Monitoring Of Core Body Temperature Research Articles

96 Evaluating the impact of macroenvironment temperature on thermoregulatory and milk quality parameters in lactating sows and their litter

Abstract Farrowing facility macroenvironment temperatures (TMacro) are often maintained at the upper end of the thermoneutral zone (24–25°C) of lactating sows, which may result in heat stress and reduced milk quality and quantity. Therefore, the study objective was to evaluate the impact of TMacro on thermoregulatory and milk quality parameters in lactating sows and their litters. In two repetitions, 37 lactating sows (parity = 3.1 ± 1.7) and their litters (d 1 litter size = 12.0 ± 1.0) were housed within 1 of 3 farrowing rooms set to different TMacro: LOW (n = 12 sows and litters; 15.0 ± 0.4°C), MID (n = 13 sows and litters; 19.3 ± 0.2°C), and HIGH (n = 12 sows and litters; 24.6 ± 0.8°C). Lactating sows and litters were monitored from d 3 of lactation until weaning (19.8 ± 0.9 d of age). All litters were provided with a 0.34 × 1.52 m heating pad. Sow respiration rates (RR, breaths per minute, BPM) were measured daily at 0800, 1200, 1600 and 2000 h by counting the number of flank movements. Vaginal temperature (TV) was measured in all sows at 10-min intervals using implanted data loggers. One sentinel piglet from each litter was implanted with a temperature recording bolus at d 2 of age to monitor core body temperature in 15-min intervals. Milk samples were collected from all sows on d 6, 12, and 18 of lactation and analyzed for true protein %, total solid %, and fat %. Data were analyzed using PROC GLIMMIX. The litter was considered the experimental unit for piglet measures, and the sow was considered the experimental unit for sow measures. Respiration rates were greater (P < 0.01) for HIGH (48 ± 2 bpm) sows versus MID (33 ± 2 BPM) and LOW (27 ± 2 bpm) sows, but no differences were detected between MID and LOW sows. A TMacro treatment by lactation day effect was observed for TV (P = 0.02), where HOT sows had greater TV on lactation d 15 (+0.31°C), 18 (+0.43°C) and 19 (+0.34°C) versus MID and LOW sows. Piglet core body temperature was reduced (P < 0.01) in the HIGH (39.07 ± 0.06 °C) versus the MID (39.31 ± 0.06 °C) and LOW (39.33 ± 0.07 °C) treatment groups, but it was similar for MID and LOW litters. Fat % was reduced for COLD (6.15 ± 0.52%) versus MID (7.35 ± 0.50%) sows on d 12, but no differences were observed when compared with HIGH sows (6.97 ± 0.52%). In conclusion, the HIGH treatment resulted in physiological heat stress for lactating sows and lowered piglet core body temperature, but it had minimal effects on measures of milk quality.

Application of the Bair Hugger™ core body temperature at wrist region with upper body warming blanket: a prospective observational study.

Body temperature monitoring is essential during the perioperative period. However, core body temperature measurement requires invasive device that may cause complications. This study aimed to evaluate the accuracy of non-invasive Bair Hugger™ core body temperature monitoring system (BHTMS) at the wrist compared with esophageal temperature under general anesthesia. Twenty adult patients of the American Society of Anesthesiologists physical status I or II were enrolled. BHTMS sensor was applied at wrist region. After tracheal intubation, an esophageal probe was inserted. Bair Hugger™ upper body warming blankets were used. Esophageal temperature (Teso) and BHTMS at wrist (Twrist) were recorded every 10 min. Total of 257 pairs of data sets were analyzed: Teso and Twrist had no statistically significant difference (P = 0.103). Median of Teso and Twrist were 36.5°C and 36.4°C. Bland-Altman analysis showed Teso - Twrist of 0.14°C ± 1.44. Subsequently, 99 pairs of 0-40 min data set were analyzed and showed significant difference at 0 and 10 min (P < 0.001) but no significant difference at 20, 30 and 40 min. Bland- Altman plot by times showed difference (Teso - Twrist) of 1.49°C ± 2.00, 0.82°C ± 1.30, 0.29°C ± 1.32, -0.03°C ± 0.84, and -0.12°C ± 0.82 at 0, 10, 20, 30 and 40 min respectively. BHTMS at wrist area under the upper body warming blanket is a potential alternative other than esophageal temperature for monitoring body temperature after 30 min of anesthesia induction.

