scholarly journals An animal tissue simulation assessing three directional displacement forces on five common tracheostomy securing techniques

2018 ◽  
Vol 100 (6) ◽  
pp. 459-463
Author(s):  
D Yap ◽  
S Goddard ◽  
M Ng ◽  
A Al-Hussaini ◽  
D Owens
Keyword(s):  
Simulation Study ◽  
Tracheostomy Tube ◽  
Animal Tissue ◽  
Continuous Suture ◽  
Lateral Direction ◽  
Oblique Direction ◽  
Tension Tests ◽  
Signed Rank ◽  
Wet Lab ◽  
Displacement Force

Introduction Several methods of securing a tracheostomy tube have been described in the literature including using ties or tapes around the neck and suturing the plastic flange to the neck in various ways. However, there are no wet lab-based studies to objectively determine the force required to displace the tracheostomy tube using different securing techniques. Ours is the first animal tissue simulation study published in the literature. Methods A simulated tracheostomy stoma was created on a sheep neck model. A tracheostomy tube was inserted into the stoma and secured using various methods. Tension tests were conducted to significantly displace the tube from the stoma. Each technique was repeated six times on different sheep necks. All results were analysed using SPSS®. Results Repeat measurements indicated that the largest displacement forces come from an oblique direction while the lowest force values were found at the lateral angle. Averages of displacement showed that medially placed sutures required the largest forces in comparison with other securing methods. Wilcoxon signed-rank testing indicated that medial and continuous suture security resists displacement at forces that otherwise displace flange and interrupted sutures. Conclusions This study has shown that any type of securing suture requires a greater displacement force than the strap of the tracheostomy tube holder alone. Medially placed sutures require a greater displacement force than those placed laterally. Displacement in the lateral direction requires the least force in comparison with movement at perpendicular or oblique angles.

Application of ruthenium red/osmium tetroxide to bacteria, plant and animal tissue

1986 ◽  
Vol 44 ◽  
pp. 54-55
Author(s):  
R. L. Grayson ◽  
N. A. Rechcigl
Keyword(s):  
Electron Microscopy ◽  
Electron Density ◽  
Osmium Tetroxide ◽  
Biological Materials ◽  
Ruthenium Red ◽  
Animal Tissue

Ruthenium red (RR), an inorganic dye was found to be useful in electron microscopy where it can combine with osmium tetroxide (OsO4) to form a complex with attraction toward anionic substances. Although Martinez-Palomo et al. (1969) were one of the first investigators to use RR together with OsO4, our computor search has shown few applications of this combination in the intervening years. The purpose of this paper is to report the results of our investigations utilizing the RR/OsO4 combination to add electron density to various biological materials. The possible mechanisms by which this may come about has been well reviewed by previous investigators (1,3a,3b,4).

Immunoelectron microscopic localization of elastic tissue in archival material using an improved method

1990 ◽  
Vol 48 (3) ◽  
pp. 794-795
Author(s):  
J. C. Fanning ◽  
J. F. White ◽  
R. Polewski ◽  
E. G. Cleary
Keyword(s):  
Normal Animal ◽  
Animal Tissue ◽  
Elastic Tissue ◽  
Human Tissues ◽  
Improved Method ◽  
Tissue Samples ◽  
Archival Material ◽  
Immuno Electron Microscopy ◽  
Arteries And Veins ◽  
Biochemical Examination

Elastic tissue is an important component of the walls of arteries and veins, of skin, of the lungs and in lesser amounts, of many other tissues. It is responsible for the rubber-like properties of the arteries and for the normal texture of young skin. It undergoes changes in a number of important diseases such as atherosclerosis and emphysema and on exposure of skin to sunlight.We have recently described methods for the localizationof elastic tissue components in normal animal and human tissues. In the study of developing and diseased tissues it is often not possible to obtain samples which have been optimally prepared for immuno-electron microscopy. Sometimes there is also a need to examine retrospectively samples collected some years previously. We have therefore developed modifications to our published methods to allow examination of human and animal tissue samples obtained at surgery or during post mortem which have subsequently been: 1. stored frozen at -35° or -70°C for biochemical examination; 2.

