Reliable Measurement Research Articles

Colloidal Probe Technique Optimization for Determination of Young's Modulus of Soft Adhesive Hydrogels.

Atomic force microscopy (AFM) is a valuable tool for determining the Young's modulus of a wide range of materials. However, it faces challenges, particularly when assessing adhesive materials like soft poly(N-isopropylacrylamide) (pNIPAM) hydrogels. This study focuses on enhancing the consistency and reliability of AFM measurements by functionally modifying AFM spherical tip cantilevers to address substrate adhesion issues with these hydrogels. Specifically, hydrophobic functionalization with 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOCTS) emerged as the most effective approach, yielding consistent and reliable Young's modulus data across various pNIPAM hydrogel samples. This work highlights the importance of optimizing data acquisition in AFM, rather than relying on postprocessing, to reduce inconsistencies in Young's modulus assessment.

Evaluation of occlusal force changes in orthognathic surgery using force sensing sensors in 3 years of follow-up

Purpose: The aimof this study was to test a prototype device called Occlusal Force Diagnostic System in relation to occlusal force adaptation following orthognathic surgery. Methods: Retrospective study of 10 patients scheduled for a bimaxillary osteotomy involving a combination of maxillary Le Fort I impaction procedure coupled with a sagittal split advancement of the mandible; in a 3 years follow-up period. Results: The selection of examiner is not a variable that affects the occlusal force (N) measured by FSS sensors in any of the experimental conditions tested. The sensor position and the surgery recovery time affects the occlusal force irrespective of the examiner selection and/or the surgery recovery time. Conclusion: The piezoelectric sensors used in the present study have shown high reliability and validity of measurement. The surgery recovery time impacts the occlusal force (N), with a 50% increase in occlusal force (N) measured after 6 months post-surgery, with the value keeping stable at 36 months. This suggests that the patient is only fully recovered from the functional point-of-view at 6 months, having from that point on an improved and stable masticatory function.

Estimation of biological variance in coherent Raman microscopy data of two cell lines using chemometrics.

Broadband Coherent Anti-Stokes Raman Scattering (BCARS) is a valuable spectroscopic imaging tool for visualizing cellular structures and lipid distributions in biomedical applications. However, the inevitable biological changes in the samples (cells/tissues/lipids) introduce spectral variations in BCARS data and make analysis challenging. In this work, we conducted a systematic study to estimate the biological variance in BCARS data of two commonly used cell lines (HEK293 and HepG2) in biomedical research. The BCARS data were acquired from two different experimental setups (Leibniz Institute of Photonics Technology (IPHT) in Jena and Politecnico di Milano (POLIMI) in Milano) to evaluate the reproducibility of results. Also, spontaneous Raman data were independently acquired at POLIMI to validate those results. First, Kramers-Kronig (KK) algorithm was utilized to retrieve Raman-like signals from the BCARS data, and a pre-processing pipeline was subsequently used to standardize the data. Principal component analysis - Linear discriminant analysis (PCA-LDA) was performed using two cross-validation (CV) methods: batch-out CV and 10-fold CV. Additionally, the analysis was repeated, considering different spectral regions of the data as input to the PCA-LDA. Finally, the classification accuracies of the two BCARS datasets were compared with the results of spontaneous Raman data. The results demonstrated that the CH band region (2770-3070 cm-1) and spectral data in the 1500-1800 cm-1 region have significantly contributed to the classification. A maximum of 100% balanced accuracies were obtained for the 10-fold CV for both BCARS setups. However, in the case of batch-out CV, it is 92.4% for the IPHT dataset and 98.8% for the POLIMI dataset. This study offers a comprehensive overview for estimating biological variance in biomedical applications. The insights gained from this analysis hold promise for improving the reliability of BCARS measurements in biomedical applications, paving the way for more accurate and meaningful spectroscopic analyses in the study of biological systems.

Reliability of variability and complexity measures for task and task-free BOLD fMRI.