A Continuously Worn Dual Temperature Sensor System for Accurate Monitoring of Core Body Temperature from the Ear Canal.

The objective of this work was to develop a temperature sensor system that accurately measures core body temperature from an ear-worn device. Two digital temperature sensors were embedded in a hearing aid shell along the thermal gradient of the ear canal to form a linear heat balance relationship. This relationship was used to determine best fit parameters for estimating body temperature. The predicted body temperatures resulted in intersubject limits of agreement (LOA) of ±0.49 °C over a range of physiologic and ambient temperatures without calibration. The newly developed hearing aid-based temperature sensor system can estimate core body temperature at an accuracy level equal to or better than many devices currently on the market. An accurate, continuously worn, temperature monitoring and tracking device may help provide early detection of illnesses, which could prove especially beneficial during pandemics and in the elderly demographic of hearing aid wearers.

Risk factors and outcomes of intraoperative hypothermia in neonatal and infant patients undergoing general anesthesia and surgery.

The incidence of intraoperative hypothermia remains high in pediatric patients during anesthesia and surgery even though core body temperature monitoring and warming systems have been greatly improved in recent years. We analyzed the risk factors and outcomes of intraoperative hypothermia in neonates and infants undergoing general anesthesia and surgery. The data on the incidence of intraoperative hypothermia, other clinical characteristics, and outcomes from electronic records of 1,091 patients (501 neonates and 590 infants between 28 days and 1 year old), who received general anesthesia and surgery, were harvested and analyzed. Intraoperative hypothermia was defined as a core temperature below 36°C during surgery. The incidence of intraoperative hypothermia in neonates was 82.83%, which was extremely higher than in infants (38.31%, p < 0.001)-the same as the lowest body temperature (35.05 ± 0.69°C vs. 35.40 ± 0.68°C, p < 0.001) and the hypothermia duration (86.6 ± 44.5 min vs. 75.0 ± 52.4 min, p < 0.001). Intraoperative hypothermia was associated with prolonged PACU, ICU, hospital stay, postoperative bleeding, and transfusion in either age group. Intraoperative hypothermia in infants was also related to prolonged postoperative extubation time and surgical site infection. After univariate and multivariate analyses, the age (OR = 0.902, p < 0.001), weight (OR = 0.480, p = 0.013), prematurity (OR = 2.793, p = 0.036), surgery time of more than 60 min (OR = 3.743, p < 0.001), prewarming (OR = 0.081, p < 0.001), received >20 mL/kg fluid (OR = 2.938, p = 0.004), and emergency surgery (OR = 2.142, p = 0.019) were associated with hypothermia in neonates. Similar to neonates, age (OR = 0.991, p < 0.001), weight (OR = 0.783, p = 0.019), surgery time >60 min (OR = 2.140, p = 0.017), pre-warming (OR = 0.017, p < 0.001), and receive >20 mL/kg fluid (OR = 3.074, p = 0.001) were relevant factors to intraoperative hypothermia in infants along with the ASA grade (OR = 4.135, p < 0.001). The incidence of intraoperative hypothermia was still high, especially in neonates, with a few detrimental complications. Neonates and infants each have their different risk factors associated with intraoperative hypothermia, but younger age, lower weight, longer surgery time, received more fluid, and no prewarming management were the common risk factors.

