Reliable Measurement Research Articles

Impact of Sonographer Experience, Insonation Angle, and Bladder Filling on Uterine Artery Doppler Measurements in the First Trimester of Pregnancy.

To investigate the influence of different measurement conditions and ultrasound training level on uterine artery pulsatility index (UtA-PI) measurements as required for combined first trimester preeclampsia (PE) screening. This was a prospective study of consecutive patients with singleton pregnancies presenting for an ultrasound examination between 11 and 14 weeks' gestation. UtA-PI measurements were conducted by residents in training and repeated by experienced sonographers thereafter. UtA-PI measurements were conducted under different examination conditions. First, the trainee sonographers performed transabdominal sagittal and transverse UtA-PI measurements without bladder filling. These measurements were then repeated by the expert sonographers. Additionally, the expert sonographers also performed transvaginal UtA-PI measurements and transabdominal measurements with bladder filling. Statistical analysis was conducted with the statistical software R and included descriptive statistics as well as 2-sided paired t tests. A total of 100 women were included in the study. Mean age was 31.7 ± 4.92 years and mean gestational week was 12.5 ± 0.53 weeks. A total of 56% were nulliparous and 44% were parous. UtA-PI was significantly lower if performed by a sonographer in training versus an experienced sonographer (P = .031). No significant difference was observed in comparing transverse and sagittal techniques (P = .241). There was also no significant difference in transabominal versus transvaginal measurements (P = .806) and with an empty versus full bladder (P = .444). Experience of sonographer has a significant impact on UtA-PI. Supervised onsite training is necessary to improve reliability and consistency of UtA-PI measurements and make PE screening reliable for implementation in a universal screening setting.

Elevated remnant cholesterol as a potential predictor for cardiovascular events in rheumatoid arthritis patients.

The risk of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA) remains inadequately defined. Consequently, this study aims to evaluate the predictive value of remnant cholesterol (RC) for assessing CVD risk in RA patients. Plasma RC levels were measured in 114 RA patients and 41 healthy controls, calculated as total cholesterol minus HDL-C and LDL-C. These levels were further analyzed using 1H-NMR lipid/metabolomics. Meanwhile, the 28-joint Disease Activity Score (DAS28) assessed RA activity. RC levels were significantly elevated in RA patients (19.0 mg/dl, p < 0.001) compared to healthy controls (14.5 mg/dl). Furthermore, RC levels were significantly elevated at 37.4 mg/dl in patients who experienced cardiovascular event (CVE) compared to 17.4 mg/dl in those without CVE (p < 0.001). To enhance the precision and reliability of RC measurements, RC concentrations were further validated using 1H-NMR spectroscopy. Additionally, a positive correlation was observed between RC levels and DAS28. Multivariate analysis identified RC as a significant predictor of CVE (odds ratio = 1.82, p = 0.013). ROC curve analysis revealed superior predictive capability of RC for CVE (AUC = 0.919, p < 0.001) compared to LDL-C (AUC = 0.669, p = 0.018), with a high sensitivity of 94.7% and a specificity of 82.1%. Elevated RC levels demonstrate greater accuracy in predicting CVE occurrence in RA patients compared to traditional measures such as LDL-C. These findings suggest that elevated RC levels may serve as a novel predictor for occurrence of CVE in RA patients, facilitating early intervention strategies based on the risk stratification.

