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Sample records for electro-mechanical implantable left

  1. Electro-Mechanical Stimulation of the Cochlea by Vibrating Cochlear Implant Electrodes.

    Science.gov (United States)

    Mueller, Mathias; Salcher, Rolf; Majdani, Omid; Lenarz, Thomas; Maier, Hannes

    2015-12-01

    Electro-acoustic stimulation (EAS) of the cochlea uses the preserved residual low-frequency hearing for acoustic stimulation in combination with electrical stimulation. The acoustic low-frequency component is amplified and high-frequency hearing is enhanced by a cochlear implant (CI). In this work, the feasibility of EAS by the floating mass transducers (FMTs) firmly attached to the implanted electrode was investigated and the achieved stapes displacement was compared with sound stimulation. Experiments were performed in eight fresh human temporal bones compliant to the ASTM standard (F2504-5). Four EAS custom-made prototypes (EAS-CMP) were tested, consisting of standard MED-EL CI electrodes with Vibrant Soundbridge (VSB) FMTs or a Bonebridge (BB) FMT tightly molded to the electrode in different orientations. The stapes footplate (SFP) response to EAS-CMP stimulation and sound stimulation was measured using a Laser Doppler Vibrometer (LDV). The SFP displacement amplitudes achieved by EAS-CMP stimulation were calculated to 1 VRMS FMT input and were pair-wise statistically compared between prototypes yielding no significant differences at frequencies ≤1 kHz. At frequencies ≤1 kHz stimulation by the BB FMT resulted in a flat and potentially highest SFP displacement amplitude of approximately -40 dB re μm at 1 VRMS input voltage. Estimated equivalent sound pressure levels achieved by the BB FMT prototype were approximately 83-90 eq. dB SPL at frequencies ≤1 kHz. The feasibility of cochlear stimulation by vibrating electrodes was shown although the achieved output level at frequencies ≤1 kHz was too low for EAS applications.

  2. Micro-Electro-Mechanical Systems

    NARCIS (Netherlands)

    Sarro, P.M.

    2008-01-01

    Micro-electro-mechanical systems (MEMS) or Microsystems technology (MST) is a fascinating and exciting field which significantly contributes to build a bridge between science and society. Physical properties and material characteristics are translated into structures and devices that can have a

  3. Micro electro-mechanical heater

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Yunje; Asif, Syed Amanulla Syed; Cyrankowski, Edward; Warren, Oden Lee

    2017-09-12

    A sub-micron scale property testing apparatus including a test subject holder and heating assembly. The assembly includes a holder base configured to couple with a sub-micron mechanical testing instrument and electro-mechanical transducer assembly. The assembly further includes a test subject stage coupled with the holder base. The test subject stage is thermally isolated from the holder base. The test subject stage includes a stage subject surface configured to receive a test subject, and a stage plate bracing the stage subject surface. The stage plate is under the stage subject surface. The test subject stage further includes a heating element adjacent to the stage subject surface, the heating element is configured to generate heat at the stage subject surface.

  4. Implantation of a Resynchronization Implantable Cardioverter Defibrillator in a Patient with Persistent Left Superior Vena Cava

    Directory of Open Access Journals (Sweden)

    Dante Antonelli

    2007-10-01

    Full Text Available Implantation of resynchronization implantable cardioverter defibrillator was performed in a patient with persistent left superior vena cava. A dual coil defibrillation lead was inserted in the right ventricle apex via a small innominate vein. Left ventricular and atrial leads were implanted through persistent left superior vena cava. Left ventricular lead was easily implanted into the postero lateral vein. Pacing thresholds and sensing values were excellent and remained stable at 18 months follow-up. Presence of persistent left superior vena cava generally makes transvenous lead implantation difficult. However when a favorable coronary sinus anatomy is also present, it may facilitate left ventricular lead positioning in the coronary sinus branches.

  5. Nano-opto-electro-mechanical systems

    Science.gov (United States)

    Midolo, Leonardo; Schliesser, Albert; Fiore, Andrea

    2018-01-01

    A new class of hybrid systems that couple optical, electrical and mechanical degrees of freedom in nanoscale devices is under development in laboratories worldwide. These nano-opto-electro-mechanical systems (NOEMS) offer unprecedented opportunities to control the flow of light in nanophotonic structures, at high speed and low power consumption. Drawing on conceptual and technological advances from the field of optomechanics, they also bear the potential for highly efficient, low-noise transducers between microwave and optical signals, in both the classical and the quantum domains. This Perspective discusses the fundamental physical limits of NOEMS, reviews the recent progress in their implementation and suggests potential avenues for further developments in this field.

  6. Nano-opto-electro-mechanical systems.

    Science.gov (United States)

    Midolo, Leonardo; Schliesser, Albert; Fiore, Andrea

    2018-01-01

    A new class of hybrid systems that couple optical, electrical and mechanical degrees of freedom in nanoscale devices is under development in laboratories worldwide. These nano-opto-electro-mechanical systems (NOEMS) offer unprecedented opportunities to control the flow of light in nanophotonic structures, at high speed and low power consumption. Drawing on conceptual and technological advances from the field of optomechanics, they also bear the potential for highly efficient, low-noise transducers between microwave and optical signals, in both the classical and the quantum domains. This Perspective discusses the fundamental physical limits of NOEMS, reviews the recent progress in their implementation and suggests potential avenues for further developments in this field.

  7. Decreased Defibrillation Threshold and Minimized Myocardial Damage With Left Axilla Implantable Cardioverter Defibrillator Implantation.

    Science.gov (United States)

    Noro, Mahito; Zhu, Xin; Enomoto, Yoshinari; Oikawa, Yasuhiro; Tatsunami, Hiroyuki; Ishii, Rina; Toyoda, Yasutake; Asami, Masako; Sahara, Naohiko; Takagi, Takahito; Narabayashi, Yuriko; Hashimoto, Hikari; Ito, Naoshi; Kujime, Shingo; Sakai, Tsuyoshi; Nakamura, Keijirou; Sakata, Takao; Abe, Haruhiko; Sugi, Kaoru

    2016-01-01

    To reduce myocardial damage caused by implantable cardioverter defibrillator (ICD) shock, the left axilla was studied as an alternative pulse generator implantation site, and compared with the traditional implantation site, the left anterior chest. Computer simulation was used to study the defibrillation conduction pattern and estimate the simulated defibrillation threshold (DFT) and myocardial damage when pulse generators were placed in the left axilla and left anterior chest, respectively; pulse generators were also newly implanted in the left axilla (n=30) and anterior chest (n=40) to compare the corresponding DFT. On simulation, when ICD generators were implanted in the left axilla, compared with the left anterior chest, the whole heart may be defibrillated with a lower defibrillation energy (left axilla 6.4 J vs. left anterior chest 12.0 J) and thus the proportion of cardiac myocardial damage may be reduced (2.1 vs. 4.2%). Clinically, ventricular fibrillation was successfully terminated with a defibrillation output ≤5 J in 86.7% (26/30) of the left axillary group, and in 27.5% (11/40) of the left anterior group (P<0.001). Clinically and theoretically, the left axilla was shown to be an improved ICD implantation site that may reduce DFT and lessen myocardial damage due to shock. Lower DFT also facilitates less myocardial damage, as a result of the lower shock required.

  8. Right heart failure post left ventricular assist device implantation.

    Science.gov (United States)

    Argiriou, Mihalis; Kolokotron, Styliani-Maria; Sakellaridis, Timothy; Argiriou, Orestis; Charitos, Christos; Zarogoulidis, Paul; Katsikogiannis, Nikolaos; Kougioumtzi, Ioanna; Machairiotis, Nikolaos; Tsiouda, Theodora; Tsakiridis, Kosmas; Zarogoulidis, Konstantinos

    2014-03-01

    Right heart failure (RHF) is a frequent complication following left ventricular assist device (LVAD) implantation. The incidence of RHF complicates 20-50% (range, 9-44%) of cases and is a major factor of postoperative morbidity and mortality. Unfortunately, despite the fact that many risk factors contributing to the development of RHF after LVAD implantation have been identified, it seems to be extremely difficult to avoid them. Prevention of RHF consists of the management of the preload and the afterload of the right ventricle with optimum inotropic support. The administration of vasodilators designed to reduce pulmonary vascular resistance is standard practice in most centers. The surgical attempt of implantation of a right ventricular assist device does not always resolve the problem and is not available in all cardiac surgery centers.

  9. Design and analysis of micro-optic-electro-mechanical accelerometer

    Science.gov (United States)

    Nayak, Jagannath; Srinivas, Talabuttala; Selvarajan, Ananth; Sastry, D. V. K.; Unnikrishanan, M. P.

    2003-10-01

    Integrated optics combined with micro-electro mechanical system (MEMS) technology offer enormous potential to improve sensitivity and performance capabilities of new sensors. In this paper, an analysis is carried out to find the feasibility and design concept of a Micro-Opto-Electro-Mechanical (MOEM) accelerometer consisting of integrated optic Mach-Zehnder interferometer, whose sensing arm is attached to a micromachined vibrating cantilever or a bridge. The analysis consists of determining changes in phase shift due to acceleration-induced refractive index and optical path length variation of MachZehender interferometer. A noise analysis is carried out to find the fundamental performance limit of different sensor configurations.

  10. Integrated micro-electro-mechanical sensor development for inertial applications

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J.J.; Kinney, R.D.; Sarsfield, J. [and others

    1998-04-01

    Electronic sensing circuitry and micro electro mechanical sense elements can be integrated to produce inertial instruments for applications unheard of a few years ago. This paper will describe the Sandia M3EMS fabrication process, inertial instruments that have been fabricated, and the results of initial characterization tests of micro-machined accelerometers.

  11. Changes in Spirometry After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Mohamedali, Burhan; Bhat, Geetha; Yost, Gardner; Tatooles, Antone

    2015-12-01

    Left ventricular assist devices (LVADs) are increasingly being used as life-saving therapy in patients with end-stage heart failure. The changes in spirometry following LVAD implantation and subsequent unloading of the left ventricle and pulmonary circulation are unknown. In this study, we explored long-term changes in spirometry after LVAD placement. In this retrospective study, we compared baseline preoperative pulmonary function test (PFT) results to post-LVAD spirometric measurements. Our results indicated that pulmonary function tests were significantly reduced after LVAD placement (forced expiratory volume in one second [FEV1 ]: 1.9 vs.1.7, P = 0.016; forced vital capacity [FVC]: 2.61 vs. 2.38, P = 0.03; diffusing capacity of the lungs for carbon monoxide [DLCO]: 14.75 vs. 11.01, P = 0.01). Subgroup analysis revealed greater impairment in lung function in patients receiving HeartMate II (Thoratec, Pleasanton, CA, USA) LVADs compared with those receiving HeartWare (HeartWare, Framingham, MA, USA) devices. These unexpected findings may result from restriction of left anterior hemi-diaphragm; however, further prospective studies to validate our findings are warranted. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  12. Nano/micro-electro mechanical systems: a patent view

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Guangyuan, E-mail: hu.guangyuan@mail.shufe.edu.cn, E-mail: hu.guangyuan@shufe.edu.cn [Shanghai University of Finance and Economics, School of Public Economics and Administration (China); Liu, Weishu [Shanghai Jiao Tong University, Antai College of Economics and Management (China)

    2015-12-15

    Combining both bibliometrics and citation network analysis, this research evaluates the global development of micro-electro mechanical systems (MEMS) research based on the Derwent Innovations Index database. We found that worldwide, the growth trajectory of MEMS patents demonstrates an approximate S shape, with United States, Japan, China, and Korea leading the global MEMS race. Evidenced by Derwent class codes, the technology structure of global MEMS patents remains steady over time. Yet there does exist a national competitiveness component among the top country players. The latecomer China has become the second most prolific country filing MEMS patents, but its patent quality still lags behind the global average.

  13. Micro-electro-mechanically switchable near infrared complementary metamaterial absorber

    Energy Technology Data Exchange (ETDEWEB)

    Pitchappa, Prakash; Pei Ho, Chong [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Institute of Microelectronics (IME), 11 Science Park Road, Singapore 117685 (Singapore); Kropelnicki, Piotr; Singh, Navab; Kwong, Dim-Lee [Institute of Microelectronics (IME), 11 Science Park Road, Singapore 117685 (Singapore); Lee, Chengkuo, E-mail: elelc@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)

    2014-05-19

    We experimentally demonstrate a micro-electro-mechanically switchable near infrared complementary metamaterial absorber by integrating the metamaterial layer to be the out of plane movable microactuator. The metamaterial layer is electrostatically actuated by applying voltage across the suspended complementary metamaterial layer and the stationary bottom metallic reflector. Thus, the effective spacing between the metamaterial layer and bottom metal reflector is varied as a function of applied voltage. With the reduction of effective spacing between the metamaterial and reflector layers, a strong spectral blue shift in the peak absorption wavelength can be achieved. With spacing change of 300 nm, the spectral shift of 0.7 μm in peak absorption wavelength was obtained for near infrared spectral region. The electro-optic switching performance of the device was characterized, and a striking switching contrast of 1500% was achieved at 2.1 μm. The reported micro-electro-mechanically tunable complementary metamaterial absorber device can potentially enable a wide range of high performance electro-optical devices, such as continuously tunable filters, modulators, and electro-optic switches that form the key components to facilitate future photonic circuit applications.

  14. A Systems Engineering Approach to Electro-Mechanical Actuator Diagnostic and Prognostic Development

    Data.gov (United States)

    National Aeronautics and Space Administration — The authors have formulated a Comprehensive Systems Engineering approach to Electro-Mechanical Actuator (EMA) Prognostics and Health Management (PHM) system...

  15. Flywheel for an electro-mechanical fastener driving tool

    Energy Technology Data Exchange (ETDEWEB)

    Crutcher, J. P.

    1985-05-28

    An improved flywheel for an electro-mechanical tool, such as a nailer or stapler. The tool is of the type provided with a driver which is frictionally moved through a working stroke by means of an electrically driven flywheel which presses the driver against a support element, such as a counterrotating flywheel, a low inertia roller, or the like. The flywheel is provided with circumferential grooves while maintaining the optimum contact area between the flywheel and the driver. The grooves provide voids along the travelling driver-flywheel contact line into which foreign material on the driver and flywheel flows to prevent build-up of such foreign material at the driver-flywheel contact area sufficient to result in loss of friction therebetween.

  16. The electro-mechanical behaviour of flexural ultrasonic transducers

    Science.gov (United States)

    Dixon, Steve; Kang, Lei; Ginestier, Michael; Wells, Christopher; Rowlands, George; Feeney, Andrew

    2017-05-01

    Flexural ultrasonic transducers are capable of high electro-mechanical coupling efficiencies for the generation or detection of ultrasound in fluids. They are the most common type of ultrasonic sensor, commonly used in parking sensors, because the devices are efficient, robust, and inexpensive. The simplest design consists of a piezoelectric disc, bonded to the inner surface of a metal cap, the face of which provides a vibrating membrane for the generation or detection of ultrasonic waves in fluids. Experimental measurements demonstrate that during the excitation of the piezoelectric element by an electrical voltage, there are three characteristic regions, where the frequency of the emitted ultrasonic wave changes during the excitation, steady-state, and the final decay process. A simple mechanical analogue model is capable of describing this behaviour.

  17. Carbon-Based Nano-Electro-Mechanical-Systems

    Science.gov (United States)

    Kaul, A. B.; Khan, A. R.; Megerian, K. G.; Epp, L.; LeDuc, G.; Bagge, L.; Jennings, A. T.; Jang, D.; Greer, J. R.

    2011-01-01

    We provide an overview of our work where carbon-based nanostructures have been applied to two-dimensional (2D) planar and three-dimensional (3D) vertically-oriented nano-electro-mechanical (NEM) switches. In the first configuration, laterally oriented single-walled nanotubes (SWNTs) synthesized using thermal chemical vapor deposition (CVD) were implemented for forming bridge-type 2D NEMS switches, where switching voltages were on the order of a few volts. In the second configuration, vertically oriented carbon nanofibers (CNFs) synthesized using plasma-enhanced (PE) CVD have been explored for their potential application in 3D NEMS. We have performed nanomechanical measurements on such vertically oriented tubes using nanoindentation to determine the mechanical properties of the CNFs. Electrostatic switching was demonstrated in the CNFs synthesized on refractory metallic nitride substrates, where a nanoprobe was used as the actuating electrode inside a scanning-electron-microscope. The switching voltages were determined to be in the tens of volts range and van der Waals interactions at these length scales appeared significant, suggesting such structures are promising for nonvolatile memory applications. A finite element model was also developed to determine a theoretical pull-in voltage which was compared to experimental results.

  18. Electro-mechanical coupling of rotating 3D beams

    Directory of Open Access Journals (Sweden)

    Stoykov S.

    2016-01-01

    Full Text Available A rotating thin-walled beam with piezoelectric element is analysed. The beam is considered to vibrate in space, hence the longitudinal, transverse and torsional deformations are taken into account. The bending deformations of the beam are modelled by assuming Timoshenko's theory. Torsion is included by considering that the cross section rotates as a rigid body but can deform in longitudinal direction due to warping. The warping function is computed preliminary by the finite element method. The equation of motion is derived by the principle of virtual work and discretized in space by the Ritz method. Electro-mechanical coupling is included in the model by considering the internal electrical energy and the electric charge output. The piezo-electric constitutive relations are used in reduced form. The beam is assumed to rotate about a fixed axis with constant speed. The equation of motion is derived in rotating coordinate system, but the influence of the rotation of the coordinate system is taken into account through the inertia forces. Results in time domain are presented for different speeds of rotation and frequencies of vibration. The influence of the speed of rotation and of the frequency of vibration on the electrical output is presented and analysed.

  19. Relationship between right and left ventricular function in candidates for implantable cardioverter defibrillator with low left ventricular ejection fraction.

    Science.gov (United States)

    Jimenez-Juan, Laura; Karur, Gauri R; Connelly, Kim A; Deva, Djeven; Yan, Raymond T; Wald, Rachel M; Singh, Sheldon; Leung, General; Oikonomou, Anastasia; Dorian, Paul; Angaran, Paul; Yan, Andrew T

    2017-04-01

    Indications for the primary prevention of sudden death using an implantable cardioverter defibrillator (ICD) are based predominantly on left ventricular ejection fraction (LVEF). However, right ventricular ejection fraction (RVEF) is also a known prognostic factor in a variety of structural heart diseases that predispose to sudden cardiac death. We sought to investigate the relationship between right and left ventricular parameters (function and volume) measured by cardiovascular magnetic resonance (CMR) among a broad spectrum of patients considered for an ICD. In this retrospective, single tertiary-care center study, consecutive patients considered for ICD implantation who were referred for LVEF assessment by CMR were included. Right and left ventricular function and volumes were measured. In total, 102 patients (age 62±14 years; 23% women) had a mean LVEF of 28±11% and RVEF of 44±12%. The left ventricular and right ventricular end diastolic volume index was 140±42 mL/m 2 and 81±27 mL/m 2 , respectively. Eighty-six (84%) patients had a LVEF right ventricular systolic dysfunction. Although there was a significant and moderate correlation between LVEF and RVEF ( r =0.40, p right ventricular systolic dysfunction (Kappa=0.041). Among patients being considered for an ICD, there is a positive but moderate correlation between LVEF and RVEF. A considerable proportion of patients who qualify for an ICD based on low LVEF have preserved RVEF, and vice versa.

  20. A Diagnostic Approach for Electro-Mechanical Actuators in Aerospace Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — Electro-mechanical actuators (EMA) are finding increasing use in aerospace applications, especially with the trend towards all all-electric aircraft and spacecraft...

  1. Experimental and Analytical Development of a Health Management System for Electro-Mechanical Actuators

    Data.gov (United States)

    National Aeronautics and Space Administration — Expanded deployment of Electro-Mechanical Actuators (EMAs) in critical applications has created much interest in EMA Prognostic Health Management (PHM), a key...

  2. Experimental Validation of a Prognostic Health Management System for Electro-Mechanical Actuators

    Data.gov (United States)

    National Aeronautics and Space Administration — The work described herein is aimed to advance prognostic health management solutions for electro-mechanical actuators and, thus, increase their reliability and...

  3. Airborne Electro-Mechanical Actuator Test Stand for Development of Prognostic Health Management Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — With the advent of the next generation of aerospace systems equipped with fly-by-wire controls, electro- mechanical actuators (EMA) are quickly becoming components...

  4. ENGAGEMENT SLIP CONTROLLER DEVELOPMENT BASED ON ACTUATOR DISPLACEMENT FOR AN ELECTRO-MECHANICAL FRICTION CLUTCH SYSTEM

    National Research Council Canada - National Science Library

    M S Che Kob; B Supriyo; K B Tawi; I I Mazali

    2015-01-01

    ...) controller algorithm to engage the dry friction clutch. The EMFC is electro-mechanically actuated using a DC motor system, such that a smooth engagement process can be performed satisfactorily...

  5. Shell-binary nanoparticle materials with variable electrical and electro-mechanical properties.

    Science.gov (United States)

    Zhang, P; Bousack, H; Dai, Y; Offenhäusser, A; Mayer, D

    2018-01-18

    Nanoparticle (NP) materials with the capability to adjust their electrical and electro-mechanical properties facilitate applications in strain sensing technology. Traditional NP materials based on single component NPs lack a systematic and effective means of tuning their electrical and electro-mechanical properties. Here, we report on a new type of shell-binary NP material fabricated by self-assembly with either homogeneous or heterogeneous arrangements of NPs. Variable electrical and electro-mechanical properties were obtained for both materials. We show that the electrical and electro-mechanical properties of these shell-binary NP materials are highly tunable and strongly affected by the NP species as well as their corresponding volume fraction ratio. The conductivity and the gauge factor of these shell-binary NP materials can be altered by about five and two orders of magnitude, respectively. These shell-binary NP materials with different arrangements of NPs also demonstrate different volume fraction dependent electro-mechanical properties. The shell-binary NP materials with a heterogeneous arrangement of NPs exhibit a peaking of the sensitivity at medium mixing ratios, which arises from the aggregation induced local strain enhancement. Studies on the electron transport regimes and micro-morphologies of these shell-binary NP materials revealed the different mechanisms accounting for the variable electrical and electro-mechanical properties. A model based on effective medium theory is used to describe the electrical and electro-mechanical properties of such shell-binary nanomaterials and shows an excellent match with experiment data. These shell-binary NP materials possess great potential applications in high-performance strain sensing technology due to their variable electrical and electro-mechanical properties.

  6. Recovery of Serum Cholesterol Predicts Survival After Left Ventricular Assist Device Implantation

    Science.gov (United States)

    Vest, Amanda R.; Kennel, Peter J.; Maldonado, Dawn; Young, James B.; Mountis, Maria M.; Naka, Yoshifumi; Colombo, Paolo C.; Mancini, Donna M.; Starling, Randall C.; Schulze, P. Christian

    2017-01-01

    Background Advanced systolic heart failure is associated with myocardial and systemic metabolic abnormalities, including low levels of total cholesterol and low-density lipoprotein. Low cholesterol and low-density lipoprotein have been associated with greater mortality in heart failure. Implantation of a left ventricular assist device (LVAD) reverses some of the metabolic derangements of advanced heart failure. Methods and Results A cohort was retrospectively assembled from 2 high-volume implantation centers, totaling 295 continuous-flow LVAD recipients with ≥2 cholesterol values available. The cohort was predominantly bridge-to-transplantation (67%), with median age of 59 years and 49% ischemic heart failure cause. Total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglyceride levels all significantly increased after LVAD implantation (median values from implantation to 3 months post implantation 125–150 mg/dL, 67–85 mg/dL, 32–42 mg/dL, and 97–126 mg/dL, respectively). On Cox proportional hazards modeling, patients achieving recovery of total cholesterol levels, defined as a median or greater change from pre implantation to 3 months post-LVAD implantation, had significantly better unadjusted survival (hazard ratio, 0.445; 95% confidence interval, 0.212–0.932) and adjusted survival (hazard ratio, 0.241; 95% confidence interval, 0.092–0.628) than those without cholesterol recovery after LVAD implantation. The continuous variable of total cholesterol at 3 months post implantation and the cholesterol increase from pre implantation to 3 months were also both significantly associated with survival during LVAD support. Conclusions Initiation of continuous-flow LVAD support was associated with significant recovery of all 4 lipid variables. Patients with a greater increase in total cholesterol by 3 months post implantation had superior survival during LVAD support. PMID:27623768

  7. On non-linear dynamics of a coupled electro-mechanical system

    DEFF Research Database (Denmark)

    Darula, Radoslav; Sorokin, Sergey

    2012-01-01

    , for mechanical system, is of the second order. The governing equations are coupled via linear and weakly non-linear terms. A classical perturbation method, a method of multiple scales, is used to find a steadystate response of the electro-mechanical system exposed to a harmonic close-resonance mechanical......Electro-mechanical devices are an example of coupled multi-disciplinary weakly non-linear systems. Dynamics of such systems is described in this paper by means of two mutually coupled differential equations. The first one, describing an electrical system, is of the first order and the second one...... excitation. The results are verified using a numerical model created in MATLAB Simulink environment. Effect of non-linear terms on dynamical response of the coupled system is investigated; the backbone and envelope curves are analyzed. The two phenomena, which exist in the electro-mechanical system: (a...

  8. Locally-Actuated Graphene-Based Nano-Electro-Mechanical Switch

    Directory of Open Access Journals (Sweden)

    Jian Sun

    2016-07-01

    Full Text Available The graphene nano-electro-mechanical switches are promising components due to their outstanding switching performance. However, most of the reported devices suffered from a large actuation voltages, hindering them from the integration in the conventional complementary metal-oxide-semiconductor (CMOS circuit. In this work, we demonstrated the graphene nano-electro-mechanical switches with the local actuation electrode via conventional nanofabrication techniques. Both cantilever-type and double-clamped beam switches were fabricated. These devices exhibited the sharp switching, reversible operation cycles, high on/off ratio, and a low actuation voltage of below 5 V, which were compatible with the CMOS circuit requirements.

  9. Single Versus Multidrug Regimen for Surgical Infection Prophylaxis in Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Aburjania, Nana; Ertmer, Brennan M; Farid, Saira; Berg, Melody; Nienaber, Juhsien J C; Tchantchaleishvili, Vakhtang; Stulak, John M; Sohail, Muhammad R

    2017-10-31

    Infection is a serious complication of left ventricular assist device (LVAD) therapy. However, an optimal antimicrobial surgical infection prophylaxis (SIP) regimen for LVAD implantation is not well established. We retrospectively reviewed all adults who underwent continuous-flow LVAD implantation from February 2007 to March 2015 at Mayo Clinic Rochester. Left ventricular assist device infection (LVADI) was defined using criteria published by the International Society for Heart and Lung Transplant. Patients excluded from the analysis included those who did not have HeartMate II or HeartWare device, patients with incomplete documentation of SIP, and those with an actively treated infection at the time of LVAD implantation. We compared risk of LVAD-specific and LVAD-related infections and all-cause mortality between SIP regimens at postoperative day 90 and 1 year using Kaplan-Meier time-to-event analyses. During study period, 239 adults underwent continuous-flow LVAD implantation at our institution where 199 patients received single-drug and 40 received multidrug SIP regimen. Median patient age was 62 years. Left ventricular assist device infection occurred in three patients (1.5%) in the single-drug group versus two patients (5.0%) in the multidrug group at 90 days (p = 0.4). There was no difference in infection-free (p = 0.4) and overall survival (p = 0.9) between two groups at 1 year. In conclusion, there was no clear benefit of using multidrug regimen as it did not impact infection-free survival or all-cause mortality compared with single-drug regimen. Prospective clinical trials are needed to further define the optimal SIP regimen for LVAD implantation.

  10. Effects on the electro-mechanical properties of aniline-doped ...

    African Journals Online (AJOL)

    The effects of Electro-mechanical properties of doped polyester fabric with aniline were investigated. The effects of various concentrations on the electrical as well as mechanical were examined and the percolation threshold was established. Chemical polymerization of aniline on Polyester in hydrochloric acid using ...

  11. A thermo-electro-mechanical simulation model for hot wire cutting of EPS foam

    DEFF Research Database (Denmark)

    Petkov, Kiril; Hattel, Jesper Henri

    2016-01-01

    A one-dimensional thermo-electro-mechanical mathematical model describing the effects taking place within a Ni-Cr20% wire used in a hot-wire cutting process for free forming and rapid prototyping of expanded polystyrene (EPS) is investigated and simulated. The model implements and solves three se...

  12. Myocardial regeneration after implantation of porcine small intestinal submucosa in the left ventricle

    Directory of Open Access Journals (Sweden)

    Cassiana Maria Garcez Ramos

    2014-04-01

    Full Text Available Introduction: Most cardiomyocytes do not regenerate after myocardial infarction. Porcine small intestinal submucosa has been shown to be effective in tissue repair. Objective: To evaluate myocardial tissue regeneration and functional effects of SIS implantation in pigs after left ventriculotomy. Methods: Fifteen pigs were assigned to two groups: porcine small intestinal submucosa (SIS (N=10 and control (N=5. The SIS group underwent a mini sternotomy, left ventriculotomy and placement of a SIS patch. The control group underwent a sham procedure. Echocardiography was performed before and 60 days after the surgical procedure. Histological analysis was performed with hematoxylin-eosin stain and markers for actin 1A4, anti sarcomeric actin, connexin43 and factor VIII. Results: Weight gain was similar in both groups. Echocardiography analysis revealed no difference between groups regarding end diastolic and systolic diameters and left ventricular ejection fraction, both pre (P=0.118, P=0.313, P=0.944 and post procedure (P=0.333, P=0.522, P=0.628. Both groups showed an increase in end diastolic (P<0,001 for both and systolic diameter 60 days after surgery (P=0.005, SIS group and P=0.004, control group. New cardiomyocytes, blood vessels and inflammatory reactions were histologically identified in the SIS group. Conclusion: SIS implantation in pigs after left ventriculotomy was associated with angiomuscular regeneration and no damage in cardiac function.

  13. A novel approach for endocardial resynchronization therapy: Initial experience with transapical implantation of the left ventricular lead

    NARCIS (Netherlands)

    I. Kassai (Imre); A. Mihalcz (Attila); C. Foldesi (Csaba); A. Kardos (Attila); T. Szili-Torok (Tamas)

    2009-01-01

    textabstractBackground: Coronary sinus lead placement for transvenous left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) has a significant failure rate at implant and a considerable dislocation rate during follow-up. For these patients epicardial pacing lead implantation is the

  14. Quantifying the effect of cardiorenal syndrome on mortality after left ventricular assist device implant.

    Science.gov (United States)

    Kirklin, James K; Naftel, David C; Kormos, Robert L; Pagani, Francis D; Myers, Susan L; Stevenson, Lynne W; Givertz, Michael M; Young, James B

    2013-12-01

    Comorbidities complicate recovery and contribute to mortality after implant of a left ventricular assist device (LVAD). Coexistent cardiac and renal dysfunction (so-called cardiorenal syndrome) increases the risk of death, both with advanced heart failure and after LVAD implantation. We analyzed patients from the Interagency Registry for Mechanically Assist Circulatory Support to better estimate postimplant mortality according to the severity of renal dysfunction. Patients with a continuous-flow LVAD were grouped according to their pre-implant level of renal dysfunction: severe was defined as dialysis and/or estimated glomerular filtration rate (eGFR) 60 mg/dl; and mild or no renal dysfunction if eGFR was ≥ 60 ml/min and BUN was cardiorenal syndrome is advanced. For patients with severe renal dysfunction and other major comorbidities, initial support with a temporary device while awaiting organ recovery before implanting a durable pump could be considered. © 2013 International Society for Heart and Lung Transplantation Published by International Society for the Heart and Lung Transplantation All rights reserved.

  15. New-Onset Left Bundle Branch Block Induced by Transcutaneous Aortic Valve Implantation.

    Science.gov (United States)

    Massoullié, Grégoire; Bordachar, Pierre; Ellenbogen, Kenneth A; Souteyrand, Géraud; Jean, Frédéric; Combaret, Nicolas; Vorilhon, Charles; Clerfond, Guillaume; Farhat, Mehdi; Ritter, Philippe; Citron, Bernard; Lusson, Jean-R; Motreff, Pascal; Ploux, Sylvain; Eschalier, Romain

    2016-03-01

    New-onset left bundle branch block (LBBB) is a specific concern of transcutaneous aortic valve implantation (TAVI) given its estimated incidence ranging from 5% to 65%. This high rate of occurrence is dependent on the type of device used (size and shape), implantation methods, and patient co-morbidities. The appearance of an LBBB after TAVI reflects a very proximal lesion of the left bundle branch as it exits the bundle of His. At times transient, its persistence can lead to permanent pacemaker implantation in 15% to 20% of cases, most often for high-degree atrioventricular block. The management of LBBB after TAVI is currently not defined by international societies resulting in individual centers developing their own management strategy. The potential consequences of LBBB are dysrhythmias (atrioventricular block, syncope, and sudden death) and functional (heart failure) complications. Prompt postprocedural recognition and management (permanent pacemaker implantation) of patients prevents the occurrence of potential complications and may constitute the preferred approach in this frail and elderly population despite additional costs and complications of cardiac pacing. Moreover, the expansion of future indications for TAVI necessitates better identification of the predictive factors for the development of LBBB. Indeed, long-term right ventricular pacing may potentially increase the risk of developing heart failure in this population. In conclusion, it is thus imperative to not only develop new aortic prostheses with a less-deleterious impact on the conduction system but also to prescribe appropriate pacing modes in this frail population. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. A case of SAPIEN XT valve fallen into left ventricle during valve-in-valve transcatheter aortic valve implantation.

    Science.gov (United States)

    Koizumi, Shigeki; Ehara, Natsuhiko; Nishiya, Kenta; Koyama, Tadaaki

    2017-06-24

    Late transcatheter heart valve embolization is a rare but life-threatening complication of transcatheter aortic valve implantation. Surgical intervention is performed for most cases, but some cases were treated by valve-in-valve transcatheter aortic valve implantation. We describe a patient in whom a 29-mm Edwards SAPIEN XT valve migrated into the left ventricular outflow tract 41 days after the initial implantation. We tried to perform valve-in-valve transcatheter aortic valve implantation using a transfemoral approach. As soon as the second transcatheter heart valve touched the first implanted valve, it fell into the left ventricle. Immediate surgical intervention was required. The first valve was removed, and surgical aortic valve replacement was successfully performed. In conclusion, we should choose surgical aortic valve replacement for late transcatheter heart valve embolization. Even if we need to treat by catheter intervention, transapical approach may be better.

  17. Patients with left bundle branch block and left axis deviation show a specific left ventricular asynchrony pattern: Implications for left ventricular lead placement during CRT implantation.

    Science.gov (United States)

    Sciarra, Luigi; Golia, Paolo; Palamà, Zefferino; Scarà, Antonio; De Ruvo, Ermenegildo; Borrelli, Alessio; Martino, Anna Maria; Minati, Monia; Fagagnini, Alessandro; Tota, Claudia; De Luca, Lucia; Grieco, Domenico; Delise, Pietro; Calò, Leonardo

    2017-10-21

    Left bundle branch block (LBBB) and left axis deviation (LAD) patients may have poor response to resynchronization therapy (CRT). We sought to assess if LBBB and LAD patients show a specific pattern of mechanical asynchrony. CRT candidates with non-ischemic cardiomyopathy and LBBB were categorized as having normal QRS axis (within -30° and +90°) or LAD (within -30° and -90°). Patients underwent tissue Doppler imaging (TDI) to measure time interval between onset of QRS complex and peak systolic velocity in ejection period (Q-peak) at basal segments of septal, inferior, lateral and anterior walls, as expression of local timing of mechanical activation. Thirty patients (mean age 70.6years; 19 males) were included. Mean left ventricular ejection fraction was 0.28±0.06. Mean QRS duration was 172.5±13.9ms. Fifteen patients showed LBBB with LAD (QRS duration 173±14; EF 0.27±0.06). The other 15 patients had LBBB with a normal QRS axis (QRS duration 172±14; EF 0.29±0.05). Among patients with LAD, Q-peak interval was significantly longer at the anterior wall in comparison to each other walls (septal 201±46ms, inferior 242±58ms, lateral 267±45ms, anterior 302±50ms; p<0.0001). Conversely, in patients without LAD Q-peak interval was longer at lateral wall, when compared to each other (septal 228±65ms, inferior 250±64ms, lateral 328±98ms, anterior 291±86ms; p<0.0001). Patients with heart failure, presenting LBBB and LAD, show a specific pattern of ventricular asynchrony, with latest activation at anterior wall. This finding could affect target vessel selection during CRT procedures in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Controlling Stiction in Nano-Electro-Mechanical Systems Using Liquid Crystals.

    Science.gov (United States)

    Buchnev, Oleksandr; Podoliak, Nina; Frank, Thomas; Kaczmarek, Malgosia; Jiang, Liudi; Fedotov, Vassili A

    2016-12-27

    Stiction is one of the major reliability issues limiting practical application of nano-electro-mechanical systems (NEMS), an emerging device technology that exploits mechanical movements on the scale of an integrated electronic circuit. We report on a discovery that stiction can be eliminated by infiltrating NEMS with nematic liquid crystals. We demonstrate this experimentally using a NEMS-based tunable photonic metamaterial, where reliable switching of optical response was achieved for the entire range of nanoscopic structural displacements admitted by the metamaterial design. Being a more straightforward and easy-to-implement alternative to the existing antistiction solutions, our approach also introduces an active mechanism of stiction control, which enables toggling between stiction-free and the usual (stiction-limited) regimes of NEMS operation. It is expected to greatly expand the functionality of electro-mechanical devices and enable the development of adaptive and smart nanosystems.

  19. Modeling of Thermo-Electro-Mechanical Manufacturing Processes Applications in Metal Forming and Resistance Welding

    CERN Document Server

    Nielsen, C V; Alves, L M; Bay, N; Martins, P A F

    2013-01-01

    Modeling of Thermo-Electro-Mechanical Manufacturing Processes with Applications in Metal Forming and Resistance Welding provides readers with a basic understanding of the fundamental ingredients in plasticity, heat transfer and electricity that are necessary to develop and proper utilize computer programs based on the finite element flow formulation.   Computer implementation of a wide range of theoretical and numerical subjects related to mesh generation, contact algorithms, elasticity, anisotropic constitutive equations, solution procedures and parallelization of equation solvers is comprehensively described.   Illustrated and enriched with selected examples obtained from industrial applications, Modeling of Thermo-Electro-Mechanical Manufacturing Processes with Applications in Metal Forming and Resistance Welding works to diminish the gap between the developers of finite element computer programs and the professional engineers with expertise in industrial joining technologies by metal forming and resista...

  20. Modelling of shear lag effect for piezo-elstodynamic structure for electro-mechanical imedance technique

    Science.gov (United States)

    Moharana, Sumedha; Bhalla, Suresh

    2015-03-01

    The impedance based structural health monitoring (SHM) techniques have utilized the electro-mechanical coupling property of piezoelectric materials (piezo-impedance transducers), due to their self-sensing nature (ability to act both as actuators and sensors), and its diminutive in shape and size, cost effectiveness and ease of installation. The adhesive bond acts as an elastic medium which facilitates the transfer of stresses and strains developed due to piezo displacement and also couples the impedance of PZT patch with that of the host structure. The sensitivity of the electro-mechanical impedance (EMI) technique can be enhanced by understanding shear mechanism phenomena of the adhesive layer. This paper reviews the existing shear lag models and discuss the recent advances in impedance based coupled piezo-structural model duly considering the shear lag effect with all responsible piezo-mechanical parameters.

  1. Micro-Electro-Mechanical Systems (MEMS) Fabrication Course Projects Review for FY15

    Science.gov (United States)

    2015-09-01

    TECHNICAL DOCUMENT 3298 September 2015 Micro-Electro-Mechanical Systems (MEMS) Fabrication Course Projects Review for FY15 Paul D. Swanson...Under authority of P. Juarez, Head Networks Division SSC Pacific S&T Workforce Development MEMS Fabrication Course Projects Review for FY15...definable polyimide ) on frontside  Coat/pattern/cure Durimide on backside  Etch through backside openings (circles) with KOH etchant  Remove Durimide

  2. Design and Development of Electro-Mechanical Twins Tipping Buckets Runoff-Meter

    Directory of Open Access Journals (Sweden)

    Olotu Yahaya

    2014-07-01

    Full Text Available Electro-mechanical tipping bucket runoff-meter was designed and developed to measure surface runoff water using locally-sourced components. The instrument consists of metallic-fabricated runoff plot area of 2 m 2 , depth 0.25 m and metal gauge of 3mm. The tipping operation was initiated by arranging the sensitive electro-mechanical components such digital micro-switch (SW1,SW2, SW3 and SW4, pair of open/close circuit breakers (No,Nc, electronic speed gear and circular rotating disc to a pair of twins buckets of runoff volume 0.141 liter capacity per bucket which corresponds to 0.25 mm runoff depth. The whole arrangement was powered by a 12V by 75 AH battery and the tipping processes was being recorded by the electro-mechanical data logger. The instrument has a measuring accuracy of ±0.001 liter per tip. It was calibrated to measure minimum and maximum runoff volume from 0.14l to 200 liters, these values correspond to 0.25 mm and 800 mm runoff depths respectively. Therefore, precise results obtained using the instrument could be used to establish strong database for measuring and storing accurate surface runoff data which in turn could be applied for hydrological modeling for sustainable water resources management and design of hydraulic structures

  3. A methodology for identification and control of electro-mechanical actuators.

    Science.gov (United States)

    Tutunji, Tarek A; Saleem, Ashraf

    2015-01-01

    Mechatronic systems are fully-integrated engineering systems that are composed of mechanical, electronic, and computer control sub-systems. These integrated systems use electro-mechanical actuators to cause the required motion. Therefore, the design of appropriate controllers for these actuators are an essential step in mechatronic system design. In this paper, a three-stage methodology for real-time identification and control of electro-mechanical actuator plants is presented, tested, and validated. First, identification models are constructed from experimental data to approximate the plants' response. Second, the identified model is used in a simulation environment for the purpose of designing a suitable controller. Finally, the designed controller is applied and tested on the real plant through Hardware-in-the-Loop (HIL) environment. The described three-stage methodology provides the following practical contributions: •Establishes an easy-to-follow methodology for controller design of electro-mechanical actuators.•Combines off-line and on-line controller design for practical performance.•Modifies the HIL concept by using physical plants with computer control (rather than virtual plants with physical controllers). Simulated and experimental results for two case studies, induction motor and vehicle drive system, are presented in order to validate the proposed methodology. These results showed that electromechanical actuators can be identified and controlled using an easy-to-duplicate and flexible procedure.

  4. Analysis method and principle of dual-mode electro-mechanical variable transmission program

    Science.gov (United States)

    Li, Hongcai; Yan, Qingdong; Xiang, Changle; Wang, Weida

    2012-05-01

    Automotive industry, as an important pillar of the national economy, has been rapidly developing in recent years. But proplems such as energy comsumption and environmental pollution are posed at the same time. Electro-mechanical variable transmission system is considered one of avilable workarounds. It is brought forward a kind of design methods of dual-mode electro-mechanical variable transmission system rotational speed characteristics and dual-mode drive diagrams. With the motor operating behavior of running in four quadrants and the speed characteristics of the simple internal and external meshing single planetary gear train, four kinds of dual-mode electro-mechanical transmission system scheme are designed. And the velocity, torque and power characteristics of one of the programs are analyzed. The magnitude of the electric split-flow power is an important factor which influences the system performance, so in the parameters matching design, it needs to reduce the power needs under the first mode of the motor. The motor, output rotational speed range and the position of the mode switching point have relationships with the characteristics design of the planetary gear set. The analysis method is to provide a reference for hybrid vehicles' design. As the involved rotational speed and torque relationships are the natural contact of every part of transmission system, a theory basis of system program and performance analysis is provided.

  5. Pre-implant left ventricular apex position predicts risk of HeartMate II pump thrombosis.

    Science.gov (United States)

    Yarboro, Leora T; Mehaffey, James Hunter; Hawkins, Robert B; Kron, Irving L; Ailawadi, Gorav; Kern, John A; Ghanta, Ravi K

    2017-12-01

    Thrombosis within a left ventricular assist device (LVAD) is a devastating complication that often necessitates device exchange. Few studies have evaluated the relationship between patient anatomy and pump thrombosis. We hypothesize that lateral displacement of the left ventricular (LV) apex increases risk for pump thrombosis. All patients who underwent primary implantation of a HeartMate II (HM2) device (Thoratec, Pleasanton, CA) at a single center (2009-2015) were evaluated. Operative mortalities and patients without imaging were excluded. The angle of the LV apex relative to the midline was measured on preoperative computed tomography scans by two independent surgeons. Pump thrombosis was defined as lactic dehydrogenase >700 with clinical symptoms of hemolysis or LVAD malfunction. Univariate and Cox Proportional Hazards analysis was performed to evaluate the impact of LV apex angle on long-term freedom from pump exchange for thrombosis. Of 122 patients who met inclusion criteria for this study, 16 (13.1%) underwent exchange for presumed pump thrombosis. Of these patients, six (37.5%) required more than one exchange. Patients undergoing exchange for thrombosis had greater LV angle (43.8 ± 9.7 vs 49.5 ± 11.2, p = 0.037) with LV apex angle being a significant predictor of LVAD exchange for thrombosis (hazard ratio = 1.047, P = 0.046). Additionally, when surgeon measurements were compared there was good inter-observer reliability (Pearson Correlation = 0.89). A laterally displaced left ventricular apex correlates with a higher risk of pump thrombosis in patients undergoing HM2 implantation. LV apex angle is an easily obtained, reproducible measurement that should be considered when selecting a ventricular assist device. © 2017 Wiley Periodicals, Inc.

  6. Drugs or implantable cardioverter-defibrillators in patients with poor left ventricular function?

    Science.gov (United States)

    Block, M; Hammel, D; Böcker, D; Borggrefe, M; Breithardt, G

    1996-09-12

    Poor left ventricular function is a predictor of sudden death. Both antiarrhythmic drugs and implantable cardioverter-defibrillators (ICDs) promise to reduce the sudden death rate in these patients and consequently improve survival. In patients without spontaneous ventricular tachyarrhythmias, only beta-blocking agents and amiodarone have been shown to reduce sudden death and improve survival in some studies, whereas class I antiarrhythmic drugs increased mortality. For patients with documented ventricular tachyarrhythmias, protection against sudden death by serially tested class I antiarrhythmic drugs is at best moderate. There is some evidence suggesting that therapy with class III antiarrhythmic drugs, either amiodarone or dl-sotalol, may reduce sudden death rates and improve overall mortality in comparison to therapy with class I antiarrhythmic drugs. ICDs have been shown to prevent sudden death reliably. In published patient cohorts in which only patients who were not inducible off antiarrhythmic drugs or still inducible on antiarrhythmic drugs received an ICD, the ICD seemed to improve overall survival in comparison to class I antiarrhythmic drugs. A small prospective randomized study that compared a conventional therapy strategy to primary ICD implantations showed an improved outcome with ICDs as therapy of first choice. However, these studies included many patients treated with class I antiarrhythmic drugs considered to be less effective. In matched control studies comparing the ICD to amiodarone or dl-sotalol, less sudden deaths and an improved overall survival could be shown for the ICD in general without stratification for left ventricular function. Thus, in patients with hemodynamically nontolerated ventricular tachyarrhythmias, the ICD seems to improve survival in comparison to class I antiarrhythmic drugs, dl-sotalol, or amiodarone. However, in patients with poor left ventricular function, therapy with ICDs seems to be less cost-effective than in

  7. Negative electro-mechanical windows are required for drug-induced Torsades de Pointes in the anesthetized guinea pig.

    Science.gov (United States)

    Guns, P-J; Johnson, D M; Weltens, E; Lissens, J

    2012-09-01

    Assessment of the propensity of novel drugs to cause proarrhythmia is essential in the drug development process. It is increasingly recognized, however, that QT prolongation alone is an imperfect surrogate marker for Torsades de Pointes (TdP) arrhythmia prediction. In the present study we investigated the behavior of a novel surrogate marker for TdP, the electro-mechanical (E-M) window, prior to triggering of TdP episodes with sympathetic stimulation after administration of a number of reference compounds. Experiments were carried out in closed chest pentobarbital anesthetized guinea pigs. Test compounds were administered intravenously together with a specific I(Ks) blocker (JNJ303; 0.2 mgkg(-1)min(-1) for 3 min) and adrenaline (0.06 mgkg(-1)min(-1) for 2 min) was applied to trigger TdP. ECG, blood- and left ventricular pressure signals were measured continuously throughout the experiments. The E-M window i.e. the duration of the mechanical systole (QLVP(end) interval) minus the duration of the electrical activity (QT interval) was assessed for individual beats. Drugs with documented TdP liability (quinidine, haloperidol, domperidone, terfenadine, moxifloxacin, ciprofloxacin and dofetilide) produced TdP in the protocol after adrenaline infusion, whereas negative control compounds (verapamil, ranolazine, amiodarone and saline) did not cause TdP arrhythmia, even though increases in repolarization times were observed. TdP were typically preceded by large (greater than -50 ms) negative electro-mechanical windows and were accompanied by aftercontractions. The present study in anesthetized guinea pigs indicates that negative E-M windows are a prerequisite for sympathetically-driven TdP induction after the administration of various agents with known proarrhythmic potential. These data are a first step in the validation of this novel protocol; however we believe that this proarrhythmia model in small animals might be a valuable additional tool in the prediction of TdP risk

  8. Unruptured retroperitoneal pregnancy implanted in the left broad ligament: A case report

    Directory of Open Access Journals (Sweden)

    Kutlešić Ranko M.

    2017-01-01

    Full Text Available Introduction. Retroperitoneal ectopic pregnancy is extremely rare, but potentially fatal condition due to possible massive hemorrhage, representing a great challenge to clinicians. Case report. We presented early retroperitoneal pregnancy in a patient with previous caesarean section, diagnosed at the sixth gestational week, located in the left broad ligament, primary treated by laparoscopy, which had to be converted to laparotomy due to massive intraoperative bleeding from the implantation site. Conclusion. High index of suspicion, combined with carefully interpreted clinical and ultrasound findings are crucial for the timely diagnosis of retroperitoneal pregnancy, before the occurrence of severe bleeding. The rising, even plateau of serum β-human chorionic gonadotropin (β-HCG levels without identification of uterine or ectopic (tubal pregnancy should cause suspicion on ectopic pregnancy in unusual location.

  9. Cardiovascular Implantable Electronic Device Infections in Left Ventricular Assist Device Recipients

    Science.gov (United States)

    Riaz, Talha; Nienaber, Juhsien JC; Baddour, Larry M.; Walker, Randall C.; Park, Soon J.; Sohail, M. Rizwan

    2013-01-01

    Background Most patients with left ventricular assist devices (LVAD) have concomitant cardiovascular implantable electronic devices (CIED). However, clinical presentation and outcome of CIED infection in the setting of LVAD has not been previously described. Methods We retrospectively reviewed 247 patients who underwent LVAD implantation at Mayo Clinic campuses in Minnesota, Arizona and Florida, from January 2005 to December 2011. Demographic and clinical data of patients that met criteria for CIED infection were extracted. Results Of 247 patients with LVADs, 215 (87%) had CIED at the time of LVAD implantation and six (2.8%) subsequently developed CIED infections. Three patients developed CIED lead-related endocarditis and other 3 had pocket infection. All 3 instances of CIED pocket infection were preceded by device generator exchange, while all three patients with CIED lead-related endocarditis had prior LVAD-related infections. Causative pathogens included Pseudomonas aeruginosa (1), coagulase-negative staphylococci (2), methicillin-resistant Staphylococcus aureus (1), a gram-positive bacillus (1), and culture-negative (2). All patients underwent complete CIED removal along with antimicrobial therapy. The 3 patients with CIED lead- related endocarditis and prior LVAD infections received chronic suppressive antibiotic therapy, and one patient had LVAD exchange. All but one remained alive at the last follow-up with a median duration of 15 months (7–46 months) from the time of CIED infection. Conclusion Patients who are receiving LVAD therapy and develop CIED infection should be managed with complete CIED removal. Chronic suppressive antibiotic therapy is warranted in cases that have concomitant LVAD infection. PMID:23998684

  10. Optical Mass Displacement Tracking: A simplified field calibration method for the electro-mechanical seismometer.

    Science.gov (United States)

    Burk, D. R.; Mackey, K. G.; Hartse, H. E.

    2016-12-01

    We have developed a simplified field calibration method for use in seismic networks that still employ the classical electro-mechanical seismometer. Smaller networks may not always have the financial capability to purchase and operate modern, state of the art equipment. Therefore these networks generally operate a modern, low-cost digitizer that is paired to an existing electro-mechanical seismometer. These systems are typically poorly calibrated. Calibration of the station is difficult to estimate because coil loading, digitizer input impedance, and amplifier gain differences vary by station and digitizer model. Therefore, it is necessary to calibrate the station channel as a complete system to take into account all components from instrument, to amplifier, to even the digitizer. Routine calibrations at the smaller networks are not always consistent, because existing calibration techniques require either specialized equipment or significant technical expertise. To improve station data quality at the small network, we developed a calibration method that utilizes open source software and a commonly available laser position sensor. Using a signal generator and a small excitation coil, we force the mass of the instrument to oscillate at various frequencies across its operating range. We then compare the channel voltage output to the laser-measured mass displacement to determine the instrument voltage sensitivity at each frequency point. Using the standard equations of forced motion, a representation of the calibration curve as a function of voltage per unit of ground velocity is calculated. A computer algorithm optimizes the curve and then translates the instrument response into a Seismic Analysis Code (SAC) poles & zeros format. Results have been demonstrated to fall within a few percent of a standard laboratory calibration. This method is an effective and affordable option for networks that employ electro-mechanical seismometers, and it is currently being deployed in

  11. Influence of micro- and nanofillers on electro-mechanical performance of silicone EAPs

    DEFF Research Database (Denmark)

    Bejenariu, Anca Gabriela; Daugaard, Anders Egede; Skov, Anne Ladegaard

    A well-known technique to improve the tear strength of rubbers is to add micro- or nanofillers. The effects of different micro- and nanofillers on the electro-mechanical behavior of silicone based dielectric elastomer are studied in this work. Several types of fillers and varied loadings are used...... to increase the overall permittivity of the silicone networks. The effect of particle size and particle size distribution on the electrical and viscoelastic properties is investigated. The aim of the paper is to find the right filler and the appropriate concentration for a suitable EAP material...

  12. A Method for Evaluating the Electro-Mechanical Characteristics of Piezoelectric Actuators during Motion

    Directory of Open Access Journals (Sweden)

    Hongzhi Jia

    2012-08-01

    Full Text Available The electro-mechanical characteristics of piezoelectric actuators which have being driven are evaluated in this paper. The force generated by actuators is measured as an inertial force of a corner cub prism which is attached to the actuators. The Doppler frequency shift of a laser beam, due to the motion of actuator, is accurately measured by a heterodyne interferometer. Subsequently, the mechanical quantities, such as velocity, acceleration, force, power and displacement, are calculated from the Doppler frequency shift. With the measurement results of current and voltage of the actuator, the relationships between electrical and mechanical characteristics are evaluated.

  13. Control and measurement of an electro-mechanical system with a phase qubit

    Science.gov (United States)

    Lecocq, Florent; Teufel, John; Allman, Michael; Cicak, Katarina; da Silva, Fabio; Sirois, Adam; Whittaker, Jed; Aumentado, Joe; Simmonds, Ray

    2013-03-01

    We discuss a hybrid device that merges an electro-mechanical system with a metastable phase qubit. The phase qubit can act as a single photon source and detector, allowing the preparation and readout of a lumped element electrical resonator, whose capacitance is formed by a mechanically compliant vacuum-gap capacitor. Via radiation pressure induced parametric coupling, we can map the quantum state of the 10 GHz electrical resonator on to the long-lived, ~10 MHz fundamental mode of the mechanical oscillator. This work opens the way toward the preparation of complex phonon states of mechanical motion. We will discuss current progress with this device.

  14. Fabrication and electrical characterization of graphene formed chemically on nickel nano electro mechanical system (NEMS) switch.

    Science.gov (United States)

    Choe, Byeong-In; Lee, Jung-Kyu; Lee, Bora; Kim, Kwanyong; Choi, Woo Young; Hong, Byung Hee; Lee, Jong-Ho

    2014-12-01

    In this work, we successfully fabricated a reliable nano-electro-mechanical system (NEMS) switch with graphene formed chemically on pre-patterned nickel (Ni) film movable beam. Its electrical characteristics were investigated in terms of current-voltage (I-V) and repetitive switching (on/off) properties. The graphene in the movable beam was selectively formed chemically only on the patterned Ni film. Graphene material may help overcome the stiction and reliability problems in nano-electro-mechanical devices. A study on graphene cantilever already has been reported by using only single or multi-layer of transferred graphene. However, the graphene selectively grown on Ni film has not been reported for NEMS switch. The graphene grown on Ni film by chemical vapor deposition method (CVD) were characterized by Raman spectroscopy. The fabricated lateral NEMS switch has w/l/t = 500 nm/20 μm/150 nm as a Ni dimension and an air-gap of -300 nm in lateral direction. The fabricated graphene movable beam formed chemically on Ni film shows reduced pull-in voltage and improved endurance (extended repetitive switching operations).

  15. Hybrid Micro-Electro-Mechanical Systems for Highly Reliable and Selective Characterization of Tank Waste

    Energy Technology Data Exchange (ETDEWEB)

    Panos G. Datskos; Michael J. Sepaniak; Nickolay Lavrik; Pampa Dutta; Mustafa Culha

    2005-12-28

    The main objective of this research program is to develop robust and reliable micro-electro-mechanical sensing systems, based on microcantilevers (MCs), that can operate in liquid environments with high levels of sensitivity and selectivity. The chemical responses of MCs result from analyte-induced differential stress at the cantilever surfaces. We aim to employ various surface nanostructuring strategies that enhance these stresses and hence the degree of static bending of the cantilevers. Receptor phases as self assembled monolayers (SAMs) and thin films are being synthesized and tested to provide selectivity. Selectivity is chemically enhanced by using different phases on individual MCs in arrays and by adding a spectroscopic component, surface enhanced Raman spectrometry (SERS), in hybrid approaches to sensing. Significant progress was made in tasks that were listed in the work plan for DOE EMSP project ''Hybrid Micro-Electro-Mechanical Systems for Highly Reliable and Selective Characterization of Tank Waste''. Several project areas are listed below and discussed and referenced to our literature on the topics.

  16. Modification and Performance Evaluation of a Low Cost Electro-Mechanically Operated Creep Testing Machine

    Directory of Open Access Journals (Sweden)

    John J. MOMOH

    2010-12-01

    Full Text Available Existing mechanically operated tensile and creep testing machine was modified to a low cost, electro-mechanically operated creep testing machine capable of determining the creep properties of aluminum, lead and thermoplastic materials as a function of applied stress, time and temperature. The modification of the testing machine was necessitated by having an electro-mechanically operated creep testing machine as a demonstration model ideal for use and laboratory demonstrations, which will provide an economical means of performing standard creep experiments. The experimental result is a more comprehensive understanding of the laboratory experience, as the technology behind the creep testing machine, the test methodology and the response of materials loaded during experiment are explored. The machine provides a low cost solution for Mechanics of Materials laboratories interested in creep testing experiment and demonstration but not capable of funding the acquisition of commercially available creep testing machines. Creep curves of strain versus time on a thermoplastic material were plotted at a stress level of 1.95MPa, 3.25MPa and 4.55MPa and temperature of 20oC, 40oC and 60oC respectively. The machine is satisfactory since it is always ready for operation at any given time.

  17. Vibration Damping Materials and Their Applications in Nano/Micro-Electro-Mechanical Systems: A Review.

    Science.gov (United States)

    Choudhary, Nitin; Kaur, Davinder

    2015-03-01

    The present review explores an overall view of the vibration damping materials ranging from traditionally used viscoelastic materials for macroscale damping to hybrid thin film heterostructures for micro-electro-mechanical systems (MEMS). Vibration damping materials like rubbers, polymers, metals, metal-matrix composites and smart materials are reviewed in terms of damping capacity, stiffness, mechanical strength and figure of merit. Nanoscale shape memory alloys, piezoelectric materials, carbon nanotubes, their composites and thin films are promising materials for future nanoscale damping devices. The main focus of this article is on our development of new vibration damping approach for MEMS structures comprising of ferroelastic/ferroelastic thin film heterostructures. For the first time, nanoindentation has been explored as an alternative tool to evaluate the damping capability of actual components (e.g., thin films for MEMS) where production of dynamic mechanical analyzer (DMA) test samples is not feasible. A comprehensive insight on the existing vibration damping materials and our new approach would definitely trigger some important applications in nano- and micro-electro-mechanical systems.

  18. Micro-electro-mechanical systems (MEMS: Technology for the 21st century

    Directory of Open Access Journals (Sweden)

    Đakov Tatjana A.

    2014-01-01

    Full Text Available Micro-electro-mechanical systems (MEMS are miniturized devices that can sense the environment, process and analyze information, and respond with a variety of mechanical and electrical actuators. MEMS consists of mechanical elements, sensors, actuators, electrical and electronics devices on a common silicon substrate. Micro-electro-mechanical systems are becoming a vital technology for modern society. Some of the advantages of MEMS devices are: very small size, very low power consumption, low cost, easy to integrate into systems or modify, small thermal constant, high resistance to vibration, shock and radiation, batch fabricated in large arrays, improved thermal expansion tolerance. MEMS technology is increasingly penetrating into our lives and improving quality of life, similar to what we experienced in the microelectronics revolution. Commercial opportunities for MEMS are rapidly growing in broad application areas, including biomedical, telecommunication, security, entertainment, aerospace, and more in both the consumer and industrial sectors on a global scale. As a breakthrough technology, MEMS is building synergy between previously unrelated fields such as biology and microelectronics. Many new MEMS and nanotechnology applications will emerge, expanding beyond that which is currently identified or known. MEMS are definitely technology for 21st century.

  19. Coupled chemo-electro-mechanical simulation of polyelectrolyte gels as actuators and sensors

    Science.gov (United States)

    Wallmersperger, Thomas; Ballhause, Dirk; Kröplin, Bernd; Günther, Margarita; Shi, Zhangman; Gerlach, Gerald

    2008-03-01

    Polyelectrolyte gels are ductile elastic electroactive materials. They consist of a polymer network with charged groups and a liquid phase with mobile ions. Changing the chemical or electric conditions in the gel-surrounding solution leads to a change of the chemo-electro-mechanical state in the gel phase: diffusion and migration of ions and solvent between the gel and solution phases trigger the swelling or shrinkage of the polymer gel. In case of chemical stimulation (change of pH or salt concentration), a swelling ratio of up to 100% may be obtained. Due to this large swelling ratio the gels exhibit excellent actuatoric capabilities. In this paper, a polyelectrolyte gel placed in a solution bath is investigated. The actuatoric and sensoric capabilities are described by a chemo-electro-mechanical model. The chemical field is represented by a convection-migration-diffusion equation while the electric field is described by a quasi-static Laplace equation. For the mechanical field a partial differential equation of first order in time is applied. Inertia effects are neglected due to the relatively slow swelling/shrinkage process. On the one hand, the coupling between the chemo-electrical and the mechanical field is realised by the differential osmotic pressure stemming from the concentration differences between gel and solution. On the other hand, the mechanical deformation influences the concentration of the bound charged groups in the gel. The three fields are solved simultaneously by applying the Newton Raphson method using finite elements in space and finite differences in time. The developed model is applicable for both, hydrogel actuators and sensors. Numerical results of swelling and bending are given for chemically and electrically stimulated polymer gels. In this paper we show the differences between the chemo-electric and the fully coupled chemo-electro-mechanical formulation for polymer gels in different solution baths. The inverse (sensor-) effect is

  20. Severe conduction defects requiring permanent pacemaker implantation in patients with a new-onset left bundle branch block after transcatheter aortic valve implantation.

    Science.gov (United States)

    Nijenhuis, V J; Van Dijk, V F; Chaldoupi, S M; Balt, J C; Ten Berg, J M

    2017-06-01

    Transcatheter aortic valve implantation (TAVI) is frequently associated with cardiac conduction defects (CCD) requiring permanent pacemaker implantation (PPI). Although new-onset left bundle branch block (LBBB) is often seen, the rate of progression to severe CCD is unclear. We aimed to find clinical and electrocardiographic (ECG) parameters associated with severe CCD requiring PPI in patients with a new-onset LBBB after TAVI and assess its effect on clinical outcome. All consecutive patients undergoing TAVI who developed a new-onset LBBB were retrospectively analysed. We excluded patients with pre-existing bundle branch block or pacemaker. Patients were divided into two groups: with or without PPI after TAVI. We included 155 patients (50% female, 80 ± 7 years), of which 37 (24%) developed CCD requiring PPI, mainly due to a total atrioventricular block (n = 17; 46%). Cardiac conduction defects requiring PPI were associated with the following pre-existing parameters: atrial fibrillation (AF), the use of digoxin, CoreValve implantation, and left heart axis. Furthermore, it was associated with the following post-procedural parameters: left heart axis, lower mean heart rate, and prolonged PQ and QRS times. During follow-up, patients with PPI showed a lower mortality rate (11 vs. 29%, P = 0.03). In patients without PPI, mortality was lower in those with narrower QRS complex and transient LBBB. The severity and persistence of a new-onset LBBB after TAVI is associated with mortality. Cardiac conduction defects requiring PPI are associated with prior AF, the use of digoxin, CoreValve implantation, and a left heart axis. In these patients, PPI portends a better prognosis than no PPI.

  1. Longer right to left ventricular activation delay at cardiac resynchronization therapy implantation is associated with improved clinical outcome in left bundle branch block patients.

    Science.gov (United States)

    Kosztin, Annamaria; Kutyifa, Valentina; Nagy, Vivien Klaudia; Geller, Laszlo; Zima, Endre; Molnar, Levente; Szilagyi, Szabolcs; Ozcan, Emin Evren; Szeplaki, Gabor; Merkely, Bela

    2016-04-01

    Data on longer right to left ventricular activation delay (RV-LV AD) predicting clinical outcome after cardiac resynchronization therapy (CRT) by left bundle branch block (LBBB) are limited. We aimed to evaluate the impact of RV-LV AD on N-terminal pro-B-type natriuretic peptide (NT-proBNP), ejection fraction (EF), and clinical outcome in patients implanted with CRT, stratified by LBBB at baseline. Heart failure (HF) patients undergoing CRT implantation with EF ≤ 35% and QRS ≥ 120 ms were evaluated based on their RV-LV AD at implantation. Baseline and 6-month clinical parameters, EF, and NT-proBNP values were assessed. The primary endpoint was HF or death, the secondary endpoint was all-cause mortality. A total of 125 patients with CRT were studied, 62% had LBBB. During the median follow-up of 2.2 years, 44 (35%) patients had HF/death, 36 (29%) patients died. Patients with RV-LV AD ≥ 86 ms (lower quartile) had significantly lower risk of HF/death [hazard ratio (HR): 0.44; 95% confidence interval (95% CI): 0.23-0.82; P = 0.001] and all-cause mortality (HR: 0.48; 95% CI: 0.23-1.00; P = 0.05), compared with those with RV-LV AD bundle branch block patients with longer RV-LV activation delay at CRT implantation had greater improvement in NT-proBNP, EF, and significantly better clinical outcome. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  2. Impact on Left Ventricular Function and Remodeling and on 1-Year Outcome in Patients With Left Bundle Branch Block After Transcatheter Aortic Valve Implantation.

