Non-significant Bias Research Articles

Concurrent Validity and Reliability of In-Person and Supervised Remote STEADI Fall Risk Assessment in Community-Dwelling Older Adults.

Physical therapists play a vital role in preventing and managing falls in older adults. With advancements in digital health and technology, community fall prevention programs need to adopt valid and reliable telehealth-based assessments. The purpose of this study was to evaluate the validity and reliability of the telehealth-based timed up and go (TUG) test, 30-second chair stand test (30s-CST), and four-stage (4-stage) balance test as functional components of the Stopping Elderly Accidents, Deaths, and Injuries (STEADI) fall risk assessment. This cross-sectional study was conducted using a convenience sample of community-dwelling older adults. The TUG, 30s-CST, and 4-stage balance test were administered in random order in 1 session in the participant's own environment. Performance was scored concurrently by an in-person and synchronous telehealth rater. The video recordings of the performances were scored by an asynchronous telehealth rater on days 1 and 30 for inter- and intra-rater reliability. Additionally, participants performed the TUG test twice, using the distance measured by the participant and the distance measured by the in-person rater. To establish the validity of telehealth-based STEADI fall risk assessments, the Intraclass Correlation Coefficient (ICC), Pearson correlation coefficient, and 95% limits of agreement were derived. Inter- and intra-rater reliability were established by calculating ICC using a 2-way mixed model. Bland-Altman plots were created for nonsignificant proportional bias tests. Thirty community-dwelling older adults participated. Based on the STEADI algorithm, 13 participants were classified as having a moderate fall risk. A comparison of in-person and synchronous telehealth ratings showed excellent ICCs (0.97-0.99) and relationships (r=0.94-0.98). Bland-Altman plots were created for all tests except for the 30s-CST (t=-2.168, P =.04). All tests had good to excellent inter-rater reliability (ICC=0.84-1.00) and intra-rater reliability (0.77-1.00). No adverse events were reported. This study suggests that telehealth-administered functional tests in the STEADI fall risk assessment are valid and reliable when technology, environment, camera view, and angle are optimally managed.

Indexes of Fat Oxidation from Ramp vs. Graded Incremental Protocols in Postmenopausal Women

The maximal rate of fat oxidation (MFO, in g∙min−1) and the relative exercise intensity at which it occurs (FATmax, as %V̇O2max) are indexes of metabolic flexibility. The time-consuming, graded exercise protocol required for MFO/FATmax determination hinders the extensive use of these indexes for individualized exercise prescription and monitoring. Purpose: validate ramp testing for MFO and FATmax measures in postmenopausal women. Methods: Seventeen healthy women (age: 54 ± 4 years, BMI 22 ± 3 kg·m−2, and V̇O2max 36.4 ± 5.3 mL·min−1), who were 4 ± 3 years from menopause, performed on a cycle-ergometer, a ramp, and a graded incremental test. Based on V̇O2 and respiratory exchange ratio from the ramp and graded protocol (i.e., the 5th minute of each step), MFO and FATmax were determined. Data from the two protocols were compared using paired t-tests, linear regression, and Bland–Altman analysis. Results: The MFO measured with a ramp protocol was not different from (0.24 ± 0.09 vs. 0.20 ± 0.08 g·min−1, p = 0.10), and moderately associated with, that of the graded protocol (r2 = 0.46). FATmax occurred at similar exercise intensity for both protocols (47.8 ± 5.1 vs. 47.5 ± 4.3 %V̇O2max, p = 0.91, r2 = 0.52). The comparison of MFO and FATmax across the protocols yields a non-significant bias but a relatively large limit of agreement (respectively, 0.05 g·min−1, LOA = −0.08, and 0.19 g·min−1; 0.3 %V̇O2max, LOA = −7.8, and 10.6 %V̇O2max). Conclusions: In postmenopausal women, ramp testing offers a valid alternative to the graded protocol for identifying MFO and FATmax. The availability of a time- and cost-efficient approach, which can be incorporated into standard ramp incremental testing, can facilitate using these indexes of metabolic flexibility in research and medicine.

Work-related Musculoskeletal Disorders among Various Occupational Workers in India: A Systematic Review and Meta-Analysis.

