Rozprawy doktorskie na temat „Swimming device”

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 31).
Currently the only human powered swimming device widely sold on the market are swim flippers. However, flippers are not efficient for the human body, and there is a potential to increase the speed while swimming with a device. This thesis is the planning, design, construction, and prototyping of a new human powered swimming device which increases human efficiency and speed in water. This device uses a squatting motion to drive counter rotating propellers up and down a threaded shaft creating the propulsion force to move the swimmer forward. The design of this device is primarily geared towards scuba divers and swimmers moving beneath the water surface. Through various tests we were able to prove that the design concept is valid, but alterations are still necessary to reach optimal speed. One such improvement would be enlarging the size of the propeller to increase the force generated with each leg thrust.
by Kristine Bunker.
S.B.

This thesis examined the benefits of physiological and performance testing of elite swimmers. The study considered the following research questions: the degree to which physiological and performance measures in training contribute to swimming performance; sources and magnitude of variability in testing, training and competition performance; the magnitudes of changes in test measures during routine training; and the reliability, validity and utility of miniaturised and automated smart sensor technology to monitor the stroke and performance times of swimmers in training. The experimental approach involved the retrospective analysis of five years of physiological and performance testing of elite level swimmers, the development of a new accelerometry-based smart sensor device to monitor swimmers in the pool, a cross-sectional study comparing the physiological and performance responses of swimmers of different levels, and the effects of an intensive 14-day training program on submaximal physiological and performance measures. Collectively, the outcomes of these studies provide a strong justification for the physiological and performance testing of elite swimmers, a quantitative framework for interpreting the magnitude of changes and differences in test scores and sources of variation, and highlight the potential utility of new smart sensor technology to automate the monitoring of a swimmer�s training performance. The first study (Chapter 2) characterises the changes and variability in test performance, physiological and anthropometric measures, and stroke mechanics of swimmers within and between seasons over their elite competitive career. Forty elite swimmers (24 male, 16 female) performed a 7 x 200-m incremental swimming step test several times each 6-month season (10 � 5 tests, spanning 0.5 to 6.0 y). Mixed linear modeling provided estimates of change in the mean and individual responses for measures based on submaximal performance (fixed 4-mM lactate), maximal performance (the seventh step), and lean mass (from skinfolds and body mass). Submaximal and maximal swim speed increased within each season from the pre to taper phase by ~2.2% for females and ~1.5% for males (95% confidence limits �1.0%), with variable contributions from stroke rate and stroke length. Most of the gains in speed were lost in the off-season, leaving a net average annual improvement of ~1.0% for females and ~0.6% for males (�1.0%). For submaximal and maximal speed, individual variation between phases was �2.2% and the typical measurement error was �0.8%. In conclusion, step test and anthropometric measures can be used to confidently monitor progressions in swimmers in an elite training program within and between seasons. The second study (Chapter 3) quantified the relationship between changes in test measures and changes in competition performance for individual elite swimmers. The primary question addressed was whether test measures could predict a swimmers performance at the major end-of-season competition. The same sample group as in Study 1 was examined. A 7 x 200-m incremental swimming step-test and anthropometry were conducted in up to four training phases each season. Correlations of changes in step-test and anthropometric measures between training phases between and within seasons, with changes in competition performance between seasons, were derived by repeated-measures mixed modeling and linear regression. Changes in competition performance were best tracked by changes in test measures between taper phases. The best single predictor of competition performance was skinfolds for females (r = -0.53). The best predictor from the step-test was stroke rate at 4-mM lactate (females, r = 0.46; males, r = 0.41); inclusion of the second-best step-test predictor in a multiple linear regression improved the correlations marginally (females, r =0.52 with speed in the seventh step included; males, r = 0.58 with peak lactate concentration included). Changes in test measures involving phases other than the taper provided weak and inconclusive correlations with changes in performance, possibly because the coaches and swimmers took corrective action when tests produced poor results. In conclusion, a combination of fitness and techniques factors are important for competitive performance. The step test is apparently a useful adjunct in a swimmer�s training preparation for tracking large changes in performance. These initial studies identified stroke mechanics as a major determinant of a swimmer�s performance. Chapter 4 details the development of a small tri-axial accelerometry-based smart sensor device (the Traqua) that enables continual monitoring of various performance/stroke characteristics in swimming. The initial focus was to develop a device that automated the detection of a swimmer�s movements, specifically lap times, stroke rate and stroke count. The Traqua consists of a tri-axial accelerometer packaged with a microprocessor, which attaches to the swimmer at the pelvis to monitor their whole body movements while swimming. This study established the failure/error rate in the first generation algorithms developed to detect the swimming-specific movements of stroke identification, laps (start, turn and finish), and strokes (stroke count and stroke rate) in a cohort of 21 elite and sub-elite swimmers. Movements were analysed across a range of swimming speeds for both freestyle and breaststroke. These initial algorithms were reasonably successful in correctly identifying the markers representing specific segments of a swimming lap in a range of swimmers across a spectrum of swimming speeds. The first iteration of the freestyle algorithm produced error-rates of 13% in detection of lap times, 5% for stroke rate, and 11% for stroke count. Subsequent improvements of the software reduced the error rate in lap and stroke detection. This improved software was used in the following two studies. The next study (Chapter 5) evaluated the reliability and validity of the Traqua against contemporary methods used for timing, stroke rate and stroke count determination. The subjects