"multi-layered microcatheter with positioning markers"

Abstract

The present invention provides a multi-layered microcatheter comprises four distinct layers proximally 111, transitioning to three layers distally 112. The inner layer is a continuous, lubricious PTFE layer for smooth advancement. Encasing this is a reinforcement layer featuring an SS304V coil 114 for structural integrity and, in the distal region, a hollow Pt10Ir marker bands 107 & 108 for visual reference during procedures. At least one marker band, preferably a strategically placed C-cut design, enhances control during manipulation by encompassing a significant portion of the catheter circumference. Braid reinforcement layer 113 encasing the reinforcement layer and extending along 60% to 95% of the microcatheter length, made from eight flat wires at a density of 70 picks per inch (PPI) to enhance stiffness for pushability while maintaining flexibility. Further, the outermost layer 2(c) is a segmented sheath made of polymeric materials. Additionally, the microcatheter is designed for ease of manufacture and cost-effectiveness.

Description

[0001] Multi-Layered Microcatheter with Positioning Markers

[0002] Field of the Invention

[0003] The present invention relates to the field of medical devices, and more particularly to a microcatheter with a multi-layered construction and marker bands for improved performance during minimally invasive procedures. Even more particularly the design of microcatheter incorporates a multi-layered construction and strategically placed marker bands to achieve a balance between pushability and flexibility.

[0004] Background of the Invention

[0005] Microcatheters are thin, flexible tubes used for accessing and navigating small blood vessels and other anatomical structures during minimally invasive procedures. They play a crucial role in delivering therapeutic agents, performing balloon angioplasty, and facilitating micro-surgical interventions. Conventional microcatheters often face challenges in terms of balancing stiffness for pushability and flexibility for maneuverability. Additionally, precise location of the catheter tip within the body can be difficult to achieve. Many researchers and inventors have worked on it and developed some related works but they are lacking in design and missing some features. Some of such inventions are discussed below.

[0006] Reference has been made to IN202127052047 titled "EMBOLIZATION CATHETER FOR REFLUX FREE DELIVERY OF MICROSPHERES", by ACCURATE MEDICAL THERAPEUTICS LTD, dated 23 / 05 / 2019 which discloses an embolization microcatheter for delivery of embolization beads to a target area, the microcatheter including a proximal end and a distal end, the distal end terminating in an end opening sized and shaped to allow delivery of a suspension of embolization beads, and a filter section located between in proximity to the distal end opening; the filter section including a large plurality of openings distributed circumferentially around a wall thereof, the filter section configured to allow outflow of the suspension fluid while preventing outflow of the embolization beads.

[0007] Another reference has been made to IN201714039503 titled "DEVICES AND METHODS FOR. REMOVAL OF ACUTE BLOCKAGES FROM BLOOD VESSELS", by S BANU dated 28 / 11 / 2016 which discloses a catheter has an expansile tip that can be delivered in a constricted form. The increased tip diameter facilitates the aspiration and removal of large clot volumes by increasing the area of the catheter tip that applies aspiration to the clot. The tip comprises a support frame which can be cut from a metal or polymer tube, covered with a thin polymer sleeve 909 containing highly elastic properties. This construction provides good push ability and high compressive resistance. The cut pattern can contain axial connections of the support frame and ring members, which will provide a large level of axial support, lateral flexibility and hoop strength to withstand aspiration. The tip of the device can contain a section proximal of the highly flexible area that can expand to except clot. This potential to increase body diameter facilitates the retrieval of large volume clots while the construction of the catheter provides good column stiffness to avoid axial collapse and still maintain good flexibility.

[0008] Another reference has been made to IN201747034325 titled "IMPLANT INSERTION SYSTEM", by Phenox GmbH dated 05 / 03 / 2015 which discloses a device for introducing an implant (1), wherein the release tube (13) protrudes into the proximal end of the implant (1), wherein an elastic contact surface is present between the inside of the implant (1) and the outside of the release tube (13), so that a frictional locking is generated between implant (1) and release tube (13), bringing about a lengthwise mobility of the implant (1) inside the microcatheter (8) by lengthwise movement of the release tube (13) distally or proximally.

[0009] 3 Another reference has been made to WO2019030761A1 titled "MICROCATHETER", by ACCURATE MEDICAL THERAPEUTICS LTD dated 2017-08-09 which discloses a microcatheter comprising an inner layer, a strike layer and an outer layer and a braided skeleton located between the inner layer and the outer layer, wherein the inner layer is made of Polytetrafluoroethylene (PTFE) and has a thickness of 0.0015 inch or less, wherein the strike layer includes a polyether block amide and has a thickness of 0.001 inch or less, and wherein a distal portion of said outer layer is made of polycarbonate-based thermoplastic polyurethane having a shore of 90A or below.