Free-living core body temperature monitoring using a wrist-worn sensor after COVID-19 booster vaccination: a pilot study

Core body temperature (CBT) is a key vital sign and fever is an important indicator of disease. In the past decade, there has been growing interest for vital sign monitoring technology that may be embedded in wearable devices, and the COVID-19 pandemic has highlighted the need for remote patient monitoring systems. While wrist-worn sensors allow continuous assessment of heart rate and oxygen saturation, reliable measurement of CBT at the wrist remains challenging. In this study, CBT was measured continuously in a free-living setting using a novel technology worn at the wrist and compared to reference core body temperature measurements, i.e., CBT values acquired with an ingestible temperature-sensing pill. Fifty individuals who received the COVID-19 booster vaccination were included. The datasets of 33 individuals were used to develop the CBT prediction algorithm, and the algorithm was then validated on the datasets of 17 participants. Mean observation time was 26.4 h and CBT > 38.0 °C occurred in 66% of the participants. CBT predicted by the wrist-worn sensor showed good correlation to the reference CBT (r = 0.72). Bland–Altman statistics showed an average bias of 0.11 °C of CBT predicted by the wrist-worn device compared to reference CBT, and limits of agreement were − 0.67 to + 0.93 °C, which is comparable to the bias and limits of agreement of commonly used tympanic membrane thermometers. The small size of the components needed for this technology would allow its integration into a variety of wearable monitoring systems assessing other vital signs and at the same time allowing maximal freedom of movement to the user.

Development of a Core Body Thermometer Applicable for High-Temperature Environment Based on the Zero-Heat-Flux Method.

Monitoring core body temperature (CBT) allows observation of heat stress and thermal comfort in various environments. By introducing a Peltier element, we improved the zero-heat-flux core body thermometer for hot environments. In this study, we performed a theoretical analysis, designed a prototype probe, and evaluated its performance through simulator experiments with human subjects. The finite element analysis shows that our design can reduce the influence of external temperature variations by as much as 1%. In the simulator experiment, the prototype probe could measure deep temperatures within an error of less than 0.1 °C, regardless of outside temperature change. In the ergometer experiment with four subjects, the average difference between the prototype probe and a commercial zero-heat-flux probe was +0.1 °C, with a 95% LOA of -0.23 °C to +0.21 °C. In the dome sauna test, the results measured in six of the seven subjects exhibited the same trend as the reference temperature. These results show that the newly developed probe with the Peltier module can measure CBT accurately, even when the ambient temperature is higher than CBT up to 42 °C.

Abstract WP113: Feasibility Of Non-invasive Brain Temperature Measurement In Acute Ischemic Stroke: A Comparison Study Of MR Thermometry Vs. Zero-Heat-Flux Sensors

Introduction: Brain-selective hypothermia is a promising neuroprotectant in acute ischemic stroke. However, a non-invasive bedside method to monitor brain temperature during cooling is lacking. We tested the feasibility and accuracy of measuring brain temperature non-invasively using sensors designed to monitor core body temperature. Methods: In this prospective single-center study, 20 patients with large or medium vessel occlusion strokes were enrolled. Patients underwent a 3T MR spectroscopy imaging (MRSI, the reference standard) and zero heat flux (ZHF) core temperature sensor measurements (3M TM Bair Hugger TM ) within 12-72 hours from admission. Two ZHF sensors were placed on each side of the forehead on the side of stroke and contralateral side and the temperatures were checked before and after MRSI. A 2x2x2 cm voxel was centered on the infarct and matching contralateral location using diffusion weighted imaging. Brain temperature on MRSI was calculated using the relative chemical shifts of water and N-acetyl aspartate. Temperature measurements of the ZHF sensors were compared to MRSI measurements. Results: The brain temperature of stroke and contralateral sides were similar using MRSI or using ZHF sensors when each modality was compared to itself by hemisphere (all p&gt;0.05). However, there was a significant difference for the ipsilateral side: median (SD) temperatures using MRSI was 36.0°C (1.8) vs 36.8°C (0.5) for sensor measurement. Bland-Altman plots showed that 95% of the observations fell within upper and lower limits of agreement of -2.1 to +3.7°C while 61% of observations fell within an agreement limit of +/- 1°C. There was an indication of an overall higher temperature measurements using the ZHF sensors compared to MRSI (Figure 1). Conclusions: More studies are needed to validate the use of ZHF thermometry in ischemic stroke including studies implementing hypothermia. Figure 1. Boxplot of stroke side MRSI compared to zero-heat-flux sensors.

