bland altman method
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Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 436
Author(s):  
Rémy Hubaut ◽  
Romain Guichard ◽  
Julia Greenfield ◽  
Mathias Blandeau

Musculoskeletal disorders in the workplace are a growing problem in Europe. The measurement of these disorders in a working environment presents multiple limitations concerning equipment and measurement reliability. The aim of this study was to evaluate the use of inertial measurement units against a reference system for their use in the workplace. Ten healthy volunteers conducted three lifting methods (snatching, pushing, and pulling) for manhole cover using a custom-made tool weighting 20 and 30 kg. Participants’ back and dominant arm were equipped with IMU, EMG, and reflective markers for VICON analysis and perception of effort was estimated at each trial using a Visual Analog Scale (VAS). The Bland–Altman method was used and results showed good agreement between IMU and VICON systems for Yaw, Pitch and Roll angles (bias values < 1, −4.4 < LOA < 3.6°). EMG results were compared to VAS results and results showed that both are a valuable means to assess efforts during tasks. This study therefore validates the use of inertial measurement units (IMU) for motion capture and its combination with electromyography (EMG) and a Visual Analogic Scale (VAS) to assess effort for use in real work situations.


2021 ◽  
pp. 112067212110692
Author(s):  
Efthymios Karmiris ◽  
Konstantinos Tsiripidis ◽  
Panos S Gartaganis ◽  
Styliani Totou ◽  
Maria-Giannoula Vasilopoulou ◽  
...  

Purpose To assess the agreement among four types of intraocular pressure (IOP) measurements: IOP obtained by Goldmann applanation tonometer (IOP-GAT),IOP obtained by an air-puff tonometer (Nidek NT-510)(IOP-NCT), the non-corrected IOP obtained by the Corneal Visualization Scheimpflug Technology (IOP-Corvis) and the biomechanically corrected IOP obtained by the Corvis ST (bIOP-Corvis) in healthy patients with a broad spectrum of IOP values. Methods: This prospective, observational study recruited 113 healthy individuals. Each patient underwent IOP evaluation via GAT, Nidek NT-510 and Corvis ST. Difference in mean in IOP readings was assessed by one-way repeated-measures analysis of variance (ANOVA).Tonometer intermethod agreement was assessed by the Bland-Altman method. The difference between the four IOP measurements was correlated against corneal (CCT) and age with Pearson’s correlation test. Results: IOP-Corvis showed the highest values (16.59  ±  3.08 mmHg),followed by IOP-NCT (16.05  ±  3.43 mmHg), IOP-GAT (15.62 ± 3.08 mmHg) and bIOP-Corvis (15.10 ± 2.67 mmHg).There were statistically significant differences in IOP measurements among all the ANOVA pairwise comparisons except between IOP-GAT and bIOP-Corvis ( p = 0.07),as well as between IOP-GAT and IOP-NCT ( p = 0.25). Bland Altman analysis revealed a notable bias (all p < 0.05) among IOP-GAT and bIOP-Corvis, IOP-GAT and IOP-Corvis, IOP-GAT and IOP-NCT, bIOP-Corvis and IOP-Corvis, bIOP-Corvis and IOP-NCT,IOP-Corvis and IOP-NCT of 0.51, −0.97, −0.43, −1.49, −0.95, 0.53 mmHg respectively. We observed a strong correlation of the difference between bIOP-Corvis and IOP-Corvis with CCT and patient age. Conclusion: Compared with GAT and Nidek NT-510, the Corvis-derived IOPs were recorded either the highest as IOP-Corvis or the lowest as bIOP-Corvis. Even if the differences among the tonometers were relatively small, the IOP values obtained with the Corvis ST, NCT and GAT were not interchangeable.


Author(s):  
Anke De Koninck ◽  
◽  
Álvaro Azevedo ◽  
Mónica Cardoso ◽  
Alexandra Teixeira ◽  
...  

