Fiber optic infrared thermometer for accurate measurement of the core temperature of the human body

Core temperature monitoring is important for the assessment and prevention of possible postoperative complications. The aim of the present study was to examine the agreement between the core temperature values and the forehead, tympanic membrane and axillary values in postoperative adult patients in clinical practice. The study measured the core temperature of 65 patients undergoing scheduled abdominal surgery using SpotOn™ and compared these with those obtained using non-contact forehead infrared, infrared tympanic and axillary thermometers. Correlation and Bland–Altman analyses were conducted for these comparisons. All temperatures were recorded at 4h intervals after postoperative arrival to the ward. Forehead temperature recordings showed a good correlation with the core temperature with excellent accuracy and was comparable to the tympanic temperature. Both forehead and tympanic thermometers can rapidly and effectively measure the core temperature during early postoperative period. Considering patients’ safety, non-contact forehead infrared thermometers may be useful for postoperative monitoring.

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Measurement of the Core Human Body Temperature by Means of Passive Acoustic Thermometry

General Reanimatology ◽

10.15360/1813-9779-2019-1-39-46 ◽

2019 ◽

Vol 15 (1) ◽

pp. 39-46 ◽

Cited By ~ 1

Author(s):

A. A. Anosov ◽

I. S. Balashov ◽

A. V. Erofeev ◽

Yu. S. Zhdankina ◽

A. A. Sharakshane ◽

...

Keyword(s):

Glucose Level ◽

Core Temperature ◽

Human Body ◽

Acoustic Radiation ◽

Integration Time ◽

Thermal Acoustic Radiation ◽

Acoustic Thermometry ◽

The Core ◽

Body Regions ◽

Passive Acoustic

The purpose of the study. To determine whether it is possible to use passive acoustic thermometry to measure the core temperature of human body regions. Materials and methods. Thermal acoustic radiation was measured by a multichannel acoustic thermograph with a threshold sensitivity of 0.3°С at an integration time of 10 s. A portable computer infrared thermograph with a sensitivity of 0.1°С was used to measure the superficial temperature. Results. Measurements of thermal acoustic radiation of the right hypochondrium of the study subject were carried out to obtain an integral temperature of the liver after intake of sugar. At the same time, blood glucose concentrations were measured. The glucose level increased from 4 to 8 mmol/l within an hour and a half; then it began to decline. The acoustic radiation temperature increased by 2°С with a half an hour delay after the increase in the glucose level. Model calculation showed that the liver temperature increased from 37 to 38°С. Conclusion. It was shown that passive acoustic thermometry can be used to measure the core temperature of different regions of the human body. The proposed method may be useful in the emergency medicine.

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Temperature Monitoring and Perioperative Thermoregulation

Anesthesiology ◽

10.1097/aln.0b013e31817f6d76 ◽

2008 ◽

Vol 109 (2) ◽

pp. 318-338 ◽

Cited By ~ 341

Author(s):

Daniel I. Sessler ◽

David S. Warner ◽

Mark A. Warner

Keyword(s):

Body Temperature ◽

General Anesthesia ◽

Core Temperature ◽

Core Body Temperature ◽

Neuraxial Anesthesia ◽

General Anesthetics ◽

The Core ◽

Core Body ◽

Dose Dependent ◽

Body Heat

Most clinically available thermometers accurately report the temperature of whatever tissue is being measured. The difficulty is that no reliably core-temperature-measuring sites are completely noninvasive and easy to use-especially in patients not undergoing general anesthesia. Nonetheless, temperature can be reliably measured in most patients. Body temperature should be measured in patients undergoing general anesthesia exceeding 30 min in duration and in patients undergoing major operations during neuraxial anesthesia. Core body temperature is normally tightly regulated. All general anesthetics produce a profound dose-dependent reduction in the core temperature, triggering cold defenses, including arteriovenous shunt vasoconstriction and shivering. Anesthetic-induced impairment of normal thermoregulatory control, with the resulting core-to-peripheral redistribution of body heat, is the primary cause of hypothermia in most patients. Neuraxial anesthesia also impairs thermoregulatory control, although to a lesser extent than does general anesthesia. Prolonged epidural analgesia is associated with hyperthermia whose cause remains unknown.

