public virtual IBFSample[] ApplyMontage(IBFSample[] samples, SignalFilter filter, int boardId, int numberOfChannels, int sampleRate)
{
var montagedSignal = new List <IBFSample>();
foreach (var nextSample in samples)
{
var newSample = new BFSampleImplementation(nextSample, NumberOfDerivations, 0, 0, 0);
for (int i = 0; i < Derivations.Count; i++)
{
var result = 0.0;
foreach (var nextChannel in Derivations[i].Channels)
{
result += nextSample.GetExgDataForChannel(nextChannel.RawChannelNumber) * nextChannel.Factor;
}
newSample.SetExgDataForChannel(i, result);
}
montagedSignal.Add(newSample);
}
samples = montagedSignal.ToArray();
if (filter != null)
{
samples = FilterBrainflowSample.FilterChunk(filter, samples, boardId, numberOfChannels, sampleRate);
}
return(samples);
}
/// <summary>
/// Add a function to the filter
/// will determine if this function has dynamic parameters of data[] only, or data[] and sampling_rate
/// </summary>
static void AddSignalFilterFunction(SignalFilter filter, MethodInfo mi, Dictionary <string, string> paramDict, object[] parameters)
{
if (paramDict.ContainsKey("sampling_rate"))
{
filter.AddFunction(new SignalFilterFunctionDataSampleRate(typeof(DataFilter).Assembly, mi, parameters));
}
else
{
filter.AddFunction(new SignalFilterFunctionData(typeof(DataFilter).Assembly, mi, parameters));
}
}
/// <summary>
/// Create a default filter for 60Hz mains noise
/// </summary>
static void CreateDefaultFilterNotch50()
{
var newFilter = new SignalFilter("default50");
MethodInfo mi = typeof(DataFilter).GetMethod("perform_bandstop", BindingFlags.Public | BindingFlags.Static);
var paramDict = new Dictionary <string, string>
{
["data"] = "",
["sampling_rate"] = "0",
["center_freq"] = "50.0",
["band_width"] = "2.0",
["order"] = "6",
["filter_type"] = "1",
["ripple"] = "1.0"
};
// create object array from parameters, casting to proper type
object[] parameters = mi.GetParameters().Select(p => paramDict[p.Name].Length > 0 ? Convert.ChangeType(paramDict[p.Name], p.ParameterType) : null).ToArray();
newFilter.AddFunction(new SignalFilterFunctionDataSampleRate(typeof(DataFilter).Assembly, mi, parameters));
mi = typeof(DataFilter).GetMethod("perform_bandpass", BindingFlags.Public | BindingFlags.Static);
paramDict = new Dictionary <string, string>
{
["data"] = "",
["sampling_rate"] = "0",
["center_freq"] = "25.5",
["band_width"] = "47",
["order"] = "2",
["filter_type"] = "0",
["ripple"] = "0.0"
};
// create object array from parameters, casting to proper type
parameters = mi.GetParameters().Select(p => paramDict[p.Name].Length > 0 ? Convert.ChangeType(paramDict[p.Name], p.ParameterType) : null).ToArray();
newFilter.AddFunction(new SignalFilterFunctionDataSampleRate(typeof(DataFilter).Assembly, mi, parameters));
mi = typeof(DataFilter).GetMethod("perform_wavelet_denoising", BindingFlags.Public | BindingFlags.Static);
paramDict = new Dictionary <string, string>
{
["data"] = "",
["wavelet"] = "db12",
["decomposition_level"] = "3",
};
// create object array from parameters, casting to proper type
parameters = mi.GetParameters().Select(p => paramDict[p.Name].Length > 0 ? Convert.ChangeType(paramDict[p.Name], p.ParameterType) : null).ToArray();
newFilter.AddFunction(new SignalFilterFunctionData(typeof(DataFilter).Assembly, mi, parameters));
Filters.Add(newFilter.Name, newFilter);
}
// Implementation
#region Implementation
/// <summary>
/// Constructor
/// </summary>
public RealTimeSignalProcessing(int boardId, int sampleRate, SignalFilter filter, ISignalMontage montage)
{
BoardId = boardId;
NumberOfChannels = BrainhatBoardShim.GetNumberOfExgChannels(BoardId);
SampleRate = sampleRate;
Filter = filter;
Montage = montage;
Name = KeyName((Filter == null ? "" : Filter.Name), Montage.Name);
PeriodMilliseconds = 33;
FilterBufferLength = 10;
ProcessingTimes = new ConcurrentQueue <double>();
FilteredData = new ConcurrentQueue <IBFSample>();
}
public static IBFSample[] FilterChunk(SignalFilter filter, IEnumerable <IBFSample> chunk, int boardId, int numberOfChannels, int sampleRate)
{
try