Work-related musculoskeletal disorders (WMSDs) are one of the most common occupational diseases, affecting various sectors such as agriculture, small-scale industries, handicrafts, construction, and banking. These disorders, caused by overexertion and repetitive motion, lead to work absenteeism, productivity loss, and economic impacts. The aim of the study is to determine the magnitude of musculoskeletal disorders among different occupational workers in India. We identified studies reporting the prevalence of WMSDs using the Nordic Musculoskeletal Questionnaire in different databases between 2005 and 2023 through searches on SCOPUS, PubMed Central, and Google Scholar. The required information was then extracted. A random effect model was used to pool estimates of prevalence with 95% CI. Publication bias was assessed by applying funnel plots. The 12-months prevalence of work-related musculoskeletal disorders (WMSDs) were reported across several occupational groups, the meta or the pooled prevalence was estimated as 0.76 (95% CI: 0.70 to 0.82) along with substantial variability in the prevalence estimates between different industries and studies. The meta-prevalence for low back pain (LBP) was estimated as 0.60 (95% CI: 0.54 to 0.66). The meta-prevalence for Neck Pain was estimated as 0.40 (95% CI: 0.34 to 0.47) while for Shoulder Pain, it was estimated as 0.36 (95% CI: 0.30 to 0.42), respectively. The risk of Bias was statistically non-significant and overall publication bias remains low as per visual inspections from funnel plot. WMSDs are prevalent across various Indian industries in significant proportion, particularly in agriculture, healthcare, and mining, leading to significant productivity loss and economic impact. The variation in prevalence highlights the need for sector-specific interventions. Addressing WMSDs requires comprehensive ergonomic and policy measures. Effective strategies are essential to mitigate these disorders' widespread impact.

Cerebral and myocardial kinetics of [11C]acetoacetate and [11C]β-hydroxybutyrate: A comparative crossover study in healthy rats

BackgroundKetone metabolism has been studied using positron emission tomography (PET) with the radiotracers [11C]acetoacetate and [11C]β-hydroxybutyrate. However, whether these two radiotracers actually yield equivalent estimates of cerebral and myocardial ketone metabolism has not yet been investigated. This study aimed to investigate and compare the kinetics of both tracers in the brain and heart of healthy rats under varying levels of circulating ketones at baseline and after a single-dose exogenous ketone ester (KE) supplement. MethodsSix healthy Sprague-Dawley rats each underwent two scans with each tracer: one following oral KE administration and one with a placebo. Cerebral kinetic parameters (Ki, VT, and cerebral metabolic rate (CMR)) were obtained using the Patlak method, whereas myocardial kinetic parameters (K1, k2, and VT) were derived using a 1-tissue compartment model. Parameters were compared through mixed-effects, correlation, and Bland-Altman analyses. ResultsGlobal CMR increased 3–4-fold in the KE group versus placebo, with strong positive correlations between CMR and plasma ketone levels for both tracers. Correlations between [11C]acetoacetate and [11C]β-hydroxybutyrate were moderate and non-significant for relative cerebral uptake expressed as Ki (ρ = 0.40) and for VT (ρ = 0.38) but strongly positive for absolute uptake, CMR (r = 0.84), with a non-significant mean bias of −0.03. In contrast, myocardial kinetics showed only non-significant weak to moderate correlations between the radiotracers (K1 (r = 0.04), k2 (r = −0.27), and VT (ρ = 0.43)), with no systematic biases. Conclusion[11C]acetoacetate and [11C]β-hydroxybutyrate can be used interchangeably for measuring global CMR in healthy rats but differ in certain cerebral and myocardial kinetics. Whether these findings are generalizable to pathological conditions warrants further studies to explore the kinetics of these tracers in disease models.

Comparison of 3D UTE free-breathing lung MRI with hyperpolarized 129Xe MRI in pediatric cystic fibrosis.

