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Poggensee KL, Collins SH. Lower limb biomechanics of fully trained exoskeleton users reveal complex mechanisms behind the reductions in energy cost with human-in-the-loop optimization. Front Robot AI 2024; 11:1283080. [PMID: 38357293 PMCID: PMC10864513 DOI: 10.3389/frobt.2024.1283080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 01/03/2024] [Indexed: 02/16/2024] Open
Abstract
Exoskeletons that assist in ankle plantarflexion can improve energy economy in locomotion. Characterizing the joint-level mechanisms behind these reductions in energy cost can lead to a better understanding of how people interact with these devices, as well as to improved device design and training protocols. We examined the biomechanical responses to exoskeleton assistance in exoskeleton users trained with a lengthened protocol. Kinematics at unassisted joints were generally unchanged by assistance, which has been observed in other ankle exoskeleton studies. Peak plantarflexion angle increased with plantarflexion assistance, which led to increased total and biological mechanical power despite decreases in biological joint torque and whole-body net metabolic energy cost. Ankle plantarflexor activity also decreased with assistance. Muscles that act about unassisted joints also increased activity for large levels of assistance, and this response should be investigated over long-term use to prevent overuse injuries.
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Affiliation(s)
- Katherine L. Poggensee
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
- Department of Rehabilitation Medicine, Erasmus MC, Rotterdam, Netherlands
- Faculty of Mechanical, Maritime and Materials Engineering (3mE), Technical University of Delft, Delft, Netherlands
| | - Steven H. Collins
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
- Department of Bioengineering, Stanford University, Stanford, CA, United States
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2
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Sun Z, Mu A, Wang C, Liu Q, Hao F, Wei J, Li W. Research on an ankle rehabilitation robot for hemiplegic patients after stroke. Proc Inst Mech Eng H 2023; 237:1177-1189. [PMID: 37706474 DOI: 10.1177/09544119231197082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
This paper proposes an ankle rehabilitation robot to assist hemiplegic patients with movement training. The robot consists of two symmetric mechanisms, allowing stroke survivors to execute ankle rehabilitation training based on physiological differences. LPMS-B sensors measure the range of movement (ROM) of the human ankle joint, and the results are used for control parameters of the robot. Control strategies for constant speed training mode, constant torque training mode, and combination training mode are put forth based on the hardware system of the robot. Experiments verify the feasibility of the robot for ankle rehabilitation training. Results show a maximum mean error of 0.3364° between the trajectory of the intact side and the affected side, a maximum mean error of 0.0335°/s between target speed and experimental speed, and a maximum mean error of 0.0775 N m between target torque and experimental torque. The ankle joint rehabilitation robot proposed in this paper can help patients complete the training well under the three control modes.
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Affiliation(s)
- Zhengdi Sun
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, Shaanxi, P.R. China
| | - Anle Mu
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, Shaanxi, P.R. China
| | - Chunbao Wang
- Department of Neurology, Shenzhen Second People's Hospital, Shenzhen, Guangdong, P.R. China
- Shenzhen Institute of Geriatrics, P.R. China
- MK Smart Robotics Co., LTD, P.R. China
| | - Quanquan Liu
- Department of Neurology, Shenzhen Second People's Hospital, Shenzhen, Guangdong, P.R. China
- Shenzhen Institute of Geriatrics, P.R. China
- MK Smart Robotics Co., LTD, P.R. China
| | - Fuxiang Hao
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, Shaanxi, P.R. China
| | - Jianjun Wei
- School of Mechanical and Transportation Engineering, Guangxi University of Science and Technology, Liuzhou, Guangxi, P.R. China
| | - Wei Li
- School of Mechanical Engineering, Zhengzhou University of Science and Technology, Zhenghzou, P.R.China
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3
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Yang S, Huang X, Zhou JM, Xue Q. Application of robotic lower limb orthosis for people with lower limb dysfunction. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:041501. [PMID: 38081284 DOI: 10.1063/5.0140319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 04/03/2023] [Indexed: 12/18/2023]
Abstract
Due to the aging of the population or diseases, the number of patients with lower limb disorders has increased, causing social concern. Scholars have designed and developed advanced robotic lower limb orthoses, which can guide patients to perform reasonable rehabilitation training with correct limb postures, enhance their daily life participation and quality of life, and help them recover quickly. In recent years, a large number of new and advanced orthopedic equipment have been developed, which require a systematic summary analysis and comparison. This article reviewed typical newly developed, robotic lower limb orthoses and their use effects, as well as the advanced theories and technologies for their applications, and systematically discussed the problems in the research, design, testing, use, and popularization of robotic lower limb orthoses, and predicted their development direction in the future research and design, to enhance the reliability, convenience, and protection functions of orthotic equipment, make its functions closer to life, and give full play to the initiative of patients in the process of rehabilitation training, and reduce costs. Robotic lower limb orthoses is poised for even greater success and development in the future.
