Works (134)

Updated: April 8th, 2024 05:48

2024 journal article

Dynamic Active Subspaces for Model Predictive Allocation in Over-Actuated Systems

IEEE CONTROL SYSTEMS LETTERS, 8, 145–150.

By: M. Singh n, K. Lambeth*, A. Iyer* & N. Sharma*

author keywords: Actuators; Task analysis; Torque; Resource management; Matrix decomposition; System dynamics; Optimal control; Hybrid neuroprosthesis; model predictive control; Koopman operator; control allocation
TL;DR: To improve computational efficiency of the MPCA, Koopman operator-based linear prediction dynamics of an over-actuated nonlinear robotic system is developed and demonstrated on a hybrid neuroprosthesis model for a trajectory tracking task. (via Semantic Scholar)
Sources: ORCID, Web Of Science, NC State University Libraries
Added: January 28, 2024

2024 journal article

Flexible Ultrasonic Transducers for Wearable Biomedical Applications: A Review on Advanced Materials, Structural Designs, and Future Prospects

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.

By: X. Xue n, H. Wu n, Q. Cai n, M. Chen n, S. Moon n, Z. Huang*, T. Kim*, C. Peng* ...

TL;DR: This article comprehensively reviews the application of flexible ultrasound transducers in the field of biomedical imaging, sensing, and therapy and highlights some promising preliminary data with recent applications. (via Semantic Scholar)
Source: ORCID
Added: January 28, 2024

2023 article

Cooperative Control of a Hybrid Exoskeleton Using Optimal Time Varying Impedance Parameters During Stair Ascent

2023 AMERICAN CONTROL CONFERENCE, ACC, pp. 2739–2744.

By: A. Iyer n, M. Singh n & N. Sharma n

Sources: Web Of Science, NC State University Libraries
Added: March 11, 2024

2023 article

Data-driven Model Predictive Control for Drop Foot Correction

2023 AMERICAN CONTROL CONFERENCE, ACC, pp. 2615–2620.

By: M. Singh n & N. Sharma*

TL;DR: Simulation and experimental results from a subject with Multiple Sclerosis show the effectiveness of the data-driven MPC scheme of FES for DFC, including the closed-loop system’s recursive feasibility and asymptotic stability analysis. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries
Added: March 11, 2024

2023 review

Deciphering the melatonin-mediated response and signalling in the regulation of heavy metal stress in plants

[Review of ]. PLANTA, 257(6).

By: M. Altaf*, N. Sharma*, D. Srivastava n, S. Mandal*, S. Adavi*, R. Jena*, R. Bairwa*, A. Gopalakrishnan* ...

author keywords: Melatonin; Heavy metal; Antioxidant enzymes; Oxidative damage; Photosynthesis; Growth
MeSH headings : Melatonin / pharmacology; Antioxidants / metabolism; Metals, Heavy / toxicity; Metals, Heavy / metabolism; Plants / metabolism; Soil Pollutants / metabolism; Soil
UN Sustainable Development Goal Categories
Sources: Web Of Science, NC State University Libraries
Added: June 5, 2023

2023 journal article

Development of a Wearable Ultrasound Transducer for Sensing Muscle Activities in Assistive Robotics Applications

BIOSENSORS-BASEL, 13(1).

By: X. Xue n, B. Zhang n, S. Moon n, G. Xu*, C. Huang*, N. Sharma n, X. Jiang n

author keywords: wearable ultrasound transducer; flexible ultrasound transducer; muscle movement; robotic prosthesis; powered exoskeleton; ultrasound imaging
MeSH headings : Animals; Swine; Robotics; Ultrasonography; Muscles; Transducers; Wearable Electronic Devices
Sources: ORCID, Web Of Science, NC State University Libraries
Added: January 16, 2023

2023 article

Evaluation of a Fused Sonomyography and Electromyography-Based Control on a Cable-Driven Ankle Exoskeleton

Zhang, Q., Lambeth, K., Sun, Z., Dodson, A., Bao, X., & Sharma, N. (2023, February 9). IEEE TRANSACTIONS ON ROBOTICS, Vol. 2.

By: Q. Zhang n, K. Lambeth n, Z. Sun, A. Dodson n, X. Bao* & N. Sharma n

author keywords: Muscles; Torque; Robots; Imaging; Legged locomotion; Neuromuscular; Force; Ankle exoskeleton; assist-as-needed (AAN) control; neuromuscular model; sonomyography; surface electromyography (sEMG); ultrasound (US) imaging
UN Sustainable Development Goal Categories
Sources: ORCID, Web Of Science, NC State University Libraries
Added: February 10, 2023

2023 article

Koopman-based Data-driven Model Predictive Control of Limb Tremor Dynamics with Online Model Updating: A Theoretical Modeling and Simulation Approach

2023 AMERICAN CONTROL CONFERENCE, ACC, pp. 2873–2878.

By: X. Xue n, A. Iyer n & N. Sharma n

TL;DR: A Koopman-based method for system identification and its application to the design of a model predictive control (MPC) scheme to suppress tremors and a recursive least squares (RLS) algorithm to improve control performance with low computational complexity are presented. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries
Added: March 11, 2024

2023 article

Nonlinear System Identification of Tremors Dynamics: A Data-driven Approximation Using Koopman Operator Theory

2023 11TH INTERNATIONAL IEEE/EMBS CONFERENCE ON NEURAL ENGINEERING, NER.

By: X. Xue n, A. Iyer n, D. Roque* & N. Sharma n

TL;DR: A data-driven method for approximating the Koopman operator is implemented, which is capable of presenting nonlinear dynamics in a linear framework and is promising for predicting the nonlinear system. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries
Added: September 5, 2023

2023 article

Robust Control Barrier Functions for Safety Using a Hybrid Neuroprosthesis

2023 AMERICAN CONTROL CONFERENCE, ACC, pp. 54–59.

By: K. Lambeth*, M. Singh* & N. Sharma*

TL;DR: Simulations show the superior performance of the proposed robust MPC-ZCBF scheme for achieving foot clearance compared to traditional ZCBFs and Euclidean safety constraints. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries
Added: March 11, 2024

2023 journal article

Towards ultrasound imaging-based closed-loop peripheral nerve stimulation for tremor suppression

CURRENT OPINION IN BIOMEDICAL ENGINEERING, 28.

By: N. Sharma n, X. Xue n, A. Iyer n, X. Jiang n & D. Roque*

author keywords: Tremor suppression; Electrical stimulation; Ultrasound imaging; Essential tremor; Parkinsonian tremor; Afferent stimulation
Sources: Web Of Science, NC State University Libraries, ORCID
Added: September 5, 2023

2022 article

A Hybrid Knee Exoskeleton Using Real-Time Ultrasound-Based Muscle Fatigue Assessment

Sheng, Z., Iyer, A., Sun, Z., Kim, K., & Sharma, N. (2022, May 19). IEEE-ASME TRANSACTIONS ON MECHATRONICS, Vol. 5.

By: Z. Sheng*, A. Iyer n, Z. Sun n, K. Kim* & N. Sharma n

Contributors: Z. Sheng*, A. Iyer n, Z. Sun n, K. Kim* & N. Sharma n

author keywords: Muscles; Ultrasonic imaging; Exoskeletons; Switches; Iron; Fatigue; Control systems; Control design; closed loop system; delay system; motion control; nonlinear control system; rehabilitation robotics; robust control; switching systems; state feedback; ultrasonic imaging
TL;DR: Results from the first experimental demonstration of a hybrid knee exoskeleton that uses ultrasound-derived muscle state feedback to coordinate electrical motors and FES are presented, suggesting a potential application in the rehabilitation of neurological disorders like spinal cord injuries and stroke. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: Web Of Science, NC State University Libraries, ORCID
Added: June 6, 2022

2022 journal article

An Iterative Learning Controller for a Switched Cooperative Allocation Strategy During Sit-to-Stand Tasks with a Hybrid Exoskeleton

IEEE Transactions on Control Systems Technology, 30(3), 1021–1036.

By: V. Molazadeh*, Q. Zhang n, X. Bao* & N. Sharma n

Contributors: V. Molazadeh*, Q. Zhang n, X. Bao* & N. Sharma n

author keywords: Iron; Muscles; Exoskeletons; Resource management; Switches; Knee; Control systems; Functional electrical stimulation (FES); hybrid exoskeleton; iterative learning control; neural networks (NNs); powered exoskeleton; virtual constraints
Sources: ORCID, Web Of Science, NC State University Libraries
Added: January 3, 2022

2022 article

Continuous Switching Control of an Input-Delayed Antagonistic Muscle Pair During Functional Electrical Stimulation

Sun, Z., Qiu, T., Iyer, A., Dicianno, B. E., & Sharma, N. (2022, June 21). IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, Vol. 6.

By: Z. Sun, T. Qiu*, A. Iyer n, B. Dicianno* & N. Sharma n

Contributors: Z. Sun, T. Qiu*, A. Iyer n, B. Dicianno* & N. Sharma n

author keywords: Muscles; Iron; Switches; Elbow; Control systems; Delays; Recruitment; Antagonistic muscles; delay systems; electromechanical delay (EMD); functional electrical stimulation (FES); Lyapunov-Krasovskii (LK) functionals; Lyapunov stability
TL;DR: A robust controller is designed to facilitate the FES of an antagonistic muscle pair during elbow flexion and extension by using a continuous switching law that maps a joint angle error to control the antagonism muscle pair. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: ORCID, Web Of Science, NC State University Libraries
Added: June 22, 2022

2022 article

Development of a wearable ultrasound transducer for sensing muscle activities in assistive robotics applications: In vivo study

2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS).

By: X. Xue n, B. Zhang n, S. Moon n, G. Xu*, C. Huang*, N. Sharma n, X. Jiang n

author keywords: ultrasound transducers; wearable transducers; flexible transducers; muscle activities detection
TL;DR: This work aims to develop a novel wearable US device for detecting muscle activities, designed, fabricated, and characterized, and the feasibility of monitoring muscle activity in different regions was demonstrated by an in vivo human experiment. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries
Added: February 6, 2023

2022 article

Editorial: Next Generation User-Adaptive Wearable Robots

Bulea, T. C., Sharma, N., Sikdar, S., & Su, H. (2022, June 22). FRONTIERS IN ROBOTICS AND AI, Vol. 9.

By: T. Bulea*, N. Sharma n, S. Sikdar* & H. Su n

Contributors: T. Bulea*, N. Sharma n, S. Sikdar* & H. Su n

author keywords: exoskeleton; wearable robot; rehabilitation; human-in-the loop; functional electric stimulation
TL;DR: One study presents a pediatric exoskeleton that provides adaptive assistance to knee extension to alleviate crouch and its evaluation in a child with cerebral palsy and two manuscripts present novel controllers which leverage reinforcement learning and their evaluation in simulation. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries, ORCID
Added: July 18, 2022

2022 article

Fused Ultrasound And Electromyography-Driven Neuromuscular Model To Improve Plantarflexion Moment Prediction Across Walking Speeds

Zhang, Q., Fragnito, N., Franz, J. R., & Sharma, N. (2022, January 11).

By: Q. Zhang n, N. Fragnito n, J. Franz n & N. Sharma n

UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Source: ORCID
Added: January 12, 2022

2022 article

Fused Ultrasound and Electromyography-driven Neuromuscular Model to Improve Plantarflexion Moment Prediction across Walking Speeds

ResearchSquare.

