scholarly journals Continuous Noninvasive Blood Gas Estimation in Critically Ill Pediatric Patients With Respiratory Failure

2020 ◽  
Author(s):  
Junzi Dong ◽  
Minnan Xu-Wilson ◽  
Bryan R. Conroy ◽  
Robinder G. Khemani ◽  
Christopher J.L. Newth
Keyword(s):  
Clinical Laboratory ◽  
Care Center ◽  
Pediatric Intensive Care ◽  
Estimation Accuracy ◽  
Validation Dataset ◽  
Blood Gas ◽  
Estimation Model ◽  
Blood Draw ◽  
Proposed Model ◽  
Clinical Laboratory Improvement Amendments

Abstract BackgroundPatients supported by mechanical ventilation require frequent invasive blood gas samples to monitor and adjust the level of support. We developed a transparent and novel blood gas estimation model to provide continuous monitoring of blood pH and arterial CO2 in between gaps of blood draws, using only readily available noninvasive data sources in ventilated patients. MethodsThe model was trained on a derivation dataset (1,883 patients, 12,344 samples) from a tertiary pediatric intensive care center, and tested on a validation dataset (286 patients, 4,030 samples) from the same center obtained at a later time. The model uses pairwise non-linear interactions between predictors and provides point-estimates of blood gas pH and arterial CO2 along with a range of prediction uncertainty.ResultsThe model predicted within Clinical Laboratory Improvement Amendments of 1988 (CLIA) acceptable blood gas machine equivalent in 74% of pH samples and 80% of PCO2 samples. Prediction uncertainty from the model improved estimation accuracy by identifying and abstaining on a minority of high-uncertainty samples.ConclusionsThe proposed model estimates blood gas pH and CO2 accurately in a large percentage of samples. The model’s abstention recommendation coupled with ranked display of top predictors for each estimation lends itself to real-time monitoring of between gaps of blood draws, and the model may be used to help users determine when a new blood draw is required and delay blood draws when not needed.

scholarly journals Hemoglobin A1c Point-of-Care Assays; A New World with a Lot of Consequences!

2009 ◽  
Vol 3 (3) ◽  
pp. 418-423 ◽  
Author(s):  
Erna Lenters-Westra ◽  
Robbert J. Slingerland
Keyword(s):  
Nurse Practitioners ◽  
Hemoglobin A1c ◽  
Clinical Laboratory ◽  
Point Of Care ◽  
Care Center ◽  
Venous Blood ◽  
Coefficients Of Variation ◽  
Rapid Result ◽  
Performance Results ◽  
Clinical Laboratory Improvement Amendments

Background: Point-of-care instruments for the measurement of hemoglobin A1c (HbA1c) may improve the glycemic control of people with diabetes by providing a rapid result if the performance of the instruments used is acceptable. A 0.5% HbA1c difference between successive results is considered a clinically relevant change. With this in mind, the In2it from Bio-Rad and the DCA Vantage from Siemens were evaluated according to Clinical and Laboratory Standards Institute (CLSI) protocols. Methods: The CLSI protocols EP-5 and EP-9 were applied to investigate precision, accuracy, and bias. The bias was compared with three certified secondary reference measurement procedures. Differences between capillary and venous blood were investigated by an end-user group consisting of nurse practitioners at a diabetes care center. Results: At HbA1c levels of 5.1 and 11.2%, total coefficients of variation (CV) for the In2it were 4.9 and 3.3%, respectively, and for the DCA Vantage were 1.7 to 1.8% and 3.7 to 5.5% depending on the lot number of the cartridges. Method comparisons showed significant lot number-dependent results for the In2it and the DCA Vantage compared with the three reference methods. No overall difference was observed between capillary and venous blood for both methods. Conclusion: Performance results of the In2it and the DCA Vantage showed variable and lot number-dependent results. To maintain the interlaboratory CV of 5% for HbA1c, the Clinical Laboratory Improvement Amendments rules for waived point-of-care instruments should be revised. An obligation for participating in external quality schemes and taking adequate action should be considered for POC instruments that perform poorly.

scholarly journals Methods for estimating vehicle queues at a marine terminal: A computational comparison

2014 ◽  
Vol 24 (3) ◽  
pp. 611-619 ◽  
Author(s):  
Gang Chen ◽  
Zhong-Zhen Yang
Keyword(s):  
Queue Length ◽  
Simulation Software ◽  
Urban Traffic ◽  
Estimation Accuracy ◽  
Estimation Model ◽  
Advantages And Disadvantages ◽  
Natural Logarithm ◽  
Length Estimation ◽  
Proposed Model ◽  
Simulation Based

