scholarly journals A Static Balancing Method for Variable Payloads by Combination of a Counterweight and Spring and Its Application as a Surgical Platform

2019 ◽  
Vol 9 (19) ◽  
pp. 3955 ◽  
Author(s):  
Woo ◽  
Seo ◽  
Yi
Keyword(s):  
Energy Expenditure ◽  
Free Space ◽  
Effective Means ◽  
Excellent Performance ◽  
Static Balancing ◽  
Effective Gravity ◽  
Safe Surgery ◽  
Balancing Conditions ◽  
Surgical Platform

Stackable mechanism architecture has demonstrated effective gravity-balancing over entire workspaces. Adjustable balancing is required when balancing is broken due to changing the payload at the distal end of a mechanism. In this paper, adjustable balancing of the stackable mechanism for a variable payload is investigated. For this, balancing conditions for three adjustable balancing methods are suggested, and a new balancing method combining a spring and counterweight is considered as an effective means of adjustable balancing for variable payloads. The excellent performance of the system is proven through experiments. Electromyography (EMG) sensors are employed to measure the amount of energy expenditure during the drilling task. It was verified through several tests that an operator holding a drill mounted at the distal end of a stackable arm felt less energy compared to an operator holding the drill directly in free space. The developed balancing arm was successfully applied during a mastoidectomy. A 3-step warning algorithm along with a braking function was found to be effective for safe surgery.

Static Balancing of Tensegrity Mechanisms

2006 ◽  
Vol 129 (3) ◽  
pp. 295-300 ◽  
Author(s):  
Marc Arsenault ◽  
Clément M. Gosselin
Keyword(s):  
Degree Of Freedom ◽  
Static Balancing ◽  
Equilibrium Configurations ◽  
Balancing Conditions ◽  
Three Degree Of Freedom

The computation of the equilibrium configurations of tensegrity mechanisms is often a very tedious task even for relatively simple architectures. However, it has been observed that the complexity of this problem is significantly reduced when gravitational loads are compensated with the use of static balancing techniques. In this work, the general static balancing conditions are adapted for the case of tensegrity mechanisms. Afterward, the modified conditions are applied to two new spatial three-degree-of-freedom tensegrity mechanisms.

Static Balancing of Spatial and Planar Parallel Manipulators With Prismatic Actuators

1998 ◽  
Author(s):  
Marc Leblond ◽  
Clément M. Gosselin
Keyword(s):  
Parallel Manipulators ◽  
Geometric Interpretation ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Static Balancing ◽  
Inertial Parameters ◽  
Dimensional Parameters ◽  
Balancing Conditions ◽  
Static Conditions ◽  
Planar Parallel Manipulators

Abstract In this paper, the static balancing of existing spatial and planar parallel manipulators by the addition of balancing elements is addressed. Static balancing is defined here as the set of conditions on manipulator dimensional and inertial parameters which, when satisfied, ensure that the weight of the links does not produce any force (or torque) at the actuators for any configuration of the manipulator, under static conditions. These conditions are derived here for spatial six-degree-of-freedom parallel manipulators and it is shown that planar three-degree-of-freedom parallel manipulators can be treated as a particular case of the spatial 6-dof mechanisms. The static balancing conditions associated with planar mechanisms can therefore easily be found, but are not given here because of space limitations. A brief geometric interpretation of the balancing conditions which are associated with statically balanced spatial mechanisms is then carried out. It is shown that balancing is generally possible even when the dimensional parameters are imposed, which is a useful property since dimensional parameters are usually obtained from kinematic design or optimization. Finally, examples of balanced planar and spatial parallel manipulators are given. Static balancing leads to considerable reduction in the actuator forces (or torques), which in turn leads to less powerful actuators and more efficient designs. Moreover, the possibility of balancing existing systems by introducing additional elements, as demonstrated here, is of interest for retrofitting existing parallel mechanisms.

Static Balancing of Tensegrity Mechanisms

2005 ◽  
Author(s):  
Marc Arsenault ◽  
Cle´ment M. Gosselin
Keyword(s):  
Degree Of Freedom ◽  
Static Balancing ◽  
Equilibrium Configurations ◽  
Balancing Conditions ◽  
Three Degree Of Freedom

The computation of the equilibrium configurations of tensegrity mechanisms is often a very tedious task even for relatively simple architectures. However, it has been observed that the complexity of this problem is significantly reduced when gravitational loads are compensated with the use of static balancing techniques. In this work, the general static balancing conditions are adapted for the case of tensegrity mechanisms. Afterwards, the modified conditions are applied to two new spatial three-degree-of-freedom tensegrity mechanisms.

