Development of a Bioinspired Underwater Robot Using a Single Actuator

2017 ◽  
Vol 51 (5) ◽  
pp. 94-102
Author(s):  
Myoung-Jae Jun ◽  
Chang-Soo Han
Keyword(s):  
The Body ◽  
Inertia Force ◽  
Underwater Robot ◽  
Restoring Force ◽  
Total Body Mass ◽  
Pectoral Fins ◽  
Propulsion Mechanism ◽  
Total Body ◽  
Motion Characteristics ◽  
Direction Opposite

Abstract We propose a novel propulsion mechanism for an underwater robot inspired by the pectoral fins of a fish. This device is referred to as the “flipper.” The flipper is connected to a rotational motor, and its shape is similar to that of the real fish's fins. The flipper using the propulsion mechanism proposed in this study has 1 degree of freedom. We can control the test robot during forward motion as well as its direction-changing operation. The experimental test robot is composed of a flipper at the front of the robot's head, together with a body and a tail/vertical fin. The electronic components are installed into the body. The tail functions to maintain the horizontal/vertical balance of the robot. Forward propulsion is achieved through the rotation of the flipper. The robot's direction can be changed by repeated oscillation of the flipper in a direction opposite to that of the desired angle. Several experiments were performed to measure the thrust force of the experimental robot and its motion characteristics in a test water pool. The experimental results show that the proposed propulsion method is viable.<def-list> Nomenclature <def-item> <term> F T </term> <def> = Thrust </def> </def-item> <def-item> <term> F I </term> <def> = Inertia force </def> </def-item> <def-item> <term> F B </term> <def> = Buoyancy </def> </def-item> <def-item> <term> B V </term> <def> = Platform volume </def> </def-item> <def-item> <term> V target </term> <def> = Target speed </def> </def-item> <def-item> <term> ρ </term> <def> = Water density </def> </def-item> <def-item> <term> P </term> <def> = Flipper pitch </def> </def-item> <def-item> <term> D </term> <def> = Drag force </def> </def-item> <def-item> <term> C D </term> <def> = Drag coefficient </def> </def-item> <def-item> <term> A </term> <def> = Projection of the frontal area </def> </def-item> <def-item> <term> T </term> <def> = Effective power </def> </def-item> <def-item> <term> P m </term> <def> = Propeller power </def> </def-item> <def-item> <term> C M </term> <def> = Center of total body mass </def> </def-item> <def-item> <term> C B </term> <def> = Center of buoyancy </def> </def-item> <def-item> <term> C F </term> <def> = Center of flipper mass </def> </def-item> <def-item> <term> F DS </term> <def> = Restoring force </def> </def-item> <def-item> <term> g </term> <def> = Gravity </def> </def-item> <def-item> <term> Q </term> <def> = Motor torque at maximum revolutions per minute </def> </def-item> <def-item> <term> rps reasonable </term> <def> = Reasonable revolutions per second </def> </def-item> </def-list>

scholarly journals Estimating body segment parameters from three-dimensional human body scans

2021 ◽  
Author(s):  
Pawel Kudzia ◽  
Erika A. Jackson ◽  
Genevieve A. Dumas
Keyword(s):  
The Body ◽  
Parameter Estimates ◽  
Body Segment ◽  
Surface Scanning ◽  
Total Body Mass ◽  
3D Surface ◽  
Longitudinal Length ◽  
Mass Moment ◽  
Total Body ◽  
Body Segment Parameters

