scholarly journals A row-generation approach for simultaneous multiple needle trajectory planning in radiofrequency ablation

2021 ◽  
Author(s):  
Shefali Kulkarni-Thaker ◽  
Dionne M Aleman ◽  
Aaron Fenster
Keyword(s):  
Radiofrequency Ablation ◽  
Trajectory Planning ◽  
Programming Model ◽  
Treatment Plan ◽  
Set Cover ◽  
Thermal Lesion ◽  
Clinical Criteria ◽  
Damage Models ◽  
Needle Trajectory ◽  
First Time

Radiofrequency ablation is a thermal therapy for moderately-sized cancerous tumors. A target is killed with high temperatures obtained due to the current passed through one or more electrodes (needles) inserted into it. The needles' trajectory must be meticulously planned to prevent interference with dense organs like bone or puncturing of critical structures like veins. By approximating the thermal lesion to an ellipse, we predefine several valid needle trajectories and then solve an integer programming model to identify pairwise valid needle positions, that meet clinical criteria, using a variation of the classic set cover model. To improve the models' tractability and scalability, we use row generation-based decomposition techniques that determines pairwise validity using two different types of cuts. Finally, we analyze target and OAR damage using several thermal damage models. Thus, for the first time we present a full treatment plan that incorporates novel trajectory planning with thermal dose computations. Our method is tested on 12 liver targets: three targets each with four different surgical margins. We show promising results that meet clinical guidelines while obtaining full target coverage.

Managing the Transition to Edentulousness Using Partial Transitional Dentures for First Time Prosthodontic Patients: Addressing Unrealistic Expectations – A Case Report

2017 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Case Report ◽  
Treatment Outcomes ◽  
Treatment Planning ◽  
Clinical Relevance ◽  
Treatment Plan ◽  
Sequential Treatment ◽  
Aesthetic Result ◽  
Abutment Teeth ◽  
First Time ◽  
Unrealistic Expectations

Aim: The aim of this report is to describe the management of a prosthodontic patient expressing unrealistic expectations with respect to the transition to edentulousness. Objectives: To outline (1) the diagnosis and explicit expectations of the patient on presentation (2) considerations made during treatment planning to address the wishes of the first time prosthodontic patient (3) a sequential treatment plan utilizing transitional partial removable dentures to manage the change to edentulousness (4) functional and aesthetic result achieved. Results: Delivery of immediate removable partial dentures retaining key abutment teeth in upper and lower arches was a viable prosthodontic solution in the transition to edentulousness of a patient expecting unrealistic treatment outcomes. Conclusions: Addressing impractical expectations and devising a treatment plan amenable to both clinician and patient is difficult. Strategies to manage these wishes in prosthodontic dentistry can include transitional partial dentures. Clinical relevance: Practitioners who encounter similar situations may consider this report valuable.

scholarly journals Research on Optimization and Design of Sustainable Urban Underground Logistics Network Framework

2020 ◽  
Vol 12 (21) ◽  
pp. 9147
Author(s):  
Hairui Wei ◽  
Anlin Li ◽  
Nana Jia
Keyword(s):  
Hybrid Method ◽  
Traffic Congestion ◽  
Urban Areas ◽  
Programming Model ◽  
Mixed Integer ◽  
Set Cover ◽  
Exhaust Emission ◽  
Logistics Network ◽  
Design And Optimization ◽  
Fuzzy Clustering Method

As a new mode of transportation, the underground logistics system (ULS) has become one of the solutions to the problems of environmental pollution and traffic congestion. Considering the environmental and economic factors in urban logistics, this paper conducts comprehensive design and optimization research on the network nodes and passages of urban underground logistics and proposes a relatively complete framework for a sustainable underground logistics network. A hybrid method is proposed, which includes the set cover model used to perform the first location of urban underground logistics nodes, the fuzzy clustering method applied to classify the located logistics nodes into the first-level and second-level nodes considering the congestion in different urban areas of the city and a mixed integer programming model proposed to optimize and design the underground logistics passage to find optimal passage parameters at every underground logistics node. Based on the above hybrid method, a sustainable underground logistics network framework including all-levels logistics nodes and passages is formed, with a subdistrict of Nanjing as a case study. The discussion of results shows that this underground logistics network framework proposal is very effective in reducing logistics time cost, exhaust emission and congestion cost. It provides support for decisions in the design and development of urban sustainable underground logistics networks.

