Electromyography (EMG) signal is one of the widely used biological signals for human motor intention prediction, which is an essential element in human-robot collaboration systems. Studies on motor ...intention prediction from EMG signal have been concentrated on classification and regression models, and there are numerous review and survey papers on classification models. However, to the best of our knowledge, there is no review paper on regression models or continuous motion prediction from EMG signal. Therefore, in this paper, we provide a comprehensive review of EMG-based motor intention prediction of continuous human upper limb motion. This review will cover the models and approaches used in continuous motion estimation, the kinematic motion parameters estimated from EMG signal, and the performance metrics utilized for system validation. From the review, we will provide some insights into future research directions on these subjects. We first review the overall structure and components of EMG-based human-robot collaboration systems. We then discuss the state of arts in continuous motion prediction of the human upper limb. Finally, we conclude the paper with a discussion of the current challenges and future research directions.
PURPOSEUpper limb masses are one of the most common presentations in the outpatient setting. However, there is a paucity of information in the literature regarding the epidemiology of upper-extremity ...masses in the pediatric population. The aim of this study was to determine the differential diagnoses and clinical characteristics in children aged ≤18 years presenting with upper limb masses. METHODSA retrospective review of patients aged ≤18 years managed at our institution over a 5-year period was performed. We obtained information on patient demographics, clinical features, radiological investigations, intraoperative features, and histology. We also evaluated the correlation between the clinical and histopathological diagnoses in patients who underwent surgery. RESULTSThere were 141 upper limb masses in our series. The mean age at presentation was 12 years (SD, 5 years). The most common presenting complaints were asymptomatic swelling, pain, and paresthesia. The majority (128; 91%) of tumors were benign; there were 5 locally aggressive tumors and 6 malignant tumors. The dominant hand was involved in 60 patients. Of 140 patients, 43 (31%) patients had surgery. The procedures included incisional biopsy, excisional biopsy, wide resection, and reconstruction. One patient required a below elbow amputation for an osteosarcoma. CONCLUSIONSTen percent of cases represented malignant or locally aggressive disease. We have used our observations to develop a clinical algorithm that can assist clinicians in evaluating and managing children and adolescents presenting with upper-extremity masses. TYPE OF STUDY/LEVEL OF EVIDENCEPrognostic IV.
To develop a self-report measure of activity performance for upper limb prosthesis users that quantifies outcomes by level of amputation and prosthesis type.
Telephone survey of 423 adults with major ...upper limb amputation (ULA) who used a prosthesis. Item generation, cognitive, and pilot testing were followed by field testing. Items were categorized as one- or two-handed. Factor and Rasch analyses evaluated unidimensionality, monotonicity, item fit, differential item functioning (DIF), and reliability. Test-retest reliability was evaluated with intraclass correlation coefficients (ICCs). Known group validity was assessed with ANOVAs.
Respondents with unilateral ULA utilized prosthesis for 24% of unilateral and 38% of bilateral tasks. Those with bilateral ULA utilized prostheses for 64% of unilateral and 46% of bilateral tasks. Factor analyses identified a One-handed Task factor (CFI = 0.963, TLI = 0.950, and RMSEA = 0.064) and a Two-Handed Task factor (CFI = 0.958, TLI = 0.953, and RMSEA = 0.053). Response categories were collapsed to address monotonicity. After DIF adjustment, person reliability was 0.49 and 0.82 for One-handed and Two-handed Task scales, respectively, and ICCs were 0.88 and 0.91. Both scales differed by amputation level (p < 0.001).
The Upper Extremity Functional Scale for Prosthesis Users (UEFS-P) measure of upper limb function of prosthesis users has promising psychometric properties.
Implications for rehabilitation
Measurement of upper limb function in persons with amputation is challenging, given currently available measures which do not explicitly grade activity performance with a prosthesis.
The Upper Extremity Functional Scale for Prosthesis Users (UEFS-P) builds upon the original Orthotics and Prosthetics User Survey (OPUS) UEFS Scale with modified instructions, a revised item set, response categories and scoring algorithm.
The UEFS-P consists of two unidimensional scales, the One-handed Tasks scale and the Two-handed Tasks scale.
The UEFS-P scales have clear advantages over existing self-report measures of upper limb function that ask about difficulty with performing functional activities without accounting for prosthesis use, and do not differentiate persons who use and do not use a prosthesis.
