scholarly journals Estimation of melatonin level and core body temperature: heart rate and heart rate variability as circadian rhythm markers

2022 ◽  
pp. 1-18
Author(s):  
Yun Jae Eo ◽  
Jingyu Park ◽  
Seohyeon Kim ◽  
Keyong Nam Lee ◽  
Seung Min Lee ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Melatonin Level ◽  
Core Body

scholarly journals Relationship between core body temperature and heart rate variability in an ultrashort sleep-wake schedule

2019 ◽  
Vol 5 (1) ◽  
pp. 45-48
Author(s):  
Christian Heinze ◽  
Martin Golz
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Rr Intervals ◽  
Sleep Episode ◽  
Power Spectral ◽  
First Results ◽  
Core Body

AbstractThe circadian rhythm that drives the human sleepwake cycle manifests itself in the variation of the core body temperature (CBT). Measuring CBT continuously, however, is intricate. Heart rate and its variability also varies notably over the course of the day, but is more accessible to measure. We present first results from a study that investigates the biorhythmic relationship between the circadian rhythm of CBT and measures of heart rate variability (HRV). Twelve subjects participated in a 50-hour experiment that was segmented into one hundred 30-minute blocks. In each block, subjects attempted to sleep for ten minutes. CBT and the ECG were continuously recorded. To date, intervals between successive heart beats (RR intervals) were determined for three subjects. From RR intervals of each attempted-sleep episode, power spectral densities (PSD) were estimated with the Lomb-Scargle periodogram and averaged into 0.02-Hz wide bands. The periodogram of each RR-frequency-band time series was estimated and compared against the periodogram of CBT, which, as expected, shows a dominant maximum at a period length of 24 hours. Mutual information, an entropy-based measure of interdependence, was used for the comparison. The highest coherence towards CBT was found for the RR-PSD between 0.24 and 0.34 Hz. This RR-PSD range usually includes the respiratory rate, which may indicate that heart rate is more closely linked to respiration at certain times of the day than at others.

Circadian Rhythm Estimation by Core Body Temperature Filtered with Simultaneously Recorded Physiological Data

1997 ◽  
Vol 36 (04/05) ◽  
pp. 306-310 ◽  
Author(s):  
T. Nakano ◽  
E. Koyama ◽  
T. Imai ◽  
H. Hagiwara
Keyword(s):  
Heart Rate ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Field Measurements ◽  
Physical Activities ◽  
Temperature Data ◽  
Physiological Data ◽  
Heart Rate Data ◽  
Core Body

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.

scholarly journals Estimation of cardiovascular drift through ear temperature during prolonged steady-state cycling: a study protocol

2021 ◽  
Vol 7 (1) ◽  
pp. e000907
Author(s):  
Giovanni Polsinelli ◽  
Angelo Rodio ◽  
Bruno Federico
Keyword(s):  
Heart Rate ◽  
Steady State ◽  
Body Temperature ◽  
Study Protocol ◽  
External Auditory Canal ◽  
Exercise Intensity ◽  
Core Body Temperature ◽  
Cardiovascular Drift ◽  
Core Body ◽  
Steady State Cycling

IntroductionThe measurement of heart rate is commonly used to estimate exercise intensity. However, during endurance performance, the relationship between heart rate and oxygen consumption may be compromised by cardiovascular drift. This physiological phenomenon mainly consists of a time-dependent increase in heart rate and decrease in systolic volume and may lead to overestimate absolute exercise intensity in prediction models based on heart rate. Previous research has established that cardiovascular drift is correlated to the increase in core body temperature during prolonged exercise. Therefore, monitoring body temperature during exercise may allow to quantify the increase in heart rate attributable to cardiovascular drift and to improve the estimate of absolute exercise intensity. Monitoring core body temperature during exercise may be invasive or inappropriate, but the external auditory canal is an easily accessible alternative site for temperature measurement.Methods and analysisThis study aims to assess the degree of correlation between trends in heart rate and in ear temperature during 120 min of steady-state cycling with intensity of 59% of heart rate reserve in a thermally neutral indoor environment. Ear temperature will be monitored both at the external auditory canal level with a contact probe and at the tympanic level with a professional infrared thermometer.Ethics and disseminationThe study protocol was approved by an independent ethics committee. The results will be submitted for publication in academic journals and disseminated to stakeholders through summary documents and information meetings.

“On-” and “off-” cells in the rostral ventromedial medulla of rats held in thermoneutral conditions: are they involved in thermoregulation?