were 14 elite and 10 sub-elite club-level swimmers. Each swimmer was required to swim seven evenly paced 200-m efforts on a 5-min cycle, graded from easy to maximal. Swimmers completed the test using their main competitive stroke (21 freestyle, 3 breaststroke). Timing was compared for each 50-m lap and total 200-m time by electronic touch pads, video coding, a hand-held manual stopwatch, and the Traqua. Stroke count was compared for video coding, self-reported counting, and the Traqua, while the stroke rate was compared via video coding, hand-held stopwatch, and the Traqua. Retest trials were conducted under the same conditions 7 d following the first test. All data from the Traqua presented in this and the subsequent studies were visually inspected for errors in the automated algorithms, where the algorithms had either failed to correctly identify the start, turn, finish or individual strokes and corrected prior to analysis. The standard error of the estimate for each of the timing methods for total 200 m was compared with the criterion electronic timing. These standard errors were as follows: Traqua (0.64 s; 90% confidence limits 0.60 � 0.69 s), Video (0.52 s; 0.49 � 0.55 s); Manual (0.63 s; 0.59 � 0.67 s). Broken down by 50-m laps, the standard error of the estimate for the Traqua compared with the electronic timing for freestyle only was: 1st 50-m 0.35 s; 2nd and 3rd 50-m 0.13 s; 4th 50-m 0.65 s. When compared with the criterion video-coding determination, the error for the stroke count was substantially lower for the Traqua (0.6 strokes.50 m-1; 0.5 � 0.6 strokes.50 m-1) compared to the self-reported measure (2.3 strokes.50 m-1; 2.5 � 2.9 strokes.50 m-1). However, the error for stroke rate was similar between the Traqua (1.5 strokes.min-1; 1.4 � 1.6 strokes.min-1) and the manual stopwatch (1.8 strokes.min-1; 1.7 � 1.9 strokes.min-1). The typical error of measurement of the Traqua was 1.99 s for 200-m time, 1.1 strokes.min-1 for stroke rate, and 1.1 strokes.50 m-1 for stroke count. In conclusion, the Traqua is comparable in accuracy to current methods for determining time and stroke rate, and better than current methods for stroke count. A substantial source of error in the Traqua timing was additional noise in the detection of the start and finish. The Traqua is probably useful for monitoring of routine training but electronic timing and video are preferred for racing and time trials. Having established the reliability and validity of the Traqua, Chapter 6 addressed the ability to discriminate the pattern of pacing between different levels of swimmers in the 7 x 200-m incremental step test. This study also sought to quantify the differences in pacing between senior and junior swimmers. Eleven senior elite swimmers (5 female, 6 male) and 10 competitive junior swimmers (3 female, 7 male) participated in this study. Each swimmer was required to swim seven evenly paced 200-m freestyle efforts on a 5-min cycle, graded from easy to maximal. The Traqua was used to measure time, stroke rate and stroke count. The senior swimmers were better able to descend in each of the 200-m efforts. Overall the senior swimmers were ~2-3 s per 50 m faster than the junior swimmers. Both groups were fastest in the first 50-m lap with the push start. The senior swimmers then descended the 50- m time for each of the subsequent laps, getting ~0.5 s faster per lap, with the final lap the fastest. In contrast, the junior swimmers swam a similar time for each of the subsequent laps. The junior swimmers were marginally more variable in their times (coefficient of variation: ~2%) compared with the senior swimmers (~1.8%). In comparison to junior swimmers, the senior swimmers in this study were faster, adopted a more uniform negative split strategy to pacing within a 200-m effort, and were more consistent in reproducing submaximal and maximal swimming speeds. The final study (Chapter 7) analysed the effect of 14-d of intensive training on the reproducibility of submaximal swimming performance in elite swimmers. Submaximal physiological and performance testing is widely used in swimming and other individual sports but the variability in test measures, and the effects of fatigue, during intensive training have surprisingly not been quantified systematically. Seven elite swimmers (3 male and 4 female) participated in an intensive 14-d training camp one month prior to the National championships. The aim of the study was to characterise the intra-session, daily and training block variability of submaximal swimming time, physiological and stroke characteristics in elite swimmers. The swimmers performed a specified submaximal 200-m effort in most sessions, after the warm-up and at the end of the session for both morning and afternoon sessions. During the efforts, swimming time and stroke mechanics were measured and physiological measures were recorded immediately on completion. The Traqua was worn by all swimmers in every training session. Mixed linear modeling was used to provide estimates of changes in the mean and individual responses (within-athlete variation as a coefficient of variation) for all measures. The swimmers were moderately slower (1.4%; �1.4%) over the 14-d training camp. The mean submaximal 200-m effort was very likely to be faster (0.7%; confidence limits �0.7%) in the afternoon compared with the morning session. The females were more variable in their submaximal performance times (CV=2.6%) than the male swimmers (1.7%). Blood lactate concentration was almost certainly lower (-23%; �10%) following higher volume in the previous session; however a higher intensity workout the previous session almost certainly leads to higher lactate (21%; �15%) in the current session. Considered together, these results indicate that the 200-m submaximal test is useful in monitoring submaximal physiological and performance measures and the negative effects of cumulative fatigue. In conclusion, changes in the physiological and performance measures derived from the poolbased progressive incremental step test are moderately correlated with changes in end-ofviii. season competition performance. The magnitudes of changes and differences in test measures between phases within a season, from season to season, and between males and females, established in this study can be applied to similar elite level swimmers preparing for major competition. The quantification of typical error of the same measures demonstrates that coaches and scientists can distinguish real and worthwhile improvements using the 7 x 200-m step test. Continual pool-based monitoring with the automated smart sensor Traqua device may provide more accurate and detailed information about a swimmer�s training adaptation than current fitness tests and monitoring methods. Finally, submaximal testing in trained swimmers is useful in monitoring progress in physiological and performance measures, and the impact of cumulative fatigue during an intensive period of training. Collectively, the outcomes of these studies indicate that routine physiological and performance testing can provide measurable benefits for elite swimmers and their coaches.