Development of the humeral head offset index for control of humeral torsion

BackgroundControl of humeral torsion can present a challenge, especially intraoperatively during closed reduction and fixation of humeral shaft fractures or 2-part surgical neck fractures of the proximal humerus. The objective of this study is to develop and validate an indirect method for the assessment of humeral torsion using an index that is linearly correlated with rotational arm position and can be derived from only a single plain radiographic image of the proximal humerus.MethodsThe Humeral Head Offset Index (HHOI) is calculated as the ratio of the medial and lateral offset of the humeral head measured from the outer cortices of the shaft on a plain radiographic or fluoroscopic image. The relationship of HHOI with humeral torsion was first verified on a sawbone model with radiopaque characteristics under fluoroscopic control. Different degrees of retroversion were simulated through manual rotation of the humerus with a digital protractor in 5° increments until 40° internally rotated and then in 5° increments until 40° externally rotated from the neutral position. The same procedure was subsequently performed digitally on Digitally Reconstructed Radiographs (DRRs) from computed tomography (CT) dataset of the sawbone. Next, the HHOI index was applied to eight randomly selected patients with total humerus CT using the same method. Spearman’s rho was calculated for the bivariate analysis of correlation between the simulated degree of retroversion and the HHOI. Strength of correlation was classified according to Koo and Li. Interrater and intrarater reliability of three blinded observers with repetition of measurement after three months were analyzed by assessing the intraclass correlation coefficient (ICC).ResultsBoth in the sawbone model and in DRRs, we demonstrated a high to very high significant linear correlation between simulated retroversion and the HHOI. ICC values demonstrated excellent interrater reliability and excellent intrarater reliability for measurement of the HHOI.ConclusionsThe HHOI is a new, simple, reliable index that has a linear relationship to the rotation of the humerus and can therefore allow an indirect control of humeral torsion in comparison to the contralateral side.

Diagnosing Dyslexia in Early School-Aged Children Using the LSTM Network and Eye Tracking Technology

Dyslexia, often referred to as a specific reading disability, affects many students around the world. It is a neurological disorder that affects the ability to recognise words, and it causes difficulties in writing and reading comprehension. Previous computer-based methods for the automatic detection of dyslexia in children have had low efficiency due to the complexity of the test administration process and the low measurement reliability of the attention measures used. This paper proposes the use of a student’s mobile device to record the spatio-temporal trajectory of attention, which is then analysed by deep neural network long short-term memory (LSTM). The study involved 145 participants (66 girls and 79 boys), all of whom were children aged 9 years. The input signal for the neural network consisted of recorded observation sessions, which were packets containing the child’s spatio-temporal attention trajectories generated during task performance. The training set was developed using stimuli from Benton tests and an expert opinion from a specialist in early childhood psychology. The coefficients of determination of R2∼0.992 were obtained for the proposed model, giving an accuracy of 97.7% for the test set. The ease of implementation of this approach in school settings and its non-stressful nature make it suitable for use with children of different ages and developmental stages, including those who have not yet learned to read. This enables early intervention, which is essential for effective educational and emotional support for children with dyslexia.

A Study on Miniaturized In-Situ Self-Calibrated Thermometers Based on Ga and Ga-Zn Fixed Points.

In order to ensure the reliability and accuracy of long-term temperature measurement where the thermometers are discommodious or even impossible to access for conventional periodical calibration, a study on miniaturized in-situ self-calibrated (MISSC) thermometers based on Ga and Ga-Zn fixed points was conducted using temperature scale transfer technology. One MISSC thermometer consists of three parts: the first is the fixed-points hardware, including a container with two cells separately filled with Ga and Ga-Zn; the second is the temperature sensing hardware, made of a Type T thermocouple; the third is the mini-power heating hardware, made of a film resistance. The measurement and calibration (M&C) system comprises a temperature measurement and data processing subsystem and a mini-power heating control subsystem. Then, an in-situ self-calibration can be carried out by mini-power heating from a room temperature of about 20 °C, and then by comparison between the measured phase transition plateau results and the standard fixed-points, i.e., Ga fixed point (about 29.76 °C) and Ga-Zn fixed point (about 25.20 °C). A series of experiments were performed, and the results show that: (1) both the proposed hardware design and the self-calibration method are feasible, and (2) the Φ16 mm × 25 mm MISSC thermometer is found to be the most miniaturized one that can realize reliable self-calibration in this study.