To compare phase-resolved functional lung (PREFUL) regional ventilation derived from a free breathing 3D UTE radial MRI acquisition to hyperpolarized 129Xe-MRI (Xe-MRI), conventional 2D multi-slice PREFUL MRI, and pulmonary function tests in pediatric cystic fibrosis (CF) lung disease. Free-breathing 3D UTE and 2D multi-slice 1H MRI as well as Xe-MRI were acquired in 12 stable pediatric CF patients. Using PREFUL, regional ventilation (RVent) maps were calculated from the free-breathing data. Ventilation defect percentage (VDP) was determined from 3D and 2D RVent maps (2D VDPRVent and 3D VDPRVent, respectively) and Xe-MRI ventilation (VDPXe). VDP was calculated for the whole lung and for eight regions based on left/right, anterior/posterior, and superior/inferior divisions of the lung. Global and regional VDP was compared between the three methods using Bland-Altman analysis, linear mixed model-based correlation, and one-way analysis of variance and multiple comparisons tests. Global 3D VDPRVent, VDPXe, and 2D VDPRVent were all strongly correlated (all R2 > 0.62, p < 0.0001) and showed minimal, non-significant bias (all <2%, p > 0.05). Three dimensional and 2D VDPRVent significantly correlated to VDPXe in most of the separate lung regions (R2 = 0.18-0.74, p < 0.04), but showed lower inter-agreement. The superior/anterior lung regions showed the least agreement between all three methods (all p > 0.12). Absolute VDP assessed by 3D UTE PREFUL MRI showed good global agreement with Xe-MRI and 2D multi-slice PREFUL MRI in pediatric CF lung disease. Therefore, 3D UTE PREFUL MRI offers a sensitive and potentially more accessible alternative to Xe-MRI for regional volumetric evaluation of ventilation.

Clinical Validation of Carotid-Femoral Pulse Wave Velocity Measurement Using a Multi-Beam Laser Vibrometer: The CARDIS Study.

Carotid-femoral pulse wave velocity (cfPWV) is the gold standard for noninvasive arterial stiffness assessment, an independent predictor of cardiovascular disease, and a potential parameter to guide therapy. However, cfPWV is not routinely measured in clinical practice due to the unavailability of a low-cost, operator-friendly, and independent device. The current study validated a novel laser Doppler vibrometry (LDV)-based measurement of cfPWV against the reference technique. In 100 (50 men) hypertensive patients, cfPWV was measured using applanation tonometry (Sphygmocor) and the novel LDV device. This device has 2 handpieces with 6 laser beams each that simultaneously measure vibrations from the skin surface at carotid and femoral sites. Pulse wave velocity is calculated using ECG for the identification of cardiac cycles. An ECG-independent method was also devised. Cardiovascular risk score was calculated for patients between 40 and 75 years old using the WHO risk scoring chart. LDV-based cfPWV correlated significantly with tonometry (r=0.86, P<0.0001 ECG-dependent [cfPWVLDV_ECG] and r=0.80, P<0.001 ECG-independent [cfPWVLDV_w/oECG] methods). Bland-Altman analysis showed nonsignificant bias (0.65 m/s) and acceptable SD (1.27 m/s) between methods. Intraobserver coefficient of variance for LDV was 4.7% (95% CI, 3.0%-5.5%), and interobserver coefficient of variance was 5.87%. CfPWV correlated significantly with CVD risk (r=0.64, P<0.001; r=0.41, P=0.003; and r=0.37, P=0.006 for tonometry, LDV-with, and LDV-without ECG, respectively). The study demonstrates clinical validity of the LDV device. The LDV provides a simple, noninvasive, operator-independent method to measure cfPWV for assessing arterial stiffness, comparable to the standard existing techniques. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03446430.

Comparison of Eye Axial Length Measurements Taken Using Partial Coherence Interferometry and OCT Biometry.

This study evaluates the inter-device measurement properties of partial coherence interferometry (PCI) and spectral domain optical coherence tomography (SD-OCT) in measuring axial length, particularly for myopia management. We recruited 82 eyes from 41 adult participants with a mean age of 31.0 ± 17.6 years and a mean spherical equivalent of -2.20 ± 2.28 D. Axial length was measured using SD-OCT and PCI for both the right and left eyes. Agreement between the two measurements was assessed using Bland-Altman analysis, and graphs and values were compared with linear mixed models. The results show a near-to-zero and non-significant bias between measurements. The 95% limits of agreement showed a value of 0.06 mm. Both devices can accurately measure the axial length. OCT biometry performed with SD-OCT can be successfully interchanged with partial coherence interferometry, but they should be cautiously interchanged when performing longitudinal comparisons.

Validity and reproducibility of the CALERA Research Sensor to estimate core temperature at different intensities of a cycling exercise in the heat