Association between epidural-related maternal fever and short-and long-term prognosis of parturients: A prospective observational study.

We aimed to explore the association between epidural-related maternal fever (ERMF) and prognosis of parturients. 159 parturients who underwent vaginal delivery under labor epidural analgesia (LEA) received noninvasive continuous core body temperature monitoring. 122 of them completed the 42-day postpartum follow-up. Parturients with body temperature ≥38°C during labor were categorized as the Fever group, while the others were categorized as the No-Fever group. Compared to No-Fever group, Fever group had a greater proportion of primiparas, greater gestational age of parturients, and longer third stage of labor. The cesarean section and forceps delivery rates, and the amount of intrapartum hemorrhage in Fever group were significantly higher. There were no significant between-group differences with respect to puerperal infection, and amniotic fluid turbidity degree, neither significant between-group difference at 42-days postpartum. We found that ERMF was associated with some short-term outcomes. However, it showed no relation with long-term prognosis of the parturients at 42-days postpartum.

Study of perfusion based theoretical model and experimental evaluation for wearable CBT measurement

Continuous and non-invasive core body temperature (CBT) monitoring is imperative to clinical diagnosis and health monitoring. Current wearable non-invasive CBT measurements ignore the role of human thermoregulation and compromise measurement accuracy under changing environmental conditions that often occur in daily wearable scenarios. In this study, a novel wearable measurement method with optimized parameters (only 1 calibration parameter) was proposed, which could monitor CBT precisely under changing environmental conditions, by improving the sensor structure and quantifying the effect of human thermoregulation directly. Firstly, the proposed method was simulated and analyzed based on finite element method (FEM), and the mean absolute error (0.095 °C) of the model over a wide range of ambient temperatures was reduced by 98.19 % compared to the traditional model. Then, two experiments under ordinary life scenarios were designed to evaluate the method: stable and changing environment experiments had the mean absolute error of 0.04 ± 0.05 °C and 0.19 ± 0.24 °C respectively. Overall, the proposed method can suppress the estimation errors caused by human thermoregulation and has the potential to continuously monitor CBT under changing environmental conditions in daily life.

Core Temperature Estimation Using The CORETm Body Temperature Sensor During A 5 Km Running Time-trial

Monitoring of core body temperature (CT) during exercise may be useful to optimize pacing and performance and prevent heat-related illnesses. Athletes are left with very few options when it comes to the measurement of CT during out-of-doors exercise conditions. Moreover, the available technology is either expensive or invasive, both of which are a deterrent to athletes. Recently, a non-invasive, affordable, wearable, compact, light, rechargeable and wireless thermal energy transfer sensor has been introduced into the market. When paired with heart rate, the manufacturer claims that the device can estimate CT with an accuracy of ±0.21 °C. PURPOSE: Compared measurements of CT obtained with a gastrointestinal pill (GP) to those estimated with the CORETM thermal energy transfer sensor during a sitting period followed by a running time-trial. METHODS: This is an ongoing study and preliminary findings are henceforth reported. Six participants (4 men, 2 women) aged 26 ± 4 yrs, with a fat-free mass (FFM) of 55 ± 8 kg, underwent a 120 min seated resting period at 20-21 °C followed by a 5 km running time-trial at 30 °C, 50% relative humidity. Participants ingested a GP 10 h prior to reporting to the laboratory. The CORETM sensor was worn according to the manufacture’s instructions, i.e., 20 cm below the armpit, and paired with a heart rate monitor. Following 20 min of sitting, participants ingested 7.5 mL/kg FFM of cold water (~ 4 °C). Measurements of CT were taken every 20 min during the sitting period and every min during the TT. RESULTS: Whereas according to the CORETM CT increased by 0.13 ± 0.08 °C during the sitting period, a decrease of 0.18 ± 0.11 °C was detected with GP. A mean bias (CORETM - GP) of - 0.22 °C at a CT of 37 °C with each additional increase in CT of 0.1 °C associated with an error of - 0.12 °C, were observed during the sitting period. A mean bias between devices of - 0.55 °C was observed during the time-trial. The mean rates of increase in CT during exercise were respectively of 0.07 ± 0.04 and 0.08 ± 0.04 °C/min for the CORETM and GP. CONCLUSION: Our results indicate that, compared with measurements derived from a GP, the CORETM 1) underestimates both CT and the rate of change in CT during a sitting period comprising cold fluid ingestion and; 2) underestimates CT but adequately estimates the rate of change in CT during a 5 km time-trial in the heat.

