Arun Agrawal, Sunil K. Agrawal,
The unmatched performance of insect flight is a motivation for bio-inspired designs of synthetic wings that can undergo large deformations in flapping flight. In this paper, we experimentally study the aerodynamic performance of a bio-inspired flexible flapping wing, which has the static load–deformation characteristics of a hawkmoth (Manduca sexta) wing, and compare it with a similar geometry rigid wing. The bio-inspired wing is designed using finite element analysis, coupled with an optimization ...
Tópico(s): Robotic Locomotion and Control
2009 - Taylor & Francis | Advanced Robotics
Abhishek Agrawal, Sunil K. Agrawal,
For gait retraining of stroke victims, there is a need for rehabilitation devices, which can support the weight of leg during walking. Machines that gravity balances the leg are potentially useful as rehabilitation devices. This paper presents gravity balancing designs for two and three links planar chains using non-zero free length springs. Non-zero free length springs are those springs which have initial free length. These springs are cheaper, easily available and can be useful when complete weight ...
Tópico(s): Cerebral Palsy and Movement Disorders
2005 - Elsevier BV | Mechanism and Machine Theory
Vineet Vashista, Neelima Agrawal, Shazlin Shaharudin, Darcy S. Reisman, Sunil K. Agrawal,
The application of external constraints and/or applied forces during movement can lead to reactive as well as adaptive changes in human motion. Previous research has shown adaptation in walking kinematics when external forces were applied to a leg. This work aims to study adaptation in human walking when externally applied forces were present on the pelvis during the swing and stance phases of both legs. A novel tethered pelvic assist device (TPAD) was used to passively apply symmetric downward forces ...
Tópico(s): Spinal Cord Injury Research
2013 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Neural Systems and Rehabilitation Engineering
Saksham Gupta, Satvik Agrawal, Sunil K. Singh, Sudhakar Kumar,
Breast cancer is the second most dangerous disease for women after lung cancer. As in most diseases, an early detection and the corresponding treatment of breast cancer increase the survival rate of patients. An automated system for detection of breast cancer is required as manual techniques are time consuming and expensive. In this study, we have proposed a novel transfer learning model that can classify an ultrasound of the breast as either normal, benign, or malignant with high accuracy. The ...
Tópico(s): Infrared Thermography in Medicine
2023 - Springer Nature | Advances in intelligent systems and computing
Rajeev Ranjan, Navneet Agrawal, Sunil K. Joshi,
Cognitive radio (CR) concept is turning out as a prominent approach used in the wireless communication network for increasing spectrum efficiency by opportunistically and mutually sharing the spectrum of contemporary networks. CR can bear high traffic loads during emergencies and major disasters by overcoming the limitations like lack of network capacity. The fundamental issues pertaining the implementation of CR network (CRN) are the presence of co-channel interference and adjacent channel interference ...
Tópico(s): Wireless Communication Networks Research
2020 - Institution of Engineering and Technology | IET Communications
Charu Agrawal, Sunil K. Raghav, Bhawna Gupta, Rakha H. Das, Ved Chaturvedi, Kalyan Goswami, Hasi R. Das,
Level of TNF-α increases significantly in synovial fluid of rheumatoid arthritis (RA) patients. It is proposed that tumor necrosis factor (TNF) microsatellite alleles may influence its expression and presumably can contribute to the disease severity. However, there is a lack of such study to predict any such association with RA in an Indian population. In this study, we investigated the differential pattern of distribution of TNF microsatellite alleles in an Indian population and its association with ...
Tópico(s): Viral Infections and Immunology Research
2005 - Elsevier BV | Archives of Medical Research
Bhawna Gupta, Charu Agrawal, Sunil K. Raghav, Swapan K. Das, Rakha H. Das, Ved Chaturvedi, Hasi R. Das,
Single nucleotide polymorphisms in the mannose-binding lectin (MBL2) gene, as well as the serum MBL2 level, have been associated with various autoimmune diseases. We investigated whether such polymorphisms and/or the serum MBL2 level were associated with rheumatoid arthritis (RA) in an Indian population. The frequency of the B variant (codon 54) of the MBL2 gene was quite frequent in the healthy Indian population and was significantly (P=6.35×10−6) lower in RA patients. We replicated this association ( ...
Tópico(s): T-cell and B-cell Immunology
2005 - Springer Nature | Journal of Human Genetics
Abhishek Agrawal, Vivek Sangwan, Sai K. Banala, Sunil K. Agrawal, Stuart A. Binder‐Macleod,
An ankle-foot orthosis (AFO) is commonly used to help subjects with weakness of ankle dorsiflexor muscles due to peripheral or central nervous system disorders. Both these disorders are due to the weakness of the tibialis anterior muscle, which results in the lack of dorsiflexion assist moment. The deformity and muscle, weakness of one joint in the lower extremity influences the stability of the adjacent joints, thereby requiring compensatory adaptations. We present an innovative ankle-foot orthosis ( ...
