Feng S.,University of Houston |
Qiang R.,Micro Engineering Inc. |
Kainz W.,U.S. Food and Drug Administration |
Chen J.,University of Houston
IEEE Transactions on Microwave Theory and Techniques | Year: 2015
This paper presents a novel technique for efficient evaluation of magnetic resonance imaging (MRI)-induced electric fields or induced voltages in the vicinity of implanted metallic leads. The technique is based on the reciprocity theorem in conjunction with the Huygens Principle. This approach allows one to decouple the micro-scale metallic lead simulation/measurement from the macro-level phantom human simulations within the MRI scanners. Consequently, the estimation of MRI-induced heating on an implanted lead, and the induced voltage on the pacemaker device can be greatly simplified. In addition, this method clearly explains the induced lead heating mechanism during MRI procedures. Several numerical examples, as well as measurement results are given to demonstrate the efficiency and accuracy of this method. © 1963-2012 IEEE.
Senda K.,Tokyo University of Agriculture and Technology |
Senda K.,Micro Engineering Inc. |
Matsuda T.,Tokyo University of Agriculture and Technology |
Tanaka K.,Tokyo University of Agriculture and Technology |
Usui H.,Tokyo University of Agriculture and Technology
IEICE Transactions on Electronics | Year: 2013
Fluoropolymer thin films were prepared by the ionassisted vapor deposition polymerization (IAD) of 2-(perfluorohexyl) ethylacrylate (Rf-6). The adhesion strength of the film to substrates was estimated by sonicating the films in water and by immersing the films into dichloro-pentafluoro propane (HCFC225). The Rf-6 polymer films by IAD showed stronger adhesion to glass compared to a spin-coated Teflon AF film. The adhesion strength was improved with increasing ion energy Eion of IAD. The IAD films showed superior adhesion to PET surface compared to the glass substrate. The Rf-6 polymer film was effective as a single-layer antireflective coating. The refractive index of the film was 1.368 (λ = 546 nm), which increased slightly with increasing E ion. IAD can be a promising method to prepare fluoropolymer thin films due to the solvent-less process and the flexibility in controlling the film characteristics by the ion energy. Copyright © 2013 The Institute of Electronics, Information and Communication Engineers.
Lian J.,Micro Engineering Inc.
Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology | Year: 2013
The aim of this study is to develop a new feature for automatic biventricular capture verification in cardiac resynchronization therapy (CRT) devices, by means of morphological analysis of the intracardiac electrogram (IEGM). The algorithm performs capture classification based on a novel adaptive signed correlation index (ASCI), which measures morphological similarity between the post-pace IEGM and a template waveform representing captured paces. To evaluate the performance of the algorithm, CRT pacemakers were implanted in six dogs. During a mean follow-up of 23 days, 175 biventricular threshold tests were conducted with various configurations of pace/sense polarities. Biventricular IEGMs were recorded and downloaded for offline analysis. Template signals for each pace/sense configuration in each chamber were created for individual dogs during the first follow-up. Each pace was annotated for capture or non-capture by visual examination of the IEGM. A total of 9991 capture paces and 4474 non-capture paces were included for morphological analysis. The calculated ASCI values were well separated for capture and non-capture paces irrespective of right/left pacing chambers, pace/sense configurations, pacing amplitude, individual dogs, and temporal proximity of the capture templates. Overall, the classification accuracy of the algorithm remained ≥99% for any ASCI cut-off value choosing between 0.18 and 0.52. This study demonstrated the feasibility to perform automatic biventricular capture verification based on morphological analysis of the IEGM.
Micro Engineering Inc. | Date: 2011-10-19
Micro Engineering Inc. | Date: 2011-12-22
By exhausting a gas in a second space (S