Monitoring body temperature of cattle using an innovative infrared photodiode thermometer

Body temperature monitoring, which plays a pivotal role in diagnosing the physiological state of an animal, depends on the methods used and their applicability within the production systems. Recent research has examined several methods, such as rectal probes, intra-vaginal radio transmitters, data loggers, reticular boluses, digital rectal, and microchip transponder thermometry RFID tags, for detecting body temperature in several locations, including the skin surface, vagina, subcutis, and rumen. However, the potential for device loss and the potential for stress induction are the drawbacks to these approaches. In this report, we propose, for the first time, the use of an innovative infrared (IR) photodiode thermometer to detect the temperature of cattle in real-time. Totally, seventy-five adult cows (Red Sindhi Cross (n = 25), Holstein Fresian (HF) Cross (n = 25), and kangayam (n = 25)), with an average age of (43.0 ± 0.4) months and a weight of 487.0 kg ± 42.5 kg, were monitored for 30 days. The surface temperatures of the rectal across the tail base (TB) and the abdominal region (ADT) were measured using an innovative infrared photodiode thermometer. The invasive rectal temperature (RT) was determined using a clinical thermometer, which is the gold standard for measuring cow temperature. The rectal temperature (RT) of n = 75 cows was strongly correlated with the temperature of tail base (TB) and closely correlated with the abdominal region (ADT) with r = 0.85, and r = 0.74 respectively. The emissivity (ε), measured by reflection, is 98.9 ± 1%. The emissivity on the cattle surface varied from 0.975 to 0.989. Our innovative infrared photo diode thermometers get rid of the problems that come with measuring temperature, such as invasive, less invasive, stressful methods, it could be used for long-term monitoring of core body temperature, which is shown to be safe as it provides better precision for inferring the core body temperature of cows. The remote server gets the cows' temperatures through Bluetooth and sends them to a central location so that the cows' health can be checked on all the time.

IOT Based Covid-19 Patients Health Monitoring System

Currently, the COVID-19 pandemic is one of the major global issues faced by health organizations. As a person enters old age, it becomes increasingly vital for them to undergo standard medical health checkups. Since it may be time-consuming and difficult for most people to get regular health checkup appointments, IoT-based arrangements can be beneficial to individuals for routine health checkups. We are utilizing the internet of things to monitor several characteristics of the patient in this project. The real-time parameters of a patient’s health are transferred to the cloud via Internet connectivity in the patient Monitoring system based on the Internet of things project. These parameters are transmitted to IoT server where people can access them from any point on the planet. We demonstrate a multi-parameter Wearable sensor system that works in tandem with the Internet of Things to provide real-time, unobtrusive Monitoring of core body temperature and heart rate. Clinical study demonstrating the importance of sustaining precise measurements of core heartbeat and body temperature in the ambulatory environment and during Activity to examine human thermoregulation. We use a wireless multisensory system to monitor the temperature of the body as well as the pulse of the heart. The system’s goal is to build a health monitoring system that can quickly measure a variety of health factors

Short Communication: Use of Infrared Thermometers for Cutaneous Temperature Recording: Agreement with the Rectal Temperature in Felis catus.

