Abstract: An information processing apparatus including a processor configured to execute a process including obtaining pieces of waveform data corresponding to a plurality of parts of a subject, the pieces of waveform data indicating a pulse wave of the subject, calculating a first index value indicating a matching degree between the pieces of waveform data, calculating a second index value indicating a matching degree between a plurality of partial waveform data for each of the pieces of waveform data, the plurality of partial waveforms data being generated by dividing each of the pieces of waveform data at predetermined time intervals, determining whether the pieces of waveform data indicates an arrhythmia based on the first index value and the second index value, and outputting information indicating a result of the determining.

Abstract: A state detection method includes: storing first information obtained from a first sensor and second information obtained from a second sensor in a predetermined segment in a storage, by a processor; specifying a behavior segment indicating a segment in which a subject performs a specific behavior and a non-behavior segment indicating a segment in which the subject does not perform the specific behavior using the second information stored in the storage, by the processor; determining a feature amount to be used for detecting a specific state of the subject using respective values of a plurality of feature amounts included in the first information stored in the storage in each of the behavior segment and the non-behavior segment and determining a threshold value for the determined feature amount, by the processor; and detecting the specific state of the subject from the information obtained from the first sensor, by the processor.

Abstract: A meal time estimation method includes: acquiring time series data of heart rate, by a processor; calculating a feature amount obtained by indexing a degree of similarity with a feature of heart rate change that appears at end of a meal from the time series data of the heart rate, by the processor; and estimating a meal time from the feature amount, by the processor.