Multidirectional motion occurs in total knee replacements (TKR), is a major factor in ultra high molecular weight polyethylene (UHMWPE) wear and is a requirement for wear tester and simulators. There are three ways the femoral component can move relative to the tibial component; sliding, rolling and gliding and these are defined by the slide to roll ratio. Previous wear tester research has investigated the effects of multidirectional motion and slide to roll ratio, individually but not combined. The project aim was to design a machine that combined multidirectional motion with variable slide to roll ratio. A three station wear testing machine was designed and built featuring flexion extension, variable anterior posterior translation, variable internal external rotation and a 2KN load per station. The TKR was simplified to a cylinder on flat. Lubrication was 25% bovine serum and each station had its own recirculation system. A million cycle validation test was successfully carried out on non-irradiated UHMWPE samples using a slide to roll ratio of 1 : 0.5 and the mean wear rate was 14.7mg/10^6 cycles. Polished areas and scratches from 3rd body abrasion were observed. Magnification revealed a fine ripple pattern with a 1-2 micron periodicity. Ripples were randomly oriented, perpendicular to the primary direction of motion and a small number were running parallel to the primary direction of motion, indicative of rolling motion. The results from the validation study show that the knee joint wear tester is capable of producing wear rates and wear mechanisms similar to those observed in other wear testers and knee joint simulators and has met the aim of the project.

Ledproteskirurgi av höft- eller knäled är idag en av de vanligaste operationerna i Sverige. Den vanligaste orsaken till ledproteskirurgi i höft och knä är artros som orsakar kronisk nedbrytning av leder. I den postoperativa vården är patienter utsatta och behöver hjälp av vårdpersonal med rehabiliteringen och smärta. Under denna vårdtid utvecklas en vårdrelation mellan patienterna och personalen, som påverkar patientens livskvalité. Syftet med studien är att belysa patienters upplevelse av personalens bemötande i samband med postoperativ vård efter operation av höft- eller knäprotes. Metoden är en litteraturstudie, där sex kvalitativa artiklar med vårdvetenskaplig ansats används. Det finns få artiklar och forskning gjord i ämnet. Fribergs (2006) modell om evidensbaserad omvårdnad och Evans (2002) modell om innehållsanalys ligger till grund för studiens metod. Resultatet presenteras utifrån fyra kategorier som är; Omvårdnaden upplevs som bra, Personalen är engagerad, Jag vågar inte ställa frågor och får heller inget veta och Jag blir inte respekterad. I varje kategori beskrivs hur patienter upplever personalens bemötande. Resultatet visar patienters både positiva och negativa upplevelser av hur personalen bemöter dem. I diskussionen diskuteras patienters vårdupplevelser under vårdtiden. Det patienter uppskattar är att vården sker genom professionella handlingar och att sjuksköterskan är vänlig, glad och lugn. / Program: Sjuksköterskeutbildning

Little is known about time to return to work (TRTW) following planned medical events. This study was a secondary analysis (n=94) to determine predictors of time to return to work following a total knee replacement for osteoarthritis. Significant predictors of delayed TRTW following a knee replacement: 1) use of workplace modifications (in 6wks vs 5 wks) and 2) poor physical function (in 7wks vs 6 wks). These findings have large implications for workers undergoing knee replacement, orthopedic clinicians, and occupational health nurses.

Epidural analgesia causes a temporary cessation of nerve conduction via administration of low concentration of local anaesthesia, or opioid, into epidural space. The resulting temporary discontinuation of nerve conduction is called central neuroaxial anaesthesia and it facilitates the process of surgical intervention. An epidural catheter is usually inserted during epidural desensitisation. It helps to control the amount of administered anaesthesia and hence to respond to surgery progress, but it also enables to keep the catheter within the epidural space for the following postoperative analgesia, which will promote timely postoperative rehabilitation and pain management.The research project was conducted on basis of quantitative and qualitative investigation. The quantitative research was performed via questionnaires directed at the nursing staff, and the qualitative research took form of semi-structured interviews with patients. The quantitative investigation was conducted in fourteen health care facilities in the Czech Republic. Respondents of the quantitative research were nurses working in orthopaedic departments, multidisciplinary ICU or ARO (Anaesthesiology Resuscitation Dept.), who provided care to patients after TKR or THR with an epidural catheter insitu. Qualitative research respondents were patients hospitalised in orthopaedic departments for TKR or THR, with epidural catheter insitu and who agreed to participate at the interview. Quantitative research data were processed in Excel 2010 and presented in graphs, frequency and contingency tables, whereas the qualitative research data were processed using charts of the Smart Art program. After the agreement with the management of health care facilities, this dissertation will promote education and aid situation improvement. The Standard of Nursing Care Assisting a Patient with Epidural Catheter during Insertion and Care will be an outcome of this project. Moreover, we will design a patient information booklet and a quality of care indicator that will focus on monitoring of complications occurrence such as infections in patients with epidural catheter. The findings may help to design a training course specialised in nursing care provision to those patients and also to provide basis for further research.

