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

TITLE OF THE INVENTION
BALLOON AND METHOD OF MANUFACURING THEREOF

APPLICANT:
Meril Corporation (I) Private Limited, an Indian company of the address Survey No. 135/139, Muktanand Marg, Bilakhia House, Pardi, Vapi, Valsad-396191 Gujarat, India.

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 to a medical device. More particularly, the present disclosure relates to a balloon and a method of manufacturing thereof.
BACKGROUND OF INVENTION
[2] A balloon is used for treatment in medical procedures, for example, angioplasty, stent implantation, etc. The balloon is used to open narrowed or obstructed blood vessels. Typically, the balloon is mounted on a catheter and inserted into an affected vessel through a small incision, guided to the site of blockage. Once in position, the balloon is inflated, compressing plaque against the vessel’s wall and expanding the vessel. This process enhances blood flow by alleviating restrictions caused due to various medical conditions and/or diseases.
[3] The balloons employed in medical procedures undergo a manufacturing process that involves various steps, for example, heating and stretching the preform axially, blow moulding, etc. Conventionally, balloons are manufactured by preparing preforms into two symmetrical halves. The symmetrical halves are prepared separately in a moulding machine. The symmetrical halves undergo fusing/thermoplasty to form a balloon. Due to fusing/ thermoplasty of two separate halves, the balloon obtained has a welding line which poses high chances of balloon rupture at the welding line during high pressure. Further, such a manufacturing process can lead to development of axial stresses in the balloons. These axial stresses play a significant role in the formation of fringe patterns, ultimately contributing to issues such as fatigue and balloon rupture.
[4] Additionally, the symmetrical halves of the balloons are blow moulded by filling the balloon with a gas and, for example, compressed nitrogen gas etc. The use of compressed nitrogen gas and thermoplasty procedures pose an extra cost on manufactures, and require specific storage and maintenance arrangements. Thus, there arises a need for a balloon that overcomes the problems associated with the conventional balloons.
SUMMARY OF INVENTION
[5] 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.
[6] The present disclosure relates to a method of manufacturing a balloon. In an embodiment, the method for manufacturing a balloon includes heating a preform ‘P’ at a first predefined temperature, for a first predefined time period. Post heating, the heated preform ‘P’ is stretched in a longitudinal direction up to a predefined length while simultaneously increasing temperature up to a threshold temperature in a second predefined time period. After longitudinally stretching the preform ‘P’ the preform ‘P’ is subjected to a vacuum suction force for radially expanding the preform ‘P’ and thereby, forming a balloon 100. The balloon 100, thus formed, has a unitary structure.
BRIEF DESCRIPTION OF DRAWINGS
[7] 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.
[8] Fig. 1 depicts a balloon 100, according to an embodiment of the present disclosure.
[9] Fig. 2 illustrates a flowchart of a method 200 for manufacturing of the balloon 100, according to an embodiment of the present disclosure.
[10] Fig. 3a depicts a heating apparatus 110 holding the preform ‘P’, according to an embodiment of the present disclosure.
[11] Fig. 3b depicts an exploded view of the heating apparatus 110 and preform ‘P’, according to an embodiment of the present disclosure.
[12] Fig. 3c depicts a moulding machine 120, according to an embodiment of the present disclosure.
[13] Fig. 3d depicts a moulding machine 120 with the preform ‘P’ post stretching operation, according to an embodiment of the present disclosure.
[14] Fig. 3e depicts the moulding machine 120 having a balloon 100, according to an embodiment of the present disclosure.
[15] Fig. 3f depicts removal of the balloon 100 from the moulding machine 120, according to an embodiment of the present disclosure.
[16] Fig. 3g depicts a robotic arm ‘R’ used to operate the heating apparatus 110 and the moulding machine 120 mounted on a table ‘Y’, emphasizing the longitudinally stretched preform ‘P’, according to an embodiment of the present disclosure.
[17] Fig. 3h depicts a robotic arm ‘R’ used to operate the heating apparatus 110 and the moulding machine 120 mounted on a table ‘Y’, emphasizing the manufactured balloon 100, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS
[18] 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.
[19] 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.
[20] 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.
[21] 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.
