Method For Continuous Measurement Research Articles

Comparison of continuous temperature measurement methods in the intensive care unit: standard bladder catheter measurements versus non-invasive transcutaneous sensors.

The purpose of this study was to compare a wearable system for body core temperature measurement versus bladder and tympanic thermometers in an intensive care setting. The question was, if continuous non-invasive sensors in the intensive care unit represent an alternative to current standard methods of invasive continuous bladder temperature measurement methods?Between May and September 2023, a comparative investigation involving 112 patients was conducted in a 20-bed surgical intensive care unit to assess various temperature probes, including those placed in the tympanic tube, bladder, and skin. To achieve this, a wireless non-invasive sensor system provided by greenTEG AG, Switzerland, was affixed to different body locations (clavicular and lateral chest) of each catheterized patient (equipped with a temperature probe) admitted to the intensive care unit. Furthermore, tympanic temperatures were recorded at specified intervals. The measurement duration ranged from a minimum of six hours to a maximum of six days, resulting in the analysis of a total of 355 simultaneous temperature measurements.In this study, a wearable temperature measurement system attached to two different body sites revealed a consistent negative bias compared to bladder temperature. In addition, the measurements were particularly influenced by body constitution. The tested system in all patients showed a mean absolute error (MAE) of 0.45°C for the lateral chest and 0.50°C for the clavicular position. Tympanic measurements had a mean absolute error of 0.35°C. In patients with body mass index (BMI) ≥ 25 the MAE increased to 0.5°C for the lateral chest and 0.56°C for the clavicular position. In contrast, the tympanic measurement had a reduced MAE of 0.32°C, which is well below this threshold when compared to bladder measurements.In conclusion the investigated system did not meet the clinically relevant acceptance criteria and showed low precision in correctly identifying fever episodes compared to invasive temperature probes, however its main advantage lies in its continuity and non-invasiveness. This makes it a potential alternative to intermittent tympanic measurement devices. In this study we were able to show, that in at least one subset of patients, the non-invasive and continuous device demonstrated a precision comparable to tympanic measurements.The accuracy of all non-invasive methods was lower than in previous studies, suggesting that the use of bladder temperature as reference and user related variations may have introduced additional errors.

A Parameter Identification Approach towards Hemodynamics based on Capnography

Research question Pulse detection decisions during cardiopulmonary resuscitation (CPR) are commonly augmented by end-tidal CO2-concentration (etCO2) levels and trend as etCO2 is a surrogate measure of systemic blood flow during (CPR)1. However, ventilatory and circulatory parameters influence the interpretability of etCO2 heavily. Recently developed methods of continuous cardiac output measurement based on capnography are not applicable during CPR due to the required controlled ventilation settings2. In this study, a parameter identification for a model of CO2 transport during resuscitation is used to estimate cardiac output based on capnography and tidal flow. Methodology After development of a compartmental ordinary differential equation (ODE) model to represent CO2 transport during CPR, parameters such as airway dead space and the level of systemic perfusion are estimated by a multishooting parameter identification approach3. To evaluate the method, tests are conducted on experimental data from a porcine model (approved by an ethics committee vote of the Austrian Federal Ministry of Education, Science and Research (GZ: 2021-0.895.386)). The estimated level of systemic perfusion is compared visually to invasively measured mean arterial pressure due to a lack of continuous cardiac output measurements as a ground truth. Results For exemplary data from a female pig (weight 50.4 kg), airway resistance was estimated to 20.8 hPa s /L, compliance: 25.2 mL/hPa, and dead space: 109 mL. Changes in cardiac output can be identified qualitatively as shown in Fig. 1. Conclusion A validated, simple ODE model for CO2 extraction during CPR could contribute quantifying the impact of ventilatory parameters on etCO2 and elucidate CO2 production, storage and transport during cardiac arrest. Assumptions on CO2 production during cardiac arrest and redistribution in the body, and the lacking cardiac output measurements complicate the analysis. Conflicts of Interest All authors have no conflict of interest to declare.

ACNN-BiLSTM: A Deep Learning Approach for Continuous Noninvasive Blood Pressure Measurement Using Multi-Wavelength PPG Fusion.

