package org.physionet.challenge2011;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import android.util.Log;
public class ChallengeEntry {
public static final String DEBUGTAG = ChallengeEntry.class.toString();
final static int FS= 500; //Sampling Frequency
final static int CH= 12;
final static int MAX_RT= 220; //Max expected beats in minutes
final static int WIN=FS*10;
final static double PKS_MIN=40/6; // Minimum number of expected peaks in 10s
final static int FRGT=(int) (FS*0.04); // Window for ignoring consecutive peaks
final static short [] W={1,1,1,-1,1,1,-1,-1,1,1,1,1}; // Weights for each channel
final static double PK_TH=500; // Peak value hardcoded based on sample data
static short [] sum = new short[WIN]; //Array for storing summed channel data
//Define Quality values (could also be defined as enum...)
final static int INIT=0;
final static int GOOD = 0;
final static int BAD = 1;
short[] data=new short[WIN*CH];
synchronized public int get_result(InputStream iFile, final ECG_MetaData m_MetaData) throws IOException {
ObjectInputStream in = new ObjectInputStream(iFile);
try {
data = (short[])in.readObject();
} catch (ClassNotFoundException e) {
e.printStackTrace();
Log.e(DEBUGTAG,"Could not open data file.");
}
int result=INIT; // Set initial result
int pks= 0; // Number of BEATS detected
double pk_memory=0; // Memory of last peak
double PKS_MAX=( MAX_RT- (m_MetaData.age+1) )/6; // Max number of expected peaks in 10s
int index=0;
while ( index < WIN) {
//Load summed data into array
sum[index]= 0; //Initialize
for(int ch=0;ch<CH;ch++){
sum[index] += W[ch]*data[index*CH + ch];
}
if((pk_memory > FRGT) && sum[index] > PK_TH){
//If peak is in acceptable range, increment count and reset memory
pks++;
pk_memory=0;
}else{
//Allow memory to forget past peak
pk_memory++;
}
index++;
//Output quality based on number of measured peaks, and age
if(pks > PKS_MAX || pks < PKS_MIN){
//Bad quality
result=BAD;
}else{
//Normal number of beats, so assume good quality
result=GOOD;
}
}
//clean-up
iFile.close();
return result;
}
}