An orthopedic immobilizer device

Abstract

The present invention discloses an orthopedic immobilizing device designed to stabilize fractured or injured body parts, comprising a hollow tube (100) with a top layer (200), bottom layer (400), and a pre-molded thermoplastic middle layer (300) positioned there between. The device utilizes a thermoplastic sheet, which having 4–10 carbon atoms, cross- linked with 5.0–95.0 wt% of a second polymer blend containing a thermoplastic liner (10.0– 90.0 wt%) and functional fillers. The material is processed at a melting temperature range of 50–80°C, molded into a sheet, and subsequently cooled to enable conformal shaping over the body part.

Description

[0001] Title - AN ORTHOPEDIC IMMOBILIZER DEVICE

[0002] FIELD OF THE INVENTION:

[0003] The present invention relates to a device for an orthopedic immobilizer. More particularly the present invention relates to a method for preparation thermoplastic sheet for the device for an orthopedic immobilizer.

[0004] BACKGROUND OF THE INVENTION:

[0005] An orthopedic immobilizer is a medical device used to stabilize a limb or a joint following an injury or surgical procedure. Injured bones, ligaments, tendons and more will incur further damages if the affect-ted areas aren’t immobilized. Immobilization is necessary for an orthopedic injury to heal properly. Immobilized material has slowly revolutionized since 3000 BCF from traditional plaster to modem day synthetic casing tape, including other sustainable immobilization material. These materials have been evolved, the traditional plaster still remains a material of choice owing to skin conform ability, low cost and availability.

[0006] Immobilization device for orthopedics is already known whereby a transformable material is embedded in a fabric that is provided with zipper, with this known immobilization device a two component plastic is taken which must be mixed to create a chemical reaction in order to obtain a hardening of the mixture. Plaster of Paris casts, however, have a number of attendant disadvantages, including a low strength-to-weight ratio, resulting in a finished cast which is very heavy and bulky. In addition, plaster of Paris casts develop their strength over a relatively long period of time, thus making it necessary to avoid weight bearing situations for up to 24 to 48 hours. Furthermore, plaster of Paris casts typically disintegrate in water, thus making it necessary to avoid bathing, showering, or other activities involving contact with water.

[0007] A significant advancement in the art was achieved when synthetic polyisocyanate prepolymers were found to be useful in formulating a resin for orthopedic casting materials. Typical commercially available synthetic orthopedic casting materials comprise a knit fiberglass fabric backing impregnated with a polyisocyanate prepolymer resin. These orthopedic casting materials can provide significant advancement over the plaster of Paris casts, including a higher strength-to-weight ratio. However, knitted fiberglass backings of conventional casting articles may become quite rough when cured and often produce casts with sharp edges. The sharp edges can cause skin abrasions and / or snag clothing. As a result, the health care worker has had to employ padding materials at the edges to attempt to avoid contact of the casting article with the skin.

[0008] In the art a wide variety of plastic materials has been used in the casting of orthopedic structures, rehabilitation technique aids, radiation therapy fixation and imaging fixation. However, only a few of these known materials are suitable for direct moulding to the patients' body because of their low melting temperature and good mould ability and elasticity in the molten state. The majority of the engineering plastics have a melting temperature which is above 100° C. These materials may be suitable for use in immobilization structures as well, provided they are moulded to a positive mould corresponding to the part of the patients' body that needs immobilization. The use of such materials however involves the additional step of making the positive mould.

[0009] U. S. Pat. No. 5,584,800 disclosed technique in which a knit fiber glass fabric is impregnated with a polyurethane resin, presents the disadvantages that fiber glass insufficiently adapts to the fine structure of the body and besides this often obstructs x- rays, thus interfering with the x-ray image. Polyester fabrics used instead of glass fiber fabric show an inferior strength-to-weight ratio. According to the noted patent, other known fixation devices are made of a thermoplastic material, which is heated to a temperature above its softening point and then moulded over the body part to be immobilized, to provide the best fit to this body part.

[0010] Still other known immobilization devices are made of plastic material with higher melting temperatures, e.g. polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) which is molded into a standard shape, and made available in a single size or a few sizes. To allow some adaptation to the body part and to provide for an improved fit, the device comprises for example Velcro® strips, with which parts of the device may be pulled towards each other and releasable fixed in that position. These immobilization devices however present insufficient fit and insufficient comfort. The insufficient fit entails the risk that the immobilization provided is insufficiently adequate and accurate. To address the limitations associated with conventional polymers such as polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) which, although generally inert, are not well-suited for prolonged skin contact, require high processing temperatures, and may pose a risk of skin irritation the present invention provides an improved immobilization system. This system comprises a thermoplastic sheet fabricated from a novel combination of biodegradable polymers, specifically selected for their ability to soften at relatively low temperatures approximately 60°C. This material formulation enables direct, hand-moldable application to the patient’s body without specialized equipment, thereby facilitating rapid, patient-specific customization. Additionally, the polymer blend is biocompatible, safe for extended dermal contact, and derived from renewable resources, offering an environmentally sustainable alternative to conventional petrochemical-based materials.

