Rehabilitation Engineering

Background: Prosthetic arm research predominantly focuses on "bionic" but not body-powered arms. However, any research orientation along user needs requires sufficiently precise workplace specifications and sufficiently hard testing. Forensic medicine is a demanding environment, also physically, also for non-disabled people, on several dimensions (e.g., distances, weights, size, temperature, time). Methods: As unilateral below elbow amputee user, the first author is in a unique position to provide direct comparison of a "bionic" myoelectric iLimb Revolution (Touch Bionics) and a customized body-powered arm which contains a number of new developments initiated or developed by the user: (1) quick lock steel wrist unit; (2) cable mount modification; (3) cast shape modeled shoulder anchor; (4) suspension with a soft double layer liner (Ohio Willowwood) and tube gauze (Molnlycke) combination. The iLimb is mounted on an epoxy socket; a lanyard fixed liner (Ohio Willowwood) contains magnetic electrodes (Liberating Technologies). An on the job usage of five years was supplemented with dedicated and focused intensive two-week use tests at work for both systems. Results: The side-by-side comparison showed that the customized body-powered arm provides reliable, comfortable, effective, powerful as well as subtle service with minimal maintenance; most notably, grip reliability, grip force regulation, grip performance, center of balance, component wear down, sweat/temperature independence and skin state are good whereas the iLimb system exhibited a number of relevant serious constraints. Conclusions: Research and development of functional prostheses may want to focus on body-powered technology as it already performs on manually demanding and heavy jobs whereas eliminating myoelectric technology's constraints seems out of reach. Relevant testing could be developed to help expediting this. This is relevant as Swiss disability insurance specifically supports prostheses that enable actual work integration. Myoelectric and cosmetic arm improvement may benefit from a less forgiving focus on perfecting anthropomorphic appearance.

The aim of this Churchill Fellowship was to investigate how leading Rehabilitation Engineering (RE) Centres around the world are using research and development and the application of technology to assist people with a disability. Inherent to this research was understanding the structure and set-up of each facility in an effort to determine how each was funded, the range of current project work, and the amount to which each facility collaborated with industry partners or tertiary institutions.

A secondary focus of this Churchill Fellowship was to investigate how the concept and process of ‘Universal Design’ (or ‘Inclusive Design’) was being taught and implemented within the field of RE.

The present study deals with an experimental (EXP) and theoretical investigation of the behavior of the retrofitted damaged RC columns with different aspect ratios and different slenderness ratios. The present study presents a new technique for retrofitting of damaged RC columns using external spiral stirrups. A total of twenty RC columns specimens with different cross-sections, (100×100), (100×150), (100×200), (100×250) and (100×300) mm, fifteen of them were 1800 mm clear height and the other five specimens were 900 mm height. All columns were tested under axial loading until failure load, then replacing the damaged concrete part by using grout mortar and restoring specimens dimension and internal reinforcement. All columns were divided into four groups as follows: Group (1) consists of five specimens having cross-sections, as mentioned with a height of 1800mm, were retrofitted by using spiral stirrups with a constant pitch of 80mm and wrapped by three plies of steel wire mesh. Group (2) consists of five specimens having the same properties were retrofitted by using external longitudinal steel bars and tied by spiral stirrups with a pitch of 80mm. Group (3) consists of five specimens having the same properties were retrofitted by using spiral stirrups with a constant pitch of 120mm and wrapped by three plies of steel wire mesh. All the mentioned techniques were applied to the columns of the group (4), which consists of five specimens having the same cross-sections and height of 900mm. Five variables were investigated as follows: Aspect ratios A SPR [defined as percentage of columns' length to width of cross-section (t/b)] were 1, 1.5, 2, 2.5 and 3. Slenderness ratio (λ) [defined as the percentage of the column's height to width (H/b)] were (15.3 and 7.6). Pitches of spiral stirrups (S) were (80 and 120mm). Using steel wire mesh and/or using external longitudinal bars with spiral stirrups. Using partial retrofitting of 1.5 of the defected length. All retrofitted damaged RC columns were tied at head and base of the applied jacket with steel clamp (30×3) mm then covered with 20mm grout mortar. The retrofitted damaged columns were tested again until failure load. The test results showed an increasing of carrying capacities for all presented techniques by various values. It is concluded that carrying capacities increase by decreasing the spiral pitching and by using external longitudinal steel bars which tied by spiral stirrups higher than using spiral stirrups wrapped by steel mesh. The horizontal displacements decrease by using longitudinal bars tied by spiral stirrups less than using spiral stirrups, which wrapped by steel mesh and by decreasing of spiral pitching. The slenderness ratio has no significant effect on used techniques. A fair agreement was found between finite element (FEA) results and experimental (EXP) results. However, the (FEA) models can identify the structural behavior of tested columns and can be an alternative for the destructive laboratory test. Finally, jacketing by external longitudinal steel bars tied by spiral stirrups proved to be an easy, inexpensive in retrofitting of damaged RC columns.