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Affiliation(s)
- Shuo Yang
- Department of Mechanical Engineering, Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry and Food Engineering Machinery and Equipment, Tianjin University of Science and Technology, Tianjin 300222, China
| | - Xin Huang
- Department of Mechanical Engineering, Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry and Food Engineering Machinery and Equipment, Tianjin University of Science and Technology, Tianjin 300222, China
| | - Jin-Man Zhou
- Department of Mechanical Engineering, Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry and Food Engineering Machinery and Equipment, Tianjin University of Science and Technology, Tianjin 300222, China
| | - Qiang Xue
- Department of Mechanical Engineering, Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry and Food Engineering Machinery and Equipment, Tianjin University of Science and Technology, Tianjin 300222, China
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Zhou Y. Recent advances in wearable actuated ankle-foot orthoses: Medical effects, design, and control. Proc Inst Mech Eng H 2023; 237:163-178. [PMID: 36515408 DOI: 10.1177/09544119221142335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This paper presents a survey on recent advances of wearable actuated ankle-foot orthoses (AAFOs). First of all, their medical functions are investigated. From the short-term aspect, they lead to rectification of pathological gaits, reduction of metabolic cost, and improvement of gait performance. After AAFO-based walking training with sufficient time, free walking performance can be enhanced. Then, key design factors are studied. First, primary design parameters are investigated. Second, common actuators are analysed. Third, human-robot interaction (HRI), ergonomics, safety, and application places, are considered. In the following section, control technologies are reviewed from the aspects of rehabilitation stages, gait feature quantities, and controller characteristics. Finally, existing problems are discussed; development trends are prospected.
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Affiliation(s)
- Yuan Zhou
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
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Chen B, Zi B, Zhou B, Wang Z. Implementation of Robotic Ankle–Foot Orthosis With an Impedance-Based Assist-as-Needed Control Strategy. JOURNAL OF MECHANISMS AND ROBOTICS 2022; 14. [DOI: 10.1115/1.4053218] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Abstract
In this paper, a robotic ankle–foot orthosis (AFO) is developed for individuals with a paretic ankle, and an impedance-based assist-as-needed controller is designed for the robotic AFO to provide adaptive assistance. First, a description of the robotic AFO hardware design is presented. Next, the design of the finite state machine is introduced, followed by an introduction to the modeling of the robotic AFO. Additionally, the control of the robotic AFO is presented. An impedance-based high-level controller that is composed of an ankle impedance based torque generation controller and an impedance controller is designed for the high-level control. A compensated low-level controller that is composed of a braking controller and a proportional-derivative controller with a compensation part is designed for the low-level control. Finally, a pilot study with eight healthy participants is conducted, and the experimental results demonstrate that with the proposed control algorithm, the robotic AFO has the potential for ankle rehabilitation by providing adaptive assistance. In the assisted condition with a high level of assistance, reductions of 8% and 20.1% of the root mean square of the tibialis anterior and lateral soleus activities are observed, respectively.
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Affiliation(s)
- Bing Chen
- School of Mechanical Engineering, Hefei University of Technology; Intelligent Interconnected Systems Laboratory of Anhui Province (Hefei University of Technology), Hefei, Anhui Province 230009, China
| | - Bin Zi
- School of Mechanical Engineering, Hefei University of Technology; Intelligent Interconnected Systems Laboratory of Anhui Province (Hefei University of Technology), Hefei, Anhui Province 230009, China
| | - Bin Zhou
- School of Mechanical Engineering, Hefei University of Technology; Intelligent Interconnected Systems Laboratory of Anhui Province (Hefei University of Technology), Hefei, Anhui Province 230009, China
| | - Zhengyu Wang
- School of Mechanical Engineering, Hefei University of Technology; Intelligent Interconnected Systems Laboratory of Anhui Province (Hefei University of Technology), Hefei, Anhui Province 230009, China
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Slade P, Kochenderfer MJ, Delp SL, Collins SH. Personalizing exoskeleton assistance while walking in the real world. Nature 2022; 610:277-282. [PMID: 36224415 PMCID: PMC9556303 DOI: 10.1038/s41586-022-05191-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 08/04/2022] [Indexed: 11/12/2022]
Abstract
Personalized exoskeleton assistance provides users with the largest improvements in walking speed1 and energy economy2-4 but requires lengthy tests under unnatural laboratory conditions. Here we show that exoskeleton optimization can be performed rapidly and under real-world conditions. We designed a portable ankle exoskeleton based on insights from tests with a versatile laboratory testbed. We developed a data-driven method for optimizing exoskeleton assistance outdoors using wearable sensors and found that it was equally effective as laboratory methods, but identified optimal parameters four times faster. We performed real-world optimization using data collected during many short bouts of walking at varying speeds. Assistance optimized during one hour of naturalistic walking in a public setting increased self-selected speed by 9 ± 4% and reduced the energy used to travel a given distance by 17 ± 5% compared with normal shoes. This assistance reduced metabolic energy consumption by 23 ± 8% when participants walked on a treadmill at a standard speed of 1.5 m s-1. Human movements encode information that can be used to personalize assistive devices and enhance performance.
