Autonomous pipeline monitoring and maintenance system: a RFID-based approach

Pipeline networks are one of the key infrastructures of our modern life. Proactive monitoring and frequent inspection of pipeline networks are very important for sustaining their safe and efficient functionalities. Existing monitoring and maintenance approaches are costly and inefficient because pipelines can be installed in large scale and in an inaccessible and hazardous environment. To overcome these challenges, we propose a novel Radio Frequency IDentification (RFID)-based Autonomous Maintenance system for Pipelines, called RAMP, which combines robotic, sensing, and RFID technologies for efficient and accurate inspection, corrective reparation, and precise geo-location information. RAMP can provide not only economical and scalable remedy but also safe and customizable solution. RAMP also allows proactive and corrective monitoring and maintenance of pipelines. One prominent advantage of RAMP is that it can be applied to a large variety of pipeline systems including water, sewer, and gas pipelines. Simulation results demonstrate the feasibility and superior performance of RAMP in comparison to the existing pipeline monitoring systems

Automatic generation of user-centric multimedia communication services

Multimedia communication services today are conceived, designed, and developed in isolation, following a stovepipe approach. This has resulted in a fragmented and incompatible set of technologies and products. Building new communication services requires a lengthy and costly development cycle, which severely limits the pace of innovation. In this paper, we address the fundamental problem of automating the development of multimedia communication services. We propose a new paradigm for creating such services through declarative specification and generation, rather than through traditional design and development. Further, the proposed paradigm pays special attention to how the end-user specifies hislher communication needs, an important requirement largely ignored in existing approaches. 1

The effects of target motion in kV-CBCT imaging

Background: To study the impact of target motion in kV-CBCT imaging. Material/Methods: To simulate the respiratory movement, dynamic phantom was programmed to move in threedimension with a period of four seconds and of two different amplitudes (PA1 and PA2). The targets of well defined geometries (cylinder, sphere, solid triangle, U-shaped and dumbbell) were made using wax. The static targets were CT imaged (reference image). Using CBCT, the targets in static and dynamic modes were imaged under full-fan beam. The line profiles along cranio-caudal direction, influence of target's initial moving phase and volume estimation using auto-contouring tool were used to analyze the effects of target motion on CBCT imaging. Results: Comparing the line profiles of targets in CBCT with CT, the length of average HU spread was reduced by 42.54±1.85%, except the cylindrical target which is by 19.35% for PA1. The percentage difference in reconstructed volume of static targets imaged using CBCT and CT (HU WW -500 to 0) ranges from -1.32% to -5.94%. The volume losses for targets imaged in dynamic mode PA1 ranges from 14.35% to 30.95% and for PA2 it was 21.29% to 43.80%. The solid triangle and cylindrical targets suffered the maximum and minimum volume losses respectively. Conclusions: Non-gated CBCT imaging of the moving targets encounters significant loss of volumetric information, due to scatter artifacts. These may result in a systematic error in re-contouring when CBCT images are used for the re-planning work

Exit fluence analysis using portal dosimetry in volumetric modulated arc therapy

AimIn measuring exit fluences, there are several sources of deviations which include the changes in the entrance fluence, changes in the detector response and patient orientation or geometry. The purpose of this work is to quantify these sources of errors.BackgroundThe use of the volumetric modulated arc therapy treatment with the help of image guidance in radiotherapy results in high accuracy of delivering complex dose distributions while sparing critical organs. The transit dosimetry has the potential of Verifying dose delivery by the linac, Multileaf collimator positional accuracy and the calculation of dose to a patient or phantom.Materials and methodsThe quantification of errors caused by a machine delivery is done by comparing static and arc picket fence test for 30 days. A RapidArc plan, created for the pelvis site was delivered without and with Rando phantom and exit portal images were acquired. The day to day dose variation were analysed by comparing the daily exit dose images during the course of treatment. The gamma criterion used for analysis is 3% dose difference and 3[[ce:hsp sp="0.25"/]]mm distance to agreement with a threshold of 10% of maximum dose.ResultsThe maximum standard deviation for the static and arc picket fence test fields were 0.19[[ce:hsp sp="0.25"/]]CU and 1.3[[ce:hsp sp="0.25"/]]CU, respectively. The delivery of the RapidArc plans without a phantom shows the maximum standard deviation of 1.85[[ce:hsp sp="0.25"/]]CU and the maximum gamma value of 0.59. The maximum gamma value for the RapidArc plan delivered with the phantom was found to be 1.2. The largest observed fluence deviation during the delivery to patient was 5.7% and the maximum standard deviation was 4.1[[ce:hsp sp="0.25"/]]CU.ConclusionIt is found from this study that the variation due to patient anatomy and interfraction organ motion is significant

Treatment planning and dosimetric comparison study on two different volumetric modulated arc therapy delivery techniques