—Severe injuries of lower extremities often lead to chronic pain and reduced walking abilities. We postulated that measuring free-living gait can provide further information about walking ability in complement to clinical evaluations. We sought to validate a method that characterizes free gaits with a wearable sensor. Over one week, 81 healthy controls (HC) and 66 chronic lower limb pain patients (CLLPP) hospitalized for multidisciplinary rehabilitation wore a simple accelerometer (Actigraph). In the acceleration signals, steady one-minute walks detected numbered 7,835 (5,085 in CLLPP and 2,750 in HC). Five gait quality measures were assessed: movement intensity, cadence, stride regularity, and short-term and long-term local dynamic stability. Gait quality variables differed significantly between CLLPP and HC (4% to 26%). Intraclass correlation coefficients (ICC) revealed moderate to high repeatability (0.71–0.91), which suggests that seven days of measurement are sufficient to assess average gait patterns. Regression analyses showed significant association (R 2 =0.44) between gait quality variables and a clinical evaluation of walking ability, i.e. the 6 minute walk test, Overall, the results show that the method is easy to implement, valid (high concurrent validity), and reliable to assess walking abilities ecologically.

Globally, there is more than half a billion disabled people due to physical, mental, or sensory deficiencies. Rehabilitation technologies help people with disabilities become more self-reliant and able to participate and integrate into work, school, social environments, or their everyday life more easily through the use of rehabilitation and assistive technologies. Assistive technologies are any hardware or software products designed to help people with disabilities to conserve or recover their functioning and improve their independence, leading to promotion of their well-being. This paper presents a review of state-of-the-art assistive technologies, their types, applications, selection criteria, challenges, and how can they be used in rehabilitation. Moreover, the paper sheds the light on the recent and promising research trends in the fields of knowledge that constitute rehabilitation engineering and assistive technologies.

The articulating surface of standard femoral knee component is as generic shape while every individual patient has a unique shape of knee joint and this is causes some problems. The Conventional femoral knee component gives a satisfactory result in many cases that carry the patient back to active lifestyle and near normal patient and especially for younger patients. Most patients' gaits are altered after a total knee replacement (TKR) due to the change in surface geometry of femoral implant. The main objective of this work is to design custom design implant as smooth-implant interface of femoral component to increase appropriate bone ingrowths and to prevent bone remodeling found in conventional knee implants, also this design maintain the articulating surface of femoral with tibial component and patellar component as natural knee to maintain the patients gait without altered. This custom design of femoral knee implant will provide better results for patients who have more active lifestyle and strenuous activities such as younger patients. The custom design was done by creating 3D models from computerized tomography (CT) scan data through computer segmentation using Materialise MIMICS software. Geomagic studio software was used in this work for smoothing, preparation of the model and convert STL file format to STEP format. The 3D model as STEP format then exported from Geomagic Studio to CAD design software such as solidworks (Solidworks, USA) for design on the femoral components of the implant. From 3D model of the femur, a custom knee implant femoral component was designed. Finite Element Analysis was used to examine and evaluate the stress distribution over the interface between the implant and femur bone. The custom design as smooth surface describe a more even stress distribution in the contact region between femur bone and implant. This stress will reduce the uneven bone remodeling; also reduce the risk of premature loosening of implant.

