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Deterre M.,University Paris - Sud | Deterre M.,Sorin Group | Lefeuvre E.,University Paris - Sud | Zhu Y.,University Paris - Sud | And 4 more authors.
Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS) | Year: 2013

This paper introduces a novel energy harvesting technique and an associated packaged device aimed at powering intracardiac active medical devices by scavenging energy from ordinary blood pressure variations. We present the innovative concept of a micro-bellows packaged implant that deforms due to cyclic blood pressure variations in the cardiac cavities. This bellows transmits stresses on a spiral-shaped piezoelectric transducer that converts mechanical deformations into electric energy. The particular shapes of the different components (bellows and spiral) are designed to dramatically increase the mechanical energy that is harvested. The miniature bellows design, fabrication through electrodeposition for high compliance and hermeticity, and experimental characterization are presented. The specific challenges that arise in spiral shapes piezoelectric harvesters working in bending mode are discussed and we present a method to predict the non-trivial optimal electrode placements for maximum efficiency. This design process is completed by an associated microfabrication method and three types of piezoelectric bimorph spiral samples with doubled-sided microstructured electrode patterns are presented. The experimental performances of these prototypes are confronted to numerical simulation. A power of 4.15 μW/cm3 at 1.5 Hz has been obtained for the best design and we predict that tens of micro-Watts per cubic centimeter could be obtained using similar design process and material. © 2013 IEEE.


Testa A.,Expansion Centres dHemodialyse de lOuest | Dejoie T.,Nantes University Hospital Center | Lecarrer D.,Nantes University Hospital Center | Wratten M.,Sorin Group | And 2 more authors.
Blood Purification | Year: 2010

In this work we investigated the acute effects of hemodiafiltration with endogenous reinfusion (HFR therapy) on the removal of free immunoglobulin light chains (FIgLCs), which may be considered members of the family of uremic toxins. In two groups of patients - group 1 (polyclonal FIgLCs production) and group 2 (monoclonal plasma cell proliferative disorders), we analyzed the pre- and postdialysis levels of κ- and λ-chains. In group 1 we observed a significant reduction of FIgLCs (p < 0.01). A similar trend was found in patients of group 2 only for κ-chains. The FIgLCs removal ratio was significantly higher for κ- than λ-chains in the two patient groups. In vitro data showed affinity of macroporous resin to binding FIgLCs. Our results show that the HFR therapy could be effective in removing FIgLCs, particularly κ-chains in dialysis patients with polyclonal and monoclonal FIgLCs production. Copyright © 2010 S. Karger AG.


Lefeuvre E.,University Paris - Sud | Risquez S.,University Paris - Sud | Woytasik M.,University Paris - Sud | Deterre M.,Sorin Group | And 2 more authors.
2013 25th International Conference on Microelectronics, ICM 2013 | Year: 2013

This paper presents devices for harvesting energy from regular blood pressure variation in heart cavities. Specific challenges of this concept are analyzed. First, a very flexible and hermetic packaging solution is proposed. Then, piezoelectric and electrostatic transducers are conceived and optimized for the pacemaker application. According to our simulations and experiments, the proposed devices should provide the targeted electrical energy of 10 μJ per heartbeat in real environment. © 2013 IEEE.


Ugalde H.R.,French Institute of Health and Medical Research | Ugalde H.R.,University of Rennes 1 | Le Rolle V.,French Institute of Health and Medical Research | Le Rolle V.,University of Rennes 1 | And 10 more authors.
2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014 | Year: 2014

Vagus nerve stimulation (VNS) is a potential therapeutic approach in a number of clinical applications. Although VNS is commonly delivered in an open-loop approach, it is now recognized that closed-loop approaches may be necessary to optimize the therapy and minimize side effects of neuro-stimulation devices. In this paper, we describe a prototype system for real-time control of the instantaneous heart rate, working synchronously with the heart period. As a first step, an on-off control method has been integrated. The system is evaluated on one sheep with induced heart failure, showing the interest of the proposed approach. © 2014 IEEE.


