Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
AUTOMATED METHOD OF MANUFACTURING A CATHETER

2. APPLICANTS:
Meril Life Sciences Pvt. Ltd., an Indian Company of the address, Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi-Gujarat 396191, India

3. The following specification particularly describes the invention and the manner in which it is to be performed:
 
FIELD OF INVENTION
[1] The present disclosure relates generally to a catheter. More particularly, the present disclosure relates to an automated method to manufacture a catheter.
BACKGROUND OF INVENTION
[2] A catheter is a thin, flexible tube used to deliver a contrast dye into a blood vessel during an angiography procedure. The procedure may be performed using X-rays to visualize the blood vessel. This allows doctors to identify one or more blockages, narrowed areas, or other abnormalities in the blood vessels, aiding in diagnosis and treatment planning.
[3] The method to manufacture the catheter is an intricate process and requires precision to ensure that the catheter meets stringent quality standards (for example, reliability, safety, etc.) given their critical role in medical procedures. Conventional method for manufacturing a catheter is associated with several significant challenges that impact both, production efficiency and product quality. A major challenge associated with the conventional method is complete reliance on manual processes and/or using semi-automated systems that require substantial human intervention at various stages of production of a catheter. The steps of the conventional method are performed with significant human involvement or with semi-automated systems that demand frequent operator adjustments and close monitoring.
[4] For example, the conventional manufacturing method involves manually mounting a pre-cut inner liner onto a pre-cut mandrel. The inner liner mounted on the mandrel are braided for each catheter. Once braided, each of the catheter undergoes a reflow lamination process, where each catheter is manually hung on a heating nozzle for reflow. This labor-intensive and time-consuming approach introduces significant inefficiencies and inconsistencies. The manual handling often leads to variations in product quality, such as uneven braiding, improper lamination, or incomplete bonding between layers.
[5] Since each inner liner is individually braided, the initial braided length may be of poor quality for each of the inner liner. This is due to the fact that the braided machine and the components thereof have to be reconfigured/repositioned for each new inner liner that has to be braided.
[6] The dependency on human labour increases the potential for errors, leading to challenges in meeting the stringent quality standards. The overall production time is extended due to the time-consuming nature of manual handling. This increase in production time directly results in higher costs, as more labour is required to manage each stage. Furthermore, the frequent need for operator intervention introduces inconsistencies in product quality, as variability arises from human factors.
[7] Therefore, there arises a need for an automated method for manufacturing a catheter that solves the aforementioned problems of the conventional methods.
SUMMARY OF INVENTION
[8] Particular embodiments of the present disclosure are described herein below with reference to the accompanying drawings, however, it is to be understood that the disclosed embodiments are mere examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[9] In an exemplary embodiment, the present disclosure relates to an automated method for manufacturing multiple catheters in one manufacturing cycle. The automated method commences by feeding a first material within a first extruder to extrude a mandrel and wound the mandrel around a first spool. Then the mandrel from the first spool along with a second material are fed within a second extruder to extrude an inner layer around the mandrel and obtain a first preform wound around a second spool. The first preform from the second spool along with one or more fibers is fed within a braiding machine to form a braided layer around the inner layer and obtain a second preform wound around a third spool. The second preform from the third spool is fed within a reflow machine to bond the inner layer to the braided layer of the second preform. Simultaneously, the second preform obtained from the reflow machine is winded around a fourth spool. The second preform from the fourth spool along with a third material are fed within a third extruder to extrude an outer layer around the braided layer and obtain a tubular component wound around a fifth spool. The tubular component is cut to pre-defined lengths resulting in multiple catheters using a cutting machine.
[10] In another exemplary embodiment, the present disclosure relates to an automated method for manufacturing multiple catheters in one manufacturing cycle. The automated method commences by feeding a first material within a first extruder to extrude a mandrel and wound the mandrel around a first spool. The mandrel from the first spool along with a second material are fed within a second extruder to extrude an inner layer around the mandrel and obtain a first preform wound around a second spool. The first preform from the second spool along with one or more fibers are fed within a braiding machine to form a braided layer around the inner layer and obtain a second preform. Simultaneously, the second preform is heated to bond the inner layer to the braided layer. The second preform is wound around a third spool. The second preform from the third spool along with a third material are fed within a third extruder to extrude an outer layer around the braided layer and obtain a tubular component wound around a fourth spool. The tubular component is cut to pre-defined lengths resulting in multiple catheters using a cutting machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[11] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentality disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[12] FIGs. 1A & 1B illustrates an axial cross-sectional view and a lateral cross-sectional view of a catheter 1 respectively, according to an embodiment of the present disclosure.
[13] FIG. 1C illustrates an enlarged view of a braided layer 18 of the catheter 1, according to an embodiment of the present disclosure.
[14] FIGs. 2A, 2B, and 2C illustrate different shapes of a distal end of the catheter 1, according to one or more embodiments of the present disclosure.
[15] FIG. 3 illustrates a flowchart of an automated method 100 for manufacturing the catheter 1, according to an embodiment of the present disclosure.
[16] FIG. 4 illustrates a lateral cross-sectional view of a mandrel 16a and an inner layer 14 of the catheter 1, according to an embodiment of the present disclosure.
[17] FIG. 5 illustrates a lateral cross-sectional view of the mandrel 16a, the inner layer 14 and a braiding layer 18 of the catheter 1 during braiding step of a braided layer 18 respectively, according to an embodiment of the present disclosure.
[18] FIG. 6 illustrates a lateral cross-sectional view of the mandrel 16a, the inner layer 14, the braiding layer 18, and an outer layer of the catheter 1 during extruding step of an outer layer 12 respectively, according to an embodiment of the present disclosure.
[19] FIG. 7 illustrates an enlarged view of a distal end 6 of the catheter 1, according to an embodiment of the present disclosure.
[20] FIG. 8 illustrates an enlarged view of a proximal end 4 of the catheter 1, according to an embodiment of the present disclosure.
[21] FIG. 9 illustrates an enlarged view of a distal end 6 of the catheter 1 depicting a hole 6a, according to an embodiment of the present disclosure.
[22] FIG. 10 illustrates a front view of a shaping plate, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[23] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like. Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[24] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[25] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[26] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[27] The present disclosure relates to an automated method to manufacture multiple multiple catheters in one manufacturing cycle. The catheter may be used in a medical procedure including, but not limited to, an angiography procedure, a percutaneous transluminal coronary angioplasty (PTCA) procedure, a neurovascular interventional procedure, a peripheral vascular procedure, a procedure for infusion of one or more therapeutic agents, a diagnostic imaging procedure, etc. In an exemplary embodiment, the catheter is used for angiography procedure.
[28] The automated method of the present disclosure significantly reduces the reliance on human intervention to manufacture the catheter. The automated method ensures precision, repeatability, and high throughput. The method enhances manufacturing efficiency, accelerates production speed, and maintains consistent quality and safety standards. Synchronized processes, such as continuous reflow operations with continuous braiding, eliminate delays and ensure seamless reinforcement and bonding. The automated method incorporates automated cutting, shaping, and laser marking to produce highly customized, accurate, and durable catheters tailored to diverse medical procedures. Further, it reduces production time and waste, ensures uniform quality, lowers overall production costs, and supports the fabrication of catheters with varying specifications, such as different sizes, shapes, or material combinations, to meet a wide range of clinical and customer needs.
[29] The automated method of the present disclosure facilitates to manufacture multiple tubular components corresponding to multiple catheters 1 in one manufacturing cycle. In an exemplary embodiment, the automated method is used to manufacture fifty tubular components in one manufacturing cycle. Depending upon the scale of operation, the number of tubular components manufactured can be either increased or decreased.