[22] In accordance with the present invention, a balloon and a method of manufacturing the same are disclosed. The balloon of the present invention is a medical device used to treat narrowed or blocked blood vessels in various medical procedures, for example, angioplasty, stent implantation, etc. The balloons include without limitation PTA and PTCA balloons. The method of manufacturing the balloon of the present disclosure includes usage of a heating apparatus and a moulding machine. The moulding machine works on a vacuum formation technology via which a balloon is manufactured from a preform. The balloon, formed from the process as per the teachings of the present invention, has a unitary structure as described below. In an embodiment, the heating apparatus is used for heating a preform up to a predefined temperature. Thereafter, the moulding machine stretches the preform in a longitudinal direction and expands the stretched preform to give it a desired shape. In an embodiment, the moulding machine employs a vacuum formation technique to inflate the preform into a desired shape.
[23] Now referring to figures, Fig. 1 depicts a balloon 100. The balloon 100 is a medical device used in medical procedures, such as, angioplasty, stent implantation, etc. The balloon 100 is configured to dilate or widen narrowed or obstructed blood vessels, restoring blood flow to the affected area. The balloon 100 has a crimped profile and an expanded profile (not shown). To deliver the balloon 100 in the affected area, the balloon 100 is maintained in the crimped profile. The balloon 100 is inflated/expanded when it reaches target site i.e., affected area. Once, the balloon 100 reaches the target site, the balloon 100 is inflated to press the plaque against the arterial walls and open up the vessel.
[24] The balloon 100 includes a distal end 100a and a proximal end 100b with a plurality of segments interspersed there between. In an embodiment, the balloon 100 includes five segments, a first segment ‘F’, a second segment ‘S’, a third segment ‘T’, a fourth segment ‘S’ and a fifth segment ‘F’. In an exemplary embodiment, the balloon 100 is horizontally symmetrical, therefore, a first segment ‘F’ and a fifth segment ‘F’ are similar. Similarly, a second segment ‘S’ and a fourth segment ‘S’ are also similar.
[25] In an embodiment, the first segment ‘F’ is located at the distal end 100a of the balloon 100. The first segment ‘F’ has a tubular shape. Similarly, the fifth segment ‘F’ is located at the proximal end 100b of the balloon 100. The fifth segment ‘F’ also, has a tubular shape. The first and fifth segment ‘F’ of the balloon 100 can be used to couple the balloon 100 with a catheter (not shown).
[26] In an embodiment, the second segment ‘S’ is distally connected to the first segment ‘F’ and proximally connected to the third segment ‘T’. The second segment ‘S’ is tapered in shape. Similarly, the fourth segment ‘S’ is distally connected to the third segment ‘T’ and proximally connected to the fifth segment ‘F’. The fourth segment ‘S’ is also tapered in shape. The taper shape of the second segment ‘S’ and the third segment ‘T’ of the balloon 100 allow easier and smooth expansion of the balloon 100 within the body vessels, for example, arteries, etc. Further, the gradual taper may help the balloon 100 pass through narrow or delicate structures with reduced resistance. The taper shape also helps in uniform distribution of air inside the balloon 100 during the expansion of the balloon 100.
[27] In an embodiment, the third segment ‘T’ is distally connected to the second segment ‘S’ and proximally connected to the fourth segment ‘S’. The third segment ‘T’ is cylindrical in shape. The cylindrical shape ensures consistent contact between the surface of the balloon 100 and the inner walls of the blood vessel. The cylindrical shape of the third segment ‘T’ of the balloon 100 allows the balloon 100 to exert uniform pressure against the wall of blood vessels. Optionally, the third segment ‘T’ can be used to mount a medical device, for example, a stent (not shown), on the balloon 100.
[28] The balloon 100 is a unitary structure made from a single preform ‘P’. That is, the complete balloon 100 is manufactured in one piece at the same time by application of a uniform vacuum pressure, eliminating the need to add additional process of bonding two halves of a balloon 100. The preform ‘P’ may be made of one or more of a medical grade polymers including but not limited to polyethylene terephthalate (PET), polyurethane (PU), nylon (11,12), polyethylene, chronoprene 25A, Polyvinyl Chloride (PVC) etc. In an embodiment of the present invention, the preform ‘P’ is made of nylon 12 for the formation of balloon 100. The method of manufacturing the balloon 100 of the present disclosure includes usage of a heating apparatus, and a moulding machine as described below. The balloon 100 manufactured by the process as per the teachings of the present invention suffers negligible cracks, fatigue or ruptures as axial stresses induced in the balloon 100 are very less due to use of vacuum forming technique. Further, the manufacturing process as per the teachings of the present invention is cost-effective as the process does not require compressed nitrogen gas. The process leads to increased productivity as balloon 100’s rejection rate is very low. Further, the manufacturing process as per the teachings of the present invention yields a balloon 100 having a uniform thickness and better Cpk value.
