Figure 5. Model errors were minimal with omnidirectional stimulation of pathways.

(A) Relative errors ((predicted value – actual value) / actual value) of evoked potential 1 (EP₁) collapsed across patients, and subdivided by electrode configuration (top) or type (bottom). (B) Model fits in patients with directional leads using all data (left), only data acquired during omnidirectional stimulation with a monopolar, ring electrode (middle), or only data acquired during directional stimulation with bipolar or segmented electrodes (right). R² = coefficient of determination. (C) Comparative model performance with only data from omnidirectional stimulation cases. Data from patients in B are emphasized (black arrow and lines). R² were indeterminate for CSBT in Patient 7, 10, and 11 because EP₀ was zero for all of their settings.