In recent years, fiber Bragg gratings (FBGs) are becoming increasingly attractive for sensing applications in biomechanics and rehabilitation engineering due to their advantageous properties like small size, light weight, biocompatibility, chemical inertness, multiplexing capability and immunity to electromagnetic interference (EMI). They also offer a high-performance alternative to conventional technologies, either for measuring a variety of physical parameters or for performing high-sensitivity biochemical analysis. FBG-based sensors demonstrated their feasibility for specific sensing applications in aeronautic, automotive, civil engineering structure monitoring and undersea oil exploration; however, their use in the field of biomechanics and rehabilitation applications is very recent and its practicality for full-scale implementation has not yet been fully established. They could be used for detecting strain in bones, pressure mapping in orthopaedic joints, stresses in intervertebral discs, chest wall deformation, pressure distribution in Human Machine Interfaces (HMIs), forces induced by tendons and ligaments, angles between body segments during gait, and many others in dental biomechanics. This article aims to provide a comprehensive overview of all the possible applications of FBG sensing technology in biomechanics and rehabilitation and the status of ongoing researches up-to-date all over the world, demonstrating the FBG advances over other existing technologies. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

www.mdpi.com/1424-8220/12/10/12890/pdf

Built after the great earthquake of 1755, Baixa Pombalina in Lisbon is both a unique example of Portuguese urbanism and a candidate for the UNESCO World Heritage List. Historic centres face major preservation and economic issues. This paper discusses how this site addresses two concerns:1) ensuring the integrity of the building’s interiors and façades; 2) conserving the main values of this unique historical centre. These requirements must be compatible with sustainability, that is, with attracting residents to live in an urban environment with high quality historic buildings.

Neuroprostheses based on electrical stimulation could potentially help disabled persons. They are based on neural interface that aim at creating an intimate contact with neural cells. The efficacy of neuroprostheses can be improved by increasing the selectivity of the neural interfaces used to stimulate specific subsets of cells. Selectivity is strongly influenced by interface design. Computer models can be useful for exploring the high dimensional space of design parameters with the aim to provide guidelines for the development of more efficient electrodes, with minimal animal use and optimization of manufacturing processes. The purpose of this study was to implement a realistic model of the performance of a transverse intrafascicular multichannel electrode (TIME) implanted into the rat sciatic nerve. A realistic finite element method (FEM) model was developed taking into account the anatomical and physiological features of the rat sciatic nerve. Electric potentials were calculated and interpolated voltages were applied to the model of a rat sciatic nerve axon, based on experimental biophysical data. Results indicate that high intrafascicular and inter-fascicular selectivity values with low current levels can be achieved with TIMEs. The selectivity of TIMEs was also compared to an extraneural electrode, showing that higher selectivity with less current can be obtained. Using this model, the robustness of electrode performances for translational and rotational displacements were evaluated.

