The Experts below are selected from a list of 213 Experts worldwide ranked by ideXlab platform
Satoshi Tadokoro - One of the best experts on this subject based on the ideXlab platform.
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Retraction Mechanism of soft torus robot with a hydrostatic skeleton
arXiv: Robotics, 2020Co-Authors: Tomoya Takahashi, Kenjiro Tadakuma, Masahiro Watanabe, Masashi Konyo, Satoshi TadokoroAbstract:Soft robots have attracted much attention in recent years owing to their high adaptability. Long articulated soft robots enable diverse operations, and tip-extending robots that navigate their environment through growth are highly effective in robotic search applications. Because the robot membrane extends from the tip, these robots can lengthen without friction from the environment. However, the flexibility of the membrane inhibits tip Retraction. Two methods have been proposed to resolve this issue; increasing the pressure of the internal fluid to reinforce rigidity, and mounting an actuator at the tip. The disadvantage of the former is that the increase is limited by the membrane pressure resistance, while the second method adds to the robot complexity. In this paper, we present a tip-Retraction Mechanism without bending motion that takes advantage of the friction from the external environment. Water is used as the internal fluid to increase ground pressure with the environment. We explore the failure pattern of the Retraction motion and propose plausible solutions by using hydrostatic skeleton robot. Additionally, we develop a prototype robot that successfully retracts by using the proposed methodology. Our solution can contribute to the advancement of mechanical design in the soft robotics field with applications to soft snakes and manipulators.
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Retraction Mechanism of Soft Torus Robot With a Hydrostatic Skeleton
IEEE Robotics and Automation Letters, 2020Co-Authors: Tomoya Takahashi, Kenjiro Tadakuma, Masahiro Watanabe, Masashi Konyo, Satoshi TadokoroAbstract:Soft robots have attracted much attention in recent years owing to their high adaptability. Long articulated soft robots enable diverse operations, and tip-extending robots that navigate their environment through growth are highly effective in robotic search applications. Robots that extend from the tip can lengthen their body without friction from the environment. However, the flexibility of the thin membrane inhibits the Retraction motion of the tip due to buckling. Two methods have been proposed to resolve this issue; increasing the pressure of the internal fluid to reinforce rigidity, and mounting an actuator at the tip. The disadvantage of the former is that the increase is limited by the membrane pressure resistance, while the second method leads to robot complexity. In this letter, we present a tip-Retraction Mechanism with a hydrostatic skeleton that can prevent buckling and takes advantage of the friction from the external environment. Water is used as the internal fluid to increase ground pressure with the environment, which is different from the conventional methods that use pneumatic. We explore the failure pattern of the Retraction motion and propose solutions by using a hydrostatic skeleton robot. Additionally, we develop a prototype robot that successfully retracts by using the proposed methodology. Our solution can contribute to the advancement of mechanical design in the soft robotics field with applications to soft snakes and manipulators.
Kim E. Reuter - One of the best experts on this subject based on the ideXlab platform.
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Evolution of anthozoan polyp Retraction Mechanisms: convergent functional morphology and evolutionary allometry of the marginal musculature in order Zoanthidea (Cnidaria: Anthozoa: Hexacorallia).
BMC Evolutionary Biology, 2015Co-Authors: Timothy D. Swain, Jennifer Schellinger, Anna M. Strimaitis, Kim E. ReuterAbstract:Background Retraction is among the most important basic behaviors of anthozoan Cnidaria polyps and is achieved through the coordinated contraction of at least six different muscle groups. Across the Anthozoa, these muscles range from unrecognizable atrophies to massive hypertrophies, producing a wide diversity of Retraction abilities and functional morphologies. The marginal musculature is often the single largest component of the Retraction Mechanism and is composed of a diversity of muscular, attachment, and structural features. Although the arrangements of these features have defined the higher taxonomy of Zoanthidea for more than 100 years, a decade of inferring phylogenies from nucleotide sequences has demonstrated fundamental misconceptions of their evolution.