Body segment parameters are inputs for a range of applications. The estimation of body segment parameters that are participant-specific is desirable as it requires fewer prior assumptions and can reduce outcome measurement errors. Commonly used methods for estimating participant-specific body segment parameters are either expensive and out of reach (medical imaging), have many underlying assumptions (geometrical modelling) or are based on a specific subset of a population (regression models). Our objective was to develop a participant-specific 3D scanning and body segmentation method that estimates body segment parameters without any assumptions about the geometry of the body, ethnic background, and gender, is low-cost, fast, and can be readily available. Using a Microsoft Kinect camera, we developed a 3D surface scanning protocol that estimated participant-specific body segment parameters. To evaluate our system, we performed repeated 3D scans of 21 healthy participants (10 male, 11 female). We used open-source software to segment each body scan into 16 segments (head, torso, abdomen, pelvis, left and right hand, forearm, upper arm, foot, shank and thigh) and wrote custom software to estimate each segment's mass, mass moment of inertia in the three principal orthogonal axes relevant to the center of the segment, longitudinal length, and center of mass. We compared our body segment parameter estimates to those obtained using two comparison methods and found that our system was consistent in estimating total body volume between repeated scans (male p=0.1194, female p = 0.2240), estimated total body mass without significant differences when compared to our comparison method and a medical scale (male p=0.8529, female p = 0.6339), and generated consistent and comparable estimates across all of the body segment parameters of interest. The work here outlines an inexpensive 3D surface scanning approach for estimating a range of participant-specific body segment parameters.

Swimming in needlefish (Belonidae): anguilliform locomotion with fins

2002 ◽  
Vol 205 (18) ◽  
pp. 2875-2884 ◽  
Author(s):  
James C. Liao
Keyword(s):  
Surface Waters ◽  
High Speed ◽  
Total Body Length ◽  
The Body ◽  
Pectoral Fins ◽  
Half Wavelength ◽  
Total Body ◽  
Length Analysis ◽  
Median Fins ◽  
Tail Beat

SUMMARYThe Atlantic needlefish (Strongylura marina) is a unique anguilliform swimmer in that it possesses prominent fins, lives in coastal surface-waters, and can propel itself across the surface of the water to escape predators. In a laboratory flow tank, steadily swimming needlefish perform a speed-dependent suite of behaviors while maintaining at least a half wavelength of undulation on the body at all times. To investigate the effects of discrete fins on anguilliform swimming, I used high-speed video to record body and fin kinematics at swimming speeds ranging from 0.25 to 2.0 Ls-1 (where L is the total body length). Analysis of axial kinematics indicates that needlefish are less efficient anguilliform swimmers than eels, indicated by their lower slip values. Body amplitudes increase with swimming speed, but unlike most fishes, tail-beat amplitude increases linearly and does not plateau at maximal swimming speeds. At 2.0 Ls-1, the propulsive wave shortens and decelerates as it travels posteriorly, owing to the prominence of the median fins in the caudal region of the body. Analyses of fin kinematics show that at 1.0 Ls-1 the dorsal and anal fins are slightly less than 180° out of phase with the body and approximately 225° out of phase with the caudal fin. Needlefish exhibit two gait transitions using their pectoral fins. At 0.25 L s-1, the pectoral fins oscillate but do not produce thrust, at 1.0 L s-1 they are held abducted from the body,forming a positive dihedral that may reduce rolling moments, and above 2.0 L s-1 they remain completely adducted.

Nouvelles données sur la masse du squelette chez les grands cétacés (Mammalia, Cetacea)

1993 ◽  
Vol 71 (4) ◽  
pp. 828-834 ◽  
Author(s):  
Daniel Robineau ◽  
Vivian de Buffrénil
Keyword(s):  
Sperm Whale ◽  
Small Sample ◽  
The Body ◽  
Medium Size ◽  
Total Body Mass ◽  
Terrestrial Mammals ◽  
Skeletal Mass ◽  
Bony Fishes ◽  
Functional Patterns ◽  
Total Body

The mass of dry and fat-free skeletons was measured in a small sample representing five species of large cetaceans: two balaenids, two balaenopterids, and one physeterid (the sperm whale). Expressed as a percentage of total body mass, skeletal mass in these animals varies from 3.5 to 5%. Such values are very close to those established previously for small to medium size toothed whales. This means that the dynamics of mass growth of the skeleton, as compared with that of the body as a whole, does not follow a positive allometry in cetaceans. Such a growth pattern differs markedly from the tendencies described in terrestrial mammals. Conversely, it is similar to that described in bony fishes. The distribution of loads within the skeletons reflects rather different functional patterns among the taxa examined here. The possible adaptive significance of these differences is discussed in reference to the locomotion of large cetaceans.

scholarly journals Estimating body segment parameters from three-dimensional human body scans