Tópico(s): Cerebral Palsy and Movement Disorders
2006 - American Society of Mechanical Engineers | Journal of Mechanical Design
Pierre Cabaraux, Sunil K. Agrawal, Huaying Cai, Rocco Salvatore Calabrò, Carlo Casali, Loïc Damm, Sarah Doss, Christophe Habas, Anja K. E. Horn, Winfried Ilg, Elan D. Louis, Hiroshi Mitoma, Vito Monaco, Maria Petracca, Alberto Ranavolo, Ashwini K. Rao, Serena Ruggieri, Tommaso Schirinzi, Mariano Serrao, Susanna Summa, Michael Strupp, Olivia Surgent, Matthis Synofzik, Shuai Tao, Hiroo Terasi, Diego Torres‐Russotto, Brittany G. Travers, Jaimie A. Roper, Mario Manto,
Tópico(s): Neurological disorders and treatments
2022 - Springer Science+Business Media | The Cerebellum
Huanghe Zhang, Ton T. H. Duong, Ashwini K. Rao, Pietro Mazzoni, Sunil K. Agrawal, Yi Guo, Damiano Zanotto,
Instrumented footwear represents a promising technology for spatiotemporal gait analysis in out-of-the-lab conditions. However, moderate accuracy impacts this technology's ability to capture subtle, but clinically meaningful, changes in gait patterns that may indicate adverse outcomes or underlying neurological conditions. This limitation hampers the use of instrumented footwear to aid functional assessments and clinical decision making. This paper introduces new transductive-learning inference ...
Tópico(s): Gait Recognition and Analysis
2022 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Neural Systems and Rehabilitation Engineering
Athar Ali, V. Fontanari, Werner Schmoelz, Sunil K. Agrawal,
Lower back pain and musculoskeletal injuries are serious concerns for workers subjected to physical workload and manual material handling tasks. Spine assistive exoskeletons are being developed to support the spine and distribute the spine load. This article presents a detailed up-to-date review on the back support exoskeletons by discussing their type (Active/Passive), structure (Rigid/Soft), power transmission methods, weight, maximum assistive force, battery technologies, tasks (lifting, bending, ...
Tópico(s): Musculoskeletal pain and rehabilitation
2021 - Frontiers Media | Frontiers in Bioengineering and Biotechnology
Yanggang Feng, Jingeng Mai, Sunil K. Agrawal, Qining Wang,
Wearable robotic devices often need electrical energy. An interesting idea is to collect mechanical energy during walking and convert it into electrical energy to recharge these devices directly. In this article, we built a light-weight robotic prosthesis (1.3 kg) with the feature of self-charging. During stance phase, the prosthetic ankle joint with damping, is driven by human dynamics. The rotated ankle joint backdrives the motor, and the motor works as a generator according to the electromagnetic ...
Tópico(s): Advanced Sensor and Energy Harvesting Materials
2020 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Robotics
Rand Hidayah, Lauri Bishop, Xin Jin, Siddharth Chamarthy, Joel Stein, Sunil K. Agrawal,
Individuals with chronic hemiparesis post-stroke exhibit gait impairments that require functional rehabilitation through training. Exoskeletal robotic assistive devices can provide a user with continuous assistance but impose movement restrictions. There are currently devices that allow unrestricted movement but provide assistance only intermittently at specific points of the gait cycle. Our design, a cable-driven active leg exoskeleton (C-ALEX), allows the user both unrestricted movement and continuous ...
Tópico(s): Muscle activation and electromyography studies
2020 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Neural Systems and Rehabilitation Engineering
Dongbao Sui, Yanhe Zhu, Sikai Zhao, Tianshuo Wang, Sunil K. Agrawal, He Zhang, Jie Zhao,
This article presents the design, fabrication, modeling, and preliminary tests of a bloodworm-inspired soft gripper for universal grasping. The gripper was designed and fabricated based on a toy called water snake wiggly (WSW). The toroidal WSW can evert itself inside-out or outside-in, just like a bloodworm everting its teeth outside to hunt and inside to feed. By driving a WSW rolling itself outside-in to wrap around the items, a bloodworm-inspired gripper was achieved with a flexible and passive ...
Tópico(s): Modular Robots and Swarm Intelligence
2020 - Mary Ann Liebert, Inc. | Soft Robotics
Muyinat Y. Osaba, Dario Martelli, Antonio Prado, Sunil K. Agrawal, Anil K. Lalwani,
Abstract Older adults have difficulty adapting to new visual information, posing a challenge to maintain balance during walking. Virtual reality can be used to study gait adaptability in response to discordant sensorimotor stimulations. This study aimed to investigate age-related modifications and propensity for visuomotor adaptations due to continuous visual perturbations during overground walking in a virtual reality headset. Twenty old and twelve young subjects walked on an instrumented walkway ...
