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https://www.readbyqxmd.com/read/28227998/monitoring-of-thermal-treatment-by-linearly-chirped-fiber-bragg-grating-sensors-feasibility-assessment-during-laser-ablation-on-ex-vivo-liver
#1
F Napoleoni, M Caponera, A Polimadei, D Tosi, P Saccomandi, E Schena, F Napoleoni, M Caponera, A Polimadei, D Tosi, P Saccomandi, E Schena, A Polimadei, P Saccomandi, D Tosi, F Napoleoni, F Schena
In this work a spatially-resolved fiber optic temperature sensor has been characterized in a wide range of gradient applied on its active area (from -35 °C to +35 °C). Preliminary experiments to assess its feasibility for application in laser ablation have been performed. The sensor under test is a linearly chirped fiber Bragg grating (FBG), with 1.5 cm-length of active area. It can be considered as a chain of several FBGs, each able to sense local temperature. The sensor response to the gradient has been analyzed in terms of its spectrum width (full width at half maximum)...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227677/multipoint-temperature-monitoring-in-liver-undergoing-computed-tomography-guided-radiofrequency-ablation-with-fiber-bragg-grating-probes
#2
P Saccomandi, E Schena, M Diana, F M Di Matteo, G Costamagna, J Marescaux, P Saccomandi, E Schena, M Diana, F M Di Matteo, G Costamagna, J Marescaux, F M Di Matteo, J Marescaux, E Schena, M Diana, G Costamagna, P Saccomandi
In this work, we investigated the temperature increment experienced by biological tissue during radiofrequency ablation (RFA). The measurements were performed by using two custom-made thermal probes based on fiber optic sensors (fiber Bragg gratings, FBGs). The two probes embed a total of 9 FBGs. Experiments were performed during RFA of an ex vivo healthy porcine liver. The RFA heating module was equipped with 5 thermocouples. Results show that the temperature increment close to the applicator (i.e., 0.6 cm-0...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227263/an-algorithm-for-rotor-tracking-in-atrial-fibrillation-using-graph-search-based-periodic-peak-detection
#3
Rupin Dalvi, Adrian Suszko, Vijay S Chauhan, Rupin Dalvi, Adrian Suszko, Vijay S Chauhan, Rupin Dalvi, Adrian Suszko, Vijay S Chauhan
Rotors are rotating electrical waves that may sustain atrial fibrillation (AF); thereby providing therapeutic targets for catheter ablation. We propose a method for identifying rotors from circular catheter recordings of bipolar intracardiac electrograms (EGM) during AF. We use dominant frequency-based periodicity detection along with a graph search algorithm to identify the most dominant periodic activations or peaks of interest in each bipolar EGM recorded by a multipolar circular catheter. We then track the activations across catheter bipoles to determine whether they conform to the rotational pattern of a rotor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227100/a-double-sided-fabrication-process-for-intrafascicular-parylene-c-based-electrode-arrays
#4
M Mueller, C Boehler, J Jaeger, M Asplund, T Stieglitz, M Mueller, C Boehler, J Jaeger, M Asplund, T Stieglitz, T Stieglitz, C Boehler, M Mueller, M Asplund, J Jaeger
After the development of a single-sided fabrication process for intrafascicular parylene C based electrode arrays tests showed that an increase in integration density can only be achieved by a double-side process. The process uses 25 μm thick platinum iridium foil, which is thinned down with the laser and sandwiched between two 10 μm thick parylene C layers. Utilizing a picosecond laser (355 nm Nd:YVO4) it was possible to fabricate 40 μm thick electrodes that can be implanted directly in the nerve without relying on additional support layers like chitosan or silk...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227088/detection-of-the-propagating-direction-of-electrical-wavefront-in-atrial-fibrillation
#5
Dongping Du, Yuncheng Du, Dongping Du, Yuncheng Du, Dongping Du, Yuncheng Du
Atrial Fibrillation (AF) is one of the most common sustained arrhythmia, which can increase the risk of heart failure and stroke. Understanding the complex electrical dynamics of AF and correctly targeting AF sources for ablation therapies remain challenging in clinical practice. This is due to the incapability to reconstruct the electrical dynamic of AF, and lack of efficient approach for AF source identification. This paper builds a multi-sale framework for modeling of the abnormal electrical propagation in AF initiated by triggers from Pulmonary Veins (PVs)...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226849/investigation-of-the-ca-2-response-of-human-hnt-astrocytes-to-laser-removal-of-cellular-processes
#6
Brad J Raos, E Scott Graham, Charles P Unsworth, Brad J Raos, E Scott Graham, Charles P Unsworth, Charles P Unsworth, Brad J Raos, E Scott Graham