[29] The balloon 100 may have a uniform thickness. The thickness of balloon 100 ranges from 25µ to 62µ. In an exemplary embodiment, the balloon 100 has a thickness of 36µ-42 µ. The balloon 100 may have an overall length ranging from 8 mm to 40 mm. In an exemplary embodiment, the balloon 100 has a length of 28 mm.
[30] In an embodiment, the tensile strength of the balloon 100 may range from 12kg/cm2 to 38 kg/cm2. In an embodiment, the tensile strength of the balloon 100 is greater than 22 kg/cm2.
[31] Fig. 2 illustrates a flowchart of a method 200 for manufacturing the above-described balloon 100.
[32] At step 201 of the said method 200, a preform ‘P’ is mounted on a mandrel 130, and placed inside a heating apparatus 110 (as shown in fig. 3a). Fig. 3a shows a heating apparatus 110 and Fig. 3b shows an exploded view of the heating apparatus 110. The heating apparatus 110 having one or more heating elements, is configured to heat the preform ‘P’. In an embodiment, the heating apparatus 110 includes two heating elements, a heating element 110a and a heating element 110b. The heating element 110a includes a semi-circular elongated heating surface ‘H’. Similarly, the heating element 110b also includes a semi-circular elongated heating surface (not shown). In an exemplary embodiment, the heating element 110a and the heating element 110b are symmetrical. The heating element 110a and the heating element 110b are configured to couple with each other, such that, the two semi-circular heating surfaces ‘H’ forms a hollow cylindrical space. The hollow cylindrical space formed due to coupling of two heating surfaces ‘H’ is utilized to place the preform ‘P’, for heating.
[33] Along with the heating apparatus 110, a mandrel 130 and a holder 135 is provided. The mandrel 130 is used to mount a preform ‘P’ on it which in turn is processed into the balloon 100. In an embodiment, the mandrel 130 has a cylindrical shape. The mandrel 130 has a diameter ranging from 0.2mm to 0.5mm depending upon diameter of balloon to be fabricated. In an embodiment, the diameter of the mandrel 130 is 0.3 mm. The mandrel can be made form stainless steel.
[34] The holder 135 is used to hold the preform ‘P’ mounted on the mandrel 130 during the, for example, heating of the preform ‘P’, stretching of the preform ‘P’, etc. The holder 135 can be a cap having a cavity. The dimensions of the cavity are selected such that the mandrel 130 can easily pass through. In an embodiment, the cavity in the holder 135 is configured to hold the mandrel 130 on which the preform ‘P’ is mounted.
[35] The preform ‘P’ is heated inside the heating apparatus 110, at a first pre-defined temperature for a first pre-defined time period. In an embodiment, the first predefined temperature and first predefined time period vary depending upon the material of preform ‘P’. For example, if the preform ‘P’ is made up of polyethylene material, the preform ‘P’ is heated at the first predefined temperature ranging from 35 °C to 65 °C for the first predefined time period ranging from 45 seconds to 60 seconds. Alternately, if the preform ‘P’ is of nylon 12 material, the preform ‘P’ is heated at the first predefined temperature ranges from 35 °C to 95 °C for the first predefined time period ranging from 75 seconds to 90 seconds. The preform ‘P’ is heated to improve its plasticity and facilitate the stretching process. Heating the preform ‘P’ softens the polymer material, allowing the polymer chains to move more freely, reducing their viscosity and enhancing the stretchability of the preform ‘P’ making it easier to shape.
[36] Post heating, at step 203 of the said method 200, the preform ‘P’ is removed from the heating apparatus 110.