Bike Desks in the Classroom: Energy Expenditure, Physical Health, Cognitive Performance, Brain Functioning, and Academic Performance

2017 ◽  
Vol 14 (6) ◽  
pp. 429-439 ◽  
Author(s):  
Tine Torbeyns ◽  
Bas de Geus ◽  
Stephen Bailey ◽  
Lieselot Decroix ◽  
Jeroen Van Cutsem ◽  
...  
Keyword(s):  
Academic Performance ◽  
Energy Expenditure ◽  
Physical Health ◽  
Cognitive Performance ◽  
Aerobic Fitness ◽  
Effective Means ◽  
Intervention Group ◽  
Control Group ◽  
Anthropometric Parameters ◽  
Brain Functioning

Background:Physical activity is positively associated with physical health, cognitive performance, brain functioning and academic performance. The aim of this study is to investigate the influence of bike desks in the classroom on adolescents’ energy expenditure, physical health, cognitive performance, brain functioning and academic performance.Methods:Forty-four adolescents were randomly assigned to control group (CG) or intervention group (IG). During 5 months, the IG used a bike desk for 4 class hours/week. Energy expenditure was measured during 6 consecutive days. Anthropometric parameters, aerobic fitness, academic performance, cognitive performance and brain functioning were assessed before (T0) and after (T1) the intervention.Results:Energy expenditure of the IG was significantly higher during the class hours in which they used the bike desks relative to normal class hours. The CG had a significantly higher BMI at T1 relative to T0 while this was not significantly different for the IG. Aerobic fitness was significantly better in the IG at T1 relative to T0. No significant effects on academic performance cognitive performance and brain functioning were observed.Conclusions:As the implementation of bike desks in the classroom did not interfere with adolescents’ academic performance, this can be seen as an effective means of reducing in-class sedentary time and improving adolescents’ physical health.

Static Balancing of Translational Parallel Mechanisms

2011 ◽  
Author(s):  
Teunis van Dam ◽  
Patrice Lambert ◽  
Just L. Herder
Keyword(s):  
Range Of Motion ◽  
Parallel Manipulators ◽  
Static Equilibrium ◽  
Static Balance ◽  
Parallel Mechanisms ◽  
Static Balancing ◽  
Delta Robot ◽  
Balancing Conditions

Static balancing is a technique to create static equilibrium throughout a certain range of motion. Static balancing for spatially moving parallel manipulators tends to result in considerable added complexity which hampers application. This paper presents a simple static balancing technique for the subclass of translational parallel manipulators such as the Delta robot. Mathematically perfect static balance is achieved without addition of links. Only springs need to be added. The concept and the balancing conditions will be presented. A prototype is being manufactured at the time of writing which demonstrates the feasibility of the concept.

scholarly journals Evaluation of the long-term effects of gastric inhibitory polypeptide–ovalbumin conjugates on insulin resistance, metabolic dysfunction, energy balance and cognition in high-fat-fed mice

2012 ◽  
Vol 108 (1) ◽  
pp. 46-56 ◽  
Author(s):  
Nigel Irwin ◽  
Ian A. Montgomery ◽  
Peter R. Flatt
Keyword(s):  
Insulin Resistance ◽  
Energy Expenditure ◽  
Plasma Insulin ◽  
Effective Means ◽  
Gastric Inhibitory Polypeptide ◽  
Metabolic Dysfunction ◽  
Long Term Effects ◽  
High Fat ◽  
Active Immunisation ◽  
Glucose Lowering

The effects of active immunisation with gastric inhibitory polypeptide (GIP) or (proline3)GIP–ovalbumin conjugates on insulin resistance, metabolic dysfunction, energy expenditure and cognition were examined in high-fat-fed mice. Normal mice were injected (subcutaneously) once every 14 d for 98 d with GIP–ovalbumin conjugates, with transfer to a high-fat diet on day 21. Active immunisation resulted in GIP antibody generation and significantly (P < 0·01 to P < 0·001) reduced circulating non-fasting plasma insulin concentrations compared to high-fat control mice from day 70 onwards. The glycaemic responses to intraperitoneal glucose or nutrient ingestion were significantly improved in all treated mice, with corresponding stimulated plasma insulin levels depressed compared to high-fat controls. These changes were associated with substantially (P < 0·001) improved glucose-lowering responses to exogenous insulin and decreases of muscle and fat TAG, pancreatic insulin, circulating total and LDL-cholesterol levels (P < 0·01 to P < 0·001). Treatment with GIP–ovalbumin conjugates was not associated with alterations in energy expenditure, indirect calorimetry or aspects of cognitive function. The observed changes were almost identical in GIP and (Pro3)GIP immunised mice and were independent of any effects on food intake or body weight. Further tests established that coupling of GIP peptides to ovalbumin abolished any intrinsic insulin-releasing or glucose-lowering activity. These results suggest that induction of GIP-neutralising antibodies with GIP–ovalbumin conjugates is an effective means of countering the metabolic abnormalities induced by high-fat feeding and does not adversely have an impact on a marker of cognition function or energy expenditure.

