Patent ID: 7909771

Claim:
A method for detecting sleep apnea from ECG data comprising: detecting heartbeats as a sequence of R waves using electrodes; using a data processing component or application-specific integrated circuit or microprocessor in recording variations of RR interval lengths occurring in said sequence of R waves as a heart rate variability in a heart rate variability log; analyzing said heart rate variability log for existing heart rate variability oscillations in a low-frequency range using an autocorrelation function C ⁡ ( τ ) = ∑ i = 0 N - τ ⁢ RR ⁡ ( i ) ⁢ RR ⁡ ( i + τ ) wherein N is a number of measured points, RR(i) is a standardized RR interval measured at index i, and τ is a time shift to shift RR in relation to itself at index i+τ, wherein τ passes through a range of integers from τ=0 up to a predefined upper limit; evaluating said heart rate variability oscillations for existing sleep apnea in a time range between 20 and 120 beats corresponding to said index i by searching for a first minimum after τ=3 and searching for a position of an absolute maximum above said first minimum.