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262296
Author(s):  
Pawel Kudzia ◽  
Erika Jackson ◽  
Genevieve Dumas
Keyword(s):  
The Body ◽  
Body Segment ◽  
Surface Scanning ◽  
Total Body Mass ◽  
Scanning Method ◽  
3D Surface ◽  
Longitudinal Length ◽  
Mass Moment ◽  
Total Body ◽  
Body Segment Parameters

Body segment parameters are inputs for a range of applications. Participant-specific estimates of body segment parameters are desirable as this requires fewer prior assumptions and can reduce outcome measurement errors. Commonly used methods for estimating participant-specific body segment parameters are either expensive and out of reach (medical imaging), have many underlying assumptions (geometrical modelling) or are based on a specific subset of a population (regression models). Our objective was to develop a participant-specific 3D scanning and body segmentation method that estimates body segment parameters without any assumptions about the geometry of the body, ethnic background, and gender, is low-cost, fast, and can be readily available. Using a Microsoft Kinect Version 2 camera, we developed a 3D surface scanning protocol that enabled the estimation of participant-specific body segment parameters. To evaluate our system, we performed repeated 3D scans of 21 healthy participants (10 male, 11 female). We used open source tools to segment each body scan into 16 segments (head, torso, abdomen, pelvis, left and right hand, forearm, upper arm, foot, shank and thigh) and wrote custom software to estimate each segment’s mass, mass moment of inertia in the three principal orthogonal axes relevant to the center of the segment, longitudinal length, and center of mass. We compared our body segment parameter estimates to those obtained using two comparison methods and found that our system was consistent in estimating total body volume between repeated scans (male p = 0.1194, female p = 0.2240), estimated total body mass without significant differences when compared to our comparison method and a medical scale (male p = 0.8529, female p = 0.6339), and generated consistent and comparable estimates across a range of the body segment parameters of interest. Our work here outlines and provides the code for an inexpensive 3D surface scanning method for estimating a range of participant-specific body segment parameters.

scholarly journals Physiomorphic Transformation in Extreme Endurance Migrants: Revisiting the Case of Bar-Tailed Godwits Preparing for Trans-Pacific Flights

2021 ◽  
Vol 9 ◽  
Author(s):  
Theunis Piersma ◽  
Robert E. Gill ◽  
Daniel R. Ruthrauff
Keyword(s):  
Body Mass ◽  
Time Window ◽  
The Body ◽  
Fat Free Mass ◽  
Published Data ◽  
Total Body Mass ◽  
Digestive Organs ◽  
Short Time Window ◽  
Muscle Groups ◽  
Total Body

In a 1998 paper entitled “Guts don’t fly: small digestive organs in obese bar-tailed godwits,” Piersma and Gill (1998) showed that the digestive organs were tiny and the fat loads huge in individuals suspected of embarking on a non-stop flight from Alaska to New Zealand. It was suggested that prior to migratory departure, these godwits would shrink the digestive organs used during fuel deposition and boost the size and capacity of exercise organs to optimize flight performance. Here we document the verity of the proposed physiomorphic changes by comparing organ sizes and body composition of bar-tailed godwits Limosa lapponica baueri collected in modesty midway during their fueling period (mid-September; fueling, n = 7) with the previously published data for godwits that had just departed on their trans-Pacific flight (October 19; flying, n = 9). Mean total body masses for the two groups were nearly identical, but nearly half of the body mass of fueling godwits consisted of water, while fat constituted over half of total body mass of flying godwits. The two groups also differed in their fat-free mass components. The heart and flight muscles were heavier in fueling godwits, but these body components constituted a relatively greater fraction of the fat-free mass in flying godwits. In contrast, organs related to digestion and homeostasis were heavier in fueling godwits, and most of these organ groups were also relatively larger in fueling godwits compared to flying godwits. These results reflect the functional importance of organ and muscle groups related to energy acquisition in fueling godwits and the consequences of flight-related exertion in flying godwits. The extreme physiomorphic changes apparently occurred over a short time window (≤1 month). We conclude that the inferences made on the basis of the 1998 paper were correct. The cues and stimuli which moderate these changes remain to be studied.