Abstract A long queue of vehicles at the gate of a marine terminal is a common traffic phenomenon in a port-city, which sometimes causes problems in urban traffic. In order to be able to solve this issue, we firstly need accurate models to estimate such a vehicle queue length. In this paper, we compare the existing methods in a case study, and evaluate their advantages and disadvantages. Particularly, we develop a simulation-based regression model, using the micro traffic simulation software PARAMIC. In simulation, it is found that the queue transient process follows a natural logarithm curve. Then, based on these curves, we develop a queue length estimation model. In the numerical experiment, the proposed model exhibits better estimation accuracy than the other existing methods

Lurking Infantile Pertussis: Experience from a Tertiary Care Center in Northern India

2020 ◽  
Vol 15 (05) ◽  
pp. 257-261
Author(s):  
Deepanjan Bhattacharya ◽  
Nabaneeta Dash ◽  
Thondi Kkandy Kavitha ◽  
Megha Sharma ◽  
Vikas Gautam ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Care Center ◽  
Tertiary Care ◽  
Pediatric Intensive Care ◽  
Care Hospital ◽  
Vaccination Policy ◽  
Leukemoid Reaction ◽  
Northern India ◽  
Male Preponderance ◽  
Laboratory Profile

Abstract Objectives The aim is to study the clinical laboratory profile and outcome of infants with laboratory confirmed pertussis. Methods In this retrospective study, records of 30 infants with laboratory confirmed pertussis, admitted to the pediatric department of a tertiary care hospital, were reviewed. Clinical features, laboratory parameters, and outcomes were noted. Results Median (interquartile range age was 10 (7–24.5) weeks, with a male preponderance. Large majority (60%) of enrolled infants were less than 16 weeks of age and nine (30%) developed pertussis even before 8 weeks of age. Cough was universal (100%), followed by rapid breathing (73%), fever (70%), and apnea (10%). Bubble continuous positive airway pressure (CPAP), nasal prongs oxygen, and invasive ventilation were required in 15 (54%), 11 (39%), and 2 (7%) infants, respectively; 12 (40%) needed to be admitted to the pediatric intensive care unit. Anemia was observed in 28 (93%) and leukemoid reaction in 15 (50%). All except one were discharged successfully. None of the mothers had received tetanus, diphtheria, and pertussis or Tdap vaccination during pregnancy. Conclusion Our study reports the continued occurrence of infantile pertussis in the community, suggesting reconsideration of our vaccination policy, including maternal immunization.

scholarly journals Cost Estimation Model Using Modified Parameters for Construction Projects

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Sae-Hyun Ji ◽  
Joseph Ahn ◽  
Hyun-Soo Lee ◽  
Kyeongjin Han
Keyword(s):  
Cost Estimation ◽  
Construction Projects ◽  
Cost Model ◽  
Influence Factors ◽  
Influential Factors ◽  
Estimation Accuracy ◽  
Estimation Model ◽  
Proposed Model ◽  
Cost Estimation Model ◽  
The Cost

Construction projects require huge amounts of capital and have many risk factors due to the unique industry characteristics. For a project to be successful, accurate cost estimation during the design phase is very important. Thus, this research aims to develop a cost estimation model where a modification method integrates influential factors with significant parameters. This study identified a modified parameter-making process, which integrates many influential factors into a small number of significant parameters. The proposed model estimates the cost using quantity-based modified parameters multiplied by their price. A case study was conducted with 24-residence building project, and the estimation accuracy of the suggested method and a CBR model were compared. The proposed model achieved higher overall cost-estimation accuracy and stability. A large number of influence factors can be modified as simple representatives and overcome the limitations of a conventional cost estimation model. The paper originality relates to providing a modified parameter-making process to enhance reliability of a cost estimation. In addition, the suggested cost model can actively respond to the iterative requirements of recalculation of the cost.

scholarly journals Inertial Sensor-Based Step Length Estimation Model by Means of Principal Component Analysis

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3527
Author(s):  
Melanija Vezočnik ◽  
Roman Kamnik ◽  
Matjaz B. Juric
Keyword(s):  
Principal Component Analysis ◽  
Human Body ◽  
Inertial Sensor ◽  
Principal Component ◽  
Step Length ◽  
Component Analysis ◽  
Indoor Positioning ◽  
Estimation Model ◽  
Length Estimation ◽  
Proposed Model