Brain activity continuously fluctuates over time, even if the brain is in controlled (e.g., experimentally induced) states. Recent years have seen an increasing interest in understanding the complexity of these temporal variations, for example with respect to developmental changes in brain function or between-person differences in healthy and clinical populations. However, the psychometric reliability of brain signal variability and complexity measures-which is an important precondition for robust individual differences as well as longitudinal research-is not yet sufficiently studied. We examined reliability (split-half correlations) and test-retest correlations for task-free (resting-state) BOLD fMRI as well as split-half correlations for seven functional task data sets from the Human Connectome Project to evaluate their reliability. We observed good to excellent split-half reliability for temporal variability measures derived from rest and task fMRI activation time series (standard deviation, mean absolute successive difference, mean squared successive difference), and moderate test-retest correlations for the same variability measures under rest conditions. Brain signal complexity estimates (several entropy and dimensionality measures) showed moderate to good reliabilities under both, rest and task activation conditions. We calculated the same measures also for time-resolved (dynamic) functional connectivity time series and observed moderate to good reliabilities for variability measures, but poor reliabilities for complexity measures derived from functional connectivity time series. Global (i.e., mean across cortical regions) measures tended to show higher reliability than region-specific variability or complexity estimates. Larger subcortical regions showed similar reliability as cortical regions, but small regions showed lower reliability, especially for complexity measures. Lastly, we also show that reliability scores are only minorly dependent on differences in scan length and replicate our results across different parcellation and denoising strategies. These results suggest that the variability and complexity of BOLD activation time series are robust measures well-suited for individual differences research. Temporal variability of global functional connectivity over time provides an important novel approach to robustly quantifying the dynamics of brain function. PRACTITIONER POINTS: Variability and complexity measures of BOLD activation show good split-half reliability and moderate test-retest reliability. Measures of variability of global functional connectivity over time can robustly quantify neural dynamics. Length of fMRI data has only a minor effect on reliability.

Layer Contour Geometric Characterization in MEX/P through CIS-Based Adaptive Edge Detection

The industrial adoption of material extrusion of polymers (MEX/P) is hindered by the geometric quality of manufactured parts. Contact image sensors (CISs), commonly used in flatbed scanners, have been proposed as a suitable technology for layer-wise characterization of contour deviations, paving the way for the application of corrective measures. Nevertheless, despite the high resolution of CIS digital images, the accurate characterization of layer contours in MEX/P is affected by contrast patterns between the layer and the background. Conventional edge-recognition algorithms struggle to comprehensively characterize layer contours, thereby diminishing the reliability of deviation measurements. In this work, we introduce a novel approach to precisely locate contour points in the context of MEX/P based on evaluating the similarity between the grayscale pattern near a particular tentative contour point and a previously defined gradient reference pattern. Initially, contrast patterns corresponding to various contour orientations and layer-to-background distances are captured. Subsequently, contour points are identified and located in the images, with coordinate measuring machine (CMM) verification serving as a ground truth. This information is then utilized by an adaptive edge-detection algorithm (AEDA) designed to identify boundaries in manufactured layers. The proposed method has been evaluated on test targets produced through MEX/P. The results indicate that the average deviation of point position compared to that achievable with a CMM in a metrology laboratory ranges from 8.02 µm to 13.11 µm within the experimental limits. This is a substantial improvement in the reliability of contour reconstruction when compared to previous research, and it could be crucial for implementing routines for the automated detection and correction of geometric deviations in AM parts.

The Influence of Accommodative Demand on Ocular Aberrations: A Study of Zernike Coefficients Repeatability and Variability

