Abstract: A TWA measuring apparatus includes: an electrocardiograph controlling section which is configured to produce an electrocardiogram from electrocardiographic signals of a subject; and a TWA measuring section which is configured to select at least two waveforms that contribute to a measurement of TWA, from the electrocardiogram, and which is configured to measure a presence of TWA by using the selected at least two waveforms.

Abstract: A derived electrocardiogram generating system includes: a personal coefficient database which stores personal coefficients specific to a subject, the personal coefficients being acquired from the subject; a population coefficient database which stores population coefficients which are average values of conversion coefficients acquired from an unspecified large number of persons belonging to a statistically significant population; and an electrocardiograph control portion: which generates a derived electrocardiogram of the subject using the personal coefficients when the personal coefficients are present in the personal coefficient database; and which generates a derived electrocardiogram of the subject using the population coefficients when the personal coefficients are absent in the personal coefficient database.