat-shrinkable outer FEP tube provides high compression in the assembly of the inner sheath, skeleton and outer laminate.After the catheter under construction has cooled, the temporary heat-shrinkable outer tube can be removed from the outside of the framework, and the FEP base layer can be axially pulled out of the assembly, making use of FEP's favorable properties regarding its ability to be pulled. This allows for a very close fit of the inner sheath against the inside of the framework.

[0015] It should be noted that the last mentioned use of such an extruded FEP base layer is a more effective and much less expensive alternative compared to the traditional use of a temporary silver-plated copper wire, which at the end of a manufacturing subprocess is axially pulled out of an inner lining of a catheter under construction.

[0016] Another advantage of the present invention is that, thanks to the high overall skeleton shear ratio (at least 40%) of the randomized skeleton wall section of the catheter wall of a catheter according to the invention, and thanks to Petition 870250095131, dated 10 / 17 / 2025, page 32 / 60 10 / 25 understandings mentioned above, as described in this document, the invention allows for the efficient incorporation of a radiopaque element (e.g., a radiopaque marker) into the catheter wall, since the radiopaque element can be perfectly located in a space of the cutting pattern, said space being delimited by the randomized skeleton, the inner layer, and the outer laminate.

[0017] In a preferred embodiment of a catheter according to the invention, said randomized skeleton strip extends at least between 0.5 mm proximal to the distal end and 100 mm proximal to the distal end. Thus, the randomized skeleton extends distally even closer to the distal end.

[0018] More preferably, the aforementioned randomized skeletal band extends at least between the distal end and 100 mm proximal to the distal end.

[0019] In another preferred embodiment of a catheter according to the invention, the overall skeleton shear ratio of the randomized skeleton wall section in said randomized skeleton range is between 60% and 85%.

[0020] In another preferred embodiment of a catheter according to the invention, a radiopaque element is incorporated into the catheter wall, wherein the radiopaque element is located in a space of the cut pattern, said space being delimited by the randomized skeleton, the inner layer and the outer laminate.

[0021] The catheter according to the invention can be incorporated as a quick-change catheter having the tubular catheter wall as a distal quick-change tubular segment that is spaced from the proximal end of the catheter. Petition 870250095131, dated 10 / 17 / 2025, page 33 / 60 11 / 25 quick-change.

[0022] Such a quick-change catheter has a proximal catheter segment, proximally from the distal quick-change tubular segment, which may, for example, be a pressure rod that is connected to the distal quick-change tubular segment. Such a pressure rod may advantageously have a circular cross-section with a diameter d 0.40 mm to support 1:1 torque from the proximal end to the distal end. Such 1:1 torque is highly desirable for this type of device, as the physician needs to be able to accurately guide the catheter towards a target site, such as a bend or a lateral branch of a vascular passage.

[0023] In another preferred embodiment of a catheter according to the invention, the tubular catheter wall being said distal quick-change tubular segment of said quick-change catheter comprises at least one lateral perfusion orifice, which extends from the lumen structure, through successive interruptions of the inner lining, the randomized skeleton and the outer laminate, to the radially external outer environment of the tubular catheter wall to allow perfusion flow transversely through the tubular catheter wall from the lumen structure to said outer environment.

[0024] Such a lateral perfusion port, or preferably a plurality of such lateral perfusion ports, may be desirable when a distal rapid-exchange tubular segment of a rapid-exchange catheter is, for example, deeply intubated into the coronary arteries during Percutaneous Coronary Intervention. Without this / these lateral perfusion port(s), the tubular segment of Petition 870250095131, dated 10 / 17 / 2025, p. 34 / 60 12 / 25 rapid distal exchange can severely reduce / block distal coronary flow and may cause procedure-induced ischemia.

[0025] An advantageous arrangement of such lateral perfusion holes could, for example, be nine lateral perfusion holes placed with equal angular spacing along a spiral path extending from 40 mm proximal to 85 mm proximal to the distal end of the distal quick-change tubular segment. In this arrangement, each of the nine lateral perfusion holes could be surrounded by a corresponding set of mutually connected randomized skeleton rods with randomized bends and / or randomized cusps. Preferably, the lateral perfusion holes should have a sufficiently small hole diameter (e.g., d 0.30 mm) to prevent the tip of a guidewire within the quick-change tubular segment from exiting such a perfusion hole and causing vessel perforation.

