PROBLEM TO BE SOLVED: To detect a heart beat time accurately and quickly, while suppressing the influence of noise, while performing batch processing of a sampling data row of an ECG waveform stored in a memory medium.SOLUTION: A heart beat detection method is configured to: determine a value obtained by subtracting a (i-1)-th number from a (i+1)-th number, as a time difference value y (i) for every sampling point i, from a sampling data row of an ECG waveform stored in a memory 1 (time difference value calculation part 2) then acquire a minimum value z (i) of the time difference value in a prescribed time region before and after the sampling point i for every sampling point i (minimum value acquisition part 3) then, determine a value obtained by subtracting the minimum value z (i) of the time difference value in the prescribed time region before and after the sampling point i from the time difference value y (i) of the sampling point i, as an index value w (i) for every sampling point i (index value calculation part 4) then, specify the index value w (i) which is at the point where is less than a prescribed threshold, and is switched to increase from decrease, as a downward peak, out of the index values w (i) of all sampling points i and determine the specified downward peak time as a heart beat time (heart beat time determination part 5).SELECTED DRAWING: Figure 15