Previous studies of robotic exoskeletons and prostheses with regenerative actuators have focused on level-ground walking. Here we analyzed the lower-limb joint mechanical power during stand-to-sit movements using inverse dynamics to estimate the biomechanical energy available for electrical regeneration. Nine subjects performed 20 sitting and standing movements while lower-limb kinematics and ground reaction forces were measured. Subject-specific body segment parameters were estimated using parameter identification. Joint mechanical power was calculated from joint torques and rotational velocities and numerically integrated over time to estimate the joint biomechanical energy. The hip absorbed the largest peak negative mechanical power (1.8 ± 0.5 W/kg), followed by the knee (0.8 ± 0.3 W/kg) and ankle (0.2 ± 0.1 W/kg). Negative mechanical work on the hip, knee, and ankle joints per stand-to-sit movement were 0.35 ± 0.06 J/kg, 0.15 ± 0.08 J/kg, and 0.02 ± 0.01 J/kg, respectively. Assuming known regenerative actuator efficiencies (i.e., maximum 63%), robotic exoskeletons and prostheses could regenerate ~26 Joules of electrical energy while sitting down, compared to ~19 Joules per walking stride. Given that these regeneration performance calculations are based on healthy young adults, future research should include seniors and/or rehabilitation patients to better estimate the biomechanical energy available for electrical regeneration.

5th International Conference on Biomedical Engineering and Science (BIOEN 2022) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications impacts and challenges of Biomedical Engineering and Science. The conference documents practical and theoretical results which make a fundamental contribution for the development of Biomedical Engineering and Science. The aim of the conference is to provide a platform to the researchers and practitioners from both academia as well as industry to meet and share cutting-edge development in the field.

Serious computer games developed for motor rehabilitation produce a more engaging and enjoyable method to participate in physical therapy, but lack of variation and a secondary focus on fun limit long-term appeal. Traditionally, the focus of serious games in a health context is on the rehabilitation of motor function, neglecting the often-absent or impaired sensory function of the patient. This paper discusses a series of approaches used to develop appropriate serious games for children with cerebral palsy targeted at the impaired sensory system, taking into consideration longevity of play experience, requirements from therapists or researchers, and the interface requirements of the participants themselves. Two of the games that were developed are provided as examples, including data and feedback from one child with cerebral palsy who evaluated the games for entertainment, engagement and replay value.

This paper presents a new method of trajectory planning in rehabilitation robotics. First were measured in healthy subject the pick to place trajectories while haptic robot is in zero impedance space. B-spline approximation is used to mathematically define the measured paths. This trajectory path serves as a central line for the rounding haptic tunnel. In addition to radial elastic and damping force an optional guidance force can be applied along the tunnel to reach the place point. The B-spline control points were observed around the robot and arm workspace. The trajectory path defined with B-splines is compared with minimum jerk and minimum torque defined trajectories. Finally are compared the pick to place movements with and without tunnel use in healthy subject and in stroke hemiplegic patient.

Scope 5 th International Conference on Biomedical Engineering and Science (BES 2021) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications impacts and challenges of Biomedical Engineering and Science. The conference documents practical and theoretical results which make a fundamental contribution for the development of Biomedical Engineering and Science. The aim of the conference is to provide a platform to the researchers and practitioners from both academia as well as industry to meet and share cutting-edge development in the field. The goal of this Conference is to bring together researchers and practitioners from academia and industry to focus on Biomedical Engineering and Science advancements, and establishing new collaborations in these areas. Original research papers, state-of-the-art reviews are invited for publication in all areas of Biomedical Engineering and Science.

Advances in computer vision and deep learning are allowing researchers to develop environment recognition systems for robotic exoskeletons and prostheses. However, small-scale and private training datasets have impeded the development and dissemination of image classification algorithms for classifying human walking environments. To address these limitations, we developed ExoNet - the first open-source, large-scale hierarchical database of high-resolution wearable camera images of human locomotion environments. Unparalleled in scale and diversity, ExoNet contains over 5.6 million images of indoor and outdoor real-world walking environments, which were collected using a lightweight wearable camera system throughout the summer, fall, and winter seasons. Approximately 923,000 images in ExoNet were human-annotated using a 12-class hierarchical labelling architecture. Available publicly through IEEE DataPort, ExoNet offers an unprecedented shared platform to train, develop, and compare next-generation image classification algorithms for human locomotion environment recognition. Besides the control of exoskeletons and prostheses, applications of ExoNet could extend to humanoids and autonomous legged robots.

