Fig 3. Cardiac responses to different combinations of VNS parameters, estimated with a Gaussian process regression for sheep 1.

The chronotropic (${\widehat{y}}_{\Delta \text{RR}}$), dromotropic (${\widehat{y}}_{\Delta \text{PR}}$) and inotropic (${\widehat{y}}_{\raisebox{1ex}{$dP$}\!\left/ \!\raisebox{-1ex}{$dt\text{max}$}\right.}$) responses are shown in the first, second and third rows, respectively. Note the different scales of each colormap. The continuous black line represents a reference threshold of 5% variation with respect to the baseline value.