As an essential physiological indicator within the human body, noninvasive continuous blood pressure (BP) measurement is critical in the prevention and treatment of cardiovascular disease. However, traditional methods of blood pressure prediction using a single-wavelength Photoplethysmographic (PPG) have bottlenecks in further improving BP prediction accuracy, which limits their development in clinical application and dissemination. To this end, this study proposed a method to fuse a four-wavelength PPG and a BP prediction model based on the attention mechanism of a convolutional neural network and bidirectional long- and short-term memory (ACNN-BiLSTM). The effectiveness of a multi-wavelength PPG fusion method for blood pressure prediction was evaluated by processing PPG signals from 162 volunteers. The study compared the performance of the PPG signals with different individual wavelengths and using a multi-wavelength PPG fusion method in blood pressure prediction, assessed using mean absolute error (MAE), root mean squared error (RMSE) and AAMI-related criteria. The experimental results showed that the ACNN-BiLSTM model achieved a better MAE ± RMSE for a systolic BP and diastolic BP of 1.67 ± 5.28 and 1.15 ± 2.53 mmHg, respectively, when using the multi-wavelength PPG fusion method. As a result, the ACNN-BiLSTM blood pressure model based on multi-wavelength PPG fusion could be considered a promising method for noninvasive continuous BP measurement.

All in a moment: Continuous response measurement method for analyzing dynamic science communication content

Science communication strategy plays a crucial role in effectively conveying scientific information to target audiences. While various models exist for developing communication strategies, many focus on measuring the effectiveness of communication efforts and adjusting these based on audience feedback. However, traditional methods of evaluating communication effectiveness often measure one component at a time and do not consider how people make decisions in real-life situations. This paper proposes the use of continuous response measurement (CRM) as a method to evaluate science communication in agricultural social science research. CRM allows for real-time measurement of how individuals make decisions in response to dynamic communication content. This paper compares different types of CRM, including in-person and virtual dial CRM, and provides resources for researchers interested in implementing this methodology. The paper also discusses various research designs that can be used with CRM, such as experimental designs, survey designs, time-series designs, focus groups, and coding content and behavior. The benefits and limitations of CRM are outlined, highlighting the need for immediate feedback and real-time response in science communication campaigns. In-person CRM is discussed, including the selection of stimuli, response prompts, data collection procedures, and data analysis. Virtual CRM is also examined, highlighting its advantages in terms of flexibility and cost-effectiveness. The paper concludes by discussing data output and analysis methods for CRM data. Overall, this paper serves as a methodological proposal for the use of CRM in agricultural social science research, emphasizing the importance of real-time measurement and response in science communication.

Real-Time Measurement of Antiglaucoma Drugs in Porcine Eyes Using Boron-Doped Diamond Microelectrodes.

The primary treatment for glaucoma, the most common cause of intermediate vision impairment, involves administering ocular hypotensive drugs in the form of topical eye drops. Observing real-time changes in the drugs that pass through the cornea and reach the anterior chamber of the eye is crucial for improving and developing safe, reliable, and effective medical treatments. Traditional methods for measuring temporal changes in drug concentrations in the aqueous humor employ separation analyzers such as LC-MS/MS. However, this technique requires multiple measurements on the eyes of various test subjects to track changes over time with a high temporal resolution. To address this issue, we have developed a measurement method that employs boron-doped diamond (BDD) microelectrodes to monitor real-time drug concentrations in the anterior chamber of the eye. First, we confirmed the electrochemical reactivity of 13 antiglaucoma drugs in a phosphate buffer solution with a pH of 7.4. Next, we optimized the method for continuous measurement of timolol maleate (TIM), a sympathetic beta-receptor antagonist, and generated calibration curves for each BDD microelectrode using aqueous humor collected from enucleated porcine eyes. We successfully demonstrated the continuous ex vivo monitoring of TIM concentrations in the anterior chambers of these enucleated porcine eyes. The results indicate that changes in intracameral TIM concentrations can be monitored through electrochemical measurements using BDD microelectrodes. This technique holds promise for future advancements in optimizing glaucoma treatment and drug administration strategies.