We demonstrate, for the first time, UV laser ablative microsurgery as a method for pruning astrocytic processes from live hNT astrocytic networks in vitro. Calcium fluorescence imaging was used to evaluate the cellular response to process ablation. The results showed that ablation of astrocyte processes induced an immediate increase in intracellular calcium level which propagated through the cells cytoplasm as a wave originating from the ablation site. The increased intracellular calcium dissipated from the body of the cell but remained high in the vicinity of the ablation site...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226730/rf-induced-energy-for-partially-implanted-catheters-a-computational-study
#7
Elena Lucano, Micaela Liberti, Tom Lloyd, Francesca Apollonio, Steve Wedan, Wolfgang Kainz, Leonardo M Angelone, Elena Lucano, Micaela Liberti, Tom Lloyd, Francesca Apollonio, Steve Wedan, Wolfgang Kainz, Leonardo M Angelone, Elena Lucano, Leonardo M Angelone, Tom Lloyd, Steve Wedan, Francesca Apollonio, Wolfgang Kainz, Micaela Liberti
Magnetic Resonance Imaging (MRI) is a radiological imaging technique widely used in clinical practice. MRI has been proposed to guide the catheters for interventional procedures, such as cardiac ablation. However, there are risks associated with this procedure, such as RF-induced heating of tissue near the catheters. The aim of this study is to develop a quantitative RF-safety method for patients with partially implanted leads at 64 MHz. RF-induced heating is related to the electric field incident along the catheter, which in turns depends on several variables, including the position of the RF feeding sources and the orientation of the polarization, which are however often unknown...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226545/a-novel-catheter-guidance-algorithm-for-localization-of-atrial-fibrillation-rotor-and-focal-sources
#8
Anthony J Salmin, Prasanth Ganesan, Kristina E Shillieto, Elizabeth M Cherry, David T Huang, Arkady M Pertsov, Behnaz Ghoraani, Anthony J Salmin, Prasanth Ganesan, Kristina E Shillieto, Elizabeth M Cherry, David T Huang, Arkady M Pertsov, Behnaz Ghoraani, Arkady M Pertsov, Behnaz Ghoraani, Anthony J Salmin, Kristina E Shillieto, Elizabeth M Cherry, Prasanth Ganesan, David T Huang
Locating atrial fibrillation (AF) focal and rotor sources can help improve target ablation therapy for AF. However, it remains unclear how to use the information provided by multi-polar diagnostic catheters (MPDC) to locate AF sources. Our aim was to develop a catheter-guidance algorithm to locate AF focal and rotor sources using a conventional MPDC. We simulated a 10 cm × 10 cm atrial tissue with focal and rotor sources using the Nygren et al. ionic model. We modeled a Lasso MPDC with 20-unipole electrodes placed with a spacing of 4...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226544/kurtosis-as-a-statistical-approach-to-identify-the-pivot-point-of-the-rotor
#9
Shivaram P Arunachalam, Elizabeth M Annoni, Siva K Mulpuru, Paul A Friedman, Elena G Tolkacheva, Shivaram P Arunachalam, Elizabeth M Annoni, Siva K Mulpuru, Paul A Friedman, Elena G Tolkacheva, Elena G Tolkacheva, Paul A Friedman, Elizabeth M Annoni, Siva K Mulpuru, Shivaram P Arunachalam
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia that causes stroke affecting more than 2.3 million people in the US. Catheter ablation to terminate AF is successful for paroxysmal AF but suffers limitations with persistent AF patients as current mapping methods cannot identify AF active substrates outside of pulmonary vein region. In this work, we developed a novel Kurtosis based mapping technique that can accurately identify pivot points of the rotors that were induced in ex-vivo isolated rabbit heart...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226543/development-of-a-novel-probabilistic-algorithm-for-localization-of-rotors-during-atrial-fibrillation
#10
Prasanth Ganesan, Anthony Salmin, Elizabeth M Cherry, Behnaz Ghoraani, Prasanth Ganesan, Anthony Salmin, Elizabeth M Cherry, Behnaz Ghoraani, Elizabeth M Cherry, Prasanth Ganesan, Behnaz Ghoraani, Anthony Salmin
Atrial fibrillation (AF) is an irregular heart rhythm that can lead to stroke and other heart-related complications. Catheter ablation has been commonly used to destroy triggering sources of AF in the atria and consequently terminate the arrhythmia. However, efficient and accurate localization of the AF sustaining sources known as rotors is a major challenge in catheter ablation. In this paper, we developed a novel probabilistic algorithm that can adaptively guide a Lasso diagnostic catheter to locate the center of a rotor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226542/towards-patient-specific-modelling-of-lesion-formation-during-radiofrequency-catheter-ablation-for-atrial-fibrillation
#11
Navjeevan Soor, Ross Morgan, Marta Varela, Oleg V Aslanidi, Navjeevan Soor, Ross Morgan, Marta Varela, Oleg V Aslanidi, Marta Varela, Navjeevan Soor, Ross Morgan, Oleg V Aslanidi