[0010] Another reference has been made to US10933226B2 titled "Intravascular devices, systems, and methods to address eye disorders", by J D FRANCO & CO LLC dated 2018-12-31 which discloses a method may include accessing an artery in communication with an ophthalmic artery of a subject, and advancing a microcatheter along the accessed artery so as to align a distal end of the microcatheter with an ostium of the ophthalmic artery, wherein the microcatheter includes a lumen having a guidewire positioned therein. In addition, the method includes proximally withdrawing the guidewire relative to the microcatheter so as to enable a distal portion of the microcatheter to assume a curved relaxed configuration, and cannulating the ostium with the distal portion of the microcatheter when the distal portion is in the curved relaxed configuration.

[0011] Another reference has been made to KR20220098399A titled "INTRAVASCULAR TREATMENT SITE ACCESS", by MICROVENTION INC dated 2016-02-10 which discloses an idea of designing to eliminate gaps between guide wires and catheters to contribute to the catheter snagging within the vasculature.

[0012] 4 Another reference has been made to EP4176829A1 titled "SUPER-BORE CATHETER WITH BRAID SUPPORTED FLARED TIP", by NEURAVI LTD dated 2021-11-03 which discloses a clot retrieval catheter with a large bore shaft and a distal braid-supported tip that is expandable to a diameter larger than the outer sheath through which it is delivered. The shaft can have a plurality of supporting braids fixed distally to a radiopaque marker band. The tip can have another plurality of supporting braids fixed proximally to the marker band and a decreasing braid angle distally so that the tip can be heat set to an expanded funnel shape. The wires of the tip braids can follow one spiral direction distally and then invert proximally back on themselves to form the other spiral direction of the braid. This inversion of the wires results in atraumatic distal hoops at the distal termination of the braid. Designs can further have spines capable of resisting elongation of the catheter shaft during a procedure.

[0013] Another reference has been made to US11389620B2 titled "Catheter and catheter kit", by SUMITOMO BAKELITE CO dated 2017-08-25 which discloses a catheter (100) includes a resin-made distal tip (80) linked to a distal end of a catheter body (10), and the distal tip (80) has a distal lumen (81) having an open distal end. The distal lumen (81) communicates with a lumen (31). The catheter (100) is an inactive type microcatheter in which an outer diameter of the distal end of the catheter body (10) is 0.6 mm or smaller and a maximum outer diameter of the distal tip (80) is 0.6 mm or smaller. A dimension of a marker (70) in an axial direction of the catheter body (10) is smaller than the maximum outer diameter of the distal tip (80), and the length of the distal tip (80) in the axial direction of the distal tip (80) is 3 times to 18 times the maximum outer diameter of the distal tip (80).

[0014] 5 Another reference has been made to US2022175404A1 titled "CATHETER. INCLUDING A RADIOPAQUE EXPANDABLE MEMBER", by COVIDIEN LP dated 2020-12-03 which discloses a catheter including an elongated body and an expandable member at a distal portion of the elongated body and defining at least part of a distal tip of the catheter. The expandable member is formed from materials that enable a distal tip of the catheter to be radiopaque without the addition of a separate radiopaque marker (e.g., a solid metal ring of radiopaque material separates from and connected to the elongated body) at the distal tip of the catheter.

[0015] Another reference has been made to EP3589348A1 titled "FLEXIBLE TIP CATHETER", by COVIDIEN LP dated 2017-03-02 which discloses a catheter including an elongated body comprising proximal and distal portions. The distal portion of the elongated body comprises an inner liner that includes a proximal liner section and a distal liner section that include different materials, and an outer jacket positioned over the inner liner. The distal liner section has a first hardness and the proximal liner section has a second hardness, where the first hardness is less than the second hardness.

[0016] Another reference has been made to IN202031001863 titled "MICROCATHETER DEVICE", by COVIDIEN LP dated 15 / 01 / 2020 which discloses a microcatheter device includes an outer tube, an inner tube positioned inside the outer tube such that a gap is created between an outer periphery of the inner tube and an inner periphery of the outer tube. A plurality of first wires helically wrapped on the outer periphery of the inner tube in a first direction along a longitudinal axis of the inner tube, a plurality of second wires helically wrapped on the outer periphery of the hollow innertube in second direction along the longitudinal axis of

[0017] 6 the inner tube, wherein the plurality of first wires and the plurality of second wires are configured to support the outer tube on the inner tube, and wherein the plurality of first wires and the plurality of second wires arranged such that a predefined angle is created between adjacent helix shapes.

