scholarly journals Concept design and design optimization of the transfemoral prosthetic leg prototype

2021 ◽  
Vol 1208 (1) ◽  
pp. 012017
Author(s):  
Remzo Dedić ◽  
Faris Ustamujić ◽  
Zlata Jelačić ◽  
Želimir Husnić ◽  
Vlado Kvesić
Keyword(s):  
Knee Joint ◽  
Ankle Joint ◽  
Hydraulic Drive ◽  
Lower Leg ◽  
Power Source ◽  
Concept Design ◽  
Biologically Inspired ◽  
Prosthetic Devices ◽  
External Power Source ◽  
External Power

Abstract The biggest challenge with today’s lower leg prosthetic devices is to climb the stairs in a biologically inspired way. When climbing the stairs, due to the large moments in the knee joint, great forces in the knee occur. Because of the magnitude of these forces, which can be up to six times the weight of a person, it is necessary to use a hydraulic drive with an external power source in the knee and ankle joint. However, most commercially available above-knee prosthetic legs only have actuation in the form of damping in the knee joint. Hence, an amputee is forced to use a healthy leg to advance to each step first while amputated leg follows.

scholarly journals Multifunctional above-knee prosthesis for stairs' walking

1987 ◽  
Vol 11 (3) ◽  
pp. 139-145 ◽  
Author(s):  
K. Koganezawa ◽  
H. Fujimoto ◽  
I. Kato
Keyword(s):  
Knee Joint ◽  
Ankle Joint ◽  
Stance Phase ◽  
Knee Prosthesis ◽  
Power Sources ◽  
Stair Ascent ◽  
Level Walking ◽  
External Power ◽  
Leg Prosthesis ◽  
Full Body

The multifunctional above-knee prosthesis WLP-7R (Waseda Leg Prosthesis - type 7 Refined) described in this study allows amputees to descend and ascend stairs with no external power sources. With the hydraulic circuit mounted in the shank, the ankle joint and the knee joint mutually conterbalance during stance phase in stair walking as well as level walking so that the following performances are obtained. The yielding (flexing) of the knee joint is prevented and smooth advance from stance-phase to swing-phase is realized in level walking. The gradual yielding of the knee joint and the ankle joint while sustaining full body weight is realized in stair descent. Reciprocal stepping with sound and disabled legs during stair ascent is also realised although the powerful extension of the knee joint during stance phase is not possible. The performance of the WLP-7R was examined by a walking experiment in which amputees could descend and ascend the stairs as well as walk on a flat surface after approximately one hour's training.

Precise quantitative addition of multiple reagents into droplets in sequence using glass fiber-induced droplet coalescence

The Analyst ◽  
2015 ◽  
Vol 140 (3) ◽  
pp. 701-705
Author(s):  
Chunyu Li ◽  
Jian Xu ◽  
Bo Ma
Keyword(s):  
Glass Fiber ◽  
Power Source ◽  
Droplet Coalescence ◽  
External Power Source ◽  
External Power ◽  
Serial Addition

Serial addition of reagents with controlled volumes is performed using a glass fiber-induced droplet coalescence method without the requirement for an external power source.

scholarly journals Noiseless intensity amplification of repetitive signals by coherent addition using the temporal Talbot effect

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Reza Maram ◽  
James Van Howe ◽  
Ming Li ◽  
José Azaña
Keyword(s):  
Optical Pulse ◽  
Wave Train ◽  
Extinction Ratio ◽  
Power Source ◽  
Wave System ◽  
Talbot Effect ◽  
Physical Processes ◽  
External Power Source ◽  
External Power ◽  
Time Average

Abstract Amplification of signal intensity is essential for initiating physical processes, diagnostics, sensing, communications and measurement. During traditional amplification, the signal is amplified by multiplying the signal carriers through an active gain process, requiring the use of an external power source. In addition, the signal is degraded by noise and distortions that typically accompany active gain processes. We show noiseless intensity amplification of repetitive optical pulse waveforms with gain from 2 to ~20 without using active gain. The proposed method uses a dispersion-induced temporal self-imaging (Talbot) effect to redistribute and coherently accumulate energy of the original repetitive waveforms into fewer replica waveforms. In addition, we show how our passive amplifier performs a real-time average of the wave-train to reduce its original noise fluctuation, as well as enhances the extinction ratio of pulses to stand above the noise floor. Our technique is applicable to repetitive waveforms in any spectral region or wave system.

