Fan grid - Tradução em português

Olá! Gostaria de saber quais são as possíveis traduções de 'fan grid' e 'spline', dentro do contexto abaixo:

"Once contours have been fitted to the surface of the tongue in an ultrasound image it is often the case
that we want to compare them. Typically, several repetitions in one condition need to be compared to
repetitions in a second condition. In this paper we propose describing the tongue contour by 42 onedimensional
values. These one-dimensional values are control points for a spline describing the tongue
contour and each is constrained to lie along a one dimensional axis of a fan grid radiating from the
centre of the probe. It is then possible to calculate the mean and standard deviation along each axis for
a set of tongue contours. Furthermore, when comparing two sets of curves, we can use a
2-tailed test on each of the 42 sets of points assuming unequal variances and unequal sample sizes by
applying the Welch-Satterthwaite equation."