AimsPermanent cardiac pacing is the only effective treatment for symptomatic bradycardia, but complications associated with conventional transvenous pacing systems are commonly related to the pacing lead and pocket. We describe the early performance of a novel self-contained miniaturized pacemaker.Methods and resultsPatients having Class I or II indication for VVI pacing underwent implantation of a Micra transcatheter pacing system, from the femoral vein and fixated in the right ventricle using four protractible nitinol tines. Prespecified objectives were >85% freedom from unanticipated serious adverse device events (safety) and <2 V 3-month mean pacing capture threshold at 0.24 ms pulse width (efficacy). Patients were implanted (n = 140) from 23 centres in 11 countries (61% male, age 77.0 ± 10.2 years) for atrioventricular block (66%) or sinus node dysfunction (29%) indications. During mean follow-up of 1.9 ± 1.8 months, the safety endpoint was met with no unanticipated serious adverse device events. Thirty adverse events related to the system or procedure occurred, mostly due to transient dysrhythmias or femoral access complications. One pericardial effusion without tamponade occurred after 18 device deployments. In 60 patients followed to 3 months, mean pacing threshold was 0.51 ± 0.22 V, and no threshold was ≥2 V, meeting the efficacy endpoint (P < 0.001). Average R-wave was 16.1 ± 5.2 mV and impedance was 650.7 ± 130 ohms.ConclusionEarly assessment shows the transcatheter pacemaker can safely and effectively be applied. Long-term safety and benefit of the pacemaker will further be evaluated in the trial.Clinical Trial RegistrationClinicalTrials.gov ID NCT02004873.

Abstract. Mobile devices with multi-touch capabilities are becoming increasingly common, largely due to the success of the Apple iPhone and iPod Touch. While there have been some advances in touchscreen accessibility for blind people, touchscreens remain inaccessible in many ways. Recent research has demonstrated that there is great potential in leveraging multi-touch capabilities to increase the accessibility of touchscreen applications for blind people. We have created No-Look Notes, an eyes-free text entry system that uses multi-touch input and audio output. No-Look Notes was implemented on Apple's iPhone platform. We have performed a within-subjects (n = 10) user study of both No-Look Notes and the text entry component of Apple's VoiceOver, the recently released official accessibility component on the iPhone. No-Look Notes significantly outperformed VoiceOver in terms of speed, accuracy and user preference.

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Leadless Implant Procedure. Two major studies have shown that leadless pacemakers are safe and effective for patients requiring right ventricular rate responsive pacing therapy. This positive result recently led to FDA approval of one of the available leadless pacing devices. While this new technology is promising, it requires a different skill set for safe implantation. In this article, we review in detail the different steps required for implantation of tine-based leadless pacemakers while providing tips and tricks to minimize

BackgroundThe introduction of transcatheter pacemaker technology has the potential to significantly reduce if not eliminate a number of complications associated with a traditional leaded pacing system. However, this technology raises new questions regarding how to manage the device at end of service, the number of devices the right ventricle (RV) can accommodate, and what patient age is appropriate for this therapy. In this study, six human cadaver hearts and one reanimated human heart (not deemed viable for transplant) were each implanted with three Micra devices in traditional pacing locations via fluoroscopic imaging.MethodsA total of six human cadaver hearts were obtained from the University of Minnesota Anatomy Bequest Program; the seventh heart was a heart not deemed viable for transplant obtained from LifeSource and then reanimated using Visible Heart® methodologies. Each heart was implanted with multiple Micras using imaging and proper delivery tools; in these, the right ventricular volumes were measured and recorded. The hearts were subsequently dissected to view the right ventricular anatomies and the positions and spacing between devices.ResultsMultiple Micra devices could be placed in each heart in traditional, clinically accepted pacing implant locations within the RV and in each case without physical device interactions. This was true even in a human heart considered to be relatively small.ConclusionsAlthough this technology is new, it was demonstrated here that within the human heart's RV, three Micra devices could be accommodated within traditional pacing locations: with the potential in some, for even more.

This fixation technology provides a novel solution to enable the attachment of a transcatheter pacemaker directly within the heart.

Multiple leadless pacemakers implanted in the RV do not appear to impact cardiac function. Therefore, it appears safe to implant multiple leadless pacemakers in the same heart.

The potentiometric and AC impedance characteristics of all solid-state sodium-selective electrodes based on planar screen-printed Ag/AgCl electrodes are described. Two solid-state designs have been investigated. The first was based on the deposition of a sodium-selective PVC membrane directly on lop of a screen-printed Ag/AgCl electrode. The second design included a NaCl doped hydrogel layer, between the PVC and Ag/AgCI layers. The hydrogel provides a mechanism to relieve any blockage to charge transfer occumng when PVC membranes are used directly on top of Ag/AgC1 and also improves adhesion between the two layers. Results suggest the electrodes display fast ion exchange kinetics, low noise and drift. The performance compares favorably to that of a conventional ion-selective electrode with internal filling solution.