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Abstract 10475: Heat Loss Augmented by Extracorporeal Circulation is Associated with Overcooling in Cardiac Arrest Survivors Who Underwent Targeted Temperature Management

Circulation ◽

10.1161/circ.144.suppl_2.10475 ◽

2021 ◽

Vol 144 (Suppl_2) ◽

Author(s):

Byungkook Lee ◽

Dong Hun Lee

Keyword(s):

Water Temperature ◽

Core Temperature ◽

Neurological Outcome ◽

Temperature Management ◽

Extracorporeal Circuit ◽

Matched Cohort ◽

Maintenance Period ◽

Neurological Outcomes ◽

The Core ◽

Poor Neurological Outcome

Introduction: Extracorporeal circuit-based salvage therapy can affect targeted temperature management (TTM) in comatose out-of-hospital cardiac arrest (OHCA) survivors. We investigated the association of patients with extracorporeal device with TTM and neurological outcome. Methods: We performed a retrospective analysis using prospectively collected data from adult comatose OHCA survivors who underwent TTM between October 2015 and December 2020. We defined patients with ECMO and/or CRRT as the extracorporeal group. We calculated the cooling rate during the induction period; the minimum, maximum, and mean time-weighted core temperatures (TWCT), and the standard deviation (SD) of the core temperature and water temperature during the maintenance period based on the temperature measured every minute. We defined the sum of TWCT more and less than 33°C as positive and negative TWCT, respectively. The primary outcome was a poor neurological outcome, defined as cerebral performance category 3-5. We used propensity score (PS) matching to adjust the characteristics of patients who required an extracorporeal circuit device. Results: Of the 223 included patients, 140 (62.8%) patients had poor neurological outcome and 40 (17.9%) patients were categorized into the extracorporeal group. The extracorporeal group had a rapid cooling rate (2.08°C/h [1.13-3.73] vs. 1.24°C/h [0.77-1.79]; p < 0.001). The extracorporeal group had lower mean core temperature; higher core temperature SD; lower positive TWCT; higher negative TWCT; and higher maximum, minimum, and mean water temperature than the no-extracorporeal group. In PS matched cohort, the extracorporeal group had a lower minimum core temperature, lower mean core temperature, higher core temperature SD, higher negative TWCT, higher maximum water temperature, and higher mean water temperature. The neurological outcomes were not different between the two groups, in either the whole or PS-matched cohort. Conclusions: The extracorporeal group achieved the target temperature earlier. The core temperature distribution during the maintenance period was further skewed below 33°C in the extracorporeal group. The extracorporeal group had similar neurological outcomes to the no-extracorporeal group.

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Simulating the action of zeitgebers on a coupled two-oscillator model of the human circadian system

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1984.247.3.r418 ◽

1984 ◽

Vol 247 (3) ◽

pp. R418-R426

Author(s):

P. H. Gander ◽

R. E. Kronauer ◽

C. A. Czeisler ◽

M. C. Moore-Ede

Keyword(s):

Core Temperature ◽

Activity Rhythm ◽

Human Subjects ◽

Model Performance ◽

The Other ◽

Oscillator Model ◽

Temporal Isolation ◽

The Core ◽

Temperature Rhythm ◽

Rest Activity

Our two-oscillator model was originally designed to describe the circadian rhythms of human subjects maintained in temporal isolation. The performance of this model in response to simulated environmental synchronizing cycles (zeitgebers) is examined here. Six distinct types of synchronization are demonstrated between the x oscillator (postulated to regulate the core temperature rhythm), the y oscillator (postulated to regulate the rest-activity rhythm), and z (the zeitgeber). Four types of synchronization are identifiable, if we consider only the periods of the three oscillators. Both x and y may be synchronized by z; either may synchronize with z while the other exhibits a different period; or x, y, and z may each show different periods. Two further classes of synchronization are discernible when phase criteria are taken into account. When either x or y is on the verge of desynchronizing from the other two oscillators, it undergoes periodic phase modulations while retaining the common overall period. The type of synchronization observed depends on the periods of x, y, and z and on the strength of the z drive. The effects of modifying each of these parameters have been systematically investigated by simulation, and model performance is summarized in terms of range of entrainment "maps." These constitute extensive sets of predictions about expected patterns of entrainment of the core temperature and rest-activity rhythms of human subjects exposed to various environmental zeitgebers. Experimental data are available against which model predictions can be tested.

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