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Outcomes and variables that impact pneumatic retinopexies
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作者 Maria V.Castanos Daniel Vail +2 位作者 Oscar Otero-Marquez Yash Shah Avnish Deobhakta 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期564-569,共6页
●AIM:To evaluate the efficacy of pneumatic retinopexy(PR)in patients undergoing PR as primary treatment for rhegmatogenous retinal detachment(RRD)and analyze the factors associated with success and failure in the stu... ●AIM:To evaluate the efficacy of pneumatic retinopexy(PR)in patients undergoing PR as primary treatment for rhegmatogenous retinal detachment(RRD)and analyze the factors associated with success and failure in the studied population.●METHODS:A retrospective chart review was done of patients with RRD treated with PR as primary management method treated at New York Eye and Ear Infirmary of Mount Sinai between January 2017 and December 2021.Primary outcome measured success or failure of PR.Secondary outcome measured best corrected visual acuity(BCVA)after PR.A separate risk analysis was done to identify and stratify risks associated with success and failure of PR.●RESULTS:A total of 179 eyes from 179 patients were included for final analysis.The 83 patients(46.37%)achieved anatomical reattachment of the retina after primary PR with no need for additional surgery.The 96 patients(53.63%)had a failed primary PR and required a PPV and 6 of them required pars plana vitrectomy(PPV)with scleral buckle(SB).In total,19 cases(10.61%)were done as temporizing pneumatics,18(94.74%)underwent PPV,and 1(5.26%)did not require further intervention.The visual acuities at postoperative month 1(POM1)for patients who underwent primary PR successfully and for those that underwent PPV after,were 0.58(20/80)and 1.03(20/200)respectively.Patients who met Pneumatic Retinopexy Versus Vitrectomy for the Management of Primary Rhegmatogenous Retinal Detachment Outcomes Randomized Trial(PIVOT)criteria had a statistically significant decreased risk of primary PR failing(hazard ratio 0.29,P=0.00).Majority of missed or new breaks were found superotemporally.●CONCLUSION:PR is a good treatment option for treating RRDs in patients that meet PIVOT criteria and can be conducted as a temporizing measure.PIVOT criteria and fovea on status decrease the risk of PR failure. 展开更多
关键词 RETINA pneumatic retinopexy rhegmatogenous retinal detachment
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Origin of postcranial skeletal pneumaticity in dinosaurs
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作者 Mathew J.WEDEL 《Integrative Zoology》 SCIE CSCD 2006年第2期80-85,共6页
The sauropodomorph Thecodontosaurus caducus and theropod Coelophysis bauri are the earliest known dinosaurs with postcranial skeletal pneumaticity.In both taxa,postcranial pneumatic features are confined to the cervic... The sauropodomorph Thecodontosaurus caducus and theropod Coelophysis bauri are the earliest known dinosaurs with postcranial skeletal pneumaticity.In both taxa,postcranial pneumatic features are confined to the cervical vertebrae.This distribution of pneumaticity in the skeleton is most consistent with pneumatization by diverticula of cervical air sacs similar to those of birds.Other hypotheses,including pneumatization by diverticula of the lungs,larynx and trachea,or cranial air spaces,are less well-supported. 展开更多
关键词 DINOSAUR pneumaticity sauropodomorph THEROPOD TRIASSIC
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Re-Densification Effect of Pressure-Injected Peptide-Hyaluronic Acid Combination on Male Androgenic Alopecia
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作者 Pablo Naranjo 《Journal of Cosmetics, Dermatological Sciences and Applications》 2024年第1期29-44,共16页
Introduction: Mechanism of male androgenic alopecia (MAGA) is complex and leads to an excessive hair shedding and decreased hair density. Oral, topical, and injectable autologous treatments demonstrate ability to stim... Introduction: Mechanism of male androgenic alopecia (MAGA) is complex and leads to an excessive hair shedding and decreased hair density. Oral, topical, and injectable autologous treatments demonstrate ability to stimulate hair re-growth, but the response is suboptimal or plateaus off. Synthetic combination of the peptide complex and hyaluronic acid (P-HA) demonstrated hair regrowth in alopecia patients. Electronically-operated pneumatic injections (EPI) generate micro-trauma in the dermis and under wound-healing conditions may enhance regeneration effect of P-HA. Methods: Subjects seeking improvement of their male pattern hair loss (Hamilton-Norwood type 2-4) received the P-HA treatments through EPI. The course included 4 treatments every two weeks over the 8-week period. In 6 months, the hair growth was assessed comparative to baseline by global clinical photography and digital phototrichograms. The treatment safety and tolerability were documented through