Accurate and reproducible delineation of breast lesions can be challenging, as the lesions may have complicated topological structures and heterogeneous intensity distributions. Diagnosis using magnetic resonance imaging (MRI) with an appropriate automatic segmentation algorithm can be a better imaging technique for the early detection of malignant breast tumours. The main objective of this system is to develop a method for automatic segmentation and the early detection of breast cancer based on the application of the watershed transform to MRI images. The algorithm was separated into three major sections: pre-processing, watershed and post-processing. After computing different segments, the final image was cleared of all noise and superimposed on the original MRI image to generate the final modified image. The algorithm successfully resulted in the automatic segmentation of the MRI images, and this can be a beneficial tool for the early detection of breast cancer. This study showed that the automatic results correctly agree with manual detection.

Previous research investigated recumbent cycle power output (PO) from the perspective of knee and hip joint biomechanics. However, ankle-foot biomechan-ics and, in particular, the effect of ankle-foot orthosis (AFO)-constrained movements on cycle PO has not been widely explored. Therefore, the purpose of this study was to determine whether AFOs of a fixed position (FP) and in dorsi-plantarflexion (DPF)-, dorsiflexion (DF)-and plantarflexion (PF)-constrained movements might influence PO during voluntary recumbent cycling exercises. Twenty-five healthy individuals participated in this study. All underwent 1-min cycling at a fixed cadence for each of the AFOs. The peak and average PO of each condition were analyzed. The peak and average PO were 27.2 ± 12.0 W (range 6–60) and 17.2 ± 9.0 W (range 2–36), respectively, during voluntary cycling. There were no significant differences in the peak PO generated by the AFOs (p = 0.083). There were also no significant differences in the average PO generated using different AFOs (p = 0.063). There were no significant differences in the changes of the hip and knee joint angles with different AFOs (p = 0.974 and p = 1.00, respectively). However, there was a significant difference in the changes of the ankle joint angle (p < 0.00). The present study observed that AFO-constrained movements did not have an influence in altering PO during voluntary recumbent cycling in healthy individuals. This finding might serve as a reference for future rehabilitative cycling protocols.

The Video games are a happy entertainment for any person and makes them feel entertained, euphoria, and awe. When played in groups, it gives personal pride, feeling emotionally close to another player, surprise, curiosity, excitement, and wonder. Many of such video games give relief for a while during stressful situations by the effective engagement. But as any good medicine for health care becomes fatal if taken too much beyond the dosage the gaming beyond limit brings in adverse effects. Apart from the extended duration, another contributing phenomenon is the game content. The game formula, paradigm and components play a vital role in deciding the influencing power of the game. Competitions in the video game market fuel it to be more attractive, powerful and to be an effective impact in the minds and characters of the youngsters to gain the business. The adverse effect of video games relays mainly on these two components and this paper suggest the remedies to burst the trap by giving findings on both the realms.

Foot orthoses and night splints have been used separately to treat patients with plantar fasciitis, but were not always successful. Combining the uses of both orthoses might give better outcomes. This study evaluated the effectiveness of a soft and self-adjustable dorsiflexion night splint in combination with an accommodative foot orthosis on patients with plantar fasciitis. Twenty-eight patients were assigned into Group A (foot orthosis only) and Group B (combinations of the foot orthosis and the dorsiflexion night splints). A Foot Function Index (FFI) questionnaire was used to evaluate the pain and functions of feet just before, 2 weeks and 8 weeks after the treatments. Results showed that subjects in Group B had significant reduction in pain scores at week 2 (p<0.001) and week 8 (p<0.001). In Group A, no statistical differences were noted in the pain (p=0.15), disability (p=0.56), activity limitation (p=0.75), and total FFI (p=0.35) scores for the three time periods. The application of foot orthoses with adjustable dorsiflextion night splints was found to be more effective than the application of foot orthoses alone in relieving foot pain in patients with plantar fasciitis.

