Automated determination of peripheral nerve stimulation parameters to achieve desired effector response – a procedural routine, preliminary studies and proposal of improvements

Table 2 Stimulation parameters and recorded responses for stimuli marked in Figure 4

ID	Stimulation parameters	Stimulus charge [nC]	Paw displacement
			Magnitude [mm]	Direction [º]	Variability [% of magnitude]
a	40 μs, BI: -400 μA, BII: -200 μA, AI + CI	24	7.05	66.2	2.0
A1	10 μs, BII: -200 μA, none, AII + CII	2	6.81	68.9	17.4
A2	Same as stimulus A1	2	7.02	74.9	8.5
b	20 μs, BIII: -400 μA, BIV: 200 μA, AIII + CIII	12	12.27	−67.1	4.2
c	40 μs, BI: -200 μA, BII: -100 μA, AI + CI	12	7.07	−41.8	4.7
C1	40 μs, BIII: -400 μA, none, AIII + BIV + CIII	16	10.25	−64.3	0.6
C2	Same as stimulus C1	16	6.99	−40.5	3.1
C3	Same as stimulus C1	16	4.77	−31.6	4.4

Responses a, b and c were chosen from the results of the stimulus–response mapping (phase 1 of the experiment) and used as the desired responses for the search performed using the automated search routine. A2 and C2 are responses produced using stimulation parameters determined in phase 2 of the experiment by the automated search routine for responses a and c, respectively. A1 and C1 are the responses recorded for the stimuli with the same parameters as A2 and C2, but generated during phase 1 of the experiment. Response C3 was recorded at the end of the experiment when verification using the same stimulation parameters as for C2 was performed (phase 3 of the experiment). Mean response values are provided (each stimulus was repeated three times every 400 μs). The stimulation parameters are provided in the following order: stimulus duration, electrode contact providing the “main pulse” and its amplitude, electrode contact providing the “steering pulse” and its amplitude, electrode contacts being grounded. For an explanation of the symbols for the electrode contacts, see Figure 3.

ISSN: 1475-925X