[0026] Alternatively, the catheter according to the invention may be incorporated as an over-the-wire (OTW) catheter, wherein the tubular catheter wall and catheter lumen structure extend along the longitudinal direction from the proximal end to the distal end.

[0027] Such an over-the-wire catheter may advantageously have an over-the-wire catheter skeleton, which extends along the longitudinal direction from the proximal end to the distal end, and which provides catheter wall reinforcement in the longitudinal direction as well as in the circumferential direction around the longitudinal direction, wherein the over-the-wire catheter skeleton is an interrupted tubular reinforcement wall obtained by microfabrication of a pattern of Petition 870250095131, dated 10 / 17 / 2025, pp. 35 / 60 13 / 25 cut in a completely uninterrupted tubular reinforcement wall made of a reinforcing material. In this case, the randomized skeleton of the randomized skeleton wall section may be just a section of the over-the-wire catheter skeleton, or it may even extend along the longitudinal direction from the proximal end to the distal end. Preferably, the over-the-wire catheter skeleton is designed to support 1:1 torqueability from the proximal end to the distal end of the over-the-wire catheter. Alternatively to the aforementioned over-the-wire skeleton, the over-the-wire catheter may, in longitudinal sections outside the range of the randomized skeleton, also be designed with, for example, wire braids or coil structures to support 1:1 torqueability.

[0028] In another preferred embodiment of a catheter according to the invention, the tubular catheter wall of said over-the-wire (OTW) catheter comprises at least one lateral perfusion orifice, which extends from the lumen structure, through successive interruptions of the inner lining, the randomized skeleton and the outer laminate, to the radially external outer environment of the tubular catheter wall to allow perfusion flow transversely through the tubular catheter wall from the lumen structure to said outer environment.

[0029] Such a lateral perfusion hole, or preferably a plurality of such lateral perfusion holes, may be desirable to avoid procedure-induced ischemia.

[0030] The invention is further elucidated herein with reference to a non-limiting embodiment and with reference Petition 870250095131, dated 10 / 17 / 2025, pp. 36 / 60 14 / 25 to the schematic figures in the attached drawings, in which the following is shown.

[0031] Fig. 1 shows, in a longitudinal side view, an example of an embodiment of a catheter according to the invention, wherein in Fig. 1 the randomized skeleton strip of the catheter wall section is indicated by a bracket mark.

[0032] Fig. 2 shows, in a perspective view, a short longitudinal section of the randomized skeleton of the catheter wall section of Fig. 1.

[0033] Fig. 3A shows a short longitudinal section of the randomized skeleton wall section of the catheter of Fig. 1, wherein the longitudinal section shown comprises a part of the randomized skeleton and wherein the view shown is a longitudinal sectional view, which contains the centerline of the catheter wall.

[0034] Fig. 3B shows a cross-section through the longitudinal section of the randomized skeleton wall section of Fig. 3A, where the cross-section shown is perpendicular to the centerline of the catheter wall.

[0035] Fig. 4 shows a portion of the short longitudinal section of the randomized skeleton from Fig. 2 again, however, this time the view shown is a top view of the longitudinal section in an imaginary unwound tube state of the longitudinal section.

[0036] Fig. 5 shows, similarly to Fig. 3A, another short longitudinal section of the randomized skeleton wall section of the catheter of Fig. 1, wherein Fig. 5 shows two lateral perfusion holes of the randomized skeleton wall section. Petition 870250095131, dated 10 / 17 / 2025, pp. 37 / 60 15 / 25

[0037] Fig. 6A shows an example of an initial Finite Element Analysis (FEA) mesh of a portion of a regular rod from an initial regular skeleton for a catheter, where the view shown is similar to the view in Fig. 4 in that the view shown is a top view of the initial FEA mesh in an imaginary unwound tube state from the initial FEA mesh.