Recently a hybrid model based on the finite element method and on a compartmental biophysical representation of peripheral nerve fibers and intraneural electrodes was developed founded on experimental physiological and histological data. The model appeared to be robust when dealing with uncertainties in parameter selection. However, an experimental validation of the findings provided by the model is required to fully characterize the potential of this approach. The recruitment properties of selective nerve stimulation using transverse intrafascicular multichannel electrodes (TIME) were investigated in this work in experiments with rats and were compared to model predictions. Animal experiments were performed using the same stimulation protocol as in the computer simulations in order to rigorously validate the model predictions and understand its limitations. Two different selectivity indexes were used, and new indexes for measuring electrode performance are proposed. The model predictions are in decent agreement with experimental results both in terms of recruitment curves and selectivity values. Results show that these models can be used for extensive studies targeting electrode shape design, active sites shape, and multipolar stimulation paradigms. From a neurophysiological point of view, the topographic organization of the rat sciatic nerve, on which the model was based, has been confirmed.

Robotic leg prostheses and exoskeletons can provide powered locomotor assistance to older adults and/or persons with physical disabilities. However, the current locomotion mode recognition systems being developed for automated high-level control and decision-making rely on mechanical, inertial, and/or neuromuscular sensors, which inherently have limited prediction horizons (i.e., analogous to walking blindfolded). Inspired by the human vision-locomotor control system, we developed an environment classification system powered by computer vision and deep learning to predict the oncoming walking environments prior to physical interaction, therein allowing for more accurate and robust high-level control decisions. In this study, we first reviewed the development of our “ExoNet” database—the largest and most diverse open-source dataset of wearable camera images of indoor and outdoor real-world walking environments, which were annotated using a hierarchical labeling architecture. We then trained and tested over a dozen state-of-the-art deep convolutional neural networks (CNNs) on the ExoNet database for image classification and automatic feature engineering, including: EfficientNetB0, InceptionV3, MobileNet, MobileNetV2, VGG16, VGG19, Xception, ResNet50, ResNet101, ResNet152, DenseNet121, DenseNet169, and DenseNet201. Finally, we quantitatively compared the benchmarked CNN architectures and their environment classification predictions using an operational metric called “NetScore,” which balances the image classification accuracy with the computational and memory storage requirements (i.e., important for onboard real-time inference with mobile computing devices). Our comparative analyses showed that the EfficientNetB0 network achieves the highest test accuracy; VGG16 the fastest inference time; and MobileNetV2 the best NetScore, which can inform the optimal architecture design or selection depending on the desired performance. Overall, this study provides a large-scale benchmark and reference for next-generation environment classification systems for robotic leg prostheses and exoskeletons.

Subjects with unilateral vestibular loss exhibit motor control impairments as shown by body and limb deviation during gait. Biofeedback devices have been shown to improve stance postural control, especially when sensory information is limited by environmental conditions or pathologies such as unilateral vestibular loss. However, the extent to which biofeedback could improve motor performance or learning while practicing a dynamic task such as narrow gait is still unknown. In this cross-over design study, 9 unilateral vestibular loss subjects practiced narrow gait with and without wearing a trunk-tilt, biofeedback device in 2 practice sessions. The biofeedback device informed the subjects of their medial-lateral angular tilt and tilt velocity during gait via vibration of the trunk. From motion analysis and tilt data, the performance of the subjects practicing tandem gait were compared over time with and without biofeedback. By practicing tandem gait, subjects reduced their trunk-tilt...

Abstract Serious computer games developed for motor rehabilitation produce a more engaging and enjoyable method to participate in physical therapy, but lack of variation and a secondary focus on fun limit long-term appeal. Traditionally, the focus of serious games in a health context is on the rehabilitation of motor function, neglecting the often-absent or impaired sensory function of the patient. This paper discusses a series of approaches used to develop appropriate serious games for children with cerebral palsy targeted at the ...

