A Systematic Review of In Vitro and In Vivo Radio Frequency Exposure Methods.

Recently, interest in the effects of radio frequency (RF) on biological systems has increased and is partially due to the advancements and increased implementations of RF into technology. As research in this area has progressed, the reliability and reproducibility of the experiments has not crossed multidisciplinary boundaries. Therefore, as researchers, it is imperative to understand the various exposure systems available as well as the aspects, both electromagnetic and biological, needed to produce a sound exposure experiment.

A Novel Idea to Improve Cardiac Output of Mechanical Circulatory Support Devices by Optimizing Kinetic Energy Transfer Available in Forward Moving Aortic Blood Flow.

Mechanical circulatory support devices (MCSDs) have gained widespread clinical acceptance as an effective heart failure (HF) therapy. The concept of harnessing the kinetic energy (KE) available in the forward aortic flow (AOF) is proposed as a novel control strategy to further increase the cardiac output (CO) provided by MCSDs. A complete mathematical development of the proposed theory and its application to an example MCSDs (two-segment extra-aortic cuff) are presented.

A far-field radio-frequency experimental exposure system with unrestrained mice.

Many studies have been performed on exploring the effects of radio-frequency (RF) energy on biological function in vivo. In particular, gene expression results have been inconclusive due, in part, to a lack of a standardized experimental procedure. This research describes a new far field RF exposure system for unrestrained murine models that reduces experimental error.

Design and In Vivo Test of a Batteryless and Fully Wireless Implantable Asynchronous Pacing System.

Unlabelled: Goal: The aim of this study is to develop a novel fully wireless and batteryless technology for cardiac pacing.

Methods: This technology uses radio frequency (RF) energy to power the implanted electrode in the heart. An implantable electrode antenna was designed for 1.

Control strategies for afterload reduction with an artificial vasculature device.

Ventricular assist devices (VADs) have been used successfully as a bridge to transplant in heart failure patients by unloading ventricular volume and restoring the circulation. An artificial vasculature device (AVD) is being developed that may better facilitate myocardial recovery than VAD by controlling the afterload experienced by the native heart and controlling the pulsatile energy entering into the arterial system from the device, potentially reconditioning the arterial system properties. The AVD is a valveless, 80 ml blood chamber with a servo-controlled pusher plate connected to the ascending aorta by a vascular graft.

Effect of pacing site on systolic mechanical restitution curves in the in vivo canine model.

Introduction: Pacing site is known to influence the contractile state of the ventricle. Non-physiologic pacing sites such as the right ventricular apex (RVA) or left ventricular freewall (LVFW) have been shown to decrease the contractile state of normal myocardium, due to abnormal electrical propagation. The impact of pacing at these sites may alter mechanical restitution (MR), a fundamental cardiac property involving the electro-mechanical regulation of contraction.

Novel means to monitor cardiac performance: the impact of the force-frequency and force-interval relationships on recirculation fraction and potentiation ratio.

Insights into intracellular calcium regulation and contractile state can be accomplished by changing pacing rate. Steady-state increases in heart rate (HR) (force-frequency relationship, FFR), and introduction of extrasystoles (ES) (force-interval relationship, FIR) have been used to investigate this relationship. This study focused on the recirculation fraction (RF) and potentiation ratio (PR), obtained from the recovery of the FFR and FIR.