Tópico(s): Injury Epidemiology and Prevention
2020 - Nature Portfolio | Scientific Reports
Xin Jin, Antonio Prado, Sunil K. Agrawal,
Exoskeletons for gait training commonly use a rigid-linked "skeleton" which makes them heavy and bulky. Cable-driven exoskeletons eliminate the rigid-linked skeleton, providing a lighter and transparent design. Current cable-driven exoskeletons are aimed only at gait assistance by providing short bursts of forces to the leg during walking. It has not yet been shown if these designs are suitable for gait retraining, where rehabilitative forces need to be continuously applied to the leg in response ...
Tópico(s): Spinal Cord Injury Research
2018 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Neural Systems and Rehabilitation Engineering
Dario Martelli, Boxi Xia, Antonio Prado, Sunil K. Agrawal,
Virtual reality (VR) has been used to study locomotor adaptability during balance-demanding tasks by exploring how humans react and adapt to the virtual environment (VE) and discordant sensorimotor stimulations. Previous research primarily focused on treadmill walking and little is known regarding the propensity for gait adaptations during overground walking and over time. To what extent healthy young adults modify and adapt gait during overground walking in a VE and with continuous multidirectional ...
Tópico(s): Effects of Vibration on Health
2018 - Elsevier BV | Gait & Posture
Joon‐Hyuk Park, Paul R. Stegall, David P. Roye, Sunil K. Agrawal,
Spine deformity is typically treated with a brace that fits around the torso and hips to correct the abnormal curve of the spine. While bracing has been shown to curtail progression of abnormal spine curves, current braces impose several limitations due to their rigid, static, and sensor-less designs: (1) forces and moments exerted by the brace cannot be measured or modulated and (2) the 3-D stiffness of the human torso has not been characterized-these may be important factors to be considered in ...
Tópico(s): Spine and Intervertebral Disc Pathology
2018 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Neural Systems and Rehabilitation Engineering
Haohan Zhang, Sunil K. Agrawal,
Head drop is a symptom commonly seen in patients with amyotrophic lateral sclerosis. These patients usually experience neck pain and have difficulty in swallowing and breathing. Static neck braces are used in current treatment. These braces, however, immobilize the head in a single configuration, which causes muscle atrophy. This letter presents the design of a dynamic neck brace for the first time in the literature, which can both measure and potentially assist in the head motion of the human user. ...
Tópico(s): Glycogen Storage Diseases and Myoclonus
2017 - Institute of Electrical and Electronics Engineers | IEEE Robotics and Automation Letters
Paul Stegall, Damiano Zanotto, Sunil K. Agrawal,
Haptic feedback affects not only the quality of training but can also influence the physical design of robotic gait trainers by determining how much force needs to be applied to the user and the nature of the force. This paper presents the design of a variable damping force tunnel and explores the effect of the shape and strength of the damping field using ALEX III, a treadmill-based exoskeleton developed at Columbia University. The study consists of 32 healthy subjects who were trained for 40 minutes ...
Tópico(s): Stroke Rehabilitation and Recovery
2017 - Institute of Electrical and Electronics Engineers | IEEE Robotics and Automation Letters
Moiz Khan, Victor Santamaria, Jiyeon Kang, Brian M. Bradley, Joseph P. Dutkowsky, Andrew M. Gordon, Sunil K. Agrawal,
Dynamic seated trunk control is required during the execution of many everyday tasks. These tasks require an intricate coordination between the head, upper and lower trunk, and the pelvis. Furthermore, reaching beyond the arm's length requires precise joint control and intersegmental coordination. With practice specificity, humans can learn particular motor skills that may be performed across contexts of similar characteristics. As new tasks are explored, human movements are learned and organized ...
Tópico(s): Cerebral Palsy and Movement Disorders
2017 - Institute of Electrical and Electronics Engineers | IEEE Robotics and Automation Letters
Jiyeon Kang, Vineet Vashista, Sunil K. Agrawal,
Pelvic movement is important to human locomotion as the center of mass is located near the center of pelvis. Lateral pelvic motion plays a crucial role to shift the center of mass on the stance leg, while swinging the other leg and keeping the body balanced. In addition, vertical pelvic movement helps to reduce metabolic energy expenditure by exchanging potential and kinetic energy during the gait cycle. However, patient groups with cerebral palsy or stroke have excessive pelvic motion that leads ...
