Wearable technologies最新文献

Industrial upper limb exoskeletons offload the upper limb during overhead tasks to help prevent musculoskeletal disorders to the shoulder. Although numerous studies showed reduced shoulder muscle activity during upper limb exoskeleton use for overhead postures, it remains unknown whether and how upper limb exoskeletons provide support over a large shoulder workspace beyond overhead work. Therefore, this study evaluated the Ottobock Paexo Shoulder over a large shoulder workspace from overhead to hip height with shoulder abduction and adduction. Upper body kinematics, muscle activity, and subjective user feedback were obtained by three-dimensional motion capture, surface EMG, and questionnaires, respectively, and captured while participants performed static and dynamic work tasks with an electric screwdriver. Participants completed these tasks (1) without the exoskeleton, (2) with a disengaged exoskeleton, (3) with moderate exoskeleton support, and (4) with high exoskeleton support. Exoskeleton support reduced deltoid muscle activity (-9 to -24 s%, p ≤ .001) in postures with an abducted shoulder, including nonoverhead postures. Exoskeleton support modestly decreased shoulder flexion (-3 to -5°, p ≤ .001) and increased shoulder abduction (2 to 5°, p ≤ .032), but the movement patterns during the dynamic task were unaffected. Additionally, exoskeleton-related effects increased with increasing support, but the subjective perception of change also increased, and perceived comfort decreased. Our results indicate that the tested exoskeleton provides support beyond overhead work and that there is a trade-off between exoskeleton support and subjective perception. Accordingly, further optimization of user-exoskeleton interaction is warranted for long-term prevention of musculoskeletal disorders in overhead workers.

System uncertainty remains a challenge for effective control of lower extremity exoskeletons, particularly in clinical populations. Adaptive control offers a potential solution by accounting for unknown system characteristics in real time. Here, we introduce the use of Gaussian-based adaptive control (GBAC) in a two-degree-of-freedom (DOF) exoskeleton for an angular position tracking task in the presence of system uncertainty. The mathematical derivation of the implicitly non-Lyapunov adaptation law is presented using Lagrangian mechanics, including a Gaussian kernel regressor and its stable convergence. We then evaluate GBAC performance in a 2-DOF simulation compared with a previously developed robust adaptive backstepping algorithm, Lyapunov-stable Slotine-Li control, and a proportional-integral-derivative (PID) controller. We additionally complete 1-DOF simulations to evaluate the effects of external disturbance and parameter uncertainty on controller performance. Finally, we evaluate GBAC experimentally in our existing 1-DOF knee exoskeleton along with Slotine-Li and PID controllers. The simulation results demonstrate the improved tracking performance and faster convergence of GBAC, especially in the presence of an external disturbance and uncertainty introduced by extra segment length and mass. The experimental results demonstrate similar performance, wherein GBAC and Slotine-Li provide stable tracking in the presence of unmodeled system dynamics; however, convergence time was faster and tracking error was lower for GBAC. Collectively, these results demonstrate that GBAC is an effective adaptive controller in the presence of system uncertainty and therefore warrants further development and investigation for use in flexible joint exoskeleton systems, particularly those designed for pediatric and/or clinical populations that have inherently high uncertainty.

Passive wearable devices are widely used for fitness and have also become fashionable. There is increasing interest in adding functionality, such as knee stability, to these compact devices, which are more convenient for daily wear than separate devices like braces or exoskeletons. This study designed and assessed flexion taping passive wearable devices (FTPW). The design emphasized providing adequate flexion moment capacity and controlling varus/valgus movement to prevent knee injuries. In this research, 20 healthy women performed single leg drop (SLD) and step-up (SU) tests with and without muscle fatigue. Knee joint angle, muscle activation, metabolic cost, and blood flow were measured across FTPW, passive wearable devices without flexion taping (PW), and control shorts (Ctrl). In the SLD test after muscle fatigue, FTPW produced a significantly larger knee flexion angle during landing. In the SU test, before and after fatigue, knee varus angle was notably higher with FTPW. Additionally, FTPW showed reduced knee flexor fatigue, indicated by smaller median frequency shifts, and improved blood flow compared to PW. No significant differences in respiratory exchange ratio were detected among the three conditions. Overall, FTPW demonstrated strong potential to enhance knee kinematics, muscle activation, and blood flow, pointing to benefits for both performance improvement and injury prevention. By delivering focused support in a compact format, FTPW may serve as an innovative passive wearable solution that supports daily movement, comfort, and daily activities. This emphasizes the device's promise as an alternative to bulkier knee aids, merging style and functionality effectively.