[0038] Fig. 6B shows, in a view similar to the view in Fig. 6A, an example of a portion of a distorted FEA mesh of a corresponding portion of a distorted rod of a distorted skeleton, said distorted FEA mesh being used in an example of a skeleton design process based on a randomization algorithm to obtain the randomized folds and / or randomized cusps of the longitudinal rod edges of the randomized skeleton of a catheter according to the invention.

[0039] The reference signs used in Figs. 1-5 refer to the aforementioned parts and aspects of the invention, as well as to related parts and aspects, as follows. --------------------catheter tubular catheter wall lumen structure proximal end --------------------distal end Randomized skeleton A -------------------cutting pattern interior lining external laminate longitudinal direction -------------------circumferential direction Petition 870250095131, dated 10 / 17 / 2025, pp. 38 / 60 16 / 25 center line ------------------- randomized skeleton wall section randomized skeleton band 21L-28L, 31L-38L ----- left-handed rods 21R-28R, 31R-38R ----- right-handed rods, 42 --------------- longitudinal edges of the rod 51, 52 ---------------lateral perfusion orifices 68-85 ----------------connection nodes 100------------------initial FEA mesh 100A ----------------- distorted FEA mesh 101-112 -------------initial FEA mesh nodes 100 103A, 104A, 107A, 108A, 111A, 112A, -- distorted nodes of the distorted FEA mesh 100A

[0040] Based on the introductory description above, including the brief description of the figures in the drawings, and based on the reference signs listed above used in Figs. 1-5, the modality of Figs. 1-5 is, for the most part, easily self-explanatory. The following additional explanations are given.

[0041] Fig. 1 shows catheter 1 with longitudinal direction 10, proximal end 4 and distal end 5. Fig. 1 also shows the randomized skeleton strip 15 of the randomized skeleton wall section 14 of catheter wall 2.

[0042] The perspective view of Fig. 2 shows that the randomized skeleton 7 of the randomized skeleton wall section 14 of catheter 1 in Fig. 1 has the left-handed rods 21L-28L and 31L-38L, the right-handed rods 21R-28R and 31R-38R, and the connecting nodes 68-85.

[0043] Figs. 3A-3B show that the wall section of Petition 870250095131, dated 10 / 17 / 2025, pp. 39 / 60 17 / 25 randomized skeleton 14 not only has skeleton 7, which comprises cutting pattern 7A, but also has inner lining 8 and outer laminate 9. In the example of Figs. 3A-3B, the lumen structure 3 of catheter 1 is a single-lumen structure. Alternatively, a catheter according to the invention may have a multi-lumen structure.

[0044] Fig. 4 shows a short longitudinal section of the randomized skeleton 7 of the randomized skeleton wall section 14 of catheter 1. In Fig. 4, the view shown is a top view in longitudinal section in an imaginary unrolled tube state of the longitudinal section. To explain the term unrolled tube, it should be noted that the randomized skeleton is a tubular wall (more particularly an interrupted tubular reinforcement wall) and that such a tubular wall can be imaginarily unrolled in a completely straight state by imaginarily unrolling it in a completely straight plane after an imaginary straight cut, parallel to the catheter centerline, made along the entire length of the tubular wall. In Fig. 4, the aforementioned imaginary straight cut is a straight line passing through the connecting nodes 68, 72, 76, 80 and 84 of the randomized skeleton 7. In Fig. 4, the reference numbers 68, 72, 76, 80 and 84 are shown both at the bottom of Fig.4 as well as at the top of Fig. 4, since the locations to which these reference numbers 68, 72, 76, 80 and 84 are pointing will join when the completely straight state of Fig. 4 is imaginarily rolled up again to form the tubular state of the randomized skeleton 7 as shown in the perspective view of Fig. 2.

[0045] From Figs. 2 and 4 (best seen in Fig. Petition 870250095131, dated 10 / 17 / 2025, pp. 40 / 60 18 / 25 4) It can be inferred that at each of the connection nodes 7083, four of the rods are connected to each other, that is, two of the left-handed rods and two of the right-handed rods. For example, at connection node 74, the two left-handed rods 33L, 34L and the two right-handed rods 33R, 34R are all interconnected.

