scholarly journals Automatic support control of an upper body exoskeleton — Method and validation using the Stuttgart Exo-Jacket

2020 ◽  
Vol 1 ◽  
Author(s):  
Raphael Singer ◽  
Christophe Maufroy ◽  
Urs Schneider
Keyword(s):  
Upper Limb ◽  
Cost Efficiency ◽  
Muscle Activation ◽  
High Reliability ◽  
Initial Step ◽  
High Accuracy ◽  
Industrial Applications ◽  
Upper Body ◽  
Upper Limbs ◽  
Control Approach

Abstract Although passive occupational exoskeletons alleviate worker physical stresses in demanding postures (e.g., overhead work), they are unsuitable in many other applications because of their lack of flexibility. Active exoskeletons that are able to dynamically adjust the delivered support are required. However, the automatic control of support provided by the exoskeleton is still a largely unsolved challenge in many applications, especially for upper limb occupational exoskeletons, where no practical and reliable approach exists. For this type of exoskeletons, a novel support control approach for lifting and carrying activities is presented here. As an initial step towards a full-fledged automatic support control (ASC), the present article focusses on the functionality of estimating the onset of user’s demand for support. In this way, intuitive behavior should be made possible. The combination of movement and muscle activation signals of the upper limbs is expected to enable high reliability, cost efficiency, and compatibility for use in industrial applications. The functionality consists of two parts: a preprocessing—the motion interpretation—and the support detection itself. Both parts were trained with different subjects, who had to move objects. The functionality was validated both in the cases of (A) an unknown subject performing known tasks and (B) a known subject performing unknown tasks. The functionality showed sound results as it achieved a high accuracy ( $$ 95\% $$ ) in training. In addition, the first validation results showed that this functionality is useful for integration in an appropriately adapted ASC and can then enable comfortable working.

Multifunction Synchro-to-Digital Conversion on Software Design

2011 ◽  
Vol 225-226 ◽  
pp. 589-592
Author(s):  
Yan Liu ◽  
Ze Gang Ye
Keyword(s):  
Software Design ◽  
High Speed ◽  
Measurement Accuracy ◽  
High Reliability ◽  
Low Cost ◽  
High Accuracy ◽  
Industrial Applications ◽  
Digital Conversion ◽  
The Cost ◽  
The Military

The current Synchro-to-Digital conversion (S/DC)with high reliability, high accuracy and widely used in the military field, but it has high cost and low tracking speed, not suitable for high speed and low-cost industrial applications. In this work, the principle of synchro and the harmonics of the synchro output signals are investigated. Multifunction S/DC software design using FFT algorithm and IIR digital filter technology is proposed. It Integrated many functions, such as angle position, harmonics analysis and filter, it also improved measurement accuracy and speed, reduced the cost. The simulation results by Matlab show that the method is feasible.

Using Inertial Sensor System to Measure the Workspace of the Surgeon's Upper Limbs during Operations

2015 ◽  
Vol 772 ◽  
pp. 329-333
Author(s):  
Ali Soroush ◽  
Farzam Farahmand
Keyword(s):  
Upper Limb ◽  
Inertial Sensors ◽  
Inertial Sensor ◽  
Kinematic Model ◽  
Experimental Results ◽  
Upper Body ◽  
Upper Limbs ◽  
Surgical Robots ◽  
Raw Data ◽  
Wearable Inertial Sensors

The aim of this study was to determine the workspace of surgeon's body for designing more efficient surgical robots in the operation rooms. Five wearable inertial sensors were placed near the wrist and elbow joints and also on the thorax of surgeons to track the orientation of upper limb. Assuming that the lengths of five segments of an upper limb were known, measurements of the inertial sensors were used to determine the position of the wrist and elbow joints via an established kinematic model. subsequently, to assess the workspace of surgeon upper body, raw data were collected in the arthroscopy and laparoscopy operations. Experimental results demonstrated that the workspaces of surgeon's joints are limited and predefined. The results can be used for designing surgical robots and surgeon body supports.

scholarly journals Code Calibration of the Eurocodes

2021 ◽  
Vol 11 (12) ◽  
pp. 5474
Author(s):  
Tuomo Poutanen
Keyword(s):  
High Reliability ◽  
High Accuracy ◽  
Variable Load ◽  
Reliability Model ◽  
Safety Factors ◽  
Rounding Errors ◽  
Code Calibration ◽  
Load Factors ◽  
Characteristic Values

