Characterisation, Design and Experimentation of a Fabric Based Wearable Joint Sensing Device on Human Elbow

2021 ◽  
pp. 1-12
Author(s):  
Jun Liang Lau ◽  
Gim Song Soh
Keyword(s):  
Elbow Flexion ◽  
Maximum Error ◽  
Healthy Human ◽  
Joint System ◽  
Left Elbow ◽  
Personal Wellness ◽  
Wide Range ◽  
Flexion Extension ◽  
Synthesis Procedure ◽  
Crank Mechanism

Abstract The use of conductive fabrics (CF) in the design of wearables for joint sensing has recently received much interest in a wide range of applications such as robotics, rehabilitation, personal wellness, sports, and entertainment. This paper evaluates a new wearable device concept that comprises a CF strain-voltage sensor embedded as part of an inverted slider-crank mechanism for joint extension sensing. This has the benefit of not requiring anthropometric information from the user to related the joint parameters to the fabric strain readings, as opposed to an existing design. Firstly, we characterize the electro-mechanical property of a commercially available CF. Secondly, we formulate the joint sensing device's geometric synthesis procedure as a constrained revolute joint system, where the CF is designed and introduced as an RPR chain to obtain an inverted slider-crank linkage. Lastly, we designed our wearable sensing device and validated against an ISC linkage fixture representing an elbow joint and an actual healthy human subject's left elbow. The ISC linkage fixture experimental setup shows that our designed joint sensing device can track the elbow extension motion of 140 with a maximum error of 7.66%. The results from our human subject's left elbow show that it can track the elbow flexion-extension at various angular motion, with error ranges between 8.55 to 12.57. These have provided us an average of Spearman's coefficient values rs at 0.95, which was considered an acceptable range.

Characterisation, Design and Experimentation of a Fabric Based Wearable Joint Sensing Device

2020 ◽  
Author(s):  
Jun Liang Lau ◽  
Gim Song Soh
Keyword(s):  
Elbow Joint ◽  
Maximum Error ◽  
Electromechanical Property ◽  
Elbow Extension ◽  
Joint System ◽  
Personal Wellness ◽  
Wide Range ◽  
Synthesis Procedure ◽  
Joint Parameters ◽  
Crank Mechanism

Abstract The use of conductive fabrics (CF) in the design of wearables for joint sensing has recently received much interest in a wide range of applications such as robotics, rehabilitation, personal wellness, sports, and entertainment. In this paper, we evaluate a new wearable device concept that comprises of a CF strain-voltage sensor embedded as part of an inverted slider-crank mechanism for joint extension sensing. This has the benefit of not requiring anthropometric information from the user to related the joint parameters to the fabric strain readings, as opposed to an existing design. Firstly, we characterize the electromechanical property of a commercially available CF. Secondly, we formulate the geometric synthesis procedure of the joint sensing device as a constrained revolute joint system, where the CF is designed and introduced as an RPR chain to obtain an inverted slider-crank linkage. Lastly, we develop and validate our wearable joint sensing device against an experimental setup that represents an elbow joint. Our concept shows that our proposed joint sensing device can track the elbow extension motion of 140° with a maximum error of 7.66%.

LIQUIDUS THERMO-BAROMETER FOR THE MODELING OF MAGNETITE — MELT EQUILIBRIUM

2018 ◽  
pp. 71-80
Author(s):  
N. S. Aryaeva ◽  
E. V. Koptev-Dvornikov ◽  
D. A. Bychkov
Keyword(s):  
Experimental Data ◽  
Liquidus Temperature ◽  
Vertical Structure ◽  
Maximum Error ◽  
Silicate Melt ◽  
System Of Equations ◽  
Wide Range ◽  
Basaltic Melts ◽  
Multidimensional Statistics