    Science.gov (United States)

    Carrabba, Nazario; Valenti, Renato; Migliorini, Angela; Marrani, Marco; Cantini, Giulia; Parodi, Guido; Dovellini, Emilio Vincenzo; Antoniucci, David

    2015-07-01

    Conflicting results have been reported about the prognostic impact of left bundle branch block (LBBB) after transcatheter aortic valve implantation (TAVI). The aim of this study was to evaluate the impact of LBBB after TAVI on left ventricular (LV) function and remodeling and on 1-year outcomes. Of 101 TAVI patients, 9 were excluded. All complications were evaluated according to the Valve Academic Research Consortium 2 definition. Of 92 patients, 34 developed LBBB without more advanced myocardial damage or inflammation biomarkers in comparison with patients without LBBB. The only predictor of new LBBB was larger baseline LV end-diastolic volume. LBBB plus advanced atrioventricular block was strongly correlated with permanent pacemaker implantation (p <0.0001). Patients with LBBB had a higher rate of permanent pacemaker implantation at 30 days (59% vs 19%, p <0.0001) and less recovery of LV systolic function and a trend toward a lower rate of LV reverse remodeling at 1 year. The development of acute kidney injury and the logistic European System for Cardiac Operative Risk Evaluation score were associated with poor outcomes (all-cause mortality and heart failure) (hazard ratio 6.86, 95% confidence interval 2.51 to 18.74, p <0.0001, and hazard ratio 1.04, 95% confidence interval 1.01 to 1.08, p = 0.021, respectively), but not LBBB. In conclusion, after TAVI, 37% of patients developed new LBBB without more advanced myocardial damage or inflammation biomarkers. LBBB was associated with a higher rate of permanent pacemaker implantation, which negatively affected the recovery of LV systolic function. The development of acute kidney injury, rather than LBBB, increases the 1-year risk for mortality and hospitalization for heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Application of Micro-Electro-Mechanical Sensors Contactless NDT of Concrete Structures.

    Science.gov (United States)

    Ham, Suyun; Popovics, John S

    2015-04-17

    The utility of micro-electro-mechanical sensors (MEMS) for application in air-coupled (contactless or noncontact) sensing to concrete nondestructive testing (NDT) is studied in this paper. The fundamental operation and characteristics of MEMS are first described. Then application of MEMS sensors toward established concrete test methods, including vibration resonance, impact-echo, ultrasonic surface wave, and multi-channel analysis of surface waves (MASW), is demonstrated. In each test application, the performance of MEMS is compared with conventional contactless and contact sensing technology. Favorable performance of the MEMS sensors demonstrates the potential of the technology for applied contactless NDT efforts. To illustrate the utility of air-coupled MEMS sensors for concrete NDT, as compared with conventional sensor technology.

  4. Multi-Level Models For Diagnosis Of Complex Electro-Mechanical Systems

    Science.gov (United States)

    Smith, John A.; Biswas, Gautam

    1989-03-01

    This paper discusses a knowledge-based system for diagnostic problem solving based on a multi-level representational structure and associated reasoning methods. The motivation behind this approach is to combine shallow evidential models for fault diagnosis with deep qualitative models that derive behavior from structural descriptions. In addition, the reasoning scheme utilizes historical data based on past experience for diagnosis. Using this integrated framework, we concentrate on the following issues: (i) Multi-level knowledge based system design, and (ii) Reasoning systems that exploit the multi-level representational structure for diagnostic problem solving. This system is applied to the diagnosis of a complex electro-mechanical system, specifically, the upper cargo door of the DC-10 aircraft in use at Federal Express Corporation.

  5. Chemo-electro-mechanical modeling of pH-sensitive hydrogels

    Science.gov (United States)

    Wallmersperger, Thomas; Keller, Karsten; Kröplin, Bernd; Günther, Margarita; Gerlach, Gerald

    2011-04-01

    Hydrogels are viscoelastic active materials. They consist of a polymer network with bound charges and a liquid phase with mobile anions and cations. In water based solutions these gels show large swelling capabilities under the influence of different possible stimulation types, such as chemical, electrical or thermal stimulation. In the present work a coupled chemo-electro-mechanical formulation for polyelectrolyte gels using the Finite Element Method (FEM) is applied. In addition to the three given fields, the dissociation reactions of the bound charges in the gel are considered. Thus, we are able to model and simulate pH-stimulation and to give the different ion concentrations, the electric potential and the mechanical displacement. Depending on the initial conditions and the dissociation ratio, different kinds of stimulation cycles can be simulated. Concluding, the developed model is applicable for chemical stimulation and can model both, hydrogel actuators and sensors.

  6. Demonstration of Vibrational Braille Code Display Using Large Displacement Micro-Electro-Mechanical Systems Actuators

    Science.gov (United States)

    Watanabe, Junpei; Ishikawa, Hiroaki; Arouette, Xavier; Matsumoto, Yasuaki; Miki, Norihisa

    2012-06-01

    In this paper, we present a vibrational Braille code display with large-displacement micro-electro-mechanical systems (MEMS) actuator arrays. Tactile receptors are more sensitive to vibrational stimuli than to static ones. Therefore, when each cell of the Braille code vibrates at optimal frequencies, subjects can recognize the codes more efficiently. We fabricated a vibrational Braille code display that used actuators consisting of piezoelectric actuators and a hydraulic displacement amplification mechanism (HDAM) as cells. The HDAM that encapsulated incompressible liquids in microchambers with two flexible polymer membranes could amplify the displacement of the MEMS actuator. We investigated the voltage required for subjects to recognize Braille codes when each cell, i.e., the large-displacement MEMS actuator, vibrated at various frequencies. Lower voltages were required at vibration frequencies higher than 50 Hz than at vibration frequencies lower than 50 Hz, which verified that the proposed vibrational Braille code display is efficient by successfully exploiting the characteristics of human tactile receptors.

  7. submitter An experimental evaluation of the fully coupled hysteretic electro-mechanical behaviour of piezoelectric actuators

    CERN Document Server

    Butcher, Mark; Giustiniani, Alessandro; Masi, Alessandro

    2016-01-01

    Piezoelectrics are the most commonly used of the multifunctional smart materials in industrial applications, because of their relatively low cost and ease of use in electric and electronic oriented applications. Nevertheless, while datasheets usually give just small signal quasi-static parameters, their full potential can only be exploited only if a full characterization is available because the maximum stroke or the higher piezo coupling coefficients are available at different electro-mechanical biases, where often small signal analysis is not valid. In this paper a method to get the quasi-static fully coupled characterization is presented. The method is tested on a commercial piezo actuator but can be extended to similar devices.

  8. Fatigue Life Assessment of Structures Using Electro-Mechanical Impedance Technique

    Science.gov (United States)

    Bhalla, S.

    2012-05-01

    This paper describes a new experimental approach for fatigue life assessment of structures based on the equivalent stiffness determined by surface bonded piezo-impedance transducers through the electro-mechanical impedance (EMI) technique. The remaining life of the component (in terms of the cycles of loading that can be sustained) is non-dimensionally correlated with the equivalent identified stiffness. The proposed approach circumvents the determination of the absolute stiffness of the joint and employs the admittance signature of the surface-bonded piezo-transducers directly. The second part of the paper briefly describes the recent advances made in the field of impedance based structural health monitoring (SHM) in terms of low-cost hardware system and improved damage diagnosis through the integration of global dynamic and EMI techniques using the same set of piezo-sensors. Other recent applications such as bio-sensors and traffic sensors pioneered at the Smart Structures and Dynamics Laboratory (SSDL) are also briefly covered.

  9. Recent trends in reinforcement corrosion assessment using piezo sensors via electro mechanical impedance technique

    Science.gov (United States)

    Visalakshi, Talakokula; Bhalla, Suresh; Gupta, Ashok; Bhattacharjee, Bishwajit

    2014-03-01

    Reinforced concrete (RC) is an economical, versatile and successful construction material as it can be moulded into a variety of shapes and finishes. In most cases, it is durable and strong, performing well throughout its service life. However, in some cases, it does not perform adequately due to various reasons, one of which is the corrosion of the embedded steel bars used as reinforcement. . Although the electro-mechanical impedance (EMI) technique is well established for damage detection and quantification of civil, mechanical and aerospace structures, only limited studies have been reported of its application for rebar corrosion detection in RC structures. This paper presents the recent trends in corrosion assessment based on the model derived from the equivalent structural parameters extracted from the impedance spectrum of concrete-rebar system using the lead zirconate titanate (PZT) sensors via EMI technique.

  10. Application of Micro-Electro-Mechanical Sensors Contactless NDT of Concrete Structures

    Directory of Open Access Journals (Sweden)

    Suyun Ham

    2015-04-01

    Full Text Available The utility of micro-electro-mechanical sensors (MEMS for application in air-coupled (contactless or noncontact sensing to concrete nondestructive testing (NDT is studied in this paper. The fundamental operation and characteristics of MEMS are first described. Then application of MEMS sensors toward established concrete test methods, including vibration resonance, impact-echo, ultrasonic surface wave, and multi-channel analysis of surface waves (MASW, is demonstrated. In each test application, the performance of MEMS is compared with conventional contactless and contact sensing technology. Favorable performance of the MEMS sensors demonstrates the potential of the technology for applied contactless NDT efforts. Objective: To illustrate the utility of air-coupled MEMS sensors for concrete NDT, as compared with conventional sensor technology.

  11. Combined percutaneous balloon mitral valvuloplasty and left atrial appendage occlusion device implantation for rheumatic mitral stenosis and atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Murdoch, Dale, E-mail: dale_murdoch@health.qld.gov.au [The Prince Charles Hospital, Brisbane (Australia); The University of Queensland, Brisbane (Australia); McAulay, Laura [The Prince Charles Hospital, Brisbane (Australia); Walters, Darren L. [The Prince Charles Hospital, Brisbane (Australia); The University of Queensland, Brisbane (Australia)

    2014-11-15

    Rheumatic heart disease is a common cause of cardiovascular morbidity and mortality worldwide, mostly in developing countries. Mitral stenosis and atrial fibrillation often coexist, related to both structural and inflammatory changes of the mitral valve and left atrium. Both predispose to left atrial thrombus formation, commonly involving the left atrial appendage. Thromboembolism can occur, with devastating consequences. We report the case of a 62 year old woman with rheumatic heart disease resulting in mitral stenosis and atrial fibrillation. Previous treatment with warfarin resulted in life-threatening gastrointestinal bleeding and she refused further anticoagulant therapy. A combined procedure was performed, including percutaneous balloon mitral valvuloplasty and left atrial appendage occlusion device implantation with the Atritech® Watchman® device. No thromboembolic or bleeding complications were encountered at one year follow-up. Long-term follow-up in a cohort of patients will be required to evaluate the safety and efficacy of this strategy.

  12. Strong scaling and speedup to 16,384 processors in cardiac electro-mechanical simulations.

    Science.gov (United States)

    Reumann, Matthias; Fitch, Blake G; Rayshubskiy, Aleksandr; Keller, David U J; Seemann, Gunnar; Dossel, Olaf; Pitman, Michael C; Rice, John J

    2009-01-01

    High performance computing is required to make feasible simulations of whole organ models of the heart with biophysically detailed cellular models in a clinical setting. Increasing model detail by simulating electrophysiology and mechanical models increases computation demands. We present scaling results of an electro - mechanical cardiac model of two ventricles and compare them to our previously published results using an electrophysiological model only. The anatomical data-set was given by both ventricles of the Visible Female data-set in a 0.2 mm resolution. Fiber orientation was included. Data decomposition for the distribution onto the distributed memory system was carried out by orthogonal recursive bisection. Load weight ratios for non-tissue vs. tissue elements used in the data decomposition were 1:1, 1:2, 1:5, 1:10, 1:25, 1:38.85, 1:50 and 1:100. The ten Tusscher et al. (2004) electrophysiological cell model was used and the Rice et al. (1999) model for the computation of the calcium transient dependent force. Scaling results for 512, 1024, 2048, 4096, 8192 and 16,384 processors were obtained for 1 ms simulation time. The simulations were carried out on an IBM Blue Gene/L supercomputer. The results show linear scaling from 512 to 16,384 processors with speedup factors between 1.82 and 2.14 between partitions. The most optimal load ratio was 1:25 for on all partitions. However, a shift towards load ratios with higher weight for the tissue elements can be recognized as can be expected when adding computational complexity to the model while keeping the same communication setup. This work demonstrates that it is potentially possible to run simulations of 0.5 s using the presented electro-mechanical cardiac model within 1.5 hours.

  13. Hybrid internal mammary to left anterior descending bypass and transaortic transcatheter aortic valve implantation: a new treatment option for patients with complex disease.

    Science.gov (United States)

    Weich, Hellmuth S vH; van Wyk, Jacques; Pecoraro, Alfonso J; Mabin, Thomas

    2014-09-01

    The case is described of a hybrid trans-aortic transcatheter aortic valve implantation and off-pump left internal mammary artery to left anterior descending artery bypass surgery in a man with a tight left main lesion and severe symptomatic aortic stenosis.

  14. The Monorail Technique to Overcome Difficult Anatomical Course During Implantation of Central Venous Port via the Left Internal Jugular Vein

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eu Hyun, E-mail: doorihyun6@gmail.com; Oh, Jung Suk; Chun, Ho Jong; Lee, Hae Giu; Choi, Byung Gil, E-mail: cbg@catholic.ac.kr [The Catholic University of Korea, Department of Radiology, Seoul St. Mary’s Hospital (Korea, Republic of)

    2017-03-15

    PurposeThe study aimed to introduce a monorail technique to overcome difficult anatomical course via left internal jugular vein in implantable port insertion.MethodsFrom 2007 to 2016, a total of 9346 patients were referred for implantable port insertion in our interventional unit, among which 79 cases were requested to insert on the left side. Our monorail technique was applied only when the technical challenge of the catheter tip entering the azygos vein instead of the superior vena cava occurred (n = 7). The technique consists of puncturing at the distal tip of the port catheter with a 21-gauge micropuncture needle and advancing a 0.018-in. hair-wire to guide and provide support for pre-assembled port.ResultsThe monorail technique was performed in seven patients and all but one case were technically successful, showing a technical success rate of 85.7%. There were no immediate or delayed complications.ConclusionsThe monorail technique is helpful to overcome the difficult anatomical course via left internal jugular vein in implantable port insertion.

  15. Piezoelectric polymer gated OFET: Cutting-edge electro-mechanical transducer for organic MEMS-based sensors

    Science.gov (United States)

    Thuau, Damien; Abbas, Mamatimin; Wantz, Guillaume; Hirsch, Lionel; Dufour, Isabelle; Ayela, Cédric

    2016-12-01

    The growth of micro electro-mechanical system (MEMS) based sensors on the electronic market is forecast to be invigorated soon by the development of a new branch of MEMS-based sensors made of organic materials. Organic MEMS have the potential to revolutionize sensor products due to their light weight, low-cost and mechanical flexibility. However, their sensitivity and stability in comparison to inorganic MEMS-based sensors have been the major concerns. In the present work, an organic MEMS sensor with a cutting-edge electro-mechanical transducer based on an active organic field effect transistor (OFET) has been demonstrated. Using poly(vinylidenefluoride/trifluoroethylene) (P(VDF-TrFE)) piezoelectric polymer as active gate dielectric in the transistor mounted on a polymeric micro-cantilever, unique electro-mechanical properties were observed. Such an advanced scheme enables highly efficient integrated electro-mechanical transduction for physical and chemical sensing applications. Record relative sensitivity over 600 in the low strain regime (<0.3%) was demonstrated, which represents a key-step for the development of highly sensitive all organic MEMS-based sensors.

  16. Piezoelectric polymer gated OFET: Cutting-edge electro-mechanical transducer for organic MEMS-based sensors.

    Science.gov (United States)

    Thuau, Damien; Abbas, Mamatimin; Wantz, Guillaume; Hirsch, Lionel; Dufour, Isabelle; Ayela, Cédric

    2016-12-07

    The growth of micro electro-mechanical system (MEMS) based sensors on the electronic market is forecast to be invigorated soon by the development of a new branch of MEMS-based sensors made of organic materials. Organic MEMS have the potential to revolutionize sensor products due to their light weight, low-cost and mechanical flexibility. However, their sensitivity and stability in comparison to inorganic MEMS-based sensors have been the major concerns. In the present work, an organic MEMS sensor with a cutting-edge electro-mechanical transducer based on an active organic field effect transistor (OFET) has been demonstrated. Using poly(vinylidenefluoride/trifluoroethylene) (P(VDF-TrFE)) piezoelectric polymer as active gate dielectric in the transistor mounted on a polymeric micro-cantilever, unique electro-mechanical properties were observed. Such an advanced scheme enables highly efficient integrated electro-mechanical transduction for physical and chemical sensing applications. Record relative sensitivity over 600 in the low strain regime (MEMS-based sensors.

  17. Maximising electro-mechanical response by minimising grain-scale strain heterogeneity in phase-change actuator ceramics

    DEFF Research Database (Denmark)

    Oddershede, Jette; Hossain, Mohammad Jahangir; Daniels, John E.

    2016-01-01

    Phase-change actuator ceramics directly couple electrical and mechanical energies through an electric-field-induced phase transformation. These materials are promising for the replacement of the most common electro-mechanical ceramic, lead zirconate titanate, which has environmental concerns. Her...

  18. More than 20 years' experience of left ventricular assist device implantation at a non-transplant Centre.

    Science.gov (United States)

    Holmberg, Erica; Ahn, Henrik; Peterzén, Bengt

    2017-12-01

    Over recent decades implantable left ventricular assist devices (LVAD) have increased the possibility of improved survival in patients with advanced heart failure who also benefit from a better quality of life. The aim of this retrospective survey was to review the clinical results of LVAD implantation at a low-volume non-transplant centre (Linköping, Sweden) between 1993 and 2016. Our aim was also to assess the mortality and morbidity rates associated with implantation of three LVAD versions at our centre, and to compare our results with those from transplant centres. A retrospective cohort study was performed examining the medical records of patients who had a HeartMate(®) (HMI, HMII, HMIII) LVAD implanted as a bridge to heart transplantation (BTT) or as destination therapy (DT) at the University Hospital, Linköping. Our main finding was a survival to heart transplantation rate of 82% among our BTT LVAD patients. The most common adverse event among our patients was infection. A higher frequency of temporary dialysis was seen in the HMII group compared to the HMI group, and the frequency of right ventricular failure was higher in our HMII material. Our data suggests that patients requiring long-term LVAD support can safely have their device implanted and cared for at a non-transplant centre.

  19. Implantable cardioverter-defibrillators improve survival after coronary artery bypass grafting in patients with severely impaired left ventricular function

    Directory of Open Access Journals (Sweden)

    Pasque Michael K

    2007-01-01

    Full Text Available Abstract Objective Patients with severe left ventricular (LV dysfunction have a poor long term survival despite complete surgical revascularization. Recent data suggests that the use of Implantable Cardioverter-Defibrillator (ICD improves survival in patients with severe LV dysfunction. We compared the survival impact of ICD implantation in patients with severe LV dysfunction who underwent CABG. Methods Between January 1996 and August 2004, 305 patients with LV ejection fraction (EF ≤25% had CABG surgery at our institution. Demographics of patients who had received an ICD (ICD+ in the post -operative period was compared to those without ICD (ICD-. Survival was evaluated by the Kaplan-Meier method. Results Of the entire group, 35 (11.5% patients received an ICD with a median of 2 (+/-2 years after CABG. Indication for ICD implantation was clinical evidence of non sustained ventricular tachycardia (NSVT. There were no differences between the 2 groups with respect to age, gender, NYHA classification, number of bypasses, or other co-morbidities. Survival at 1, 3 and 5 years was 88%, 79%, and 67% for the ICD- group compared to 94%, 89% and 83% for the ICD+ group, respectively (figure, p Conclusion Implantation of ICD after CABG confers improved short and long term survival benefit to patients with severe LV dysfunction. Prophylactic ICD implantation in the setting of severe LV dysfunction and CABG surgery should be considered.

  20. Low-power feedback-enhanced electro-mechanical impedance (FEMI) sensors

    Science.gov (United States)

    Jang, Ji Eun; Yue, C. Patrick

    2008-03-01

    Electro-mechanical impedance (EMI) method utilizing smart piezoelectric sensors has emerged as a promising technology for structural health monitoring in civil, mechanical and aerospace engineering. However, two major limiting factors have prevented field deployment of this method in real life. First, smart piezoelectric sensors, such as Lead Zirconate Titanate (PZT) patches, are highly sensitive to environmental changes such as temperature, humidity, and vibration. Secondly, bulky and expensive equipment is needed for performing impedance measurement. This paper proposes a feedback-enhanced electro-mechanical impedance (FEMI) technique for improving robustness against environmental variations and a design of a low-power EMI sensor with built-in measurement circuitries based on this new technique. The proposed FEMI technique employs a feedback scheme to amplify the peaking characteristics of the natural resonance frequencies in the EMI frequency response. The feedback loop includes a phase-locked loop (PLL) and a transimpedance amplifier (TIA). An analog EMI measurement circuit is developed to replace bulky EMI measurement instruments. To keep the power consumption low, the proposed system does not require any analog-to-digital conversion or DSP circuit blocks, but uses a simple analog mixer to multiply input and output waveforms of the PZT sensor, and then extract the EMI amplitude by passing the mixer output through a low-pass filter (LPF). The performance of the proposed FEMI sensor is verified by simulations using MATLAB. Simulated natural frequency peaks in the EMI spectrum are noticeably sharper with the feedback scheme than the one without feedback. As a result, the natural frequency shift due to any structural change can be more easily detected. To quantify the shift of these natural frequency peaks, the root mean square deviation (RMSD) of the difference between cases with and without damage is calculated. The simulation results show that the RMSD with

  1. DETERMINATION OF TRANSMISSION GEAR RATIO IN MECHANICAL PART OF TRACTOR ELECTRO-MECHANICAL TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Ch. I. Zhdanovich

    2016-01-01

    Full Text Available A methodology has been developed for selection of gear number and transmission gear ratios in mechanical part of a wheel-type tractor with electro-mechanical transmission containing a propulsion asynchronous electric motor with variablefrequency control. The paper proposes to determine a transmission gear ratio on the basis of the following: provision of wheel torque dependence on tractor speed which is the best one for a traction process and during transfer from one gear to the other; provision of nominal operational mode of the electric motor for all tractor operations where it is working for a long period of time; provision of minimum possible number of gears; complete realization of internal combustion engine power on the tractor wheels at limit operational mode of the electric motor. As a characteristic of the asynchronous electric motor with variable-frequency control contains various portions which can be used either completely or partially due to operating conditions, the gear number is determined in the process of transmission gear ration finding but not prior to this. A wheel torque of the tractor with electro-mechanical transmission can be limited according to the following factors: grip of wheel with supporting surface; maximum power of an internal combustion engine which can be transferred to the wheels and a torque which is developed by a propulsion electric motor. It is not proposed to exceed nominal operational mode of the propulsion electric motor for all the operations of the tractor if it is working for a long period of time because in the case of significant excess of the nominal operational mode of the asynchronous electric motor its rather long operation leads to low efficiency and high losses in power, large heat liberation and consequently requires to develop more complicated system for electric motor cooling. An excess of nominal electric motor torque can be justified for short-term operational modes because in this case

  2. Complications Associated With Implantable Cardioverter Defibrillators in Adults With Congenital Heart Disease or Left Ventricular Noncompaction Cardiomyopathy (From the NCDR(®) Implantable Cardioverter-Defibrillator Registry).

    Science.gov (United States)

    Gleva, Marye J; Wang, Yongfei; Curtis, Jeptha P; Berul, Charles I; Huddleston, Charles B; Poole, Jeanne E

    2017-11-15

    Patients with childhood heart disease are living longer and entering adulthood, and may undergo implantable cardioverter-defibrillator (ICD) implantation to reduce the risk of sudden death. We evaluated the characteristics of adult patients with congenital heart disease or left ventricular noncompaction cardiomyopathy (LVNC) in the National Cardiovascular Disease Registry ICD Registry and determined ICD-related in-hospital complications. Patients with LVNC or transposition of the great arteries, tetralogy of Fallot, Ebstein's anomaly, atrial septal defect, ventricular septal defect, or common ventricle were identified in the registry. In-hospital complications were compared among different diagnoses using the chi-square test for categorical variables and the F-test in analyses of variance for continuous variables. A total of 3,077 patients were identified. The mean age was 48.0 ± 16.0 years, and 39.9% were female. Single-chamber ICDs were implanted in 25.2%, dual chamber in 41.9%, and cardiac resynchronization in 30.8%. Intraprocedural or postprocedural complications occurred in 70 patients (2.3%); there were 6 in-hospital deaths (0.2%). The most frequent complications were acute lead dislodgments, pneumothorax, and hematomas. Patients with Ebstein's anomaly had the greatest complication rate (8.3%, p = 0.03). The complication rate was 1.55% in single-chamber devices, 1.86% in dual chamber, and 3.5% in cardiac resynchronization (p < 0.001). For initial implants, the complication rate was 2.55%, 1.62% in generator replacements, and 8.77% in lead revisions (p = 0.001). In conclusion, in this large contemporary adult cohort of congenital heart disease and LVNC patients who underwent ICD implant procedures, periprocedural complication rates were low. Lead-related risks predominated. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Laser-induced damage threshold of camera sensors and micro-opto-electro-mechanical systems

    Science.gov (United States)

    Schwarz, Bastian; Ritt, Gunnar; Körber, Michael; Eberle, Bernd

    2016-10-01

    The continuous development of laser systems towards more compact and efficient devices constitutes an increasing threat to electro-optical imaging sensors such as complementary metal-oxide-semiconductors (CMOS) and charge-coupled devices (CCD). These types of electronic sensors are used in day-to-day life but also in military or civil security applications. In camera systems dedicated to specific tasks, also micro-opto-electro-mechanical systems (MOEMS) like a digital micromirror device (DMD) are part of the optical setup. In such systems, the DMD can be located at an intermediate focal plane of the optics and it is also susceptible to laser damage. The goal of our work is to enhance the knowledge of damaging effects on such devices exposed to laser light. The experimental setup for the investigation of laser-induced damage is described in detail. As laser sources both pulsed lasers and continuous-wave (CW) lasers are used. The laser-induced damage threshold (LIDT) is determined by the single-shot method by increasing the pulse energy from pulse to pulse or in the case of CW-lasers, by increasing the laser power. Furthermore, we investigate the morphology of laser-induced damage patterns and the dependence of the number of destructed device elements on the laser pulse energy or laser power. In addition to the destruction of single pixels, we observe aftereffects like persisting dead columns or rows of pixels in the sensor image.

  4. [Electro-mechanic steering device for head-lamp mounted miniature video cameras].

    Science.gov (United States)

    Ilgner, J; Westhofen, M

    2003-05-01

    Endoscopic or microscopic video recordings set a widely established standard for medico-legal documentation of operative procedures. In addition, they are an essential part of undergraduate as well as postgraduate medical education. Macroscopic operations in the head and neck can be recorded by miniaturised video cameras attached to the surgeon's head lamp. The authors present an electro-mechanic steering device which has been designed to overcome the parallax error created with a head-mounted video camera, especially as the distance of the camera to the operative field varies. The device can be operated by the theatre staff, while the sterility of the operative field is maintained and the surgeon's physical working range remains unrestricted. As the video image is reliably centred to the operative field throughout the procedure, a better orientation and understanding for spectators who are unfamiliar with the surgical steps is obtained. While other adverse factors to macroscopic head-mounted video recordings, such as involuntary head movements of the surgeon, remain unchanged, the device adds to a higher quality of video documentation as it relieves the surgeon from adjusting the image field to the regions of interest. Additional benefit could be derived from an auto-focus feature or from image stabilising devices.

  5. Wireless biomedical signal monitoring device on wheelchair using noncontact electro-mechanical film sensor.

    Science.gov (United States)

    Kim, Jong-Myoung; Hong, Joo-Hyun; Cho, Myeong-Chan; Cha, Eun-Jong; Lee, Tae-Soo

    2007-01-01

    The present study purposed to measure the BCG (Ballistocardiogram) of subjects on a wheelchair using a noncontact electro-mechanical film sensor (EMFi sensor) and detect the respiratory rate from BCG in real-time while the subjects are moving. In order to measure wirelessly the BCG of subjects moving on a wheelchair, we made a seat-type noncontact EMFi sensor and developed a transmitter and a receiver using Zigbee wireless RF communication technology. The sensor is embedded with a 3-axis accelerometer to remove the noise of wheelchair vibration from BCG signal. Signal obtained from each sensor goes through the A/D converter and is recorded in the SD (Secure Digital) card in PDA (Personal Digital Assistance) with a receiving part. We also developed a PC (Personal Computer) data analysis program, analyzed data recorded in the SD card using the program, and presented the results in graph. Lastly, this study demonstrated that a warning message can be sent from PDA to the remote server via a CDMA (Code Division Multiple Access) network in case the person on wheelchair falls in emergency. Our experiment was carried out with healthy male and female adults in their 20s who volunteered to help this research. The results of analyzing collected data will show that the respiratory rate can be measured in real-time on a moving wheelchair.

  6. Electro-mechanical vibration analysis of functionally graded piezoelectric porous plates in the translation state

    Science.gov (United States)

    Wang, Yan Qing

    2018-02-01

    To provide reference for aerospace structural design, electro-mechanical vibrations of functionally graded piezoelectric material (FGPM) plates carrying porosities in the translation state are investigated. A modified power law formulation is employed to depict the material properties of the plates in the thickness direction. Three terms of inertial forces are taken into account due to the translation of plates. The geometrical nonlinearity is considered by adopting the von Kármán non-linear relations. Using the d'Alembert's principle, the nonlinear governing equation of the out-of-plane motion of the plates is derived. The equation is further discretized to a system of ordinary differential equations using the Galerkin method, which are subsequently solved via the harmonic balance method. Then, the approximate analytical results are validated by utilizing the adaptive step-size fourth-order Runge-Kutta technique. Additionally, the stability of the steady state responses is examined by means of the perturbation technique. Linear and nonlinear vibration analyses are both carried out and results display some interesting dynamic phenomenon for translational porous FGPM plates. Parametric study shows that the vibration characteristics of the present inhomogeneous structure depend on several key physical parameters.

  7. Micro electro-mechanical system piezoelectric cantilever array for a broadband vibration energy harvester.

    Science.gov (United States)

    Chun, Inwoo; Lee, Hyun-Woo; Kwon, Kwang-Ho

    2014-12-01

    Limited energy sources of ubiquitous sensor networks (USNs) such as fuel cells and batteries have grave drawbacks such as the need for replacements and re-charging owing to their short durability and environmental pollution. Energy harvesting which is converting environmental mechanical vibration into electrical energy has been researched with some piezoelectric materials and various cantilever designs to increase the efficiency of energy-harvesting devices. In this study, we focused on an energy-harvesting cantilever with a broadband vibration frequency. We fabricated a lead zirconate titanate (PZT) cantilever array with various Si proof masses on small beams (5.5 mm x 0.5 mm x 0.5 mm). We obtained broadband resonant frequencies ranging between 127 Hz and 136 Hz using a micro electro-mechanical system (MEMS) process. In order to obtain broadband resonant characteristics, the cantilever array was comprised of six cantilevers with different resonant frequencies. We obtained an output power of about 2.461 μW at an acceleration of 0.23 g and a resistance of 4 kΩ. The measured bandwidth of the resonant frequency was approximately 9 Hz (127-136 Hz), which is about six times wider than the bandwidth of a single cantilever.

  8. Design of Electro-Mechanical Dual-Acting Pulley Continuously Variable Transmission

    Directory of Open Access Journals (Sweden)

    K.B. Tawi

    2015-06-01

    Full Text Available Pulley-based continuously variable transmission (CVT with a metal pushing V-belt is fast becoming the preferred choice for global carmakers due to its potential particularly in terms of fuel efficiency thanks to its continuous and wide ratio range. Nevertheless, the existing CVTs still face the issues of high power consumption from the engine because of the application of an electro-hydro-mechanical (EHM actuation system for its ratio changing process and clamping force mechanism. To address this issue, researchers from Universiti Teknologi Malaysia have successfully developed the prototype of an electro-mechanical dual-acting pulley continuously variable transmission (EMDAP CVT for automotive applications. The prototype of EMDAP CVT is developed for a maximum input torque of 160 Nm with the application of a metal pushing V-belt. The results from the testing prove that the prototype can vary its ratio from 2.8 to 0.6 and no continuous power is required to maintain a constant CVT ratio. These results suggest that the prototype is workable and future testing in a real car is possible.

  9. Genetic algorithm for the design of electro-mechanical sigma delta modulator MEMS sensors.

    Science.gov (United States)

    Wilcock, Reuben; Kraft, Michael

    2011-01-01

    This paper describes a novel design methodology using non-linear models for complex closed loop electro-mechanical sigma-delta modulators (EMΣΔM) that is based on genetic algorithms and statistical variation analysis. The proposed methodology is capable of quickly and efficiently designing high performance, high order, closed loop, near-optimal systems that are robust to sensor fabrication tolerances and electronic component variation. The use of full non-linear system models allows significant higher order non-ideal effects to be taken into account, improving accuracy and confidence in the results. To demonstrate the effectiveness of the approach, two design examples are presented including a 5th order low-pass EMΣΔM for a MEMS accelerometer, and a 6th order band-pass EMΣΔM for the sense mode of a MEMS gyroscope. Each example was designed using the system in less than one day, with very little manual intervention. The strength of the approach is verified by SNR performances of 109.2 dB and 92.4 dB for the low-pass and band-pass system respectively, coupled with excellent immunities to fabrication tolerances and parameter mismatch.

  10. Application of Higher Order Hamiltonian Approach to the Nonlinear Vibration of Micro Electro Mechanical Systems

    Directory of Open Access Journals (Sweden)

    S. Sadeghzadeh

    Full Text Available Abstract This paper implements the higher order Hamiltonian method to analyze an electrostatically actuated nonlinear micro beam-based micro electro mechanical oscillator. First, second and third approximate solutions are obtained, and the frequency responses of the system are compared with energy balance method solution and previously solved Variational Approach (VA and exact solution. After driving the equation of motion based on the Euler-Bernoulli beam theory, Galerkin method has been used to simplify the nonlinear equation of motion. Higher order Hamiltonian approach has been used to solve the problem and introduce a design strategy. Phase plane diagram of electrostatically actuated micro beam has plotted to show the stability of presented nonlinear system and natural frequencies are calculated to use for resonator design. According to the numerical results, the second approximate is more acceptable and results show that one could obtain a predesign strategy by prediction of effects of mechanical properties and electrical coefficients on the stability and free vibration of common electrostatically actuated micro beam.

  11. Experimental Identification of Smartphones Using Fingerprints of Built-In Micro-Electro Mechanical Systems (MEMS).

    Science.gov (United States)

    Baldini, Gianmarco; Steri, Gary; Dimc, Franc; Giuliani, Raimondo; Kamnik, Roman

    2016-06-03

    The correct identification of smartphones has various applications in the field of security or the fight against counterfeiting. As the level of sophistication in counterfeit electronics increases, detection procedures must become more accurate but also not destructive for the smartphone under testing. Some components of the smartphone are more likely to reveal their authenticity even without a physical inspection, since they are characterized by hardware fingerprints detectable by simply examining the data they provide. This is the case of MEMS (Micro Electro-Mechanical Systems) components like accelerometers and gyroscopes, where tiny differences and imprecisions in the manufacturing process determine unique patterns in the data output. In this paper, we present the experimental evaluation of the identification of smartphones through their built-in MEMS components. In our study, three different phones of the same model are subject to repeatable movements (composing a repeatable scenario) using an high precision robotic arm. The measurements from MEMS for each repeatable scenario are collected and analyzed. The identification algorithm is based on the extraction of the statistical features of the collected data for each scenario. The features are used in a support vector machine (SVM) classifier to identify the smartphone. The results of the evaluation are presented for different combinations of features and Inertial Measurement Unit (IMU) outputs, which show that detection accuracy of higher than 90% is achievable.

  12. Experimental Identification of Smartphones Using Fingerprints of Built-In Micro-Electro Mechanical Systems (MEMS

    Directory of Open Access Journals (Sweden)

    Gianmarco Baldini

    2016-06-01

    Full Text Available The correct identification of smartphones has various applications in the field of security or the fight against counterfeiting. As the level of sophistication in counterfeit electronics increases, detection procedures must become more accurate but also not destructive for the smartphone under testing. Some components of the smartphone are more likely to reveal their authenticity even without a physical inspection, since they are characterized by hardware fingerprints detectable by simply examining the data they provide. This is the case of MEMS (Micro Electro-Mechanical Systems components like accelerometers and gyroscopes, where tiny differences and imprecisions in the manufacturing process determine unique patterns in the data output. In this paper, we present the experimental evaluation of the identification of smartphones through their built-in MEMS components. In our study, three different phones of the same model are subject to repeatable movements (composing a repeatable scenario using an high precision robotic arm. The measurements from MEMS for each repeatable scenario are collected and analyzed. The identification algorithm is based on the extraction of the statistical features of the collected data for each scenario. The features are used in a support vector machine (SVM classifier to identify the smartphone. The results of the evaluation are presented for different combinations of features and Inertial Measurement Unit (IMU outputs, which show that detection accuracy of higher than 90% is achievable.

  13. Multi-MHz micro-electro-mechanical sensors for atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Legrand, Bernard, E-mail: bernard.legrand@laas.fr [LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, F-31400 Toulouse (France); Salvetat, Jean-Paul [CRPP, 115 avenue Schweitzer, F-33600 Pessac (France); Walter, Benjamin; Faucher, Marc; Théron, Didier [IEMN, avenue Henri Poincaré, F-59652 Villeneuve d’Ascq (France); Aimé, Jean-Pierre [CBMN, allée Geoffroy Saint Hilaire, Bât. B14, F-33600 Pessac (France)

    2017-04-15

    Silicon ring-shaped micro-electro-mechanical resonators have been fabricated and used as probes for dynamic atomic force microscopy (AFM) experiments. They offer resotnance frequency above 10 MHz, which is notably greater than that of usual cantilevers and quartz-based AFM probes. On-chip electrical actuation and readout of the tip oscillation are obtained by means of built-in capacitive transducers. Displacement and force resolutions have been determined from noise analysis at 1.5 fm/√Hz and 0.4 pN/√Hz, respectively. Despite the high effective stiffness of the probes, the tip-surface interaction force is kept below 1 nN by using vibration amplitude significantly below 100 pm and setpoint close to the free vibration conditions. Imaging capabilities in amplitude- and frequency-modulation AFM modes have been demonstrated on block copolymer surfaces. Z-spectroscopy experiments revealed that the tip is vibrating in permanent contact with the viscoelastic material, with a pinned contact line. Results are compared to those obtained with commercial AFM cantilevers driven at large amplitudes (>10 nm). - Highlights: • Silicon MEMS resonators are used as AFM probes above 10 MHz. • Integrated capacitive transducers drive and sense sub-nanometer tip oscillation. • Force resolution is below 1 pN/√Hz. • Block copolymer surface is imaged using AM and FM AFM modes. • Probes are operated at small vibration amplitude in permanent viscoelastic contact.

  14. Temperature and time dependence of the electro-mechanical properties of flexible active fiber composites

    Science.gov (United States)

    Ben Atitallah, H.; Ounaies, Z.; Muliana, A.

    2016-04-01

    Active fiber composites (AFCs) are comprised of piezoelectric fibers embedded in a polymeric matrix. AFCs use interdigitated electrodes, which produce electric field lines parallel to the fiber direction, thus taking advantage of the larger d 33 piezoelectric coefficient. The polymer volume content of the AFCs is generally more than 50%; since polymers tend to have behaviors affected by their viscoelastic characteristics especially at elevated temperatures, it is necessary to understand the thermo-electro-mechanical behavior of AFCs at different loading rates. In this study, mechanical, electrical and electromechanical properties of AFCs were measured at different isothermal temperatures, namely 25 °C, 50 °C and 75 °C and at different loading rates. The measurements of all the properties of AFCs were done along the fiber direction. It was found that at higher temperatures, the modulus and tensile strength decreased for all strain rates and the strain at failure increased. The remnant polarization increased with decrease in frequency and increase in temperature; however, the coercive field decreased with temperature and was not affected by the frequency. Due to the viscoelastic behavior of the epoxy, the piezoelectric coefficient d 33 increased at higher temperature and lower frequency. It was also noted that this coefficient is dependent on the magnitude of the electric field.

  15. Using Neural Networks in Decision Making for a Reconfigurable Electro Mechanical Actuator (EMA)

    Science.gov (United States)

    Latino, Carl D.

    2001-01-01

    The objectives of this project were to demonstrate applicability and advantages of a neural network approach for evaluating the performance of an electro-mechanical actuator (EMA). The EMA in question was intended for the X-37 Advanced Technology Vehicle. It will have redundant components for safety and reliability. The neural networks for this application are to monitor the operation of the redundant electronics that control the actuator in real time and decide on the operating configuration. The system we proposed consists of the actuator, sensors, control circuitry and dedicated (embedded) processors. The main purpose of the study was to develop suitable hardware and neural network capable of allowing real time reconfiguration decisions to be made. This approach was to be compared to other methods such as fuzzy logic and knowledge based systems considered for the same application. Over the course of the project a more general objective was the identification of the other neural network applications and the education of interested NASA personnel on the topic of Neural Networks.

  16. Performance and management of implantable lithium battery systems for left ventricular assist devices and total artificial hearts

    Science.gov (United States)

    Dodd, J.; Kishiyama, C.; Mukainakano, Hiroshi; Nagata, M.; Tsukamoto, H.

    A lithium ion cell designed for implantable medical devices was tested for its performance as a power source for left ventricular assist devices (LVAD) or total artificial hearts (TAH). These two cardiovascular devices require high power, and thus a high current (0.5-3 A) and high voltage (20-30 V). Since these are implantable medical devices, in addition to high power capability, the power source should have long cycle life and calendar life, as well as high safety. The QL0700I, a 700 mAh cell, was cycled at 0.5 C rate as well as at 1.5 C rate, and the cycle life capacity retention was evaluated after numerous cycles. A battery pack consisting of seven QL0700I cells in series, with a battery management system (BMS) connected, was tested for rate capability as well as safety protection.

  17. Left ventricular dimension decrement index early after axial flow assist device implantation: A novel risk marker for late pump thrombosis.

    Science.gov (United States)

    Joyce, Emer; Stewart, Garrick C; Hickey, Maryclare; Coakley, Lara; Rivero, Jose M; Gosev, Igor; Givertz, Michael M; Couper, Gregory S; Mehra, Mandeep R

    2015-12-01

    It is increasingly recognized that pump thrombosis most likely represents the end stage of a complex interaction between the patient-pump interface. We hypothesized that early patient/pump mismatch, as manifested by suboptimal left ventricular (LV) unloading early after left ventricular assist device (LVAD) implantation, may be a harbinger of increased risk for later LVAD thrombosis. In 64 patients (59 ± 11 years old, 78% men, 44% destination therapy) discharged alive without thrombosis or other device malfunction after first HeartMate II LVAD implantation (between January 2011 and June 2014), LV dimensions in end diastole (LVIDd) and end systole (LVIDs) were compared between pre-implant and optimal set speed pre-discharge echocardiography. LV dimension decrement indices (pre-implant dimension - optimal set speed dimension ÷ pre-implant dimension × 100) for LVIDd [LVIDdDI] and LVIDs [LVIDsDI] were calculated. The incidence of pump thrombosis was 0.06 per patient year (n = 18, median time 8 [interquartile range 2, 17] months). Baseline characteristics including pre-operative LVIDd and LVIDs were similar between LVAD thrombosis and no thrombosis groups. After ventricular assist device implantation, set speed and other ramp parameters did not differ between groups. However, LVIDdDI (19 ± 13% vs 25 ± 11%, p = 0.04) and LVIDsDI (16 ± 16% vs 27 ± 13%, p = 0.008) were significantly lower in patients with later pump thrombosis. A cutoff value of ≤15% using receiver operating characteristic curve analysis was 83% sensitive for LVIDdDI and LVIDsDI for predicting pump thrombosis. Patients with LVIDdDI of >15% vs ≤15% were significantly more likely to be free of pump thrombosis over a median follow-up period of 15 (interquartile range 9, 26) months (log-rank test, p = 0.045). LV dimension decrement index at optimized speed setting on pre-discharge echocardiography is associated with LVAD thrombosis. Copyright © 2015 International Society for Heart and Lung

  18. Piezoelectric polymer gated OFET: Cutting-edge electro-mechanical transducer for organic MEMS-based sensors

    OpenAIRE

    Damien Thuau; Mamatimin Abbas; Guillaume Wantz; Lionel Hirsch; Isabelle Dufour; Cédric Ayela

    2016-01-01

    The growth of micro electro-mechanical system (MEMS) based sensors on the electronic market is forecast to be invigorated soon by the development of a new branch of MEMS-based sensors made of organic materials. Organic MEMS have the potential to revolutionize sensor products due to their light weight, low-cost and mechanical flexibility. However, their sensitivity and stability in comparison to inorganic MEMS-based sensors have been the major concerns. In the present work, an organic MEMS sen...

  19. MEMS (Micro-Electro-Mechanical Systems) for Automotive and Consumer Electronics

    Science.gov (United States)

    Marek, Jiri; Gómez, Udo-Martin

    MEMS sensors gained over the last two decades an impressive width of applications: (a) ESP: A car is skidding and stabilizes itself without driver intervention (b) Free-fall detection: A laptop falls to the floor and protects the hard drive by parking the read/write drive head automatically before impact. (c) Airbag: An airbag fires before the driver/occupant involved in an impending automotive crash impacts the steering wheel, thereby significantly reducing physical injury risk. MEMS sensors are sensing the environmental conditions and are giving input to electronic control systems. These crucial MEMS sensors are making system reactions to human needs more intelligent, precise, and at much faster reaction rates than humanly possible. Important prerequisites for the success of sensors are their size, functionality, power consumption, and costs. This technical progress in sensor development is realized by micro-machining. The development of these processes was the breakthrough to industrial mass-production for micro-electro-mechanical systems (MEMS). Besides leading-edge micromechanical processes, innovative and robust ASIC designs, thorough simulations of the electrical and mechanical behaviour, a deep understanding of the interactions (mainly over temperature and lifetime) of the package and the mechanical structures are needed. This was achieved over the last 20 years by intense and successful development activities combined with the experience of volume production of billions of sensors. This chapter gives an overview of current MEMS technology, its applications and the market share. The MEMS processes are described, and the challenges of MEMS, compared to standard IC fabrication, are discussed. The evolution of MEMS requirements is presented, and a short survey of MEMS applications is shown. Concepts of newest inertial sensors for ESP-systems are given with an emphasis on the design concepts of the sensing element and the evaluation circuit for achieving

  20. A high performance data parallel tensor contraction framework: Application to coupled electro-mechanics

    Science.gov (United States)

    Poya, Roman; Gil, Antonio J.; Ortigosa, Rogelio

    2017-07-01

    The paper presents aspects of implementation of a new high performance tensor contraction framework for the numerical analysis of coupled and multi-physics problems on streaming architectures. In addition to explicit SIMD instructions and smart expression templates, the framework introduces domain specific constructs for the tensor cross product and its associated algebra recently rediscovered by Bonet et al. (2015, 2016) in the context of solid mechanics. The two key ingredients of the presented expression template engine are as follows. First, the capability to mathematically transform complex chains of operations to simpler equivalent expressions, while potentially avoiding routes with higher levels of computational complexity and, second, to perform a compile time depth-first or breadth-first search to find the optimal contraction indices of a large tensor network in order to minimise the number of floating point operations. For optimisations of tensor contraction such as loop transformation, loop fusion and data locality optimisations, the framework relies heavily on compile time technologies rather than source-to-source translation or JIT techniques. Every aspect of the framework is examined through relevant performance benchmarks, including the impact of data parallelism on the performance of isomorphic and nonisomorphic tensor products, the FLOP and memory I/O optimality in the evaluation of tensor networks, the compilation cost and memory footprint of the framework and the performance of tensor cross product kernels. The framework is then applied to finite element analysis of coupled electro-mechanical problems to assess the speed-ups achieved in kernel-based numerical integration of complex electroelastic energy functionals. In this context, domain-aware expression templates combined with SIMD instructions are shown to provide a significant speed-up over the classical low-level style programming techniques.

  1. Long-term prognostic value of risk scores after drug-eluting stent implantation for unprotected left main coronary artery: A pooled analysis of the ISAR-LEFT-MAIN and ISAR-LEFT-MAIN 2 randomized clinical trials.

    Science.gov (United States)

    Xhepa, Erion; Tada, Tomohisa; Kufner, Sebastian; Ndrepepa, Gjin; Byrne, Robert A; Kreutzer, Johanna; Ibrahim, Tareq; Tiroch, Klaus; Valgimigli, Marco; Tölg, Ralf; Cassese, Salvatore; Fusaro, Massimiliano; Schunkert, Heribert; Laugwitz, Karl L; Mehilli, Julinda; Kastrati, Adnan

    2017-01-01

    To evaluate the long-term prognostic value of risk scores in the setting of drug-eluting stent (DES) implantation for uLMCA. Data on the prognostic value of novel risk scores developed to select the most appropriate revascularization strategy in patients undergoing DES implantation for uLMCA disease are relatively limited. The study represents a patient-level pooled analysis of the ISAR-LEFT-MAIN (607 patients randomized to paclitaxel-eluting or sirolimus-eluting stents) and the ISAR-LEFT-MAIN-2 (650 patients randomized to everolimus-eluting or zotarolimus-eluting stents) randomized trials. The Syntax Score (SxScore) as well the Syntax Score II (SS-II), the EuroSCORE and the Global Risk Classification (GRC) were calculated. The primary outcome was all-cause mortality. At a mean follow-up of 3 years there were 160 deaths (12.7%). The death-incidence was significantly higher in the upper tertiles than in the intermediate or lower ones for all risk scores (log-rank test P risk scores were able to stratify the mortality risk at long-term follow-up. EuroSCORE was the only risk score that significantly improved the discriminatory power of a multivariable model to predict long-term mortality. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. First-in-man implantation of left ventricular partitioning device in a patient with chronic heart failure: twelve-month follow-up.

    Science.gov (United States)

    Otasevic, Petar; Sagic, Dragan; Antonic, Zelimir; Nikolic, Serjan D; Khairakhan, Alexander; Radovancevic, Branislav; Gradinac, Sinisa

    2007-09-01

    The ventricular partitioning device (VPD) (Cardiokinetix Inc., Redwood City, Calif) is a novel device that is deployed percutaneously in the left ventricle in patients with anteroapical regional wall motion abnormalities after a myocardial infarction (MI) to partition the ventricle and segregate the dysfunctional region. In this case report we present the first implantation of the VPD in a human, with a 12-month efficacy and safety follow-up. A 48-year-old man had an anterior MI in 2004. A coronary angiogram showed an occlusion of the proximal segment of the left anterior descending artery with no stenosis on other major epicardial vessels. Echocardiography revealed a dilated left ventricle (62 mm) with anteroapical wall motion abnormalities, no apical thrombus, a calculated ejection fraction of 26.8% (by Simpson biplane formula), and an end-systolic volume index (ESVi) of 76.8 mL/m(2). The VPD implant was delivered percutaneously from the femoral artery by the standard techniques for left-sided heart catheterization. The postimplantation course was uneventful. Echocardiography on discharge showed the VPD implanted at the apex, with a left ventricular ejection fraction of 30.9% and an ESVi of 57.2 mL/m(2). Left ventricular ejection fraction and ESVi remained improved during the 12-month follow-up. This case report demonstrates that VPD implantation in this particular patient was feasible and that it may provide a nonsurgical approach to prevent or reverse left ventricle remodeling.

  3. Implantation of VVI pacemaker in a patient with dextrocardia, persistent left superior vena cava, and sick sinus syndrome

    Science.gov (United States)

    Guo, Gongliang; Yang, Lili; Wu, Jinyi; Sun, Liqun

    2017-01-01

    Abstract Background: Dextrocardia, or right-lying heart, is an uncommon congenital heart disease in which the apex of the heart is located on the right side of chest. Persistent left superior vena cava (PLSVA) is a rare venous anomaly that is often associated with the abnormalities of cardiac transduction system. A case with combination of dextrocardia, persistent left superior vena cava, and sick sinus syndrome has not been reported. Methods: We used different techniques including cardiac color Doppler echocardiography, 24-hour Holter monitoring, and abdominal ultrasound to make a diagnosis and treated the patient by implanting a VVI pacemaker. Results: A 50-year-old woman was admitted with a syncope. Angiography of the right atrium and superior vena cava, echocardiography, electrocardiography, and abdominal ultrasound revealed the presence of the combination of mirror image dextrocardia, PLSVA, and sick sinus syndrome. The complex structural anomalies presented great technical challenges for interventional treatments. After thorough examination and understanding of the structural anatomy and anomalies of the superior and inferior vena cava and cardiac chambers, we successfully treated this patient by implanting a VVI pacemaker. Conclusion: Physicians must be aware of the complexity of the morphological and anatomical structures of dextrocardia accompanying PLSVC. Given that the diagnosis of situs inversus was performed at a relatively advanced age, it is therefore important to make such a correct diagnosis followed by appropriate therapeutic intervention. PMID:28151908

  4. Intravascular ultrasound-guided stenting of left main stem dissection after medtronic corevalve implantation

    NARCIS (Netherlands)

    N.M. van Mieghem (Nicolas); P.P.T. de Jaegere (Peter)

    2013-01-01

    textabstractTranscatheter aortic valve implantation (TAVI) implies the introduction, positioning, and deployment of a stented bioprosthesis in the (calcified) native aortic valve. We report an at first glance uneventful TAVI with the Medtronic Corevalve System, which was followed by transient

  5. Angioplastia del seno coronario en el implante de electrodo del ventrículo izquierdo Angioplasty of coronary sinus in left ventricle electrode implant

    Directory of Open Access Journals (Sweden)

    Alejandro Orjuela

    2011-07-01

    Full Text Available Con el incremento de implantes de dispositivos de estimulación cardíaca en pacientes con miocardiopatía dilatada, el diseno día a día más sofisticado de los mismos para satisfacer los requerimientos de los pacientes con cambios anatómicos que surgen como consecuencia de la misma dilatación cardíaca, tales como modificaciones en el calibre, curso, longitud y número de venas coronarias, cada vez se encuentran mayores dificultades para lograr los objetivos anatómicos, en particular el sitio ideal de posicionamiento del electrodo de estimulación ventricular izquierda en el seno coronario. Esta situación limita, en algunos casos, el beneficio terapéutico de esta técnica, viéndose, en ocasiones, en la necesidad de someter al paciente a toracotomía para posicionar el electrodo en el epicardio posterolateral del ventrículo izquierdo. Es así como, con el objetivo de abreviar los tiempos y la morbimortalidad e incrementar el éxito del implante, se disenó una estrategia basada en la técnica de hemodinámica para vencer las obstrucciones de las arterias coronarias y lograr, mediante angioplastia de las estrecheces del seno coronario, un abordaje más preciso a un determinado vaso epicárdico preseleccionado. Se describe la técnica usada en la angioplastia del seno coronario para este propósito.The design of devices of cardiac stimulation in patients with dilated cardiomyopathy has become more sophisticated due to the increment of its implantation, devices that must satisfy the requirements for patients with anatomical changes that appear as a consequence of the cardiac dilation such as caliber modifications, course, length and number of coronary veins. Every time is more difficult to achieve the anatomical objectives, particularly the ideal place for the left ventricular stimulation electrode position in the coronary sinus. This situation limits in some cases the therapeutical benefit of this technique, occasionally facing to the

  6. Early History and Challenges of Implantable Electronics

    OpenAIRE

    KO, WEN H.

    2012-01-01

    Implantable systems for biomedical research and clinical care are now a flourishing field of activities in academia as well as industrial institutions. The broad field includes experimental explorations in electronics, mechanical, chemical, and biological components and systems, and the combination of all these. Today virtually all implants involve both electronic circuits and micro-electro-mechanical-systems (MEMS). This article offers a very brief glance back at the early history of implant...

  7. Frequency and Consequences of Right-Sided Heart Failure After Continuous-Flow Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Kurihara, Chitaru; Critsinelis, Andre C; Kawabori, Masashi; Sugiura, Tadahisa; Loor, Gabriel; Civitello, Andrew B; Morgan, Jeffrey A

    2018-02-01

    Postoperative right-sided heart failure (RHF) is a common complication after continuous-flow left ventricular assist device implantation. Studies have examined RHF in the perioperative period, but few have assessed late-onset RHF. We analyzed the incidence of early and late RHF in patients with HeartMate II and HeartWare left ventricular assist devices and associated morbidity, mortality, and independent predictors of RHF. We retrospectively analyzed records of 526 patients with chronic heart failure who underwent continuous-flow left ventricular assist device implantation; 147 (27.9%) developed RHF (early RHF, n = 87, 16.5%; late RHF, n = 74, 14.4%). We examined demographics, postoperative complications, and long-term survival rate. Patients with RHF or late RHF had higher mortality (p RHF. Patients with RHF had a higher incidence of acute kidney injury (20.4% vs 11.9%, p = 0.01). Device type did not affect the incidence of early, late, or overall RHF. Patients with severe RHF requiring right ventricular assist device support had a low success of bridge to transplantation (11.1% vs 33.3%, p = 0.02). In Cox regression models, RHF was an independent predictor of mortality (hazard ratio = 1.69, 95% confidence interval = 1.28 to 2.22, p RHF were identified. RHF was significantly associated with increased mortality and a higher incidence of postoperative acute kidney injury. RHF decreased the success rate of bridging patients to transplantation when a right ventricular assist device was required. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Institutional Cost Comparison Between Heart Transplants and Left Ventricular Assist Device Implantations.

    Science.gov (United States)

    Chimanji, Neeraj; Kilic, Arman; Hasan, Ayesha; Higgins, Robert S D; Whitson, Bryan A; Kilic, Ahmet

    2016-12-01

    Increased numbers of end-stage heart failure patients and improved technology have led to increased use of left ventricular assist devices as a viable alternative to heart transplants. Given the current economic climate, we compared costs of heart transplant versus device placement. Medical records of patients who received heart transplants or left ventricular assist devices were cross-referenced with institutional financial data. The device cohort was limited to those receiving durable (not temporary) devices. Index admission, 1-year readmission, and overall 1-year charges were compared using standard statistical methods. Of 184 identified patients with end-stage heart failure surgical therapy, 121 received left ventricular assist devices, 43 had heart transplants, and 20 received left ventricular assist devices as bridge to heart transplant; these latter patients were excluded from our analyses. At index admission, mean charges were $863 433 ± $398 427 for device patients and $725 877 ± $488 685 for transplant patients (P = .05). One-year mean readmission rates were similar (4.65/transplant patient and 4.53/device patient; P = .94), with corresponding 1-year survival rates of 87.8% and 78.0% (P = .04). Total readmission charges during year 1 were $169 732 ± $242 366 for device patients and $201 682 ± $297 565 for transplant patients (P = .08), with corresponding overall charges at 1 year of $1 029 732 ± $450 498 and $927 559 ± $562 404 (P = .49). During the first year, heart transplant and left ventricular assist device placement have similar costs. Initial index admission costs seem to favor heart transplant, with device pump costs accounting for some of the difference. From a 1-year survival perspective, heart transplant may be more effective; however, with lack of suitable donors, left ventricular assist devices are valuable in the armamentarium of advanced heart failure surgical options.

  9. Use of Prothrombin Complex Concentrate in Patients during Heart Transplantation after Implantation of a Left Ventricular Mechanical Support System

    Directory of Open Access Journals (Sweden)

    V. V. Lomivorotov

    2012-01-01

    Full Text Available Heart transplantation in patients after implantation of mechanical cardiac support devices entails an extremely high risk for perioperative bleeding. Recombinant activated coagulation factor VII is presently used to reduce the volume of bleeding in this patient group. There are parallel data on its administration-induced thromboembolic events in the literature. This paper describes a case of using a prothrombin complex concentrate in a patient during explantation of a left ventricular bypass system and subsequent orthotopic heart transplantation in the presence of significant hypocoagulation. At the end of a surgery, 1200 IU of the agent was used at a remaining bleeding rate of more than 1000 ml/hour. Within the first 24 hours after surgery, the rate of discharge drainage was less than 100 ml/hour. A control plain chest X-ray study revealed massive left-sided hydrothorax on day 2 postsurgery. The left pleural cavity was revised under thoracoscopic guidance and 1000 ml of blood clots were evacuated. Although the administration of prothrombin complex concentrate did not guard against re-intervention, its use seems a promising strategy in life-threatening bleedings in patients after explantation of mechanical cardiac support devices. Further multicenter investigations are required to determine the efficacy and safety of prothrom-bin complex concentration in cardiac surgery. Key words: Recombinant activated coagulation factor VII, prothrombin complex concentration, mechanical cardiac support device, orthotopic heart transplantation.

  10. Understanding the quasi-static thermo-electro-mechanical response of piezoelectric materials

    Science.gov (United States)

    Ganley, Jeffrey Mark

    2007-12-01

    Piezoelectricity describes the behavior of a class of materials which exhibit a relationship between mechanical strain and electrical field. Piezoelectric materials can be crystals (e.g. quartz), ceramic (e.g. lead-zirconate-titanate---PZT---the primary focus of the present research), or polymers (e.g. polyvinylidine-fluoride - PVDF). Piezopolymers and piezoceramics offer a significant improvement in piezoelectric properties over naturally occurring piezoelectrics like quartz. In the last five years, research in piezoelectrics has begun to change focus from the more traditional sensor/actuator applications to utilizing piezoelectric materials in energy harvesting applications. The present research will explore the very low frequency response of piezoelectrics, including several energy harvesting applications, as well as the interactions between thermal, mechanical and electrical energy in a thermally driven piezoelectric energy generation system. In Chapter 1, the history of piezoelectric research and development is given, along with an overview of piezoelectricity for those readers who are not familiar with the topic. In Chapter 2, current investigations in piezoelectric energy harvesting research are summarized. The present research, namely understanding the quasi-static thermo-electro-mechanical response of piezoelectric materials is also summarized. In addition, two applications: thermal management in a satellite and energy harvesting from a vibrating highway bridge are detailed as motivators for the present research. Chapter 3 gives a summary of the relevant piezoelectric theory. In addition, electrical circuit theory and thermodynamic heat capacity/heat energy considerations required to complete the present research are given. Chapter 4 provides a summary of the experimental testing completed during the course of the present research. Significant testing, including determination of the PZT/Aluminum substrate sample time constants, thermal calibration testing

  11. Is mesocardia with left-sided caval vein draining to coronary sinus a contraindication for a percutaneous pulmonary valve implantation? A case description.

    Science.gov (United States)

    Kantzis, Marinos; Happel, Christoph M; Haas, Nikolaus A

    2017-10-04

    Introduction Although the right jugular vein approach for percutaneous pulmonary valve implantation is well described, there are no reports that describe a percutaneous pulmonary valve implantation through a left superior caval vein to coronary sinus pathway. Case A 14-year-old female with tetralogy of Fallot, mesocardia, left superior caval vein draining into the coronary sinus, and hemiazygos continuation of the inferior caval vein underwent ventricular septal defect closure, with homograft insertion from the right ventricle to the pulmonary artery, patch augmentation of the left pulmonary artery, and creation of an atrial communication. Thereafter followed numerous catheterisations and interventions with stent implantation for stenosis of the left pulmonary artery and the homograft, as did device closure of the atrial communication. When she was a 12-year-old, the indications for a percutaneous pulmonary valve implantation were fulfilled and she underwent implantation of a 22 mm Melody® valve through the left superior caval vein. The extra-stiff exchange wire was pre-formed into a "U-spiral"-type configuration, according to the underlying anatomy, in order to provide a smooth route for the delivery of stents, to create the landing zone, and for the implantation of the Melody "ensemble". The procedure was performed under deep sedation according to our standard protocol. The duration of the procedure was 172 min and the radiation time was 24.9 min. On the basis of this unique experience, percutaneous pulmonary valve implantation is safe and feasible even in patients with unusual anatomy. Crucial is the "U-spiral" shaped configuration of the guide wire.

  12. Macrovascular and microvascular function after implantation of left ventricular assist devices in end-stage heart failure: Role of microparticles.

    Science.gov (United States)

    Sansone, Roberto; Stanske, Beate; Keymel, Stefanie; Schuler, Dominik; Horn, Patrick; Saeed, Diyar; Boeken, Udo; Westenfeld, Ralf; Lichtenberg, Artur; Kelm, Malte; Heiss, Christian

    2015-07-01

    The hemodynamic vascular consequences of implanting left ventricular assist devices (LVADs) have not been studied in detail. We investigated the effect of LVAD implantation compared with heart transplant (HTx) on microvascular and macrovascular function in patients with end-stage heart failure and evaluated whether microparticles may play a role in LVAD-related endothelial dysfunction. Vascular function was assessed in patients with end-stage heart failure awaiting HTx, patients who had undergone implantation of a continuous-flow centrifugal LVAD, and patients who had already received a HTx. Macrovascular function was measured by flow-mediated vasodilation (FMD) using high-resolution ultrasound of the brachial artery. Microvascular function was assessed in the forearm during reactive hyperemia using laser Doppler perfusion imaging and pulsed wave Doppler. Age-matched patients without heart failure and without coronary artery disease (CAD) (healthy control subjects) and patients with stable CAD served as control subjects. Circulating red blood cell (CD253(+)), leukocyte (CD45(+)), platelet (CD31(+)/CD41(+)), and endothelial cell (CD31(+)/CD41(-), CD62e(+), CD144(+)) microparticles were determined by flow cytometry and free hemoglobin by enzyme-linked immunosorbent assay. FMD and microvascular function were significantly impaired in patients with end-stage heart failure compared with healthy control subjects and patients with stable CAD. LVAD implantation led to recovery of microvascular function, but not FMD. In parallel, increased free hemoglobin was observed along with red and white cell microparticles and endothelial and platelet microparticles. This finding indicates destruction of blood cells with release of hemoglobin and activation of endothelial cells. HTx and LVAD implantation led to similar improvements in microvascular function. FMD increased and microparticle levels decreased in patients with HTx, whereas shear stress during reactive hyperemia was

  13. Thoracoscopic Left Cardiac Sympathetic Denervation for a Patient with Catecholaminergic Polymorphic Ventricular Tachycardia and Recurrent Implantable Cardioverter-Defibrillator Shocks

    Directory of Open Access Journals (Sweden)

    Woo-Sik Yu

    2015-06-01

    Full Text Available A patient presented with loss of consciousness and conversion. During an exercise test, catecholaminergic polymorphic ventricular tachycardia (CPVT resulted in cardiac arrest. He started taking medication (a beta-blocker and flecainide and an implantable cardioverter defibrillator (ICD was inserted, but the ventricular tachycardia did not resolve. Left cardiac sympathetic denervation (LCSD was then performed under general anesthesia, and the patient was discharged on the second postoperative day without complications. One month after the operation, no shock had been administered by the ICD, and an exercise stress test did not induce ventricular tachycardia. Although beta- blockers are the gold standard of therapy in patients with CPVT, thoracoscopic LCSD is safe and can be an effective alternative treatment option for patients with intractable CPVT.

  14. Small wind turbine performance evaluation using field test data and a coupled aero-electro-mechanical model

    Science.gov (United States)

    Wallace, Brian D.

