Abstract.
In field measurements, monitoring of core body temperature is influenced by physical
activities; therefore, the estimation of circadian rhythm from the data may not be
exact. The purpose of this study is to design a core body temperature filter in order
to reduce artifacts induced by physical activities using simultaneously recorded physiological
data such as heart rate data.
The effects of physical activities on core body temperature and heart rate are assessed
through three experiments. Based on the above knowledge, a core body temperature filter
was designed. The filter removes part of rectal temperature data as artifact when
heart rate rises above a predetermined threshold. As a result, most of the spike-like
noise was removed and the filtered temperature data showed sinusoidal variation more
than the unfiltered data. The mesor of the estimated rhythm significantly decreased.
This filtering method can provide more precise information about circadian rhythm,
especially in field measurements.
Keywords:
Core Body Temperature - Masking - Filtering - Heart Rate - Circadian Rhythm