Spatial Static Gravity Balancing With Ideal Springs

2004 ◽  
Author(s):  
Freek L. S. te Riele ◽  
Just L. Herder ◽  
Edsko E. G. Hekman
Keyword(s):  
Potential Energy ◽  
Inverted Pendulum ◽  
Spherical Joint ◽  
Static Balancing ◽  
Energy Expression ◽  
Energy Consideration ◽  
Balancing Conditions ◽  
Spring Mechanism ◽  
Potential Energy Expression

This paper discusses mechanisms that allow for perfect static balancing of rotations about a fixed spherical joint by means of ideal springs. Using a potential energy consideration, balancing conditions of a spatial three-spring balancer will be derived. It will be shown that not satisfying these conditions causes non-constant terms in the potential energy expression of the spring-mechanism, which can be eliminated by coupling the spring-mechanism to an inverted pendulum.

An Ultrastructural Study of Chronic Pyelonephritis in Macaca Arctoides

1976 ◽  
Vol 34 ◽  
pp. 310-311
Author(s):  
T.W. Smith ◽  
J.A. Roberts ◽  
B.J. Martin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ultrastructural Study ◽  
Effective Means ◽  
Chronic Pyelonephritis ◽  
Macaca Arctoides ◽  
Left Ureter ◽  
E Coli ◽  
Transmission Electron ◽  
Sizeable Number

Chronic pyelonephritis is one of the most common diseases of the kidney and accounts for a sizeable number of cases of renal insufficiency in man, however its pathogenesis requires further elucidation. Transmission electron microscopy may serve as a uniquely effective means of observing details of the nature of this disease. The present paper describes preliminary results of an ultrastructural study of chronic pyelonephritis in Macaca arctoides (stumptail monkey).The infection was induced in these experiments in a retrograde fashion by means of a unilateral catheterization of the left ureter whereby an innoculum of 10 cc of broth containing approximately 2 billion E. coli per cc and radio-opaque dye were injected under pressure (mimicing vesico-ureteric reflux).

Computer programs for the calculation of x-ray intensities emitted by elements in multi-layer structures

1990 ◽  
Vol 48 (2) ◽  
pp. 216-217
Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers ◽  
J.M. Dijkstra
Keyword(s):  
Software Package ◽  
Light Element ◽  
Matrix Correction ◽  
Excellent Performance ◽  
Element Analysis ◽  
X Ray ◽  
Know How ◽  
Accurate Knowledge ◽  
Layer Structures ◽  
Bulk Matrix

For the calculation of X-ray intensities emitted by elements present in multi-layer systems it is vital to have an accurate knowledge of the x-ray ionization vs. mass-depth (ϕ(ρz)) curves as a function of accelerating voltage and atomic number of films and substrate. Once this knowledge is available the way is open to the analysis of thin films in which both the thicknesses as well as the compositions can usually be determined simultaneously.Our bulk matrix correction “PROZA” with its proven excellent performance for a wide variety of applications (e.g., ultra-light element analysis, extremes in accelerating voltage) has been used as the basis for the development of the software package discussed here. The PROZA program is based on our own modifications of the surface-centred Gaussian ϕ(ρz) model, originally introduced by Packwood and Brown. For its extension towards thin film applications it is required to know how the 4 Gaussian parameters α, β, γ and ϕ(o) for each element in each of the films are affected by the film thickness and the presence of other layers and the substrate.

A compendium of G-protein–coupled receptors and cyclic nucleotide regulation of adipose tissue metabolism and energy expenditure

2020 ◽  
Vol 134 (5) ◽  
pp. 473-512 ◽  
Author(s):  
Ryan P. Ceddia ◽  
Sheila Collins
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Signaling Pathways ◽  
G Protein ◽  
Uncoupling Protein ◽  
Beige Adipocytes ◽  
Nucleotide Regulation ◽  
Ucp1 Expression ◽  
Thermogenic Adipocytes ◽  
G Protein Coupled

Abstract With the ever-increasing burden of obesity and Type 2 diabetes, it is generally acknowledged that there remains a need for developing new therapeutics. One potential mechanism to combat obesity is to raise energy expenditure via increasing the amount of uncoupled respiration from the mitochondria-rich brown and beige adipocytes. With the recent appreciation of thermogenic adipocytes in humans, much effort is being made to elucidate the signaling pathways that regulate the browning of adipose tissue. In this review, we focus on the ligand–receptor signaling pathways that influence the cyclic nucleotides, cAMP and cGMP, in adipocytes. We chose to focus on G-protein–coupled receptor (GPCR), guanylyl cyclase and phosphodiesterase regulation of adipocytes because they are the targets of a large proportion of all currently available therapeutics. Furthermore, there is a large overlap in their signaling pathways, as signaling events that raise cAMP or cGMP generally increase adipocyte lipolysis and cause changes that are commonly referred to as browning: increasing mitochondrial biogenesis, uncoupling protein 1 (UCP1) expression and respiration.

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