Article
Automation & Control Systems
Xinyu Tian, Shaoping Wang, Xingjian Wang, Dengpeng Dong, Yuwei Zhang
Summary: This article introduces a new compliant powered ankle prosthesis driven by electro-hydraulic technology, which solves the contradiction between output power and prosthetic mass, providing sufficient output performance. The prosthesis utilizes high-speed valves and hydraulic systems for precise control, and has been tested through a series of experiments to validate its effectiveness.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Automation & Control Systems
Xinyu Tian, Shaoping Wang, Xingjian Wang, Dengpeng Dong, Yuwei Zhang
Summary: The new compliant powered ankle prosthesis driven by electro-hydraulic technology solves the contradiction between output power and prosthetic mass, providing sufficient performance with lower installed power. The patented design combines hydraulic components for energy storage and release control, and utilizes high-speed ON-OFF valves for real-time hydraulic damping adjustment, achieving an efficiency of 62% in experiments.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Robotics
Krishan Bhakta, Jonathan Camargo, William Compton, Kinsey Herrin, Aaron Young
Summary: Machine learning models, developed in this study, show excellent accuracy in rapidly determining walking speed for both subject dependent and subject independent algorithms. The real-time continuous determination at 50 Hz allows for good performance even when walking speed changes rapidly.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Multidisciplinary Sciences
Zane A. A. Colvin, Jana R. R. Montgomery, Alena M. M. Grabowski
Summary: People with transtibial amputation using passive-elastic prostheses have higher leg muscle activity and metabolic cost than non-amputees. Stance-phase powered prostheses can reduce metabolic cost for amputees. However, differences in leg muscle activity between different prostheses do not fully explain the differences in metabolic cost.
ROYAL SOCIETY OPEN SCIENCE
(2022)
Article
Robotics
Sarah Hood, Lukas Gabert, Tommaso Lenzi
Summary: This study presents an adaptive stair ascent controller for individuals with above-knee amputations, allowing them to climb stairs of varying heights with their preferred gait patterns and cadence. By modulating the prosthesis position and torque-angle relationship, the controller provides toe clearance and torque assistance for different stair heights.
IEEE TRANSACTIONS ON ROBOTICS
(2022)
Article
Engineering, Biomedical
Xiangyu Peng, Yadrianna Acosta-Sojo, Man Wu, Leia Stirling
Summary: This study aimed to evaluate people's sensitivity to changes in exoskeleton actuation timing and its associated ankle angle changes. Participants wore an active ankle exoskeleton and compared pairs of torque profiles with different actuation timings while walking on a treadmill. The results showed individual differences in sensitivity towards actuation timing and associated ankle angle changes, providing insights into how people perceive changes in exoskeleton control parameters.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2022)
Article
Robotics
Chinmay Jategaonkar, Yogesh Singh, Vineet Vashista
Summary: This study investigates the effect of ankle exoskeletons on ankle joint motion in healthy individuals, revealing the impact of residual damping on gait adaptation. It is significant for future exoskeleton design and rehabilitation paradigm decisions.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2022)
Article
Biochemistry & Molecular Biology
Marshall K. Ishmael, Dante Archangeli, Tommaso Lenzi
Summary: The study demonstrates that an autonomous powered hip exoskeleton can significantly improve walking economy and therefore quality of life for individuals with above-knee amputation. The exoskeleton, which adds energy at the hip joint, greatly reduces the metabolic cost of walking, similar to removing a 12-kg backpack from a nonamputee. This solution has the potential to enhance mobility and improve the overall well-being of above-knee amputees.
Article
Engineering, Biomedical
Harrison L. Bartlett, Shane T. King, Michael Goldfarb, Brian E. Lawson
Summary: This paper presents a semi-powered ankle prosthesis and a unified controller that can provide biomimetic behavior for individuals with transtibial amputations, allowing for level and sloped walking without the need to identify ground slope or adjust control parameters. Experimental results demonstrate that the system can maintain consistent external quasi-stiffness similar to that of healthy individuals across various ground slopes.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2021)
Article
Automation & Control Systems
Jingjing Liu, Noor Azuan Abu Osman, Mouaz Al Kouzbary, Hamza Al Kouzbary, Nasrul Anuar Abd Razak, Hanie Nadia Shasmin, Nooranida Arifin
Summary: The paper discusses the importance of selecting and optimizing suitable elastic actuators in the design of powered ankle-foot prostheses, proposing a method to effectively reduce peak mechanical power and mean energy consumption power by optimizing with different elastic elements. The experiments found that UPEA and SE+UPEA both significantly improved in performance after optimization, recommended as the selection basis for the design of powered ankle-foot prostheses.