The value of error-correcting responses for cognitive assessment in games

Traditional conflict-based cognitive assessment tools are highly behaviorally restrictive, which prevents them from capturing the dynamic nature of human cognition, such as the tendency to make error-correcting responses. The cognitive game Tunnel Runner measures interference control, response inhibition, and response-rule switching in a less restrictive manner than traditional cognitive assessment tools by giving players movement control after an initial response and encouraging error-correcting responses. Nevertheless, error-correcting responses remain unused due to a limited understanding of what they measure and how to use them. To facilitate the use of error-correcting responses to measure and understand human cognition, we developed theoretically-grounded measures of error-correcting responses in Tunnel Runner and assessed whether they reflected the same cognitive functions measured via initial responses. Furthermore, we evaluated the measurement potential of error-correcting responses. We found that initial and error-correcting responses similarly reflected players’ response inhibition and interference control, but not their response-rule switching. Furthermore, combining the two response types increased the reliability of interference control and response inhibition measurements. Lastly, error-correcting responses showed the potential to measure response inhibition on their own. Our results pave the way toward understanding and using post-decision change of mind data for cognitive measurement and other research and application contexts.

Developing a reference method for indirect measurement of pasture evapotranspiration at sub-meter spatial resolution

To establish an indirect method for estimating and partitioning pasture evapotranspiration, it is vital to develop a direct reference method that aligns with the required temporal and spatial resolution. An evapotranspiration chamber offers an effective solution as it is easy to deploy and operates at an appropriate measurement scale. In this study, we prepared and tested a closed hemispherical chamber for on-site measurements of evaporation and/or transpiration. Advanced data monitoring and logging techniques were integrated to enhance the precision and reliability of direct in-field evapotranspiration measurements. During laboratory testing, vapor accumulation within the chamber was monitored to identify the best representative segment of the vapor accumulation curve. Results indicated that the instrument stabilizes its readings within 5 to 10 s post-deployment in laboratory settings. The subsequent 15 s produce stable readings that best represent actual vapor accumulation. The optimal fan speed, producing an air speed of 5.36 ms−1 at the vicinity of the fan within the chamber, paired with a wire mesh above the vapor-producing surface, yielded the best results. The study established a calibration factor (C) of 1.02 based on the actual water loss and vapor accumulation readings from the sensors at this fan speed. Advanced data analytics were applied to derive the calibration factor and to calculate the values of evapotranspiration from the changing microclimate within the chamber. Direction towards complete automation and the limitations of the chamber in field measurement are provided. The chamber was also tested under field conditions, and the paper examines its practical application and necessary adjustments for field measurements.

Psychometric properties of computerized adaptive testing for chronic obstructive pulmonary disease patient-reported outcome measurement

BackgroundComputerized adaptive testing (CAT) is an effective way to reduce time, repetitious redundancy, and respond burden, and has been used to measure outcomes in many diseases. This study aimed to develop and validate a comprehensive disease-specific CAT for chronic obstructive pulmonary disease (COPD) patient-reported outcome measurement.MethodsThe discrimination and difficulty of the items from the modified patient-reported outcome scale for COPD (mCOPD-PRO) were analyzed using item response theory. Then the initial item, item selection method, ability estimation method, and stopping criteria were further set based on Concerto platform to form the CAT. Finally, the reliability and validity were validated.ResultsThe item discrimination ranged from 1.05 to 2.71, and the item difficulty ranged from − 3.08 to 3.65. The measurement reliability of the CAT ranged from 0.910 to 0.922 using random method, while that ranged from 0.910 to 0.924 using maximum Fisher information (MFI) method. The content validity was good. The correlation coefficient between theta of the CAT and COPD assessment test and modified Medical Research Council dyspnea scale scores using random method was 0.628 and 0.540 (P < 0.001; P < 0.001) respectively, while that using MFI method was 0.347 and 0.328 (P = 0.007; P = 0.010) respectively. About 11 items (reducing by 59.3%) on average were tested using random method, while about seven items (reducing by 74.1%) on average using MFI method. The correlation coefficient between theta of the CAT and mCOPD-PRO total scores using random method was 0.919 (P < 0.001), while that using MFI method was 0.760 (P < 0.001).ConclusionsThe comprehensive disease-specific CAT for COPD patient-reported outcome measurement is well developed with good psychometric properties, which can provide an efficient, accurate, and user-friendly measurement for patient-reported outcome of COPD.