[30] Now referring to the figures, FIGs. 1A & 1B illustrate an axial and a lateral cross-sectional view of an exemplary catheter 1 respectively, according to an embodiment of the present disclosure. The catheter 1 may include a plurality of components including, but not limited to, a tubular component 2, a tip 7, a hub 10, a strain relief component 8, etc.
[31] The tubular component 2 of the catheter 1 extends between a proximal end 4 and a distal end 6. The proximal end 4 of a catheter refers to the end of the catheter 1 closest to the operator, typically remaining outside the patient's body for handling, control, or connection to other devices. The distal end 6 is the end of the catheter 1 farthest from the operator, designed to be inserted into the patient's body to reach a target site for diagnosis or treatment. The tubular component 2 has a pre-defined length ranging from 1000 mm to 1100 mm. In an exemplary embodiment, the length of the tubular component 2 is 1050 mm. The tubular component 2 has a pre-defined inner diameter and a pre-defined outer diameter ranging from 1 mm to 1.5 mm and 1.5 mm to 2 mm respectively. In an exemplary embodiment, the inner diameter and the outer diameter of the tubular component 2 is 1.10 mm and 1.70 mm, respectively.
[32] The tubular component 2 includes a plurality of layers. In an exemplary embodiment, as shown in FIG. 1B, the tubular component 2 includes three layers, namely, an inner layer 14, a braided layer 18, and an outer layer 12. The inner layer 14 is the innermost layer of the tubular component 2. The outer layer 12 is the outermost layer of the tubular component 2. The braided layer 18 is disposed between the inner layer 14 and the outer layer 12, or embedded therebetween.
[33] The inner layer 14 extends along a portion of length or the entire length of the tubular component 2. In an exemplary embodiment, the inner layer 14 extends along the entire length of the tubular component 2. The inner layer 14 has a pre-defined outer diameter ranging from 1.0 mm to 1.5 mm. The inner layer 14 has a pre-defined thickness ranging from 0.05 mm to 0.20 mm. In an exemplary embodiment, the outer diameter and thickness of the inner layer 14 is 1.10 mm and 0.10 mm, respectively. The inner layer 14 is made of one or more materials including, but not limited to, polyurethane (PU), polytetrafluoroethylene (PTFE), polyethylene (PE), Nylon, Pebax, etc. In an exemplary embodiment, the inner layer 14 is made of polyurethane (PU). The inner layer 14 has a lateral cross-sectional shape including, but not limited to, circular, oval, elliptical, polygonal, etc. In an exemplary embodiment, the lateral cross-sectional shape of the inner layer 14 is circular. The inner layer 14 has a consistent thickness and surface smoothness.
[34] As shown in Fig. 1B, the inner layer 14 defines a lumen 16. The lumen 16 enables passage of one or more medical devices (like guide wire), therapeutic agents (like drugs, saline, etc.) or the like through the length of the catheter 1.
[35] The braided layer 18 is disposed around the inner layer 14 to provide strength and reinforcement to the tubular component 2. The braided layer 18 extends along a portion of length or the entire length of the tubular component 2. In an exemplary embodiment, the braided layer 18 extends along the entire length of the tubular component 2. The braided layer 18 includes one or more fibers braided or weaved in a crisscross pattern to create a mesh like structure around the inner layer 14.
[36] The braided layer 18 has an outer diameter ranging from 1.5 mm to 2.0 mm. The braided layer 18 has a thickness ranging from 0.2 mm to 0.5 mm. In an exemplary embodiment, the outer diameter and thickness of the braided layer 18 is 1.70 mm and 0.30 mm, respectively. The braided layer 18 provides a balanced combination of flexibility and support, enabling precise navigation of the catheter 1 through complex anatomies.
[37] The fiber of the braiding layer 18 has a diameter ranging from 0.05 mm to 0.1 mm. In an exemplary embodiment, the diameter of the fiber is 0.08 mm. The fiber of the braiding layer 18 is made of one or more materials including, but not limited to, stainless steel, nitinol, etc. In an exemplary embodiment, the fiber is made of stainless steel.
[38] The fiber(s) of the braiding layer are braided in a pre-defined pattern. In an embodiment, as shown in FIG. 1C, the one or more fibers of the braided layer 18 have a two-over-two braiding pattern in a single-wire configuration. In another embodiment, the one or more fibers of the braided layer 18 have a two-over-two braiding pattern in a double-wire configuration. A braid angle between any of the two over two wire structure may range from 80 to 84 degrees. In an exemplary embodiment, the braid angle between any of the two over two wire structure is 80.84 degrees. The braided layer 18 provides enhanced mechanical properties such as torqueability, pushability, kink resistance, flexibility, stiffness, and radial strength.
[39] The outer layer 12 is disposed around the braided layer 18 and serves as an outer covering of the tubular component 2. The outer layer 12 extends along a portion of length or the entire length of the tubular component 2. In an exemplary embodiment, the outer layer 12 extends along the entire length of the tubular component 2. The outer layer 12 has a pre-defined outer diameter ranging from 1.5 mm to 2.5 mm. The outer layer 12 has a pre-defined thickness ranging from 0.2 mm to 0.5 mm. In an exemplary embodiment, the outer diameter and thickness of the outer layer 12 is 2 mm and 0.2 mm, respectively. The outer layer 12 is made of one or more materials including, but not limited to, nylon, Polyurethane (PU), Pebax or Polyethylene (PE), etc. In an exemplary embodiment, the outer layer 12 is made of nylon. The outer layer 12 has a lateral cross-sectional shape including, but not limited to, circular, elliptical, or oval, etc. In an exemplary embodiment, the lateral cross-sectional shape of the outer layer 12 is circular.
[40] The outer layer 12 improves the catheter’s 1 strength, flexibility, and surface smoothness and also improves its durability during different medical applications. The outer layer 12 provides a protective covering to the tubular component 2. The protective covering provides a smooth, biocompatible surface for safe interaction with bodily tissues/fluids. The outer layer 12 enhances lubricity, reduces friction during insertion, and shields the braided layer 18 and the inner layer 14 from external damage.
[41] Additionally, and optionally, the tip 7 is coupled to the distal end 6 of the tubular component 2. The tip 7 is coupled to the tubular component 2 by at least one of adhesive bonding, crimping, heat shrinking, solvent bonding, welding, mechanical coupling, and the like. In an exemplary embodiment, the tip 7 is coupled to the distal end 6 of the tubular component 2 by way of welding. In an exemplary embodiment, the tip 7 is made of polyurethane (PU). The tip 7 has a lateral cross-sectional shape including, but not limited to, semi-circular, dome-shape, conical, etc. In an exemplary embodiment, the lateral cross-sectional shape of the tip 7 is semicircle. The tip 7 has a pre-defined length ranging from 10 mm to 20 mm. The tip 7 has a pre-defined diameter ranging from 1.5 mm to 3.0 mm. In an exemplary embodiment, the length and diameter of the tip 7 is 15 mm and 2 mm, respectively. The tip 7 may either be solid or hollow. In an exemplary embodiment, the tip 7 is hollow. The tip 7 defines a soft and atraumatic end of the catheter 1. The tip 7 of the catheter 1 helps in safe and precise navigation of the catheter 1 through the body’s tortuous vessels or cavities during different medical applications. The tip 7 helps to provide directional control and access to target sites during medical procedures.
[42] Additionally, or optionally, the tip 7 may include one or more sections. In an exemplary embodiment, the tip 7 includes two sections, namely a flexible and a stiff section. The flexible section is soft, atraumatic and made of a low-durometer material for safety and vessel protection. The flexible section is of the tip 7 is coupled to the tubular component 2. The stiff section has a relatively higher stiffness compared to the flexible section. The stiff section helps in pushability and torque response, forming a gradual transition for optimal catheter performance. The stiff section of the tip 7 is the distal most section of the catheter 1.