A BSTRACT Background: Acute upper-limb ischemia (AULI) is not always as limb-threatening as those in the leg, so thrombo-embolectomy is not always as necessary for limb salvage. Objective: To ...evaluate “the outcomes of limb and life at the end of one month, in patients with AULI” and to analyze the following factors: presentation from the time of the acute event, evaluation of limb at the time of presentation regarding its viability, and compare the outcomes in early presentation vs late presentation. Methodology: This was a retrospective study; hence, clinical profiles of all patients during the past seven years were reviewed for those presenting with AULI. Data on anticoagulation were collected, imaging and operative procedures were extracted. All statistical analyses were performed using SPSS 11.0 for Windows. Results: In our study, 25 (42.4%) patients were included due to native arterial thrombosis, 11 (18.6%) due to embolic disease, and the same percentage due to exposure to a high-altitude area (HAA) (more than 9000 feet). 4 (6.8%) patients had thoracic outlet syndrome and cervical rib, and 5 (8.5%) had hypercoagulable disorder. Our study population was younger with a mean of 44.9 years with an SD of 13, and the majority were male (5 out of 59 were female). 16 were active smokers, and 2 were former smokers. The left upper limb incidence was 59% ( n = 35), and the right upper limb was 41% ( n = 24). In our study, the most common site was the brachial artery 53% (26 out of 49) and axillary artery 35% (17 out of 49) when iatrogenic, traumatic, and thoracic outlet syndromes are excluded. Out of the 59 patients, 39 patients had undergone color Doppler flow imaging of the affected limb and 30 patients had undergone CT angiography of the arch and the limb. Two patients presented with gangrene to the forearm, and 12 patients underwent Colour doppler flow imaging (CDFI) before they presented to our center. In our study, 37% of the patients presented within 48 hours of the onset of symptoms, out of which above-elbow amputation was done in only 1 patient, that is, 4.5%, and 24% of the patients presented within an 8–14-day period, among which one patient (11%) had undergone above-elbow amputation and 22% of the patients presented after 14 days, in which there were 2 above-elbow-amputation patients (15%) with a statistically non-significant P value of 0.5. A total of 45 patients were managed with anticoagulation. A detailed discussion on the treatment outcome of each case has been presented in the article. Conclusion: CT angiography, when available, is a well-accepted first-line investigation for AULI. When we compare AULI with lower-limb ischemia, collateral circulation conservative management is also an option, provided that it is not associated with tissue loss. AULI like lower-limb ischemia has better limb salvage when diagnosed and intervened early.
When fatigued, the wrist extensors, which are the primary wrist stabilizers, impair distal upper limb motor performance in a surprisingly similar way as when fatiguing the wrist flexors. It is ...possible that the wrist extensors are so active as antagonists that they develop an equal degree of fatigue during wrist flexion contractions, making it difficult to truly isolate their impact on performance. Thus, the purpose of this study was to examine how wrist flexion/extension forces are impaired following either agonist or antagonist sustained submaximal wrist contractions. 13 male participants attended four laboratory sessions. In these sessions, fatigue was induced via a sustained submaximal isometric contraction of either wrist flexion or extension. These contractions were held for up to 10 min at 20% of the participant's baseline maximal voluntary contraction (MVC) force. Throughout the sustained contraction, intermittent agonist (matching the sustained contraction) or antagonist (opposing the sustained contraction) MVCs were performed. Unsurprisingly, agonist MVC forces decreased significantly more than antagonist (Agonist: 58.5%, Antagonist: 86.5% of MVC, P < 0.001). However, while there were no differences in antagonist wrist extension and flexion MVC decreases (Wrist Flexion: 87.5%, Wrist Extension: 85.5%, P = 0.41), wrist extension MVCs did decrease significantly more than wrist flexion MVCs when forces were expressed relative to the agonist (P = 0.036). These findings partially support the hypothesis that the wrist extensors may be more susceptible to developing fatigue when functioning as antagonists than the wrist flexors. This work will help equip future research into the motor control of the upper limb and the prevention of forearm-related musculoskeletal disorders.
Limb amputation can lead to significant functional challenges in daily activities, prompting amputees to use prosthetic devices (PDs). However, the cognitive demands of PDs and usability issues have ...resulted in user rejections. This study aimed to create a Human Performance Model for Upper-Limb Prosthetic Devices (HPM-UP). The model used formulations of learnability, error rate, memory load, efficiency, and satisfaction to assess usability. The model was validated in an experiment with 30 healthy participants using a bypass prosthetic device. Findings indicated that the HPM-UP successfully predicted the usability of prosthetic devices, aligning with human subject data. This research proposes a quantitative approach to predict upper limb prosthetic device usability by quantifying each dimension and computationally connecting them. The model, available on Github and executable with Rstudio, could enable clinicians to assess and analyze the human performance of various commercial prostheses, aiding in recommending optimal devices for patients.