This article addresses the process to optimally select safety factors and characteristic values for the Eurocodes. Five amendments to the present codes are proposed: (1) The load factors are fixed, γG = γQ, by making the characteristic load of the variable load changeable, it simplifies the codes and lessens the calculation work. (2) Currently, the characteristic load of the variable load is the same for all variable loads. It creates excess safety and material waste for the variable loads with low variation. This deficiency can be avoided by applying the same amendment as above. (3) Various materials fit with different accuracy in the reliability model. This article explains two options to reduce this difficulty. (4) A method to avoid rounding errors in the safety factors is explained. (5) The current safety factors are usually set by minimizing the reliability indexes regarding the target when the obtained codes include considerable safe and unsafe design cases with the variability ratio (high reliability/low) of about 1.4. The proposed three code models match the target β50 = 3.2 with high accuracy, no unsafe design cases and insignificant safe design cases with the variability ratio 1.07, 1.03 and 1.04.

scholarly journals Is there a relationship between the overhead press and split jerk maximum performance? Influence of sex

2021 ◽  
pp. 174795412110204
Author(s):  
Marcos A Soriano ◽  
G Gregory Haff ◽  
Paul Comfort ◽  
Francisco J Amaro-Gahete ◽  
Antonio Torres-González ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Body Mass ◽  
Upper Limb ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Training Experience ◽  
Maximum Performance ◽  
Repetition Maximum ◽  
Intraclass Correlation Coefficients

The aims of this study were to (I) determine the differences and relationship between the overhead press and split jerk performance in athletes involved in weightlifting training, and (II) explore the magnitude of these differences in one-repetition maximum (1RM) performances between sexes. Sixty-one men (age: 30.4 ± 6.7 years; height: 1.8 ± 0.5 m; body mass 82.5 ± 8.5 kg; weightlifting training experience: 3.7 ± 3.5 yrs) and 21 women (age: 29.5 ± 5.2 yrs; height: 1.7 ± 0.5 m; body mass: 62.6 ± 5.7 kg; weightlifting training experience: 3.0 ± 1.5 yrs) participated. The 1RM performance of the overhead press and split jerk were assessed for all participants, with the overhead press assessed on two occasions to determine between-session reliability. The intraclass correlation coefficients (ICC) and 95% confidence intervals showed a high reliability for the overhead press ICC = 0.98 (0.97 – 0.99). A very strong correlation and significant differences were found between the overhead press and split jerk 1RM performances for all participants (r = 0.90 [0.93 – 0.85], 60.2 ± 18.3 kg, 95.7 ± 29.3 kg, p ≤ 0.001). Men demonstrated stronger correlations between the overhead press and split jerk 1RM performances (r = 0.83 [0.73-0.90], p ≤ 0.001) compared with women (r = 0.56 [0.17-0.80], p = 0.008). These results provide evidence that 1RM performance of the overhead press and split jerk performance are highly related, highlighting the importance of upper-limb strength in the split jerk maximum performance.

Differences in muscular activation and fatigue for intermittent and constant load

2005 ◽  
Vol 5 (1) ◽  
pp. 43-56
Author(s):  
Danuta Roman-Liu ◽  
Krzysztof Kȩdzior
Keyword(s):  
External Force ◽  
Upper Limb ◽  
Muscle Activation ◽  
Regression Line ◽  
Constant Load ◽  
Median Frequency ◽  
Experimental Conditions ◽  
Emg Signal ◽  
Limb Posture ◽  
Muscular Activation

The aim of this study was to compare the influence of constant or intermittent load on muscle activation and fatigue. The analysis and assessment of muscular activation and fatigue was based on surface EMG measurements from eight muscles (seven muscles of the right upper limb and trapezius muscle). Two EMG signal parameters were analyzed for each of the experimental conditions distinguished by the value of the external force and the character of the load – constant or intermittent. The amplitude related to its maximum (AMP) and the slope of the regression line between time and median frequency (SMF) were the EMG parameters that were analyzed. The results showed that constant load caused higher muscular fatigue than intermittent load despite the lower value of the external force and lower muscle activation. Results suggest that additional external force might influence muscle activation and fatigue more than upper limb posture. The results of the study support the thesis that all biomechanical factors which influence upper limb load and fatigue (upper limb posture, external force and time sequences) should be considered when work stands and work processes are designed. They also indicate that constant load should be especially avoided.

