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Clamart, France

Donal E.,Rennes University Hospital Center | Donal E.,French Institute of Health and Medical Research | Donal E.,University of Rennes 1 | Giorgis L.,French Institute of Health and Medical Research | And 15 more authors.
Europace | Year: 2011

Aims: Optimization of cardiac resynchronization therapy (CRT) requires the gathering of cardiac functional information. An accurate timing of the phases of the cardiac cycle is key in the optimization process. Methods and results: We compared Doppler echocardiography to an automated system, based on the recording of sonR (formerly endocardial acceleration), in the detection of mitral and aortic valves closures and measurements of the duration of systole and diastole. We prospectively studied, under various conditions of cardiac stimulation, 75 recipients of CRT systems (69% men), whose mean age was 72 ± 9.2 years, left ventricular ejection fraction 35 ± 11%, baseline QRS duration 154 ± 29 ms, and New York Heart Association functional class 3.0 ± 0.7. We simultaneously recorded (i) sonR, detected by a non-invasive piezoelectric micro-accelerometer sensor clipped onto an electrode located in the parasternal region, (b) electrocardiogram, and (c) Doppler audio signals, using a multichannel data acquisition and analysis system. The correlation between timing of mitral and aortic valve closure by sonR vs. Doppler signals was examined by linear regression analysis. Correlation coefficients and the average absolute error were calculated. A concordance in the timing of the mitral (r = 0.86, error =9.7 ms) and aortic (r = 0.93, error =9.7 ms) valves closure was observed between the two methods in 94 of patients. Similarly, sonR and the Doppler-derived measurements of systolic (r = 0.85, error =13.4 ms) and diastolic (r = 0.99, error = 12 ms) interval durations were concordant in 80% of patients. Conclusion: A high concordance was found between sonR and the cardiac ultrasound in the timings of aortic and mitral valve closures and in the estimation of systolic and diastolic intervals durations. These observations suggest that sonR could be used to monitor cardiac function and adaptively optimize CRT systems. © The Author 2010.

MULTICARDE is a Tecsan ANR exploratory project that was launched in 2007 and ended up in 2009. ELA Medical (SORIN Group) and the CEA-Leti were associated for this development. The project aims at enhancing the therapy for congestive heart failure based on biventricular electrical resynchronization therapy. Several studies proved the efficiency of this therapy, which remains subjected to the good positioning of the left pacing lead. The MULTICARDE project develops a programmable multi-electrodes pacing to improve the hemodynamic status of the patient. Multiple constraints must be taken into account for this kind of project, such as the power consumption, the size and the interoperability towards leads' standards. To address these requirements an innovative collective packaging process was developed to integrate electronics inside the lead. © 2010 Elsevier Masson SAS. All rights reserved.

Poree F.,French Institute of Health and Medical Research | Poree F.,University of Rennes 1 | Kachenoura A.,French Institute of Health and Medical Research | Kachenoura A.,University of Rennes 1 | And 8 more authors.
IEEE Transactions on Biomedical Engineering | Year: 2013

This study proposes a method to facilitate the remote follow up of patients suffering from cardiac pathologies and treated with an implantable device, by synthesizing a 12-lead surface ECG from the intracardiac electrograms (EGM) recorded by the device. Two methods (direct and indirect), based on dynamic time-delay artificial neural networks (TDNNs) are proposed and compared with classical linear approaches. The direct method aims to estimate 12 different transfer functions between the EGM and each surface ECG signal. The indirect method is based on a preliminary orthogonalization phase of the available EGM and ECG signals, and the application of the TDNN between these orthogonalized signals, using only three transfer functions. These methods are evaluated on a dataset issued from 15 patients. Correlation coefficients calculated between the synthesized and the real ECG show that the proposed TDNN methods represent an efficient way to synthesize 12-lead ECG, from two or four EGM and perform better than the linear ones. We also evaluate the results as a function of the EGM configuration. Results are also supported by the comparison of extracted features and a qualitative analysis performed by a cardiologist. © 1964-2012 IEEE.

Tillocher T.,University of Orleans | Lefaucheux P.,University of Orleans | Boutaud B.,Sorin CRM | Dussart R.,University of Orleans
Journal of Micromechanics and Microengineering | Year: 2014

Titanium is increasingly used as a platform material in microdevices dedicated to biological and bio medical applications. Existing processes for titanium deep etching use a chlorine based chemistry. This paper reports on a low reproducibility for such chemistries when titanium samples are glued onto a silicon carrier wafer. In this case, a SiOCl layer redeposits on the chamber walls as well as on the sample surface. This leads to a decrease of the etch rate and the formation of a very high roughness with a similar morphology as black silicon. The alternated process for the deep etching of titanium (APETi) described in this paper has been designed to improve the overall reproducibility by preventing high roughness formation. It is a time-multiplexed process where Cl2/Ar plasma steps are alternated with SF6 plasma steps. The first step aims at etching with vertical walls (anisotropy) while the second aims at reducing the roughness by removing SiOCl from the sample surface. © 2014 IOP Publishing Ltd.

Cinquin P.,French National Center for Scientific Research | Cosnier S.,French National Center for Scientific Research | Belgacem N.,Grenoble Institute of Technology | Cosnier M.L.,CEA Grenoble | And 2 more authors.
Journal of Physics: Conference Series | Year: 2013

An Implantable BioFuel Cell (IBFC) is a device that produces power only from the chemicals that are naturally occurring inside the body. We have been working on two approaches to creating an IBFC. The first approach is to use chemicals such as glucose and oxygen to provide the fuel for an enzymatic IBFC. The second approach is to use electrolytes such as sodium to provide the fuel for a biomimetic IBFC. © Published under licence by IOP Publishing Ltd.

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