Smartphone-Based Assessment of Mobility and Manual Dexterity in Adult People with Spinal Muscular Atrophy.

More responsive, reliable, and clinically valid endpoints of disability are essential to reduce size, duration, and burden of clinical trials in adult persons with spinal muscular atrophy (aPwSMA). The aim is to investigate the feasibility of smartphone-based assessments in aPwSMA and provide evidence on the reliability and construct validity of sensor-derived measures (SDMs) of mobility and manual dexterity collected remotely in aPwSMA. Data were collected from 59 aPwSMA (23 walkers, 20 sitters and 16 non-sitters) and 30 age-matched healthy controls (HC). SDMs were extracted from five smartphone-based tests capturing mobility and manual dexterity, which were administered in-clinic and remotely in daily life for four weeks. Reliability (Intraclass Correlation Coefficients, ICC) and construct validity (ability to discriminate between HC and aPwSMA and correlations with Revised Upper Limb Module, RULM and Hammersmith Functional Scale - Expanded HFMSE) were quantified for all SDMs. The smartphone-based assessments proved feasible, with 92.1% average adherence in aPwSMA. The SDMs allowed to reliably assess both mobility and dexterity (ICC > 0.75 for 14/22 SDMs). Twenty-one out of 22 SDMs significantly discriminated between HC and aPwSMA. The highest correlations with the RULM were observed for SDMs from the manual dexterity tests in both non-sitters (Typing, ρ= 0.78) and sitters (Pinching, ρ= 0.75). In walkers, the highest correlation was between mobility tests and HFMSE (5 U-Turns, ρ= 0.79). This exploratory study provides preliminary evidence for the usability of smartphone-based assessments of mobility and manual dexterity in aPwSMA when deployed remotely in participants' daily life. Reliability and construct validity of SDMs remotely collected in real-life was demonstrated, which is a pre-requisite for their use in longitudinal trials. Additionally, three novel smartphone-based performance outcome assessments were successfully established for aPwSMA. Upon further validation of responsiveness to interventions, this technology holds potential to increase the efficiency of clinical trials in aPwSMA.

Study on the Ensuring of Reliability and Repeatability of Research in the Area of Marine Ecology through Calibration of Underwater Acoustics Devices

This paper emphasizes the crucial needs and reasons to ensure the reliability and repeatability of underwater acoustic measurements. As an exemplification of the aforementioned acoustic measurements challenges, the development of metrological infrastructure in the area of underwater acoustics in GUM (Central Office of Measures, Poland) is presented. An analysis of presented solutions was carried out mainly in the low frequency range, in comparison with other solutions recently developed worldwide. Moreover, factors influencing the sensitivity of hydroacoustic measuring devices are discussed. The summary of this discussion outlines the further works aimed at ensuring the reliability and repeatability of underwater acoustic measurements. The conclusions present the current state of the calibration infrastructure of underwater acoustic devices, with particular emphasis on marine ecology and fisheries sciences.

Validity and Reliability of Movesense HR+ ECG Measurements for High-Intensity Running and Cycling.