The adoption of upper limb myoelectric prosthesis is limited by the lack of closed control loop systems. Although the efferent control has already been integrated into these devices, the sensory feedback restoration in the afferent channel still remains an open challenge. Transcutaneous electrical nerve stimulation (TENS) is a promising method for generating somatotopic sensory feedback, allowing the closure of the control loop system. The application of this technique is limited by cumbersome and grid-powered electrical stimulators, making them unsuitable for everyday life, whereas most portable stimulators available on the market are designed for other purposes (e.g., muscular stimulation or pain therapy) and present limited stimulation wave customization. The stimulation devices employed in the literature often produce not fully suitable stimulation parameters and are frequently validated through procedures that do not fully clarify their practical application for sensory feedback restoration. The research aims to present a novel wearable TENS stimulation device (46 g, 62 × 49 × 20 mm) suitable for sensory feedback application. The validation was achieved through a benchtop test and a preliminary analysis on 10 healthy participants comparing the qualities, intensities, and stimulated areas of the sensations elicited by the proposed device and a reference stimulator. The proposed device is capable of delivering charge-balanced stimulation waves over skin-like resistive load and eliciting tingling and vibration sensations with similar intensities compared to the adopted reference.

The Myoshirt, an active exosuit, provides gravity compensation for the shoulders. This study evaluated the impact of the Myoshirt on range of motion (ROM), endurance, and activities of daily living (ADLs) performance through tests involving nine participants with varying levels of arm impairments and diverse pathologies. Optical motion capture was used to quantify ROM of the shoulder and elbow joints during isolated movements and functional tasks. Endurance was quantified through a timed isometric shoulder flexion task, and a battery of ADL tasks was used to measure the perceived support of the exosuit, along with changes in movement quality. Feedback and usability insights were gathered with surveys. The Myoshirt did not significantly improve ROM during isolated movements (shoulder flexion, shoulder abduction, and elbow flexion/extension), but during the reaching phase of a functional drinking task elbow extension increased significantly by 13.5% (t = 7.52, p = .002). Participants could also keep their arms elevated 78.7% longer (t = 1.942, p = .047). Patients also reported less perceived difficulty with ADLs while using the device, and a therapist reported improved execution quality. Participants who self-reported severe impairment levels tended to derive greater benefits compared to those with milder impairments. These findings highlight the potential of the Myoshirt as an assistive device, particularly for individuals with severe impairments, while emphasizing the need for further refinement.

Accurate estimation of finger joint stiffness is important in assessing the hand condition of stroke patients and developing effective rehabilitation plans. Recent technological advances have enabled the efficient performance of hand therapy and assessment by estimating joint stiffness using soft actuators. While joint modular soft actuators have enabled cost-effective and personalized stiffness estimation, existing approaches face limitations. A corrective approach based on an analytical model suffers from actuator-finger and inter-actuator interactions, particularly in multi-joint systems. In contrast, a data-driven approach struggles with generalization due to limited availability of labeled data. In this study, we proposed a method for energy conservation-based online tuning of the analytical model using an artificial neural network (ANN) to address these challenges. By analyzing each term in the analytical model, we identified causes of estimation error and introduced correction parameters that satisfy energy balance within the actuator-finger complex. The ANN enhances the analytical model's adaptability to measurement data, thereby improving estimation accuracy. The results show that our method outperforms the conventional corrective approach and exhibits better generalization potential than the purely data-driven approach. In addition, the method also proved effective in estimating stiffness in human subjects, where errors tend to be larger than in prototype experiments. This study is an essential step toward the realization of personalized rehabilitation.

