Grass square wave calibrators work nicely as voltage dividers.
#Visual testing conjuction vs easy eeg how to
Otherwise, follow the instructions in step 3 on how to use a voltage divider to decrease the output of a function generator to the approximate amplitude of slow wave EEG. If the function generator can produce a signal similar in amplitude to human EEG, skip to step 4. The 3.5 Hz frequency is high enough that the amplifier's low frequency filter does not affect the amplitude of the wave. Human EEG slow waves are typically 100 to 500 μV in amplitude therefore, use a signal such as a 200-μV, 3.5-Hz sine wave for calibration. As discussed in the background, this form of calibration is not sufficient to ensure the stability of the recordings. Follow the manufacturer's instructions as to how often the amplifier should be internally calibrated. Most amplifiers have some form of internal calibration. This section provides details on calibrating the recorder with an external signal of known amplitude.
#Visual testing conjuction vs easy eeg software
Other ambulatory recorders include Lifelines Trackit, and Embla.ĮEG analysis software such as PassPlus from Delta Software. The recorder used for this protocol was a Grass Aura. A multimeter or oscilloscope can be used to measure the higher amplitude sine waves prior to voltage reduction).Ĭables and connectors to connect calibration equipment to EEG recorder.Īmbulatory EEG recorder. (Alternatively a function generator that produces a higher amplitude sine wave can be attached to a voltage divider such as the Grass Instruments SWC Square Wave Oscillator (no longer in production) to achieve a signal similar in amplitude to the EEG. Grass-Technologies, Neurotronics, and Falk Minnow Services produce devices that generate signals in this range with about 98% accuracy.
Non-acetone collodion remover such as Mavidon Collodion Remover (MVAP and Integra Neurosupplies)Īdhesive tape remover pads (produced by Dynarex supplied by (MVAP and Integra Neurosupplies)įunction generator that can produce a sine wave approximately the same amplitude of an EEG signal, i.e. (MVAP and Integra Neurosupplies)ġ” wide adhesive type tape such as 3M Durapore or 3M Transpore White (MVAP and Integra Neurosupplies)Ĭonnection from electrodes to EEG recorder such as a head-box or electrode connector box, typically supplied with the EEG recorder.
Gauze pad separated from four layer thickness to two layer thickness and trimmed to 3.5 cm × 2.5 cm.Ĭollodion (produced by Mavidon Medical available from MVAP and Integra Neurosupplies)Īir compressor (20 PSI output) with foot pedal switch and ~4 m of tubing attached to an electrode applicator tip. Subject who has provided informed consent and is dressed in sleeping attireĪ well ventilated room for electrode applicationĪbrading cream, such as NuPrep, SkinPure, or Lemon Prep from a supplier such as Integra NeuroSupplies or MVAP.Įlectrode conductive paste, such as Ten20 (MVAP and Integra Neurosupplies)Įlectrode conductive gel, such as Signa gel (MVAP and Integra Neurosupplies)ĮEG electrodes – gold or silver/silver chloride10 mm diameter cup electrodes with a 48” wire lead with safety connector (Grass, MVAP and Integra Neurosupplies) Materials (Rather than metric units, materials are listed in commonly available dimensions.) Note: Research involving human subjects should adhere to all local and national regulations that ensure protection of human subjects. This protocol assumes that the subjects have been appropriately screened and are suitable for study. The subject's sleep schedule in the days prior to recording can greatly affect the sleep and EEG on the recording night, as can various illegal, prescription, and over the counter drugs. The EEG recorded on a study night depends strongly on the subject's history prior to recording. The following protocol describes calibration and EEG recording on an ambulatory recorder, but a clinical recorder in a laboratory could substitute for an ambulatory recorder. Computer digitization and recording have replaced paper recording, and handheld ambulatory recorders now can replace whole racks of amplifiers. EEG amplifiers and recording instruments have changed greatly in the past 20 years. The protocol provides instruction on EEG recorder calibration, electrode application, EEG recording, and spectral analysis of the EEG. Although the focus is on use for sleep research, the methods can be adapted for other fields of neuroscience investigation. This unit presents methods for recording and analyzing the human electroencephalogram (EEG). EEG Recording and Analysis for Sleep Research
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