A system of equations of thermobarometer for magnetite-silicate melt equilibrium was obtained by method of multidimensional statistics of 93 experimental data of a magnetite solubility in basaltic melts. Equations reproduce experimental data in a wide range of basalt compositions, temperatures and pressures with small errors. Verification of thermobarometers showed the maximum error in liquidus temperature reproducing does not exceed ±7 °C. The level of cumulative magnetite appearance in the vertical structure of Tsypringa, Kivakka, Burakovsky intrusions predicted with errors from ±10 to ±50 m.

scholarly journals Measurements of Tendon Movement Within the Bicipital Groove After Suprapectoral Intra-articular Biceps Tenodesis in a Cadaveric Model

2021 ◽  
Vol 9 (1) ◽  
pp. 232596712097753
Author(s):  
Brian J. Kelly ◽  
Alan W. Reynolds ◽  
Patrick J. Schimoler ◽  
Alexander Kharlamov ◽  
Mark Carl Miller ◽  
...  
Keyword(s):  
Biceps Tendon ◽  
Full Range ◽  
Elbow Flexion ◽  
Biceps Tenodesis ◽  
Bicipital Groove ◽  
Biceps Tenotomy ◽  
Flexion Extension ◽  
Before And After ◽  
Long Head ◽  
Scapular Motion

Background: Lesions of the long head of the biceps can be successfully treated with biceps tenotomy or tenodesis when surgical management is elected. The advantage of a tenodesis is that it prevents the potential development of a cosmetic deformity or cramping muscle pain. Proponents of a subpectoral tenodesis believe that “groove pain” may remain a problem after suprapectoral tenodesis as a result of persistent motion of the tendon within the bicipital groove. Purpose/Hypothesis: To evaluate the motion of the biceps tendon within the bicipital groove before and after a suprapectoral intra-articular tenodesis. The hypothesis was that there would be minimal to no motion of the biceps tendon within the bicipital groove after tenodesis. Study Design: Controlled laboratory study. Methods: Six fresh-frozen cadaveric arms were dissected to expose the long head of the biceps tendon as well as the bicipital groove. Inclinometers and fiducials (optical markers) were used to measure the motions of the scapula, forearm, and biceps tendon through a full range of shoulder and elbow motions. A suprapectoral biceps tenodesis was then performed, and the motions were repeated. The motion of the biceps tendon was quantified as a function of scapular or forearm motion in each plane, both before and after the tenodesis. Results: There was minimal motion of the native biceps tendon during elbow flexion and extension but significant motion during all planes of scapular motion before tenodesis, with the most motion occurring during shoulder flexion-extension (20.73 ± 8.21 mm). The motion of the biceps tendon after tenodesis was significantly reduced during every plane of scapular motion compared with the native state ( P < .01 in all planes of motion), with a maximum motion of only 1.57 mm. Conclusion: There was a statistically significant reduction in motion of the biceps tendon in all planes of scapular motion after the intra-articular biceps tenodesis. The motion of the biceps tendon within the bicipital groove was essentially eliminated after the suprapectoral biceps tenodesis. Clinical Relevance: This arthroscopic suprapectoral tenodesis technique can significantly reduce motion of the biceps tendon within the groove in this cadaveric study, possibly reducing the likelihood of groove pain in the clinical setting.

On LES Methods Applied to Seal Geometries

2012 ◽  
Author(s):  
James Tyacke ◽  
Richard Jefferson-Loveday ◽  
Paul Tucker
Keyword(s):  
Maximum Error ◽  
Labyrinth Seal ◽  
Navier Stokes ◽  
Final Solution ◽  
Complex Flow ◽  
Eddy Simulation ◽  
Wide Range ◽  
Large Eddy ◽  
Rans Models ◽  
Flow Through