Recent heatwaves have highlighted the importance of accurate and continuous core temperature (TCORE) monitoring in sports settings. For example, accentuated rises in TCORE caused by physical exercises under environmental heat stress increase the risk of heat illnesses. Thus, using valid and reproducible devices is essential to ensure safe sports practice. In this study, we assessed the validity and reproducibility of the Calera Research Sensor (CRS) in estimating the TCORE of male and female participants during cycling exercise in a hot environment. Seven male (age: 36.2 ± 10.1 years) and eight female cyclists (age: 30.1 ± 5.0 years) underwent two identical cycling trials in a dry-bulb temperature of 32 °C and relative humidity of 60%. The protocol consisted of an initial 10-min rest followed by a 60-min exercise comprising 10 min at 20%, 25 min at 55%, and 25 min at 75% of maximal aerobic power, and an additional 25 min of post-exercise recovery. TCORE was recorded simultaneously every minute using a gastrointestinal capsule (TGi) and the CRS (TSENSOR). Bland–Altman analysis was performed to calculate bias, upper (LCS) and lower (LCI) concordance limits, and the 95% confidence interval (95%CI). The maximum acceptable difference between the two devices was predetermined at ±0.4 °C. A mixed linear model was used to assess the paired differences between the two measurement systems, considering the participants, trials, and environmental conditions as random effects and the cycling stages as fixed effects. An intra-class correlation coefficient (ICC) of 0.98 was recorded when analyzing data from the entire experiment. A non-significant bias value of 0.01 °C, LCS of 0.38 °C, LCI of −0.35 °C, and CI95% of ±0.36 °C were found. When analyzing data according to the participants’ sex, CRS reproducibility was high in both sexes: ICC values of 0.98 and 0.99 were reported for males and females, respectively. CI95% was 0.35 °C in experiments with males and 0.37 °C with females, thereby falling within the acceptable margin of difference. Therefore, CRS was considered valid (compared to TGi) and reproducible in estimating TCORE in both sexes at various intensities of cycling exercise in the heat.

Comparison of rectal thermometry with the alternative undertail, axillary, and inguinal temperature measurements in sheep

This study was conducted to ascertain the suitability of alternative locations for temperature measurement, with reference to rectal thermometry in sheep, using a digital thermometer (DT). The study employed a single-factor multilevel design, considering anatomical location (site) as the main factor. This anatomical location factor had four conditions, including rectal (rectalDTt), undertail (undertailDTt), inguinal (inguinalDTt), and axillary (axillaryDTt) locations. A total of 16 sheep were recruited for the study, and each treatment had eight replicates. The data obtained were descriptively analyzed using means and standard deviations, while inferential statistics included analysis of variance (ANOVA), Pearson’s correlation, Tukey’s test, t-test, and Bland-Altman plot. The mean inguinalDTt was the highest (39.51 ± 0.31℃), while the lowest was the mean undertailDTt (38.97±0.45). The effect of anatomical location on temperature readings was statistically significant. The difference between mean rectalDTt and inguinalDTt, or axillaryDTt was not significant. The rectalDTt measurements were significantly correlated with those of each treatment. Equivalence analysis revealed a non-significant bias between the rectalDTt and inguinalDTt pair. The Bland-Altman plot showed a good level of correlation and considerable agreement between rectalDTt and inguinalDTt measurements. In conclusion, temperature measurement at the inguinal location results in readings that are similar to those of rectal thermometry and thus may be of clinical importance in the future, particularly with digital thermometer application in sheep.

Interference of bovine hemoglobin-based oxygen carrier-201 (Hemopure) on four hematology analyzers.

Hemoglobin-based oxygen carriers, for example HBOC-201 (Hemopure), are aimed to bridge acute anemia when blood transfusion is not available or refused by the patient. However, since HBOC-201 appears free in plasma, it interferes with laboratory tests. This study presents an overview of HBOC-201 interference on four commonly used hematology analyzers and suggests treatment monitoring possibilities. Blood samples were spiked with therapeutic doses of HBOC-201 and nine hematology parameters were measured with the Sysmex XN-20, Siemens Advia 2120i, Abbott Alinity Hq and Abbot Cell Dyn Sapphire hematology analyzers. The results were compared to control samples and the bias was determined. Most parameters, including all cell counts, hematocrit and MCV, showed a non-significant bias compared to control. However, the standard, total hemoglobin (Hb) measurement as well as MCH and MCHC showed poor agreement with control, as HBOC-201 was included in this measurement. Yet, the flow cytometry-based Hb method quantified intracellular Hb in spiked samples, excluding HBOC-201. Of all included hematology parameters, only total Hb and the associated MCH and MCHC suffered from interference. In contrast, the flow cytometry-based Hb measurement provided an accurate measure of intracellular Hb. The difference between total Hb and cellular Hb represents the HBOC-201 concentration and can be used to monitor HBOC-201 treatment.

Comparison of inertial records during anticipatory postural adjustments obtained with devices of different masses.