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Evolution of anthozoan polyp Retraction Mechanisms: convergent functional morphology and evolutionary allometry of the marginal musculature in order Zoanthidea (Cnidaria: Anthozoa: Hexacorallia)
BMC Evolutionary Biology, 2015Co-Authors: Timothy D. Swain, Jennifer Schellinger, Anna M. Strimaitis, Kim E. ReuterAbstract:Background Retraction is among the most important basic behaviors of anthozoan Cnidaria polyps and is achieved through the coordinated contraction of at least six different muscle groups. Across the Anthozoa, these muscles range from unrecognizable atrophies to massive hypertrophies, producing a wide diversity of Retraction abilities and functional morphologies. The marginal musculature is often the single largest component of the Retraction Mechanism and is composed of a diversity of muscular, attachment, and structural features. Although the arrangements of these features have defined the higher taxonomy of Zoanthidea for more than 100 years, a decade of inferring phylogenies from nucleotide sequences has demonstrated fundamental misconceptions of their evolution. Results Here we expand the diversity of known marginal muscle forms from two to at least ten basic states and reconstruct the evolution of its functional morphology across the most comprehensive molecular phylogeny available. We demonstrate that the evolution of these forms follows a series of transitions that are much more complex than previously hypothesized and converge on similar forms multiple times. Evolution of the marginal musculature and its attachment and support structures are partially scaled according to variation in polyp and muscle size, but also vary through evolutionary allometry. Conclusions Although the Retraction Mechanisms are diverse and their evolutionary histories complex, their morphologies are largely reflective of the evolutionary relationships among Zoanthidea higher taxa and may offer a key feature for integrative systematics. The convergence on similar forms across multiple linages of Zoanthidea mirrors the evolution of the marginal musculature in another anthozoan order (Actiniaria). The marginal musculature varies through evolutionary allometry of functional morphologies in response to requirements for additional force and resistance, and the specific ecological and symbiotic functions of individual taxa.
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Evolution of anthozoan polyp Retraction Mechanisms: convergent functional morphology and evolutionary allometry of the marginal musculature in order Zoanthidea (Cnidaria: Anthozoa: Hexacorallia).
BMC evolutionary biology, 2015Co-Authors: Timothy D. Swain, Jennifer Schellinger, Anna M. Strimaitis, Kim E. ReuterAbstract:Retraction is among the most important basic behaviors of anthozoan Cnidaria polyps and is achieved through the coordinated contraction of at least six different muscle groups. Across the Anthozoa, these muscles range from unrecognizable atrophies to massive hypertrophies, producing a wide diversity of Retraction abilities and functional morphologies. The marginal musculature is often the single largest component of the Retraction Mechanism and is composed of a diversity of muscular, attachment, and structural features. Although the arrangements of these features have defined the higher taxonomy of Zoanthidea for more than 100 years, a decade of inferring phylogenies from nucleotide sequences has demonstrated fundamental misconceptions of their evolution. Here we expand the diversity of known marginal muscle forms from two to at least ten basic states and reconstruct the evolution of its functional morphology across the most comprehensive molecular phylogeny available. We demonstrate that the evolution of these forms follows a series of transitions that are much more complex than previously hypothesized and converge on similar forms multiple times. Evolution of the marginal musculature and its attachment and support structures are partially scaled according to variation in polyp and muscle size, but also vary through evolutionary allometry. Although the Retraction Mechanisms are diverse and their evolutionary histories complex, their morphologies are largely reflective of the evolutionary relationships among Zoanthidea higher taxa and may offer a key feature for integrative systematics. The convergence on similar forms across multiple linages of Zoanthidea mirrors the evolution of the marginal musculature in another anthozoan order (Actiniaria). The marginal musculature varies through evolutionary allometry of functional morphologies in response to requirements for additional force and resistance, and the specific ecological and symbiotic functions of individual taxa.
Tomoya Takahashi - One of the best experts on this subject based on the ideXlab platform.
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Retraction Mechanism of soft torus robot with a hydrostatic skeleton
arXiv: Robotics, 2020Co-Authors: Tomoya Takahashi, Kenjiro Tadakuma, Masahiro Watanabe, Masashi Konyo, Satoshi TadokoroAbstract:Soft robots have attracted much attention in recent years owing to their high adaptability. Long articulated soft robots enable diverse operations, and tip-extending robots that navigate their environment through growth are highly effective in robotic search applications. Because the robot membrane extends from the tip, these robots can lengthen without friction from the environment. However, the flexibility of the membrane inhibits tip Retraction. Two methods have been proposed to resolve this issue; increasing the pressure of the internal fluid to reinforce rigidity, and mounting an actuator at the tip. The disadvantage of the former is that the increase is limited by the membrane pressure resistance, while the second method adds to the robot complexity. In this paper, we present a tip-Retraction Mechanism without bending motion that takes advantage of the friction from the external environment. Water is used as the internal fluid to increase ground pressure with the environment. We explore the failure pattern of the Retraction motion and propose plausible solutions by using hydrostatic skeleton robot. Additionally, we develop a prototype robot that successfully retracts by using the proposed methodology. Our solution can contribute to the advancement of mechanical design in the soft robotics field with applications to soft snakes and manipulators.
