Indirect Temperature Measurement in High Frequency Heating Systems

One of the biggest challenges of fused deposition modeling (FDM)/fused filament fabrication (FFF) 3D-printing is maintaining consistent quality of layer-to-layer adhesion, and on the larger scale, homogeneity of material inside the whole printed object. An approach for mitigating and/or resolving those problems, based on the rapid and reliable control of the extruded material temperature during the printing process, was proposed. High frequency induction heating of the nozzle with a minimum mass (<1 g) was used. To ensure the required dynamic characteristics of heating and cooling processes in a high power (peak power > 300 W) heating system, an indirect (eddy current) temperature measurement method was proposed. It is based on dynamic analysis over various temperature-dependent parameters directly in the process of heating. To ensure better temperature measurement accuracy, a series-parallel resonant circuit containing an induction heating coil, an approach of desired signal detection, algorithms for digital signal processing and a regression model that determines the dependence of the desired signal on temperature and magnetic field strength were proposed. The testbed system designed to confirm the results of the conducted research showed the effectiveness of the proposed indirect measurement method. With an accuracy of ±3 °C, the measurement time is 20 ms in the operating temperature range from 50 to 350 °C. The designed temperature control system based on an indirect measurement method will provide high mechanical properties and consistent quality of printed objects.

Monitoring Body Fluids in Textiles: Combining Impedance and Thermal Principles in a Printed, Wearable, and Washable Sensor

This work explores the feasibility of coupling two different techniques, the impedance and the transient plane source (TPS) principle, to quantify the moisture content and its compositional parameters simultaneously. The sensor is realized directly on textiles with the use of printing and coating technology. Impedance measurements use the fluid's electrical properties, while the TPS measurements are based on the thermal effusivity of the liquid. Impedance and TPS measurements show equal competency in measuring the fluid volume with a lowest measurable quantity of 0.5 μL, enabling ultralow volume passive measurements for sweat analysis. Both sensor principles were tested by monitoring the drying of a wet cloth and the measurements show perfect repeatability and accuracy. Nevertheless, when the biofluid property changes, the TPS sensor does not reflect this information on its readings, whereas, on the other hand, impedance can provide information on compositional changes. However, since the volume of the fluid changes simultaneously, one cannot differentiate between a volume change and a compositional change from impedance measurements alone. Therefore, we show in this work that we can apply impedance to measure the compositional properties; meanwhile, the TPS measurements accurately carry out volume measurements irrespective of the interferences from its compositional variations. To prove this, both of these techniques are applied for the quantification and composition monitoring of sweat, showing the capability to measure moisture content and compositional parameters simultaneously. TPS measurements can also be an indicator of the local temperature of the medium confined by the sensor, and it does not influence the fluid parameters. Compiling both impedance and thermal sensors in a single platform triggers smart wearable prospects of metering the liquid volume and simultaneously analyzing other compositional changes and body temperature. Finally, the repeatability and stability of the sensor readings and the washability of the device are tested. This device could be a potential sensing tool in real-life applications, such as wound monitoring and sweat analysis, and could be a promising addition toward future smart wearable sensors.

In Situ Thermography During Laser Powder Bed Fusion of a Nickel Superalloy 625 Artifact with Various Overhangs and Supports

This document provides details on the experiment and associated measurement files available fordownload in the dataset “In Situ Thermography During Laser Powder Bed Fusion of a Nickel Superalloy 625 Artifact with Various Overhangs and Supports.” The measurements were acquired during the fabrication of a small nickel superalloy 625 (IN625) artifact using a commercial laser powder bed fusion (LPBF) system. The artifact consists of two half-arch features with increasing slopes for overhangs. These overhangs range from 5° from vertical to 85° from vertical in increments of 10°. The artifact geometry and process are controlled to ensure consistent processing along the overhang geometry. This control enables the effect of overhang geometry and support structures to be isolated from effects of inter-layer scan strategy variations. The measurements include high-speed thermography of each layer, from which radiance temperature, cooling rate, and melt pool length are calculated.

