Neuropace RNS System - Capturing Real-Time ECoG Data

Programming Instructions 55
RNS
®
System User Manual
IMPEDANCE MEASUREMENTS
Impedance measurements are useful for verifying the integrity of a particular electrode. Each
impedance measurement delivers a single pulse of current between an electrode and the
neurostimulator canister (can) to measure the voltage that results as the current flows. Impedance
measurements are reported in Ohms (voltage divided by current).
Abnormal impedance values are measurements greater than 3500 Ohms or less than 250 Ohms. If
impedance measurements are abnormally high, there may be insufficient charge to deliver therapy.
Refer to the Troubleshooting section of this manual for additional information on abnormal
impedance measurements and insufficient charge.
Measuring Impedances between Electrodes and the Can (Each Electrode to the Neurostimulator)
1. Position the wand over the neurostimulator.
2. Go to R
EVIEW DATA tab.
3. Select the M
EASUREMENTS tab.
4. Select the C
URRENT to be delivered.
5. Select A
NODE or CATHODE for the neurostimulator can.
6. Select the M
EASURE button to deliver the single pulse of current.
Note: After the impedance measurements are performed, it is recommended to repeat the
measurement with opposite polarity.
Note: The neurostimulator cannot measure impedance while an episode is being detected
or during any type of therapy delivery. Disable detection and/or therapies or wait for a
detected episode or therapy delivery to finish in order to continue with a successful
impedance measurement.
B
ATTERY VOLTAGE MEASUREMENTS
Normal RNS
®
Neurostimulator battery voltage measurements are between 2.70 and 3.10 Volts.
When the battery voltage measurement drops to 2.75 Volts or less, neurostimulator replacement is
recommended.
Measuring the Battery Voltage
1. Go to REVIEW DATA tab.
2. Select the M
EASUREMENTS tab.
3. Select the M
EASURE button.
C
APTURING REAL-TIME ECOGS
Real-time ECoG capture is useful in evaluating the ECoG signals, adjusting the amplifier gain
settings, and storing real-time ECoG records. Stored real-time ECoG records are available during
detection stimulation, R
EVIEW REPORTS, and ARCHIVED DATA programmer sessions. The real-time
ECoG is classified as user saved.
Note: It is important to remember that the lead labels and montage must be programmed before
real-time ECoGs may be viewed.