The aim of this work was to develop devices for elite athletes to record performance related parameters during their training. A device was initially designed and built for rowing to record the motion of the boat. This was to gain understanding of motion signals in a one dimensional plane. The device uses a iPAQ handheld computer for recording and display of data to the user. Using the knowledge obtained from the accelerometer data of the rowing system an initial prototype device was designed and constructed for use in swimming. This device was required to be wearable whilst the swimmer was training, thus it had to record the data onboard. A second version of the swimming device was constructed to improve the usability of the device. The swimming device has fully sealed electronics, wireless charging and infrared communications. The device records three dimensional acceleration patterns at 150Hz, and can store over 6 hours of data using the internal memory. The device can operate for greater than 12 hours before needing to be recharged. The data collected from the swimming device was used to develop processing algorithms to extract when the swimmers push off from the wall, the type of stroke they are swimming, and for freestyle the stroke count. The results of the wall push off algorithm were compared against manual hand timing with 90% algorithm results being with ±1 second of the hand timing data. The stroke type identification algorithm determines which stroke is being swum and presently has an accuracy of 95%. The results of the freestyle stroke count algorithm were compared against manual stroke counts from raw accelerometers data and underwater video. Of the 164 data sets analysed over 90% of the algorithm results were within ±1 strokes of the manual recorded stroke counts.

