Measurement Methods
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Александра Алексеевна Троценко ◽  
Александр Викторович Кобелев ◽  
Александр Петрович Николаев ◽  
Аза Валерьевна Писарева

В статье представлена разработка технического проекта по созданию прибора для неинвазивной оценки параметров центральной гемодинамики. Сердечно-сосудистые заболевания являются основной причиной смерти во всем мире: ни по какой другой причине ежегодно не умирает столько людей, сколько от патологий сердца. По оценкам, за последние годы от сердечных заболеваний умерло 17,9 миллиона человек, что составило 31% всех случаев смерти в мире. Другой известной причиной смертей являются различные аритмии. Таким образом, из-за растущего количества людей, страдающих патологий сердца, необходимо во время лечения как можно подробнее изучать состояние сердечно-сосудистой системы во избежание негативных последствий. Чтобы обеспечить более высокую результативность лечения, используется метод электроимпедансной реокардиографии, который позволяет оценить суммарное кровенаполнение органов и тканей. Целью данной статьи являлась разработка технического проекта по созданию прибора для неинвазивной оценки параметров центральной гемодинамики. Представлен теоретический этап разработки технического устройства. Описаны существующие методы измерений - трансторакальные или прекордиальные для нахождения необходимых параметров сердечно-сосудистой системы с помощью реокардиографии. Предложены технические характеристики разрабатываемой биотехнической системы, а также схема и описание прибора The article presents the development of a technical project for the creation of a device for non-invasive assessment of the parameters of central hemodynamics. Cardiovascular disease is the leading cause of death worldwide: for no other reason as many people die every year as from heart disease. An estimated 17.9 million people have died from heart disease in recent years, accounting for 31% of all deaths worldwide. Various arrhythmias are another known cause of death. Thus, due to the growing number of people suffering from heart pathologies, it is necessary during treatment to study the state of the cardiovascular system in as much detail as possible in order to avoid negative consequences. To ensure a higher efficiency of treatment, the method of electrical impedance rheocardiography is used, which allows to assess the total blood volume of organs and tissues. The purpose of this article was to develop a technical project to create a device for non-invasive assessment of the parameters of central hemodynamics. The theoretical stage of the development of a technical device is presented. The existing measurement methods are described - transthoracic or precordial to find the necessary parameters of the cardiovascular system using rheocardiography. The technical characteristics of the developed biotechnical system, as well as the scheme and description of the device are proposed

2021 ◽  
Xiaolong Chen ◽  
Stone Sima ◽  
Harvinder Sandhu ◽  
Jeff Kuan ◽  
Ashish Diwan

Purpose: To evaluate intra- and inter-rater agreement and reliability of seven reported disc height index (DHI) measurement methods on standing lateral X-ray of lumbar spine. Methods: The adult patients who had standing lateral X-ray of lumbar spine were recruited. Seven methods were used to measure DHI of each lumbar intervertebral disc level. Bland and Altman Limits of Agreement (LOA) with standard difference were calculated to examine intra- and inter-rater agreements between two out of seven methods for DHI. Intra-class correlations (ICC) with 95% confidence intervals were calculated to assess intra- and inter-rater reliability. Results: The intra-rater reliability in DHI measurements for 288 participants were ICCs from 0.807 (0.794, 0.812) to 0.922 (0.913, 0.946) by rater 1 (SS) and from 0.827 (0.802, 0.841) to 0.918 (0.806, 0.823) by rater 2 (XC). Method 2, 3, and 5 on all segmental levels had bias (95% CI does not include zero) or/and out of the acceptable cut-off proportion (>50%). A total of 609 outliers in 9174 segmental levels LOA range. Inter-rater reliability was good-to-excellent in all but method 2 (0.736 (0.712, 0.759)) and method 5 (0.634 (0.598, 0.667)). ICCs of related lines to good-to-excellent reliability methods was excellent in all but only indirect line in method 1 and 4 (ICCs lie in the range from 0.8 to 0.9). Conclusion: Following structured protocol, intra- and inter-rater reliability was good-to-excellent for most DHI measurement methods on X-ray. However, in the presence of vertebral rotation, one should exercise caution in using complicated methods to define vertebral landmarks. Keywords: Lumbar disc herniation, discectomy, disc height, disc height index, agreement, reliability.