Radiofrequency catheter ablation procedures are a first-line method of clinical treatment for atrial fibrillation. However, they suffer from suboptimal success rates and are also prone to potentially serious adverse effects. These limitations can be at least partially attributed to the inter- and intra-patient variations in atrial wall thickness, and could be mitigated by patient-specific approaches to the procedure. In this study, a modelling approach to optimising ablation procedures in subject-specific 3D atrial geometries was applied...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226509/design-of-a-dual-slot-antenna-for-small-animal-microwave-ablation-studies
#12
Tyler J Moon, Christopher L Brace, Tyler J Moon, Christopher L Brace, Christopher L Brace, Tyler J Moon
This study presents the development of a dual-slot antenna for small animal tumor ablation. By using a dual-slot design at 8 GHz, it was hypothesized that smaller and more spherical ablations can be produced. After computer-aided design optimization, antennas were fabricated and ablations performed at 5-20 W for 15-120 s with the objective of creating ablations with a diameter/length aspect ratio of at least 0.9. The new dual-slot design at 8 GHz created significantly more spherical ablations than a commercial antenna at 2...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226508/temperature-monitoring-during-radiofrequency-ablation-of-liver-in-vivo-trials
#13
P Saccomandi, G Frauenfelder, C Massaroni, M A Caponera, A Polimadei, F Taffoni, F M Di Matteo, G Costamagna, F Giurazza, E Schena, P Saccomandi, G Frauenfelder, C Massaroni, M A Caponera, A Polimadei, F Taffoni, F M Di Matteo, G Costamagna, F Giurazza, E Schena, F Taffoni, F M Di Matteo, F Giurazza, E Schena, G Costamagna, A Polimadei, G Frauenfelder, P Saccomandi, C Massaroni
Radiofrequency ablation (RFA) is a minimally invasive procedure used to treat tumors by means of hyperthermia, mostly through percutaneous approach. The tissue temperature plays a pivotal role in the achievement of the target volume heating, while sparing the surrounding healthy tissue from thermal damage. Several techniques for thermometry during RFA are investigated, most of them based on the use of single-point measurement system (e.g., thermocouples). The measurement of temperature map is crucial for the real-time control and fine adjustment of the treatment settings, to optimize the shape and size of the ablated volume...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226507/theranostic-microwave-applicator-suitable-for-minimal-invasive-therapy-of-malignant-tissue
#14
Carolin Reimann, Margarita Puentes, Martin Schusler, Frank Hubner, Babak Bazrafshan, Thomas J Vogl, Rolf Jakoby, Carolin Reimann, Margarita Puentes, Martin Schusler, Frank Hubner, Babak Bazrafshan, Thomas J Vogl, Rolf Jakoby, Rolf Jakoby, Carolin Reimann, Babak Bazrafshan, Thomas J Vogl, Frank Hubner, Margarita Puentes
A microwave applicator is presented that realizes the theranostic approach by providing two operation modes to detect and treat tumor cells, exemplary in the liver. The tool is based on a planar sensor structure with Split Ring Resonators (SRR) as key elements. For the detection, changes in dielectric properties caused by tissue abnormalities are evaluated by analyzing shifts in the resonance frequency of the SRR. For the treatment mode, the input power is amplified to the specific resonance frequency and microwave ablation is performed...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226451/non-invasive-imaging-of-ventricular-activation-during-pacing-and-arrhythmia-methods-and-validation
#15
Long Yu, Steven Pogwizd, Bin He, Long Yu, Steven Pogwizd, Bin He, Bin He, Steven Pogwizd, Long Yu
Cardiovascular disease continued to be a leading killer world widely. Each year, about 400,000 cases of sudden cardiac arrest are reported in the U.S. alone. Clinically, radio-frequency ablative procedure has become widely applied in the treatment of ventricular arrhythmia. Non-invasive approaches have been demonstrated to be able to provide important information on the arrhythmogenesis and potentially assist in the clinical practice. In this work, we develop and validate a novel temporal sparse based imaging method, Cardiac Electrical Sparse Imaging (CESI)...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226000/efficacy-and-safety-of-a-single-radiofrequency-ablation-of-solid-benign-non-functioning-thyroid-nodules
#16
Roberto Cesareo, Andrea Palermo, Valerio Pasqualini, Carla Simeoni, Alessandro Casini, Giuseppe Pelle, Silvia Manfrini, Giuseppe Campagna, Roberto Cianni
Objective: The objective of our study is to evaluate the clinical outcomes and safety of radiofrequency thermal ablation (RFA) for benign thyroid nodules (BTNs) over a 1-year follow-up. Subjects and methods: This is a monocentric retrospective study. Forty-eight patients with solid, non-functioning BTNs were treated by RFA using a 17G internally cooled electrode. We categorized thyroid nodules as small (≤ 12 mL), medium (12 to 30 mL), or large (over 30 mL). BTNs volume reduction, thyroid function, cosmetic and compressive score changes and side effect evaluation at 6 and 12 months were evaluated...
