missedBeatDetector

missedBeatDetector Finds missed beats in the signal
 Analyses consecutive RR-intervals to detect signs of missed beats.

 For each interval, the sum of its neighbors is computed:
           sum = interval(i-1) + interval(i+1)
 An interval is deemed noisy when:
       interval(i) > sum - sum*toleratedeviationPercent
 and:  interval(i) < sum - sum*toleratedeviationPercent

 Inputs:
    interval - The RR-interval data
    toleratedeviationPercent - Tolerated variation in %

 Outputs:
    errors - Boolean Array, 1 for errors

0001 function errors = missedBeatDetector( interval, toleratedeviationPercent )
0002 %missedBeatDetector Finds missed beats in the signal
0003 % Analyses consecutive RR-intervals to detect signs of missed beats.
0004 %
0005 % For each interval, the sum of its neighbors is computed:
0006 %           sum = interval(i-1) + interval(i+1)
0007 % An interval is deemed noisy when:
0008 %       interval(i) > sum - sum*toleratedeviationPercent
0009 % and:  interval(i) < sum - sum*toleratedeviationPercent
0010 %
0011 % Inputs:
0012 %    interval - The RR-interval data
0013 %    toleratedeviationPercent - Tolerated variation in %
0014 %
0015 % Outputs:
0016 %    errors - Boolean Array, 1 for errors
0017 %
0018 
0019 allowedDeviation = toleratedeviationPercent / 100;
0020 
0021 errors = zeros(1,length(interval));
0022 
0023 for i = 2:length(interval)-1
0024     % double of 2 adjacent hardbeats: missed peak
0025     sumPrevNext = interval(i-1) + interval(i+1);
0026     deviation = allowedDeviation * sumPrevNext;
0027     if(interval(i) > (sumPrevNext - deviation) && interval(i) < (sumPrevNext + deviation))
0028         errors(i) = 1;
0029     end
0030 end
0031 end
0032