The very first application of active exoskeleton robot was to provide external power to a soldier so that he can carry additional weight than his strength. Since then this technology has focused on ...developing systems for assisting and augmenting human power. Later this technology is expanded into other applications such as limb rehabilitation and tele-operations. Exoskeleton research is still a growing area and demands multi-disciplinary approaches in solving complex technical issues. In this paper, the developments of active upper-limb exoskeleton robots are reviewed. This paper presents the major developments occurred in the history, the key milestones during the evolution and major research challenges in the present day context of hardware systems of upper-limb exoskeleton robots. Moreover, the paper provides a classification, a comparison and a design overview of mechanisms, actuation and power transmission of most of the upper-limb exoskeleton robots that have been found in the literature. A brief review on the control methods of upper-limb exoskeleton robots is also presented. At the end, a discussion on the future directions of the upper-limb exoskeleton robots was included.
•Reviews developments of active upper-limb exoskeleton robots.•Presents major developments of exoskeleton hardware systems occurred in history.•Identifies major research challenges in exoskeleton robots.•Provides a classification, a comparison and a design overview of mechanisms and actuation.•Presents future directions in upper-limb exoskeleton robots.
Upper-limb impairment after stroke is caused by weakness, loss of individual joint control, spasticity, and abnormal synergies. Upper-limb movement frequently involves abnormal, stereotyped, and ...fixed synergies, likely related to the increased use of sub-cortical networks following the stroke. The flexible coordination of the shoulder and elbow joints is also disrupted. New methods for motor learning, based on the stimulation of activity-dependent neural plasticity have been developed. These include robots that can adaptively assist active movements and generate many movement repetitions. However, most of these robots only control the movement of the hand in space. The aim of the present text is to analyze the potential of robotic exoskeletons to specifically rehabilitate joint motion and particularly inter-joint coordination. First, a review of studies on upper-limb coordination in stroke patients is presented and the potential for recovery of coordination is examined. Second, issues relating to the mechanical design of exoskeletons and the transmission of constraints between the robotic and human limbs are discussed. The third section considers the development of different methods to control exoskeletons: existing rehabilitation devices and approaches to the control and rehabilitation of joint coordinations are then reviewed, along with preliminary clinical results available. Finally, perspectives and future strategies for the design of control mechanisms for rehabilitation exoskeletons are discussed.
Wearability of clothing is important for enhancing work efficiency and resistance among industrial workers. In this study, we developed wearable suit designs for shoulder and upper limb support when ...lifting objects considering the wearability of the user in the development stage. We provide basic data on the wearability of functional clothing and wearable suits, with emphasis on improving safety and work efficiency. Two distinct wearable suit designs, namely long- and short-sleeved, were developed and evaluated with a primary focus on wearer comfort. Employing a comprehensive approach encompassing textile analysis, performance assessment, brainwave investigation, and satisfaction surveys, this study provides objective insights for refining the wearability in wearable suit development. A short-sleeved design is recommended for the development of wearable suits tailored to assist industrial workers in tasks requiring muscle strength for heavy loads and repetitive motions. Our results provide foundational data on the wearability of robotic suits in a bid to enhance the safety and efficiency of industrial workers.
•Development of wearable suits to assist industrial workers with heavy lifting and repetitive tasks.•Wearable suit design and performance evaluation in terms of textile metrics.•EEG measurements of participants and assessment of brain states.•Satisfaction survey to appraise the design of wearable suits.
Various measures have been proposed to quantify upper-limb use through wrist-worn inertial measurement units. The two most popular traditional measures of upper-limb use - thresholded activity counts ...(TAC) and the gross movement (GM) score suffer from high sensitivity and low specificity, and vice versa. We previously proposed a hybrid version of these two measures - the GMAC - that showed better overall detection performance than TAC and GM. In this paper, we answer two critical questions to improve the GMAC measure's usefulness: (a) can it be implemented using only the accelerometer data? (b) what are its optimal parameter values? Here, we propose a modified GMAC using only the accelerometer data and optimize its parameters to develop: (a) a generic measure that is both limb- and subject-independent, and (b) limb-specific measures that were only subject-independent. The optimized GMAC showed better detection performance than the previous GMAC and surprisingly had comparable performance to the best-performing machine learning-based measure (random forest inter-subject model). In hemiparetic data, its performance was similar to the previous GMAC and the random forest inter-subject model; the limb-specific GMAC measure, however, had a better performance than the generic measure. The optimized limb-specific GMAC is a simple, interpretable alternative to a machine learning-based inter-subject model. The optimized GMAC can be a valuable measure for offline or real-time detection and feedback of upper limb use. The preliminary results of this study, based on a small dataset, need to be validated on a larger dataset to evaluate its generalizability.
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