Purpose To evaluate the repeatability of the Zernike coefficients in healthy eyes when monocular accommodation was stimulated at different vergences demands. Methods A total of 36 right eyes from healthy volunteers were prospectively and consecutively recruited for this study. Wavefront aberrometry was conducted to objectively characterize the ocular optical quality during accommodation, from the individual’s far point to a 5 D accommodation demand in steps of 0.5 D. The repeatability of Zernike coefficients up to the fourth order was assessed by calculating the within-eye repeatability (Sw), the coefficient of repeatability (CR), the coefficient of variation (CV), and the intraclass correlation coefficient (ICC) as an indicator of measurement reliability. Results Correlation among repeated measurements showed high reliability (ICC > 0.513) for all parameters measured except some fourth-order Zernike coefficients, C(4, −4) (ICC < 0.766), C(4, −2) (ICC < 0.875), C(4, 2) (ICC < 0.778) and C(4, 4) (ICC < 0.811). Greater repeatability and less variability were obtained for high-order Zernike coefficients (CR < 0.154), although an increase in CR in the coefficients analyzed was observed with increasing accommodative demand. No clear trend was evident in CV; however, it was observed that the low-order Zernike coefficients exhibit lower CV (CV < 1.93) compared to the high-order Zernike coefficients (CV > 0). Conclusions The reliability of Zernike coefficients up to the fourth order in healthy young individuals demonstrated a strong consistency in measuring terms up to the fourth order, with more variability observed for high-order terms. The Zernike coefficients up to the third order exhibited the highest level of repeatability.

The Ambiguous Cue Task: Measurement reliability of an experimental paradigm for the assessment of interpretation bias and associations with mental health.

Interpretation biases in the processing of ambiguous affective information are assumed to play an important role in the onset and maintenance of emotional disorders. Reports of low reliability for experimental measures of cognitive biases have called into question previous findings on the association of these measures with markers of mental health and demonstrated the need to systematically evaluate measurement reliability for measures of cognitive biases. We evaluated reliability and correlations with self-report measures of mental health for interpretation bias scores derived from the Ambiguous Cue Task (ACT), an experimental paradigm for the assessment of approach-avoidance behavior towards ambiguous affective stimuli. For a non-clinical sample, the measurement of an interpretation bias with the ACT showed high internal consistency (rSB = .91 - .96, N = 354) and acceptable 2-week test-retest correlations (rPearson = .61 - .65, n = 109). Correlations between the ACT interpretation bias scores and mental health-related self-report measures of personality and well-being were generally small (r ≤ |.11|) and statistically not significant when correcting for multiple comparisons. These findings suggest that in non-clinical populations, individual differences in the interpretation of ambiguous affective information as assessed with the ACT do not show a clear association with self-report markers of mental health. However, in allowing for a highly reliable measurement of interpretation bias, the ACT provides a valuable tool for studies considering potentially small effect sizes in non-clinical populations by studying bigger samples as well as for work on clinical populations, for which potentially greater effects can be expected.

Is Quantitative Radiographic Measurement of Acetabular Version Reliable in Anteverted and Retroverted Hips?