INTERNATIONAL JOURNAL OF CONTROL AUTOMATION AND SYSTEMS
(2022)
Article
Computer Science, Artificial Intelligence
Shawanee' Patrick, Namita Anil Kumar, Woolim Hong, Pilwon Hur
Summary: This study investigates the impact of toe-joint stiffness on walking with a powered transfemoral prosthesis for amputees. The study finds that lower stiffness reduces push-off assistance and results in compensatory movements, while higher stiffness increases power generation on the prosthetic side.
FRONTIERS IN NEUROROBOTICS
(2022)
Article
Engineering, Biomedical
Gholamreza Khademi, Dan Simon
Summary: The study introduces a new optimization framework for achieving accurate and low-complexity locomotion mode recognition systems in powered prostheses. Results show that the system trained with optimal feature subsets performs equally well in terms of performance compared to the system trained with the full feature set.
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
(2021)
Article
Computer Science, Artificial Intelligence
Namita Anil Kumar, Shawanee Patrick, Woolim Hong, Pilwon Hur
Summary: Customization of a lower-limb powered prosthesis controller is still a challenge. This study proposes a control framework using impedance control and trajectory tracking, with transition facilitated by Bezier curves. The derived impedance functions vary during the stance phase for the knee and ankle, and were simplified using principal component analysis. The resulting basis functions' weights exhibit monotonic trends with upslope and downslope walking, revealing a relationship between joint parameter functions and slope angle. The controller generated a healthy human gait similar to that found in healthy walking.
FRONTIERS IN NEUROROBOTICS
(2022)
Article
Biophysics
Jay Kim, Emily S. Gardinier, Vibha Vempala, Deanna H. Gates
Summary: Individuals with transtibial amputation (TTA) exhibit greater muscle activity in the intact limb gluteus medius and residual limb vastus medialis when walking with a powered prosthesis, but changes in muscle activity do not consistently correlate with changes in metabolic cost. Effective stabilization of the residual limb during stance may lead to metabolic benefits for individuals using a powered prosthesis.
JOURNAL OF BIOMECHANICS
(2021)
Article
Robotics
T. Kevin Best, Cara Gonzalez Welker, Elliott J. Rouse, Robert D. Gregg
Summary: Most previous walking controllers for prostheses require manual tuning of user-specific parameters and are only suitable for specific task conditions. This article introduces a data-driven, phase-based controller that enables biomimetic locomotion in variable-task walking.
IEEE TRANSACTIONS ON ROBOTICS
(2023)
Article
Engineering, Biomedical
I-Chieh Lee, Bretta L. Fylstra, Ming Liu, Tommaso Lenzi, He Huang
Summary: The study found that individuals with unilateral transfemoral amputation leverage task redundancy to regulate step and stride variability for energy economy. Amputee gait showed lower energy recovery rate and greater variability compared to non-amputee gait. Results also indicated differences in step characteristics and limitations of passive prosthetic devices.
JOURNAL OF NEUROENGINEERING AND REHABILITATION
(2022)
Article
Robotics
Sarah Hood, Lukas Gabert, Tommaso Lenzi
Summary: This study presents an adaptive stair ascent controller for individuals with above-knee amputations, allowing them to climb stairs of varying heights with their preferred gait patterns and cadence. By modulating the prosthesis position and torque-angle relationship, the controller provides toe clearance and torque assistance for different stair heights.
IEEE TRANSACTIONS ON ROBOTICS
(2022)
Article
Multidisciplinary Sciences
Sarah Hood, Suzi Creveling, Lukas Gabert, Minh Tran, Tommaso Lenzi
Summary: Walking and stair ambulation with powered knee and ankle prostheses is possible for individuals with bilateral above-knee amputations. Powered prostheses can restore natural leg movements and enable different gait patterns, while also restoring the necessary biomechanical functions for walking and stair ascent.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Biomedical
Grace R. Hunt, Sarah Hood, Lukas Gabert, Tommaso Lenzi
Summary: Using a powered prosthesis can improve symmetry, speed, and effort for above-knee amputees, potentially enhancing quality of life.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2023)
Article
Automation & Control Systems
Marshall K. Ishmael, Dante Archangeli, Tommaso Lenzi
Summary: This article presents the design, development, and validation of an autonomous powered hip exoskeleton with high torque density. The exoskeleton is capable of assisting users in activities such as walking, running, and climbing stairs.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Chemistry, Analytical
Rosemarie Murray, Joel Mendez, Lukas Gabert, Nicholas P. Fey, Honghai Liu, Tommaso Lenzi
Summary: This study demonstrates that A-mode ultrasound can classify ambulation mode with comparable, and in some cases, superior accuracy to mechanical sensing. It provides additional useful information about the user's gait beyond what is provided by mechanical sensors, suggesting its potential to improve ambulation mode classification.
