User`s manual

Cerebus® User’s Manual
Revision 13.00 / LB-0028 Page 53
Impedance Tester
Note: A patient cable is required for impedance measurements. Contact Blackrock Microsystems Sales at
[e-mail] for more information
Impedance Tester runs an analysis on each channel to ensure proper impedance of every electrode. When selected, a
dialog box is displayed instructing the user to flip the impedance switch located on the patient cable to the
impedance position, marked with a + sign. Data cannot be recorded when the system is in impedance mode. The
impedance function can read impedances of about 50 kΩ (at 1 kHz) or greater. If an impedance measurement is
below 50 kΩ (at 1 kHz) an information box will pop up on the screen stating that the electrode impedance is below
50 kΩ but will not give a number. Steps to measure impedances are stated below:
Figure 48 - Auto Impedance
1) Click on Impedance Tester on Central. The Auto Impedance app will open. If data is being recorded, the user will be
prompted to stop recording or cancel the impedance test. The user will also be given the chance to stop the recording
from the dialog.
2) A dialog box will be displayed notifying that Auto Impedance is checking the impedance switch to ensure it is in the
Impedance position. If not, the user will be prompted to flip the switch to Impedance mode.
3) Auto Impedance checks the array reference wires before beginning.
4) Impedance data is collected then the Auto Impedance screen is displayed. All channels are measured simultaneously.
The measurement takes about one minute. Impedance readings are displayed for every channel. Tolerance is defaulted
to 100-800 Ω. If any channels display numbers outside tolerance, the box will turn yellow (below) or red (over) to
indicate out of range values.
5) Open View  Options to display the Impedance Calculation Settings.
6) Open the Edit menu or right-click one of the bad channels to display the properties menu.
7) Select Disable Bad Channels to mark out-of-tolerance channels with a display border.
8) When the other Central modules are opened, the disabled channels will be blank or marked with an “X”.
9) Click File/Save Values to save the settings to a data in a text file on the hard drive.
10) Click File/Exit to quit Impedance testing. Auto Impedance will check the switch.
11) A dialog will be displayed instructing you to flip the Impedance switch to the Normal position. When the switch has
been toggled to the Normal position, Auto Impedance restores original channel settings and will close. Do not leave the
impedance switch in the Impedance position when not in the Auto Impedance feature. If the switch is accidentally
switched to the Impedance position when not testing, significant noise will be present invalidating the recorded data.