scholarly journals Applications of a novel radiotelemetry method for the measurement of intrathoracic pressures and physiological rhythms in freely behaving mice

2020 ◽  
Vol 129 (4) ◽  
pp. 992-1005
Author(s):  
Andrew J. Foster ◽  
Jade P. Marrow ◽  
Melissa A. Allwood ◽  
Keith R. Brunt ◽  
Jeremy A. Simpson
Keyword(s):  
Heart Rate ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Respiratory Function ◽  
Intrathoracic Pressure ◽  
Hypoxic Stress ◽  
Chronic Recording ◽  
Respiratory Parameters ◽  
Freely Behaving ◽  
First Time

We have demonstrated for the first time in mice that radiotelemetry is an effective tool for the continuous and chronic recording of intrathoracic pressure (ITP) to facilitate circadian rhythm analyses. We show that continuous 24-h hypoxic stress alters the circadian rhythms of heart rate, body temperature, activity, and respiratory parameters, acutely and perpetually, through normoxic recovery. Radiotelemetry of ITP can complement traditional methods for evaluating respiratory function and better our understanding of respiratory pathophysiology.

scholarly journals Effects of diazepam, ketamine HCl and sevoflurane anesthesia on vital and recovery values of nine long legged buzzards (Buteo rufinus) upon wing amputation

2018 ◽  
Vol 69 (3) ◽  
pp. 1071
Author(s):  
C. T. İŞLER ◽  
M. E. ALTUĞ ◽  
Z. YURTAL ◽  
M. Z.Y. DEVECI
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Sevoflurane Anesthesia ◽  
Preoperative Period ◽  
Time Effects ◽  
Vital Functions ◽  
Significant Difference ◽  
First Time ◽  
Ketamine Hcl ◽  
Vital Parameters

In this clinical study, effects of diazepam + ketamine HCl + sevoflurane anesthesia on vital functions and recovery duration and qualityofnine long legged buzzards were evaluated upon wing amputation. Operation was decided for long legged buzzards and heartand breathingrate, body temperature, and reflexes of long legged buzzards were evaluated before, during and after the anesthesia. Diazepam and ketamine HCl injection increased the heart rate whereas it was decreased by sevoflurane. Respiratory rate decreased upon sevoflurane application. Body temperature decreased during anesthesia. Recovery began in the 3rd minute after cessation of sevoflurane administration with return of eye reflexes and completedin the 35th minute. It was observed that although birdsrecovered from anesthesia, danger of hypothermia persisted for a long time.There was a significant difference between the respiratory and heart rates during the ketamine HCl and sevofluraneanesthesia from those in the preoperative period. However, there was no statistically significant difference between pre and post operative periods in terms of vital parameters. For the first time, effects of diazepam + ketamine HCl + sevoflurane anesthesia combination on vital parameters are evaluated in long legged buzzards in Turkey.

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 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.

Selected Contribution: Circadian rhythm variation in activity, body temperature, and heart rate between C3H/HeJ and C57BL/6J inbred strains

2002 ◽  
Vol 92 (2) ◽  
pp. 870-877 ◽  
Author(s):  
Clarke G. Tankersley ◽  
Rafael Irizarry ◽  
Susan Flanders ◽  
Richard Rabold
Keyword(s):  
Heart Rate ◽  
Circadian Rhythm ◽  
Body Temperature ◽  
Genetic Model ◽  
Inbred Strains ◽  
Repeated Measurements ◽  
Circadian Regulation ◽  
Dark Phase ◽  
Cardiorespiratory Control ◽  
Deep Body Temperature

Inbred mice have been routinely used in studies of genetic effects that determine behavioral variation due to circadian rhythm. In addition to activity patterns (Act), we aimed to characterize variations in the circadian rhythm of deep-body temperature (Tdb) and heart rate (HR) in a specific genetic model of differential cardiorespiratory control. Radiotelemeters were implanted in C3H/HeJ (C3; n = 11) and C57BL/6J (B6; n = 11) inbred strains. Reciprocal first-generation offspring, B6C3F1/J (B6F1; n = 8) and C3B6F1 (C3F1; n = 3) mice, were included to initiate an evaluation of heritable phenotypes. Mice were housed individually in a facility maintained at 23–24°C, and the light-dark cycle was set at 12-h intervals. In each animal, repeated measurements were obtained at 30-min intervals, and the circadian patterns of Act, Tdb, and HR were assessed by novel statistical methods that detailed the periodic function for each strain. During the dark phase, B6 mice demonstrated two distinct peaks in Act and Tdb relative to a single early peak for C3 mice. In contrast to the parental strains, B6F1 and C3F1 mice demonstrated intermediate second peaks in Act and Tdb. With respect to HR, the C3 strain demonstrated a significantly ( P < 0.01) greater daily average compared with B6 mice. The circadian rhythm in HR differed significantly from the Act and Tdb patterns in B6 mice (but not in C3 mice); that is, the periodicity in HR for B6 mice preceded the rise and fall in Act and Tdb during both peaks. The B6 phenotype was also observed in F1 mice. In conclusion, these data suggest that the circadian regulation of Act, Tdb, and HR vary significantly among C3, B6, and F1 mice. Furthermore, phenotypic differences between C3 and B6 strains can be used to explore the genetic basis for differential circadian regulation of body temperature and HR.

Influence of ageing on circadian rhythm of heart rate variability in healthy subjects

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Agostino Accardo ◽  
Marco Merlo ◽  
Giulia Silveri ◽  
Lucia Del Popolo ◽  
Luca Dalla Libera ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Circadian Rhythm ◽  
Healthy Subjects

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.

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