Article
Robotics
Minh Tran, Lukas Gabert, Sarah Hood, Tommaso Lenzi
Summary: Robotic leg prostheses that replicate the biomechanical functions of the missing biological leg have the potential to improve mobility and quality of life for lower-limb amputees. However, existing powered prostheses are heavier, bigger, and have shorter battery life compared to passive prostheses, which limits their clinical viability. In this study, researchers present a robotic leg prosthesis that replicates the key biomechanical functions of the knee, ankle, and toe while matching the weight, size, and battery life of conventional prostheses. Preclinical tests show that this prosthesis allows for common ambulation activities with close to normative kinematics and kinetics, and users can walk on level ground indefinitely without charging the battery in passive mode.
Article
Engineering, Biomedical
Marshall K. K. Ishmael, Andrew Gunnell, Kai Pruyn, Suzi Creveling, Grace Hunt, Sarah Hood, Dante Archangeli, K. Bo Foreman, Tommaso Lenzi
Summary: This study investigates the biomechanics of individuals with above-knee amputations walking with and without a unilateral powered hip exoskeleton. The findings suggest that assisting the residual limb can reduce the energy consumption of the residual hip, which is important for understanding walking economy in individuals with disabilities.
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Biomedical
Grace R. Hunt, Sarah Hood, Lukas Gabert, Tommaso Lenzi
Summary: In this study, it was found that a powered knee-ankle prosthesis significantly improved weight-bearing symmetry during sit-down compared to passive prostheses for above-knee amputees. However, there was no corresponding decrease in muscle effort in the intact quadricep muscle. These results indicate the potential of powered prosthetic devices to improve balance during sit-down and provide insight for future development of powered prosthetics.
JOURNAL OF NEUROENGINEERING AND REHABILITATION
(2023)
Article
Engineering, Mechanical
Minh Tran, Lukas Gabert, Tommaso Lenzi
Summary: Across different fields within robotics, there is a need for lightweight, efficient actuators with human-like performance. Linkage-based passive variable transmissions and torque-sensitive transmissions have emerged as promising solutions by increasing actuator efficiency and power density, but their modeling and analysis are still open research topics. This paper introduces the sensitivity between input displacement and output torque as a key metric to analyze the performance of these complex mechanisms in dynamic tasks. The sensitivity model is validated through experiments with powered knee prostheses and proves its usefulness in predicting actuators' dynamic performance.
Article
Engineering, Biomedical
Joel Mendez, Rosemarie Murray, Lukas Gabert, Nicholas P. Fey, Honghai Liu, Tommaso Lenzi
Summary: Lower-limb powered prostheses require a reliable sensing modality for volitional control of ambulation. Surface electromyography (EMG) suffers from limitations, but A-mode ultrasound has shown promise for better resolution and specificity. This study demonstrates that A-mode ultrasound sensing can accurately predict walking kinematics for individuals with a transfemoral amputation.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2023)
Proceedings Paper
Engineering, Biomedical
Sergei V. Sarkisian, Andrew J. Gunnell, K. Bo Foreman, Tommaso Lenzi
Summary: This study investigates the use of a powered knee exoskeleton controlled by EMG signals to assist stroke patients during sit-to-stand transitions. The results demonstrate decreased knee torques and EMG signals, as well as improved medial-lateral balance, suggesting the efficacy of powered exoskeletons for high-torque tasks with stroke survivors.
2022 INTERNATIONAL CONFERENCE ON REHABILITATION ROBOTICS (ICORR)
(2022)
Proceedings Paper
Engineering, Biomedical
Dante Archangeli, Marshall K. Ishmael, Tommaso Lenzi
Summary: Autonomous powered exoskeletons have the potential to improve gait and walking ability in individuals with hemiparesis, but there is limited research on this population. In this case study, an individual with hemiparesis experienced a 30% increase in walking speed when using an autonomous powered hip exoskeleton. Biomechanical analysis revealed that this improvement was due to the exoskeleton enabling longer strides on the hemiparetic side. This study provides valuable information for future exoskeleton development and clinical study design.
2022 INTERNATIONAL CONFERENCE ON REHABILITATION ROBOTICS (ICORR)
(2022)