An Investigation on High-Resolution Temperature Measurement in Precision Fly-Cutting

The loads acting on a workpiece during machining processes determine the modification of the surface of the final workpiece and, thus, its functional properties. In this work, a method that uses thermocouples to measure the temperature in precision fly-cutting machining with high spatial and temporal resolution is presented. Experiments were conducted for various materials and machining parameters. We compare experimental measurement data with results from modern and advanced machining process simulation and find a good match between experimental and simulation results. Therefore, the simulation is validated by experimental data and can be used to calculate realistic internal loads of machining processes.

Optical Fiber Pyrometer Designs for Temperature Measurements Depending on Object Size

The modelling of temperature measurements using optical fiber pyrometers for different hot object sizes with new generalized integration limits is presented. The closed equations for the calculus of the radiated power that is coupled to the optical fiber for two specific scenarios are proposed. Accurate predictions of critical distance for avoiding errors in the optical fiber end location depending on fiber types and object sizes for guiding good designs are reported. A detailed model for estimating errors depending on target size and distance is provided. Two-color fiber pyrometers as a general solution are also discussed.

Temperature Measurement of a Bullet in Flight

This study answers a primary question concerning how the temperature changes during the flight of a bullet. To answer the question, the authors performed unique research to measure the initial temperatures of bullet surfaces and applied it to four kinds of projectiles in a series of field experiments. The technique determines the temperature changes on metallic objects in flight that reach a velocity of 300 to 900 m/s. Until now, the tests of temperature change available in the literature include virtual points that are adopted to ideal laboratory conditions using classic thermomechanical equations. The authors conducted the first study of its kind, in which is considered four projectiles in field conditions in which a metallic bullet leaves a rifle barrel after a powder deflagration. During this process, heat is partly transferred to the bullet from the initial explosion of the powder and barrel-bullet friction. In this case, the temperature determination of a bullet is complex because it concerns different points on the external surface. Thus, for the first time the authors measured the temperatures at different position on the bullet surface. Moreover, the authors showed that basic thermodynamic equations allow for the credible prediction of such behavior if the initial conditions are identified correctly. This novel identification of the initial conditions of temperature and velocity of flying bullets was not presented anywhere else up to now.

Thermal Condition of Muscle Area Around the Temporomandibular Joint in Patient with Systemic Lupus Erythematosus Using Infrared Thermography Application: A Case Report

Recently, the use of infrared thermography in medical has been increasingly developed and widely used in medical devices to detect diseases, including one used in the field of dentistry, which can be used to detect joint conditions in case of temporomandibular disorder (TMD). Some literature has shown this method of infrared thermography was used to determine the surface temperature of the skin based on the emission of infrared radiation from the body. Thermal measurement is also a noninvasive method that does not provide patient inconvenience, but its application until now has not been so wide. The case study reported on the description of thermal condition of muscle area around temporomandibular joint (TMJ) in a 42-year-old woman with systemic lupus erythematosus (SLE) disease. She had experienced TMD. Infrared thermography is applied to observe the thermal condition of the muscle area around the right and left joints by thermal detection. Thermal measurement was obtained on infrared image capture, and the temperature difference was found to be greater than 0.3°C. Several studies have shown that temperature in the area around TMJ was higher, and thermal asymmetry was greater in individuals with joint disorder/TMD when compared with normal groups.

Iron oxide/gold nanoparticles-decorated reduced graphene oxide nanohybrid as the thermo-radiotherapy agent

The main focus of the current study is the fabrication of a multifunctional nanohybrid based on graphene oxide (GO)/iron oxide/gold nanoparticles (NPs) as the combinatorial cancer treatment agent. Gold and iron oxide NPs formed on the GONPs via the in situ synthesis approach. The characterisations showed that gold and iron oxide NPs formed onto the GO. Cell toxicity assessment revealed that the fabricated nanohybrid exhibited negligible toxicity against MCF-7 cells in low doses (<50 ppm). Temperature measurement showed a time and dose-dependent heat elevation under the interaction of the nanohybrid with the radio frequency (RF) wave. The highest temperature was recorded using 200 ppm concentration nanohybrid during 40 min exposure. The combinatorial treatments demonstrated that the maximum cell death (average of 53%) was induced with the combination of the nanohybrid with RF waves and radiotherapy (RT). The mechanistic study using the flow cytometry technique illustrated that early apoptosis was the main underlying cell death. Moreover, the dose enhancement factor of 1.63 and 2.63 were obtained from RT and RF, respectively. To sum up, the authors' findings indicated that the prepared nanohybrid could be considered as multifunctional and combinatorial cancer therapy agents.