The acetabular version is crucial for hip function, and its accurate assessment is necessary for treating patients with hip disorders. Current studies reveal discrepancies in the precision of quantitative radiographic measurements versus CT measurements, but there is a lack of focused analysis on anteverted versus retroverted hips. This study aims to fill this gap by directly comparing the reliability of these two methods in assessing varied hip configurations. (1) How reliable are quantitative radiographic and CT methods in measuring the acetabular version angle? (2) Is there any difference in the reliability of acetabular version angle measurements using radiography compared with CT in anteverted and retroverted hips? (3) What is the extent of variation in acetabular version measurements when quantitative radiographic and CT methods are compared in anteverted and retroverted hips? We searched our image archives for patients who had received both radiographs and CT scans between January 2020 and June 2022 and found 84 patients who met the criteria. From these patients, we selected those who presented with hip pain of different causes and who had no previous elective and/or hip trauma surgery, no hip dysplasia, and results from adequate radiographic examinations. Accordingly, 73% (61 of 84) of the patients were included in this study, and angle measurements were performed on both hips of these patients (122 hips). Standardized positioning was meticulously verified for all plain radiographs and CT scans utilized in the measurement process. We measured quantitative angles and assessed qualitative signs of retroversion, including crossover, posterior wall, and ischial spine findings. We considered a hip with at least one of these findings a retroverted hip, and the hips without these findings were included in the anteverted hip group. Three clinicians took measurements independently. Measurement reliability and agreement were examined using intraobserver and interobserver intraclass correlation coefficients (ICCs), with statistical analyses including paired and independent t-tests. To investigate the reliability of quantitative radiographic and CT methods, we assessed both intraobserver and interobserver agreements. To explore the reliability disparities in measuring the acetabular version via radiography and CT in anteverted and retroverted hips, we analyzed the agreement between measurements from both modalities in the hip groups. Furthermore, to evaluate the degree of variation in acetabular version measurements when comparing quantitative radiographic and CT methods in anteverted and retroverted hips, we utilized paired and independent t-tests to examine the measurement differences within these hip categories. The difference between radiographic and CT measurements was also evaluated by Bland-Altman analysis. Quantitative radiographic measurements showed intraobserver and interobserver reliabilities with ICCs of 0.87 (95% CI 0.84 to 0.91) and 0.78 (95% CI 0.75 to 0.82), respectively, and CT measurements demonstrated higher reliabilities with ICCs of 0.92 (95% CI 0.90 to 0.93) and 0.91 (95% CI 0.89 to 0.92), respectively. The reliability of measuring the acetabular version in anteverted hips was moderate, with an ICC of 0.59 (95% CI 0.49 to 0.68). In contrast, retroverted hips showed an ICC of -0.41 (95% CI -1.17 to 0.08), indicating a lack of consistency between quantitative radiographic and CT measurements. Variation in measurement on plain radiographs in anteverted hips was less than that of retroverted hips (mean ± SD absolute difference between anteverted hips and retroverted hips 3° ± 3° versus 6° ± 4°; p = 0.0001), indicating greater variability in the radiographic measurement of retroverted hips. According to Bland-Altman analysis, we observed that the difference between radiographic and CT measurements was well outside the CI, especially in retroverted hips. Although quantitative radiographic measurement demonstrates acceptable intraobserver and interobserver reliabilities, its precision is lower than that of CT-based measurements. Specifically, quantitative radiographic methods are prone to a larger margin of error in retroverted hips. For more precise assessments of acetabular version, especially in retroverted hips, we recommend using CT measurement instead of the radiographic method. Level III, diagnostic study.

Patient experiences with blood pressure measurement methods for hypertension diagnosis: Qualitative findings from the BP-CHECK study.

Out-of-office blood pressure (BP) measurement is recommended when making a new hypertension diagnosis. In practice, however, hypertension is primarily diagnosed using clinic BP. The study objective was to understand patient attitudes about accuracy and patient-centeredness regarding hypertension diagnostic methods. Qualitative study within a randomized controlled diagnostic study conducted between May 2017 and March 2019 comparing the accuracy and acceptability of BP measurement methods among patients in an integrated healthcare delivery system. All participants completed 24-hour ambulatory blood pressure monitoring (ABPM), plus either clinic BP, home BP monitoring (HBPM), or kiosk BP diagnostic testing. Qualitative interviewees (aged 31-76 years, n=35) were recruited from the main study. Participants who completed HBPM found it to be comfortable and low burden, and believed it produced accurate results. Participants in the clinic arm described clinic measurements as inconvenient. Participants in the kiosk arm overall did not favor kiosks due to concerns about accuracy and privacy. Participants described ABPM as the most accurate method due to repeated measurements over the 24-hour period in real-world contexts, but many found it uncomfortable and disruptive. Participants also noted methods that involved repeated measures such as HBPM and ABPM particularly influenced their understanding of whether or not they had hypertension. Hypertension diagnostic methods that include more BP measurements help patients gain a deeper understanding of BP variability and the lower reliability of infrequent measurements in clinic. These findings warrant implementing strategies to enhance out-office BP diagnostic testing in primary care.

Mobile toolbox (MTB) remote measures of executive function and processing speed: development and validation.

