The Experts below are selected from a list of 23310 Experts worldwide ranked by ideXlab platform
David L Ross - One of the best experts on this subject based on the ideXlab platform.
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high spatial resolution Thermal Mapping of radiofrequency ablation lesions using a novel thermochromic liquid crystal myocardial phantom
Journal of Cardiovascular Electrophysiology, 2013Co-Authors: Sujitha Thavapalachandran, Christine Midekin, W Chik, Gopal Sivagangabalan, Jim Pouliopoulos, M A Barry, David L Ross, Stuart P ThomasAbstract:BACKGROUND: Radiofrequency (RF) ablation causes Thermal mediated irreversible myocardial necrosis. This study aimed to (i) characterize the Thermal characteristics of RF ablation lesions with high spatial resolution using a thermochromic liquid crystal (TLC) myocardial phantom; and (ii) compare the thermochromic lesions with in vivo and in vitro ablation lesions. METHODS AND RESULTS: The myocardial phantom was constructed from a vertical sheet of TLC film, with color change between 50 °C (red) to 78 °C (black), embedded within a gel matrix, with impedance titrated to equal that of myocardium. Saline, with impedance titrated to blood values at 37 °C, was used as supernatant. A total of 51 RF ablations were performed. This comprised 17 ablations in the thermochromic gel phantom, bovine myocardial in vitro targets and ovine in vivo ablations, respectively. There was no difference in lesion dimensions between the thermochromic gel and in vivo ablations (lesion width 10.2 ± 0.2 vs 10.2 ± 2.4, P = 0.93; and depth 6.3 ± 0.1 vs 6.5 ± 1.7, P = 0.74). The spatial resolution of the thermochromic film was tested using 2 Thermal point-sources that were progressively opposed and was demonstrated to be <300 μm. CONCLUSIONS: High spatial resolution Thermal Mapping of in vitro RF lesions with spatial resolution of at least 300 μm is possible using a thermochromic liquid crystal myocardial phantom model, with a good correlation to in vivo RF ablations. This model may be useful for assessing the Thermal characteristics of RF lesions created using different ablation parameters and catheter technologies.
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High Spatial Resolution Thermal Mapping of Radiofrequency Ablation Lesions Using a Novel Thermochromic Liquid Crystal Myocardial Phantom
Journal of cardiovascular electrophysiology, 2013Co-Authors: W Chik, Sujitha Thavapalachandran, Christine Midekin, Gopal Sivagangabalan, Jim Pouliopoulos, M A Barry, David L Ross, Stuart P Thomas, Toon Wei Lim, Alistair McewanAbstract:High-Resolution Thermal Mapping of RF Ablation LesionsBackground Radiofrequency (RF) ablation causes Thermal mediated irreversible myocardial necrosis. This study aimed to (i) characterize the Thermal characteristics of RF ablation lesions with high spatial resolution using a thermochromic liquid crystal (TLC) myocardial phantom; and (ii) compare the thermochromic lesions with in vivo and in vitro ablation lesions. Methods and Results The myocardial phantom was constructed from a vertical sheet of TLC film, with color change between 50 °C (red) to 78 °C (black), embedded within a gel matrix, with impedance titrated to equal that of myocardium. Saline, with impedance titrated to blood values at 37 °C, was used as supernatant. A total of 51 RF ablations were performed. This comprised 17 ablations in the thermochromic gel phantom, bovine myocardial in vitro targets and ovine in vivo ablations, respectively. There was no difference in lesion dimensions between the thermochromic gel and in vivo ablations (lesion width 10.2 ± 0.2 vs 10.2 ± 2.4, P = 0.93; and depth 6.3 ± 0.1 vs 6.5 ± 1.7, P = 0.74). The spatial resolution of the thermochromic film was tested using 2 Thermal point-sources that were progressively opposed and was demonstrated to be
W Chik - One of the best experts on this subject based on the ideXlab platform.
