Evoke
®
SCS System Clinical Manual
CLIN-UMAN-005175
Revision: 9.00
Page 54 of 101
b. If current was increasing touch
Next
to start the current decreasing.
c. Touch
Cancel
to turn stimulation off and stop the chronaxie and rheobase
measurement.
12. After completion of the measurement, the stimulation settings will return to their state
prior to the initiation of the measurement.
13. Touch
Continue
to return to the neurophysiological measurement menu
14. Touch the
Cancel
button to close the neurophysiological measurements menu.
15. Use the CDV to calculate chronaxie and rheobase using the data that was collected.
Refer to Evoke SCS System Clinical Data Viewer User Manual for instructions.
7.8.3
Conduction velocity measurement
Collect data to estimate the velocity at which elicited neural responses travel up or down the
spinal cord. The CPA automatically moves the measurement and reference electrode (if
applicable) at a fixed current level.
To perform a conduction velocity measurement:
1. Choose the stimulation electrode configuration and settings.
2. Touch
Conduction Velocity
from the neurophysiological measurement menu.
3. Touch
Fixed Reference
for recording configurations in which the reference
electrode
is to remain fixed.
4. Touch
Fixed Distance
for recording configurations in which the reference
electrode
is to remain a fixed distance from the measurement electrode.
5. Set the initial measurement electrode positions (see Figure 7.13):
a. The measurement electrode is usually placed near the stimulation and return
electrodes (with a gap of at least 1 blank electrode).
Caution
: To avoid patient discomfort do NOT place the recording electrode
directly adjacent to any stimulation electrodes (stimulation or return).
b. For fixed reference recordings, the reference electrode is usually placed on the
case electrode (E25), or on the end of the lead furthest from the stimulation
electrodes.