Step initiation involves anticipatory postural adjustments (APAs) that can be measured using inertial measurement units (IMUs) such as accelerometers. However, previous research has shown heterogeneity in terms of the population studied, sensors used, and methods employed. Validity against gold standard measurements was only found in some studies, and the weight of the sensors varied from 10 to 110 g. The weight of the device is a crucial factor to consider when assessing APAs, as APAs exhibit significantly lower magnitudes and are characterized by discrete oscillations in acceleration paths. This study aims to validate the performance of a commercially available ultra-light sensor weighing only 5.6 g compared to a 168-g smartphone for measuring APAs during step initiation, using a video capture kinematics system as the gold standard. The hypothesis is that APA oscillation measurements obtained with the ultra-light sensor will exhibit greater similarity to those acquired using video capture than those obtained using a smartphone. Twenty subjects were evaluated using a commercial lightweight MetaMotionC accelerometer, a smartphone and a system of cameras-kinematics with a reflective marker on lumbar vertebrae. The subjects initiated 10 trials of gait after a randomized command from the experimenter and APA variables were extracted: APAonset, APAamp, PEAKtime. A repeated measures ANOVA with post-hoc test analyzed the effect of device on APA measurements. Bland-Altman plots were used to evaluate agreement between MetaMotionC, smartphone, and kinematics measurements. Pearson's correlation coefficients were used to assess device correlation. Percentage error was calculated for each inertial sensor against kinematics. A paired Student's t-test compared th devices percentage error. The study found no significant difference in temporal variables APAonset and PEAKtime between MetaMotionC, smartphone, and kinematic instruments, but a significant difference for variable APAamp, with MetaMotionC yielding smaller measurements. The MetaMotionC had a near-perfect correlation with kinematic data in APAonset and APAamp, while the smartphone had a very large correlation in APAamp and a near-perfect correlation in APAonset and PEAKtime. Bland-Altman plots showed non-significant bias between smartphone and kinematics for all variables, while there was a significant bias between MetaMotionC and kinematics for APAamp. The percentage of relative error was not significantly different between the smartphone and MetaMotionC. The temporal analysis can be assessed using ultralight sensors and smartphones, as MetaMotionC and smartphone-based measurements have been found to be valid compared to kinematics. However, caution should be exercised when using ultralight sensors for amplitude measurements, as additional research is necessary to determine their effectiveness in this regard.

Suitability of Inguinal and Axillary Sites for Temperature Measurement Using Digital Thermometers: A Comparison with Rectal Thermometry in Broiler Chickens

Core body temperature is one of the physiological parameters that must be assessed during the monitoring of the thermic and or health status of broiler chickens. In this regard, cloacal thermometry is a standard method used for temperature measurement although it has many drawbacks. This study was conducted to explore the suitability of other anatomical sites for temperature measurement using a digital thermometer. This was a single-factor experiment that considered the anatomical site as the main factor with three levels (treatments), including cloacal (DTtcloacal), axillary (DTtaxillary), and inguinal (DTtinguinal) sites. Out of 84 broiler chickens, a total of 28 chickens were randomly selected for temperature measurement. The temperature was measured for each anatomical site, and the readings were analyzed using appropriate statistics. The cloacal site had the highest mean temperature (41.40 ± 0.17℃), while the lowest mean value was observed for the axillary site (41.12 ± 0.19℃). There was no significant difference between the mean cloacal and inguinal temperatures. The cloacal and inguinal temperature readings were significantly correlated. The results for the cloacal and inguinal temperature measurements revealed a non-significant bias. The agreement interval between these two methods was sufficiently lower than the maximum acceptable difference between the anatomical sites. Both cloacal and inguinal temperature measurements had similar median points. The results indicated an underestimation of the temperature readings for the axillary site compared to those of the other sites. In conclusion, this study has revealed that the application of a digital thermometer using the inguinal site gives temperature readings that are similar to those of the conventional cloacal method.