Objective: To evaluate the potential of the buccolingual dimension of the permanent mandibular canine roots as a sex estimator, using midsagittal cone-beam computed tomography images. Methods: In this retrospective study, 58 Portuguese patients (27 female and 31 male) aged 18-60 years were assessed. The maximum buccolingual dimension of the cervical root was measured in the midsagittal plane through cone-beam computed tomography images. The Bland-Altman method was applied for the reliability analysis, and a receiver operating characteristics (ROC) curve was obtained for accuracy analysis. Results: The buccolingual root dimension on the mandibular canine showed statistically significant differences between sexes (t56 df = 4.871; p<0.0005). The optimal cut-off to differentiate males from females was 6.64 mm. The area under the curve (AUC) was 83.5% (p<0.0005). An overall accuracy of 79% was obtained. The percentage of males correctly estimated was 77.4%, compared to 81.5% of females. Conclusions: Our data suggest that canines’ buccolingual root dimension can serve as a complementary tool for sex estimation in a forensic context.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Saurabh Kumar Gupta ◽  
Dievya Gohil ◽  
Girish Ch. Panigrahi ◽  
Swati Vaykar ◽  
Pallavi Rane ◽  
...  

Abstract Objectives Autoanalyzers are used in clinical haematology for analysis of blood samples in clinical as well as in nonclinical studies. The results from these analyzers vary from machine to machine. In this study, we compared the lymphocyte and neutrophil count of mouse blood between ADVIA 2120i, Horiba Yumizen H2500 and CellaVision analyzers against manual counting as gold standard. Methods Blood samples from 28 female BALB/c mice were collected and analyzed. Agreement between different autoanalyzers and manual counting were determined by Bland–Altman method. Results A high level of agreement was found between CellaVision and manual technique for lymphocyte (Bias=4.75, 95% limits of agreement −14 to 24) and neutrophil count (Bias=0.68 (−17 to 19)). Agreement in lymphocyte count was also observed between ADVIA and manual counting, but to a lesser extent compared to CellaVision (Bias=13.9 (−10.45 to 38.27)). However, no agreement was observed for ADVIA (Neutrophils), Horiba (lymphocytes and neutrophils) with manual counting. Conclusions Our data suggests that CellaVision could be used for the differential counting of neutrophil and lymphocytes in mouse blood sample.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Weiwei Chen ◽  
Jing Fu ◽  
Ali Sun ◽  
Lei Li ◽  
Yunyun Sun ◽  
...  

Abstract Background Decreased best corrected visual acuity among children should be treated early in life, and vision screening in schoolchildren is an efficient and feasible selection for developing countries. Thus, the screening accuracy of different visual acuity tests is the key point for making vision screening strategies. The present study aims to explore the screening accuracy of uncorrected visual acuity (UCVA) and pin-hole corrected visual acuity (PCVA) using different vision chart in the detection of decreased best-corrected visual acuity (BCVA) among schoolchildren. Methods Grade one primary schoolchildren in urban Lhasa with data of UCVA using tumbling E chart (UCVAE), PCVA using tumbling E chart (PCVAE), UCVA using Lea Symbols chart (UCVAL), PCVA using Lea Symbols chart (PCVAL) and BCVA using Lea Symbols chart were reviewed. Decreased BCVA was defined as BCVA≤20/32(≥0.2 logMAR). Difference, reliability, and diagnostic parameters in the detection of decreased BCVA of different visual acuity results were analyzed. Results Overall, 1672 children aged 6.58 ± 0.44 years fulfilling the criteria. The prevalence of decreased BCVA was 6.8%. Although no significant differences were found between UCVAE vs UCVAL (p = .84, paired t-test) as well as PCVAE vs PCVAL (p = .24), the ICC between them was low (0.68 and 0.57, respectively). The average difference between BCVA and UCVAE, UCVAL, PCVAE, PCVAL was logMAR -0.08 (− 0.37, 0.21), − 0.08 (− 0.29, 0.17), − 0.05 (− 0.30, 0.19), − 0.06 (− 0.23, 0.12) using Bland–Altman method. The area under the receiver operating characteristic curve of UCVAE, PCVAE, UCVAL, PCVAL for the detection of decreased BCVA was 0.78 (0.73, 0.84), 0.76 (0.71, 0.82), 0.95 (0.94, 0.96), 0.93 (0.91, 0.95), respectively. Conclusion Pinhole does not increase the screening accuracy of detecting decreased BCVA in grade one primary schoolchildren. Visual acuity test using Lea Symbols is more efficient than Tumbling E in the screening of that age. Trial registration Data were maily from the Lhasa Childhood Eye Study which has finished the clinical registration on (ChiCTR1900026693).