Clinical Application of Scalp Cluster Needling Combined with Bobath Technique in Upper Limb Spastic Paralysis After Stroke of Vertebral Artery Type

2021 ◽  
Author(s):  
Aimin Gong ◽  
Mengjie Zeng ◽  
Zhiquan Wu
Keyword(s):  
Treatment Group ◽  
Acupuncture Therapy ◽  
Vertebral Artery ◽  
Upper Limb ◽  
Training Group ◽  
Control Group ◽  
Upper Limbs ◽  
Spastic Paralysis ◽  
Rehabilitation Training ◽  
The Difference

To observe the difference in clinical effects of scalp-point cluster acupuncture combined with rehabilitation training in treating spastic paralysis of upper limbs after stroke. Using a randomized controlled design, 96 patients with upper limb spastic paralysis after stroke were randomly divided into two groups: treatment group (scalp acupuncture plus rehabilitation training group 48 cases), control group (rehabilitation training group 48 cases). After 2 courses of treatment, it was judged by observing clinical efficacy evaluation, Ashworth classification, and Fugl-Meyer (FMA) score. The total effective rate was 91.7% in the treatment group and 68.7% in the control group; the difference between the two groups was statistically significant (P <0.05). Before treatment, the difference in Ashworth classification between the two groups was not statistically significant (P> 0.05); after treatment, the difference between the two groups was statistically significant (P <0.01). After treatment, the difference between the two groups was statistically significant (P＜0.05). The Fugl-Meyer (FMA) scores of the two groups of patients before treatment were comparable (P>0.05), and there were significant differences between the two groups after treatment (P <0.05). The difference of Fugl-Meyer (FMA) scores between the two groups was statistically significant (P < 0.01). Scalp cluster acupuncture therapy is more effective than traditional acupuncture therapy alone in treating vertebral artery type cervical spondylosis. Scalp cluster acupuncture combined with Bobath technique is effective in treating spastic paralysis of upper limbs after stroke, and it is worthy of clinical application.

Effect of Mirror Box Therapy on Muscle Activation Strategies after Upper Limb Amputation

2018 ◽  
Vol 31 (1) ◽  
pp. 154-155 ◽  
Author(s):  
L.F. Fernandes ◽  
S.G. Shimano
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Limb Amputation ◽  
Upper Limb Amputation ◽  
Mirror Box

scholarly journals O EFEITO DA REALIDADE VIRTUAL NA CAPACIDADE FUNCIONAL DE MEMBROS SUPERIORES EM INDIVÍDUOS COM HEMIPARESIA

2020 ◽  
Vol 12 (1) ◽  
pp. 38-44
Author(s):  
Nicoly Ribeiro Uliam ◽  
Isabella Cristina Leoci ◽  
Silas de Oliveira Damasceno ◽  
Caroline Nunes Gonzaga ◽  
Isabela Bortolim Frasson ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Upper Limb ◽  
Functional Capacity ◽  
Normal Function ◽  
Manual Dexterity ◽  
Upper Limbs ◽  
Partial Loss ◽  
Nine Hole Peg Test

Stroke maylead to total and/or partial loss of normal function inone of the upper limbs, and therehabilitation is one of the main focuses of physiotherapists.The objective was to analyze the effects of virtual reality on upper limb functional capacity in individuals with hemiparesis. Initially they were evaluated for manual dexterity by the Nine Hole Peg Test (NHPT) and Box and Blocks Test (BBT) then be conductedto perform a 16-session protocol using virtual reality game through Nintendo WiiTMconsole. ™.We included 10 individuals with mean age of 64.5±9.54 and did not demonstrated significant results when comparing the moments, only a small effect (d=0.23) was found in the left upper limb in the NHPT. It was concluded, there was no significant improvement in the functional capacity of the upper limbs using virtual reality in individuals with hemiparesis.

scholarly journals Muscle Activation during Exergame Playing

2016 ◽  
pp. 312-341 ◽  
Author(s):  
Pooya Soltani ◽  
João Paulo Vilas-Boas
Keyword(s):  
Upper Limb ◽  
Healthy Subjects ◽  
Muscle Activation ◽  
Low Cost ◽  
Coding System ◽  
User Research ◽  
Preliminary Results ◽  
Upper Trapezius ◽  
Game Developers ◽  
Muscular Coordination

Exergames may provide low-cost solutions for playing, training and rehabilitation. Exergame user research, studies the interaction between an exergame and users, in order to provide feedback for game developers and safe and meaningful game play. Detailed evaluations and a coding system based on muscle activation levels are necessary to characterize. This is important when it comes to use exergames in purposes other than fun. The purpose of this chapter was to characterize the muscle activation during a swimming exergame and to compare the level of activation during different conditions. Healthy subjects played bouts of exergame using Xbox360 and Kinect. Muscle activation was monitored for desired muscles on dominant upper limb using wireless electromyography system. An investigation of muscular coordination was also conducted to provide activation sequences of studied muscles. Preliminary results showed that upper trapezius was the most active muscle in all techniques. Results can provide insights for practitioners to have a baseline on application of exergames in their routines.

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