Nine Large Eddy Simulation (LES) methods are used to simulate flow through two labyrinth seal geometries and are compared with a wide range of Reynolds-Averaged Navier-Stokes (RANS) solutions. These involve one-equation, two-equation and Reynolds Stress RANS models. Also applied are linear and nonlinear pure LES models, hybrid RANS-Numerical-LES (RANS-NLES) and Numerical-LES (NLES). RANS is found to have a maximum error and a scatter of 20%. A similar level of scatter is also found among the same turbulence model implemented in different codes. In a design context, this makes RANS unusable as a final solution. Results show that LES and RANS-NLES is capable of accurately predicting flow behaviour of two seals with a scatter of less than 5%. The complex flow physics gives rise to both laminar and turbulent zones making most LES models inappropriate. Nonetheless, this is found to have minimal tangible results impact. In accord with experimental observations, the ability of LES to find multiple solutions due to solution non-uniqueness is also observed.

Clinical findings in C5-C6 and C5-C7 root palsies with brachial plexus traction lesions

2012 ◽  
Vol 38 (3) ◽  
pp. 237-241 ◽  
Author(s):  
J. A. Bertelli ◽  
M. F. Ghizoni
Keyword(s):  
Brachial Plexus ◽  
External Rotation ◽  
Elbow Flexion ◽  
Clinical Findings ◽  
Hand Strength ◽  
Shoulder Abduction ◽  
Finger Extension ◽  
Root Injury ◽  
Flexion Extension

Stretch injuries of the C5-C7 roots of the brachial plexus traditionally have been associated with palsies of shoulder abduction/external rotation, elbow flexion/extension, and wrist, thumb, and finger extension. Based on current myotome maps we hypothesized that, as far as motion is concerned, palsies involving C5-C6 and C5-C7 root injuries should be similar. In 38 patients with upper-type palsies of the brachial plexus, we examined for correlations between clinical findings and root injury level, as documented by CT tomomyeloscan. Contrary to commonly held beliefs, C5-C7 root injuries were not associated with loss of extension of the elbow, wrist, thumb, or fingers, but residual hand strength was much lower with C5-C7 vs C5-C6 lesions.

scholarly journals Holistic Approach to Design, Test, and Optimize Stand-Alone SOFC-Reformer Systems

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 348
Author(s):  
Michael Höber ◽  
Benjamin Königshofer ◽  
Philipp Wachter ◽  
Gjorgji Nusev ◽  
Pavle Boskoski ◽  
...  
Keyword(s):  
Rural Communities ◽  
High Efficiency ◽  
Diffusion Processes ◽  
Holistic Approach ◽  
Maximum Error ◽  
Gas Diffusion ◽  
Electrochemical Analysis ◽  
Internal Reforming ◽  
Operation Conditions ◽  
Wide Range

Reliable electrical and thermal energy supplies are basic requirements for modern societies and their food supply. Stand-alone stationary power generators based on solid oxide fuel cells (SOFC) represent an attractive solution to the problems of providing the energy required in both rural communities and in rurally-based industries such as those of the agricultural industry. The great advantages of SOFC-based systems are high efficiency and high fuel flexibility. A wide range of commercially available fuels can be used with no or low-effort pre-treatment. In this study, a design process for stand-alone system consisting of a reformer unit and an SOFC-based power generator is presented and tested. An adequate agreement between the measured and simulated values for the gas compositions after a reformer unit is observed with a maximum error of 3 vol% (volume percent). Theoretical degradation free operation conditions determined by employing equilibrium calculations are identified to be steam to carbon ratio (H2O/C) higher 0.6 for auto-thermal reformation and H2O/C higher 1 for internal reforming. The produced gas mixtures are used to fuel large planar electrolyte supported cells (ESC). Current densities up to 500 mA/cm2 at 0.75 V are reached under internal reforming conditions without degradation of the cells anode during the more than 500 h long-term test run. More detailed electrochemical analysis of SOFCs fed with different fuel mixtures showed that major losses are caused by gas diffusion processes.

scholarly journals Analysis of human-exoskeleton interactions: an elbow flexion/extension case study