[0011] The present invention providing a new immobilization system which is very quick ideally can be set up within 5-10 mins to save healthcare professional’s time, without any tedious procedure and it should be more hygienic, safe and comfortable for the patient as well. An immobilization device which is suitable for use in a wide variety of applications, for example orthopaedics, physical rehabilitation, diagnostic imaging and radiation therapy and podiatry. It is further the aim of the present invention to provide an immobilization device which shows an improved adaptability to the body part that needs immobilization and to the position in which the body part is to be immobilized.

[0012] SUMMARY OF THE INVENTION:

[0013] The main objective of the present invention to provide an orthopedic immobilizer device comprising; a.) a hollow tube (100) having a top layer (200) and a bottom layer (400); b.) a middle layer (300) is arranged between a top layer (200) and a bottom layer (400) of the a hollow tube (100); wherein, the middle layer (300) is pre-molded thermoplastic sheet; c.) top layer (200) including respective edge regions (202) that are aligned and configured to attach with corresponding respective edge regions (402) of the bottom layer (400); which create hollow shape (403) to fix the middle layer (300) into the bottom layer (400). Another object of the present invention to provide an orthopedic immobilizer device wherein a hollow tube (100) involving polygon matrix lattice (101) for admitting air to the skin and allowing sweat to evaporate.

[0014] Another object of the present invention to provide an orthopedic immobilizer device wherein top layer (200) and a bottom layer (400) are hydrophobic, made from silicone rubber.

[0015] Another object of the present invention to provide an orthopedic immobilizer device wherein top layer (200) and a bottom layer (400) having thickness 0.5 mm to 2.0 mm.

[0016] Further object of the present invention to provide a thermoplastic sheet comprises: a. Component A at least one thermoplastic polymer having 4-10 carbon atoms is present in amount of 5.0 % to 95.0 %w / w;

[0017] R is -CH3, -OH, -CH3CH2CHOHCH3

[0018] R1is - (CH2)5OCH3, -CH2CH (CH3) OH, - (CH2)4COO (CH2)2OH, -CH3b. Component B blend of polymers is present in amount of 10.0 to 90.0 %w / w ; c. Component C mixture of fillers are present in amount of 5% to 25% w / w; d. Component D additive selected from acrylic oligomer epoxy group is present in amount of 0.5% to 2.0%w / w; e. Component E biodegradable thermoplastic starch selected from corn, potato and cassava is present in amount of 10% to 60% w / w.

[0019] Another object of the present invention to provide thermoplastic sheet where in component A thermoplastic polymer having 4-10 carbon atoms selected from polycaprolactone, polyethylene adipate, polyhydroxybutyrate, polyvinyl acetate.

[0020] Another object of the present invention to provide thermoplastic sheet where in component B where in mixture of polymer with thermoplastic liner selected from polylactic acid and polybutylene adipate-co-terephthalate, blend of Poly(hexylene succinate) and polylactic acid, blend of polylactic acid and Polyethylene glycol, blend of Polybutylene Succinate and polybutylene adipate-co-terephthalate. Another object of the present invention to provide thermoplastic sheet for orthopedic immobilizer device having which is molded by injection method at 60°C.

[0021] Another object of the present invention to provide comfort to the patient and higher flexibility and reduced rigidity.

[0022] Yet another object of the invention to provide an orthopaedic immobilizer device which is washable and allows patient to maintain skin hygiene. Moreover, said immobilizer device provides convenience for doing day to day work during treatment.

[0023] Yet another object of the present invention is a method for forming a matrix orthopedic Immobilizer for immobilizing a body of a patient to allow healing.

[0024] Yet another object of the present invention is to provide a method for producing an orthopedic immobilizer device having thermoplastic sheet comprising following steps: a. blend component A, component B, component C and component D and E melt atl50- 180 °C; b. mold the above blended mixture into the thermoplastic sheet by injection method at a 165-170 °C; c. arrange the thermoplastic sheet between a top and a bottom layer of silicone rubber and cure the assembly at a temperature range of 120-180 °C to obtain the final thermoplastic orthopedic immobilizer device.