    A series of field tests and theoretical analyses were performed on various wind turbine rotor designs at two Penn State residential-scale wind-electric facilities. This work involved the prediction and experimental measurement of the electrical and aerodynamic performance of three wind turbines; a 3 kW rated Whisper 175, 2.4 kW rated Skystream 3.7, and the Penn State designed Carolus wind turbine. Both the Skystream and Whisper 175 wind turbines are OEM blades which were originally installed at the facilities. The Carolus rotor is a carbon-fiber composite 2-bladed machine, designed and assembled at Penn State, with the intent of replacing the Whisper 175 rotor at the off-grid system. Rotor aerodynamic performance is modeled using WT_Perf, a National Renewable Energy Laboratory developed Blade Element Momentum theory based performance prediction code. Steady-state power curves are predicted by coupling experimentally determined electrical characteristics with the aerodynamic performance of the rotor simulated with WT_Perf. A dynamometer test stand is used to establish the electromechanical efficiencies of the wind-electric system generator. Through the coupling of WT_Perf and dynamometer test results, an aero-electro-mechanical analysis procedure is developed and provides accurate predictions of wind system performance. The analysis of three different wind turbines gives a comprehensive assessment of the capability of the field test facilities and the accuracy of aero-electro-mechanical analysis procedures. Results from this study show that the Carolus and Whisper 175 rotors are running at higher tip-speed ratios than are optimum for power production. The aero-electro-mechanical analysis predicted the high operating tip-speed ratios of the rotors and was accurate at predicting output power for the systems. It is shown that the wind turbines operate at high tip-speeds because of a miss-match between the aerodynamic drive torque and the operating torque of the wind

  15. Impact of implantable defibrillators and resynchronization therapy on outcome in patients with left ventricular dysfunction--a meta-analysis

    DEFF Research Database (Denmark)

    Abdulla, Jawdat; Haarbo, Jens; Køber, Lars

    2006-01-01

    BACKGROUND: The clinical benefits of cardiac resynchronization therapy (CRT) and primary prophylactic implantable cardioverter defibrillator (ICD) in patients with left ventricular systolic dysfunction (LVSD) are debated. OBJECTIVE: To evaluate by a meta-analysis the effect of CRT and prophylactic...... ICD therapy in patients with LVSD. METHODS: Eligible trials evaluating the effect of CRT vs. no-CRT, ICD vs. no-ICD and adding ICD to CRT vs. no-ICD were selected and meta-analyzed. The outcomes were: all cause mortality, cardiac mortality, hospitalization for heart failure and change in exercise...... tolerance and New York Heart Association class. RESULTS: Implantation of CRT reduced all cause mortality odds ratio (OR) = 0.73 (0.60-0.89) p = 0.002 and hospitalization for heart failure OR = 0.60 (0.45, 0.80) p = 0.001, increased peak oxygen consumption by 1.77 (0.32-3.22) ml/kg/min p = 0.017 and improved...

  16. Acute Reverse Remodelling After Transcatheter Aortic Valve Implantation: A Link Between Myocardial Fibrosis and Left Ventricular Mass Regression.

    Science.gov (United States)

    Dobson, Laura Elizabeth; Musa, Tarique A; Uddin, Akhlaque; Fairbairn, Timothy A; Swoboda, Peter P; Erhayiem, Bara; Foley, James; Garg, Pankaj; Haaf, Philip; Fent, Graham J; Malkin, Christopher J; Blackman, Daniel J; Plein, Sven; Greenwood, John P

    2016-12-01

    Despite the wealth of data showing the positive effects on cardiac reverse remodelling in the long-term, the immediate effects of transcatheter aortic valve implantation (TAVI) on the left ventricle are yet to be comprehensively described using cardiovascular magnetic resonance imaging. Also, the link between myocardial fibrosis and acute left ventricular (LV) mass regression is unknown. Fifty-seven patients with severe aortic stenosis awaiting TAVI underwent paired cardiovascular magnetic resonance scans before and early after the procedure (4 [interquartile range, 3-5] days). LV mass, volume, and function were measured. Late gadolinium enhancement (LGE) imaging was performed to assess for the presence of and pattern of myocardial fibrosis. After the procedure, 53 (95%) patients experienced an immediate (10.1 ± 7.1%) reduction in indexed LV mass (LVMi) from 76 ± 15.5 to 68.4 ± 14.7 g/m(2) (P reverse remodelling occurs immediately after TAVI, with significant LV mass regression in the total population and an improvement in LVEF in those with preexisting LV impairment. Those without myocardial fibrosis at baseline experience greater LV mass regression than those with fibrosis. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  17. Cardiogenic shock associated with loco-regional anesthesia rescued with left ventricular assist device implantation

    Directory of Open Access Journals (Sweden)

    Droogan Christopher

    2010-12-01

    Full Text Available Abstract A healthy 53 year old man developed profound cardiogenic shock following instillation of bupivacaine-lidocaine-epinephrine solution as a locoregional anesthetic for elective outpatient shoulder surgery. Intubation, resuscitation, and transfer to the nearby hospital were done: echocardiography showed profound biventricular dysfunction; cardiac catheterization showed normal coronary arteries. Despite placement of an intra-aortic balloon pump and intravenous vasoactive drugs, the patient remained in shock. Stabilization was achieved with emergent institution of cardiopulmonary bypass and placement of a temporary left ventricular assist device (LVAD. Twenty-four hours later, cardiac function normalized and the LVAD was removed. The patient was discharged five days later and remained with normal heart function in three-year follow-up.

  18. Estimation of the cost of electro-mechanical equipment for small hydropower plants - review and comparison of methods

    Science.gov (United States)

    Lipiński, Seweryn; Olkowski, Tomasz

    2017-10-01

    The estimate of the cost of electro-mechanical equipment for new small hydropower plants most often amounts to about 30-40% of the total budget. In case of modernization of existing installations, this estimation represents the main cost. This matter constitutes a research problem for at least few decades. Many models have been developed for that purpose. The aim of our work was to collect and analyse formulas that allow estimation of the cost of investment in electro-mechanical equipment for small hydropower plants. Over a dozen functions were analysed. To achieve the aim of our work, these functions were converted into the form allowing their comparison. Then the costs were simulated with respect to plants' powers and net heads; such approach is novel and allows deeper discussion of the problem, as well as drawing broader conclusions. The following conclusions can be drawn: significant differences in results obtained by using various formulas were observed; there is a need for a wide study based on national investments in small hydropower plants that would allow to develop equations based on local data; the obtained formulas would let to determinate the costs of modernization or a new construction of small hydropower plant more precisely; special attention should be payed to formulas considering turbine type.

  19. Microcontroller Based Proportional Derivative Plus Conditional Integral Controller for Electro-Mechanical Dual Acting Pulley Continuously Variable Transmission Ratio Control

    Science.gov (United States)

    Budianto, A.; Tawi, K. B.; Hussein, M.; Supriyo, B.; Ariyono, S.; Che Kob, M. S.; Ezlamy Zulkifli, Mohd; K, Khairuldean A.; Daraoh, Aishah

    2012-09-01

    Electro-Mechanical Dual Acting Pulley (EMDAP) Continuously Variable Transmission (CVT) is a transmission utilized by electro-mechanical actuated system. It has a potential to reduce energy consumption because it only needs power during changing CVT ratio and no power is needed to maintain CVT ratio due to self lock mechanism design. This paper proposed simple proportional derivative plus conditional integral (PDCI) controller to control EMDAP CVT ratio which can be simply implemented on a microcontroller. This proposed controller used Astrom-Hagglund method and Ziegler-Nichols formula to tune PDCI gain. The Proportional Derivative controller is directly activated from the start but Integral controller is only activated when the error value reaches error value setting point. Simulation using Matlab/Simulink software was conducted to evaluate PDCI system performance. The simulation results showed PDCI controller has ability to perform maximum overshoot 0.1%, 0.001 steady state error and 0.5s settling time. For clamping condition, settling time is about 11.46s during changing ratio from 2.0 to 0.7, while for release condition, settling time is about 8.33s during changing ratio from 0.7 to 2.0.

  20. Prospective Randomized Evaluation of Implantable Cardioverter-Defibrillator Programming in Patients With a Left Ventricular Assist Device.

    Science.gov (United States)

    Richardson, Travis D; Hale, Leslie; Arteaga, Christopher; Xu, Meng; Keebler, Mary; Schlendorf, Kelly; Danter, Matthew; Shah, Ashish; Lindenfeld, JoAnn; Ellis, Christopher R

    2018-02-23

    Ventricular arrhythmias are common in patients with left ventricular assist devices (LVADs) but are often hemodynamically tolerated. Optimal implantable cardioverter defibrillator (ICD) tachy-programming strategies in patients with LVAD have not been determined. We sought to determine if an ultra-conservative ICD programming strategy in patients with LVAD affects ICD shocks. Adult patients with an existing ICD undergoing continuous flow LVAD implantation were randomized to standard ICD programming by their treating physician or an ultra-conservative ICD programming strategy utilizing maximal allowable intervals to detection in the ventricular fibrillation and ventricular tachycardia zones with use of ATP. Patients with cardiac resynchronization therapy (CRT) devices were also randomized to CRT ON or OFF. Patients were followed a minimum of 6 months. The primary outcome was time to first ICD shock. Among the 83 patients studied, we found no statistically significant difference in time to first ICD shock or total ICD shocks between groups. In the ultra-conservative group 16% of patients experienced at least one shock compared with 21% in the control group ( P =0.66). There was no difference in mortality, arrhythmic hospitalization, or hospitalization for heart failure. In the 41 patients with CRT ICDs fewer shocks were observed with CRT-ON but this was not statistically significant: 10% of patients with CRT-ON (n=21) versus 38% with CRT-OFF (n=20) received shocks ( P =0.08). An ultra-conservative programming strategy did not reduce ICD shocks. Programming restrictions on ventricular tachycardia and ventricular fibrillation zone therapy should be reconsidered for the LVAD population. The role of CRT in patients with LVAD warrants further investigation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01977703. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  1. Predictive factor and clinical consequence of left bundle-branch block after a transcatheter aortic valve implantation.

    Science.gov (United States)

    Nishiyama, Takahiko; Tanosaki, Sho; Tanaka, Makoto; Yanagisawa, Ryo; Yashima, Fumiaki; Kimura, Takehiro; Arai, Takahide; Tsuruta, Hikaru; Murata, Mitsushige; Aizawa, Yoshiyasu; Kohno, Takashi; Maekawa, Yuichiro; Hayashida, Kentaro; Takatsuki, Seiji; Fukuda, Keiichi

    2017-01-15

    Atrioventricular conduction disturbances can develop after transcatherter aortic valve implantations (TAVIs) with balloon-expandable valves because the conduction system exists adjacent to the aortic valve. However, the clinical consequence of patients with new onset conduction disturbances is not clear. This study aimed to assess the incidence and progress of new-onset conduction disturbances following TAVIs and the cardiac function evaluated by echocardiography. This study consisted of 90 consecutive patients that underwent TAVIs with Edwards SAPIEN XT valves in a single center. Atrioventricular conduction system disturbances were assessed by electrocardiography and echocardiography up to 6months post TAVI. Twenty patients (22%) developed new onset complete left bundle branch block (CLBBB) or received pacemaker implantations (PMIs) during the follow-up. At 6months after the procedure, 4 patients underwent PMIs for complete AV block (CAVB), and 4 patients had persistent CLBBB. Those that developed CLBBB and AVB had a higher morbidity from hypertension and lower estimated glomerular filtration rate (eGFR). The ECG, TTE, and CT parameters did not differ between the two groups. The ratio of the valve and LVOT area was significantly associated with a higher cumulative risk of events (HR, 3.005; 95% CI, 1.034-8.736; P<0.05). Up to 20% of patients developed new CLBBB or CAVB and more than half were expected to recover. However, it required attention because approximately 40% were persistent. The ratio of the valve to LVOT area was an independent predictor. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Clinical outcomes after implantation of a centrifugal flow left ventricular assist device and concurrent cardiac valve procedures.

    Science.gov (United States)

    Milano, Carmelo; Pagani, Francis D; Slaughter, Mark S; Pham, Duc Thinh; Hathaway, David R; Jacoski, Mary V; Najarian, Kevin B; Aaronson, Keith D

    2014-09-09

    Cardiac valve procedures are commonly performed concurrently during implantation of left ventricular assist devices, but the added procedural risk has not been studied in detail. Data from patients receiving the HeartWare Ventricular Assist Device in the ADVANCE bridge to transplant (BTT) trial and continued access protocol were reviewed. Of 382 consecutive patients who completed follow-up between August 2008 and June 2013 (mean time on support 389 days, median 271 days), 262 (68.6%) underwent isolated HeartWare Ventricular Assist Device implantation, 75 (19.6%) a concurrent valve procedure, and 45 (11.8%) concurrent nonvalvular procedures. Of the concurrent valve procedures, 56 were tricuspid, 13 aortic, and 6 mitral. Survival was similar between groups (79% for concurrent valve procedures and 85% for HeartWare Ventricular Assist Device only at 1 year; P=0.33). Concurrent valve procedures were also associated with increased unadjusted early right heart failure (RHF). A multivariable analysis for death and RHF (121 total events) identified female sex (odds ratio=2.0 [95% confidence interval, 1.2-3.3; P=0.0053]) and preimplant tricuspid regurgitation severity (odds ratio=2.9 [95% confidence interval, 1.8-4.8, PRHF compared with those who received TVP (0.19 versus 0.05 events per patient-year, respectively; P=0.024). Compared with HeartWare Ventricular Assist Device alone, survival was equivalent for the concurrent valve procedure group. Tricuspid regurgitation severity was the most important predictor of increased postoperative RHF, and concurrent TVP was not an independent predictor of RHF overall. Concurrent TVP may reduce the rate of late RHF for patients with significant preimplant tricuspid insufficiency. http://www.clinicaltrials.gov. Unique identifier: NCT00751972. © 2014 American Heart Association, Inc.

  3. Activated Hemostatic Biomarkers in Patients with Implanted Left Ventricle Assist Devices: Are Heparin and/or Clopidogrel Justified?

    Science.gov (United States)

    Pacholewicz, Jerzy; Kuliczkowski, Wiktor; Kaczmarski, Jacek; Zakliczyński, Michał; Garbacz, Marcin; Zembala, Marian; Serebruany, Victor

    2015-01-01

    Adequate anticoagulation represents a major problem for left ventricle assist device (LVAD) utilization in patients awaiting heart transplantation as well as for regeneration of the native heart. The proper management of hemostatic abnormalities during LVAD support may improve survival by reducing the incidence of hemorrhagic and/or thromboembolic complications. A 40-year-old man with implanted pulsatile LVAD due to dilated cardiomyopathy received aspirin and warfarin. The patient underwent serial weekly monitoring of hemostatic biomarkers including international normalization ratio, prothrombin time, prothrombin activity, activated partial thromboplastin time, fibrinogen, D-dimer, platelet aggregation induced by adenosine diphosphate and arachidonic acid, platelet count, and mean platelet volume. The external pump was exchanged three times - twice because of a clot formation in the blood chamber of the pump, and once according to the standard protocol. LVAD use was consistently associated with enhanced adenosine diphosphate-induced platelet aggregation independent from the timing of clot formation or external pump exchange. Among coagulation indices, increased D-dimer holds predictive value for clot formation. The fibrinogen level peaked before the first pump exchange and was twice as high than the average values. Gradual improvement in exercise capacity was observed 2 years after implantation, after which the patient underwent a controlled stress test in the stop mode of the LVAD and the device was successfully explanted. Serial assessment of hemostatic biomarkers may benefit and triage LVAD patients. Consistent platelet activation during long-term LVAD may justify the addition of clopidogrel, while high D-dimer and/or elevated fibrinogen may indicate adding heparin to the conventional antithrombotic regimen. Randomized evidence is needed to test such a hypothesis. © 2015 S. Karger AG, Basel.

  4. Reservations about the Selvester QRS score in left bundle branch block - Experience in patients with transcatheter aortic valve implantation.

    Science.gov (United States)

    Poels, Thomas T; Kats, Suzanne; Veenstra, Leo; van Ommen, Vincent; Maessen, Jos G; Prinzen, Frits W

    The Selvester QRS score (S-score) estimates myocardial scar using electrocardiographic criteria. We evaluated the S-score for left bundle branch block (LBBB). Studied were 36 patients who developed persistent LBBB upon transcatheter aortic valve implantation (TAVI, TAVI-LBBB group) and 36 matched patients with persistent narrow QRS (TAVI-nQRS group). Electrocardiograms were recorded before and briefly after TAVI and during ~6months follow-up. S-score was calculated using criteria for hypertrophic (in absence of LBBB) or LBBB hearts. In TAVI-LBBB patients correlation between S-scores pre-TAVI and post-TAVI was absent (R 2 =0.023). High S-scores post-TAVI occurred in patients with low pre-TAVI scores. Pre-post TAVI scores correlated weakly in TAVI-nQRS (R 2 =0.182), indicating a possible influence of ventricular unloading by TAVI. In both groups S-scores at post-TAVI and follow-up compared reasonably (R 2 =0.389 and R 2 =0.386), indicating reproducibility in more stable conditions. This study indicates that the use of the LBBB S-score criteria overestimates scar size and that caution is recommended in the use of the score in patients with LBBB. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  5. Failing left ventricle to ascending aorta conduit-Hybrid implantation of a melody valve and NuMed covered stent.

    Science.gov (United States)

    Gössl, Mario; Johnson, Jonathan N; Hagler, Donald J

    2014-04-01

    We present the case of a 36-year-old woman with increasing shortness of breath, a new 3/4 diastolic murmur, and a complex history of LV outflow tract obstruction. She has undergone multiple surgeries including the replacement of her old LV apex to ascending aorta conduit with a 20-mm Gore-Tex tube graft, addition of a 24-mm homograft sutured between the conduit and the LV apex, and insertion of a 21-mm Freestyle porcine valve conduit between the Gore-Tex tube graft and allograft at age 23. The current assessment showed a failing Freestyle conduit prosthesis leading to left heart decompensation. Due to substantial surgical risk, the patient underwent successful implantation of a Melody valve into the Gore-Tex tube and exclusion of the failing Freestyle bioprosthesis with a NuMed CP stent in a hybrid procedure. The case nicely illustrates the collaborative potential of cardiovascular surgeons and interventional cardiologists in the new arena of a hybrid operating room. Complex hybrid procedures like the current one, especially those including percutaneous placements of valves, offer therapeutic options for patients that are otherwise too high risk for conventional open heart surgery. Copyright © 2013 Wiley Periodicals, Inc.

  6. Effects of pacemaker, implantable cardioverter-defibrillator, and left ventricular leads on CT-based attenuation correction.

    Science.gov (United States)

    Suzuki, Akira; Koshida, Kichiro; Matsubara, Kosuke

    2014-03-01

    CT-based attenuation correction (CTAC) of myocardial SPECT images has been becoming more popular--and the application of SPECT/CT increasing--because it prevents attenuation-induced image degradation. However, CTAC can be affected by overestimation of counts caused by metals. It is possible that pacemaker, left ventricle (LV), and implantable cardioverter-defibrillator (ICD) leads have an influence on myocardial SPECT findings. The present study investigated the impact of these leads on SPECT with CTAC. Pacemaker, LV, and ICD leads were examined using a simple phantom and a cardiac phantom. The effects of metal artifacts from leads in high-resolution mode and ultra-high-resolution mode were assessed using a simple phantom. Images and polar maps were generated from the cardiac phantom. The pacemaker and LV leads essentially had no influence, whereas the ICD lead resulted in maximal (6%) overestimation in a study investigating which metals cause artifacts that affect CTAC. None of the leads seriously influenced CTAC when the cardiac phantom was used. Small pacemaker or ICD and LV leads will cause a slight overestimation, but CTAC should be used because it can correct attenuation of the inferior and anteroseptal walls on SPECT images.

  7. Determinants of Left Ventricular Mass Regression in Patients with Severe Symptomatic Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

    Science.gov (United States)

    Weissler-Snir, Adaya; Shapira, Yaron; Sagie, Alexander; Kazum, Shirit; Assali, Abid; Vaknin-Assa, Hana; Bental, Tamir; Codner, Pablo; Orvin, Katia; Kornowski, Ran; Vaturi, Mordehay

    2015-05-01

    The dynamics of left ventricular mass (LVM) regression following the relief of chronic left ventricular pressure overload are prone to variation. The study aim was to identify determinants of LVM regression following transcatheter aortic valve implantation (TAVI). A total of 134 patients undergoing TAVI was identified. A retrospective analysis was performed of LVM indexed to body surface area (LVMi), calculated using transthoracic echocardiography at baseline and at six to 12 months post-TAVI. At six to 12 months after TAVI, there was a significant reduction in mean LVMi (from 118.2 ± 26.67 g/m2 to 103.4 ± 27.07 g/m2; p < 0.001) driven by a decrease in left ventricular wall thickness. The relative wall thickness (RWT) was decreased (0.54 ± 0.10 cm versus 0.51 ± 0.09 cm; p = 0.006), whereas the prevalence of concentric remodeling (RWT ≥ 0.42) remained unchanged (85.1% versus 80.6%; p = 0.3). However, 47 patients (35.1%) demonstrated significant LVMi regression, but had a lower baseline LVMi than patients who demonstrated significant regression (109.8 ± 25.8 g/m2 versus 122 ± 26.1 g/m2; p = 0.008) but had otherwise similar characteristics. A greater magnitude of LVMi reduction was associated with a greater baseline LVMi (r = 0.39; p < 0.001), where patients with LVMi in the highest quartile had the most substantial reduction in LVMi (p < 0.001). Multivariable analysis identified pre-TAVI LVMi as the sole independent predictor of LVMi regression at six to 12 months post-TAVI (P = 0.45; 95% confidence interval 0.255-0.534; p < 0.001). LVM regression at six to months post-TAVI was variable, with about one-third of patients not showing a significant regression. Only baseline LVM predicted LVM regression; patients with a higher baseline LVM demonstrated a greater regression.

  8. Compact multichannel high-resolution micro-electro-mechanical systems-based interrogator for Fiber Bragg grating sensing.

    Science.gov (United States)

    Ganziy, D; Rose, B; Bang, O

    2017-04-20

    We propose a novel type of compact high-resolution multichannel micro-electro-mechanical systems (MEMS)-based interrogator, where we replace the linear detector with a digital micromirror device (DMD). The DMD is typically cheaper and has better pixel sampling than an InGaAs detector used in the 1550 nm range, which leads to cost reduction and better performance. Moreover, the DMD is a 2D array, which means that multichannel systems can be implemented without any additional optical components in the interrogator. This makes the proposed interrogator highly cost-effective, particularly for multichannel systems. The digital nature of the DMD also provides opportunities for advanced programmable Hadamard spectroscopy, which, without significant penalties, can greatly improve the wavelength fit resolution. Our results show that DMDs can be used in high-resolution spectroscopy and for Fiber Bragg grating (FBG) interrogation.

  9. Compact multichannel high-resolution micro-electro-mechanical systems-based interrogator for Fiber Bragg grating sensing

    DEFF Research Database (Denmark)

    Ganziy, Denis; Rose, Bjarke; Bang, Ole

    2017-01-01

    We propose a novel type of compact high-resolution multichannel micro-electro-mechanical systems (MEMS)-based interrogator, where we replace the linear detector with a digital micromirror device (DMD). The DMD is typically cheaper and has better pixel sampling than an InGaAs detector used...... in the 1550 nm range, which leads to cost reduction and better performance. Moreover, the DMD is a 2D array, which means that multichannel systems can be implemented without any additional optical components in the interrogator. This makes the proposed interrogator highly cost-effective, particularly...... for multichannel systems. The digital nature of the DMD also provides opportunities for advanced programmable Hadamard spectroscopy, which, without significant penalties, can greatly improve the wavelength fit resolution. Our results show that DMDs can be used in high-resolution spectroscopy and for Fiber Bragg...

  10. Electro-mechanical response of a 3D nerve bundle model to mechanical loads leading to axonal injury.

    Science.gov (United States)

    Cinelli, I; Destrade, M; Duffy, M; McHugh, P

    2017-07-01

    Axonal damage is one of the most common pathological features of traumatic brain injury, leading to abnormalities in signal propagation for nervous systems. We present a 3D fully coupled electro-mechanical model of a nerve bundle, made with the finite element software Abaqus 6.13-3. The model includes a real-time coupling, modulated threshold for spiking activation and independent alteration of the electrical properties for each 3-layer fibre within the bundle. Compression and tension are simulated to induce damage at the nerve membrane. Changes in strain, stress distribution and neural activity are investigated for myelinated and unmyelinated nerve fibres, by considering the cases of an intact and of a traumatized nerve membrane. Results show greater changes in transmitting action potential in the myelinated fibre.

  11. Three-dimensional profile measurement of micro-electro-mechanical systems structures based on infrared light reflection interference

    Science.gov (United States)

    Shi, Jianhua; Han, Bingchen

    2017-11-01

    A new method of measuring the three-dimensional (3D) profile of micro-electro-mechanical systems (MEMS) structures based on infrared light reflection interference is developed in this paper. The application of reflection interference technology in a 3D profile reconstruction is extended from white light to infrared light. The measurement system comprised an infrared light source, an interference microscope, an infrared light charge-coupled device, a ceramic piezo and a data acquisition system. The 3D profile of the MEMS device structures was obtained by vertical scanning interferometry and it is consistent with the scanning electron microscope image. The results indicate that the lateral resolution is 0.18 um and the vertical resolution is 1 nm.

  12. An electro-mechanically coupled model for the dynamic behavior of a dielectric electro-active polymer actuator

    Science.gov (United States)

    Hodgins, M.; Rizzello, G.; Naso, D.; York, A.; Seelecke, S.

    2014-10-01

    Dielectric electro-active polymer (DEAP) technology holds promise for enabling lightweight, energy efficient, and scalable actuators. The circular DEAP actuator configuration (also known as cone or diaphragm actuator) in particular shows potential in applications such as pumps, valves, micro-positioners and loudspeakers. For a quantitative prediction of the actuator behavior as well as for design optimization tasks, material models which can reproduce the coupled electromechanical behavior inherent to these actuators are necessary. This paper presents a non-linear viscoelastic model based on an electro-mechanical Ogden free energy expression for the DEAP. The DEAP model is coupled with a spring/mass system to study the dynamic performance of such a representative system from static behavior to 50 Hz. The system is identified and validated by several different experiments.

  13. Simplified Design and Optimization of Slotless Synchronous PM Machine for Micro-Satellite Electro-Mechanical Batteries

    Directory of Open Access Journals (Sweden)

    ABDI, B.

    2009-10-01

    Full Text Available Electro-mechanical batteries have important advantages as compared with chemical batteries, especially in low earth orbit satellites applications. High speed slotless external rotor permanent magnet machines are used in these systems as Motor/Generator. Proper material and structure for space applications are introduced. A simplified analytic design method is given for this type of machines. Finally, the optimization of machine in order to have maximum efficiency and minimum volume and weight are given in this paper. Particle swarm optimization is used as the optimization algorithm and the finite element-based simulations are used to confirm the design and optimization process and show less than 1.2% error in parametric design.

  14. Robust Clamping Force Control of an Electro-Mechanical Brake System for Application to Commercial City Buses

    Directory of Open Access Journals (Sweden)

    Sangjune Eum

    2017-02-01

    Full Text Available This paper proposes a sensor-less robust force control method for improving the control performance of an electro-mechanical brake (EMB which is applicable to commercial city buses. The EMB generates the accurate clamping force commanded by a driver through an independent motor control at each wheel instead of using existing mechanical components. In general, an EMB undergoes parameter variation and a backdrivability problem. For this reason, the cascade control strategy (e.g., force-position cascade control structure is proposed and the disturbance observer is employed to enhance control robustness against model variations. Additionally, this paper proposed the clamping force estimation method for a sensor-less control, i.e., the clamping force observer (CFO. Finally, in order to confirm the performance and effectiveness of a proposed robust control method, several experiments are performed and analyzed.

  15. Percutaneous implantation of the left ventricular partitioning device for chronic heart failure: a pilot study with 1-year follow-up.

    Science.gov (United States)

    Sagic, Dragan; Otasevic, Petar; Sievert, Horst; Elsasser, Albrecht; Mitrovic, Veselin; Gradinac, Sinisa

    2010-06-01

    To assess short-term safety defined as the successful delivery and deployment of the ventricular partitioning device (VPD) implant, as well as 12-month functional, clinical, and haemodynamic effectiveness. Ventricular partitioning device implantation was successful in 15/18 (83%) patients with anteroapical regional wall motion abnormalities following myocardial infarction. In one patient, the VPD was removed 3 days post implantation and the patient subsequently died due to extra-cardiac sepsis. When compared with baseline, there was significant improvement at 6 and 12 months following VPD implantation in NYHA class (2.21 +/- 0.57 vs. 1.28 +/- 0.46 vs. 1.23 +/- 0.4.3, respectively, P < 0.001 for both), left ventricular (LV) end-systolic volume (189 +/- 45 vs. 142 +/- 29 vs. 151 +/- 48 mL/m(2), respectively, P < 0.001 for both), and LV end-diastolic volume (260 +/- 47 vs. 208 +/- 33 vs. 222 +/- 58 mL/m(2), respectively, P < 0.001 for both). After 12 months, an improvement in LV ejection fraction was noted (28 +/- 7 vs. 32 +/- 7 vs. 33 +/- 9%, respectively, P = 0.02) as well as improvement in 6 min walk distance (382 +/- 123 vs. 409 +/- 7 vs. 425 +/- 140 m) when compared with pre-procedural values. Our data indicate that VPD implantation is safe and feasible, and that VPD implantation improves LV haemodynamics and functional capacity in the 12 months following the procedure.

  16. Smart materials fabrication and materials for micro-electro-mechanical systems; Symposium Proceedings, San Francisco, CA, Apr. 28-30, 1992

    Science.gov (United States)

    Jardine, A. Peter (Editor); Johnson, George C. (Editor); Crowson, Andrew (Editor); Allen, Mark (Editor)

    1992-01-01

    A conference on the rapidly developing fields of `smart materials' and micro-electro-mechanical systems produced papers in the areas of fabrication and characterization of ferroelectric thin films; polycrystalline silicon; optical, chemical, and biological sensors; thin film shape memory alloys; materials characterization; and alternative materials and applications.

  17. Coronary Venous Dissection from Left Ventricular Lead Placement During Cardiac Resynchronization Therapy With Defibrillator Implantation and Associated in-Hospital Adverse Events (from the NCDR ICD Registry).

    Science.gov (United States)

    Hsu, Jonathan C; Varosy, Paul D; Bao, Haikun; Dewland, Thomas A; Curtis, Jeptha P; Marcus, Gregory M

    2018-01-01

    Coronary venous dissection is a known complication of left ventricular lead placement during implantation of a cardiac resynchronization with defibrillator (CRT-D) system. A large-scale evaluation of the prevalence of coronary venous dissection and associated in-hospital clinical outcomes has not been performed. We sought to identify predictors of coronary venous dissection and evaluate subsequent in-hospital adverse events in those with the complication. We studied 140,991 first-time CRT-D recipients in the implantable cardioverter-defibrillator (ICD) Registry implanted between 2006 and 2011. Using hierarchical multivariable logistic regression adjusting for patient, implanting physician, and hospital characteristics, we examined predictors of coronary venous dissection and its association with other major complications, length of hospital stay, and in-hospital mortality. Coronary venous dissection occurred in 392 patients (0.28%). After multivariable adjustment, female gender and left bundle branch block were associated with greater odds of coronary venous dissection. Conversely, atrial fibrillation, previous coronary artery bypass graft, and higher implanter procedure volume were associated with lower odds of coronary venous dissection (all p values 3 days (OR 1.71, 95% CI 1.29 to 2.29, p <0.0001), but not in-hospital death (OR 0.78, 95% CI 0.12 to 5.25, p = 0.8012). In conclusion, in a large population of first-time CRT-D recipients, specific patient and implanter characteristics predicted coronary venous dissection risk. Coronary venous dissection was associated with major in-hospital complications and prolonged hospitalization, but not death. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The Malone Antegrade Continence Enema (MACE principle in children: is it important if the conduit is implanted in the left or the right colon?

    Directory of Open Access Journals (Sweden)

    Karine F. Meyer

    2008-03-01

    Full Text Available OBJECTIVE: The aim of the study was to determine which was the optimal side for the conduit to be placed (right or left colon for antegrade continence enema implantation. MATERIALS AND METHODS: Between July 1999 and March 2006, 31 patients underwent the construction of a catheterizable conduit using the Malone principle (MACE In 22 cases the conduit was re-implanted in the right colon and in 9 cases in the left colon. There were 20 male patients and 11 female patients, with a mean age of 10.23 years. The follow-up period varied from 3 from 83 months (average 25 months. Right and left implantation of the conduit in the colon were compared with regards to the presence of complications, volume of the solution utilized, frequency of colonic lavage, time needed for performing the enema, and degree of satisfaction. RESULTS: One patient with the conduit in the right colon, using the appendix, lost the mechanism after two month follow-up. Thirty patients remain clean and are all capable of performing self-catheterization. No statistically significant differences were found between the groups regarding the variables studied: complications (p = 1.000, solution volume (p = 0.996, time required (p = 0.790 and patient's rating (p = 0.670. The lavage frequency required for patients with the conduit in the right colon may be lower. CONCLUSION: The MACE principle was considered effective for treating fecal retention and leaks, independent of the implantation site. The success of this surgery appears to be directly related to the patient's motivation and not to the technique utilized.

  19. Outcome after implantation of cardiac resynchronization/defibrillation systems in patients with congestive heart failure and left bundle-branch block.

    Science.gov (United States)

    Pfau, Giselher; Schilling, Thomas; Kozian, Alf; Lux, Anke; Götte, A; Huth, Christof; Hachenberg, Thomas

    2010-02-01

    The implantation of cardiac resynchronization/defibrillation devices (CRT-Ds) increasingly is used in patients with congestive heart failure and left bundle-branch block. There are no data on the effects of anesthesia and surgery on outcome after implantation. A retrospective, observational study; postoperative survey. University hospital. Three hundred forty-one patients (258 men/83 women, 63 +/- 9 years) with congestive heart failure and left bundle-branch block who underwent CRT-D implantation in 1996 to 2005. Perioperative data were retrieved from the patients' records. Cardiologists caring for the patients were contacted to obtain information on current New York Heart Association (NYHA) status and mortality after CRT-D implantation. Preoperatively, 45 patients were classified as NYHA II, 246 as NYHA III, and 50 as NYHA IV. CRT was performed via thoracotomy in 100 and transvenously in 241 cases. General anesthesia (propofol or sevoflurane and remifentanil) was performed in 273 and local anesthesia (lidocaine) in 68 patients. Hypotension occurred mainly during general anesthesia (43% v 4%). The 30-day mortality was 0%. The postoperative survey started in 2006 and was completed by 215 patients. The mean survival time was 77 months; 151 patients survived the study period. Outcome was not influenced by local and general anesthesia. Presence of preoperative NYHA class >II (odds ratio [OR] = 1.6, confidence interval [CI] = 0.5-5.1), mitral regurgitation (OR = 2.5, CI = 1.2-5.5), and serum creatinine >1.1 mg/dL (OR = 3.0, CI = 1.5-6.2) resulted in an inferior prognosis. In patients with severely impaired cardiac function, general anesthesia for the implantation of a biventricular pacing device can be used with justifiable risk. The method of anesthesia did not influence outcome. Copyright 2010 Elsevier Inc. All rights reserved.

  20. A risk score to predict the absence of left ventricular reverse remodeling: Implications for the timing of ICD implantation in primary prevention.

    Science.gov (United States)

    Pérez-Rodon, Jordi; Galve, Enrique; Pérez-Bocanegra, Carmen; Soriano-Sánchez, Teresa; Recio-Iglesias, Jesús; Domingo-Baldrich, Eva; Alzola-Guevara, Mila; Ferreira-González, Ignacio; Marsal, Josep Ramon; Ribera-Solé, Aida; Gutierrez García-Moreno, Laura; Cruz-Carlos, Luz María; Rivas-Gandara, Nuria; Roca-Luque, Ivo; Francisco-Pascual, Jaume; Evangelista-Masip, Artur; Moya-Mitjans, Àngel; García-Dorado, David

    2017-11-25

    A prophylactic implantable cardioverter defibrillator (ICD) in patients with heart failure and reduced left ventricular ejection fraction (HFrEF) is only indicated when left ventricular ejection fraction (LVEF) reassessment remains ≤35% after 3-6 months on optimal pharmacological therapy. However, LVEF may not improve during this period and the patient may be exposed to an unnecessary risk of sudden cardiac death. This study aimed to determine the incidence and predictors of the absence of left ventricular reverse remodeling (LVRR) after pharmacological treatment optimization in patients with HFrEF to design a risk score of absence of LVRR. Consecutive outpatients with LVEF ≤35% were included in this observational prospective study. Up-titration of angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs), beta-blockers, mineralocorticoid receptor antagonists (MRAs), and ivabradine was performed in our Heart Failure (HF) Unit. The absence of LVRR was defined as the persistence of an LVEF ≤35% at the 6-month follow-up. One hundred and twenty patients were included. At the 6-month follow-up, 64%, 76%, 72%, and 7% of patients were at 100% of the target dose of ACE inhibitors/ARBs, beta-blockers, MRAs, and ivabradine, respectively. LVRR was observed in 48% of the patients. Ischemic cardiomyopathy, prolonged HF duration, and larger left ventricular end-diastolic diameter index (LVEDDI) were independent predictors of the absence of LVRR. The risk score based on these predictors showed a c-statistic value of 0.81. Pharmacological treatment optimization is associated with LVRR in approximately half of cases, reducing potential ICD indications in parallel. However, ischemic cardiomyopathy, prolonged HF duration, and larger LVEDDI predict the absence of LVRR and favor ICD implantation without delay. The risk score based on the former predictors may help the clinician with the timing of ICD implantation. Copyright © 2017 Japanese College of

  1. Hybrid nanocomposites based on electroactive hydrogels and cellulose nanocrystals for high-sensitivity electro-mechanical underwater actuation

    Science.gov (United States)

    Santaniello, Tommaso; Migliorini, Lorenzo; Locatelli, Erica; Monaco, Ilaria; Yan, Yunsong; Lenardi, Cristina; Comes Franchini, Mauro; Milani, Paolo

    2017-08-01

    We report the synthesis, fabrication and characterization of a hybrid hydrogel/cellulose nanocomposite, which exhibits high-performance electro-mechanical underwater actuation and high sensitivity in response to electrical stimuli below the standard potential of water electrolysis. The macromolecular structure of the material is constituted by an electroactive hydrogel, obtained through a photo-polymerization reaction with the use of three vinylic co-monomers: Na-4-vinylbenzenesulfonate, 2-hydroxyethylmethacrylate, and acrylonitrile. Different amounts (from 0.1% to 1.4% w/w) of biodegradable cellulose nanocrystals (CNCs) with sulfonate surface groups, obtained through the acidic hydrolysis of sulphite pulp lapsheets, are physically incorporated into the gel matrix during the synthesis step. Freestanding thin films of the nanocomposites are molded, and their swelling, mechanical and responsive properties are fully characterized. We observed that the embedding of the CNCs enhanced both the material Young’s modulus and its sensitivity to the applied electric field in the sub-volt regime (down to 5 mV cm-1). A demonstrator integrating multiple actuators that cooperatively bend together, mimicking the motion of an electro-valve, is also prototyped and tested. The presented nanocomposite is suitable for the development of soft smart components for bio-robotic applications and cells-based and bio-hybrid fluidic devices fabrication.

  2. Effects of mechanical feedback on the stability of cardiac scroll waves: A bidomain electro-mechanical simulation study

    Science.gov (United States)

    Colli Franzone, P.; Pavarino, L. F.; Scacchi, S.

    2017-09-01

    In this work, we investigate the influence of cardiac tissue deformation on re-entrant wave dynamics. We have developed a 3D strongly coupled electro-mechanical Bidomain model posed on an ideal monoventricular geometry, including fiber direction anisotropy and stretch-activated currents (SACs). The cardiac mechanical deformation influences the bioelectrical activity with two main mechanical feedback: (a) the geometric feedback (GEF) due to the presence of the deformation gradient in the diffusion coefficients and in a convective term depending on the deformation rate and (b) the mechano-electric feedback (MEF) due to SACs. Here, we investigate the relative contribution of these two factors with respect to scroll wave stability. We extend the previous works [Keldermann et al., Am. J. Physiol. Heart Circ. Physiol. 299, H134-H143 (2010) and Hu et al., PLoS One 8(4), e60287 (2013)] that were based on the Monodomain model and a simple non-selective linear SAC, while here we consider the full Bidomain model and both selective and non-selective components of SACs. Our simulation results show that the stability of cardiac scroll waves is influenced by MEF, which in case of low reversal potential of non-selective SACs might be responsible for the onset of ventricular fibrillation; GEF increases the scroll wave meandering but does not determine the scroll wave stability.

  3. Focused Ion Beam Preparation of Specimens for Micro-Electro-Mechanical System-based Transmission Electron Microscopy Heating Experiments.

    Science.gov (United States)

    Vijayan, Sriram; Jinschek, Joerg R; Kujawa, Stephan; Greiser, Jens; Aindow, Mark

    2017-08-01

    Micro-electro-mechanical systems (MEMS)-based heating holders offer exceptional control of temperature and heating/cooling rates for transmission electron microscopy experiments. The use of such devices is relatively straightforward for nano-particulate samples, but the preparation of specimens from bulk samples by focused ion beam (FIB) milling presents significant challenges. These include: poor mechanical integrity and site selectivity of the specimen, ion beam damage to the specimen and/or MEMS device during thinning, and difficulties in transferring the specimen onto the MEMS device. Here, we describe a novel FIB protocol for the preparation and transfer of specimens from bulk samples, which involves a specimen geometry that provides mechanical support to the electron-transparent region, while maximizing the area of that region and the contact area with the heater plate on the MEMS chip. The method utilizes an inclined stage block that minimizes exposure of the chip to the ion beam during milling. This block also allows for accurate and gentle placement of the FIB-cut specimen onto the chip by using simultaneous electron and ion beam imaging during transfer. Preliminary data from Si and Ag on Si samples are presented to demonstrate the quality of the specimens that can be obtained and their stability during in situ heating experiments.

  4. Evaluation of performance of portable respiratory monitoring system based on micro-electro-mechanical-system for respiratory gated radiotherapy

    Science.gov (United States)

    Moon, Sun Young; Sung, Jiwon; Yoon, Myonggeun; Chung, Mijoo; Chung, Weon Kuu; Kim, Dong Wook

    2015-08-01

    In respiratory-gated radiotherapy of patients with lung or liver cancer, the patient's respiratory pattern and repeatability are important factors affecting therapy accuracy; it has been reported that these factors can be controlled if patients undergo respiration training. As such, this study evaluates the feasibility of micro-electro-mechanical-system (MEMS) in radiotherapy by investigating the effect of radiation on a miniature portable respiratory monitoring system based on the MEMS system, which is currently under development. Using a patient respiration simulation phantom, the time-acceleration graph measured by a normal sensor according to the phantom's respiratory movement before irradiation and the change in this graph with accumulated dose were compared using the baseline slope and the change in amplitude and period of the sine wave. The results showed that with a 400Gy accumulated dose in the sensor, a baseline shift occurred and both the amplitude and period changed. As a result, if the MEMS is applied in respiratory-gated radiotherapy, the sensor should be replaced after use with roughly 6-10 patients so as to ensure continued therapy accuracy, based on the characteristics of the sensor itself. In the future, a more diverse range of sensors should be similarly evaluated.

  5. Chaotic dynamic and control for micro-electro-mechanical systems of massive storage with harmonic base excitation

    Energy Technology Data Exchange (ETDEWEB)

    Perez Polo, Manuel F. [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, Escuela Politecnica Superior, Campus de San Vicente, 03071 Alicante (Spain)], E-mail: manolo@dfists.ua.es; Perez Molina, Manuel [Facultad de Ciencias Matematicas, Universidad Nacional de Educacion a Distancia. UNED, C/Boyero 12-1A, Alicante 03007 (Spain)], E-mail: ma_perez_m@hotmail.com; Gil Chica, Javier [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, Escuela Politecnica Superior, Campus de San Vicente, 03071 Alicante (Spain)], E-mail: gil@dfists.ua.es

    2009-02-15

    This paper explores chaotic behaviour and control of micro-electro-mechanical systems (MEMS), which consist of thousands of small read/write probe tips that access gigabytes of data stored in a non-volatile magnetic surface. The model of the system is formed by two masses connected by a nonlinear spring and a viscous damping. The paper shows that, by means of an adequate feedback law, the masses can behave as two coupled Duffing's oscillators, which may reach chaotic behaviour when harmonic forces are applied. The chaotic motion is destroyed by applying the following control strategies: (i) static output feedback control law with constant forces and (ii) geometric nonlinear control. The aim is to drive the masses to a set point even with harmonic base excitation, by using chaotic dynamics and nonlinear control. The paper shows that it is possible to obtain a positioning time around a few ms with sub-nanometre accuracy, velocities, accelerations and forces, as it appears in the design of present MEMS devices. Numerical simulations are used to verify the mathematical discussions.

  6. Risk factors for the development of right ventricular failure after left ventricular assist device implantation-a single-centre retrospective with focus on deformation imaging.

    Science.gov (United States)

    Boegershausen, Nadia; Zayat, Rashad; Aljalloud, Ali; Musetti, Giulia; Goetzenich, Andreas; Tewarie, Lachmandath; Moza, Ajay; Amerini, Andrea; Autschbach, Rüdiger; Hatam, Nima

    2017-12-01

    Right heart failure (RHF) after the implantation of a left ventricular assist device (LVAD) remains a dreaded postoperative complication. Using 2D speckle-tracking echocardiography, it is possible to acquire right ventricular global and regional function. The aim of our study was to assess whether speckle-tracking echocardiography values will better predict the RHF post-continuous-flow LVAD implantation. From January 2014 to January 2016, 54 patients who underwent LVAD implantation were included and retrospectively analysed. Clinical, invasive haemodynamic (right and left heart catheterization), laboratory and transthoracic echocardiography data were reviewed. Multivariable logistic regression was performed using RHF as dependent variable. Thirteen patients (24%) developed RHF. These patients had significantly elevated procalcitonin (P = 0.011), elevated central venous pressure (CVP) pre- and post-LVAD implantation (P = 0.002 and 0.031, respectively), higher right ventricular (RV) and pulmonary systolic pressure (P = 0.016 and 0.013, respectively), higher Michigan Risk Score (P = 0.001) and a lower peak systolic longitudinal strain of the basal RV free wall (P = 0.032). Haemoglobin, procalcitonin, RV systolic pressure, basal right ventricular free wall and pre-CVP entered the final multivariable analysis, only basal right ventricular free wall (P RHF. The sensitivity and specificity of the final model were 85.7% and 95.4%, respectively. The negative predictive value reached 94%. 2D strain parameters of the RV free wall seem to be auspicious for RV function and predicting RHF. Moreover, intraoperative CVP should not be neglected since elevated values proved to be highly associated with RHF. Our results represent a valuable supplement to other scores by considering both echocardiography and intraoperative data.

  7. Relationship between pre-implant interleukin-6 levels, inflammatory response, and early outcome in patients supported by left ventricular assist device: a prospective study.

    Directory of Open Access Journals (Sweden)

    Raffaele Caruso

    Full Text Available PURPOSE: The immune response is crucial in the development of multi-organ failure (MOF and complications in end-stage heart failure patients supported by left ventricular assist device (LVAD. However, at pre-implant, the association between inflammatory state and post-LVAD outcome is not yet clarified. Aim of the study was to assess the relationship among pre-implant levels of immune-related cytokines, postoperative inflammatory response and 3-month outcome in LVAD-patients. METHODS: In 41 patients undergoing LVAD implantation, plasma levels of interleukin (IL-6, IL-8, crucial for monocyte modulation, and urine neopterin/creatinine ratio (Neo/Cr, marker of monocyte activation, were assessed preoperatively, at 3 days, 1 and 4 weeks post-LVAD. MOF was evaluated by total sequential organ failure assessment (tSOFA score. Intensive care unit (ICU-death and/or post-LVAD tSOFA ≥11 was considered as main adverse outcome. Length of ICU-stay, 1 week-tSOFA score, hospitalisation and 3-month survival were considered additional end-points. RESULTS: During ICU-stay, 8 patients died of MOF, while 8 of the survivors experienced severe MOF with postoperative tSOFA score ≥11. Pre-implant level of IL-6 ≥ 8.3 pg/mL was identified as significant marker of discrimination between patients with or without adverse outcome (OR 6.642, 95% CI 1.201-36.509, p = 0.030. Patients were divided according to pre-implant IL-6 cutoff of 8.3 pg/ml in A [3.5 (1.2-6.1 pg/mL] and B [24.6 (16.4-38.0 pg/mL] groups. Among pre-implant variables, only white blood cells count was independently associated with pre-implant IL-6 levels higher than 8.3 pg/ml (OR 1.491, 95% CI 1.004-2.217, p = 0.048. The ICU-stay and hospitalisation resulted longer in B-group (p = 0.001 and p = 0.030, respectively. Postoperatively, 1 week-tSOFA score, IL-8 and Neo/Cr levels were higher in B-group. CONCLUSIONS: LVAD-candidates with elevated pre-implant levels of IL-6 are associated, after

  8. Vibro-Acoustic Analysis of Computer Disk Drive Components with Emphasis on Electro-Mechanical Noise Sources.

    Science.gov (United States)

    Lee, Ming-Ran

    Vibro-acoustic characteristics of compact electro -mechanical devices are not well understood. This study examines fundamental research issues in this area through the example case of a 3.5" personal computer hard disk drive. In particular, a narrow band mathematical model of the drive has been developed to predict prominent pure tones over the high frequency range (1-6.5 KHz). Through detailed analytical studies, it has been found that the motor torque pulsation of the brushless d.c. motor is the source for this noise problem. Accordingly, a simplified disk drive model consisting of motor driving a single disk is used to investigate key components, with emphasis on the development of new mathematical models to describe the source, path and radiator characteristics. Two different mathematical models have been developed for brushless d.c. motor to predict the torque spectrum associated with invertor switching logic, pulse width modulation control scheme, eccentricity, and magnetic saturation. Frequency contents of predicted variables are identified and matched with measured sound data. Additionally, the Galerkin's method (or modified harmonic balance) is also employed successfully to develop an efficient computational scheme which predicts the Fourier coefficients of torque pulsations directly including various effects associated with inductance harmonics and the fluctuation of rotor angular velocity. For the radiator (annular disk), modal base formulations of sound radiation have been developed by approximating disk eigen-functions. Specifically, the effects of modal coupling and source rotation on radiated sound are investigated. Analytical predictions match well with numerical results obtained by using a boundary element program. New mobility transfer functions (path) are derived to couple the source and radiator formulations in order to construct an overall vibro-acoustic model. Potential areas of further research including experimental validation are discussed.

  9. Comparison of incidence and predictors of left bundle branch block after transcatheter aortic valve implantation using the CoreValve versus the Edwards valve.

    Science.gov (United States)

    Franzoni, Irene; Latib, Azeem; Maisano, Francesco; Costopoulos, Charis; Testa, Luca; Figini, Filippo; Giannini, Francesco; Basavarajaiah, Sandeep; Mussardo, Marco; Slavich, Massimo; Taramasso, Maurizio; Cioni, Micaela; Longoni, Matteo; Ferrarello, Santo; Radinovic, Andrea; Sala, Simone; Ajello, Silvia; Sticchi, Alessandro; Giglio, Manuela; Agricola, Eustachio; Chieffo, Alaide; Montorfano, Matteo; Alfieri, Ottavio; Colombo, Antonio

    2013-08-15

    Conduction disorders and permanent pacemaker implantation are common complications in patients who undergo transcatheter aortic valve implantation (TAVI). The aim of this study was to assess the incidence and clinical significance of new bundle branch block in patients who underwent TAVI with the Medtronic CoreValve Revalving System (MCRS) or the Edwards SAPIEN valve (ESV). Data from 238 patients with no previous pacemaker implantation, left bundle branch block (LBBB) or right bundle branch block at baseline electrocardiography who underwent TAVI with either MCRS (n = 87) or ESV (n = 151) bioprostheses from 2007 to 2011 were analyzed. New-onset LBBB occurred in 26.5% patients (n = 63): 13.5% with the ESV (n = 20) and 50.0% with the MCRS (n = 43) (p = 0.001). Permanent pacemaker implantation was required in 12.7% of patients (n = 8) because of complete atrioventricular block (ESV n = 2, MCRS n = 4), LBBB and first degree atrioventricular block (MCRS n = 1) and new-onset LBBB associated with sinus bradycardia (MCRS n = 1). At discharge, LBBB persisted in 8.6% of ESV patients (n = 13) and 32.2% of MCRS patients (n = 28) (p = 0.001). On multivariate analysis, the only predictor of LBBB was MCRS use (odds ratio 7.2, 95% confidence interval 2.9 to 17.4, p bundle branch block was documented in 4.6% of patients (n = 11), with no statistically significant differences between the ESV and MCRS. In conclusion, new-onset LBBB is a frequent intraventricular conduction disturbance after TAVI with a higher incidence with the MCRS compared with the ESV. LBBB persists in most patients, but in this cohort, it was not a predictor of overall or cardiovascular mortality or permanent pacemaker implantation. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Superior transseptal approach to mitral valve is associated with a higher need for pacemaker implantation than the left atrial approach

    DEFF Research Database (Denmark)

    Lukac, Peter; Hjortdal, Vibeke E; Pedersen, Anders K

    2006-01-01

    BACKGROUND: Several studies suggest that the superior transseptal approach to mitral valve surgery leads to sinus node dysfunction. The clinical consequences are not known. METHODS: Consecutive patients undergoing surgery for mitral valve disease from November 16, 1994 through January 26, 2004 were...... to adjust for possible confounders. RESULTS: We included 577 patients, 150 in group A and 427 in group B. Forty-four patients had a pacemaker implanted after the surgery; 17 in group A and 27 in group B (p = 0.010). The superior transseptal approach was an independent risk factor of pacemaker implantation...

  11. Identification of differentially expressed transcripts and pathways in blood one week and six months following implant of left ventricular assist devices.

    Directory of Open Access Journals (Sweden)

    Adam Mitchell

    Full Text Available INTRODUCTION: Continuous-flow left ventricular assist devices (LVADs are an established therapy for patients with end-stage heart failure. The short- and long-term impact of these devices on peripheral blood gene expression has not been characterized, and may provide insight into the molecular pathways mediated in response to left ventricular remodeling and an improvement in overall systemic circulation. We performed RNA sequencing to identify genes and pathways influenced by these devices. METHODS: RNA was extracted from blood of 9 heart failure patients (8 male prior to LVAD implantation, and at 7 and 180 days postoperatively. Libraries were sequenced on an Illumina HiSeq2000 and sequences mapped to the human Ensembl GRCh37.67 genome assembly. RESULTS: A specific set of genes involved in regulating cellular immune response, antigen presentation, and T cell activation and survival were down-regulated 7 days after LVAD placement. 6 months following LVAD placement, the expression levels of these genes were significantly increased; yet importantly, remained significantly lower than age and sex-matched samples from healthy controls. CONCLUSIONS: In summary, this genomic analysis identified a significant decrease in the expression of genes that promote a healthy immune response in patients with heart failure that was partially restored 6 months following LVAD implant.

  12. Implantation of VVI pacemaker in a patient with dextrocardia, persistent left superior vena cava, and sick sinus syndrome: A case report.

    Science.gov (United States)

    Guo, Gongliang; Yang, Lili; Wu, Jinyi; Sun, Liqun

    2017-02-01

    Dextrocardia, or right-lying heart, is an uncommon congenital heart disease in which the apex of the heart is located on the right side of chest. Persistent left superior vena cava (PLSVA) is a rare venous anomaly that is often associated with the abnormalities of cardiac transduction system. A case with combination of dextrocardia, persistent left superior vena cava, and sick sinus syndrome has not been reported. We used different techniques including cardiac color Doppler echocardiography, 24-hour Holter monitoring, and abdominal ultrasound to make a diagnosis and treated the patient by implanting a VVI pacemaker. A 50-year-old woman was admitted with a syncope. Angiography of the right atrium and superior vena cava, echocardiography, electrocardiography, and abdominal ultrasound revealed the presence of the combination of mirror image dextrocardia, PLSVA, and sick sinus syndrome. The complex structural anomalies presented great technical challenges for interventional treatments. After thorough examination and understanding of the structural anatomy and anomalies of the superior and inferior vena cava and cardiac chambers, we successfully treated this patient by implanting a VVI pacemaker. Physicians must be aware of the complexity of the morphological and anatomical structures of dextrocardia accompanying PLSVC. Given that the diagnosis of situs inversus was performed at a relatively advanced age, it is therefore important to make such a correct diagnosis followed by appropriate therapeutic intervention.

  13. Early History and Challenges of Implantable Electronics.

    Science.gov (United States)

    Ko, Wen H

    2012-06-01

    Implantable systems for biomedical research and clinical care are now a flourishing field of activities in academia as well as industrial institutions. The broad field includes experimental explorations in electronics, mechanical, chemical, and biological components and systems, and the combination of all these. Today virtually all implants involve both electronic circuits and micro-electro-mechanical-systems (MEMS). This article offers a very brief glance back at the early history of implant electronics in the period from the 1950s to the 1970s, by employing selected examples from the author's research. This short review also discusses the challenges of implantable electronics at present, and suggests some potentially important trends in the future research and development of implantable microsystems. It is aimed as an introduction of implantable/attached electronic systems to research engineers that are interested in implantable systems as a section of Biomedical Instrumentations.

  14. The Prognostic Impact of New-Onset Persistent Left Bundle Branch Block Following Transcatheter Aortic Valve Implantation: A Meta-analysis.

    Science.gov (United States)

    Ando, Tomo; Takagi, Hisato

    2016-09-01

    New-onset persistent left bundle branch block (NOP-LBBB) is one of the most common conduction disturbances after transcatheter aortic valve implantation (TAVI). We hypothesized that NOP-LBBB may have a clinically negative impact after TAVI. To find out, we conducted a systematic literature search of the MEDLINE/PubMed and Embase databases. Observational studies that reported clinical outcomes of NOP-LBBB patients after TAVI were included. The random-effects model was used to combine odds ratios, risk ratios, or hazard ratios (HRs) with 95% confidence intervals. Adjusted HRs were utilized over unadjusted HRs or risk ratios when available. A total of 4049 patients (807 and 3242 patients with and without NOP-LBBB, respectively) were included. Perioperative (in-hospital or 30-day) and midterm all-cause mortality and midterm cardiovascular mortality were comparable between the groups. The NOP-LBBB patients experienced a higher rate of permanent pacemaker implantation (HR: 2.09, 95% confidence interval: 1.12-3.90, P = 0.021, I(2) = 83%) during midterm follow-up. We found that NOP-LBBB after TAVI resulted in higher permanent pacemaker implantation but did not negatively affect the midterm prognosis. Therefore, careful observation during the follow-up is required. © 2016 Wiley Periodicals, Inc.

  15. Contralateral transvenous left ventricular lead placement of implantable devices with pre-sternal tunnelling in chronically obstructed subclavian veins

    Directory of Open Access Journals (Sweden)

    Praveen P. Sadarmin

    2015-03-01

    Full Text Available Cardiac resynchronisation therapy (CRT is a recognised therapy for the management of severe left ventricular dysfunction, advanced congestive cardiac failure (NYHA III or IV, ventricular dyssynchrony (either broad LBBB or mechanical dyssynchrony on echocardiography and failure of optimal medical therapy to achieve improvement in clinical status. Upgrading right ventricular pacemakers or defibrillators to biventricular devices is common and we describe here, 2 such cases of biventricular upgrade with blocked venous access on the ipsilateral side and successful placement of left ventricular leads following pre-sternal tunnelling from the contralateral side.

  16. Technical developments: use of targeting guide wire in left subclavian puncture during percutaneous implantation of port-catheter systems using the catheter tip fixation method

    Energy Technology Data Exchange (ETDEWEB)

    Yamagami, Takuji; Kato, Takeharu; Nakamura, Toshiyuki; Iida, Shigeharu; Tanaka, Osamu; Nishimura, Tsunehiko [Department of Radiology, Kyoto Prefectural University of Medicine, 465 Kajii, Kawaramachi-Hirokoji, Kamigyo, Kyoto 602-8566 (Japan)

    2003-04-01

    Our objective was to evaluate the feasibility and safety of a new method in approaching the access route percutaneously for the implantable port-catheter system for repeated hepatic arterial infusion chemotherapy. Fifteen patients underwent port-catheter system placement via the left subclavian artery with the catheter tip fixed within the gastroduodenal artery with embolic materials and a catheter side hole opening to the common hepatic artery. Before port-catheter placement, the right gastric artery was embolized via the femoral catheter access. Then a 0.035-in. guide wire was inserted from the right femoral artery to the left subclavian artery. The guide wire was left in place during puncture by the needle as an access route for catheter placement. At the time of puncture, the tip of the puncture needle was aimed at the guide wire placed in the subclavian artery beforehand. In all 15 patients the procedure was successfully completed in a reasonable time (mean time 95.0 min, range 50-240 min). Complications occurred in two patients: a transient numbness of the arm in 1 patient and a mild hematoma detected in the subcutaneous pocket in another patient. This experience indicates the possibility of using a targeting guide wire in puncture of the subclavian artery as an access route for catheter placement. (orig.)

  17. PR interval identifies clinical response in patients with non-left bundle branch block: a Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy substudy.

    Science.gov (United States)

    Kutyifa, Valentina; Stockburger, Martin; Daubert, James P; Holmqvist, Fredrik; Olshansky, Brian; Schuger, Claudio; Klein, Helmut; Goldenberg, Ilan; Brenyo, Andrew; McNitt, Scott; Merkely, Bela; Zareba, Wojciech; Moss, Arthur J

    2014-08-01

    In Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT), patients with non-left bundle branch block (LBBB; including right bundle branch block, intraventricular conduction delay) did not have clinical benefit from cardiac resynchronization therapy with defibrillator (CRT-D). We hypothesized that baseline PR interval modulates clinical response to CRT-D therapy in patients with non-LBBB. Non-LBBB patients (n=537; 30%) were divided into 2 groups based on their baseline PR interval as normal (including minimally prolonged) PR (PR <230 ms) and prolonged PR (PR ≥230 ms). The primary end point was heart failure or death. Separate secondary end points included heart failure events and all-cause mortality. Cox proportional hazards regression models were used to compare risk of end point events by CRT-D to implantable cardioverter defibrillator therapy in the PR subgroups. There were 96 patients (22%) with a prolonged PR and 438 patients (78%) with a normal PR interval. In non-LBBB patients with a prolonged PR interval, CRT-D treatment was associated with a 73% reduction in the risk of heart failure/death (hazard ratio, 0.27; 95% confidence interval, 0.13-0.57; P<0.001) and 81% decrease in the risk of all-cause mortality (hazard ratio, 0.19; 95% confidence interval, 0.13-0.57; P<0.001) compared with implantable cardioverter defibrillator therapy. In non-LBBB patients with normal PR, CRT-D therapy was associated with a trend toward an increased risk of heart failure/death (hazard ratio, 1.45; 95% confidence interval, 0.96-2.19; P=0.078; interaction P<0.001) and a more than 2-fold higher mortality (hazard ratio, 2.14; 95% confidence interval, 1.12-4.09; P=0.022; interaction P<0.001) compared with implantable cardioverter defibrillator therapy. The data support the use of CRT-D in MADIT-CRT non-LBBB patients with a prolonged PR interval. In non-LBBB patients with a normal PR interval, implantation of a CRT-D may be deleterious

  18. ECG myocardial scar quantification predicts reverse left ventricular remodeling and survival after cardiac resynchronization therapy implantation: A retrospective pilot study.

    Science.gov (United States)

    Atwater, Brett D; Babatunde, Adefolakemi; Swan, Christopher; Wieslander, Bjorn; Andresen, Abraham; Rabineau, Dawn; Tomfohr, Jennifer; Wagner, Galen; Jackson, Kevin P; Daubert, James P

    2015-01-01

    Electrocardiographic (ECG) LV scar quantification may improve prediction of CRT response. Data were abstracted in 76 patients who underwent a first CRT implantation at 2 US centers. Selvester QRS scar quantification was performed using the LBBB modified QRS scoring method. Seven clinical variables previously associated with reverse LV remodeling (RLVR) and QRS score were included in logistic regression analysis. Survival was compared across QRS score quartiles using Kaplan-Meier curves. RLVR occurred more frequently in patients with QRS score ≤ 5 (63%) than QRS score>5 (22%), (OR=5.83, 95% CI=2.11-16.07). After adjustment for clinical variables using logistic regression, QRS score>5 predicted RLVR (Chi-square=20.3, P=0.005, AUC=0.782). Patients in the lowest quartile of QRS score (<4) had improved survival compared to patients in the other QRS score quartiles (P=0.037). ECG quantified LV scar predicts RLVR and long-term survival in patients with LBBB undergoing CRT implantation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Transcatheter treatment of heart failure with preserved or mildly reduced ejection fraction using a novel interatrial implant to lower left atrial pressure

    DEFF Research Database (Denmark)

    Søndergaard, Lars; Reddy, Vivek; Kaye, David

    2014-01-01

    BACKGROUND: Heart failure with preserved or mildly reduced ejection fraction (HFpEF) is common and, to date, therapeutic options are limited. Increased left atrial pressure is a key contributor to the symptoms associated with HFpEF, particularly during physical activity. We report the 30-day......Hg (exercise); and ≥1 hospitalization for heart failure within the past 12 months, or persistent NYHA class III/IV for at least 3 months. Mean age, LVEF, and NYHA class were 70 ± 12 years, 57 ± 9%, and 3.2 ± 0.4, respectively. Most patients had significant co-morbidities. The interatrial septal device (IASD...... patients, one class in five patients, and worsened by one class in one patient. No patient developed pulmonary hypertension. Two serious adverse events occurred; heart failure re-hospitalization, and implant malposition successfully treated with a new device. CONCLUSION: Contemporary management of HFp...

  20. A comparison of the health status and psychological distress of partners of patients with a left ventricular assist device versus an implantable cardioverter defibrillator

    DEFF Research Database (Denmark)

    Brouwers, Corline; Caliskan, Kadir; de Jonge, Nicolaas

    2014-01-01

    and is therefore an important aspect in the care of LVAD and ICD patients. METHODS: Multi-center prospective observational study with 6 months follow-up of 33 LVAD partners (27% men; mean age = 54 ± 10 years) and 414 ICD partners (22% men; mean age = 60 ± 12 years). RESULTS: LVAD partners reported better physical...... (F = 10.71, p = .001) but poorer mental health status (F = 14.82, p ...OBJECTIVE: To examine if the caregiving for patients with a left ventricular assist device (LVAD) is related to a poorer health status and more distress compared to patients with an implantable cardioverter defibrillator (ICD). BACKGROUND: Partners distress may influence patient outcomes...

  1. Coronary sinus activation patterns in patients with and without left bundle branch block undergoing electroanatomic mapping system-guided cardiac resynchronization therapy device implantation.

    Science.gov (United States)

    Del Greco, Maurizio; Zorzi, Alessandro; Di Matteo, Irene; Cima, Anna; Maines, Massimiliano; Angheben, Carlo; Catanzariti, Domenico

    2017-02-01

    Implantation of the left ventricular (LV) lead in segments with delayed electrical activation may improve response to cardiac resynchronization therapy (CRT). The purpose of this study was to evaluate the amount and regional distribution of LV electrical delay (LVED) in patients with or without left bundle branch block (LBBB). We enrolled 60 patients who underwent electroanatomic mapping system-guided CRT device implantation. Activation mapping of the coronary sinus (CS) branches was performed using an insulated guidewire. LVED was defined as the interval between the beginning of the QRS complex on the surface electrocardiogram (ECG) and the local electrogram and expressed in milliseconds or as percentage of the total QRS duration (LVED%). Forty-three patients showed a LBBB and 17 a non-LBBB electrocardiographic pattern. A total of 148 CS branches (mean 2.5 per patient; range 2-4 per patient) were mapped. Patients with LBBB showed higher maximum LVED (135 ms [108-150 ms] vs 100 ms [103-110 ms]; P branches showing LVED >50% of the total QRS duration, >75% of the total QRS duration, and >85 ms was significantly higher in patients with LBBB than in patients without LBBB. Patients without LBBB showed lower LVED and more heterogeneous electrical activation of the CS than did patients with LBBB. This finding may contribute to a lower rate of response to CRT of patients without LBBB and suggests the use of activation mapping to guide LV lead placement. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  2. Autologous bone marrow cell implantation attenuates left ventricular remodeling and improves heart function in porcine myocardial infarction: an echocardiographic, six-month angiographic, and molecular-cellular study.

