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3D kinematic analysis of patients’ gait before and after unilateral total hip replacement

Kolářová Kateřina, Vodička Tomáš, Bozděch Michal, Repko Martin

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 2

165--171

EN

Purpose: The purpose of the study was to describe changes in the kinematic parameters in the patients’ gait after total hip replacement. Methods: Research group of men in the end stage of osteoarthritis indicated to the THR (n = 10; age 54.1 ± 7.5 years; weight 92.2 ± 9.6 kg; height 179.7 ± 5.9 cm). All participants underwent a total of three measurements: before surgery, 3 and 6 months after the surgery. Using the 3D kinematic analysis system, the patients’ gait was recorded during each measurement session and kinematic analysis was carried out. The parameters that were monitored included the sagittal range of motion while walking in the ankle, the knee and the hip joints of the operated and the unoperated limb, and the range in the hip joint’s frontal plane, the rotation of pelvis in the frontal and transverse planes, as well as the speed of walking and the walking step length. Results: Significant increases were found in sagittal range of motion in the operated hip joint, sagittal range of motion in the ankle joint on the unoperated side and in the walking step length of the unoperated limb. Conclusions: During walking after a THR, the sagittal range of motion in the ankle of the unoperated limb increases. Also, the range of motion in the sagittal plane on the operated joint increases, which is related to the lengthening of the step of the unoperated lower limb.

2

Wybrane zagadnienia oceny ryzyka w odniesieniu do systemów sterowania ruchem kolejowym

Szmel Dariusz, Zabłocki Wiesław, Ilczuk Przemysław, Kochan Andrzej

Prace Naukowe Politechniki Warszawskiej. Transport

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2019

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z. 127

81--91

PL

W artykule przedstawiono wybrane metody oceny i analizy ryzyka systemów sterowania ruchem kolejowym w odniesieniu do poziomu całego systemu kolejowego. Rozpatrywane są wybrane metody stosowane na początkowym etapie tworzenia wymagań bezpieczeństwa i odnoszące się do wstępnej definicji systemu określonej na dużym poziomie abstrakcji. Dyskutowane są także kwestie zastosowania podejścia holistycznego i zarządzania ryzykiem szczątkowym. Przedstawiono modele ryzyka oraz poszczególne kroki analizy, wyceny i oceny ryzyka obejmujące m.in. identyfikację zagrożeń, analizę skutków oraz wybór zasady akceptacji ryzyka. Kluczowym aspektem podjętym w artykule jest propozycja wyznaczania ilościowych celów bezpieczeństwa opartych o wskaźnik THR, jako istotnego parametru w dalszych analizach systemu w szczególności w zastosowaniach komputerowych. W rozważaniach uwzględniono aktualne podstawy normatywne oraz przepisy prawa regulujące obszar oceny ryzyka na kolei w tym dyrektywy i rozporządzenia dotyczące interoperacyjności i bezpieczeństwa.

EN

In the article the selected methods of the risk assessment and analysis of signalling railway systems in reference to the whole railway system were introduced. The selected methods applied at the very first stage of safety requirements definition within the preliminary system definition described at high level of abstraction will be considered. It will be discussed the application of holistic approach with management of residual risk. The risk models will be presented as well as steps of the assessment, analysis and evaluation of risk including hazard identification, consequences analysis and selection of risk acceptance principles. Key aspect in the article will be the determination of quantitative safety targets based on THR indicator as an important parameter for further hazard analysis of the system in particular in computer application. Normative and legislation requirements in scope of risk assessment for the railway system will be taken into consideration including the interoperability and safety directives and decrees regulations.

3

Semi-formal methods in safety railway control systems validation

Magott J., Lewiński A., Perzyński T

Archives of Transport System Telematics

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2013

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Vol. 6, iss. 1

32--36

EN

Th e paper deals with extending the obligatory methods of safety proof of railway control and management computer systems towards more formalized methods based on mathematical apparatus. Such semi-formal methods are recommended by existing EU standards for the design, but also to demonstrate safe operation in accordance with the principle of the rail fail-safe rule, where no single error does not lead to catastrophic situations. Th e paper proposes an extension method of FTA (Fault Tree Analysis) method to FTTD (Fault Tree with Time Dependencies), and an analysis of THR method (Tolerable Hazard Rate) to the analysis of probability of catastrophic fault based on stationary Markov processes. Basic methods and their extension are shown on typical examples of rail automation systems: cross-level protection system and interlocking system.