Guidelines in Practice: Hypothermia Prevention

All patients are at risk for unplanned hypothermia in the perioperative practice setting. Adverse outcomes attributed to hypothermia include myocardial events, surgical site infections, poor wound healing, increased blood loss, and prolonged postanesthesia care unit stays. The AORN "Guideline for prevention of hypothermia" includes recommendations for measuring the patient's body temperature, selecting methods for prevention of unplanned hypothermia, and implementing the selected insulation and warming interventions. This article discusses guideline recommendations related to using a consistent temperature measurement method through all phases of perioperative care, assessing risk for hypothermia in all patients, and prewarming perioperative patients. A scenario provides an example in which an interdisciplinary facility team uses a gap analysis and a risk assessment to determine the process for implementing recommendations from this guideline. Perioperative RNs should review the entire guideline for additional information and for guidance when creating and updating policies and procedures related to unplanned hypothermia.

Lead-Wire-Resistance Compensation Technique Using a Single Zener Diode for Two-Wire Resistance Temperature Detectors (RTDs)

In remote measurement systems, the lead wire resistance of the resistance sensor will produce a large measurement error. In order to ensure the accuracy of remote measurement, a novel lead-wire-resistance compensation technique is proposed, which is suitable for a two-wire resistance temperature detector. By connecting a zener diode in parallel with the resistance temperature detector (RTD) and an interface circuit specially designed for it, the lead-wire-resistance value can be accurately measured by virtue of the constant voltage characteristic of the zener diode when reverse breakdown occurs, and compensation can thereby be made when calculating the resistance of RTD. Through simulation verification and practical circuit testing, when the sensor resistance is in 848–2120 Ω scope and the lead wire resistance is less than 50 Ω, the proposed technology can ensure the measuring error of the sensor resistance within ±1 Ω and the temperature measurement error within ±0.3 °C for RTDs performing 1000 Ω at 0 °C. Therefore, this method is able to accurately compensate the measurement error caused by the lead wire resistance in two-wire RTDsand is suitable for most applications.

In Situ Thermography of the Metal Bridge Structures Fabricated for the 2018 Additive Manufacturing Benchmark Test Series (AM-Bench 2018)

This document provides details on the files available for download in the data set “In situ thermography of the metal bridge structures fabricated for the 2018 Additive Manufacturing Benchmark Test Series (AM-Bench 2018).” The experiments were performed to support the 2018 AM-Bench1 Class 01 experiments consisting of metal three-dimensional (3D) builds. The modeling community was invited to predict the following: (1) part deflection, (2) residual elastic strains, (3) microstructure, (4) phase fractions, and (5) phase evolution. Details for these proposed challenges and the postprocess measurement results can be found at their respective links on the AM-Bench website.

An open-label, randomised controlled trial on the effectiveness of the Orve + wrap® versus Forced Air Warming in restoring normothermia in the postanaesthetic care unit

AIMS AND OBJECTIVES

To determine the clinical effectiveness and safety of the Orve + wrap® thermal blanket.

BACKGROUND

Inadvertent perioperative hypothermia is a common problem in postanaesthetic care units and can have significant effects on patients' postoperative morbidity. Despite its commercial availability, there is no clinical evidence on the effectiveness of Orve + wrap®.

DESIGN

A single centre prospective, open-label, noninferiority randomised controlled trial.

METHODS

Postoperative hypothermic (35.0-35.9°C) patients who had undergone elective surgery were randomised to receive either Orve + wrap® or Forced Air Warming during their PACU stay. Patient temperatures were recorded every 10 min using zero-heat-flux thermometry. This study is reported using CONSORT Extension checklist for noninferiority and equivalence trials.