The aim of this work was to develop devices for elite athletes to record performance related parameters during their training. A device was initially designed and built for rowing to record the motion of the boat. This was to gain understanding of motion signals in a one dimensional plane. The device uses a iPAQ handheld computer for recording and display of data to the user. Using the knowledge obtained from the accelerometer data of the rowing system an initial prototype device was designed and constructed for use in swimming. This device was required to be wearable whilst the swimmer was training, thus it had to record the data onboard. A second version of the swimming device was constructed to improve the usability of the device. The swimming device has fully sealed electronics, wireless charging and infrared communications. The device records three dimensional acceleration patterns at 150Hz, and can store over 6 hours of data using the internal memory. The device can operate for greater than 12 hours before needing to be recharged. The data collected from the swimming device was used to develop processing algorithms to extract when the swimmers push off from the wall, the type of stroke they are swimming, and for freestyle the stroke count. The results of the wall push off algorithm were compared against manual hand timing with 90% algorithm results being with ±1 second of the hand timing data. The stroke type identification algorithm determines which stroke is being swum and presently has an accuracy of 95%. The results of the freestyle stroke count algorithm were compared against manual stroke counts from raw accelerometers data and underwater video. Of the 164 data sets analysed over 90% of the algorithm results were within ±1 strokes of the manual recorded stroke counts.
Thesis (Masters)
Master of Philosophy (MPhil)
School of Microelectronic Engineering
Full Text

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.
Includes bibliographical references (leaves 63-64).
Biomimetic swimming devices that employ compliant mechanisms have shown promise as an alternative to current biomimetic design approaches that involve the use of complex mechanisms. The additional stealth, ruggedness, and efficiency of this approach means that such devices could perform important tasks such as reconnaissance and underwater mapping. Many of these applications also require high levels of maneuverability and closed-loop control. However, maneuverability and heading control are two areas that are relatively unexplored with regard to such devices. Therefore, in order to study maneuverability and control, this thesis outlines a simple dynamic model to predict the maneuvering behavior of compliant biomimetic swimming devices. A comparison of the model predictions with experimental data is also presented. Lastly, the dynamic model is used to successfully design, simulate and implement a compass-based heading control system.
by Anirban Mazumdar.
S.B.

