Thymatron
®
System IV Instructions for Use
39
with attached lead-wires is connected to the front panel; and the lead-wires are clipped to the monitoring
electrodes.
When the IMPEDANCE TEST button is pressed and held, the word “TESTING”, will briefly appear in the 8-
digit L.E.D. Then a number ranging from 0 to >3000 ohm, representing the static impedance, will appear. When
the IMPEDANCE TEST button is released, the number is replaced by the message “BASELINE”. The
“BASELINE” message indicates that baseline EEG collection is in progress. When baseline EEG collection has
been accomplished, the word “READY” will appear in the L.E.D. It normally takes about 6-10 seconds for
“READY” to appear.
However, moving the patient’s head, touching or moving the monitoring electrodes, lead-wires, or monitoring
cable during baseline EEG collection will prolong the process by introducing EEG artifact. The less the patient
and monitoring connections are moved or touched during baseline EEG collection, the sooner the “READY”
message will appear, and the patient will be ready to treat. If necessary, stop ventilating the patient for the few
seconds it takes for the “READY” message to appear. Place the lead-wires so that they will not be disturbed by
the anesthetist. Each pair of wires can be taped together about every 6 inches to minimize movement and artifact.
NOTE: If the “READY” message does not appear before the treatment stimulus dose is administered, there will
be neither an Ictal Line™ nor EEG endpoint determinations nor seizure quality measurements because an
adequate baseline was not obtained. However, the treatment itself will not be affected.
It is not necessary for the Thymapad™ stimulus electrodes to be applied in order to obtain a baseline EEG
collection. Do not be concerned with an impedance reading >3000 ohms when no stimulus electrodes have been
applied; baseline EEG collection will proceed anyway. Static impedance will be tested after the stimulus
electrodes have been applied. Repeated pressing of the IMPEDANCE TEST button does not interfere with
baseline EEG collection.
TIP: It is strongly recommended to initiate baseline EEG collection by pressing the IMPEDANCE TEST button
on the Thymatron® System IV’s front panel as soon as the monitoring electrodes and a ground electrode have
been applied., even before applying the Thymapad™ stimulus electrodes (e.g., while the patient is fully awake
and before anesthesia has been administered). This will provide the longest possible period of baseline EEG
collection, maximizing the likelihood that a good baseline will be collected by the time the treatment stimulus is
administered.
STIMULUS DOSE SELECTION
The Thymatron® System IV is shipped with the LOW 0.5 program enabled. This is the recommended choice for
the first treatment in all patients for whom there is no prior information concerning ECT response or seizure
threshold. When desired, the FlexDial™ can be used to select stimulus parameters specifically tailored to the
patient’s established requirements, or to select from among other factory- or user- set stimulus programs.
However, we recommend use of the LOW 0.5 program wherever possible, because it provides a broadly
effective stimulus that is in the physiological range for most patients.
Rotate the PERCENT ENERGY dial to display the available stimulus settings (range: 5% to 100% ENERGY in