By: Q. Zhang, N. Fragnito, J. Franz & N. Sharma

Contributors: Q. Zhang, N. Fragnito, J. Franz & N. Sharma

Source: ORCID
Added: July 28, 2022

2022 journal article

Fused ultrasound and electromyography-driven neuromuscular model to improve plantarflexion moment prediction across walking speeds

Journal of NeuroEngineering and Rehabilitation, 19(1).

By: Q. Zhang n, N. Fragnito n, J. Franz n & N. Sharma n

Contributors: Q. Zhang n, N. Fragnito n, J. Franz n & N. Sharma n

author keywords: Human intent prediction; Neuromuscular model; B-mode ultrasound imaging; Surface electromyography; Rehabilitative/assistive robotics; Sensor fusion
MeSH headings : Ankle Joint / physiology; Electromyography / methods; Humans; Muscle, Skeletal / diagnostic imaging; Muscle, Skeletal / physiology; Walking / physiology; Walking Speed
TL;DR: The proposed sEMG-US imaging-driven Hill-type neuromuscular model can significantly improve the net plantarflexion moment prediction accuracy across multiple walking speeds, implying that the proposed HNM can be potentially used in bio-inspired control strategies for rehabilitative devices due to its superior prediction. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Source: ORCID
Added: August 10, 2022

2022 journal article

Personalized fusion of ultrasound and electromyography-derived neuromuscular features increases prediction accuracy of ankle moment during plantarflexion

BIOMEDICAL SIGNAL PROCESSING AND CONTROL, 71.

By: Q. Zhang n, W. Clark n, J. Franz n & N. Sharma n

Contributors: Q. Zhang n, W. Clark n, J. Franz n & N. Sharma n

author keywords: Ultrasound imaging; Surface electromyography; Isometric ankle plantarflexion; Support vector machine regression; Feedforward neural network; Human effort prediction
TL;DR: Findings indicate that the combination of sEMG signals and US imaging is a superior sensing modality for predicting human plantarflexion intention and can enable future clinical rehabilitation devices. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries, ORCID
Added: October 4, 2021

2022 journal article

Ultrasound Echogenicity as an Indicator of Muscle Fatigue during Functional Electrical Stimulation

SENSORS, 22(1).

By: Q. Zhang n, A. Iyer n, K. Lambeth n, K. Kim* & N. Sharma n

Contributors: Q. Zhang n, A. Iyer n, K. Lambeth n, K. Kim* & N. Sharma n

author keywords: muscle fatigue; electrical stimulation; ankle joint; biomechanical phenomena; ultrasonography; linear models; nonlinear dynamics
MeSH headings : Electric Stimulation; Humans; Isometric Contraction; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Ultrasonography
TL;DR: The findings in this study indicate that the US echogenicity signal is a computationally efficient signal that strongly represents FES-induced muscle fatigue and its potential real-time implementation to detect fatigue can facilitate an FES closed-loop controller design that considers the Fes- induced muscle fatigue. (via Semantic Scholar)
Sources: ORCID, Web Of Science, NC State University Libraries
Added: January 8, 2022

2022 article

Ultrasound Imaging-Based Closed-Loop Control of Functional Electrical Stimulation for Drop Foot Correction

Zhang, Q., Lambeth, K., Iyer, A., Sun, Z., & Sharma, N. (2022, September 30). IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, Vol. 9.

By: Q. Zhang n, K. Lambeth n, A. Iyer n, Z. Sun n & N. Sharma n

Contributors: Q. Zhang n, K. Lambeth n, A. Iyer n, Z. Sun n & N. Sharma n

author keywords: Ankle dorsiflexion; drop foot; functional electrical stimulation (FES); nonlinear control; sampled-data observer (SDO); ultrasound (US) imaging
TL;DR: The use of ultrasound (US) echogenicity as an indicator of FES-evoked muscle activation is explored and a methodology to integrate US in an FES control framework is provided, which will likely benefit persons with drop foot and those with other mobility disorders. (via Semantic Scholar)
Sources: ORCID, Web Of Science, NC State University Libraries
Added: October 1, 2022

2022 chapter

Ultrasound-Based Sensing and Control of Functional Electrical Stimulation for Ankle Joint Dorsiflexion: Preliminary Study

In Biosystems and Biorobotics (Vol. 27, pp. 307–311).

By: Q. Zhang*, A. Iyer* & N. Sharma*

Contributors: Q. Zhang*, A. Iyer* & N. Sharma*

TL;DR: An ultrasound (US) imaging approach is proposed to observe muscle activation and fatigue levels during FES-elicited ankle dorsiflexors and shows the effectiveness of the proposed control method, and the superior tracking performance compared to a traditional control method where the muscleactivation and fatigue are computed from an off-line identified model. (via Semantic Scholar)
Source: ORCID
Added: July 28, 2022

2021 journal article

A Dual-Modal Approach Using Electromyography and Sonomyography Improves Prediction of Dynamic Ankle Movement: A Case Study

IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, 29, 1944–1954.

By: Q. Zhang n, A. Iyer n, Z. Sun n, K. Kim n & N. Sharma n

Contributors: Q. Zhang n, A. Iyer n, Z. Sun n, K. Kim n & N. Sharma n

author keywords: Imaging; Sensors; Legged locomotion; Feature extraction; Neuromuscular; Dynamics; Biomedical imaging; B-mode ultrasound imaging; surface electromyography; machine learning regression; dynamic ankle dorsiflexion motion; human limb intent
MeSH headings : Ankle; Ankle Joint; Electromyography; Humans; Movement; Muscle, Skeletal
TL;DR: The findings show that potentially the dual-modal sensing approach can be used as a superior sensing modality to predict human intent of a continuous motion and implemented for volitional control of clinical rehabilitative and assistive devices. (via Semantic Scholar)
Sources: ORCID, Web Of Science, NC State University Libraries
Added: September 28, 2021

2021 conference paper

A Tube-based Model Predictive Control Method for Joint Angle Tracking with Functional Electrical Stimulation and An Electric Motor Assist

2021 American Control Conference (ACC), 2021-May, 1390–1395.

By: Z. Sun n, X. Bao*, Q. Zhang n, K. Lambeth n & N. Sharma n

Contributors: Z. Sun n, X. Bao*, Q. Zhang n, K. Lambeth n & N. Sharma n

Event: 2021 American Control Conference (ACC)

TL;DR: A novel tube-based MPC method for tracking control of a human limb angle by cooperatively using FES and electric motor inputs is derived and shows robust performance despite modeling uncertainties. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2021 journal article

A Tube-based Model Predictive Control Method to Regulate a Knee Joint with Functional Electrical Stimulation and Electric Motor Assist

IEEE Transactions on Control Systems Technology, 29(5), 2180–2191.

By: X. Bao*, Z. Sheng*, B. Dicianno* & N. Sharma n

Contributors: X. Bao*, Z. Sheng*, B. Dicianno* & N. Sharma n

author keywords: Iron; Electric motors; Muscles; Knee; Torque; Legged locomotion; Real-time systems; Biological control system; exoskeleton; functional electrical stimulation (FES); hybrid neuroprosthesis; model predictive control (MPC); position control; robust control
TL;DR: A tube-based model predictive control (MPC) method is developed to obtain robust and optimal coordination between FES and an electric motor during a knee regulation task and is proved to have recursive feasibility, compliance to input constraints, and exponentially bounded stability. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Sources: ORCID, Web Of Science, NC State University Libraries
Added: August 12, 2021

2021 journal article

Evaluation of Non-Invasive Ankle Joint Effort Prediction Methods for Use in Neurorehabilitation Using Electromyography and Ultrasound Imaging

IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, 68(3), 1044–1055.

By: Q. Zhang n, A. Iyer n, K. Kim* & N. Sharma*

Contributors: Q. Zhang n, A. Iyer n, K. Kim* & N. Sharma*

author keywords: Neuromuscular; Biomedical measurement; Force; Mathematical model; Imaging; Dynamics; Ankle dorsiflexion; electromyography; feedforward neural network; linear regression; neuromuscular model; ultrasound imaging
MeSH headings : Ankle Joint / diagnostic imaging; Electromyography; Humans; Isometric Contraction; Muscle, Skeletal / diagnostic imaging; Neurological Rehabilitation; Ultrasonography
TL;DR: A comparative study of ultrasound imaging (US)-derived neuromuscular signals and sEMG signals for their use in predicting isometric ankle dorsiflexion moment indicates FFNN or HNM approach and using pennation angle or fascicle length predict human ankle movement intent with higher accuracy. (via Semantic Scholar)
Sources: Web Of Science, ORCID, NC State University Libraries
Added: March 22, 2021

2021 conference paper

Plantarflexion Moment Prediction during the Walking Stance Phase with an sEMG-Ultrasound Imaging-Driven Model

2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), 2021-January, 6267–6272.

By: Q. Zhang*, N. Fragnito*, A. Myers* & N. Sharma*

Contributors: Q. Zhang*, N. Fragnito*, A. Myers* & N. Sharma*

Event: 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society at Mexico on November 1-5, 2021

MeSH headings : Ankle / diagnostic imaging; Ankle Joint / diagnostic imaging; Electromyography; Humans; Ultrasonography; Walking
TL;DR: The findings show that the sEMG-US imaging-driven MLM can significantly improve the prediction of net PF moment during the walking stance phase at multiple speeds and potentially can be used as a superior joint motion intent model in advanced and intelligent control strategies for rehabilitative exoskeletons. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries, ORCID
Added: April 25, 2022

2021 journal article

Shared Control of a Powered Exoskeleton and Functional Electrical Stimulation Using Iterative Learning

FRONTIERS IN ROBOTICS AND AI, 8.

By: V. Molazadeh*, Q. Zhang n, X. Bao*, B. Dicianno* & N. Sharma n

Contributors: V. Molazadeh*, Q. Zhang n, X. Bao*, B. Dicianno* & N. Sharma n

author keywords: exoskeleton; wearable robot; shared control; iterative learning; functional electrical stimulation (FES)
Sources: Web Of Science, NC State University Libraries, ORCID
Added: November 29, 2021

2021 journal article

Switched Control of an N-Degree-of-Freedom Input Delayed Wearable Robotic System

Automatica, 125.

By: Z. Sheng*, Z. Sun n, V. Molazadeh* & N. Sharma n

Contributors: Z. Sheng*, Z. Sun n, V. Molazadeh* & N. Sharma n

author keywords: Wearable robotics; Input delay; Switched control; Multiple Lyapunov functional analysis
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: Web Of Science, NC State University Libraries, ORCID
Added: May 17, 2021

2021 journal article

Ultra-High-Frame-Rate Ultrasound Monitoring of Muscle Contractility Changes Due to Neuromuscular Electrical Stimulation

ANNALS OF BIOMEDICAL ENGINEERING, 49(1), 262–275.

By: Z. Sheng*, N. Sharma* & K. Kim*

Contributors: Z. Sheng*, N. Sharma* & K. Kim*

author keywords: Ultrasound imaging; Ultrasound speckle tracking; Neuromuscular electrical stimulation (NMES); Muscle fatigue effects
MeSH headings : Adult; Electric Stimulation; Female; Humans; Isometric Contraction; Male; Muscle Fatigue / physiology; Quadriceps Muscle / diagnostic imaging; Quadriceps Muscle / physiology; Ultrasonography; Young Adult
TL;DR: In this study, instantaneous strain maps of a contracting muscle were derived from ultra-high-frame-rate (2 kHz) ultrasound images to quantify the contractility and results indicate that the proposed measurements from ultrasound images are promising to quantify the muscle contractility changes during NMES. (via Semantic Scholar)
Sources: Web Of Science, ORCID, NC State University Libraries
Added: June 15, 2020

2021 conference paper

Ultrasound Echogenicity-based Assessment of Muscle Fatigue During Functional Electrical Stimulation

2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), 5948–5952.