The ability to remotely monitor cognitive skills is increasing with the ubiquity of smartphones. The Mobile Toolbox (MTB) is a new measurement system that includes measures assessing Executive Functioning (EF) and Processing Speed (PS): Arrow Matching, Shape-Color Sorting, and Number-Symbol Match. The purpose of this study was to assess their psychometric properties. MTB measures were developed for smartphone administration based on constructs measured in the NIH Toolbox® (NIHTB). Psychometric properties of the resulting measures were evaluated in three studies with participants ages 18 to 90. In Study 1 (N = 92), participants completed MTB measures in the lab and were administered both equivalent NIH TB measures and other external measures of similar cognitive constructs. In Study 2 (N = 1,021), participants completed the equivalent NIHTB measures in the lab and then took the MTB measures on their own, remotely. In Study 3 (N = 168), participants completed MTB measures twice remotely, two weeks apart. All three measures exhibited very high internal consistency and strong test-retest reliability, as well as moderately high correlations with comparable NIHTB tests and moderate correlations with external measures of similar constructs. Phone operating system (iOS vs. Android) had a significant impact on performance for Arrow Matching and Shape-Color Sorting, but no impact on either validity or reliability. Results support the reliability and convergent validity of MTB EF and PS measures for use across the adult lifespan in remote, self-administered designs.

LIF measurement in a partially saturated and partially absorbed regime

The problems of laser-induced fluorescence (LIF) measurements in a partially saturated regime with spatially dependent laser intensity in the sample (caused by absorption) are analyzed. The obtained equations are tested by means of LIF of free tellurium atoms in a plasma of an atmospheric pressure dielectric barrier discharge (DBD) by comparing fluorescence and absorption measurements. The results show a high reliability of LIF measurements.

Comparing the reliability of physical activity questionnaires in community-dwelling adults with stroke

ABSTRACT Background Physical activity (PA) is important for people with stroke, but the reliability of PA questionnaires used in this population has been relatively unexplored. Objective To compare the internal consistency, test-retest, and absolute reliability of 3 commonly used PA questionnaires in adults with stroke. Methods Participants reported their PA levels twice, 2–3 days apart, using the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD), International Physical Activity Questionnaire (IPAQ), and Global Physical Activity Questionnaire (GPAQ). Intraclass correlation coefficients (ICC2,1) were calculated for test-retest reliability, Cronbach’s alpha (α) for internal consistency, and standard error of measurement (SEM) and minimal detectable change (MDC95) for absolute reliability. Results Twenty-eight people (64.4 years, 50% female, 5.2 years post-stroke) participated. Internal consistency was acceptable for total scores on the IPAQ ( α = 0.79) and GPAQ ( α = 0.74), but only domain-level scores for the GPAQ ( α = 0.71–0.88). In the full sample, test-retest reliability was good for the PASIPD (ICC2,1 = 0.83) but poor for the IPAQ and GPAQ (ICC2,1 <0.50). After excluding participants self-reporting true changes in PA, all questionnaires had good test-retest reliability (ICC2,1 = 0.77–0.88). SEM and MDC95 were lowest for the PASIPD (188.8 and 523.3 MET-minutes/week, respectively). Conclusions In adults with stroke, the IPAQ and GPAQ had adequate total-questionnaire internal consistency, and the GPAQ had acceptable domain-level internal consistency. When true change in PA did not occur, test-retest reliability was good for all questionnaires. We suggest clinicians and rehabilitation scientists can use any of the three questionnaires, but may consider the GPAQ due to acceptable internal consistency and test-retest reliability.

Comparing the reliability of physical activity questionnaires in community-dwelling adults with stroke