Crystal structure of a layered phosphate molybdate K2Gd(PO4)(MoO4)

The title compound dipotassium gadolinium(III) phosphate(V) molybdate(VI), K2Gd(PO4)(MoO4), was synthesized from a high-temperature melt starting from GdF3 as a source of gadolinium. Its structure is isotypic with other M I 2 M III(M VIO4)(PO4) compounds, where M I = Na, K or Cs, and M III = rare-earth cation, M VI = Mo or W. The three-dimensional framework is built up from [Gd(PO4)(MoO4)] anionic sheets, which are organized by adhesion of [GdPO4] layers and [MoO4] tetrahedra stacked above and below these layers. The interstitial space is occupied by K cations having eightfold oxygen coordination. The polyhedron of GdO8 was estimated to be a triangular dodecahedron by the continuous shape measurement method.

Continuous broadband microwave electric field measurement in Rydberg atoms based on the DC Stark effect

We demonstrate a method for broadband tunable continuous frequency electric field measurement based on the DC Stark effect in Rydberg atoms. In our experiment, we place a pair of parallel electrode plates inside the atomic vapor cell, utilizing the DC Stark effect to induce splitting and shifting of the Rydberg energy levels, thereby altering the resonance frequency of the Stark subpeaks. By employing the 52D5/2 Rydberg state, we achieve electric field measurements in the frequency range of 5.083–14.470 GHz. At an EDC of 3.45 V/cm and a resonant microwave frequency of 14.470 GHz, using heterodyne technology, the microwave electric field sensitivity is 538.89 μV/cm/√Hz, with a linear dynamic range of 23 dB. In comparison, a Rydberg heterodyne receiver with an EDC of 0 V/cm and a resonant microwave frequency of 5.083 GHz has a sensitivity of 5.43 μV/cm/√Hz and a linear dynamic range of 51 dB. This work will promote the study of atomic microwave receivers in continuous microwave frequency measurement.

Continuous Telemetric In Utero Tracheal Pressure Measurements in Fetal Lambs.

Normal in utero lung development and growth rely upon the expansion of airspaces and the controlled efflux of lung liquid into the amniotic space. Infants with congenital diaphragmatic hernia (CDH) also have lung hypoplasia due to occupation of the chest cavity by the stomach and bowel and, in the most severe cases, the liver. Balloon tracheal occlusion reduces the severity of lung hypoplasia in fetuses with CDH but increases the risk of premature birth. Understanding the optimal occlusion pressure and duration required to improve lung hypoplasia with tracheal occlusion is essential to improving in utero corrective treatments for CDH. The study reports a new method for continuous measurement of the intratracheal and amniotic pressures in an unoccluded and occluded fetal lamb surgical model of CDH. Time-pregnant Merino ewes underwent two recovery hysterotomies: the first at ~80 days of gestation to create the CDH, and the second at ~101 days of gestation to occlude the fetal trachea and implant an intratracheal and amniotic pressure measurement device. Lambs were delivered at ~142 days, and the pressure measurement device was removed and cleaned. The data were downloaded and filtered using a 6 h window. Transrespiratory pressure was calculated.

Theory of continental drift – causes of the motion. Outline of the theory

The theory of mantle convection currents as the cause of lithospheric plate movements has several major problems, including the absence of an adequate energy source. As shown in our previous contribution, an unbiased interpretation of geochemical data does not support the assumptions of a significant amount of radionuclides in the lower mantle or even in the core. It is our assertion that solar radiation is the primary energy source in the lithosphere. This energy is converted into mechanical energy via thermoelastic waves, even in depths with minimal temperature fluctuations. This has been confirmed by various methods of continuous stress measurement. The periodic and quasiperiodic thermoelastic reversible deformations, such as the circadian and annual cycles (including tidal periods), can also cause irreversible deformations due to the ratcheting mechanism. The 2D model showed that the strength limit is exceeded in 0.3 % of all diurnal cycles during the year. As a consequence, continents tend to extend while the oceanic lithosphere is pushed and overthrusted between continents. The middle-ocean ridges, similar to continental rifts, are filled by ascending magma which is one example of the ratcheting mechanism. The final plate movements are determined by the distribution of major continents and the overall westward drift of the lithosphere, which is slower for deep-rooted plates like the Indian one. Large asteroid impacts are important triggers (and possibly significant energy sources) of discrete events, like the formation of hotspots and large igneous provinces.