[0025] Yet another object of the present invention is to provide the thermoplastic sheet, which is biodegradable and re-moldable at low temperatures.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS:

[0027] The objects, features and advantages of the invention will best be understood from the following description of various embodiments thereof, selected for purposes of illustration, and shown in the accompanying figures.

[0028] Figure 1 - Isometric view of the assembled thermoplastic immobilizer device. Figure 2 - Isometric view of the thermoplastic immobilizer device showing the top layer, middle layer, and bottom layer.

[0029] Figure 3 - Exploded view of the thermoplastic immobilizer device showing the top layer, middle layer, and bottom layer.

[0030] Figure 4 - Cross-sectional side view illustrating the positioning of the central attachment interfaces and fixation members.

[0031] DETAILED DESCRIPTION OF THE INVENTION:

[0032] The present invention is to provide an orthopedic immobilizing device for immobilizing fractured or injured body parts which comprises thermoplastic sheet which is mouldable at a temperature that can be supported by the body.

[0033] Thermoplastic materials are formable when heated and acquire rigidity when cooled. Fillers, elastomers and resins like polycaprolactone are added into thermoplastics to increase memory, stiffness, durability and mold ability, while inorganic fillers improve the rate of cooling and heating. The application procedure of thermoplastic casts is similar to that of plaster but the present invention provides cleaner working conditions compared to plaster casting. In the present invention thermoplastic sheet which is coated between top and bottom layer of silicone rubber reheated at relatively low temperatures for remolding to alter the cast position without removal, enhancing their cost benefit.

[0034] The present invention is to provide a device wherein top layer and bottom layer of immobilizer form a polygon hollow and interconnected tube wherein top layer and bottom layer is made up from synthetic polymer. Moreover, top layer and bottom layer moulded with each other to create cavity said a polygon hollow tube. The shape of top layer and bottom layer can be any matrix polygon selected from rectangle, pentagon, octagon, triangle, rhombus, circle; but most preferable shape is hexagon matrix.

[0035] The hexagon shape defines as a shape or a plane having equal or unequal six straight sides and angles. The advantage of hexagon shape is matrix arrangement of said hexagon provides maximum strength and minimizes use of material. In the present invention the position, fixation, mobilization of immobilization device is for one or more body parts. Wherein the device comprises a sheet of thermoplastic material, which is used in numerous medical applications such as rehabilitation and orthopedics, for the immobilization of injured ligaments, muscular or bone structure. The device has been moulded into a desired shape. The said device minimizes of consumption of time and moulded to certain degree to take shape of any body part.

[0036] In one embodiment, as illustrated in Figure 2, there is provided an exploded view of a thermoplastic immobilizer device comprising the middle layer (300), being a pre-molded thermoplastic sheet, is shaped to conform to the anatomical profile of the limb or body part to be immobilized. The thermoplastic material is selected for its biocompatibility, high strength-to-weight ratio, and thermal formability, allowing for pre-configuration during manufacturing to match specific orthopedic applications. The use of a pre-molded configuration eliminates the need for on-site shaping or custom molding, thereby reducing application time and ensuring repeatable fit and function.

[0037] The top layer (200) is provided with respective edge regions (202), which are precisely aligned and configured to mate with corresponding edge regions (402) of the bottom layer (400). Upon engagement, these aligned edge regions collectively define a hollow shape (403), within which the middle layer (300) is securely positioned. This hollow structure (403) not only ensures proper fixation of the middle layer (300) but also contributes to the mechanical integrity and stability of the overall device. The configuration prevents displacement or shifting of the middle layer during use, thereby maintaining consistent immobilization and patient support throughout the period of application.

[0038] The bottom layer (400) is structurally enhanced with integrally formed retention features that interact with the middle layer (300), securing it in a fixed position within the hollow cavity (403). These structural hollow shape prevent axial and lateral displacement of the thermoplastic insert during dynamic movements or external forces encountered in clinical use.

[0039] The orthopedic immobilizer device may further incorporate fastening elements or bonding features at the mating edge regions (202, 402), such as mechanical interlocks, ultrasonic welds, or medical-grade adhesives, to ensure a secure and tamper-resistant assembly. These joining mechanisms enhance the device's durability and reduce the risk of delamination or layer separation during prolonged use.