By: Q. Zhang*, A. Iyer*, K. Lambeth*, K. Kim* & N. Sharma*

Contributors: Q. Zhang*, A. Iyer*, K. Lambeth*, K. Kim* & N. Sharma*

Event: 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society at Mexico on November 1-5, 2021

MeSH headings : Electric Stimulation; Electromyography; Humans; Isometric Contraction; Muscle Fatigue; Ultrasonography
TL;DR: The findings indicate that US echogenicity may be a promising computationally efficient indicator for assessing FES-induced muscle fatigue and may aid in the design of muscle-in-the-loop FES controllers that consider the onset of muscle fatigue. (via Semantic Scholar)
Sources: Web Of Science, NC State University Libraries, ORCID
Added: April 25, 2022

2020 conference paper

An Ultrasound Imaging Based Observer for Estimating NMES-Induced Muscle Fatigue: Theory and Simulation

Volume 1: Adaptive/Intelligent Sys. Control; Driver Assistance/Autonomous Tech.; Control Design Methods; Nonlinear Control; Robotics; Assistive/Rehabilitation Devices; Biomedical/Neural Systems; Building Energy Systems; Connected Vehicle Systems; Control/Estimation of Energy Systems; Control Apps.; Smart Buildings/Microgrids; Education; Human-Robot Systems; Soft Mechatronics/Robotic Components/Systems; Energy/Power Systems; Energy Storage; Estimation/Identification; Vehicle Efficiency/Emissions, 1.

By: Z. Sheng*, K. Kim* & N. Sharma n

Contributors: Z. Sheng*, K. Kim* & N. Sharma n

Event: ASME 2020 Dynamic Systems and Control Conference

TL;DR: A novel state observer is proposed that combines a mathematical predictive fatigue model and intermittent feedback from ultrasound-derived strain images to effectively estimate the NMES-induced muscle fatigue. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2020 conference paper

Analysis of Tremor During Grasp Using Ultrasound Imaging: Preliminary Study

Proceedings of the 8th IEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics, 2020-November, 533–538.

By: A. Iyer n, Z. Sheng*, Q. Zhang n, K. Kim* & N. Sharma n

Contributors: A. Iyer n, Z. Sheng*, Q. Zhang n, K. Kim* & N. Sharma n

Event: 8th IEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob) at New York on November 29 - December 1, 2020

TL;DR: The frequency for tremor participants fall within accepted frequency ranges for Parkinson’s Disease and Essential Tremor, and thus can be representative of the actual tremor frequency. (via Semantic Scholar)
Sources: NC State University Libraries, NC State University Libraries, ORCID
Added: September 23, 2021

2020 chapter

Hybrid Wearable Robotic Exoskeletons for Human Walking

In Wearable Robotics (pp. 347–364).

By: J. Moreno, S. Mohammed*, N. Sharma* & A. del-Ama

Contributors: J. Moreno, S. Mohammed*, N. Sharma* & A. Del-Ama

TL;DR: This chapter aims at revising in detail the recent advances in such hybrid robotic technology as well as new perspectives on assistive and neurorehabilitation applications and provides an updated overview of the technology and its perspectives with regard to real use aswell as directions for future research in this field. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2020 chapter

Model Predictive Control-Based Knee Actuator Allocation During a Standing-Up Motion with a Powered Exoskeleton and Functional Electrical Stimulation

In R. Vinjamuri (Ed.), Advances in Motor Neuroprostheses (pp. 89–100).

By: X. Bao*, V. Molazadeh*, A. Dodson n & N. Sharma n

Contributors: X. Bao*, V. Molazadeh*, A. Dodson n & N. Sharma n

Ed(s): R. Vinjamuri

TL;DR: A lower-limb powered exoskeleton is combined with functional electrical stimulation of the quadriceps muscle to achieve a standing-up motion using a fatigue dynamical model and a feedback controller that stabilizes the desired standing- up motion. (via Semantic Scholar)
Sources: NC State University Libraries, NC State University Libraries, ORCID
Added: September 23, 2021

2020 journal article

Prediction of Ankle Dorsiflexion Moment by Combined Ultrasound Sonography and Electromyography

IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, 28(1), 318–327.

By: Q. Zhang*, K. Kim* & N. Sharma*

Contributors: Q. Zhang*, K. Kim* & N. Sharma*

author keywords: Ankle dorsiflexion; voluntary contraction force; ultrasound sonography; electromyography; pennation angle; muscle fascicle; neuromusculoskeletal model
MeSH headings : Adult; Algorithms; Ankle / diagnostic imaging; Ankle / physiology; Ankle Joint / diagnostic imaging; Ankle Joint / physiology; Biomechanical Phenomena; Electric Stimulation; Electromyography / methods; Humans; Isometric Contraction; Male; Movement / physiology; Muscle, Skeletal / physiology; Self-Help Devices; Ultrasonography / methods; Young Adult
TL;DR: A new model-based intention detection method that combines signals from both surface electromyography (sEMG) and ultrasound (US) sonography to predict isometric volitional ankle dorsiflexion moment is proposed, which has a better prediction accuracy compared to a prediction model that uses sole sEMG or sole US sonography. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Sources: Web Of Science, ORCID, NC State University Libraries
Added: February 3, 2020

2020 journal article

Quantitative Assessment of Changes in Muscle Contractility Due to Fatigue During NMES: An Ultrasound Imaging Approach

IEEE Transactions on Biomedical Engineering, 67(3), 832–841.

By: Z. Sheng*, N. Sharma* & K. Kim*

Contributors: Z. Sheng*, N. Sharma* & K. Kim*

author keywords: Muscles; Fatigue; Strain; Ultrasonic imaging; Biomedical measurement; Imaging; Force; Ultrasound imaging; neuromuscular electrical stimulation (NMES); muscle fatigue
MeSH headings : Adult; Algorithms; Electric Stimulation / adverse effects; Electric Stimulation / methods; Female; Humans; Image Processing, Computer-Assisted; Knee / diagnostic imaging; Knee / physiology; Male; Muscle Contraction / physiology; Muscle Fatigue / physiology; Quadriceps Muscle / diagnostic imaging; Quadriceps Muscle / physiology; Ultrasonography / methods; Young Adult
TL;DR: Ultrasound imaging with the proposed methodology is a promising tool for a direct NMES-induced fatigue assessment and facilitates new strategies to alleviate the effects of the NMES -induced fatigue. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Source: ORCID
Added: August 12, 2021

2020 conference paper

Sampled-Data Observer Based Dynamic Surface Control of Delayed Neuromuscular Functional Electrical Stimulation

[Paper]. Volume 1: Adaptive/Intelligent Sys. Control; Driver Assistance/Autonomous Tech.; Control Design Methods; Nonlinear Control; Robotics; Assistive/Rehabilitation Devices; Biomedical/Neural Systems; Building Energy Systems; Connected Vehicle Systems; Control/Estimation of Energy Systems; Control Apps.; Smart Buildings/Microgrids; Education; Human-Robot Systems; Soft Mechatronics/Robotic Components/Systems; Energy/Power Systems; Energy Storage; Estimation/Identification; Vehicle Efficiency/Emissions, 1(DSCC2020-3225).

By: Q. Zhang n, A. Iyer n, Z. Sun n, A. Dodson n & N. Sharma n

Contributors: Q. Zhang n, A. Iyer n, Z. Sun n, A. Dodson n & N. Sharma n

Event: ASME 2020 Dynamic Systems and Control Conference on October 5-7, 2020

TL;DR: Stability analysis based on the Lyapunov-Krasovskii function proves that the SDO-based DSC plus delay compensation (SDO-DSC-DC) approach achieves semi-global uniformly ultimately bounded (SGUUB) tracking performance. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2020 journal article

Using Person-Specific Muscle Fatigue Characteristics to Optimally Allocate Control in a Hybrid Exoskeleton—Preliminary Results

IEEE Transactions on Medical Robotics and Bionics, 2(2), 226–235.

By: X. Bao*, V. Molazadeh*, A. Dodson n, B. Dicianno* & N. Sharma n

Contributors: X. Bao*, V. Molazadeh*, A. Dodson n, B. Dicianno* & N. Sharma n

author keywords: Functional electrical stimulation; powered exoskeleton; muscle fatigue; nonlinear control; model predictive control; hybrid neuroprosthesis
TL;DR: The experimental results show that the proposed hierarchical control design is a promising method to effect shared control in a hybrid exoskeleton. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2020 conference paper

Volitional Contractility Assessment of Plantar Flexors by Using Non-invasive Neuromuscular Measurements

2020 8th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob), 2020-November, 515–520.

By: Q. Zhang n, A. Iyer n, K. Kim* & N. Sharma n

Contributors: Q. Zhang n, A. Iyer n, K. Kim* & N. Sharma n

Event: 2020 8th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob)

TL;DR: US imaging can be used as a new sensing modality to measure or predict human lower limb motion intent in clinical rehabilitation devices and imply that using US imagingderived signals improves the accuracy of predicting volitional effort on human plantar flexors. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2019 journal article

A Robust Iterative Learning Switching Controller for following Virtual Constraints: Application to a Hybrid Neuroprosthesis

IFAC-PapersOnLine, 51(34), 28–33.

By: V. Molazadeh*, Z. Sheng*, X. Bao* & N. Sharma*

Contributors: V. Molazadeh*, Z. Sheng*, X. Bao* & N. Sharma*

TL;DR: The synthesis of iterative learning control with sliding-mode control improves tracking performance and accuracy and the effectiveness of the new iterativeLearning control for output tracking is verified in a simple model of walking that has active actuation at the hip joints. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2019 conference paper

Ankle Dorsiflexion Strength Monitoring by Combining Sonomyography and Electromyography

2019 IEEE 16th International Conference on Rehabilitation Robotics (ICORR), 2019-June, 240–245.

By: Q. Zhang*, Z. Sheng*, F. Moore-Clingenpeel*, K. Kim* & N. Sharma*

Contributors: Q. Zhang*, Z. Sheng*, F. Moore-Clingenpeel*, K. Kim* & N. Sharma*

Event: 2019 IEEE 16th International Conference on Rehabilitation Robotics (ICORR) at Toronto, Ontario, Canada on June 24-28, 2019

MeSH headings : Adult; Ankle / physiology; Electromyography; Humans; Isometric Contraction / physiology; Linear Models; Male; Muscle, Skeletal / physiology; Range of Motion, Articular / physiology; Signal Processing, Computer-Assisted; Ultrasonics
TL;DR: The new method shows an improved linear correlation with the muscle strength, compared to the correlations between the Muscle strength and sole sEMG signal or sole PA signal, where the R-squared values are improved by 4.21 % and 1.99 %. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2019 journal article

Lyapunov-based Model Predictive Control of an Input Delayed Functional Electrical Simulation

IFAC-PapersOnLine, 51(34), 290–295.