Simple SummaryThe recording of body temperature by rectal temperature assessments is a stressful procedure for cats. For this purpose, alternative methods for using rectal digital thermometers to monitor body temperature were investigated. Skin temperature was recorded in 20 cats, in 5 different body regions, and compared with the rectal temperature. The obtained data indicated that the cutaneous temperature recorded by the infrared thermometers was not in agreement with the data recorded by the digital thermometer in the rectum.In veterinary medicine, the gold standard for assessing body temperature is rectal temperature assessment. Considering that this procedure is stressful for many species, in particular for cats, it could be clinically important to consider an alternative approach for the monitoring of core body temperature. The aim of this study was to test if cutaneous temperature measurements by means of different infrared thermometers are in agreement with the most commonly used method for body temperature measurement in cats. The cutaneous temperature was recorded in the jugular, shoulder, rib, flank, and inner thigh, using three different non-contact infrared thermometers (IR1, IR2, and IR3) in 20 cats. The cutaneous temperature was then compared to the rectal temperature, recorded by means of a digital thermometer. The obtained data indicated that the cutaneous temperature recorded by the infrared thermometers was not in agreement with the data recorded by the digital thermometer in the rectum. In cats, the use of non-contact infrared thermometers gave no reproducible or constant data to justify their application for the recording of body temperature instead of rectal temperature recording. In addition, the infrared temperature measurement devices generated results that were not in good agreement among themselves, providing a novel result of clinical importance.

IOT Based Health Monitoring System for Covid Patients Monitoring

Currently, the COVID-19 pandemic is one of the major global issues faced by health organizations. As a person enters old age, it becomes increasingly vital for them to undergo standard medical health checkups. Since it may be time-consuming and difficult for most people to get regular health checkup appointments, IoT-based arrangements can be beneficial to individuals for routine health checkups. We are utilizing the internet of things to monitor several characteristics of the patient in this project. The real-time parameters of a patient’s health are transferred to the cloud via Internet connectivity in the patient Monitoring system based on the Internet of things project. These parameters are transmitted to IoT server where people can access them from any point on the planet. We demonstrate a multi-parameter Wearable sensor system that works in tandem with the Internet of Things to provide real-time, unobtrusive Monitoring of core body temperature and heart rate. Clinical study demonstrating the importance of sustaining precise measurements of core heartbeat and body temperature in the ambulatory environment and during Activity to examine human thermoregulation. We use a wireless multisensory system to monitor the temperature of the body as well as the pulse of the heart.

Non-Invasive Monitoring of Core Body Temperature for Targeted Temperature Management in Post-Cardiac Arrest Care.

ImportanceAccurate monitoring of core body temperature is integral to targeted temperature management (TTM) following cardiac arrest. However, there are no reliable non-invasive methods for monitoring temperature during TTM.ObjectivesWe compared the accuracy and precision of a novel non-invasive Zero-Heat-Flux Thermometer (SpotOn™) to a standard invasive esophageal probe in a cohort of patients undergoing TTM post-cardiac arrest.Design, Setting, and ParticipantsWe prospectively enrolled 20 patients undergoing post-cardiac arrest care in the intensive care units at the London Health Sciences Centre in London, Canada. A SpotOn™ probe was applied on each patient's forehead, while an esophageal temperature probe was inserted, and both temperature readings were recorded at 1-min intervals for the duration of TTM.Main outcomes and MeasuresWe compared the SpotOn™ and esophageal monitors using the Bland–Altman analysis and the Pearson correlation, with accuracy set as a primary outcome. Secondary outcomes included precision and correlation. Bias exceeding 0.1°C and limits of agreement exceeding 0.5°C were considered clinically important.ResultsSixteen (80%) of patients had complete data used in the final analysis. The median (interquartile range) duration of recording was 38 (12–56) h. Compared to the esophageal probe, SpotOn™ had a bias of 0.06 ± 0.45°C and 95% limits of agreement of −0.83 to 0.95°C. The Pearson correlation coefficient was 0.97 (95% confidence interval 0.9663–0.9678), with a two-tailed p < 0.0001.Conclusion and RelevanceThe SpotOn™ is an accurate method that may enable non-invasive monitoring of core body temperature during TTM, although its precision is slightly worse than the predefined 0.5°C when compared to invasive esophageal probe.