[0046] From Figs. 2 and 4 (best seen in Fig. 4) it can be further inferred that each of the rods shown 21L-28L, 31L-38L, 21R-28R and 31R-38R has a corresponding pair of two mutually opposite longitudinal rod edges side by side, wherein each of said longitudinal rod edges has randomized bends and / or randomized cusps. For simplicity, in Figs. 2 and 4 for only one of the rods shown, these longitudinal rod edges have been indicated with reference numbers. See the two mutually opposite longitudinal rod edges 41 and 42 of the right-handed rod 33R. From Figs. 2 and 4 it will be readily observed that each rod of the randomized skeleton 7 of a catheter 1 according to the invention has a unique shape.

[0047] In the introduction to this disclosure, it was mentioned that a catheter according to the invention can be incorporated as a quick-change catheter having the tubular catheter wall as a distal quick-change tubular segment that is spaced from the proximal end of the quick-change catheter. It was also mentioned that the catheter can alternatively be incorporated as an over-the-wire (OTW) catheter, wherein the tubular catheter wall and catheter lumen structure extend along the longitudinal direction from the proximal end to the distal end. It was further mentioned that in both embodiments Petition 870250095131, dated 10 / 17 / 2025, pp. 41 / 60 19 / 25 (quick-change catheter or over-the-wire catheter), the tubular catheter wall may comprise at least one lateral perfusion orifice, which extends from the lumen structure, through successive interruptions of the inner lining, the randomized skeleton and the outer laminate, to the radially external external environment of the tubular catheter wall to allow perfusion flow transversely through the tubular catheter wall from the lumen structure to said external environment.

[0048] Two of these lateral perfusion orifices 51 and 52 of the randomized skeleton wall section 14 are shown in Fig. 5. It is seen in Fig. 5 that each of the lateral perfusion orifices 51, 52 extends from the lumen structure 3, through successive interruptions of the inner lining 8, the randomized skeleton 7 and the outer laminate 9, to the radially external outer environment of the tubular catheter wall 2 to allow perfusion flow transversely through the tubular catheter wall 2 from the lumen structure 3 to said outer environment. The perfusion flow has been indicated by two curved S-arrows. In radial view over the imaginary unrolled tube state of the randomized skeleton 7 shown in Fig. 4, the lateral perfusion orifices 51, 52 may, for example, have circular or oval shapes, wherein each lateral perfusion orifice passes through a corresponding void of the cut pattern 7A.In other words, this lateral perfusion orifice does not intercept any of the 21L-28L, 31L-38L, 21R-28R, and 31R-38R rods, but passes between them.

[0049] The randomized skeleton of a catheter according to the invention can, for example, be designed as follows. As a starting point, a design is taken of Petition 870250095131, dated 10 / 17 / 2025, pp. 42 / 60 20 / 25 Initial regular skeleton, comprising a plurality of interconnected regular rods with regular longitudinal rod edges (i.e., non-randomized rod edges), wherein the initial regular skeleton was analyzed by Finite Element Analysis (FEA) software to meet various design specifications (such as strength and stiffness properties) for the catheter to be designed. In a subsequent distortion step of the skeleton design process, the initial regular skeleton is distorted using a randomization algorithm that transforms the regular longitudinal rod edges into longitudinal rod edges with randomized bends and / or randomized cusps (an example of such a randomization algorithm is elucidated further below). The randomized skeleton thus obtained is then analyzed by the FEA software.If desired, this distortion step can be repeated several times to obtain different randomized skeleton designs to submit each of them to FEA. A final design chosen from a catheter according to the invention with such a randomized skeleton is analyzed by FEA software in order to ensure that the randomized skeleton design with randomized bends and / or randomized cusps of the longitudinal stem edges meets various design specifications for the final catheter design.

[0050] Generally, compared to a regular (i.e., non-randomized) skeleton, a corresponding randomized skeleton, obtained by randomization from said regular skeleton, results in a randomized skeleton with large-scale strength and stiffness properties that are comparable to those of a regular non-randomized skeleton, but with small-scale bonding properties with the Petition 870250095131, dated 10 / 17 / 2025, pp. 43 / 60 21 / 25 inner lining and outer laminate are better with the randomized skeleton, while also the torque properties of the catheter are better with the randomized skeleton.