By: Z. Sun*, X. Bao* & N. Sharma*

Contributors: Z. Sun*, X. Bao* & N. Sharma*

author keywords: FES; LMPC; EMD
TL;DR: A Lyapunov-based model predictive control method to control knee extension during an input-delayed neuromuscular electrical stimulation that achieves system stability despite an unknown constant input delay and imperfectly estimated model parameters is developed. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2019 journal article

Model Predictive Control of a Feedback-Linearized Hybrid Neuroprosthetic System With a Barrier Penalty

Journal of Computational and Nonlinear Dynamics, 14(10).

By: X. Bao*, N. Kirsch, A. Dodson* & N. Sharma*

Contributors: X. Bao*, N. Kirsch, A. Dodson* & N. Sharma*

TL;DR: An electric motor-assist is proposed to alleviate the fatigue effects by sharing work load with FES and the dynamics is feedback linearized so that the nominal model inside the MPC method becomes linear. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2019 conference paper

Muscle Fatigue Assessment in a Wearable Neuroprosthesis Using Ultrasound Strain Imaging

Sheng, Z., Sharma, N., & Kim, K. (2019, June 24). Presented at the International Functional Electrical Stimulation Society Conference, Toronto, Canada.

By: Z. Sheng, N. Sharma & K. Kim

Event: International Functional Electrical Stimulation Society Conference at Toronto, Canada on June 24-28, 2019

Source: NC State University Libraries
Added: September 23, 2021

2019 conference paper

Neural-Network Based Iterative Learning Control of a Hybrid Exoskeleton with an MPC Allocation Strategy

[Paper]. Proceedings of the ASME Dynamic Systems Control Conference, 1(DSCC2019-9191).

By: V. Molazadeh*, Q. Zhang*, X. Bao* & N. Sharma*

Contributors: V. Molazadeh*, Q. Zhang*, X. Bao* & N. Sharma*

Event: Dynamic Systems and Control (DSC) Conference at Park City, UT on October 8-11, 2019

TL;DR: A novel neural network based iterative learning controller for a hybrid exoskeleton uses a model predictive control strategy to address modeling uncertainties and stabilizes the hybrid system for sitting to standing and standing to sitting scenarios. (via Semantic Scholar)
Sources: ORCID, NC State University Libraries, NC State University Libraries
Added: September 24, 2021

2019 speech

New Control and Sensing Approaches for Integrating Functional Electrical Stimulation in a Wearable Exoskeletons

Sharma, N. (2019, February). Presented at the Joint Department of Biomedical Engineering Raleigh: North Carolina State University, University of North Carolina at Chapel Hill.

By: N. Sharma

Event: at Joint Department of Biomedical Engineering Raleigh: North Carolina State University, University of North Carolina at Chapel Hill on February 25, 2019

Source: NC State University Libraries
Added: September 26, 2021

2019 conference paper

Observer Design for a Nonlinear Neuromuscular System with Multi-rate Sampled and Delayed Output Measurements

2019 American Control Conference (ACC), 2019-July, 872–877.

By: Q. Zhang*, Z. Sheng*, K. Kim* & N. Sharma*

Contributors: Q. Zhang*, Z. Sheng*, K. Kim* & N. Sharma*

Event: 2019 American Control Conference (ACC)

TL;DR: An observer design is proposed to estimate ankle kinematics that are elicited volitionally by constructing a Lyapunov-Krasovskii function, sufficient conditions are derived to prove the exponential stability of the estimation error. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2019 journal article

Sub-optimally solving actuator redundancy in a hybrid neuroprosthetic system with a multi-layer neural network structure

International Journal of Intelligent Robotics and Applications, 3(3), 298–313.

By: X. Bao*, Z. Mao*, P. Munro, Z. Sun* & N. Sharma*

Contributors: X. Bao*, Z. Mao*, P. Munro, Z. Sun* & N. Sharma*

author keywords: Hybrid neuroprosthesis; Actuator redundancy; Rehabilitation; Neural network; Reinforcement learning
TL;DR: A novel identification and control structure that contains a recurrent neural network (RNN) and several feedforward neural networks (FNNs), trained by supervised learning to identify the system dynamics, and experimentally validated on a seated human participant using a single joint hybrid neuroprosthesis. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2019 conference paper

Tube-based Model Predictive Control of An Input Delayed Functional Electrical Stimulation

2019 American Control Conference (ACC), 2019-July, 5420–5425.

By: Z. Sun*, X. Bao* & N. Sharma*

Contributors: Z. Sun*, X. Bao* & N. Sharma*

Event: 2019 American Control Conference (ACC)

TL;DR: A novel tube-based MPC for controlling knee extension elicited through FES was developed, and the EMD compensation controller was chosen to be the tube that reduced the error between the nominal MPC and the output of the real system. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2019 journal article

Ultrasound Tracking of the Acoustically Actuated Microswimmer

IEEE Transactions on Biomedical Engineering, 66(11), 3231–3237.

By: Q. Chen*, F. Liu*, Z. Xiao*, N. Sharma*, S. Cho* & K. Kim*

Contributors: Q. Chen*, F. Liu*, Z. Xiao*, N. Sharma*, S. Cho* & K. Kim*

author keywords: Microswimmer; acoustically actuated; ultrasound tracking; biomedical applications
MeSH headings : Acoustics; Algorithms; Biomedical Engineering / instrumentation; Drug Delivery Systems; Equipment Design; Microbubbles; Microtechnology / instrumentation; Motion; Phantoms, Imaging; Ultrasonography / methods; Video Recording
TL;DR: Ultrasound imaging is a promising candidate for noninvasively tracking the motion of microswimmers inside the body in biomedical applications and may further promote the real-time control strategy for the microswimmer. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2018 journal article

A Control Scheme That Uses Dynamic Postural Synergies to Coordinate a Hybrid Walking Neuroprosthesis: Theory and Experiments

Frontiers in Neuroscience, 12(APR).

By: N. Alibeji*, V. Molazadeh*, B. Dicianno* & N. Sharma*

Contributors: N. Alibeji*, V. Molazadeh*, B. Dicianno* & N. Sharma*

author keywords: hybrid neuroprosthesis; synergy; nonlinear control; neuromuscular stimulation; Lyapunov
TL;DR: A muscle synergy-inspired control framework is used to derive the controller and is motivated mainly to address the actuator redundancy issue and was demonstrated experimentally on an able-bodied subject and person with an incomplete spinal cord injury. (via Semantic Scholar)
UN Sustainable Development Goal Categories
7. Affordable and Clean Energy (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2018 journal article

A Muscle Synergy-Inspired Control Design to Coordinate Functional Electrical Stimulation and a Powered Exoskeleton: Artificial Generation of Synergies to Reduce Input Dimensionality

IEEE Control Systems, 38(6), 35–60.

By: N. Alibeji*, V. Molazadeh*, F. Moore-Clingenpeel* & N. Sharma*

Contributors: N. Alibeji*, V. Molazadeh*, F. Moore-Clingenpeel* & N. Sharma*

TL;DR: Rec rehabilitative interventions including functional electrical stimulation (FES) and powered exoskeletons have the potential to mitigate secondary health complications, lower medical expenses, and achieve independent ambulation in individuals following an SCI. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2018 conference paper

A Within-Stride Switching Controller for Walking with Virtual Constraints: Application to a Hybrid Neuroprosthesis

2018 Annual American Control Conference (ACC), 2018-June, 5286–5291.

By: V. Molazadeh*, Z. Sheng* & N. Sharma*

Contributors: V. Molazadeh*, Z. Sheng* & N. Sharma*

Event: 2018 Annual American Control Conference (ACC)

TL;DR: This paper investigated if a switching controller and optimal virtual constraint design for a class of walking exoskeleton with redundant actuation can achieve a stable walking limit cycle and found it proven to achieve exponential stability despite arbitrary switching. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2018 article

A supplementary condition for the convergence of the control policy during adaptive dynamic programming

ArXiv. http://www.scopus.com/inward/record.url?eid=2-s2.0-85098840725&partnerID=MN8TOARS

By: X. Bao, Z. Mao & N. Sharma

Contributors: X. Bao, Z. Mao & N. Sharma

Source: ORCID
Added: July 28, 2022

2018 article

A theoretical difficulty in approximate dynamic programming with input constraints

ArXiv. http://www.scopus.com/inward/record.url?eid=2-s2.0-85098820021&partnerID=MN8TOARS

By: X. Bao, Z. Mao & N. Sharma

Contributors: X. Bao, Z. Mao & N. Sharma

Source: ORCID
Added: July 28, 2022

2018 conference paper

An Active-Subspace-Based Algorithm for Reducing Redundancy in a Hybrid Neuroprosthesis

2018 IEEE Conference on Decision and Control (CDC), 2018-December, 4849–4854.

By: F. Moore-Clingenpeel*, V. Molazadeh* & N. Sharma*

Contributors: F. Moore-Clingenpeel*, V. Molazadeh* & N. Sharma*

Event: 2018 IEEE Conference on Decision and Control (CDC) at Miami, FL on December 17-19, 2018

TL;DR: This work has developed a novel technique based on active subspaces to reduce the dimensionality of the redundant control system and shows that by using this algorithm, synergies can be calculated more quickly than performing dynamic optimization. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2018 journal article

Dynamic optimization of stimulation frequency to reduce isometric muscle fatigue using a modified Hill‐Huxley model

Muscle & Nerve, 57(4), 634–641.

By: B. Doll*, N. Kirsch*, X. Bao*, B. Dicianno* & N. Sharma*

Contributors: B. Doll*, N. Kirsch*, X. Bao*, B. Dicianno* & N. Sharma*

author keywords: dynamic optimization; FES; functional electrical stimulation; Hill-Huxley model; muscle fatigue; muscle force prediction; neuromuscular electrical stimulation
MeSH headings : Adult; Electric Stimulation / methods; Healthy Volunteers; Humans; Isometric Contraction; Male; Muscle Fatigue; Nonlinear Dynamics; Quadriceps Muscle; Young Adult
TL;DR: Optimal frequency modulation during functional electrical stimulation (FES) may minimize or delay the onset of FES‐induced muscle fatigue. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2018 conference paper

Hybrid Dynamical System Model and Robust Control of a Hybrid Neuroprosthesis Under Fatigue Based Switching

2018 Annual American Control Conference (ACC), 2018-June, 1446–1451.

By: Z. Sheng*, V. Molazadeh* & N. Sharma*

Contributors: Z. Sheng*, V. Molazadeh* & N. Sharma*

Event: 2018 Annual American Control Conference (ACC)

TL;DR: A hybrid neuroprosthesis controller that integrates a modified PD-based robust controller to compensate for electromechanical delay during functional electrical stimulation and a variable structure controller to control a powered exoskeleton is developed. (via Semantic Scholar)
UN Sustainable Development Goal Categories
7. Affordable and Clean Energy (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2018 journal article

Model-Based Dynamic Control Allocation in a Hybrid Neuroprosthesis

IEEE Transactions on Neural Systems and Rehabilitation Engineering, 26(1), 224–232.

