Multi-objective Design Optimization for a Steerable Needle for Soft Tissue Surgery

Author(s):  
Alexander Leibinger ◽  
Matthew Oldfield ◽  
Ferdinando Rodriguez y Baena
2019 ◽  
Vol 6 (1) ◽  
pp. e000233
Author(s):  
Jorge Espinel-Rupérez ◽  
Maria Dolores Martín-Ríos ◽  
Veronica Salazar ◽  
Maria Rosario Baquero-Artigao ◽  
Gustavo Ortiz-Díez

ObjectivesTo determine (1) the incidence of surgical site infection (SSI) in patients undergoing soft tissue surgery at a veterinary teaching hospital and to study (2) and describe the main risk factors associated with SSI and (3) assess the economic impact of SSI.DesignProspective cohort study.SettingVeterinary teaching hospital.Participants184 dogs undergoing soft tissue surgery during a 12-month period (October 2013 to September 2014).Primary outcome measureSurgical site infection.ResultsOut of the 184 patients analysed, SSI was diagnosed in 16 (8.7 per cent) patients, 13 (81.3 per cent) were classified as superficial incisional infection, 2 (12.5 per cent) as deep incisional infection and 1 (6.3 per cent) as organ/space infection. The administration of steroidal anti-inflammatory drugs (P=0.028), preoperative hyperglycaemia (P=0.015), surgical times longer than 60 minutes (P=0.013), urinary catheterisation (P=0.037) and wrong use of the Elizabethan collar (P=0.025) were identified as risk factors. Total costs increased 74.4 per cent, with an increase in postsurgical costs of 142.2 per cent.ConclusionsThe incidence of SSI was higher than the incidence reported in other published studies, although they were within expected ranges when a surveillance system was implemented. This incidence correlated with an increase in costs. Additionally new important risk factors for its development were detected.


Author(s):  
J. Schiffmann

Small scale turbomachines in domestic heat pumps reach high efficiency and provide oil-free solutions which improve heat-exchanger performance and offer major advantages in the design of advanced thermodynamic cycles. An appropriate turbocompressor for domestic air based heat pumps requires the ability to operate on a wide range of inlet pressure, pressure ratios and mass flows, confronting the designer with the necessity to compromise between range and efficiency. Further the design of small-scale direct driven turbomachines is a complex and interdisciplinary task. Textbook design procedures propose to split such systems into subcomponents and to design and optimize each element individually. This common procedure, however, tends to neglect the interactions between the different components leading to suboptimal solutions. The authors propose an approach based on the integrated philosophy for designing and optimizing gas bearing supported, direct driven turbocompressors for applications with challenging requirements with regards to operation range and efficiency. Using previously validated reduced order models for the different components an integrated model of the compressor is implemented and the optimum system found via multi-objective optimization. It is shown that compared to standard design procedure the integrated approach yields an increase of the seasonal compressor efficiency of more than 12 points. Further a design optimization based sensitivity analysis allows to investigate the influence of design constraints determined prior to optimization such as impeller surface roughness, rotor material and impeller force. A relaxation of these constrains yields additional room for improvement. Reduced impeller force improves efficiency due to a smaller thrust bearing mainly, whereas a lighter rotor material improves rotordynamic performance. A hydraulically smoother impeller surface improves the overall efficiency considerably by reducing aerodynamic losses. A combination of the relaxation of the 3 design constraints yields an additional improvement of 6 points compared to the original optimization process. The integrated design and optimization procedure implemented in the case of a complex design problem thus clearly shows its advantages compared to traditional design methods by allowing a truly exhaustive search for optimum solutions throughout the complete design space. It can be used for both design optimization and for design analysis.


2021 ◽  
Vol 9 (5) ◽  
pp. 478
Author(s):  
Hao Chen ◽  
Weikun Li ◽  
Weicheng Cui ◽  
Ping Yang ◽  
Linke Chen

Biomimetic robotic fish systems have attracted huge attention due to the advantages of flexibility and adaptability. They are typically complex systems that involve many disciplines. The design of robotic fish is a multi-objective multidisciplinary design optimization problem. However, the research on the design optimization of robotic fish is rare. In this paper, by combining an efficient multidisciplinary design optimization approach and a novel multi-objective optimization algorithm, a multi-objective multidisciplinary design optimization (MMDO) strategy named IDF-DMOEOA is proposed for the conceptual design of a three-joint robotic fish system. In the proposed IDF-DMOEOA strategy, the individual discipline feasible (IDF) approach is adopted. A novel multi-objective optimization algorithm, disruption-based multi-objective equilibrium optimization algorithm (DMOEOA), is utilized as the optimizer. The proposed MMDO strategy is first applied to the design optimization of the robotic fish system, and the robotic fish system is decomposed into four disciplines: hydrodynamics, propulsion, weight and equilibrium, and energy. The computational fluid dynamics (CFD) method is employed to predict the robotic fish’s hydrodynamics characteristics, and the backpropagation neural network is adopted as the surrogate model to reduce the CFD method’s computational expense. The optimization results indicate that the optimized robotic fish shows better performance than the initial design, proving the proposed IDF-DMOEOA strategy’s effectiveness.


2011 ◽  
Vol 264-265 ◽  
pp. 1719-1724 ◽  
Author(s):  
A.K.M. Mohiuddin ◽  
Md. Ataur Rahman ◽  
Yap Haw Shin

This paper aims to demonstrate the effectiveness of Multi-Objective Genetic Algorithm Optimization and its practical application on the automobile engine valve timing where the variation of performance parameters required for finest tuning to obtain the optimal engine performances. The primary concern is to acquire the clear picture of the implementation of Multi-Objective Genetic Algorithm and the essential of variable valve timing effects on the engine performances in various engine speeds. Majority of the research works in this project were in CAE software environment and method to implement optimization to 1D engine simulation. The paper conducts robust design optimization of CAMPRO 1.6L (S4PH) engine valve timing at various engine speeds using multiobjective genetic algorithm (MOGA) for the future variable valve timing (VVT) system research and development. This paper involves engine modelling in 1D software simulation environment, GT-Power. The GT-Power model is run simultaneously with mode Frontier to perform multiobjective optimization.


2011 ◽  
Vol 11 (1) ◽  
pp. 489-499 ◽  
Author(s):  
S.N. Omkar ◽  
J. Senthilnath ◽  
Rahul Khandelwal ◽  
G. Narayana Naik ◽  
S. Gopalakrishnan

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