[0051] An example of the aforementioned randomization algorithm used in the aforementioned example skeleton design process is now elucidated with reference to Figs. 6A-6B.

[0052] As seen in the radial view in the randomized skeleton, each regular rod of an initial regular skeleton is modeled by an initial FEA mesh with an initial set of nodes. Fig. 6A shows the initial FEA mesh 100 of a portion of a regular rod of the initial regular skeleton, where the initial FEA mesh 100 has nodes 101-112. In the distortion step of the skeleton design process, some of these nodes 101-112 are each displaced in the longitudinal and / or circumferential direction to obtain a distorted FEA mesh of a corresponding portion of a distorted rod. Other nodes 101-112 are not displaced at all to become part of said distorted FEA mesh. In the example shown in Figs. In Figures 6A and 6B, nodes 103, 104, 107, 108, 111, and 112 of the initial FEA mesh 100 in Fig. 6A are randomly shifted to become the distorted nodes 103A, 104A, 107A, 108A, 111A, and 112A of the distorted FEA mesh 100A in Fig. 6B.The other nodes 101, 102, 105, 106, 109, and 110 of the initial FEA mesh 100 in Fig. 6A are those that are not displaced to become part of the distorted FEA mesh 100A.

[0053] The distorted FEA mesh 100A in Fig. 6B is only a very small portion of a larger distorted FEA mesh of a complete randomized skeleton 7 of Petition 870250095131, dated 10 / 17 / 2025, pp. 44 / 60 22 / 25 a catheter according to the invention. Such a larger distorted FEA mesh is used in the Finite Element Analysis of the randomized skeleton 7. The randomized shapes of all longitudinal rod edges 41, 42 of the randomized skeleton 7 can be determined by curvature fitting with respect to the nodes of such a larger distorted FEA mesh. Thus, a portion of a longitudinal rod edge 41 can be the result of curvature fitting with respect to nodes 101, 103A, 105, 107A, 109 and 111A of the distorted FEA mesh 100A in Fig. 6B, while a portion of a longitudinal rod edge 42 can be the result of curvature fitting with respect to nodes 102, 104A, 106, 108A, 110 and 112A of the distorted FEA mesh 100A. Fig. 4 illustrates the results of such curvature adjustment for all left-handed rods 21L28L, 31L-38L and for all right-handed rods 21R-28R, 31R-38R. It can be seen that each rod in Fig. 4 has a unique shape (see also Fig. 2).

[0054] As mentioned, in the present randomization algorithm example, nodes 103, 104, 107, 108, 111, and 112 of the initial FEA mesh 100 in Fig. 6A were randomly shifted to become the distorted nodes 103A, 104A, 107A, 108A, 111A, and 112A of the distorted FEA mesh 100A in Fig. 6B. From Fig. 6B, which additionally shows the positions of nodes 103, 104, 107, 108, 111, and 112, it can be seen that the distorted nodes 103A, 104A, 107A, 108A, 111A, and 112A are the result of randomized shifting. In the example shown, randomization follows a Normal distribution, which means that the displacement distances involved in said displacement will also have a Normal distribution due to the large number of nodes that need to be moved to create a randomized skeleton. Petition 870250095131, dated 10 / 17 / 2025, pp. 45 / 60 23 / 25 complete is designed. It is possible to limit the maximum and / or minimum displacement distance involved in the aforementioned randomization algorithm displacement by predetermined values. Generally, the randomization algorithm can be based on randomization by several other types of distribution than the aforementioned Normal distribution, such as, for example, Lognormal, Loglogistic or Weibull distributions.

[0055] The invention can be practiced with many different structures, many different materials, many different shapes and many different dimensions of the randomized skeleton, inner sheath and outer laminate of the catheter, and with many different features and many different accessories of the catheter, such as the many different structures, the many different materials, the many different shapes and the many different dimensions of skeletons, inner sheaths and outer laminates, and the many different features and many different accessories that are used in known catheters to administer medical therapy to a remote site in a body, provided that the catheter is within the scope of the appended claims. Furthermore, many different processes can be used to design a randomized skeleton of a catheter according to the invention, and many different randomization algorithms can be used therein.