[43] The hub 10 is coupled to the proximal end 4 of the tubular component 2. The hub 10 is coupled to the tubular component 2 by at least one of adhesive bonding, crimping, heat shrinking, solvent bonding, welding, molding, ultrasonic welding, and the like. The molding process may be at least one of injection molding, over molding, insert molding, compression molding, micro-molding, and the like. In an embodiment, the hub 10 is coupled to the proximal end 4 of the tubular component 2 by an insert molding process. The hub 10 has a length ranging from 2 cm to 4 cm. In an exemplary embodiment, the length of the hub 10 is 2.7 cm. The hub 10 is made of one or more materials including at least one of polycarbonates, polyurethane, nylon, polyethylene, polyvinyl chloride (PVC), thermoplastic elastomer (TPE), silicone rubber, and the like. In an exemplary embodiment, the hub 10 is made of polycarbonate. The hub 10 may have a structure selected from the group of straight, winged, Y-shaped, T-shaped threaded, tapered, and flared. In an exemplary embodiment, as shown in Fig. 1A, the structure of the hub 10 is winged. The hub 10 helps to connect the catheter 1 to other medical devices or equipment and provide a secure connection for proper functioning during medical procedures.
[44] The strain relief component 8 is at least partially disposed around the hub 10 and the tubular component 2 towards the proximal end 4. The strain relief component 8 has a length ranging from 3 cm to 5 cm. In an exemplary embodiment, the length of the strain relief component 8 is 3.5 cm. The strain relief component 8 is made of one or more materials including at least one of polycarbonates, polyurethane, nylon, polyethylene, polyvinyl chloride (PVC), thermoplastic elastomer (TPE), silicone rubber, and the like. In an exemplary embodiment, the strain relief component 8 is made of thermoplastic polyurethane (TPU). The strain relief component 8 may have a shape selected from the group of tapered, coiled, bellows, ribbed, stepped, flared, conical, and helical shape. In exemplary embodiment, the shape of the strain relief component 8 is ribbed. The strain relief component 8 helps to provide support and flexibility, prevents kinking or damage to the catheter 1 during handling or insertion, and ensure the integrity of the connection between the hub 10 and the tubular component 2.
[45] Additionally, or optionally, the catheter 1 may include one or more holes (not shown) disposed towards the distal end 6 of the tubular component 2. In an exemplary embodiment, the tubular component 2 is provided with one hole. The hole may extend through at least one layer of the plurality of layers of the tubular component 2. In an exemplary embodiment, the hole extends through the inner layer 14, the braided layer 18, and the outer layer 12, while preserving the structural integrity of the catheter 1. The hole enable passage to fluid delivery or guidewire exit. The hole may have a pre-defined cross-sectional surface area ranging from 40,000 micrometre square to 41,000 micrometre square. In an exemplary embodiment, the catheter 1 includes one hole at the distal end 6 having an area of 40,6549.06 micrometre square.
[46] FIG. 2 illustrates different shapes of the distal end 6 (and tip 7) of the catheter 1, according to one or more embodiments of the present disclosure. The distal end 6 of the catheter 1 may be shaped to suit specific anatomical or procedural requirements and may assume a configuration such as Judkins, Amplatz, Bern, Multipurpose, Cobra, Yankauer, Sheath, Pigtail, and Simpson shapes. As illustrated in FIG. 2A, the distal end 6 of the catheter 1 has a pigtail shape, that features a coiled tip designed to minimize vessel trauma and facilitate safe contrast injection. As illustrated in FIG. 2B, the distal end 6 of the catheter 1 has a Judkins shape, characterized by a preformed curve used primarily for selective coronary artery engagement. As illustrated in FIG. 2C, the distal end 6 of the catheter 1 has a Amplatz shape, having a more aggressive curvature suitable for accessing difficult or posterior vessel anatomies.
[47] FIG. 3 illustrates a flowchart of an automated method 100 (or method 100) for manufacturing multiple catheters 1 in one manufacturing cycle, according to an embodiment of the present disclosure.
[48] The method 100 commences at step 102 by obtaining a mandrel 16a (as shown in Fig. 4). The mandrel 16a corresponds to the shape of the lumen 16 of the inner layer 14 of the tubular component 2. The step involves feeding a first material wounded on a spool within a first extruder. The first extruder automatically draws the first material from the spool to extrude the mandrel 16a. The mandrel 16a provides a supporting structure for the preparation of the plurality of layers of the tubular component 2 in the subsequent steps of the method 100. The mandrel 16a has a diameter ranging from 0.8 mm to 3.0 mm. In an exemplary embodiment, the diameter of the mandrel 16a is 1.5 mm. The mandrel 16a may either be solid or hollow. In an exemplary embodiment, the mandrel 16a is solid. The mandrel 16a has a lateral cross-sectional shape including, but not limited to, circular for uniform layer deposition during the extrusion process, although other shapes like oval or elliptical, etc. are within the scope of the teachings of the present disclosure. In an exemplary embodiment, the lateral cross-sectional shape of the mandrel 16a is circular. The first material used for the extrusion of the mandrel 16a is at least one of polyoxymethylene (POM), pebax, polyvinyl chloride (PVC), polyurethane (PU), silicone, polyethylene (PE), polypropylene (PP), nylon, polyamide, polytetrafluoroethylene (PTFE), thermoplastic elastomers, polyether block amide, polycarbonate (PC), polylactic acid. In an exemplary embodiment, the first material used to extrude the mandrel 16a is polyoxymethylene (POM).
[49] In an exemplary embodiment, a single-screw extruder with a 24:1 (Length:Diameter) ratio having circular die head, screw diameter of approximately 20-25 mm, and a variable-speed drive ranging from 0 to 100 RPM is used, equipped with three to four with heating zones set between 100 °C and 250 °C. The feeding rate of the first material from the spool to the extruder corresponds to the RPM at which the variable-speed drive of the extruder is set. In an exemplary embodiment, the extruder is set at 175 °C to extrude the mandrel 16a. Other functionally equivalent extruders are also within the scope of the teachings of the present disclosure.
[50] In another aspect, the first extruder may be coupled with a processing circuitry (not shown) to control parameters such as temperature, flow rate of the extruded first material, feed rate of the first material, etc. This allows for precise control over the dimensions, thickness, surface smoothness, and uniformity of the first material applied by the extruders.
[51] Additionally, or optionally, the mandrel 16a extruded by the first extruder is wounded around a first spool. In an embodiment, post extrusion of the mandrel 16a, the mandrel 16a is wound simultaneously and automatically around the first spool by using a motorized winding mechanism that is synchronized with the first extruder.
[52] At step 104, a first preform is obtained. This involves feeding the mandrel 16a from the first spool along with a spool of a second material within a second extruder to continuously extrude the inner layer 14 around an outer surface of the mandrel 16a and wound the first preform around a second spool. In an exemplary embodiment, the mandrel 16a from the first spool is fed along with a second material within the second extruder to extrude an inner layer 14 around the mandrel (16a) and obtain a first preform wound around the second spool. The second extruder automatically draws the mandrel 16a and the second material from the respective spools. The inner layer 14 has an outer diameter ranging from 1.0 mm to 1.5 mm. The inner layer 14 has a thickness ranging from 0.1 mm to 0.3 mm. In an exemplary embodiment, the outer diameter and thickness of the inner layer 14 is 1.2 mm and 0.2 mm, respectively. The inner layer 14 has a lateral cross-sectional shape including, but not limited to, circular, oval, etc. In an exemplary embodiment, the lateral cross-sectional shape of the inner layer 14 is circular. The second material used to extrude the inner layer 14 is at least one of polyoxymethylene (POM), pebax, polyvinyl chloride (PVC), polyurethane (PU), silicone, polyethylene (PE), polypropylene (PP), nylon, polyamide, polytetrafluoroethylene (PTFE), thermoplastic elastomers, polyether block amide, polycarbonate (PC), polylactic acid. In an exemplary embodiment, the second material used to extrude the inner layer 14 is polyurethane (PU).
