Three-dimensional wound surface area calculations with a CAD surface element model

A quadrature scheme is presented for the calculation of three-dimensional (3-D) wound surface area from a 3-D CAD surface element model (SEM) and a two-dimensional (2-D) wound image. The algorithm employs discrete summation over the 2-D wound region with local curvature obtained from the SEM. An approximation is derived for the error due to elemental discretization, and is found to be negligible for the resolution considered here. The alternative method of direct summation over surface element space is shown to result in significant fringe error along the wound boundary.