T. M. Macrobert, Spherictrl Hiirmonics-,4n Elerrientcrn Treatise on Hurrwnic Functions with Appliccitions. Data Transmission from an Implantable Biotelemeter by Load-shift Keying Using Circuit Configuration Modulator

The torso surface can be represented by any complete set of orthogonal functions, such as Fourier functions. However, unlike the 2and 3-D Fourier representations [20], [21], the surface harmonic expansion method can reconstruct the boundary shapes from an arbitrary set of measured boundary points, regardless of their placement and ordering. In addition, compared to the interpolation techniques [22], the boundary is described by the sum of known functions in a simple and continuous form. Recently, Nielsen et al. [23] presented an efficient way for reconstruction of the heart surfaces. This description can also be extended to realistic torso models. Although their method is an important contribution to realistic modeling techniques, it is highly labor-intensive [23].