ABSTRACT Background Physical activity (PA) is important for people with stroke, but the reliability of PA questionnaires used in this population has been relatively unexplored. Objective To compare the internal consistency, test-retest, and absolute reliability of 3 commonly used PA questionnaires in adults with stroke. Methods Participants reported their PA levels twice, 2–3 days apart, using the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD), International Physical Activity Questionnaire (IPAQ), and Global Physical Activity Questionnaire (GPAQ). Intraclass correlation coefficients (ICC2,1) were calculated for test-retest reliability, Cronbach’s alpha (α) for internal consistency, and standard error of measurement (SEM) and minimal detectable change (MDC95) for absolute reliability. Results Twenty-eight people (64.4 years, 50% female, 5.2 years post-stroke) participated. Internal consistency was acceptable for total scores on the IPAQ ( α = 0.79) and GPAQ ( α = 0.74), but only domain-level scores for the GPAQ ( α = 0.71–0.88). In the full sample, test-retest reliability was good for the PASIPD (ICC2,1 = 0.83) but poor for the IPAQ and GPAQ (ICC2,1 <0.50). After excluding participants self-reporting true changes in PA, all questionnaires had good test-retest reliability (ICC2,1 = 0.77–0.88). SEM and MDC95 were lowest for the PASIPD (188.8 and 523.3 MET-minutes/week, respectively). Conclusions In adults with stroke, the IPAQ and GPAQ had adequate total-questionnaire internal consistency, and the GPAQ had acceptable domain-level internal consistency. When true change in PA did not occur, test-retest reliability was good for all questionnaires. We suggest clinicians and rehabilitation scientists can use any of the three questionnaires, but may consider the GPAQ due to acceptable internal consistency and test-retest reliability.

Enhancing Accuracy In 3D Defocusing Particle Tracking Using 3D-Printed Ramp

Three-dimensional defocusing particle tracking velocimetry (3D DPTV) is an emerging tool for investigating fluid motion within microfluidic devices, where observation is typically limited to a single direction. This technique enables the reconstruction of 3D flow fields by analyzing the defocused particle images. The accuracy of 3D DPTV significantly relies on the collection of a proper calibration image stack containing particle images with precisely known defocus distances. One major challenge is to insert a microscale calibration target inside the microfluidic devices due to the small length scales of microfluidic devices. While the alternative approaches such as using tilted glass slides or conducting z-scans of particles fixed at the bottom wall, face several limitations. Here, we present the application of a two-photon polymerization (2PP) based method to manufacture a microscale reference ramp as the calibration target. We demonstrate the fabrication of a precise reference ramp structure that spans the desired calibration range to enhance accuracy in 3D defocusing particle tracking. We experimentally and computationally compare the result with the commonly employed methods to obtain the calibration image stack. The performance of the 2PP-based calibration ramps is compared with the z-scanning method using the General Particle tracking (GPTV). The results demonstrate that the z-scanning method underestimates the defocused distances compared to the ground truth provided by the ramp approach, with the error increasing as the defocused distance grows. The integration of microscale calibration targets using 2PP fabrication method offers a significant advancement in the reliability and accuracy of 3D DPTV measurements in microfluidic systems. By enabling precise, device-specific calibration, this approach can enhance the fidelity of flow field reconstructions, benefiting a wide range of microfluidic applications that rely on detailed velocity field information.

Impact of Trunk Stabilization Training on Cricketers with Chronic Non-Specific Low Back Pain

Background: The endeavour of this study was to check the impact of trunk stabilization training on cricketers suffering from chronic non-specific low back pain. Objectives: The objectives of the study was to examine the effects of trunk stabilizing exercises in cricketers with chronic low back pain for the change in level of pain, disability and improvement of endurance of trunk muscles. Methods: The related literature was searched and reviewed for the efficacy of interventions, reliability and validity of outcome measures. Quasi-experimental approach was chosen for conducting the study with pre-intervention and post-intervention evaluation of the outcomes. Convenient sampling and random allocation in to groups were used to select and assign the sample that comprised of 15 subjects in each groups out of total sample size of 30. Standardized tools such as VAS for evaluating the pain, modified Oswestry LBP disability questionnaire for evaluating disability trunk stabilization exercises to check improvement of endurance of trunk muscles were utilized. Trunk stabilization exercises with warm up, stretching and cool down were given to group A (experimental group). Hitting pads and back care advice was given in the form of a leaflet to the group B (control group). Results: The data were analysed with help of SPSS version 21. Paired t-test was done for intra group analysis and un-paired t-test for intergroup analysis. The results of the study suggested that there was significant difference between the difference in mean values of pain, disability and endurance between the group-A&amp;B. The findings also suggested that there was significant difference within group-A and group-B for pain, disability and endurance. Conclusion: This study concluded that on both groups, the significant reductions were seen in pain, disability and endurance of subjects after 8 weeks of intervention. However, there was more reduction in pain, disability and endurance in group-A (experimental group)