RESULTS

Between December 2016-October 2018, 129 patients were randomised to receive either Orve + wrap® blanket (n = 65, 50.3%) or Forced Air Warming (n = 64, 49.7%). The mean 60-min postoperative temperature of patients receiving Orve + wrap® blanket was 36.2 and 36.3°C for the patients receiving Forced Air Warming. The predefined noninferiority margin of a mean difference in temperature of 0.3°C was not reached between the groups at 60 min. Additionally, there were no statistical differences between adverse event rates across these groups.

CONCLUSIONS

In the context of this study, warming patients with the Orve + wrap® was noninferior to Forced Air Warming. There were comparable rates of associated postoperative consequences of warming (shivering, hypotension, arrhythmias or surgical site infections), between the groups.

RELEVANCE TO CLINICAL PRACTICE

The Orve + wrap® potentially provides an alternative warming method to Forced Air Warming for patients requiring short-term postoperative warming. However, there are still a number of unknowns regarding the Orve + wrap® performance and further exploration is required.

High-Temperature Sensitivity in Stimulated Brillouin Scattering of 1060 nm Single-Mode Fibers

With the rapid advancement of Yb-doped fiber lasers (YDFL) whose output wavelength is near 1060 nm, passive fibers to carry the high optical power at the spectral range are also gaining significant importance. Stimulated Brillouin scattering (SBS) in the passive fibers connecting components in the lasers, especially, can set a fundamental limit in the power handling of YDFL systems. We experimentally analyzed SBS characteristics of passive single mode fibers (SMF) at a wavelength of 1060 nm. For two types of SMFs (Corning HI1060 and HI1060Flex), the Brillouin frequency (ν_Β), its linewidth (Δν_Β), and their variations with respect to the input laser power and the surrounding temperature were experimentally measured, along with the SBS threshold power (P_th). The optical heterodyne detection method was used to identify temperature-dependent SBS characteristics of fibers, and we found SMFs at λ = 1060 nm showed a temperature sensitivity in SBS frequency shift more than 40% higher than in conventional SMFs operating in C-band. Detailed procedures to measure the SBS properties are explained, and a new potential of 1060 nm SMF as a distributed temperature sensor is also discussed.

Measurements of Temperature Distribution for High Temperature Steel Plates Based on Digital Image Correlation

Temperature distribution is an important process parameter of steel plates during electromagnetic induction heating treatment. This study uses the digital image correlation method to develop an effective non-contact temperature measurement that allows obtaining valuable information about the temperature value of a high temperature steel plate specimen and analyzing its temperature distribution. A principle of thermal radiation temperature measurement based on the color chagre couled device (CCD) technology was introduced. The image processing system encapsulates the image update module, form mode module, image event module and temperature analysis module. The error analysis and temperature calibration were carried out to make sure the error deviation of the measurement system was within a small range. The temperature distribution of B1500HS at high temperature was analyzed by the designed measurement system which was in good agreement with the result from Raynger 3i Plus temperature gun, indicating that the measurement system based on image processing basically meets the requirements of temperature distribution measurement of a high temperature steel plate, and provides an important reference for a high temperature steel plate in non-contact temperature distribution measurement.

Early detection of deep wound infection in bladder exstrophy and hypospadias using a novel intervention

OBJECTIVE

To introduce a practical technique for the early detection and prompt management of a probable bladder dehiscence (BD) and glanular dehiscence (GD) in patients with bladder exstrophy epispadias complex (BEEC) and hypospadias.

METHOD

In this prospective study, paediatric patients with BEEC (group 1) and with proximal hypospadias (group 2) underwent body temperature measurement using a non-contact infrared radiant digital temperature measurement device in four body regions, including the surgical wound, forehead, right hand, and right foot at eight hour intervals, postoperatively. This technique was performed to detect wound temperature rises before whole body temperature rise or visible local wound skin redness, cellulitis or any sign of inflammation or wound dehiscence (WD).

RESULTS

A total of 24 paediatric patients were recruited. Temperature rise in the surgical wound area was discovered in two patients with BEEC. The temperature reached 39.2°C in the first case (12 days postoperative) and 39.4°C in the second case (16 days postoperative). Urinalysis, urine culture, and clean surgical wound sampling was performed and the presence of Gram-positive microorganisms was detected. Both patients were managed with intravenous imipenem and vancomycin. After changing the antibiotic regimen, wound temperature was gradually decreased to 37.2°C in the first patient by day 16, and to 36.9°C in the second patient by day 21, without rise in body temperature. Other patients in group 1 and all patients in group 2 had normal wound temperature fluctuations within the follow-up period.