February 13, 2017: Archives of Endocrinology and Metabolism
https://www.readbyqxmd.com/read/28225581/effect-of-sonication-duration-and-power-on-ablation-depth-during-mr-guided-focused-ultrasound-of-bone
#17
Matthew D Bucknor, Eugene Ozhinsky, Rutwik Shah, Roland Krug, Viola Rieke
PURPOSE: To evaluate the effect of differences in sonication duration and power on the size of postcontrast ablation zone following magnetic resonance-guided focused ultrasound (MRgFUS) of bone in a swine femoral bone model. MATERIALS AND METHODS: Experimental procedures received approval from the Institutional Committee on Animal Research. MRgFUS was used to create two thermal lesions in the left femur of six pigs. Each target was subjected to six sonications. 400J of energy was used for each sonication...
February 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28225067/generation-of-gross-chromosomal-rearrangements-by-a-single-engineered-dna-double-strand-break
#18
Zhijun Qiu, Zhenhua Zhang, Anna Roschke, Tamas Varga, Peter D Aplan
Gross chromosomal rearrangements (GCRs), including translocations, inversions amplifications, and deletions, can be causal events leading to malignant transformation. GCRs are thought to be triggered by DNA double strand breaks (DSBs), which in turn can be spontaneous or induced by external agents (eg. cytotoxic chemotherapy, ionizing radiation). It has been shown that induction of DNA DSBs at two defined loci can produce stable balanced chromosomal translocations, however, a single engineered DNA DSB could not...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28224278/the-need-of-prophylactic-central-lymph-node-dissection-is-controversial-in-terms-of-postoperative-thyroglobulin-follow-up-of-patients-with-cn0-papillary-thyroid-cancer
#19
Mehmet Hakan Korkmaz, Bülent Öcal, Güleser Saylam, Erman Çakal, Ömer Bayır, Esra Tutal, Emel Çadallı Tatar
PURPOSE: The objective of this study was to investigate whether prophylactic central lymph node dissection (pCLND) facilitates postoperative thyroglobulin (Tg) follow-up in the patients with papillary thyroid carcinoma (PTC). We also questioned whether radioactive iodine (RAI) remnant ablation provides any further advantage in this regard. METHODS: The records of patients with low-intermediate risk PTC who underwent either only total thyroidectomy (TT) or TT in conjunction with pCLND were reviewed...
February 21, 2017: Langenbeck's Archives of Surgery
https://www.readbyqxmd.com/read/28224045/dj-1-maintains-energy-and-glucose-homeostasis-by-regulating-the-function-of-brown-adipose-tissue
#20
Rong Wu, Xiao-Meng Liu, Jian-Guang Sun, Hong Chen, Jun Ma, Meng Dong, Shengyi Peng, Ji-Qiu Wang, Jian-Qing Ding, Dong-Hao Li, John R Speakman, Guang Ning, Wanzhu Jin, Zengqiang Yuan
DJ-1 protein is involved in multiple physiological processes, including Parkinson's disease. However, the role of DJ-1 in the metabolism is largely unknown. Here we found that DJ-1 maintained energy balance and glucose homeostasisvia regulating brown adipose tissue (BAT) activity. DJ-1-deficient mice reduced body mass, increased energy expenditure and improved insulin sensitivity. DJ-1 deletion also resisted high-fat-diet (HFD) induced obesity and insulin resistance. Accordingly, DJ-1 transgene triggered autonomous obesity and glucose intolerance...
2017: Cell Discovery
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