Low Ambient Temperature Exposition Impairs the Accuracy of a Non-invasive Heat-Flux Thermometer.

BackgroundIndirect core body temperature (CBT) monitoring from skin sensors is gaining attention for in-field applications thanks to non-invasivity, portability, and easy probe positioning. Among skin sensors, heat-flux devices, such as the so-called Double Sensor (DS), have demonstrated reliability under various experimental and clinical conditions. Still, their accuracy at low ambient temperatures is unknown. In this randomized cross-over trial, we tested the effects of cold temperature exposition on DS performance in tracking CBT.MethodsTwenty-one participants were exposed to a warm (23.2 ± 0.4°C) and cold (−18.7 ± 1.0°C) room condition for 10 min, following a randomized cross-over design. The accuracy of the DS to estimate CBT in both settings was assessed by quantitative comparison with esophageal (reference) and tympanic (comparator) thermometers, using Bland–Altman and correlation analyses (Pearson’s correlation coefficient, r, and Lin’s concordance correlation coefficient, CCC).ResultsIn the warm room setting, the DS showed a moderate agreement with the esophageal sensor [bias = 0.09 (−1.51; 1.69) °C, r = 0.40 (p = 0.069), CCC = 0.22 (−0.006; 0.43)] and tympanic sensor [bias = 2.74 (1.13; 4.35) °C, r = 0.54 (p < 0.05), CCC = 0.09 (0.008; 0.16)]. DS accuracy significantly deteriorated in the cold room setting, where DS temperature overestimated esophageal temperature [bias = 2.16 (−0.89; 5.22) °C, r = 0.02 (0.94), CCC = 0.002 (−0.05; 0.06)]. Previous exposition to the cold influenced temperature values measured by the DS in the warm room setting, where significant differences (p < 0.00001) in DS temperature were observed between randomization groups.ConclusionDS accuracy is influenced by environmental conditions and previous exposure to cold settings. These results suggest the present inadequacy of the DS device for in-field applications in low-temperature environments and advocate further technological advancements and proper sensor insulation to improve performance in these conditions.

Accuracy of Algorithm to Non-Invasively Predict Core Body Temperature Using the Kenzen Wearable Device.

With climate change increasing global temperatures, more workers are exposed to hotter ambient temperatures that exacerbate risk for heat injury and illness. Continuously monitoring core body temperature (TC) can help workers avoid reaching unsafe TC. However, continuous TC measurements are currently cost-prohibitive or invasive for daily use. Here, we show that Kenzen’s wearable device can accurately predict TC compared to gold standard TC measurements (rectal probe or gastrointestinal pill). Data from four different studies (n = 52 trials; 27 unique subjects; >4000 min data) were used to develop and validate Kenzen’s machine learning TC algorithm, which uses subject’s real-time physiological data combined with baseline anthropometric data. We show Kenzen’s TC algorithm meets pre-established accuracy criteria compared to gold standard TC: mean absolute error = 0.25 °C, root mean squared error = 0.30 °C, Pearson r correlation = 0.94, standard error of the measurement = 0.18 °C, and mean bias = 0.07 °C. Overall, the Kenzen TC algorithm is accurate for a wide range of TC, environmental temperatures (13–43 °C), light to vigorous heart rate zones, and both biological sexes. To our knowledge, this is the first study demonstrating a wearable device can accurately predict TC in real-time, thus offering workers protection from heat injuries and illnesses.