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Affiliation(s)
- Patrick Slade
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Mykel J Kochenderfer
- Department of Aeronautics and Astronautics, Stanford University, Stanford, CA, USA
| | - Scott L Delp
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Steven H Collins
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA.
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Tomc M, Zadravec M, Olensek A, Matjacic Z. Harnessing Energy of a Treadmill for Push-Off Assistance During Walking: a Proof of Concept study. IEEE Int Conf Rehabil Robot 2022; 2022:1-6. [PMID: 36176127 DOI: 10.1109/icorr55369.2022.9896554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Various approaches in ankle exoskeleton design and control have recently been proposed and implemented, but few have been able to produce devices suitable for rehabilitation in clinical environment. In a recent in-silico study, we proposed a novel device: Ankle Exoskeleton using Treadmill Actuation for Push-off assistance (AN-EXTRA-Push). Using a brake and an elastic tendon, it harnesses energy of a moving treadmill during stance phase, then releases it during push-off to aid with plantarflexion torque generation. Simulation studies suggest inherent synchrony between the body's own efforts and ANEXTRA-Push assistance, allowing for intuitive use and simple control of the device. In this contribution we describe a mock-up device and the findings of a proof of concept study. Kinematics, ground reaction forces, interaction forces and EMG signals were measured for one subject walking with AN-EXTRA-Push with different levels of assistance. Using AN-EXTRA-Push did not result in substantial changes in the subject's kinematics and the activity of ankle plantarflexor muscles was successfully reduced. Preliminary results suggest that the concept is promising and appear to confirm the conclusions drawn from our previous simulation study.
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Reducing the energy cost of walking with low assistance levels through optimized hip flexion assistance from a soft exosuit. Sci Rep 2022; 12:11004. [PMID: 35768486 PMCID: PMC9243082 DOI: 10.1038/s41598-022-14784-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 06/13/2022] [Indexed: 11/09/2022] Open
Abstract
As we age, humans see natural decreases in muscle force and power which leads to a slower, less efficient gait. Improving mobility for both healthy individuals and those with muscle impairments/weakness has been a goal for exoskeleton designers for decades. In this work, we discover that significant reductions in the energy cost required for walking can be achieved with almost 50% less mechanical power compared to the state of the art. This was achieved by leveraging human-in-the-loop optimization to understand the importance of individualized assistance for hip flexion, a relatively unexplored joint motion. Specifically, we show that a tethered hip flexion exosuit can reduce the metabolic rate of walking by up to 15.2 ± 2.6%, compared to locomotion with assistance turned off (equivalent to 14.8% reduction compared to not wearing the exosuit). This large metabolic reduction was achieved with surprisingly low assistance magnitudes (average of 89 N, ~ 24% of normal hip flexion torque). Furthermore, the ratio of metabolic reduction to the positive exosuit power delivered was 1.8 times higher than ratios previously found for hip extension and ankle plantarflexion. These findings motivated the design of a lightweight (2.31 kg) and portable hip flexion assisting exosuit, that demonstrated a 7.2 ± 2.9% metabolic reduction compared to walking without the exosuit. The high ratio of metabolic reduction to exosuit power measured in this study supports previous simulation findings and provides compelling evidence that hip flexion may be an efficient joint motion to target when considering how to create practical and lightweight wearable robots to support improved mobility.