the whole study period. Results: Twelve men (30-45 years old) completed the treatment course with high tolerability and without adverse events. Post-treatment assessment of the previously bald areas showed improved coverage on the clinical photographs. The phototrichograms demonstrated statistically significant increase in terminal hair density by 36%, cumulative hair thickness by 37%, and follicular units by 20%;all contributing to a 38% increase in cumulated hair density (all p Conclusion: Electronic pneumatic injections are well tolerated and can be safely used for the needle-free administration of the peptide-hyaluronic acid combination in MAGA therapy. We achieved significant hair re-densification in the balding scalp. The exact role of the EPI-induced impact in the hair re-growth mechanism remains to be ascertained. . 展开更多
关键词 Jet Injections Electronic Pneumatic Injections Male Androgenic Alopecia Bioactive Peptides EnerJet
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Experimental research and energy analysis of a new type of dry ice powder pneumatic rock breaking technology 被引量:2
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作者 Xiaofei Wang Shaobin Hu +2 位作者 Enyuan Wang Qiang Zhang Bing Liu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第4期423-435,共13页
When the traditional drill and blast method is applied to rock crushing projects,it has strong vibration,loud noise and dust pollution,so it cannot be used in densely populated areas such as urban public works.We deve... When the traditional drill and blast method is applied to rock crushing projects,it has strong vibration,loud noise and dust pollution,so it cannot be used in densely populated areas such as urban public works.We developed a supercritical CO_(2)true triaxial pneumatic rock-breaking experimental system,and conducted laboratory and field tests of dry ice powder pneumatic rock-breaking.The characteristics of the blast-induced vibration velocity waveform and the evolution of the vibration velocity and frequency with the focal distance were analyzed and discussed.The fracturing mechanism of dry ice powder pneumatic rock breaking is studied.The research results show that:(1)The vibration velocity induced by dry ice powder pneumatic rock breaking decays as a power function with the increase of the focal distance;(2)The vibration frequency caused by dry ice powder pneumatic rock breaking is mainly distributed in 1–120 Hz.Due to the dispersion effect,the dominant frequency of 10–30 Hz appears abnormally attenuated;(3)The traditional CO_(2)phase change fracturing energy calculation formula is also applicable to dry ice pneumatic rock breaking technology,and the trinitrotoluene(TNT)equivalent of fracturing energy is applicable to the Sadovsky formula;(4)Dry ice powder pneumatic rock breaking is shock wave and highenergy gas acting together to fracture rock,which can be divided into three stages,among which the gas wedge action of high-energy gas plays a dominant role in rock mass damage. 展开更多
关键词 Dry ice powder pneumatic rock breaking Cracking mechanism Energy analysis Vibration frequency
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Ultralong Stretchable Soft Actuator(US2A):Design,Modeling and Application
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作者 Wenbiao Wang Yunfei Zhu +1 位作者 Shibo Cai Guanjun Bao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第1期280-291,共12页
Actuator plays a significant role in soft robotics.This paper proposed an ultralong stretchable soft actuator(US2A)with a variable and sizeable maximum elongation.The US2A is composed of a silicone rubber tube and a b... Actuator plays a significant role in soft robotics.This paper proposed an ultralong stretchable soft actuator(US2A)with a variable and sizeable maximum elongation.The US2A is composed of a silicone rubber tube and a bellows woven sleeve.The maximal extension can be conveniently regulated by just adjusting the wrinkles’initial angle of the bellows woven sleeve.The kinematics of US2A could be obtained by geometrically analyzing the structure of the bellows woven sleeve when the silicone rubber tube is inflated.Based on the principle of virtual work,the actuating models have been established:the pressure-elongation model and the pressure-force model.These models reflect the influence of the silicone tube’s shell thickness and material properties on the pneumatic muscle’s performance,which facilitates the optimal design of US2A for various working conditions.The experimental results showed that the maximum elongation of the US2A prototype is 257%,and the effective elongation could be variably regulated in the range of 0 and 257%.The proposed models were also verified by pressure-elongation and pressure-force experiments,with an average error of 5%and 2.5%,respectively.Finally,based on the US2A,we designed a pneumatic rehabilitation glove,soft arm robot,and rigid-soft coupling continuous robot,which further verified the feasibility of US2A as a soft driving component. 展开更多
