Although accurate modeling of the thermal performance irrigated-tip electrodes in radiofrequency cardiac ablation requires solution a triple coupled problem involving simultaneous electrical conduction, heat transfer, and fluid dynamics, certain cases it is difficult to combine software with expertise necessary solve these problems, so that reduced models have be considered. We here focus on model which avoids dynamics by setting constant temperature at electrode tip. Our aim was compare...

Luminal esophageal temperature (LET) monitoring is commonly employed during catheter ablation of atrial fibrillation (AF) to detect high temperatures radiofrequency (RF) delivery along the posterior wall left atrium. However, it has been recently suggested that in some cases probe itself may serve as an RF "antenna" and promote thermal injury. The aim this study was assess electrical interferences induced by different types commercially available probes (ETPs) on ablation.In study, we...

Advanced constructive materials, such as electrochromic smart windows (ECSWs) and building integrated photovoltaics modules (BIPV), can improve the energy efficiency in buildings. A good optical thermal characterization of these elements is necessary to assess compare their performance. The existing testing procedures for glass buildings are applied both types elements, it considered that while suitable allow comparison two technologies, indoor not valid BIPV nor ECSWs, because temperature...

Purpose: The thermal effect of the intramyocardial blood perfusion on size lesions created by radiofrequency cardiac ablation (RFCA) has not been adequately studied to date. Our objective was assess impact including this phenomenon in RFCA computer modelling terms lesion depth created.Methods: A model built and simulations were conducted term bioheat equation. This mimics flow (i.e., perfusion) wall at site which is being hence represents a heat removing mechanism. When considered, rates...

Purpose Most modeling studies on radiofrequency cardiac ablation (RFCA) are based limited-domain models, which means the computational domain is restricted to a few centimeters of myocardium and blood around active electrode. When mimicking constant power RFCA procedures (e.g., atrial fibrillation ablation) it important know how much absorbed electrode in rest tissues before reaching dispersive electrode.Methods 3D thorax full models were built by progressively incorporating different organs...

Radiofrequency (RF)-induced ablation can be carried out inside ducts and vessels by simultaneously dragging a bipolar catheter while applying RF power. Our objective was to characterize the relation between pullback speed, impedance progress, temperature distribution.We built numerical model including catheter, which is dragged duct power applied pair of electrodes. The solved triple-coupled electrical, thermal, mechanical problem. Lesions were assessed an Arrhenius model. model's thermal...

Background: Pulsed Electric Field (PEF) ablation has been recently proposed to ablate cardiac ganglionic plexi (GP) aimed treat atrial fibrillation. The effect of metal intracoronary stents in the vicinity electrode not yet assessed. Methods: A 2D numerical model was developed accounting for different tissues involved PEF with an irrigated device. coronary artery (with and without a stent) considered near source (0.25 1 mm separation). 1000 V/cm threshold used estimate ‘PEF-zone’. Results:...

There are many areas where Wireless Sensor Networks (WSN) can offer innovative solutions for environmental monitoring applications and the meteorological community, but due to their complexity in terms of energy constraints low performance devices, very few real deployments be found. In this paper we will explain detail design, implementation evaluation a sparse WSN that has been working maintenance-free over 12 months. The network designed purposes, several motes, attached lampposts,...

Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application currently aimed at creating "strip lesion" to connect the electrode tips; however, electrical and thermal performance during bipolar unknown. The objective of this paper was study temperature electric field distributions PRF. Methods: authors developed computer models assess possible ablative effect caused by accumulated spikes, along with any electroporation effects field. also modeled...

Currently the appearance of really low power wireless transceivers is motivating use renewable energies to embedded sensor nodes in many applications. Nevertheless, energy storage and its degradation still keep on being main issues design any battery powered device. We present an autonomous source based a new system architecture, which uses scavenging replenish two different rechargeable buffers instead conventional single one. Combining appropriately degradable large backup (Lithium-Ion)...

Externally irrigated radiofrequency (RF) electrodes have been widely used to thermally ablate tumors in surface tissue and coagulate the transection plane during a surgical resection. As far as we know, no mathematical model has yet developed study electrical thermal performance of these electrodes, especially role saline layer that forms around electrode. Numerical models TissueLink device DS3.0 (Salient Surgical Technologies, Portsmouth, NH, USA) were developed. Irrigation was modeled...

Background: Baseline impedance, radiofrequency current, and impedance drop during catheter ablation are thought to predict effective lesion formation. However, quantifying the contributions of local versus remote impedances provides insights into limitations indices using those parameters. Methods: An in silico model left atrial was used based on human thoracic measurements solved for (1) initial (Z), (2) percentage power delivered myocardium blood (3) total (4) heating, (5) size after a 25...

Even though the preliminary experimental data suggests that cardiac Pulsed Field Ablation (PFA) could be superior to radiofrequency ablation (RFA) in terms of being able ablate viable myocardium separated from catheter by collagen and fat, as yet there is no formal physical-based analysis describes process which fat can affect electric field distribution. Our objective was thus determine electrical impact intramyocardial during PFA means computer modeling. Computer models were built...

Impedance plethysmography applied to the head by using a pair of electrodes attached scalp surface is known as bipolar Rheoencephalography or REG I and was originally proposed measure changes in cerebral blood volume related heartbeat. soon discarded favor other configurations, since most signal shown be heavily contaminated extracranial flow. The main goal this study identify compare part caused flow with that originating from non-extracranial sources.A clinical involving thirty-six healthy...

The outcomes of catheter ablation scar-mediated ventricular tachycardia (VT) remain far from perfect. presence fat as a component the underlying substrate for VT could be relevant since this entity can seriously impede passage RF current due to its low electrical conductivity.Computer models were built in order investigate means by which spatial heterogeneity different tissues represented within infarct zone, including viable myocardium, fibrous tissue, and fat, influence temperature...

To model the evolution of peak temperature and volume damaged esophagus during after radiofrequency (RF) ablation using low power-moderate duration (LPMD) versus high power-short (HPSD) or very power-very short (VHPVSD) settings.An in silico simulation RF accounting for left atrial wall thickness, nearby organs tissues, as well catheter contact force. The used Arrhenius equation to derive a thermal damage estimate esophageal over time application under conditions LPMD (30 W, 20 s), HPSD (50...

A foveated camera has been designed and fabricated. The is implemented using a new CMOS sensor which incorporates log-polar transformation. This transformation specially interesting properties for image processing including the information selective reduction some invariances. structure of this permits an individual access to each pixel, exactly in same way that RAM. very property makes big difference between CCD based camera. In other hand, nature implies important fixed pattern noise due...

A new foveated CMOS image sensor has been designed and fabricated. The photocell elements transform the light into current, then, in a continuous way, voltage without charge integration. This kind of sensing cell already employed sensors for normal cameras, but never sensors. presented tries to emulate human eye pixel resulting with space variant distribution pixels. Consequences this are different size matrix, non orthogonal shapes that integrate pixel, and, as result, response every...

In spite of the great efforts made by scientific community, up to now there is no agreement about rheoencephalography (REG) capability reflect cerebral blood flow (CBF). Moreover, a standard procedure and optimal electrode arrangement have not been established yet. previous study, we found, using classical four-shell spherical model head solving it numerical methods that, theoretically, could exist an register REG II free extracranial contribution. this paper, studied influence scalp...