Inertial sensor-based step length estimation has become increasingly important with the emergence of pedestrian-dead-reckoning-based (PDR-based) indoor positioning. So far, many refined step length estimation models have been proposed to overcome the inaccuracy in estimating distance walked. Both the kinematics associated with the human body during walking and actual step lengths are rarely used in their derivation. Our paper presents a new step length estimation model that utilizes acceleration magnitude. To the best of our knowledge, we are the first to employ principal component analysis (PCA) to characterize the experimental data for the derivation of the model. These data were collected from anatomical landmarks on the human body during walking using a highly accurate optical measurement system. We evaluated the performance of the proposed model for four typical smartphone positions for long-term human walking and obtained promising results: the proposed model outperformed all acceleration-based models selected for the comparison producing an overall mean absolute stride length estimation error of 6.44 cm. The proposed model was also least affected by walking speed and smartphone position among acceleration-based models and is unaffected by smartphone orientation. Therefore, the proposed model can be used in the PDR-based indoor positioning with an important advantage that no special care regarding orientation is needed in attaching the smartphone to a particular body segment. All the sensory data acquired by smartphones that we utilized for evaluation are publicly available and include more than 10 h of walking measurements.

scholarly journals Predicting Daily Dry Matter Intake Using Feed Intake of First Two Hours after Feeding in Mid and Late Lactation Dairy Cows with Fed Ration Three Times Per Day

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 104
Author(s):  
Shulin Liang ◽  
Chaoqun Wu ◽  
Wenchao Peng ◽  
Jian-Xin Liu ◽  
Hui-Zeng Sun
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Dry Matter ◽  
Prediction Equation ◽  
Dry Matter Intake ◽  
Validation Dataset ◽  
Nutrient Requirements ◽  
Independent Dataset ◽  
Lactating Dairy Cows ◽  
Proposed Model

The objective of this study was to evaluate the feasibility of using the dry matter intake of first 2 h after feeding (DMI-2h), body weight (BW), and milk yield to estimate daily DMI in mid and late lactating dairy cows with fed ration three times per day. Our dataset included 2840 individual observations from 76 cows enrolled in two studies, of which 2259 observations served as development dataset (DDS) from 54 cows and 581 observations acted as the validation dataset (VDS) from 22 cows. The descriptive statistics of these variables were 26.0 ± 2.77 kg/day (mean ± standard deviation) of DMI, 14.9 ± 3.68 kg/day of DMI-2h, 35.0 ± 5.48 kg/day of milk yield, and 636 ± 82.6 kg/day of BW in DDS and 23.2 ± 4.72 kg/day of DMI, 12.6 ± 4.08 kg/day of DMI-2h, 30.4 ± 5.85 kg/day of milk yield, and 597 ± 63.7 kg/day of BW in VDS, respectively. A multiple regression analysis was conducted using the REG procedure of SAS to develop the forecasting models for DMI. The proposed prediction equation was: DMI (kg/day) = 8.499 + 0.2725 × DMI-2h (kg/day) + 0.2132 × Milk yield (kg/day) + 0.0095 × BW (kg/day) (R2 = 0.46, mean bias = 0 kg/day, RMSPE = 1.26 kg/day). Moreover, when compared with the prediction equation for DMI in Nutrient Requirements of Dairy Cattle (2001) using the independent dataset (VDS), our proposed model shows higher R2 (0.22 vs. 0.07) and smaller mean bias (−0.10 vs. 1.52 kg/day) and RMSPE (1.77 vs. 2.34 kg/day). Overall, we constructed a feasible forecasting model with better precision and accuracy in predicting daily DMI of dairy cows in mid and late lactation when fed ration three times per day.

scholarly journals A Phenomenological Primary–Secondary–Tertiary Creep Model for Polymer-Bonded Composite Materials

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2353
Author(s):  
Xiaochang Duan ◽  
Hongwei Yuan ◽  
Wei Tang ◽  
Jingjing He ◽  
Xuefei Guan
Keyword(s):  
Composite Materials ◽  
Creep Behavior ◽  
Reference Model ◽  
Creep Model ◽  
Creep Process ◽  
Validation Dataset ◽  
Testing Conditions ◽  
Proposed Model ◽  
Testing Data ◽  
Bonded Composite

This study develops a unified phenomenological creep model for polymer-bonded composite materials, allowing for predicting the creep behavior in the three creep stages, namely the primary, the secondary, and the tertiary stages under sustained compressive stresses. Creep testing is performed using material specimens under several conditions with a temperature range of 20 °C–50 °C and a compressive stress range of 15 MPa–25 MPa. The testing data reveal that the strain rate–time response exhibits the transient, steady, and unstable stages under each of the testing conditions. A rational function-based creep rate equation is proposed to describe the full creep behavior under each of the testing conditions. By further correlating the resulting model parameters with temperature and stress and developing a Larson–Miller parameter-based rupture time prediction model, a unified phenomenological model is established. An independent validation dataset and third-party testing data are used to verify the effectiveness and accuracy of the proposed model. The performance of the proposed model is compared with that of an existing reference model. The verification and comparison results show that the model can describe all the three stages of the creep process, and the proposed model outperforms the reference model by yielding 28.5% smaller root mean squared errors on average.

