Orthogonal polynomials used as soft tissue energy density functions

A mathematical method is developed for computing the coefficients of soft tissue energy density polynomials, satisfying certain constraints. The polynomial coefficients are computed in the least squares sense. It is demonstrated that this method: (a) determines up to 30 polynomial coefficients whereas the unmodified least squares method based on Maclaurin power series determines up to nine coefficients; and (b) increases numerical stability and accuracy by several orders of magnitude. All computations are carried out in single precision on a LSI-11/23 laboratory minicomputer. The algorithm is particularly useful for on-line data analysis using small laboratory computers.