[0040] Additionally, the internal cavity defined by the hollow structure (403) can be designed to allow for controlled ventilation and moisture management around the middle layer (300), thus improving wearer comfort and reducing the risk of skin maceration. The geometry of the hollow tube (100), combined with the material selection and integrated structural features, results in a lightweight, ergonomic, and functionally robust orthopedic immobilizer suitable for clinical and ambulatory settings.

[0041] The layered configuration — with the thermoplastic middle layer (300) sandwiched between the top and bottom structural layers — allows for modular construction and customization of the immobilizer device. This configuration contributes to improved mechanical performance, patient comfort, and anatomical conformity.

[0042] The design is particularly suited for orthopedic applications where temporary or semipermanent immobilization of limbs or joints is required, such as in fracture management, post-operative recovery, or soft tissue support. The use of thermoplastic materials permits thermoforming, allowing the device to be re-moulded or reshaped during application for patient-specific fitment.

[0043] The present invention is to provide a device wherein polygon hollow tube provides equal distribution of curable liquid or gel throughout the said immobilizer without bubble formation. Polygon hollow tube provides less surface tension so that fluid flows easily into said tube. Polygon shape of tube prevents tubes from collapsing and improves structural strength of said apparatus. Matrix form of said polygon provides structural strength as each edge and each corner of said polygon rigidly attached with another adjacent polygon and provide strong bond with each other. The top layer and the bottom layer of an immobilizer are hydrophobic.

[0044] One of the embodiments of the present invention is to provide an immobilizer having polygon matrix shape which is admitting air to the skin and allowing sweat to evaporate. Different colors of pigments are mixed with synthetic material and composition of thermoplastic material for achieving aesthetic appearance. A novel immobilization system which very quick ideally can be set up within 5-10 mins to save healthcare professional’s time without any messy procedure and also more hygienic, safe and provide more comfort to the patient.

[0045] In the present invention, the use of medical-grade silicone rubber in the construction of the orthopedic immobilizer offers significant functional advantages. The silicone rubber inherently resists water retention and inhibits the growth of fungi and bacteria, thereby enhancing the device’s hygiene and suitability for prolonged clinical use. Additionally, due to its inherent elasticity, the prefabricated immobilizer exhibits stretch ability, enabling it to conform to a wide range of anatomical variations and skin contours, thus accommodating different limb sizes without compromising fit or comfort.

[0046] The top layer (200) and bottom layer (400) of the device, both formed from silicone rubber, serve as protective and adaptive interfaces for the thermoplastic middle layer (300). These layers provide structural flexibility and cushioning, which facilitates the even distribution of pressure during application and enhances patient comfort. Moreover, the elasticity of the silicone layers aids in retaining the thermoplastic core in place during reheating and molding, ensuring uniform adaptation to the body while maintaining the mechanical integrity of the assembly during use.

[0047] The present invention is to provide an immobilizer having polygon shape hollow tubes which provide more stretchability, stable structure and geometric advantages of polygon shape hollow tubes provides more deformation to the immobilizer. For an example, most preferably shape of hollow tubes of immobilizer is hexagon. If one can stretch a hexagon shape hollow tube then it configures a shape of rectangle which provides more stretchability; whereas if one can stretch a rectangular shape of hollow tube then it will destroy the structure. So that, polygon shape hollow tube provides more stable structure.

[0048] The present invention disclosed a method of preparation of thermoplastic sheet by blending polycaprolactone with other polymers and through the utilization of a twin extruder machine. Subsequently, the resulting composite materials are shaped into a hexagonal form via an injection molding machine. Following this, the prepared sheet is positioned within a mold to generate a sheath by introducing silicone rubber material onto the external surface. The structure is securely held within the mold for sheathing. The silicon rubber cure after applying the temperature. According to the embodiment of the present invention thermoplastic sheet is prepared from comprises following; a. Component A at least one thermoplastic polymer having 4-10 carbon atoms is present in amount of 5.0 % to 95.0 %w / w;

[0049] R is -CH3, -OH, -CH3CH2CHOHCH3

[0050] R1is - (CH2)5OCH3, -CH2CH (CH3) OH, - (CH2)4COO (CH2)2OH, -CH3b. Component B blend of polymers is present in amount of 10.0 to 90.0 %w / w; c. Component C mixture of fillers are present in amount of 5% to 25% w / w; d. Component D additive selected from acrylic oligomer epoxy group is present in amount of 0.5% to 2.0%w / w; e. Component E biodegradable thermoplastic starch selected from corn, potato and cassava is present in amount of 10% to 60% w / w.