By: N. Kirsch, X. Bao, N. Alibeji, B. Dicianno & N. Sharma*

Contributors: N. Kirsch, X. Bao, N. Alibeji, B. Dicianno & N. Sharma*

author keywords: Hybrid neuroprosthesis; model predictive control; dynamic control allocation; functional electrical stimulation; muscle fatigue; medical control systems
MeSH headings : Adult; Algorithms; Biomechanical Phenomena; Computer Systems; Electric Stimulation Therapy; Exoskeleton Device; Gait Disorders, Neurologic / rehabilitation; Humans; Leg; Male; Models, Neurological; Muscle Fatigue; Muscle, Skeletal / physiopathology; Neural Prostheses; Paraplegia / rehabilitation; Prosthesis Design; Spinal Cord Injuries / physiopathology; Spinal Cord Injuries / rehabilitation
TL;DR: A model predictive control-based dynamic control allocation (DCA) is used to allocate control between FES and the electric motor that simultaneously maintain a desired knee angle and validate the hybrid technology’s potential use in walking rehabilitation. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2017 journal article

A Modified Dynamic Surface Controller for Delayed Neuromuscular Electrical Stimulation

IEEE/ASME Transactions on Mechatronics, 22(4), 1755–1764.

By: N. Alibeji*, N. Kirsch*, B. Dicianno* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch*, B. Dicianno* & N. Sharma*

author keywords: Activation dynamics; delay systems; dynamic surface control; feedback; input delays; Lyapunov methods; nonlinear controls; nonlinear control systems; neuromuscular electrical stimulation
TL;DR: A dynamic surface control approach was used to design a proportional-integral-derivative (PID)-based NMES controller that compensates for electromechanical delays in the activation dynamics and supports the hypothesis that a control design that includes muscle activation improves the NMES control performance. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2017 journal article

A Non-Linear Control Method to Compensate for Muscle Fatigue during Neuromuscular Electrical Stimulation

Frontiers in Robotics and AI, 4(DEC).

By: N. Sharma*, N. Kirsch*, N. Alibeji* & W. Dixon*

Contributors: N. Sharma*, N. Kirsch*, N. Alibeji* & W. Dixon*

author keywords: integrator backstepping; neural networks; muscle fatigue; Lyapunov stability; neuromuscular electrical stimulation
TL;DR: The objective of this article is to develop an NMES controller that incorporates the effects of muscle fatigue during NMES-induced non-isometric contraction of the human quadriceps femoris muscle. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2017 journal article

A Nonlinear Dynamics-Based Estimator for Functional Electrical Stimulation: Preliminary Results From Lower-Leg Extension Experiments

IEEE Transactions on Neural Systems and Rehabilitation Engineering, 25(12), 2365–2374.

By: M. Allen*, Q. Zhong*, N. Kirsch*, A. Dani*, W. Clark* & N. Sharma*

Contributors: M. Allen*, Q. Zhong*, N. Kirsch*, A. Dani*, W. Clark* & N. Sharma*

author keywords: State-dependent coefficient; extended kalman filter; rotation matrix; functional electrical stimulation; nonlinear state estimator
MeSH headings : Algorithms; Biomechanical Phenomena; Electric Stimulation / instrumentation; Healthy Volunteers; Humans; Isometric Contraction / physiology; Joints / anatomy & histology; Joints / physiology; Knee Joint / anatomy & histology; Knee Joint / physiology; Leg / anatomy & histology; Leg / physiology; Muscle, Skeletal / physiology; Nonlinear Dynamics
TL;DR: A new class of nonlinear state estimation technique called state-dependent coefficient (SDC) estimation to accurately predict joint angles from IMU measurements to predict knee joint angle measurements during functional electrical stimulation of the quadriceps muscle is presented. (via Semantic Scholar)
Sources: ORCID, Crossref, NC State University Libraries
Added: August 12, 2021

2017 journal article

A PID-Type Robust Input Delay Compensation Method for Uncertain Euler–Lagrange Systems

IEEE Transactions on Control Systems Technology, 25(6), 2235–2242.

By: N. Alibeji* & N. Sharma*

Contributors: N. Alibeji* & N. Sharma*

author keywords: Delay compensation; Euler-Lagrange systems; robust control; unknown input delay.
TL;DR: The result in this brief extends a modified proportional-integral derivative (PID)-type controller that contains a distributed delay term to Euler–Lagrange systems with an unknown constant input delay. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Source: ORCID
Added: August 12, 2021

2017 conference paper

A Tube-based Model Predictive Control Method for Sharing Control Inputs in a Hybrid Neuroprosthesis

Bao, X., Sheng, Z., & Sharma, N. (2017, October 24). Presented at the IROS workshop on Assistance and Service Robotics in a Human Environment, Vancouver, British Columbia, Canada.

By: X. Bao, Z. Sheng & N. Sharma

Event: IROS workshop on Assistance and Service Robotics in a Human Environment at Vancouver, British Columbia, Canada on October 24-28, 2017

Source: NC State University Libraries
Added: September 24, 2021

2017 conference paper

A recurrent neural network based MPC for a hybrid neuroprosthesis system

2017 IEEE 56th Annual Conference on Decision and Control (CDC), 2018-January, 4715–4720.

By: X. Bao*, Z. Sun* & N. Sharma*

Contributors: X. Bao*, Z. Sun* & N. Sharma*

Event: 2017 IEEE 56th Annual Conference on Decision and Control (CDC)

TL;DR: A three-layer recurrence neural network (RNN) is developed in this paper, in which backpropagation through time (BPTT) is used as training technique and the internal states are used to represent the unmeasurable states. (via Semantic Scholar)
Sources: ORCID, Crossref, NC State University Libraries
Added: September 23, 2021

2017 journal article

An adaptive low-dimensional control to compensate for actuator redundancy and FES-induced muscle fatigue in a hybrid neuroprosthesis

Control Engineering Practice, 59, 204–219.

By: N. Alibeji*, N. Kirsch* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch* & N. Sharma*

author keywords: Functional electrical stimulation; Muscle fatigue; Dynamic surface control; Synergies; Human inspired control; Adaptive control; State estimator; Input delays; Electromechanical delays
TL;DR: A human motor control inspired control scheme is combined with a dynamic surface control method to overcome certain control challenges in a hybrid neuroprosthesis to restore walking and standing function in persons with paraplegia. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2017 journal article

Bilateral control of functional electrical stimulation and robotics-based telerehabilitation

International Journal of Intelligent Robotics and Applications, 1(1), 6–18.

By: N. Alibeji*, B. Dicianno* & N. Sharma*

Contributors: N. Alibeji*, B. Dicianno* & N. Sharma*

TL;DR: A position-synchronization controller is derived for FES-based telerehabilitation to provide physical assistance that can be controlled remotely and is shown to effectively synchronize the system despite unknown and different delays in the forward and backward channels. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2017 chapter

Dynamic Optimization of a Hybrid Gait Neuroprosthesis to Improve Efficiency and Walking Duration: A Simulation Study

In J. Ibáñez, J. González-Vargas, J. Azorín, M. Akay, & J. Pons (Eds.), Converging Clinical and Engineering Research on Neurorehabilitation II (pp. 687–691).

By: N. Kirsch*, N. Alibeji*, M. Redfern* & N. Sharma*

Contributors: N. Kirsch*, N. Alibeji*, M. Redfern* & N. Sharma*

Ed(s): J. Ibáñez, J. González-Vargas, J. Azorín, M. Akay & J. Pons

TL;DR: It is proposed that a hybrid system, which uses FES and an actuated orthosis, is capable of achieving greater walking durations than an FES only system and more energetically efficient than a lower-limb exoskeleton. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2017 conference paper

Experimental demonstration of a delay compensating controller in a hybrid walking neuroprosthesis

2017 8th International IEEE/EMBS Conference on Neural Engineering (NER), 465–468.

By: A. Dodson*, N. Alibeji* & N. Sharma*

Contributors: A. Dodson*, N. Alibeji* & N. Sharma*

Event: 2017 8th International IEEE/EMBS Conference on Neural Engineering (NER)

TL;DR: This neuroprosthesis controller is combined within a finite state machine that also features gait detection, wherein force sensors in the foot can detect gait phases and create a fully automated and functional assisted gait cycle. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2017 conference paper

Human Motor Control Inspired Controller to Compensate for Actuator Redundancy in a Hybrid Neuroprosthesis

Workshop on Assistance and Service Robotics in a Human Environment. Presented at the 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems, Vancouver, British Columbia, Canada.

By: N. Sharma

Event: 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems at Vancouver, British Columbia, Canada on September 24-28, 2017

Source: NC State University Libraries
Added: September 23, 2021

2017 chapter

Modeling and Dynamic Optimization of a Hybrid Neuroprosthesis for Gait Restoration

In J. Ueda & Y. Kurita (Eds.), Human Modelling for Bio-Inspired Robotics (pp. 139–159).

By: N. Sharma* & N. Kirsch*

Contributors: N. Sharma* & N. Kirsch*

Ed(s): J. Ueda & Y. Kurita

TL;DR: It is shown that dynamic optimization can be used to compute stimulation/torque profiles and their corresponding joint angle trajectories which minimize electrical stimulation and walker push or pull forces. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2017 journal article

Nonlinear model predictive control of functional electrical stimulation

Control Engineering Practice, 58, 319–331.

By: N. Kirsch*, N. Alibeji* & N. Sharma*

Contributors: N. Kirsch*, N. Alibeji* & N. Sharma*

author keywords: Functional electrical stimulation; Nonlinear model predictive control; Muscle parameter identification; Rehabilitation engineering; Gradient projection algorithm
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2017 chapter

Preliminary Experiments of an Adaptive Low-Dimensional Control for a Hybrid Neuroprosthesis

In J. Ibáñez, J. González-Vargas, J. Azorín, M. Akay, & J. Pons (Eds.), Converging Clinical and Engineering Research on Neurorehabilitation II (pp. 693–697).

By: N. Alibeji*, N. Kirsch* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch* & N. Sharma*

Ed(s): J. Ibáñez, J. González-Vargas, J. Azorín, M. Akay & J. Pons

TL;DR: Experimental results of a recently developed low-dimensional controller, which is inspired from the muscle synergy principle, are presented and performed on an able-bodied subject in a configuration where only one leg is actuated in a cycling manner while the contralateral leg was fixed. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2017 conference paper

Shared control of functional electrical stimulation and an electric motor in a hybrid neuroprosthesis

Sharma, N. (2017, May 29). Presented at the 2017 IEEE International Conference on Robotics and Automation (ICRA) : Innovation, Entrepreneurship, and Real-world Sollutions, Marina Bay Sands, Singapore.

By: N. Sharma

Event: 2017 IEEE International Conference on Robotics and Automation (ICRA) : Innovation, Entrepreneurship, and Real-world Sollutions at Marina Bay Sands, Singapore on May 29 - June 3, 2017

Source: NC State University Libraries
Added: September 23, 2021

2017 speech

Shared control of functional electrical stimulation and an electric motor in a hybrid neuroprosthesis

Sharma, S. (2017, March). Presented at the Institute of Robotics and Intelligent Machines, Georgia Institute of Technology, Atlanta, Georgia.

By: S. Sharma

Event: Institute of Robotics and Intelligent Machines at Georgia Institute of Technology, Atlanta, Georgia on March 8, 2017

Source: NC State University Libraries
Added: September 24, 2021

2016 speech

Control methods for shared use of an electrically-stimulated human muscle and a robot in a hybrid neuroprosthetic

Sharma, N. (2016, June). Presented at the Robotics Science Systems Workshop on Human Robot Collaboration, University of Michigan, Ann Arbor, MI.