A REVIEW OF TWAK SHARIR W. S. R. TO PADADARI

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Mohan Yende ◽  
Jayashree S Gohane ◽  
Thosar Sheetal Laxman
Keyword(s):  
Body Weight ◽  
External Surface ◽  
External Auditory Meatus ◽  
The Body ◽  
Whole Body ◽  
Lateral Aspect ◽  
Total Body Mass ◽  
Research Article ◽  
Total Body ◽  
Soil And Water

Padadari is one of the commonest & most negligible disease. It is observed that people are least bothered about their feet though feet bear the whole body weight. In India 80% of population live in rural area. Most of them work in farms in wet soil and water also. So incidence of cracking the skin of the foot is very common. For management of Padadari knowledge of skin is very important. The skin covers the entire external surface of the body, including the external auditory meatus, the lateral aspect of tympanic membrane and vestibule of the nose. Skin forms about 8% of the total body mass. It is one of the largest organs of the body in surface area and weight. In adult, the skin covers an area about 2 square meters and weighs 4.5-5 kg. Its thickness is 0.5-4mm, depending on location, maturation and ageing. All of Acharyas explain briefly about Twak Sharir , in this research article we try to focus on Twak Sharir. Key Words-  Padadari, Twaka, crack heel,

scholarly journals Melanocortin antagonism ameliorates muscle wasting and inflammation in chronic kidney disease

2012 ◽  
Vol 303 (9) ◽  
pp. F1315-F1324 ◽  
Author(s):  
Wai W. Cheung ◽  
Robert H. Mak
Keyword(s):  
Chronic Kidney Disease ◽  
Body Composition ◽  
Kidney Disease ◽  
Body Mass ◽  
Muscle Wasting ◽  
The Body ◽  
Central Administration ◽  
Total Body Mass ◽  
Body Composition Change ◽  
Total Body

Aberrant melanocortin signaling has been implicated in the pathogenesis of wasting in chronic kidney disease (CKD). Previously, we demonstrated that agouti-related peptide (AgRP), a melenocortin-4 receptor antagonist, reduced CKD-associated cachexia in CKD mice. Our previous studies with AgRP utilized dual energy X-ray (DXA) densitometry to assess the body composition in mice (Cheung W, Kuo HJ, Markison S, Chen C, Foster AC, Marks DL, Mak RH. J Am Soc Nephrol 18: 2517–2524, 2007; Cheung W, Yu PX, Little BM, Cone RD, Marks DL, Mak RH. J Clin Invest 115: 1659–1665, 2005). DXA is unable to differentiate water content in mice, and fluid retention in CKD may lead to an overestimate of lean mass. In this study, we employed quantitative magnetic resonance technique to evaluate body composition change following central administration of AgRP in a CKD mouse model. AgRP treatment improved energy expenditure, total body mass, fat mass, and lean body mass in CKD mouse. We also investigated the effect of CKD-associated cachexia on the signaling pathways leading to wasting in skeletal muscle, as well as whether these changes can be ameliorated by central administration of AgRP. AgRP treatment caused an overall decrease in proinflammatory cytokines, which may be one important mechanism of its effects. Muscle wasting in CKD may be due to the activation of proteolytic pathways as well as inhibition of myogenesis and muscle regeneration processes. Our results suggest that these aberrant pathological pathways leading to muscle wasting in CKD mice were ameliorated by central administration of AgRP.

scholarly journals The Relationship between Initial Tacrolimus Metabolism Rate and Recipients Body Composition in Kidney Transplantation

2021 ◽  
Vol 10 (24) ◽  
pp. 5793
Author(s):  
Aureliusz Kolonko ◽  
Patrycja Pokora ◽  
Natalia Słabiak-Błaż ◽  
Beata Czerwieńska ◽  
Henryk Karkoszka ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Mass ◽  
Multivariate Regression Analysis ◽  
The Body ◽  
Tacrolimus Concentration ◽  
Kidney Transplant Recipients ◽  
Visceral Fat Area ◽  
Total Body Mass ◽  
Total Body ◽  
The Relationship