[0051] In the present invention compound A is thermoplastic polymers derived from monomer units containing 4 to 10 carbon atoms are generally classified as aliphatic polyesters or polyolefins. These materials exhibit thermo reversible behavior, whereby they soften upon heating and resolidify upon cooling without undergoing substantial chemical transformation. This characteristic enables their suitability for multiple cycles of thermal processing and reshaping.

[0052] Thermoplastic polymers composed of monomer units with 4 to 10 carbon atoms exhibit a range of melting points, typically between 60°C and 180°C, contingent upon their molecular architecture. Aliphatic polyesters such as polycaprolactone (PCL), polylactic acid (PLA), and polyhydroxyalkanoates (PHAs) demonstrate inherent biodegradability, whereas polyolefins within this carbon range are generally non-biodegradable. Their mechanical performance is influenced by factors such as crystallinity and molecular weight, with higher carbon content often contributing to enhanced flexibility and reduced glass transition temperatures. These polymers are extensively utilized in applications including medical devices, orthopedic immobilizers, biodegradable packaging films, and additive manufacturing (3D printing). Owing to their tunable thermal and mechanical properties, along with favorable biocompatibility and low-temperature processability, they present a sustainable alternative to conventional petroleum-based thermoplastics in both biomedical and environmental contexts.

[0053] In the present invention thermoplastic polymer having 4-10 carbon atoms selected from polycaprolactone, polyethylene adipate, polyhydroxybutyrate, polyvinyl acetate, a blend of one of these materials with another polymer, co-polymers or blends or combinations of two or more of these materials.

[0054] Polycaprolactone (PCL) is semi-crystalline aliphatic polyester obtained via the ringopening polymerization of 8-caprolactone. It is characterized by a low melting temperature in the range of approximately 58-62 °C and a glass transition temperature near 60 °C, conferring significant flexibility and making it well-suited for thermoplastic applications that require low-temperature processing. PCL demonstrates outstanding biocompatibility, biodegradability, and mechanical integrity. Its degradation under physiological conditions proceeds slowly, primarily through hydrolytic cleavage of the ester bonds within its polymer backbone, enabling its use in long-term biomedical and orthopedic applications.

[0055] Polyethylene adipate (PEA) is biodegradable aliphatic polyester produced via the polycondensation reaction between ethylene glycol and adipic acid. Classified within the poly (alkylene adipate) family, PEA is characterized by its high flexibility, low glass transition temperature (Tg), and pronounced susceptibility to both hydrolytic and enzymatic degradation. Due to these properties, PEA has attracted considerable interest for use in biomedical, environmental, and packaging applications, particularly as a functional component in biodegradable polymer blends aimed at enhancing flexibility and degradability.

[0056] In the present orthopedic immobilization systems, polyhydroxybutyrate is primarily considered as a biodegradable reinforcement or matrix polymer. Its rigid, high-strength structure can be leveraged in splints or braces that require dimensional stability and mechanical integrity. However, due to its inherent brittleness, PHB is often blended with softer, more ductile polymers (such as PCL or polyethylene adipate) to enhance impact resistance and formability. polyhydroxybutyrate can also be incorporated into multi-layer composite structures, where it provides structural rigidity while other layers (e.g., silicone rubber or flexible thermoplastics) ensure comfort and adaptability. In the present invention compound B is blend of polymers blend of polylactic acid and polybutylene adipate-co-terephthalate, blend of Poly(hexylene succinate) and polylactic acid, blend of polylactic acid and Polyethylene glycol, blend of Polybutylene Succinate and polybutylene adipate-co-terephthalate.

[0057] Polylactic Acid (PLA) is a biodegradable thermoplastic polymer belonging to the class of aliphatic polyesters. It is primarily produced via ring-opening polymerization of lactide (a cyclic dimer of lactic acid) or through the direct polycondensation of lactic acid. Lactic acid, the fundamental monomer, is obtained from renewable, plant-based sources such as corn starch, sugarcane, or cassava, making PLA a bio-based and sustainable material.

[0058] In the present orthopedic immobilization systems, polybutylene adipate-co-terephthalate (PBAT) serves as a versatile material component due to its inherent flexibility, toughness, and biodegradability. It can function as a flexible matrix phase within multi-layer thermoplastic composites, enhancing conformability and patient comfort. Additionally, PBAT is frequently employed as a toughening modifier in blends with rigid biopolymers such as polylactic acid (PLA), effectively mitigating brittleness and improving impact resistance. In laminated structures, PBAT contributes to flexural durability, particularly in zones requiring localized deformation without material failure.