2021 ◽  
Vol 21 (1) ◽  
Mayu Hiraishi ◽  
Kensuke Tanioka ◽  
Toshio Shimokawa

Abstract Background To assure the equivalence between new clinical measurement methods and the standard methods, the four-quadrant plot and the plot’s concordance rate is used in clinical practice, along with Bland-Altman analysis. The conventional concordance rate does not consider the correlation among the data on individual subjects, which may affect its proper evaluation. Methods We propose a new concordance rate for the four-quadrant plot based on multivariate normal distribution to take into account the covariance within each individual subject. The proposed concordance rate is formulated as the conditional probability of the agreement. It contains a parameter to set the minimum concordant number between two measurement methods, which is regarded as agreement. This parameter allows flexibility in the interpretation of the results. Results Through numerical simulations, the AUC value of the proposed method was 0.967, while that of the conventional concordance rate was 0.938. In the application to a real example, the AUC value of the proposed method was 0.999 and that of the conventional concordance rate was 0.964. Conclusion From the results of numerical simulations and a real example, the proposed concordance rate showed better accuracy and higher diagnosability than the conventional approaches.

2021 ◽  
Andrew Ward ◽  
Anthony Falls ◽  
Craig Rutland

The U.S. Army Engineer Research and Development Center (ERDC) has developed a method for predicting surface friction response by use of ground vehicles equipped with deceleration-based measurement devices. Specifically, the ERDC has developed models and measurement methods between the Findlay Irvine Mk2 GripTester and a variety of deceleration measurement devices: Bowmonk AFM2 Mk3, Xsens MTi-G-710, two Android smartphones, and two iOS smartphones. These models show positive correlation between ground vehicle deceleration and fixed-slip surface continuous surface friction measurement. This effort extends prior work conducted by the U.S. Army ERDC in developing highly correlative models between the Findlay Irvine Mk2 GripTester and actual C-17 braking deceleration, measured via the runway condition rating (RCR) system. The models and measurement methods detailed here are of considerable use to semi-prepared airfield managers around the world needing to measure safe landing conditions following inclement weather. This work provides the tools necessary for airfield managers to quantify safe landing conditions for C-17 aircraft by using easily obtainable equipment and simple test standards.

2021 ◽  
pp. 229255032110428
Kathryn Uhlman ◽  
Hassaan Abdel Khalik ◽  
Jessica Murphy ◽  
Marta Karpinski ◽  
Achilles Thoma

Purpose: There is a lack of scientific consensus on the best arthroplasty implant option for proximal interphalangeal joint (PIPJ) arthritis, due to diversity in outcome reporting and measurement methods. The development of a standardized core outcome set (COS) and standard outcome measures could mitigate this issue. This study catalogs the reported outcomes and outcome measures found in PIPJ arthroplasty studies, which can be used in the first step of developing a COS. Methods: A database search of MEDLINE, EMBASE, and Web of Science (January 1, 2010, to March 10, 2021) was performed to retrieve studies that reported outcomes of the 3 most common primary PIPJ arthroplasty implants: silicone, pyrocarbon, and metal-polyethylene. The primary objectives of this study include reported outcomes and outcome measures. Secondary objectives include clinimetric properties of outcome measures, study design, and implant types. Results: Fifty articles met inclusion criteria. Of the included studies, 41 (82%) were case series, 8 (16%) were cohort studies, and 1 (2%) was a randomized control trial. Thirty-three unique outcomes were identified. Fifteen (46%) outcomes were clinician-reported and 26 (79%) were patient-reported. Eighteen unique outcome measures were identified. Of the outcome measures, 15 (83%) were patient-reported, 1 (6%) was clinician-reported, and 2 (11%) were reported by both patients and clinicians. Conclusions: Substantial heterogeneity was found in reported outcomes and outcome measures across studies evaluating PIPJ arthroplasty, impeding knowledge translation. The development of a COS for PIPJ arthroplasty is necessary to help compare and pool data across studies, and advance scientific knowledge.