A prevalent morphology in the microscopic world of artificial microswimmers, bacteria and viruses is that of a helix. The intriguingly different physics at play at the small scale level make it necessary for bacteria to employ swimming strategies different from our everyday experience, such as the rotation of a helical filament. Bio-inspired microswimmers that mimic bacterial locomotion achieve propulsion at the microscale level using magnetically actuated, rotating helical filaments. A promising application of these artificial microswimmers is in non-invasive medicine, for drug delivery to tumours or microsurgery. Two crucial features need to be addressed in the design of microswimmers. First, the ability to selectively control large ensembles and second, the adaptivity to move through complex conduit geometries, such as the constrictions and curves of the tortuous tumour microvasculature. In this dissertation, a mechanics-based selective control mechanism for magnetic microswimmers is proposed, and a model and simulation of an elastic helix passing through a constricted microchannel are developed. Thereafter, a theoretical framework is developed for the propulsion by stiff elastic filaments in viscous fluids. In order to address this fluid-structure problem, a pertubative, asymptotic, elastohydrodynamic approach is used to characterise the deformation that arises from and in turn affects the motion. This framework is applied to the helical filaments of bacteria and magnetically actuated microswimmers. The dissertation then turns to the sub-bacterial scale of bacteriophage viruses, 'phages' for short, that infect bacteria by ejecting their genetic material and replicating inside their host. The valuable insight that phages can offer in our fight against pathogenic bacteria and the possibility of phage therapy as an alternative to antibiotics, are of paramount importance to tackle antibiotics resistance. In contrast to typical phages, flagellotropic phages first attach to bacterial flagella, and have the striking ability to reach the cell body for infection, despite their lack of independent motion. The last part of the dissertation develops the first theoretical model for the nut-and-bolt mechanism (proposed by Berg and Anderson in 1973). A nut being rotated will move along a bolt. Similarly, a phage wraps itself around a flagellum possessing helical grooves, and exploits the rotation of the flagellum in order to passively travel along and towards the cell body, according to this mechanism. The predictions from the model agree with experimental observations with respect to directionality, speed and the requirements for succesful translocation.

Este estudo teve como objetivo analisar a influência da utilização de flutuadores na aquisição das habilidades aquáticas, através da comparação de dois grupos de crianças iniciantes em um programa de atividades aquáticas. A amostra foi composta por 17 crianças, com idade entre 36 e 47 meses. Um grupo composto por 8 crianças, participou das aulas fazendo uso dos flutuadores (CFlut), e o segundo grupo, composto por 9 crianças, participou das aulas sem a utilização dos flutuadores (SFlut). Os alunos participaram de uma intervenção com duração de oito semanas, duas aulas por semana e cada aula possuía 30 minutos de duração. Foi utilizada a Escala de Erbaugh para avaliar a aquisição das habilidades aquáticas em dois momentos avaliativos: no período pré-intervenção e no período pósintervenção. Para análise dos dados utilizou-se estatística descritiva (mediana, valores mínimos a máximos) e testes para comparação intra e inter-grupos para dados não-paramétricos (Testes de Wilcoxon e U de Mann-Whitney, respectivamente). Não houve diferenças significativas entre os dois grupos, quando os grupos foram comparados em relação à soma geral das tarefas. No entanto, nas três tarefas que constituem os deslocamentos e, ainda, na tarefa de saltos, o grupo sem flutuadores apresentou melhores resultados. Apesar de os resultados terem demonstrado superioridade do grupo sem flutuadores em relação ao grupo com flutuadores em algumas habilidades, o uso dos flutuadores não deve ser condenado. Isso porque este tipo de material oferece maiores possibilidades de interação com o meio líquido, atuando como um aspecto motivacional para a aprendizagem, principalmente para aquelas crianças que sentem-se inseguras em relação ao meio líquido.
The present study was designed to analyze the influence of flotation devices (armbands) on the aquatic abilities acquisition, by comparing two groups of children without early experience in aquatic abilities. Seventeen children (ages up from 36 to 47 months) composed the sample. An eight-child group took part of the classes using floats (with flotation devices –WFl) and the second group, with by nine children, did it without the usage of floats (no flotation devices – NFl). Both group of children participated of the intervention for eight weeks, at a two-30-minute class per week basis. The Erbaugh Scale was used on two different occasions to assess the aquatic abilities acquisition: the pre-intervention period and pos-intervention period. For data analysis it was used descriptive statistics (median, minimum and maximum values) and comparison tests for non-parametric data (Wilcoxon and U de Mann-Whitney Test). No significant differences between the two groups were found, when assessed regarding the sum of the tasks. However, in the three tasks that constitute the displacements, and yet the jumping tasks, the NFl group presented better results. Though the final results demonstrated a level of superiority for the NFl group over the WFl group in some of aquatic abilities, flotation devices cannot be despised, because this type of equipment offer more possibilities of interaction with the aquatic environment, and they work as a motivational tool for learning, especially for the children showing insecurity towards the aquatic environment.