Phenotyping of architecture traits of loblolly pine trees using stereo machine vision and deep learning: Stem diameter, branch angle, and branch diameter

Loblolly pine is one of the most planted forest tree species in the Southern United States for sawtimber production. The sawtimber yield potential of a pine tree is significantly impacted by its stem and branch architecture, which is of important focus in tree improvement programs. However, phenotyping these traits in the upper crown of pine trees is currently based on subjective visual assessments. This study investigated the feasibility of quantifying stem diameter, branch angle, and branch diameter of six-year-old loblolly pine trees in a progeny test using stereo 3D imaging, deep learning-based instance segmentation, and image and point cloud processing techniques. Instance segmentation of branches and stems was performed as well as principal component analysis (PCA) in 2D images, followed by 3D reconstruction of the segmented organs. The resulting 3D point clouds were further processed using random sample consensus (RANSAC) and statistical outlier removal to extract stem diameter, branch angle, and branch diameter. When compared to the manual ground-truth measurements, the three system-derived parameters achieved RMSEs of 0.055 m, 5.0˚, and 5.6 mm, respectively. In addition, Bland-Altman analyses showed that the stem diameter and branch angle estimations were found with limits of agreement of±0.098 m and±9.8˚, respectively, with nonsignificant biases. On the other hand, branch diameter estimation showed −12.1 mm and 9.3 mm for lower and upper limits of agreement with a bias. The proposed system demonstrates promising potential as a high-throughput low-cost precision phenotyping tool for the characterization of loblolly pine tree architecture under field conditions, facilitating the selection of superior genotypes with improved sawtimber properties.

Estimation of demographic parameters of some plant species accounting for imperfect detection probabilities

AbstractDetection probability (p) in plants is imperfect in natural conditions due to several factors. This imperfect detectability is rarely accounted for in the estimation of demographic parameters, such as survival probabilities (S) or transition rates between different life states or size classes (ψ), which may result in inaccurate quantitative information about plant populations. In this study, we used previously collected data of five plant species belonging to different families with contrasting life forms and habitats (Flaveria chlorifolia,Mammillaria hernandezii,Neobuxbaumia macrocephala,Govenia lagenophora, andCastilleja tenuiflora), data simulations, multi‐state models (a demographic tool that explicitly accounts forp), and direct estimation of survival and transition rates (i.e., assuming perfect detection) to identify in which species, states, or demographic parameters the bias caused by ignoring our imperfect detectability is more severe. Detection was imperfect (p &lt; 1) for all our study species. In general, ignoring detection probabilities yielded underestimated survival and transition rates in all five species. Biases caused by assuming perfect detection were also large and significant, mainly in inconspicuous life states and size classes, such as seedlings and dry individuals. In contrast, considering detection probabilities resulted in fewer underestimated survival and transition rates, with smaller and mostly nonsignificant biases. Intriguingly, some transitions were overestimated even when accounting for detection probabilities. Our findings highlight the importance of considering that detection of most plant species is imperfect in the field, even in species that are apparently conspicuous, to avoid incorrect inferences about plant populations.

Single-heartbeat cardiac cine imaging via jointly regularized nonrigid motion-corrected reconstruction.

The aim of the current study was to develop a novel approach for 2D breath-hold cardiac cine imaging from a single heartbeat, by combining cardiac motion-corrected reconstructions and nonrigidly aligned patch-based regularization. Conventional cardiac cine imaging is obtained via motion-resolved reconstructions of data acquired over multiple heartbeats. Here, we achieve single-heartbeat cine imaging by incorporating nonrigid cardiac motion correction into the reconstruction of each cardiac phase, in conjunction with a motion-aligned patch-based regularization. The proposed Motion-Corrected CINE (MC-CINE) incorporates all acquired data into the reconstruction of each (motion-corrected) cardiac phase, resulting in a better posed problem than motion-resolved approaches. MC-CINE was compared with iterative sensitivity encoding (itSENSE) and Extra-Dimensional Golden Angle Radial Sparse Parallel (XD-GRASP) in 14 healthy subjects in terms of image sharpness, reader scoring (range: 1-5) and reader ranking (range: 1-9) of image quality, and single-slice left ventricular assessment. MC-CINE was significantly superior to both itSENSE and XD-GRASP using 20 heartbeats, two heartbeats, and one heartbeat. Iterative SENSE, XD-GRASP, and MC-CINE achieved a sharpness of 74%, 74%, and 82% using 20 heartbeats, and 53%, 66%, and 82% with one heartbeat, respectively. The corresponding results for reader scoring were 4.0, 4.7, and 4.9 with 20 heartbeats, and 1.1, 3.0, and 3.9 with one heartbeat. The corresponding results for reader ranking were 5.3, 7.3, and 8.6 with 20 heartbeats, and 1.0, 3.2, and 5.4 with one heartbeat. MC-CINE using a single heartbeat presented nonsignificant differences in image quality to itSENSE with 20 heartbeats. MC-CINE and XD-GRASP at one heartbeat both presented a nonsignificant negative bias of less than 2% in ejection fraction relative to the reference itSENSE. It was concluded that the proposed MC-CINE significantly improves image quality relative to itSENSE and XD-GRASP, enabling 2D cine from a single heartbeat.

