A Wearable Magnetocardiography Imaging System

PROJECT SUMMARY Recent studies have shown radiation therapy (RT) ablation to be a highly promising alternative therapy for patients with drug-refractory VT who are unable to undergo catheter-based ablation. Ideally, RT ablation is performed in conjunction with noninvasive electrophysiology (EP) imaging, such as ECG imaging (ECGI), so that the entire procedure is noninvasive; however, currently noninvasive EP imaging is much less accurate than RT and needs to be significantly improved to realize the full potential of RT ablation. In this project, we propose to utilize magnetocardiography (MCG) to develop an MCG imaging (MCGI) system. In comparison to ECG, MCG provides fundamental advantages for source localization and imaging due to the favorable transmission properties of magnetic signals. From a practical standpoint, MCG is more convenient because it is a contactless technique, whereas ECGI requires application of a large array of electrodes. The proposed system will be based on a revolutionary type of magnetic sensor, known as an optically-pumped magnetometer (OPM), which was first brought to market by our company. OPMs are far more practical than SQUID magnetometers because they are smaller, less expensive, and operate at room temperature. This will enable construction of an MCGI system with a conformal sensor array that covers the entire torso. The overall goal is to construct an MCGI system with improved accuracy and ease-of-use, compared to current ECGI/MCGI systems. The Phase I aims are to 1) determine an optimal sensor configuration for the MCGI system based on analysis of the spatial properties of the signal, 2) design a compact magnetic shield that is patient-friendly and minimizes the space requirements of the system, 3) devise a strategy for rapid, accurate digitization of the sensor locations, and 4) demonstrate the feasibility of key aspects of the proposed techniques in a small study of normal subjects.