关键词 Soft robotics Soft actuator Pneumatic artificial muscle MODELING
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Performance of large-diameter pneumatic down-the-hole (DTH) hammers: A focus on influences of the hammer structure
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作者 Pin-Lu Cao Hong-Yu Cao +3 位作者 Jin-E Cao Cheng-Da Wen Bao-Yi Chen Shan-Shan Yao 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期2399-2412,共14页
Pneumatic down-the-hole (DTH) hammer has been extensively used in air drillings through hard and ultra-hard geological formations. Numerical modeling can offer close observation on the working behaviors by visualizing... Pneumatic down-the-hole (DTH) hammer has been extensively used in air drillings through hard and ultra-hard geological formations. Numerical modeling can offer close observation on the working behaviors by visualizing internal pressure status as well as provide reliable performance predictions for large-diameter DTH hammers to which conventional empirical and experimental approaches cannot be applied. In this study, CFD simulations coupled with dynamic meshing are utilized to simulate the air flow and piston movement inside the large-diameter DTH hammers. The numerical modeling scheme is verified against a theoretical model published in literature. Effects of structural parameters on hammer performance, including piston mass, piston upper-end diameter, piston groove diameter, and lengths of intake and exhaust stroke in both front and rear chambers, are analyzed in detail by virtue of sets of numerical simulations. The simulations suggest that changing the intake stroke of front chamber has a negligible influence on hammer performance while increasing the piston groove would lower all the four indicators of hammer performance, including impact energy, impact frequency, maximum stroke, and air consumption rate. Changing the other structural parameters demonstrates mixed effects on the performance indicators. Based on the numerical simulations, a large GQ-400 DTH hammer has been designed for reduced air consumption rate and tested in a field drilling practice. The air drilling test with the designed hammer provided a penetration rate 1.7 times faster than that of conventional mud drilling. 展开更多
关键词 Pneumatic down-the-hole(DTH)hammer Computational fluid dynamics Dynamic mesh Gas turbulent flow Piston impact performance
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Changing the Air Parameters in the Cotton Pneumatic Transport Pipe
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作者 Sarimsakov Olimjon Sattarov Nurillo +1 位作者 Oripov Nodirbek Kholmirzaev Farhod 《Engineering(科研)》 CAS 2023年第2期68-74,共7页
This scientific article examines the issue of changes in the density and speed of the airflow in the pipeline pneumatic conveying equipment used in ginneries, analyzes the causes of changes in the density and speed of... This scientific article examines the issue of changes in the density and speed of the airflow in the pipeline pneumatic conveying equipment used in ginneries, analyzes the causes of changes in the density and speed of air. 展开更多
关键词 Pneumatic Transport Actual Pressure Vacuum Monomeric Pressure VENTILATOR Cotton Cleaning
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Theoretical and Practical Studies of Determining the Force of the Lifting-Lowering of the Roll Box
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作者 Usmonov Shuxratjon Kamoljonovich 《Engineering(科研)》 CAS 2023年第1期47-57,共11页
The lifting and lowering mechanism of the roll box of the saw gin, being an integral part of the ginning process, is used when starting the electric motor of the saw cylinder until its rated speed is reached to preven... The lifting and lowering mechanism of the roll box of the saw gin, being an integral part of the ginning process, is used when starting the electric motor of the saw cylinder until its rated speed is reached to prevent an increase in the load current on it, as well as to start the ginning process. The article defines the kinematics of the movement, and also studies the regularity of the movement of the roll box of the saw gin when lifting it with the help of a pneumatic drive. The kinematics of the roll box movement was determined through experimental studies. Knowing the equation of motion, using the second-order Lagrange equation, the regularity of the change in the lifting force of the roll box was determined. Here the system is closed, its degree of freedom is equal to one. The angle of rotation of the roll box is taken as a generalized coordinate. Numerical results were obtained using the Matlab software environment. The theoretical analysis and graphs for determining the lifting force of the roll box are presented. To study the kinematics of lifting the roll box, a method and a test bench have been developed. According to him, when the roll box was raised, its movement was recorded on video, the image was processed using the After Effect and CorelDraw programs, and the movement of the rod attachment point to the roll box was determined. And also the equation for changing the angle of rotation of the roll box is determined using the Matlab Curve Fiting program. 展开更多