scholarly journals Towards Routine Implementation of Liquid Biopsies in Cancer Management: It Is Always Too Early, until Suddenly It Is Too Late

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 103
Author(s):  
Maarten J. IJzerman ◽  
Jasper de Boer ◽  
Arun Azad ◽  
Koen Degeling ◽  
Joel Geoghegan ◽  
...  
Keyword(s):  
Clinical Utility ◽  
Clinical Laboratory ◽  
Genomic Analysis ◽  
Current Evidence ◽  
Liquid Biopsies ◽  
Blood Draw ◽  
Minimum Quality Standards ◽  
Cancer Management ◽  
Alternative Funding ◽  
And Performance

Blood-based liquid biopsies are considered a new and promising diagnostic and monitoring tool for cancer. As liquid biopsies only require a blood draw, they are non-invasive, potentially more rapid and assumed to be a less costly alternative to genomic analysis of tissue biopsies. A multi-disciplinary workshop (n = 98 registrations) was organized to discuss routine implementation of liquid biopsies in cancer management. Real-time polls were used to engage with experts’ about the current evidence of clinical utility and the barriers to implementation of liquid biopsies. Clinical, laboratory and health economics presentations were given to illustrate the opportunities and current levels of evidence, followed by three moderated break-out sessions to discuss applications. The workshop concluded that tumor-informed assays using next-generation sequencing (NGS) or PCR-based genotyping assays will most likely provide better clinical utility than tumor-agnostic assays, yet at a higher cost. For routine application, it will be essential to determine clinical utility, to define the minimum quality standards and performance of testing platforms and to ensure their use is integrated into current clinical workflows including how they complement tissue biopsies and imaging. Early health economic models may help identifying the most viable application of liquid biopsies. Alternative funding models for the translation of complex molecular diagnostics, such as liquid biopsies, may also be explored if clinical utility has been demonstrated and when their use is recommended in multi-disciplinary consensus guidelines.

scholarly journals Analytical Model for Estimating the Impact of Changing the Nominal Power Parameter in LTE

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
A. B. Vallejo-Mora ◽  
M. Toril ◽  
S. Luna-Ramírez ◽  
M. Regueira ◽  
S. Pedraza
Keyword(s):  
Analytical Model ◽  
Mobile Networks ◽  
Radio Resource Management ◽  
Estimation Accuracy ◽  
Model Assessment ◽  
Power Parameter ◽  
Management Procedure ◽  
Proposed Model ◽  
A Cell ◽  
The Impact

UpLink Power Control (ULPC) is a key radio resource management procedure in mobile networks. In this paper, an analytical model for estimating the impact of increasing the nominal power parameter in the ULPC algorithm for the Physical Uplink Shared CHannel (PUSCH) in Long Term Evolution (LTE) is presented. The aim of the model is to predict the effect of changing the nominal power parameter in a cell on the interference and Signal-to-Interference-plus-Noise Ratio (SINR) of that cell and its neighbors from network statistics. Model assessment is carried out by means of a field trial where the nominal power parameter is increased in some cells of a live LTE network. Results show that the proposed model achieves reasonable estimation accuracy, provided uplink traffic does not change significantly.

Estimation of Time-Dependent Turning Fractions at Signalized Intersections

1998 ◽  
Vol 1644 (1) ◽  
pp. 142-149 ◽  
Author(s):  
Gang-Len Chang ◽  
Xianding Tao
Keyword(s):  
Signalized Intersections ◽  
Efficient Estimation ◽  
Estimation Accuracy ◽  
Time Interval ◽  
Short Time Interval ◽  
Simulation Experiments ◽  
Proposed Model ◽  
Short Time ◽  
Estimation Of Time ◽  
Additional Constraints

An effective method for estimating time-varying turning fractions at signalized intersections is described. With the inclusion of approximate intersection delay, the proposed model can account for the impacts of signal setting on the dynamic distribution of intersection flows. To improve the estimation accuracy, the use of preestimated turning fractions from a relatively longer time interval has been proposed to serve as additional constraints for the same estimation but over a short time interval. The results of extensive simulation experiments indicated that the proposed method can yield sufficiently accurate as well as efficient estimation of dynamic turning fractions for signalized intersections.

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