ECG-Free Heartbeat Detection in Seismocardiography Signals via Template Matching.

Cardiac monitoring can be performed by means of an accelerometer attached to a subject's chest, which produces the Seismocardiography (SCG) signal. Detection of SCG heartbeats is commonly carried out by taking advantage of a simultaneous electrocardiogram (ECG). SCG-based long-term monitoring would certainly be less obtrusive and easier to implement without an ECG. Few studies have addressed this issue using a variety of complex approaches. This study proposes a novel approach to ECG-free heartbeat detection in SCG signals via template matching, based on normalized cross-correlation as heartbeats similarity measure. The algorithm was tested on the SCG signals acquired from 77 patients with valvular heart diseases, available from a public database. The performance of the proposed approach was assessed in terms of sensitivity and positive predictive value (PPV) of the heartbeat detection and accuracy of inter-beat intervals measurement. Sensitivity and PPV of 96% and 97%, respectively, were obtained by considering templates that included both systolic and diastolic complexes. Regression, correlation, and Bland-Altman analyses carried out on inter-beat intervals reported slope and intercept of 0.997 and 2.8 ms (R2 > 0.999), as well as non-significant bias and limits of agreement of ±7.8 ms. The results are comparable or superior to those achieved by far more complex algorithms, also based on artificial intelligence. The low computational burden of the proposed approach makes it suitable for direct implementation in wearable devices.

Analytical validation of the modified Westergren method on the automated erythrocyte sedimentation rate analyzer CUBE 30 touch.

Analytical validation of automated erythrocyte sedimentation rate (ESR) analyzers is necessary prior to their implementation into routine practice. Our aim was toperform the analytical validation of the modified Westergren method applied on the CUBE 30 touch analyzer (Diesse, Siena, Italy). Validation included determination of within-run and between-run precision following the Clinical and Laboratory Standards Institute EP15-A3 protocol, comparison with the reference Westergren method, sample stability assessment at both room temperature and 4°C, after 4, 8 and24-h storage, and checking the extent of hemolysis and lipemia interference. Coefficients of variation (CVs) for within-run precision were 5.2% for the normal and 2.6% for the abnormal range, while between-run CVs were 9.4 and 2.2%, respectively. Comparison with the Westergren method (n=191) yielded Spearman's correlation coefficient of 0.93, noconstant nor proportional difference [y=0.4 (95% CI:-1.7-1.0)+1.06 (95% CI: 1.00-1.14)x] and a non-significant mean absolute bias of-2.6mm (95% CI:-5.3-0.2). Lower comparability was evidenced with increasing ESR values, with both constant and proportional differences for ESR values between 40 and 80mm, and above 80mm. Sample stability was not compromised up to 8-h storage both at room temperature (p=0.054) and 4°C (p=0.421). Hemolysis did not affect ESR measurement up to 1.0g/L of free hemoglobin (p=0.089), while lipemia index above 5.0g/L affects the ESR result (p=0.004). This study proved that CUBE 30 touch provides reliable ESR measurement and satisfactory comparability with the reference Westergren methods, with minor variation related to methodological differences.

Rapid MRI Assessment of Long-Axis Strain to Indicate Systolic Dysfunction in Patients With Sickle Cell Disease.