By: N. Sharma

Event: Robotics Science Systems Workshop on Human Robot Collaboration at University of Michigan, Ann Arbor, MI on June 18, 2016

Source: NC State University Libraries
Added: September 24, 2021

2016 conference paper

Dynamic control allocation of a feedback linearized hybrid neuroprosthetic system

2016 American Control Conference (ACC), 2016-July, 3976–3981.

By: X. Bao*, N. Kirsch* & N. Sharma*

Contributors: X. Bao*, N. Kirsch* & N. Sharma*

Event: 2016 American Control Conference (ACC)

TL;DR: Model predictive control (MPC) is used to solve an optimal control trajectory for the feedback linearized musculoskeletal system, which simplifies the optimal control problem; therefore, may reduce the computational load for MPC. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2016 conference paper

Robust compensation of electromechanical delay during neuromuscular electrical stimulation of antagonistic muscles

2016 American Control Conference (ACC), 2016-July, 4871–4876.

By: T. Qiu*, N. Alibeji* & N. Sharma*

Contributors: T. Qiu*, N. Alibeji* & N. Sharma*

Event: 2016 American Control Conference (ACC) at Boston, MA on July 6-8, 2016

TL;DR: A robust delay compensation controller for EMDs in antagonistic muscles is presented and a Lyapunov stability analysis yields uniformly ultimately bounded tracking for a human limb joint actuated by antagonistic muscle pair. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2016 speech

Shared control of functional electrical stimulation and an electric motor in a hybrid neuroprosthesis

Sharma, N. (2016, March). Presented at the Department of Sports Medicine, University of Pittsburgh, Pittsburgh, PA.

By: N. Sharma

Event: at Department of Sports Medicine, University of Pittsburgh, Pittsburgh, PA on March 1, 2016

Source: NC State University Libraries
Added: September 26, 2021

2016 speech

Shared control of functional electrical stimulation and an electric motor in a hybrid neuroprosthesis

Sharma, N. (2016, November). Presented at the Department of Engineering Science and Mechanics at Pennsylvania State University, State College, PA.

By: N. Sharma

Event: at Department of Engineering Science and Mechanics at Pennsylvania State University, State College, PA on November 16, 2016

Source: NC State University Libraries
Added: September 30, 2021

2016 conference paper

Switching control of functional electrical stimulation and motor assist for muscle fatigue compensation

2016 American Control Conference (ACC), 2016-July, 4865–4870.

By: N. Kirsch*, N. Alibeji*, B. Dicianno* & N. Sharma*

Contributors: N. Kirsch*, N. Alibeji*, B. Dicianno* & N. Sharma*

Event: 2016 American Control Conference (ACC) at Boston, MA on July 6-8, 2016

TL;DR: A second order sliding mode controller cascaded with a feedback linearization controller for a switched, FES and electric motor, system is used and it is shown that prolonged knee movements can be elicited through the switched system. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2015 journal article

A Muscle Synergy-Inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis

Frontiers in Bioengineering and Biotechnology, 3, 203.

By: N. Alibeji*, N. Kirsch* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch* & N. Sharma*

author keywords: non-linear control; adaptive control; time-invariant synergies; functional electrical stimulation; hybrid neuroprosthesis
TL;DR: Inspired by the muscle synergy principle, a low dimensional controller to control multiple effectors: FES of multiple muscles and electric motors is designed and may help to compensate for other time-varying phenomena. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2015 journal article

An Adaptive Low-Dimensional Control for a Hybrid Neuroprosthesis

IFAC-PapersOnLine, 48(20), 303–308.

By: N. Alibeji*, N. Kirsch* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch* & N. Sharma*

TL;DR: A low-dimensional controller inspired from the muscle synergy principle is designed that requires few control signals to actuate multiple effectors in a hybrid neuroprostheses and yields semi-global uniformly ultimately boundedness. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2015 speech

Closed-loop Control Methods for a Hybrid Neuroprosthesis

Sharma, N. (2015, June). Presented at the Human Engineering Research Laboratories, University of Pittsburgh, Pittsburgh, PA.

By: N. Sharma

Event: Human Engineering Research Laboratories at University of Pittsburgh, Pittsburgh, PA on June 22, 2015

Source: NC State University Libraries
Added: September 24, 2021

2015 speech

Closed-loop Control Methods for a Hybrid Neuroprosthesis

Sharma, N. (2015, October). Presented at the Panther Rounds Speaker (UPMC Mercy), Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA.

By: N. Sharma

Event: at Panther Rounds Speaker (UPMC Mercy), Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA on October 21, 2015

Source: NC State University Libraries
Added: September 30, 2021

2015 conference paper

Dynamic surface control of neuromuscular electrical stimulation of a musculoskeletal system with activation dynamics and an input delay

2015 American Control Conference (ACC), 2015-July, 631–636.

By: N. Alibeji*, N. Kirsch* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch* & N. Sharma*

Event: 2015 American Control Conference (ACC)

TL;DR: A dynamic surface control (DSC) approach was used to design an NMES controller that compensates for EMD in the activation dynamics and achieves semi-global uniformly ultimately bounded (SGUUB) tracking for the delayed musculoskeletal system. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2015 conference paper

Expectation Maximization Method to Identify an Electrically Stimulated Musculoskeletal Model

[Paper]. Volume 2: Diagnostics and Detection; Drilling; Dynamics and Control of Wind Energy Systems; Energy Harvesting; Estimation and Identification; Flexible and Smart Structure Control; Fuels Cells/Energy Storage; Human Robot Interaction; HVAC Building Energy Management; Industrial Applications; Intelligent Transportation Systems; Manufacturing; Mechatronics; Modelling and Validation; Motion and Vibration Control Applications, 2(DSCC2015-9956).

By: H. Ravichandar*, A. Dani*, J. Khadijah-Hajdu*, N. Kirsch*, Q. Zhong* & N. Sharma*

Contributors: H. Ravichandar*, A. Dani*, J. Khadijah-Hajdu*, N. Kirsch*, Q. Zhong* & N. Sharma*

Event: ASME 2015 Dynamic Systems and Control Conference

TL;DR: A system identification algorithm for a musculoskeletal system using an approximate expectation maximization (E-M) using a dynamic model of the lower leg with a fixed ankle is presented. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2015 journal article

Further Results on Predictor-Based Control of Neuromuscular Electrical Stimulation

IEEE Transactions on Neural Systems and Rehabilitation Engineering, 23(6), 1095–1105.

By: N. Alibeji*, N. Kirsch*, S. Farrokhi* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch*, S. Farrokhi* & N. Sharma*

author keywords: Electromechanical delay; functional electrical stimulation; input delay; Lyapunov-Krasovskii functionals; Lyapunov Methods; neuromuscular electrical stimulation (NMES); nonlinear control
MeSH headings : Adult; Algorithms; Arm / physiology; Electric Stimulation; Healthy Volunteers; Humans; Leg / innervation; Leg / physiology; Male; Models, Neurological; Movement; Musculoskeletal Physiological Phenomena; Nonlinear Dynamics; Psychomotor Performance / physiology; Walking / physiology; Young Adult
TL;DR: A new predictor-based closed-loop controller called proportional integral derivative controller with delay compensation (PID-DC) is presented in this paper, designed to compensate for EMDs during NMES. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2015 conference paper

Nonlinear Model Predictive Control of Functional Electrical Stimulation

Volume 2: Diagnostics and Detection; Drilling; Dynamics and Control of Wind Energy Systems; Energy Harvesting; Estimation and Identification; Flexible and Smart Structure Control; Fuels Cells/Energy Storage; Human Robot Interaction; HVAC Building Energy Management; Industrial Applications; Intelligent Transportation Systems; Manufacturing; Mechatronics; Modelling and Validation; Motion and Vibration Control Applications, 2.

By: N. Kirsch*, N. Alibeji* & N. Sharma*

Contributors: N. Kirsch*, N. Alibeji* & N. Sharma*

Event: ASME 2015 Dynamic Systems and Control Conference

TL;DR: A gradient projection-based model predictive controller is used for an approximate optimal control of a knee extension neuroprosthesis using a control Lyapunov function as a terminal cost to ensure stability of the model predictive control. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2015 journal article

Optimization of a Stimulation Train based on a Predictive Model of Muscle Force and Fatigue

IFAC-PapersOnLine, 48(20), 338–342.

By: B. Doll*, N. Kirsch* & N. Sharma*

Contributors: B. Doll*, N. Kirsch* & N. Sharma*

TL;DR: Preliminary results show that optimizing stimulation patterns, based on a subject specific predictive mathematical model, may potentially delay the onset of muscle fatigue while obtaining desired force profiles. (via Semantic Scholar)
Sources: Crossref, NC State University Libraries, ORCID
Added: September 23, 2021

2014 conference paper

A discrete-time nonlinear estimator for an orthosis-aided gait

ASME 2014 Dynamic Systems and Control Conference, DSCC 2014, 1. http://www.scopus.com/inward/record.url?eid=2-s2.0-84929353401&partnerID=MN8TOARS

By: A. Dani & N. Sharma

Contributors: A. Dani & N. Sharma

Source: ORCID
Added: August 12, 2021

2014 conference paper

A semi-active hybrid neuroprosthesis for restoring lower limb function in paraplegics

2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014, 2557–2560.

By: N. Kirsch, N. Alibeji, L. Fisher, C. Gregory & N. Sharma*

Contributors: N. Kirsch, N. Alibeji, L. Fisher, C. Gregory & N. Sharma*

MeSH headings : Electric Stimulation Therapy / instrumentation; Gait / physiology; Hip / physiopathology; Humans; Knee / physiopathology; Lower Extremity / physiopathology; Neural Prostheses; Orthotic Devices; Paraplegia / rehabilitation; Walking / physiology
TL;DR: The initial testing of a semi-active hybrid walking neuroprosthesis using a finite state machine that uses a recently developed nonlinear controller for position tracking control of the hip motors and cues from the hip angle to actuate FES and other components is demonstrated. (via Semantic Scholar)
UN Sustainable Development Goal Categories
14. Life Below Water (OpenAlex)
Source: ORCID
Added: August 12, 2021

2014 conference paper

A state synchronization controller for functional electrical stimulation-based telerehabilitation

ASME 2014 Dynamic Systems and Control Conference, DSCC 2014, 3.

By: N. Alibeji*, N. Kirsch*, A. Sethi* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch*, A. Sethi* & N. Sharma*

TL;DR: A position-synchronization controller for functional electrical stimulation (FES)-based telerehabilitation synchronizes an FES-driven human limb with a remote physical therapist’s manipulator despite constant bilateral communication delays. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2014 journal article

Dynamic optimization of FES and orthosis-based walking using simple models

IEEE Transactions on Neural Systems and Rehabilitation Engineering, 22(1), 114–126.

By: N. Sharma*, V. Mushahwar* & R. Stein*

Contributors: N. Sharma*, V. Mushahwar* & R. Stein*

author keywords: Dynamic optimization; functional electrical stimulation; hybrid orthosis; optimal control; walking model
MeSH headings : Computer Simulation; Electric Stimulation Therapy / methods; Gait; Gait Disorders, Neurologic / physiopathology; Gait Disorders, Neurologic / rehabilitation; Humans; Leg / physiopathology; Models, Biological; Muscle Contraction; Muscle, Skeletal / physiopathology; Orthotic Devices; Range of Motion, Articular; Therapy, Computer-Assisted / methods
TL;DR: Dynamic optimization can be utilized to compute gait parameters such as step length, steady state velocity, and joint angle trajectories in future clinical implementation of FES and orthosis-based walking. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2014 conference paper

Model predictive control-based dynamic control allocation in a hybrid neuroprosthesis

ASME 2014 Dynamic Systems and Control Conference, DSCC 2014, 3.