Deterre M.,CNRS Fundamental Electronics Institute | Deterre M.,Sorin Group | Lefeuvre E.,CNRS Fundamental Electronics Institute | Zhu Y.,CNRS Fundamental Electronics Institute | And 3 more authors.
Journal of Microelectromechanical Systems | Year: 2014

This paper presents the design, fabrication, and tests of a microspiral-shaped piezoelectric energy harvester and its associated microfabricated packaging that collects energy from ordinary blood pressure variations in the cardiac environment. This device could become a life-lasting, miniaturized energy source for active implantable medical devices such as leadless pacemakers. We present the concept and tested prototypes of 10 μm thin and ultra-flexible electrodeposited microbellows (6 mm diameter, 21 mm 3 volume) as a new type of implant packaging. It enables direct blood pressure harvesting and permits a high efficiency of energy transfer to a transducer operating in quasi-static mode and hence adaptable and unaffected by frequent heartbeat frequency changes. Spiral-shaped piezoelectric transducers are introduced for their flexibility and large incoming mechanical energy. Non-trivial optimal electrodes placement and best spiral design parameters are studied and discussed. Three types of spiral prototypes (11 mm3 volume each) with doubled-sided microstructured electrode patterns are presented and characterized. A power of 3 μ J/cm3/heartbeat and a transduction efficiency of 5.7× 10-3 have been obtained for the best designs at 1.5 Hz and we predict that twice as much could be obtained using similar design process and material. Through implementing smart adapted electronic circuits, a potential additional tenfold increase in power output could be achieved, which would be sufficient to power a leadless pacemaker. © 2013 IEEE.


Jamieson W.R.E.,University of British Columbia | Forgie W.R.,Dalhousie University | Hayden R.I.,University of British Columbia | Langlois Y.,McGill University | And 4 more authors.
Thoracic and Cardiovascular Surgeon | Year: 2010

Background: Documentation of the hemodynamics of the Mitroflow aortic pericardial bioprosthesis has been incomplete. The aim of the study was to provide reference effective orifice areas for the implant calculation of effective orifice area indexes to avoid prosthesis-patient mismatch. Methods: Echocardiograms were evaluated in 55 patients (39 females, 16 males), mean age 77.0±6.9 years (range 5190 years). The mean time of the studies was 11.0 months. The prosthesis sizes and numbers evaluated were 19mm (n=13), 21mm (n=19), 23mm (n=13) and 25mm (n=10). Results: Peak aortic velocities averaged from 2.2 to 2.7m/sec, mean gradients from 10.6 to 15.1mmHg, peak gradients from 20.7 to 29.7mmHg, and effective orifice area (EOA) from 1.4 to 1.8cm 2. When accounting for the subaortic velocity, mean gradients averaged from 7.5 to 10.0mmHg, and peak gradients averaged 15.1 to 23.5mmHg. The effective orifice area indexes ranged from 0.8 to 1.0cm2/m 2. The mean postoperative left ventricular mass index was 101.6gm/m2. Conclusions: The in vivo effective orifice areas by valve size of the Mitroflow aortic pericardial bioprosthesis provide the opportunity of avoiding obstructive characteristics for all valve sizes, including optimizing the management of the small aortic annulus. © Georg Thieme Verlag KG Stuttgart.


Duchateau N.,University of Barcelona | Duchateau N.,Institute dInvestigacions Biomediques August Pi I Sunyer | Duchateau N.,University Pompeu Fabra | Sitges M.,University of Barcelona | And 23 more authors.
International Journal of Cardiovascular Imaging | Year: 2014