[0018] Another reference has been made to IN201921051839 titled "EMBOLIZATION COIL ASSEMBLY AND METHOD OF PREPARATION THEREOF", by Meril Life Sciences Pvt. Ltd dated 13 / 12 / 2019 which discloses an embolization coil assembly (100) having an embolization coil (10) and a delivery system (20) is disclosed. The embolization coil (10) has a delivery and a deployed configuration. The embolization coil further includes a secondary coil (10a) having a first section (lOal) and a second section (10a2). The first section (lOal) and the second section (10a2) are linearly disposed in the delivery configuration and attain a first predefined shape and a second predefined shape respectively in the deployed configuration. The secondary coil (10a) is formed by reshaping a primary coil made from a super elastic shape memory material. The delivery system (20) includes a delivery wire (20a) having a tapered profile. A holding member (20b) is attached to the secondary coil (10a). An introducer sheath (20c) of the delivery system (20) is used for carrying the embolization coil (10) and the delivery wire (20a) at the target site.

[0019] Another reference has been made to 11341 / DELNP / 2013 titled "DISTAL ACCESS ASPIRATION GUIDE CATHETER", by COVIDIEN LP dated 30 / 06 / 2011 which discloses an Distal access aspiration guide catheter system and methods for delivering implantable devices, catheters, or sub - o stances in or near and / or restoring flow through body lumens, such as blood vessel lumens are described. A distal access aspiration guide

[0020] 7 catheter having a proximal, medial, and distal possessing high flexibility, high resistance to kinking and a large lumen to wall thickness ratio.

[0021] Another reference has been made to WO2019155285A2 titled "FLEXIBLE DELIVERY SYSTEM AND IMPLANTABLE STENT FOR SURGICAL USE", by STENTORIUM LTD dated 2018-02-12 which discloses a tube, which would be used to facilitate the movement of an object through the lumen of the tube or over the outside of the tube. The invention could also be used as a stent designed for indwelling in a body, where its purpose would be to assist in the drainage of liquid from one part of the body to another. The expected use of the tube would be in minimally invasive surgical procedures where greater flexibility, radial strength and pushability than that provided by prior art are desirable to improve the speed of operations and the success rate of operations; to reduce the level of trauma caused to patients and to improve patient recovery rate. It could have use in applications requiring an exceptionally flexible and highly pushable tubing such as invasive surgery in vessels that are or have become tortuous and narrow, such as veterinary procedures for small animals, paediatric ureteral conditions, angioplasty for certain conditions and certain neurovascular work.

[0022] Another reference has been made to WO2019030761A1 titled "MICROCATHETER", by ACCURATE MEDICAL THERAPEUTICS LTD dated 2017-08-09 which discloses a microcatheter comprising an inner layer, a strike layer and an outer layer and a braided skeleton located between the inner layer and the outer layer, wherein the inner layer is made of Polytetrafluoroethylene (PTFE) and has a thickness of 0.0015 inch or less, wherein the strike layer includes a polyether block amide and has a thickness of 0.001 inch or less, and wherein a distal portion of said outer

[0023] 8 layer is made of polycarbonate-based thermoplastic polyurethane having a shore of 90A or below.

[0024] Another reference has been made to US10780246B2 titled "Vascular microcatheter", by CALLISYN BIOMEDICAL INC dated 2014-09-12 which discloses a microcatheter with a tapering wall thickness shaft having varying stiffness / flexibility along its length from proximal end near the medical practitioner to the distal end near the target site in the patient, such as with at least three segments. The shaft is prepared of a thermoplastic material having varying composition along its length. The distal end may be shaped according to the required use just prior to the medical procedure. The microcatheter is particularly adapted for the delivery of microspheric compositions for treatment of tumors or fibroids by embolization of peripheral blood vessels of the tumor or fibroid.

[0025] Another reference has been made to CN113198084A titled "Peripheral vessel interventional therapy microcatheter", by SHENZHEN MAIPUQI MEDICAL TECH CO LTD dated 2021-04-26 which discloses a peripheral vessel interventional therapy microcatheter which comprises a catheter body; the catheter body comprises a tail catheter, a middle catheter and a front catheter; the tail catheter, the middle catheter and the front catheter are communicated, and each of the tail catheter, the middle catheter and the front catheter comprises a methyl ethyl ether anhydrous maleic acid copolymer hydrophilic coating layer; the outer layer and the middle layer of the catheter body are made of polyamide elastomers, the inner layer is made of polytetrafluoroethylene, the woven mesh of the catheter body is made of stainless steel, a catheter seat is made of polycarbonate, the tail catheter is provided with a radiopaque marker made of platinum-iridium alloy, and the tail catheter is coated with a methyl ethyl ether anhydrous maleic acid copolymer hydrophilic coating layer; the catheter body is designed by five sections of materials with

[0026] 9 different hardness; the catheter seat is a transparent conical joint, and the catheter body is woven by stainless steel; and the inner layer of the catheter body is the polytetrafluoroethylene coating layer, so that the microcatheter has good controllability, pushing performance, twisting performance and tracking performance, and is more suitable for peripheral vessel interventional therapy.