CONCLUSION

Postoperative periodical temperature measurement by a non-contact infrared radiant digital temperature measurement device is a safe and feasible technique that has the ability to detect deep wound infection, and may prevent the occurrence of WD before any visible sign of inflammation.

The Impact of an Ice Slurry-Induced Gastrointestinal Heat Sink on Gastrointestinal and Rectal Temperatures Following Exercise

Gastrointestinal temperature (Tgint) measurement with a telemetric pill (TP) is increasingly used in exercise science. Contact of cool water with a TP invalidates Tgint assessment. However, what effect a heat sink created in the proximity of a TP may have on the assessment of Tgint remains unknown. We examined the impact of an ice slurry-induced heat sink on Tgint and rectal temperature (Trec) following exercise. After 20 min of seating (20–22 °C, 25–40% relative humidity (RH)), 11 men completed two intersperse exercise periods (31–32 °C, 35% RH) at 75–80% of estimated maximal heart rate until a Trec increase of 1 °C above baseline level. Following the first exercise period, participants were seated for 45 min and ingested 7.5 g·kg⁻¹ of thermoneutral water, whereas, following the second period, they ingested 7.5 g·kg⁻¹ of ice slurry. Both Tgint and Trec were measured continuously. The TPs were swallowed 10 h prior to the experiments. A bias ≤0.27 °C was taken as an indication that Tgint and Trec provided similar core temperature indices. Mean biases and 95% limits of agreement during passive sitting, first exercise, water ingestion, second exercise, and ice slurry ingestion periods were 0.16 ± 0.53, 0.13 ± 0.41, 0.21 ± 0.70, 0.17 ± 0.50, and 0.18 ± 0.66 °C, respectively. The rates of decrease in Tgint and Trec did not differ between the water and ice slurry ingestion periods. Our results indicate that ice slurry ingestion following exercise does not impact TP-derived assessment of Tgint compared with Trec.

New Approach to Analysis of Selected Measurement and Monitoring Systems Solutions in Ship Technology

This paper is dedicated to certain types of measurement in ship systems, analyzed based on selected case studies. In the introductory part, a simplified structure of a modern cargo ship as an object of measurement and control is presented. Next, the role of measurement in the ship’s operation process is described and commented on, with focus on specifics of local and remote control, both manual and automatic. The key part of the paper is dedicated to a short overview of selected examples of measuring and monitoring systems. The basic criteria for the aforementioned selection are the vital role of the considered systems for safe and effective ship operation as well as documented innovative contribution of Gdynia Maritime University (GMU) in development of the state-of-the-art in the analysed area of measurement. Based on these criteria, the monitoring of operational parameters of main engine and temperature measurement in the ships hazardous areas have been chosen. The aforementioned measurement and monitoring systems are analysed, taking into account both innovation of technical solutions together with their ship technology environment conditions and related legal requirements. Finally, some concluding remarks are formulated.

Hydrogel Heart Model with Temperature Memory Properties for Surgical Simulation

The continual development of surgical technology has led to a demand for surgical simulators for evaluating and improving the surgical technique of surgeons. To meet these needs, simulators must incorporate a sensing function into the organ model for evaluating the surgical techniques. However, it is difficult to incorporate a temperature sensor into the conventional cardiac training model. In this study, we propose a heart model for surgical training of cardiac catheter ablation made from hydrogel, which has temperature memory properties. The heart model consists of a photo-crosslinkable hydrogel mixed with an irreversible temperature indicator that exhibits a color change from magenta to colorless at 55 °C. The Young’s modulus, electrical resistivity, thermal conductivity, and specific heat capacity of the hydrogel material were evaluated and compared with those of human heart. Furthermore, temperature calibration based on the color of the hydrogel material confirmed that the temperature measurement accuracy of the material is ±0.18 °C (at 56 °C). A heart model for catheter ablation was fabricated using the hydrogel material and a molding method, and the color change due to temperature change was evaluated.

