Detecting Atrial Fibrillation, Method of and Apparatus for
First Claim
Patent Images
1. A method of determining possible atrial fibrillation, said method comprising the steps of:
- 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 each as a respective percent of the mean;
recalculating the mean and calculating a standard deviation based on the succession of time intervals that are at or between the upper and lower boundary values only without regard to those time intervals that may be less than the lower boundary value or higher than the upper boundary value, anddetermining possible atrial fibrillation based upon a quotient formed by dividing the standard deviation by the recalculated mean and comparing the quotient with a threshold;
if the quotient exceeds the threshold value, the rhythm is atrial fibrillation.
0 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus to determine possible atrial fibrillation or absence of atrial fibrillation that includes detecting pulse rhythms from a succession of time intervals each corresponding to a respective interval of time between successive pulse beats; analyzing the detected pulse rhythms to make a determination of possible atrial fibrillation; indicating the possible atrial fibrillation from the determination; or making a determination of the absence of atrial fibrillation.
-
Citations
14 Claims
-
1. A method of determining possible atrial fibrillation, said method comprising the steps of:
-
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 each as a respective percent of the mean; recalculating the mean and calculating a standard deviation based on the succession of time intervals that are at or between the upper and lower boundary values only without regard to those time intervals that may be 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;
if the quotient exceeds the threshold value, the rhythm is atrial fibrillation. - View Dependent Claims (3, 4, 5)
-
-
2. A method of determining rhythms that are not atrial fibrillation, said method comprising the steps of:
-
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 each as a respective percent of the said mean; recalculating the mean and calculating a standard deviation based on the succession of time intervals that are at or between the upper and lower boundary values only without regard to those time intervals that may be less than the lower boundary value or higher than the upper boundary; 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;
if the quotient is less than the threshold value, the rhythm is not atrial fibrillation.
-
-
6. A method of determining possible atrial fibrillation, said method comprising the steps of:
-
sorting a sequence of pulse beat intervals by length from shortest to longest or longest to shortest; determining N where N is the number of time intervals between successive pulse beats; calculating an irregularity index I1 for the first n time intervals, the irregularity index I1 being a quotient of a mean and a standard deviation of a first n time intervals; calculating an irregularity index I2 for the n time intervals beginning with a second time interval, the irregularity index I2 being a quotient of a a mean and a standard deviation of n time intervals beginning with the second time interval; and continuing to calculate an irregularity index Im where m ranges from one until N−
(n−
1);determining possible atrial fibrillation based on what percent, P, of the said irregularity indices I1, I2, . . . IN-(n-1), are less than a threshold value T in that if P exceeds a cutoff value, Pcutoff, then the rhythm is considered to show an absence of atrial fibrillation, and If P is less than or equal to a cutoff value, Pcutoff, then the rhythm is considered atrial fibrillation. - View Dependent Claims (7, 8)
-
-
9. An apparatus for determining possible atrial fibrillation, comprising:
-
a detector configured to detect irregular pulse rhythms from a succession of time intervals each corresponding to a respective interval of time between successive pulse beats of a sequence of the pulse beats; a processor configured to analyze the detected irregular pulse rhythms for making a determination of possible atrial fibrillation;
the processor being configured to detect a plurality of pulse beats including the sequence of pulse beats using a sphygmomanometer or a plethysmograph; andan indicator configured to indicate the possible atrial fibrillation based on the determination.
-
-
10. An apparatus to determine possible atrial fibrillation, comprising
means for ascertaining a mean of a succession of time intervals corresponding to that of a sequence of pulse beats; -
means for determining lower and upper boundary values as a respective percent of the said mean; means for recalculating a mean and calculating a standard deviation of the succession of time intervals that are at or between the lower and upper boundary values only without regard to those time intervals that may be less than the lower boundary value or higher than the upper boundary, and means for determining possible atrial fibrillation based upon a quotient formed by dividing said standard deviation by said recalculated mean and comparing the quotient with a threshold value. - View Dependent Claims (11)
-
-
12. An apparatus to determine possible atrial fibrillation, comprising
means for sorting pulse beat intervals by length from shortest to longest or longest to shortest; -
means for determining N where N is the number of time intervals between successive pulse beats; means for calculating an irregularity index I1 for the first n time intervals, the irregularity index I1 being a quotient of a mean and a standard deviation of a first n time intervals; means for calculating an irregularity index I2 for the n time intervals beginning with the second time interval, the irregularity index I2 being a quotient of a mean and a standard deviation of n time intervals beginning with the second time interval; means for continuing to calculate an irregularity index Im where m ranges from one until N−
(n-1);means for determining possible atrial fibrillation based on what percent, P, of the said irregularity indices I1, I2, . . . IN-(n-1), are less than a threshold value T in that if P exceeds a cutoff value, Pcutoff, then the rhythm is not atrial fibrillation and If P is less than or equal to a cutoff value, Pcutoff, then the rhythm is atrial fibrillation.
-
-
13. A method for determining the absence of atrial fibrillation when there is a presence of abnormal pulse beats, said method comprising the steps of:
-
detecting an abnormal pulse rhythm from a succession of time intervals between pulse beats; and analyzing with equipment the abnormal pulse rhythm to make a determination that the abnormal pulse rhythm is not an indication of atrial fibrillation.
-
-
14. An apparatus for determining the absence of atrial fibrillation when there is a presence of abnormal pulse beats comprising:
-
a detector to detect abnormal pulse rhythm from a succession of time intervals between pulse beats; a processor configured to analyze the detected abnormal pulse rhythm for making a determination of an absence of atrial fibrillation; and an indicator configured to indicate the absence of atrial fibrillation based on the determination.
-
Specification