2014 ◽  
Vol 112 (9) ◽  
pp. 2199-2217 ◽  
Author(s):  
Nabil El Bitar ◽  
Bernard Pollin ◽  
Daniel Le Bars
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Rostral Ventromedial Medulla ◽  
Sequence Of Events ◽  
Ventromedial Medulla ◽  
Cyclic Variations ◽  
On And Off Cells ◽  
Core Body

In thermal neutral condition, rats display cyclic variations of the vasomotion of the tail and paws, synchronized with fluctuations of blood pressure, heart rate, and core body temperature. “On-” and “off-” cells located in the rostral ventromedial medulla, a cerebral structure implicated in somatic sympathetic drive, 1) exhibit similar spontaneous cyclic activities in antiphase and 2) are activated and inhibited by thermal nociceptive stimuli, respectively. We aimed at evaluating the implication of such neurons in autonomic regulation by establishing correlations between their firing and blood pressure, heart rate, and skin and core body temperature variations. When, during a cycle, a relative high core body temperature was reached, the on-cells were activated and within half a minute, the off-cells and blood pressure were depressed, followed by heart rate depression within a further minute; vasodilatation of the tail followed invariably within ∼3 min, often completed with vasodilatation of hind paws. The outcome was an increased heat loss that lessened the core body temperature. When the decrease of core body temperature achieved a few tenths of degrees, sympathetic activation switches off and converse variations occurred, providing cycles of three to seven periods/h. On- and off-cell activities were correlated with inhibition and activation of the sympathetic system, respectively. The temporal sequence of events was as follows: core body temperature → on-cell → off-cell ∼ blood pressure → heart rate → skin temperature → core body temperature. The function of on- and off-cells in nociception should be reexamined, taking into account their correlation with autonomic regulations.

scholarly journals The Impact of Central and Peripheral Cyclooxygenase Enzyme Inhibition on Exercise-Induced Elevations in Core Body Temperature

2017 ◽  
Vol 12 (5) ◽  
pp. 662-667 ◽  
Author(s):  
Matthijs T.W. Veltmeijer ◽  
Dineke Veeneman ◽  
Coen C.C.W. Bongers ◽  
Mihai G. Netea ◽  
Jos W. van der Meer ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Skin Temperature ◽  
Core Body Temperature ◽  
Exercise Tests ◽  
Hypothalamic Temperature ◽  
Set Point ◽  
Exercise Induced ◽  
Core Body ◽  
The Impact

Purpose:Exercise increases core body temperature (TC) due to metabolic heat production. However, the exercise-induced release of inflammatory cytokines including interleukin-6 (IL-6) may also contribute to the rise in TC by increasing the hypothalamic temperature set point. This study investigated whether the exercise-induced increase in TC is partly caused by an altered hypothalamic temperature set point.Methods:Fifteen healthy, active men age 36 ± 14 y were recruited. Subjects performed submaximal treadmill exercise in 3 randomized test conditions: (1) 400 mg ibuprofen and 1000 mg acetaminophen (IBU/APAP), (2) 1000 mg acetaminophen (APAP), and (3) a control condition (CTRL). Acetaminophen and ibuprofen were used to block the effect of IL-6 at a central and peripheral level, respectively. TC, skin temperature, and heart rate were measured continuously during the submaximal exercise tests.Results:Baseline values of TC, skin temperature, and heart rate did not differ across conditions. Serum IL-6 concentrations increased in all 3 conditions. A significantly lower peak TC was observed in IBU/APAP (38.8°C ± 0.4°C) vs CTRL (39.2°C ± 0.5°C, P = .02) but not in APAP (38.9°C ± 0.4°C) vs CTRL. Similarly, a lower ΔTC was observed in IBU/APAP (1.7°C ± 0.3°C) vs CTRL (2.0°C ± 0.5°C, P < .02) but not in APAP (1.7°C ± 0.5°C) vs CTRL. No differences were observed in skin temperature and heart-rate responses across conditions.Conclusions:The combined administration of acetaminophen and ibuprofen resulted in an attenuated increase in TC during exercise compared with a CTRL. This observation suggests that a prostaglandin-E2-induced elevated hypothalamic temperature set point may contribute to the exercise-induced rise in TC.

scholarly journals Subtle Cardiovascular Dysfunction in the Unilateral 6-Hydroxydopamine-Lesioned Rat

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
K. Slack ◽  
R. Billing ◽  
S. Matthews ◽  
H. N. Allbutt ◽  
R. Einstein ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Locomotor Activity ◽  
Core Body Temperature ◽  
Diurnal Rhythms ◽  
Sensorimotor Function ◽  
Cardiovascular Autonomic Dysfunction ◽  
Sham Surgery ◽  
6 Hydroxydopamine ◽  
Core Body

The present study evaluated whether the unilateral 6-hydroxydopamine (6-OHDA) model of Parkinson's disease produces autonomic deficits. Autonomic parameters were assessed by implanting a small radiofrequency telemetry device which measured heart rate variability (HRV), diurnal rhythms of heart rate (HR), core body temperature (cBT) and locomotor activity (LA). Rats then received 6-OHDA lesion or sham surgery. 6-OHDA lesioned rats exhibited head and body axis biases, defective sensorimotor function (“disengage” test), and prominent apomorphine rotation (allP<.05versus controls). Diurnal rhythm of HR was lower for 6-OHDA lesioned rats (n=8) versus controls (n=6;P<.05). Whilst HR decreased similarly in both groups during the day, there was a greater decrease in HR for the 6-OHDA lesioned rats at night (by 38 b.p.m. relative to 17 b.p.m. for controls). LA and cBT did not differ between surgery groups. This study indicates the unilateral 6-OHDA model of PD shows subtle signs of cardiovascular autonomic dysfunction.

