Patent ID: 11918367
Assignee: MEDTRONIC, INC.
Field: Medical technology (Instruments)
Classification: CPC A  G | IPC A

Claim 8:
9. The insertable cardiac monitoring device of claim 8, wherein the at least a portion of the cardiac signal comprises the R-wave, and wherein as part of determining whether the at least a portion of the cardiac signal is noisy, the processing circuitry is configured to:
determine an R-wave peak of the R-wave;
determine a plurality of first differences between a first plurality of samples of the cardiac signal, a first sample of the first plurality of samples being before the R-wave peak and a last sample of the first plurality of samples being after the R-wave peak, each of the plurality of first differences being a difference in amplitude of a respective sample of the first plurality of samples and a next sample of the first plurality of samples;
determine a plurality of second differences between each of the plurality of first differences and a respective next difference of the plurality of first differences;
determine whether there is a sign change between each of the plurality of first differences and the respective next difference of the plurality of first differences;
for each determined sign change, determine whether a magnitude of a respective corresponding second difference value is greater than a first positive predetermined noise threshold or lower than a first negative predetermined noise threshold;
calculate a total number of the corresponding second difference values having the magnitude greater than the positive first predetermined noise threshold or lower than the negative first predetermined noise threshold; and
determine whether the calculated total number is greater than a second predetermined noise threshold.