Estimation of the Biphasic Property in a Female’s Menstrual Cycle from Cutaneous Temperature Measured During Sleep

Abstract

This paper proposes a method to estimate a woman's menstrual cycle based on the hidden Markov model (HMM). A tiny device was developed that attaches around the abdominal region to measure cutaneous temperature at 10-min intervals during sleep. The measured temperature data were encoded as a two-dimensional image (QR code, i.e., quick response code) and displayed in the LCD window of the device. A mobile phone captured the QR code image, decoded the information and transmitted the data to a database server. The collected data were analyzed by three steps to estimate the biphasic temperature property in a menstrual cycle. The key step was an HMM-based step between preprocessing and postprocessing. A discrete Markov model, with two hidden phases, was assumed to represent higher- and lower-temperature phases during a menstrual cycle. The proposed method was verified by the data collected from 30 female participants, aged from 14 to 46, over six consecutive months. By comparing the estimated results with individual records from the participants, 71.6% of 190 menstrual cycles were correctly estimated. The sensitivity and positive predictability were 91.8 and 96.6%, respectively. This objective evaluation provides a promising approach for managing premenstrual syndrome and birth control.

Nocturnal finger skin temperature in menstrual cycle tracking: ambulatory pilot study using a wearable Oura ring

“…The temperature values of the menstrual cycle component were used by all the algorithms in menstrual cycle phase tracking. The ovulation day is related to the rise in daily temperature and the start of menstruation to the decline in daily temperature [9].…”

“…Progesterone, as a thermogenic hormone, is considered to be responsible for the rise in BBT that typically occurs at 1–3 days post ovulation. Though utilizing body temperature is mostly used in detection of fertility related phases, few studies have also used it in prediction of menstrual cycle length or the start of menstruation [8, 9].…”

“…Most of the studies using different kinds of skin-attached temperature sensors assessing menstrual cycle and conducted under laboratory conditions with a few hours of measurement time once or twice per follicular and luteal phase have not found any differences in skin temperatures between menstrual cycle phases [20, 21]. However, in ambulatory studies, skin temperatures have been found to have a biphasic temperature property, with higher values in the luteal phase and lower values in the follicular phase [9, 11], and to be in phase with oral temperature measured in the morning [11].…”

Thermometry and interpretation of body temperature

“…The comparative performance evaluation results shown that all three kinds of BTs can estimate the biphasic property in a menstrual cycle, CBT has the best accuracy, BBT is slightly lower accuracy but competitive enough with CBT, SBT has the poorest performance due to severe measurement artifact. It is also confirmed that reliable relative changes instead of accurate absolute values of BT are more important in estimating the biphasic property in a menstrual cycle [56][57][58].…”

Current Developments in Wearable Thermometers

“…A touchable skin thermometer known as Ran s Night [11,12] has been developed and applied for monitoring night-time skin temperature under clothing. The device is 17 × 41 × 84 mm in size, 59 g in weight and has an accuracy of ±0.5 C for a temperature range of 32-40 C. The sensor is attached around the abdominal region and measures cutaneous temperature at 10 min intervals during sleep.…”