关键词 Saw Gin Roll Box Pneumatic Cylinder ROD Angular Velocity Angular Acceleration Gravity Forces Driving Force Moment of Inertia Function
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Fault Detection and Diagnosis of Pneumatic Control Valve Based on a Hybrid Deep Learning Model
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作者 HAO Hongtao WANG Kai 《Instrumentation》 2023年第4期12-26,共15页
As the growing requirements for the stability and safety of process industries,the fault detection and diagnosis of pneumatic control valves have crucial practical significance.Many of the approaches were presented in... As the growing requirements for the stability and safety of process industries,the fault detection and diagnosis of pneumatic control valves have crucial practical significance.Many of the approaches were presented in the literature to diagnose faults through the comparison of residual sequences with thresholds.In this study,a novel hybrid neural network model has been developed to address the issue of pneumatic control valve fault diagnosis.First,the feature extractor automatically extracts in-depth features of the signals through multi-scale convolutional neural networks with different kernel sizes,which not only adequately explores the local distinguishable features,but also takes into account the global features.The extracted features are then fused by the feature fusion layer to reduce redundant features.Finally,the long short-term memory for fault identification and the dense layer for fault classification.Experimental results demonstrate that the average test accuracy is above 94%and 16 out of the 19 conditions can be successfully detected in the simulated actual industrial environment.The effectiveness and practicability of the proposed method have been verified through a comparative analysis with existing intelligent fault diagnosis methods,and the results suggest that the developed model has better robustness. 展开更多
关键词 Pneumatic Control Valve Feature Fusion Fault Diagnosis Convolutional Neural Network Long Short-term Memory
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基于学习生物体运动的一种人工筋驱动器的研究 被引量:1
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作者 林良明 夏炎 +1 位作者 丁洪 田社平 《仪器仪表学报》 EI CAS CSCD 北大核心 1996年第S1期287-290,共4页
本文从仿生学的观点,学习生物体的原理,研究微型机器人的机构和控制问题,是开发微型机电系统的一个关键技术。介绍了生物体运动的基本特征,并从学习生物体运动的设计原理出发,对一种具有与人体肌肉类似特性的空气压人工筋进行了实... 本文从仿生学的观点,学习生物体的原理,研究微型机器人的机构和控制问题,是开发微型机电系统的一个关键技术。介绍了生物体运动的基本特征,并从学习生物体运动的设计原理出发,对一种具有与人体肌肉类似特性的空气压人工筋进行了实验研究,表明它有可能成为一种新颖的柔性进机器人的驱动器,在医疗及微小空间作业的特种机器人中获得应用。 展开更多
关键词 micro-robot RUBBER PNEUMATIC Artificial Muscle.
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基于FluidSIM Pneumatics软件的气动及机电一体化设计 被引量:28
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作者 杨存智 《煤矿机械》 北大核心 2004年第9期63-65,共3页
气压传动及机电一体化系统设计在现代机械设计中占有很重要的地位。介绍德国FESTO公司开发的FluidSIMPneumatics软件。对该软件的主要技术要求、功能以及气压传动与机电一体化系统的设计方法作了详细的介绍。它为学习者和工程技术人员... 气压传动及机电一体化系统设计在现代机械设计中占有很重要的地位。介绍德国FESTO公司开发的FluidSIMPneumatics软件。对该软件的主要技术要求、功能以及气压传动与机电一体化系统的设计方法作了详细的介绍。它为学习者和工程技术人员提供了分析、研究、设计。 展开更多
关键词 F1uidSIM PNEUMATICS 电控系统 机电一体化 设计
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Braincase Anatomy of the Basal Theropod Sinosaurus from the Early Jurassic of China 被引量:2
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作者 XING Lida Ariana PAULINA-CARABAJAL +5 位作者 Philip J.CURRIE XU Xing ZHANG Jianping WANG Tao Michael E.BURNS DONG Zhiming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第6期1653-1664,共12页
The neuroanatomy of the mid-sized theropod Sinosaurus triassicus from the Lower Jurassic Lufeng Formation, Lufeng Basin in Yunnan Province, China was studied using X-ray computed tomography. The braincase is character... The neuroanatomy of the mid-sized theropod Sinosaurus triassicus from the Lower Jurassic Lufeng Formation, Lufeng Basin in Yunnan Province, China was studied using X-ray computed tomography. The braincase is characterized by a large supraoccipital knob that is capped by a posterior projection of the parietal and two external foramina for the caudal middle cerebral vein, which is completely enclosed by the supraoccipital. The basicranium has well defined, short basipterygoid processes that project ventral to the basal tubera. The basisphenoid is expanded, projects posteroventrally, and is pierced by four pneumatic recesses. The endocranial morphology resembles that observed in other basal theropods—in particular some allosauroids—and has a strongly marked pontine flexure and a large dorsal expansion. The inner ear morphology is also similar to that observed in other basal theropods, with slender semicircular canals. The anterior semicircular canal is 20% larger than the posterior semicircular canal, and the angle formed between them is less than 90° when seen in dorsal view. 展开更多
