Effects of cardiac growth on electrical dyssynchrony in the single ventricle patient

Single ventricle patients, including those with hypoplastic left heart syndrome (HLHS), typically undergo three palliative heart surgeries culminating in the Fontan procedure. HLHS is associated with high rates of morbidity and mortality, and many patients develop arrhythmias, electrical dyssynchrony, and eventually ventricular failure....

Impact of Obesity on Atrial Electrophysiological Substrate

(1) Background. Obesity is a well-established worldwide recognised risk factor for atrial fibrillation (AF). Prior review papers reported on the associations between obesity and AF development, but not on the relation between obesity and atrial electrophysiology. We therefore conducted a systematic review to describe the current knowledge of...

Biophysical mechanisms responsible for ultrasound neuromodulation in bilayer lipid membranes: Enabling the research that uncovers the mysterious interactions between ultrasound and neurons

Medical technology has seen great progress over the last centuries, developing increasingly more specialised therapy to benefit human health. The rise of the pharmaceutical industry and the research it drives are contributors to this success. However, in humanity's attempt to tackle more and more complex health issues, the conventional methods...

Modelling and Analysis of Atrial Epicardial Electrograms: An approach based on graph signal processing and confirmatory factor analysis

Atrial fibrillation (AF) is a frequently encountered cardiac arrhythmia characterized by rapid and irregular atrial activity, which increases the risk of strokes, heart failure and other heart-related complications. The mechanisms of AF are complicated. Although various mechanisms were proposed in previous research, the precise mechanisms of AF...

A compact microscope for voltage imaging

Voltage imaging and optogenetics offer new routes to optically detect and influence neural dynamics. Optimized hardware is necessary to make the most of these new techniques. Here we present the Octoscope, a versatile, multimodal device for all-optical electrophysiology. We illustrate its concept and design and demonstrate its capability to...

Recording Neuronal Activity On Chip with Segmented 3D Microelectrode Arrays

We present preliminary recordings on chip of three-dimensional (3D) electric neuronal activity from cultures of cortical neurons derived from human-induced pluripotent stem cells (hiPSCs). The recordings were obtained through 3D microelectrode arrays (MEAs) composed of truncated, 90 μm-high Si micropyramids endowed with multiple, electrically...

How drugs modulate the performance of the human heart

Many drugs interact with ion channels in the cells of our heart and trigger heart rhythm disorders with potentially fatal consequences. Computational modeling can provide mechanistic insight into the onset and propagation of drug-induced arrhythmias, but the effect of drugs on the mechanical performance of the heart remains poorly understood....

Atrial fibrillation fingerprinting

Atrial fibrillation (AF) is a common age-related cardiac arrhythmia. AF is characterized by rapid and irregular electrical activity of the heart leading to a higher risk of stroke and heart failure. During AF, the upper chambers of the heart, called atria, experience chaotic electrical wave propagation. However, despite the various mechanisms...

Microelectronic design of a pseudo voltage clamp for a 0.18um CMOS-based mesoscale neural interface for intracellular in-vitro recording and stimulation

The need to understand how the brain works has sparked interest in electrode arrays to record neural signals. Intracellular recordings with nanoelectrodes that penetrate the cell allow better signal quality and additional functions such as voltage clamping to set the neuron's transmembrane voltage. The voltage clamp aims to facilitate the...

Cardiac mapping on ex vivo perfused porcine slaughterhouse hearts: A Langendorff perfusion protocol for epicardial mapping on isolated beating hearts

Cardiac mapping techniques, in which an electrode-array is placed directly on the surface of the heart, were developed to gain a better insight in the underlying electropathology of cardiac arrhythmias. This procedure is performed in patients undergoing cardiac surgery, but here not all relevant cardiac structures and conduction inquiries can be...

A compact matrix model for atrial electrograms for tissue conductivity estimation

Finding the hidden parameters of the cardiac electrophysiological model would help to gain more insight on the mechanisms underlying atrial fibrillation, and subsequently, facilitate the diagnosis and treatment of the disease in later stages. In this work, we aim to estimate tissue conductivity from recorded electrograms as an indication of...

Design and MEMS Microfabrication of an Optrode for Combined Optogenetics and Electrophysiology Studies

Optogenetics is a biological technique that uses light to control cells in living tissues, typically neurons, that have been genetically modified to express light-sensitive ion channels. Using this technique, neuroscientists can investigate the neural circuits underlying neurological diseases with a higher spatio-temporal resolution when...

Stretchable Micro-Electrode Arrays for Electrophysiology

A potential serious side effect of drugs is cardiotoxicity which can result in lethal heart arrhythmias. Cardiotoxicity has been the leading cause of drug withdrawals from the market in the past decades, and has been responsible for costly failures in late stage clinical trials. This highlights the unmet need in the pharmaceutical industry for...

Design of efficient and safe neural stimulators: A multidisciplinary approach

Neural stimulation is an established treatment methodology for an increasing number of diseases. Electrical Stimulation injects a stimulation signal through electrodes that are implanted in the target area of the central or peripheral nervous system in order to evoke a specific neuronal response that suppresses or treats pathological activity....

Disruption of Functional Brain Networks in Alzheimer’s Disease: What Can We Learn from Graph Spectral Analysis of Resting-State Magnetoencephalography?

In Alzheimer’s disease (AD), structural and functional brain network organization is disturbed. However, many of the present network analysis measures require a priori assumptions and methodological choices that influence outcomes and interpretations. Graph spectral analysis (GSA) is a more direct algebraic method that describes network...

Numerical schemes for the simulation of three-dimensional cardiac electrical propagation in patient-specific ventricular geometries

This paper introduces different numerical strategies in computational electrophysiology, based on the Finite Element Method to handle the space discretization of the governing equations. The long-term goal is to apply these computational techniques to study the three-dimensional electrical propagation in patient-specific ventricular geometries,...