Table 3.

Using electrode arrays to approximate the optimal model electrode configurations^a

Description			Performance (RPU or AUC)b of Arrays
Case	Orientation	Element	Optimalc	3387	3389	Vercise	12-electrode
Efficiency	parallel	AOP	97	100	100	100	95
Efficiency	parallel	TA	93	100	100	100	87
Efficiency	parallel	LN	88	100	100	100	77
Efficiency	perp.	AOP	29	161	284	283	32
Efficiency	perp.	TA	34	161	282	282	39
Efficiency	perp.	LN	25	161	284	283	36
Selectivity	parallel over perp.	AOP over AOP	16	28	11	11	13
Selectivity	perp. over parallel	AOP over AOP	94	84	84	86	96
Selectivity	parallel over parallel	TA over AOP	86	86	86	86	86
Selectivity	parallel over perp.	TA over AOP	100	99	99	99	100

^aBiphasic stimulation of neural elements ≤ 5 mm from origin.

^bRelative power usage (RPU) for efficiency and area under curve (AUC) for selectivity (see Section 2.2).

^cSee figures 4a, 5a, and 6a for optimal 3-electrode configurations.

Abbreviations: AOP = axon of passage, TA = terminating axon, LN = local neuron, perp. = perpendicular.