    Science.gov (United States)

    Leu, Steve; Sun, Cheuk-Kwan; Sheu, Jiunn-Jye; Chang, Li-Teh; Yuen, Chun-Man; Yen, Chia-Hung; Chiang, Chiang-Hua; Ko, Sheung-Fat; Pei, Sung-Nan; Chua, Sarah; Youssef, Ali A; Wu, Chiung-Jen; Yip, Hon-Kan

    2011-07-15

    We investigated the potential benefits and the underlying mechanisms of autologous bone marrow-derived mononuclear cell (BMDMNC) implantation in a porcine model of acute anterior wall myocardial infarction (AAWMI) by studying 6-month left ventricular (LV) function and LV remodeling. After being aspirated from the iliac crest and cultured for 1 week, BMDMNCs were implanted immediately after AAWMI induction through the left anterior descending artery ligation. Thirty male mini-pigs (16-18 kg) were equally divided into group 1 [AAWMI plus saline injection into infarct-ischemia area (IA)], group 2 (AAWMI plus 3.0 × 10⁷ BMDMNC transplantation into non-IA), group 3 (AAWMI plus 3.0 × 10⁷ BMDMNC transplantation into IA), group 4 (sham control plus 3.0 × 10⁷ BMDMNC transplantation into LV myocardium), and group 5 (normal control). By day 90, echocardiography demonstrated an increased LV end-diastolic and end-systolic dimensions but reduced LV ejection fraction (LVEF) in groups 1 and 2 than in other groups (all p infarct area, the number of small vessels and mRNA expressions of endothelial nitric oxide synthase, Bcl-2, interleukin (IL)-10, and peroxisome proliferator-activated receptor-γ coactivator-1α were lower, whereas the number of apoptotic nuclei, caspase-3, Bax, endothelin-1, IL-8, and matrix metalloproteinase was higher in groups 1 and 2 than in other groups (all p < 0.01). Autologous BMDMNC transplantation into IA rather non-IA improves LV function and reduces LV remodeling via eliciting a broad-spectrum of molecular-cellular defensive mechanisms. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  3. Novel method of predicting the optimal atrioventricular delay in patients with complete AV block, normal left ventricular function and an implanted DDD pacemaker.

    Science.gov (United States)

    Miki, Yuko; Ishikawa, Toshiyuki; Matsushita, Kohei; Yamakawa, Youhei; Matsumoto, Katsumi; Sumita, Shinichi; Uchino, Kazuaki; Kimura, Kazuo; Umemura, Satoshi

    2009-04-01

    The optimal atrioventricular (AV) delay setting is important for achieving optimal AV synchrony in patients with an implanted DDD pacemaker. Using pulsed Doppler echocardiography is the most common method of predicting the optimal AV delay, but it is a complicated and time-consuming method. Therefore, an automatic optimizing function of the AV delay at different atrial rates is desirable for achieving a favorable hemodynamic state. This study aimed to predict the optimal AV delay using phonocardiography. The amplitude of the first heart sound (S1) recorded on the phonocardiogram was measured with different AV delays in 6 patents with complete AV block, normal left ventricular function and an implanted DDD pacemaker. The correlation between the amplitude of S1 and the length of the AV delay was a cubic curve (y=974.15x(3)-23.084x(2)-8.0074x+0.7495, R2=0.9511). The length of the AV delay at the inflection point of the curve showed a significant positive correlation with the optimal AV delay determined by pulsed Doppler echocardiography (R=0.9254, P<0.01). This study demonstrated a novel simple method of predicting the optimal AV delay using phono-cardiography.

  4. Terapia de resincronización con implante de electrodo ventricular izquierdo por vía epicárdica Resynchronization therapy with left ventricular electrode implant via epicardium

    Directory of Open Access Journals (Sweden)

    Francisco Gómez

    2007-12-01

    casos. No se presentaron complicaciones durante el procedimiento ni estimulación diafragmática o desalojo del eléctrodo epicárdico después de seis meses de seguimiento. Conclusión: se demostró que la implantación de marcapasos tricameral para resincronización cardiaca con la utilización de electrodo epicárdico ventricular izquierdo, es una terapia segura, con la cual se obtienen parámetros adecuados de implantación y normofunción del dispositivo.Introduction: heart resynchronization therapy is safe and effective for improving functional class and quality of life and to diminish mortality in patients with heart failure in functional state III and IV with optimal medical therapy. Methods: we report the procedure realized to a group of patients in the Cardiovascular and Transplant Unit at the University Hospital San Vicente de Paul and the Antioquia University between November 2004 and February 2006, to whom a tricameral pacemaker for cardiac resynchronization was implanted, inserting the left ventricular electrode via epicardium. Patients chosen for the insertion fulfilled the heart failure state C or D criteria, according to the NYHA III or IV classification, corroborated with functional test 120ms. and echocardiographic criteria of intra-ventricular, inter-ventricular or atrio-ventricular dyssynchronism. Results: 9 patients were included: 5 men and 4 women with mean age 57 years; 8 patients had left His bundle block. The implant procedure was realized in two times: the first one in the hemodynamics ward where an electrode in right atrium and right ventricle was put, and the second one in the operating room where an electrode in the left ventricle via epicardium through left anterior mini-thoracotomy was implanted. Total procedure time oscillated between 35 and 210 minutes with a mean of 105 minutes, and less than this in the last patients. Intra-operative measures show a mean stimulation threshold of 0.9 mV; QRST duration was less than 130 ms. after

  5. Management issues during HeartWare left ventricular assist device implantation and the role of transesophageal echocardiography

    Directory of Open Access Journals (Sweden)

    Sanjay Orathi Patangi

    2013-01-01

    Full Text Available Left ventricular assist devices (LVAD are increasingly used for mechanical circulatory support of patients with severe heart failure, primarily as a bridge to heart transplantation. Transesophageal echocardiography (TEE plays a major role in the clinical decision making during insertion of the devices and in the post-operative management of these patients. The detection of structural and device-related mechanical abnormalities is critical for optimal functioning of assist device. In this review article, we describe the usefulness of TEE for optimal perioperative management of patients presenting for HeartWare LVAD insertion.

  6. Impact of new-onset persistent left bundle branch block on late clinical outcomes in patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve.

    Science.gov (United States)

    Urena, Marina; Webb, John G; Cheema, Asim; Serra, Vicenç; Toggweiler, Stefan; Barbanti, Marco; Cheung, Anson; Ye, Jian; Dumont, Eric; DeLarochellière, Robert; Doyle, Daniel; Al Lawati, Hatim A; Peterson, Marc; Chisholm, Robert; Igual, Albert; Ribeiro, Henrique Barbosa; Nombela-Franco, Luis; Philippon, François; Garcia Del Blanco, Bruno; Rodés-Cabau, Josep

    2014-02-01

    The aim of this study was to determine the impact of new-onset persistent left bundle branch block (NOP-LBBB) on late outcomes after transcatheter aortic valve implantation (TAVI). The impact of NOP-LBBB after TAVI remains controversial. A total of 668 consecutive patients who underwent TAVI with a balloon-expandable valve without pre-existing LBBB or permanent pacemaker implantation (PPI) were included. Electrocardiograms were obtained at baseline, immediately after the procedure, and daily until hospital discharge. Patients were followed at 1, 6, and 12 months and yearly thereafter. New-onset LBBB occurred in 128 patients (19.2%) immediately after TAVI and persisted at hospital discharge in 79 patients (11.8%). At a median follow-up of 13 months (range 3 to 27 months), there were no differences in mortality rate between the NOP-LBBB and no NOP-LBBB groups (27.8% vs. 28.4%; adjusted-hazard ratio: 0.87 [95% confidence interval (CI): 0.55 to 1.37]; p = 0.54). There were no differences between groups regarding cardiovascular mortality (p = 0.82), sudden death (p = 0.87), rehospitalizations for all causes (p = 0.11), or heart failure (p = 0.55). NOP-LBBB was the only factor associated with an increased rate of PPI during the follow-up period (13.9% vs. 3.0%; hazard ratio: 4.29 [95% CI: 2.03 to 9.07], p < 0.001. NOP-LBBB was also associated with a lack of left ventricular ejection fraction improvement and poorer New York Heart Association functional class at follow-up (p < 0.02 for both). NOP-LBBB occurred in ∼1 of 10 patients who had undergone TAVI with a balloon-expandable valve. NOP-LBBB was associated with a higher rate of PPI, a lack of improvement in left ventricular ejection fraction, and a poorer functional status, but did not increase the risk of global or cardiovascular mortality or rehospitalizations at 1-year follow-up. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  7. Predictors of changes in health status between and within patients 12 months post left ventricular assist device implantation

    DEFF Research Database (Denmark)

    Brouwers, Corline; de Jonge, Nicolaas; Caliskan, Kadir

    2014-01-01

    improvements in health status between baseline and 3 months follow-up as assessed by the KCCQ (clinical summary score: F = 33.49, P physical component score: F = 31.59, P mental component score: F = 21.77, P ...BACKGROUND: Improving patient-reported outcomes (e.g. health status) has become an important goal in left ventricular assist device (LVAD) therapy, in addition to reducing mortality and morbidity. We examined predictors of changes in health status scores between and within patients 12 months post......-patient variance of the mental component summary scores (82.6%), but not the KCCQ overall summary score (41.9%), KCCQ clinical summary score (36.2%) and physical component summary scores (23.2%), was explained by the sociodemographic, clinical and psychological factors. CONCLUSION: The majority of LVAD patients...

  8. Comparative analysis of von Willebrand factor profiles after implantation of left ventricular assist device and total artificial heart.

    Science.gov (United States)

    Reich, H J; Morgan, J; Arabia, F; Czer, L; Moriguchi, J; Ramzy, D; Esmailian, F; Lam, L; Dunhill, J; Volod, O

    2017-08-01

    Essentials Bleeding is a major source of morbidity during mechanical circulatory support. von Willebrand factor (VWF) multimer loss may contribute to bleeding. Different patterns of VWF multimer loss were seen with the two device types. This is the first report of total artificial heart associated VWF multimer loss. Background Bleeding remains a challenge during mechanical circulatory support and underlying mechanisms are incompletely understood. Functional von Willebrand factor (VWF) impairment because of loss of high-molecular-weight multimers (MWMs) produces acquired von Willebrand disease (VWD) after left ventricular assist device (LVAD). Little is known about VWF multimers with total artificial hearts (TAHs). Here, VWF profiles with LVADs and TAHs are compared using a VWD panel. Methods VWD evaluations for patients with LVAD or TAH (2013-14) were retrospectively analyzed and included: VWF activity (ristocetin cofactor, VWF:RCo), VWF antigen (VWF:Ag), ratio of VWF:RCo to VWF:Ag, and quantitative VWF multimeric analysis. Results Twelve patients with LVADs and 12 with TAHs underwent VWD evaluation. All had either normal (47.8%) or elevated (52.2%) VWF:RCo, normal (26.1%) or elevated (73.9%) VWF:Ag and 50.0% were disproportional (ratio ≤ 0.7). Multimeric analysis showed abnormal patterns in all patients with LVADs: seven with high MWM loss; five with highest MWM loss. With TAH, 10/12 patients had abnormal patterns: all with highest MWM loss. High MWM loss correlated with presence of LVAD and highest MWM loss with TAH. Increased low MWMs were detected in 22/24. Conclusion Using VWF multimeric analysis, abnormalities after LVAD or TAH were detected that would be missed with measurements of VWF level alone: loss of high MWM predominantly in LVAD, loss of highest MWM in TAH, and elevated levels of low MWM in both. This is the first study to describe TAH-associated highest MWM loss, which may contribute to bleeding. © 2017 International Society on Thrombosis and

  9. Frailty and Clinical Outcomes in Advanced Heart Failure Patients Undergoing Left Ventricular Assist Device Implantation: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Tse, Gary; Gong, Mengqi; Wong, Sunny Hei; Wu, William K K; Bazoukis, George; Lampropoulos, Konstantinos; Wong, Wing Tak; Xia, Yunlong; Wong, Martin C S; Liu, Tong; Woo, Jean

    2017-11-09

    Frailty has been identified as a risk factor for adverse clinical outcomes after cardiac intervention or surgery. However, whether it increases the risk of adverse outcomes in patients undergoing left ventricular assist device (LVAD) therapy has been controversial. Therefore, we conducted a systematic review and meta-analysis of the frailty measures and clinical outcomes of length of stay and mortality in this setting. PubMed and Embase were searched until September 11, 2017, for studies evaluating the association between frailty and clinical outcomes in advanced heart failure patients undergoing LVAD implantation. A total of 46 and 79 entries were retrieved from our search strategy. A total of 13 studies involving 3435 patients were included in the final meta-analysis (mean age: 57.7 ± 15.3 years; 79% male, follow-up duration was 13 ± 14 months). Compared to nonfrail patients (n = 2721), frail patients (n = 579) had significantly longer time-to-extubation (n = 3; mean difference: 45 ± 6 hours; I(2): 0%) and hospital length of stay (n = 4; mean difference: 2.9 ± 1.2 days; P = .001; I(2): 21%). Frailty was not a predictor of inpatient or short-term mortality [n = 3; hazard ratio (HR): 1.22, 95% confidence interval (CI): 0.66-2.26; P > .05; I(2): 0%] but predicted long-term mortality (n = 7; HR: 1.44, 95% CI: 1.15-1.80; P = .001; I(2): 0%). Frailty leads to significantly longer time to extubation, hospital length of stay, and long-term mortality in advanced heart failure patients who have undergone LVAD implantation. Older patients being considered for LVAD implantation should therefore be assessed for frailty status. The risk and benefit of the procedure should be explained to the patient, emphasizing that frailty increases the likelihood of adverse clinical outcomes. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  10. Nano-Electro-Mechanical (NEM) Relay Devices and Technology for Ultra-Low Energy Digital Integrated Circuits

    Science.gov (United States)

    2013-05-01

    Design of ion- implanted MOSFET’s with very small physical dimensions,” Journal of Solid-State Circuits, vol. 9, pp. 256-268, 1974. 14 [6...stiction and welding at the contacts remains a key issue [2]-[4], [6]. Coating one of the contact electrodes with a thin SiO2 layer can improve...become prone to welding -induced stiction at the contact due to Joule heating from excessively high current flow. Additionally, a 2T switch is not

  11. Serum Brain Natriuretic Peptide Concentration 60 Days after Surgery as a Predictor of Long-term Prognosis in Patients Implanted with a Left Ventricular Assist Device.

    Science.gov (United States)

    Sato, Takuma; Seguchi, Osamu; Iwashima, Yoshio; Yanase, Masanobu; Nakajima, Seiko; Hieda, Michinari; Watanabe, Takuya; Sunami, Haruki; Murata, Yoshihiro; Hata, Hiroki; Fujita, Tomoyuki; Kobayashi, Junjiro; Nakatani, Takeshi

    2015-04-23

    Mechanical circulatory support by a left ventricular assist device (LVAD) is used to bridge patients with advanced heart failure to transplant or as a definitive treatment. We retrospectively sought predictors of long-term outcome in a cohort of 83 patients who had undergone LVAD treatment. We subjected patients' perioperative clinical data to statistical analysis to establish parameters associated with all-cause mortality, and the cut-off values, sensitivity and specificity of those that had a statistically significant relationship with survival. Mean follow up was 717 days (standard deviation 334 days, range 17-1592 days). Fourteen patients (16.8%) died, but nine (10.8%) were weaned from support. Serum brain natriuretic peptide (BNP) concentration measured 60 days after implantation was significantly associated with all-cause mortality. The optimal BNP cut-off value to predict death during LVAD support was 322 pg/ml, with a sensitivity of 71.4% and specificity of 79.8%. Two-year survival was 92.0% in those with 60-day serum BNP concentration Creative Commons Attribution-Non Commercial-No Derivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.

  12. A delayed splenic rupture after transcatheter arterial embolization required total splenectomy in a patient with an implantable left ventricular assist device.

    Science.gov (United States)

    Kitahara, Hiroto; Nawata, Kan; Kinoshita, Osamu; Itoda, Yoshifumi; Kimura, Mitsutoshi; Yamauchi, Haruo; Ono, Minoru

    2016-12-01

    We successfully managed a splenic injury and delayed splenic rupture in a patient with an implantable left ventricular assist device (iLVAD). A 42-year-old man with an iLVAD for idiopathic dilated cardiomyopathy was admitted to our department complaining of dizziness. Laboratory data showed severe anemia, and computed tomography demonstrated a traumatic splenic injury. Following conservative treatment, partial splenic embolization was performed. Fifteen days after the intervention, the patient went into hemorrhagic shock due to delayed splenic rupture. Emergency total splenic embolization was performed, and total splenectomy was conducted later to prevent re-bleeding or abscess formation. His postoperative course was uneventful, and he was discharged on postoperative day 22. Finally, he underwent orthotropic heart transplantation without post-splenectomy sepsis or thrombotic complications 472 days after splenectomy. Splenic injury should be considered as a possible complication of iLVAD. In addition, careful follow-up after transcatheter arterial embolization for splenic injury is essential for managing delayed splenic rupture.

  13. Derivation and Validation of a Novel Right-Sided Heart Failure Model After Implantation of Continuous Flow Left Ventricular Assist Devices:The EUROMACS (European Registry for Patients with Mechanical Circulatory Support) Right-Sided Heart Failure Risk Score.

    Science.gov (United States)

    Soliman, Osama I; Akin, Sakir; Muslem, Rahatullah; Boersma, Eric; Manintveld, Olivier C; Krabatsch, Thomas; Gummert, Jan F; de By, Theo M M H; Bogers, Ad J J C; Zijlstra, Felix; Mohacsi, Paul; Caliskan, Kadir

    2017-08-27

    Background -The aim of the study was to derive and validate a novel risk score for early right-sided heart failure (RHF) after left ventricular assist device implantation. Methods -The European Registry for Patients with Mechanical irculatory Support (EUROMACS) was used to identify adult patients undergoing continuous-flow left ventricular assist device implantation with mainstream devices. Eligible patients (n=2988) were randomly divided into derivation (n=2000) and validation (n=988) cohorts. The primary outcome was early (RHF, defined as receiving short- or long-term rightsided circulatory support, continuous inotropic support for ≥14 days, or nitric oxide ventilation for ≥48 hours. The secondary outcome was all-cause mortality and length of stay in the intensive care unit. Covariates found to be associated with RHF (exploratory univariate PRHF in the derivation cohort occurred in 433 patients (21.7%) after left ventricular assist device implantation and was associated with a lower 1-year (53% versus 71%; PRHF. RHF risk ranged from 11% (low risk score 0-2) to 43.1% (high risk score >4; PRHF, respectively (PRHF risk score outperformed (PRHF. Conclusions -This novel EUROMACS-RHF risk score outperformed currently known risk scores and clinical predictors of early postoperative RHF. This novel score may be useful for tailored risk-based clinical assessment and management of patients with advanced HF evaluated for ventricular assist device therapy.

  14. Thermal evolution of surface blistering and exfoliation due to ion-implanted hydrogen monomers into Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket

    Energy Technology Data Exchange (ETDEWEB)

    Liang, J.H., E-mail: jhliang@ess.nthu.edu.tw [Institute of Nuclear Engineering and Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 300, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Hu, C.H.; Bai, C.Y. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Chao, D.S. [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 300, Taiwan (China); Lin, C.M. [Department of Applied Science, National Hsinchu University of Education, Hsinchu 300, Taiwan (China)

    2012-08-01

    This study investigated the dependence of surface blistering and exfoliation phenomena on post-annealing time in H{sup +}-implanted Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket . Czochralski-grown n-type Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket wafers were room-temperature ion-implanted with 40 keV hydrogen monomers to a fluence of 5 Multiplication-Sign 10{sup 16} cm{sup -2}, and followed by furnace annealing treatments at 400 and 500 Degree-Sign C for various durations ranging from 0.25 to 3 h. The corresponding analysis results for Si Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket (Liang et al., 2008); (Bai, 2007) were adopted in order to make comparisons. The evolution of blister formation and growth for Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket at 400 Degree-Sign C has a shorter characteristic time compared to Si Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket . However, there is a longer characteristic time when annealing takes place at 500 Degree-Sign C. In addition, no craters were observed for Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket annealed at 400 Degree-Sign C while the opposite is true for Si Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket . The evolution of crater development for Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket annealed at 500 Degree-Sign C has a longer characteristic time compared to Si Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket . These results are attributed to the fact that compared to Si Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket , Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket has a smaller surface binding energy of silicon atoms and a larger areal number density of silicon atoms on the plane perpendicular to the incident-ion axis. Furthermore, Si Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket has a

  15. Principles for efficient damping of electro-mechanical oscillations in power networks; Principer foer effektiv daempning av systemvida pendlingar i elkraftnaet

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Lars

    2000-07-01

    This master-thesis report deals with the problem of power oscillations in power networks. The purpose of the work has been to study electro-mechanical oscillations in power systems and in a methodical way analyze the system to identify interesting properties. To increase the damping of especially the inter-area modes, the use of Power System Stabilizers has been investigated. In the control with PSS, local signals such as active power and angular velocity of the generator have first been used as measuring signals. The benefits of using global measuring signals have then been examined. The global signals examined are the derivative of the bus voltage phase angle and also the generators active power. An approach to study the zeros in a control loop is presented and gives, with the use of global measuring signals, a way of choosing a measuring signal to the PSS that affects the control in a beneficial way. A model of the Brazilian south/southeast power system has been used as a test system in the report. To analyze the system, modal analysis has been used and simulations have been performed in EUROSTAG for evaluation of control designs. In use of global signals, communication of signals is needed and therefore the effects of disturbances in this communication need to be considered. The effect of delays in the different signals has been studied and also the scenario of total loss of communication.

  16. Acceleration of dormant storage effects to address the reliability of silicon surface micromachined Micro-Electro-Mechanical Systems (MEMS).

    Energy Technology Data Exchange (ETDEWEB)

    Cox, James V.; Candelaria, Sam A.; Dugger, Michael Thomas; Duesterhaus, Michelle Ann; Tanner, Danelle Mary; Timpe, Shannon J.; Ohlhausen, James Anthony; Skousen, Troy J.; Jenkins, Mark W.; Jokiel, Bernhard, Jr.; Walraven, Jeremy Allen; Parson, Ted Blair

    2006-06-01

    water or contaminants that can cause movable structures to adhere. These analysis methods also indicated significant variability in the coverage of lubricating molecules from one coating process to another, even for identical processing conditions. The variability was due to residual molecules left in the deposition chamber after incomplete cleaning. The coating process was modified to result in improved uniformity and total coverage. Still, a direct correlation was found between the resulting static friction behavior of MEMS interfaces, and the absolute monolayer coverage. While experimental results indicated that many devices would fail to start after aging, the modeling approach used here predicted that all the devices should start. Adhesion modeling based upon values of adhesion energy from cantilever beams is therefore inadequate. Material deposition that bridged gaps was observed in some devices, and potentially inhibits start-up more than the adhesion model indicates. Advances were made in our ability to model MEMS devices, but additional combined experimental-modeling studies will be needed to advance the work to a point of providing predictive capability. The methodology developed here should prove useful in future assessments of device aging, however. Namely, it consisted of measuring interface properties, determining how they change with time, developing a model of device behavior incorporating interface behavior, and then using the age-aware interface behavior model to predict device function.

  17. Coupled magneto-electro-mechanical lumped parameter model for a novel vibration-based magneto-electro-elastic energy harvesting systems

    Science.gov (United States)

    Shirbani, Meisam Moory; Shishesaz, Mohammad; Hajnayeb, Ali; Sedighi, Hamid Mohammad

    2017-06-01

    The objective of this paper is to present a coupled magneto-electro-mechanical (MEM) lumped parameter model for the response of the proposed magneto-electro-elastic (MEE) energy harvesting systems under base excitation. The proposed model can be used to create self-powering systems, which are not limited to a finite battery energy. As a novel approach, the MEE composites are used instead of the conventional piezoelectric materials in order to enhance the harvested electrical power. The considered structure consists of a MEE layer deposited on a layer of non-MEE material, in the framework of unimorph cantilever bars (longitudinal displacement) and beams (transverse displacement). To use the generated electrical potential, two electrodes are connected to the top and bottom surfaces of the MEE layer. Additionally, a stationary external coil is wrapped around the vibrating structure to induce a voltage in the coil by the magnetic field generated in the MEE layer. In order to simplify the design procedure of the proposed energy harvester and obtain closed form solutions, a lumped parameter model is prepared. As a first step in modeling process, the governing constitutive equations, Gauss's and Faraday's laws, are used to derive the coupled MEM differential equations. The derived equations are then solved analytically to obtain the dynamic behavior and the harvested voltages and powers of the proposed energy harvesting systems. Finally, the influences of the parameters that affect the performance of the MEE energy harvesters such as excitation frequency, external resistive loads and number of coil turns are discussed in detail. The results clearly show the benefit of the coil circuit implementation, whereby significant increases in the total useful harvested power as much as 38% and 36% are obtained for the beam and bar systems, respectively.

  18. [From implantable cardioverter-defibrillator to cardiac resynchronization therapy with the use of epicardial left ventricular lead. The evolution of the treatment of post inflammatory heart failure--a case report].

    Science.gov (United States)

    Gepner, Katarzyna; Sterliński, Maciej; Przybylski, Andrzej; Maciag, Aleksander; Kołsut, Piotr; Szwed, Hanna

    2006-10-01

    The authors present a case of a 77-year-old man with heart failure in the course of dilated cardiomyopathy (DCM) and atrial fibrillation (AF), after implantation of an automatic cardioverter-defibrillator (ICD) due to recurrent symptomatic ventricular tachycardia (VT). Addition of cardiac resynchronization therapy (CRT) was decided due to the heart-failure dependent intensification of the arrhythmia and poststimulation enlargement of QRS. CRT was led to withdraw patient's arrhythmia and to improvement of the general condition of the patient for approximately one year. After the arrhythmia reoccurred due to dislocation of the electrode in the coronary sinus with loss of left ventricle stimulation. Multiple attempts at restoration of resynchronization function via a transvenous approach failed. The patient was qualified for implantation of an epicardial left ventricle electrode. The surgery was combined with a planned exchange of ICD-CRT. Basing on a 6-month observation period an improvement heart performance and general state of health have been observed. No arrhythmic event has been noted in device memory. Performed procedures are picturing the evolution of in pacing techniques and automatic defibrillation in Poland over recent years.

  19. Relation of QRS Duration to Clinical Benefit of Cardiac Resynchronization Therapy in Mild Heart Failure Patients Without Left Bundle Branch Block: The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy Substudy.

    Science.gov (United States)

    Biton, Yitschak; Kutyifa, Valentina; Cygankiewicz, Iwona; Goldenberg, Ilan; Klein, Helmut; McNitt, Scott; Polonsky, Bronislava; Ruwald, Anne Christine; Ruwald, Martin H; Moss, Arthur J; Zareba, Wojciech

    2016-02-01

    There are conflicting data regarding the efficacy of cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and without left bundle branch block. We evaluated the long-term clinical outcomes of 537 non-left bundle branch block patients with mild HF enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) study by QRS duration or morphology further stratified by PR interval. At 7 years of follow-up, the cumulative probability of HF hospitalization or death was 45% versus 56% among patients randomized to implantable cardioverter-defibrillator and CRT with defibrillator (CRT-D), respectively (P=0.209). Multivariable-adjusted subgroup analysis by QRS duration showed that patients from the lower quartile QRS duration group (≤ 134 ms) experienced 2.4-fold (P=0.015) increased risk for HF hospitalization or death with CRT-D versus implantable cardioverter-defibrillator only therapy, whereas the effect of CRT-D in patients from the upper quartiles group (QRS>134 ms) was neutral (hazard ratio [HR] =0.97, P=0.86; P value for interaction =0.024). In a second analysis incorporating PR interval, patients with prolonged QRS (>134 ms) and prolonged PR (>230 ms) were protected with CRT-D (HR=0.31, P=0.003), whereas the association was neutral with prolonged QRS (>134 ms) and shorter PR (≤ 230 ms;, HR=1.19, P=0.386; P value for interaction =0.002). The effect was neutral, regardless of morphology, right bundle branch block (HR=1.01, P=0.975), and intraventricular conduction delay (HR=1.31, P=0.172). Overall, patients with mild HF but without left bundle branch block morphology did not derive clinical benefit with CRT-D during long-term follow-up. Relatively shorter QRS was associated with a significantly increased risk with CRT-D relative to implantable cardioverter-defibrillator -only. URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00180271, NCT01294449, and NCT02060110. © 2016

  20. Cochlear Implants

    Science.gov (United States)

    ... implant procedure Welcome to the Food and Drug Administration (FDA) website on cochlear implants. Cochlear implants are electronic hearing devices. Doctors implant cochlear implants into people ...

  1. Effects of alloying and local order in AuNi contacts for Ohmic radio frequency micro electro mechanical systems switches via multi-scale simulation

    Science.gov (United States)

    Gaddy, Benjamin E.; Kingon, Angus I.; Irving, Douglas L.

    2013-05-01

    Ohmic RF-MEMS switches hold much promise for low power wireless communication, but long-term degradation currently plagues their reliable use. Failure in these devices occurs at the contact and is complicated by the fact that the same asperities that bear the mechanical load are also important to the flow of electrical current needed for signal processing. Materials selection holds the key to overcoming the barriers that prevent widespread use. Current efforts in materials selection have been based on the material's (or alloy's) ability to resist oxidation as well as its room-temperature properties, such as hardness and electrical conductivity. No ideal solution has yet been found via this route. This may be due, in part, to the fact that the in-use changes to the local environment of the asperity are not included in the selection criteria. For example, Joule heating would be expected to raise the local temperature of the asperity and impose a non-equilibrium thermal gradient in the same region expected to respond to mechanical actuation. We propose that these conditions should be considered in the selection process, as they would be expected to alter mechanical, electrical, and chemical mechanisms in the vicinity of the surface. To this end, we simulate the actuation of an Ohmic radio frequency micro electro mechanical systems switch by using a multi-scale method to model a current-carrying asperity in contact with a polycrystalline substrate. Our method couples continuum solutions of electrical and thermal transport equations to an underlying molecular dynamics simulation. We present simulations of gold-nickel asperities and substrates in order to evaluate the influence of alloying and local order on the early stages of contact actuation. The room temperature response of these materials is compared to the response of the material when a voltage is applied. Au-Ni interactions are accounted for through modification of the existing Zhou embedded atom method

  2. Strange bedfellows: the Bundestag’s free vote on pre-implantation genetic diagnosis (PGD reveals how Germany’s restrictive bioethics legislation is shaped by a Christian Democratic/New Left issue-coalition

    Directory of Open Access Journals (Sweden)

    Kai Arzheimer

    2015-08-01

    Full Text Available Germany’s bioethical legislation presents a puzzle: given structural factors, the country should be at the forefront of reproductive medicine, but its embryology regime remains one of the strictest in Western Europe. Past research has linked this fact to an unusual coalition of Christian and New Left groups, which both draw a connection from modern embryology to eugenics under the Nazis. In this article, the workings of this alleged alliance are demonstrated at the micro-level for the first time. The behaviour of individual MPs in a crucial free vote on pre-implantation genetic diagnosis (PGD is modelled using data on their political, sectoral and religious affiliations. Identifying as a Catholic and membership in Christian organisations are strong predictors of resistance to PGD. Even more importantly, net of religious and professional ties, affiliation with either the Christian Democrats or the left-libertarian Green party is closely linked to restrictive bioethical preferences. The modest liberalisation in 2011 was contingent on external factors and the overwhelming support of the historically unusually large FDP delegation. With the FDP no longer represented in parliament and the Christian Democratic/New Left issue coalition even stronger than before, further liberalisation is unlikely.

  3. Coronary Artery Bypass Surgery Versus Drug-Eluting Stent Implantation for Left Main or Multivessel Coronary Artery Disease A Meta-Analysis of Individual Patient Data

    NARCIS (Netherlands)

    Lee, Cheol Whan; Ahn, Jung-Min; Cavalcante, Rafael; Sotomi, Yohei; Onuma, Yoshinobu; Suwannasom, Pannipa; Tenekecioglu, Erhan; Yun, Sung-Cheol; Park, Duk-Woo; Kang, Soo-Jin; Lee, Seung-Whan; Kim, Young-Hak; Park, Seong-Wook; Serruys, Patrick W.; Park, Seung-Jung

    2016-01-01

    OBJECTIVES The authors undertook a patient-level meta-analysis to compare long-term outcomes after coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) with drug-eluting stents (DES) in 3,280 patients with left main or multivessel coronary artery disease (CAD).

  4. Predictors of long-term outcomes after bypass grafting versus drug-eluting stent implantation for left main or multivessel coronary artery disease

    NARCIS (Netherlands)

    Chang, Mineok; Lee, Cheol Whan; Ahn, Jung-Min; Cavalcante, Rafael; Sotomi, Yohei; Onuma, Yoshinobu; Han, Minkyu; Park, Seong-Wook; Serruys, Patrick W.; Park, Seung-Jung

    2017-01-01

    Background: We assessed predictors of long-term outcomes after coronary artery bypass grafting (CABG) versus those after percutaneous coronary intervention (PCI) with drug-eluting stents (DES) in 3,230 patients with left main or multivessel coronary artery disease (CAD). Methods and Results: Data

  5. Heart rate variability density analysis (Dyx) for identification of appropriate implantable cardioverter defibrillator recipients among elderly patients with acute myocardial infarction and left ventricular systolic dysfunction

    DEFF Research Database (Denmark)

    Jørgensen, Rikke Mørch; Levitan, Jacob; Halevi, Zohar

    2015-01-01

    to diagnose the primary endpoint of near-fatal or fatal ventricular tachyarrhythmias likely preventable by an implantable cardioverter defibrillator (ICD), during a period of 2 years. A Dyx ≤ 1.96 was considered abnormal. The secondary endpoint was cardiovascular death. At enrolment 59 patients (24%) had...... a Dyx ≤ 1.96 and 20 experienced a primary endpoint. A Dyx ≤ 1.96 was associated with a significantly increased risk for malignant arrhythmias [hazards ratio (HR) = 4.36 (1.81-10.52), P = 0.001] and cardiovascular death [HR = 3.47 (1.38-8.74), P = 0.008]. Compared with important clinical risk parameters...

  6. Left Main Coronary Artery Compression following Melody Pulmonary Valve Implantation: Use of Impella Support as Rescue Therapy and Perioperative Challenges with ECMO

    Directory of Open Access Journals (Sweden)

    Erica D. Wittwer

    2014-01-01

    Full Text Available The purpose of this case is to describe the complex perioperative management of a 30-year-old woman with congenital heart disease and multiple resternotomies presenting with pulmonary homograft dysfunction and evaluation for percutaneous pulmonary valve replacement. Transvenous, transcatheter Melody valve placement caused left main coronary artery occlusion and cardiogenic shock. An Impella ventricular assist device (VAD provided rescue therapy during operating room transport for valve removal and pulmonary homograft replacement. ECMO support was required following surgery. Several days later during an attempted ECMO wean, her hemodynamics deteriorated abruptly. Transesophageal and epicardial echocardiography identified pulmonary graft obstruction, requiring homograft revision due to large thrombosis. This case illustrates a role for Impella VAD as bridge to definitive procedure after left coronary occlusion and describes management of complex perioperative ECMO support challenges.

  7. Terapia de resincronización con implante de electrodo ventricular izquierdo por vía epicárdica Resynchronization therapy with left ventricular electrode implant via epicardium

    OpenAIRE

    Francisco Gómez; Boris V Astudillo; Orrego, Carlos M.; Manuel A Coronado; Juan M Senior

    2007-01-01

    Introducción: la terapia de resincronización cardiaca es segura y efectiva para mejorar la clase funcional y la calidad de vida, y reducir la mortalidad en pacientes con falla cardiaca en estado funcional III y IV con terapia médica óptima. Métodos: este es el reporte del procedimiento realizado a un grupo de pacientes a quienes se les implantó un marcapasos tricameral para resincronización cardiaca, con inserción del electrodo ventricular izquierdo por vía epicárdica, realizado en la Unidad ...

  8. Cochlear implant

    Science.gov (United States)

    Hearing loss - cochlear implant; Sensorineural - cochlear; Deaf - cochlear; Deafness - cochlear ... of the cochlear implant. WHO USES A COCHLEAR IMPLANT? Cochlear implants allow deaf people to receive and process ...

  9. Cardiac sympathetic innervation assessed with (123)I-MIBG retains prognostic utility in diabetic patients with severe left ventricular dysfunction evaluated for primary prevention implantable cardioverter-defibrillator.

    Science.gov (United States)

    García-González, P; Fabregat-Andrés, Ó; Cozar-Santiago, P; Sánchez-Jurado, R; Estornell-Erill, J; Valle-Muñoz, A; Quesada-Dorador, A; Payá-Serrano, R; Ferrer-Rebolleda, J; Ridocci-Soriano, F

    2016-01-01

    Scintigraphy with iodine-123-metaiodobenzylguanidine ((123)I-MIBG) is a non-invasive tool for the assessment of cardiac sympathetic innervation (CSI) that has proven to be an independent predictor of survival. Recent studies have shown that diabetic patients with heart failure (HF) have a higher deterioration in CSI. It is unknown if (123)I-MIBG has the same predictive value for diabetic and non-diabetic patients with advanced HF. An analysis is performed to determine whether CSI with (123)I-MIBG retains prognostic utility in diabetic patients with HF, evaluated for a primary prevention implantable cardioverter-defibrillator (ICD). Seventy-eight consecutive HF patients (48 diabetic) evaluated for primary prevention ICD implantation were prospectively enrolled and underwent (123)I-MIBG to assess CSI (heart-to-mediastinum ratio - HMR). A Cox proportional hazards multivariate analysis was used to determine the influence of (123)I-MIBG images for prediction of cardiac events in both diabetic and non-diabetic patients. The primary end-point was a composite of arrhythmic event, cardiac death, or admission due to HF. During a mean follow-up of 19.5 [9.3-29.3] months, the primary end-point occurred in 24 (31%) patients. Late HMR was significantly lower in diabetic patients (1.30 vs. 1.41, p=0.014). Late HMR≤1.30 was an independent predictor of cardiac events in diabetic (hazard ratio 4.53; p=0.012) and non-diabetic patients (hazard ratio 12.31; p=0.023). Diabetic patients with HF evaluated for primary prevention ICD show a higher deterioration in CSI than non-diabetics; nevertheless (123)I-MIBG imaging retained prognostic utility for both diabetic and non-diabetic patients. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  10. Everolimus-eluting stent implantation for unprotected left main coronary artery stenosis. The PRECOMBAT-2 (Premier of Randomized Comparison of Bypass Surgery versus Angioplasty Using Sirolimus-Eluting Stent in Patients with Left Main Coronary Artery Disease) study.

    Science.gov (United States)

    Kim, Young-Hak; Park, Duk-Woo; Ahn, Jung-Min; Yun, Sung-Cheol; Song, Hae Geun; Lee, Jong-Young; Kim, Won-Jang; Kang, Soo-Jin; Lee, Seung-Whan; Lee, Cheol Whan; Park, Seong-Wook; Jang, Yangsoo; Jeong, Myung-Ho; Kim, Hyo-Soo; Hur, Seung-Ho; Rha, Seung-Woon; Lim, Do-Sun; Her, Sung-Ho; Seung, Ki Bae; Seong, In-Whan; Park, Seung-Jung

    2012-07-01

    This study sought to evaluate the safety and efficacy of second-generation drug-eluting stents (DES) for patients with unprotected left main coronary artery (ULMCA) stenosis. The clinical benefit of second-generation DES for ULMCA stenosis has not been determined. The authors assessed 334 consecutive patients who received everolimus-eluting stents (EES) for ULMCA stenosis between 2009 and 2010. The 18-month incidence rates of major adverse cardiac or cerebrovascular events (MACCE), including death, myocardial infarction (MI), stroke, or ischemia-driven target vessel revascularization (TVR), were compared with those of a randomized study comparing patients who received sirolimus-eluting stents (SES) (n = 327) or coronary artery bypass grafts (CABG) (n = 272). EES (8.9%) showed a comparable incidence of MACCE as SES (10.8%; adjusted hazard ratio [aHR] of EES: 0.84; 95% confidence interval [CI]: 0.51 to 1.40; p = 0.51) and CABG (6.7%, aHR of EES: 1.40; 95% CI: 0.78 to 2.54; p = 0.26). The composite incidence of death, MI, or stroke also did not differ among patients receiving EES (3.3%), SES (3.7%; aHR of EES: 0.63; 95% CI: 0.27 to 1.47; p = 0.29), and CABG (4.8%; aHR of EES: 0.67; 95% CI: 0.29 to 1.54; p = 0.34). However, the incidence of ischemia-driven TVR in the EES group (6.5%) was higher than in the CABG group (2.6%, aHR of EES: 2.77; 95% CI: 1.17 to 6.58; p = 0.02), but comparable to SES (8.2%, aHR of EES: 1.14; 95% CI: 0.64 to 2.06; p = 0.65). Angiographic restenosis rates were similar in the SES and EES groups (13.8% vs. 9.2%, p = 0.16). Second-generation EES had a similar 18-month risk of MACCE for ULMCA stenosis as first-generation SES or CABG. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  11. Monitoring of slope-instabilities and deformations with Micro-Electro-Mechanical-Systems (MEMS) in wireless ad-hoc Sensor Networks

    Science.gov (United States)

    Arnhardt, C.; Fernández-Steeger, T. M.; Azzam, R.

    2009-04-01

    In most mountainous regions, landslides represent a major threat to human life, properties and infrastructures. Nowadays existing landslide monitoring systems are often characterized by high efforts in terms of purchase, installation, maintenance, manpower and material. In addition (or because of this) only small areas or selective points of the endangered zone can be observed by the system. Therefore the improvement of existing and the development of new monitoring and warning systems are of high relevance. The joint project "Sensor based Landslide Early Warning Systems" (SLEWS) deals with the development of a prototypic Alarm- and Early Warning system (EWS) for different types of landslides using low-cost micro-sensors (MEMS) integrated in a wireless sensor network (WSN). Modern so called Ad-Hoc, Multi-Hop wireless sensor networks (WSN) are characterized by a self organizing and self-healing capacity of the system (autonomous systems). The network consists of numerous individual and own energy-supply operating sensor nodes, that can send data packages from their measuring devices (here: MEMS) over other nodes (Multi-Hop) to a collection point (gateway). The gateway provides the interface to central processing and data retrieval units (PC, Laptop or server) outside the network. In order to detect and monitor the different landslide processes (like fall, topple, spreading or sliding) 3D MEMS capacitive sensors made from single silicon crystals and glass were chosen to measure acceleration, tilting and altitude changes. Based on the so called MEMS (Micro-Electro-Mechanical Systems) technology, the sensors combine very small mechanical and electronic units, sensing elements and transducers on a small microchip. The mass production of such type of sensors allows low cost applications in different areas (like automobile industries, medicine, and automation technology). Apart from the small and so space saving size and the low costs another advantage is the energy

  12. Left ventricular performance during triggered left ventricular pacing in patients with cardiac resynchronization therapy and left bundle branch block

    DEFF Research Database (Denmark)

    Witt, Christoffer Tobias; Kronborg, Mads Brix; Nohr, Ellen Aagaard

    2016-01-01

    complex >150 ms, QRS complex narrowing under CRT, and sinus rhythm were included ≥3 months after CRT implantation. Echocardiographic assessment of left ventricular ejection fraction (LVEF), global peak systolic longitudinal strain (GLS), and contraction pattern by 2D strain was performed during intrinsic......PURPOSE: To assess the acute effect of triggered left ventricular pacing (tLVp) on left ventricular performance and contraction pattern in patients with heart failure, left bundle branch block (LBBB), and cardiac resynchronization therapy (CRT). METHODS: Twenty-three patients with pre-implant QRS...

  13. Comparative analysis of electro-mechanical characteristic of a three-phase induction motor with 1,5 CV with high performance and conventional one; Analise comparativa das caracteristicas eletromecanicas entre um motor de inducao trifasico de 1,5CV de alto-rendimento e convencional

    Energy Technology Data Exchange (ETDEWEB)

    Mendieta, J.C.V. [Dalkia, Rio de Janeiro, RJ (Brazil); Bertoleti, P.H.F.; Magalhaes Sobrinho, P. [Universidade Estadual Paulista (LAMOTRIZ/UNESP), Guaratingueta, SP (Brazil). Lab. de Otimizacao de Sistemas Motrizes Industriais; Souza, T.M. [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil)

    2009-07-01

    In Brazil, the electric power consumed by three-phase induction motors corresponding to approximately 55% of total electric power consumed by the industrial sector. Therefore, a thorough analysis of this type of engine under the questions of energy saving, economic viability and electro-mechanical characteristics are needed. This work deals with the comparative analysis for two motors three-phase induction, one conventional and another with high performance (manufacturer WEG and IP55 protection grade), aiming to obtain the necessary relationships to do an economical and electro-mechanical analysis.

  14. Short-term mechanical circulatory support as a bridge to durable left ventricular assist device implantation in refractory cardiogenic shock: a systematic review and meta-analysis.

    Science.gov (United States)

    den Uil, Corstiaan A; Akin, Sakir; Jewbali, Lucia S; Dos Reis Miranda, Dinis; Brugts, Jasper J; Constantinescu, Alina A; Kappetein, Arie Pieter; Caliskan, Kadir

    2017-07-01

    Short-term mechanical circulatory support (MCS) is increasingly used as a bridge to decision in patients with refractory cardiogenic shock. Subsequently, these patients might be bridged to durable MCS either as a bridge to candidacy/transplantation, or as destination therapy. The aim of this study was to review support duration and clinical outcome of short-term MCS in cardiogenic shock, and to analyse application of this technology as a bridge to long-term cardiac support (left ventricular assist device, LVAD) from 2006 till June 2016. Using Cochrane Register of Trials, Embase and Medline, a systematic review was performed on patients with cardiogenic shock from acute myocardial infarction, end-stage cardiomyopathy, or acute myocarditis, receiving short-term MCS. Studies on periprocedural, post-cardiotomy and cardiopulmonary resuscitation support were excluded. Thirty-nine studies, mainly registries of heterogeneous patient populations (n = 4151 patients), were identified. Depending on the device used (intra-aortic balloon pump, TandemHeart, Impella 2.5, Impella 5.0, CentriMag and peripheral veno-arterial extracorporeal membrane oxygenation), mean support duration was (range) 1.6-25 days and the mean proportion of short-term MCS patients discharged was (range) 45-66%. The mean proportion of bridge to durable LVAD was (range) 3-30%. Bridge to durable LVAD was most frequently performed in patients with end-stage cardiomyopathy (22 [12-35]%). We conclude that temporary MCS can be used to bridge patients with cardiogenic shock towards durable LVAD. Clinicians are encouraged to share their results in a large multicentre registry in order to investigate optimal device selection and best duration of support. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  15. Different impact of aortic regurgitation assessed by aortic root angiography after transcatheter aortic valve implantation according to baseline left ventricular ejection fraction and N-terminal pro-B-type natriuretic peptide.

    Science.gov (United States)

    Kaneko, Hidehiro; Hoelschermann, Frank; Schau, Thomas; Tambor, Grit; Neuss, Michael; Butter, Christian

    2017-05-31

    Transcatheter aortic valve implantation (TAVI) is an alternative therapeutic option for severe aortic stenosis. Aortic regurgitation (AR) is commonly observed after TAVI and increases the mortality rate. We hypothesized that the influence of significant AR, defined as that more severe than mild AR, on survival rate after TAVI might differ according to the baseline left ventricular ejection fraction (LVEF) and N-terminal pro-B-type natriuretic peptide (NT-pro BNP) level. We categorized 856 patients who underwent transfemoral TAVI into 2 groups according to their baseline LVEF (5000 pg/mL). Significant AR was observed in 92 patients (11%). Among patients with significant AR, the proportion of patients with CoreValve/EvolutR implantation was higher than that of patients with SAPIEN XT/3 implantation. Kaplan-Meier curves and the log-rank test showed that significant AR was not associated with 1-year mortality in patients with LVEF ≥40% and those with NT-pro BNP level ≤5000 pg/mL. On the other hand, it was significantly associated with a higher 1-year mortality in patients with LVEF 5000 pg/mL (p = 0.011). Similarly, multivariate Cox regression analysis showed that the presence of AR was significantly associated with a higher 1-year mortality in patients with LVEF 5000 pg/mL (p = 0.004, HR = 3.221). However, AR was not significantly associated with a higher 1-year mortality in patients with LVEF ≥40% and NT-pro BNP level ≤5000 pg/mL. Thus, the impact of significant AR on mortality after TAVI seems to be considerable in patients with reduced LVEF or high NT-pro BNP levels, but not those with preserved LVEF or low NT-pro BNP levels, suggesting that the influence of AR differs depending on the baseline LVEF and NT-pro BNP level.

  16. Evaluating the effect of pressure on the diaphragm micro- electro-mechanical thickness and the amount of shift in medical applications

    Directory of Open Access Journals (Sweden)

    Nazli Zargarpour

    2017-04-01

    Full Text Available In this paper, the influence of design parameters on the sensitive microphone diaphragm for use in implantable medical applications is presented. The different parameters such as diaphragm shape, size, thickness and different applied pressures on the diaphragm has been considered. The effect of changes in these parameters on the displacement and stress in a variety of shapes of diaphragm is discussed. In order to design the optimal shape of the proposed diaphragm for the considered parameters, it has been simulated and analyzed in software COMSOL. According to the parameters, the diaphragm shapes of square, rectangular and oval with respect to the intended user, average central displacement in human hearing frequency range 20Hz-20KHz are nm 5. 5, nm2. 6, and nm 130 respectively . According to the results of the simulations, the oval-shaped diaphragm that has been studies in this paper, the possibility of implanted medical applications, performance is optimal than other shapes. In addition, the piezoelectric material is PZT which used in the design of the diaphragm.

  17. Temperature-dependent electro-mechanical actuation sensitivity in stiffness-tunable BaTiO3/polydimethylsiloxane dielectric elastomer nanocomposites

    Science.gov (United States)

    Zhao, Hang; Zhang, Ling; Yang, Min-Hao; Dang, Zhi-Min; Bai, Jinbo

    2015-03-01

    Stiffness-tunable BaTiO3/polydimethylsiloxane (BT/PDMS) dielectric elastomer composites using dimethylsilicone oil (DMSO) as the stiffness tuner were prepared. Significant improvements in both electromechanical actuation sensitivity (0%-490%) and actuation areal strain (0%-350%) can be observed from BT/PDMS samples with DMSO, which should be mainly contributed to the physical swelling behavior. Under wide testing temperature range, the stiffness-tuned BT/PDMS composite exhibited an excellent thermal stability of both dielectric and mechanical performance. The electromechanical sensitivity of BT/PDMS composite can be effectively tuned higher than that of VHB 4910 acrylics via the addition of DMSO under in vivo temperature range (20 °C-40 °C). This simple way endows PDMS-based composites the higher performance for being applied as implantable dielectric elastomer materials.

  18. Remote powering and data communication for implanted biomedical systems

    CERN Document Server

    Kilinc, Enver Gurhan; Maloberti, Franco

    2016-01-01

    This book describes new circuits and systems for implantable biomedical applications and explains the design of a batteryless, remotely-powered implantable micro-system, designed for long-term patient monitoring.  Following new trends in implantable biomedical applications, the authors demonstrate a system which is capable of efficient, remote powering and reliable data communication.  Novel architecture and design methodologies are used to transfer power with a low-power, optimized inductive link and data is transmitted by a reliable communication link.  Additionally, an electro-mechanical solution is presented for tracking and monitoring the implantable system, while the patient is mobile.  ·         Describes practical example of an implantable batteryless biomedical system; ·         Analyzes and compares various energy harvesting and power transfer methods; ·         Describes design of remote powering link and data communication of the implantable system, comparing differe...

  19. Implantable cardiac monitors in high-risk post-infarction patients with cardiac autonomic dysfunction and moderately reduced left ventricular ejection fraction: Design and rationale of the SMART-MI trial.

    Science.gov (United States)

    Hamm, Wolfgang; Rizas, Konstantinos D; Stülpnagel, Lukas von; Vdovin, Nikolay; Massberg, Steffen; Kääb, Stefan; Bauer, Axel

    2017-08-01

    Most deaths after myocardial infarction (MI) occur in patients with left ventricular ejection fraction (LVEF) >35%, for whom no specific prophylactic strategies exist. Deceleration capacity (DC) of heart rate and periodic repolarization dynamics (PRD) are noninvasive electrophysiological markers depending on the vagal and sympathetic tone. The combination of abnormal DC and/or PRD identifies a new high-risk group among postinfarction patients with LVEF 36%-50%. This new high-risk group has similar characteristics with respect to prognosis and patient numbers to those of the established high-risk group identified by LVEF ≤ 35%. The SMART-MI trial is an investigator-initiated randomized prospective multicenter trial that tests the efficacy of implantable cardiac monitors (ICM) in this new high-risk group. The study will enroll approximately 1,600 survivors of acute MI with sinus rhythm and an LVEF of 35%-50% in 17 centers in Germany who will be tested for presence of cardiac autonomic dysfunction. Four hundred patients with either abnormal DC (≤2.5 ms) and/or PRD (≥5.75deg2) will be randomized in a 1:1 fashion to intensive follow-up via telemonitoring using an ICM device (experimental arm) or conventional follow-up (control arm). For the ICM arm, specific treatment paths have been developed according to current guidelines. The primary end point is time to detection of predefined serious arrhythmic events during follow-up, including atrial fibrillation ≥6minutes, nonsustained ventricular tachycardia (cycle length≤320 ms; ≥40 beats), atrioventricular block ≥IIb, and sustained ventricular tachycardia/ventricular fibrillation. The median follow-up period is 18months with a minimum follow-up of 6months. The effect of remote monitoring on clinical outcomes will be tested as secondary outcome measure (ClinicalTrials.gov NCT02594488). Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Yield of left ventricular dyssynchrony by gated SPECT MPI in patients with heart failure prior to implantable cardioverter-defibrillator or cardiac resynchronization therapy with a defibrillator: Characteristics and prediction of cardiac outcome.

    Science.gov (United States)

    Zafrir, Nili; Bental, Tamir; Strasberg, Boris; Solodky, Alejandro; Mats, Israel; Gutstein, Ariel; Kornowski, Ran

    2017-02-01

    Mechanical left ventricular dyssynchrony (MLVD) might contribute in the therapeutic decision-making in patients with heart failure (HF) prior to cardiac resynchronization therapy (CRT). Our aim was to assess MLVD in patients with HF prior to implantable cardioverter-defibrillator (ICD) compared to patients with CRT-D. In a prospective study, patients with LVEF ≤ 35% who were scheduled for ICD or CRT-D, underwent gated SPECT myocardial perfusion imaging with technetium 99m sestamibi within 3 months prior procedure. MLVD was measured by phase analysis. The study cohort consisted of 143 patients, 71 with ICD and 72 with CRT-D. Age 68.3 ± 11 and LVEF 24 ± 6%. Phase standard deviation (SD) was 62.5 ± 18 and 59.7 ± 20 (P = NS), respectively. During follow-up of 23.7 ± 12.1 months, there were 10 vs 14 cardiac death in ICD and CRT-D, respectively (P = NS), hospitalization for HF, in 34 vs 53 (P < .001). In multivariate analysis, Phase SD was the independent predictor for cardiac death [HR 2.66 (95% CI 1.046-6.768), P = .04]. Kaplan-Meier curves of phase SD of 60° significantly identified ICD patients with and without cardiac deaths and hospitalization for HF exacerbation. MLVD by phase SD can identify patients with cardiac events and predict cardiac death in patients treated with ICD.

  1. Impact of New-Onset Left Bundle Branch Block and Periprocedural Permanent Pacemaker Implantation on Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Regueiro, Ander; Abdul-Jawad Altisent, Omar; Del Trigo, María; Campelo-Parada, Francisco; Puri, Rishi; Urena, Marina; Philippon, François; Rodés-Cabau, Josep

    2016-05-01

    Available data on the clinical impact of new-onset left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR) remains controversial. We aimed to evaluate the impact of (1) periprocedural new-onset LBBB or PPI post-TAVR on cardiac mortality and all-cause 1-year mortality and (2) new-onset LBBB on the need for PPI at 1-year follow-up. We performed a systematic search from PubMed and EMBASE databases for studies reporting raw data on new-onset LBBB post-TAVR and the need for PPI or mortality at 1-year follow-up, or on 1-year mortality according to the need for periprocedural PPI post-TAVR. Data from 17 studies, including 4756 patients (8 studies) and 7032 patients (11 studies) for the evaluation of the impact of new-onset LBBB and periprocedural PPI post-TAVR were sourced, respectively (with 2 studies used for both outcomes). New-onset LBBB post-TAVR was associated with a higher risk of PPI (risk ratio [RR], 2.18; 95% confidence interval [CI], 1.28-3.70) and cardiac death (RR, 1.39; 95% CI, 1.04-1.86) during follow-up, as well with a tendency toward an increase in all-cause mortality (RR, 1.21; 95% CI, 0.98-1.50). Periprocedural PPI post-TAVR was not associated with any increased risk of all-cause mortality at 1 year (RR, 1.03; 95% CI, 0.9-1.18), yet a tendency toward a protective effect on cardiac death was observed (RR, 0.78; 95% CI, 0.60-1.03). New-onset LBBB post-TAVR is a marker of an increased risk of cardiac death and need for PPI at 1-year follow-up. The need for PPI early post-TAVR did not increase the risk of death. © 2016 American Heart Association, Inc.

  2. New strict left bundle branch block criteria reflect left ventricular activation differences

    DEFF Research Database (Denmark)

    Emerek, Kasper Janus Grønn; Risum, Niels; Hjortshøj, Søren Pihlkjær

    2015-01-01

    AIMS: Pacing lead electrical delays and strict left bundle branch block (LBBB) criteria were assessed against cardiac resynchronization therapy (CRT) outcome. METHODS: Forty-nine patients with LBBB and QRS duration >130 milliseconds underwent CRT-implantation. Sensed right ventricular to left...

  3. Giant and thrombosed left ventricular aneurysm.

    Science.gov (United States)

    de Agustin, Jose Alberto; de Diego, Jose Juan Gomez; Marcos-Alberca, Pedro; Rodrigo, Jose Luis; Almeria, Carlos; Mahia, Patricia; Luaces, Maria; Garcia-Fernandez, Miguel Angel; Macaya, Carlos; de Isla, Leopoldo Perez

    2015-07-26

    Left ventricular aneurysms are a frequent complication of acute extensive myocardial infarction and are most commonly located at the ventricular apex. A timely diagnosis is vital due to the serious complications that can occur, including heart failure, thromboembolism, or tachyarrhythmias. We report the case of a 78-year-old male with history of previous anterior myocardial infarction and currently under evaluation by chronic heart failure. Transthoracic echocardiogram revealed a huge thrombosed and calcified anteroapical left ventricular aneurysm. Coronary angiography demonstrated that the left anterior descending artery was chronically occluded, and revealed a big and spherical mass with calcified borders in the left hemithorax. Left ventriculogram confirmed that this spherical mass was a giant calcified left ventricular aneurysm, causing very severe left ventricular systolic dysfunction. The patient underwent cardioverter-defibrillator implantation for primary prevention.

  4. Silicone implant incompatibility syndrome (SIIS) in a 57-year-old woman with unilateral silicone breast implant

    DEFF Research Database (Denmark)

    Schierbeck, Juliane; Davidsen, Jesper Rømhild; Grindsted Nielsen, Sanne

    2017-01-01

    implants can lead to different interstitial lung manifestations predominantly with granuloma evolvement, leading to the so-called silicone implant incompatibility syndrome (SIIS). This case describes a 57-year-old woman with multiple lung infiltrations and a left-sided breast implant. The implant had been...

  5. Automatization Project for the Carl-Zeiss-Jena Coudè Telescope of the Simón Bolívar Planetarium I. The Electro-Mechanic System

    Science.gov (United States)

    Núñez, A.; Maharaj, A.; Muñoz, A. G.

    2009-05-01

    The ``Complejo Científico, Cultural y Turístico Simón Bolívar'' (CCCTSB), located in Maracaibo, Venezuela, lodges the Simón Bolívar Planetarium and an 150 mm aperture, 2250 mm focal length Carl-Zeiss-Jena Coudè refractor telescope. In this work we discuss the schematics for the automatization project of this Telescope, the planned improvements, methodology, engines, micro-controllers, interfaces and the uptodate status of the project. This project is working on the first two levels of the automation pyramid, the sensor -- actuator level and the control or Plant floor level. The Process control level correspond to the software related section. This mean that this project work immediately with the electrical, electronic and mechanical stuffs, and with the assembler micro controller language. All the pc related stuff, like GUI (Graphic user interfaces), remote control, Grid database, and others, correspond to the next two automation pyramid levels. The idea is that little human intervention will be required to manipulate the telescope, only giving a pair of coordinates to ubicate and follow an object on the sky. A set of three servomotors, coupling it with the telescope with a gear box, are going to manipulate right ascension, declination and focus movement. For the dome rotation, a three phase induction motor will be used. For dome aperture/closure it is suggested a DC motor powered with solar panels. All those actuators are controlled by a 8 bits micro-controller, which receive the coordinate imput, the signal from the position sensors and have the PID control algorithm. This algorithm is tuned based on the mathematical model of the telescope electro-mechanical instrumentation.

  6. Nano electro-mechanical optoelectronic tunable VCSEL.

    Science.gov (United States)

    Huang, Michael C Y; Zhou, Ye; Chang-Hasnain, Connie J

    2007-02-05

    We report a novel electrostatic actuated nano-electromechanical optoelectronic (NEMO) tunable vertical-cavity surface-emitting laser (VCSEL) centered at 850 nm. By integrating a movable, single-layer (230 nm), high-index-contrast subwavelength grating (HCG) as the VCSEL top mirror, single mode emission (SMSR >40 dB) and continuous wavelength tuning (~2.5 nm) was obtained at room temperature under CW operation. The small footprint of HCG enables the scaling down of each of the cantilever dimensions by a factor of 10, leading to 1000 times reduction in mass, which potentially increases the mechanical resonant frequency and tuning speed.

  7. [Osteoradionecrosis and dental implants].

    Science.gov (United States)

    Ben Slama, L; Hasni, W; De Labrouhe, C; Bado, F; Bertrand, J-C

    2008-12-01

    Osteoradionecrosis (ORN) is a severe complication of radiation therapy (RT). A triggering factor is frequently present. It is often a dental, periodental, or surgical traumatism. We report the case of a bilateral ORN: the first lesion appeared 3months after the end of RT around the osteosynthesis plate and was treated by mandibular resection. The second lesion appeared 40months after RT on the opposite side, due to peri-implantitis. Dental implants had been inserted 10years before cancer therapy. No case of ORN in post-implantation RT had been previously reported. A 75-year-old woman was admitted for a squamous cell carcinoma of the right cheek extending to the intermaxillary commissure, the maxillary tuberosity, the soft palate, the lingual junction, and the vestibule up to the second premolar area. There was no suspicious lymph node. She had undergone dental implant procedure 15 and 10 years before, respectively, one in the second premolar position of the right maxilla and four in the premolar and molar left mandible area. All of them were osseo-integrated and charged. A trans-mandibular buccopharyngectomy with modified radical neck dissection was performed, completed by RT. The total dose of irradiation was 65Gy in the oral cavity and 45Gy on cervical and supraclavicular areas. Delayed mucosal healing was observed on the right mandible and ORN appeared in this area 3months after the end of irradiation. Mandibular resection was necessary. Later, the right maxillary implant was lost, and multiple dental extractions were required. Forty months after RT, peri-implantitis was observed on the left side of the mandible, complicated by ORN and pathological fracture. No surgical reconstruction could be performed because of the patient's age and state. The patient was carrying a complete removable maxillary prosthesis on latest follow-up. This was the first case of ORN on dental implants placed before RT. RT is a risk factor of implant failure, a relatively rare and

  8. Aspectos técnicos do implante de eletrodo para estimulação ventricular esquerda através do seio coronariano, com a utilização de anatomia radiológica e eletrograma intracavitário, na terapia de ressincronização cardíaca Technical aspects of lead implantation for left ventricle pacing through the coronary sinus, using anatomic radiology and intracavitary electrography in the cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Fernando Sérgio Oliva de Souza

    2005-09-01

    Full Text Available OBJETIVO: Apresentar a experiência de 157 implantes utilizando uma técnica simplificada para cateterização do seio coronariano, baseada no eletrograma intracavitário e anatomia radiológica, demonstrando o porcentual de sucesso e tempo total de utilização de radioscopia. MÉTODO: De outubro de 2001 a fevereiro de 2005, foram realizados 157 implantes de marcapasso biventricular em pacientes previamente selecionados, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, demonstrando a taxa de sucesso, complicações e tempo total de utilização de radioscopia. RESULTADOS: O implante do sistema, utilizando-se a estimulação do ventrículo esquerdo via seio coronariano, não foi possível em onze procedimentos. Em 20 pacientes foram observadas dificuldades na canulação do óstio coronário e em 39 pacientes observou-se dificuldade de progressão do eletrodo através do seio coronário. O tempo médio de utilização de radioscopia foi 18,27 ± 15,46 min. CONCLUSÃO: A técnica de implante, proposta pelo autor, utilizando o eletrograma intracavitário e anatomia radiológica, demonstrou ser segura e eficaz para canulação do óstio do seio coronário, necessitando de reduzidos tempos de radioscopia.OBJECTIVE: To present the experience of 157 implantations using a simplified technique for coronary sinus catheterization, based on the atrial component of the intracavitary electrogram and radiological anatomy, showing the success rate and total time of radioscopy use. METHOD: From October 2001 to February 2005, 157 biventricular pacemaker implantations were performed in previously selected patients, using radiological anatomy and observation of the intracavitary electrogram, focusing on the atrial component. Here we show the success rate, complications and total time of radioscopy use. RESULTS: The implantation of the system employing left ventricular pacing via the coronary sinus was not possible in 11 patients

  9. Energy harvesting by implantable abiotically catalyzed glucose fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kerzenmacher, S.; von Stetten, F. [Laboratory for MEMS Applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, D-79110 Freiburg (Germany); Ducree, J. [HSG-IMIT, Wilhelm-Schickard-Str. 10, D-78052 Villingen-Schwenningen (Germany); Zengerle, R. [Laboratory for MEMS Applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, D-79110 Freiburg (Germany); HSG-IMIT, Wilhelm-Schickard-Str. 10, D-78052 Villingen-Schwenningen (Germany)

    2008-07-15

    Implantable glucose fuel cells are a promising approach to realize an autonomous energy supply for medical implants that solely relies on the electrochemical reaction of oxygen and glucose. Key advantage over conventional batteries is the abundant availability of both reactants in body fluids, rendering the need for regular replacement or external recharging mechanisms obsolete. Implantable glucose fuel cells, based on abiotic catalysts such as noble metals and activated carbon, have already been developed as power supply for cardiac pacemakers in the late-1960s. Whereas, in vitro and preliminary in vivo studies demonstrated their long-term stability, the performance of these fuel cells is limited to the {mu}W-range. Consequently, no further developments have been reported since high-capacity lithium iodine batteries for cardiac pacemakers became available in the mid-1970s. In recent years research has been focused on enzymatically catalyzed glucose fuel cells. They offer higher power densities than their abiotically catalyzed counterparts, but the limited enzyme stability impedes long-term application. In this context, the trend towards increasingly energy-efficient low power MEMS (micro-electro-mechanical systems) implants has revived the interest in abiotic catalysts as a long-term stable alternative. This review covers the state-of-the-art in implantable abiotically catalyzed glucose fuel cells and their development since the 1960s. Different embodiment concepts are presented and the historical achievements of academic and industrial research groups are critically reviewed. Special regard is given to the applicability of the concept as sustainable micro-power generator for implantable devices. (author)

  10. Bilateral Poly Implant Prothèse Implant Rupture: An Uncommon Presentation

    Directory of Open Access Journals (Sweden)

    Peter Mallon

    2013-07-01

    Full Text Available Summary: A woman in her 50s underwent delayed bilateral Poly Implant Prothèse implant reconstruction following mastectomy for breast cancer. Symptoms of implant rupture developed 43 months after surgery with an erythematous rash on her trunk. The rash then spread to her reconstructed breast mounds. Initial ultrasound scan and magnetic resonance imaging were normal; however, subsequent magnetic resonance imaging demonstrated left implant rupture only. In theater, following removal of both implants, both were found to be ruptured. The rash on her trunk resolved within 3 weeks in the postoperative period. Chemical analyses of silicone in both implants confirmed a nonauthorized silicone source; in addition, the chemical structure was significantly different between the left and right implant, perhaps explaining the variation in presentation.