Comparison of heat generation between guided and conventional implant surgery for single and sequential drilling protocols-An in vitro study

OBJECTIVES

The aim of this in vitro study was to compare the heat generation during guided osteotomy preparation (GOP) with that of a conventional approach (CA) for a single and sequential drilling protocol.

METHODS

Temperature measurements were performed during standardized osteotomy preparations in polyurethane foam blocks with an infrared camera. The four groups included single and sequential drilling with and without the use of a surgical guide. In the first group (single CA) and the second group (single GOP), only the final drills diameters were applied once. In the third group (sequential CA) and the fourth group (sequential GOP), two to four drills with increasing diameters were applied. Guided and conventional as well as single and sequential drilling were compared using a one-way ANOVA with Tukey post hoc test. The level of statistical significance was set at α = 0.05.

RESULTS

Guided osteotomy preparation showed statistically significant higher temperatures than CA for the 2.2 mm, the 3.5 mm, and the 4.2 mm drill (p = 0.032, p = 0.005 and p < 0.001, respectively). Sequential drilling led to higher heat generation and longer duration of latent heat than single drilling. For all drilling procedures, the duration of heat exposure over critical temperature was less than 1 min, except for the sequential GOP drilling protocol with the 4.2 mm drill (76 s).

CONCLUSIONS

Guided drilling requires specific attention to heat development. When guided implant surgery is performed, a single drilling procedure could alleviate heat production compared to a sequential procedure.

Johnson Noise Thermometry

Johnson noise thermometers infer thermodynamic temperature from measurements of the thermally-induced current fluctuations that occur in all electrical conductors. This paper reviews the status of Johnson noise thermometry and its prospects for both metrological measurements and for practical applications in industry. The review begins with a brief description of the foundations and principles of Johnson noise thermometry before outlining the many different techniques and technological breakthroughs that have enabled the application of JNT to high-accuracy, cryogenic, and industrial thermometry. Finally, the future of noise thermometry is considered. As the only purely electronic approach to thermodynamic temperature measurement, Johnson noise thermometry has appeal for metrological applications at temperatures ranging from below 1 μK up to 800 K. With the rapid advances in digital technologies, there are also expectations that noise thermometry will become a practical option for some industrial applications reaching temperatures above 2000 K.

Reporting of thermography parameters in biology: a systematic review of thermal imaging literature

Infrared (IR) thermography, where temperature measurements are made with IR cameras, has proven to be a very useful and widely used tool in biological science. Several thermography parameters are critical to the proper operation of thermal cameras and the accuracy of measurements, and these must usually be provided to the camera. Failure to account for these parameters may lead to less accurate measurements. Furthermore, the failure to provide information of parameter choices in reports may compromise appraisal of accuracy and replicate studies. In this review, we investigate how well biologists report thermography parameters. This is done through a systematic review of biological thermography literature that included articles published between years 2007 and 2017. We found that in primary biological thermography papers, which make some kind of quantitative temperature measurement, 48% fail to report values used for emissivity (an object's capacity to emit thermal radiation relative to a black body radiator), which is the minimum level of reporting that should take place. This finding highlights the need for life scientists to take into account and report key parameter information when carrying out thermography, in the future.

Femtosecond Laser Microprinting of a Polymer Optical Fiber Interferometer for High-Sensitivity Temperature Measurement

Femtosecond laser induced multi-photon polymerization technique can be applied to fabricate an ultracompact polymer optical fiber interferometer which was embedded in a section of hollow core fiber. The production of the photoresin, used in this work, is described. Such a device has been used for temperature measurement, due to its excellent thermal properties. Transmission spectrum, structural morphology, and temperature response of the polymer optical fiber interferometer are experimentally investigated. A high wavelength sensitivity of 6.5 nm/°C is achieved over a temperature range from 25 °C to 30 °C. The proposed polymer optical fiber interferometer exhibits high temperature sensitivity, excellent mechanical strength, and ultra-high integration. More complex fiber-integrated polymer function micro/nano structures produced by this technique may result in more applications in optical fiber communication and optical fiber sensors.

