Novel active magnetorheological knee prosthesis presents low energy consumption during ground walking

2021 ◽  
pp. 1045389X2098392
Author(s):  
Rafhael Milanezi de Andrade ◽  
Jordana Simões Ribeiro Martins ◽  
Marcos Pinotti ◽  
Antônio Bento Filho ◽  
Claysson Bruno Santos Vimieiro
Keyword(s):  
Energy Consumption ◽  
Stance Phase ◽  
Gait Cycle ◽  
Dynamic Models ◽  
Knee Prosthesis ◽  
Regenerative Braking ◽  
Harmonic Drive ◽  
Low Energy Consumption ◽  
Energetic Expenditure ◽  
Over Ground Walking

This study analyses the energy consumption of an active magnetorheological knee (AMRK) actuator that was designed for transfemoral prostheses. The system was developed as an operational motor unit (MU), which consists of an EC motor, a harmonic drive and a magnetorheological (MR) clutch, that operates in parallel with an MR brake. The dynamic models of the MR brake and MU were used to simulate the system’s energetic expenditure during over-ground walking under three different working conditions: using the complete AMRK; using just its motor-reducer, to operate as a common active knee prosthesis (CAKP), and using just the MR brake, to operate as a common semi-active knee prosthesis (CSAKP). The results are used to compare the MR devices power consumptions with that of the motor-reducer. As previously hypothesized, to use the MR brake in the swing phase is more energetically efficient than using the motor-reducer to drive the joint. Even if using the motor-reducer in regenerative braking mode during the stance phase, the differences in power consumption among the systems are remarkable. The AMRK expended 16.3 J during a gait cycle, which was 1.6 times less than the energy expenditure of the CAKP (26.6 J), whereas the CSAKP required just 6.0 J.

scholarly journals Galloping Trajectory Generation of a Legged Transport Robot Based on Energy Consumption Optimization

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yaguang Zhu ◽  
Tong Guo
Keyword(s):  
Energy Consumption ◽  
Trajectory Planning ◽  
Stance Phase ◽  
Gait Cycle ◽  
Complex Surface ◽  
Walking Robots ◽  
Joint Torques ◽  
Energy Consumption Optimization ◽  
System Energy ◽  
Lift Off

Legged walking robots have very strong operation ability in the complex surface and they are very suitable for transportation of tools, materials, and equipment in unstructured environment. Aiming at the problems of energy consumption of legged transport robot during the fast moving, a method of galloping trajectory planning based on energy consumption optimization is proposed. By establishing transition angle polynomials of flight phase, lift-off phase, and stance phase and constraint condition between each state phase, the locomotion equations of the ellipse trajectory are derived. The transition angle of each state phase is introduced into the system energy consumption equations, and the energy optimization index based on transition angles is established. Inverse kinematics solution and trajectory planning in one gait cycle are applied to genetic algorithm process to solve the nonlinear programming problem. The results show that the optimized distribution of transition angles of state phases is more reasonable, and joint torques and system energy consumption are reduced effectively. Thus, the method mentioned above has a great significance to realize fast operation outdoors of transport robot.

A Study on the Use of Bipolar-Particles-Electrodes in Decolorization of Dyeing Effluents and Its Principle

1987 ◽  
Vol 19 (3-4) ◽  
pp. 391-400 ◽  
Author(s):  
Zhou Ding ◽  
Cai Wei Min ◽  
Wang Qun Hui
Keyword(s):  
Energy Consumption ◽  
High Efficiency ◽  
Low Energy ◽  
Acid Dyes ◽  
Underlying Principle ◽  
Low Energy Consumption ◽  
Transparent Liquid

This paper studies the use of bipolar-particles-electrodes in the decolorization of dyeing effluents. Treatment of highly colored solutions of various soluble dyes (such as direct, reactive, cationic or acid dyes) and also samples of dyeing effluents gave rise to an almost colorless transparent liquid, with removal of CODcr and BOD5 being as high as over 80%. The method is characterized by its high efficiency, low energy consumption and long performance life. A discussion of the underlying principle is given.

scholarly journals Analysis of Friction in Total Knee Prosthesis during a Standard Gait Cycle

Lubricants ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 36
Author(s):  
Matúš Ranuša ◽  
Markus A. Wimmer ◽  
Spencer Fullam ◽  
Martin Vrbka ◽  
Ivan Křupka
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Computational Models ◽  
Gait Cycle ◽  
Knee Prosthesis ◽  
Shear Stresses ◽  
Cobalt Chromium ◽  
Joint Friction ◽  
The Coefficient Of Friction ◽  
Total Knee

Total knee arthroplasty is on the rise worldwide. Despite its success, revision surgeries are also increasing. According to the American Joint Replacement Registry 2020, 3.3% of revision surgeries are due to wear, and 24.2% are due to mechanical loosening. The combination of shear stresses and wear particles occurring at the bone/implant interface can lead to local osteolysis. Although the shear stresses are partially driven by joint friction, relatively little is known about the evolution of the coefficient of friction (CoF) during a gait cycle in total knee replacement. Here we describe the CoF during a gait cycle and investigate its association with kinematics (slide–roll-ratio), applied load, and relative velocity. The artificial knee was simulated by cobalt–chromium condyle on a flat ultra-high-molecular-weight polyethylene (UHMWPE) tibial plateau, lubricated by either water or proteinaceous solution. We found that the CoF is not a constant but fluctuates between the values close to 0 and 0.15. Cross-correlation suggested that this is primarily an effect of the slide–roll ratio and the contact pressure. There was no difference in the CoF between water and proteinaceous solution. Knowledge about the CoF behavior during a gait cycle will help to increase the accuracy of future computational models of total knee replacement.

scholarly journals A Long-Distance Communication Architecture for Medical Devices Based on LoRaWAN Protocol

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 940
Author(s):  
Nicoleta Cristina Gaitan
Keyword(s):  
Energy Consumption ◽  
Long Range ◽  
Medical Devices ◽  
Low Energy ◽  
Area Network ◽  
Wide Area Network ◽  
Long Distance ◽  
Communication Architecture ◽  
Low Energy Consumption ◽  
Distance Communication

Recent market studies show that the market for remote monitoring devices of different medical parameters will grow exponentially. Globally, more than 4 million individuals will be monitored remotely from the perspective of different health parameters by 2023. Of particular importance is the way of remote transmission of the information acquired from the medical sensors. At this time, there are several methods such as Bluetooth, WI-FI, or other wireless communication interfaces. Recently, the communication based on LoRa (Long Range) technology has had an explosive development that allows the transmission of information over long distances with low energy consumption. The implementation of the IoT (Internet of Things) applications using LoRa devices based on open Long Range Wide-Area Network (LoRaWAN) protocol for long distances with low energy consumption can also be used in the medical field. Therefore, in this paper, we proposed and developed a long-distance communication architecture for medical devices based on the LoRaWAN protocol that allows data communications over a distance of more than 10 km.

Absorbent cotton derived mesoporous CeO2 hollow tubule for enhanced detection of p-xylene at low energy consumption

2021 ◽  
pp. 159774
Author(s):  
Jing-Shuo Liu ◽  
Bao-Yu Song ◽  
Jing Huang ◽  
Zhao-Peng Deng ◽  
Xian-Fa Zhang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Low Energy ◽  
Absorbent Cotton ◽  
Low Energy Consumption ◽  
Mesoporous Ceo2
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