scholarly journals Plasmodium vivax resistance to chloroquine (R2) and mefloquine (R3) in Brazilian Amazon region

1999 ◽  
Vol 32 (1) ◽  
pp. 67-68 ◽  
Author(s):  
Maria das Graças C. Alecrim ◽  
Wilson Alecrim ◽  
Vanize Macêdo
Keyword(s):  
Plasmodium Vivax ◽  
Brazilian Amazon ◽  
Amazon Region ◽  
Clinical Criteria ◽  
Brazilian Amazon Region ◽  
Criteria For Diagnosis ◽  
First Time

We report for the first time a patient with malaria due to Plasmodium vivax who showed R2 resistance to chloroquine and R3 resistance to mefloquine in the Brazilian Amazon region based on WHO clinical criteria for diagnosis of malaria resistance. Failure was observed with unsupervised oral chloroquine, chloroquine under rigorous supervision and mefloquine in the same scheme. Finally, the patient was cured with oral artesunate.

The PHEV Charging Infrastructure Planning (PCIP) Problem

2010 ◽  
Vol 11 (2) ◽  
Author(s):  
Yogesh Dashora ◽  
John W Barnes ◽  
Rekha S Pillai ◽  
Todd E Combs ◽  
Michael Hilliard ◽  
...  
Keyword(s):  
Programming Model ◽  
National Laboratory ◽  
Ghg Emissions ◽  
Geographic Location ◽  
Mixed Integer ◽  
Infrastructure Planning ◽  
Charging Infrastructure ◽  
Oak Ridge ◽  
Charging Station ◽  
First Time

Increasing debates over a gasoline independent future and the reduction of greenhouse gas (GHG) emissions has led to a surge in plug-in hybrid electric vehicles (PHEVs) being developed around the world. The majority of PHEV related research has been directed at improving engine and battery operations, studying future PHEV impacts on the grid, and projecting future PHEV charging infrastructure requirements. Due to the limited all-electric range of PHEVs, a daytime PHEV charging infrastructure will be required for most PHEV daily usage. In this paper, for the first time, we present a mixed integer mathematical programming model to solve the PHEV charging infrastructure planning (PCIP) problem for organizations with thousands of people working within a defined geographic location and parking lots well suited to charging station installations. Our case study, based on the Oak Ridge National Laboratory (ORNL) campus, produced encouraging results, indicates the viability of the modeling approach and substantiates the importance of considering both employee convenience and appropriate grid connections in the PCIP problem.

scholarly journals Thermal and electric Characteristics of High-power Short-duration Radiofrequency Ablation and Standard Radiofrequency Ablation: A Computer Simulation Study

2021 ◽  
Author(s):  
Kaihao Gu ◽  
Shengjie Yan ◽  
Xiaomei Wu
Keyword(s):  
Radiofrequency Ablation ◽  
Short Duration ◽  
High Power ◽  
Lesion Size ◽  
Lesion Volume ◽  
Rf Ablation ◽  
Thermal Lesion ◽  
Lesion Depth ◽  
Lesion Diameter ◽  
Rate Of Increase

Abstract Background: High power-short duration ablation is an emerging conception for cardiac RF treatment. But the biophysical ablation properties of this technique have not been fully explored. This study compared the electric field characteristics and thermal lesion dimension in High power-short duration (HP-SD) radio frequency (RF) ablation and standard RF ablation by using the finite element method. Results: The results demonstrated that the lesion size and temperature in HP–SD RF ablation increased faster than standard RF ablation. The thermal lesion volume in both ablation modes demonstrated a linear increase and the rate of increase of HP–SD RF ablation grew faster than that of standard RF ablation. For HP–SD application at 50 W for 5 s, the lesion depth was shallower (1.74 to 2.1 mm vs 2.40 to 3.15 mm) and the surface lesion diameter was broader (2.76 to 3.32 mm vs 2.42 to 2.66 mm) than that for standard RF ablation at 25 W for 30 s. Conclusion: Compared with standard RF ablation, HP–SD RF ablation creates a broader lesion width and surface lesion diameter but shallower lesion depth, with a faster increase in temperature. HP–SD ablation is more able to achieve uniform and contiguous lesion shape, which is a suitable for point-to-point RF ablation procedures.Higher temperature was formed in deeper space of cardiac tissue in HP–SD ablation. The duration of HP–SD ablation should be strictly controlled for preventing the steam occur in tissue.

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