A Leadless Ventricular Pacemaker Providing Atrioventricular Synchronous Pacing in the Real-World Setting: 12-Month Results from the Micra AV Post-Approval Registry.

BACKGROUND Advances in leadless pacemaker technology have enabled accelerometer-based atrioventricular (AV) synchronous pacing by sensing atrial mechanical contraction. OBJECTIVES To report performance of the Micra AV leadless pacemaker from the worldwide Micra AV post-approval registry (PAR) through 12-months. METHODS The Micra AV PAR is a prospective single-arm observational registry designed to assess safety and effectiveness of Micra AV in a real-world setting. For the present interim analysis, major complications and system revisions through 12-months were summarized and compared to a historical cohort of 2,667 transvenous dual-chamber pacing patients. RESULTS The device was successfully implanted in 796 of 801 patients (99.4%) at 97 centers in 19 countries. Micra AV patients were older (74.1 vs. 71.1 years, P90%. CONCLUSIONS The Micra AV leadless pacemaker was implanted with a high rate of success in patients with multiple co-morbidities, with a significantly lower rate of complications and system revisions through 12-months compared to a historical cohort of patients with transvenous dual-chamber pacemakers

Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed

Does endometriosis affect professional life? A matched case-control study in Switzerland, Germany and Austria.

OBJECTIVES Endometriosis is a gynaecological disease most commonly causing severe and chronic pelvic pain as well as an impaired quality of life. The aim of this study was to investigate if and how endometriosis affects choices regarding professional life as well as the quality of daily working life. DESIGN, SETTING AND PARTICIPANTS In the context of a multicentre case-control study, we collected data from 505 women with surgically/histologically confirmed diagnosis of endometriosis and 505 matched controls. Study participants were recruited prospectively in hospitals and doctors' practices in Switzerland, Germany and Austria. Using a detailed questionnaire, the study investigated work-life and career choices of study participants. MAIN OUTCOME MEASURES Associations between endometriosis/disease symptoms and limitations in career development as well as ability to work. RESULTS Women with endometriosis were less often able to work in their desired profession than women from the control group (adjusted OR=1.84, 95% CI: 1.15 to 2.94, R2=0.029, p=0.001) and they had to take health-related limitations into consideration in their career decisions to a significantly higher degree than women in the control group (OR=4.79, 95% CI: 2.30 to 9.96, R2=0.063, p<0.001). Among women with endometriosis, chronic pain was significantly associated with increased sick leave (OR=3.52, 95% CI: 2.02 to 6.13, R2=0.072, p<0.001) as well as with loss of productivity at work (OR=3.08, 95% CI: 2.11 to 4.50, R2=0.087, p<0.001). CONCLUSIONS Endometriosis is associated with impairment of professional life, in particular with regard to career choices. Further research to develop strategies to support endometriosis-affected women in realising professional opportunities is recommended. TRIAL REGISTRATION NUMBER NCT02511626; Pre-results

Motion detection with NMR markers using real‐time field tracking in the laboratory frame

Purpose: To enhance the utility of motion detection with nuclear magnetic resonance (NMR) markers by removing the need for sequence-dependent calibration. Methods: Two sets of NMR markers are used for simultaneous observation of magnetic field dynamics during imaging procedures. A set of stationary markers at known positions in the laboratory frame serves to determine the field evolution in that frame. Concurrent recording from a set of head-mounted markers then permits calculating their lab-frame positions and derived rigid-body motion parameters. The precision and accuracy of this approach are evaluated relative to current calibration-based solutions. Use for prospective motion correction is then demonstrated in high-resolution imaging of long scan duration. Results: Motion detection with real-time field tracking overcomes the need for explicit calibration without compromising precision, which is assessed at 10 to 30 µm. Relative to full conventional calibration, it is found to offer superior robustness against thermal drift. Relative to more economical modes of calibration, it achieves substantially higher accuracy. Prospective motion correction based on real-time field tracking resulted in consistently high image quality even when head motion exceeded the image resolution by one order of magnitude. Conclusion: Real-time field tracking enables motion detection with NMR markers without calibration overhead and thus overcomes a key obstacle toward routine use. In addition, it renders this mode of motion tracking more robust against system imperfections

Simultaneous feedback control for joint field and motion correction in brain MRI

T2*-weighted gradient-echo sequences count among the most widely used techniques in neuroimaging and offer rich magnitude and phase contrast. The susceptibility effects underlying this contrast scale with B0, making T2*-weighted imaging particularly interesting at high field. High field also benefits baseline sensitivity and thus facilitates high-resolution studies. However, enhanced susceptibility effects and high target resolution come with inherent challenges. Relying on long echo times, T2*-weighted imaging not only benefits from enhanced local susceptibility effects but also suffers from increased field fluctuations due to moving body parts and breathing. High resolution, in turn, renders neuroimaging particularly vulnerable to motion of the head. This work reports the implementation and characterization of a system that aims to jointly address these issues. It is based on the simultaneous operation of two control loops, one for field stabilization and one for motion correction. The key challenge with this approach is that the two loops both operate on the magnetic field in the imaging volume and are thus prone to mutual interference and potential instability. This issue is addressed at the levels of sensing, timing, and control parameters. Performance assessment shows the resulting system to be stable and exhibit adequate loop decoupling, precision, and bandwidth. Simultaneous field and motion control is then demonstrated in examples of T2*-weighted in vivo imaging at 7T.ISSN:1053-8119ISSN:1095-957

Gradient system characterization by impulse response measurements with a dynamic field camera

This work demonstrates a fast, sensitive method of characterizing the dynamic performance of MR gradient systems. The accuracy of gradient time-courses is often compromised by field imperfections of various causes, including eddy currents and mechanical oscillations. Characterizing these perturbations is instrumental for corrections by pre-emphasis or post hoc signal processing. Herein, a gradient chain is treated as a linear time-invariant system, whose impulse response function is determined by measuring field responses to known gradient inputs. Triangular inputs are used to probe the system and response measurements are performed with a dynamic field camera consisting of NMR probes. In experiments on a whole-body MR system, it is shown that the proposed method yields impulse response functions of high temporal and spectral resolution. Besides basic properties such as bandwidth and delay, it also captures subtle features such as mechanically induced field oscillations. For validation, measured response functions were used to predict gradient field evolutions, which was achieved with an error below 0.2%. The field camera used records responses of various spatial orders simultaneously, rendering the method suitable also for studying cross-responses and dynamic shim systems. It thus holds promise for a range of applications, including pre-emphasis optimization, quality assurance, and image reconstruction