[0059] In the present invention mixture of Polylactic Acid and polybutylene adipate-co- terephthalate laminated with silicone layers and enhancing wearability while maintaining the device's structural function.

[0060] In the present invention compound C is fillers which are selected from calcium carbonate, barium sulfate, talc, fumed silica, titanium dioxide.

[0061] In the present invention a sheet of thermoplastic material for the production of immobilized device, where in the thermoplastic material heated between 50-80°C.

[0062] Polycaprolactone has excellent air permeability and low melting point thermo plasticity due to its hexagonal-like structure. This allows it to be easily reshaped by heating in hot water at 60-70 °C, making the process simple. Additionally, the cast of this invention is lightweight and thin compared to a conventional polyurethane cast, making it easier for the wearer to wear and use.

[0063] In the present invention mixture of polycaprolactone (PCL) or PLA-based blends, soften at moderate temperatures (typically 55-70 °C), enabling the liner to be directly molded to the patient's anatomy. These results in improved immobilization precision enhanced compliance with body contours and reduced need for prefabricated sizing.

[0064] In the present invention compound E is thermoplastic starch which is selected from corn starch, potato starch and cassava starch.

[0065] In the present invention, thermoplastic starch is employed as a biodegradable matrix material and may be blended with other biodegradable polymers such as polylactic acid (PLA), poly caprolactone (PCL), and polybutylene adipate-co-terephthalate (PBAT) to enhance its mechanical properties, flexibility, and resistance to moisture. This polymeric blend enables the formulation of composite materials with tunable performance characteristics, thereby rendering them suitable for orthopedic immobilization applications that require both structural integrity and conformability.

[0066] In the present invention the thermoplastic polymers (Component A), selected from aliphatic and copolymeric biodegradable polymers, provide thermal processability, enabling efficient fabrication via injection molding. These polymers also impart the necessary mechanical integrity, including tensile strength and flexibility, required for orthopedic immobilization applications.

[0067] In the present invention, the blend of polymers (Compound B) comprises a combination of polymers which help to low-melting and high-performance thermoplastic materials deliver and enhanced processability, mechanical strength, and flexibility. The formulation is designed to exhibit controlled thermal behavior suitable for low-temperature molding applications, while maintaining structural integrity and resilience under mechanical stress. Compound B enables uniform sheet formation with consistent thermoplastic response, making it particularly suitable for orthopedic immobilization devices requiring precise contouring and durable performance.

[0068] Inorganic fillers (Component C), such as calcium carbonate, talc, or titanium dioxide, are incorporated to modulate the density, rigidity, and dimensional stability of the final composition. These fillers also contribute to cost optimization and can enhance the surface finish and printability of the molded device.

[0069] The acrylic oligomer-based epoxy additives (Component D) act as reactive compatibilizers and mechanical modifiers. These low molecular weight functional oligomers facilitate interfacial adhesion between the hydrophilic starch matrix and hydrophobic polymer phases, resulting in improved phase dispersion, mechanical interlocking, and overall composite toughness. Furthermore, they assist in enhancing crosslink density under thermal or UV curing conditions, depending on the formulation, thereby improving mechanical resilience and long-term stability of the immobilizer.

[0070] The biodegradable thermoplastic starch (Component E) functions primarily as a bulkforming and environmentally degradable matrix within the composite system. It contributes to the overall biodegradability and reduces the reliance on petrochemical-based polymers, thereby enhancing the sustainability profile of the material.

[0071] The process of the preparation of thermoplastic sheet comprises following steps:

[0072] Step 1- blend component A, component B, component C and component D and E melt at 150-180 °C;

[0073] Step-2 mold the above blended mixture into the thermoplastic sheet by injection method at a 165-170 °C;

[0074] Step-3 arrange the thermoplastic sheet between a top and a bottom layer of silicone rubber and cure the assembly at a temperature range of 120-180 °C to obtain the final thermoplastic orthopedic immobilizer device.

[0075] Example 1: Process of the preparation of thermoplastic sheet

[0076] Process for preparation of thermoplastic sheet: As above mentioned

[0077] Example 2: Process of the preparation of thermoplastic sheet

[0078] Process for preparation of thermoplastic sheet: As above mentioned

[0079] Example 3: Process of the preparation of thermoplastic sheet Process for preparation of thermoplastic sheet: As above mentioned

[0080] Example 4: Process of the preparation of thermoplastic sheet Process for preparation of thermoplastic sheet: As above mentioned

[0081] Example 5: Process of the preparation of thermoplastic sheet

[0082] Process for preparation of thermoplastic sheet: As above mentioned

[0083] Evaluation of Thermoplastic Sheet Properties:

[0084] The thermoplastic sheet was subjected to a comprehensive battery of standardized tests to quantitatively assess its mechanical, thermal, physical, and functional performance parameters. All evaluations were carried out in accordance with established ASTM and ISO testing protocols, ensuring methodological reliability and regulatory compliance. The primary objective of these tests was to determine the material’s suitability for use in orthopedic immobilization applications.