Reliability, concurrent validity, and clinical feasibility of measurement methods determining volume in patients with lower limb lymphedema and healthy controls

Purpose To investigate reliability, concurrent validity, and clinical feasibility of measurements assessing volume in patients with lower limb lymphedema (LLL) and healthy controls. Materials and methods To investigate intra- and interrater reliability, 47 patients with LLL and 30 healthy controls were assessed three times by two assessors. To investigate between session reliability, 50 participants were reassessed two weeks later. Each assessment included measurements of the midline region (hip circumference; suprapubic volume), leg volume (perimeter every 4 cm; Perometer®), and foot volume (water displacement; figure-of-eight method). Concurrent validity was assessed with correlation coefficients. Measurements were timed and practical limitations were reviewed. Clinical trial registration number: NCT: 05269264. Results Measurements of the total volume of different regions showed weak to very high intraclass correlation coefficients (ICCs) (0.131–998). Absolute and relative volume differences had lower ICC values (0.360–0.976). A strong correlation was found between the total volumes of the same region. The Perometer® and figure-of-eight method were the fastest method for leg and foot volume, respectively. Conclusions The assessed total volumes might be more valuable in assessing the evolution of volume in bilateral LLL than the calculated absolute and relative differences between both limbs. The Perometer® and figure-of-eight method were the most time efficient for leg and foot volume, respectively. Implications for rehabilitation Lymphedema is a chronic condition for which a reliable and clinically feasible assessment of volume is essential for the diagnosis, treatment decisions, and the evaluation of the treatment. This study shows that the total leg/foot volumes were more reliable than the calculated absolute and relative differences between both limbs and could therefore more valuable to evaluate bilateral lower limb lymphedema. For the assessment of leg volume, the Perometer® was the most reliable and fastest method. For the evaluation of the foot volume, the figure-of-eight method was overall the best method.

Reliability, concurrent validity, and clinical feasibility of measurement methods determining volume in patients with lower limb lymphedema and healthy controls

Purpose To investigate reliability, concurrent validity, and clinical feasibility of measurements assessing volume in patients with lower limb lymphedema (LLL) and healthy controls. Materials and methods To investigate intra- and interrater reliability, 47 patients with LLL and 30 healthy controls were assessed three times by two assessors. To investigate between session reliability, 50 participants were reassessed two weeks later. Each assessment included measurements of the midline region (hip circumference; suprapubic volume), leg volume (perimeter every 4 cm; Perometer®), and foot volume (water displacement; figure-of-eight method). Concurrent validity was assessed with correlation coefficients. Measurements were timed and practical limitations were reviewed. Clinical trial registration number: NCT: 05269264. Results Measurements of the total volume of different regions showed weak to very high intraclass correlation coefficients (ICCs) (0.131–998). Absolute and relative volume differences had lower ICC values (0.360–0.976). A strong correlation was found between the total volumes of the same region. The Perometer® and figure-of-eight method were the fastest method for leg and foot volume, respectively. Conclusions The assessed total volumes might be more valuable in assessing the evolution of volume in bilateral LLL than the calculated absolute and relative differences between both limbs. The Perometer® and figure-of-eight method were the most time efficient for leg and foot volume, respectively. Implications for rehabilitation Lymphedema is a chronic condition for which a reliable and clinically feasible assessment of volume is essential for the diagnosis, treatment decisions, and the evaluation of the treatment. This study shows that the total leg/foot volumes were more reliable than the calculated absolute and relative differences between both limbs and could therefore more valuable to evaluate bilateral lower limb lymphedema. For the assessment of leg volume, the Perometer® was the most reliable and fastest method. For the evaluation of the foot volume, the figure-of-eight method was overall the best method.

