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Device Type (device + type)

Distribution by Scientific Domains

Medical Sciences	66%

Selected Abstracts

Transcatheter Intracardiac Echocardiography-Assisted Closure of Interatrial Shunts: Complications and Midterm Follow-Up

ECHOCARDIOGRAPHY, Issue 2 2009
Gianluca Rigatelli M.D.
Objective: It has been suggested that intracardiac echocardiography (ICE) improves the safety and effectiveness of transcatheter device-based closure of interatrial shunts, but the impact of this technique on midterm follow-up is unknown. We sought to prospectively evaluate midterm follow-up results of ICE-aided transcatheter closure of interatrial shunts in adults. Methods: Over a 48-month period, we prospectively enrolled 140 consecutive patients (mean age 43 ± 15. 5 years, 98 females) who had been referred to our center for catheter-based closure of interatrial shunts. All patients were screened with transesophageal echocardiography (TEE) before the operation. Patients who met the inclusion criteria underwent ICE study and attempted closure. Immediate success rates, predischarge occlusion rates, complication rates, as well as fluoroscopy and procedural times, patients' radiological exposure, midterm complication rates, and midterm occlusion rates were evaluated. Results: One hundred patients out of 140 (71.4%) underwent an attempt at transcatheter closure. After ICE study and measurements, the TEE-planned device type and size was changed in 31 patients with patent foramen ovale whereas the TEE-planned device size was changed in 41 patients with atrial septal defect (globally 72%). Procedural success rate, predischarge occlusion rate, and complication rate were 99, 90.7, and 12%, respectively. On mean follow-up of 36.6 ± 14.8 months the follow-up occlusion rate was 96.5%. No aortic erosion or device thrombosis was observed. Conclusions: ICE-guided interatrial shunt transcatheter closure is safe and effective and appears to have excellent midterm results thus avoiding the complications caused by device oversizing, such as aortic erosion and device thrombosis. [source]

Effect of flow field heterogeneity in coagulators on aggregate size and structure

AICHE JOURNAL, Issue 10 2010
Lyonel Ehrl
Abstract Aggregate size and structure were investigated under turbulent conditions in stirred tank (ST) and Taylor,Couette-type (TC-type) devices. Root-mean-square radius of gyration, ,Rg,, and zero-angle intensity of scattered light, I(0), were acquired as a function of stirring intensity, characterized by an experimentally obtained average hydrodynamic stress, ,,,exp, determined by torque measurements. Evaluating aggregate images revealed that aggregate structure and shape are independent of the device type. However, in TC-type devices, the aggregates grow to three to four times larger sizes than inside ST, although the same ,,,exp was used in both coagulators. As confirmed by computational fluid dynamics, this can be attributed to the differences in the maximum hydrodynamic stress in ST compared with those in TC-type devices. In contrast, the power-law scaling of ,Rg, and I(0) with ,,,exp is preserved for all investigated devices, with an exponent approximately equal to ,0.5 and ,0.7, respectively. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source]

Magnetic Resonance Imaging of Implantable Cardiac Rhythm Devices at 3.0 Tesla

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2008
J. ROD GIMBEL M.D.
Background: A relaxation of the prohibition of scanning cardiac rhythm device patients is underway, largely because of the growing experience of safe scanning events at 1.5T. Magnetic resonance imaging (MRI) at 3T is becoming more common and may pose a different risk profile and outcome of MRI of cardiac device patients. Methods: No restrictions were placed on pacemaker dependency, region scanned, device type, or manufacturer. Sixteen scans at 3T were performed with an electrophysiologist present on 14 patients with a variety of devices from various manufacturers. An "MRI-S" strategy was used. Multimodal monitoring was required. Device interrogation was performed prior to, immediately after, and 1,3 months after the MRI. For nonpacemaker-dependent device patients, attempts were made to turn all device features off (with OOO programming the goal) conceptually rendering the device "invisible." In pacemaker-dependent patients, the device was programmed to asynchronous mode at highest output for the duration of the scan with the goal of rendering the device conceptually "invulnerable" to MRI effects. The specific absorption rate (SAR) was limited to 2W/kg. Results: All patients were successfully scanned. No arrhythmias were noted. No significant change in the programmed parameters, pacing thresholds, sensing, impedance, or battery parameters was noted. The insertable loop recorder (ILR) recorded prolonged artifactual asystole during MRI. One patient noted chest burning during the scan. Conclusions: Device patients may undergo carefully tailored 3T MRI scans when pre-MRI reprogramming of the device occurs in conjunction with extensive monitoring, supervision, and follow-up. [source]