[53] In an exemplary embodiment, a single-screw extruder with a 24:1 (Length:Diameter) ratio having circular die head, a screw diameter of approximately 20–25 mm, and equipped with three to four heating zones operating between 100 °C and 250 °C is used. The extruder may include a variable-speed drive that allows an extrusion speed in the range of 1 to 5 meters per minute. The feeding rate of the mandrel 16a and the second material from the first spool to the extruder corresponds to the extrusion speed at which the variable-speed drive of the extruder is set. In an exemplary embodiment, the extruder is set at 175 °C to extrude the inner layer 14. Other functionally equivalent extruders are also within the scope of the teachings of the present disclosure.
[54] In another aspect, the second extruder may be coupled with the processing circuitry (not shown) to control parameters such as temperature, flow rate of the extruded second material, and feed rate of the second material, etc. This allows for precise control over the dimensions, thickness, surface smoothness, and uniformity of the second material applied by the extruders.
[55] Additionally, or optionally, the first preform extruded by the second extruder is wound around a second spool. In an embodiment, post extrusion of the first preform, the first preform is wound simultaneously and automatically around the second spool by using a motorized winding mechanism that is synchronized with the second extruder. A cross-sectional view of the preform after step 104 is depicted in Fig. 4. The preform includes the mandrel 16a and the inner layer 14 disposed around the mandrel 16a.
[56] At step 106, a second preform is obtained. This involves feeding the second spool containing the first preform obtained from step 104 along with one or more spools of fibers within a braiding machine to continuously form the braided layer 18 around the inner layer 14 and wound the second preform around a third spool. The braiding machine automatically draws the first preform and one or more fibers from the respective spool. The braided layer 18 may be formed by braiding one or more fibers around an outer surface of the inner layer 14 to enhance the flexibility, kink resistance, structural strength and torque response of the catheter 1. The second preform and the one or more fibers are continuously and automatically fed from the respective spools to the braiding machine. Braiding the entire length of the inner layer 14 provides uniform braiding pattern along the entire length of the inner layer 14.
[57] The fiber of the braiding layer 18 has a diameter ranging from 0.05 mm to 0.2 mm. In an exemplary embodiment, the diameter of the fiber is 0.1 mm. In an exemplary embodiment, the fiber is made of stainless steel. The fiber(s) of the braiding layer are braided in a pre-defined pattern. In an embodiment, as shown in Fig. 1C, the one or more fibers of the braided layer 18 have a two-over-two braiding pattern in a single-wire configuration. In another embodiment, the one or more fibers of the braided layer 18 have a two-over-two braiding pattern in a double-wire configuration. A braid angle between any of the two over two wire structure may range from 80 to 84 degrees. In an exemplary embodiment, the braid angle between any of the two over two wire structure is 80.84 degrees. The braided layer 18 provides enhanced mechanical properties such as torqueability, pushability, kink resistance, flexibility, stiffness, and radial strength.
[58] In an exemplary embodiment, a 32-carrier braiding machine equipped with 32 bobbins operating in a two-over-two braiding pattern can be used. The braiding machine is capable of producing braid angles between 45° and 85°, using fibers with diameters ranging from 0.05 mm to 0.2 mm. The fiber tension can be adjusted within a range of 0.5 to 5 N, and the braiding machine operates at speeds between 10 and 50 RPM. The braiding density ranges between 10 to 40 fibers per unit length. The braiding machine is equipped with computerized controls and is designed to operate within a cleanroom environment. The feeding rate of the one or more fibers and the preform from the respective spools to the braiding machine corresponds to the speed at which the braiding machine is set. In an exemplary embodiment, the braiding machine is set at 30 RPM to prepare the two-over-two braiding pattern over the outer surface of the inner layer 14. Other functionally equivalent braided machines are also within the scope of the teachings of the present disclosure.
[59] In another aspect, the braiding machine may be coupled with the processing circuitry (not shown) configured to select the one or more fibers used to form the mesh-like structure in the form of the braided layer 18.
[60] Additionally, or optionally, the second preform is wounded around a third spool. In an embodiment, post braiding of the second preform, the second preform is wound simultaneously and automatically around the third spool by using a motorized winding mechanism that is synchronized with the braiding machine. A cross-sectional view of the preform after step 106 is depicted in Fig. 5. The preform includes the mandrel 16a and the inner layer 14 disposed around the mandrel 16a. The braiding layer 18 is disposed around the inner layer 14.
[61] At step 108, the second preform is heated to bond (and embed) the braided layer 18 to the inner layer 14. This involves feeding the third spool containing the second preform within a reflow machine to continuously bond (and embed) the braided layer 18 with the inner layer 14. The reflow machine automatically draws the second preform from the third spool to a nozzle (not shown) of the reflow machine. Specifically, the second preform is heated using the nozzle inside the reflow machine to evenly and momentarily melt the inner layer 14 and bond the inner layer 14 to the braiding layer 18. This process helps ensure a smooth and uniform finish, while also improving the strength, flexibility, and surface quality of the catheter 1.
[62] In an exemplary embodiment, the reflow machine includes a continuous preform feeding rate ranging from 2.0 m/min to 3.0 m/min and nozzle heating with temperature control ranging from 150°C to 300°C is used. The reflow machine is designed to bond the braided layer 18 to the inner layer 14. In an exemplary embodiment, the nozzle is set at 255°C to bond the braided layer 18 to the inner layer 14. The feeding rate of the preform from the spool to the nozzle of the reflow machine is set at 2.5 m/min.
[63] In another aspect, the reflow machine may be coupled with processing circuitry (not shown) configured to control the feeding rate and the temperature of the nozzle inside the reflow machine to properly bond the braided layer 18 with the inner layer 14 of the catheter 1.
[64] Additionally, or optionally, the second preform obtained from the reflow machine is wounded around a fourth spool. In an embodiment, post heating of the second preform, the second preform is wound simultaneously and automatically around the fourth spool by using a motorized winding mechanism that is synchronized with the reflow machine.
[65] Although the braiding of the one or more fibers at step 106 and heating the preform at step 108 are described with the examples of two distinct apparatus, i.e., the braiding machine and the reflow machine, the two steps can be executed simultaneously by providing a line heater or the like in the braiding machine (for simultaneously heating the second preform after braiding to bond the inner layer 14 to the braided layer 18) and the same is within the scope of the teachings of the present disclosure. The line heater is set at a temperature ranging from 150°C to 300°C. In an exemplary embodiment, the line heater is set at 255°C to bond the braided layer 18 to the inner layer 14.
[66] At step 110, the tubular component 2 is obtained. This involves feeding the fourth spool containing the second preform (or the third spool containing the second preform if a line heater was used simultaneously while forming the braiding layer 18) along with a spool of a third material within a third extruder to continuously form the outer layer 12 around the braided layer 18 and wound the tubular component 2 around a fifth spool. The third extruder automatically draws the second preform and the third material from the respective spools. The plurality of outer layer 12 may be formed by extruding the third material around the braided layer 18 to make the tubular component 2 of the catheter 1 stronger, more flexible, smoother, evenly coated, and to secure the braided layer 18 for improved durability and accurate shape. The third material used for the extrusion of the outer layer 12 is at least one of polyoxymethylene (POM), pebax, polyvinyl chloride (PVC), polyurethane (PU), silicone, polyethylene (PE), polypropylene (PP), nylon, polyamide, polytetrafluoroethylene (PTFE), thermoplastic elastomers, polyether block amide, polycarbonate (PC), polylactic acid. In an exemplary embodiment, the third material used to extrude the outer layer 12 is nylon.