[0027] Another reference has been made to CN215082769U titled "Peripheral vessel interventional therapy microcatheter", by SHENZHEN MAIPUQI MEDICAL TECH CO LTD dated 2021-04-21 which discloses a peripheral vessel interventional therapy microcatheter which comprises a catheter seat and a catheter body, the catheter body is arranged on one side of the interior of the catheter seat, a connecting tube is arranged on one side of the catheter seat, a connector is arranged on the outer side of the connecting tube, threads are arranged on one side of the connecting tube, and the connector is connected with the catheter seat. A polyamide elastomer is arranged on the outer side of the interior of the pipe body, and a polytetrafluoroethylene coating is arranged on the inner side of the pipe body. According to the peripheral vessel interventional therapy microcatheter, the hydrophilic coating is arranged on the outer side of the catheter body, the hydrophilic coating is made of the methyl ethyl ether anhydrous maleic acid copolymer, before the catheter body is guided into, sterile normal saline containing heparin is injected into one side of the catheter base, and then the hydrophilic coating on the outer side of the catheter body can be activated; and the polytetrafluoroethylene coating is arranged in the cavity, so that selective intubation can be carried out more easily, a contrast agent, an embolism material and a medicinal preparation can be conveniently conveyed, and the problem that the frictional resistance between the tube body and the blood vessel is larger is solved.

[0028] 10 Another reference has been made to WO2019087191A1 titled "EMBOLIZATION CATHETER. WITH INTEGRAL FILTER", by ACCURATE MEDICAL THERAPEUTICS LTD [IL] dated 2017-11-02 which discloses an embolization microcatheter is configured to deliver embolization particles to a target area and minimize or prevent embolization of a non-target area. The microcatheter includes a section, located between the distal and proximal ends of the microcatheter, having a skeleton formed of braided wires and a polymeric layer intercalated into and / or overlaying the skeleton. This section includes a plurality of axial slits, each slit having a smallest cross-sectional dimension configured to prevent outflow of the embolization particles.

[0029] Another reference has been made to US10420563B2 titled "Delivery system insertable through body lumen", by NEUROGAMI MEDICAL INC dated 2016-07-08 which discloses a system for delivering a device into a body lumen of a patient, the system including a device having a marker band and a tube at a proximal portion, and a pusher member having a ribbon and a ball or hook at a distal portion of the delivery member and a compression coil positioned over the ribbon, the ball or hook releasably engageable with the tube.

[0030] Another reference has been made to US10881419B2 titled "Intravascular thromboembolectomy method", by THROMBX MEDICAL INC dated 2011-07-26 which discloses a method for increasing or restoring a flow in a body lumen can treat conditions related to a stroke, such as an ischemic stroke, by removing an occlusion from a blood vessel and / or reopen a blood vessel. The method makes use of a device that includes a central wire, a pusher tube, a distal structure, and a proximal structure into the blood vessel, in which the distal structure is closed at its proximal end. A clot or occlusion present in the body lumen such as an

[0031] 11 artery may be engaged in and / or between the distal and proximal engaging elements. Further, the positions of one or both of the engaging elements and the distance between them can be adjusted to ensure the engagement of the clot or occlusion.

[0032] Another reference has been made to WO2010068793A1 titled "MICROCATHETER", by MICROVENTION INC; GULACHENSKI JOSEPH dated 2008-12-10 which discloses a microcatheter comprises a coil formed over an inner liner. The coil is covered with a series of outer jacket segments that decrease in durometer relative to proximally adjacent segments. Preferably, these segments have angled ends that allow each segment to be inserted and bonded into the segment prior to it. The outer jacket ultimately terminates at a distal of the microcatheter with the segment having the lowest durometer.

[0033] However, none of the above discussed inventions relates to multilayered microcatheter that comprises four distinct layers in the proximal section and three layers in the distal region, offering a balance between oushabilitv and flexibility. The microcatheter consists of an inner layer which made of PTFE and runs full length of the device, said inner layer is surrounded bv SS304V coil and a hollow tube marker band made of otlOir is placed over the coil at distal region. The first marker is placed 0.5 to 1.5 mm awav from the distal tio and the second marker is placed at 30mm distance from the first marker band. At least one marker band is C-cut covering 70% of the catheter circumference, said C-cut marker band is preferably a second marker band. For enhanced control, a braided reinforcement layer constructed from flat wires encloses the coil. This braid layer, typically 70 nicks oer inch (PPP, offers a balance between stiffness for stability and flexibility for smooth

[0034] 12 navigation. It usually covers 60% to 95% of the catheter's length. The fourth layer is made of polymeric materials melt flown onto the reinforcement layers, having plurality of segments where a soft short segment loaded with radiooague material incorporated between 2 segments of proximal hard material.