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high spatial resolution Thermal Mapping of radiofrequency ablation lesions using a novel thermochromic liquid crystal myocardial phantom
Journal of Cardiovascular Electrophysiology, 2013Co-Authors: Sujitha Thavapalachandran, Christine Midekin, W Chik, Gopal Sivagangabalan, Jim Pouliopoulos, M A Barry, David L Ross, Stuart P ThomasAbstract:BACKGROUND: Radiofrequency (RF) ablation causes Thermal mediated irreversible myocardial necrosis. This study aimed to (i) characterize the Thermal characteristics of RF ablation lesions with high spatial resolution using a thermochromic liquid crystal (TLC) myocardial phantom; and (ii) compare the thermochromic lesions with in vivo and in vitro ablation lesions. METHODS AND RESULTS: The myocardial phantom was constructed from a vertical sheet of TLC film, with color change between 50 °C (red) to 78 °C (black), embedded within a gel matrix, with impedance titrated to equal that of myocardium. Saline, with impedance titrated to blood values at 37 °C, was used as supernatant. A total of 51 RF ablations were performed. This comprised 17 ablations in the thermochromic gel phantom, bovine myocardial in vitro targets and ovine in vivo ablations, respectively. There was no difference in lesion dimensions between the thermochromic gel and in vivo ablations (lesion width 10.2 ± 0.2 vs 10.2 ± 2.4, P = 0.93; and depth 6.3 ± 0.1 vs 6.5 ± 1.7, P = 0.74). The spatial resolution of the thermochromic film was tested using 2 Thermal point-sources that were progressively opposed and was demonstrated to be <300 μm. CONCLUSIONS: High spatial resolution Thermal Mapping of in vitro RF lesions with spatial resolution of at least 300 μm is possible using a thermochromic liquid crystal myocardial phantom model, with a good correlation to in vivo RF ablations. This model may be useful for assessing the Thermal characteristics of RF lesions created using different ablation parameters and catheter technologies.
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High Spatial Resolution Thermal Mapping of Radiofrequency Ablation Lesions Using a Novel Thermochromic Liquid Crystal Myocardial Phantom
Journal of cardiovascular electrophysiology, 2013Co-Authors: W Chik, Sujitha Thavapalachandran, Christine Midekin, Gopal Sivagangabalan, Jim Pouliopoulos, M A Barry, David L Ross, Stuart P Thomas, Toon Wei Lim, Alistair McewanAbstract:High-Resolution Thermal Mapping of RF Ablation LesionsBackground Radiofrequency (RF) ablation causes Thermal mediated irreversible myocardial necrosis. This study aimed to (i) characterize the Thermal characteristics of RF ablation lesions with high spatial resolution using a thermochromic liquid crystal (TLC) myocardial phantom; and (ii) compare the thermochromic lesions with in vivo and in vitro ablation lesions. Methods and Results The myocardial phantom was constructed from a vertical sheet of TLC film, with color change between 50 °C (red) to 78 °C (black), embedded within a gel matrix, with impedance titrated to equal that of myocardium. Saline, with impedance titrated to blood values at 37 °C, was used as supernatant. A total of 51 RF ablations were performed. This comprised 17 ablations in the thermochromic gel phantom, bovine myocardial in vitro targets and ovine in vivo ablations, respectively. There was no difference in lesion dimensions between the thermochromic gel and in vivo ablations (lesion width 10.2 ± 0.2 vs 10.2 ± 2.4, P = 0.93; and depth 6.3 ± 0.1 vs 6.5 ± 1.7, P = 0.74). The spatial resolution of the thermochromic film was tested using 2 Thermal point-sources that were progressively opposed and was demonstrated to be
Parthasarathy Ranganathan - One of the best experts on this subject based on the ideXlab platform.
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weatherman automated online and predictive Thermal Mapping and management for data centers
International Conference on Autonomic Computing, 2006Co-Authors: Justin Moore, Jeffrey S Chase, Parthasarathy RanganathanAbstract:Recent advances have demonstrated the potential benefits of coordinated management of Thermal load in data centers, including reduced cooling costs and improved resistance to cooling system failures. A key unresolved obstacle to the practical implementation of Thermal load management is the ability to predict the effects of workload distribution and cooling configurations on temperatures within a data center enclosure. The interactions between workload, cooling and temperature are dependent on complex factors that are unique to each data center, including physical room layout, hardware power consumption and cooling capacity; this dictates an approach that formulates management policies for each data center based on these properties. We propose and evaluate a simple, flexible method to infer a detailed model of Thermal behavior within a data center from a stream of instrumentation data. This data - taken during normal data center operation - includes continuous readings taken from external temperature sensors, server instrumentation and computer room air conditioning units. Experimental results from a representative data center show that automatic Thermal Mapping can predict accurately the heat distribution resulting from a given workload distribution and cooling configuration, thereby removing the need for static or manual configuration of Thermal load management systems. We also demonstrate how our approach adapts to preserve accuracy across changes to cluster attributes that affect Thermal behavior - such as cooling settings, workload distribution and power consumption.