The Effects of Thoracic and Cervical Spinal Cord Lesions on the Circadian Rhythm of Core Body Temperature

2011 ◽  
Vol 28 (2) ◽  
pp. 146-154 ◽  
Author(s):  
Dick H. J. Thijssen ◽  
Thijs M. H. Eijsvogels ◽  
Marina Hesse ◽  
Dov B. Ballak ◽  
Greg Atkinson ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Cervical Spinal Cord ◽  
Core Body Temperature ◽  
Spinal Cord Lesions ◽  
Core Body

scholarly journals Effects of Pre-cooling and Per-cooling on Neural, Physiological, and Functional Responses in Active Young Girls

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Seyedeh Somayeh Razavi ◽  
Amirabbas Monazzami ◽  
Zahra Nikosefat
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Temperature ◽  
Repeated Measures ◽  
Blood Pressure Monitoring ◽  
Core Body Temperature ◽  
Control Group ◽  
Functional Responses ◽  
Young Girls ◽  
Core Body

Background: Stressful environments, especially air temperature, have significant effects on human physiological responses to physical activity. Objectives: The current study aimed to determine the effects of pre-cooling and per-cooling on neural, physiological, and functional responses in active young girls. Methods: Twelve active girls (age 24.6 ± 1.4, weight 55.46 ± 8.18, height 165.1 ± 5.91) were tested in three separate sessions with intervals of three days between each session. All subjects performed the Balke test in three groups either without an ice vest (control and pre-cooling) or with an ice vest (per-cooling) in each session, randomly. Pre-cooling was applied with an ice vest for 30 min just before the test, while per-cooling was used with an ice vest from the beginning of the test to exhaustion. A Buerer FT-70 digital thermometer, polar-FT60 heart rate monitoring, Microlife blood pressure monitoring, and ELISA technique were used to measure core body temperature, heart rate, blood pressure, dopamine, cortisol, and lactate dehydrogenase, respectively. Two-way repeated-measures ANOVA was applied to analyze the data with a confidence interval of 95%. Results: The heart rate and core body temperature significantly decreased at the end of the test in the pre-cooling and per-cooling groups (P < 0.05). There was an improved performance with an increase in Tmax in the per-cooling group compared to the control group (P < 0.05) although this difference was not significant in the pre-cooling group compared to the control group (P > 0.05). Dopamine, cortisol, and lactate dehydrogenize increased in the groups in comparison with the pretest (P < 0.05) even though these differences were not significant in the comparison between the groups (P > 0.05). Conclusion: The findings suggest that pre-cooling and per-cooling could be used as a beneficial method to improve performance due to not only a decrease in core body temperature and heart rate but also an increase in the level of dopamine and cortisol. Moreover, per-cooling was more effective than pre-cooling to increase performance.

A prelude to wearable technology for the measurement and restoration of core body temperature and heart rate in athletes suffering from hypothermia

2021 ◽  
pp. 095441192110511
Author(s):  
Choudhary Sobhan Shakeel ◽  
Umer Hassan ◽  
Fatema Ilyas ◽  
Munira Muhammadi Zariwala ◽  
Salman Muhammad Ilyas ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Wearable Technology ◽  
Breathing Rate ◽  
Normal Heart Rate ◽  
Internal Core ◽  
Definitive Solution ◽  
Rate Sensor ◽  
Core Body

An individual who is in good physical health tends to exhibit an internal core temperature of 37°C and a heart rate of 60–100 beats per minute. Increase in the temperature of the surrounding environment can serve as the basis for the onset of the condition of Hypothermia. Hypothermia acts as one of the most significant barriers being faced by winter athletes and starts initially with an increase in the heart and breathing rate. However, if the condition persists it can lead to reduction in the heart and breathing rate and ultimately results in cardiac failure. Although, jackets are commercially available, they tend to operate manually and furthermore, do not serve the primary purpose of counteracting the condition of hypothermia, particularly experienced by athletes taking part in winter sports. The objective of this study is to design a heating jacket that enables effective counteraction of the condition of Hypothermia. It enables precise measurement of the of core body temperature with the aid of a pyroelectric sensor. Along with this, a pulse rate sensor for detecting the accurate heart rate has been incorporated on the index finger. Five heating pads would get activated to attain optimal temperature, in case the core body temperature of <37°C is detected. If the condition of hypothermia advances to the moderate stage, two additional heating pads will get activated and provide extra warmth to attain normal heart rate along with core body temperature. Overall, this wearable technology serves as a definitive solution to counteract the condition of hypothermia only when the internal parameters exhibit that you actually have it. The results of the study exhibited that this prototype can be utilized for detecting and treating the condition of Hypothermia.

Sign in / Sign up

Export Citation Format

Share Document