[67] In an exemplary embodiment, the extruder may be set at a temperature ranging from 150°C to 350°C, an extrusion speed of 5 to 30 meters per minute, and an adjustable output pressure between 50 and 250 bar. The extruder may have a single-screw or twin-screw configuration, with a barrel diameter ranging from 30 to 80 mm. A precision die head with an opening size of 2 to 10 mm is used to ensure uniform coating. The extrusion process is controlled through automated systems that regulate material feeding, screw speed, and temperature. The machine is equipped with an integrated cooling system. The entire process is carried out in a cleanroom environment to maintain quality and cleanliness of the catheter 1. The feeding rate of the preform and the third material from the respective spools to the extruder corresponds to the extrusion speed at which the extruder is set. In an exemplary embodiment, the extruder is set at 250 °C, 150 bar to extrude the outer layer 12. Other functionally equivalent extruders are also within the scope of the teachings of the present disclosure.
[68] Additionally, or optionally, the tubular component 2 provided over the mandrel 16a is wound around a fifth spool. In an embodiment, post extrusion of the tubular component 2, the tubular component 2 is wound simultaneously and automatically around the fifth spool by using a motorized winding mechanism that is synchronized with the third extruder. A cross-sectional view of the tubular component 2 after step 110 is depicted in Fig. 6. The tubular component 2 includes the mandrel 16a and the inner layer 14 disposed around the mandrel 16a. The braiding layer 18 is disposed around the inner layer 14. And, the outer layer 12 is disposed around the braiding layer 18.
[69] At step 112, the tubular component 2 obtained from step 110 is cut to obtain multiple tubular components 2. Each tubular component corresponds to one catheter 1. The length of the catheter to be cut by a cutting machine may be pre-defined. In other words, the tubular component 2 is cut to pre-defined lengths resulting in multiple catheters 1. The tubular component 2 is continuously and automatically fed from the fifth spool to the cutting machine. The pre-defined length ranges from 1 cm to 120 cm. The pre-defined length depends upon the requirement and application of the catheter 1. This enables smooth and accurate cutting without introducing tension or deformation in the tubular component 2. In another aspect, the cutting machine may be coupled with a processing circuitry configured to rotate the spool simultaneously while the tubular component 2 undergoes the cutting step. After cutting the tubular component 2, the mandrel 16a is removed from within the tubular component 2.
[70] In an exemplary embodiment, an automatic programmable medical tubing cutter equipped with a motorized spool unwinder, feeding rollers, and a high-precision blade is used as the cutting machine. The cutter provides programmable cutting lengths from 1 cm to 120 cm through a touchscreen human-machine interface (HMI), ensuring minimal tension during the cutting process. An operator is to input the pre-defined cutting length of which the catheters are to be made. The cutting step is controlled by a programmable logic controller (PLC), with synchronized spool rotation for smooth and accurate feeding. Other functionally equivalent cutting machines are also within the scope of the teachings of the present disclosure.
[71] Alternatively, the first extruder from step 102, the second extruder from step 104, the braiding machine from step 106, the reflow machine from step 108, the third extruder from step 110 and the cutting machine from step 112 are arranged serially one after the other such that the output from one step is directly fed into the apparatus of the next step and the same is within the scope of the teachings of the present disclosure.
[72] Alternatively, the first extruder from step 102, the second extruder from step 104, the braiding machine having the line heather from step 106, the third extruder from step 110 and the cutting machine from step 112 are arranged serially one after the other such that the output from one step is directly fed into the apparatus of the next step and the same is within the scope of the teachings of the present disclosure.
[73] The steps 102-112 of the method 100 facilitates to manufacture multiple tubular component 2 corresponding to multiple catheters 1 in one manufacturing cycle. In an exemplary embodiment, the step 102-112 is used to manufacture fifty tubular components 2 in one manufacturing cycle. Depending upon the scale of operation, the number of tubular components 2 manufactured can be either increased or decreased.
[74] At an optional step 114, the loose ends of the one or more fibers of the braided layer 18 are secured by one a welding, thermal bonding, mechanical trimming and over jacketing. Securing the loose ends of the fibers of the braided layer 18 prevents delamination of the fibers and ensuring structural integrity. In an exemplary embodiment, the loose ends of the fibers are welded using a welding machine. In another exemplary embodiment, the loose ends of the fibers are thermally fused/bonded by a hot air gun/heat block. In yet another exemplary embodiment, the loose ends of the fibers are mechanically trimmed and a heat-shrink or polymer jacket is placed over the area to secure them. Other functionally equivalent techniques to secure the loose ends of the fibers are also within the scope of the teachings of the present disclosure.
[75] At an optional step 116, the distal end 6 of the tubular component 2 is coupled with the tip 7. The coupling step of the tip 7 may be done by way of adhesive bonding, snap-fitting, compression bonding, heat shrinking, thermal bonding, over jacketing, and the like. This provides a smooth and secure connection, enhancing flexibility, durability, and patient safety.
[76] In an exemplary embodiment, the coupling step of the tip 7 may be done by way of welding. A stainless-steel mandrel (not shown) is used to support lumen 16 of the tubular component 2 and maintain precise alignment between the tubular component 2 and the tip 7. This alignment facilitates accurate heat transfer during the welding process. The welded tip 7 ensures a seamless transition between different ends of the catheter 1 that helps in improved navigation through blood vessels. Other functionally equivalent welding machines are also within the scope of the teachings of the present disclosure.
[77] At an optional step 118, a free end of the tip 7 is chamfered (as shown in FIG. 14a). This provides a smooth and rounded finish at the tip 7, enhancing patient safety by reducing the risk of vascular injury during navigation. Furthermore, the chamfering step improves and eases catheter insertion and navigation and enhances the flexibility of the tip 7. Fig. 7 depicts the tip 7 after being chamfered.
[78] In an exemplary embodiment, a heated mandrel or thermal tip flaring tool is used to chamfer the tip 7 of the tubular component 2. The tool typically operates at a temperature ranging between 90°C and 130°C, with a dwell time of 2 to 5 seconds, depending on the material properties of the tip 7 and/or the alignment of the tip 7 and the mandrel/tool. In an exemplary embodiment, the free end of the tip 7 is chamfered using a heated mandrel set at 110 °C for 3 seconds. Other functionally equivalent chamfering tools are also within the scope of the teachings of the present disclosure.
[79] At an optional step 120, the proximal end 4 of the tubular component 2 is flared (as shown in FIG. 14b). This provides better connector attachment, improves handling, and ensures a secure fit with the hub 10 and the strain relief component 8. Fig. 8 depicts the proximal end 4 of the tubular component 2 after being flared.
[80] In an exemplary embodiment, the proximal end 4 of the tubular component 2 is flared using a heated flaring die or thermal mandrel, operating at temperatures between 90°C and 130°C with a dwell time of 2 to 5 seconds. The flaring process may involve pneumatic or manual insertion of the tubular component 2 to ensure a consistent flare shape and diameter across the proximal end 4 of the tubular component 2. In an exemplary embodiment, the proximal end of the tubular component 2 is flared using a heated flaring die set at 110 °C for 3 seconds. Other functionally equivalent flaring tools are also within the scope of the teachings of the present disclosure.
