A FIELD-COMPATIBLE METHOD FOR INTERPOLATING BIOPOTENTIALS

Mapping of bioelectric potentials over a given surface (e.g., the tors o surface, the scalp) often requires interpolation of potentials into regions of missing data. Existing interpolation methods introduce sign ificant errors when interpolating into large regions of high potential gradients, due mostly to their incompatibility with the properties of the three-dimensional (3D) potential field. In this paper, an interpo lation method, inverse-forward (LF) interpolation, was developed to be consistent with Laplace's equation that governs the 3D field in the v olume conductor bounded by the mapped surface. This method is evaluate d in an experimental heart-torso preparation in the context of electro cardiographic body surface potential mapping. Results demonstrate that IF interpolation is able to recreate major potential features such as a potential minimum and high potential gradients within a large regio n of missing data. Other commonly used interpolation methods failed to reconstruct major potential features or preserve high potential gradi ents. An example of IF interpolation with patient data is provided to illustrate its applicability in the actual clinical setting. Applicati on of IF interpolation in the context of noninvasive reconstruction of epicardial potentials (the ''inverse problem'') is also examined. (C) 1998 Biomedical Engineering Society. [S0090-6964(98)01501-X].