碩士
朝陽科技大學
資訊與通訊系
104
In this thesis, we propose a recognition method to determine human swimming situation. In recent year, the triathlon event is very popular, to avoid athletes went into shock suddenly and no one found the situation in crowded environment, so we performed several calculation formula to collect swimming data, these formula contains Mean, Standard deviation, Kurtosis, Skewness, Correlation, Signal Magnitude Area and Variation which can be judgment swimming state, a method that can be record human various action with smartphone device, according to compare with these calculation formula, in our experiment that we find one of good formula to separate swimming state by Standard deviation, we can avoid lots of accident which is shock suddenly in swimming situation. In this paper, we propose some kind of acceleration algorithm method by G-sensor to calculate human is swimming or stopped. Keywords: Android device, G-sensor, Acceleration, Swimming status recognition.

碩士
國立臺北科技大學
機電整合研究所
95
Swimming is one kind of sports and exercises, which is very good to health. So far, there is no learning device for swimming. The swimming pools are not enough and the available open hours for most swimming pools are not all the year round. It is, therefore, inconvenient for the beginners and persons who take swimming as a regular exercise as well. This thesis presents a new design of learning/exercise device for learning swimming and swim exercise without swimming pools. It could increase the convenience of learning, exercising and rehabilitating. Firstly, we analyzed the paths of hands’ and legs’ motions for breaststroke swimming. The results of this analysis are used to synthesize the required cam mechanisms to perform such specified motions and to guide the swimmers to follow the exact paths of hands and legs. This design uses Pro/Engineer Wildfire 2.0 software to do dimensional synthesis. Through the simulations in Pro/Engineer Wildfire 2.0, the design requirements and its feasibility have been confirmed.

碩士
國立臺北科技大學
機電整合研究所
97
Swimming, one kind of sports and exercises, is very good to health and feasible for all people as well. So far, there is no exercising device for swimming, and the swimming pools are not enough and the available open hours are limited as well. The available time for outdoors swimming pools are dependent on the weather. Therefore, it is very inconvenient for the swimming-lovers to workout by swimming. This study presents a new conceptual design of exercising device for breast stroke swimming. Firstly, calculate the resisting forces of a swimmer during swimming in breast stroke to design the required loading device. Then, design the required mechanism for this novel exercising device which consists of linkages, gears and cams. This design uses SolidWorks software to design all the parts and assemble the whole device. The feasibility of this completed device has been confirmed through the simulation in SolidWorks software and a simple prototype of this device.

碩士
國立交通大學
機械工程系所
102
Swimming is a quite healthy sport, but there are many problems needed to overcome during the learning process. If we can let people familiar with the movements of swimming through a training mechanism in advance, people can have better efficiency in learning swimming in water. In freestyle swimming, there are 70% of main propulsive forces is applied by arms. Through the analysis of the swimming movements of many excellent athletes, we found that most of them use S-shape stroke and I-shape stroke, and the S-shape stroke is more beneficial to bring efficient force in sculling process, but hard to control. This study reports the standard sculling trajectory and the assessments by biomechanics method, and the design of a functional training mechanism for the novices or redressing the posture for swimmers. This study is consist of four main subject, respectively are: (1) Editing 3D trajectory in animation software 3ds Max、(2) simulating tension of muscle in biomedicine software OpenSim、(3)designing sculling training mechanism and (4) deriving mechanism kinetics. We employ animation software to editing 3D trajectory, and refer to the trajectory of the freestyle champion to establish standard trajectory. Then, we use biomedicine software to calculate the static tension of muscle in moving process, and verify if the established movement in animation software is appropriate or not. According to designing process of this study, we complete the mechanism conforming to expectation of standard swimming posture by controlling the trajectory of the forearm. This study assesses the samples of S-shape stroke and I-shape stroke. In the analysis of mechanism, we check and remove the interferences by institutional dynamic simulation. We calculate the displacement angles by Inverse kinematics, verify the degree of freedom of the mechanism, and afford the applications of drive controller and plan by the displacement angles.