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Application of Wearable Sensors in Actuation and Control of Powered Ankle Exoskeletons: A Comprehensive Review. SENSORS 2022; 22:s22062244. [PMID: 35336413 PMCID: PMC8954890 DOI: 10.3390/s22062244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/28/2022] [Accepted: 03/08/2022] [Indexed: 02/06/2023]
Abstract
Powered ankle exoskeletons (PAEs) are robotic devices developed for gait assistance, rehabilitation, and augmentation. To fulfil their purposes, PAEs vastly rely heavily on their sensor systems. Human–machine interface sensors collect the biomechanical signals from the human user to inform the higher level of the control hierarchy about the user’s locomotion intention and requirement, whereas machine–machine interface sensors monitor the output of the actuation unit to ensure precise tracking of the high-level control commands via the low-level control scheme. The current article aims to provide a comprehensive review of how wearable sensor technology has contributed to the actuation and control of the PAEs developed over the past two decades. The control schemes and actuation principles employed in the reviewed PAEs, as well as their interaction with the integrated sensor systems, are investigated in this review. Further, the role of wearable sensors in overcoming the main challenges in developing fully autonomous portable PAEs is discussed. Finally, a brief discussion on how the recent technology advancements in wearable sensors, including environment—machine interface sensors, could promote the future generation of fully autonomous portable PAEs is provided.
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Tomc M, Matjačić Z. Harnessing Energy of a Treadmill for Push-Off Assistance During Walking: In-Silico Feasibility Study. Front Bioeng Biotechnol 2022; 10:832087. [PMID: 35252141 PMCID: PMC8889039 DOI: 10.3389/fbioe.2022.832087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
Regaining efficient push-off is a crucial step in restitution of walking ability in impaired individuals. Inspired by the elastic nature of ankle plantarflexor muscle-tendon complex, we propose a novel rehabilitation device: Ankle Exoskeleton using Treadmill Actuation for Push-off assistance (AN-EXTRA-Push). Using a brake and an elastic tendon, it harnesses energy of a moving treadmill during stance phase, then releases it during push-off to aid with plantarflexion torque generation. We studied the feasibility of such a device and explored some key design and control parameters. A parameter sweep of three key parameters (brake engagement timing, brake disengagement timing and elastic tendon stiffness) was conducted in-silico. Results suggest that such a device is feasible and might inherently possess some features that simplify its control. Brake engagement timing and elastic tendon stiffness values determine the level of exoskeleton assistance. Our study affirms that timing of assistive torque is crucial, especially the timing of assistance termination which is determined by brake disengagement timing. Insights acquired by this study should serve as a basis for designing an experimental device and conducting studies on effects of AN-EXTRA-Push in humans.
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Affiliation(s)
- Matej Tomc
- Research and Development Unit, University Rehabilitation Institute Republic of Slovenia, Ljubljana, Slovenia
- Laboratory of Robotics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
- *Correspondence: Matej Tomc,
| | - Zlatko Matjačić
- Research and Development Unit, University Rehabilitation Institute Republic of Slovenia, Ljubljana, Slovenia
- Laboratory of Robotics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
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Bardelli R, Harlaar J, Morone G, Tomba P, Esquenazi A, Benedetti MG. The Codivilla Spring: from then to now and beyond. Eur J Phys Rehabil Med 2021; 57:1012-1019. [PMID: 33861038 DOI: 10.23736/s1973-9087.21.06822-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The ankle-foot-orthosis (AFO), originally called Codivilla Spring, is an orthotic device prescribed to the patients with foot drop due to neurological diseases in order to control the range of motion of the ankle joint, to compensate for the muscle weakness/spasticity thus optimizing the gait function. In this paper, a historical revision of the most known and used AFO worldwide from the origin of its name and the first applications at the Rizzoli Orthopedic Institute to the most advanced solutions in use today is covered. Through the critical analysis of historical documents available, the paper reports on the controversy about the true inventor of the Codivilla Spring during the first decades of the twentieth century. Main current adult and child AFOs, in terms of their design and indications are presented. Finally, possible approaches for the selection of the correct orthosis and the individual prescription are discussed in order to manage specific mechanical neuromuscular deficiencies of the subject's ankle-foot complex optimizing walking efficiency.
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Affiliation(s)
- Roberta Bardelli
- Physical Medicine and Rehabilitation Unit, IRCCS-Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Jaap Harlaar
- Clinical Technology & Technical Medicine, Delft University of Technology, Rotterdam Erasmus MC & Leiden UMC, Rotterdam, the Nederlands
| | | | - Patrizia Tomba
- Scientific Library, IRCCS-Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Alberto Esquenazi
- Department of PM&R, MossRehab and Einstein Healthcare Network, Elkins Park, PA, USA
| | - Maria Grazia Benedetti
- Physical Medicine and Rehabilitation Unit, IRCCS-Istituto Ortopedico Rizzoli, Bologna, Italy -
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