Name of the Technology : Injection Mouldable Polymeric Composite Based Passive Polycentric Knee Joint
Disability Sector : Locomotor Disability
Function : Mobility/ Holding aids
Category of research : Making existing technology/product cost effective
Brief description of the product/ technology:
According to Census India 2001, a 2.13 % of the total population of India constitutes the disabled population, where 57.5 and 42.5 % corresponds to the male and female amputee. It was found that out of total amputation 28 % contributes to the locomotive disability; however, in contrast as per National Sample Survey Organization (NSSO) the locomotive disability was noticed to be 51 % in 2002, Walia G. K . As per disability statistics in Census India , the locomotive disability is one of the major disabilities in India, where a 20.2 % of people fall under physical disability out of 2.5 % of total disability in India.
It was observed from the literature that the Knee joints have the complicated structure, including complex spring or hydraulic mechanisms to achieve the desired performance, which has resulted in high cost, heavy weight, difficult to maintain and repair and inadequate reliability. Further, there are many amputees in India, who are not able to afford the prosthetic leg due to its cost. In order to overcome the above said limitations, the passive polymeric prosthetic knee joint having the significant advantages such as light weight, inexpensive, high stability, compatible knee adapter, extension bias, integrated form of polycentric and single axis knee joint, extended service life, reduced environmental degradation, easy maintenance and repair, compression spring for single axis access and single axis pin for connecting the links over conventional knee joint was developed at IIT Guwahati. Moreover, the amputee walking simulator was also designed and developed for testing the polycentric knee joint before the patient trial. Since, the developed passive polycentric knee joint is within the affordable cost with increased functional performance it is a remarkable benefit for the amputee in developing and under developed countries.
The prosthetic knee joint was developed with the design feature of extension bias, conversion of multi axes to single axis and provision for assembling with existing socket adapter. Different design constraints were followed for achieving the appropriate kinematics of the knee joint. The crank-rocker-crank mechanism was used and the stopper was placed at 90 and 115° flexion of the knee joint in order to stop the motion at full extension and flexion. The dynamic analysis of the proposed knee joint confirmed the path followed by the human walking trajectory. The selection of extension spring stiffness and the type of extension assist were also optimized. It was found that the weight of the knee joint and the terminal impact were observed to be decreased with the usage of polymer knee joint. The polymer acts as a damper to absorb the shock during the heel raise. The walking speed was increased with the addition of spring as an extension bias. The duration of swing phase, terminal impact and the heel rise were decreased with the addition of extension bias. The addition of friction decreases the heel rise and terminal impact of the amputee. The extension bumper decreases the terminal impact of the amputee.
The developed product has the added advantages of inexpensive, made of locally available material, capable of manual assembly, considerate of local climate and working conditions, durable, easy to repair, easy fabrication of components using local production capability, reproducible by local personnel, technically functional, biomechanically appropriate, adequately cosmetic and socially acceptable.
The product is being tried for different patients, who are from Tamilnadu, Assam, and Meghalaya
Readiness level of the product/technology: Pilot Deployments Carried Out and Feedback Consolidated
Anticipated time to reach the next readiness level: 3 to 6 months
Anticipated time for the technology/product to come in the market: 6 to 12 months
Any Hindrance(s) being faced w.r.t. the development of product/technology: Lack of Funds, Lack of Industry Partner
Anticipated cost: INR 2500
Dr. S. Kanagaraj/ Associate Proffesor Room No. D-305
Department of Mechanical Engineering
Indian Institute of Technology Guwahati