4

Follow up of biocompatibity of new total hip joint endoprosthesis in a canine model

Rehak L'., Zitnansky M., Soltes I., Horecky J.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 1

260-263

EN

Purpose: of this paper was the follow up of biologic compatibility and functional use of new type endoprosthesis in a canine model. Design/methodology/approach: Prospective animal study with evaluation of new type ZRM of titanium alloy cementless total hip replacement (THR) in dogs in 2007. We used congruent ceramic head and polyethylene acetabular inlay. That is the gold standard in THR. The methods of X ray imaging evaluation after implantation and overgrowth evaluation were employed. We evaluated loading and use of the leg during walking and running. Total hip joint replacements were implanted in 6 dogs – German Shepards under general anesthesia. The follow up time was 6 months. We compared X ray findings after the operation and after 6 months, wound healing, use of THR during leg loading and biocompatibility of THR in femur and pelvis. Findings: The femoral and acetabular components were anchored using a press-fit technique. We found good biocompatibility in 5 dogs with good loading during walking and running, one complication with femoral fracture and wound abscess. At six months, there was good bony ongrowth of the THR in 5 dogs and small overgrowth on the surface of THR in one dog, deemed as complication. In the same animal, explanation of the THR was performed, due to fracture. Research limitations/implications: This study was not monitored. In the future, we would like to perform a randomized study design with a control group. Practical implications: The new THR developed by authors can restore function in canine model of damaged hip joint. The press fit anchorage of the cup allowed firm adhesion of the cup surface to the pelvic bone and likewise, the femoral component demonstrated firm fixation in the proximal femur. Originality/value: This paper is original by presenting the first results of new THR in canine model. The value of this paper is in laying groundwork for human study in the future.

5

Evaluation of the compatibility of ceramic ball head and femoral stem taper on the new type THR

Rehak L., Zitnansky M.

Archives of Materials Science and Engineering

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2010

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Vol. 44, nr 1

58-61

EN

Purpose: of this paper was follow up of compatibility of femoral component taper from TiAl6V4 ELI acc.ISO5832-3 and ceramic head of the new type of total hip join replacement THR - ZRM in vitro. Design/methodology/approach: from december 2006 to august 2007 we have tested THR taper component and ball ceramic head. On the base of our patents ( SK, CZ, EU, USA) from 1999 to 2006 we have designed and developed the new type of cementlesss THR - ZRM. These total hip replacements were tested in our prospective study. We have evaluated compatibility and loading resistance of taper of THR ZRM made from TiAl6V4alloy ELI and ceramic ball head Biolox forte (28-12/14L) by tests of burst strength, pull out, rotational stability, fatigue and post-fatigue. Tests were monitored independent observer. Findings: in the burst test were tested 7 parts and average loading was 54 kN. The reached values comply with the requirements according to CeramTec procedure VA 02 04 4129 and the FDA Guidance document for the preparation of premarket notifications for ceramic ball hip systems. In the fatigue test all specimens test at a maximum load of 14 kN reached 10 million cycles without mechanical failure. The post fatigue test was performed with load of 46 kN and no failure of head and taper system was observed. The pull-off tests were made with pull out strength of 1439 N has been used on 5 parts and no pullout of ceramic ball head of taper femoral component was observed. Last was the test of rotational stability, where ball head was rotational stable under strength of 1254 Ncm. Research limitations/implications: this study was performed on the small group of spices but enough relevant according FDA and international ISO prescriptions. Originality/value: this study is original by publishing first results of the new cementless THR- ZRM tests of compatibility and fatigue of metal taper and ceramic ball head. Value of this paper is in vitro testing and prepares ZRM cementless THR for clinical use in human.

6

Problemy automatycznego montażu i bezołowiowego lutowania rozpływowego elementów przewlekanych w technologii THR

Sitek J.

Elektronika : konstrukcje, technologie, zastosowania

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2009

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Vol. 50, nr 7

92-97

PL

W artykule podano podstawowe informacje związane z technologią THR, która umożliwia jednoczesne lutowanie elementów powierzchniowych i przewlekanych podczas lutowania rozpływowego w piecach. Opisano problemy jakie można napotkać podczas wdrażania tej technologii do praktyki przemysłowej oraz wskazano ich rozwiązania.

EN

The article shows basic information related with the THR technology which THT and SMD components allow to simultaneously reflow soldering in convection ovens. The problems which could be find during implementation this technology and practical tips were described also.

7

Assembly and soldering problems in lead-free through hole reflow technique

Sitek J., Bukat K., Kościelski M.

Materiały Elektroniczne

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2008

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T. 36, nr 4

157-170

EN

Through hole, reflow THR is a technique that allows through-hole components to be soldered, together with SMD (Surface Mount Device) in the same reflow soldering process. The investigation results of lead-free THR manufacturing process were shown in this paper. The test boards containing different SMT passive and active components as well as components dedicated to the THR technique were used in the investigation. The influence of solder paste printing process as well as lead-free reflow soldering process on solder joints quality were reported. The obtained results have shown that parameters of the both above-mentioned processes are the most crucial in SMT containing THR technique.

PL

THR jest techniką lutowania, która umożliwia jednoczesne lutowanie rozpływowe elementów przewlekanych i SMD. W artykule przedstawiono wyniki badań bezołowiowego procesu THR. Podczas badań wykorzystano płytki testowe zawierające różnorodne elementy SMD oraz podzespoły dedykowane do techniki THR. Zbadano wpływ procesu nadruku pasty lutowniczej oraz bezołowiowego procesu lutowania rozpływowego na jakość połączeń lutowanych. Wyniki badań ukazały, że parametry obu wspomnianych wyżej operacji są bardzo istotne w SMT zawierającej technikę THR.