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ICAC - Weatherman: Automated, Online and Predictive Thermal Mapping and Management for Data Centers
2006 IEEE International Conference on Autonomic Computing, 1Co-Authors: Justin D. Moore, Jeffrey S Chase, Parthasarathy RanganathanAbstract:Recent advances have demonstrated the potential benefits of coordinated management of Thermal load in data centers, including reduced cooling costs and improved resistance to cooling system failures. A key unresolved obstacle to the practical implementation of Thermal load management is the ability to predict the effects of workload distribution and cooling configurations on temperatures within a data center enclosure. The interactions between workload, cooling and temperature are dependent on complex factors that are unique to each data center, including physical room layout, hardware power consumption and cooling capacity; this dictates an approach that formulates management policies for each data center based on these properties. We propose and evaluate a simple, flexible method to infer a detailed model of Thermal behavior within a data center from a stream of instrumentation data. This data - taken during normal data center operation - includes continuous readings taken from external temperature sensors, server instrumentation and computer room air conditioning units. Experimental results from a representative data center show that automatic Thermal Mapping can predict accurately the heat distribution resulting from a given workload distribution and cooling configuration, thereby removing the need for static or manual configuration of Thermal load management systems. We also demonstrate how our approach adapts to preserve accuracy across changes to cluster attributes that affect Thermal behavior - such as cooling settings, workload distribution and power consumption.
Adnan Al-anbuky - One of the best experts on this subject based on the ideXlab platform.
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Neuro Wireless Sensor Network architecture: Cool stores dynamic Thermal Mapping
2011 IEEE Sensors Applications Symposium, 2011Co-Authors: Naresh Yamani, Adnan Al-anbukyAbstract:This work focuses on developing cool store's Thermal Mapping system based on the neuro Wireless Sensor Network (nWSN). The network intelligence is taken care of by the sensor network embedded neural net. The target application of the architecture development is for cool stores with emphasis on meat storage. The meat quality is a significant characteristic within the cold chain management. Temperature is the main parameter that needs to be monitored. nWSN architecture deals with the distributed neural network (NN) that predicts the temperature variations within the space. WSN nodes have categorized into infrastructural sensor nodes and portable sensor nodes. The neural net algorithm is embedded into the fully functional infrastructural nodes while portable nodes provide the surrounding information. The portable nodes that are attached to the meat carcass are dynamically establishing connection with one of the infrastructural nodes. The overall network formulates clusters based on Dijkstra's algorithm. The Nodes Message interaction (NMi) model is developed to organize the communication between the infrastructural nodes and portable nodes. This work disclosed the viability of nWSN architecture to execute further on a real-time test bed. It is found that the Mean Absolute Error (MAE) at the infrastructural nodes has a variation of 1°C. The resulting MAE is considerably good where nWSN can be capable of yielding similar applications of predictions.
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Query based nWSN data processing for spatial Thermal Mapping
2011 Seventh International Conference on Intelligent Sensors Sensor Networks and Information Processing, 2011Co-Authors: Naresh Yamani, Adnan Al-anbukyAbstract:This work discusses enhancing the neuroWSN architecture that has been developed for spatial Thermal Mapping with query system for time synchronization and relevant aggregation at the sensor level. The neural net training process at the cluster head requires synchronization of the incoming data from all the portable nodes. An approach for buffering and query management system is proposed here to fulfil this requirement. An QnDP (Query based nWSN Data Processing) algorithm is developed to validate the scenario. It can also handle the common aggregate functions along with the temperature and location data of each portable sensor node through the use of memory buffers. Every portable and infrastructural sensor node has its own cache/buffer to accommodate data storage for each parameter. The parameters of a query request are dynamically assigned to the response data when it propagates to any sensor node. The Query Based neuro Wireless Sensor Network (QB-nWSN) is designed using IBMs Mote Runner environment. Queries transmit and receive times are recorded for a sample of tests. The results and experimental setup revealed its viability to test further on a real time test bed.