In this thesis, we propose a novel measurement methodology for long term monitoring and assessment of stroke survivors’ functional motion. Our long-term goal is to measure and provide feedback about changes in functional movements that happen in everyday environments across days, months or years. The research contained in the thesis consists of three parts. First, therapists were interviewed to determine common observations they make about stroke survivors functional activity for the purpose of assessment. Protocol analysis was used to gain insight onto parts of the body as well as motor symptoms that were particular points of focus. Next, a prototype system was built to measure functional movement and its ability to capture statistics that discriminate between levels of functional impairment was tested. The technologies explored were primarily chosen because they are inexpensive and robust. They include simple computer vision and force sensing devices. Several different score predi...

Segmentation in Computerized Tomography (CT) images of human extremities particularly for a tissue of interest is a difficult task in medical image processing. Human operator interventions require at times when an automatic segmentation method fails and gives incorrect results. This is often true in medical image processing where segmentation is difficult due to the restrictions imposed by image acquisition, pathology and biological tissue variations. Initially the CT scanning of a normal male adult volunteer foot done and acquisition of CT scan data set completed and a manual procedure for segmenting bone tissues was adopted. The segmentation carried out slice-by-slice on 88 CT image slices in Materialise’s Interactive Medical Image Control System (MIMICS) software. This finally gives a three dimensional (3D) representation of a human foot skeletal. This specific skeletal 3D foot representation provides its prototype realization and helps in determining the shape and size of foot’s...

A sensory apparatus to monitor pressure distribution on the physical human-robot interface of lower-limb exoskeletons is presented. We propose a distributed measure of the interaction pressure over the whole contact area between the user and the machine as an alternative measurement method of human-robot interaction. To obtain this measure, an array of newly-developed soft silicone pressure sensors is inserted between the limb and the mechanical interface that connects the robot to the user, in direct contact with the wearer&#x27;s skin. Compared to state-of-the-art measures, the advantage of this approach is that it allows for a distributed measure of the interaction pressure, which could be useful for the assessment of safety and comfort of human-robot interaction. This paper presents the new sensor and its characterization, and the development of an interaction measurement apparatus, which is applied to a lower-limb rehabilitation robot. The system is calibrated, and an example i...

Subjects with unilateral vestibular loss exhibit motor control impairments as shown by body and limb deviation during gait. Biofeedback devices have been shown to improve stance postural control, especially when sensory information is limited by environmental conditions or pathologies such as unilateral vestibular loss. However, the extent to which biofeedback could improve motor performance or learning while practicing a dynamic task such as narrow gait is still unknown. In this cross-over design study, 9 unilateral vestibular loss subjects practiced narrow gait with and without wearing a trunk-tilt, biofeedback device in 2 practice sessions. The biofeedback device informed the subjects of their medial-lateral angular tilt and tilt velocity during gait via vibration of the trunk. From motion analysis and tilt data, the performance of the subjects practicing tandem gait were compared over time with and without biofeedback. By practicing tandem gait, subjects reduced their trunk-tilt...

We propose a novel method for movement assistance that is based on adaptive oscillators, i.e., mathematical tools that are capable of extracting the high-level features (amplitude, frequency, and offset) of a periodic signal. Such an oscillator acts like a filter on these features, but keeps its output in phase with respect to the input signal. Using a simple inverse model, we predicted the torque produced by human participants during rhythmic flexion-extension of the elbow. Feeding back a fraction of this estimated torque to the participant through an elbow exoskeleton, we were able to prove the assistance efficiency through a marked decrease of the biceps and triceps electromyography. Importantly, since the oscillator adapted to the movement imposed by the user, the method flexibly allowed us to change the movement pattern and was still efficient during the nonstationary epochs. This method holds promise for the development of new robot-assisted rehabilitation protocols because it does not require prespecifying a reference trajectory and does not require complex signal sensing or single-user calibration: the only signal that is measured is the position of the augmented joint. In this paper, we further demonstrate that this assistance was very intuitive for the participants who adapted almost instantaneously.