A Novel Convolutional Neural Network Deep Learning Implementation for Cuffless Heart Rate and Blood Pressure Estimation

Cardiovascular diseases (CVDs) affect components of the circulatory system responsible for transporting blood through blood vessels. The measurement of the mechanical force acting on the walls of blood vessels, as well as the blood flow between heartbeats and when the heart is at rest, is known as blood pressure (BP). Regular assessment of BP can aid in the prevention and early detection of CVDs. In the present research, a deep learning algorithm was developed to accurately calculate both blood pressure (BP) and heart rate (HR) by extracting relevant features from photoplethysmogram (PPG), electrocardiogram (ECG), and ABP signals. This algorithm was implemented using the Medical Information Mart for Intensive Care (MIMIC-II) dataset. It captures vital blood pressure-related features extracted from the PPG signal and accounts for the time relationship with the ECG. The algorithm also determines the values of systolic blood pressure (SBP) and diastolic blood pressure (DBP) based on the ABP waveform through a convolutional neural network and stepwise multivariate linear regression. In comparison with other established BP measurement methods, our proposed approach achieved better results, with a mean absolute error (MAE) of approximately 4.7 mmHg for SBP and 2.1 mmHg for DBP, respectively. The standard deviation (STD) for SBP and DBP was approximately 7.6 mmHg and 3.9 mmHg, respectively. This study makes a valuable contribution to the healthcare field by introducing a novel, cost-effective continuous BP measurement method with improved accuracy while also minimizing the data dimension without losing any important information.

A novel calibration method for continuous airborne metal measurements: Implications for aerosol source apportionment

Continuous metal monitors have been widely used in environmental monitoring due to the high temporal resolution, high detection limit, and necessity for near real-time source apportionment. However, the reliability of the conventional calibration method, the deviation caused by uncalibrated monitoring data, and the subsequent impact on source identification results are rarely discussed. In this study, a reliable multi-point calibration approach by Primary Standard Aerosol Mass Concentration Calibration System (PAMAS) for the Xact625i Ambient Metals Monitor was developed and applied. The measured data was almost meaningless in the low-concentration range with bias even exceeding 100 % by using the conventional single-point calibration method based on thin-film standards. PAMAS was utilized to generate aerosols with known concentrations of the 20 metal elements including Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Sr, Cd, Sn, Sb, Ba, Tl, Pb, and Bi, in two concentration ranges of 150–1200 ng m−3 and 2.5–30 ng m−3 to validate the Xact625i Monitor. The results showed that the elemental concentrations were underestimated, especially in the low-concentration range, only for Cr, As, and Sr with slopes close to unity (1.00 ± 0.03). After calibration by PAMAS, the slopes of the linear relationships between measured and standard concentrations were all unity for the 19 elements in the high-concentration range, and close to unity for the 15 elements in the low-concentration range, and the accuracy of the remaining elements was also improved. After considering the calibration of aerosol metal data, it was found the number of source factors and their contributions to metals and PM2.5 in Chongming Dongtan, China, based on the PMF model significantly changed. This study highlighted the need of developing reliable calibration methods for online aerosol monitoring instruments and implied that the source apportionment results could be biased without careful data calibration.

A novel method for continuous measurements of clinical practice guideline adherence.

Clinical practice guidelines (hereafter 'guidelines') are crucial in providing evidence-based recommendations for physicians and multidisciplinary teams to make informed decisions regarding diagnostics and treatment in various diseases, including cancer. While guideline implementation has been shown to reduce (unwanted) variability and improve outcome of care, monitoring of adherence to guidelines remains challenging. Real-world data collected from cancer registries can provide a continuous source for monitoring adherence levels. In this work, we describe a novel structured approach to guideline evaluation using real-world data that enables continuous monitoring. This method was applied to endometrial cancer patients in the Netherlands and implemented through a prototype web-based dashboard that enables interactive usage and supports various analyses. The guideline under study was parsed into clinical decision trees (CDTs) and an information standard was drawn up. A dataset from the Netherlands Cancer Registry (NCR) was used and data items from both instruments were mapped. By comparing guideline recommendations with real-world data an adherence classification was determined. The developed prototype can be used to identify and prioritize potential topics for guideline updates. CDTs revealed 68 data items for recording in an information standard. Thirty-two data items from the NCR were mapped onto information standard data items. Four CDTs could sufficiently be populated with NCR data. The developed methodology can evaluate a guideline to identify potential improvements in recommendations and the success of the implementation strategy. In addition, it is able to identify patient and disease characteristics that influence decision-making in clinical practice. The method supports a cyclical process of developing, implementing and evaluating guidelines and can be scaled to other diseases and settings. It contributes to a learning healthcare cycle that integrates real-world data with external knowledge.