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaowu Ying ◽  
Kaiyue Tian ◽  
Kaiyu Zhang ◽  
Xiaohui Ma ◽  
Hongming Guo

Abstract Background This study aimed to assess the accuracy of virtual surgical planning (VSP) in segmental osteotomy in combination with bimaxillary orthognathic surgery with surgery first approach (SFA) by means of three-dimensional (3D) measuring and superimposition, so as to promote the application of digital technology in combined orthodontic-orthognathic treatment. Methods 20 patients treated with segmental osteotomy in combination with bimaxillary orthognathic surgery with SFA from 2018 to 2020 were included. All of them acquired VSP performed by ProPlan CMF 3.0 software (Materialise Corporation, Belgium). The preoperative (T0) 3D model of VSP and the postoperative (T1) 3D model, reconstructed by the cone-beam computed tomography (CBCT) data acquired one week after surgery, were compared by measuring the 3D coordinates of the landmarks as well as 3D model superimposition for deviation analysis. The deviation analysis was achieved by Geomagic Studio 2013 (3D Systems Corporation, USA). The differences which represented the accuracy of VSP were evaluated by the root mean square deviation (RMSD) and the Bland–Altman method. Results There was no statistically significant difference between the 3D coordinates of T1 and T0 (P > 0.05), and the mean overall RMSD was 1.37 mm, within the clinical relevance of 2 mm. The RMSD of sagittal direction (1.76 mm) was greater than that of coronal and vertical directions (1.09 mm and 1.24 mm), and the RMSD of maxillary and mandibular aspects were basically equal (1.30 mm and 1.45 mm). The Bland–Altman method showed the T0 and T1 measurements were in good agreement. The mean RMSD obtained from the deviation analysis was 1.85 mm, within the clinical relevance. Conclusions VSP in segmental osteotomy in combination with bimaxillary orthognathic surgery with SFA proved to acquire accurate outcome in this study.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrés Gené-Sampedro ◽  
Pedro Miguel Lourenço Monteiro ◽  
Inmaculada Bueno-Gimeno ◽  
Javier Gene-Morales ◽  
David P. Piñero

AbstractThis study evaluates in terms of reliability, internal consistency, and validity a modification of the Adult Developmental Eye Movement (ADEM) test, ADEM with distractors (ADEMd), designed to analyse oculomotor system, visual processing and visual attentional behaviour. 302 healthy subjects participated in the study (20–86 years old). Intrasession repeatability was evaluated by analysing the correlation between the time needed to read different parts of the test. Inter-session analyses were carried in 40 subjects by calculating intraclass correlation coefficients and using the Bland–Altman method. Validity was assessed in the outcomes obtained according to age as well as investigating the correlation between ADEMd and attentional useful field of vision (UFOV) test. Correlation coefficients between times need to read each sheet were ≥ 0.95 (p < 0.001). The inter-session intraclass correlation coefficient ranged from 0.81 in the horizontal distractor sheet to 0.97 in the vertical sheet. Bland–Altman analysis showed clinically acceptable limits of agreement. Statistically significant correlations were found between age and ADEMd outcomes (r ≥ 0.55, p < 0.001). Processing velocity, divided attention and selective attention measured with the UFOV were correlated with the horizontal distractor times (r ≥ 0.32, p < 0.001). ADEMd test may be a useful clinical tool to evaluate the combined interaction of ocular movements and visual attentional behaviour.


2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S52-S52
Author(s):  
J K Lee ◽  
S Li

