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Physician’s Manual — VNS Therapy Programming Software (8.1)
10.4.3.
High Lead Impedance, Low Lead Impedance, or
Low Output Current on a Diagnostic Test at
follow-up visit for Model 103, 104, and 105 Pulse
Generators
High Lead impedance (
≥
5300 Ohms), low Lead impedance (
≤
600 Ohms),
or low output current at a follow-up visit can be attributed to any of these
causes.
Lead discontinuity
Lead disconnection from the Pulse Generator
Fibrosis between the nerve and the electrode
Electrode detachment from the nerve
Pulse Generator not able to deliver programmed stimulation
Defective Pulse Generator
Short-circuit condition within the Lead
To alleviate the condition, perform these steps (see Figure 45 on page 84):
1. Interrogate the device.
2. Perform a System Diagnostics and record the results.
If the output current reports “LOW” and Lead impedance reports
“HIGH” (
≥
5300 Ohms), then there is possible
Lead discontinuity
Lead disconnection from the Pulse Generator
Fibrosis between the nerve and electrode
Electrode detachment from the nerve
Defective Pulse Generator
If the output current reports “OK” and Lead impedance reports
“LOW” (
≤
600 Ohms), then there is a possibility of a short-circuit
condition within the Lead or defective Pulse Generator.
If the output current reports “OK” and Lead impedance reports
“HIGH” (
≥
5300 Ohms), then there is a possibility of a Lead
discontinuity, Lead disconnection from the Pulse Generator,
fibrosis between the nerve and the electrode, electrode detachment
from the nerve, or defective Pulse Generator.
If the output current reports “LOW” and Lead impedance reports
“OK”, then the Pulse Generator cannot deliver programmed
output due to increased impedance. Consider lowering the output
current while increasing pulse width.
3. Contact LivaNova at 1 (866) 882-8804 (U.S. and Canada) or
+1 (281) 228-7330 (Worldwide) to report any incidents of high
impedance, low impedance, or low output current.