[37] At step 205 of the said method 200, the heated preform ‘P’ mounted on the mandrel 130 with the holder 135, is placed inside a mould ‘M’ of a moulding machine 120. Fig. 3c shows the moulding machine 120, in an exemplary embodiment. The moulding machine 120 is configured to provide longitudinal and radial stretch to the preform ‘P’, according to an embodiment. In an embodiment, the moulding machine 120 includes two moulding elements, a moulding element 120a and a moulding element 120b. The moulding element 120a includes a cavity ‘C1’. Similarly, the moulding element 120b includes a cavity ‘C2’. In an exemplary embodiment, the moulding element 120a and the moulding element 120b are symmetrical, similarly the cavities C1 and C2 are also symmetrical. The moulding element 120a and the moulding element 120b are configured to couple with each other, such that, the two cavities C1 and C2 when combined, form the mould ‘M’. The mould ‘M depicts a shape, similar as of the balloon 100, so as to give the preform ‘P’ the shape of the balloon 100. The mould ‘M’ thus formed due to coupling of two cavities C1 and C2 encloses the preform ‘P’, for longitudinal and radial stretching of the preform ‘P’. The moulding machine 120, also includes a heater (not shown) to generate heat inside the mould ‘M’.
[38] At step 207 of the said method 200, the heated preform ‘P’ is reheated from the first predefined temperature to a threshold temperature in a second predefined time period inside the moulding machine 120. Simultaneously, the preform ‘P’ is subjected to a longitudinal stretching operation inside the moulding machine 120. The preform ‘P’ is stretched up to a predefined length. The predefined length may vary between 25 to 30% of the actual length of the preform ‘P’. In an exemplary embodiment, the preform ‘P’ is increased about 27.5% of the actual length of the preform ‘P’ (% increase in length is denoted as ‘L’ and depicted in Fig. 3d and 3g). For stretching the preform ‘P’, the preform ‘P’ is positioned under a stretching rod (not shown) of the moulding machine 120. The stretching rod stretches the preform ‘P’ according to the desired mould ‘M’ length.
[39] In an embodiment, the threshold temperature and the second predefined time period may vary depending upon the material of preform ‘P’. For example, if the preform ‘P’ is made up of polyethylene material, the preform ‘P’ is heated up to the threshold temperature ranging from 90 °C to 120 °C in the second predefined time period ranging from 30 seconds to 45 seconds. Alternately, if the preform ‘P’ is of nylon 12 material, the preform ‘P’ is heated up to the threshold temperature ranging from 95 °C to 135 °C in the second predefined time period ranging from 45 seconds to 60 seconds. The longitudinal stretching aligns the polymer chains of the preform ‘P’, improving the orientation of the preform ‘P’. As a result, the preform ‘P’ has enhanced mechanical properties, such as, increased tensile strength. Longitudinal stretching also helps to control the wall thickness and overall geometry of the end product i.e., balloon 100, ensuring uniform distribution of material throughout the balloon 100.
[40] The force applied for longitudinally stretching the preform ‘P’ ranges from 4 bar to 10 bar. In an embodiment, the force applied for longitudinally stretching the preform ‘P’ is 5 bar to 6 bar.
[41] Post longitudinal stretching operation, at step 209, the longitudinally stretched preform ‘P’ is subjected to vacuum suction force for radially expanding the preform ‘P’, inside the moulding machine 120. In an exemplary embodiment, the moulding machine 120 includes a plurality of vacuum channels 121. The plurality of vacuum channels 121 are provided to create vacuum inside the mould ‘M’ once the plurality of vacuum channels 121 are coupled to respective vacuum ports 123 of the mould ‘M’.
[42] The vacuum suction force is generated in the mould ‘M’ of the moulding machine 120 through the plurality of vacuum channels 121 and the vacuum ports 123 via the external vacuum forming device. Due to the vacuum suction force created inside the mould ‘M’ via the vacuum ports 123, the pre-heated and longitudinally stretched, preform ‘P’ is pulled towards the inner surface of the mould ‘M’ till the desired shape of the balloon 100 is obtained. The vacuum suction pressure ranges from 10-1Pa to 10-6Pa. In an embodiment, the vacuum suction pressure may vary depending upon the material of the preform ‘P’. For example, for a preform ‘P’ made up of nylon 12, vacuum suction pressure ranges from 10-2Pa to 10-4Pa. The use of vacuum formation technique results in lower axial stresses as the balloon 100 is not inflated under pressure. The balloon 100, thus formed, has greater structural integrity and durability and reduced internal strain along its length, thereby reduced fringe patterns, too. Henceforth, the chances failure of balloon 100 due to fatigue and bursts are reduced.