Low-cost, portable devices capable of accurate physiological measurements are attractive tools for coaches, athletes, and practitioners. The purpose of this study was primarily to establish the validity and reliability of Movesense HR+ ECG measurements compared to the criterion three-lead ECG, and secondarily, to test the industry leader Garmin HRM. Twenty-one healthy adults participated in running and cycling incremental test protocols to exhaustion, both with rest before and after. Movesense HR+ demonstrated consistent and accurate R-peak detection, with an overall sensitivity of 99.7% and precision of 99.6% compared to the criterion; Garmin HRM sensitivity and precision were 84.7% and 87.7%, respectively. Bland-Altman analysis compared to the criterion indicated mean differences (SD) in RR' intervals of 0.23 (22.3) ms for Movesense HR+ at rest and 0.38 (18.7) ms during the incremental test. The mean difference for Garmin HRM-Pro at rest was -8.5 (111.5) ms and 27.7 (128.7) ms for the incremental test. The incremental test correlation was very strong (r = 0.98) between Movesense HR+ and criterion, and moderate (r = 0.66) for Garmin HRM-Pro. This study developed a robust peak detection algorithm and data collection protocol for Movesense HR+ and established its validity and reliability for ECG measurement.

Quantitative assessment of rotator cuff injuries using synthetic MRI and IDEAL-IQ imaging techniques

PurposeTo evaluate synthetic magnetic resonance imaging (SyMRI) and iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL-IQ) imaging for a comprehensive evaluation of rotator cuff injuries (RCI). MethodsNinety-seven patients with RCI were classified into four groups based on the arthroscopic results: (grade II), partial tear (grade III), complete tear (grade IV), and controls (grade I). T1 (Transverse Relaxation Time 1), T2 (Transverse Relaxation Time 2), proton density (PD), and fat fraction (FF) were evaluated using SyMRI and IDEAL-IQ. Measurement reliability was assessed using intraclass correlation coefficients (ICC). The diagnostic potential for grading RCI was evaluated using ordinal regression and ROC analyses. ResultsA high measurement reliability (ICC > 0.7) was observed across subregions. T1 and T2 significantly varied across grades, particularly T2 in the lateral subregion between grades III and IV (P < 0.001) and the central subregion between grades II and III (P < 0.001). ROC analyses yielded valuable diagnostic accuracy, including T2 in the lateral subregion with an AUC of 0.891, distinguishing grade I from grade IV. Positive correlations were found between T2 values in specific shoulder subregions and injury grade (r = 0.615 for lateral, r = 0.542 for medial, both P < 0.001). In grade IV, FF was notably increased in the supraspinatus, infraspinatus, and subscapularis muscles compared with grades I-III. There were no significant FF variations in the teres minor muscle among grades. ConclusionsQuantitative MRI parameters from SyMRI and IDEAL-IQ, especially T2 and FF, may classify and assess RCI severity. The results could help improve the accuracy of diagnosing different grades of RCI, offering clinicians additional tools for improving patient outcomes through personalized medicine.

P084 BLOOD PRESSURES MEASUREMENT WITH SITTING ON THE FLOOR POSITION FOR THE HOME BLOOD PRESSURE MONITORING FOR ASIAN LIFESTYLE

Objectives: The current standard method for home blood pressure (BP) measurement involves taking measurements while sitting in a chair. In cultures where floor sitting is common as like in Asian countries, the protocol only using sitting on the chair position can not be applied because of a lack of research for interchangeability. Methods &amp; Materials: Among the participants who visited for evaluation of central blood pressure or pulse wave velocity, a total of 116 participants who agreed to participate in the study were randomly selected. All subjects rested for 5 minutes, and BP measurements were taken at 1-minute intervals according to a randomly assigned order of standard method (chair-sitting) and BP in a seated on the floor (floor-sitting). Results: Of the 116 participants, the median age was 67.5 (with an interquartile range of 59.0 to 75.0), and 82% were male. There were no significant differences in systolic BP (SBP, 127.0 [115.0, 142.2] mmHg in chair-sitting and 129.0 [115.5, 142.2] mmHg in floor-sitting, P = 0.228) and diastolic BP (DBP, 73.5 [66.0, 83.0] mmHg in chair-sitting and 72.0 [66.8, 81.3] mmHg in floor-sitting, P = 0.839) between the two positions. Conclusions: These findings provide important insights into securing the reliability of home BP measurements through the commonly practiced floor-sitting posture in cultures where floor sitting is common. Furthermore, this could serve as substantial evidence for providing specific home BP measurement guidelines to patients who adhere to a floor-sitting lifestyle.