AimTo compare and evaluate the performance of two different volumetric modulated arc therapy delivery techniques.BackgroundVolumetric modulated arc therapy is a novel technique that has recently been made available for clinical use. Planning and dosimetric comparison study was done for Elekta VMAT and Varian RapidArc for different treatment sites.Materials and methodsTen patients were selected for the planning comparison study. This includes 2 head and neck, 2 oesophagus, 1 bladder, 3 cervix and 2 rectum cases. Total dose of 50[[ce:hsp sp="0.25"/]]Gy was given for all the plans. All plans were done for RapidArc using Eclipse and for Elekta VMAT with Monaco treatment planning system. All plans were generated with 6[[ce:hsp sp="0.25"/]]MV X-rays for both RapidArc and Elekta VMAT. Plans were evaluated based on the ability to meet the dose volume histogram, dose homogeneity index, radiation conformity index, estimated radiation delivery time, integral dose and monitor units needed to deliver the prescribed dose.ResultsRapidArc plans achieved the best conformity (CI95%[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]1.08[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.07) while Elekta VMAT plans were slightly inferior (CI95%[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]1.10[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.05). The in-homogeneity in the PTV was highest with Elekta VMAT with HI equal to 0.12[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.02[[ce:hsp sp="0.25"/]]Gy when compared to RapidArc with 0.08[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.03. Significant changes were observed between the RapidArc and Elekta VMAT plans in terms of the healthy tissue mean dose and integral dose. Elekta VMAT plans show a reduction in the healthy tissue mean dose (6.92[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]2.90)[[ce:hsp sp="0.25"/]]Gy when compared to RapidArc (7.83[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]3.31)[[ce:hsp sp="0.25"/]]Gy. The integral dose is found to be inferior with Elekta VMAT (11.50[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]6.49)[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]104[[ce:hsp sp="0.25"/]]Gy[[ce:hsp sp="0.25"/]]cm3 when compared to RapidArc (13.11[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]7.52)[[ce:hsp sp="0.25"/]]×[[ce:hsp sp="0.25"/]]104[[ce:hsp sp="0.25"/]]Gy[[ce:hsp sp="0.25"/]]cm3. Both Varian RapidArc and Elekta VMAT respected the planning objective for all organs at risk. Gamma analysis result for the pre-treatment quality assurance shows good agreement between the planned and delivered fluence for 3[[ce:hsp sp="0.25"/]]mm DTA, 3% DD for all the evaluated points inside the PTV, for both VMAT and RapidArc techniques.ConclusionThe study concludes that a variable gantry speed with variable dose rate is important for efficient arc therapy delivery. RapidArc presents a slight improvement in the OAR sparing with better target coverage when compared to Elekta VMAT. Trivial differences were noted in all the plans for organ at risk but the two techniques provided satisfactory conformal avoidance and conformation

A study on the correlation between plan complexity and gamma index analysis in patient specific quality assurance of volumetric modulated arc therapy

AimTo evaluate the new Octavius 4D system for patient specific quality assurance and to study the correlation between plan complexity and gamma index analysis in patient specific quality assurance of VMAT using the Octavius 4D system.BackgroundMcNiven (2010) proposed a study to evaluate the utility of a complexity metric, the Modulation Complexity Score, to evaluate the relationship of the metric with deliverability in IMRT.Materials and methodsEvaluation of the Octavius 4D system was carried out by gamma evaluation of user defined MLC created patterns and AAPM TG 119 benchmark plans. The relationship between plan complexity expressed as Modulation Complexity Score (MCS) and the gamma index analysis was established by a planar and volumetric gamma analysis of 106 clinically approved VMAT patient plans of different sites.ResultsAverage volumetric 3D global gamma evaluation (3[[ce:hsp sp="0.25"/]]mm/3%) results for the evaluation plans was 97.41% for 6[[ce:hsp sp="0.25"/]]MV X-rays and 98.30% for 15[[ce:hsp sp="0.25"/]]MV X-rays. Average MCS values for the head and neck, pelvic and thoracic plans were 0.2224, 0.3615 and 0.1874. Average volumetric 3D global gamma analysis (3[[ce:hsp sp="0.25"/]]mm/3%) results for the head and neck, pelvic and thoracic VMAT plans were 95.45%, 97.51% and 96.98%, respectively. Out of 90 correlation analyses between the MCS and gamma passing rate, only 3 had the r value greater than 0.5.ConclusionsThe Octavius 4D system is a suitable device for patient specific pretreatment QA. Global and local gamma analysis results showed a weak correlation with the MCS

A Communication Virtual Machine

The convergence of data, voice and multimedia communication over digital networks, coupled with continuous improvement in network capacity and reliability has significantly enriched the ways we communicate. However, the stovepipe approach used to develop today’s communication applications and tools results in rigid technology, limited utility, lengthy and costly development cycle, difficulty in integration, and hinders innovation. In this paper, we present a fundamentally different approach, which we call Communication Virtual Machine (CVM) to address these problems. CVM provides a user-centric, modeldriven approach for conceiving, synthesizing and delivering communication solutions across application domains. We argue that CVM represents a far more effective paradigm for engineering communication solutions. The concept, architecture, modeling language, prototypical design and implementation of CVM are discussed

A unified architectural model for on-demand user-centric communications

The rapid growth of networking technologies has drastically changed the way we communicate and enabled a wide range of communication applications. However, these applications have been conceived, designed, and developed separately with little or no connection to each other, resulting in a fragmented and incompatible set of technologies and products. Building new communication applications requires a lengthy and costly development cycle, which severely limits the pace of innovation. Current applications are also typically incapable of responding to changes in user communication needs as well as changing network infrastructure and device technology. In this article, we address these issues and present the Unified Communication Model (UCM), a new and user-centric approach for conceiving, generating, and delivering communication applications on-demand. We also introduce a prototype design and implementation of UCM and discuss future research directions toward realizing next generation communication applications. 1