[0085] • Tensile properties (ASTM D638): to determine ultimate tensile strength and elongation at break.

[0086] • Flexural modulus (ASTM D790): to evaluate bending stiffness and structural rigidity.

[0087] • Impact resistance (ASTM D256): to assess the material’s toughness under dynamic loading.

[0088] • Thermal softening behavior (Vicat softening point, ASTM DI 525): to characterize thermoformability range.

[0089] • Water absorption (ASTM D570): to assess dimensional stability in humid conditions.

[0090] • Biodegradability (ISO 14855): to measure disintegration and mass loss under controlled composting conditions.

[0091] The material's thermoformability was further validated through heating cycles where sheets were brought to their softening temperature (50-70 °C) and conformed to anatomical forms to simulate clinical molding. Subsequent mechanical evaluations confirmed dimensional stability and structural retention upon cooling, as well as reformability after multiple heating cycles.

[0092] Additional assessments were conducted to confirm clinical readiness, including:

[0093] • Sterilization resistance (autoclaving at 121 °C for 20 minutes): to ensure thermal and morphological integrity post-sterilization.

[0094] • Surface hardness (ASTM D2240): to validate material durability during prolonged use.

[0095] • Biocompatibility testing (ISO 10993-10): to rule out dermal irritation and ensure safe skin contact.

[0096] To reduce application time and improve clinical efficiency, the orthopedic immobilizer device of the present invention is pre-molded to a semi-anatomical shape corresponding to various body parts. These pre-formed devices, available in multiple sizes, can be selectively heated to a softening temperature sufficient to enable localized deformation. This allows final molding and conforming directly onto the specific anatomical region, ensuring a precise fit while minimizing the overall fabrication and fitting time.

[0097] The present invention relates to a thermoplastic orthopedic immobilizing device comprising a hollow structure (100) formed by a top layer (200) and a bottom layer (400), encapsulating a pre-moulded thermoplastic middle layer (300) composed of a polycaprolactone-based polymer blend. The top (200) and bottom (400) layers, made of medical-grade silicone rubber, are interlocked at respective edge regions (202, 402) and thermally cured at 120-180 °C to form a flexible, multi-layered assembly.

[0098] The cured device is reheated to its thermoplastic transition range (typically between 60- 70°C), rendering the middle layer sufficiently pliable for manual manipulation. The softened immobilizer is then applied over the injured anatomical region — such as a fractured limb or joint — and shaped to the patient's contour by the clinician. Upon cooling to ambient or body temperature, the device regains rigidity, maintaining its conformed shape to deliver targeted immobilization and anatomical support. This customized fit enhances patient comfort, minimizes secondary injury, and ensures effective orthopedic stabilization.

[0099] The present invention relates to a novel immobilization system designed for rapid deployment, with an ideal setup time of approximately 5 to 10 minutes, thereby significantly reducing procedural delays and optimizing the workflow for healthcare professionals. The system eliminates the need for complex or messy preparation steps, offering a clean, efficient, and user-friendly solution. It emphasizes improved hygiene, safety, and patient comfort by utilizing biocompatible, non-toxic materials and thermoplastic composites that conform to the patient's anatomy with minimal discomfort.

[0100] Furthermore, the immobilization device is engineered for versatility across a broad spectrum of clinical applications, including orthopedics, physical rehabilitation, diagnostic imaging, radiation therapy, and podiatry. The device exhibits enhanced anatomical adaptability, allowing precise conformation to the body part requiring immobilization and accommodating the specific positional requirements dictated by the clinical scenario. This adaptability is achieved through the use of thermoformable, multi-layered materials that maintain structural integrity while offering localized moldability, thereby ensuring both functional stability and patient-specific customization.

[0101] The thermoplastic immobilizer device of the present invention is engineered to enable adjustability and customization to accommodate patient-specific anatomical and clinical requirements. The device may be fabricated in a range of predefined sizes or alternatively provided as a universal-size blank, which may be thermoformed and selectively trimmed to conform to the patient’s morphology. The middle layer (300), composed of a thermoformable polymeric material, is capable of being reheated and re- moulded postinitial application, thereby facilitating adjustments in response to changes in limb dimensions, such as swelling reduction or fit optimization. In certain embodiments, the device permits partial disassembly, wherein the top layer (200) and / or bottom layer (400) may be selectively detached and replaced to allow for internal inspection, component hygiene, or replacement without complete device removal.