  11. Implantable contraception.

    Science.gov (United States)

    Meckstroth, K R; Darney, P D

    2000-12-01

    Although levonorgestrel contraceptive implants have been available for over 15 years, innovations have only recently led to a wider choice. These new implants offer easier insertion and removal and other advantages depending on the type of progestin. Implants prevent pregnancy by several mechanisms, including inhibition of ovulation and luteal function and alteration of cervical mucus and the endometrium. The high efficacy and ease of maintenance make implants an ideal contraceptive for many women, including adolescents, a population that uses implants infrequently but reports high satisfaction. Implants are appropriate for women who are breastfeeding, who have contraindications to estrogen, or who have diseases such as diabetes, hypertension, sickle cell anemia, or an HIV infection because implants have few metabolic or hematologic effects. Long-term use has not been associated with a decrease in BMD and generally leads to increased blood levels and iron stores. Women who wish to space their pregnancies appreciate the nearly immediate onset of action with insertion and the rapid termination of all effects with removal. All types of implants lead to menstrual changes and other side effects in some women. Adverse effects that occur in implant users more than the general population include headaches and acne. Women must be thoroughly counseled regarding the potential for menstrual alteration, side effects, and sexually transmitted infections if they do not use condoms. Despite their initial high cost, implants are a cost-effective method over several years, even when discontinued before the life of the implant.

  12. Dental Implant Surgery

    Science.gov (United States)

    ... to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, surgery, and is ... to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, surgery, and is ...

  13. Hypoplastic left heart syndrome

    Science.gov (United States)

    HLHS; Congenital heart - hypoplastic left heart; Cyanotic heart disease - hypoplastic left heart ... Hypoplastic left heart is a rare type of congenital heart disease. It is more common in males than in females. As ...

  14. Comparison of one-year clinical outcomes between intravascular ultrasound-guided versus angiography-guided implantation of drug-eluting stents for left main lesions: A single-center analysis of a 1,016-patient cohort

    NARCIS (Netherlands)

    X.-F. Gao (Xiao-Fei); J. Kan (Jing); Y. Zhang (Yaojun); J.-J. Zhang (Jun-Jie); N.-L. Tian (Nai-Liang); F. Ye (Fei); Z. Ge (Zhen); P.-X. Xiao (Ping-Xi); F. Chen (Feng); G.S. Mintz (Gary); S.-L. Chen (Shao-Liang)

    2014-01-01

    textabstractBackground: The importance of intravascular ultrasound (IVUS)-guided stenting of the unprotected left main coronary artery (ULMCA) remains controversial and has not been fully studied in the subset of patients with ULMCA. This study evaluated the clinical outcome of IVUS-guided stenting

  15. Intraprocedural left ventricular free wall rupture diagnosed by left ventriculogram in a patient with infero-posterior myocardial infarction and severe aortic stenosis.

    Science.gov (United States)

    Konishi, Takao; Funayama, Naohiro; Yamamoto, Tadashi; Nishihara, Hiroshi; Hotta, Daisuke; Kikuchi, Kenjiro; Yokoyama, Hideo; Ohori, Katsumi

    2016-06-06

    Left ventricular wall rupture remains a major lethal complication of acute myocardial infarction and hypertension is a well-known predisposing factor of cardiac rupture after myocardial infarction. An 87-year-old man was admitted to our hospital, diagnosed as acute myocardial infarction (AMI). The echocardiogram showed 0.67-cm(2) aortic valve, consistent with severe aortic stenosis (AS). A coronary angiography showed a chronic occlusion of the proximal left circumflex artery and a 99 % stenosis and thrombus in the mid right coronary artery. During percutaneous angioplasty of the latter, transient hypotension and bradycardia developed at the time of balloon inflation, and low doses of noradrenaline and etilefrine were intravenously administered as needed. The patient suddenly lost consciousness and developed electro-mechanical dissociation. Cardio-pulmonary resuscitation followed by insertion of an intra-aortic balloon pump (IABP) and percutaneous cardiopulmonary support were initiated. The echocardiogram revealed moderate pericardial effusion, though the site of free wall rupture was not distinctly visible. A left ventriculogram clearly showed an infero-posterior apical wall rupture. Surgical treatment was withheld because of the interim development of brain death. In this patient, who presented with severe AS, the administration of catecholamine to stabilize the blood pressure probably increased the intraventricular pressures considerably despite apparently normal measurements of the central aortic pressure. IABP, temporary pacemaker, or both are recommended instead of intravenous catecholamines for patients with AMI complicated with significant AS to stabilize hemodynamic function during angioplasty.

  16. A new strategy for development of transducers for middle ear implants.

    Science.gov (United States)

    Urquiza, Rafael; López-García, Javier

    2015-02-01

    The new strategy was efficient in designing and fabricating a new transducer for middle ear implants. The transducer could overcome important limitations (implantability of transducers, functional needs) of practical application of currently existing implants. The strategy uncovers the potential of translational research in this area of audiology. To present an overview of research and development (R&D) strategic aspects and its practical implementation through one example of transducer development based on micro-electro-mechanical systems (MEMS) technology. (a) Rationale of technology in relation to the anatomical and functional features of the middle ear and implant requirements, (b) description and explanation of the different stages and decision-making process for the R&D of a MEMS transducer based on published pieces with their own experimental methods. This R&D strategy focuses on achieving minute-size transducers by using MEMS technology. The process allows a designing-simulation-testing circle to be accomplished on the bench by special software, before fabrication and in vivo testing. The strategy, consequently, saves animal experiments, empowers the design capabilities and allows the fabrication of customized transducers for special problems. The developed prototypes are in the range of millimetres, fit the requirements of new implants and can be fabricated on a large scale and at low cost.

  17. Transfer characteristics of subretinal visual implants: corneally recorded implant responses.

    Science.gov (United States)

    Stingl, K; Bartz-Schmidt, K U; Braun, A; Gekeler, F; Greppmaier, U; Schatz, A; Stett, A; Strasser, T; Kitiratschky, V; Zrenner, E

    2016-10-01

    The subretinal Alpha IMS visual implant is a CE-approved medical device for restoration of visual functions in blind patients with end-stage outer retina degeneration. We present a method to test the function of the implant objectively in vivo using standard electroretinographic equipment and to assess the devices' parameter range for an optimal perception. Subretinal implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) consists of 1500 photodiode-amplifier-electrode units and is implanted surgically into the subretinal space in blind retinitis pigmentosa patients. The voltages that regulate the amplifiers' sensitivity (V gl) and gain (V bias), related to the perception of contrast and brightness, respectively, are adjusted manually on a handheld power supply device. Corneally recorded implant responses (CRIR) to full-field illumination with long duration flashes in various implant settings for brightness gain (V bias) and amplifiers' sensitivity (V gl) are measured using electroretinographic setup with a Ganzfeld bowl in a protocol of increasing stimulus luminances up to 1000 cd/m2. CRIRs are a meaningful tool for assessing the transfer characteristic curves of the electronic implant in vivo monitoring the implants' voltage output as a function of log luminance in a sigmoidal shape. Changing the amplifiers' sensitivity (V gl) shifts the curve left or right along the log luminance axis. Adjustment of the gain (V bias) changes the maximal output. Contrast perception is only possible within the luminance range of the increasing slope of the function. The technical function of subretinal visual implants can be measured objectively using a standard electroretinographic setup. CRIRs help the patient to optimise the perception by adjusting the gain and luminance range of the device and are a useful tool for clinicians to objectively assess the function of subretinal visual implants in vivo.

  18. Haemodynamic Benefit of Cardiac Resynchronisation Therapy Requires Left Bundle Branch Block: A Case Report

    NARCIS (Netherlands)

    Bogaard, M.D.; Leenders, G.E.H.; Doevendans, P.A.F.M.; Meine, M.

    A 55-year-old woman with dilated cardiomyopathy and rate-dependent left bundle branch block had a cardiac resynchronisation therapy (CRT) device implanted. During implantation, the maximum rate of left ventricular pressure rise (dP/dtmax) was measured invasively. This case presents

  19. Living donor liver transplantation with hyperreduced left lateral segments.

    Science.gov (United States)

    Kasahara, Mureo; Fukuda, Akinari; Yokoyama, Satoshi; Sato, Shuichi; Tanaka, Hideaki; Kuroda, Tatsuo; Honna, Toshiro

    2008-08-01

    Liver transplantation is now an established technique to treat children with end-stage liver disease. Implantation of left lateral segment grafts (Couidaud's segments II and III) can be a problem in small infants because of a large-for-size graft. Reduced left lateral segmental liver transplantation has been recently introduced for small infants to mitigate the problem of large-for-size graft. Further reduction of the left lateral segment graft increases the possibility of supplying an adequate hyperreduced left lateral segment graft as an alternative surgical technique. We report 3 cases of our experience of transplantation using hyperreduced left lateral segment grafts from living donors.

  20. Left axis deviation.

    Science.gov (United States)

    MacKenzie, Ross

    2005-01-01

    Left axis deviation is one of the most commonly encountered ECG abnormalities. Its presence should alert medical directors and underwriters to the possibility of underlying structural heart disease. Many of the causes of left axis deviation are apparent from the clinical findings. Left anterior fascicular block is one of the commonest causes of left axis deviation and has specific ECG criteria for its diagnosis.

  1. Development of clinically relevant implantable pressure sensors: perspectives and challenges.

    Science.gov (United States)

    Clausen, Ingelin; Glott, Thomas

    2014-09-22

    This review describes different aspects to consider when developing implantable pressure sensor systems. Measurement of pressure is in general highly important in clinical practice and medical research. Due to the small size, light weight and low energy consumption Micro Electro Mechanical Systems (MEMS) technology represents new possibilities for monitoring of physiological parameters inside the human body. Development of clinical relevant sensors requires close collaboration between technological experts and medical clinicians.  Site of operation, size restrictions, patient safety, and required measurement range and resolution, are only some conditions that must be taken into account. An implantable device has to operate under very hostile conditions. Long-term in vivo pressure measurements are particularly demanding because the pressure sensitive part of the sensor must be in direct or indirect physical contact with the medium for which we want to detect the pressure. New sensor packaging concepts are demanded and must be developed through combined effort between scientists in MEMS technology, material science, and biology. Before launching a new medical device on the market, clinical studies must be performed. Regulatory documents and international standards set the premises for how such studies shall be conducted and reported.

  2. Development of Clinically Relevant Implantable Pressure Sensors: Perspectives and Challenges

    Directory of Open Access Journals (Sweden)

    Ingelin Clausen

    2014-09-01

    Full Text Available This review describes different aspects to consider when developing implantable pressure sensor systems. Measurement of pressure is in general highly important in clinical practice and medical research. Due to the small size, light weight and low energy consumption Micro Electro Mechanical Systems (MEMS technology represents new possibilities for monitoring of physiological parameters inside the human body. Development of clinical relevant sensors requires close collaboration between technological experts and medical clinicians.  Site of operation, size restrictions, patient safety, and required measurement range and resolution, are only some conditions that must be taken into account. An implantable device has to operate under very hostile conditions. Long-term in vivo pressure measurements are particularly demanding because the pressure sensitive part of the sensor must be in direct or indirect physical contact with the medium for which we want to detect the pressure. New sensor packaging concepts are demanded and must be developed through combined effort between scientists in MEMS technology, material science, and biology. Before launching a new medical device on the market, clinical studies must be performed. Regulatory documents and international standards set the premises for how such studies shall be conducted and reported.

  3. Implant contraception.

    Science.gov (United States)

    Meckstroth, K R; Darney, P D

    2001-12-01

    The experience of 6 million Norplant users has led to several more advanced implants. Implanon is a single-rod implant system containing a low androgenic progestin and requires 1 to 2 minutes for insertion and removal. Like other implants, Implanon prevents pregnancy by changing the character of the cervical mucus and interfering with luteal function. Unlike Norplant, though, Implanon is designed to prevent ovulation for the full duration of use. Implant contraception has several advantages over other types of contraception including high efficacy, minimal required maintenance, absence of estrogen, and rapid return of fertility after discontinuation. Implants can be a good choice for adolescents; women with hypertension, diabetes, anemia, endometriosis, or other medical problems; and women who are breast-feeding. Irregular bleeding is the most common adverse effect of implants and can be treated with several medication regimens. Preinsertion counseling, however, is the most important factor in ensuring satisfaction with implants. Unfortunately, no implant system is currently available in the United States since August 2000, but Implanon is expected to reach the U.S. market within the next 2 years.

  4. About Implantable Contraception

    Science.gov (United States)

    ... Helping Your Child Deal With Death About Implantable Contraception KidsHealth > For Parents > About Implantable Contraception Print A ... How Much Does It Cost? What Is Implantable Contraception? Implantable contraception (often called the birth control implant) ...

  5. Influence of bacterial colonization of the healing screws on peri-implant tissue

    Directory of Open Access Journals (Sweden)

    Simonetta D'Ercole

    2013-06-01

    Conclusion: The healing screws left in situ for a period of 90 days caused a peri-implant inflammation and the presence of periodontal pathogenic bacteria in the peri-implant sulcus, due to the plaque accumulation on screw surfaces.

  6. Ligature-induced peri-implantitis in mice.

    Science.gov (United States)

    Pirih, F Q; Hiyari, S; Barroso, A D V; Jorge, A C A; Perussolo, J; Atti, E; Tetradis, S; Camargo, P M

    2015-08-01

    Peri-implantitis has a prevalence of 11-47%, involves destruction of peri-implant bone and may lead to implant loss. A detailed understanding of the pathogenesis of peri-implantitis is lacking. The objective of this study was to develop a murine model of experimental peri-implantitis. Machined, smooth-surface, screw-shaped titanium implants were placed in the healed alveolar bone of the left maxillary molars of C57BL/6J male mice, 8 wk after tooth extraction. Peri-implantitis was induced by securing silk ligatures around the head of the implant fixtures. Implant survival and peri-implant bone levels were analyzed by micro-computed tomography (micro-CT) scans and histology, 12 wk after ligature placement. Implant survival was 60% (six of 10) for implants with ligatures and 100% (eight of eight) for controls. Micro-CT revealed significantly greater bone loss around the implants that received ligatures and that survived, compared with controls. The radiographic findings were confirmed via histology and toluidine blue staining. This study describes a murine model of experimental peri-implantitis around screw-shaped titanium implants placed in the edentulous alveolar bone. This model should be a useful tool to dissect pathogenic mechanisms of peri-implantitis and evaluate potential treatment interventions. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Penile Implants

    Science.gov (United States)

    ... men with erectile dysfunction (ED) to get an erection. Penile implants are typically recommended after other treatments for ... the scrotum, and two inflatable cylinders inside the penis. To achieve an erection, you pump the fluid from the reservoir into ...

  8. Cochlear Implants

    Science.gov (United States)

    ... the skin. An implant does not restore normal hearing. It can help a person understand speech. Children and adults can benefit from them. National Institute on Deafness and Other Communication Disorders

  9. Cochlear implant by adult

    OpenAIRE

    Kratochvílová, Tereza

    2011-01-01

    Bachelor thesis "The cochlear implant in an adult deaf" deals primarily with the cochlear implant. The most extensive part of the thesis talks about this topic, which also talks about the development and design of cochlear implants, explains the difference between cochlear implantation and tribal implantation and describes operation of implant and the subsequent setting of the implant. This section is also dedicated to binaural cochlear implantation, myths of cochlear implants and problems wh...

  10. Samsung Electro-Mechanics - электронные компоненты: прорыв на российском рынке

    OpenAIRE

    Асташкевич, Павел

    2002-01-01

    — Марка Samsung хорошо известна в России в основном благодаря бытовой технике этой компании. Нашим читателям было бы интересно больше узнать о Samsung Electro-Mechanics.

  11. EXPERIENCE OF USING INDIVIDUAL TITAN IMPLANTS IN NASAL RECONSTRUCTION SURGERY

    Directory of Open Access Journals (Sweden)

    V. V. Epishev

    2016-01-01

    Full Text Available Aim. Clinical use of implants based on patient’s individual topographic anatomical features. Materials and methods. The paper describes two case reports involving the correction of nasal anatomical structure affected during the surgery for facial cancer. Using selective laser sintering technology we manufactured 2 intricate 3D-deformed individual implants from Ti70V30 alloy powders. Implant design was based on CAT/MRT data. Clinical use was conducted on the premises of the department of head and neck surgery in Chelyabinsk Regional Oncological Dispensary. Results. In the fi rst case we obtained an impressive functional result – huge and wide nasal cavity, nose skeleton, and easy nasal breathing. In 30 days we performed endoscopic video-analysis (via nasal passages which showed that 65% of implant surface was covered with mucosa. In the second case, the designed implant allowed the combined surgery including excision of soft tissues, atypical resection of the upper jaw (left part and the left cheek, left maxillary sinusotomy and reconstruction of the left part of the nose and the left cheek with implant and skin fl ap. Conclusion. Clinical use revealed pros and contras of the applied technology. Among contras there are relatively high cost of technology, high standards of competency of a surgeon, a programmer and engineers. Pros include free modeling and setting the implant parameters before operation, exact match between implant size/shape and topographic anatomical data of a certain patient. 

  12. Intervention for replacing missing teeth: Different types of implants - evidence summary of updated Cochrane review

    OpenAIRE

    Balendra Pratap Singh; Hemant Jivanani

    2015-01-01

    Around 1300 different types of dental implants are available worldwide and the implant manufacturers are resorting to aggressive marketing strategies; claiming their implants to provide a superior outcome. The clinician is left with a constant dilemma on which implant to choose for better clinical outcome and welfare of the patient. Moreover, in India, economical consideration is a concern too. The dentist has to select an implant that provides a good result and is economical. Cochrane system...

  13. Early dental implant failure in patient associated with oral bisphosphonates

    Directory of Open Access Journals (Sweden)

    Ridhimaa Gupta

    2012-01-01

    Full Text Available Oral bisphosphonates are routinely prescribed to post menopausal women. These have shown to increase the risk of osteonecrosis. However, this action may be augmented by local factors. A case report is presented showing an early implant failure in a patient taking oral bisphosphonates. Two implants were placed in left maxillary incisor area. Central incisor was associated with a previous endodontic failure and extraction. Lateral incisor was avulsed 3 years back. After 4 weeks of an implant placement, necrotic bone was evident along with the failing implant in central incisor area. This case report emphasizes on the incidence and an increased risk of implant failure in patients taking oral bisphosphonates.

  14. Review: implants.

    Science.gov (United States)

    Ashton, P; Blandford, D L; Pearson, P A; Jaffe, G J; Martin, D F; Nussenblatt, R B

    1994-01-01

    An implantable sustained release device has been developed to treat chronic disorders of the eye. The device, consisting of a central core of drug encased in layers of permeable and impermeable polymers, can be implanted subconjunctivally or intravitreally. This technique was used to develop a ganciclovir device which, when implanted into the vitreous, maintains therapeutic vitreous levels of drug for 8 months. Initial studies in patients with cytomegalovirus (CMV) retinitis indicate that this treatment may offer better control of the disease and fewer side effects than existing therapies. Cyclosporine A devices were prepared for the treatment of uveitis. Early data suggests that these devices maintain therapeutic levels in the vitreous for approximately 3 years. Work on efficacy and toxicity is continuing. Although clinical applications of these devices are likely to be restricted to diseases requiring chronic drug therapy, they can be used to investigate optimal delivery rates. Subconjunctivally implanted devices releasing 5-FU for 12 days maintained filters in cynomolgus monkeys for 3 months. Similar devices maintained low intraocular pressure in 75% of high risk filter patients.

  15. Implant rehabilitation of partial maxillectomy edentulous patien

    Directory of Open Access Journals (Sweden)

    Mahesh E Gowda

    2013-01-01

    Full Text Available Edentulous patients with maxillectomy defects present a significant challenge for prosthetic rehabilitation and the adaptive capabilities of the patient as retention is highly compromised. Hence, the option of using endosseous implants to increase obturator retention has been used. A patient of mucormycosis of the left maxilla was treated with surgical excision. After satisfactory healing, definitive implant supported magnet retained prosthesis was fabricated for the patient. Implants with magnetic units offer a practical method of improving the retention of obturators provided acceptable prosthetic protocols are followed for the rehabilitation.

  16. Method for the placement of palatal implants.

    Science.gov (United States)

    Tosun, Tosun; Keles, Ahmet; Erverdi, Nejat

    2002-01-01

    Palatal implants have been used in the last 2 decades to eliminate headgear wear and to establish stationary anchorage. The aim of this investigation was to establish a method and easy protocol for palatal implant placement. The study comprised 8 male and 15 female patients each having a 4.5 x 8-mm stepped screw titanium implant placed in the palatal region for orthodontic purposes. A surgical template containing metal drill housing was prepared. Angulation of the drill housing was controlled according to the radiologic tracing of the maxilla transferred to a plaster cast section in the paramedian plane. Implants were placed using a noninvasive technique (incision, flap, and suture elimination) and left transmucosally to facilitate the surgical procedure and reduce operations. The paramedian region was selected so as to avoid connective tissues of the palatine suture and because it was considered to be a suitable host site for implant placement. After 3 months of healing, all implants were osseointegrated and no implant was lost throughout the orthodontic treatment. Palatal implants can be used effectively for anchorage maintenance and space-gaining procedures. Usage of a 3-dimensional surgical template eliminated faulty implant placement, reduced chair time, and minimized trauma to the tissues while enhancing osseointegration.

  17. Unruptured aneurysm of the left sinus of Valsalva compressing the left main coronary artery: successful percutaneous treatment.

    Science.gov (United States)

    Hausinger, P; Sasi, V; Volford, G; Bitay, M; Bogáts, G; Thury, A; Palkó, A; Forster, T; Nemes, A

    2014-09-01

    Aneurysm of the left sinus of Valsalva is an extremely rare entity. It may be asymptomatic and incidentally discovered, or may be symptomatic and manifest acutely with compression of adjacent cardiac structures. Encasement of the left main coronary artery by such an aneurysm is a recognized but infrequent complication that can lead to severe coronary insufficiency. Surgical decompression of the left main coronary artery is the standard treatment for such conditions. We describe a patient presenting with extrinsic compression of the left main coronary artery by a large unruptured aneurysm of the left sinus of Valsalva occurring 4 months after unsuccessful surgical repair. Since reoperation was considered high-risk for the patient, successful fractional flow reserve- and intravascular ultrasound-guided percutaneous treatment of the left main coronary artery was performed with implantation of one bare-metal stent.

  18. Total Artificial Heart Implantation Blood Pressure Management as Resolving Treatment for Massive Hemolysis following Total Artificial Heart Implantation.

    Science.gov (United States)

    Ghodsizad, Ali; Koerner, Michael M; El-Banayosy, A; Zeriouh, Mohamed; Ruhparwar, Arjang; Loebe, Matthias

    2016-10-21

    The SynCardia Total Artificial Heart (TAH) has been used for patients with biventricular failure, who cannot be managed with implantation of a left ventricular (LV) assist device. Following TAH implantation, our patient developed severe hemolysis, which could only be managed successfully by aggressive blood pressure control [Ohashi 2003; Nakata 1998].

  19. [Left superior veina cava and endocardial stimulation (author's transl)].

    Science.gov (United States)

    Aubert, M; Machecourt, J; Denis, B; Contamin, C

    A left superior veina cava may be troublesome for endocardial lead's placement during permanent pace maker's implantation. We have operated upon one patient with this anomaly. We report the anatomic frequency of this congenital malformation and the technics used to obtain a satisfactory permanent pacing.

  20. Screening for heart transplantation and left ventricular assist system

    DEFF Research Database (Denmark)

    Lund, Lars H; Trochu, Jean-Noel; Meyns, Bart

    2018-01-01

    BACKGROUND: Heart transplantation (HTx) and implantable left ventricular assist systems (LVAS) improve outcomes in advanced heart failure but may be underutilized. We hypothesized that screening can identify appropriate candidates. METHODS AND RESULTS: The ScrEEning for advanced Heart Failure tre...

  1. Transnasal Endoscopy Removal of Dislodged Dental Implant: A Case Report.

    Science.gov (United States)

    Lim, Daniel; Parumo, Rosliza; Chai, Ma Bee; Shanmuganathan, Jothi

    2017-06-01

    Displacement of dental implants into the maxillary sinus is a rare complication. This article presents a case of displaced dental implant into maxillary sinus. Retrieval of the dental implant from left maxillary sinus was performed via endoscopic sinus surgery. This case highlighted a delayed referral of a 53-year-old male by a general dental practitioner for management of a dislodged dental implant into the left maxillary antrum. The implant was dislodged during placement of a healing abutment 4 months after implant insertion to replace missing 25. Cone beam computerized tomography revealed the displaced implant was located at the ostium of the left nose. A sudden change in sinonasal pressure when the patient took a deep breath during the procedure may have created a negative pressure and suction effect causing the implant to be dislodged and embedded at the ostium. In view of its position, a referral to an otorhinolaryngologist was made for endoscopic removal of the displaced implant. This case also highlighted the need for inter disciplinary cooperation in the management of such a complication for the best interest of the patients.

  2. Understanding left-handedness

    National Research Council Canada - National Science Library

    Gutwinski, Stefan; Löscher, Anna; Mahler, Lieselotte; Kalbitzer, Jan; Heinz, Andreas; Bermpohl, Felix

    2011-01-01

    .... In this article, we present these findings from a medical perspective. We selectively searched the PubMed online database for articles including the terms "handedness," "left handedness," "right handedness," and "cerebral lateralization...

  3. Left Ventricular Hypertrophy

    Science.gov (United States)

    ... need to restrict certain physical activities, such as weightlifting, which may temporarily raise your blood pressure. The ... Accessed April 6, 2015. Chatterjee S, et al. Meta-analysis of left ventricular hypertrophy and sustained arrhythmias. American ...

  4. Double inlet left ventricle

    Science.gov (United States)

    ... Univentricular heart; Univentricular heart of the left ventricular type; Congenital heart defect - DILV; ... BF, St. Geme JW, Schor NF. Cyanotic congenital heart disease. In: Kliegman RM, Stanton BF, St. Geme JW, ...

  5. Left heart catheterization

    Science.gov (United States)

    Catheterization - left heart ... to help guide the catheters up into your heart and arteries. Dye (sometimes called "contrast") will be ... in the blood vessels that lead to your heart. The catheter is then moved through the aortic ...

  6. Cardiac Resynchronization Therapy Relieves Intractable Angina Due to Exercise-Induced Left Bundle Branch Block Without Left Ventricular Systolic Dysfunction: A Detailed Case Study.

    Science.gov (United States)

    Czuriga, Daniel; Lim, Pitt O

    2016-05-01

    Exercise-induced left bundle branch block is rare and can be demonstrated with exercise testing. When the heart rate reaches a certain threshold, the QRS widens into left bundle branch block. This paper describes a patient with exercise-induced left bundle branch block related angina and dyspnea, who responded to cardiac resynchronization therapy. We documented the potential benefits of cardiac resynchronization therapy with a left ventricular rapid pacing study prior to its implantation. Although exercise-induced left bundle branch block is not a current indication for cardiac resynchronization therapy in patients such as ours, it could be considered when conventional drug therapy fails. © 2016 Wiley Periodicals, Inc.

  7. Dental Implant Macro-Design Features Can Impact the Dynamics of Osseointegration.

    Science.gov (United States)

    Vivan Cardoso, Marcio; Vandamme, Katleen; Chaudhari, Amol; De Rycker, Judith; Van Meerbeek, Bart; Naert, Ignace; Duyck, Joke

    2015-08-01

    The purpose of this study was to compare the clinical performance of two dental implant types possessing a different macro-design in the in vivo pig model. Titanium Aadva(TM) implants (GC, Tokyo, Japan) were compared with OsseoSpeed(TM) implants (Astra, Mölndal, Sweden), with the Aadva implant displaying significant larger inter-thread dimensions than the OsseoSpeed implant. Implants were installed in the parietal bone of 12 domestic pigs and left for healing for either 1 or 3 months. Implant osseointegration was evaluated by quantitative histology (bone volume relative to the tissue volume [BV/TV]; bone-to-implant contact [BIC]) for distinct implant regions (collar, body, total implant length) with specific implant thread features. The Wilcoxon-Mann-Whitney nonparametric test with α = 0.05 was performed. An inferior amount of bone enveloping the Aadva implant compared with the OsseoSpeed implant was observed, in particular at the implant body part with its considerable inter-thread gaps (p design negatively affected the amount of bone in direct contact with the implant for this specific implant part (p design features can impact the dynamics of implant osseointegration. Consideration of specific implant macro-design features should be made relative to the biological and mechanical microenvironment. © 2013 Wiley Periodicals, Inc.

  8. Uso rutinario del balón de contra-pulsación aórtica preoperatorio en pacientes con enfermedad del tronco común izquierdo sometidos a cirugía de revascularización coronaria Routine use of preoperative intra-aortic balloon pump counterpulsation (IABP implantation in patients with left main coronary artery disease undergoing coronary revascularization surgery

    Directory of Open Access Journals (Sweden)

    Andrés Fernández

    2008-08-01

    cuidados intensivos se infectaron 6,5% de los pacientes con balón y 3% del grupo sin balón (p=0,49 y hubo sepsis en 4,3% del grupo con balón y en ninguno del grupo restante (p=0,23. La letalidad en la unidad de cuidados intensivos se presentó en 2,2% del grupo de balón y en 3% del otro grupo (p=0,06. No ocurrió mortalidad intrahospitalaria fuera de la unidad de cuidados intensivos como tampoco mortalidad a 30 días después del alta. El tiempo de estancia en la misma unidad fue de 4,13 días en el grupo de balón y 2,7 días en el grupo sin balón, sin diferencia estadísticamente significativa entre éstos (p=0,154. El tiempo de ventilación mecánica en el grupo de balón fue de 1,96 días mientras que en el otro grupo fue de 1,18 días sin diferencia estadísticamente significativa (p=0,288. Con respecto a los pacientes que recibieron balón de contra pulsación intra-aórtico, el promedio de uso de balón fue de 1,32 días y no se presentaron complicaciones vasculares relacionadas con su uso. Conclusiones: este estudio sugiere que con el uso rutinario del balón de contra pulsación aórtica previo a la cirugía electiva de revascularización coronaria en pacientes cuya única indicación sea la lesión severa del tronco común izquierdo, no se obtiene beneficio en cuanto a letalidad y tiempo de estancia en la unidad de cuidados intensivos, ni con respecto al tiempo de ventilación mecánica. Tampoco se encontró mayor riesgo de desarrollar infección o sepsis en la misma unidad.Background: Left main coronary artery disease as the only criterion for intra-aortic balloon counterpulsation implantation is an indication which evidence is limited to experts’ recommendations; therefore, studies that may give a higher level of evidence are required. For this reason, we developed in our institution a study that evaluated the experience in the use of IABP in patients with left main coronary artery disease undergoing coronary revascularization surgery. Objective

  9. Left-handedness and health

    National Research Council Canada - National Science Library

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    .... There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness...

  10. Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Mehrnaz Karimi

    1993-03-01

    Full Text Available People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss. In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter, stimulator and receiver, and electrode array.

  11. Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Mehrnaz Karimi

    1992-04-01

    Full Text Available People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss . In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter, stimulator and receiver, and electrode array.

  12. Breast reconstruction - implants

    Science.gov (United States)

    Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... to make reconstruction easier. If you will have breast reconstruction later, your surgeon will remove enough skin ...

  13. Degradation of implant materials

    CERN Document Server

    Eliaz, Noam

    2012-01-01

    This book surveys the degradation of implant materials, reviewing in detail such failure mechanisms as corrosion, fatigue and wear, along with monitoring techniques. Surveys common implant biomaterials, as well as procedures for implant retrieval and analysis.

  14. Hernia Surgical Mesh Implants

    Science.gov (United States)

    ... Procedures Implants and Prosthetics Hernia Surgical Mesh Implants Hernia Surgical Mesh Implants Share Tweet Linkedin Pin it ... between patients and their surgeons. What is a Hernia? A hernia occurs when an organ, intestine or ...

  15. [Experimental study of delayed implantation on bone grafts].

    Science.gov (United States)

    Zhang, Guo-Zhi; Zhang, Guo-Quan

    2007-05-01

    To explore the feasibility of transplantation of frozen autogenous mandible with delayed implantation. Operations were performed to create two defects in the bilateral mandible of 16 dogs. The left defect was grafted by composite transplantation of frozen autogenous mandible (immersed in -196 degrees C liquid nitrogen) with fresh cancellous ilium (composite transplantation group, CTG). The right defect was grafted by fresh ilium (iliac transplantation group, ITG). Three months after transplantation one IMZ TPS dental implant was placed into the graft of each side. At 3, 6, 9, 12 weeks postoperatively, 4 animals were sacrificed respectively and the grafts with dental implant were harvested for gross observation, X-Ray examination and histological evaluation to compare peri-implant bone healing between composite transplantation group and iliac transplantation group. There was no absorbing bone density reducing image of peri-implant at each stage. The quantified X-Ray gray extent displayed obvious variation of interfacial bone density between two kinds of grafts at 3 weeks, 6 weeks and 9 weeks after implantation. The composite transplantation group obviously surpassed the iliac transplantation group. At 12 weeks after the implantation, there was no significant difference between the peri-implant bones of both sides. There was satisfactory osseointegration between the implants and the two kinds of grafts. The healing style of peri-implant bone was similar. Good osseointegration was performed between the implant and the composite transplantation of frozen autogenous mandible following delayed implantation.

  16. Towards an Implantable, Low Flow Micropump That Uses No Power in the Blocked-Flow State

    Directory of Open Access Journals (Sweden)

    Dean G. Johnson

    2016-06-01

    Full Text Available Low flow rate micropumps play an increasingly important role in drug therapy research. Infusions to small biological structures and lab-on-a-chip applications require ultra-low flow rates and will benefit from the ability to expend no power in the blocked-flow state. Here we present a planar micropump based on gallium phase-change actuation that leverages expansion during solidification to occlude the flow channel in the off-power state. The presented four chamber peristaltic micropump was fabricated with a combination of Micro Electro Mechanical System (MEMS techniques and additive manufacturing direct write technologies. The device is 7 mm × 13 mm × 1 mm (<100 mm3 with the flow channel and exterior coated with biocompatible Parylene-C, critical for implantable applications. Controllable pump rates from 18 to 104 nL/min were demonstrated, with 11.1 ± 0.35 nL pumped per actuation at an efficiency of 11 mJ/nL. The normally-closed state of the gallium actuator prevents flow and diffusion between the pump and the biological system or lab-on-a-chip, without consuming power. This is especially important for implanted applications with periodic drug delivery regimens.

  17. Nanotechnology and Dental Implants

    OpenAIRE

    Sandrine Lavenus; Guy Louarn; Pierre Layrolle

    2010-01-01

    The long-term clinical success of dental implants is related to their early osseointegration. This paper reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone-to-implant contact is desired for a biomechanical anchoring of i...

  18. [Recurrent left atrial myxoma].

    Science.gov (United States)

    Moreno Martínez, Francisco L; Lagomasino Hidalgo, Alvaro; Mirabal Rodríguez, Roger; López Bermúdez, Félix H; López Bernal, Omaida J

    2003-01-01

    Primary cardiac tumors are rare. Mixomas are the most common among them; 75% are located in the left atrium, 20% in the right atrium, and the rest in the ventricles. The seldom appear in atrio-ventricular valves. Recidivant mixoma are also rare, appearing in 1-5% of all patients that have undergone surgical treatment of a mixoma. In this paper we present our experience with a female patient, who 8 years after having been operated of a left atrial mixoma, began with symptoms of mild heart failure. Transthoracic echocardiography revealed recurrence of the tumor, and was therefore subjected to a second open-heart surgery from which she recovered without complications.

  19. Development of a wireless intra-ocular pressure monitoring system for incorporation into a therapeutic glaucoma drainage implant

    Science.gov (United States)

    Kakaday, Tarun; Plunkett, Malcolm; McInnes, Steven; Li, Jim S. Jimmy; Voelcker, Nicolas H.; Craig, Jamie E.

    2008-12-01

    Glaucoma is a common cause of blindness. Wireless, continuous monitoring of intraocular pressure (IOP) is an important, unsolved goal in managing glaucoma. An IOP monitoring system incorporated into a glaucoma drainage implant (GDI) overcomes the design complexity associated with incorporating a similar system in a more confined space within the eye. The device consists of a micro-electro-mechanical systems (MEMS) based capacitive pressure sensor integrated with an inductor printed directly onto a polyimide printed circuit board (PCB). The device is designed to be incorporated onto the external plate of a therapeutic GDI. The resonance frequency changes as a function of IOP, and is tracked remotely using a spectrum analyzer. A theoretical model for the reader antenna was developed to enable maximal inductive coupling with the IOP sensor implant. Pressure chamber tests indicate that the sensor implant has adequate sensitivity in the IOP range with excellent reproducibility over time. Additionally, we show that sensor sensitivity does not change significantly after encapsulation with polydimethylsiloxane (PDMS) to protect the device from fluid environment. In vitro experiments showed that the signal measured wirelessly through sheep corneal and scleral tissue was adequate indicating potential for using the system in human subjects.

  20. Complications after cardiac implantable electronic device implantations

    DEFF Research Database (Denmark)

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard

    2013-01-01

    Complications after cardiac implantable electronic device (CIED) treatment, including permanent pacemakers (PMs), cardiac resynchronization therapy devices with defibrillators (CRT-Ds) or without (CRT-Ps), and implantable cardioverter defibrillators (ICDs), are associated with increased patient...

  1. Left atrial appendage occlusion

    Directory of Open Access Journals (Sweden)

    Ahmad Mirdamadi

    2013-01-01

    Full Text Available Left atrial appendage (LAA occlusion is a treatment strategy to prevent blood clot formation in atrial appendage. Although, LAA occlusion usually was done by catheter-based techniques, especially percutaneous trans-luminal mitral commissurotomy (PTMC, it can be done during closed and open mitral valve commissurotomy (CMVC, OMVC and mitral valve replacement (MVR too. Nowadays, PTMC is performed as an optimal management of severe mitral stenosis (MS and many patients currently are treated by PTMC instead of previous surgical methods. One of the most important contraindications of PTMC is presence of clot in LAA. So, each patient who suffers of severe MS is evaluated by Trans-Esophageal Echocardiogram to rule out thrombus in LAA before PTMC. At open heart surgery, replacement of the mitral valve was performed for 49-year-old woman. Also, left atrial appendage occlusion was done during surgery. Immediately after surgery, echocardiography demonstrates an echo imitated the presence of a thrombus in left atrial appendage area, although there was not any evidence of thrombus in pre-pump TEE. We can conclude from this case report that when we suspect of thrombus of left atrial, we should obtain exact history of previous surgery of mitral valve to avoid misdiagnosis clotted LAA, instead of obliterated LAA. Consequently, it can prevent additional evaluations and treatments such as oral anticoagulation and exclusion or postponing surgeries including PTMC.

  2. The left minor fissure.

    Science.gov (United States)

    Austin, J H

    1986-11-01

    A left minor fissure (LMF) has been described anatomically as being present in 8%-18% of left lungs. Analogous to the right minor fissure (RMF), the LMF separates the anterior segment of the left upper lobe from the lingula. Two thousand consecutive normal radiographic examinations of the adult chest (posteroanterior, left lateral views with the subjects in the erect position) were reviewed prospectively. A definite LMF was identified in 32 of the subjects (1.6%). The fissure was dome-shaped (convex superior) on at least one projection in 26 (81%) of 32 subjects. The position of the LMF was usually more cephalad than that of the RMF (25 of 31 subjects, or 81%). The lateral end of the LMF was usually superior to the medial end (25 of 32; 78%) and rarely inferior to the medial end (three of 32; 9%). The LMF infrequently was horizontal (four of 32; 12%). In a number of additional patients whose control chest radiographs showed no evidence of an LMF, subsequent radiographs revealed an LMF outlined by active pulmonary or pleural disease.

  3. Left Ventricular Hypertrophy

    Science.gov (United States)

    ... AskMayoExpert. What tests are needed to confirm the diagnosis of hypertrophic cardiomyopathy (HCM) and what is the role of genetic testing? Rochester, Minn.: Mayo Foundation for Medical Education and Research; ... diagnosis in patients with hypertrophied left ventricles. Heart. 2014; ...

  4. Hypoplastic left heart syndrome

    Directory of Open Access Journals (Sweden)

    Thiagarajan Ravi

    2007-05-01

    Full Text Available Abstract Hypoplastic left heart syndrome(HLHS refers to the abnormal development of the left-sided cardiac structures, resulting in obstruction to blood flow from the left ventricular outflow tract. In addition, the syndrome includes underdevelopment of the left ventricle, aorta, and aortic arch, as well as mitral atresia or stenosis. HLHS has been reported to occur in approximately 0.016 to 0.036% of all live births. Newborn infants with the condition generally are born at full term and initially appear healthy. As the arterial duct closes, the systemic perfusion becomes decreased, resulting in hypoxemia, acidosis, and shock. Usually, no heart murmur, or a non-specific heart murmur, may be detected. The second heart sound is loud and single because of aortic atresia. Often the liver is enlarged secondary to congestive heart failure. The embryologic cause of the disease, as in the case of most congenital cardiac defects, is not fully known. The most useful diagnostic modality is the echocardiogram. The syndrome can be diagnosed by fetal echocardiography between 18 and 22 weeks of gestation. Differential diagnosis includes other left-sided obstructive lesions where the systemic circulation is dependent on ductal flow (critical aortic stenosis, coarctation of the aorta, interrupted aortic arch. Children with the syndrome require surgery as neonates, as they have duct-dependent systemic circulation. Currently, there are two major modalities, primary cardiac transplantation or a series of staged functionally univentricular palliations. The treatment chosen is dependent on the preference of the institution, its experience, and also preference. Although survival following initial surgical intervention has improved significantly over the last 20 years, significant mortality and morbidity are present for both surgical strategies. As a result pediatric cardiologists continue to be challenged by discussions with families regarding initial decision

  5. Predictors of permanent pacemaker implantation after transfemoral aortic valve implantation with the Lotus valve.

    Science.gov (United States)

    Keßler, Mirjam; Gonska, Birgid; Seeger, Julia; Rottbauer, Wolfgang; Wöhrle, Jochen

    2017-10-01

    Permanent pacemaker implantation (PPMI) after transcatheter aortic valve implantation is of high clinical relevance, but PPMI rates differ widely between valve types. Although the Lotus valve can be repositioned, reported rates for PPMI are high. The predictors of PPMI after Lotus valve implantation have not been defined yet. We analyzed the impact of preexisting conduction disturbances, depth of implantation, oversizing, and amount of calcification on PPMI in 216 patients with severe symptomatic aortic stenosis underdoing Lotus valve implantation. PPMI was required in 39.8% of patients. Patients with need for PPMI compared with patients without need for PPMI had more often the following criteria: male gender (P=.035); preprocedural right bundle-branch block (RBBB) (16.3% vs 0, P<.001); atrioventricular (AV) block first degree (26.7% vs 10.1%, P=.004); higher calcium volume of the left coronary cusp (63.1±87.5 mm(3) vs 42.8±49.3 mm(3), P=.05); and deeper valve implantation at right coronary (P=.011), noncoronary (P=.026), and left coronary (P=.012) position. Oversizing in relation to annulus and left ventricular outflow tract did not have an impact on need for PPMI. By multiple regression analysis, preprocedural AV block first degree (P=.005), RBBB (P<.001), and depth of implantation (P=.006) were independent risk factors for need of PPMI. In patients with severe aortic stenosis receiving transfemoral Lotus valve, preexisting AV block first degree, RBBB, and implantation depth are independent predictors of PPMI, highlighting the importance of careful valve positioning. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Treatment Alternatives to Negotiate Peri-Implantitis

    Science.gov (United States)

    Machtei, Eli E.

    2014-01-01

    Peri-implant diseases are becoming a major health issue in dentistry. Despite the magnitude of this problem and the potential grave consequences, commonly acceptable treatment protocols are missing. Hence, the present paper reviews the literature treatment of peri-implantitis in order to explore their benefits and limitations. Treatment of peri-implantitis may include surgical and nonsurgical approaches, either individually or combined. Nonsurgical therapy is aimed at removing local irritants from the implants' surface with or without surface decontamination and possibly some additional adjunctive therapies agents or devices. Systemic antibiotics may also be incorporated. Surgical therapy is aimed at removing any residual subgingival deposits and additionally reducing the peri-implant pockets depth. This can be done alone or in conjunction with either osseous respective approach or regenerative approach. Finally, if all fails, explantation might be the best alternative in order to arrest the destruction of the osseous structure around the implant, thus preserving whatever is left in this site for future reconstruction. The available literature is still lacking with large heterogeneity in the clinical response thus suggesting possible underlying predisposing conditions that are not all clear to us. Therefore, at present time treatment of peri-implantitis should be considered possible but not necessarily predictable. PMID:26556414

  7. Electrocardiographic imaging-based recognition of possible induced bundle branch blocks during transcatheter aortic valve implantations

    NARCIS (Netherlands)

    Dam, P.M. van; Proniewska, K.; Maugenest, A.M.; Mieghem, N.M. van; Maan, A.C.; Jaegere, P.P. de; Bruining, N.

    2014-01-01

    AIMS: Conventional electrocardiogram (ECG)-based diagnosis of left bundle branch block (LBBB) in patients with left ventricular hypertrophy (LVH) is ambiguous. Left ventricular hypertrophy is often seen in patients with severe aortic stenosis in which a transcatheter aortic valve implantation (TAVI)

  8. Left ventricular mural thrombus

    Energy Technology Data Exchange (ETDEWEB)

    Nixon, J.V.

    1983-08-01

    The identification of mural thrombus in patients with left ventricular aneurysm and mural thrombus probably warrants consideration of long-term anticoagulation. In patients with acute, large, anterior or anteroapical, transmural myocardial infarctions, serial noninvasive examinations are warranted to define a group of patients at high risk for the development of left ventricular aneurysm and/or mural thrombus. Anticoagulants should be considered in patients in whom mural thrombi develop as a complication of their infarction. Patients with congestive cardiomyopathy should be considered for long-term anticoagulation. These recommendations are all tempered by the realization that the use of anticoagulant therapy is not without its own risks. The decision to anticoagulate must be balanced against each individual patient's suitability for such therapy and the individual likelihood of the development of side effects.

  9. Retrograde peri-implantitis

    Directory of Open Access Journals (Sweden)

    Mohamed Jumshad

    2010-01-01

    Full Text Available Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation.

  10. Impact of dental implant insertion method on the peri-implant bone tissue: Experimental study

    Directory of Open Access Journals (Sweden)

    Stamatović Novak

    2013-01-01

    Full Text Available Background/Aim. The function of dental implants depends on their stability in bone tissue over extended period of time, i.e. on osseointegration. The process through which osseointegration is achieved depends on several factors, surgical insertion method being one of them. The aim of this study was to histopathologically compare the impact of the surgical method of implant insertion on the peri-implant bone tissue. Methods. The experiment was performed on 9 dogs. Eight weeks following the extraction of lower premolars implants were inserted using the one-stage method on the right mandibular side and two-stage method on the left side. Three months after implantation the animals were sacrificed. Three distinct regions of bone tissue were histopathologically analyzed, the results were scored and compared. Results. In the specimens of one-stage implants increased amount of collagen fibers was found in 5 specimens where tissue necrosis was also observed. Only moderate osteoblastic activity was found in 3 sections. The analysis of bone-to-implant contact region revealed statistically significantly better results regarding the amount of collagen tissue fibers for the implants inserted in the two-stage method (Wa = 59 105, α = 0.05. No necrosis and osteoblastic activity were observed. Conclusion. Better results were achieved by the two-stage method in bone-to-implant contact region regarding the amount of collagen tissue, while the results were identical regarding the osteoblastic activity and bone tissue necrosis. There was no difference between the methods in the bone-implant interface region. In the bone tissue adjacent to the implant the results were identical regarding the amount of collagen tissue, osteoblastic reaction and bone tissue necrosis, while better results were achieved by the two-stage method regarding the number of osteocytes.

  11. Management of a fractured, nonremovable implant: a clinical report with a 12-month follow-up.

    Science.gov (United States)

    Quaranta, Alessandro; Iezzi, Giovanna; Poli, Ottavia; Piattelli, Adriano; Perrotti, Vittoria

    2015-04-01

    Implant failures could be due to biological or mechanical factors, which also include fracture of the fixture. The present report presents a case of a single fractured implant placed in the left mandibular molar region. Since the residual portion of the fixture was perfectly osseointegrated with no signs of peri-implantitis, and in direct contact with the roof of the inferior alveolar nerve canal, it was decided to treat the patient with a short implant positioned on top of the fractured, and not removing the fractured implant. Clinical and radiographical follow-up was performed for 12 months after loading. Periimplant soft tissues healing and implant osseointegration were achieved 6 months after implant placement; at the end of the follow-up a periimplant bone remodeling of 0.3 mm was observed. In conclusion, short implants could be taken into consideration as a treatment option in cases of nonremovable implants and sufficient residual bone height.

  12. Optimising the dichotomy limit for left ventricular ejection fraction in selecting patients for defibrillator therapy after myocardial infarction

    DEFF Research Database (Denmark)

    Yap, Yee Guan; Duong, Trinh; Bland, J Martin

    2007-01-01

    BACKGROUND: The selection of patients for prophylactic implantable cardioverter-defibrilator (ICD) treatment after myocardial infarction (MI) remains controversial. AIM: To determine the optimum left ventricular ejection fraction (LVEF) dichotomy limit for ICD treatment in patients with a history...

  13. Compound control strategy used in Electro-Mechanical Actuator (EMA)

    Science.gov (United States)

    Fu, Yongling; Yan, Meng

    2017-01-01

    This article briefly describes the overall structure of the loading test rig; establish mathematical model of loading EMA, analyze its stability, surplus force and other properties in MATLAB; propose a compound control strategy combined speed feedback, PID and feed-forward compensation based on structure invariance principle. To verify the effectiveness of the control strategy, do a co-simulation by designing a controller based on the control strategy above in MATLAB and building the EMA model in AMESim. The results show that the compound control strategy can significantly improve dynamic tracking accuracy and reduce surplus force.

  14. Carbon Nanotube Based Nano-Electro-Mechanical Systems (NEMS)

    Science.gov (United States)

    Han, Jie; Dai, Hongjie; Saini, Subhash

    1998-01-01

    Carbon nanotubes (CNT) enable nanoelectromechanical systems (NEMS) because of their inherent nanostructure, intrinsic electric conductivity and mechanical resilience. The collaborative work between Stanford (experiment) and NASA Ames (theory and simulation) has made progress in two types of CNT based NEMS for nanoelectronics and sensor applications. The CNT tipped scanning probe microscopy (SPM) is a NEMS in which CNT tips are used for nanoscale probing, imaging and manipulating. It showed great improvement in probing surfaces and biological systems over conventional tips. We have recently applied it to write (lithography) and read (image) uniform SiO2 lines on large Si surface area at speed up to 0.5 mm per s. Preliminary work using approximately 10 nm multiwall nanotube tips produced approximately 10 nm structures and showed that the CNT tips didn't wear down when crashed as conventional tips often do. This presents a solution to the long standing tip-wear problem in SPM nanolithography. We have also explored potential of CNT tips in imaging DNA in water. Preliminary experiment using 10 nm CNT tips reached 5 nm resolution. The 1 nm nanolithography and 1 nm DNA imaging can be expected by using approximately 1 nm CNT tips. In contrast to CNT tipped SPM, we also fabricated CNT devices on silicon wafer in which CNTs connect patterned metallic lines on SiO2/Si by a simple chemical vapor deposition process. Using conventional lithography for silicon wafer, we have been able to obtain CNT based transistors and sensors. Investigations of the CNT NEMS as physical, biological and chemical sensors are in progress and will be discussed.

  15. Sliding mode control on electro-mechanical systems

    Directory of Open Access Journals (Sweden)

    Utkin Vadim I.

    2002-01-01

    Full Text Available The first sliding mode control application may be found in the papers back in the 1930s in Russia. With its versatile yet simple design procedure the methodology is proven to be one of the most powerful solutions for many practical control designs. For the sake of demonstration this paper is oriented towards application aspects of sliding mode control methodology. First the design approach based on the regularization is generalized for mechanical systems. It is shown that stability of zero dynamics should be taken into account when the regular form consists of blocks of second-order equations. Majority of applications in the paper are related to control and estimation methods of automotive industry. New theoretical methods are developed in the context of these studies: sliding made nonlinear observers, observers with binary measurements, parameter estimation in systems with sliding mode control.

  16. Micro-electro-mechanical optical cross-connects (OXCs)

    Science.gov (United States)

    Zhang, Xu M.; Liu, Ai Q.; Wang, Fang; Liu, Z.; Lu, C.

    2001-10-01

    This paper reports the design, fabrication, and testing of drawbridge micromirrors that is used to form a monolithic 4 X 4 optical crossconnect (OXC) having dimensions about 4 mm X 4 mm. The OXC is composed of 16 individual drawbridge micromirrors that are fabricated by the surface micromachining technology and then manually assembled. In each drawbridge micromirror the mirror is driven by electrostatic force to cut off the laser beam or let it pass through, enabling the switching. The measured switching times range from 94 microsecond(s) to 181.1 microsecond(s) for the switches with different bending bean sizes. The configuration of this OXC is scalable and capable to build up a large array of OXC system.

  17. Prognostics Enhanced Reconfigurable Control of Electro-Mechanical Actuators

    Data.gov (United States)

    National Aeronautics and Space Administration — Actuator systems are employed widely in aerospace, transportation and industrial processes to provide power to critical loads, such as aircraft control surfaces....

  18. Micro-electro-mechanical systems phosphoric acid fuel cell

    Science.gov (United States)

    Sopchak, David A.; Morse, Jeffrey D.; Upadhye, Ravindra S.; Kotovsky, Jack; Graff, Robert T.

    2010-12-21

    A phosphoric acid fuel cell system comprising a porous electrolyte support, a phosphoric acid electrolyte in the porous electrolyte support, a cathode electrode contacting the phosphoric acid electrolyte, and an anode electrode contacting the phosphoric acid electrolyte.

  19. A flexible electro-mechanical design information system

    NARCIS (Netherlands)

    Basson, Anton H.; Bonnema, Gerrit Maarten; Liu, Y.; Liu, Yang; Horvath, Imre; Xirouchakis, Paul

    2004-01-01

    Design information systems are of increasing importance due to globalization of product development, increasing complexity of products (in terms of product variants and range of technologies employed) and increasing emphasis on improving product development efficiency (shortening times, reducing

  20. Aerodynamic Optimization for Distributed Electro Mechanical Actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Traditional hydraulic actuation and control surface layout both limit span wise control of lift distribution, and require large volume within wing cross-section,...

  1. Influence of nickel addition on magnetic and electro-mechanical ...

    Indian Academy of Sciences (India)

    Unknown

    The coil is wound on the core such that core and stator are then mechanically joined to complete the ... depend on the heat treatment under hydrogen atmosphere. (Bozorth 1951; Enoch and Fudge 1966; Scholefield et ... much dependent on processing and heat treatment. The parts made from these alloys were annealed in ...

  2. (Electro-) mechanical characteristics of electrostatically driven vacuum encapsulated polysilicon resonators

    NARCIS (Netherlands)

    Tilmans, H.A.C.; Tilmans, H.A.C.; Legtenberg, Rob; Legtenberg, R.; Schurer, H.; Schurer, H.; IJntema, D.J.; Ijntema, D.J.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

    The design, fabrication and performance of vacuum-encapsulated electrostatically driven polysilicon resonating beams, 210-510 μm long, 100 μm wide, and 1.5 μm thick, are described. The shortest beams have a fundamental frequency of 324 kHz, a gauge factor of 2400 and a quality factor of 600 at

  3. Modeling Strategies for Electro-Mechanical Microsystems with Uncertainty Quantification

    NARCIS (Netherlands)

    Hannot, S.D.A.

    2010-01-01

    Microsystems are very small sensors and actuators, manufactured with the same technology as computer chips. Well known applications of these machines are the acceleration sensors in the Wii game console and the iPhone. At the micrometer length scales of microsystems the physical forces behave

  4. Congenital left ventricular apical aneurysm presenting as ventricular tachycardia.

    Science.gov (United States)

    Amado, José; Marques, Nuno; Candeias, Rui; Gago, Paula; de Jesus, Ilídio

    2016-10-01

    The authors present the case of a 34-year-old male patient seen in our department due to palpitations. On the electrocardiogram monomorphic ventricular tachycardia (VT) was documented, treated successfully with amiodarone. The subsequent study revealed a normal echocardiogram and an apical aneurysm of the left ventricle on magnetic resonance imaging, confirmed by computed tomography coronary angiography that also excluded coronary disease. He underwent an electrophysiological study to determine the origin of the VT and to perform catheter ablation using electroanatomical mapping. VT was induced and radiofrequency applications were performed in the left ventricular aneurysm area. VT was no longer inducible, with acute success. Despite this it was decided to implant a subcutaneous implantable cardioverter-defibrillator (ICD). Eight months after the ablation the patient was admitted again due to VT, treated by the ICD. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Left-atrial-appendage occluder migrates in an asymptomatic patient.

    Science.gov (United States)

    Pisani, Paolo; Sandrelli, Luca; Fabbrocini, Mario; Tesler, Ugo Filippo; Medici, Dante

    2014-08-01

    Percutaneous closure of the left atrial appendage (LAA) is a new approach to the prevention of cardioembolic events in patients with atrial fibrillation. We implanted an LAA occlusion device (Amplatzer™ Cardiac Plug) in a 70-year-old woman via a transseptal approach. Upon her discharge from the hospital, a transthoracic echocardiogram showed stable anchoring of the device; 6 months after implantation, a routine transthoracic echocardiogram revealed migration of the occluder into the left ventricular outflow tract, in the absence of symptoms. We surgically removed the device from the mitral subvalvular apparatus and closed the LAA with sutures. This case shows that percutaneous LAA occlusion can result in serious adverse events, including device migration in the absence of signs or symptoms; therefore, careful follow-up monitoring is mandatory.

  6. Left Ventricular Pseudoaneurysm Perceived as a Left Lung Mass

    Directory of Open Access Journals (Sweden)

    Ugur Gocen

    2013-02-01

    Full Text Available Left ventricular pseudo-aneurysm is a rare complication of aneurysmectomy. We present a case of surgically-treated left ventricular pseudo-aneurysm which was diagnosed three years after coronary artery bypass grafting and left ventricular aneurysmectomy. The presenting symptoms, diagnostic evaluation and surgical repair are described. [Cukurova Med J 2013; 38(1.000: 123-125

  7. Treatment Alternatives to Negotiate Peri-Implantitis

    Directory of Open Access Journals (Sweden)

    Eli E. Machtei

    2014-01-01

    Full Text Available Peri-implant diseases are becoming a major health issue in dentistry. Despite the magnitude of this problem and the potential grave consequences, commonly acceptable treatment protocols are missing. Hence, the present paper reviews the literature treatment of peri-implantitis in order to explore their benefits and limitations. Treatment of peri-implantitis may include surgical and nonsurgical approaches, either individually or combined. Nonsurgical therapy is aimed at removing local irritants from the implants’ surface with or without surface decontamination and possibly some additional adjunctive therapies agents or devices. Systemic antibiotics may also be incorporated. Surgical therapy is aimed at removing any residual subgingival deposits and additionally reducing the peri-implant pockets depth. This can be done alone or in conjunction with either osseous respective approach or regenerative approach. Finally, if all fails, explantation might be the best alternative in order to arrest the destruction of the osseous structure around the implant, thus preserving whatever is left in this site for future reconstruction. The available literature is still lacking with large heterogeneity in the clinical response thus suggesting possible underlying predisposing conditions that are not all clear to us. Therefore, at present time treatment of peri-implantitis should be considered possible but not necessarily predictable.

  8. Three-dimensional residual strain in midanterior canine left ventricle

    OpenAIRE

    Costa, Kevin D; MAY-NEWMAN, KAREN; FARR, DYAN; O’Dell, Walter G.; McCulloch, Andrew D.; Omens, Jeffrey H.

    1997-01-01

    All previous studies of residual strain in the ventricular wall have been based on one- or two-dimensional measurements. Transmural distributions of three-dimensional (3-D) residual strains were measured by biplane radiography of columns of lead beads implanted in the midanterior free wall of the canine left ventricle (LV). 3-D bead coordinates were reconstructed with the isolated arrested LV in the zero-pressure state and again after local residual stress had been relieved by excising a tran...

  9. The bioceramic implant: evaluation of implant exposures in 419 implants.

    Science.gov (United States)

    Jordan, David R; Klapper, Stephen R; Gilberg, Steven M; Dutton, Jonathan J; Wong, Amy; Mawn, Louise

    2010-01-01

    To compare the rate of exposure in the immediate 3-month postoperative follow-up period with the rate of exposure after the immediate postoperative period in 419 anophthalmic patients with a bioceramic (aluminum oxide) orbital implant. This is a retrospective, clinical case series of 419 patients who received a bioceramic orbital implant. All patients who presented to five oculofacial surgeons (D.J., S.G., J.D., S.K., L.M.) from January 1, 2000, to June 1, 2007, who received a bioceramic orbital implant and had a minimum of 3 months of follow-up were included in this study. The authors analyzed age, gender, type of surgery, implant size, peg system, follow-up duration, time of pegging, and problems encountered. The data from the patients with greater than 3 months of follow-up with exposure of the bioceramic implant are detailed in this report. There were 353 patients followed for 3 to 96 months with an average of 30 months of follow-up (median 23 months). Implant exposure occurred in 32/353 bioceramic implants (9.1%). Six of the 32 (19%) exposures occurred during the 90-day postoperative period (average 2.1 months). Twenty-six (81%) exposures occurred outside of the 90-day postoperative period (average 27.5 months, range 4-82 months). Implant exposures can occur anytime postimplant placement. This review discovered an implant exposure rate of 9.1%, with the majority of the exposures occurring after the postoperative follow-up period. Patients with porous orbital implants should be followed on a long-term basis to detect this complication.

  10. Cortical Plasticity after Cochlear Implantation

    Directory of Open Access Journals (Sweden)

    B. Petersen

    2013-01-01

    tomography at three time points: within 14 days, three months, and six months after switch-on. Fifteen recently implanted adult implant recipients listened to running speech or speech-like noise in four sequential PET sessions at each milestone. CI listeners with postlingual hearing loss showed differential activation of left superior temporal gyrus during speech and speech-like stimuli, unlike CI listeners with prelingual hearing loss. Furthermore, Broca’s area was activated as an effect of time, but only in CI listeners with postlingual hearing loss. The study demonstrates that adaptation to the cochlear implant is highly related to the history of hearing loss. Speech processing in patients whose hearing loss occurred after the acquisition of language involves brain areas associated with speech comprehension, which is not the case for patients whose hearing loss occurred before the acquisition of language. Finally, the findings confirm the key role of Broca’s area in restoration of speech perception, but only in individuals in whom Broca’s area has been active prior to the loss of hearing.

  11. Implant success!!!.....simplified

    Directory of Open Access Journals (Sweden)

    Luthra Kaushal

    2009-01-01

    Full Text Available The endeavor towards life-like restoration has helped nurture new vistas in the art and science of implant dentistry. The protocol of "restoration-driven implant placement" ensures that the implant is an apical extension of the ideal future restoration and not the opposite. Meticulous pre-implant evaluation of soft and hard tissues, diagnostic cast and use of aesthetic wax-up and radiographic template combined with surgical template can simplify the intricate roadmap for appropriate implant treatment. By applying the harmony of artistic skill, scientific knowledge and clinical expertise, we can simply master the outstanding implant success in requisites of aesthetics, phonetics and function.

  12. Implant success!!!.....simplified.

    Science.gov (United States)

    Luthra, Kaushal K

    2009-01-01

    The endeavor towards life-like restoration has helped nurture new vistas in the art and science of implant dentistry. The protocol of "restoration-driven implant placement" ensures that the implant is an apical extension of the ideal future restoration and not the opposite. Meticulous pre-implant evaluation of soft and hard tissues, diagnostic cast and use of aesthetic wax-up and radiographic template combined with surgical template can simplify the intricate roadmap for appropriate implant treatment.By applying the harmony of artistic skill, scientific knowledge and clinical expertise, we can simply master the outstanding implant success in requisites of aesthetics, phonetics and function.

  13. The effects of laser microtexturing of the dental implant collar on crestal bone levels and peri-implant health.

    Science.gov (United States)

    Botos, Spyros; Yousef, Hoda; Zweig, Barry; Flinton, Robert; Weiner, Saul

    2011-01-01

    Polished and machined collars have been advocated for dental implants to reduce plaque accumulation and crestal bone loss. More recent research has suggested that a roughened titanium surface promotes osseointegration and connective tissue attachment. The purpose of this research was to compare crestal bone height adjacent to implants with laser-microtextured and machined collars from two different implant systems. Four implants, two with laser-microtextured collars and two with machined collars, were placed in the anterior mandible to serve as overdenture abutments. They were placed in alternating order, and the distal microtextured- and machined-collar implants were loaded with ball abutments. The mesial implants were left unloaded. The distal implants were immediately loaded with prefabricated dentures. Plaque Index, Bleeding Index, and probing depths (PDs) were measured after 6 and 12 months for the loaded implants. Bone loss for both groups (loaded and unloaded) was evaluated via standardized radiographs. Plaque and bleeding values were similar for both implant types. The microtextured-collar implants showed shallower PDs (0.36 ± 0.5 mm and 0.43 ± 0.51 mm) than those with machined collars (1.14 ± 0.77 mm and 1.64 ± 0.93 mm; bone loss for both loaded (0.19 ± 0.15 mm and 0.42 ± 0.34 mm) and unloaded groups (0.15 ± 0.15 mm and 0.29 ± 0.20 mm) than the machined implants for both the loaded (0.72 ± 0.5 mm and 1.13 ± 0.61 mm) and unloaded groups (0.29 ± 0.28 mm and 0.55 ± 0.32 mm). Application of laser-microtextured grooves to the implant collar resulted in shallower PDs and less peri-implant crestal bone loss than that seen around implants with machined collars.

  14. Re-osseointegration after treatment of peri-implantitis at different implant surfaces. An experimental study in the dog.