Investigation of dynamic micromechanical properties of biodegradable elastic material by continuous stiffness measurement analysis

Micromechanical properties of polymeric materials play a critical role in various biological applications in terms of their biocompatibility and mechanical durability. Apart from material properties such as modulus and density, viscoelastic properties play a crucial role during the design and fabrication of devices. Here, we investigated the viscoelastic properties of poly (glycerol sebacate) (PGS), a widely used bioresorbable elastic material, through the nanoindentation technique, configured by the continuous stiffness measurement (CSM) method at frequencies from 10 Hz to 50 Hz. The results revealed that the storage modulus (E’) depends on the test frequency and cannot be ignored as the results showed significant changes. Additionally, increasing the curing temperature of PGS specimens between 150 to 170°C allows modifying the storage modulus of samples between 0.52 MPa and 1.05 MPa at 10 Hz. The results were also confirmed using the dynamic mechanical measurements to validate the reliability of the CSM nanoindentation technique.

Application of Hydrosol to Aerosol Based Metrology to Predict Wafer Defects from Process Chemical Contamination

A method for continuous measurement of particle and particle precursor material in high purity liquids using aerosolization and condensation particle courting (A+CPC) is presented. A process for correlating wafter defects with the concentration values measured using A+CPC using Sequential Spin Coating + Surface Enhanced Particle Sizing (SSC + SEPS) is described. The method was applied to monitor the rinsate of an ion exchange resin following the SEMI C93 guide. The results showed correlation between the methods and the concentration values were used to calculate a deposition factor (liquid concentration/surface concentration) on the order of 1E5 (#/ml)/(#/cm2).

Effect of contact angle hysteresis on measuring matric suction in unsaturated sandy soil

The contact angle plays an important role in matric suction of unsaturated soils, but few studies consider the effect of contact angle hysteresis on matric suction. In this paper, taking sandy soil as an example, the influence of contact angle hysteresis on the suction of unsaturated soil matric is studied by soil particle model calculation and experimental method. The results show under the same water content condition, the smaller the contact angle is, the larger the matric suction is and the phenomenon of water repellency appears. Under the low water content of unsaturated soil, when the contact angle is less than 90°, it will also produce water repulsion phenomenon, which is different from the hydrophilic characteristics of the contact angle is less than 90° in the capillary law. When the water content is the same, with the increase of contact angle, matric suction will decrease. With the increase of water content, matric suction is not affected by soil contact angle. In the process of dehumidification, the apparent contact angle of the sandy soil with the same water content less than receding contact Angle; there is a difference in matric suction between continuous measurement method and discontinuous measurement method, and continuous measurement’ matric suction greater than discontinuous measurement’ matric suction. This study provides some theoretical basis and reference for the study of matric suction of unsaturated soil.

Effect of external dead space removal on CO2 homeostasis in mechanically ventilated adult Covid-19 patients.

Patients with Covid-19 respiratory failure present with hypoxemia, often in combination with hypercapnia. In this prospective, observational study we examined the effect of removing external dead space (DS) on CO2 -homeostasis in mechanically ventilated Covid-19 patients. In addition, volumetric capnography was validated for its ability to estimate external DS volume using in vitro measured DS volumes as reference. In total, 10 patients with acute respiratory distress syndrome from Covid-19 were included. Volumetric capnography, mechanical ventilation, and arterial blood gas data were analyzed before and after removal of external DS and analyzed for potentially significant changes in response to DS removal. Measurements of external DS were obtained in circuit using volumetric capnography and compared to actual measured DS volumes off the circuit. After the removal of external DS, the alveolar minute ventilation and CO2 elimination improved, notwithstanding unchanged respiratory rate and tidal volumes. The increase in CO2 elimination was associated with a decrease in arterial CO2 partial pressure (PaCO2 ). The volumetric capnography method for assessment of external DS showed a low bias of -9 mL (lower limit of agreement -40, 95% CI -60 to -20 mL, upper limit of agreement 21 mL, 95% CI: 1-40 mL) and a percentage error of 48% compared to absolute values measured in vitro. Removal of external DS increased alveolar minute ventilation and CO2 elimination in Covid-19 patients with respiratory failure in the current study. This was associated with a decrease in PaCO2 . This may indicate a decreased CO2 production due to decreased work of breathing and more effective gas-exchange in response to DS removal. In addition, volumetric capnography appears to be a clinically feasible method for continuous measurement of external DS in the current study and may be of value in optimizing ventilator treatment.