Abstract Introduction/Objective Insulin-like Growth Factor 1 (IGF-1) is a biomarker for the evaluation of growth hormone activity in the hypothalamic-pituitary axis. The current most common methodology for IGF-1 measurement is automated immunometric assays. In this study, we compared the IGF-1 on Siemens Immulite 2000, DiaSorin Liaison XL and IDS iSYS. Methods/Case Report Residual 30-110 serum specimens were randomly selected from routine hospital orders. IGF- 1 was measured on these three platforms and compared with Passing-Bablok regression. Bias was evaluated using the Bland-Altman method. Results (if a Case Study enter NA) Weighted Deming regression analysis showed approximately 80% and 56% positive bias on IDS iSYS and DiaSorin Liaison, compared with Siemens Immulite (iSYS=1.81*Immulite-117.65, r=0.91; Liaison=1.56*Immulite-4.58, r=0.98). There was approximately 8% positive bias on Liaison, compared with iSYS (Liaison=1.08*iSYS+0.56, r=0.99). The Passing-Bablok regression analysis revealed approximately 67% and 54% positive bias (iSYS=1.67*Immulite-75, r=0.91; Liaison=1.54*Immulite-3.44, r=0.91). Approximately 8% positive bias on Liaison was observed, compared with iSYS (Liaison=1.08*iSYS+5.65, r=0.99). The Bland-Altman plot showed the agreement between iSYS and Immulite IGF-1 was on average 129.6±123.3 ng/mL, 98.6±148.8 ng/mL between Liaison and Immulite and 37.0±46.5 ng/mL between Liaison and iSYS. Conclusion Immunoassays rely on the specificity of antibodies. There are wide variations between different immunoassay platforms for IGF-1 measurement. The standardization of IGF-1 assay is lack. It would be a challenge for clinicians to monitor IGF-1 or treat the patients with pituitary disorders, when switching to another platform. The potential impact of the variations in IGF-1 measurement between different immunoassay platforms should be aware.


2021 ◽  
Author(s):  
Obaid Kousha ◽  
Amritpal Chaggar ◽  
Sergio Pagliarini

Abstract BACKGROUNDIn ophthalmology clinics, the visual acuity (VA) is usually measured by non-refracting healthcare professionals (HCPs). We compared the ‘real world’ or clinic measured VA versus the best-corrected visual acuity measurement in patients with neovascular age-related macular degeneration (nAMD).METHODSDuring the same clinical session using Early Treatment of Diabetic Retinopathy Study (ETDRS) vision chart, monocular distance VA was measured by non-refracting HCPs in nAMD patients and compared to the monocular distance VA measured by an optometrist with subjective refractive correction (BCVA). The study was powered to detect a difference of >5 ETDRS letters between the groups and for HCP measured VA to detect a BCVA between 6/12 and 6/96 (National Institute of Health and Care Excellence condition of approval of nAMD treatment with licensed drugs in the UK).RESULTSData from 167 patients (324 eyes) were analysed. Absolute mean difference in BCVA versus HCP measured VA was 5.71 (95% confidence interval (CI) 5.10-6.41) ETDRS letters (p-value<0.001). Using Bland-Altman method, limits of agreement between the two groups was found to be between 18.39 and -14.66 ETDRS letters. The prevalence of BCVA between 6/12 and 6/96 was 53.40% (95% CI 47.96-58.83%). In detecting this BCVA bracket, the non-refracting HCP measured VA had a sensitivity of 91.91% (95% CI 87.84-95.97%) and a specificity of 84.77% (95% CI 79.04-90.50%). CONCLUSIONSThe ‘real world’ HCP measured VA was found to have considerable inaccuracy and imprecision when compared to BCVA in nAMD patients. Unreliable VA measurement can have important implications in assessing and treating eye conditions, including nAMD.


2021 ◽  
pp. 107110072110345
Author(s):  
Peter Kvarda ◽  
Nicola Krähenbühl ◽  
Roman Susdorf ◽  
Arne Burssens ◽  
Roxa Ruiz ◽  
...  

Background: A reliable assessment of the ankle using weightbearing radiography remains challenging. Semiautomated 3-dimensional (3D) measurements derived from weightbearing computed tomography (WBCT) scans may provide a more reliable approach. Methods: Thirty healthy individuals without any foot and ankle disorder were analyzed. We assessed 6 widely used ankle parameters (4 angles and 2 distances) using either semiautomated 3D (based on WBCT scans) or traditional 2-dimensional (2D; based on conventional radiographs) measurements. The reliability and discrepancy between both techniques were compared using intraclass correlation coefficients and the Bland-Altman method. Results: Five of 6 variables showed a lower reliability when derived from 2D measurements. The mean of 3 variables differed between the techniques: the 3D technique assessed that the talonavicular coverage angle was 18.9 degrees higher, the axial talocalcaneal angle was 5.5 degrees higher, and the talocalcaneal overlap was 3.7 mm lower when compared with 2D measurements. Conclusion: Semiautomated 3D measurements derived from WBCT scans provide more reliable information on ankle alignment compared with 2D measurements based on weightbearing radiographs. Future studies may show to what extent these parameters could contribute to current diagnostic algorithms and treatment concepts. Level of Evidence: Not applicable.


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