Tópico(s): Spinal Cord Injury Research
2017 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Neural Systems and Rehabilitation Engineering
Jiyeon Kang, Dario Martelli, Vineet Vashista, Isis E. Martínez-Hernández, Heakyung Kim, Sunil K. Agrawal,
Robotic training of children with crouch gait improved posture and walking by enhancing muscle strength and coordination.
Tópico(s): Nerve Injury and Rehabilitation
2017 - American Association for the Advancement of Science | Science Robotics
Lauri Bishop, Moiz Khan, Dario Martelli, Lori Quinn, Joel Stein, Sunil K. Agrawal,
Many robotic devices in rehabilitation incorporate an assist-as-needed haptic guidance paradigm to promote training. This error reduction model, while beneficial for skill acquisition, could be detrimental for long-term retention. Error augmentation (EA) models have been explored as alternatives. A robotic Tethered Pelvic Assist Device has been developed to study force application to the pelvis on gait and was used here to induce weight shift onto the paretic (error reduction) or nonparetic (error ...
Tópico(s): Musculoskeletal pain and rehabilitation
2017 - Lippincott Williams & Wilkins | American Journal of Physical Medicine & Rehabilitation
Huanghe Zhang, Damiano Zanotto, Sunil K. Agrawal,
Quantitative analysis of the plantar pressure distribution during dynamic tasks can facilitate diagnosis of foot and ankle dysfunctions and prevent potential injuries by providing detailed information about weight bearing and weight shifting patterns. Traditional laboratory measurements are currently limited by high operating costs and lack of portability. The use of instrumented insoles capable of capturing kinematic and kinetic gait parameters as subjects perform out-of-the-lab dynamic activities ...
Tópico(s): Muscle activation and electromyography studies
2017 - Institute of Electrical and Electronics Engineers | IEEE Robotics and Automation Letters
Luca Barbazza, Damiano Zanotto, Giulio Rosati, Sunil K. Agrawal,
In this paper, a planar underactuated cable-driven micro-macro robot is presented. The system consists of two-link passive serial manipulator attached to a cable-suspended parallel robot. The system is conceived for applications requiring point-to-point motions inside large workspaces in the presence of obstacles: The serial arm allows us to reach points close to the obstacles that would not be reachable by the cable robot alone due to cable-obstacle interference. The kinematic and dynamic models ...
Tópico(s): Dynamics and Control of Mechanical Systems
2017 - Institute of Electrical and Electronics Engineers | IEEE Robotics and Automation Letters
Chifu Yang, Jinsong Zhao, Liyi Li, Sunil K. Agrawal,
Robotic spine brace based on parallel-actuated robotic system is a new device for treatment and sensing of scoliosis, however, the strong dynamic coupling and anisotropy problem of parallel manipulators result in accuracy loss of rehabilitation force control, including big error in direction and value of force. A novel active force control strategy named modal space force control is proposed to solve these problems. Considering the electrical driven system and contact environment, the mathematical ...
Tópico(s): Teleoperation and Haptic Systems
2017 - Elsevier BV | ISA Transactions
Saeed Abdolshah, Damiano Zanotto, Giulio Rosati, Sunil K. Agrawal,
Adaptive cable-driven parallel robots are a special subclass of cable-driven systems in which the locations of the pulley blocks are modified as a function of the end-effector pose to obtain optimal values of given performance indices within a target workspace. Due to their augmented kinematic redundancy, such systems enable larger workspace volume and higher performance compared to traditional designs featuring the same number of cables. Previous studies have introduced a systematic method to optimize ...
Tópico(s): Piezoelectric Actuators and Control
2017 - ASM International | Journal of Mechanisms and Robotics
Haohan Zhang, Sunil K. Agrawal,
Dropped head syndrome is often seen in patients with neurological disorders, such as amyotrophic lateral sclerosis. Static collars are often prescribed to these patients to support their head. These collars support the head in one position but do not allow motion to the head. In this letter, we present a novel active neck brace to address this issue and provide assistance to the patients to improve their neck range of motion. This brace has three degrees-of-freedom and allows improved range of motion ...
Tópico(s): Glycogen Storage Diseases and Myoclonus
2017 - Institute of Electrical and Electronics Engineers | IEEE Robotics and Automation Letters
Gabriele Ligorio, Damiano Zanotto, A.M. Sabatini, Sunil K. Agrawal,
Magnetic-inertial measurement units (MIMUs) are often used to measure the joint angles between two body segments. To obtain anatomically meaningful joint angles, each MIMU must be computationally aligned (i.e., calibrated) with the anatomical rotation axes. In this paper, a novel four-step functional calibration method is presented for the elbow joint, which relies on a two-degrees-of-freedom elbow model. In each step, subjects are asked to perform a simple task involving either one-dimensional motions ...
Tópico(s): Sports Performance and Training
2017 - Elsevier BV | Journal of Biomechanics