Reliability of Rehabilitative Musculoskeletal Sonography for Measuring the Visible Cross-Sectional Area of Suboccipital Muscles.

Aims The primary aim of this study is to assess the reliability of rehabilitative sonography as a non-invasive imaging technique for measuring the visible cross-sectional area (CSA) of the deep suboccipital muscles. Objectives Objectives involve determining both the intra-rater and inter-rater reliability of sonographic measurements to ensure consistent and reproducible results across different sessions and examiners. The ultimate goal is to validate rehabilitative sonography as a reliable tool for clinical and research applications in the assessment and management of musculoskeletal (MSK) conditions involving the deep suboccipital muscles. Design and setting Seventeen participants, including nine women and eight men without neck or vertebral pain, were evaluated using MSK sonography. The visible CSA of suboccipital muscles was assessed using real-time B-mode sonography in a sitting position with a linear probe (5 cm, 7.5 MHz) aligned perpendicularly to the muscle fibers of the rectus capitis posterior minor (RCPM) in one sonogram and the obliquus capitis inferior (OCI) and rectus capitis posterior major (RCPMJ) in another. Two experienced examiners performed sonography measurements, and the procedure was repeated one hour and again one day later. Results Intra-class correlation coefficient (ICC) values for Examiner 1 were 0.84 and 0.79 for RCPM, 0.84 and 0.71 for RCPMJ, and 0.86 and 0.77 for OCI at the one-hour and one-day repetitions, respectively. ICC values for Examiner 2 were 0.86 and 0.77 for RCPM, 0.77 and 0.86 for RCPMJ, and 0.61 and 0.64 for OCI at the one-hour and one-day repetitions, respectively. Inter-rater ICC values were 0.77 for RCPM, 0.82 for RCPMJ, and 0.68 for OCI. Standard error of measurement (SEM) values for Examiner 1 were 11.63 and 13.92 mm² for RCPM, 10.30 and 7.91 mm² for RCPMJ, and 22.84 and 34.61 mm² for OCI. SEM values for Examiner 2 were 11.82 and 13.40 mm² for RCPM, 11.91 and 7.04 mm² for RCPMJ, and 39.20 and 37.73 mm² for OCI. SEM values between examiners were 13.74 mm² for RCPM, 10.36 mm² for RCPMJ, and 36.03 mm² for OCI. Conclusions These findings suggest that sonography is a reliable method for measuring the CSA of the RCPM, RCPMJ, and OCI muscles, provided that the examiners are well-trained and consistent in their techniques and that the average of three measurements is used.

Systematic Review On The Effect Of Evaporation On The Evaluation Of Serum Electrolyte Levels

Evaporation is a critical factor that can influence the accuracy and reliability of serum electrolyte measurements. This systematic review aims to assess the impact of evaporation on serum electrolyte levels and its implications for clinical and laboratory practices. We analyzed studies that investigated the effects of evaporation on various electrolytes, including sodium, potassium, chloride, and bicarbonate. The review highlights the mechanisms by which evaporation affects electrolyte concentrations, evaluates different strategies to mitigate these effects, and provides recommendations for best practices in serum electrolyte analysis

Reliability and validity of a measure of service providers' perceptions of child and parent engagement in pediatric rehabilitation therapy sessions.