[0035] Objectives of the Invention

[0036] The main objective of the invention is to provide a multi-layered microcatheter design that offers a balance between pushability for easy navigation within vessels and flexibility.

[0037] Another objective of the invention is to provide a microcatheter with a four-layer proximal section and a three-layer distal region.

[0038] Another objective of the invention is to provide a microcatheter with a reinforced structure using an SS304V coil for flexibility.

[0039] Another objective of the invention is to incorporate hollow PtlOIr marker bands in the distal region for clear visual reference during minimally invasive procedures.

[0040] Another objective of the invention is to provide a microcatheter with at least one strategically placed C-cut marker band to enhance adhesion and control during manipulation.

[0041] Another objective of the invention is to provide a microcatheter with a braid reinforcement that formed using eight flat wires for increased stiffness and pushability while maintaining some flexibility.

[0042] Another objective of the invention is to provide a microcatheter with an outer segmented jacket made of polymeric materials for improved durability.

[0043] Another objective of the invention is to provide a microcatheter that incorporates alternating proximal hard segments and a distal soft

[0044] 13 segment containing radiopaque material, and an additional short radiopaque segment is positioned at the distal end of the stiff portion.

[0045] Summary of the Invention

[0046] The present invention provides a multi-layered microcatheter with positioning markers, comprising of 4 layers in the proximal section and 3 layers at distal most region, an inner layer of the catheter is made of PTFE and surrounded by SS304V Coil, a hallow tube marker bands made of ptlOir is placed over the coil at distal region, the first marker is placed 0.5-1.5mm away from the distal tip and the second marker is placed at 30mm distance from the first marker band, at least one marker band is C-cut covering 70% of the catheter circumference and the coil reinforcement layer is surrounded by Braid reinforcement. Further, braid reinforcement formed using eight flat wires for increased stiffness and pushability while maintaining flexibility. The braid reinforcement extends approximately 60% to 95% of the catheter length. The braid reinforcement is made at 70PPI (Picks per inch) to increase the stiffness and providing pushability. Finally, the outermost layer is a segmented sheath made of polymeric materials. This sheath features alternating segments: a stiffer material proximally positioned for stability, and a softer, radiopaque segment distally located for clear visualization at the catheter tip. This unique multi-layered design offers a valuable tool for minimally invasive procedures. It combines the benefits of a smooth inner layer for easy navigation, a reinforced structure for stability, visual reference markers for precise control, and a segmented outer sheath for both maneuverability and clear visualization. The said multi-layered microcatheter simplifies and improves the effectiveness of minimally invasive procedures, making it a versatile tool for various clinical

[0047] 14 applications. The microcatheter is also designed for ease of manufacture and cost-effectiveness.

[0048] Statement of the Invention

[0049] Accordingly, the present invention provides a multi-layered microcatheter with positioning markers a unique four-layered structure proximally, transitioning to three layers distally; the inner layer is a continuous inner layer made of PTFE, offering a lubricious surface for easy advancement; said inner layer is then reinforced with an SS304V coil for structural integrity; in the distal region, a hollow PtlOIr marker band encircles the coil, serving as a visual reference during procedures; these marker bands, particularly the strategically placed C-cut design, enhance control during manipulation; the braid reinforcement formed using flat wires for increased stiffness and pushability while maintaining flexibility; the braid reinforcement extends approximately 60% to 95% of the catheter length and made at 70PPI (Picks per inch) to increase the stiffness and providing moderate flexibility; finally, the outermost layer is a segmented sheath made of polymeric materials with positioning markers at distal region for indicating stiff segment and at proximal region to let physician know of length inside the body.

[0050] Brief Description of Drawings

[0051] Figure 1: represents a multi-layered microcatheter with positioning markers.

[0052] Figure 2: represents tube marker bands 2(a), distal portion 2(b) and an outer layer of an elongated body 2(c) of a multi-layered microcatheter.

[0053] Figure 3: represents a C-cut marker band. The figures are merely for illustration purpose and shall not be construed to limit the scope of the invention.

[0054] Detailed Description of the Invention

[0055] It should be noted that the particular description and embodiments set forth in the specification below are merely exemplary of the wide variety and arrangement of instructions which can be employed with the present invention. The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. All the features disclosed in this specification may be replaced by similar other or alternative features performing similar or same or equivalent purposes. Thus, unless expressly stated otherwise, they all are within the scope of present invention. Various modifications or substitutions are also possible without departing from the scope or spirit of the present invention. Therefore, it is to be understood that this specification has been described by way of the most preferred embodiments and for the purposes of illustration and not limitation.