Passy-Muir Speaking Valve Use in a Children's Hospital: An Interdisciplinary Approach

2008 ◽  
Vol 18 (2) ◽  
pp. 76-86 ◽  
Author(s):  
Lauren Hofmann ◽  
Joseph Bolton ◽  
Susan Ferry
Keyword(s):  
Tracheostomy Tube ◽  
Pediatric Population ◽  
Interdisciplinary Approach ◽  
Extended Period ◽  
Speech Development ◽  
Tube Placement ◽  
Background Information ◽  
Speaking Valve ◽  
Children's Hospital ◽  
Children’S Hospital

Abstract At The Children's Hospital of Philadelphia (CHOP) we treat many children requiring tracheostomy tube placement. With potential for a tracheostomy tube to be in place for an extended period of time, these children may be at risk for long-term disruption to normal speech development. As such, speaking valves that restore more normal phonation are often key tools in the effort to restore speech and promote more typical language development in this population. However, successful use of speaking valves is frequently more challenging with infant and pediatric patients than with adult patients. The purpose of this article is to review background information related to speaking valves, the indications for one-way valve use, criteria for candidacy, and the benefits of using speaking valves in the pediatric population. This review will emphasize the importance of interdisciplinary collaboration from the perspectives of speech-language pathology and respiratory therapy. Along with the background information, we will present current practices and a case study to illustrate a safe and systematic approach to speaking valve implementation based upon our experiences.

An Alternative to Cohen's κ

2006 ◽  
Vol 11 (1) ◽  
pp. 12-24 ◽  
Author(s):  
Alexander von Eye
Keyword(s):  
Simulation Study ◽  
Null Hypothesis ◽  
Categorical Variables ◽  
Alternative Measure ◽  
Rater Agreement ◽  
Verbal Processing ◽  
Heavy Tailed ◽  
Applicant Selection

At the level of manifest categorical variables, a large number of coefficients and models for the examination of rater agreement has been proposed and used. The most popular of these is Cohen's κ. In this article, a new coefficient, κ s , is proposed as an alternative measure of rater agreement. Both κ and κ s allow researchers to determine whether agreement in groups of two or more raters is significantly beyond chance. Stouffer's z is used to test the null hypothesis that κ s = 0. The coefficient κ s allows one, in addition to evaluating rater agreement in a fashion parallel to κ, to (1) examine subsets of cells in agreement tables, (2) examine cells that indicate disagreement, (3) consider alternative chance models, (4) take covariates into account, and (5) compare independent samples. Results from a simulation study are reported, which suggest that (a) the four measures of rater agreement, Cohen's κ, Brennan and Prediger's κ n , raw agreement, and κ s are sensitive to the same data characteristics when evaluating rater agreement and (b) both the z-statistic for Cohen's κ and Stouffer's z for κ s are unimodally and symmetrically distributed, but slightly heavy-tailed. Examples use data from verbal processing and applicant selection.

Comparison of Principal Component Solutions in Two Populations

Methodology ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Gregor Sočan
Keyword(s):  
Simulation Study ◽  
Principal Components ◽  
Common Factor ◽  
Principal Component ◽  
Component Model ◽  
Bootstrap Procedure ◽  
Factor Loadings ◽  
Component Loadings ◽  
Principal Component Model ◽  
Two Populations

Abstract. When principal component solutions are compared across two groups, a question arises whether the extracted components have the same interpretation in both populations. The problem can be approached by testing null hypotheses stating that the congruence coefficients between pairs of vectors of component loadings are equal to 1. Chan, Leung, Chan, Ho, and Yung (1999) proposed a bootstrap procedure for testing the hypothesis of perfect congruence between vectors of common factor loadings. We demonstrate that the procedure by Chan et al. is both theoretically and empirically inadequate for the application on principal components. We propose a modification of their procedure, which constructs the resampling space according to the characteristics of the principal component model. The results of a simulation study show satisfactory empirical properties of the modified procedure.

Assessing Person Fit With the Information Matrix Test

Methodology ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Jochen Ranger ◽  
Jörg-Tobias Kuhn
Keyword(s):  
Simulation Study ◽  
Type I Error ◽  
Information Matrix ◽  
Small Samples ◽  
Type I ◽  
Person Fit ◽  
Power Of The Test ◽  
Order Expansion ◽  
Trait Stability ◽  
Information Matrix Test

In this manuscript, a new approach to the analysis of person fit is presented that is based on the information matrix test of White (1982) . This test can be interpreted as a test of trait stability during the measurement situation. The test follows approximately a χ2-distribution. In small samples, the approximation can be improved by a higher-order expansion. The performance of the test is explored in a simulation study. This simulation study suggests that the test adheres to the nominal Type-I error rate well, although it tends to be conservative in very short scales. The power of the test is compared to the power of four alternative tests of person fit. This comparison corroborates that the power of the information matrix test is similar to the power of the alternative tests. Advantages and areas of application of the information matrix test are discussed.

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