CardioFit: a WebGL-based tool for fast and efficient parametrization of cardiac action potential models to fit user-provided data.

Cardiac action potential models allow examination of a variety of cardiac dynamics, including how behaviour may change under specific interventions. To study a specific scenario, including patient-specific cases, model parameter sets must be found that accurately reproduce the dynamics of interest. To facilitate this complex and time-consuming process, we present CardioFit, an interactive browser-based tool that uses the particle swarm optimization (PSO) algorithm implemented in JavaScript and takes advantage of the WebGL API for hardware acceleration. Our tool allows rapid customization and can find low-error fittings to user-provided voltage time series or action potential duration data from multiple cycle lengths in a few iterations (10-32), corresponding to a runtime of a few seconds on most machines. Additionally, our tool focuses on ease of use and flexibility, providing a webpage interface that allows users to select a subset of parameters to fit, set the range of values each parameter is allowed to assume, and control the PSO algorithm hyperparameters. We demonstrate our tool's utility by fitting a variety of models to different datasets, showing how convergence is affected by model choice, dataset properties and PSO algorithmic settings, and explaining new insights gained about the physiological and dynamical roles of the model parameters.