[0056] The present invention provides a multi-layered microcatheter with positioning markers specifically optimized for minimally invasive procedures. The said microcatheter 1 incorporates a unique multi-layered structure comprises of a thin inner layer, a coil layer with a variable pitch is positioned over the thin inner layer, a braid layer is positioned over a portion of the coil layer and, the outer jacket layer is melt-flowed onto the braided layer and coil layer, and it is bonded to the thin inner layer, offers distinct advantages for both navigation and control. The said multilayered microcatheter comprises of 4 layers in the proximal section and 3 layers at distal most region, an inner layer of the catheter is made of PTFE and surrounded by SS304V Coil, a hallow tube marker bands made of ptlOir is placed over the coil at distal region 2(a), the first marker 108

[0057] 16 is placed 0.5mm to 1.5mm away from the distal tip 109 and the second marker 107 is placed at 30mm distance from the first marker band 108, at least one marker band is C-cut covering 70% of the catheter circumference and the coil reinforcement layer is surrounded by Braid reinforcement.

[0058] The present invention provides a multi-layered design, meticulously crafted to excel within delicate vascular structures. Each layer plays a vital role in optimizing both pushability and flexibility for exceptional performance. A full-length inner layer made of polytetrafluoroethylene (PTFE) having a thickness in the range of 0.0004 to 0.0025 inches. This material ensures effortless navigation devices through it, during procedures with its smooth, lubricious surface. The wall thickness, ranging from 0.00075 to 0.0015 inches, strikes a perfect balance between strength and flexibility. To enhance control and visualization, said microcatheter 1 comprises the inner layer which is a SS304V coil reinforcement. The inner PTFE is surrounded by SS304V Coil and runs full length of the device except the distal tip region (0.5mm to 2 mm length) 109. The coil is made of round wire with 0.001" diameter and pitch ranging from 0.0015 to 0.006 inches.

[0059] This coil, with a diameter of 0.001 inches, provides flexibility so that catheters do not get damaged when traveling through tortuous anatomies. The design incorporates a variable pitch - wider coils proximally for better pushability and tighter coils distally for improved flexibility.

[0060] The distal tip 109 of the microcatheter optionally incorporate one or two hollow tube markers crafted from PtlOIr (Platinum-Iridium alloy). A hallow 0.001" thickness tube marker bands made of ptlOir is placed over the coil at distal region. The first marker 108 is placed 0.5 to 1.5mm

[0061] 17 away from the distal tip 109 and the second marker 107 is placed at 30mm distance from the first marker band 108 enhance fluoroscopic visualization during procedures. The coil reinforcement layer is surrounded by Braid reinforcement and the braid reinforcement extends approximately 60% to 95% of the catheter length 113. At least one marker band utilizes a C-cut design encompassing around 70% of the catheter's circumference, typically implemented on the second marker band. A braided reinforcement layer, constructed from eight flat SS304V, 0.0005"X0.0025" wires, encloses the coil. This braid layer 113, typically 70 picks per inch (PPI), offers a crucial balance between stiffness for stability and flexibility for smooth navigation.

[0062] A microcatheter shaft with positioning markers (104 8t 105), comprising: an outer jacket layer 2(c), comprising: a plurality of polymer materials, wherein a relatively soft short segment loaded with radiopaque filler is placed at the proximal portion 104 of the catheter to provide physician with catheter position (90cm mark). Wherein another short segment loaded with radiopaque filler is placed at the distal end region of the stiff portion 105 so as to provide physician position of stiff region. A thin inner layer, a Coil layer with variable pitch positioned over the thin inner layer, a Braid layer positioned over a portion of coil layer, Wherein the outer jacket 2(c) layers are melt flowed onto the braided layer 113, and coil layer 114, and is bonded with the thin inner layer.

[0063] A microcatheter shaft incorporates positioning markers. It comprises an outer jacket layer made of a polymer material. A relatively soft, short segment loaded with a radiopaque filler (Biocl or tungsten or BaS04, (Bio)2COs) ranging between 30% to 75%, and positioned at the proximal portion of the catheter 104 to provide the physician with catheter location. Another short segment loaded with a radiopaque filler is

[0064] 18 positioned at the distal end 105 of the stiff portion to provide the physician with the location of the stiff region. The distal 70-110cm of the catheter is coated with a hydrophilic material for improved lubricity. Finally, a short radiopaque segment at the distal end 105 specifically provides physicians to identify the precise location of the stiff region. Further, said multi-layered structure empowers the microcatheter to excel within delicate vascular structures, offering exceptional performance through a combination of optimal navigation, pushability, control, and clear visualization.