Cable-driven exoskeletons have recently shown great promise in the rehabilitation of stroke survivors. Numerical modeling/simulation provides a cost- and time-effective approach to fine-tuning design parameters of the exoskeletons, hence reducing the need for expensive and time-consuming experimental trials. This study investigated using a cable-driven lower limb rehabilitation exoskeleton (C-LREX) to correct stroke-impaired gait and track reference healthy trajectories. The impact of different levels of impairment and subject anthropometry variation on the model's performance was studied. The C-LREX model was successful in assisting the impaired limb to track the reference trajectory in all impaired gait patterns, except for higher impairment levels (>20° range of motion deviation at the hip joint). Subject anthropometry variation did not affect trajectory tracking when the cable routing was scaled to fit the user's anthropometry. This study confirmed that the C-LREX model could simulate various impaired lower limb gait patterns in the sagittal plane and determine the cable tension requirements needed to correct the impairment. Future work includes expanding the framework to incorporate frontal plane motion and to validate C-LREX performance in assisting biplanar impaired motion.

Lightweight, adjustable, and affordable devices are needed to enable the next generation of effective, wearable adjuncts for rehabilitation. Used at home or in a rehabilitation setting, these devices have the potential to reduce compound pressures on hospitals and social care systems. Despite recent developments in soft wearable robots, many of these devices restrict the range of motion and lack quantitative assessment of moment transfer to the wearer. The decoupled design of our wearable device for upper-limb rehabilitation successfully delivers almost the full range of motion to the user, with a mean maximum flexion angle of 149° (SD = 8.5). In this article, for the first time, we show that in tests involving a wide range of participants, 82% of the moment produced by the actuator is applied to the wearer. This testing of elbow flexion moment transfer supports the effectiveness of the device. This research is a step toward effective pneumatic soft robotic wearable devices that are adaptable to a wide range of users - a necessary prerequisite for their widespread adoption in health care.

In the last two decades, the adoption of exoskeletal devices for the reduction of the biomechanical overload of workers has hugely increased. They allow relief of the biomechanical load of the operator and ensure the operator's contact with the object without binding its interaction. In this work, the biomechanical and physiological effects on the user wearing upper limb passive exoskeletons have been evaluated to highlight the benefits and possible drawbacks introduced by their use in typical manufacturing tasks. MATE and PAEXO Shoulder passive exoskeletons have been assessed during the execution of different working gestures among static, dynamic, and quasi-static tasks on 16 healthy volunteers. The obtained results confirm that the adoption of such systems significantly impacts the users by reducing the muscular load, increasing endurance, and reducing the perceived effort. Moreover, this analysis pointed out the specific benefits introduced by one exoskeleton with respect to the other according to the specific task. The MATE has the potential to reduce muscle load during the execution of static tasks. Conversely, the PAEXO Shoulder positively impacts the users' biomechanical performances in dynamic tasks.

Occupational shoulder exoskeletons can relieve workers during strenuous overhead work. Passive solutions are lightweight, robust, and cost-effective, but they can also restrict user movement, have limited support, and cannot dynamically adapt to different working conditions. Semi-active and active systems are still mostly the subject of research, and existing systems are heavy or have limited performance and support. Here, we present a lightweight semi-active exoskeleton for shoulder support that incorporates a novel motorized torque adjustment mechanism that varies the effective lever arm with which a spring applies force to the supporting joint. The mechanism is integrated into lateral structures and can be actuated via Bowden cables with motors located on the user's back. The technical performance of the system was experimentally characterized in terms of its dynamic support torque profiles at six different support levels. Furthermore, adjustment times and energy consumption were investigated. The system showed plateau-like support torque profiles in the intended working range and could be adjusted from nearly 0 Nm up to 12 Nm of maximum support per arm. Adjustment times varied between 0.5 s for the adjustment of 20% of the total adjustment range and 1.0 s for a full activation/deactivation. Adjustments consumed between 0.1 As and 1.9 As of battery charge, allowing long operating times of up to one working day, using only a small 2 Ah battery. As a result, the exoskeleton provides high performance by combining comparatively high support, rapid motorized support adjustment, and low energy consumption in a lightweight design.