Design of under-actuated serial structures with non-identical modules to match desired finger postures

Noronha, Bernardo; Kulkarni, Suhas Raghavendra; Little, Kieran; Accoto, Dino

doi:10.1109/biorob49111.2020.9224457

Cited by 3 publications

(3 citation statements)

References 18 publications

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“…This is achieved by using structures composed of serially connected 3-D printed elements (MJF Plastic PA 12, HP) that are attached to the back of the index and middle fingers and the thumb (Fig. 1b), previously introduced in [36]. The use of this underactuated hyper-redundant mechanism allows for a high level of adaptability that is expressed in 2 ways: 1) the structures conform to different postures, creating minimal interference in hand motion when the device is not being actuated; 2) the structures are adaptable to different hand sizes, hence allowing for a single device to be used by many users.…”

Section: B Hand Exoskeletonmentioning

confidence: 99%

Soft, Lightweight Wearable Robots to Support the Upper Limb in Activities of Daily Living: A Feasibility Study on Chronic Stroke Patients

Noronha

Little

et al. 2022

IEEE Trans. Neural Syst. Rehabil. Eng.

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Stroke can be a devastating condition that impairs the upper limb and reduces mobility. Wearable robots can aid impaired users by supporting performance of Activities of Daily Living (ADLs). In the past decade, soft devices have become popular due to their inherent malleable and low-weight properties that makes them generally safer and more ergonomic. In this study, we present an improved version of our previously developed gravity-compensating upper limb exosuit and introduce a novel hand exoskeleton. The latter uses 3D-printed structures that are attached to the back of the fingers which prevent undesired hyperextension of joints. We explored the feasibility of using this integrated system in a sample of 10 chronic stroke patients who performed 10 ADLs. We observed a significant reduction of 30.3 ± 3.5% (mean ± standard error), 31.2 ± 3.2% and 14.0 ± 5.1% in the mean muscular activity of the Biceps Brachii (BB), Anterior Deltoid (AD) and Extensor Digitorum Communis muscles, respectively. Additionally, we observed a reduction of 14.0 ± 11.5%, 14.7 ± 6.9% and 12.8 ± 4.4% in the coactivation of the pairs of muscles BB and Triceps Brachii (TB), BB and AD, and TB and Pectoralis Major (PM), respectively, typically associated to pathological muscular synergies, without significant degradation of healthy muscular coactivation. There was also a significant increase of elbow flexion angle (12.1±1.5°). These results further cement the potential of using lightweight wearable devices to assist impaired users.

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Section: B Hand Exoskeletonmentioning

confidence: 99%

Soft, Lightweight Wearable Robots to Support the Upper Limb in Activities of Daily Living: A Feasibility Study on Chronic Stroke Patients

Noronha

Little

et al. 2022

IEEE Trans. Neural Syst. Rehabil. Eng.

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“…Hybrid devices are not nearly as prevalent as soft or rigid ones (14%), but one can observe from Figure 2.6 that this is a growing field. They can be achieved in different ways: a non-continuum rigid structure that has many more DOFs than the ones needed, attached to a soft framework [35,39,74,75]; a mechanism that alternates between soft and rigid segments with a soft interface between it and the hand [76]; a soft actuator that is encased in a rigid segmented structure [77]; a system with a constrained sliding type of transmission [38,48]. These devices are promising because they exhibit some advantages of both soft and rigid mechanisms: they have stiff parts that withstand the applied forces and improve safety, while at the same time having soft components that improve wearability.…”

Section: Analysis Of Devices and Current Trendsmentioning

confidence: 99%

“…Plastic PA 12, HP) that are attached to the back of the index and middle fingers and the thumb (Fig. 3.1b), previously introduced in [75]. The use of this underactuated hyperredundant mechanism allows for a high level of adaptability that is expressed in 2 ways: 1) the structures conform to different postures, creating minimal interference in hand motion 3.2.…”

Section: Hand Exoskeletonmentioning

confidence: 99%

Cable-driven underactuated wearable robotic devices for hand assistance

Bernardo¹

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To address the first aim, we carried out a feasibility clinical trial with ten post-stroke patients performing Activities of Daily Living (ADLs). We evaluated the physiological and kinematic effects of using a preliminary version of our hand exoskeleton that supported only finger extension combined with an elbow-assisting soft wearable robot (exosuit). We observed a reduction in the mean electromyographic (EMG) activity of the Biceps Brachii (BB), Anterior Deltoid (AD) and Extensor Digitorum Communis (EDC) muscles, as well as in the coactivation of pairs of muscles typically associated with pathological synergies. Questionnaires filled out by the participants, alongside discussions with healthcare professionals, provided positive and constructive feedback. This encouraged our continued efforts to develop and refine the device to expand its functionalities.The next step was to develop a model of the behaviour of the structures for defined input tensions on the wires. The main design parameter considered in the model is the rotational stiffness of the joints. By selecting different joint stiffness values, specific motions can be achieved. An optimisation-based framework was developed to automatically adjust the design of the structures to the dimensions of the user's hands. The optimisation goal was to follow the first postural synergy of the hand, which is known to encode a large amount of information regarding common patterns of human hands in daily life.We experimentally verified the created model, and obtained low error of the angular trajectory of the structure's joints, also observing low Cartesian position error of the elements. Then, a 3D-printed index finger (dimensioned following the average male user) was actuated by a structure, and the finger's angular trajectories were compared to the simulated ones. Low errors were obtained for the Metacarpophalangeal (MCP) and Proximal Interphalangeal (PIP) joints, and a moderate error for the Distal Interphalangeal (DIP) joint. Importantly, we observed that the stiffness of the structure could be modulated by controlling the tensions applied on the flexion and extension tendons: increasing the co-contraction of the tendons resulted in an increased stiffness at the joints. The fingertip forces exerted by the structure were evaluated, and reached the desired threshold corresponding to the values typically applied by therapists on low to moderately impaired stroke patients. Finally, in a qualitative manner, we demonstrated the successful grasping of a diverse set of objects typically used in rehabilitation settings.The first main contribution of this thesis is the demonstration of the potential that wearable robots have in aiding the upper limbs of impaired users in ADLs. This provides an important building block of evidence towards the use of robotic devices for assistance. The next main contribution is an underactuated mechanism for hand assistance. This is coupled with an automatic, model-based procedure that designs structures optimised to achieve the first postur...

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Exoskeletal Devices for Hand Assistance and Rehabilitation: A Comprehensive Analysis of State-of-the-Art Technologies

Noronha

Accoto

2021

IEEE Trans. Med. Robot. Bionics

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Design of under-actuated serial structures with non-identical modules to match desired finger postures

Cited by 3 publications

References 18 publications

Soft, Lightweight Wearable Robots to Support the Upper Limb in Activities of Daily Living: A Feasibility Study on Chronic Stroke Patients

Soft, Lightweight Wearable Robots to Support the Upper Limb in Activities of Daily Living: A Feasibility Study on Chronic Stroke Patients

Cable-driven underactuated wearable robotic devices for hand assistance

Exoskeletal Devices for Hand Assistance and Rehabilitation: A Comprehensive Analysis of State-of-the-Art Technologies

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