Patent ID: 7680532

Claim:
A method of determining possible atrial fibrillation, said method comprising: detecting a sequence of pulse beats to provide a succession of time intervals corresponding to the sequence of pulse beats; ascertaining a mean of the succession of time intervals; determining lower and upper boundary values of the time intervals each as a respective percent of the mean; recalculating the mean based on only the time intervals that are at or between the upper and lower boundary values and not based on the time intervals that are less than the lower boundary value or higher than the upper boundary value; calculating a standard deviation based on only the time intervals that are at or between the upper and lower boundary values and not based on the time intervals that are less than the lower boundary value or higher than the upper boundary value; and determining possible atrial fibrillation based upon a quotient formed by dividing the standard deviation by the recalculated mean and comparing the quotient with a threshold value; if the quotient exceeds the threshold value, the rhythm is atrial fibrillation.