[43] In an embodiment, the post moulding, holding time may vary depending upon the material of the preform ‘P’. For example, if the preform ‘P’ is made of polyethylene material, the preform ‘P’ is held, for 30 to 45 seconds. Similarly, if the preform ‘P’ is made from nylon 12 material, the preform ‘P’ is held, for 45 to 60 seconds.
[44] Post step 209, the mould M and thereby the balloon 100 inside the mould M is immediately cooled with the help of, for example, chilled water. The cooling cycle may be repeated more than once to attain the desired temperature of the balloon 100.
[45] In an embodiment, the balloon 100 is kept in the moulding machine 120 for a total time period ranging from 300 seconds to 420 seconds, this includes a total time taken to carry the process, such as, longitudinally stretching, radially stretching, holding and cooling etc inside the moulding machine 120. At step 211 of the said method 200, the balloon 100 is removed from the moulding machine 120 (depicted in Fig. 3f).
[46] The entire process of manufacturing the balloon 100 may be facilitated by a robotic arm ‘R’ (depicted in Figs. 3g and 3h). Fig. 3g and 3h depicts diagrammatic illustration of the manufacturing setup. The heating apparatus 110 and the moulding machine 120 are mounted on a rotary table ‘Y’. After each step are performed, the rotary table ‘Y’ rotates, so that the required device (a heating apparatus 110 or a moulding machine 120) is aligned with the robotic arm ‘R’. The robotic arm ‘R’, holds the holder 135 and inserts/removes the preform ‘P’ and/or the balloon 100, as required. Fig. 3g and 3h includes two moulding machines 120, mounted on the rotary table ‘Y’ to illustrate the process of longitudinal stretch and radial stretch, separately. In an exemplary embodiment, the process of longitudinal stretch and radial stretch is carried out in the same moulding machine 120.
[47] The proposed method uses a vacuum forming technique. A vacuum suction is used to shape and mold the preform ‘P’, creating the desired balloon shape. The use of vacuum suction results in lower axial stresses as the balloon is not inflated under pressure. The balloon, thus formed, has greater structural integrity and durability and reduced internal strain along its length, thereby reduced fringe patterns, too. Henceforth, the chances of balloon failure due to fatigue and bursts are reduced.
[48] 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 teachings of the present invention is/are used. , Claims:WE CLAIM
1. A method (200) of manufacturing a balloon (100), the method (200) comprises of:
a. heating a preform ‘P’ at a first predefined temperature, for a first predefined time period;
b. stretching the heated preform ‘P’ in a longitudinal direction up to a predefined length, while simultaneously increasing the temperature up to a threshold temperature in a second predefined time period; and
c. subjecting the stretched preform ‘P’ to a vacuum suction force for radially expanding the preform ‘P’ thereby, forming a balloon (100),
wherein the balloon (100), thus formed, has a unitary structure.
2. The method (200) as claimed in claim 1, wherein the balloon (100) is made of one or more of polyethylene terephthalate, polyethylene, polyurethane, nylon (11,12), chronoprene 25A and Polyvinyl Chloride (PVC).
3. The method (200) as claimed in claim 1, wherein post radially expanding the balloon (100), the method 200 includes cooling the balloon (100).
4. The method (200) as claimed in claim 1, wherein the balloon (100) includes a uniform thickness, wherein the thickness of the balloon (100) ranges from 36µ to 42µ.
5. The method (200) as claimed in claim 1, wherein the first predefined temperature ranges from 35 °C to 95 °C.
6. The method (200) as claimed in claim 1, wherein the first predefined time period ranges from 75 seconds to 90 seconds.
7. The method (200) as claimed in claim 1, wherein the threshold temperature ranges from 95 °C to 135°C.
8. The method (200) as claimed in claim 1, wherein the second predefined time period ranges from 45 seconds to 60 seconds.
9. The method (200) as claimed in claim 1, wherein the vacuum suction pressure ranges from 10-2Pa to 10-4Pa.
10. The method (200) as claimed in claim 1, wherein stretching the heated preform ‘P’ in the longitudinal direction includes stretching the heated preform ‘P’ in the longitudinal direction by applying a force ranging from 5 bar to 6 bar.