2021 ◽  
Vol 5 (4) ◽  
pp. 244
Wolfgang E. Lorenz ◽  
Matthias Kulcke

This article contributes to clarifying the questions of whether and how fractal geometry, i.e., some of its main properties, are suitable to characterize architectural designs. This is done in reference to complexity-related aesthetic qualities in architecture, taking advantage of the measurability of one of them; the fractal dimension. Research in this area so far, has focused on 2-dimensional elevation plans. The authors present several methods to be used on a variety of source formats, among them a recent method to analyze pictures taken from buildings, i.e., 2.5-dimensional representations, to discuss the potential that lies within their combination. Color analysis methods will provide further information on the significance of a multilayered production and observation of results in this realm. In this publication results from the box-counting method are combined with a coordinate-based method for analyzing redundancy of proportions and their interrelations as well as the potential to include further layers of comparison are discussed. It presents a new area of box-counting implementation, a methodologically redesigned gradient analysis and its new algorithm as well as the combination of both. This research shows that in future systems it will be crucial to integrate several strategies to measure balanced aesthetic complexity in architecture.

2021 ◽  
Vol 13 (23) ◽  
pp. 13188
Floris Goerlandt ◽  
Jie Li ◽  
Genserik Reniers

Risk perception is important in organizational and societal governance contexts. This article presents a high-level analysis of risk perception research using Web of Science core collection databases, scientometrics methods and visualization tools. The focus is on trends in outputs, geographical and temporal trends, and patterns in the associated scientific categories. Thematic clusters and temporal dynamics of focus topics are identified using keyword analysis. A co-citation analysis is performed to identify the evolution of research fronts and key documents. The results indicate that research output is growing fast, with most contributions originating from western countries. The domain is highly interdisciplinary, rooted in psychology and social sciences, but branching into domains related to environmental sciences, medicine, and engineering. Significant research themes focus on perceptions related to health, with a focus on cancer, human immunodeficiency virus, and epidemiology, natural hazards and major disasters, traffic accidents, technological and industrial risks, and customer trust. Risk perception research originated from consumer choice decisions, with subsequent research fronts focusing on understanding the risk perception concept, and on developing taxonomies and measurement methods. Applied research fronts focus on environmental hazards, traffic accidents, breast cancer and, more recently, e-commerce transactions and flood risk. Based on the results, various avenues for future research are described.

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7237
Grzegorz Bartnik ◽  
Kazimierz Józefiak ◽  
Małgorzata Superczyńska ◽  
Magdalena Czerwińska ◽  
Witold Krajewski ◽  

During firing from a mortar, an important issue is the parameters of compressibility of the ground on which the mortar is placed. This affects the operation of the mortar (including safety). During the qualification tests of the mortar, the influence of different types of terrains on its strength and work during shooting should be examined. Until now, in the Polish standardization documents there was no clear description of the ground parameters used for these kinds of tests. Analysis of the literature also did not allow to determine the dependence of the mortars displacement in the function of the type of ground and its geotechnical parameters. In view of the above, it has become important to draw up a research problem in the form of determining the types of soil with parameters, enabling the mortar tests to be carried out in conditions as close as possible to combat conditions. Therefore, the authors carried out the theoretical calculations and field tests with the use of geotechnical methods such as static and dynamic load tests to determine the parameters of the ground for mortar testing. Preliminary tests were conducted using the prescribed measurement methods and a comparative mortar firing test. Subsequently, an analysis of the results was carried out and the possibilities of using the tested methods of measuring the parameters of soil compressibility were determined.

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