{
if (chunk == null || chunk.Count() == 0)
{
throw new ArgumentException("Invalid chunk");
}
// copy the data for filtering
var filteredSamples = new List <IBFSample>(chunk.Select(x => new BFSampleImplementation(x)));
for (int i = 0; i < numberOfChannels; i++)
{
var filtered = filter.ApplyFilter(chunk.GetExgDataForChannel(i), sampleRate);
for (int j = 0; j < chunk.Count(); j++)
{
filteredSamples[j].SetExgDataForChannel(i, filtered[j]);
}
}
var lastTimeStamp = chunk.First().TimeStamp;
int lastSampleIndex = (int)chunk.First().SampleIndex;
for (int i = 0; i < filteredSamples.Count; i++)
{
filteredSamples[i].TimeStamp = lastTimeStamp + filteredSamples[i].SampleIndex.TimeBetweenSamples(lastSampleIndex, boardId, sampleRate);
lastTimeStamp = filteredSamples[i].TimeStamp;
lastSampleIndex = (int)filteredSamples[i].SampleIndex;
}
return(filteredSamples.ToArray());
}
catch (Exception e)
{
throw e;
}
}
//public async Task<SignalFiltering> StartSignalFilteringAsync()
//{
// var filterName = ActiveFilters.FirstOrDefault().Key;
// if (filterName != null)
// return await StartSignalFilteringAsync(filterName);
// return null;
//}
/// <summary>
/// Start the signal filtering task
/// </summary>
public async Task <RealTimeSignalProcessing> StartRealTimeSignalProcessingAsync(SignalFilter filter, ISignalMontage montage)
{
var useMontage = montage;
if (useMontage == null)
{
useMontage = SignalMontages.MakeDefaultMontage(NumberOfChannels);
}
var montageName = useMontage.Name;
var filterName = filter == null ? "XXXDEFAULTXXX" : filter.Name;
if (CancelTokenSource == null)
{
Log?.Invoke(this, new LogEventArgs(Name, this, "StartSignalFiltering", $"You must start the processor first.", LogLevel.ERROR));
return(null);
}
if (ActiveFilters.ContainsKey(RealTimeSignalProcessing.KeyName(filterName, montageName)))
{
return(ActiveFilters[RealTimeSignalProcessing.KeyName(filterName, montageName)]);
}
var newFilter = new RealTimeSignalProcessing(BoardId, SampleRate, filter, useMontage)
{
FilterBufferLength = 30,
};
newFilter.GetRawChunk = GetRawChunk;
newFilter.Log += OnComponentLog;
ActiveFilters.Add(RealTimeSignalProcessing.KeyName(filterName, montageName), newFilter);
await newFilter.StartRealTimeProcessingAsync();
return(newFilter);
}
/// <summary>
/// Load filter definitions from XML file
/// </summary>
public void LoadSignalFilters(string xmlFilePath)
{
try
{
Filters.Clear();
using (var reader = new StreamReader(xmlFilePath))
{
var doc = XDocument.Load(reader);
var filters = doc.Element("brainHatSignalFilters")?.Element("Filters")?.Elements("Filter");
if (filters == null)
{
throw new Exception("Document does not hae a <Filters> element.");
}
foreach (var nextFilter in filters)
{
var filterName = nextFilter.Element("Name")?.Value;
if (filterName == null || Filters.ContainsKey(filterName))
{
throw new Exception("Filter does not have a name or name is duplicated.");
}
var newFilter = new SignalFilter(filterName);
var functions = nextFilter.Element("Functions")?.Elements("Function");
if (functions == null)
{
throw new Exception($"Filter {filterName} does not have any functions.");
}
foreach (var nextFunction in nextFilter.Element("Functions")?.Elements("Function"))
{
// get function name from XML
var functionName = nextFunction.Attribute("Name")?.Value;
// get method from DataFilter class
MethodInfo mi = typeof(DataFilter).GetMethod(functionName, BindingFlags.Public | BindingFlags.Static);
if (mi == null)
{
throw new Exception($"Filter {filterName} specifies an invalid function");
}
// get dictionary of parameters from XML
var paramDict = nextFunction.Elements("Parameter").ToDictionary(d => d.Attribute("Name").Value, d => d.Attribute("Value").Value);
// create object array from parameters, casting to proper type
object[] parameters = mi.GetParameters().Select(p => paramDict[p.Name].Length > 0 ? Convert.ChangeType(paramDict[p.Name], p.ParameterType) : null).ToArray();
AddSignalFilterFunction(newFilter, mi, paramDict, parameters);
}
Filters.Add(filterName, newFilter);
}
}
}
catch (Exception e)
{
throw e;
}
}