[0056] Regarding the general ratio of skeleton cutting, the following general observation is made. If, throughout a continuous longitudinal section of a catheter wall, the catheter wall has a completely uninterrupted tubular metal reinforcement wall, then Petition 870250095131, dated 10 / 17 / 2025, pp. 46 / 60 24 / 25 example, in the form of a completely uninterrupted metal hypotube, then the said longitudinal section has a total skeleton shear ratio of 0%.

[0057] In the example shown, the randomized skeleton 7 has the following dimensions. The randomized skeleton strip 15 extends between the distal end 5 and 150.0 mm proximal to the distal end 5. Therefore, the randomized skeleton 7 has a length of 150.0 mm in the longitudinal direction 10. The randomized skeleton 7 has an outer diameter of 1.651 mm and an inner diameter of 1.529 mm. It should be noted that in the example shown, the randomized skeleton 7 terminates at the distal end 5 of the catheter 1. Alternatively, however, the inner sheath 8 and / or the outer laminate 9 may extend slightly distally beyond the randomized skeleton 7 to make the distal end 5 atraumatic.

[0058] It should be further noted that, according to the invention, the typical dimensions of some parts and aspects of the invention and the applicable practical ranges of such dimensions may be as follows in the case of the catheter being a microcatheter for interventional cardiovascular or neurovascular applications. The effective length of the catheter (as measured from the distal end of a catheter hub) may be in the range between 130 cm and 160 cm and may typically be 135 cm. The maximum outer diameter of the randomized skeleton wall section of the tubular catheter wall may be in the range between 0.60 mm and 1.20 mm and may typically be 0.75 mm, although noting that the word maximum in the term maximum outer diameter is referring to the maximum value considered over the entire length of the skeleton wall section. Petition 870250095131, dated 10 / 17 / 2025, pp. 47 / 60 25 / 25 randomized. The minimum internal diameter of the randomized skeleton wall section of the tubular catheter wall can range between 0.36 mm and 0.55 mm and can typically be 0.45 mm, although noting that the word minimum in the term minimum internal diameter refers to the minimum value considered along the entire length of the randomized skeleton wall section. For example, the following typical combinations of maximum external diameter and minimum internal diameter of the first randomized skeleton wall section are possible: maximum external diameter of 0.75 mm in combination with minimum internal diameter of 0.45 mm, maximum external diameter of 1.20 mm in combination with minimum internal diameter of 0.55 mm, or maximum external diameter of 0.60 mm in combination with minimum internal diameter of 0.36 mm.

[0059] However, the present invention can be incorporated into various other catheters for administering medical therapy to a remote site in a body, which may be non-vascular and / or non-microcatheters, such as, for example, catheters for administering medical therapy to renal vessels, fallopian tubes and other vessels and sites like these. In such cases, the typical dimensions of some parts and aspects of the invention and the applicable practical ranges of such dimensions may differ from those mentioned above for microcatheters for interventional cardiovascular or neurovascular applications. Petition 870250095131, dated 10 / 17 / 2025, pp. 48 / 60