Inkjet Printing,Process and Its Applications

ADVANCED MATERIALS, Issue 6 2010
Madhusudan Singh
Abstract In this Progress Report we provide an update on recent developments in inkjet printing technology and its applications, which include organic thin-film transistors, light-emitting diodes, solar cells, conductive structures, memory devices, sensors, and biological/pharmaceutical tasks. Various classes of materials and device types are in turn examined and an opinion is offered about the nature of the progress that has been achieved. [source]

Cryogen spray cooling: Effects of droplet size and spray density on heat removal

LASERS IN SURGERY AND MEDICINE, Issue 2 2001
Brian M. Pikkula BS
Abstract Background and Objective Cryogen spray cooling (CSC) is an effective method to reduce or eliminate non-specific injury to the epidermis during laser treatment of various dermatological disorders. In previous CSC investigations, fuel injectors have been used to deliver the cryogen onto the skin surface. The objective of this study was to examine cryogen atomization and heat removal characteristics of various cryogen delivery devices. Study Design/Materials and Methods Various cryogen delivery device types including fuel injectors, atomizers, and a device currently used in clinical settings were investigated. Cryogen mass was measured at the delivery device output orifice. Cryogen droplet size profiling for various cryogen delivery devices was estimated by optically imaging the droplets in flight. Heat removal for various cryogen delivery devices was estimated over a range of spraying distances by temperature measurements in an skin phantom used in conjunction with an inverse heat conduction model. Results A substantial range of mass outputs were measured for the cryogen delivery devices while heat removal varied by less than a factor of two. Droplet profiling demonstrated differences in droplet size and spray density. Conclusions Results of this study show that variation in heat removal by different cryogen delivery devices is modest despite the relatively large difference in cryogen mass output and droplet size. A non-linear relationship between heat removal by various devices and droplet size and spray density was observed. Lasers Surg. Med. 28:103,112, 2001. © 2001 Wiley-Liss, Inc. [source]

A Comparison of ICD Implantations in the United States Versus Italy

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2007
STEVEN M. GREENBERG M.D.
Background: The benefits conferred by implantable cardioverter defibrillators (ICDs) have expanded to primary prevention. The advancements in ICD therapy (ACT) registry in the United States and the Italian ICD registry (IIR) examine changing trends in ICD implantation in their respective countries. Data from these registries may be useful for comparison of transcontinental differences in ICD utilization. Methods: This study includes initial implantations in patients enrolled in ACT and IIR. A comparative analysis was performed for device indications based on primary or secondary prevention. Sub-group analyses by device types (single, dual chamber, or cardiac resynchronization) were performed. Results: This analysis included 4,547 primary implantations in ACT and 6,491 in IIR. The groups were similar with respect to age. There were 82% primary and 18% secondary prevention indications in ACT, versus 42% primary and 58% secondary prevention indications in IIR (P < 0.001). There was a significantly higher rate of dual chamber ICD implants in ACT than in IIR for both primary (35.7% vs 23.7%, P < 0.001) and secondary prevention (52.3% vs 36.9%, P < 0.001). Conversely, more CRT-D were implanted in IIR than in ACT (primary prevention 46.5% vs 32.0%; secondary prevention 29.0% vs 13.0%, P < 0.001). Conclusions: Significant differences were observed in the types of indications for ICDs between ACT and IIR. Device prescription differed significantly between countries. The specific reasons for differences in ICD implantation patterns in these two countries are unclear. These observations warrant further investigations to determine if these differences are associated with different qualities of life and clinical outcomes. [source]