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Retraction Mechanism of Soft Torus Robot With a Hydrostatic Skeleton
IEEE Robotics and Automation Letters, 2020Co-Authors: Tomoya Takahashi, Kenjiro Tadakuma, Masahiro Watanabe, Masashi Konyo, Satoshi TadokoroAbstract:Soft robots have attracted much attention in recent years owing to their high adaptability. Long articulated soft robots enable diverse operations, and tip-extending robots that navigate their environment through growth are highly effective in robotic search applications. Robots that extend from the tip can lengthen their body without friction from the environment. However, the flexibility of the thin membrane inhibits the Retraction motion of the tip due to buckling. Two methods have been proposed to resolve this issue; increasing the pressure of the internal fluid to reinforce rigidity, and mounting an actuator at the tip. The disadvantage of the former is that the increase is limited by the membrane pressure resistance, while the second method leads to robot complexity. In this letter, we present a tip-Retraction Mechanism with a hydrostatic skeleton that can prevent buckling and takes advantage of the friction from the external environment. Water is used as the internal fluid to increase ground pressure with the environment, which is different from the conventional methods that use pneumatic. We explore the failure pattern of the Retraction motion and propose solutions by using a hydrostatic skeleton robot. Additionally, we develop a prototype robot that successfully retracts by using the proposed methodology. Our solution can contribute to the advancement of mechanical design in the soft robotics field with applications to soft snakes and manipulators.
Donna Haiduven - One of the best experts on this subject based on the ideXlab platform.
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Comparison of visual versus microscopic methods to detect blood splatter from an intravascular catheter with engineered sharps injury protection.
Infection Control and Hospital Epidemiology, 2013Co-Authors: Aiysha Ansari, Padmaja Ramaiah, Lillian Collazo, Hamisu M. Salihu, Donna HaiduvenAbstract:OBJECTIVE: To determine whether retractable intravenous devices produced blood splatter and whether blood splatter frequency differed between visual and microscopy detection methods. METHODS: In this laboratory-based experiment, 105 venipunctures were performed in a simulated brachial vein containing mock venous blood. The Retraction Mechanism was activated in a testing chamber with precut fabric filters, placed at 3 different locations, to capture blood splatter. Differences in filter mass, visual inspection, and microscopic analysis for presence of blood on filters were the units of analysis. Descriptive statistics, paired Student t tests, and κ statistics were used for data analysis. RESULTS: Blood splatter was detected visually and microscopically as follows: filter A, 70% and 71%, respectively; filter B, 12% and 9%, respectively; and filter C, 13% and 10%, respectively. A statistically significant difference was observed in the mean mass of filter A between before and after activation when confirmed by the naked eye (P = .014) and microscopically (P = .0092). Substantial agreement between methods was observed for filter A (κ - 0.78 [95% confidence interval, 0.64-0.92]), filter B (κ - 0.73 [95% confidence interval, 0.51-0.95]), and filter C (κ - 0.75 [95% confidence interval, 0.55-0.96]). However, blood was detected by microscopy and not by the naked eye in 7 instances (7%). CONCLUSIONS: Our findings demonstrate that splatter, which can potentially expose healthcare workers (HCWs) to bloodborne pathogens, is associated with the activation of intravascular catheters with Retraction Mechanisms. HCWs may not detect this splatter when it occurs and may not report a splash to mucous membranes or nonintact skin. The need to wear personal protective equipment when using such devices is reinforced.
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A pilot study to measure the compressive and tensile forces required to use retractable intramuscular safety syringes.
American Journal of Infection Control, 2006Co-Authors: Donna Haiduven, Shawn P. Applegarth, Heidi Disalvo, Sitha Mangipudy, Jason Konopack, June M. FisherAbstract:BACKGROUND/OBJECTIVES: Even though retractable intramuscular safety syringes are designed to be activated while still in the patient's muscle or subcutaneous tissue, there are reports of healthcare workers activating these devices outside of the patient. This may be due to perceptions that the force required to activate the Retraction Mechanism may cause added discomfort to the patient. If such concerns could be substantiated, the possibility for a sharps injury still exists if these safety devices are not utilized correctly, in essence defeating their intended purpose. The objective of this pilot study was to determine the forces required to operate retractable safety syringes in order to evaluate potential adverse occupational health and patient safety issues. METHODS: A newly-developed product evaluation laboratory at the James A. Haley Veterans Administration Patient Safety Center in Tampa, Florida, provided the controlled setting for evaluating safer needle devices in this pilot study. Four brands (100 each) of retractable syringes were tested, using a digital force gauge, in air and in a simulated patient material (SPM). Compressive forces were measured while activating the Retraction Mechanism in both air and SPM. Tensile forces were measured while withdrawing 2 cc of saline into the syringe barrel. Two-way analysis of variance and Duncan's Multiple Range test were used in the statistical analysis. RESULTS: The compressive forces demonstrated by the four devices in both air and SPM measured from a low of 0.52 lbs to a high of 22.02 lbs (range = 21.97 lbs). The mean compressive force was greater in SPM than in air in all four devices. There was a statistically significant compressive force difference between activation in air and SPM in devices 1 and 2 (p ≤ 0. 05). The tensile forces measured from a low of 0.06 lbs to a high of 2.18 lbs (range = 2.12 lbs). The tensile forces for all devices were lower than the compressive forces. Analysis of variance demonstrated a significant difference between the means of the four tensile groups (p CONCLUSIONS: There was considerable variability in the measured compressive force between devices yet the compressive force was still greater in SPM than in air. The results of this pilot study pose needlestick injury potential and device training issues for healthcare workers, as well as possible future impacts on the design of this type of safety device. The cumulative ergonomic effects of compressive and tensile forces require further investigation. Replication of this study by multiple researchers, using numerous needles and syringe sizes, is recommended.
