A space tech spin-off from the Indian Space Research Organisation (ISRO) is expected to help above-knee amputees to walk with a comfortable gait. The microprocessor-controlled knees (MPKs) being developed by the space agency offer ''extended capabilities for the amputee than those offered by the passive limbs that do not use microprocessors,'' the ISRO said on Friday.
The 'smart' MPKs are being developed by ISRO's Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, under a memorandum of understanding (MoU) with the National Institute for Locomotor Disabilities (NILD), Pt. Deendayal Upadhyaya National Institute for Persons with Physical Disabilities, and the Artificial Limb Manufacturing Corporation of India (ALIMCO).
''Thus far, a 1.6 kg MPK has enabled an amputee to walk about 100 m with minimum support. Efforts to improve the performance are under way,'' said ISRO.
MPKs currently available commercially in India are imported. Costs range from ₹10 lakh to ₹60 lakh depending on the complexity and functionality. The MPKs under development, once commercialised, are expected to cost around ₹4 lakh to ₹5 lakh.
The MPK comprises a microprocessor, hydraulic damper, load and knee angle sensors, composite knee-case, lithium-ion battery, electrical harness and interface elements. The microprocessor detects the state of gait using sensor data. The control software estimates the real-time damping needed to attain the desired gait by changing the stiffness of the system which is achieved by a DC motor-operated hydraulic damper.
''Walking parameters specific to amputees can be set using PC-based software to improve one’s comfort. The interface plots the parameters in real time during walking,'' said ISRO.
Initially 'walking trials' were conducted with non-amputees. This enabled the updating of the control software and fine-tuning of the parameters. On obtaining clearance from the Joint Project Monitoring Committee (JPMC), the device was tested on an amputee. The trials were conducted at the NILD lab jointly by NILD and VSSC.
Researchers are incorporating more features into the system so that the artificial limb can be used in uneven terrains with more comfort.