[0065] Referring to figure 1, that represents a multi-layered microcatheter comprises of proximal section 111, distal portion or distal end 112, an opening 102, hub 101, an elongated body 110, positioning markers 104 & 105, distal tip 109, C-cut marker bands 107 & 108, braided portion 113, coiling portion 114 and a strain relief 103 is of tapered shape coupled to a hub 101, provides structural support to the catheter, helping to prevent kinking of the catheter. The said catheter is comprised of 4 layers in the proximal section 111 and 3 layers at distal most region 112. The first layer is made of PTFE, second layer made of SS304 coil end to end, third layer is braided layer made of eight wires in tube form up to 60%-95% of catheter length 106 and fourth layer is thermoplastic layer with varying hardness. Furthermore, a portion is composed of plastic materials with varying hardness, with a softer material segments located in the outer jacket in between hard material. Both the braided and coiled portions start at the proximal section, with the braided section extending from 60 to 95% of the catheter's length 113, while the coiled portion covers end to end 114 except for the distal tip 109.

[0066] Referring to figure 2, that represents a PtlOIR tube marker bands 107 8t 108, distal portion 2(b) and an outer jacket 2(c). The first marker 108

[0067] 19 is placed 0.5-1.5mm away from the distal tip 109 and the second marker

[0068] 107 is placed at 30mm distance from the first marker band 108. The braid reinforcement 113 is made at 70PPI (Picks per inch) to increase the stiffness and providing push ability provided up to 60%-95% of catheter length 106. The Braid reinforcement is formed using eight SS304V, 0.0005"X0.0025" Flat Wires. Furthermore, a positioning marker 104 is located 90 cm proximal to the distal tip 109 to indicate to the physician that the initial 90 cm portion has entered the body, and second positioning marker 105 is placed at the end of soft segment to allow physician to understand location of stiff segment so as to not push the stiff portion into tortuous anatomies.

[0069] Referring to figure 3, that represents marker band with a C-cut design. The said marker band features a C-cut design formed by removing a 30+ 10 degrees segment from a circular band.

[0070] So accordingly, the present invention provides a multi-layered microcatheter with positioning markers, comprising of: a hub 101, an opening 102, a kink protector 103 coupled to a hub 101, an elongated body 110, positioning markers 104 8t 105, four layers in the proximal section 111 and three layers at distal most region 112, an inner layer of the catheter is made of PTFE and surrounded by SS304V Coil 114, a hallow tube marker bands 107 & 108 made of ptlOir are placed over the coil at distal region 2(a), C-cut marker bands 107 8t 108, a first marker

[0071] 108 is placed 0.5-1.5mm away from the distal tip 109 and the second marker 107 is placed at 30mm distance from the first marker band 108, one marker band is C-cut covering 70% of the catheter circumference and the coil reinforcement layer 114 is surrounded by braid reinforcement 113; an outer jacket layer 2(c) is made of polymeric materials melt flown onto the reinforcement layers, having segmented structure;

[0072] 20 wherein a relatively soft, short segment loaded with radiopaque filler is placed at the proximal section to indicate the catheter placement, while another short segment loaded with radiopaque filler is placed at the distal end region of the stiff portion to visualize the position of the stiff region.

[0073] In an exemplary embodiment microcatheter comprises of a thin inner layer, a coil layer 114 with a variable pitch is positioned over the thin inner layer, a braid layer 113 is positioned over a portion of the coil layer and, the outer jacket layer 2(c) is melt-flowed onto the braided layer and coil layer, and it is bonded to the thin inner layer.

[0074] In another embodiment, said an inner PTFE (polytetrafluoroethylene) having a thickness in the range of 0.0004 to 0.0025 inches is surrounded by SS304V Coil 114 and runs full length of the device except the distal tip region 109.

[0075] In another embodiment, said reinforcement layer comprising an SS304V coil formed using a round wire with pitch ranging from 0.0015 to 0.006 inches for structural integrity and flexibility.

[0076] In another embodiment, said braid reinforcement layer 113 encasing the reinforcement layer and extending along 60% to 95% of the microcatheter length, made from eight flat wires at a density of 70 picks per inch (PPI) to enhance stiffness for pushability.

[0077] In another embodiment, said an outer jacket layer 2(c) made of a polymer material and features a segmented structure with varying hardness, a relatively soft, short segment loaded with a radiopaque filler ranging between 30% to 75%, and positioned at the proximal portion of the catheter; another short segment loaded with a radiopaque filler is positioned at the distal end of the stiff portion.

[0078] 21 In another embodiment, said an elongated body 110 divided into stiff and flexible region; the proximal section 111, extending from the proximal end to the positioning marker 105, is stiff, while the distal section 112, from the positioning marker 105 to the distal tip 109, is flexible.

[0079] In another embodiment, said a positioning marker 104 is located 90 cm proximal to the distal tip 109 to indicate to the physician that the initial 90 cm portion has entered the body, and second positioning marker 105 is placed at the end of soft segment to allow physician to understand location of stiff segment.