In cardiac resynchronization therapy (CRT), specific changes in motion/deformation happen with left-bundle- branch-block (LBBB) and following treatment. However, they remain sub-optimally studied. We propose a two-fold improvement of their characterization. This includes controlling them through an experimental model and using more suitable quantification techniques. We used a swine model of acute LBBB and CRT with/without chronic infarct (pure-LBBB: N = 11; LBBB + left-anterior- descending infarct: N = 11). Myocardial displacement, velocity and strain were extracted from short-axis echocardiographic sequences using 2D speckle-tracking. The data was transformed to a single spatiotemporal system of coordinates to perform subject comparisons and quantify pattern changes at similar locations and instants. Pure-LBBB animals showed a specific intra-ventricular dyssynchrony pattern with LBBB (11/11 animals), and the recovery towards a normal pattern with CRT (10/11 animals). Pattern variability was low within the pure-LBBB population, as quantified by our method. This was not correctly assessed by more conventional measurements. Infarct presence affected the pattern distribution and CRT efficiency (improvements in 6/11 animals). Pattern changes correlated with global cardiac function (global circumferential strain) changes in all the animals (corrected: P LBBBvsBaseline < 0.001, PCRTvsBaseline = NS; non-corrected: PLBBBvsBaseline = NS, PCRTvsBaseline = 0.028). Our LBBB/CRT experimental model allowed controlling specific factors responsible for changes in mechanical dyssynchrony and therapy. We illustrated the importance of our quantification method to study these changes and their variability. Our findings confirm the importance of myocardial viability and of specific LBBB-related mechanical dyssynchrony patterns. © Springer Science+Business Media 2014.


Bonnet S.,CEA Grenoble | Rubeck C.,CEA Grenoble | Agache V.,CEA Grenoble | Bourgerette A.,CEA Grenoble | And 8 more authors.
International IEEE/EMBS Conference on Neural Engineering, NER | Year: 2013

This paper describes the design, microfabrication, characterization and experimental validation of a 6-contact cuff electrode embedded in a parylene-based flexible support. This type of electrode is well suited for both peripheral nerve recording and stimulation and offers improved spatial selectivity as compared to conventional ring electrodes. Both measured and modeled impedance spectra are detailed. An experimental validation is performed on an earthworm with both multi-contact cuff (MCC) electrode recording and ring stimulation electrodes. Single fiber action potentials, elicited by the electrical stimulation, are well discriminated on the 6 contacts. Spontaneous activity is also recorded with burst of spikes. © 2013 IEEE.


Rigol M.,University of Barcelona | Solanes N.,University of Barcelona | Fernandez-Armenta J.,University of Barcelona | Silva E.,University of Barcelona | And 9 more authors.
Journal of Cardiovascular Translational Research | Year: 2013

Animal models that mimic human electrical and mechanical dyssynchrony often associated with chronic heart failure would provide an essential tool to investigate factors influencing response to cardiac resynchronization therapy. A standardized closed-chest porcine model of left bundle branch block (LBBB) was developed using 16 pigs. Radiofrequency applications were performed to induce LBBB, which was confirmed by QRS widening, a surface electrocardiogram pattern concordant with LBBB, and a prolonged activation time from endocardial. Echocardiography confirmed abnormal motion of the septum, which was not present at the baseline echocardiogram. High susceptibility of pigs to ventricular fibrillation during the endocardial ablation was overcome by applying high-rate pacing during radiofrequency applications. This is the first study to devise a closed-chest porcine model of LBBB that closely reproduces abnormalities found in patients with electrical and mechanical cardiac dyssynchrony, and provides a useful tool to investigate the basic mechanisms underlying cardiac resynchronization therapy benefits in heart failure. © 2013 Springer Science+Business Media New York.


Bottausci F.,CEA Grenoble | Baleras F.,CEA Grenoble | Pudda C.,CEA Grenoble | Cochet M.,CEA Grenoble | And 10 more authors.
International IEEE/EMBS Conference on Neural Engineering, NER | Year: 2015

This paper describes the fabrication and the packaging of a flexible parylene-based multi-contact electrode embedded in a silicone-based cuff. This type of electrode is well suited for peripheral nerve recording and offers improved spatial selectivity. We conducted mechanical and electrical tests for assessing the reliability by using an accelerated lifetime protocol. Test structures made with platinum sandwiched with parylene C were designed. The accelerated lifetime soaking tests in phosphate buffered saline (PBS) solution at 67°C showed a longer life time (approximatively 4.5 years) with a dehydration bake introduction in the process flow and a parylene thickness increase. A specific test bench was developed for the mechanical cycling and for evaluating the mechanical robustness of the thin film devices. © 2015 IEEE.

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