This research work draws on previous experimental research and aims to further develop and refine a biosignal measurement device that will allow the capture of a swimmer’s biosignals via Bluetooth. It also encompasses the construction of a dashboard that will allow a swimming instructor or coach to monitor and improve the athletes’ swimming practice.
O âmbito deste trabalho incide no desenvolvimento/criação de um dispositivo de medição de biosinais (acelerometria, eletromiografia e eletrocardiografia) para que através de uma conexão via Bluetooth seja feita a captura destes valores num nadador. Abrange ainda o desenvolvimento de um dashboard que permite ao treinador acompanhar e melhorar os treinos de um atleta.

碩士
國立臺北科技大學
製造科技研究所
96
Swimming is one kind of sports and exercises, which is very good to health and feasible for all people. So far, there is no learning or exercising device for swim. In addition, the outdoor swimming pools are not enough and their opening hours are limited as well. It is, therefore, inconvenient for the beginners and the exercisers. This paper presents a conceptual design of learning device for freestyle swimming. It could guide the required coordinated motion of hands and feet for the beginner. Firstly, we analyzed the paths of hands’ motion and path for freestyle from a motion picture with PhotoImpact software. The results of this analysis are used to synthesize the required cam mechanisms to guide the users to follow the motion of hands and legs. This design uses Pro/ENGINEER software to design parts and assemble those parts into the device. The feasibility of this completed device, which consists of cams, has been confirmed through the dynamic simulation in Pro/ENGINEER software. Regarding the exercising device of swimming, all available existing devices or in the patents do not provide the correct path of hands and legs in freestyle swimming for the users. Even though providing correct paths for exercising device is not so important, this function could be useful for the user to improve their swimming skill, and therefore it could optimize the exercising device’s function. The other purpose of this study is to design an exercising device in accordance with the paths obtained and the loads of freestyle swimming. A novel design of exercising device has been presented. Through the dynamic simulation in Pro/ENGINEER, its feasibility has been confirmed.

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ABSTRACT: Tympanostomy tube insertion is the second most common surgery in children, and is mostly indicated for recurrent otitis media, or for chronic otitis media with effusion (OME). Almost every surgeon prescribes water precautions after surgery because of fear of water causing middle ear inflammation. These precautions include at least wearing ear plugs and head bands while swimming, showering or bathing. However, the evidence for such pleas has been questioned. Some authors, weighting also the impact on quality of life, economic burden, and the weak evidence of benefice from such precautions, have been dropping these measures. We proposed to evaluate how deep must one submerge the head to allow water passing through the tube in the tympanic membrane; to evaluate whether such precautions have relevant effect on quality of life; and whether there is any difference between prescribing water precautions or not. Using a computerized fluid dynamics model, we found that on reasonable depths and common conditions, water is not passing the ventilation tube. With this model we determined that including the auditory (pharyngotympanic) tube mechanism in the model is critical. Secondarily, we also learned, using the model, that on surface conditions, increasing the external auditory canal (external acoustic meatus) pressure pushes the liquids on the external auditory canal through the tube, and this is enlightening to the understanding of topical therapy with ear drops. With a randomized controlled trial, we compared two groups with and without protection when exposed to water, and found that children with OME operated with ventilation tube insertion improved their global quality of life. This improvement is significant, irrespective of the season of surgery, water activities frequency, or gender. It is also significant whether water protection is prescribed or not, and both groups (with and without protection) improved quality of life significantly after surgery, and with no observed statistical difference, meaning no impact from protection cares. Also, from this randomized controlled trial, we did not observe a difference in the prevalence of otorrhea after myringotomy with tubes for otitis media with effusion when prescribing or not water protection. And otorrhea incidence shows no apparent association with water exposure in our study population, but it does so with upper respiratory tract infection. These results support the recent guidelines from the American Academy of Otorhinolaryngology, which discourages the routine use of water protections in children with tympanostomy tubes.