2017 ◽  
Vol 20 (sup1) ◽  
pp. S9-S10 ◽  
Author(s):  
S. Bastide ◽  
N. Vignais ◽  
F. Geffard ◽  
B. Berret
Keyword(s):  
Elbow Flexion ◽  
Flexion Extension

scholarly journals Inveterate elbow dislocation: surgical reduction with triceps lengthening

2021 ◽  
Vol 8 (9) ◽  
Keyword(s):  
Mayo Clinic ◽  
Physical Therapist ◽  
Elbow Dislocation ◽  
Elbow Flexion ◽  
Plaster Cast ◽  
Lateral Approach ◽  
Surgical Reduction ◽  
Left Elbow ◽  
Triceps Muscle ◽  
K Wires

Inveterate elbow dislocations remain common in developing countries. We report the case of a 17-year-old child who consulted us after six months of trauma to the left elbow. Clinical examination revealed a deformed elbow, locked in extension with a mobility sector of 5°. The Mayo Clinic Elbow performance score was sixty-six; the downstream vasculo-nervous examination was normal. The face and profile X-ray of the elbow showed a pure posterolateral elbow dislocation. We used the posterior medial para-tricipital and lateral approach, a first stage of arthrolysis was performed. A complete reduction was achieved by progressive and non-traumatic gentle maneuvers. Intraoperative elbow flexion was less than 80°, indicating a retraction of the triceps muscle, so a Z-lengthening plasty was necessary. This reduction was then fixed with two olecranon-humeral K-wires. At the third week, the plaster cast and K-wires were removed. The patient was subsequently referred to a physical therapist. After a ten-month follow-up, an undistorted and functional elbow with a gain of twenty-one points according to the Mayo Clinic score was obtained. Surgical reduction of a neglected elbow dislocation with triceps lengthening plasty, followed by a codified physical therapy program, results in a remarkable restoration of elbow function and stability. Keyword : elbow, dislocation, inveterate, reduction, triceps.

Effect of experimental muscle pain on maximal voluntary activation of human biceps brachii muscle

2011 ◽  
Vol 111 (3) ◽  
pp. 743-750 ◽  
Author(s):  
Serajul I. Khan ◽  
Chris J. McNeil ◽  
Simon C. Gandevia ◽  
Janet L. Taylor
Keyword(s):  
Hypertonic Saline ◽  
Muscle Pain ◽  
Biceps Brachii ◽  
Elbow Flexion ◽  
Voluntary Activation ◽  
Psychophysical Experiment ◽  
Motor Point ◽  
Experimental Muscle Pain ◽  
Wide Range ◽  
Motor Cortical

Muscle pain has widespread effects on motor performance, but the effect of pain on voluntary activation, which is the level of neural drive to contracting muscle, is not known. To determine whether induced muscle pain reduces voluntary activation during maximal voluntary contractions, voluntary activation of elbow flexors was assessed with both motor-point stimulation and transcranial magnetic stimulation over the motor cortex. In addition, we performed a psychophysical experiment to investigate the effect of induced muscle pain across a wide range of submaximal efforts (5–75% maximum). In all studies, elbow flexion torque was recorded before, during, and after experimental muscle pain by injection of 1 ml of 5% hypertonic saline into biceps. Injection of hypertonic saline evoked deep pain in the muscle (pain rating ∼5 on a scale from 0 to 10). Experimental muscle pain caused a small (∼5%) but significant reduction of maximal voluntary torque in the motor-point and motor cortical studies ( P < 0.001 and P = 0.045, respectively; n = 7). By contrast, experimental muscle pain had no significant effect on voluntary activation when assessed with motor-point and motor cortical stimulation although voluntary activation tested with motor-point stimulation was reduced by ∼2% in contractions after pain had resolved ( P = 0.003). Furthermore, induced muscle pain had no significant effect on torque output during submaximal efforts ( P > 0.05; n = 6), which suggests that muscle pain did not alter the relationship between the sense of effort and production of voluntary torque. Hence, the present study suggests that transient experimental muscle pain in biceps brachii has a limited effect on central motor pathways.

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