Krishna P. Baidya

Primary impetus for the development of composite materials for medical usage came from orthopedic implant application. In case of metal alloys stiffness mismatch causes stress shielding in applications such as bone plates, total hip replacement, and total knee replacement. Moreover, the metal alloys and ceramics are radio opaque, and in some cases they result in undesirable artifacts in X-ray radiography. In the case of polymer composite materials the radio transparency can be adjusted by… Show more

Primary impetus for the development of composite materials for medical usage came from orthopedic implant application. In case of metal alloys stiffness mismatch causes stress shielding in applications such as bone plates, total hip replacement, and total knee replacement. Moreover, the metal alloys and ceramics are radio opaque, and in some cases they result in undesirable artifacts in X-ray radiography. In the case of polymer composite materials the radio transparency can be adjusted by adding contrast medium to the polymer. More over the polymer composite materials are fully compatible with the modern diagnostic methods such as computed tomography (CT) and magnetic resonance imaging (MRI) as they are non-magnetic.
The current study reports the development of a radiolucent fiber reinforced polymer composite material for a biomedical device, Ilizarov external fixator. Material fabrication and characterization are described. Quantitative X-ray radiographic analysis was carried out to choose the best from the probable materials.
The Finite Element Method (FEM) was employed to determine the worst possible in service loading condition, and the ring dimensions were modified accordingly. Half ring prototypes were produced using two types of composite materials: knitted aramid fiber fabric reinforced epoxy and random short carbon (RSC) fiber reinforced epoxy. The in-plane compressive strength and axial stiffness of the complete frame were measured according to ASTM specifications. The performance was evaluated and compared to an existing system in simulated in-service conditions.

April 2003 vol. 22 no. 6 563-590 Show less

The use of a radiolucent composite material permits easier and more accurate radiographic evaluation of the bone healing process, and results in a much lighter system. The finite element method (FEM) is employed to determine the worst possible in-service loading condition and the ring dimensions are modified accordingly. Half-ring prototypes are produced using two types of composite materials: knitted aramid fibre fabric reinforced epoxy and random short carbon (RSC) fibre reinforced epoxy. The… Show more

The use of a radiolucent composite material permits easier and more accurate radiographic evaluation of the bone healing process, and results in a much lighter system. The finite element method (FEM) is employed to determine the worst possible in-service loading condition and the ring dimensions are modified accordingly. Half-ring prototypes are produced using two types of composite materials: knitted aramid fibre fabric reinforced epoxy and random short carbon (RSC) fibre reinforced epoxy. The in-plane compressive strength and axial stiffness of the complete frame are tested according to ASTM specifications. The performance is evaluated, and compared with an existing system in simulated in-service conditions.
January 1, 2001 vol. 215 no. 1 11-23 Show less

X-ray radiographic examination of the bone fracture healing process is a widely used method in the treatment and management of patients. Medical devices made of metallic alloys reportedly produce considerable artifacts that make the interpretation of radiographs difficult. Fiber reinforced polymer composite materials have been proposed to replace metallic alloys in certain medical devices because of their radiolucency, light weight, and tailorable mechanical properties. The primary objective of… Show more

X-ray radiographic examination of the bone fracture healing process is a widely used method in the treatment and management of patients. Medical devices made of metallic alloys reportedly produce considerable artifacts that make the interpretation of radiographs difficult. Fiber reinforced polymer composite materials have been proposed to replace metallic alloys in certain medical devices because of their radiolucency, light weight, and tailorable mechanical properties. The primary objective of this paper is to provide a comparable radiographic analysis of different fiber reinforced polymer composites that are considered suitable for biomedical applications. Composite materials investigated consist of glass, aramid (Kevlar-29), and carbon reinforcement fibers, and epoxy and polyether-ether-ketone (PEEK) matrices. The total mass attenuation coefficient of each material was measured using clinical X-rays (50 kev). The carbon fiber reinforced composites were found to be more radiolucent than the glass and kevlar fiber reinforced composites.

J Biomater Appl January 2001 vol. 15 no. 3 279-289 Show less

Current work reports the design and evaluation of circular rings for Ilizarov external fixator system. A radiolucent composite material of knitted aramid fibre (and short chopped carbon) and epoxy resin is used to replace stainless steel, currently the most commonly used material. The use of a radiolucent composite material permits easier and more accurate radiographic evaluation of the healing process, and results in a much lighter system. The half ring was modelled by the Finite Element… Show more

Current work reports the design and evaluation of circular rings for Ilizarov external fixator system. A radiolucent composite material of knitted aramid fibre (and short chopped carbon) and epoxy resin is used to replace stainless steel, currently the most commonly used material. The use of a radiolucent composite material permits easier and more accurate radiographic evaluation of the healing process, and results in a much lighter system. The half ring was modelled by the Finite Element Method (FEM) for the worst possible in service loading condition. Prototype of the half ring is produced using two different fabrics. Knitted fibre (Kevlar-29) and short chopped carbon fibre is used as reinforcement of the epoxy resin matrix. In-plane compressive strength and stiffness were tested according to the ASTM specification. The performance was evaluated and compared to an existing system in simulated in service conditions. Show less

Current work reports the design and evaluation of circular rings for Ilizarov external fixator system. A radiolucent composite material of knitted aramid fibre (and short chopped carbon) and epoxy resin is used to replace stainless steel, currently the most commonly used material. The use of a radiolucent composite material permits easier and more accurate radiographic evaluation of the healing process, and results in a much lighter system. Finite Element Method (FEM) is employed to determine… Show more

Current work reports the design and evaluation of circular rings for Ilizarov external fixator system. A radiolucent composite material of knitted aramid fibre (and short chopped carbon) and epoxy resin is used to replace stainless steel, currently the most commonly used material. The use of a radiolucent composite material permits easier and more accurate radiographic evaluation of the healing process, and results in a much lighter system. Finite Element Method (FEM) is employed to determine the worst possible in service loading condition and modify the ring dimension accordingly. Prototype of the half ring is produced using two different fabrics. Knitted Aramid fibre (Kevlar-29) and short chopped carbon fibre is used as reinforcement for epoxy resin matrix. In-plane compressive strength and axial stiffness of the complete frame were tested according to the ASTM specification. The performance was evaluated and compared to an existing system in simulated in-service conditions. Show less