Cognionics CGX Mobile-128 Руководство - Страница 12

Просмотреть онлайн или скачать pdf Руководство для Медицинское оборудование Cognionics CGX Mobile-128. Cognionics CGX Mobile-128 20 страниц.

Understanding Readings (20 Channels Shown For Clarity)

Pulse Artifact

Mild Power Line Artifact

Strong Power Line Artifact

EEG sensors are sensitive

enough to detect small

electrical signals on the

cortex. Occasionally, sensors

may lie directly atop a blood

vessel. When this occurs,

sensors may detect the

subject's pulse. Slightly move

the sensors to reduce pulse

artifacts.

Power lines operate between

50 and 60 Hz. Unsecured

power sources may leak

electromagnetic frequencies.

Because EEG records

frequencies from 1hz to about

40hz, power line noise may

negatively impact recordings

on all channels. This is

especially the case when

connection between sensor

and scalp is poor.

To avoid power line artifacts,

have subjects sitting at

least 3 feet from power

cords, plugged-in devices,

and lighting or overhead

fluorescent lights. The

Mobile-128 shields the

sensors from environmental

noise, but issues can still

occur with poor skin contact.

If power line artifacts appear

on all channels, lightly wet A1

Reference Drypad Ear Sensor.