[81] At an optional step 122, the proximal end 4 of the tubular component 2 is coupled to the hub 10. The coupling step of the hub 10 may be done by way of adhesive bonding, snap-fitting, compression bonding, heat shrinking and the like. In an exemplary embodiment, the coupling step of the hub 10 is performed using an insert molding process. In the insert molding process, the proximal end 4 of tubular component 2 along with the hub 10 is placed into a cavity of a mold and a molten material is injected within the said cavity of the mold. The molten material is cooled and solidified to form the strain relief component 8 around the proximal end 4 of the tubular component 2 and the hub 10. In other words, the strain relief component 8 is formed at least partially around the hub 10 and the proximal end 4 of the tubular component 2. This provides secure attachment, improves durability, and allows flexibility at the junction, minimizing stress and preventing damage during use. The strain relief component 8 is made of one or more materials including at least one of polycarbonates, polyurethane, nylon, polyethylene, polyvinyl chloride (PVC), thermoplastic elastomer (TPE), silicone rubber, and the like. In an exemplary embodiment, the strain relief component 8 is made of thermoplastic polyurethane (TPU).
[82] At an optional step 124, one or more marks or gradations are marked on the hub 10 using a laser marking machine. These markings may include logos, size indicators, or lot numbers, applied without damaging the material/surface of the hub 10. The marking step ensures high visibility, wear resistance, and permanent identification, meeting regulatory and customer requirements.
[83] In an exemplary embodiment, a UV laser marking machine is used, featuring high beam quality, a small focused spot size, and a high peak power density of approximately 10⁹ W/cm². The laser marking machine operates with a pulse repetition frequency ranging from 20 to 100 kHz, making it well-suited for fine, high-speed, and non-damaging marking on medical devices. Other functionally equivalent laser marking machines are also within the scope of the teachings of the present disclosure.
[84] At an optional step 126, at least a layer of coating of lubricant or the like is coated at least partially on an outer surface of the tubular component 2 by way of a coating machine. The coating on the surface of the tubular component 2 may be hydrophilic coating, polyethylene glycol (PEG) coating, silicon coating, hybrid coating, silicon with hydrophilic coating, and the like. The hydrophilic coating is at least one of polyethylene glycol (PEG), polyvinyl alcohol (PVA), hydroxyethyl methacrylate (HEMA), silicone-based polymers, copolymer blends (PEG, PVA, HEMA, Silicone), etc. In an exemplary embodiment, the coating machine may be a hydrophilic coating machine that absorbs water to create a smooth, slippery surface, improving patient safety and procedural efficiency. This provides frictionless coating and enhances lubricity that helps in easier navigation through blood vessels and minimizing the risk of vessel trauma.
[85] In an exemplary embodiment, a hydrophilic coating machine with integrated UV LED curing is used, combining dip coating and UV LED curing in a single setup. The machine features PLC-controlled precision parameters, supports multiple product types, and delivers a uniform hydrophilic coating with high lubricity, making it ideal for catheter applications in vascular procedures. Other functionally equivalent coating machines are also within the scope of the teachings of the present disclosure.
[86] At an optional step 128, the distal end 6 of the tubular component 2 and tip 7 is shaped using a shaping plate (as shown in Fig. 10). The shaping plate refers to a shaping fixture or mold that may be used to form the desired shape of the catheter 1. In an exemplary embodiment, the shaping plate is typically constructed from aluminum to provide both durability and low friction during the shaping process. The catheter 1 is positioned onto the shaping plate with its distal end 6 aligned within the mold's contours, allowing for controlled and consistent shaping. The catheter 1 is securely restrained using fixtures or clamps, which may be adjustable to accommodate various sizes of the catheter 1 and to ensure proper alignment. These fixtures are designed to prevent any unwanted movement of the catheter 1 throughout the shaping process.
[87] The distal end 6 of tubular component 2 of the catheter 1 and tip 7 may be heated and placed in the shaping plate to achieve the required bending configuration. This ensures controlled flexibility, trackability, dimensional accuracy, consistent bending, reduced risk of deformation and optimal functionality during specific medical applications.
[88] In an exemplary embodiment, the shaping process may involve heating the distal end 6 of the catheter 1 to a temperature ranging between 90°C and 140°C, depending on the material of the tubular component 2/tip 7. Heating may be performed using hot air, a heat gun, or a heated shaping block. The catheter 1 is held in place on the aluminum shaping plate, with its distal end 6 aligned to the mold contours, and restrained using adjustable fixtures or clamps to maintain precise alignment. The catheter 1 is maintained in the mold of the shaping plate for a dwell time of 10 to 60 seconds, depending on the required shape. After shaping, cooling is carried out using either ambient air or a water spray to set the final geometry.
[89] At an optional step 130, one or more holes is punched at the distal end 6 of the tubular component 2 using a punching machine. These holes may allow for functions, such as fluid delivery or guidewire exit for specific medical applications. Fig. 9 depicts the hole 6a being punched on the distal end 6 of the tubular component 2.
[90] In an exemplary embodiment, a precision punching machine is used to create holes at the distal end 6 of the catheter 1 for fluid delivery or guidewire exit. The catheter 1 is positioned on a punching fixture and secured using a clamping system, which holds the tubular component 2 firmly in place to ensure accurate hole formation. The punching step offers high precision, minimizing deformation or damage to the catheter 1 during the operation.
[91] Now the catheter of the present disclosure will be explained with help of the following examples.
[92] Example 1: Preparing multiple catheters using a conventional method
[93] Using the conventional method, 50 catheters were made. For each of the 50 catheters, the mandrel, the inner layer, and the outer layer were separately obtained and manually cut using a blade. For each of the 50 catheters, the inner layer was manually mounted over the mandrel. Each of the sub-assemblies of the mandrel and catheter was mounted on the braiding machine one at a time. Before loading each of the said sub-assemblies, the braiding machine was manually set up by mounting the fibers to be braided on the sub-assemblies. After the braiding was done, each of the sub-assemblies was manually cut and removed from the braiding machine. Since, the capacity of the braiding machine was to braid one sub-assemblies at a time, the process was repeated 50 times to braid all the sub-assemblies. Due to restarting the braiding machine for each of the sub-assemblies, the braiding done on the initial portion of all the braided sub-assemblies were non-uniform.
[94] The braided sub-assemblies were manually mounted inside a reflow machine. The reflow machine heated the braided sub-assemblies to bond the braided layer to the inner layer. The reflow machine had a capacity to operate with five braided sub-assemblies at a time. Hence, the process was repeated 10 times to bond all the braided sub-assemblies. Thereafter, the outer layer was manually mounted on each of the braided sub-assemblies to obtain 50 tubular components. The mandrel of the 50 tubular components were then removed. And, the 50 tubular components were coupled to respective hubs and tips at respective ends to obtain the catheters. Since, the conventional method was heavily dependent on human intervention, the time taken and the cost involved to manufacture the 50 catheters were very high.
[95] Example 2: Preparing multiple catheters 1 in one manufacturing cycle using the method 100
[96] Using the method 100, 50 catheters 1 were made. A spool of polyoxymethylene (POM) was placed inside a first extruder and the mandrel 16a having length of 55300 mm was extruded. The mandrel 16a was collected and wound around a first spool. The parameters at which the first extruder was operated is tabulated below in Table i.
(Table i)
Screw diameter 22 mm
Length-to-Diameter (L:D) ratio 24:1
Drive speed (RPM) 60 RPM
Number of heating zones 3
Heating zone temperatures Zone 1 – 150 °C,
Zone 2 – 175 °C
Zone 3 – 200 °C
Die head shape Circular
Extrusion temperature 175 °C
Material feeding rate Corresponding to drive speed (i.e., 60 RPM)
[97] The first spool containing the mandrel 16a and a spool containing polyurethane was placed in a second extruder. The second extruder was used to extrude the inner layer 14 over the outer surface of the mandrel 16a. A first preform (having length of 55300 mm) obtained from the second extruder was wounded around a second spool. The parameters at which the second extruder was operated is tabulated below in Table ii.