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Object-Centric Thermal Mapping: A wireless sensor network perspective
SENSORS 2009 IEEE, 2009Co-Authors: Naresh Yamani, Adnan Al-anbukyAbstract:This work mainly focuses on developing a concept towards building an object-centric Thermal Mapping (OCT Map) environment based on the use of wireless sensor networks. The sensor network is represented through infrastructural sensors of any functional space like the cool-room or a food-store. These sensors facilitate initial values for the calculation of the temperature at a given location within the space. In this work, artificial neural networks (ANN) are used for predicting the Thermal map of a given space. It is found that the estimated temperature distributions at any arbitrary points have considerably low root mean square error (RMSE). However the accuracy of the prediction and number of infrastructural nodes are concerned, at 8 infrastructural nodes and the room volume of 4500 m3, the temperature can be predicted with at least RMS error of 0.02°C. The results divulged that the design of using neural networks for temperature Mapping is feasible.
Stuart P Thomas - One of the best experts on this subject based on the ideXlab platform.
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high spatial resolution Thermal Mapping of radiofrequency ablation lesions using a novel thermochromic liquid crystal myocardial phantom
Journal of Cardiovascular Electrophysiology, 2013Co-Authors: Sujitha Thavapalachandran, Christine Midekin, W Chik, Gopal Sivagangabalan, Jim Pouliopoulos, M A Barry, David L Ross, Stuart P ThomasAbstract:BACKGROUND: Radiofrequency (RF) ablation causes Thermal mediated irreversible myocardial necrosis. This study aimed to (i) characterize the Thermal characteristics of RF ablation lesions with high spatial resolution using a thermochromic liquid crystal (TLC) myocardial phantom; and (ii) compare the thermochromic lesions with in vivo and in vitro ablation lesions. METHODS AND RESULTS: The myocardial phantom was constructed from a vertical sheet of TLC film, with color change between 50 °C (red) to 78 °C (black), embedded within a gel matrix, with impedance titrated to equal that of myocardium. Saline, with impedance titrated to blood values at 37 °C, was used as supernatant. A total of 51 RF ablations were performed. This comprised 17 ablations in the thermochromic gel phantom, bovine myocardial in vitro targets and ovine in vivo ablations, respectively. There was no difference in lesion dimensions between the thermochromic gel and in vivo ablations (lesion width 10.2 ± 0.2 vs 10.2 ± 2.4, P = 0.93; and depth 6.3 ± 0.1 vs 6.5 ± 1.7, P = 0.74). The spatial resolution of the thermochromic film was tested using 2 Thermal point-sources that were progressively opposed and was demonstrated to be <300 μm. CONCLUSIONS: High spatial resolution Thermal Mapping of in vitro RF lesions with spatial resolution of at least 300 μm is possible using a thermochromic liquid crystal myocardial phantom model, with a good correlation to in vivo RF ablations. This model may be useful for assessing the Thermal characteristics of RF lesions created using different ablation parameters and catheter technologies.
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High Spatial Resolution Thermal Mapping of Radiofrequency Ablation Lesions Using a Novel Thermochromic Liquid Crystal Myocardial Phantom
Journal of cardiovascular electrophysiology, 2013Co-Authors: W Chik, Sujitha Thavapalachandran, Christine Midekin, Gopal Sivagangabalan, Jim Pouliopoulos, M A Barry, David L Ross, Stuart P Thomas, Toon Wei Lim, Alistair McewanAbstract:High-Resolution Thermal Mapping of RF Ablation LesionsBackground Radiofrequency (RF) ablation causes Thermal mediated irreversible myocardial necrosis. This study aimed to (i) characterize the Thermal characteristics of RF ablation lesions with high spatial resolution using a thermochromic liquid crystal (TLC) myocardial phantom; and (ii) compare the thermochromic lesions with in vivo and in vitro ablation lesions. Methods and Results The myocardial phantom was constructed from a vertical sheet of TLC film, with color change between 50 °C (red) to 78 °C (black), embedded within a gel matrix, with impedance titrated to equal that of myocardium. Saline, with impedance titrated to blood values at 37 °C, was used as supernatant. A total of 51 RF ablations were performed. This comprised 17 ablations in the thermochromic gel phantom, bovine myocardial in vitro targets and ovine in vivo ablations, respectively. There was no difference in lesion dimensions between the thermochromic gel and in vivo ablations (lesion width 10.2 ± 0.2 vs 10.2 ± 2.4, P = 0.93; and depth 6.3 ± 0.1 vs 6.5 ± 1.7, P = 0.74). The spatial resolution of the thermochromic film was tested using 2 Thermal point-sources that were progressively opposed and was demonstrated to be
