Analyzing Human Circadian Rhythm By Filtering Heart

Circadian rhythm is an endogenous cyclical 24-hour period of human biological activity and it causes various physiological data to show periodicity.In this paper,in order to highlight and further analyze the rhythm of human's heart rate,we designed several appropriate filters to filter out the interfering factors in the daily heart rate data which collected from volunteers.The main contributions of the paper included:(1)It was found that the characteristic pattern of human daytime heart rate was essentially different from that of mice.As for mice,the characteristic of mice activity was that their activity usually had two peaks,and the first peak was generally higher than the second one.While for humans,by filtering algorithm,we found that the data of daytime heart rate still had strong objectivity in the statistical sense while comparing with the objective resting one.a)The existence of three peaks was essential.The results showed that the proportion of one person's sum of the days with three peaks to all of his days and the proportion of the days for all volunteers with three peaks to all whole days were close to 50%.b)It became quite common that the last peak was higher than the first one among humans than mice,and we found the corresponding proportion was 54.22%when we went through all the people's data.(2)Through the analysis of resting heart rate to get related indicators of human rhythm.The trough phase of the individual's resting heart rate was obtained by the filtering algorithm and according to the phase distribution we can distinguish the human into five different types.Besides,it was found that the heart rate changes regularly during sleep and the number of cycles per night is between 3.5 and 5 by changing the cut-off frequency of the filter and filtering the resting heart rate.This cycle may be related to the sleep cycle.The innovation of this paper thesis was to design different filters for analyzing human circadian heart rate data,and found some interesting results which are distinguished from that in mice.Furthermore,we also made a classification for the phase of rhythm according to the results.The significance of this thesis:The filtering parameters of daytime and night heart rate within 24 hours was designed,and the characteristics of the activity which were different from that in mice were obtained,which provided an idea for biological research.Besides,the classification of human rhythm in this paper provided a reference for interfering with people's lifestyles and maintaining a healthy life habit.