Mind Peak WaveRider Manual de instrucciones descargar pdf (Pagina 19)

WaveRider Operating Manual

Notes on Attaching Brainwave Electrodes

Attaching electrodes is more of an art than a science. It is not unusual for new users of

electrodes to have difficulty establishing a good brainwave electrode contact.

Electrode contact is extremely important. If electrodes do not make a good contact the

WaveRider will display random environmental noise rather than electrophysiological data. If

signals resembling brainwaves are displayed that appear identical whether or not the

electrodes are attached to the body, this indicates a poor connection.

A bad signal may be caused by a poor electrode connection and/or improper leadwire

placement. Electrode contact and leadwire placement are the most important aspects of noise

cancellation.

Sources of poor electrode contact include:

• Poorly attached electrodes,

• High skin impedance (due to skin that is oily, dirty or that has a lot of dead skin cells),

• Dirty or oxidized electrodes. (See below for information on cleaning electrodes).

Sources of improper leadwire placement include:

• Long lead wires,

• Lead wires being moved,

• Lead wires that pass by a source of electrical noise such as a computer monitor.

How to Determine Electrode Contact Quality

Whether a good signal has been achieved is determined by viewing the strip chart of the

channel to which the electrodes are attached. Poor electrode contact can result in the strip

chart displaying two different conditions. In the first condition the signal displays

insufficient amplitude ( i.e. vertical movement) under appropriate amplification (usually

range 7 for brainwaves). The signal should typically occupy at least 30% of the vertical

height of the strip chart window under appropriate amplification. In the second condition a

signal with substantial amplitude is displayed, but the signal displays environmental noise

rather than a biological signal. The environmental noise will usually be interference from 50

or 60 hertz power lines, but can also be caused other electronic devices such as computer

monitors.

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Mind Peak WaveRider Manual de instrucciones Pagina 19