    Science.gov (United States)

    Persson, L G; Berglundh, T; Lindhe, J; Sennerby, L

    2001-12-01

    Peri-implantitis is a condition that includes soft tissue inflammation and rapid loss of bone. Treatment of peri-implantitis includes both antimicrobial and bone augmenting methods. The question of whether true re-osseointegration may occur following treatment of peri-implantitis is controversial. The aim of this study was to investigate whether the character of the implant surface was of importance for the occurrence of re-osseointegration following treatment of peri-implantitis. Four beagle dogs were used. The mandibular premolars were extracted. After 12 months, 3 ITI(R) solid screw dental implants were placed in each side of the mandible. In the left side, implants with a turned surface (Turned sites) were used, while in the right side implants with a SLA surface (SLA sites) were placed. After 3 months of healing, peri-implantitis was induced by ligature placement and plaque accumulation. When about 50% of the initial bone support was lost, the ligatures were removed. Five weeks later, treatment was initiated. Each animal received tablets of Amoxicillin and Metronidazole for a period of 17 days. Three days after the start of the antibiotic regimen, one implant site (experimental site) in each quadrant was exposed to local therapy. Following flap elevation, the exposed titanium surface was cleaned with the use of cotton pellets soaked in saline. The implants were submerged. Six months later, biopsies were obtained. Treatment resulted in a 72% bone fill of the bone defects at Turned sites and 76% at SLA sites. The amount of re-osseointegration was 22% at Turned sites and 84% at SLA sites. A treatment regimen that included (i) systemic administration of antibiotics combined with (ii) granulation tissue removal and implant surface cleaning resulted in resolution of peri-implantitis and bone fill in adjacent bone defects. Further, while substantial "re-osseointegration" occurred to an implant with a rough surface (SLA), bone growth on a previously exposed smooth

  15. Persistent Left Superior Vena Cava Associated with Hemiazygos Vein Draining in It and Absence of Left Brachiocephalic Vein, in a Patient with Congenital Heart Defect

    Directory of Open Access Journals (Sweden)

    Opincariu Diana

    2016-09-01

    Full Text Available Persistent left superior vena cava is an anomalous vein that derives from a malfunction of obliteration of the left common cardinal vein during intrauterine life. The diagnosis can be suggested by a dilated coronary sinus as seen in echocardiography, or other imagistic methods. Due to the lack of hemodynamic impairment, and consequently with few or no symptoms, this vascular anomaly is frequently discovered incidentally. In this brief report we present the case of a 35-year-old male known with a complex congenital cardiovascular malformation that included atrial septum defect, persistent left superior vena cava and anomalous right pulmonary vein drainage in the PLSVC, diagnosed with sinoatrial block that required pacemaker implantation. Due to the patient’s medical history, investigations to decide the best approach needed for pacemaker implantation were performed, including a thoracic CT that incidentally found additional anomalies — the hemiazygos vein draining in PLSVC and the lack of the left brachiocephalic vein.

  16. Idiopathic Fascicular Left Ventricular Tachycardia.

    Science.gov (United States)

    Alahmad, Yaser; Asaad, Nidal Ahmad; Arafa, Salaheddin Omran; Ahmad Khan, Shahul Hameed; Mahmoud, Alsayed

    2017-01-01

    Idiopathic left fascicular ventricular tachycardia (ILFVT) is characterized by right bundle branch block morphology and left axis deviation. We report a case of idiopathic left ventricular fascicular tachycardia in a young 31-year-old male patient presenting with a narrow complex tachycardia.

  17. Idiopathic Fascicular Left Ventricular Tachycardia

    OpenAIRE

    Alahmad, Yaser; Asaad, Nidal Ahmad; Arafa, Salaheddin Omran; Ahmad Khan, Shahul Hameed; Mahmoud, Alsayed

    2017-01-01

    Idiopathic left fascicular ventricular tachycardia (ILFVT) is characterized by right bundle branch block morphology and left axis deviation. We report a case of idiopathic left ventricular fascicular tachycardia in a young 31-year-old male patient presenting with a narrow complex tachycardia.

  18. Choice of cochlear implant side in a paediatric population.

    Science.gov (United States)

    Sürmelioğlu, O; Cetik, F; Tarkan, O; Ozdemir, S; Tuncer, U; Kiroğlu, M; Sahin, R

    2014-06-01

    To compare the effect of right- or left-sided cochlear implantation on listening skills in a paediatric population. A retrospective analysis was conducted on the listening skills performance data of children who were operated on and followed up at the Çukurova University Department of Otorhinolaryngology between 2007 and 2011. Sixty-three patients were included in the study. Patients were evaluated using the Listening Progress Profile, the Meaningful Auditory Integration Scale and the littlEARS test. The mean age of the children was two years (range of one to five years). Twenty-nine patients were male and 34 were female. Twenty-eight patients were implanted in the right ear and 35 in the left ear. There were no statistically significant differences between right and left ear implantees in terms of listening skills performance. This study indicates that the choice of cochlear implant side is not crucial for the development of listening skills.

  19. Left ventricular scar impact on left ventricular synchronization parameters and outcomes of cardiac resynchronization therapy.

    Science.gov (United States)

    Ahmed, Walid; Samy, Wael; Tayeh, Osama; Behairy, Noha; Abd El Fattah, Alia

    2016-11-01

    Left ventricular scar, including global scar and lateral wall, plays an important role in predicting response to cardiac resynchronization therapy (CRT). Thirty patients underwent CRT implantation. Assessment of left ventricular (LV) dyssynchrony was done through Gated SPECT LV phase analysis. Pre-implantation cardiac magnetic resonance (CMR) with late gadolinium enhancement technique to examine LV scar burden. Echocardiographic examination of LV end-systolic volume (LVES) prior to CRT and 6 months later. Thirty patients received CRT (mean age 58.7±9.0, 24 males). Reverse LV remodeling (decline ≥15% from baseline VES) was documented in 19 patients. Temporal changes in LV dyssynchrony parameters were correlated to LV reverse remodeling. Applying ROC for predicting CRT non-response showed a cutoff 36.5% of global LV scar burden had a sensitivity of 81.8% and specificity of 68.4%. A cutoff for lateral wall scar burden 40.5% of whole lateral wall had a sensitivity of 72.7% and specificity of 68.4%. Reverse LV remodeling is associated with temporal improvements in LV dyssynchrony parameters. LV scar had an unfavorable impact on CRT response. Both global and lateral wall scar burden could predict CRT nonresponse status. Copyright © 2016. Published by Elsevier Ireland Ltd.

  20. [Biomaterials in cochlear implants].

    Science.gov (United States)

    Stöver, T; Lenarz, T

    2009-05-01

    Cochlear implants (CI) represent the "gold standard" for the treatment of congenitally deaf children and postlingually deafened adults. Thus, cochlear implantation is a success story of new bionic prosthesis development. Owing to routine application of cochlear implants in adults but also in very young children (below the age of one), high demands are placed on the implants. This is especially true for biocompatibility aspects of surface materials of implant parts which are in contact with the human body. In addition, there are various mechanical requirements which certain components of the implants must fulfil, such as flexibility of the electrode array and mechanical resistance of the implant housing. Due to the close contact of the implant to the middle ear mucosa and because the electrode array is positioned in the perilymphatic space via cochleostomy, there is a potential risk of bacterial transferral along the electrode array into the cochlea. Various requirements that have to be fulfilled by cochlear implants, such as biocompatibility, electrode micromechanics, and although a very high level of technical standards has been carried out there is still demand for the improvement of implants as well as of the materials used for manufacturing, ultimately leading to increased implant performance. General considerations of material aspects related to cochlear implants as well as potential future perspectives of implant development will be discussed.

  1. Subcutaneous implantable defibrillator: State-of-the art 2013

    OpenAIRE

    Akerström, Finn; Arias, Miguel A; Pachón, Marta; Puchol, Alberto; Jiménez-López, Jesús

    2013-01-01

    The subcutaneous implantable cardioverter-defibrillator (S-ICD) has recently been approved for commercial use in Europe, New Zealand and the United States. It is comprised of a pulse generator, placed subcutaneously in a left lateral position, and a parasternal subcutaneous lead-electrode with two sensing electrodes separated by a shocking coil. Being an entirely subcutaneous system it avoids important periprocedural and long-term complications associated with transvenous implantable cardiove...

  2. Implantable Medical Devices

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...

  3. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  4. [Left-handedness and health].

    Science.gov (United States)

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome), developmental disorders (autism, dislexia and sttutering) and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about "anomalous" cerebral domination, as a consequence of hormonal disbalance.

  5. [Implantation of Strecker's endocoronary prosthesis. Apropos of 21 cases].

    Science.gov (United States)

    Larrazet, F; Dupouy, P; Dubois-Randé, J L; Kvasnicka, J; Geschwind, H J

    1994-03-01

    The aim of this study was to assess the safety and efficacy of implantation of Strecker coronary stents. The implantation was performed in 21 patients during elective angioplasty (N = 18) or in emergency situations (N = 3). The indications were acute occlusion after angioplasty (N = 3), restenosis (N = 12), incomplete balloon angioplasty results (N = 4) and implantation of first intent (N = 2). The site of implantation was a venous bypass graft in 9 cases, the left anterior descending artery in 5 cases, the right coronary artery in 4 cases and the left circumflex in 3 cases. The average length of the lesions was 8.4 +/- 4.1 mm, including 15 short ( 10 mm) lesions. Four lesions were located at an acute angle (> 45 degrees) and 4 at the site of origin of a side branch. The diameter of the normal segment of the treated artery was 3 mm in 9 cases. Seven 3 mm, five 3.5 mm, six 4 mm and three 4.5 mm diameter stents were implanted. There were no failures to position or implant the stents. After the implantation, the minimal lernen diameter of the artery at the angioplasty site was greater than that obtained with balloon (2.87 +/- 0.67 mm versus 1.83 +/- 1.11 mm, p < 0.001). There was no early restenosis at control angiography at 24 hours (2.78 +/- 0.20 mm versus 2.87 +/- 0.67 mm NS).(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Understanding left-handedness.

    Science.gov (United States)

    Gutwinski, Stefan; Löscher, Anna; Mahler, Lieselotte; Kalbitzer, Jan; Heinz, Andreas; Bermpohl, Felix

    2011-12-01

    The human cerebrum is asymmetrical, consisting of two hemispheres with differing functions. Recent epidemiological and neurobiological research has shed new light on the development of the cerebral lateralization of motor processes, including handedness. In this article, we present these findings from a medical perspective. We selectively searched the PubMed online database for articles including the terms "handedness," "left handedness," "right handedness," and "cerebral lateralization." Highly ranked and commonly cited articles were included in our analysis. The emergence of handedness has been explained by physiological and pathological models. Handedness arose early in evolution and has probably been constitutive for the development of higher cognitive functions. For instance, handedness may have provided the basis for the development of speech and fine motor skills, both of which have played a critical role in the evolution of mankind. The disadvantages of certain types of handedness are discussed, as some cases seem to be associated with disease. The consideration of handedness from the epidemiological, neurobiological, and medical points of view provides insight into cerebral lateralization.

  7. Left ventricular noncompaction.

    Science.gov (United States)

    Ichida, Fukiko

    2009-01-01

    Left ventricular noncompaction (LVNC) is a recently defined cardiomyopathy characterized by a pattern of prominent trabecular meshwork and deep intertrabecular recesses, and is thought to be caused by arrest of normal endomyocardial morphogenesis. Although LVNC has been classified as a primary cardiomyopathy of genetic origin, its definition and diagnostic criteria are still being debated. Isolated LVNC was thought to be rare; however, heightened awareness has resulted in an increased detection of the morphological features of LVNC in routine clinical practice, especially in the adult population. Clinical manifestations are highly variable, ranging from no symptoms to disabling congestive heart failure, arrhythmias, and systemic thromboemboli. LVNC, like other forms of inherited cardiomyopathy, is genetically heterogeneous and can be inherited as an autosomal-dominant or X-linked recessive disorder. It has been linked to mutations in several genes, including LIM domain binding protein 3 (ZASP), alpha-dystrobrevin (DTNA), tafazzin (TAZ/G4.5) and those encoding sarcomeric proteins. However, the relatively small contribution of known mutations to the disease, compared with the higher proportion of familial cases suggests that other elusive genes remain to be identified.

  8. Diagnostic Imaging for Implants

    Directory of Open Access Journals (Sweden)

    Sanjay M Mallya

    2004-01-01

    Full Text Available Dental implants are a popular modality for permanent tooth replacement. The key to successful implant placement, its subsequent osseointegration and the final prosthetic rehabilitation is proper preoperative assessment. Diagnostic imaging plays an important role in the pre- and post-surgical evaluation process. Imaging is used to evaluate suitability of implant sites, aid in selection of appropriate implants, and finally evaluate implant placement and osseointegration. This article reviews the role of diagnostic imaging in the various phases and the advantages and limitations of the numerous imaging modalities.

  9. Intravascular ultrasound assessment of distal left main bifurcation disease: the importance of the polygon of confluence of the left main, left anterior descending, and left circumflex arteries.

    Science.gov (United States)

    Kang, Soo-Jin; Mintz, Gary S; Oh, Jun-Hyok; Park, Duk-Woo; Lee, Seung-Whan; Kim, Young-Hak; Lee, Cheol Whan; Park, Seong-Wook; Park, Seung-Jung

    2013-11-01

    The polygon of confluence (POC) represents the zone of confluence of the distal left main (LM), ostial left anterior descending (LAD), and ostial left circumflex (LCX) arteries. We used intravascular ultrasound (IVUS) to assess the POC pre and post-drug-eluting stent implantation for unprotected distal LM disease. Four segments within 82 LM bifurcation lesions were defined by longitudinal IVUS reconstruction: (1) ostial LAD, (2) POC, and (3) distal LM (DLM)--from LAD-pullback, and (4) ostial LCX from LCX-pullback. Preprocedural minimum lumen area (MLA) and poststenting minimum stent area (MSA) within the LM were mainly located within the POC (51 and 71%). On ROC analysis, a cut-off of the MLA within the POC of 6.1 mm(2) predicted significant LCX carinal stenosis (85% sensitivity, 52% specificity, AUC = 0.7, 95% CI = 0.57-0.78, P < 0.01). Poststenting MSA within the distal LM proximal to the carina (to include DLM and POC) positively correlated with the preprocedural MLA within the POC (r = 0.283, P = 0.02); it was significantly smaller in 48 lesions with a pre-PCI MLA within the POC < 6.1 mm(2) versus 25 lesions with a pre-PCI MLA ≥6.1 mm(2) (7.5 ± 2.1 mm(2) vs. 8.6 ± 2.0 mm(2), P = 0.04). Independent predictors for poststenting LCX carinal MLA also included preprocedural MLA within the POC (β = 0.240, 95% CI = 0.004-0.353, P = 0.04). The MLA within the POC was a good surrogate reflecting the overall severity of LM bifurcation disease including ostial LCX stenosis pre-PCI and the ability to expand a stent within the distal LM as well as final ostial LCX lumen area post-PCI. Copyright © 2011 Wiley Periodicals, Inc.

  10. [Spanish Implantable Cardioverter-Defibrillator Registry. Fourth Official Report of the Spanish Society of Cardiology Working Group on Implantable Cardioverter-Defibrillators (2007)].

    Science.gov (United States)

    Peinado Peinado, Rafael; Torrecilla, Esteban G; Ormaetxe, José; Alvarez, Miguel

    2008-11-01

    This article presents the 2007 findings of the Spanish Implantable Cardioverter-Defibrillator (ICD) Registry, established by the Working Group on Implantable Cardioverter-Defibrillators, Electrophysiology and Arrhythmia Section, Spanish Society of Cardiology. The Spanish Society of Cardiology received prospective data recorded on a single-page questionnaire on 96.6% of device implantations. Overall, 3,291 implantations were reported (90.1% of the estimated total). The reported implantation rate was 72.8 per million inhabitants, and 77.1% were first implantations. The majority of ICDs were implanted in males (mean age, 61 [12] years) in functional class II with severe or moderate-to-severe left ventricular dysfunction. The most frequent form of heart disease was ischemic heart disease, followed by dilated cardiomyopathy. Indications for primary prevention remained unchanged relative to the previous year and now account for half of all first implantations, with an increasing number of patients with dilated cardiomyopathy. The number of ICDs incorporating cardiac resynchronization therapy has increased slightly and now comprises 30.1% of the total. Around 70% of ICD implantations were performed in an electrophysiology laboratory by a cardiac electrophysiologist. The incidence of complications was very low. The 2007 Spanish Implantable Cardioverter-Defibrillator Registry contains data on more than 90% of all ICD implantations performed in Spain, thereby confirming that it has become increasingly representative in recent years. The number of implantations has continued to grow, though the proportion carried out for primary prevention has stabilized at around 50%.

  11. Subcutaneous implantable cardioverter-defibrillator: Initial experience.

    Science.gov (United States)

    Galvão, Pedro; Cavaco, Diogo; Adragão, Pedro; Costa, Francisco; Carmo, Pedro; Morgado, Francisco; Bernardo, Ricardo; Nunes, Manuela; Abecasis, Miguel; Neves, José; Mendes, Miguel

    2014-09-01

    Implantable cardioverter-defibrillators (ICDs) are important tools in the prevention of sudden death, but implantation requires transvenous access, which is associated with complications. Subcutaneous implantable cardioverter-defibrillators (S-ICDs) may prevent some of these complications. To evaluate the therapeutics and complications associated with S-ICD systems. S-ICD implantation was planned in 23 patients, for whom the indications were vascular access problems, increased risk of infection or young patients with long predicted follow-up. The population consisted of four patients with ischemic heart disease, three of them on hemodialysis (two with subclavian vein thrombosis), five with left ventricular noncompaction, four with Brugada syndrome, three with arrhythmogenic right ventricular cardiomyopathy, one with transposition of the great vessels, two with dilated cardiomyopathy and four with hypertrophic cardiomyopathy. S-ICDs were implanted in 21 patients, two having failed to fulfil the initial screening criteria. Mean implantation time was 77 minutes, with no complications. Defibrillation tests were performed, and in one patient the generator had to be repositioned to obtain an acceptable threshold. In a mean follow-up of 14 months, 10 patients had S-ICD shocks, which were appropriate in half of them; one developed infection, one needed early replacement due to loss of telemetry and one patient died of noncardiac cause. S-ICD implantation can be performed by cardiologists with a high success rate. Initial experience appears favorable, but further studies are needed with longer follow-up times to assess the safety and efficacy of this strategy compared to conventional devices. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  12. Stenting of the Superior Vena Cava and Left Brachiocephalic Vein with Preserving the Central Venous Catheter in Situ

    Energy Technology Data Exchange (ETDEWEB)

    Isfort, Peter; Penzkofer, Tobias; Goerg, Fabian; Mahnken, Andreas H. [University Hospital RWTH Aachen, Aachen(Korea, Republic of)

    2011-10-15

    Stenting of the central veins is well established for treating localized venous stenosis. The techniques regarding catheter preservation for central venous catheters in the superior vena cava have been described. We describe here a method for stent implantation in the superior vena cava and the left brachiocephalic vein, and principally via a single jugular venous puncture, while saving a left sided jugular central venous catheter in a patient suffering from central venous stenosis of the superior vena cava and the left brachiocephalic vein.

  13. Nanoscale characterization of bone-implant interface and biomechanical modulation of bone ingrowth

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Paul A. [Tissue Engineering Laboratory MC 841, Departments of Anatomy and Cell Biology, Bioengineering, and Orthodontics, University of Illinois at Chicago, Chicago, 801 South Paulina Street, Illinois 60612 (United States)]. E-mail: pclark4@gmail.com; Clark, Andrew M. [Tissue Engineering Laboratory MC 841, Departments of Anatomy and Cell Biology, Bioengineering, and Orthodontics, University of Illinois at Chicago, Chicago, 801 South Paulina Street, Illinois 60612 (United States); Rodriguez, Anthony [Tissue Engineering Laboratory MC 841, Departments of Anatomy and Cell Biology, Bioengineering, and Orthodontics, University of Illinois at Chicago, Chicago, 801 South Paulina Street, Illinois 60612 (United States); Hussain, Mohammad A. [Tissue Engineering Laboratory MC 841, Departments of Anatomy and Cell Biology, Bioengineering, and Orthodontics, University of Illinois at Chicago, Chicago, 801 South Paulina Street, Illinois 60612 (United States); Mao, Jeremy J. [Tissue Engineering Laboratory MC 841, Departments of Anatomy and Cell Biology, Bioengineering, and Orthodontics, University of Illinois at Chicago, Chicago, 801 South Paulina Street, Illinois 60612 (United States)]. E-mail: jmao2@uic.edu

    2007-04-15

    Bone-implant interface is characterized by an array of cells and macromolecules. This study investigated the nanomechancial properties of bone-implant interface using atomic force microscopy in vitro, and the mechanical modulation of implant bone ingrowth in vivo using bone histomorphometry. Upon harvest of screw-type titanium implants placed in vivo in the rabbit maxilla and proximal femur for 4 weeks, nanoindentation was performed in the bone-implant interface at 60-{mu}m intervals radially from the implant surface. The average Young's Moduli (E) of the maxillary bone-implant interface was 1.13 {+-} 0.27 MPa, lacking significant differences at all intervals. In contrast, an increasing gradient of E was observed radially from the femur bone-implant interface: 0.87 {+-} 0.25 MPa to 2.24 {+-} 0.69 MPa, representing significant differences among several 60-{mu}m intervals. In a separate experiment, bone healing was allowed for 6 weeks for proximal femur implants. The right femoral implant received axial cyclic loading at 200 mN and 1 Hz for 10 min/d over 12 days, whereas the left femoral implant served as control. Cyclic loading induced significantly higher bone volume, osteoblast numbers per endocortical bone surface, mineral apposition rate, and bone formation rate than controls. These data demonstrate nanoscale and microscale characterizations of bone-implant interface, and mechanical modulation of bone ingrowth surrounding titanium implants.

  14. Radiographic Evaluation of Crestal Bone Loss Around Dental Implants in Maxilla and Mandible: One Year Prospective Clinical Study

    Science.gov (United States)

    Ajanović, Muhamed; Hamzić, Adis; Redžepagić, Sead; Kamber-Ćesir, Alma; Tosum, Selma

    2015-01-01

    Purpose The aim of the study was to analyze the amount of maxillary and mandibular crestal bone loss around Bredent Sky Blue type of implants of different dimensions one year after implantation. Materials and Methods 36 implants of diameter 3.5 x 10 mm were inserted in the maxilla and 12 in the mandible. 52 implants of diameter 4.0 x 8 mm were inserted in the maxilla, and 61 in the mandible (two-stage implant surgery). Results No statistically significant differences were found between the right and left side of the maxilla and between the right and left side of the mandible at the implant sites regarding distal and mesial bone losses as shown by analysis of variance (ANOVA). Conclusion Statistically significant differences were found between anterior maxilla, posterior maxilla and anterior mandible and posterior mandible at implant sites regarding distal and mesial bone losses as shown by analysis of variance (ANOVA). PMID:27688395

  15. A Giant Left Atrial Myxoma

    Directory of Open Access Journals (Sweden)

    Medhat F. Zaher

    2014-01-01

    Full Text Available Atrial myxomas are the most common primary cardiac tumors. Patients with left atrial myxomas generally present with mechanical obstruction of blood flow, systemic embolization, and constitutional symptoms. We present a case of an unusually large left atrial myxoma discovered incidentally in a patient with longstanding dyspnea being managed as bronchial asthma.

  16. Myxoma of the Left Ventricle

    Science.gov (United States)

    Novoa, José; Delgado, Antonio; Alonso, Ana

    2014-01-01

    This report concerns a 69-year-old woman who presented with an asymptomatic myxoma in the left ventricle. The tumor was successfully excised. We provide a very brief review of 72 other published cases of surgically treated left ventricular myxoma. PMID:25120392

  17. Two Lefts in Latin America?

    DEFF Research Database (Denmark)

    Christensen, Steen Fryba

    In this working paper I list five researchers' categorizations of the Latin American left in power (april 2006) in a schematic form. The most important criteria for the categorizations are given.......In this working paper I list five researchers' categorizations of the Latin American left in power (april 2006) in a schematic form. The most important criteria for the categorizations are given....

  18. Left-handedness and health

    Directory of Open Access Journals (Sweden)

    Milenković Sanja

    2010-01-01

    Full Text Available Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome, developmental disorders (autism, dislexia and sttutering and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about 'anomalous' cerebral domination, as a consequence of hormonal disbalance. .

  19. Left ventricular wall stress compendium.

    Science.gov (United States)

    Zhong, L; Ghista, D N; Tan, R S

    2012-01-01

    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

  20. Subxiphoid approach to epicardial implantation of implantable cardioverter defibrillators in children.

    Science.gov (United States)

    Haydin, Sertac; Saygi, Murat; Ergul, Yakup; Ozyilmaz, Isa; Ozturk, Erkut; Akdeniz, Celal; Tuzcu, Volkan

    2013-08-01

    Epicardial implantation of implantable cardioverter defibrillators (ICDs) is considered in the presence of intracardiac shunt, venous access issue, or small body size. We report our experience with epicardial ICD coil implantation using a minimally invasive method. Nine patients who underwent epicardial ICD implantation were included. The median age was 7.4 years (3.9-9.6 years) and the median weight was 15 kg (12-24 kg). Diagnosis at the time of implantation included long QT syndrome (n = 5), catecholaminergic polymorphic ventricular tachycardia (n = 2), hypertrophic cardiomyopathy (n = 1), and fast monomorphic ventricular tachycardia (n = 1). The minimally invasive method involved a subxiphoid incision to place the epicardial pacing leads. The ICD coil was placed in the transverse sinus in four patients using an access path posterior to the heart. The second approach involved a path anterior to the heart to reach the epicardial location posterior to the left atrial appendage in the five remaining patients. No fluoroscopy was used in either approach. The median defibrillation threshold (DFT) at implantation was 7.5 J. Lower DFTs were observed in the anterior approach (10 J vs 5 J). Appropriate ICD shocks were observed in three patients during the median 18-month follow-up period (0.3-28 months). No inappropriate shocks were noted. One patient developed pericardial tamponade 39 days after the procedure and was surgically drained. Minimally invasive epicardial ICD coil implantation in children with low DFT values is possible. The anterior implantation approach appears superior to the posterior approach. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

  1. CASE REPORT Breast cancer in a patient with silicone implants ...

    African Journals Online (AJOL)

    than in the breast mass. Breast cancer in a patient with silicone implants. R A Ahmed, MB ChB. Department of Radiology, Kalafong Hospital, University of Pretoria. CASE REPORT. Fig. 1. Inhomogeneous poorly outlined vascular mass in the left upper outer quadrant at two o'clock. Note the microcalcifications. This was the.

  2. Failures in implants

    Directory of Open Access Journals (Sweden)

    E Prashanti

    2011-01-01

    Full Text Available The burning problem that all the implantologists are confronted today is the complications and failures occurring with the treatment of osseointegrated implants. To further optimize the treatment outcome, etiologies and factors associated with implant failures should be elucidated. Conceivably such knowledge is needed for developing adequate treatment and prevention strategies. Hence, this paper is intended to provide an insight regarding various aspects of failures that affect dental implants.

  3. A review: Cochlear implants

    OpenAIRE

    Batman, Ç.; Üneri, C.; Şehitoijlu, M.A.

    1991-01-01

    Electrical stimulation of the auditory system in deaf individuals has been first explained in 1935 by Andreev et al. and in 1940 by Jones et al, resulting in sensation of hearing (1,2). These attempts are facilitated by Djourno et al who first implanted electrical devices in two subjects in 1957 (3). But this type of stimulation has been a controversy until 1974, when cochlear implant was successfully implanted by W.F. House. Since that time over 5000 individuals have been implanted with a va...

  4. Ion implantation technology

    CERN Document Server

    Downey, DF; Jones, KS; Ryding, G

    1993-01-01

    Ion implantation technology has made a major contribution to the dramatic advances in integrated circuit technology since the early 1970's. The ever-present need for accurate models in ion implanted species will become absolutely vital in the future due to shrinking feature sizes. Successful wide application of ion implantation, as well as exploitation of newly identified opportunities, will require the development of comprehensive implant models. The 141 papers (including 24 invited papers) in this volume address the most recent developments in this field. New structures and possible approach

  5. Investigation of Pathogenic Genes in Peri-Implantitis from Implant Clustering Failure Patients: A Whole-Exome Sequencing Pilot Study

    Science.gov (United States)

    Lee, Soohyung; Kim, Ji-Young; Hwang, Jihye; Kim, Sanguk; Lee, Jae-Hoon; Han, Dong-Hoo

    2014-01-01

    Peri-implantitis is a frequently occurring gum disease linked to multi-factorial traits with various environmental and genetic causalities and no known concrete pathogenesis. The varying severity of peri-implantitis among patients with relatively similar environments suggests a genetic aspect which needs to be investigated to understand and regulate the pathogenesis of the disease. Six unrelated individuals with multiple clusterization implant failure due to severe peri-implantitis were chosen for this study. These six individuals had relatively healthy lifestyles, with minimal environmental causalities affecting peri-implantitis. Research was undertaken to investigate pathogenic genes in peri-implantitis albeit with a small number of subjects and incomplete elimination of environmental causalities. Whole-exome sequencing was performed on collected saliva samples via self DNA collection kit. Common variants with minor allele frequencies (MAF) > = 0.05 from all control datasets were eliminated and variants having high and moderate impact and loss of function were used for comparison. Gene set enrichment analysis was performed to reveal functional groups associated with the genetic variants. 2,022 genes were left after filtering against dbSNP, the 1000 Genomes East Asian population, and healthy Korean randomized subsample data (GSK project). 175 (p-value implant failure. This result may demonstrate the feasibility of and provide pilot data for a larger research project aimed at discovering biomarkers for early diagnosis of peri-implantitis. PMID:24921256

  6. Evaluation of stress patterns produced by implant-retained overdentures and implant-retained fixed partial denture.

    Science.gov (United States)

    Mazaro, José Vitor Quinelli; Filho, Humberto Gennari; Vedovatto, Eduardo; Pellizzer, Eduardo Piza; Rezende, Maria Cristina Rosifini Alves; Zavanelli, Adriana Cristina

    2011-11-01

    The purposes of this study were to photoelastically measure the biomechanical behavior of 4 implants retaining different cantilevered bar mandibular overdenture designs and to compare a fixed partial denture (FPD). A photoelastic model of a human edentulous mandible was fabricated, which contained 4 screw-type implants (3.75 × 10 mm) embedded in the parasymphyseal area. An FPD and 3 overdenture designs with the following attachments were evaluated: 3 plastic Hader clips, 1 Hader clip with 2 posterior resilient cap attachments, and 3 ball/O-ring attachments. Vertical occlusal forces of 100 N were applied between the central incisor and unilaterally to the right and left second premolars and second molars. Stresses that developed in the supporting structure were monitored photoelastically and recorded photographically. The results showed that the anterior loading, the overdenture with 3 plastic Hader clips, displayed the largest stress concentration at the medium implant. With premolar loading, the FPD and overdenture with 3 plastic Hader clips displayed the highest stresses to the ipsilateral terminal implant. With molar loading, the overdenture with 3 ball/O-ring attachments displayed the most uniform stress distribution in the posterior edentulous ridge, with less overloading in the terminal implant. It was concluded that vertical forces applied to the bar-clip overdenture and FPD created immediate stress patterns of greater magnitude and concentration on the ipsilateral implants, whereas the ball/O-ring attachments transferred minimal stress to the implants. The increased cantilever in the FPD caused the highest stresses to the terminal implant.

  7. Multicenter Automatic Defibrillator Implantation Trial-Subcutaneous Implantable Cardioverter Defibrillator (MADIT S-ICD): Design and clinical protocol

    NARCIS (Netherlands)

    Kutyifa, Valentina; Beck, Christopher; Brown, Mary W.; Cannom, David; Daubert, James; Estes, Mark; Greenberg, Henry; Goldenberg, Ilan; Hammes, Stephen; Huang, David; Klein, Helmut; Knops, Reinoud; Kosiborod, Mikhail; Poole, Jeanne; Schuger, Claudio; Singh, Jagmeet P.; Solomon, Scott; Wilber, David; Zareba, Wojciech; Moss, Arthur J.

    2017-01-01

    Patients with diabetes mellitus, prior myocardial infarction, older age, and a relatively preserved left ventricular ejection fraction remain at risk for sudden cardiac death that is potentially amenable by the subcutaneous implantable cardioverter defibrillator with a good risk-benefit profile. The

  8. In vivo osseointegration of dental implants with an antimicrobial peptide coating.

    Science.gov (United States)

    Chen, X; Zhou, X C; Liu, S; Wu, R F; Aparicio, C; Wu, J Y

    2017-05-01

    This study aimed to evaluate the in vivo osseointegration of implants with hydrophobic antimicrobial GL13K-peptide coating in rabbit femoral condyles by micro-CT and histological analysis. Six male Japanese Rabbits (4 months old and weighing 2.5 kg each) were included in this study. Twelve implants (3.75 mm wide, 7 mm long) were randomly distributed in two groups, with six implants in the experimental group coated with GL13K peptide and six implants in the control group without surface coating. Each implant in the test and the control group was randomly implanted in the left or right side of femoral condyles. On one side randomly-selected of the femur, each rabbit received a drill that was left without implant as control for the natural healing of bone. After 3 weeks of healing radiographic evaluation of the implant sites was taken. After 6 weeks of healing, rabbits were sacrificed for evaluation of the short-term osseointegration of the dental implants using digital radiography, micro-CT and histology analysis. To perform evaluation of osseointegration, implant location and group was double blinded for surgeon and histology/radiology researcher. Two rabbits died of wound infection in sites with non-coated implants 2 weeks after surgery. Thus, at least four rabbits per group survived after 6 weeks of healing. The wounds healed without suppuration and inflammation. No implant was loose after 6 weeks of healing. Radiography observations showed good osseointegration after 3 and 6 weeks postoperatively, which proved that the tissues followed a natural healing process. Micro-CT reconstruction and analysis showed that there was no statistically significant difference (P > 0.05) in volume of bone around the implant between implants coated with GL13K peptide and implants without coating. Histomorphometric analysis also showed that the mineralized bone area was no statistically different (P > 0.05) between implants coated with GL13K peptide and

  9. The effect of different atrioventricular delays on left atrium and left atrial appendage function in patients with DDD pacemaker.

    Science.gov (United States)

    Kanadaşı, Mehmet; Caylı, Murat; Sahin, Durmuş Yıldıray; Sen, Ömer; Koç, Mevlüt; Usal, Ayhan; Batur, Mustafa Kemal; Demirtaş, Mustafa

    2011-07-01

    Although it has been known that optimization of atrioventricular delay (AVD) has favorable effect on the left ventricular functions in patients with DDD pacemaker, the effect of different AVDs on left atrium (LA) and left atrial appendage (LAA) functions has not been exactly evaluated. The aim of the present study was to assess the effect of different AVDs on LA and LAA functions in DDD pacemaker implanted patients with atrioventricular block. Forty-eight patients with DDD pacemaker were enrolled into the study. Patients were divided into two groups according to the echocardiographic diastolic function: Group I (normal diastolic function) and Group II (diastolic dysfunction). LAA emptying velocity on pulsed wave Doppler and LAA late systolic wave velocity by using tissue Doppler were recorded. Patients were paced for five successive continuous pacing periods of 10 minutes duration using five selective AVDs (80-250 ms). Significant effect on LA and LAA functions has not been observed by the setting of AVD in Group I. However, when the AVD was gradually shortened form 150 ms to 80 ms, LA and LAA functions gradually decreased in Group II patients. When AVD increased to 200 ms, LA and LAA functions were improved. Further increase in AVD resulted in decreased LA and LAA functions. Setting of AVD has not significant effect on the LA and LAA functions in patients with normal diastolic function, but moderate prolongation of AVD in physiological limits improved LA and LAA functions in DDD pacemaker implanted patients with diastolic dysfunction. © 2011, Wiley Periodicals, Inc.

  10. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  11. Vineberg Procedure by "Vineberg technique modified by Lobo Filho": morbidity and mortality in the imediate post operative period, angiography results and flow analyze of the left internal thoracic artery implanted Procedimento de Vineberg pela técnica de "Vineberg modificada por Lobo Filho": morbi-mortalidade imediata, resultados angiográficos e análise do fluxo na artéria torácica interna esquerda implantada

    Directory of Open Access Journals (Sweden)

    José Glauco Lobo Filho

    2003-10-01

    Full Text Available BACKGROUND: The Vineberg procedure consists in inserting the internal thoracic artery in the ischemic left ventricle muscle. The main question is the ability of this artery to supply adequate flow for the isquemic miocardium. OBJECTIVES: To evaluate angiographic results of Vineberg procedure by the Vineberg technique modified by Lobo Filho, the morbidity and mortality in the imediate post operative period (POP and analysis of the flow of the implanted left internal thoracic artery (LITA at rest and under stress. METHOD: Between September 1999 and April 2002, in our service, eight patients were operated by the above describe technique, in which the implant of the internal thoracic artery in the intimacy of the left ventricle muscle is achieved using a kit used for the introduction of the endocardial leads of pacemakers through the subclavian vein. After six months, they went to angiographic and doppler evaluation. For the LITA study with the doppler we divided the sample into two groups: "Vineberg group", formed by the eigth patients mentioned above; and "control group" formed by 20 patients in whom the LITA recascularize directly the anterior interventricular artery. The angiographic study demonstrade patency of all the grafts in both groups. With the doppler, it was measured the output and flow velocity in the grafts. The analysis of data obtained was taken with T-test for paired and unpaired samples. RESULTS: There were no deaths or complications in imediate POP. The angiographic study showed 100% patency. The total output of Vineberg group was 55% of the ones in the Control group. In both groups, the total output increased with the stress. CONCLUSIONS: The Vineberg technique modified by Lobo Filho can be used with low rates of morbidity and mortality, high index of patency providing a significant blood flow at rest and under stress.INTRODUÇÃO: O procedimento de Vineberg consiste no implante da artéria torácica interna na musculatura isqu

  12. The importance of tricuspid regurgitation and right ventricular overload in ICD/CRT recipients: beside the left, beyond the left.

    Science.gov (United States)

    Fazio, Serafino; Carlomagno, Guido

    2011-10-01

    Device therapy for advanced heart failure has become increasingly employed in the last 10 years. Several retrospective studies have postulated a harmful effect of implantable cardioverter-defibrillator (ICD) lead placement on tricuspid valve function and right heart hemodynamics, in particular among patients with preexisting pulmonary vascular overload and both left and right ventricular remodeling/dysfunction. This functional hypothesis is also supported by long-term clinical follow-up analyses of ICD and cardiac resynchronization therapy recipients. In this viewpoint, we propose that the possibility of worsening tricuspid regurgitation and consequent hemodynamic deterioration following device implantation should be considered in future studies, as well as in the preimplant evaluation of individual candidates among other clinical factors.  ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.

  13. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

  14. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...

  15. Implantable CMOS Biomedical Devices

    Directory of Open Access Journals (Sweden)

    Toshihiko Noda

    2009-11-01

    Full Text Available The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented.

  16. Right colon cancer: Left behind.

    Science.gov (United States)

    Gervaz, P; Usel, M; Rapiti, E; Chappuis, P; Neyroud-Kaspar, I; Bouchardy, C

    2016-09-01

    Prognosis of colon cancer (CC) has steadily improved during the past three decades. This trend, however, may vary according to proximal (right) or distal (left) tumor location. We studied if improvement in survival was greater for left than for right CC. We included all CC recorded at the Geneva population-based registry between 1980 and 2006. We compared patients, tumor and treatment characteristics between left and right CC by logistic regression and compared CC specific survival by Cox models taking into account putative confounders. We also compared changes in survival between CC location in early and late years of observation. Among the 3396 CC patients, 1334 (39%) had right-sided and 2062 (61%) left-sided tumors. In the early 1980s, 5-year specific survival was identical for right and left CCs (49% vs. 48%). During the study period, a dramatic improvement in survival was observed for patients with left-sided cancers (Hazard ratio [HR]: 0.42, 95% confidence interval [CI]: 0.29-0.62, p colon cancer patients, those with right-sided lesions have by far the worse prognosis. Change of strategic management in this subgroup is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Silicone Breast Implants: A Rare Cause of Pleural Effusion

    Directory of Open Access Journals (Sweden)

    Imam H. Shaik

    2015-01-01

    Full Text Available Pleural effusions are one of the rarest complications reported in patients with silicone gel filled breast implants. The silicone implants have potential to provoke chronic inflammation of pleura and subsequent pulmonary complications such as pleural effusion. Herein, we report a 44-year-old female who presented with left sided pleural effusion, six weeks after a silicone breast implantation surgery. The most common infectious, inflammatory, and malignant causes of pleural effusion were excluded with pleural fluid cytology and cultures. With recurrent effusion in the setting of recent surgery, the chemical reaction to silicone breast implants was sought and exploration was performed which revealed foreign body reaction (FBR to silicone material. The symptoms dramatically improved after the explantation.

  18. Complications of Zygomatic Implants: Our Clinical Experience with 4 Cases

    Science.gov (United States)

    Tzerbos, Fotios; Theologie-Lygidakis, Nadia; Fakitsas, Dimitrios; Fakitsas, Ioannis

    2016-01-01

    Zygomatic implants have been used for rehabilitation of the edentulous atrophic maxilla as an alternative to bone grafting for almost two decades resulting in satisfactory clinical outcomes. However, the patients with edentulous atrophic maxilla treated using this technique may present serious complications that could put the prosthetic restoration at risk. Four cases are reported in this paper, one case with a cutaneous fistula in the left zygomatic-orbital area caused by aseptic necrosis at the apical part of the implant, which was treated with the surgical removal of this part, a second case with loss of the right zygomatic implant due to failure of osseointegration and two cases of periimplantitis that resulted in partial and complete removal of the implant, respectively. All patients who had complications were treated without compromising the restoration which remained functional after appropriately modified treatment. PMID:27847399

  19. Challenging pacemaker implantation in a patient with acquired dextrocardia after pneumonectomy, skoliosis and complete heart block.

    Science.gov (United States)

    Hamm, Karsten; Haghi, Dariush; Borggrefe, Martin; Kuschyk, Jürgen

    2010-09-01

    Pacemaker implantation after pneumonectomy is rare and there have been no previously reported cases of acquired dextrocardia after implantation. The authors report the case of a pacemaker implantation in a patient with complete heart block, impaired left ventricular function, sclerosis of heart valves and radiation induced vasculopathy resulting in ostial stenosis of the right coronary artery 30 years after radiochemotherapy in childhood. Acquired dextrocardia after right pneumonectomy for mucoepidermoid carcinoma made implantation a challenge due to and poor fluoroscopic visualization of the heart and increased radio-opacity of the right chest when compared to congenital dextrocardia.

  20. Left atrial appendage occlusion: A better alternative to anticoagulation?

    Science.gov (United States)

    Akin, Ibrahim; Nienaber, Christoph A

    2017-02-26

    Non-valvular atrial fibrillation is associated with a significantly increased risk of embolic stroke due to blood clot forming predominantly in the left atrial appendage (LAA). Preventive measures to avoid embolic events are permanent administration of anticoagulants or surgical closure of the LAA. Various clinical trials provide evidence about safety, effectiveness and therapeutic success of LAA occlusion using various cardiac occluder devices. The use of such implants for interventional closure of the LAA is likely to become a valuable alternative for stroke prevention, especially in patients with contraindication for oral anticoagulation as safety, clinical benefit and cost-effectiveness of LAA occlusion has recently been demonstrated.

  1. Severe metallosis and elevated chromium in serum following implantation of the joint unloading implant system.

    Science.gov (United States)

    Wolff, Matthias; Haasper, Carl; Zahar, Akos; Gauck, Christian; Gehrke, Thorsten; Citak, Mustafa

    2017-12-01

    In recent years, the minimally invasive joint-preserving implant system has been developed. The main goal of this device is to unload the medial knee compartment without affecting the lateral compartment. The current authors describe a severe metallosis and elevated chromium in serum following implantation of the joint unloading implant system of a 50-year-old male patient, presented to our hospital 3 years after implantation of a KineSpring System into his left knee due to unicompartmental medial osteoarthritis (OA) in an external hospital. Radiographs showed radiological signs for loosening of the screws in the tibia and a progressive OA on the medial and patellofemoral compartments. Revision surgery with removing of the unloading device was performed at our hospital. The intraoperative situs presented a severe metallosis around the device. Five days after revision surgery, the laboratory parameters revealed an elevated value for chromium in serum, while nickel and cobalt values in serum were normal. Reliable clinical data about the long-term results of the KineSpring System is desperately needed. Further studies are warranted to work out the effects of cobalt and chromium levels and further side effects following the implantation of the extra-articular absorber system.

  2. Length of the drilling holes of zygomatic implants inserted with the standard technique or a revised method: a comparative study in dry skulls

    OpenAIRE

    Corvello, Paula; Montagner, Aline; Batista, Felipe; Smidt, Ricardo; Shinkai, Rosemary Sadami Arai

    2011-01-01

    AIM: This study aimed to evaluate the length of the holes drilled for the placement of zygomatic implants using two surgical techniques: the original Brånemark and the Exteriorized (extrasinus) protocols. The most frequent implant length used and position where the implants emerged in the zygomatic bone were recorded. MATERIALS AND METHODS: Both surgical techniques for inserting zygomatic implants were performed on the right and left sides of 18 dry adult skulls. The depth of the drilling hol...

  3. Left atrial appendage occlusion: pilot study of a fourth-generation, minimally invasive device.

    Science.gov (United States)

    Fumoto, Hideyuki; Gillinov, A Marc; Saraiva, Roberto M; Horai, Tetsuya; Anzai, Tomohiro; Takaseya, Tohru; Shiose, Akira; Arakawa, Yoko; Vince, D Geoffrey; Dessoffy, Raymond; Fukamachi, Kiyotaka

    2012-01-01

    Exclusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The aim of this study was to evaluate the feasibility and efficacy of a fourth-generation atrial exclusion device developed for minimally invasive applications. The novel atrial exclusion device consists of two polymer beams and two elastomeric bands that connect the two beams at either end. Fifteen mongrel dogs were implanted with the device at the base of the left atrial appendage through a median sternotomy and were evaluated at 30 (n = 7), 90 (n = 6), and 180 (n = 2) days after implantation by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histology. Left atrial appendage exclusion was completed without hemodynamic instability. Coronary angiography revealed that the left circumflex artery was patent in all cases. A new endothelial tissue layer developed, as expected, on the occluded orifice of the left atrium. This novel atrial exclusion device achieved easy, reliable, and safe exclusion of the left atrial appendage, with favorable histological results in a canine model for up to 6 months. Clinical application could provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

  4. Biologic response of immediately versus delayed loaded implants supporting ill-fitting prostheses: an animal study.

    Science.gov (United States)

    Duyck, Joke; Vrielinck, Luc; Lambrichts, Ivo; Abe, Yasuhiko; Schepers, Serge; Politis, Constantin; Naert, Ignace

    2005-01-01

    Computer-assisted preoperative implant planning and transfer toward the patient allow the production of a prosthesis prior to surgery. This implies that the prosthesis can be installed immediately following implant insertion. An inherent disadvantage of this is a cumulated error, which can lead to prosthesis misfit owing to topographic deviations of the planned versus the installed implants. The aim of this study was to determine whether prosthesis misfit is compromising the osseointegration of immediately versus delayed loaded implants and whether freshly installed implants adapt to the prosthesis. In each of five New Zealand White rabbits, two experimental conditions were compared. One tibia harbored the so-called test implant, which originally showed a vertical misfit of about 500 microm with the prosthesis to which it was tightened immediately after implant installation. The control implant was installed in the other tibia and was allowed to heal during 9 weeks before the prosthesis with the vertical misfit of about 500 microm was connected to it. The prostheses were left in place for 12 weeks, after which the animals were sacrificed. All implants healed uneventfully. There were no statistically significant differences between the biologic responses of test and control implants. With a three-dimensional laser scanner, significantly more displacement of the test implants toward the prostheses was observed compared with the control implants. This led to a significant decrease in prosthesis misfit for the test implants compared with the control implants. This study indicates that prosthesis misfit does not per se lead to biologic failure of immediately loaded or of already osseointegrated implants. In addition, immediately loaded implants seem to topographically adapt to the prosthesis, thereby minimizing the existing misfit.

  5. Histological and Histomorphometrical Analysis on a Loaded Implant With Platform-Switching and Conical Connection: A Case Report.

    Science.gov (United States)

    Iezzi, Giovanna; Iaculli, Flavia; Calcaterra, Roberta; Piattelli, Adriano; Di Girolamo, Michele; Baggi, Luigi

    2017-06-01

    The association of Morse taper implant-abutment design with the use of a smaller abutment diameter (platform switching) may improve dental implant success rate and prevent peri-implant bone loss. The aim of the present study was to histologically and histomorphometrically evaluate the behavior of peri-implant tissues around an implant with a conical connection associated with platform switching. A platform-switched Morse-cone connection implant was inserted in the left posterior mandible of a 61-year-old patient. The implant was inserted at the level of the alveolar crest. After 11 months from placement and 6 months of loading, the implant was retrieved for psychological reasons and processed for histological evaluation. The retrieved implant was wholly surrounded by bone tissue, except for a small area in the apical portion. At higher magnification, in the coronal portion of the implant, it was possible to observe bone directly at the implant platform level. No resorption of the coronal bone was present, except for 0.2 mm on the vestibular aspect. Crestally, bone remodeling with areas of newly formed bone was detected; the bone-implant contact was 73.9%. Apposition of bone was detected even upon the platform. Peri-implant crestal bone preservation can be achieved with the combination of Morse taper conical internal implant-abutment connection with the use of a smaller abutment diameter (platform-switching).

  6. Ventricular fibrillation induced by coagulating mode bipolar electrocautery during pacemaker implantation in Myotonic Dystrophy type 1 patient

    OpenAIRE

    Russo, Vincenzo; Rago, Anna; Di Meo, Federica; CIOPPA, NADIA DELLA; PAPA, ANDREA ANTONIO; Russo, Maria Giovanna; Nigro, Gerardo

    2014-01-01

    The occurrence of ventricular fibrillation, induced by bipolar electrocautery during elective dual chamber pacemaker implantation, is reported in a patient affected by Myotonic Distrophy type 1 with normal left ventricular ejection fraction

  7. Ventricular fibrillation induced by coagulating mode bipolar electrocautery during pacemaker implantation in Myotonic Dystrophy type 1 patient.

    Science.gov (United States)

    Russo, Vincenzo; Rago, Anna; DI Meo, Federica; Cioppa, Nadia Della; Papa, Andrea Antonio; Russo, Maria Giovanna; Nigro, Gerardo

    2014-12-01

    The occurrence of ventricular fibrillation, induced by bipolar electrocautery during elective dual chamber pacemaker implantation, is reported in a patient affected by Myotonic Distrophy type 1 with normal left ventricular ejection fraction.

  8. Dental Implant Systems

    Science.gov (United States)

    Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

    2010-01-01

    Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

  9. Implants in the hand; Implantate der Hand

    Energy Technology Data Exchange (ETDEWEB)

    Wanivenhaus, A. [Medizinische Universitaet, Universitaetsklinik fuer Orthopaedie, Wien (Austria)

    2006-09-15

    Increasingly, implants in the region of hand joints and the wrist represent an alternative for the treatment of post-traumatic, inflamed, or degenerative joint damage. The diversity of hand functions also results in varied solutions, which are effective in their stability, mobility, and distraction. Different materials are necessary for this, and they require subtile radiological control. The native X-ray represents the substantial method to observe migration of the implants. Each interface between titanium, ceramic, zirconium, pyrocarbon, and silicon to the bone has to be assessed differently in order to obtain a relevant statement. The finger joints and to a limited extent the wrist represent the artificial joints with limited alternative therapy. Other implants in the hand should only be applied after strict indication and patient compliance, as arthrodesis and resection arthroplasty have shown very good long-term results. (orig.) [German] Implantate im Bereich der Gelenke der Hand und des Handgelenks stellen zunehmend Alternativen bei der Versorgung posttraumatischer, entzuendlicher oder degenerativer Gelenkschaeden dar. Die Vielfalt der Handfunktionen fuehrt auch zu unterschiedlichen Loesungen, die durch Stabilitaet, Mobilitaet und Distraktion wirksam werden. Dafuer sind unterschiedliche Materialien erforderlich, die eine subtile radiologische Kontrolle erfordern. Das Nativroentgen stellt das wesentlichste Verfahren zur Verlaufsbeobachtung von Implantaten dar. Das Interface zwischen Titan, Keramik, Zirkonium, Pyrokarbon und Silikon zum Knochen muss unterschiedlich bewertet werden, um relevante Aussagen treffen zu koennen. Die Fingergelenke und in begrenztem Ausmass auch das Handgelenk stellen Kunstgelenke mit geringen Alternativtherapiemoeglichkeiten dar. Die uebrigen Implantate der Hand sollten nur bei strenger Indikationsstellung und hoher Patientencompliance Anwendung finden, da Arthrodese oder Resektionsarthroplastik gute Langzeitresultate aufweisen. (orig.)

  10. Septic lens implantation syndrome in a cat.

    Science.gov (United States)

    Dalesandro, Nicole; Stiles, Jean; Miller, Margaret

    2011-09-01

    A 13-year-old female spayed domestic shorthair cat was presented initially for a change in the appearance of the left eye. On initial examination, a small penetrating wound was suspected as the cause for a corneal scar, an anterior cortical incipient cataract and mild iritis. The cat was not re-presented until 1 year later at which time ocular pain was marked. Severe anterior uveitis and glaucoma were diagnosed and the eye enucleated. Histopathology documented intralenticular coccoid bacteria and septic lens implantation syndrome. © 2011 American College of Veterinary Ophthalmologists.

  11. Silicon induces minimal thromboinflammatory response during 28-day intravascular implant testing

    Science.gov (United States)

    Melvin, Melissa E.; Fissell, William H; Roy, Shuvo; Brown, David L

    2015-01-01

    Microelectromechanical systems (MEMS) are used to machine miniaturized implantable medical devices. Our group has used MEMS technology to develop hemofiltration membranes for use in renal replacement therapy which possess enhanced selectivity and permeability. The use of silicon in blood-contacting environments may be limited, however, due to contact activation of the coagulation cascade by silicon which form the surface oxides in atmospheric conditions. As well, reports of long-term biocompatibility of blood-contacting silicon devices are lacking. The aims of this pilot study were: 1) to develop a model for investigating the effects of intravascular implants and 2) to characterize the degree of thrombosis and tissue inflammation incited by prolonged implantation of silicon materials. Silicon implants with and without polyethylene glycol (PEG) coatings were surgically implanted transluminally through rat femoral veins. Gore-Tex and stainless steel implants served as controls. Implants were left in vivo for four weeks. All femoral veins remained patent. Veins associated with silicon implants exhibited rare thrombi and occasional mild perivascular inflammation. In contrast, Gore-Tex and stainless steel controls caused moderate vein thrombosis and provoked a moderate to marked cellular infiltrate. Under scanning electron microscopy, bare silicon implants were found to have significant adherent microthrombi, while PEG-treated implants showed no evidence of thrombi. PEG-treated silicon appears to be biocompatible and holds potential as an excellent material with which to construct an implantable, miniaturized hemofiltration membrane. PMID:20431483

  12. Smoking and dental implants

    OpenAIRE

    Kasat, V.; Ladda, R

    2012-01-01

    Smoking is a prevalent behaviour in the population. The aim of this review is to bring to light the effects of smoking on dental implants. These facts will assist dental professionals when implants are planned in tobacco users. A search of “PubMed” was made with the key words “dental implant,” “nicotine,” “smoking,” “tobacco,” and “osseointegration.” Also, publications on tobacco control by the Government of India were considered. For review, only those articles published from 1988 onward in ...

  13. Optimization of dental implantation

    Science.gov (United States)

    Dol, Aleksandr V.; Ivanov, Dmitriy V.

    2017-02-01

    Modern dentistry can not exist without dental implantation. This work is devoted to study of the "bone-implant" system and to optimization of dental prostheses installation. Modern non-invasive methods such as MRI an 3D-scanning as well as numerical calculations and 3D-prototyping allow to optimize all of stages of dental prosthetics. An integrated approach to the planning of implant surgery can significantly reduce the risk of complications in the first few days after treatment, and throughout the period of operation of the prosthesis.

  14. Producing The New Regressive Left

    DEFF Research Database (Denmark)

    Crone, Christine

    to be a committed artist, and how that translates into supporting al-Assad’s rule in Syria; the Ramadan programme Harrir Aqlak’s attempt to relaunch an intellectual renaissance and to promote religious pluralism; and finally, al-Mayadeen’s cooperation with the pan-Latin American TV station TeleSur and its ambitions...... becomes clear from the analytical chapters is the emergence of the new cross-ideological alliance of The New Regressive Left. This emerging coalition between Shia Muslims, religious minorities, parts of the Arab Left, secular cultural producers, and the remnants of the political,strategic resistance...

  15. DEALING WITH DENTAL IMPLANT FAILURES

    Science.gov (United States)

    Levin, Liran

    2008-01-01

    An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options. When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them. PMID:19089213

  16. Dealing with dental implant failures

    Directory of Open Access Journals (Sweden)

    Liran Levin

    2008-06-01

    Full Text Available An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options.When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them.

  17. Photoelastic Stress Analysis Surrounding Implant-Supported Prosthesis and Alveolar Ridge on Mandibular Overdentures

    Directory of Open Access Journals (Sweden)

    Dorival Pedroso da Silva

    2010-01-01

    Full Text Available The purpose of this research was to evaluate the maximum stress around osseointegrated implants and alveolar ridge, in a mandible with left partial resection through a photoelastic mandibular model. The first group consisted of two implants: traditional model (T, implants placed in the position of both canines; fulcrum model (F, implants placed in the position of left canine CL and right lateral incisor LiR. Both models linked through a bar and clips. The second group was consisted of three implants, with implants placed in the position of both canines (CR and CL and the right lateral incisor (LiR, which composed four groups: (1 model with 3 “O” rings, (2 model 2 ERAs, bar with clips, (3 model 2 ERAs bar without clips; (4 model “O” ring bar and ERA. An axial and an oblique load of 6.8 kgf was applied on a overdenture at the 1st Pm, 2nd Pm, and 1st M. Results showed that the area around the left canine (CL was practically free of stress; the left lateral incisor (LiL developed only small tensions, and low stress in all the other cases; the right canine tooth suffered the largest concentrations of stress, mainly with the ERA retention mechanism.

  18. Risks of Breast Implants

    Science.gov (United States)

    ... Tissue Disease The FDA has not detected any association between silicone gel-filled breast implants and connective tissue disease, breast cancer, or reproductive problems. In order to rule out ...

  19. Superelastic Orthopedic Implant Coatings

    Science.gov (United States)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  20. Implantable Cardioverter Defibrillator

    Science.gov (United States)

    ... for example, iPods) Household appliances, such as microwave ovens High-tension wires Metal detectors Industrial welders Electrical ... of Having an Implantable Cardioverter Defibrillator? An ICD works well at detecting and stopping certain life-threatening ...

  1. Ion Implantation of Polymers

    DEFF Research Database (Denmark)

    Popok, Vladimir

    2012-01-01

    The current paper presents a state-of-the-art review in the field of ion implantation of polymers. Numerous published studies of polymers modified by ion beams are analysed. General aspects of ion stopping, latent track formation and changes of structure and composition of organic materials...... are discussed. Related to that, the effects of radiothermolysis, degassing and carbonisation are considered. Specificity of depth distributions of implanted into polymers impurities is analysed and the case of high-fluence implantation is emphasised. Within rather broad topic of ion bombardment, the focus...... is put on the low-energy implantation of metal ions causing the nucleation and growth of nanoparticles in the shallow polymer layers. Electrical, optical and magnetic properties of metal/polymer composites are under the discussion and the approaches towards practical applications are overviewed....

  2. Analgesia in implant dentistry.

    Science.gov (United States)

    Garg, Arun

    2011-06-01

    This month's feature article offers a review of analgesics commonly used in implant dentistry. While the placement of an implant is certainly of the utmost importance to the practitioner, ensuring adequate pain control during and after the procedure is one of the more important aspects to the patient. Selecting the most effective and appropriate agent to control swelling, pain, and anxiety requires a broad knowledge of these classes of medication.

  3. Biomaterials in cochlear implants

    OpenAIRE

    Lenarz, Thomas; Stöver, Timo

    2011-01-01

    The cochlear implant (CI) represents, for almost 25 years now, the gold standard in the treatment of children born deaf and for postlingually deafened adults. These devices thus constitute the greatest success story in the field of ‘neurobionic’ prostheses. Their (now routine) fitting in adults, and especially in young children and even babies, places exacting demands on these implants, particularly with regard to the biocompatibility of a CI’s surface components. Furthermore, certain parts o...

  4. Ion implantation. L'implantation ionique

    Energy Technology Data Exchange (ETDEWEB)

    Tousset, J. (Lyon-1 Univ., 69 - Villeurbanne (FR). Inst. de Physique Nucleaire)

    1989-10-01

    The ion implantation technique which has been used in the semiconductor industry for more than 20 years, is now gradually becoming adopted as a surface treatment process for various materials, particularly metals and ceramics. The aim is to improve wear, fatigue and or corrosion resistance. Its characteristic features are the absence of an interface between the modified surface layer and the substrate, and the conservation of the initial component dimensions and volume, since the process does not involve heating. Another characteristic concerns the nature of the chemical species created in the treated zone, whose formation does not necessarily correspond to thermodynamic equilibrum, and which can be amorphous or metastable. In its simple form, the technique is limited due to the low thickness affected. This paper definies the basic principles of the technique, the methods used for characterising the implanted zone, and the present and potential fields of application. 13 refs.

  5. Contraceptive implants: current perspectives

    Directory of Open Access Journals (Sweden)

    Rowlands S

    2014-09-01

    Full Text Available Sam Rowlands,1,2 Stephen Searle3 1Centre of Postgraduate Medical Research and Education, School of Health and Social Care, Bournemouth University, Bournemouth, United Kingdom; 2Dorset HealthCare, Bournemouth, United Kingdom; 3Sexual Health Services, Chesterfield, United KingdomAbstract: Progestin-only contraceptive implants are a highly cost-effective form of long-acting reversible contraception. They are the most effective reversible contraceptives and are of a similar effectiveness to sterilization. Pregnancies are rare in women using this method of contraception, and those that do occur must be fully investigated, with an ultrasound scan of the arm and serum etonogestrel level if the implant cannot be located. There are very few contraindications to use of implants, and they have an excellent safety profile. Both acceptability and continuation with the method are high. Noncontraceptive benefits include improvements in dysmenorrhea, ovulatory pain, and endometriosis. Problematic bleeding is a relatively common adverse effect that must be covered in preinsertion information-giving and supported adequately if it occurs. Recognized training for both insertion and removal should be undertaken. Care needs to be taken at both insertion and removal to avoid neurovascular injury. Implants should always be palpable; if they are not, noninsertion should be assumed until disproven. Etonogestrel implants are now radiopaque, which aids localization. Anticipated difficult removals should be performed by specially trained experts. Keywords: contraceptive, subdermal implant, etonogestrel, levonorgestrel, progestin-only, long-acting reversible contraception

  6. Biomaterials in cochlear implants

    Science.gov (United States)

    Stöver, Timo; Lenarz, Thomas

    2011-01-01

    The cochlear implant (CI) represents, for almost 25 years now, the gold standard in the treatment of children born deaf and for postlingually deafened adults. These devices thus constitute the greatest success story in the field of ‘neurobionic’ prostheses. Their (now routine) fitting in adults, and especially in young children and even babies, places exacting demands on these implants, particularly with regard to the biocompatibility of a CI’s surface components. Furthermore, certain parts of the implant face considerable mechanical challenges, such as the need for the electrode array to be flexible and resistant to breakage, and for the implant casing to be able to withstand external forces. As these implants are in the immediate vicinity of the middle-ear mucosa and of the junction to the perilymph of the cochlea, the risk exists – at least in principle – that bacteria may spread along the electrode array into the cochlea. The wide-ranging requirements made of the CI in terms of biocompatibility and the electrode mechanism mean that there is still further scope – despite the fact that CIs are already technically highly sophisticated – for ongoing improvements to the properties of these implants and their constituent materials, thus enhancing the effectiveness of these devices. This paper will therefore discuss fundamental material aspects of CIs as well as the potential for their future development. PMID:22073103

  7. Comparative radiographic and resonance frequency analyses of the peri-implant tissue after dental implants placement using flap and flapless techniques: an experimental study on domestic pigs.

    Science.gov (United States)

    Vlahović, Zoran; Mihailović, Branko; Lazić, Zoran; Golubović, Mileta

    2013-06-01

    Flapless implant surgery has become very important issue during recent years, mostly thanks to computerization of dentistry and software planning of dental implants placements. The aim of this study was to compare flap and flapless surgical techniques for implant placement through radiographic and radiofrequency analyses. The experiment was made in five domestic pigs. Nine weeks following domestic pigs teeth extraction, implants were placed, on the right side using surgical technique flap, and flapless on the left side. Digital dental Xrays were applied to determine primary dental implant stability quality (ISQ). At certain intervals, not later than three months, the experimental animals were sacrificed, and just before it, control X-rays were applied to measure dental implants stability. Radiographic analysis showed that peri-implant bone resorption in the first 4 weeks following placement implants with flap and flapless surgical techniques was negligible. After the 3 months, mean value of peri-implant bone resorption of the implants placed using flap tehnique was 1.86 mm, and of those placed using flapless tehnique was 1.13 mm. In relation to the primary dental implant stability in the first and second week there was an expected decrease in ISQ values, but it was less expressed in the dental implants placed using the flapless technique. In the third week the ISQ values were increased in the dental implants placed by using both techniques, but the increase in flapless implant placement was higher (7.4 ISQ) than in flap implant placement (1.5 ISQ). The upward trend continued in a 4-week period, and after 3 months the dental implant stability values in the implants placed using flap technique were higher than the primary stability for 7.1 ISQ, and in the implants placed using flapless technique were higher comparing to the primary stability for 10.1 ISQ units. Based on the results of radiographic and resonance frequency analyses it can be concluded that the flapless

  8. Comparative radiographic and resonance frequency analyses of the peri-implant tissue after dental implants placement using flap and flapless techniques: An experimental study on domestic pigs

    Directory of Open Access Journals (Sweden)

    Vlahović Zoran

    2013-01-01

    Full Text Available Background/Aim. Flapless implant surgery has become very important issue during recent years, mostly thanks to computerization of dentistry and software planning of dental implants placements. The aim of this study was to compare flap and flapless surgical techniques for implant placement through radiographic and radiofrequency analyses. Methods. The experiment was made in five domestic pigs. Nine weeks following domestic pigs teeth extraction, implants were placed, on the right side using surgical technique flap, and flapless on the left side. Digital dental Xrays were applied to determine primary dental implant stability quality (ISQ. At certain intervals, not later than three months, the experimental animals were sacrificed, and just before it, control X-rays were applied to measure dental implants stability. Results. Radiographic analysis showed that peri-implant bone resorption in the first 4 weeks following placement implants with flap and flapless surgical techniques was negligible. After the 3 months, mean value of peri-implant bone resorption of the implants placed using flap technique was 1.86 mm, and of those placed using flapless technique was 1.13 mm. In relation to the primary dental implant stability in the first and second week there was an expected decrease in ISQ values, but it was less expressed in the dental implants placed using the flapless technique. In the third week the ISQ values were increased in the dental implants placed by using both techniques, but the increase in flapless implant placement was higher (7.4 ISQ than in flap implant placement (1.5 ISQ. The upward trend continued in a 4- week period, and after 3 months the dental implant stability values in the implants placed using flap technique were higher than the primary stability for 7.1 ISQ, and in the implants placed using flapless technique were higher comparing to the primary stability for 10.1 ISQ units. Conclusion. Based on the results of radiographic and

  9. Left Ventricular Assist Devices for Lifelong Support.

    Science.gov (United States)

    Pinney, Sean P; Anyanwu, Anelechi C; Lala, Anuradha; Teuteberg, Jeffrey J; Uriel, Nir; Mehra, Mandeep R

    2017-06-13

    Continuous-flow left ventricular assist devices (LVADs) have revolutionized advanced heart failure care. These compact, fully implantable heart pumps are capable of providing meaningful increases in survival, functional capacity, and quality of life. Implantation volumes continue to grow, but several challenges remain to be overcome before LVADs will be considered as the therapy of choice for all patients with advanced heart failure. They must be able to consistently extend survival for the long term (7 to 10 years), rather than the midterm (3 to 5 years) more typical of contemporary devices; they must incorporate design elements that reduce shear stress and avoid stasis to reduce the frequent adverse events of bleeding, stroke, and pump thrombosis; and they must become more cost-effective. The advancements in engineering, implantation technique, and medical management detailed in this review will highlight the progress made toward achieving lifelong LVAD support and the challenges that remain. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. Delayed loss of hearing after hearing preservation cochlear implantation: Human temporal bone pathology and implications for etiology.