(Table ii)
Screw diameter 22 mm
Length-to-Diameter (L:D) ratio 24:1
Extrusion speed 3 meters per minute
Number of heating zones 3
Heating zone temperatures Zone 1 – 120 °C,
Zone 2 – 175 °C
Zone 3 – 230 °C
Die head shape Circular
Extrusion temperature 175 °C
Material feeding rate Corresponding to extrusion speed (i.e., 3 meters per minute)
[98] The second spool containing the first preform and spools containing one or more fibers of stainless steel was placed in a braiding machine. The braiding machine was used to braid the fibers of the braided layer 18 over the first preform and simultaneously heat the first preform using a line heater (maintained at 255 °C) to obtain a second preform having length of 55300 mm. Further, the second preform obtained from the braiding machine was wounded around a third spool. The braiding layer 18 obtained was uniform throughout the length of the second preform (except for one small portion at the start). The parameters at which the braiding machine was operated is tabulated below in Table iii.
(Table iii)
Fiber diameter 0.050 mm
Braiding angle 80°
Braiding pattern Two-over-two (Double Wire)
Braiding density 40 fibers per unit length
[99] The third spool containing the second preform and a spool containing nylon was placed in a third extruder. The third extruder was used to extrude the outer layer 12 over the outer surface of the braided layer 18 and obtain the tubular component 2 having length of 55300 mm. Furthermore, the tubular component 2 was wounded over a fourth spool. The parameters at which the third extruder was operated is tabulated below in Table iv.
(Table iv)
Extruder Temperature
250°C
Extrusion Speed 20 meters per minute
Output Pressure
150 bar
Die Head Size precision die head with an opening of 4 mm
Barrel Diameter 60 mm
[100] The fourth spool containing the tubular component 2 was placed in a cutting machine. The cutting machine was used to cut the tubular component 2 to produce 50 tubular component 2. Each tubular component 2 had a length of 1105 mm. The mandrel 16a was removed from each of the tubular components 2. The loose ends of the braided layers were welded. The tip 7 was coupled to each of the 50 tubular components 2. The tip 7 was chamfered and the proximal end 4 of the tubular component 2 was flared. The hub 10 was coupled to the flared proximal ends 4 of the tubular component 2. A strain relief component 8 made of thermoplastic polyurethane was insert molded around the proximal end 4 of the tubular component and at least partially over the hub 10. A coating of polyethylene glycol was applied on the tubular components 2. A hole 6a is punched at the distal end 6 of the tubular component 2. The time taken and the cost involved were significantly less to manufacture the 50 catheters 1 compared to the conventional method described in Example 1.
[101] Example 3: Preparing multiple catheters 1 in one manufacturing cycle using the method 100
[102] Using the method 100, 50 catheters 1 were made. A spool of polyoxymethylene (POM) was placed inside a first extruder and the mandrel 16a having length of 55300 mm was extruded. The mandrel 16a was collected and wound around a first spool. The parameters at which the first extruder was operated is tabulated below in Table v.
(Table v)
Screw diameter 22 mm
Length-to-Diameter (L:D) ratio 24:1
Drive speed (RPM) 60 RPM
Number of heating zones 3
Heating zone temperatures Zone 1 – 150 °C,
Zone 2 – 175 °C
Zone 3 – 200 °C
Die head shape Circular
Extrusion temperature 175 °C
Material feeding rate Corresponding to drive speed (i.e., 60 RPM)
[103] The first spool containing the mandrel 16a and a spool containing polyurethane was placed in a second extruder. The second extruder was used to extrude the inner layer 14 over the outer surface of the mandrel 16a. A first preform (having length of 55300 mm) obtained from the second extruder was wounded around a second spool. The parameters at which the second extruder was operated is tabulated below in Table vi.
(Table vi)
Screw diameter 22 mm
Length-to-Diameter (L:D) ratio 24:1
Extrusion speed 3 meters per minute
Number of heating zones 3
Heating zone temperatures Zone 1 – 120 °C,
Zone 2 – 175 °C
Zone 3 – 230 °C
Die head shape Circular
Extrusion temperature 175 °C
Material feeding rate Corresponding to extrusion speed (i.e., 3 meters per minute)
[104] The second spool containing the first preform and spools containing one or more fibers of stainless steel was placed in a braiding machine. The braiding machine was used to braid the fibers of the braided layer 18 over the first preform and obtain a second preform having length of 55300 mm. Further, the second preform obtained from the braiding machine was wounded around a third spool. The braiding layer 18 obtained was uniform throughout the length of the second preform (except for one small portion at the start). The parameters at which the braiding machine was operated is tabulated below in Table vii.
(Table vii)
Fiber diameter 0.050 mm
Braiding angle 80°
Braiding pattern Two-over-two (Double Wire)
Braiding density 40 fibers per unit length
[105] The third spool containing the second preform was fed to a reflow machine. The reflow machine bonded the braiding layer 18 to the inner layer 14. The second preform obtained from the reflow machine was wounded around a fourth spool. The parameters at which the reflow machine was operated is tabulated below in Table viii.
(Table viii)
Feeding rate 2.5 meter per minute
Nozzel temperature 255°C
[106] The fourth spool containing the second preform and a spool containing nylon was placed in a third extruder. The third extruder was used to extrude the outer layer 12 over the outer surface of the braided layer 18 and obtain the tubular component 2 having length of 55300 mm. Furthermore, the tubular component 2 was wounded over a fifth spool. The parameters at which the third extruder was operated is tabulated below in Table ix.
(Table ix)
Extruder Temperature
250°C
Extrusion Speed 20 meters per minute
Output Pressure
150 bar
Die Head Size precision die head with an opening of 4 mm
Barrel Diameter 60 mm
[107] The fifth spool containing the tubular component 2 was placed in a cutting machine. The cutting machine was used to cut the tubular component 2 to produce 50 tubular component 2. Each tubular component 2 had a length of 1105 mm. The mandrel 16a was removed from each of the tubular components 2. The loose ends of the braided layers were welded. The tip 7 was coupled to each of the 50 tubular components 2. The tip 7 was chamfered and the proximal end 4 of the tubular component 2 was flared. The hub 10 was coupled to the flared proximal ends 4 of the tubular component 2. A strain relief component 8 made of thermoplastic polyurethane was insert molded around the proximal end 4 of the tubular component and at least partially over the hub 10. A coating of polyethylene glycol was applied on the tubular components 2. A hole 6a is punched at the distal end 6 of the tubular component 2. The time taken and the cost involved were significantly less to manufacture the 50 catheters 1 compared to the conventional method described in Example 1.
[108] Example 4: Friction test of the catheter 1 obtained from Example 2 above
[109] The friction test was conducted to evaluate the surface lubricity of the catheter obtained from example 2 embodiments having different coatings. The objective of this test was to quantify the coefficient of friction (COF) between the catheter surface and a simulated vascular environment, representing the ease of navigation through vasculature during clinical procedures.
[110] The test was performed using a custom linear friction testing apparatus, equipped with a high-precision load cell. A constant load of 200 grams was applied vertically to ensure uniform contact between the catheter 1 and simulated vascular channel during movement. The system measures the force required to move the catheter 1, allowing calculation of the coefficient of friction.
[111] Each catheter sample was advanced in a linear path through a 100 mm test channel, and force data was recorded in three consecutive length segments: distal, middle, and proximal. Both maximum and average force values were measured for each segment to evaluate consistency and detect any changes in frictional behavior along the catheter length.