Addressing variability in cell electrorotation through holographic imaging and correction factors

This study addresses the variations observed in electrorotation measurements due to cell positioning and movement. Electrorotation provides a non-disruptive method for inferring the electrical properties of individual cells. However, its widespread adoption is hindered by significant variation in the observed speed. By mitigating the impact of positional dependencies and other influencing factors, our methodology opens avenues for broader applications of electrorotation in single-cell analysis without the need for complex setups to trap and retain the cell in place. Our novel approach combines multi-plane imaging with mathematical treatment of rotation data. This method uses a conventional quadrupole chip and lens-free imaging to track cell movement, resulting in a simpler design and set-up. Through numerical simulations incorporating cell coordinates, chip design, and experimental parameters, we calculate the variation in torque for each position. These values serve as the basis for the correction factors. Validation experiments with T-lymphocytes and fibroblasts show that the correction factors reduce electrorotation speed variation due to cell movement, with an average reduction to 21% and 18%, respectively. These corrections also revealed previously concealed changes in cell properties, in response to external stimuli, thereby enhancing the reliability of measurements and enabling broader applications in single-cell analysis.

Validity and Reliability of Sensor-based Measures of Lower Limb Range of Motion in Soccer Players: a Cross-sectional Study.

A deficit in range of motion (ROM) is considered a risk factor for lower extremity injuries in soccer. Analog goniometers are used to measure the ROM of a joint. Sensor-based methods are increasingly being developed, but their quality of testing has not been sufficiently investigated. The purpose of this study was to determine the agreement and the intra- and inter-tester reliability of sensor-based lower extremity ROM measures in soccer players. 36 symptom-free male amateur soccer players (age: 26.3±4.7 years) were included in the study. Three out of five physiotherapists were randomly selected to perform the measurements. Two testers performed the measurements (1. ROM knee from sitting; 2. extension deficit knee from sitting; 3. ROM knee from standing; 4. ROM ankle dorsiflexion [DF] during lunge; 5. ROM ankle plantar flexion [PF] while sitting on a chair) with the digital sensor (index test). The third examiner performed the measurements with the analog goniometer using the neutral-zero method with the subjects in the supine position (reference standard). Pearson's correlation coefficient r, Bland-Altman analysis (BAA), and intraclass correlation coefficient (ICC) were used for statistical analysis (p≤0.05). Only measurements 4 and 5 showed acceptable mean differences of 8.4° (DF) and -10.2° (PF) in the BAA. Measurement 1 showed a moderate correlation (r=0.582). The sensor-based measurements of knee and ankle ROM revealed excellent intra- and inter-tester reliability (ICC =0.949-0.986; ICC =0.895-0.968). However, they showed limited agreement with the established reference standard used here, which can be explained by the different starting positions between the index test and the reference standard.

Reliability of anthropometric measurements of a digi-board in comparison to an analog height board in Namibian children under 5 years.

Poor measurement quality has set back the utility of anthropometry in defining childhood malnutrition, prompting calls for alternative measurement techniques. This study aimed to assess the reliability of anthropometric measurements using a digital height board in comparison to an analog height board in Namibian children under 5 years of age. A cross-sectional, descriptive study was conducted (n = 425) between the age of 6 and 59 months, using anthropometric measurements of weight, height and mid-upper arm circumference. Two trained enumerators each collected four height measurements of each child: two using an analog height board and two using a digi-board. The repeated height measurements between and within the enumerators were used to determine intra- and interobserver reliability. Reliability of the digi-board was assessed using the technical error of measurement (TEM), relative TEM (%TEM), intraclass correlation and a Bland-Altman analysis to assess the agreement between the two methods. In all these assessments, the analog height board was considered as the gold standard and used for comparison. The digi-board showed superiority to the analog height board in terms of reliability (analog TEM = 0.22, digi-board TEM = 0.16). Although the digi-board has potential to improve child anthropometry, further clinical and large survey studies are needed to validate the used of this tool in routine population-based surveys.