    Science.gov (United States)

    Quesnel, Alicia M; Nakajima, Hideko Heidi; Rosowski, John J; Hansen, Marlan R; Gantz, Bruce J; Nadol, Joseph B

    2016-03-01

    After initially successful preservation of residual hearing with cochlear implantation, some patients experience subsequent delayed hearing loss. The etiology of such delayed hearing loss is unknown. Human temporal bone pathology is critically important in investigating the etiology, and directing future efforts to maximize long term hearing preservation in cochlear implant patients. Here we present the temporal bone pathology from a patient implanted during life with an Iowa/Nucleus Hybrid S8 implant, with initially preserved residual hearing and subsequent hearing loss. Both temporal bones were removed for histologic processing and evaluated. Complete clinical and audiologic records were available. He had bilateral symmetric high frequency severe to profound hearing loss prior to implantation. Since he was implanted unilaterally, the unimplanted ear was presumed to be representative of the pre-implantation pathology related to his hearing loss. The implanted and contralateral unimplanted temporal bones both showed complete degeneration of inner hair cells and outer hair cells in the basal half of the cochleae, and only mild patchy loss of inner hair cells and outer hair cells in the apical half. The total spiral ganglion neuron counts were similar in both ears: 15,138 (56% of normal for age) in the unimplanted right ear and 13,722 (51% of normal for age) in the implanted left ear. In the basal turn of the implanted left cochlea, loose fibrous tissue and new bone formation filled the scala tympani, and part of the scala vestibuli. Delayed loss of initially preserved hearing after cochlear implantation was not explained by additional post-implantation degeneration of hair cells or spiral ganglion neurons in this patient. Decreased compliance at the round window and increased damping in the scala tympani due to intracochlear fibrosis and new bone formation might explain part of the post-implantation hearing loss. Reduction of the inflammatory and immune response to

  11. Short dental implants: an emerging concept in implant treatment.

    Science.gov (United States)

    Al-Hashedi, Ashwaq Ali; Taiyeb Ali, Tara Bai; Yunus, Norsiah

    2014-06-01

    Short implants have been advocated as a treatment option in many clinical situations where the use of conventional implants is limited. This review outlines the effectiveness and clinical outcomes of using short implants as a valid treatment option in the rehabilitation of edentulous atrophic alveolar ridges. Initially, an electronic search was performed on the following databases: Medline, PubMed, Embase, Cochrane Database of Systematic Reviews, and DARE using key words from January 1990 until May 2012. An additional hand search was included for the relevant articles in the following journals: International Journal of Oral and Maxillofacial Implants, Clinical Oral Implants Research, Journal of Clinical Periodontology, International Journal of Periodontics, Journal of Periodontology, and Clinical Implant Dentistry and Related Research. Any relevant papers from the journals' references were hand searched. Articles were included if they provided detailed data on implant length, reported survival rates, mentioned measures for implant failure, were in the English language, involved human subjects, and researched implants inserted in healed atrophic ridges with a follow-up period of at least 1 year after implant-prosthesis loading. Short implants demonstrated a high rate of success in the replacement of missing teeth in especially atrophic alveolar ridges. The advanced technology and improvement of the implant surfaces have encouraged the success of short implants to a comparable level to that of standard implants. However, further randomized controlled clinical trials and prospective studies with longer follow-up periods are needed.

  12. The influence of right ventricular apical pacing on left atrial volume in patients with normal left ventricular function

    Directory of Open Access Journals (Sweden)

    AR Moaref1

    2008-03-01

    Full Text Available Background: Right ventricular apical (RVA pacing has been reported to induce several deleterious effects particularly in the presence of structural heart disease but can also involve patients with normal left ventricular (LV function. Left atrial (LA enlargement is one of these effects, but the majority of studies have measured LA dimension rather than volume.Objective: The present prospective study was designed to assess the effect of RVA pacing on LA volume in patients with normal LV function.Patients and Methods: The study comprised 41 consecutive patients with LV ejection fraction ≥ 45% and LV end diastolic dimension ≤ 56 mm who underwent single-or dual- chamber pacemaker implantation in RVA and followed for LA volume measurement and pacemaker analysis at least during the ensuing 4.2 months. Results: In all, 21 patients were excluded from the study due to five spontaneous wide QRS complex (≥120msec, one recent acute coronary syndrome,one significant valvular heart disease, three pacing frequency <90%, eight death or losing follow up in three cases. In remaining 20 patients, LA volume ragned from 21 to 54 mm3 with mean of 37.3±9.7 mm3 prior to pacemaker implantation that increased to 31 to 103 mm3 (54.3±17.0 during follow-up (P<0.001.Conclusion: RVA pacing might lead to an increase in LA volume even in patients with normal LV function.

  13. What Research Tells Us About Left Handedness.

    Science.gov (United States)

    Arnold, Rita

    Left handed people have had bad publicity throughout history, and the resulting myths and disadvantages of left handedness have often not been properly dealt with in the classroom. Our language itself maintains a bias against the left, and many other cultures have defined the left as disreputable. Today's life style also provides many physical…

  14. [Histological observation of microscrews anchorage implant-bone interface loaded with different orthodontic condition].

    Science.gov (United States)

    Jiang, Xiao-hong; Zhang, Yan; Han, Xue; Liu, Ji-hui; Ma, Tian-chi

    2008-12-01

    To study the stability of the microscrew implant anchorage under different loading force and different timing and observe the integration of the implant to the bone. Thirty-six titanium alloy microscrew implants were implanted into three dogs' maxilla and mandible. The implants were divided into two groups: one with immediate implant loading and the other with delayed implant loading. In the delayed loading group, the microscrew implants that were implanted into the right maxilla and mandible were unloaded temporarily. Four weeks later, these dogs, together with the immediate loading group, whose microscrew implants were implanted into the left maxilla and mandible, were loaded at the same time. The mesial screw was unloaded. Two distal screws were loaded with force: 1.96N on the maxilla, and 3.92N on the mandibular. After 12 weeks, the dogs were sacrificed. The specimen were fixed and decalcified. Subsequently, immunohistochemical stain for BMP-2 was employed. The specimen were assessed with image analysis system to analyze the average grey scale. The data were analyzed using Student's t test and one-way ANOVA with SPSS 10.0 software package. BMP-2 staining showed that there was significant difference between the immediate loading group(1.96N,3.92N), delayed loading group(1.96N,3.92N) and non-loading group at average gray value (P0.05). Both the immediate and the delayed implant loading can strengthen the attachment and integration of the implant to the bone. The timing of the loading force has no significant impact on the stabilization of the microscrew implants.

  15. Cataract surgery following KAMRA presbyopic implant

    Directory of Open Access Journals (Sweden)

    Tan TE

    2013-09-01

    Full Text Available Tien-En Tan,1,2 Jodhbir S Mehta2–4 1Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore National Eye Centre, Singapore; 3Singapore Eye Research Institute, Singapore; 4Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore Abstract: Intrastromal corneal inlays are an emerging treatment for presbyopic patients. The KAMRA™ small aperture inlay was the first such inlay to receive Conformité Européenne (CE marking in 2005. It has been shown to improve uncorrected near and intermediate visual acuity without adversely affecting uncorrected distance visual acuity. Due to the age of presbyopic patients, they may eventually develop cataracts. In two such cases, we found that cataract surgery with the KAMRA implant left in place was not technically more difficult, and that the surgical procedure could be improved by additional ocular rotations to improve visualization. Biometry readings were reliable, and it appeared that the SRK/T formula was accurate for calculation of intraocular lens power. Cataract surgery with the KAMRA implant left in situ is a viable option for patients. Keywords: cataract surgery, KAMRA, corneal inlay, AcuTarget, presbyopia

  16. Silicon defects characterization for low temperature ion implantation and RTA process

    Energy Technology Data Exchange (ETDEWEB)

    Martirani Paolillo, Diego; Margutti, Giovanni; De Biase, Marco [LFoundry s.r.l. Avezzano (Italy); Barozzi, Mario; Giubertoni, Damiano [Fondazione Bruno Kessler, Trento (Italy); Spaggiari, Claudio [Axcelis Technologies Srl, Agrate Brianza (Italy)

    2015-12-15

    In the last years a lot of effort has been directed in order to reduce silicon defects eventually formed during the ion implantation/anneal sequence used in the fabrication of CMOS devices. In this work we explored the effect of ion implant dose rate and temperature on the formation of silicon defects for high fluence {sup 49}BF{sub 2} implantations. The considered processes (implantation and annealing) conditions are those typically used to form the source/drain regions of p-channel transistors in the submicron technology node and will be detailed in the document. Characterization of implant damage and extended silicon defects left after anneal has been performed by TEM. Dopant distribution and dopant activation has been investigated by SIMS and SRP analysis. We have verified that implant dose rate and temperature modulate the thickness of the amorphous silicon observed after implant, as well as the concentrations of silicon defects left after anneal. Effect of high dose rate low temperature implantation on product device was also evaluated, showing a reduction of leakage current on p-channel transistors. Experimental set up, results and possible explanation will be reported and discussed in the paper.

  17. Brain plasticity and cortical correlates of osseoperception revealed by punctate mechanical stimulation of osseointegrated oral implants during fMRI.

    Science.gov (United States)

    Habre-Hallage, Pascale; Dricot, Laurence; Jacobs, Reinhilde; van Steenberghe, Daniel; Reychler, Hervé; Grandin, Cecile B

    2012-01-01

    Our aim was to unveil the cortical neural correlates of osseoperception, i.e. the tactile sensation perceived when loading a bone-anchored implant, by taking oral implants as a model. This was performed in a cross-sectional observational study with 9 volunteering patients and 10 age-matched controls. For each patient, functional magnetic resonance imaging (fRMI) recordings were made during punctate mechanical stimulation of either teeth or osseointegrated implants in the maxillary incisor area. During fMRI recordings, 1 Hz punctate tactile stimuli were applied either on a maxillary left central incisor, canine tooth or central incisor implant. A block design paradigm was used to stimulate, in 9 patients, maxillary left central incisor implants (I21-p) and maxillary left canines (T23-p). In 10 control subjects, maxillary left central incisors and canines (T21-c, T23-c) were stimulated. Random effect group analyses were performed for each stimulated site, and differences in cortical activity elicited when loading teeth or implants were examined using ANOVA. As a group, patients activated somatosensory area S2 bilaterally for both I21 and T23, while controls activated S1 and S2 bilaterally for T21 and T23. At an individual level, S1 was activated by 4/9 implants, mainly on the ipsilateral side. The stimulated implants activated a larger bilateral cortical network outside the somatosensory areas: in parietal, frontal and insular lobes, the main clusters being located in the inferior frontal gyri. Stimulation of T23 in patients resulted in an activation pattern intermediate between that of the implants and that of natural teeth. This study demonstrates that punctate mechanical stimulation of oral implants activates both primary and secondary cortical somatosensory areas. It also suggests that brain plasticity occurs when extracted teeth are replaced by endosseous implants. This cortical activation may represent the underlying mechanism of osseoperception.

  18. Atypical Case of Three Dental Implants Displaced into the Maxillary Sinus

    Directory of Open Access Journals (Sweden)

    João Felipe Bonatto Bruniera

    2015-01-01

    Full Text Available Oral rehabilitation with dental implants has become a routine treatment in contemporary dentistry. The displacement of dental implants into the sinus membrane, a complication related to the maxillary sinus, is one of the most common accidents reported in the literature. The treatment for this complication is the surgical removal of the implant. A 60-year-old woman with three dental implants displaced into the maxillary sinus (one implant displaced into the left maxillary sinus and two implants displaced into the right maxillary sinus underwent surgery for removal of the implants. The surgery to remove the implants was performed under local anesthesia through the Caldwell-Luc technique. The patient was subsequently administered antibiotic, anti-inflammatory, and analgesic drugs. The patient returned 7 days after the surgery for suture removal and is being regularly monitored to determine whether future rehabilitation of the edentulous area is necessary. In conclusion, surgical removal of the dental implant displaced into the maxillary sinus is the treatment of choice. This technique is appropriate because it allows the use of local anesthesia and provides direct visualization for the removal of the implants.

  19. Brånemark and ITI dental implants in the human bone-grafted maxilla: a comparative evaluation

    DEFF Research Database (Denmark)

    Pinholt, Else M

    2003-01-01

    and the patients were followed between 20 and 67 months post implantation. The bone graft was transplanted to add bony volume in the maxillary sinus, the anterior floor of the nose and/or the alveolar ridge. After a healing period of 4(1/2) months, dental implants were inserted and left for healing for 8 months......The development of new characteristics concerning implant surface makes it interesting to clinically compare different implant systems in the bone-grafted maxilla. The aim of this evaluation was to compare clinical data of a two-staged procedure on the augmented extremely atrophic maxilla using...... either Brånemark- or ITI-fixures. In 25 patients (18 females, seven males) the severely atrophied maxilla was reconstructed with autogenous iliac or mandibular bone and either Brånemark or ITI implants. Seventy-eight Brånemark implants and 80 SLA-ITI implants were inserted in the augmented bone...

  20. Heart monitoring using left ventricle impedance and ventricular electrocardiography in left ventricular assist device patients.

    Science.gov (United States)

    Her, Keun; Ahn, Chi Bum; Park, Sung Min; Choi, Seong Wook

    2015-03-21

    Patients who develop critical arrhythmia during left ventricular assist device (LVAD) perfusion have a low survival rate. For diagnosis of unexpected heart abnormalities, new heart-monitoring methods are required for patients supported by LVAD perfusion. Ventricular electrocardiography using electrodes implanted in the ventricle to detect heart contractions is unsuitable if the heart is abnormal. Left ventricular impedance (LVI) is useful for monitoring heart movement but does not show abnormal action potential in the heart muscle. To detect detailed abnormal heart conditions, we obtained ventricular electrocardiograms (v-ECGs) and LVI simultaneously in porcine models connected to LVADs. In the porcine models, electrodes were set on the heart apex and ascending aorta for real-time measurements of v-ECGs and LVI. As the carrier current frequency of the LVI was adjusted to 30 kHz, it was easily derived from the original v-ECG signal by using a high-pass filter (cutoff: 10 kHz). In addition, v-ECGs with a frequency band of 0.1 - 120 Hz were easily derived using a low-pass filter. Simultaneous v-ECG and LVI data were compared to detect heart volume changes during the Q-T period when the heart contracted. A new real-time algorithm for comparison of v-ECGs and LVI determined whether the porcine heartbeats were normal or abnormal. Several abnormal heartbeats were detected using the LVADs operating in asynchronous mode, most of which were premature ventricle contractions (PVCs). To evaluate the accuracy of the new method, the results obtained were compared to normal ECG data and cardiac output measured simultaneously using commercial devices. The new method provided more accurate detection of abnormal heart movements. This method can be used for various heart diseases, even those in which the cardiac output is heavily affected by LVAD operation.

  1. Left Activism, Succour and Selfhood

    DEFF Research Database (Denmark)

    Hughes, Celia Penelope

    2014-01-01

    At the height of mass activity on the Left, the ascendancy of the women's liberation movement (WLM), and the beginnings of real social and personal change for men and women, the 1970s are increasingly seen as the decade when sixties permissiveness began to be truly felt in Britain. This article...... draws upon a personal archive of correspondence from this turbulent decade, between two revolutionary women, Di Parkin and Annie Howells. It argues that the women's letters form an important contribution to new understandings about the construction of the post-war gendered self. The letters represent...... an interchange of motherhood, domesticity, far-left politics, and close female friendship. The article will show how the women's epistolary friendship offers intimate insight into female self-fashioning at a breakthrough social and political moment in 1970s Britain. As they reflected on some of the key political...

  2. A new variant of aberrant left brachiocephalic trunk in mam: case report and literature review.

    Science.gov (United States)

    Szpinda, Michał

    2005-02-01

    Importance is placed on aberrant arteries in the radiological and surgical literature. A normal left brachiocephalic trunk is characteristic for the right aortic arch. However, an aberrant left brachiocephalic trunk arising as the last branch of the aortic arch on the left side has not yet been described in the literature. Described here is a new variant of the retro-oesophageal aberrant left brachiocephalic trunk, occasionally observed in a patient during diagnostic investigation or surgical treatment for steno-obstructive involvement of the carotid district. The triple anomaly of the left aortic arch consisted of: 1. the presence of a hypoplastic left brachiocephalic trunk behind the oesophagus, 2. the absence of a brachiocephalic trunk on the right side and 3. separate origins of the arteries on the right side, with the right common artery preceding the right subclavian artery. In front of the trachea an 8-mm prosthetic PTFE was implanted from the proximal segment of the right subclavian artery to the junction of the left common carotid and left subclavian arteries. The author demonstrates the inadequacy of auxiliary investigations to detect aberrant arteries, which may only be identified precisely intra-operatively.

  3. Ventricular Energetics in Pediatric Left Ventricular Assist Device Patients: A Retrospective Clinical Study.

    Science.gov (United States)

    Di Molfetta, Arianna; Ferrari, Gianfranco; Iacobelli, Roberta; Filippelli, Sergio; Di Chiara, Luca; Guccione, Paolo; Amodeo, Antonio

    The aim of this study is to estimate the trend of right and left energetic parameters in left ventricular assist device (LVAD) pediatric patients. Echocardiographic data were retrospectively collected at the baseline, in the acute phase after and at the monthly follow-ups till the LVAD explantation to estimate left and right ventricular energetic parameters. A significant relationship between the left and right ventricular energetic parameter trends was found along all the study period. Left ventricular end-systolic pressure-volume relationship improved till the follow-up of 2 months and then progressively decreases. Left arteroventricular coupling decreases after the LVAD, and right arteroventricular coupling decreases at the short-term follow-up. Left ventricular external work, potential energy, and pressure-volume area decrease at the short-term follow-up and then increase progressively. Right ventricular external work, potential energy, and pressure-volume area increase after the LVAD implantation. Left (right) cardiac mechanical efficiency is improved (worsened) by the LVAD. Energetic variables show that the LVAD benefits could decrease over time. A continuous and patient tailored LVAD setting could contribute to prolong LVAD benefits. The introduction of energetic parameters could lead to a more complete evaluation of LVAD patients' outcome which is a multiparametric process.

  4. Left-handedness and health

    OpenAIRE

    Milenković Sanja; Belojević Goran; Kocijančić Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered ...

  5. Corrosion on spinal implants.

    Science.gov (United States)

    Kirkpatrick, John S; Venugopalan, Ramakrishna; Beck, Preston; Lemons, Jack

    2005-06-01

    Modular spine implants are used as an aid to obtaining fusion, but fretting and corrosion occur between modular components in a biologic environment. Forty-eight spinal implant constructs manufactured by a variety of companies were retrieved from 47 patients and were subjected to surface analysis stereomicroscopy. Stainless-steel implants (n = 23) had either semirigid constructs with mild or no surface alteration (n = 7) or rigid constructs with moderate or severe alteration (n = 16). Surface damage was consistent with previously observed mechanically assisted crevice corrosion phenomena. Titanium alloy implants (n = 25) showed no significant corrosion but had three constructs with fatigue failure of anchoring screws. One cobalt alloy construct showed no evidence of corrosion. Long-term effects of fretting and corrosion are unclear, and minimization of these phenomena seems justified. Selection of modular components with similar materials and surface finish may help the surgeon minimize localized changes over time. Stainless-steel implants with rigid interconnections and those with different surface finishes between rods and connectors are most susceptible to corrosion.

  6. Interface Biology of Implants

    Science.gov (United States)

    Nebe, Barbara

    2009-01-01

    Implants are widely used in various clinical disciplines to replace or stabilize organs. The challenge for the future is to apply implant materials to specifically control the biology of the surrounding tissue for repair and regeneration. This field of research is highly interdisciplinary and combines scientists from technical and life sciences disciplines. To successfully apply materials for regenerative processes in the body, the understanding of the mechanisms at the interface between cells or tissues and the artificial material is of critical importance. The research focuses on stem cells, design of material surfaces, and mechanisms of cell adhesion. For the third time around 200 scientists met in Rostock, Germany for the international symposium “Interface Biology of Implants.” The aim of the symposium is to promote the interdisciplinary dialogue between the scientists from the different disciplines to develop smart implants for medical use. In addition, researchers from basic sciences, notably cell biology presented new findings concerning mechanisms of cell adhesion to stimulate research in the applied field of implant technology. PMID:19690468

  7. Psychological intervention following implantation of an implantable defibrillator

    DEFF Research Database (Denmark)

    Pedersen, Susanne S.; van den Broek, Krista C; Sears, Samuel F

    2007-01-01

    The medical benefits of the implantable cardioverter defibrillator (ICD) are unequivocal, but a subgroup of patients experiences emotional difficulties following implantation. For this subgroup, some form of psychological intervention may be warranted. This review provides an overview of current...

  8. Functional asymmetry between the left and right human fusiform gyrus explored through electrical brain stimulation.

    Science.gov (United States)

    Rangarajan, Vinitha; Parvizi, Josef

    2016-03-01

    The ventral temporal cortex (VTC) contains several areas with selective responses to words, numbers, faces, and objects as demonstrated by numerous human and primate imaging and electrophysiological studies. Our recent work using electrocorticography (ECoG) confirmed the presence of face-selective neuronal populations in the human fusiform gyrus (FG) in patients implanted with intracranial electrodes in either the left or right hemisphere. Electrical brain stimulation (EBS) disrupted the conscious perception of faces only when it was delivered in the right, but not left, FG. In contrast to our previous findings, here we report both negative and positive EBS effects in right and left FG, respectively. The presence of right hemisphere language dominance in the first, and strong left-handedness and poor language processing performance in the second case, provide indirect clues about the functional architecture of the human VTC in relation to hemispheric asymmetries in language processing and handedness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Management of peri-implantitis

    Science.gov (United States)

    Prathapachandran, Jayachandran; Suresh, Neethu

    2012-01-01

    Peri-implantitis is a site-specific infectious disease that causes an inflammatory process in soft tissues, and bone loss around an osseointegrated implant in function. The etiology of the implant infection is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, external morphology, and excessive mechanical load. The microorganisms most commonly associated with implant failure are spirochetes and mobile forms of Gram-negative anaerobes, unless the origin is the result of simple mechanical overload. Diagnosis is based on changes of color in the gingiva, bleeding and probing depth of peri-implant pockets, suppuration, X-ray, and gradual loss of bone height around the tooth. Treatment will differ depending upon whether it is a case of peri-implant mucositis or peri-implantitis. The management of implant infection should be focused on the control of infection, the detoxification of the implant surface, and regeneration of the alveolar bone. This review article deals with the various treatment options in the management of peri-implantitis. The article also gives a brief description of the etiopathogenesis, clinical features, and diagnosis of peri-implantitis. PMID:23559913

  10. Management of peri-implantitis

    Directory of Open Access Journals (Sweden)

    Jayachandran Prathapachandran

    2012-01-01

    Full Text Available Peri-implantitis is a site-specific infectious disease that causes an inflammatory process in soft tissues, and bone loss around an osseointegrated implant in function. The etiology of the implant infection is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, external morphology, and excessive mechanical load. The microorganisms most commonly associated with implant failure are spirochetes and mobile forms of Gram-negative anaerobes, unless the origin is the result of simple mechanical overload. Diagnosis is based on changes of color in the gingiva, bleeding and probing depth of peri-implant pockets, suppuration, X-ray, and gradual loss of bone height around the tooth. Treatment will differ depending upon whether it is a case of peri-implant mucositis or peri-implantitis. The management of implant infection should be focused on the control of infection, the detoxification of the implant surface, and regeneration of the alveolar bone. This review article deals with the various treatment options in the management of peri-implantitis. The article also gives a brief description of the etiopathogenesis, clinical features, and diagnosis of peri-implantitis.

  11. Implant therapy in irradiated patients.

    Science.gov (United States)

    Sammartino, Gilberto; Marenzi, Gaetano; Cioffi, Iacopo; Teté, Stefano; Mortellaro, Carmen

    2011-03-01

    In this multicenter study, submerged implants were prospectively followed to evaluate their long-term prognosis in irradiated patients. In a total of 77 patients treated for oral or neck cancer, 188 implants were consecutively placed. After a healing period, the successfully integrated implants were restored with 69 removable and 38 fixed restorations. The implants cumulative survival and success rates were evaluated over a period of at least 36 months. In addition, cumulative success rates were calculated for implant subgroups divided per implant site (mandible or maxilla), radiation dosage, and the time interval between the last irradiation and implant placement. During the healing period, 20 implants did not successfully integrate, whereas 168 implants were classified as success (including both survival and success rates). The analysis of implant subgroups showed slightly more favorable cumulative success rate for mandibular implants (98.4%) compared with maxillary implants (57.1%) and clearly better success rate for a radiation dosage minor of 50-Gy doses. A time greater than 12 months as interval between last irradiation and implant placement seems not to promote better clinical results.

  12. A pictorial essay of breast implant imaging and implant complications.

    Science.gov (United States)

    Arslan, Gozde; Celik, Levent; Cubuk, Rahmi

    2016-01-01

    Nowadays as more breast conserving surgeries and mastectomies are being performed, more breast implants are being used. Follow-up of these patients is as important as treatment. We, radiologists should be aware of normal imaging appearance of implants during follow ups. We should also be aware of complications which we may encounter during controls. In our essay, we aim to show the normal and pathological appearence of implants by sharing ultrasound, mammography and MR images from our clinic. Breast, Implants, MRI, Rupture.

  13. Silicone Gel-Filled Breast Implants

    Science.gov (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin it ... options Linkedin Pin it Email Print Description: Silicone gel-filled breast implants have a silicone outer shell ...

  14. Dental implants: A review.

    Science.gov (United States)

    Guillaume, B

    2016-12-01

    A high number of patients have one or more missing tooth and it is estimated that one in four American subjects over the age of 74 have lost all their natural teeth. Many options exist to replace missing teeth but dental implants have become one of the most used biomaterial to replace one (or more) missing tooth over the last decades. Contemporary dental implants made with titanium have been proven safe and effective in large series of patients. This review considers the main historical facts concerned with dental implants and present the different critical factors that will ensure a good osseo-integration that will ensure a stable prosthesis anchorage. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Evaluation of polymethylmethacrylate as ocular implant in rabbits subjected to evisceration

    OpenAIRE

    Arianne Pontes Oriá; Francisco de Assis Dórea Neto; Luís Alberto dos Santos; Evandro de Toledo Piza; Adriana Torrecilhas Jorge Brunelli; Celina Tie Nishimori; Ana Letícia Groszewicz de Souza; Deusdete Conceição Gomes Junior; José Luiz Laus

    2012-01-01

    Spheres of different types of material are used for the replacement of lost volume after removal of the eye bulb or its content to prevent contraction of the orbital cavity. The aim of this study was to evaluate the scope of polymethylmethacrylate (PMMA) used as intraocular implant in eviscerated rabbit eye. Twelve New Zealand rabbits underwent unilateral evisceration of the left eye, with subsequent implantation of PMMA sphere 12 mm in diameter. Clinical evaluation was performed daily during...

  16. Surface characteristics of implants influence their bone integration after simultaneous placement of implant and GBR membrane.

    Science.gov (United States)

    Lima, Luiz A; Fuchs-Wehrle, Anita M; Lang, Niklaus P; Hämmerle, Christoph H F; Liberti, Edson; Pompeu, Eduardo; Todescan, José H

    2003-12-01

    The purpose of this study was to evaluate the influence of titanium surface characteristics on bone integration of implants, and to describe the pattern of peri-implant tissue healing after simultaneous implant placement and guided bone regeneration. In four healthy mongrel dogs mandibular premolars were extracted. Two weeks following full mouth prophylaxis and 4 months after extractions, simultaneous membrane and implant surgeries were performed. Efforts were made to produce bony defects with dimensions of 7 x 7 x 7 mm. Into these, 24 standard ITI implants (diameter = 4.1 mm; length = 8 mm) with either a titanium plasma-sprayed (TPS) or a machined surface (MS) were placed. Although implants were inserted 4 mm into cancellous bone, difficulties in achieving optimal primary stability were encountered. All dogs were maintained on a soft diet. Chlorhexidine rinses were performed three times a week. Full mouth prophylaxis was performed every 2 weeks. In the case of membrane exposure, the membranes were removed prematurely (4-6 or 14-15 weeks after surgery). Two dogs were sacrificed at 16 weeks and two at 24 weeks after surgery. Nondecalcified histologic sections were processed and histometric analyses were carried out. When membranes were removed after 4-6 weeks, a vertical bone growth (VB) of 45-61% of the original defect was noted. After membrane removal at 14-15 weeks, similar VB was observed. However, if membranes were left in situ for 24 weeks, VB was between 79% and 96%. In this group of sites, the VB was 66% at 16 weeks and 86% at 24 weeks. Osseointegration in the regenerated bone area ranged from 12% to 32% for the TPS and from 0.0% to 3.6% for the MS implants at 16 and 24 weeks combined. Osseointegration in the pristine host bone area ranged from 16% to 35% for the TPS and from 0.0% to 11% for the MS sites at 16 and 24 weeks. In conclusion, the fraction of implant-bone integration was much higher in the pristine bone compared to that in the regenerated bone

  17. Systolic left ventricular function according to left ventricular concentricity and dilatation in hypertensive patients

    DEFF Research Database (Denmark)

    Bang, Casper; Gerdts, Eva; Aurigemma, Gerard P

    2013-01-01

    Left ventricular hypertrophy [LVH, high left ventricular mass (LVM)] is traditionally classified as concentric or eccentric based on left ventricular relative wall thickness. We evaluated left ventricular systolic function in a new four-group LVH classification based on left ventricular dilatatio...

  18. Surface smoothing and template partitioning for cranial implant CAD

    Science.gov (United States)

    Min, Kyoung-june; Dean, David

    2005-04-01

    Employing patient-specific prefabricated implants can be an effective treatment for large cranial defects (i.e., > 25 cm2). We have previously demonstrated the use of Computer Aided Design (CAD) software that starts with the patient"s 3D head CT-scan. A template is accurately matched to the pre-detected skull defect margin. For unilateral cranial defects the template is derived from a left-to-right mirrored skull image. However, two problems arise: (1) slice edge artifacts generated during isosurface polygonalization are inherited by the final implant; and (2) partitioning (i.e., cookie-cutting) the implant surface from the mirrored skull image usually results in curvature discontinuities across the interface between the patient"s defect and the implant. To solve these problems, we introduce a novel space curve-to-surface partitioning algorithm following a ray-casting surface re-sampling and smoothing procedure. Specifically, the ray-cast re-sampling is followed by bilinear interpolation and low-pass filtering. The resulting surface has a highly regular grid-like topological structure of quadrilaterally arranged triangles. Then, we replace the regions to be partitioned with predefined sets of triangular elements thereby cutting the template surface to accurately fit the defect margin at high resolution and without surface curvature discontinuities. Comparisons of the CAD implants for five patients against the manually generated implant that the patient actually received show an average implant-patient gap of 0.45mm for the former and 2.96mm for the latter. Also, average maximum normalized curvature of interfacing surfaces was found to be smoother, 0.043, for the former than the latter, 0.097. This indicates that the CAD implants would provide a significantly better fit.

  19. Mic ghid de terapie cu gold implant la animale

    Directory of Open Access Journals (Sweden)

    Emilia Abrudean

    2016-06-01

    Full Text Available The gold Implant (GI has started to become important in the fight against chronic musculoskeletal pain in the '90s in Germany. GI has had success, because he left behind the traditional Chinese acupuncture (TCA and evolved as an orthopedic conservative method, involving all the locomotor system. In this review paper are presented essential information about this new technique for veterinary medicine. Are presented: mechanism of action, IA techniques, the main implant points, the main indications of this technique, processes and dynamic post-operative interventions, combinations with other methods, limits of the gold implant. The paper supports, for the first time in our country, the popularization of this method especially effective in locomotion disorders in animals.

  20. Successful treatment of annular rupture during transcatheter aortic valve implantation.

    Science.gov (United States)

    Unic, Daniel; Sutlic, Zeljko; Starcevic, Boris; Bradic, Nikola; Baric, Davor; Rudez, Igor

    2017-04-01

    Annular rupture presents a rare but potentially fatal complication of transcatheter aortic valve implantation (TAVI). Although it can be subtle and subclinical in presentation, most severe forms present with hemodynamic instability and represent true emergencies requiring a more invasive treatment, even conventional surgery. We present a case of successful treatment of annular rupture by left ventricular outflow tract patch and surgical aortic valve replacement.

  1. Optimization of dental implant treatment

    National Research Council Canada - National Science Library

    Dmitriy V. Ivanov; Aleksandr V. Dol; Dmitriy A. Smirnov

    2016-01-01

    Aim ― Modern dentistry cannot exist without dental implantation. The lifetime of the installed implants depends on condition of the bone and on the quality of the treatment planning and surgery technique...

  2. Evaluation of guided bone generation around implants placed into fresh extraction sockets: an experimental study in dogs

    DEFF Research Database (Denmark)

    Gotfredsen, K; Nimb, L; Buser, D

    1993-01-01

    . The objective of this study was to evaluate the crestal bone healing response adjacent to implants placed immediately into fresh extraction sockets with and without covering membranes. Eight adult mongrel dogs had the third and fourth mandibular premolars extracted bilaterally. Thirty-two submerged titanium...... hollow-screw implants were inserted immediately into the extraction sockets. On the right side, the implants were covered with an expanded polytetrafluorethylene membrane, whereas the left side served as a control. One dog was killed after 2 weeks, one after 4 weeks, and six after 12 weeks. Soft tissue...... dehiscence developed over 10 implants (12-week dogs) covered with membranes. Dehiscence was noted histologically over three contralateral control implants. When soft tissue dehiscence occurred and the membrane was left exposed without oral hygiene during healing, the degree of bone integration...

  3. Ventricular arrhythmias due to left ventricular noncompaction cardiomyopathy: a diagnosis in hindsight.

    Science.gov (United States)

    Liang, Jackson J; McKenzie, Kyle M; Cha, Yong-Mei

    2014-02-01

    Left ventricular noncompaction cardiomyopathy is a rare congenital cardiomyopathy which predisposes to sudden cardiac death. We describe the case of a 24 year-old man who had previously received an implantable cardioverter-defibrillator for sustained ventricular tachycardia and was later diagnosed with left ventricular noncompaction cardiomyopathy during a hospitalisation for device infection. Copyright © 2013 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  4. Spontaneous resolution of left bundle branch block and biventricular stimulation lead to reverse remodeling in dyssynchronopathy.

    Science.gov (United States)

    Kloosterman, Mariëlle; Rienstra, Michiel; Van Gelder, Isabelle C; Maass, Alexander H

    2016-01-01

    Left bundle branch block (LBBB) is considered a marker of underlying structural cardiac disease. To determine whether LBBB is cause or consequence of deterioration of left ventricular (LV) function is difficult as both are often diagnosed concomitantly. We discuss a patient where reversal of LBBB and subsequent normalization of LV function was observed after 2 different therapies, first after start of heart failure medication, and years later after implantation of a cardiac resynchronization device. This indicates that LBBB per se may result in the development of non-ischemic cardiomyopathy and that LBBB resolution can lead to reverse remodeling in dyssynchronopathy. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Aortic embolization of an Edwards SAPIEN prosthesis due to sigmoid left ventricular hypertrophy: Case report.

    Science.gov (United States)

    Yuksel, Isa Öner; Koklu, Erkan; Arslan, Sakir; Cagirci, Goksel; Kucukseymen, Selcuk

    2016-06-01

    Transcatheter aortic valve implantation (TAVI) is considered an alternative therapy in high-risk patients with severe aortic stenosis. Although a minimally invasive procedure, it is not free from complications, one of which is valve embolization at the time of TAVI. We present a case of embolization of a balloon-expandable aortic valve due to sigmoid left ventricular hypertrophy and managed with a second valve without surgery. The embolized valve was repositioned in the aortic arch between the left common carotid artery and the brachiocephalic trunk. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  6. Complications of permanent cardiac pacing in patients with persistent left superior vena cava.

    Science.gov (United States)

    Polewczyk, Anna; Kutarski, Andrzej; Czekajska-Chehab, Elżbieta; Adamczyk, Piotr; Boczar, Krzysztof; Polewczyk, Maciej; Janion, Marianna

    2014-01-01

    Persistent left superior vena cava (PLSVC) is present in about 0.3-0.5% of the general population and in about 12% of patients with other abnormalities. This congenital anomaly is usually asymptomatic and does not cause any physiological problems. However, it may become a significant problem in multiple clinical situations. Various complications related to PLVSC are encountered in anesthesiological, nephrological, oncological and cardiological procedures. The presence of PLSVC is usually incidentally detected during placement of pacemaker (PM), implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT) leads. Technical difficulties during lead positioning (especially ventricular leads) are commonly known and often described in the literature. The purpose of the present study was to evaluate the specific methods used for implantation of increasingly complicated pacing systems, finding an optimal strategy in patients with PLSVC, especially with electrotherapy complications. We performed a single-center retrospective analysis of 11 patients (7 women and 4 men, mean age 60.4 ± 13 years) with PLSVC hospitalized in single Cardiology Department between 2000 and 2012. The clinical characteristic, indications for PM/ICD/CRT implantation, technique of implantation and complications were evaluated. In PLSVC patients, different indications for pacing or resynchronization therapy were represented: sick sinus syndrome (SSS) in 4 patients, 3rd degree atrio-ventricular (AV) block in 4 patients, dilated cardiomyopathy with left bundle branch block in 2 patients, dilated cardiomyopathy and non-sustained ventricular tachycardia episodes in 1 patient. In patients no. 1, 3, 4 and 10 the complications necessitated the change of leads or type of pacing. Transvenous lead extraction was successfully performed in patient no. 1 and 10 with re-implantation of new leads via PLSVC in patient no. 1 and via right superior vena cava in patient no. 10. Patient no. 3

  7. Investigation of pathogenic genes in peri-implantitis from implant clustering failure patients: a whole-exome sequencing pilot study.

    Directory of Open Access Journals (Sweden)

    Soohyung Lee

    Full Text Available Peri-implantitis is a frequently occurring gum disease linked to multi-factorial traits with various environmental and genetic causalities and no known concrete pathogenesis. The varying severity of peri-implantitis among patients with relatively similar environments suggests a genetic aspect which needs to be investigated to understand and regulate the pathogenesis of the disease. Six unrelated individuals with multiple clusterization implant failure due to severe peri-implantitis were chosen for this study. These six individuals had relatively healthy lifestyles, with minimal environmental causalities affecting peri-implantitis. Research was undertaken to investigate pathogenic genes in peri-implantitis albeit with a small number of subjects and incomplete elimination of environmental causalities. Whole-exome sequencing was performed on collected saliva samples via self DNA collection kit. Common variants with minor allele frequencies (MAF > = 0.05 from all control datasets were eliminated and variants having high and moderate impact and loss of function were used for comparison. Gene set enrichment analysis was performed to reveal functional groups associated with the genetic variants. 2,022 genes were left after filtering against dbSNP, the 1000 Genomes East Asian population, and healthy Korean randomized subsample data (GSK project. 175 (p-value <0.05 out of 927 gene sets were obtained via GSEA (DAVID. The top 10 was chosen (p-value <0.05 from cluster enrichment showing significance of cytoskeleton, cell adhesion, and metal ion binding. Network analysis was applied to find relationships between functional clusters. Among the functional groups, ion metal binding was located in the center of all clusters, indicating dysfunction of regulation in metal ion concentration might affect cell morphology or cell adhesion, resulting in implant failure. This result may demonstrate the feasibility of and provide pilot data for a larger research

  8. Percutaneous Implantation of A Parachute Device For Treatment of Ischemic Heart Failure

    Energy Technology Data Exchange (ETDEWEB)

    Cilingiroglu, Mehmet, E-mail: mcilingiroglu@yahoo.com; Rollefson, William A.; Mego, David

    2013-07-15

    Congestive heart failure (CHF) secondary to ischemic cardiomyopathy is associated with significant morbidity and mortality despite currently available medical therapy. The Parachute{sup TM} device is a novel left ventricular partitioning device that is delivered percutaneously in the left ventricle (LV) in patients with anteroapical regional wall motion abnormalities, dilated LV and systolic dysfunction after anterior myocardial infarction with favorable clinical and LV hemodynamic improvements post-implantation. Here, we do review the current literature and present a case of the Parachute device implantation.

  9. Percutaneous implantation of a parachute device for treatment of ischemic heart failure.

    Science.gov (United States)

    Cilingiroglu, Mehmet; Rollefson, William A; Mego, David

    2013-01-01

    Congestive heart failure (CHF) secondary to ischemic cardiomyopathy is associated with significant morbidity and mortality despite currently available medical therapy. The Parachute(TM) device is a novel left ventricular partitioning device that is delivered percutaneously in the left ventricle (LV) in patients with anteroapical regional wall motion abnormalities, dilated LV and systolic dysfunction after anterior myocardial infarction with favorable clinical and LV hemodynamic improvements post-implantation. Here, we do review the current literature and present a case of the Parachute device implantation. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Spontaneous Rotation of a Toric Implantable Collamer Lens

    Directory of Open Access Journals (Sweden)

    Alejandro Navas

    2010-11-01

    Full Text Available We present a case of toric implantable collamer lens (TICL spontaneous rotation in a patient with myopic astigmatism. A 23-year-old female underwent TICL implantation. Preoperative uncorrected visual acuity (UCVA was 20/800 and 20/1200, respectively, with –7.75 –4.25 × 0° and –8.25 –5.25 × 180°. The left eye achieved an UCVA of 20/30. After 3 months of successful implantation of TICL in the left eye, the patient presented with a sudden decrease in visual acuity in the left eye. UCVA was 20/100 with a refraction of +2.50 –4.50 × 165°. We observed the toric marks with a 30° rotation from the original position and decided to reposition the TICL, obtaining a final UCVA of 20/25, which remained stable at 6 months’ follow-up. TICL can present a considerable rotation that compromises visual acuity. The relocation of TICL is a safe and effective procedure to recover visual acuity due to significant spontaneous TICL rotation.

  11. Computer-guided Implant dentistry.

    Science.gov (United States)

    Schnitman, Paul A

    2007-01-01

    Computer-guided minimally invasive implant treatment promises to revolutionize the way we practice implant dentistry. This new technology allows implants and associated restorations to be precisely placed at the same procedure directly through the gingiva in an hour or less. Since there is no incision, there is minimal postoperative discomfort or swelling and no sutures.

  12. Recent advances in dental implants.

    Science.gov (United States)

    Hong, Do Gia Khang; Oh, Ji-Hyeon

    2017-12-01

    Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

  13. Biomimetic approach to dental implants.

    Science.gov (United States)

    Kim, Tae-Il; Jang, Jun-Hyeog; Kim, Hae-Won; Knowles, Jonathan C; Ku, Young

    2008-01-01

    Titanium, as an implant material, is regarded to be durable and biocompatible, which allows functional replacement of missing teeth. Successful dental implantation depends on an osseointegration phenomenon, a direct structural and functional binding reaction between bone and implant. It is well known that physicochemical characteristics of the dental implant surface, such as roughness, topography, chemistry, and electrical charge affect the biological reactions occurring at the interface of tissue and implant. Therefore, considerable efforts have been made to modify the surface of titanium implants which are based on mechanical, physical and chemical treatments. Recently, biological molecules were introduced onto the surface of implants to stimulate osteogenic cells in the early stage of implantation and consequently accelerate bone formation around implant and subsequent rapid implant stabilization. A range of extracellular matrix components, designed peptides, and growth factors have been proposed as the biological moiety. In this review, we address several issues related to the biology of dental implants and discuss biomimetic modification of the implant surface as a novel approach to obtain successful osseointegration.

  14. Rebuilding the US Health Left

    Directory of Open Access Journals (Sweden)

    Victor W. Sidel, MD

    2010-02-01

    Full Text Available With this issue Social Medicine begins a series of invited papers on the topic: “Rebuilding the US Health Left.” In this editorial we will outline our vision for this series. We undertake this project aware that our good friend and mentor, Dr. Walter Lear, one of the leading health activists of the 20th century, lies critically ill. Walter was the creator and custodian of the US Health Left Archives, a collection that is now with the University of Pennsylvania library. The collection reminds us of the important role left health care workers played in US history throughout the 20th century. They advocated for a national health program (Committee on the Costs of Medical Care, Physicians Forum, Medical Care Section/APHA, HealthPAC, Physicians for a National Health Program, National Physicians Alliance, provided international solidarity (American Soviet Medical Society, international brigades during the Spanish Civil War, Central American Solidarity Movement, Committee to Help Chilean Health Workers, Doctors for Global Health, traced the connections between disease and social class (Sigerist Circle, Spirit of 1848, APHA, fought for workers’ health (Councils for Occupational Safety and Health; Occupational Health and Safety Section, APHA participated in anti-war movements (Medical Committee for Human Rights, Physicians for Social Responsibility, International Physicians for the Prevention of Nuclear War, created new models of health care delivery (Health Cooperatives, Prepaid Health Maintenance Organizations, Community Health Centers, National Health Service Corps, Free Clinics, were central to the struggle for women’s rights (Planned Parenthood, Physicians for Reproductive Choice and Health, supported the civil rights movement both in medicine and in the broader society (National Medical Association, Medical Committee for Human Rights, played key roles in the movement for gay rights (ACT-UP, Gay & Lesbian Medical Association, Lesbian, Gay

  15. Treatment of peri-implantitis and the failing implant.

    Science.gov (United States)

    Robertson, Kevin; Shahbazian, Timothy; MacLeod, Stephen

    2015-04-01

    Appropriate treatment of implants is becoming increasingly important for the general dentist as the number of implants placed per year continues to increase. Early diagnosis of peri-implantitis is imperative; initiating the correct treatment protocol depends on a proper diagnosis. Several risk factors exist for the development of peri-implantitis, which can guide patient selection and treatment planning. Treatment of peri-implantitis should be tailored to the severity of the lesion (as outlined by the cumulative interceptive supportive treatment protocol), ranging from mechanical debridement to explantation. Several surgical and nonsurgical treatment alternatives exist. There is little consensus on superior treatment methods. Published by Elsevier Inc.

  16. Transfemoral transcatheter aortic valve implantation in a patient with a severe aortic stenosis and cardiogenic shock requiring intra-aortic balloon pump support.

    Science.gov (United States)

    Chodór, Piotr; Wilczek, Krzysztof; Przybylski, Roman; Świątkowski, Andrzej; Głowacki, Jan; Kalarus, Zbigniew; Zembala, Marian

    2015-01-01

    The following paper presents a patient with severe aortic stenosis and severely reduced left ventricular ejection fraction with intra-aortic balloon pump counterpulsation support, who underwent transfemoral aortic valve implantation of a CoreValve prosthesis.

  17. Remote actuated valve implant

    Science.gov (United States)

    McKnight, Timothy E; Johnson, Anthony; Moise, Jr., Kenneth J; Ericson, Milton Nance; Baba, Justin S; Wilgen, John B; Evans, III, Boyd McCutchen

    2014-02-25

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  18. Implantable enzyme amperometric biosensors.

    Science.gov (United States)

    Kotanen, Christian N; Moussy, Francis Gabriel; Carrara, Sandro; Guiseppi-Elie, Anthony

    2012-05-15

    The implantable enzyme amperometric biosensor continues as the dominant in vivo format for the detection, monitoring and reporting of biochemical analytes related to a wide range of pathologies. Widely used in animal studies, there is increasing emphasis on their use in diabetes care and management, the management of trauma-associated hemorrhage and in critical care monitoring by intensivists in the ICU. These frontier opportunities demand continuous indwelling performance for up to several years, well in excess of the currently approved seven days. This review outlines the many challenges to successful deployment of chronically implantable amperometric enzyme biosensors and emphasizes the emerging technological approaches in their continued development. The foreign body response plays a prominent role in implantable biotransducer failure. Topics considering the approaches to mitigate the inflammatory response, use of biomimetic chemistries, nanostructured topographies, drug eluting constructs, and tissue-to-device interface modulus matching are reviewed. Similarly, factors that influence biotransducer performance such as enzyme stability, substrate interference, mediator selection and calibration are reviewed. For the biosensor system, the opportunities and challenges of integration, guided by footprint requirements, the limitations of mixed signal electronics, and power requirements, has produced three systems approaches. The potential is great. However, integration along the multiple length scales needed to address fundamental issues and integration across the diverse disciplines needed to achieve success of these highly integrated systems, continues to be a challenge in the development and deployment of implantable amperometric enzyme biosensor systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Remote actuated valve implant

    Energy Technology Data Exchange (ETDEWEB)

    McKnight, Timothy E.; Johnson, Anthony; Moise, Kenneth J.; Ericson, Milton Nance; Baba, Justin S.; Wilgen, John B.; Evans, Boyd Mccutchen

    2016-05-10

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  20. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2011-01-01

    Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two-stage pro......Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two......-stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during...... the period 1999 to 2006; 239 one-stage procedures and 353 two-stage procedures. The postoperative course through November 2009 was evaluated by cumulative incidence adjusting for competing risks for the selected outcomes; hematoma, infection, seroma, implant rupture, severe capsular contracture (modified...

  1. Middle ear implants

    Directory of Open Access Journals (Sweden)

    K S Gangadhara Somayaji

    2013-01-01

    Full Text Available Hearing loss is becoming more common in the society living in cities with lot of background noise around, and frequent use of gadgets like mobile phones, MP3s, and IPods are adding to the problem. The loss may involve the conductive or perceptive pathway. Majority of the patients with conductive hearing loss will revert back to normal hearing levels with medical and/or surgical treatment. However, in sensorineural hearing loss, many factors are involved in the management. Though traditionally hearing aids in various forms are the most commonly used modality in managing these patients, there are some drawbacks associated with them. Implantable middle ear amplifiers represent the most recent breakthrough in the management of hearing loss. Middle ear implants are surgically implanted electronic devices that aim to correct hearing loss by stimulating the ossicular chain or middle ear. Of late, they are also being used in the management of congenital conductive hearing loss and certain cases of chronic otitis media with residual hearing loss. The article aims to provide general information about the technology, indications and contraindications, selection of candidates, available systems, and advantages of middle ear implants. (MEI

  2. Dental Implant Surgery

    Science.gov (United States)

    ... upper jaw protrude into one of your sinus cavities How you prepare Because dental implants require one or more surgical procedures, you ... can take several months, helps provide a solid base for your new artificial tooth ... teeth. Placing the abutment When osseointegration is complete, you ...

  3. Corrosion of bio implants

    Indian Academy of Sciences (India)

    Chemical stability, mechanical behaviour and biocompatibility in body fluids and tissues are the basic requirements for successful application of implant materials in bone fractures and replacements. Corrosion is one of the major processes affecting the life and service of orthopaedic devices made of metals and alloys used ...

  4. Implantable Impedance Plethysmography

    Directory of Open Access Journals (Sweden)

    Michael Theodor

    2014-08-01

    Full Text Available We demonstrate by theory, as well as by ex vivo and in vivo measurements that impedance plethysmography, applied extravascularly directly on large arteries, is a viable method for monitoring various cardiovascular parameters, such as blood pressure, with high accuracy. The sensor is designed as an implant to monitor cardiac events and arteriosclerotic progression over the long term.

  5. [Retinal implants. Patients' expectations].

    Science.gov (United States)

    Gusseck, H

    2005-10-01

    The "Pro Retina" Society and the "Retina Implant" Foundation, two patients associations with the goal of "preventing blindness," view the "Retina Implant" project as a possibility for providing blind individuals a modicum of restored vision. Both patients associations cultivated a cooperative relationship with researchers and policy makers already during the research phase, introducing the wishes and concerns of patients into considerations and providing information and the groundwork for acceptance in society and among those who may potentially benefit from the method. An initial survey of patients, the visually impaired, and blind people revealed that recovery of sight not only represents a medical and technical problem but that it also involves numerous psychosocial implications. By adhering to ethical standards in implantations, in particular by taking patient autonomy into consideration, anxieties and fears can be reduced. It would appear from early positive results in a short-term clinical study that soon successful chronic retinal implantation can be expected. The dedication displayed by physicians, researchers, and the industry as well as the willingness of the Federal Ministry for Research to take the risk are appreciated and greatfully accepted by the patients and their relatives.

  6. Implantable Drug Dispenser

    Science.gov (United States)

    Collins, E. R. J.

    1983-01-01

    Drugs such as insulin are injected as needed directly into bloodstream by compact implantable dispensing unit. Two vapor cavities produce opposing forces on drug-chamber diaphragm. Heaters in cavities allow control of direction and rate of motion of bellows. Dispensing capsule fitted with coil so batteries can be recharged by induction.

  7. Paediatric cochlear implantation

    African Journals Online (AJOL)

    Chantel

    The internal portion consists of a multi- channel electrode array that is implanted in the cochlea and is attached to a receiv- er/stimulator, an antenna and a .... ties, cerebral palsy, sensory integra- tion problems, blindness and autism can be considered as CI candidates. The literature shows that CIs benefit children with hear-.

  8. Pectin nanocoating of titanium implant surfaces - an experimental study in rabbits

    DEFF Research Database (Denmark)

    Gurzawska, Katarzyna Aleksandra; Dirscherl, Kai; Jørgensen, Bodil

    2017-01-01

    that may increase adhesion of bone proteins, and bone cells at the implant surface. Nanocoating with pectins, plant cell wall-derived polysaccharides, is frequently done using rhamnogalacturonan-I (RG-I). AIM: The aim of the study was to evaluate the effect of nanocoating titanium implants with plant cell......) into the left and right tibia of rabbits. Machined titanium implants without RG-I nanocoating were used as controls (n = 32). Total number of 128 implants was placed in tibias of 16 rabbits. Fluorochrome bone labels, calcein green and alizarin red S were given intravenously after 9 and 12 days, respectively....... The bone response to the nanocoated implants was analyzed qualitatively and quantitatively after 2, 4, 6, and 8 weeks of healing using light microscopy and histomorphometric methods. RESULTS: The RG-I coating influenced the surface chemical composition; wettability and roughness, making the surface more...

  9. Influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient satisfaction

    Science.gov (United States)

    Pellicer-Chover, Hilario; Cervera-Ballester, Juan; Peñarrocha-Oltra, David; Bagán, Leticia; Peñarrocha-Diago, María

    2016-01-01

    Background To assess the influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient comfort and stability, speech, functionality and overall satisfaction. Material and Methods A retrospective clinical study was made of patients subjected to rehabilitation of atrophic maxilla with complete maxillary implant-supported fixed prostheses involving a minimum of two zygomatic implants (one on each side) in conjunction with premaxillary implants, and with 12 months of follow-up after implant loading. Subjects used a VAS to score general satisfaction, comfort and stability, speech and functionality, and the results were analyzed in relation to the prosthetic arm length of the zygomatic implants 12 months after prosthetic delivery. Results Twenty-two patients participated in the study, receiving 22 prostheses anchored on 148 implants (44 were zygomatic and 94 were conventional implants). The mean right and left prosthetic arm length was 5.9±2.4 mm and 6.1±2.7 mm, respectively, with no statistically significant differences between them (p=0.576). The mean scores referred to comfort/retention, speech, functionality and overall satisfaction were high - no correlation being found between prosthetic arm length and patient satisfaction (p=0.815). Conclusions No relationship could be identified between prosthetic arm length (palatal position) and patient satisfaction. Key words:Zygomatic implants, patient satisfaction, zygomatic prosthesis, prosthetic arm length. PMID:26946206

  10. Immediate functional loading of implants placed with flapless surgery versus conventional implants in partially edentulous patients: a 3-year randomized controlled clinical trial.

    Science.gov (United States)

    Cannizzaro, Gioacchino; Leone, Michele; Consolo, Ugo; Ferri, Vittorio; Esposito, Marco

    2008-01-01

    To compare the efficacy of immediate functionally loaded implants placed with a flapless procedure (test group) versus implants placed after flap elevation and conventional load-free healing (control group) in partially edentulous patients. Forty patients were randomized: 20 to the flapless immediately loaded group and 20 to the conventional group. To be immediately loaded, implants had to be inserted with a minimum torque > 45 Ncm. Implants in the immediately loaded group were provided with full acrylic resin temporary restorations the same day. Implants in the conventional group were submerged (anterior region) or left unsubmerged (posterior region) and were left load-free for 3 months (mandibles) or 4 months (maxillae). Provisional restorations were replaced with definitive single metal-ceramic crowns 1 month postloading. Outcome measures were prosthesis and implant failures, biological and prosthetic complications, postoperative edema, pain, and use of analgesics. Independent sample chi2 tests, Mann-Whitney tests, t tests, and paired t tests were used with a significance level of .05. Fifty-two implants were placed in the flapless group and 56 in the conventionally loaded group. In the flapless group, 1 flap had to be raised to control the direction of the bur and 1 implant did not reach the planned primary stability and was treated as belonging to the conventional group. After 3 years no dropouts or failures occurred. There was no statistically significant difference for complications; however, patients in the conventional group had significantly more postoperative edema and pain and consumed more analgesics than those in the flapless group. Osstell values were significantly higher at baseline in the flapless group (P = .033). When comparing baseline data with years 1, 2, and 3 within each group, mean Osstell values of the flapless group did not increase, whereas there were statistically significant increases in the Periotest values. Implants can be

  11. Correction of Malpositioned Implants through Periodontal Surgery and Prosthetic Rehabilitation Using Angled Abutment

    Science.gov (United States)

    de Avila, Érica Dorigatti; de Barros-Filho, Luiz Antônio Borelli; de Andrade, Marcelo Ferrarezi; Mollo, Francisco de Assis; de Barros, Luiz Antônio Borelli

    2014-01-01

    When dental implants are malpositioned in relation to the adjacent teeth and alveolar bone or in an excessive buccal or lingual position, the final prosthesis rehabilitation impairs the peri-implant health of the gingival tissues and the aesthetics of the patient. Thus, the purpose of this case was to report and discuss a multidisciplinary protocol for the treatment of a compromised maxillary tooth in a patient with an abscess in his right central incisor due to an excessive buccal implant position. The patient presented with an implant-supported provisional restoration on his right maxillary central incisor and a traumatic injury in his left central incisor. The treatment protocol consisted in (i) abutment substitution to compensate the incorrect angulation of the implant, (ii) clinical crown lengthening, (iii) atraumatic extraction of the left central incisor, and (iv) immediate implant placement. Finally, (v) a custom abutment was fabricated to obtain a harmonious gingival contour around the prosthetic crown. In conclusion, when implants are incorrectly positioned in relation to the adjacent teeth, associated with soft-tissue defects, the challenge to create a harmonious mucogingival contours may be achieved with an interdisciplinary approach and with the placement of an appropriate custom abutment. PMID:24955259

  12. Correction of Malpositioned Implants through Periodontal Surgery and Prosthetic Rehabilitation Using Angled Abutment

    Directory of Open Access Journals (Sweden)

    Érica Dorigatti de Avila

    2014-01-01

    Full Text Available When dental implants are malpositioned in relation to the adjacent teeth and alveolar bone or in an excessive buccal or lingual position, the final prosthesis rehabilitation impairs the peri-implant health of the gingival tissues and the aesthetics of the patient. Thus, the purpose of this case was to report and discuss a multidisciplinary protocol for the treatment of a compromised maxillary tooth in a patient with an abscess in his right central incisor due to an excessive buccal implant position. The patient presented with an implant-supported provisional restoration on his right maxillary central incisor and a traumatic injury in his left central incisor. The treatment protocol consisted in (i abutment substitution to compensate the incorrect angulation of the implant, (ii clinical crown lengthening, (iii atraumatic extraction of the left central incisor, and (iv immediate implant placement. Finally, (v a custom abutment was fabricated to obtain a harmonious gingival contour around the prosthetic crown. In conclusion, when implants are incorrectly positioned in relation to the adjacent teeth, associated with soft-tissue defects, the challenge to create a harmonious mucogingival contours may be achieved with an interdisciplinary approach and with the placement of an appropriate custom abutment.

  13. Prospective review of integral implants.

    Science.gov (United States)

    Block, M S; Kent, J N

    1992-01-01

    There are several factors that strongly correlate to HA-coated implant success and the prevention of implant morbidity. Surgical placement must be performed without compromise in technique. Implants placed into thin ridges or those that had dehiscence of their surface did not uniformly gain bone attachment levels during the healing period. Countersinking implants in extraction sites was critical; labial bone implant defects should be grafted with particulate HA. HA grafts to labial bone defects at the time of implant placement surgery are still short-term. Primary closure of all implant surgical sites prevented epithelial invagination into the surgical site and is associated with improved bone height around implants. Premature exposure of the implant during the healing period is associated with crestal bone loss. Loading forces should be physiologic, with maintenance of a physiologic equilibrium by a balanced restoration. Bone bulk should be created or preserved. Bone around implants may adversely respond to excessive loading forces. In the posterior maxilla, crestal bone loss has been observed that seems to result from excessive cantilever-type forces placed on the implants or from when implants are placed in the posterior mandible developed progressive bone loss that was associated with several factors. These factors included articulation against a natural occlusion, a horizontal ridge contour level with the external oblique ridge, a nonhygienic restoration, and the lack of keratinized gingiva against the abutment. Whether titanium implants develop progressive bone loss in the face of these factors is unknown. The presence of keratinized gingiva strongly correlated to bone maintenance in the posterior mandible. Because of this statistically significant finding, implant exposure should preserve all keratinized gingiva by transposing it labially to the implants. Most patients who receive implants for dental restoration have lost teeth because of caries and

  14. On Covers and Left-Corner Parses

    NARCIS (Netherlands)

    op den Akker, Hendrikus J.A.; Asveld, P.R.J.; Nijholt, Antinus

    1987-01-01

    A transformation is defined which is a modification of a classic transformation on context-free grammars. By means of this transformation, a proof is presented of the fact that any cycle-free context-free grammar can be left-to-left-corner covered by a non-left-recursive grammar. The proof method is

  15. Left Ventricular Pseudoaneurysm Found by CT Scan

    OpenAIRE

    Hirose, Hitoshi; Matsunaga, Iwao; Strong, Michael D

    2008-01-01

    A 62-year-old male with a previous coronary artery bypass grafting underwent CT scan for evaluation of left epigastric pain. Findings showed a large left ventricular pseudoaneurysm, which was subsequently confirmed by left ventriculogram. The pseudoaneurysm was successfully repaired surgically.

  16. Planning Implant Placement on 3D Stereolithographic Models Applied with Immediate Loading of Implant-Supported Hybrid Prostheses After Multiple Extractions: A Case Series.

    Science.gov (United States)

    Aires, Ian; Berger, Joel

    2016-01-01

    The aim of this noninterventional, retrospective case series was to evaluate the outcome of immediately loaded implants in patients with failing dentitions that require bone tabling using a bone reduction guide and a surgical guide manufactured directly on three-dimensional (3D) stereolithographic models. Consecutive patients with failing dentition and at least two remaining teeth who were treated in a single center between December 14, 2009 and September 23, 2013 were eligible. All patients receiving implants loaded with a hybrid prosthesis on the same day as extraction with their surgery planned on 3D models and performed using a surgical guide manufactured in a laboratory on the planning model were included. Patients who had undergone bone grafting procedures were excluded. Descriptive statistical analyses of available data were performed, including life-table calculations to derive a cumulative survival rate (CSR). Two hundred twenty-eight patients (105 females and 123 males) received 1,657 implants (NobelActive) in 321 arches, in most cases 5 implants (range, 5 to 7) per arch. Ten preexisting implants were used. The mean insertion torque was 60.02 ± 13.1 Ncm (range, 15 to 75 Ncm). The definitive abutment was placed on the same day as surgery in all cases, and the definitive prosthesis (n = 304) was delivered after a mean of 7.9 ± 2.6 months. All implants were followed for 20.01 ± 11.3 months (range, 0 to 52 months) from implant insertion. Four implants (3 patients) had delayed loading, and one implant was left as a sleeping implant. Eight implants among six patients failed, two of the implants after prosthesis delivery. The CSR of the placed implants was 99.4% at implant level and 96.2% at patient level. Planning on 3D models to remove bone and place implants using custom-made bone reduction and surgical guides with immediate loading on the same day as extraction of remaining teeth was safe and effective for implant survival and rehabilitation of patients

  17. Surface morphology analysis of dental implants following insertion into bone using scanning electron microscopy: a pilot study.

    Science.gov (United States)

    Deppe, Herbert; Grünberg, Christina; Thomas, Mücke; Sculean, Anton; Benner, Klaus-Ulrich; Bauer, Florian J M

    2015-11-01

    Dental implants have become essential in reconstructive dentistry. Primary healing is determined by the design of their surface. The aim of this pilot study has been to investigate whether the morphology of the sandblasted and acid-etched (SLA(®) ) surface remains unaffected after the insertion process into human bone. Two edentulous-atrophied human jaw specimens were used. Six brand new Straumann Standard RN implants with an SLA(®) surface and having a diameter of 3.3 mm and a length of 12 mm were inserted. Another two implants of the same type, but not inserted into bone, served as a reference. After explantation, the four implants were cleaned in an ultrasonic bath and two were left uncleaned. All eight implants were inspected by SEM for qualitative surface changes. All four implants showed relevant changes of the topography at the apical thread flanks. The non-cleaned implants showed an almost complete coverage of the surface by a honeycomb-like structure, consistent with bone residues. The reference implants showed no changes. The results indicate that, for the osseointegration of dental implants, subtractive modifications of implant surfaces are less important than the reestablishment of the destroyed TiO2 layer. Further studies of other implant surfaces are required to verify the present results. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Engineered porous metals for implants

    Science.gov (United States)

    Vamsi Krishna, B.; Xue, Weichang; Bose, Susmita; Bandyopadhyay, Amit

    2008-05-01

    Interest is significant in patient-specific implants with the possibility of guided tissue regeneration, particularly for load-bearing implants. For such implants to succeed, novel design approaches and fabrication technologies that can achieve balanced mechanical and functional performance in the implants are necessary. This article is focused on porous load-bearing implants with tailored micro-as well as macrostructures using laser-engineered net shaping (LENS™), a solid freeform fabrication or rapid prototyping technique that can be used to manufacture patient-specific implants. This review provides an insight into LENS, some properties of porous metals, and the potential applications of this process to fabricate unitized structures which can eliminate longstanding challenges in load-bearing implants to increase their in-vivo lifetime, such as in a total hip prosthesis.