关键词 Neuroanatomy paleoneurology Dinosaur inner ear pneumaticity Early Jurassic Yunnan
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Current status in the treatment options for esophageal achalasia 被引量:15
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作者 Seng-Kee Chuah Chien-Hua Chiu +5 位作者 Wei-Chen Tai Jyong-Hong Lee Hung-I Lu Chi-Sin Changchien Ping-Huei Tseng Keng-Liang Wu 《World Journal of Gastroenterology》 SCIE CAS 2013年第33期5421-5429,共9页
Recent advances in the treatment of achalasia include the use of high-resolution manometry to predict the outcome of patients and the introduction of peroral endoscopic myotomy(POEM).The first multicenter randomized,c... Recent advances in the treatment of achalasia include the use of high-resolution manometry to predict the outcome of patients and the introduction of peroral endoscopic myotomy(POEM).The first multicenter randomized,controlled,2-year follow-up study conducted by the European Achalasia Trial group indicated that laparoscopic Heller myotomy(LHM)was not superior to pneumatic dilations(PD).Publications on the long-term success of laparoscopic surgery continue to emerge.In addition,laparoscopic single-site surgery is applicable to advanced laparoscopic operations such as LHM and anterior fundoplication.The optimal treatment option is an ongoing matter of debate.In this review,we provide an update of the current progress in the treatment of esophageal achalasia.Unless new conclusive data prove otherwise,LHM is considered the most durable treatment for achalasia at the expense of increased reflux-associated complications.However,PD is the first choice for non-surgical treatment and is more costeffective.Repeated PD according to an"on-demand"strategy based on symptom recurrence can achieve long-term remission.Decision making should be based on clinical evidence that identifies a subcategory of patients who would benefit from specific treatment options.POEM has shown promise but its long-term efficacy and safety need to be assessed further. 展开更多
关键词 Esophageal ACHALASIA ENDOSCOPIC pneumatic DILATIONS BOTULINUM injection Peroral ENDOSCOPIC MYOTOMY Minimally invasive HELLER MYOTOMY
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PILOT LEAKAGE'S INFLUENCES ON THE PERFORMANCES OF EXTRA HIGH PRESSURE PROPORTIONAL PNEUMATIC VALVE 被引量:12
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作者 ChenYize WangXuanyin XuZhipeng TaoGuoliang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第2期208-211,共4页
A mathematic model is built up to analyze the influences of a pilot valve'sleakage on the performances of pneumatic pressure proportional valve, and the performances aresimulated by using MATLAB. The results indic... A mathematic model is built up to analyze the influences of a pilot valve'sleakage on the performances of pneumatic pressure proportional valve, and the performances aresimulated by using MATLAB. The results indicate that using slide pilot valve in the valve system isfeasible, but the leakage's influences can not be neglected, especially it may induce instability ina low output pressure situation. A pilot valve using too large throttle window will cause the valveoscillate. To improve the working condition of pilot valve, a method adopting different widths oftwo throttle window is proposed. According to our simulation, this method balances the pressure dropbetween the two stage throttle ports, and reduces the influences of pilot valve's leakage. 展开更多
关键词 PNEUMATIC Proportional valve Mathematic model Leakage simulation
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Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles 被引量:8
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作者 Ji-Zhuang Fan Wei Zhang +2 位作者 Peng-Cheng Kong He-Gao Cai Gang-Feng Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第5期1123-1132,共10页
Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. How- ever, the application and nonlinearity of the pneumat... Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. How- ever, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the indepen- dent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the sim- ulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller. 展开更多
关键词 Frog-inspired robot Pneumatic muscle High-speed switch valve Pneumatic model
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Plants as concept generators for biomimetic light-weight structures with variable stiffness and self-repair mechanisms 被引量:10
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作者 Thomas Speck Tom Masselter +3 位作者 Bettina Prüm Olga Speck Rolf Luchsinger Siegfried Fink 《Journal of Bionic Engineering》 SCIE EI CSCD 2004年第4期199-205,共7页