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From bedside to bench: A pilot study to measure the force required to activate a retractable safety syringe
American Journal of Infection Control, 2005Co-Authors: Jason Konopack, Heidi Disalvo, Shawn P. Applegarth, Donna HaiduvenAbstract:BACKGROUND/OBJECTIVES: This laboratory in Tampa, Florida, has established a program to evaluate objective and subjective criteria for safer needle devices designed to prevent or reduce sharps injuries in healthcare workers. The goal of this pilot study was to determine whether the force required to activate one particular retractable intramuscular syringe was due to the activation media or the healthcare worker. METHODS: One hundred devices of a particular brand were subjected to activation while suspended in the air and while the needle was inserted into simulated patient material (SPM). Each researcher tested 25 devices in air first and 25 in SPM first, resetting the device before switching media. After each activation, the compression force needed to activate the Retraction Mechanism on each individual syringe was measured in pounds (lbs.) using a Com-Ten™ Model # CER02000 Digital Force Gauge (DFG). The data were immediately recorded in an Excel™ spreadsheet. RESULTS: Overall, the mean activation force was significantly greater (p = 0.05) while the needle was activated in SPM (3.56 lbs.) versus air (2.80 lbs.), regardless of the sequence or researcher. In addition, there was a statistically significant difference, regardless of sequence, in the device's mean activation force between researchers 1 and 2 (2.78 lbs. versus 3.57 lbs.; p = 0.05). CONCLUSIONS: In healthcare settings, the force required to activate the device is clinically relevant. If a healthcare worker perceives that force required to activate the device equates with pain felt by the patient, then the HCW may activate the device while in the air, increasing the risk of sharps injury. This would also defeat the purpose of this particular safety Mechanism, of particular concern as this category of device generally costs more than other safety intramuscular syringes. We demonstrated a significant difference in mean force using one particular device due to the media in which the device was activated. This has implications for manufacturers in designing future models. Significant variability existed between healthcare workers in the force necessary to activate the retractable Mechanism of an intramuscular device. In future studies of this kind, we recommend that one researcher be used in initial pilot studies in the laboratory setting. Finally, the phenomenon of perceived versus exerted force and whether force equates with pain are two areas for potential future studies.
Bradley D. Olsen - One of the best experts on this subject based on the ideXlab platform.
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Diffusion Mechanisms of Entangled Rod–Coil Diblock Copolymers
Macromolecules, 2013Co-Authors: Muzhou Wang, Ksenia Timachova, Bradley D. OlsenAbstract:Mechanisms of entangled rod–coil diblock copolymer diffusion are investigated using tracer diffusion simulations and experiments in a matrix of entangled coil homopolymers, demonstrating that the diffusion Mechanisms first identified in coil–rod–coil triblocks are universal for various molecular architectures. Diffusion measurements were performed using both Kremer–Grest molecular dynamics simulations and forced Rayleigh scattering experiments. In the large rod regime, diffusivity decreases exponentially with increasing coil size as predicted by an arm Retraction Mechanism. The ratio of diblock to rod homopolymer diffusivity was approximately equal to the ratio for triblocks squared, suggesting that the two coil blocks of the coil–rod–coil triblock relax independently. In the small rod regime, both experiments and simulation show that the slowing of diffusion with increasing rod length is the same for rod–coil diblock and coil–rod–coil triblock copolymers. This behavior occurs because both types of molecu...
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Diffusion of Entangled Rod–Coil Block Copolymers
ACS Macro Letters, 2012Co-Authors: Muzhou Wang, Alfredo Alexander-katz, Bradley D. OlsenAbstract:The diffusion of entangled rod–coil block copolymers is investigated by molecular dynamics (MD) simulations, and theories are introduced that describe the observed features and underlying physics. The reptation of rod–coil block copolymers is dominated by the mismatch between the curvature of the rod and coil entanglement tubes, which results in dramatically slower diffusion of rod–coils compared to the rod and coil homopolymers. For small rods, a local curvature-dependent free energy penalty results in a rough energy surface inside the entanglement tube, causing diffusivity to decrease with rod length. For large rods, rotational hindrances on the rod dominate, causing the coil block to relax by an arm Retraction Mechanism and diffusivity to decrease exponentially with coil size.