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Sabut S.K.,Indian Institute of Technology Kharagpur | Kumar R.,National Institute for the Orthopaedically Handicapped | Mahadevappa M.,Indian Institute of Technology Kharagpur
Journal of Medical Engineering and Technology | Year: 2010

A programmable and portable multi-pattern transcutaneous neuromuscular stimulator was developed and evaluated for correction of foot drop in stroke subjects. The stimulator unit was designed to optimize functionality while keeping its size and power consumption to a minimum. It had two channels of biphasic stimulation (charge-balanced and constant current), and all parameters were programmable to accommodate a range of stimulation profiles. The 'natural' electromyographic (EMG) pattern of tibialis anterior (TA) muscle stimulation envelope algorithms and constant amplitude stimulation envelope was provided for foot drop corrections in stroke patients. A foot-switch sensor was used to trigger the device in the swing phase of gait cycle. Various tests on prototype units were performed, including output power characteristics with a skin model, and tested with a stroke subject to validate the results. This paper provides a detailed description of the hardware and block-level functional electrical stimulation (FES) system design for applications in stroke rehabilitation. © 2010 Informa UK Ltd.

Kundu R.,University of Calcutta | Chakrabarti A.,University of Calcutta | Lenka P.,National Institute for the Orthopaedically Handicapped
Advances in Intelligent Systems and Computing | Year: 2015

Evaluation of lumbolumbar (LL) angle of the vertebral column from medical images is a common measure in case of patients suffering from lower back pain (LBP). There are five lumbar vertebrae (L1-L5). The angle formed between the slope of L1 and slope of L5 is the LL angle. This paper presents a computational technique for automated measurement of the LL angle from computerized tomography (CT) images using digital image processing techniques. The computation of LL angle comprises of four major steps: (i) image denoising (ii) segmentation of vertebral column (iii) morphological operations, and (iv) statistical estimation. To the best of our knowledge, the proposed technique for automated LL angle from CT images is the first of its kind. The segmentation based on s-t cut gives a promising result. We have performed our experiments over 30 CT images and have achieved satisfactory results in automated detection with an accuracy of 80 %. © Springer India 2015.

Bhowmick A.,University of Calcutta | Kundu P.P.,University of Calcutta | Kumar R.,National Institute for the Orthopaedically Handicapped | Das M.,University of Calcutta
Advances in Polymer Technology | Year: 2014

In this paper, we report a simple approach for the fabrication of bone-like composite materials (BCMs) by blending chitosan (CTS), a natural polysaccharide, nano-hydroxyapatite as bone mineral, and polymethylmethacrylate- co-polyhydroxyethylmethacrylate (PMMA-co-PHEMA) as bone cement. Fourier transform infrared spectroscopy and X-ray diffraction (XRD) studies were performed to determine the components of composites. Scanning electron microscopy study of composites revealed a well-dispersed flake-like structure with increasing content of PMMA-co-PHEMA. The water-uptake ability of the BCMs was also found to increase with increasing the PMMA-co-PHEMA content. Study of mechanical properties revealed that the Young's modulus and stiffness increased significantly after the addition of PMMA-co-PHEMA in BCMs compared with CTS-HAP blend. © 2013 Wiley Periodicals, Inc.

Sabut S.K.,Indian Institute of Technology Kharagpur | Kumar R.,National Institute for the Orthopaedically Handicapped | Mahadevappa M.,Indian Institute of Technology Kharagpur
International Conference on Systems in Medicine and Biology, ICSMB 2010 - Proceedings | Year: 2010

A real-time detection of the foot pressure sensor with feedback controlled functional electrical stimulation (FES) system for the correction of foot drop in hemiplegics has been developed and tested with a volunteer. The foot pressure signals from subject were utilised as modulating signal and controlling the stimulation amplitude of the FES system. These foot pressure detectors are the essential component of a cycle-to-cycle controller for FES gait. It will determine the foot pressure when the affected leg of subject at stance phase of gait cycle. The controller then will assess the pressure on the sensors and serve as a real time controlled for adjustment of the intensity of electrical stimulation, which is to be used for the next gait cycle while the subject is walking using FES device. At the same time the heel switch was used to measure the gait parameters such as stride length and walking speed during walking experiments, proved the effectiveness of the system. © 2010 IEEE.

Sabut S.K.,Indian Institute of Technology Kharagpur | Sikdar C.,National Institute for the Orthopaedically Handicapped | Kumar R.,National Institute for the Orthopaedically Handicapped | Mahadevappa M.,National Institute for the Orthopaedically Handicapped
Journal of Mechanics in Medicine and Biology | Year: 2011

Functional electrical stimulation (FES) allows active exercises for correction of foot drop in stroke patients. Our objective is to evaluate and compare the effects of FES therapy in walking ability, calf muscle spasticity, and lower-extremity motor recovery between subacute and chronic stroke patients. Twenty consecutive hemiplegic patients having foot drop were assigned either to subacute or chronic group. Both group subjects were treated with conventional rehabilitation program combined with FES therapy for 12 weeks. All subjects received the electrical stimulation to the peroneal nerve of paretic limb for 1530 min while walking. After being treated with FES-based rehabilitation program, subacute subjects showed a mean increase in walking speed of 31.3% and chronic subjects of 19.1% and the physiological cost index (PCI), with a reduction of 66.7% in subacute subjects and 46.4% in chronic subjects between the beginning and end of the trial. Improvement was also measured in gait parameters such as cadence, step and stride lengths, ankle joint range of motion (ROM), calf muscle spasticity, and lower-extremity motor recovery assessed by Fugl-Meyer score in both group subjects, but subacute subjects improved better compared with chronic subjects. In conclusion, early and intensive interventions of FES therapy combine with conventional rehabilitation program could significantly improve the waking ability and recovery of lower-extremity motor functions in stroke survivors. © 2011 World Scientific Publishing Company.

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