Plants possess many structural and functional properties that have a high potential to serve as concept generators for the production of biomimetic technical materials and structures. We present data on two features... Plants possess many structural and functional properties that have a high potential to serve as concept generators for the production of biomimetic technical materials and structures. We present data on two features of plants (variable stiffness due to pressure changes in cellular structures and rapid self-repair functions) that may be used as models for biomimetic projects. 展开更多
关键词 BIONICS biomimetics SELF-REPAIR pneumatic structures Tensairity Aristolochia 1
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Efficacy of peroral endoscopic myotomy vs other achalasia treatments in improving esophageal function 被引量:7
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作者 Madhusudhan R Sanaka Umar Hayat +8 位作者 Prashanthi N Thota Ramprasad Jegadeesan Monica Ray Scott L Gabbard Neha Wadhwa Rocio Lopez Mark E Baker Sudish Murthy Siva Raja 《World Journal of Gastroenterology》 SCIE CAS 2016年第20期4918-4925,共8页
AIM: To assess and compare the esophageal function after peroral endoscopic myotomy(POEM) vs other conventional treatments in achalasia.METHODS: Chart review of all achalasia patients who underwent POEM, laparoscopic ... AIM: To assess and compare the esophageal function after peroral endoscopic myotomy(POEM) vs other conventional treatments in achalasia.METHODS: Chart review of all achalasia patients who underwent POEM, laparoscopic Heller myotomy(LHM) or pneumatic dilation(PD) at our institution between January 2012 and March 2015 was performed. Patient demographics, type of achalasia, prior treatments, pre- and post-treatment timed barium swallow(TBE) and high-resolution esophageal manometry(HREM) findings were compared between the three treatment groups. Patients who had both pre- and 2 mo posttreatment TBE or HREM were included in the final analysis. TBE parameters compared were barium column height, width and volume of barium remaining at 1 and 5 min. HREM parameters compared were basal lower esophageal sphincter(LES) pressures and LES-integrated relaxation pressures(IRP). Data are presented as mean ± SD, median [25th, 75 th percentiles] or frequency(percent). Analysis of variance, KruskalWallis test, Pearsons χ~2 test and Fishers Exact tests were used for analysis.RESULTS: A total of 200 achalasia patients were included of which 36 underwent POEM, 22 underwent PD and 142 underwent LHM. POEM patients were older(55.4 ± 16.8 years vs 46.5 ± 15.7 years, P = 0.013) and had higher BMI than LHM(29.1 ± 5.9 kg/m^2 vs 26 ± 5.1 kg/m^2, P = 0.012). More number of patients in POEM and PD groups had undergone prior treatments compared to LHM group(72.2% vs 68.2% vs 44.3% respectively, P = 0.003). At 2 mo post-treatment, all TBE parameters including barium column height, width and volume remaining at 1 and 5 min improved significantly in all three treatment groups(P = 0.01 to P < 0.001) except the column height at 1 min in PD group(P = 0.11). At 2 mo post-treatment, there was significant improvement in basal LES pressure and LES-IRP in both LHM(40.5 mm Hg vs 14.5 mm Hg and 24 mm Hg vs 7.1 mm Hg respectively, P < 0.001) and POEM groups(38.7 mm Hg vs 11.4 mm Hg and 23.6 mm Hg vs 6.6 mm Hg respectively, P < 0.001). However, when the efficacy of three treatments were compared to each other in terms of improvement in TBE or HREM parameters at 2 mo, there was no significant difference(P > 0.05).CONCLUSION: POEM, PD and LHM were all effective in improving esophageal function in achalasia at shortterm. There was no difference in efficacy between the three treatments. 展开更多
关键词 ACHALASIA DYSPHAGIA HELLER MYOTOMY Peroral endoscopic MYOTOMY MANOMETRY Pneumatic DILATION
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Adaptive Backstepping Slide Mode Control of Pneumatic Position Servo System 被引量:10
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作者 REN Haipeng FAN Juntao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第5期1003-1009,共7页
With the price decreasing of the pneumatic proportional valve and the high performance micro controller, the simple structure and high tracking performance pneumatic servo system demonstrates more application potentia... With the price decreasing of the pneumatic proportional valve and the high performance micro controller, the simple structure and high tracking performance pneumatic servo system demonstrates more application potential in many fields. However, most existing control methods with high tracking performance need to know the model information and to use pressure sensor. This limits the application of the pneumatic servo system. An adaptive backstepping slide mode control method is proposed for pneumatic position servo system. The proposed method designs adaptive slide mode controller using backstepping design technique. The controller parameter adaptive law is derived from Lyapunov analysis to guarantee the stability of the system. A theorem is testified to show that the state of closed-loop system is uniformly bounded, and the closed-loop system is stable. The advantages of the proposed method include that system dynamic model parameters are not required for the controller design, uncertain parameters bounds are not need, and the bulk and expensive pressure sensor is not needed as well. Experimental performance, as compared with some existing methods. results show that the designed controller can achieve better tracking 展开更多