A photovoltaic self-powered gas sensor based on a single-walled carbon nanotube/Si heterojunction

Nanoscale ◽  
2017 ◽  
Vol 9 (47) ◽  
pp. 18579-18583 ◽  
Author(s):  
L. Liu ◽  
G. H. Li ◽  
Y. Wang ◽  
Y. Y. Wang ◽  
T. Li ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Visible Light ◽  
Gas Sensor ◽  
Power Source ◽  
Single Walled Carbon Nanotube ◽  
External Power Source ◽  
External Power ◽  
Gas Molecules ◽  
Self Powered ◽  
Trace Concentrations

A self-powered gas sensor activated by visible light which can detect trace concentrations of gas molecules without an external power source.

Portable Pneumatic Power-Harvesting Ankle-Foot-Orthosis

2008 ◽  
Author(s):  
Robin Chin ◽  
Elizabeth T. Hsiao-Wecksler ◽  
Eric Loth ◽  
Andrew Alleyne ◽  
Scott Manwaring ◽  
...  
Keyword(s):  
Power Source ◽  
Power Harvesting ◽  
Ankle Motion ◽  
Ankle Foot Orthosis ◽  
Locking Mechanism ◽  
External Power Source ◽  
Cam Follower ◽  
External Power ◽  
Pneumatic Power ◽  
Foot Orthosis

In this paper, we present a novel ankle-foot-orthosis (AFO) design that controls ankle motion by providing a plantarflexion stop with free dorsiflexion during gait. The biomechanical controls are accomplished with a unique application of a cam-follower design that uses pneumatic power harvested via an air bellow embedded into the insole of the AFO (Figure 1). This portable design is self-contained and does not require any external power source to provide for the plantarflexion stop locking mechanism. It is the first step in a series of untethered fluid-powered orthotic devices.

scholarly journals A 3D-printed hand-powered centrifuge for molecular biology

2019 ◽  
Author(s):  
Gaurav Byagathvalli ◽  
Aaron F. Pomerantz ◽  
Soham Sinha ◽  
Janet Standeven ◽  
M. Saad Bhamla
Keyword(s):  
Molecular Biology ◽  
Low Cost ◽  
Power Source ◽  
Medical Diagnostics ◽  
Resource Limited Settings ◽  
Resource Limited ◽  
External Power Source ◽  
External Power ◽  
3D Printed ◽  
Proof Of Principle

The centrifuge is an essential tool for many aspects of research and medical diagnostics. However, conventional centrifuges are often inaccessible outside of conventional laboratory settings, such as remote field sites, require a constant external power source, and can be prohibitively costly in resource-limited settings and STEM-focused programs. Here we present the 3D-Fuge, a 3D-printed hand-powered centrifuge, as a novel alternative to standard benchtop centrifuges. Based on the design principles of a paper-based centrifuge, this 3D-printed instrument increases the volume capacity to 2 mL and can reach hand-powered centrifugation speeds up to 6,000 rpm. The 3D-Fuge devices presented here are capable of centrifugation of a wide variety of different solutions such as spinning down samples for biomarker applications and performing nucleotide extractions as part of a portable molecular lab setup. We introduce the design and proof-of-principle trials that demonstrate the utility of low-cost 3D printed centrifuges for use in remote and educational settings.

scholarly journals Recent Advances in Self-Powered Electrochemical Systems

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Linglin Zhou ◽  
Di Liu ◽  
Li Liu ◽  
Lixia He ◽  
Xia Cao ◽  
...  
Keyword(s):  
Mechanical Energy ◽  
Power Source ◽  
Triboelectric Nanogenerator ◽  
Application Domain ◽  
Important Research ◽  
Electrochemical System ◽  
Electrochemical Systems ◽  
External Power Source ◽  
External Power ◽  
Self Powered

Electrochemistry, one of the most important research and production technology, has been widely applicated in various fields. However, the requirement of external power source is a major challenge to its development. To solve this issue, developing self-powered electrochemical system (SPES) that can work by collecting energy from the environment is highly desired. The invention of triboelectric nanogenerator (TENG), which can transform mechanical energy into electricity, is a promising approach to build SPES by integrating with electrochemistry. In this view, the latest representative achievements of SPES based on TENG are comprehensively reviewed. By harvesting various mechanical energy, five SPESs are built, including electrochemical pollutants treatment, electrochemical synthesis, electrochemical sensor, electrochromic reaction, and anticorrosion system, according to the application domain. Additionally, the perspective for promoting the development of SPES is discussed.

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