There is growing interest in client engagement in pediatric rehabilitation. This article investigated the psychometric properties of a measure of service providers' perceptions of the affective, cognitive and behavioural engagement of both children with disabilities and their parents in pediatric rehabilitation therapy sessions. Test-retest reliability of the Pediatric Rehabilitation Intervention Measure of Engagement-Service Provider version (PRIME-SP) was examined using engagement ratings made by 60 service providers for 77 children and 73 parents. Construct validity was examined using the known-group validity technique, utilizing service providers' ratings of the engagement of parents and their children attending the same session with the service provider. We hypothesized that there would be significantly different, yet moderately correlated engagement ratings for children and their parents. There was evidence of moderate test-retest reliability for the child ratings, indicative of dynamicity across occasions, but also a degree of consistency, as aligned with our expectations. Service providers' ratings of parent and child engagement were not significantly correlated and paired t-tests indicated significantly higher engagement scores for parents than children. The study provides preliminary evidence to support the reliability and validity of the PRIME-SP as a tool for service providers to document, reflect on and monitor child and/or parent engagement.

Evaluating the accuracy of planar gated blood pool processing software using simulated patient studies

Planar gated blood pool (GBP-P) radionuclide imaging is a valuable non-invasive technique for assessing left ventricular ejection fraction (LVEF). Serial cardiac imaging can be performed to monitor the potential decline in LVEF among patients undergoing cardiotoxic chemotherapy. Consequently, accurate LVEF determination becomes paramount. While commercial software programs have enhanced the LVEF values' reproducibility, concerns remain regarding their accuracy. This study aimed to generate a database of GBP-P studies with known LVEF values using Monte Carlo simulations and to assess LVEF values' accuracy using four commercial software programs.We utilised anthropomorphic 4D-XCAT models to generate 64 clinically realistic GBP-P studies with Monte Carlo simulations. Four commercial software programs (Alfanuclear, Siemens, General Electric Xeleris, and Mediso Tera-Tomo) were used to process these simulated studies. The accuracy and reproducibility of the LVEF values determined with these software programs and the intra- and inter-observer reproducibility of the LVEF values were assessed.Our study revealed a strong correlation between LVEF values calculated by the software programs and the true LVEF values derived from the 4D-XCAT models. However, all the software programs slightly underestimated LVEF at lower LVEF values. Intra- and inter-observer reliability for LVEF measurements was excellent.Accurate LVEF assessment is crucial for determining the patient's cardiac function before initiating and during chemotherapy treatment. The observed underestimation, particularly at lower LVEF values, emphasises the need for the accurate and reproducible determination of these values to avoid excluding suitable candidates for chemotherapy. The software programs' excellent intra- and inter-observer reliability highlights their potential to reduce subjectivity when using the semi-automatic processing option.This study confirms the accuracy and reliability of these commercial software programs in determining LVEF values from simulated GBP-P studies. Future research should investigate strategies to mitigate the underestimation biases and extend findings to diverse patient populations.Gated blood pool studies, left ventricular ejection fraction, Monte Carlo simulations, 4D-XCAT models.

Intra- and Inter-Rater Reliability of Linear and Nonlinear Measures of Short-Term Heart Rate Variability Following Combat-Related Traumatic Injury.

Heart rate variability (HRV) is a marker of autonomic function. However, the reliability of short-term HRV measurement in individuals with combat-related traumatic injury (CRTI) remains undetermined. An intra- and inter-rater reliability study was conducted using a subsample (n = 35) of British servicemen with CRTI enrolled in the ongoing ADVANCE study. A five-minute epoch of single-lead electrocardiogram data collected during spontaneous breathing was used to measure HRV. HRV analyses were independently performed by two examiners using Kubios. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), minimum detectable change (MDC), and coefficient of variance were calculated for linear [root mean square of successive difference (RMSSD), standard deviation of NN interval, low-frequency, high-frequency, total power] and nonlinear (SD1-2, acceleration and deceleration capacities, sample entropy) measures. Bland-Altman %plots were used to assess bias in intra- and inter-rater HRV data. The mean age of participants was 39.3 ± 6.3 years. An excellent ICC score of 0.9998 (95% CI 0.9997, 0.9999) was observed for intra-rater analyses of RMSSD, and similar excellent ICC scores were seen for all other HRV measures. The inter-rater reliability analyses produced an excellent ICC score (range 0.97-1.00). Comparatively, frequency-domain measures produced higher MDC% and SEM% scores than time-domain and nonlinear measures in both inter- and intra-rater analyses. The Bland-Altman plots revealed relatively higher bias for frequency-domain and nonlinear measures than time-domain measures. ECG-related short-term HRV measures were reliable in injured servicemen under spontaneous breathing. However, the reliability appeared better with the time-domain measure than frequency-domain and nonlinear measures in this sample.

