Recording Of Evoked Responses - MAGSTIM 2002 Manual

Magstim Model 200
2
staiting point, gradually increasing, in 10% steps, until a response is
indicated.
3. Press the RUN key and the ARMED indicator will illuminate.
4. When the READY LED illuminates, it indicates that the instrument is
ready to discharge a magnetic pulse.
5. Hold the stimulating coil over the area to be stimulated. Activate the
coil by pressing and maintaining pressure on one, or both, of the
trigger enable switches at the base of the coil.
6. A magnetic pulse can then be produced by depressing the TRIGGER
button (15), by depressing the footswitch, or by applying a Trigger
Input to the TRIGGER INPUT connector on the rear panel. An
internal click will sound and the READY LED will extinguish,
indicating that the Magstim has dischai·ged. When the Magstim has
recharged to the set output power level the READY LED will
illuminate and the system is ready to be re-triggered.
The instrument will continuously discharge and recharge if the
TRIGGER key or foot switch is pressed and held, and the safety
switch on the coil is depressed.
6.3 RECORDING OF EVOKED RESPONSES
In general the electrophysiological responses to magnetic stimulation can
be recorded using the same methods
a<;
for conventional electrical
stimulation. The recording instrument can be triggered from the
TRIGGER OUTPUT socket on the rear panel of the Magstim Model
200
2
•
Alternatively, the Magstim can be triggered by the recording
equipment via the TRIGGER INPUT socket on the rear panel of the
Magstim.
To avoid excessive stimulus artefact occurring on the recordings the
following practices are recommended:
1. Artifact is reduced by keeping the length of loose individual leads to a
minimum. This is best done by keeping all recording leads (active
electrodes and the reference) mnning next to each other. Twisting or
taping the leads together will prove helpful.
2. The recording and reference leads, and the amplifier, should be kept a
minimum of 0.5m away from the magnetic stimulator and the
stimulator coil and its cable whenever possible.
3. The use of a larger reference electrode is recommended to reduce
impedance. For your information, The Magstim Company Limited
The Magstim Company Limited 3001-23-USA 19 August 24, 2006