Evoke
®
SCS System Clinical Manual
CLIN-UMAN-005175
Revision: 9.00
Page 30 of 101
signal quality by adjusting the ECAP measurement settings (see Section 6.10) and/or
adjusting the stimulation settings (see Section 6.8).
Figure 6.19: The Activation plot – ECAP amplitude (μV) versus Current (mA).
6. If the criteria for the activation plot are met, select the patient sensitivity value that is
closest to the measured sensitivity value, rounded up
, in the
measurement and feedback settings menu (see Section 8.2). The minimum patient
sensitivity is 14 µV/mA.
6.12
Set appropriate limits and increments
Prior to final testing, appropriate limits and increments should be set for each program that the
patient has saved to their stimulator (see Section 6.15). Refer to Table 6.1 for guidelines on
determining appropriate values.
The limits (both stimulation current and ECAP target) should be tested to ensure that the
stimulator has enough range to allow the patient to receive therapy at a comfortable level
across a range of postures (e.g. leaning forward, leaning back, standing, sitting, and walking),
and adjusted accordingly if required.
The increments (stimulation current and ECAP target) should be tested above patient
perception threshold to ensure that each step can be felt by the patient, ensuring that it is not
too large (e.g. large changes in intensity) or too small (e.g. no noticeable changes in intensity),
and adjusted accordingly if required.
Note:
The settings may need to be adjusted following testing of each program (see
Section 6.13 and 6.14).
Measured
Sensitivity
Stimulator output current axis
ECAP
measurement
axis
Estimated slope of
Activation Plot (gray line)
Point where ECAP measurement
starts to increase (ECAP threshold)