By: N. Kirsch*, N. Alibeji* & N. Sharma*

Contributors: N. Kirsch*, N. Alibeji* & N. Sharma*

TL;DR: It is proposed that a model predictive control (MPC)-based control design can be used to optimally distribute joint torque, and can adapt as the muscle fatigue sets in. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2014 conference paper

Nonlinear estimation of gait kinematics during functional electrical stimulation and orthosis-based walking

2014 American Control Conference, 4778–4783.

By: N. Sharma* & A. Dani*

Contributors: N. Sharma* & A. Dani*

Event: 2014 American Control Conference - ACC 2014 at Portland, OR on June 4-6, 2014

TL;DR: A state-dependent coefficient (SDC)-based nonlinear estimator is developed to estimate the lower limb angles which can be used to decide when the FES signal should be applied to the leg during the different phases of walking. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Sources: ORCID, Crossref, NC State University Libraries
Added: August 12, 2021

2013 journal article

Adaptive inverse optimal neuromuscular electrical stimulation

IEEE Transactions on Cybernetics, 43(6), 1710–1718.

By: Q. Wang*, N. Sharma*, M. Johnson*, C. Gregory* & W. Dixon*

Contributors: Q. Wang*, N. Sharma*, M. Johnson*, C. Gregory* & W. Dixon*

author keywords: Functional electrical stimulation (FES); inverse optimal control; Lyapunov stability; neural network (NN); neuromuscular electrical stimulation; nonlinear system control
MeSH headings : Adaptation, Physiological / physiology; Adult; Algorithms; Biofeedback, Psychology / methods; Biofeedback, Psychology / physiology; Electric Stimulation Therapy / methods; Humans; Knee Joint / physiology; Male; Muscle Contraction / physiology; Muscle, Skeletal / physiology; Range of Motion, Articular / physiology; Therapy, Computer-Assisted / methods
Source: ORCID
Added: August 12, 2021

2013 conference paper

Control of functional electrical stimulation in the presence of electromechanical and communication delays

International IEEE/EMBS Conference on Neural Engineering, NER, 299–302.

By: N. Alibeji*, N. Kirsch* & N. Sharma*

Contributors: N. Alibeji*, N. Kirsch* & N. Sharma*

TL;DR: The experimental results obtained with the new automatic control method, designed to achieve position tracking between a user and the remote manipulator device, show its superior performance in comparison to the proportional integral derivative (PID) controller. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2013 conference paper

Optimized control of different actuation strategies for FES and orthosis aided gait

ASME 2013 Dynamic Systems and Control Conference, DSCC 2013, 1.

By: N. Kirsch*, N. Alibeji* & N. Sharma*

Contributors: N. Kirsch*, N. Alibeji* & N. Sharma*

TL;DR: It is shown that dynamic optimization can be used to compute stimulation/torque profiles and their corresponding joint angle trajectories which minimize electrical stimulation and walker push or pull forces. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2013 journal article

Saturated control of an uncertain nonlinear system with input delay

Automatica, 49(6), 1741–1747.

By: N. Fischer*, A. Dani*, N. Sharma* & W. Dixon*

Contributors: N. Fischer*, A. Dani*, N. Sharma* & W. Dixon*

author keywords: Saturated control; Input delay; Nonlinear control; Lyapunov-Krasovskii functional
TL;DR: A Lyapunov-based stability analysis utilizing LyapUNov-Krasovskii (LK) functionals is provided to prove uniformly ultimately bounded tracking despite uncertainties in the dynamics. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2012 conference paper

A predictor-based compensation for electromechanical delay during neuromuscular electrical stimulation-II

Proceedings of the American Control Conference, 5604–5609. http://www.scopus.com/inward/record.url?eid=2-s2.0-84869406024&partnerID=MN8TOARS

By: N. Sharma

Contributors: N. Sharma

Source: ORCID
Added: August 12, 2021

2012 journal article

Closed-loop neural network-based NMES control for human limb tracking

IEEE Transactions on Control Systems Technology, 20(3), 712–725.

By: N. Sharma*, C. Gregory*, M. Johnson* & W. Dixon*

Contributors: N. Sharma*, C. Gregory*, M. Johnson* & W. Dixon*

author keywords: Asymptotic stability; closed-loop control of functional electrical stimulation (FES); neural networks (NNs); neuromuscular electrical stimulation (NMES); non-isometric contractions; nonlinear control; robust integral of the sign of the error (RISE)-based feedback
TL;DR: Efforts in this paper focus on the use of a NN feedforward controller that is augmented with a continuous robust feedback term to yield an asymptotic result (in lieu of typical uniformly ultimately bounded stability). (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2012 conference paper

Gait planning and double support phase model for functional electrical stimulation-based walking

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS, 1904–1907.

By: N. Sharma* & R. Stein*

Contributors: N. Sharma* & R. Stein*

MeSH headings : Electric Stimulation; Gait / physiology; Humans; Leg / physiology; Models, Theoretical; Thigh / physiology; Torque; Walking / physiology
TL;DR: Lower limb segment angle trajectories are computed from simple mathematical models developed to represent functional electrical stimulation (FES) and a novel brace based walking to design walking trajectories that minimize muscle activations and arm reaction forces generated from the walker. (via Semantic Scholar)
UN Sustainable Development Goal Categories
11. Sustainable Cities and Communities (OpenAlex)
Source: ORCID
Added: August 12, 2021

2012 journal article

Gait planning and double support phase model for functional electrical stimulation-based walking.

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference, 2012, 1904–1907. http://www.scopus.com/inward/record.url?eid=2-s2.0-84880821464&partnerID=MN8TOARS

By: N. Sharma & R. Stein

Contributors: N. Sharma & R. Stein

Source: ORCID
Added: August 12, 2021

2012 speech

Lyapunov-based Control and Trajectory Planning for Restoring Human Limb Function

Sharma, N. (2012, February). Presented at the Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA.

By: N. Sharma

Event: at Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA

Source: NC State University Libraries
Added: September 30, 2021

2012 speech

Lyapunov-based Control and Trajectory Planning for Restoring Human Limb Function,

Sharma, N. (2012, March). Presented at the Department of Mechanical Engineering, University of California Riverside, Riverside, CA.

By: N. Sharma

Event: Department of Mechanical Engineering at University of California Riverside, Riverside, CA

Source: NC State University Libraries
Added: September 24, 2021

2012 speech

Nonlinear Control and Optimization Methods for Functional Electrical Stimulation

Sharma, N. (2012, January). Presented at the Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.

By: N. Sharma

Event: Department of Mechanical Engineering at University of Alberta, Edmonton, AB, Canada

Source: NC State University Libraries
Added: September 23, 2021

2012 speech

Nonlinear Control and Optimization Methods for Functional Electrical Stimulation

Sharma, N. (2012, February). Department of Biomedical Engineering, presented at the Department of Biomedical Engineering, University of California, Davis, Davis, CA.

By: N. Sharma

Event: Department of Biomedical Engineering at University of California, Davis, Davis, CA

Source: NC State University Libraries
Added: September 24, 2021

2012 speech

Nonlinear Control and Optimization Methods for Restoring Walking via Neuroprosthetics

(2012, April). Presented at the Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA.

Nitin Sharma

Event: at Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA

Source: NC State University Libraries
Added: September 30, 2021

2012 speech

Nonlinear Control and Optimization Methods for Restoring Walking via Neuroprosthetics

Sharma, N. (2012, March). Presented at the Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE.

By: N. Sharma

Event: at Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE

Source: NC State University Libraries
Added: September 30, 2021

2012 conference paper

RISE-based control of an uncertain nonlinear system with time-varying state delays

Proceedings of the IEEE Conference on Decision and Control, 3502–3507.

By: N. Fischer*, R. Kamalapurkar*, N. Sharma* & W. Dixon*

Contributors: N. Fischer*, R. Kamalapurkar*, N. Sharma* & W. Dixon*

TL;DR: A neural network is augmented with a robust integral of the sign of the error control structure to achieve semi-global asymptotic tracking in the presence of unknown, arbitrarily large, time-varying delays, not linear-in-the-parameters uncertainty and additive bounded disturbances. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Source: ORCID
Added: August 12, 2021

2012 journal article

Rise-based adaptive control of a control affine uncertain nonlinear system with unknown state delays

IEEE Transactions on Automatic Control, 57(1), 255–259.

By: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

Contributors: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

author keywords: Desired compensation adaptation law (DCAL)
TL;DR: A robust adaptive control method and a delay-free gradient-based desired compensation adaptation law (DCAL) are utilized to compensate for unknown time-delays, linearly parameterizable uncertainties, and additive bounded disturbances for a general nonlinear system. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Source: ORCID
Added: August 12, 2021

2011 journal article

A novel modulation strategy to increase stimulation duration in neuromuscular electrical stimulation

Muscle and Nerve, 44(3), 382–387.

By: R. Downey*, M. Bellman*, N. Sharma*, Q. Wang*, C. Gregory* & W. Dixon*

Contributors: R. Downey*, M. Bellman*, N. Sharma*, Q. Wang*, C. Gregory* & W. Dixon*

author keywords: amplitude modulation; frequency modulation; functional electrical stimulation; muscle fatigue; neuromuscular electrical stimulation
MeSH headings : Adult; Electric Stimulation; Electric Stimulation Therapy / methods; Feedback, Physiological / physiology; Female; Humans; Male; Muscle Contraction / physiology; Muscle Fatigue / physiology; Neuromuscular Diseases / physiopathology; Neuromuscular Diseases / therapy; Quadriceps Muscle / physiopathology; Task Performance and Analysis; Time Factors
TL;DR: Compared with constant‐frequency stimulation, results indicate that using an error‐driven strategy to vary the stimulation frequency during amplitude modulation increases the number of successful contractions during non‐isometric conditions. (via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being (OpenAlex)
Source: ORCID
Added: August 12, 2021

2011 journal article

Asymptotic tracking by a reinforcement learning-based adaptive critic controller

Journal of Control Theory and Applications, 9(3), 400–409.

By: S. Bhasin*, N. Sharma*, P. Patre* & W. Dixon*

Contributors: S. Bhasin*, N. Sharma*, P. Patre* & W. Dixon*

TL;DR: A continuous-time AC controller is developed that yields asymptotic tracking of a class of uncertain nonlinear systems with bounded disturbances that approximates the plant dynamics and generates appropriate control actions. (via Semantic Scholar)
UN Sustainable Development Goal Categories
16. Peace, Justice and Strong Institutions (OpenAlex)
Source: ORCID
Added: August 12, 2021

2011 conference paper

Optimal trajectory planning for a constrained functional electrical stimulation-based human walking

2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2011, 603–607.

By: N. Sharma* & R. Stein*

Contributors: N. Sharma* & R. Stein*

Event: 2011 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society at Boston, MA on August 30 - September 3, 2011

MeSH headings : Algorithms; Electric Stimulation Therapy / methods; Gait Disorders, Neurologic / rehabilitation; Humans; Leg / physiopathology; Muscle Contraction; Muscle, Skeletal / physiopathology; Therapy, Computer-Assisted / methods
TL;DR: A dynamic model representing FES-elicited walking constrained by an orthosis and a walker and the design of optimal stimulation and force profiles that minimize muscle activations via FES and arm reaction forces from the walker is presented. (via Semantic Scholar)
Sources: ORCID, Crossref, NC State University Libraries
Added: August 12, 2021

2011 journal article

Predictor-based compensation for electromechanical delay during neuromuscular electrical stimulation

IEEE Transactions on Neural Systems and Rehabilitation Engineering, 19(6), 601–611.

