Evoke
®
SCS System Clinical Manual
CLIN-UMAN-005175
Revision: 9.00
Page 19 of 101
Figure 6.9: Impedances displayed on the 24 electrodes and CLS case (E25).
3. An electrode with a cross through it
has high impedance (> 4000 Ω) and may
be disconnected. A disconnected electrode shows an impedance of ∞ and cannot be
used for stimulation. Measurement electrodes that are disconnected will not record
valid ECAPs.
Note:
The CLS case cannot be used for stimulation and may show as high impedance
(> 4000 Ω). The CLS case may be used for recording even if high impedance is shown.
4. Electrodes with a lightning bolt through them
may be shorted (< 50 Ω) and care
should be taken when programming.
Caution:
If the electrodes show an open circuit (i.e. disconnected):
•
Wipe any blood or fluid off the lead connection contacts.
•
If the system is fully implanted, a high impedance may indicate that the lead is
broken or dislodged from the header and the patient may require revision
surgery if stimulation cannot be adequately reprogrammed.
Note
: When connected to an eCLS the CLS case is disconnected and cannot be used.
6.6
Set up lead orientation
1. Touch the handle at the bottom of the lead image to move it up, down, or switch sides
to a position that reflects the lead location in the most recent fluoroscopy image (see
Figure 6.10). This will aid in determining the best stimulation and measurement
electrode combination.
2. If a recent fluoroscopy image is not available then use the lead offset test to estimate
the vertical alignment of the implanted leads (see Section 7.8.4).