[0080] In another embodiment, said marker bands being a C-cut design 3 encompassing substantially 70% of the microcatheter circumference; the first marker 108 is placed 0.5-1.5mm away from the distal tip 109 and the second marker 107 is placed at 30mm distance from the first marker band 108.

[0081] In another embodiment, said the distal 70-110cm of the catheter is coated with a hydrophilic material for improved lubricity.

[0082] While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the present invention is to cover all such changes and modifications as fall within the true spirit and scopeof this invention.

[0083] Advantages of the Invention

[0084] 1. The lubricious PTFE inner layer and strategically designed braid reinforcement layers allow for smooth navigation.

[0085] 2. The braided reinforcement, Improves the pushability, torque response.

[0086] 22 The radiopaque segments along the length of the catheter allows for clear visualization of the catheter tip. The SS304V coil reinforcement layer provides the microcatheter with flexibility, preventing kinking during navigation and maintains lumen integrity in bend positions. The design prioritizes ease of manufacture, potentially making the microcatheter a more affordable option for healthcare providers. The multi-layered design caters to various clinical applications by offering a balance of pushability, flexibility, and visualization.

[0087] 23

Claims

We Claim1. A multi-layered microcatheter with positioning markers, comprising of: a hub 101, an opening 102, a strain relief 103 coupled to a hub 101, an elongated body 110, positioning markers 104 & 105, four layers in the proximal section 111 and three layers at distal most region 112, an inner layer of the catheter is made of PTFE and surrounded by SS304V coil 114, a hallow tube marker bands 107 & 108 made of ptlOir are placed over the coil at distal region 2(a), C-cut marker bands 107 8t 108, a first marker 108 is placed 0.5-1.5mm away from the distal tip 109 and the second marker 107 is placed at 30mm distance from the first marker band 108, at least one marker band is C-cut covering 70% of the catheter circumference and the coil reinforcement layer 114 is surrounded by braid reinforcement 113; an outer jacket layer 2(c) is made of polymeric materials melt flown onto the reinforcement layers, having segmented structure; wherein a relatively soft, short segment loaded with radiopaque filler is placed at the proximal section to indicate the catheter length, while another short segment loaded with radiopaque filler is placed at the distal end region of the stiff portion to visualize the position of the stiff region.

2. The multi-layered microcatheter, as claimed in claim 1, wherein said microcatheter comprises of a thin inner layer, a coil layer 114 with a variable pitch is positioned over the thin inner layer, a braid layer 113 is positioned over a portion of the coil layer and, the outer jacket layer 2(c) is melt-flowed onto the braided layer and coil layer, and it is bonded to the thin inner layer.

3. The multi-layered microcatheter, as claimed in claim 1, wherein said inner PTFE (polytetrafluoroethylene) having a thickness in the range of 0.0004 to 0.0025 inches is surrounded by SS304V Coil114 and runs full length of the device except the distal tip region 109.

4. The multi-layered microcatheter, as claimed in claim 1, wherein said reinforcement layer comprising an SS304V coil formed using a round wire with pitch ranging from 0.0015 to 0.006 inches for structural integrity and flexibility.

5. The multi-layered microcatheter, as claimed in claim 1, wherein said braid reinforcement layer 113 encasing the reinforcement layer and extending along 60% to 95% of the microcatheter length, made from eight flat wires at a density of 70 picks per inch (PPI) to enhance stiffness for pushability.

6. The multi-layered microcatheter, as claimed in claim 1, wherein said an outer jacket layer 2(c) made of a polymer material and features a segmented structure with varying hardness, a relatively soft, short segment loaded with a radiopaque filler ranging between 30% to 75%, and positioned at the proximal portion of the catheter; another short segment loaded with a radiopaque filler is positioned at the distal end of the stiff portion.

7. The multi-layered microcatheter, as described in claim 1, wherein said an elongated body 110 divided into stiff and flexible region; the proximal section 111, extending from the proximal end to the positioning marker 105, is stiff, while the distal section 112, from the positioning marker 105 to the distal tip 109, is flexible.

8. The multi-layered microcatheter, as claimed in claim 1, wherein said a positioning marker 104 is located 90 cm proximal to the distal tip 109 to indicate to the physician that the initial 90 cm portion has entered the body, and second positioning marker 105 is placed at the end of soft segment to allow physician to understand location of stiff segment.

9. The multi-layered microcatheter, as claimed in claim 1, wherein said marker bands being a C-cut design 3 encompassing substantially 70% of the microcatheter circumference; the first marker 108 is placed 0.5-1.5mm away from the distal tip 109 and the second marker 107 is placed at 30mm distance from the first marker band 108.

10. The multi-layered microcatheter, as claimed in claim 1, wherein said the distal 70-110cm of the catheter is coated with a hydrophilic material for improved lubricity.

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