There are several premises that the body composition of kidney transplant recipients may play a role in tacrolimus metabolism early after transplantation. The present study aimed at analyzing the relationship between the body composition parameters assessed by bioimpedance analysis (BIA) and initial tacrolimus metabolism. Immediately prior to transplantation, BIA using InBody 770 device was performed in 122 subjects. Tacrolimus concentration-to-dose (C/D) ratio was calculated based on the first blood trough level measurement. There was no difference in phase angle, visceral fat area, lean body mass index (LBMI) and the proportion of lean mass as a percentage of total body mass between the subgroups of slow and fast metabolizers. However, subjects with LBMI ≥ median value of 18.7 kg/m2, despite similar initial tacrolimus dose per kg of body weight, were characterized by a significantly lower tacrolimus C/D ratio (median 1.39 vs. 1.67, respectively; p < 0.05) in comparison with the subgroup of lower LBMI. Multivariate regression analysis confirmed that age (rpartial = 0.322; p < 0.001) and LBMI (rpartial = −0.254; p < 0.01) independently influenced the tacrolimus C/D ratio. A LBMI assessed by BIA may influence the tacrolimus metabolism in the early post-transplant period and can be a useful in the optimization of initial tacrolimus dosing.

Effects of stomach stones on the buoyancy and equilibrium of a floating crocodilian: a computational analysis

2003 ◽  
Vol 81 (8) ◽  
pp. 1346-1357 ◽  
Author(s):  
Donald M Henderson
Keyword(s):  
Body Mass ◽  
Computational Analysis ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
The Body ◽  
Alligator Mississippiensis ◽  
Total Body Mass ◽  
Total Body ◽  
Negatively Buoyant ◽  
Buoyancy Control

A three-dimensional mathematical/computational model of the crocodilian Alligator mississippiensis has been developed to investigate the influence of gastroliths on crocodilian buoyancy. The model is self-correcting, recovers from large perturbations, and can replicate the body orientations and degrees of immersion seen in living crocodilians that have attained equilibrium with respect to the competing forces of buoyancy and weight. For a range of lung deflations where the model was still positively buoyant, adding gastroliths of mass equal to 1% of the body mass has the effect of lowering the body, on average, by 2.6% of the maximum trunk depth while simultaneously increasing the inclination of the body with its sagittal plane. With the lungs fully inflated, the model would become negatively buoyant only when loaded with stones weighing more than 6% of the total body mass. Without gastroliths the body would sink when the lungs were deflated by 40%–50%. In all situations the model was resistant to capsizing. The relatively small amounts of gastroliths (<2% body mass) found in aquatic tetrapods are considered to be inconsequential for buoyancy and stability, and the lungs are the principle agent for hydrostatic buoyancy control.

Research Recommendations for Applying Vitamin A-Labelled Isotope Dilution Techniques to Improve Human Vitamin A Nutrition

2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 52-59 ◽  
Author(s):  
Sherry A. Tanumihardjo ◽  
Anura V. Kurpad ◽  
Janet R. Hunt
Keyword(s):  
Public Health ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Human Subjects ◽  
The Body ◽  
Pool Size ◽  
Serum Retinol ◽  
Vitamin A Status ◽  
Status Assessment ◽  
Total Body

The current use of serum retinol concentrations as a measurement of subclinical vitamin A deficiency is unsatisfactory for many reasons. The best technique available for vitamin A status assessment in humans is the measurement of total body pool size. Pool size is measured by the administration of retinol labelled with stable isotopes of carbon or hydrogen that are safe for human subjects, with subsequent measurement of the dilution of the labelled retinol within the body pool. However, the isotope techniques are time-consuming, technically challenging, and relatively expensive. There is also a need to assess different types of tracers and doses, and to establish clear guidelines for the use and interpretation of this method in different populations. Field-friendly improvements are desirable to encourage the application of this technique in developing countries where the need is greatest for monitoring the risk of vitamin A deficiency, the effectiveness of public health interventions, and the potential of hypervitaminosis due to combined supplement and fortification programs. These techniques should be applied to validate other less technical methods of assessing vitamin A deficiency. Another area of public health relevance for this technique is to understand the bioconversion of β-carotene to vitamin A, and its relation to existing vitamin A status, for future dietary diversification programs.

Sign in / Sign up

Export Citation Format

Share Document