public Electrode(string name, int windowSizeEEG = 180, double influenceEEG = .2, double zThresholdEEG = 3.5, int windowSizeBand = 10, double influenceBand = 0, double zThresholdBand = 3.5)
{
Name = name;
// set electrode parameters
WindowSizeEEG = windowSizeEEG;
InfluenceEEG = influenceEEG;
ZThresholdEEG = zThresholdEEG;
// band data parameters
WindowSizeBand = windowSizeBand;
InfluenceBand = influenceBand;
ZThresholdBand = zThresholdBand;
// initialize eeg data containers
EEGRaw = new EEGData();
Theta = new EEGData();
Alpha = new EEGData();
BetaL = new EEGData();
BetaH = new EEGData();
Gamma = new EEGData();
}
// recieves historical data and current data point (cld. be band or raw signal) as input
// indicates whether current data point represents a peak as output
public static bool hasPeak(EEGData eegData, double currSignal, bool isBand = false)
{
int windowSizePeak = new int();
double influencePeak = new double();
double zThresholdPeak = new double();
// change parameters based on whether band or raw eeg
if (isBand)
{
windowSizePeak = WindowSizeBand;
influencePeak = InfluenceBand;
zThresholdPeak = ZThresholdBand;
}
else
{
windowSizePeak = WindowSizeEEG;
influencePeak = InfluenceEEG;
zThresholdPeak = ZThresholdEEG;
}
var isPeak = false;
// if preload still needs to occur
if (eegData.WindowValues.Count < windowSizePeak)
{
eegData.WindowValues.Add(currSignal);
// calculate window average
eegData.MovingAvg = eegData.WindowValues.Average();
// calculate window standard deviation
eegData.MovingStd = Math.Sqrt(eegData.WindowValues.Average(v => Math.Pow(v - eegData.MovingAvg, 2)));
return(false);
}
// indicate preload is done
else
{
if (isBand)
{
IsBandPreload = false;
}
else
{
IsEEGPreLoad = false;
}
}
// set decision boundaries for file write
eegData.UpperBound = eegData.MovingAvg + (zThresholdPeak * eegData.MovingStd);
eegData.LowerBound = eegData.MovingAvg - (zThresholdPeak * eegData.MovingStd);
// if extreme
if (Math.Abs(currSignal - eegData.MovingAvg) > zThresholdPeak * eegData.MovingStd)
{
// if peak
if (currSignal > eegData.MovingAvg)
{
// set last value of window equal to current value
currSignal = influencePeak * currSignal + (1 - influencePeak) * currSignal;
isPeak = true;
}
}
// set last value of window equal to current value after removing old data
eegData.WindowValues.RemoveAt(0);
eegData.WindowValues.Add(currSignal);
// calculate window average
eegData.MovingAvg = eegData.WindowValues.Average();
// calculate window standard deviation
eegData.MovingStd = Math.Sqrt(eegData.WindowValues.Average(v => Math.Pow(v - eegData.MovingAvg, 2)));
return(isPeak);
}