Claims

1 / 5 CLAIMS 1. Catheter (1) for administering medical therapy to a remote site in a body, characterized in that: the catheter has a proximal end (4), a distal end (5) and a longitudinal direction (10) extending from the proximal end to the distal end; the catheter comprises a tubular catheter wall (2), which surrounds a catheter lumen structure (3) and extends from the distal end (5), proximally along the longitudinal direction, to at least 100 mm proximal to the distal end; the catheter wall (2) comprises a randomized skeleton wall section (14), which extends in a randomized skeleton strip (15) along the longitudinal direction, wherein said randomized skeleton strip extends at least between 10 mm proximal to the distal end and 100 mm proximal to the distal end (5);the randomized skeleton wall section (14) comprises: — a randomized skeleton (7), which extends at least along said randomized skeleton strip and which provides catheter wall reinforcement (2) in the longitudinal direction (10) as well as in a circumferential direction (11) around the longitudinal direction (10), wherein the randomized skeleton (7) is an interrupted tubular reinforcement wall obtained by microfabricating a cutting pattern (7A) in a fully uninterrupted tubular reinforcement wall made of a reinforcement material, — an inner liner (8), which is coaxially encircled by said randomized skeleton (7) in relation to a centerline (12) of the catheter wall (2), and — an outer laminate (9), which coaxially encircles said randomized skeleton (7) in relation to the centerline (12) of the catheter wall;The randomized skeleton (7) comprises a plurality of interconnected rods (21L-28L, 31L-38L, 21R-28R, 31R-38R), wherein, as seen in radial view in the randomized skeleton, said radial view being radially in a cylindrical coordinate system with respect to the centerline (12): — each of said rods (21L-28L, 31L-38L, 21R-28R, 31R-38R) has a corresponding pair of two mutually opposite longitudinal rod edges (41, 42) side by side, which determine a corresponding distribution of tangential thickness of a rod in question longitudinally along the rod in question, said tangential thickness being tangentially in a cylindrical coordinate system with respect to the centerline (12), — said longitudinal rod edges (41, 42) are boundary to the aforementioned cut pattern (7A), and — each of the aforementioned longitudinal edges of the stem (41, 42) has randomized folds and / or randomized cusps;A general skeleton cutting ratio of a longitudinal section of the catheter wall (2) in a longitudinal strip along the longitudinal direction (10) is defined as the percentage of: — the volume of all parts, within said longitudinal strip, of said reinforcement material being cut from said fully uninterrupted tubular reinforcement wall in accordance with said microfabricated cutting pattern (7A), in relation to — the volume of all parts, within said longitudinal strip, of said reinforcement material of said fully uninterrupted tubular reinforcement wall; and the general skeleton cutting ratio of the randomized skeleton wall section (14) in said randomized skeleton strip (15) is between 40% and 90%.

2. Catheter (1), according to claim 1, characterized in that said randomized skeletal band (15) extends at least between 0.5 mm proximal to the distal end (5) and 100 mm proximal to the distal end (5).

3. Catheter (1), according to claim 2, characterized in that said randomized skeletal band (15) extends at least between the distal end (5) and 100 mm proximal to the distal end (5).

4. Catheter (1), according to any one of claims 1 to 3, characterized in that the overall skeleton shear ratio of the randomized skeleton wall section (14) in said randomized skeleton strip (15) is between 60% and 85%.

5. Catheter (1), according to any one of claims 1 to 4, characterized in that a radiopaque element is incorporated into the catheter wall (2), wherein the radiopaque element is located in a cut pattern space (7A), said space being delimited by the randomized skeleton (7), the inner layer (8) and the outer laminate (9).

6. Catheter (1), according to any one of claims 1 to 5, characterized in that the Petition 870250095131, dated 10 / 17 / 2025, page 51 / 60 4 / 5 catheter is a quick-change catheter having the tubular catheter wall (2) as a distal quick-change tubular segment that is spaced from the proximal end (4) of the quick-change catheter.

7. Catheter (1), according to claim 6, characterized in that the tubular catheter wall (2), said distal quick-change tubular segment of said quick-change catheter, comprises at least one lateral perfusion orifice (51, 52), which extends from the lumen structure (3), through successive interruptions of the inner lining (8), the randomized skeleton (7) and the outer laminate (9), to the radially external outer environment of the tubular catheter wall (2) to allow perfusion flow transversely through the tubular catheter wall (2) from the lumen structure (3) to said outer environment.

8. Catheter (1), according to any one of claims 1 to 5, characterized in that the catheter is an over-the-wire (OTW) catheter, wherein the tubular catheter wall (2) and the lumen structure (3) of the catheter extend along the longitudinal direction (10) from the proximal end (4) to the distal end (5).

9. Catheter (1), according to claim 8, characterized in that the tubular catheter wall (2) of said over-the-wire (OTW) catheter comprises at least one lateral perfusion orifice (51, 52), extending from the lumen structure (3), through successive interruptions of the inner lining (8), the randomized skeleton (7) and the outer laminate (9), to the radially external external environment of the tubular catheter wall (2) to allow perfusion flow transversely through the tubular catheter wall (2) from the lumen structure (3) to said external environment.

Images