Comparisons of Core Temperature Between a Telemetric Pill and Heart Rate Estimated Core Temperature in Firefighters

BackgroundFirefighters may experience high environmental temperatures or carry out intensive physical tasks, or both, which leads to increased core body temperature and risk of fatalities. Hence there is a need to remotely and non-invasively monitor core body temperature. MethodsEstimated (heart rate algorithm) and actual core body temperature (ingested telemetric pill) measures were collected simultaneously for comparison during training exercises on 44 firefighter volunteers. ResultsPrediction of core body temperature varied, with no specific identifiable pattern between the algorithm values and directly measured body core temperatures. Group agreement of Lin's Concordance of 0.74 (95% Upper 0.75, lower CI 0.73), was deemed poor. ConclusionFrom individual agreement data Lin's Concordance was variable (Min 0.11, CI 0.13–0.01; Max 0.83, CI 0.86–0.80), indicating that the heart rate algorithm approach was not suitable for core body temperature monitoring in this population group, especially at the higher more critical core body temperatures seen.

Reliability and Validity of the CORE Sensor to Assess Core Body Temperature during Cycling Exercise.

Monitoring core body temperature (Tc) during training and competitions, especially in a hot environment, can help enhance an athlete’s performance, as well as lower the risk for heat stroke. Accordingly, a noninvasive sensor that allows reliable monitoring of Tc would be highly beneficial in this context. One such novel non-invasive sensor was recently introduced onto the market (CORE, greenTEG, Rümlang, Switzerland), but, to our knowledge, a validation study of this device has not yet been reported. Therefore, the purpose of this study was to evaluate the validity and reliability of the CORE sensor. In Study I, 12 males were subjected to a low-to-moderate heat load by performing, on two separate occasions several days apart, two identical 60-min bouts of steady-state cycling in the laboratory at 19 °C and 30% relative humidity. In Study II, 13 males were subjected to moderate-to-high heat load by performing 90 min of cycling in the laboratory at 31 °C and 39% relative humidity. In both cases the core body temperatures indicated by the CORE sensor were compared to the corresponding values obtained using a rectal sensor (Trec). The first major finding was that the reliability of the CORE sensor is acceptable, since the mean bias between the two identical trials of exercise (0.02 °C) was not statistically significant. However, under both levels of heat load, the body temperature indicated by the CORE sensor did not agree well with Trec, with approximately 50% of all paired measurements differing by more than the predefined threshold for validity of ≤0.3 °C. In conclusion, the results obtained do not support the manufacturer’s claim that the CORE sensor provides a valid measure of core body temperature.

The use of forced air warmer for the prevention of inadvertent perioperative hypothermia under general anaesthesia - A prospective observational study

Temperature is an important parameter which determines patient outcomes perioperatively. Iatrogenic hypothermia during surgery under general anaesthesia leads to significant side effects which can be corrected with the use of active body surface warming devices like the forced air warmer. A prospective observational study was conducted with a sample size of 362 which included patients of either sex aged 18-65years posted for any elective surgery under general anaesthesia lasting &amp;#62;60 and ≤180minutes. Baseline oral temperature was recorded preoperatively. Patients were warmed with forced air warmer intraoperatively at 44°C with half hourly monitoring of nasopharyngeal temperature until extubation. Intravenous fluids were given at room temperature. Further, oral temperature was monitored at 15 and 60 minutes in post anaesthesia care unit and patients were warmed if hypothermic or shivering. The final mean intraoperative temperature (nasopharyngeal) was 36.01⁰C (n=362) with a range from 34.7⁰C to 37.1⁰C. 139 of 362(n) (38.4%) patients were hypothermic (&amp;#60;36⁰C) at the end of surgery. 61.6% of patients were normothermic. In 9 patients (2.5%, n=362) the forced air warmer was turned off due to over heating (temperature &amp;#62;37⁰C). 33 patients (n=362, 9.1%) had shivering postoperatively. Comparing the nasopharyngeal temperature (mean) at half hourly intervals post induction revealed statistically significant results (p&amp;#60;0.001). The establishment of near constant temperature (36±0.03°C) following the initial fall in core body temperature can be attributed to the forced air warmer. However, it is imperative to continuously monitor core body temperature to detect temperature changes(hypo/hyperthermia) in order to use the device safely as chances of overheating is always present.