A High Precision, Wireless Temperature Measurement System for Pervasive Computing Applications

This paper describes the design and calibration of a highly accurate temperature measurement system for pervasive computing applications. A negative temperature coefficient (NTC) thermistor with high resistance tolerance is interfaced through a conditioning circuit to a 12-bit digital converter of a wireless microcontroller. The system is calibrated to minimize the effect of component uncertainties and achieves an accuracy of ±0.03 °C on average (±0.05 °C in worst cases) in a 5 °C to 45 °C range. The calibration process is based on a continuous temperature sweep, while calibration data are simultaneously logged to reduce the delays and cost of conventional calibration approaches. An uncertainty analysis is performed to support the validity of the reported performance results. The described approach for interfacing the thermistor to the hardware platform can be straightforwardly adjusted for different thermistors, temperature ranges/accuracy levels/resolutions, and voltage ranges. The low power communication combined with the energy consumption optimization adopted enable an operation to be autonomic for several months to years depending on the application's measurement frequency requirements. The system cost is approximately $45 USD in components, while its design and compact size allow its integration with extended monitoring systems in various pervasive computing environments. The system has been thoroughly tested and validated in a field trial concerning a precision agriculture application and is currently used in a health monitoring application.

Comparison of temperature measurements in esophagus and urinary bladder in comatose patients after cardiac arrest undergoing mild therapeutic hypothermia

BACKGROUND

Mild therapeutic hypothermia (MTH) is a recommended method of treatment for comatose out-of-hospital cardiac arrest (OHCA) survivors. However, the proper site of temperature measurement in MTH is still not defined. The aim of this study was to compare temperature measurements in the esophagus and urinary bladder in comatose post-OHCA patients treated with MTH.

METHODS

This temperature comparison protocol was a part of a prospective, observational, multicenter cohort study. The study population included 36 unconscious patients after resuscitation for OHCA. The patient's core temperature was independently measured every hour during MTH in the urinary bladder and in the esophagus.

RESULTS

The mean temperature was lower in the esophagus (differences during induction phase: 1.04 ± 0.92°C, p < 0.0001; stabilization phase: 0.54 ± 0.39°C, p < 0.0001; rewarming phase: 0.40 ± 0.47°C, p < 0.0001). Nevertheless, a strong correlation between both sites was found (R2 = 0.83, p < 0.001). The decrease in temperature observed in the esophagus during the induction phase was faster when compared with the urinary bladder (1.09 ± 0.71°C/h vs. 0.83 ± 0.41°C/h; p = 0.002). As a consequence, time to reach temperature < 34.0°C was longer when temperature was measured in the urinary bladder (the difference between medians of the time 1.0 [0-1.5] h, p < 0.001).

CONCLUSIONS

Urinary bladder temperature measurements may lag behind temperature changes measured in the esophagus. Monitoring temperature simultaneously in the esophagus and in the urinary bladder is an accessible and reliable combination, although esophageal measurements seem to better reflect the dynamics of temperature changes, thus it seems to be more appropriate for MTH control. ClinicalTrials.gov Identifier: NCT02611934.

Regulation and Measurement of the Heat Generated by Automatic Tooth Preparation in a Confined Space

OBJECTIVE

The aim of this study was to assess and regulate heat generation in the dental pulp cavity and circumambient temperature around a tooth during laser ablation with a femtosecond laser in a confined space.

BACKGROUND DATA

The automatic tooth preparing technique is one of the traditional oral clinical technology innovations. In this technique, a robot controlled an ultrashort pulse laser to automatically complete the three-dimensional teeth preparing in a confined space. The temperature control is the main measure for protecting the tooth nerve.

METHODS

Ten tooth specimens were irradiated with a femtosecond laser controlled by a robot in a confined space to generate 10 teeth preparation. During the process, four thermocouple sensors were used to record the pulp cavity and circumambient environment temperatures with or without air cooling. A statistical analysis of the temperatures was performed between the conditions with and without air cooling (p < 0.05).

RESULTS

The recordings showed that the temperature with air cooling was lower than that without air cooling and that the heat generated in the pulp cavity was lower than the threshold for dental pulp damage.

CONCLUSIONS

These results indicate that femtosecond laser ablation with air cooling might be an appropriate method for automatic tooth preparing.