40 of 92 — 26-0008-1100/5
(Worldwide)
Physician’s Manual — VNS Therapy Programming Software (8.1)
Figure 23.
SYSTEM DIAGNOSTICS Screen
Caution:
For Models 100, 101, and 102 Pulse Generators, avoid
performing the System Diagnostics on Pulse Generators for which the
output current is normally less than 1 mA because the patient may
experience increased sensation, coughing, a flushed face, or other
adverse effects. See the physician’s manual for the VNS Therapy Pulse
Generators for a complete list of possible adverse events.
Caution:
During a System Diagnostic for Model 103, 104, and 105
Pulse Generators, a test pulse of 0.25 mA is first used to assess the
Lead impedance. After the Impedance assessment, the behavior of the
diagnostic test is dependent upon the value of the output current
programmed in the Pulse Generator. If the output current is set to 0.0
mA, the diagnostic test is run with an output current of 1.0 mA, a pulse
width of 500
μ
sec, and a frequency of 20 Hz. If the output current is
programmed greater than 0.0 mA, the diagnostic test is run at the
programmed settings.
4.2.2.4.
Normal Mode Diagnostics
The Normal Mode Diagnostics test indicates whether or not the device
(Models 100, 101, and 102) is able to deliver the programmed output
current (see Figure 24). The test should be performed routinely at follow-
up visits if the patient can tolerate an output current of at least 0.75 mA.
Results for this test are generally not reliable if the output current is
programmed to less than 0.75 mA, frequency to less than 15 Hz, or ON
time to less than 30 sec.
If Normal Mode test results indicate high lead impedance, a System
Diagnostics can aid in diagnosing the cause. An output status reading of
“LIMIT” for the Normal Mode Diagnostics indicates that the programmed
Models 100, 101, 102 Models 103, 104, 105