Combined Lactate Glucose Ratio as a Novel Marker for Rapid Diagnosis of Cerebrospinal Fluid Bacterial Infection in Neurosurgical Patients: Diagnostic Accuracy Study and Benchtop Analyzer Correlation

ObjectiveThis study aimed to assess the diagnostic accuracy of a novel marker, the combined lactate-to-glucose ratio (CLGR), in identifying cerebrospinal fluid (CSF) bacterial infection (CBI) in neurosurgical patients. Additionally, it seeks to establish cut-off values for CLGR and evaluate the reliability of measurement using blood gas analyzer (BGA). MethodsCSF samples were collected from two neurosurgical centers in Kuala Lumpur, Malaysia, between January 2022 and October 2023. Conventional markers and CLGR were quantified using standard laboratory methods, with BGA utilized for measurement when feasible. Samples were categorized into confirmed CBI-positive (CBI+) and CBI-negative (CBI-) groups. Marker performance was compared, and receiver operating characteristic analysis conducted. Pearson's correlation assessed the agreement between BGA and laboratory measurements. ResultsAmong the 130 CSF samples, 11 were CBI+. Both cLac and CLGR were significantly elevated in the CBI+ group (p<0.001). The area under the curve (AUC) for cLac and CLGR was 0.990 and 0.994, respectively. Using a cut-off of 6.0mmol/L, cLac demonstrated sensitivity of 100%, specificity of 93.3%, positive predictive value (PPV) of 57.9%, negative predictive value (NPV) of 100%, and diagnostic accuracy of 93.9%. CLGR ≥20.0 showed even higher accuracy: 100.0% sensitivity, 98.6% specificity, 84.6% PPV, 100% NPV, and overall accuracy of 98.5%. Both markers maintained excellent performance in blood-stained CSF. BGA measurements correlated well with laboratory results (r=0.980 & 0.999, respectively, p<0.001). ConclusionsCLac levels ≥6.0mmol/L and CLGR ≥20.0 accurately identified CBI in neurosurgical patients, with CLGR exhibiting superior efficacy. The potential for instant BGA measurement suggests promise for point-of-care testing.

The Balance N1 Is Larger in Children With Anxiety and Associated With the Error-Related Negativity

BackgroundThe error-related negativity (ERN) is a brain response evoked by mistakes on cognitive tasks that is enhanced with anxiety and can predict the subsequent onset or exacerbation of anxiety in children and adolescents. A physical disturbance to standing balance evokes a brain response called the balance N1 that resembles the ERN in scalp topography and in response to a variety of moderating factors. We recently found that the balance N1 and ERN correlate in amplitude across small adult samples. MethodsIn the current study, we tested the effect of anxiety on the balance N1 in children (ages 9–12 years) with and without diagnosed anxiety disorders (38 children with generalized anxiety, social anxiety, and/or obsessive-compulsive disorder and 50 children without these disorders). We measured the balance N1 in response to sudden release of support from a forward leaning posture, the ERN in response to mistakes on a Go/NoGo task, and anxiety symptoms using child- and parent-report forms of the Screen for Child Anxiety and Related Emotional Disorders. ResultsBoth the balance N1 and the ERN were larger in the anxious group. The balance N1 was also associated with both the ERN and parent report of child anxiety symptom severity across individuals. ConclusionsThe higher measurement reliability of the balance N1 than the ERN and greater experimental control over errors suggest that balance paradigms may provide a more powerful method for investigating individual differences in error-related brain activity related to anxiety.