Study on Temperature Measurement Model of Rare Earth Metal Electrolysis Based on Infrared Image

The temperature of rare earth electrolysis plays an important role in the process of electrolysis control. It is the main parameter to control the efficiency of electrolysis. In production practice, most of the process parameters are controlled by the artificial thermocouple temperature measurement method. This extensive technical management method greatly affects the accuracy of production control. And the traditional thermocouple temperature measurement is artificial and slow, not timely, short life, and has other issues. Therefore, it is extremely urgent to explore a continuous and safe surface temperature measurement method to achieve precise control of process parameters. Therefore, based on the principle of infrared temperature measurement, this paper introduces the theory of infrared temperature measurement, uses Matlab software to extract the average gray value of the infrared image, and obtains the infrared temperature measurement model by least square method and bp neural network for temperature and gray fitting curve. At the same time, the experimental data are measured, and the model is verified. This method provides a reference for online temperature measurement of electrolytic molten metal.

Continuous Time-Domain Measurement Method of Rayleigh Backscattered Light With Coherent Detection

This paper shows the results of continuous time-domain measurement of Rayleigh backscattered light. Experimental results show that we can measure the variation of the phase of the backscattered light from a specific point of the fibers where we applied sinusoidally varying stress at a frequency of 140 kHz. We expect that the method will find application to continuously measure the rapid variation of external perturbation in the time domain at a specific point in the fibers.

基于Kinect传感器的玉米植株三维重构与性状提取

Aiming at the problems of low precision, strong subjectivity, and continuous measurement in the current measurement methods of corn phenotypic traits, a method of measuring corn phenotypic traits with high precision, low cost, easy carrying and continuous measurement was proposed. Firstly, the three-dimensional scanning device Kinect 2.0 is used to collect corn information and process and reconstruct the collected point cloud. Then, the stem and leaf point clouds were segmented by straight-through filtering, ellipse fitting and region growth segmentation. Finally, the phenotypic parameters of corn were obtained by triangulation and plane fitting for the segmented corn leaves, and the accuracy was analyzed. The results showed that the accuracy of corn plant height was 97.622 %, the average relative error of stem long axis was 9.46 %, the average relative error of stem short axis was 11.17 %, and the accuracy of leaf area was 95.577 %. Studies have shown that this method provides a new method for continuous measurement of phenotypic traits in corn.

A non-contact continuous blood pressure measurement method based on video stream

Hypertension is the primary disease that endangers human health. A convenient and accurate blood pressure measurement method can help to prevent the hypertension. This paper proposed a continuous blood pressure measurement method based on facial video signal. Firstly, color distortion filtering and independent component analysis were used to extract the video pulse wave of the region of interest in the facial video signal, and the multi-dimensional feature extraction of the pulse wave was preformed based on the time-frequency domain and physiological principles; Secondly, an integrated feature selection method was designed to extract the universal optimal feature subset; After that, we compared the single person blood pressure measurement models established by Elman neural network based on particle swarm optimization, support vector machine (SVM) and deep belief network; Finally, we used SVM algorithm to build a general blood pressure prediction model, which was compared and evaluated with the real blood pressure value. The experimental results showed that the blood pressure measurement results based on facial video were in good agreement with the standard blood pressure values. Comparing the estimated blood pressure from the video with standard blood pressure value, the mean absolute error (MAE) of systolic blood pressure was 4.9 mm Hg with a standard deviation (STD) of 5.9 mm Hg, and the MAE of diastolic blood pressure was 4.6 mm Hg with a STD of 5.0 mm Hg, which met the AAMI standards. The non-contact blood pressure measurement method based on video stream proposed in this paper can be used for blood pressure measurement.