关键词 pneumatic position servo system adaptive backstepping design slide mode control uncertain parameter tracking accuracy
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Pressure induced stability: from pneumatic structures to Tensairity~ 被引量:7
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作者 Rolf H. Luchsinger Mauro Pedretti Andreas Reinhard 《Journal of Bionic Engineering》 SCIE EI CSCD 2004年第3期141-148,共5页
Structural stabilization by a pressurized fluid is very common in nature, however hardly found in technology. Car tires, hot air balloons, airships and airhouses are among the few technical exceptions, which are stab... Structural stabilization by a pressurized fluid is very common in nature, however hardly found in technology. Car tires, hot air balloons, airships and airhouses are among the few technical exceptions, which are stabilized by a compressed medium, typically air. Restricted by simple geometries and a very limited load bearing capacity these pneumatic structures could succeed only in very specialized applications. Nevertheless, prospective concepts ag has systematically investigated pneumatic structures during the last few years. As a major result, it was demonstrated that almost any shape can be made with pneumatic structures and that astonishing structures such as the pneumatic airplane Stingray can be realized even with low air pressure. On top of that, Airlight Ltd. in close collaboration with prospective concepts ag has recently developed the fundamental new structural concept Tensairity. The synergetic combination of an inflated structure with conventional structural elements such as cables and struts yields pneumatic light-weight structures with the load bearing capacity of steel girders. Thus, complex forms and high strength open up many new opportunities for pressure induced stability in technology. An overview of these recent developments is presented and the close relationship of pneumatic structures with biology is outlined. 展开更多
关键词 pneumatic structures tensairity web technology AVIATION self-repairing membrane
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Real Gas Effects on Charging and Discharging Processes of High Pressure Pneumatics 被引量:6
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作者 LUO Yuxi WANG Xuanyin GE Yaozheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第1期61-68,共8页
The high pressure pneumatic system has been applied to special industries. It may cause errors when we analyze high pressure pneumatics under ideal gas assumption. However, the real gas effect on the performances of h... The high pressure pneumatic system has been applied to special industries. It may cause errors when we analyze high pressure pneumatics under ideal gas assumption. However, the real gas effect on the performances of high pressure pneumatics is seldom investigated. In this paper, the real gas effects on air enthalpy and internal energy are estimated firstly to study the real gas effect on the energy conversion. Under ideal gas assumption, enthalpy and internal energy are solely related to air temperature. The estimation result indicates that the pressure enthalpy and pressure internal energy of real pneumatic air obviously decrease the values of enthalpy and internal energy for high pressure pneumatics, and the values of pressure enthalpy and pressure internal energy are close. Based on the relationship among pressure, enthalpy and internal energy, the real gas effects on charging and discharging processes of high pressure pneumatics are estimated, which indicates that the real gas effect accelerates the temperature and pressure decreasing rates during discharging process, and decelerates their increasing rates during charging process. According to the above analysis, and for the inconvenience in building the simulation model for real gas and the difficulty of measuring the detail thermal capacities of pneumatics, a method to compensate the real gas effect under ideal gas assumption is proposed by modulating the thermal capacity of the pneumatic container in simulation. The experiments of switching expansion reduction (SER) for high pressure pneumatics are used to verify this compensating method. SER includes the discharging process of supply tanks and the charging process of expansion tank. The simulated and experimental results of SER are highly consistent. The proposed compensation method provides a convenient way to obtain more realistic simulation results for high pressure pneumatics. 展开更多
关键词 real gas effect pneumatic simulation model high pressure pneumatics
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