  19. Left Ventricular Assist Devices: The Adolescence of a Disruptive Technology.

    Science.gov (United States)

    Pinney, Sean P

    2015-10-01

    Clinical outcomes for patients with advanced heart failure receiving left ventricular assist devices are driven by appropriate patient selection, refined surgical technique, and coordinated medical care. Perhaps even more important is innovative pump design. The introduction and widespread adoption of continuous-flow ventricular assist devices has led to a paradigm shift within the field of mechanical circulatory support, making the promise of lifetime device therapy closer to reality. The disruption caused by this new technology, on the one hand, produced meaningful improvements in patient survival and quality of life, but also introduced new clinical challenges, such as bleeding, pump thrombosis, and acquired valvular heart disease. Further evolution within this field will require financial investment to sustain innovation leading to a fully implantable, durable, and cost-effective pump for a larger segment of patients with advanced heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Percutaneous left atrial appendage closure for stroke prevention

    DEFF Research Database (Denmark)

    De Backer, Ole; Loupis, Anastasia M; Ihlemann, Nikolaj

    2014-01-01

    INTRODUCTION: In atrial fibrillation (AF) patients with an increased stroke risk, oral anticoagulation (OAC) is the standard treatment for stroke prevention. However, this therapy carries a high risk of major bleeding. Percutaneous closure of the left atrial appendage (LAA) is suggested...... as an alternative option for stroke prevention in AF patients with contraindication(s) for OAC treatment. MATERIAL AND METHODS: A total of 42 patients underwent percutaneous LAA closure. In this report, we describe our experience with this procedure. RESULTS: The patients treated were AF patients with a high stroke...... risk (CHADS-VASc 4.5±1.4) and contra-indication(s) for OAC and/or a high bleeding risk (HAS-BLED 3.7±0.9). A history of intracerebral bleeding was the most common reason for LAA closure. Successful implantation was obtained in 41 of 42 patients. One major peri-procedural complication occurred; a major...

  1. Cataract surgery in patients with left ventricular assist device support.

    Science.gov (United States)

    Eghrari, Allen O; Rivers, Richard J; Alkharashi, Majed; Rajaii, Fatemeh; Nyhan, Daniel; Sikder, Shameema

    2014-04-01

    Left ventricular assist devices (LVADs) have been increasingly used for 20 years in terminally ill patients with advanced heart failure or awaiting cardiac transplantation. Despite improvement in morbidity and mortality from use of these devices, quality of life may be limited by cataract. Access to cataract surgery in this predominantly elderly population is essential but limited by unfamiliarity with these devices. We describe phacoemulsification and intraocular lens implantation in 2 patients with LVADs. The patients had extensive preoperative cardiology evaluations and were instructed to continue warfarin through the day of surgery. Monitored sedation was used with fentanyl and midazolam. Both patients experienced significant improvement in visual acuity and quality of life. Neither experienced intraoperative hemodynamic instability. Cataract surgery may be safely performed in patients with LVAD support when adequate monitoring resources are available. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  2. Immediate breast reconstruction with anatomical implants following mastectomy: The radiation perspective

    Energy Technology Data Exchange (ETDEWEB)

    Ben-David, Merav, E-mail: Merav.ben-david@sheba.health.gov.il [Radiation Oncology Unit, Chaim Sheba Medical Center, Ramat Gan (Israel); Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Granot, Hila [Radiation Oncology Unit, Chaim Sheba Medical Center, Ramat Gan (Israel); Gelernter, Ilana [Statistical Laboratory, School of Mathematics, Tel Aviv University, Tel Aviv (Israel); Scheflan, Michael [Department of Surgery, Assuta and Herzliya Medical Centers, Ramat Gan (Israel)

    2016-07-01

    Immediate implant-based breast reconstruction followed by postmastectomy radiation therapy (PMRT) is controversial because of the risk of compromised treatment plans and concerns regarding cosmetic outcomes. We evaluated the effects of immediate direct-to-implant breast reconstruction with anatomical implants on the quality of PMRT delivered by 3-dimensional conformal radiotherapy (3D-CRT). In this retrospective, single-institution study, patients who had undergone reconstruction with direct anatomic implant, performed by a single surgeon, received 3D-CRT between 2008 and 2013. For each patient, 2 plans (including or excluding internal mammary nodes [IMN]) were created and calculated. The primary end point was the dose distribution among reconstructed breasts, heart, lungs, and IMNs, and between right and left breasts. Of 29 consecutive patients, 11 received right-sided and 18 received left-sided PMRT to a total dose of 50 Gy. For plans excluding IMN coverage, mean D{sub mean} for right and left reconstructed breasts was 49.09 Gy (98.2% of the prescribed dose) and 48.51 Gy (97.0%), respectively. For plans including IMNs, mean D{sub mean} was 49.15 Gy (98.3%) for right and 48.46 Gy (96.9%) for left reconstructed breasts; the mean IMN D{sub mean} was 47.27 Gy (right) and 47.89 Gy (left). Heart D{sub mean} was below 1.56 Gy for all plans. Mean total lung volume receiving a dose of ≥ 20 Gy was 13.80% to 19.47%. PMRT can be delivered effectively and safely by 3D-CRT after direct-to-implant breast reconstruction with anatomical implants, even if patients require IMN treatment.

  3. OLOGEN® implant in the management of glaucoma in an unusual case of Axenfeld-Rieger syndrome

    Directory of Open Access Journals (Sweden)

    O K Radhakrishnan

    2014-01-01

    Full Text Available We report an unusual case of Axenfeld-Rieger Syndrome with secondary glaucoma managed with Ologen® implant. A 35-year-old male presented with complaints of decreased vision in both eyes of 22 years duration. His best corrected visual acuity (BCVA was no perception of light in right eye and 20/30 in left eye. Gonioscopy revealed anterior insertion of iris into trabecular meshwork, prominent iris processes and broad-based synechiae with prominent Schwalbe′s line along the angle circumference with cord-like structures taking its origin at the level of Schwalbe′s line in both eyes. Fundus examination revealed total glaucomatous optic atrophy in right eye with 0.9:1 cup disc ratio with bipolar notch in left eye. Humphrey visual field analysis showed superior and inferior arcuate scotoma in left eye. Intraocular pressure measured by Goldman applanation tonometry was 30 mmHg and 26 mmHg in right and left eye, respectively. After an unsuccessful medical management, he underwent trabeculectomy with Ologen® implant under local anesthesia in his left eye. Postoperatively, at the end of one year, intraocular pressure (IOP in his left eye was controlled without medication. This case highlights the management of secondary angle closure glaucoma in Axenfeld-Rieger syndrome with Ologen® implant.

  4. Anesthesia management for MitraClip device implantation

    Directory of Open Access Journals (Sweden)

    Harikrishnan Kothandan

    2014-01-01

    Full Text Available Aims and Objectives: Percutaneous MitraClip implantation has been demonstrated as an alternative procedure in high-risk patients with symptomatic severe mitral regurgitation (MR who are not suitable (or denied mitral valve repair/replacement due to excessive co morbidity. The MitraClip implantation was performed under general anesthesia and with 3-dimensional transesophageal echocardiography (TEE and fluoroscopic guidance. Materials and Methods: Peri-operative patient data were extracted from the electronic and paper medical records of 21 patients who underwent MitraClip implantations. Results: Four MitraClip implantation were performed in the catheterization laboratory; remaining 17 were performed in the hybrid operating theatre. In 2 patients, procedure was aborted, in one due to migration of the Chiari network into the left atrium and in second one, the leaflets and chords of the mitral valve torn during clipping resulting in consideration for open surgery. In the remaining 19 patients, MitraClip was implanted and the patients showed acute reduction of severe MR to mild-moderate MR. All the patients had invasive blood pressure monitoring and the initial six patients had central venous catheterization prior to the procedure. Intravenous heparin was administered after the guiding catheter was introduced through the inter-atrial septum and activated clotting time was maintained beyond 250 s throughout the procedure. Protamine was administered at the end of the procedure. All the patients were monitored in the intensive care unit after the procedure. Conclusions: Percutaneous MitraClip implantation is a feasible alternative in high-risk patients with symptomatic severe MR. Anesthesia management requirements are similar to open surgical mitral valve repair or replacement. TEE plays a vital role during the MitraClip implantation.

  5. Heterogeneity of left ventricular wall thickening mechanisms.

    Science.gov (United States)

    Cheng, Allen; Nguyen, Tom C; Malinowski, Marcin; Daughters, George T; Miller, D Craig; Ingels, Neil B

    2008-08-12

    Myocardial fibers are grouped into lamina (or sheets) 3 to 4 cells thick. Fiber shortening produces systolic left ventricular (LV) wall thickening primarily by laminar extension, thickening, and shear, but the regional variability and transmural distribution of these 3 mechanisms are incompletely understood. Nine sheep had transmural radiopaque markers inserted into the anterior basal and lateral equatorial LV. Four-dimensional marker dynamics were studied with biplane videofluoroscopy to measure circumferential, longitudinal, and radial systolic strains in the epicardium, midwall, and endocardium. Fiber and sheet angles from quantitative histology allowed transformation of these strains into transmural contributions of sheet extension, thickening, and shear to systolic wall thickening. At all depths, systolic wall thickening in the anterior basal region was 1.6 to 1.9 times that in the lateral equatorial region. Interestingly, however, systolic fiber shortening was identical at each transmural depth in these regions. Endocardial anterior basal sheet thickening was >2 times greater than in the lateral equatorial region (epicardium, 0.16+/-0.15 versus 0.03+/-0.06; endocardium, 0.45+/-0.40 versus 0.17+/-0.09). Midwall sheet extension was >2 times that in the lateral wall (0.22+/-0.12 versus 0.09+/-0.06). Epicardial and midwall sheet shears in the anterior wall were approximately 2 times higher than in the lateral wall (epicardium, 0.14+/-0.07 versus 0.05+/-0.03; midwall, 0.21+/-0.12 versus 0.12+/-0.06). These data demonstrate fundamentally different regional contributions of laminar mechanisms for amplifying fiber shortening to systolic wall thickening. Systolic fiber shortening was identical at each transmural depth in both the anterior and lateral LV sites. However, systolic wall thickening of the anterior site was much greater than that of the lateral site. Fiber shortening drives systolic wall thickening, but sheet dynamics and orientations are of great

  6. Efter cochlear implant

    DEFF Research Database (Denmark)

    Højen, Anders

    2007-01-01

      Dit barn har netop fået et cochlear implant. Hvad nu? Skal barnet fokusere udelukkende på at lære talt sprog, eller skal det også lære/fortsætte med tegnsprog eller støttetegn? Det er et vanskeligt spørgsmål, og før valget foretages, er det vigtigt at vurdere hvilke konsekvenser valget har, dels...... for den sproglige udvikling isoleret set, og dels for barnets udvikling ud fra en helhedsbetragtning. Dette indlæg fokuserer på, hvilke forventninger man kan have til cochlear implant-brugeres sproglige udvikling med talt sprog alene, hhv. med to sprog (tale og tegn). Disse forventninger er baseret på...

  7. Efter cochlear implant

    DEFF Research Database (Denmark)

    Højen, Anders

    Dit barn har netop fået et cochlear implant. Hvad nu? Skal barnet fokusere udelukkende på at lære talt sprog, eller skal det også lære/fortsætte med tegnsprog eller støttetegn? Det er et vanskeligt spørgsmål, og før valget foretages, er det vigtigt at vurdere hvilke konsekvenser valget har, dels...... for den sproglige udvikling isoleret set, og dels for barnets udvikling ud fra en helhedsbetragtning. Dette indlæg fokuserer på, hvilke forventninger man kan have til cochlear implant-brugeres sproglige udvikling med talt sprog alene, hhv. med to sprog (tale og tegn). Disse forventninger er baseret på...

  8. COCHLEAR IMPLANTATION IN IRAN

    Directory of Open Access Journals (Sweden)

    M.H. Khalessi

    1996-07-01

    Full Text Available Deafness has been considered a non - resolving problem until the invention of cochlear implantation (CI. We are reporting the pre- and post-operative results of 14 patients underwent CI, for the first time in Iran, at the cochlear implantation Clinic of Tehran University of Medical Sciences. Four of our patients were able to hold a telephone conversation without difficulty 3 months post-operatively and the rest achieved considerable scores on audiologic tests and a remarkable improvement over 9 month interval between the two sets of tests. Also we have addressed the dramatic improvement in the quality of life of these patients in this paper as well as the results of promontory stimulation and audiometry.

  9. [Implantable middle ear hearing aids].

    Science.gov (United States)

    à Wengen, D F

    2004-01-01

    Conventional acoustic hearing aids are limited in their performance. Due to physical laws their amplification of sound is limited to within 5 kHz. However, the frequencies between 5 and 10 kHz are essential for understanding consonants. Words can only be understood correctly if their consonants can be understood. Furthermore noise amplification remains a problem with hearing aids. Other problems consist of recurrent infections of the external auditory canal, intolerance for occlusion of the ear canal, feedback noise, and resonances in speech or singing. Implantable middle ear hearing aids like the Soundbridge of Symphonix-Siemens and the MET of Otologics offer improved amplification and a more natural sound. Since the first implantation of a Soundbridge in Switzerland in 1996 almost one thousand patients have been implanted worldwide. The currents systems are semi-implantable. The external audio processor containing the microphone, computer chip, battery and radio system is worn in the hair bearing area behind the ear. Implantation is only considered after unsuccessful fitting of conventional hearing aids. In Switzerland the cost for these implantable hearing aids is covered by social insurances. Initially the cost for an implant is higher than for hearing aids. However, hearing aids need replacement every 5 or 6 years whereas implants will last 20 to 30 years. Due to the superior sound quality and the improved understanding of speech in noise, the number of patients with implantable hearing aids will certainly increase in the next years. Other middle ear implants are in clinical testing.

  10. Tubo-uterine implantation.

    Science.gov (United States)

    Green-armytage, V G

    1957-02-01

    After characterizing 2 types of patients presenting with tubal infertility (1 that is "as a rule overweight (the uterus is fixed (and there is easily palpable tubo-uterine pathology," and 1 that is "slim, young, intelligent and often beautiful", 12 1-sentence suggestions are made to increase the success of tubo-uterine implantations in the second type of presenting patient (because the first group has, in the author's mind, disappointing prognosis). Figures are the bulk of the document, with 3 figures demonstrating the type of operation, 3 showing the scheme of the operation, 1 figure showing a posterior view of the implanted tube in utero with a polyethylene prosthesis in situ down to the cervix, and 1 figure showing the instruments used in the operation. A few points of experience the author shares are: 1) operate immediately after a menstrual period; 2) give antibiotics prophylactically and after the procedure; 3) use a Bonney Myomectomy Clamp to elevate the uterus; 4) never use a knife or bistoury at the cornua; 5) use polyethylene rods, when available; and 6) caesarean section is the indicated delivery route after tubo-uterine implantation. Out of 38 patients with the requisite history and findings who have been operated on by this author, 14 have gone to full-term, i.e., 36.1%; 2 have aborted, giving a pregnancy rate of 42.2%, and there was 1 ectopic pregnancy.

  11. Cochlear implants in children implanted in Jordan: A parental overview.

    Science.gov (United States)

    Alkhamra, Rana A

    2015-07-01

    Exploring the perspective of parents on the cochlear implant process in Jordan. Sixty parents of deaf children were surveyed on the information gathering process prior to cochlear implant surgery, and their implant outcome expectations post-surgery. Whether child or parent characteristics may impact parents' post-surgical expectations was explored. Although parents used a variety of information sources when considering a cochlear implant, the ear, nose and throat doctor comprised their major source of information (60%). Parents received a range of information prior to cochlear implant but agreed (93.3%) on the need for a multidisciplinary team approach. Post-surgically, parents' expected major developments in the areas of spoken language (97%), and auditory skills (100%). Receiving education in mainstream schools (92%) was expected too. Parents perceived the cochlear implant decision as the best decision they can make for their child (98.3%). A significant correlation was found between parents contentment with the cochlear implant decision and expecting developments in the area of reading and writing (r=0.7). Child's age at implantation and age at hearing loss diagnosis significantly affected parents' post-implant outcome expectations (pparents agree on the need for a comprehensive multidisciplinary team approach during the different stages of the cochlear implant process. Parents' education about cochlear implants prior to the surgery can affect their post-surgical outcome expectations. The parental perspective presented in this study can help professionals develop better understanding of parents' needs and expectations and henceforth improve their services and support during the different stages of the cochlear implant process. Copyright © 2015. Published by Elsevier Ireland Ltd.

  12. New dental implant selection criterion based on implant design.

    Science.gov (United States)

    El-Anwar, Mohamed I; El-Zawahry, Mohamed M; Ibraheem, Eman M; Nassani, Mohammad Zakaria; ElGabry, Hisham

    2017-01-01

    A comparative study between threaded and plain dental implant designs was performed to find out a new criterion for dental implant selection. Several dental implant designs with a systematic increase in diameter and length were positioned in a cylindrical-shaped bone section and analyzed using finite element method. Four loading types were tested on different dental implant designs; tension of 50 N, compression of 100 N, bending of 20 N, and torque of 2 Nm, to derive design curves. Better stress distribution on both spongy and cortical bone was noted with an increase in dental implant diameter and length. With the increase in dental implant side area, a stress reduction in the surrounding bones was observed, where threaded dental implants showed better behavior over the plain ones. Increasing value of ratio between dental implant side area and its cross-sectional area reduces stresses transferred to cortical and spongy bones. The use of implants with higher ratio of side area to cross-section area, especially with weak jaw bone, is recommended.

  13. Sub-meninges Implantation Reduces Immune Response to Neural Implants

    Science.gov (United States)

    Markwardt, Neil T.; Stokol, Jodi; Rennaker, Robert L.

    2013-01-01

    Glial scar formation around neural interfaces inhibits their ability to acquire usable signals from the surrounding neurons. To improve neural recording performance, the inflammatory response and glial scarring must be minimized. Previous work has indicated that meningeally derived cells participate in the immune response, and it is possible that the meninges may grow down around the shank of a neural implant, contributing to the formation of the glial scar. This study examines whether the glial scar can be reduced by placing a neural probe completely below the meninges. Rats were implanted with sets of loose microwire implants placed either completely below the meninges or implanted conventionally with the upper end penetrating the meninges, but not attached to the skull. Histological analysis was performed 4 weeks following surgical implantation to evaluate the glial scar. Our results found that sub-meninges implants showed an average reduction in reactive astrocyte activity of 63% compared to trans-meninges implants. Microglial activity was also reduced for sub-meninges implants. These results suggest that techniques that isolate implants from the meninges offer the potential to reduce the encapsulation response which should improve chronic recording quality and stability. PMID:23370311

  14. Model for end-stage liver disease predicts right ventricular failure in patients with left ventricular assist devices.

    Science.gov (United States)

    Yost, Gardner L; Coyle, Laura; Bhat, Geetha; Tatooles, Antone J

    2016-03-01

    High rates of right ventricular failure continue to affect postoperative outcomes in patients implanted with left ventricular assist devices (LVADs). Development of right ventricular failure and implantation with right ventricular assist devices is known to be associated with significantly increased mortality. The model for end-stage liver disease (MELD) score is an effective means of evaluating liver dysfunction. We investigated the prognostic utility of postoperative MELD on post-LVAD implantation outcomes. MELD scores, demographic data, and outcomes including length of stay, survival, and postoperative right ventricular failure were collected for 256 patients implanted with continuous flow LVADs. Regression and Kaplan-Meier analyses were used to investigate the relationship between MELD and all outcomes. Increased MELD score was found to be an independent predictor of both right heart failure and necessity for RVAD implantation (OR 1.097, CI 1.040-1.158, p = 0.001; OR 1.121, CI 1.015, p = 0.024, respectively). Patients with RV failure and who underwent RVAD implantation had reduced postoperative survival compared to patients with RV dysfunction (no RV failure = 651.4 ± 609.8 days, RV failure = 392.6 ± 444.8 days, RVAD = 89.3 ± 72.8 days; p < 0.001). In conclusion, MELD can be used to reliably predict postoperative right heart failure and the necessity for RVAD implantation. Those patients with RV failure and RVADs experience significantly increased postoperative mortality compared to those without RV dysfunction.

  15. Isolated persistent left superior vena cava: A case report and its clinical implications

    Directory of Open Access Journals (Sweden)

    Samarjit Bisoyi

    2017-01-01

    Full Text Available The venous anomaly of a persistent left superior vena cava (PLSVC affects 0.3%-0.5% of the general population. PLSVC with absent right superior vena cava, also termed as "isolated PLSVC," is an extremely rare venous anomaly. Almost half of the patients with isolated PLSVC have cardiac anomalies in the form of atrial septal defect, endocardial cushion defects, or tetralogy of Fallot. Isolated PLSVC is usually innocuous. Its discovery, however, has important clinical implications. It can pose clinical difficulties with central venous access, cardiothoracic surgeries, and pacemaker implantation. When it drains to the left atrium, it may create a right to left shunt. In this case report, we present the incidental finding of isolated PLSVC in a patient who underwent aortic valve replacement. Awareness about this condition and its variations is important to avoid complications.

  16. Implantation of the Subcutaneous Implantable Cardioverter-Defibrillator: An Evaluation of 4 Implantation Techniques.

    Science.gov (United States)

    Brouwer, Tom F; Miller, Marc A; Quast, Anne-Floor B E; Palaniswamy, Chandrasekar; Dukkipati, Srinivas R; Reddy, Vivek; Wilde, Arthur A; Willner, Jonathan M; Knops, Reinoud E

    2017-01-01

    Alternative techniques to the traditional 3-incision subcutaneous implantation of the subcutaneous implantable cardioverter-defibrillator may offer procedural and cosmetic advantages. We evaluate 4 different implant techniques of the subcutaneous implantable cardioverter-defibrillator. Patients implanted with subcutaneous implantable cardioverter-defibrillators from 2 hospitals between 2009 and 2016 were included. Four implantation techniques were used depending on physician preference and patient characteristics. The 2- and 3-incision techniques both place the pulse generator subcutaneously, but the 2-incision technique omits the superior parasternal incision for lead positioning. Submuscular implantation places the pulse generator underneath the serratus anterior muscle and subfascial implantation underneath the fascial layer on the anterior side of the serratus anterior muscle. Reported outcomes include perioperative parameters, defibrillation testing, and clinical follow-up. A total of 246 patients were included with a median age of 47 years and 37% female. Fifty-four patients were implanted with the 3-incision technique, 118 with the 2-incision technique, 38 with submuscular, and 37 with subfascial. Defibrillation test efficacy and shock lead impedance during testing did not differ among the groups; respectively, P=0.46 and P=0.18. The 2-incision technique resulted in the shortest procedure duration and time-to-hospital discharge compared with the other techniques (P<0.001). A total of 18 complications occurred, but there were no significant differences between the groups (P=0.21). All infections occurred in subcutaneous implants (3-incision, n=3; 2-incision, n=4). In the 2-incision group, there were no lead displacements. The presented implantation techniques are feasible alternatives to the standard 3-incision subcutaneous implantation, and the 2-incision technique resulted in shortest procedure duration. © 2017 American Heart Association, Inc.

  17. Postsurgical Cystoid Macular Edema following Posterior Chamber Toric Phakic Intraocular Lens Implantation Surgery: A Case Report

    Directory of Open Access Journals (Sweden)

    Julide Canan Umurhan Akkan

    2015-07-01

    Full Text Available Purpose: To describe a case of cystoid macular edema (CME developing after posterior chamber toric phakic intraocular lens (PIOL implantation. Methods: Case report. Results: A 33-year-old male underwent implantation of toric implantable collamer lenses (ICL, a new generation of PIOLs, for both eyes. Preoperative best spectacle-corrected distance visual acuity (BCVA was 20/25 in the right eye and 20/32 in the left eye, with a manifest refraction of -9.25 -4.0 × 4° and -9.75 -4.25 × 171°, respectively. On day 1 postoperatively, the left eye had an uncorrected distance visual acuity (UDVA of 20/60 with a refraction of +2.0 -3.5 × 11°. Despite the rotation of the PIOL, the cylindrical refractive component persisted in the left eye with a refraction of +2.0 -3.5 × 11°. Two weeks after the initial surgery, he presented with a decrease in his visual acuity in the left eye. The UDVA and BCVA were both 20/100 in the left eye with a refraction of +2.0 -4.25 × 3°. Dilated fundus examination and macular optical coherence tomography revealed a CME in the left eye. Following topical nepafenac therapy and explantation of the ICL, we observed a complete resolution of the CME at 3 months with an improvement in BCVA to 20/32 in the left eye. Conclusions: To our knowledge, this is the first reported case of postsurgical CME following toric ICL implantation. In cases of phakic eyes with an intact posterior capsule, postsurgical CME can develop, thus highlighting the purpose of this report.

  18. Intervention for replacing missing teeth: Different types of implants - evidence summary of updated Cochrane review

    Directory of Open Access Journals (Sweden)

    Balendra Pratap Singh

    2015-01-01

    Full Text Available Around 1300 different types of dental implants are available worldwide and the implant manufacturers are resorting to aggressive marketing strategies; claiming their implants to provide a superior outcome. The clinician is left with a constant dilemma on which implant to choose for better clinical outcome and welfare of the patient. Moreover, in India, economical consideration is a concern too. The dentist has to select an implant that provides a good result and is economical. Cochrane systematic reviews provide the gold standard evidence for intervention, diagnosis, etc., and follow a strict quality control. A Cochrane systematic review was done to shed light on whether the different implant surface modifications, shapes or materials significantly influence clinical outcomes. All randomized controlled trials (RCTs till January 17, 2014 were searched and out of the 81 trials, only 27 met the inclusion criteria. This evidence summary from the review concludes that based on the available literature; there is no evidence of any one type of implant being superior to another. There is weak evidence showing roughened dental implants are more prone to bone loss due to periimplantitis. This review indicated that there is a need for well-designed RCTs, with long-term follow-up and low bias. Moreover, none of the included studies was from India, which also points out the need for improving the quality of RCTs conducted in India.

  19. Experimental acrylonitrile butadiene styrene and polyamide evisceration implant: a rabbit clinical and histopathology study

    Directory of Open Access Journals (Sweden)

    D.C. Gomes Júnior

    Full Text Available ABSTRACT The purpose of this study was to evaluate acrylonitrile butadiene styrene (ABS and polyamide implants in rabbits submitted to evisceration at the macroscopic and microstructure level and to assess clinical response and histopathological changes as well. For the experimental study implants of 12mm diameter were prepared by rapid prototyping, weighed and the outer and inner surfaces evaluated macroscopically and by electron microscopy. In addition, a compression test was performed and ultrastructural damage was then determined. After evisceration of the left eyeball, nine New Zealand rabbits received ABS implants and nine others received polyamide implants. The animals were assessed daily for 15 days after surgery and every seven days until the end of the study (90 days. Histopathological evaluation was performed at 15, 45 and 90 days after surgery. The ABS implants weighed approximately 0.44g, while the polyamide ones weighed 0.61g. Scanning electron microscopy demonstrated that the ABS implants had regular-sized, equidistant micropores, while the polyamide ones showed micropores of various sizes. The force required to fracture the ABS implant was 14.39 ±0.60 Mpa, while for the polyamide one, it was 16.80 ±1.05 Mpa. Fifteen days after surgery, we observed centripetal tissue infiltration and scarce inflammatory infiltrate. Implants may be used in the filling of anophthalmic cavities, because they are inert, biocompatible and allow tissue integration.

  20. Influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient satisfaction.

    Science.gov (United States)

    Pellicer-Chover, H; Cervera-Ballester, J; Peñarrocha-Oltra, D; Bagán, L; Peñarrocha-Diago, M A; Peñarrocha-Diago, M

    2016-05-01

    To assess the influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient comfort and stability, speech, functionality and overall satisfaction. A retrospective clinical study was made of patients subjected to rehabilitation of atrophic maxilla with complete maxillary implant-supported fixed prostheses involving a minimum of two zygomatic implants (one on each side) in conjunction with premaxillary implants, and with 12 months of follow-up after implant loading. Subjects used a VAS to score general satisfaction, comfort and stability, speech and functionality, and the results were analyzed in relation to the prosthetic arm length of the zygomatic implants 12 months after prosthetic delivery. Twenty-two patients participated in the study, receiving 22 prostheses anchored on 148 implants (44 were zygomatic and 94 were conventional implants). The mean right and left prosthetic arm length was 5.9±2.4 mm and 6.1±2.7 mm, respectively, with no statistically significant differences between them (p=0.576). The mean scores referred to comfort/retention, speech, functionality and overall satisfaction were high - no correlation being found between prosthetic arm length and patient satisfaction (p=0.815). No relationship could be identified between prosthetic arm length (palatal position) and patient satisfaction.

  1. Cardiac memory during rather than after termination of left bundle branch block.

    Science.gov (United States)

    Littmann, Laszlo; Proctor, Patrick A; Givens, Priscilla M

    2014-01-01

    An 83-year-old woman with chronic left bundle branch block and remote history of pacemaker implantation for intermittent AV block was hospitalized for fatigue and leg swelling. She had no cardiac complaints. Routine 12-lead electrocardiogram showed sinus rhythm with left bundle branch block. There were diffuse negative T waves in the inferior and anterolateral leads that were concordant with the QRS complexes. Echocardiogram was normal and nuclear perfusion heart scan showed no abnormality. It was noted that the negative T waves during left bundle branch block were in the exact same leads as were the deep negative QRS complexes during ventricular pacing. The electrocardiographic changes were consistent with cardiac memory. This case is unique because cardiac memory in patients with intermittent left bundle branch block typically occurs when the QRS complexes normalize and not during left bundle branch block itself. Our findings indicate that memory Ts can develop not only after normalization of wide complex rhythms but also with alternating wide complex rhythms as in the presented case where a ventricular paced rhythm was replaced by left bundle branch block. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Heart rhythm at the time of death documented by an implantable loop recorder

    DEFF Research Database (Denmark)

    Gang, Uffe Jakob Ortved; Jøns, Christian; Jørgensen, Rikke Mørch

    2010-01-01

    The aims of this study were to describe arrhythmias documented with an implantable loop recorder (ILR) in post-acute myocardial infarction (AMI) patients with left ventricular dysfunction at the time of death and to establish the correlation to mode of death....

  3. Heart rhythm at the time of death documented by an implantable loop recorder

    DEFF Research Database (Denmark)

    Gang, Uffe Jakob Ortved; Jøns, Christian; Jørgensen, Rikke Mørch

    2009-01-01

    Aims The aims of this study were to describe arrhythmias documented with an implantable loop recorder (ILR) in post-acute myocardial infarction (AMI) patients with left ventricular dysfunction at the time of death and to establish the correlation to mode of death. Methods and results Post-mortem ...

  4. Radiotherapy for breast cancer is not associated with increased risk of cied implantation

    DEFF Research Database (Denmark)

    Johansen, J. B.; Rehammar, J. C.; Jorgensen, O. D.

    2015-01-01

    tests were calculated. Results: Among 18,308 women treated with radiotherapy for early-stage breast cancer, 179 women had a CIED implanted (166 pacemakers, 13 ICD) subsequent to radiotherapy, 90 in 9,315 left sided and 89 in 8,993 right sided breast cancers. Follow-up time was minimum 8 years...

  5. Radiographic evaluation of anatomical variables in maxilla and mandible in relation to dental implant placement

    Directory of Open Access Journals (Sweden)

    Poornima Chandra

    2016-01-01

    Conclusion: The location and morphology of anatomical structures of the jaws vary not only in different populations but also within the same population. The amount of bone available also showed variations in the same population and in the same individual on the right and left sides. The limiting anatomical structures govern the amount of bone available for possible implant placement.

  6. Soft tissue response to zirconia and titanium implant abutments : an in vivo within-subject comparison

    NARCIS (Netherlands)

    van Brakel, Ralph; Meijer, Gert J.; Verhoeven, Jan Willem; Jansen, John; de Putter, Cornelis; Cune, Marco S.

    2012-01-01

    Aim To compare the health of the soft tissues towards zirconia and titanium abutments in man, as observed using histological data. Material and Methods Twenty patients received two mandibular implants with either a zirconia or titanium abutment (split mouth study design, left-right randomization).

  7. Successful Implantation of Coronary Sinus Lead after Balloon Angioplasty of a Coronary Vein Stenosis

    Directory of Open Access Journals (Sweden)

    Mohammad Hasan Namazi

    2007-12-01

    Full Text Available A 55-year-old man referred for cardiac resynchronization therapy (CRT due to severe heart failure. A severe stenosis in the coronary sinus vein after the posterior branch disallowed the insertion of the lead. Nevertheless, the stenosis was dilated and the left ventricle (LV lead was implanted in the lateral marginal branch.

  8. Aborted sudden cardiac death in a patient with implantable loop recorder

    Directory of Open Access Journals (Sweden)

    Mohammad Alasti, MD

    2017-03-01

    Full Text Available We discuss a 46-year-old man with history of hypertension and inferior wall myocardial infarction and mild left ventricular dysfunction who presented with aborted sudden cardiac death due to episodes of ventricular tachyarrhythmia detected by a Reveal-LINQ which had been implanted one year prior to presentation.

  9. Anatomy and Physiology of Left Ventricular Suction Induced by Rotary Blood Pumps.

    Science.gov (United States)

    Salamonsen, Robert Francis; Lim, Einly; Moloney, John; Lovell, Nigel Hamilton; Rosenfeldt, Franklin L

    2015-08-01

    This study in five large greyhound dogs implanted with a VentrAssist left ventricular assist device focused on identification of the precise site and physiological changes induced by or underlying the complication of left ventricular suction. Pressure sensors were placed in left and right atria, proximal and distal left ventricle, and proximal aorta while dual perivascular and tubing ultrasonic flow meters measured blood flow in the aortic root and pump outlet cannula. When suction occurred, end-systolic pressure gradients between proximal and distal regions of the left ventricle on the order of 40-160 mm Hg indicated an occlusive process of variable intensity in the distal ventricle. A variable negative flow difference between end systole and end diastole (0.5-3.4 L/min) was observed. This was presumably mediated by variable apposition of the free and septal walls of the ventricle at the pump inlet cannula orifice which lasted approximately 100 ms. This apposition, by inducing an end-systolic flow deficit, terminated the suction process by relieving the imbalance between pump requirement and delivery from the right ventricle. Immediately preceding this event, however, unnaturally low end-systolic pressures occurred in the left atrium and proximal left ventricle which in four dogs lasted for 80-120 ms. In one dog, however, this collapse progressed to a new level and remained at approximately -5 mm Hg across four heart beats at which point suction was relieved by manual reduction in pump speed. Because these pressures were associated with a pulmonary capillary wedge pressure of -5 mm Hg as well, they indicate total collapse of the entire pulmonary venous system, left atrium, and left ventricle which persisted until pump flow requirement was relieved by reducing pump speed. We suggest that this collapse caused the whole vascular region from pulmonary capillaries to distal left ventricle to behave as a Starling resistance which further reduced right

  10. Ion Implantation In Optical Fibres

    Science.gov (United States)

    McStay, Daniel

    1989-10-01

    Some initial results on the implantation of single- and multi-mode optical fibres are described. Fibres are wound onto a bobin system for insertion into the implantation chamber. Long and short lengths of fibres as well as discrete elements along a fibre have been implanted. Refractive index changes of 5 x 10-3 have been produced in the fibres, leading to new guiding properties. A large dose dependent fluorescence and attenuation increase is also produced in the fibre.

  11. Dental implant infection and decontaimination

    OpenAIRE

    Mongra, Avtar Chander

    2012-01-01

    The ability of bacteria to adhere titanium implant surfaces has been confirmed in various studies. Elimination of bacteria from the implant surface is necessary in order to terminate the source of infection and disrupt the formation of bio-film. Biomaterial therapies using fibers, gels, and beads to deliver antibiotics have been used in the treatment of Peri-implantitis..There is possibility of development of recombinant protein using r -DNA technology and using the application of tissue engi...

  12. Current trends in dental implants

    OpenAIRE

    Gaviria, Laura; Salcido, John Paul; Guda, Teja; Ong, Joo L.

    2014-01-01

    Tooth loss is very a very common problem; therefore, the use of dental implants is also a common practice. Although research on dental implant designs, materials and techniques has increased in the past few years and is expected to expand in the future, there is still a lot of work involved in the use of better biomaterials, implant design, surface modification and functionalization of surfaces to improve the long-term outcomes of the treatment. This paper provides a brief history and evoluti...

  13. New evidence for favourable effects on haemodynamics and ventricular performance after Parachute(®) implantation in humans.

    Science.gov (United States)

    Schmidt, Tobias; Frerker, Christian; Thielsen, Thomas; Dotz, Inge; Wohlmuth, Peter; Kuck, Karl-Heinz; Schäfer, Ulrich

    2014-10-01

    The Parachute(®) Ventricular Partitioning Device offers an additional strategy for heart failure patients with exclusion of the infarcted wall to decrease left ventricular volumes, myocardial work, and wall stress. The aim of the present study was to evaluate if Parachute implantation might influence acute haemodynamic and functional performance in patients with left ventricular aneurysm after anteroapical infarction. Sixteen patients underwent a Parachute device implantation. Invasive right and left heart haemodynamic assessments as well as left ventricular analysis for evaluating left ventricle end-diastolic and end-systolic volumes, and regional ventricular function were analysed. After implantation a significant increase in stroke volume (+25.4%, P = 0.0005), stroke volume index (+26.5%, P = 0.0005), cardiac output (+25.8%, P < 0.0001) and cardiac index (+25.9%, P < 0.0001) was found. In addition to an increase in mean aortic (P = 0.0050) and pulmonary pressure (P = 0.0347), there were significant increases in stroke work index (P = 0.0003), left (P = 0.0015) and right (P = 0.0024) ventricular stroke work index as well as left and right cardiac work index (both P = 0.0001), while the remaining haemodynamic parameters remained unchanged. Left ventricular analysis showed an acute reduction of the left ventricular end-diastolic volume (-18.0%, P < 0.0001) and left ventricular end-systolic volume (-26.3%, P < 0.0001) and an increase in ejection fraction from 22.9 to 30.6% (+38.4%, P < 0.0001). Most interestingly, the basal wall segments displayed an increased contribution to the left ventricular ejection fraction with increased wall motion in nearly all segments (except the apex region). The data demonstrate the acute haemodynamic efficacy of Parachute device implantation. The implantation of the device displays immediate significant left ventricular volume reduction leading to an acute improved right and left

  14. Immediate Direct-To-Implant Breast Reconstruction Using Anatomical Implants

    Directory of Open Access Journals (Sweden)

    Sung-Eun Kim

    2014-09-01

    Full Text Available BackgroundIn 2012, a new anatomic breast implant of form-stable silicone gel was introduced onto the Korean market. The intended use of this implant is in the area of aesthetic breast surgery, and many reports are promising. Thus far, however, there have been no reports on the use of this implant for breast reconstruction in Korea. We used this breast implant in breast reconstruction surgery and report our early experience.MethodsFrom November 2012 to April 2013, the Natrelle Style 410 form-stable anatomically shaped cohesive silicone gel-filled breast implant was used in 31 breasts of 30 patients for implant breast reconstruction with an acellular dermal matrix. Patients were treated with skin-sparing mastectomies followed by immediate breast reconstruction.ResultsThe mean breast resection volume was 240 mL (range, 83-540 mL. The mean size of the breast implants was 217 mL (range, 125-395 mL. Breast shape outcomes were considered acceptable. Infection and skin thinning occurred in one patient each, and hematoma and seroma did not occur. Three cases of wound dehiscence occurred, one requiring surgical intervention, while the others healed with conservative treatment in one month. Rippling did not occur. So far, complications such as capsular contracture and malrotation of breast implant have not yet arisen.ConclusionsBy using anatomic breast implants in breast reconstruction, we achieved satisfactory results with aesthetics better than those obtained with round breast implants. Therefore, we concluded that the anatomical implant is suitable for breast reconstruction.

  15. Atrial enlargement in symptomatic heart block patients with preserved left ventricular function: possibly related to atrioventricular dyssynchrony.

    Science.gov (United States)

    Lin, Yu-Sheng; Guo, G Bih-Fang; Chen, Yung-Lung; Tsai, Tzu-Hsien; Pan, Kuo-Li; Liu, Wen-Hao; Chen, Mien-Cheng

    2011-05-05

    Right ventricular apical pacing may possibly induce atrial dilatation as a consequence of atrioventricular dyssynchrony. However, atrial enlargement associated with atrioventricular dyssynchrony due to atrioventricular block has never been studied. This case-control survey involved 90 patients with symptomatic atrioventricular block [29 patients with Mobitz type 2 atrioventricular block, 22 patients with high degree of atrioventricular block and 39 patients with complete atrioventricular block]. The control group comprised 54 age- and sex-matched patients with sick sinus syndrome and intact intrinsic atrioventricular conduction. The M-mode measurements were obtained before implant and the left and right atrial areas were measured by planimetry. The peri-implant right atrial area (17.4±3.7 vs. 15.3±3.4 cm2, p=0.002), left atrial area (24.9±4.2 vs. 21.0±3.7 cm2, pblock patients than in sick sinus syndrome patients. The two groups had similar left ventricular ejection fraction. The right atrial area (p=0.01) and left atrial area (p=0.006) remained significantly greater in atrioventricular block patients than in sick sinus syndrome patients after adjustments for age, gender, body surface area, left ventricular dimension and left ventricular ejection fraction in multiple logistic regression analysis. Atrial enlargement occurs in patients with symptomatic atrioventricular block. This phenomenon is possibly related to atrioventricular dyssynchrony. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  16. Cochlear implant assessment: imaging issues

    Energy Technology Data Exchange (ETDEWEB)

    Marsot-Dupuch, K. E-mail: kathlyn.marsot-dupuch@bct.ap-hop-paris.fr; Meyer, B

    2001-11-01

    Cochlear implants are electronic auditory prostheses used to rehabilitate deafened persons who have lost their hair cells. They are partly worn externally and partly implanted in the ear. They provide a direct stimulation of the spiral ganglion cells of the cochlear nerve by bypassing the destroyed hair cells. The objectives of this article are to summarise what head and neck surgeons need to know before cochlear implantation and to describe the imaging study protocol used and anomalies to look for. A few explanations are resumed about placement of a brainstem implant.

  17. Antibacterial coatings on titanium implants.

    Science.gov (United States)

    Zhao, Lingzhou; Chu, Paul K; Zhang, Yumei; Wu, Zhifen

    2009-10-01

    Titanium and titanium alloys are key biomedical materials because of their good biocompatibility and mechanical properties. Nevertheless, infection on and around titanium implants still remains a problem which is usually difficult to treat and may lead to eventual implant removal. As a result, preventive measures are necessary to mitigate implant-frelated infection. One important strategy is to render the implant surface antibacterial by impeding the formation of a biofilm. A number of approaches have been proposed for this purpose and they are reviewed in this article. (c) 2009 Wiley Periodicals, Inc.

  18. Untreated silicone breast implant rupture

    DEFF Research Database (Denmark)

    Hölmich, Lisbet R; Vejborg, Ilse M; Conrad, Carsten

    2004-01-01

    were evaluated. Comparisons were also made for self-reported breast symptoms occurring during the study period and for changes in serum values of antinuclear antibodies, rheumatoid factor, and cardiolipin antibodies immunoglobulin G and immunoglobulin M. The majority of the women with implant rupture...... that implant rupture is a relatively harmless condition, which only rarely progresses and gives rise to notable symptoms. Even so, because of a small risk of silicone spread, the authors suggest that women with implant ruptures be followed clinically, if not operated on. Because implant ruptures often occur...

  19. Direct left ventricular endocardial pacing: an alternative when traditional resynchronization via coronary sinus is not feasible or effective.

    Science.gov (United States)

    Moriña-Vázquez, Pablo; Roa-Garrido, Jessica; Fernández-Gómez, Juan M; Venegas-Gamero, José; Pichardo, Rafael B; Carranza, Manuel H

    2013-06-01

    Biventricular pacing through the coronary sinus (CS) is effective for the treatment of patients with heart failure and left bundle-branch block. However, this approach is not always feasible. Although surgical epicardial lead implantation is an alternative, the technique may be deleterious in some patients. Thus, direct left ventricular (LV) endocardial pacing under local anesthesia may be an option. We describe our technique and analyze the results of direct LV endocardial pacing. Fourteen patients with failed resynchronization via CS (April 2006-September 2011) were selected. Using a femoral approach, we performed transseptal puncture and LV mapping, then fixed the active lead where the longest electrical delay was observed; the generator was placed in the anterior thigh. For resynchronization, eight patients with a device previously implanted through the upper veins received a single-chamber generator that was set to the VVT mode to sense the subclavian pacing spike. Six patients received a complete femoral resynchronization system with either a defibrillator or pacemaker. Patients were followed for 6-54 months. The LV lead was successfully implanted in all cases. Two patients experienced excessive bleeding and two died during follow-up. All except one improved at least one New York Heart Association class and experienced improved left ventricle ejection fraction. One patient with recurrent episodes of ventricular fibrillation was asymptomatic. Direct LV endocardial pacing is safe and may be a less risky, more efficient alternative than surgical epicardial lead implantation for resynchronization via CS. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

  20. Biomechanical evaluation of different abutment-implant connections - A nonlinear finite element analysis

    Science.gov (United States)

    Ishak, Muhammad Ikman; Shafi, Aisyah Ahmad; Rosli, M. U.; Khor, C. Y.; Zakaria, M. S.; Rahim, Wan Mohd Faizal Wan Abd; Jamalludin, Mohd Riduan

    2017-09-01

    The success of dental implant surgery is majorly dependent on the stability of prosthesis to anchor to implant body as well as the integration of implant body to bone. The attachment between dental implant body and abutment plays a vital role in attributing to the stability of dental implant system. A good connection between implant body cavity to abutment may minimize the complications of abutment loosening and implant fractures as widely reported in clinical findings. The aim of this paper is to investigate the effect of different abutment-implant connections on stress dispersion within the abutment and implant bodies as well as displacement of implant body via three-dimensional (3-D) finite element analysis (FEA). A 3-D model of mandible was reconstructed from computed tomography (CT) image datasets using an image-processing software with the selected region of interest was the left side covering the second premolar, first molar and second molar regions. The bone was modelled as compact (cortical) and porous (cancellous) structures. Besides, three implant bodies and three generic models of abutment with different types of connections - tapered interference fit (TIF), tapered integrated screwed-in (TIS) and screw retention (SR) were created using computer-aided design (CAD) software and all models were then analysed via 3D FEA software. Occlusal forces of 114.6 N, 17.2 N and 23.4 N were applied in the axial, lingual and mesio-distal directions, respectively, on the top surface of first molar crown. All planes of the mandibular bone model were rigidly fixed. The result exhibited that abutment with TIS connection produced the most favourable stress and displacement outcomes as compared to other attachment types. This is due to the existence of integrated screw at the bottom portion of tapered abutment which increases the motion resistance.

  1. Finite Element Analysis of Bone Stress in the Posterior Mandible Using Regular and Short Implants, in the Same Context, with Splinted and Nonsplinted Prostheses.

    Science.gov (United States)

    Toniollo, Marcelo Bighetti; Macedo, Ana Paula; Pupim, Denise; Zaparolli, Danilo; da Gloria Chiarello de Mattos, Maria

    The aim of this study was to compare the bone stress generated by rehabilitation using regular and short-length Morse taper implants (11 and 5 mm, respectively) in the same context and allied with splinted (SP) and nonsplinted (NSP) prostheses in the posterior area of the mandible using finite element analysis. Three-dimensional geometric models using regular implants (Ø4 × 11 mm) and short implants (Ø4 × 5 mm) were simulated with a left posterior mandible that had the first premolar tooth and all teeth posterior to that premolar removed. The four experimental groups were as follows: Group 1 NSP (two regular implants and one short implant rehabilitated with nonsplinted prostheses), Group 1 SP (two regular implants and one short implant rehabilitated with splinted prostheses), Group 2 NSP (one regular implant and two short implants rehabilitated with nonsplinted prostheses), and Group 2 SP (one regular implant and two short implants rehabilitated with splinted prostheses). Oblique forces were simulated in molars (365 N) and premolars (200 N). Qualitative and quantitative analyses of the minimum principal stress in bone were performed using the ANSYS Workbench software, version 10.0. The splinted prostheses decreased the stress to the surrounding bone of short implants. Moreover, they also decreased the stress on the surrounding bone adjacent to the tooth. However, the splinted prostheses generated higher stress in the coverage of the surrounding bone for regular intermediate implants and prominently in the bone at the implant cervical region, at the edge crest, compared with the individualized groups. The benefits in the use of splinted prostheses are notable for the preservation of the bone surrounding the short implants and tooth; however, it is necessary to evaluate each clinical situation because, in this context, the regular implants are at higher stress than the individualized implants.

  2. Total Artificial Heart Implantation After Undifferentiated High-Grade Sarcoma Excision.

    Science.gov (United States)

    Kremer, Jamila; Farag, Mina; Arif, Rawa; Brcic, Andreas; Sabashnikov, Anton; Schmack, Bastian; Popov, Aron-Frederik; Karck, Matthias; Dohmen, Pascal M; Ruhparwar, Arjang; Weymann, Alexander

    2016-11-02

    BACKGROUND Total artificial heart (TAH) implantation in patients with aggressive tumor infiltration of the heart can be challenging. CASE REPORT We report on a patient with a rare primary undifferentiated high-grade spindle cell sarcoma of the mitral valve and in the left atrium, first diagnosed in 2014. The referring center did a first resection in 2014. In the course of 17 months, computer tomography (CT) scan again showed massive invasion of the mitral valve and left atrium. Partial resection and mitral valve replacement was not an option. We did a subtotal heart excision with total artificial heart implantation. In this report we discuss complications, risk factors, and perioperative management of this patient. CONCLUSIONS Patients with aggressive tumors of the heart can be considered for TAH implantation.

  3. Vertical Root Fracture: Preservation of the Alveolar Ridge Using Immediate Implants

    Directory of Open Access Journals (Sweden)

    Edmar de Oliveira Oya

    2014-01-01

    Full Text Available Teeth with vertical root fracture (VRF have complete or incomplete fractures that begin in the root and extend toward the occlusal surface. The most frequent causes of VRF originate from physical trauma, occlusal prematurity, inadequate endodontic treatment, and iatrogenic causes. Diagnose is difficult and delay can cause stomatognathic system problem. The purpose of this case report was to evaluate immediate implant placement after extraction of teeth with vertical root fracture. For the 1st case, the VRF in 1st left lower molar was confirmed during surgical flap and at the same time, the tooth was removed and immediate implant was placed. For the 2nd case, the VRF 1st left lower molar was confirmed during endodontic access and at the same appointment, the tooth was removed and the immediate implant is placed. Several studies have shown that immediate implants have similar success rates when compared with late implants. Consider that this approach is a safe procedure with favorable prognosis. In cases of VRF, the main factor to be considered is the presence of adequate bone support and immediate implants can preserve the vertical bone height, adding the fact that good patient compliance reduces the number of surgical interventions and promotes the functionality of stomatognathic system.

  4. Multiplicativity of left centralizers forcing additivity

    Directory of Open Access Journals (Sweden)

    Mohammad Sayed Tammam El-Sayiad

    2014-01-01

    Full Text Available A multiplicative left centralizer for an associative ring R is a map satisfying T(xy = T\\(xy for all x,y in R. T is not assumed to be additive. In this paper we deal with the additivity of the multiplicative left centralizers in a ring which contains an idempotent element. Specially, we study additivity for multiplicative left centralizers in prime and semiprime rings which contain an idempotent element.

  5. Polygonal Area of Prosthesis Support with Straight and Tilted Dental Implants in Edentulous Maxillae.

    Science.gov (United States)

    Wentaschek, Stefan; Lehmann, Karl Martin; Scheller, Herbert; Weibrich, Gernot; Behneke, Nikolaus

    2016-01-01

    The aim of this in vitro study was to assess the increase in the polygonal area of implant-retained prosthesis supports in edentulous maxillae with the use of tilted distal implants compared with the use of straight distal implants, using a variety of implant lengths. A total of 25 DICOM datasets of atrophic edentulous maxillae were provided. Bone augmentations in the molar region had to be avoided. Two straight reference implants were virtually inserted in the anterior region. Two additional implants were placed far distally on both sides (4 groups: [1] straight, 12-mm length; [2] straight, 10 mm; [3] straight, 8 mm; [4] tilted, 12-16 mm). The resulting implant-supported polygon was measured for each of the 4 groups using three-dimensional planning software. The mean sagittal depth of the supported polygon in Group 1 was 9.9 mm (standard deviation [SD] 4.4) on the right and 10.2 mm (SD 4.4) on the left, and it was 33.7 mm (SD 5.8) in width. For Group 2, the mean sagittal depth was 11.5 mm (SD 5.0) on the right and 11.9 mm (SD 4.7) on the left, and the width was 35.2 mm (SD 5.6). The measurements for Group 3 were 13.8 mm (SD 4.9) deep on the right, 13.8 mm (SD 5.1) deep on the left, and 37.0 mm (SD 5.4) in width. For Group 4, the depth was 15.8 mm (SD 4.9) on the right and 16.4 mm (SD 5.8) on the left, and the width was 39.0 mm (SD 5.1). The area of implant-retained prosthesis support can be enlarged by the use of tilted implants (12 to 16 mm in length, 42 to 45 degrees) compared to the use of straight 8-mm implants (resulting increase: about 15%).

  6. Cilia in vertebrate left-right patterning.

    Science.gov (United States)

    Dasgupta, Agnik; Amack, Jeffrey D

    2016-12-19

    Understanding how left-right (LR) asymmetry is generated in vertebrate embryos is an important problem in developmental biology. In humans, a failure to align the left and right sides of cardiovascular and/or gastrointestinal systems often results in birth defects. Evidence from patients and animal models has implicated cilia in the process of left-right patterning. Here, we review the proposed functions for cilia in establishing LR asymmetry, which include creating transient leftward fluid flows in an embryonic 'left-right organizer'. These flows direct asymmetric activation of a conserved Nodal (TGFβ) signalling pathway that guides asymmetric morphogenesis of developing organs. We discuss the leading hypotheses for how cilia-generated asymmetric fluid flows are translated into asymmetric molecular signals. We also discuss emerging mechanisms that control the subcellular positioning of cilia and the cellular architecture of the left-right organizer, both of which are critical for effective cilia function during left-right patterning. Finally, using mosaic cell-labelling and time-lapse imaging in the zebrafish embryo, we provide new evidence that precursor cells maintain their relative positions as they give rise to the ciliated left-right organizer. This suggests the possibility that these cells acquire left-right positional information prior to the appearance of cilia.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

  7. Left Ventricular Thrombosis in Ulcerative Colitis

    Directory of Open Access Journals (Sweden)

    Tarek Saleh

    2010-07-01

    Full Text Available Left ventricular thrombi usually occur in the setting of an acute myocardial infarction, left ventricular aneurysm, or dilated cardiomyopathy. In the absence of ventricular wall motion abnormalities, they are rare. This report describes a patient with ulcerative colitis in whom two-dimensional echocardiography revealed a left intraventricular mass. Thrombosis in ulcerative colitis is a serious condition and can occur in a very young population. This case also shows that left ventricular thrombi can occur in the active setting of ulcerative colitis.

  8. Left-sided omental torsion: CT appearance

    Energy Technology Data Exchange (ETDEWEB)

    Aoun, N.; Haddad-Zebouni, S.; Slaba, S.; Ghossain, M. [Hotel-Dieu de France Hospital, Beirut (Lebanon). Dept. of Radiology; Noun, R. [Hotel-Dieu de France Hospital, Beirut (Lebanon). Dept. of General Surgery

    2001-01-01

    A 34-year-old male presented with exquisite left flank pain. Computed tomography showed a hyperdense vascular structure surrounded by whirling linear streaks situated in the greater omentum under the splenic flexure of the colon. Omental stranding extended caudally into the pelvis where part of the inflamed omentum entered a left inguinal hernia sac. Surgery revealed left-sided torsion of the greater omentum. Left-sided omental torsion is infrequent and pre-operative diagnosis is rarely established. The CT findings of an omental fatty mass with a whirling pattern is characteristic of omental torsion. Preoperative diagnosis is important because conservative management has been suggested. (orig.)

  9. Anarchy, socialism and a Darwinian left.

    Science.gov (United States)

    Clarke, Ellen

    2006-03-01

    In A Darwinian left Peter Singer aims to reconcile Darwinian theory with left wing politics, using evolutionary game theory and in particular a model proposed by Robert Axelrod, which shows that cooperation can be an evolutionarily successful strategy. In this paper I will show that whilst Axelrod's model can give support to a kind of left wing politics, it is not the kind that Singer himself envisages. In fact, it is shown that there are insurmountable problems for the idea of increasing Axelrodian cooperation within a welfare state. My surprising conclusion will be that a Darwinian left worthy of the name would be anarchistic.

  10. Fine trabecularized carbon: ideal material and texture for percutaneous device system of permanent left ventricular assist device.

    Science.gov (United States)

    Tagusari, O; Yamazaki, K; Litwak, P; Kojima, A; Klein, E C; Antaki, J F; Watach, M; Gordon, L M; Kono, K; Mori, T; Koyanagi, H; Griffith, B P; Kormos, R L

    1998-06-01

    The development of a percutaneous artificial internal organ system requires a reliable biocompatible connection between the external environment and the inside of the human body. Such is necessary for the success of a permanent left ventricular assist device. However, the search for a satisfactory interface at the epidermal level has proven to be difficult. Carbon has been proposed for this application, but its texture does not typically promote ingrowth from surrounding tissue. We have therefore employed a new processing method to produce a fine trabecularized carbon implant. The method for preparing the implant involves infiltrating low temperature pyrolytic carbon into the surface of a carbon core which is wrapped with carbon fabric. This results in a tightly woven porous structure of carbon (carbon fiber diameter: 35-50 microm, maximal pore size >200 microm) with gradually increasing porosity from 15-75%. We implanted test samples percutaneously in a calf for in vivo histological evaluation. Thirty days after implantation epidermal downgrowth was minimal. Microscopic analysis revealed that a thin fibrous capsule surrounded the implant, and mature connective tissue with accompanying blood vessels filled the pores of the fine trabecularized carbon layer. From these results we suggest that fine trabecularized carbon is ideally suited for a percutaneous device system in a permanent left ventricular assist device.

  11. Decompression Retinopathy after ExPRESS Shunt Implantation for Steroid-Induced Ocular Hypertension: A Case Report

    Directory of Open Access Journals (Sweden)

    Khawla Abu Samra

    2011-01-01

    Full Text Available Purpose. To present a unique case of decompression retinopathy after the implantation of ExPRESS drainage device. Method. A 25-year-old female patient underwent implantation of ExPRESS drainage device in the left eye for the management of steroid-induced ocular hypertension. Results. On the postoperative day one, best-corrected visual acuity in the left eye was 20/50. Fundus examination revealed diffuse intraretinal hemorrhages, some white-centered, throughout the retina. There was also marked tortuosity to the retinal vasculature and no evidence of choroidal effusion. Intravenous fluorescein angiography and indocyanine green did not contribute to the aetiopathogenesis. Conclusion. Decompression retinopathy can occur following the implantation of ExPRESS drainage device. It is very important to be aware of this complication in patients with relatively high intraocular pressure who is planned for filtration surgery, including the ExPRESS implant.

  12. Age at implantation and auditory memory in cochlear implanted children.

    Science.gov (United States)

    Mikic, B; Miric, D; Nikolic-Mikic, M; Ostojic, S; Asanovic, M

    2014-05-01

    Early cochlear implantation, before the age of 3 years, provides the best outcome regarding listening, speech, cognition an memory due to maximal central nervous system plasticity. Intensive postoperative training improves not only auditory performance and language, but affects auditory memory as well. The aim of this study was to discover if the age at implantation affects auditory memory function in cochlear implanted children. A total of 50 cochlear implanted children aged 4 to 8 years were enrolled in this study: early implanted (1-3y) n = 27 and late implanted (4-6y) n = 23. Two types of memory tests were used: Immediate Verbal Memory Test and Forward and Backward Digit Span Test. Early implanted children performed better on both verbal and numeric tasks of auditory memory. The difference was statistically significant, especially on the complex tasks. Early cochlear implantation, before the age of 3 years, significantly improve auditory memory and contribute to better cognitive and education outcomes.

  13. Zirconia dental implants: a literature review

    National Research Council Canada - National Science Library

    Özkurt, Zeynep; Kazazoğlu, Ender

    2011-01-01

    Titanium and titanium alloys are widely used for fabrication of dental implants. Because of potential immunologic and possible esthetic compromises with titanium implants, novel implant technologies are being developed...

  14. Untreated silicone breast implant rupture.

    Science.gov (United States)

    Hölmich, Lisbet R; Vejborg, Ilse M; Conrad, Carsten; Sletting, Susanne; Høier-Madsen, Mimi; Fryzek, Jon P; McLaughlin, Joseph K; Kjøller, Kim; Wiik, Allan; Friis, Søren

    2004-07-01

    Implant rupture is a well-known complication of breast implant surgery that can pass unnoticed by both patient and physician. To date, no prospective study has addressed the possible health implications of silicone breast implant rupture. The aim of the present study was to evaluate whether untreated ruptures are associated with changes over time in magnetic resonance imaging findings, serologic markers, or self-reported breast symptoms. A baseline magnetic resonance imaging examination was performed in 1999 on 271 women who were randomly chosen from a larger cohort of women having cosmetic breast implants for a median period of 12 years (range, 3 to 25 years). A follow-up magnetic resonance imaging examination was carried out in 2001, excluding women who underwent explantation in the period between the two magnetic resonance imaging examinations (n = 44). On the basis of these examinations, the authors identified 64 women who had at least one ruptured implant at the first magnetic resonance imaging examination and, for comparison, all women who had intact implants at both examinations (n = 98). Magnetic resonance images from the two examinations were compared and changes in rupture configuration were evaluated. Comparisons were also made for self-reported breast symptoms occurring during the study period and for changes in serum values of antinuclear antibodies, rheumatoid factor, and cardiolipin antibodies immunoglobulin G and immunoglobulin M. The majority of the women with implant rupture had no visible magnetic resonance imaging changes of their ruptured implants. For 11 implants (11 percent) in 10 women, the authors observed progression of silicone seepage, either as a conversion from intracapsular into extracapsular rupture (n = 7), as progression of extra-capsular silicone (n = 3), or as increasing herniation of the silicone within the fibrous capsule (n = 1); however, in most cases, these changes were minor. Some changes could be ascribed to trauma, but

  15. Left atrial systolic force in hypertensive patients with left ventricular hypertrophy: the LIFE study

    DEFF Research Database (Denmark)

    Chinali, M.; Simone, G. de; Wachtell, K.

    2008-01-01

    with larger left ventricular diameter and higher left ventricular mass index (both P hypertrophy was greater (84 vs. 64%; P cardiac output......In hypertensive patients without prevalent cardiovascular disease, enhanced left atrial systolic force is associated with left ventricular hypertrophy and increased preload. It also predicts cardiovascular events in a population with high prevalence of obesity. Relations between left atrial......, transmitral peak E velocities and peak A velocities; and lower E/A ratio (all P hypertrophy, but normal left ventricular chamber systolic function with increased...

  16. Cost-Effectiveness of Adding Cardiac Resynchronization Therapy to an Implantable Cardioverter-Defibrillator Among Patients With Mild Heart Failure

    DEFF Research Database (Denmark)

    Woo, Christopher Y; Strandberg, Erika J; Schmiegelow, Michelle D

    2015-01-01

    -defibrillator (ICD) alone among patients with left ventricular systolic dysfunction, prolonged intraventricular conduction, and mild heart failure. DESIGN: Markov decision model. DATA SOURCES: Clinical trials, clinical registries, claims data from Centers for Medicare & Medicaid Services, and Centers for Disease......BACKGROUND: Cardiac resynchronization therapy (CRT) reduces mortality and heart failure hospitalizations in patients with mild heart failure. OBJECTIVE: To estimate the cost-effectiveness of adding CRT to an implantable cardioverter-defibrillator (CRT-D) compared with implantable cardioverter...

  17. Use of the Impella 2.5 left ventricular assist device in a patient with cardiogenic shock secondary to takotsubo cardiomyopathy

    OpenAIRE

    Rashed, Ahmed; Won, Sekon; Saad, Marwan; Schreiber, Theodore

    2015-01-01

    We report a case of cardiogenic shock, believed to be secondary to stress-induced cardiomyopathy, managed by an Impella 2.5 assist device. Apical ballooning pattern was evident on left ventriculogram with no significant coronary artery disease on coronary angiography. Cardiogenic shock was initially managed medically with inotropes and vasopressors, but because the patient was clinically deteriorating, an Impella 2.5 left ventricular assist device was implanted. Remarkable recovery occurred w...

  18. Piezosurgery in implant dentistry

    Directory of Open Access Journals (Sweden)

    Stübinger S

    2015-11-01

    Full Text Available Stefan Stübinger,1 Andres Stricker,2 Britt-Isabelle Berg3,4 1Hightech Research Center of Cranio-maxillofacial Surgery, University of Basel, Allschwil, Switzerland; 2Private Practice, Konstanz, Germany; 3Department of Cranio-maxillofacial Surgery, University Hospital Basel, Basel, Switzerland; 4Division of Oral and Maxillofacial Radiology, Columbia University Medical Center, New York, NY, USA Abstract: Piezosurgery, or the use of piezoelectric devices, is being applied increasingly in oral and maxillofacial surgery. The main advantages of this technique are precise and selective cuttings, the avoidance of thermal damage, and the preservation of soft-tissue structures. Through the application of piezoelectric surgery, implant-site preparation, bone grafting, sinus-floor elevation, edentulous ridge splitting or the lateralization of the inferior alveolar nerve are very technically feasible. This clinical overview gives a short summary of the current literature and outlines the advantages and disadvantages of piezoelectric bone surgery in implant dentistry. Overall, piezoelectric surgery is superior to other methods that utilize mechanical instruments. Handling of delicate or compromised hard- and soft-tissue conditions can be performed with less risk for the patient. With respect to current and future innovative surgical concepts, piezoelectric surgery offers a wide range of new possibilities to perform customized and minimally invasive osteotomies. Keywords: implantology, piezoelectric device, piezosurgery, maxillary sinus elevation, bone grafting, osteotomy, edentulous ridge splitting

  19. Sequential provisional implant prosthodontics therapy.

    Science.gov (United States)

    Zinner, Ira D; Markovits, Stanley; Jansen, Curtis E; Reid, Patrick E; Schnader, Yale E; Shapiro, Herbert J

    2012-01-01

    The fabrication and long-term use of first- and second-stage provisional implant prostheses is critical to create a favorable prognosis for function and esthetics of a fixed-implant supported prosthesis. The fixed metal and acrylic resin cemented first-stage prosthesis, as reviewed in Part I, is needed for prevention of adjacent and opposing tooth movement, pressure on the implant site as well as protection to avoid micromovement of the freshly placed implant body. The second-stage prosthesis, reviewed in Part II, should be used following implant uncovering and abutment installation. The patient wears this provisional prosthesis until maturation of the bone and healing of soft tissues. The second-stage provisional prosthesis is also a fail-safe mechanism for possible early implant failures and also can be used with late failures and/or for the necessity to repair the definitive prosthesis. In addition, the screw-retained provisional prosthesis is used if and when an implant requires removal or other implants are to be placed as in a sequential approach. The creation and use of both first- and second-stage provisional prostheses involve a restorative dentist, dental technician, surgeon, and patient to work as a team. If the dentist alone cannot do diagnosis and treatment planning, surgery, and laboratory techniques, he or she needs help by employing the expertise of a surgeon and a laboratory technician. This team approach is essential for optimum results.

  20. NEGATIVE IMPLANT - A RETROSPECTIVE STUDY

    NARCIS (Netherlands)

    LANDESZ, M; WORST, JGF; SIERTSEMA, JV; VANRIJ, G

    1993-01-01

    Implantation of a negative power intraocular lens is one of the options for surgical correction of high myopia. We studied 36 eyes with a Fechner Worst Claw Lens, implanted in Groningen between March 1987 and November 1991. The preoperative myopia ranged from -7.00 to -30.00 diopters. Twentyone eyes