[112] Table 1 below presents the maximum and average frictional force values along with average coefficient of friction (COF) recorded across three length segments for each catheter embodiment tested under a constant 200 g load in a simulated environment:
Coatings Length Segments Max. force value of the test Avg. force value of the test Avg. COF
Hydrophilic + Silicon Coating Distal 138.6gm 66.92gm 0.312
Hydrophilic + Silicon Coating Middle 80.65gm 36.88gm 0.173
Hydrophilic + Silicon Coating Proximal 236gm 91.38gm 0.427
Hydrophilic Coating Distal 146.85gm 47gm 0.233
Hydrophilic Coating Middle 33gm 12.33gm 0.060
Hydrophilic Coating Proximal 36gm 17.32gm 0.063
Silicon + Hydrophilic Coating Distal 196gm 98.5gm 0.368
Silicon + Hydrophilic Coating Middle 169gm 98.6gm 0.475
Silicon + Hydrophilic Coating Proximal 202gm 116.56gm 0.522
Uncoated Distal 352gm 322.86gm 1.599
Uncoated Middle 374gm 331.07gm 1.634
Uncoated Proximal 349.7gm 316.54gm 1.582

[113] Example 5: Kink test of the catheter 1 obtained from Example 2 above
[114] The kink resistance test was conducted to evaluate the mechanical integrity and flexibility of catheter obtained from example 2 under progressive bending conditions. The objective of this test was to determine the minimum bend radius at which catheter maintains tubular component patency without structural collapse, simulating resistance to kinking during navigation through tortuous vascular anatomy.
[115] The test was performed using a custom bending apparatus consisting of a series of smooth cylindrical with decreasing radii. The catheter sample was bent over cylindrical with radii of 35, 30, 25, 20, 15, 12, 10, 8, and 5, in sequential order. At each radius, the catheter was visually inspected and tested for lumen occlusion or collapse using an air pressure in range between 2 to 10 atmospheres. The catheters were found to be okay in visual inspection.
[116] Example 6: Stiffness test of the catheter 1 obtained from Example 2 above
[117] A stiffness test was conducted to assess the longitudinal rigidity of different catheter embodiments obtained from example 2. The objective of the test was to quantify the catheter tubular component resistance to bending under applied force, which directly correlates with its pushability and trackability during navigation through vascular pathways.
[118] The test was performed using a universal mechanical testing machine equipped with a load cell and a point bend fixture. The load cell is a device that measures the force applied to the catheter. The specific load cell model may vary depending on the force range required for testing, and it ensures precise measurement of force during the test. Further, the point bend fixture is used to apply a specific bending force to the catheter at defined points. It ensures that the catheter undergoes a consistent bend under controlled conditions to measure its resistance to bending (stiffness).
[119] Table 2 below presents the maximum and average force values recorded for each catheter sample tested under a specific load in a simulated environment:
Coatings Length Segments Max. force Displacement at Maximum Force Stiffness
Hydrophilic + Silicon Coating Distal 0.91 4.97 0.183
Hydrophilic + Silicon Coating Middle 0.85 4.99 0.170
Hydrophilic + Silicon Coating Proximal 0.83 4.95 0.167
Hydrophilic Coating Distal 0.75 4.97 0.150
Hydrophilic Coating Middle 0.77 4.99 0.154
Hydrophilic Coating Proximal 0.76 5.00 0.152
Silicon + Hydrophilic Coating Distal 0.69 5.00 0.139
Silicon + Hydrophilic Coating Middle 0.71 4.99 0.142
Silicon + Hydrophilic Coating Proximal 0.71 5.00 0.141
Silicon Coating Distal 0.34 5.00 0.07
Silicon Coating Middle 0.32 5.00 0.07
Silicon Coating Proximal 0.31 5.00 0.06

[120] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teaching of the present invention is/are used. , C , Claims:We claim,
1. An automated method (100) for manufacturing multiple catheters (1) in one manufacturing cycle, comprising:
a. feeding a first material within a first extruder to extrude a mandrel (16a) and wound the mandrel (16a) around a first spool;
b. feeding the mandrel (16a) from the first spool along with a second material within a second extruder to extrude an inner layer (14) around the mandrel (16a) and obtain a first preform wound around a second spool;
c. feeding the first preform from the second spool along with one or more fibers within a braiding machine to form a braided layer (18) around the inner layer (14) and obtain a second preform wound around a third spool;
d. feeding the second preform from the third spool within a reflow machine to bond the braided layer (18) to the inner layer (14) of the second preform, and simultaneously winding the second preform obtained from the reflow machine around a fourth spool;
e. feeding the second preform from the fourth spool along with a third material within a third extruder to extrude an outer layer (12) around the braided layer (18) and obtain a tubular component (2) wound around a fifth spool; and
f. cutting the tubular component (2) to pre-defined lengths resulting in multiple catheters (1) using a cutting machine.
2. The automated method (100) as claimed in claim 1, wherein the method (100) includes removing the mandrel (16a) from within the tubular component (2) and securing loose ends of the one or more fibers of the braided layer (18).
3. The automated method (100) as claimed in claim 1, wherein the method (100) includes coupling a tip (7) to a distal end (6) of the tubular component (2).
4. The automated method (100) as claimed in claim 3, wherein the method (100) includes chamfering a free end of the tip (7).
5. The automated method (100) as claimed in claim 3, wherein the method (100) includes shaping the distal end (6) of the tubular component (2) and the tip (7).
6. The automated method (100) as claimed in claim 1, wherein the method (100) includes flaring a proximal end (4) of the tubular component (2).
7. The automated method (100) as claimed in claim 1, wherein the method (100) includes coupling a hub (10) to a proximal end (4) of the tubular component (2).
8. The automated method (100) as claimed in claim 7, wherein the method (100) includes forming a strain relief component (8) at least partially around the hub (10) and the proximal end (4) of the tubular component (2).
9. The automated method (100) as claimed in claim 1, wherein the method (100) includes forming a layer of coating at least partially over the tubular component (2).
10. The automated method (100) as claimed in claim 9, wherein the step of forming a layer of coating includes forming a layer of at least one of hydrophilic coating, polyethylene glycol (PEG) coating, silicon coating, hybrid coating, or silicon with hydrophilic coating.
11. The automated method (100) as claimed in claim 1, wherein the method (100) includes punching at least one hole adjacent to a distal end (6) of the tubular component (2).
12. The automated method (100) as claimed in claim 1, wherein the step of feeding the first material within the first extruder, feeding the second material within the second extruder, or feeding the third material within the third extruder includes feeding at least one of polyoxymethylene (POM), pebax, polyvinyl chloride (PVC), polyurethane (PU), silicone, polyethylene (PE), polypropylene (PP), nylon, polyamide, polytetrafluoroethylene (PTFE), thermoplastic elastomers, polyether block amide, polycarbonate (PC), or polylactic acid.
13. The automated method (100) as claimed in claim 1, wherein the step of feeding the one or more fibers within the braiding machine includes feeding stainless steel.
14. The automated method (100) as claimed in claim 1, wherein the step of forming the braided layer (18) around the inner layer (14) includes braiding a two-over-two braiding pattern with a braid angle ranging from 80 to 84 degrees.
15. An automated method (100) for manufacturing multiple catheters (1) in one manufacturing cycle, comprising:
a. feeding a first material within a first extruder to extrude a mandrel (16a) and wound the mandrel (16a) around a first spool;
b. feeding the mandrel (16a) from the first spool along with a second material within a second extruder to extrude an inner layer (14) around the mandrel (16a) and obtain a first preform wound around a second spool;
c. feeding the first preform from the second spool along with one or more fibers within a braiding machine to form a braided layer (18) around the inner layer (14) and obtain a second preform, and simultaneously heating the second preform to bond the inner layer (14) to the braided layer (18), the second preform being wound around a third spool;
d. feeding the second preform from the third spool along with a third material within a third extruder to extrude an outer layer (12) around the braided layer (18) and obtain a tubular component (2) wound around a fifth spool; and
e. cutting the tubular component (2) to pre-defined lengths resulting in multiple catheters (1) using a cutting machine.