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This work deals with the issue of packaging and heat transfer. Especially this work focused on QFN and BGA packages. Nowadays most sophisticated conventional solution. First part deals with analysis of the current status of packages. Next part is analyze the issue of heat transfer in electronic systems. The following section is an experimental dealing with simulation in ANSYS Workbench and validation of these simulations by designed test structures. At the end is evaluated properties and behavior of these packages.

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No description available.

It has been noticed that the need for total knee replacement surgery is increasing for Asian region. A total knee replacement is a permanent surgical solution for a patient having debilitating pain in knee joint suffering from arthritis. In this surgery, knee joint is replaced with components made up of bio-compatible materials after which the patient can resume the normal day to day activities. Western population has bigger build compared to Asian population. Most of the total knee replacement prosthesis are designed for western population. When these total knee prosthesis are used for Asian population, they cause a mismatch leading to various clinical complications such as reduced range of motion and pain. The studies have been limited to clinical complications caused by the mismatch. To address this limitation, current study is aimed to find the mechanical implications such as stress distribution, maximum stresses, maximum displacements etc., caused by mismatch of total knee replacement components with knee. A surgeon selects total knee components for a patient based on some critical dimensions of femur and tibia bone of knee. In addition, a method to accurately calculate these dimensions of the femur and tibia bone of a real knee was developed in the current study. This method calculated the points of curvature greater than a threshold (decided based on the radius of the curvature) found out using the formula of curvature. Further, the highest point was calculated based on maximum height from a line drawn between initial and final point within the captured points, also the extreme points were calculated based on the sign change in slope of points within the captured points, giving multiple points on the boundary of bones extracted in an MRI image of a patient. The distance between two selected farthest points, out of these points, in specific direction was the basis for selection of the TKR components. Total knee replacement components were modeled in Geomatics Studio 12 software, bones were modeled in Rhinoceros 5 software, assembly of bones and total knee replacements components was done in Solid works 2013 software, the finite element model of the assembly was developed in Hyper mesh 11 software and, the stress analysis and post processing was done in ABAQUS 6.13 software. A static, implicit non linear analysis was performed. Simulations were performed for two conditions: at standing (0o of flexion) and at hyper-flexed (120o of flexion). In order to figure out if there were any mechanical implications of mismatch, the full model of assembly consisting of femur, tibia and fibula bones assembled with total knee replacement components, and the reduced model consisting of only total knee replacement components were simulated separately, results of which have been discussed in the current thesis. In this work, the effect of change of length of ligaments at 120o of flexion in detail was also studied. This study brought out various outcomes of contact mechanics and kinematics between the components of total knee replacement prosthesis.

Tato práce se zabývá pokročilou technologií výroby personalizovaných kloubních implantátů metodou EBM za použití titanové slitiny Ti6Al4V-ELI a navrhuje nový unikátní design kolenního implantátu společně s metodologií jeho inserce, přičemž tato řešení jsou součástí patentové přihlášky č. PV 2020-459. Toto neinvazivní řešení náhrady kolenního kloubu je šetrnější k pacientovi, maximálně chrání jeho zdravé tkáně a kosti, navíc se dá předpokládat vyšší životnost implantátu ve srovnání s tradičními dostupnými řešeními. Byla uskutečněna výroba vzorků z materiálu Ti6Al4V-ELI metodou EBM, proveden rozbor jejich materiálových, mechanických, technologických a únavových vlastností. Dále byly popsány pokročilé metody zobrazování, úpravy a tvorby kloubních ploch a použity k vyvinutí nového designu personalizovaného kloubního implantátu společně s inovační technologií jeho inserce a nástroji potřebnými k její úspěšné realizaci. Toto nové řešení bylo úspěšně ověřeno mnoha testy i výrobou Ti6Al4V-ELI a CoCrMo prototypů implantátů metodou EBM. Proveditelnost a použití v praxi bylo konzultováno a schváleno odborníky v této oblasti.