By: N. Sharma*, C. Gregory & W. Dixon

Contributors: N. Sharma*, C. Gregory & W. Dixon

author keywords: Electromechanical delay; functional electrical stimulation; input delay; Lyapunov-Krasovskii functionals; neuromuscular electrical stimulation (NMES); nonlinear control
MeSH headings : Adult; Algorithms; Electric Stimulation / instrumentation; Electric Stimulation / methods; Electromyography; Electrophysiology; Equipment Design; Female; Forecasting; Humans; Knee Joint / physiology; Lower Extremity / physiology; Male; Mechanical Phenomena; Muscle, Skeletal / innervation; Muscle, Skeletal / physiology; Nonlinear Dynamics; Young Adult
TL;DR: This paper provides control development and a mathematical stability analysis of a NMES controller with a predictive term that actively accounts for EMD through the development of a novel predictor-type method to address the delay in the voltage input to the muscle. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2011 journal article

Predictor-based control for an uncertain EulerLagrange system with input delay

Automatica, 47(11), 2332–2342.

By: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

Contributors: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

author keywords: Input delay compensation; Uncertainty; Nonlinear control; Lyapunov-based control; Lyapunov-Krasovskii functionals
TL;DR: Control of nonlinear systems with actuator delay is a challenging problem because of the need to develop some form of prediction of the nonlinear dynamics, and Lyapunov-Krasovskii functionals are used within a LyapUNov-based stability analysis to prove semi-global uniformly ultimately bounded tracking. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2011 conference paper

Saturated control of an uncertain Euler-Lagrange system with input delay

Proceedings of the IEEE Conference on Decision and Control, 7587–7592.

By: N. Fischer*, A. Dani*, N. Sharma* & W. Dixon*

Contributors: N. Fischer*, A. Dani*, N. Sharma* & W. Dixon*

TL;DR: This paper examines saturated control of a general class of uncertain nonlinear Euler-Lagrange systems with time-delayed actuation and additive bounded disturbances with a Lyapunov-based stability analysis to prove uniformly ultimately bounded tracking despite uncertainties in the dynamics. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2010 conference paper

Adaptive inverse optimal neuromuscular electrical stimulation

IEEE International Symposium on Intelligent Control - Proceedings, 1287–1292.

By: Q. Wang*, N. Sharma*, M. Johnson* & W. Dixon*

Contributors: Q. Wang*, N. Sharma*, M. Johnson* & W. Dixon*

TL;DR: Efforts in this paper focus on the development of a first ever inverse optimal NMES controller that yields an optimal limb tracking result, designed that achieves desired limb trajectory tracking while simultaneously minimizing a cost functional that is positive in the error states and stimulation input. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2010 conference paper

Asymptotic optimal control of neuromuscular electrical stimulation

Proceedings of the IEEE Conference on Decision and Control, 839–844.

By: Q. Wang*, N. Sharma*, M. Johnson* & W. Dixon*

Contributors: Q. Wang*, N. Sharma*, M. Johnson* & W. Dixon*

TL;DR: In this paper, a NMES controller is developed to minimize a quadratic cost functional to balance asymptotic trajectory tracking performance and control effort, potentially reducing overstimulation of the muscle. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2010 conference paper

Compensating Input Delay and Muscle Fatigue during Neuromuscular Electrical Stimulation Control

Sharma, N., & Dixon, W. E. (2010, April 22). Presented at the Symposium on Emerging Topics in Control and Modeling: Biomedical Systems, Urbana, IL. http://biomedsym.beckman.illinois.edu/posters/Sharma2.pdf

By: N. Sharma & W. Dixon

Event: Symposium on Emerging Topics in Control and Modeling: Biomedical Systems at Urbana, IL on April 22-23, 2010

Source: NC State University Libraries
Added: September 23, 2021

2010 conference paper

Lyapunov-based Control Methods for Neuromuscular Electrical Stimulation

Sharma, N. (2010, September). Presented at the Alberta Motor Control Meeting, Kananaskis, AB, Canada.

By: N. Sharma

Event: Alberta Motor Control Meeting at Kananaskis, AB, Canada

Source: NC State University Libraries
Added: September 23, 2021

2010 conference paper

Nonlinear control of NMES: Incorporating fatigue and calcium dynamics

Proceedings of the ASME Dynamic Systems and Control Conference 2009, DSCC2009, (PART A), 705–712.

By: N. Sharma*, P. Patre*, C. Gregory* & W. Dixon*

Contributors: N. Sharma*, P. Patre*, C. Gregory* & W. Dixon*

TL;DR: A neural network-based estimate of the fatigue model mismatch is incorporated in a nonlinear controller through a backstepping based method to control the human quadriceps femoris muscle undergoing non-isometric contractions. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2010 conference paper

Predictor-based control for an uncertain Euler-Lagrange system with input delay

Proceedings of the 2010 American Control Conference, 1422–1427.

By: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

Contributors: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

Event: 2010 American Control Conference (ACC 2010) at Baltimore, MD on June 30 - July 2, 2010

Sources: Crossref, ORCID
Added: August 12, 2021

2010 conference paper

RISE-based adaptive control of an uncertain nonlinear system with unknown state delays

Proceedings of the IEEE Conference on Decision and Control, 1773–1778.

By: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

Contributors: N. Sharma*, S. Bhasin*, Q. Wang* & W. Dixon*

TL;DR: A robust adaptive control method, a gradient-based desired compensation adaptation law (DCAL), and a Lyapunov-Kravoskii (LK) functional-based delay control term are utilized to compensate for unknown time-delays, linearly parameterizable uncertainties, and additive bounded disturbances for a general nonlinear system. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2010 conference paper

Robust asymptotic tracking of a class of nonlinear systems using an adaptive critic based controller

Proceedings of the 2010 American Control Conference, ACC 2010, 3223–3228. http://www.scopus.com/inward/record.url?eid=2-s2.0-77957804698&partnerID=MN8TOARS

By: S. Bhasin, N. Sharma, P. Patre & W. Dixon

Contributors: S. Bhasin, N. Sharma, P. Patre & W. Dixon

Source: ORCID
Added: August 12, 2021

2009 journal article

Nonlinear neuromuscular electrical stimulation tracking control of a human limb

IEEE Transactions on Neural Systems and Rehabilitation Engineering, 17(6), 576–584.

By: N. Sharma*, K. Stegath, C. Gregory & W. Dixon

Contributors: N. Sharma*, K. Stegath, C. Gregory & W. Dixon

author keywords: Asymptotic stability; Lyapunov methods; neuromuscular electrical stimulation (NMES); nonlinear control; RISE feedback
MeSH headings : Adult; Algorithms; Electric Stimulation / methods; Feedback, Physiological / physiology; Female; Humans; Knee Joint / physiology; Male; Movement / physiology; Muscle Contraction / physiology; Muscle, Skeletal / innervation; Muscle, Skeletal / physiology; Task Performance and Analysis; Young Adult
TL;DR: A nonlinear control method is developed to control the human quadriceps femoris muscle undergoing nonisometric contractions and can be proven to yield asymptotic stability for a nonlinear muscle model in the presence of bounded nonlinear disturbances. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2008 journal article

Comparing the force- and excursion-frequency relationships in human skeletal muscle

Muscle and Nerve, 38(6), 1627–1629.

By: C. Gregory*, C. Bickel*, N. Sharma* & W. Dixon*

Contributors: C. Gregory*, C. Bickel*, N. Sharma* & W. Dixon*

author keywords: electrical stimulation; force; muscle
MeSH headings : Adult; Electric Stimulation; Female; Humans; Isometric Contraction / physiology; Leg / physiology; Male; Muscle Contraction / physiology; Muscle, Skeletal / physiology; Young Adult
TL;DR: The impact of varying stimulation frequency is consistent between isometric and dynamic contractions and the predictability of the force– and excursion–frequency relationships is extremely strong across stimulation intensities. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2008 conference paper

Modified neural network-based electrical stimulation for human limb tracking

IEEE International Symposium on Intelligent Control - Proceedings, 1320–1325.

By: N. Sharma*, C. Gregory*, M. Johnson* & W. Dixon*

Contributors: N. Sharma*, C. Gregory*, M. Johnson* & W. Dixon*

TL;DR: This paper focuses on the use of a neural network feedforward controller that is augmented with a continuous robust feedback term to yield an asymptotic result in closed-loop control of skeletal muscle. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2008 conference paper

Nonlinear tracking control of a human limb via neuromuscular electrical stimulation

Proceedings of the American Control Conference, 1941–1946.

By: K. Stegath*, N. Sharma*, C. Gregory* & W. Dixon*

Contributors: K. Stegath*, N. Sharma*, C. Gregory* & W. Dixon*

TL;DR: A nonlinear control method that uses neuromuscular electrical stimulation to control the human quadriceps femoris muscle undergoing non- isometric contractions and can be proven to yield asymptotic stability for a nonlinear muscle model in the presence of bounded nonlinear disturbances. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2007 conference paper

An extremum seeking method for non-isometric neuromuscular electrical stimulation

Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics, 2528–2532.

By: K. Stegath*, N. Sharma*, C. Gregory* & W. Dixon*

Contributors: K. Stegath*, N. Sharma*, C. Gregory* & W. Dixon*

TL;DR: An optimal extremum seeking approach is developed in this paper to identify frequency and voltage modulation parameters for a neuromuscular electrical stimulation control objective. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

2007 conference paper

Experimental demonstration of rise-based NMES of human quadriceps muscle

2007 IEEE/NIH Life Science Systems and Applications Workshop, LISA, 43–46.

By: K. Stegath*, N. Sharma*, C. Gregory* & W. Dixon*

Contributors: K. Stegath*, N. Sharma*, C. Gregory* & W. Dixon*

TL;DR: The nonlinear control method explored in this paper uses voltage modulation for controlling human quadriceps femoris muscle undergoing non-isometric neuromuscular electrical stimulation to provide computer controlled stimulation to enable the lower limb of a human to either go to a desired constant position or follow a time-varying desired trajectory. (via Semantic Scholar)
Source: ORCID
Added: August 12, 2021

Employment

Updated: September 3rd, 2019 21:18

2019 - present

North Carolina State University Raleigh, NC, US
Associate Professor Biomedical Engineering

2012 - 2019

University of Pittsburgh Pittsburgh, PA, US
Assistant Professor Mechanical Engineering and Materials Science

2010 - 2012

University of Alberta Faculty of Science Edmonton, AB, CA
Postdoctoral Fellow Physiology

Education

Updated: August 16th, 2015 11:32

2006 - 2010

University of Florida Gainesville, FL, US
PhD/Mechanical Engineering Mechanical Engineering

2006 - 2008

University of Florida Gainesville, FL, US
M.S. Mechanical Engineering PhD

2000 - 2004

Thapar University Patiala, Punjab, IN
B.E. Industrial Engineering Industrial Engineering

Funding History

Funding history based on the linked ORCID record. Updated: August 16th, 2015 11:35

grant May 1, 2015 - April 30, 2018
Coordinating Electrical Stimulation and Motor Assist in a Hybrid Neuroprosthesis Using Control Strategies Inspired by Human Motor Control
National Science Foundation - Directorate for Engineering
grant July 1, 2011 - June 30, 2012
Design of Optimal Walking Trajectories to Restore Safe and Metabolically Efficient Movement in Mobility-impaired Persons
Alberta Innovates - Health Solutions

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