Patients with sickle cell disease (SCD) have a unique form of cardiomyopathy. However, left ventricular ejection fraction (LVEF) is often preserved. Monoplanar long-axis strain (LAS) can be assessed from MRI four-chamber views and may be better at detecting mild systolic dysfunction in these patients. To compare LAS (monoplanar and biplanar) with LVEF as a marker of systolic dysfunction in SCD patients. Retrospective. A total of 20 patients with genetically proven SCD (35 MRI examinations), 39 healthy controls, and 124 patients with systemic iron overload (for validation purposes). 1.5 T/3T. Cine balanced steady-state free-precession. Rapidly assessed biplanar LAS from four- and two-chamber views was correlated with age and compared to LVEF by two operators. For validation, biplanar LAS was compared to global longitudinal strain (GLS) using MRI feature-tracking in 124 patients with systemic iron overload. Bland-Altman analysis. Wilcoxon-Mann-Whitney test and Spearman-rank correlation (correlation coefficient, rS ). Receiver-operating-characteristic (ROC) curve analysis (area under the curve, AUC). Bivariate discriminant analysis. Significance level: P < 0.01. There was strong correlation between biplanar LAS and GLS using feature tracking (rS =0.73). Interoperator agreement showed nonsignificant bias for biplanar LAS (-0.02%; ±95%-agreement interval -2.2%/2.2%, P= 0.9). Biplanar LAS increased significantly with age in controls (rS =0.70). In SCD patients, biplanar LAS was better correlated with age than monoplanar LAS (r2 =0.53, standard error of estimate, SEE=1.4% vs. r2 =0.37;SEE=2.0%). ROC analysis of LVEF, biplanar LAS, and age-adjusted Z-scores Z (LAS(age)) showed AUCs of 0.69, 0.75, and 0.86 for differentiation between SCD patients and controls. Bivariate discriminant analysis of biplanar Z (LAS(age)) and LVEF revealed a sensitivity of 63% and a specificity of 95%. Rapidly assessed biplanar LAS demonstrated high diagnostic accuracy and was an indicator of mild systolic dysfunction in patients with SCD. Biplanar LAS provided more precise measurements than monoplanar, and normalization to age increased diagnostic accuracy. 3. Stage 2.

Wearable in-ear pulse oximetry validly measures oxygen saturation between 70% and 100%: A prospective agreement study.

Postoperative monitoring outside intensive and post-anaesthesia care units is seldom, partly due to lack of suitable and approved systems. We therefore aim to validate the oxygen saturation (SpO2) and pulse rate measurement of the in-ear sensor c-med° alpha with a reference pulse oximeter. This prospective agreement study was conducted in 12 healthy (ASA 1) adult (18-50 years) volunteers according to the EN ISO 80601-2-61. The sitting volunteers were equipped with the finger pulse oximeter Rad-5 and two c-med° alpha sensors in each ear. The inspiratory oxygen content was reduced via a tight-fitting breathing mask to achieve five defined plateaus with stable SpO2 between 99% and 70%. The deviation of the SpO2 and pulse rate measurements of the c-med° alpha from those of the Rad-5 was calculated using the mean square error (Arms). Bias and limits of agreement between both devices were calculated using the Bland-Altman technique. The precision was compared based on the repeatability coefficients. The c-med° alpha measured SpO2 had an Arms = 1.9% relative to the Rad-5, a non-significant bias (-0.1% (-0.2% to 0.0%)), levels of agreement from -4.0% to 3.8%, and the same repeatability coefficient (0.8% vs. 0.8%). The c-med° alpha measured pulse rate did not deviate from the one measured with the certified finger pulse oximeter (bias: 0.1 min-1 (0 to 0.1 min-1), level of agreement: -3.6 to 3.7 min-1, Arms: 1.8 min-1). The c-med° alpha fulfils the EN ISO 80601-2-61 standard and is sufficiently accurate for measuring SpO2 and pulse rate in healthy adults at rest. EUDAMED No. CIV-21-03-036033.

Systematic review and meta-analysis of global prevalence of neurotoxic and hemotoxic snakebite envenomation.

The World Health Organization estimates that there are approximately 5.4 million snakebites and 1.8-2.7 million cases of envenomation, with 81 410-137 880 deaths each year worldwide. To estimate the prevalence of neurotoxic and haemotoxic snakebite envenomation through a comprehensive systematic review and meta-analysis. We searched Medline/PubMed, Scopus and Cochrane Library up to January 2021 using keywords such as snakebite and snake envenomation. Bibliographic and random searches were also performed. Prospective or retrospective observational studies and randomized controlled trials were included for the review. We included 271 of 9711 studies published between 1963 and 2020. The pooled prevalence of snakebite from 188 studies with a total of 207 235 participants showed the highest prevalence in North America (69.20%; 95% confidence interval, CI: 57.06-81.34%) and lowest in Africa (28.10%; 95% CI: 22.22-33.98%). There was a pooled prevalence of 24.94% (95% CI: 22.84-27.03%) for haemotoxicity, with a highest prevalence of coagulopathy (43.76%; 95% CI: 33.15-54.37%). The overall prevalence of neurotoxicity was 38.20% (95% CI: 31.88-44.53%), with a highest prevalence of ptosis (53.57%; 95% CI: 38.51-68.62%). There was a higher prevalence of snakebites in North America. The most prevalent haemotoxicity and neurotoxicity were coagulopathy and ptosis, respectively. The overall quality of evidence was good with a non-significant publication bias.