[0102] Furthermore, the edge bonding interfaces may incorporate adjustable tension features, such as snap-fit connectors or compression-based engagement elements, enabling ergonomic adjustment and patient comfort. The device may also be configured to support auxiliary components including, but not limited to, medical -grade padding, cryotherapy or thermal packs, and electronic sensor modules for real-time monitoring of therapeutic parameters such as temperature, pressure, or movement.

Claims

CLAIMSI / We Claim1. An orthopedic immobilizer device comprising: a. a hollow tube (100) having a top layer (200) and a bottom layer (400); b. a middle layer (300) arranged between a top layer (200) and a bottom layer (400) of the a hollow tube (100); wherein, the middle layer (300) is pre moulded thermoplastic sheet; c. top layer (200) including respective edge regions (202) that are aligned and configured to attach with corresponding respective edge regions (402) of the bottom layer (400); which create hollow shape (403) to fix the middle layer (300) into the bottom layer (400).

2. The orthopaedic immobilizer device claimed in claim 1, wherein a hollow tube (100) involving polygon matrix lattice (101) for admitting air to the skin and allowing sweat to evaporate.

3. The orthopaedic immobilizer device claimed in claim 1, wherein a hollow tube (100) having hexagonal shape.

4. The orthopaedic immobilizer device claimed in claim 1, wherein top layer (200) and a bottom layer (400) are hydrophobic.

5. The orthopaedic immobilizer device claimed in claim 1, wherein top layer (200) and a bottom layer (400) are made from silicone rubber.

6. The orthopaedic immobilizer device claimed in claim 1, wherein the middle layer (300) arranged into hollow tube (100) using an injection moulding.

7. The orthopaedic immobilizer device as claimed in claim 1, where in a top layer (200) and a bottom layer (400) having thickness 0.5 mm to 2.0 mm.

8. A thermoplastic sheet for orthopedic immobilizer device comprising; a. Component A at least one thermoplastic polymer having 4-10 carbon atoms is present in amount of 5.0 % to 95.0 %w / w;R is -CH3, -OH, -CH3CH2CHOHCH3R1is - (CH2)5OCH3, -CH2CH (CH3) OH, - (CH2)4COO (CH2)2OH, -CH3b. Component B blend of polymers is present in amount of 10.0 to 90.0 %w / w; c. Component C mixture of fillers are present in amount of 5% to 25% w / w; d. Component D additive selected from acrylic oligomer epoxy group is present in amount of 0.5% to 2.0%w / w; e. Component E biodegradable thermoplastic starch is present in amount of 10%to 60% w / w.

9. The thermoplastic sheet as claimed in claim 7, where in thermoplastic polymer having 4-10 carbon atoms selected from poly caprolactone, polyethylene adipate, polyhydroxybutyrate, polyvinyl acetate.

10. The thermoplastic sheet as claimed in claim 7, where in blend of polymers selected from blend of polylactic acid and polybutylene adipate-co-terephthalate, blend of Poly(hexylene succinate) and polylactic acid, blend of polylactic acid and Polyethylene glycol, blend of Polybutylene Succinate and polybutylene adipate-co-terephthalate.

11. The thermoplastic sheets as claimed in claim 7, where in fillers are selected from calcium carbonate, barium sulfate, talc, fumed silica, titanium dioxide.

12. The thermoplastic sheet as claimed in claim 7, where in biodegradable thermoplastic starch selected from corn, potato and cassava.

13. The thermoplastic sheet as claimed in claim 7, where in thermoplastic sheet is molded by injection method at 60°C.

14. The orthopedic immobilizer device having thermoplastic sheet as claimed in claim 7, wherein thermoplastic sheet having thickness between 1mm to 5mm.

15. A method for producing a thermoplastic sheet comprising following steps: a. blend component A, component B, component C and component D and component E melt atl50-180 °C;b. mold the above blended mixture into the thermoplastic sheet by injection method at a 165-170 °C; c. arrange the thermoplastic sheet between a top and a bottom layer of silicone rubber and cure the assembly at a temperature range of 120-180 °C to obtain the final thermoplastic orthopedic immobilizer device.

16. The thermoplastic sheet as claimed in claim 7, where in the thermoplastic sheet is biodegradable and re-moldable at low temperatures.

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