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Análise de fadiga em próteses odontológicas implanto-suportada sob carregamento multiaxiais. / Analysis of failure in implanto-supported odontological prostheses under multiaxial loading.Losada, Henry Figueredo 13 November 2018 (has links)
Próteses odontológicas são estruturas que restituem a função mastigatória e substituem componentes dentários danificados. A maioria dos estudos em próteses odontológicas que envolve métodos analíticos clássicos de análise de estrutura são inviáveis e situações nas quais a experimentação é dificultosa. Estas próteses, sob condições reais de carregamentos cíclicos (mastigação), são repetidamente sujeitas à estados de tensões multiaxiais cíclicas. Neste sentido, a natureza cíclica do carregamento, a qual os componentes das próteses são submetidos, sugere que o modo de falha por fadiga possui maior relevância neste tipo de estrutura. O desenvolvimento da computação eo aumento das capacidades de processamentos tem permitido maior implementação dos métodos numéricos, como o Métodos de Elementos Finitos (MEF). Através deste método (MEF) se realiza a modelagem do comportamento mecânico ajustadas à realidade física dos fatores biomecânicos envolvidos. Em uma revisão bibliográfica, verificou-se que a maioria dos livros e artigos encontrados não apresentam informação detalhadas sobre a previsão da vida baseado em análises de fadiga multiaxial que utilizem o MEF para cálculo das próteses odontológicas. O objetivo deste trabalho foi propor um modelo numérico computacional utilizando o MEF para avaliar a vida à fadiga em próteses odontológicas submetidas a carregamentos multiaxiais. Para isso, foi empregada a manipulação de imagens adquiridas, ensaios experimentais normativos, Análise por Elemento Finitos (FEA) na previsão de vida à fadiga aplicada tanto em carregamento uniaxial ou multiaxial, a contabilização do dano por fadiga em carregamento multiaxial de amplitude variáveis, otimização e implementação de subrotina para as interfaces APDL -MATLAB. Os resultados mostraram que, através das técnicas de aquisição de dados de imagens (Micro-CT) e medições mecânicas combinadas com métodos numéricos consegue-se modelar uma estrutura complexa como uma prótese dental. / Dental prostheses are structures that restore the masticatory function and replace damaged dental components. Most studies on dental prostheses involve that classical analytical methods of structure analysis are infeasible and situations in which experimentation is difficult. These prostheses, under real conditions of cyclic loading (chewing), are repeatedly subjected to cyclic multiaxial stress states. In this sense, the cyclical nature of the loading, to which the components of the prosthesis are submitted, suggests that the fatigue failure mode has greater relevance in this type of structure. The development of computation and the increase of processing capacities have allowed greater implementation of numerical methods, such as Finite Element Methods (FEM). Through this method (FEM) it is performed the modeling of the mechanical behavior which is adjusted to the physical reality of the involved biomechanical factors. In a bibliographical review, it was verified that most of the books and articles found do not present detailed information about the prediction of life based on analyzes of multiaxial fatigue that use the FEM to calculate the dental prostheses. The objective of this research was to propose a computational numerical model using the FEM to evaluate the life to the fatigue in dental prostheses submitted to multiaxial loads. For this, we used the manipulation of acquired images, normative experimental tests, Finite Element analysis (FEA) in the prediction of life to the fatigue applied in either uniaxial or multiaxial loading, the counting of the fatigue damage in multiaxial amplitude variable loading, optimization and implementation of the subroutine for the APDL -MATLAB interfaces. The results showed that, through the techniques of image data acquisition (Micro-CT) and mechanical measurements combined with numerical methods, it is possible to model a complex structure such as a dental prostheses.
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Investigations into the use of nano-based antimicrobial and osteoconductive coatings for bone implantsMemarzadeh, Kaveh January 2014 (has links)
Objectives: Orthopaedic and dental implants are prone to frequent infections. This can lead to detrimental and often irreversible outcomes for many patients. The objective of this study was to develop a novel system using zinc oxide nanoparticles (nZnO) as a coating material that inhibits both bacterial adhesion / growth and promotes osteoblast growth. Methods and Results: Initially bacteria (S. aureus, E. coli, S. epidermidis and P. aeruginosa) were exposed to different concentrations of zinc oxide nanoparticulate suspensions (250 μg/mL, 500 μg/mL, 1000 μg/mL and 2500 μg/mL); with the higher concentrations of the suspensions demonstrating significant bactericidal effects. A novel electrohydrodynamic atomization coating technique (EHDA) was used to deposit mixtures of nZnO and nano-hydroxyapatite (nHA) onto the surface of glass samples (1 cm2). Exposure of the coated samples to phosphate buffered saline (PBS) and adult bovine serum (ABS) and measurement of bactericidal activity demonstrated superior antimicrobial activity for 100% and 75% nZnO composite coated samples. Lactate dehydrogenase (LDH) release from osteoblast-like cells (UMR-106 and MG-63) exposed to both nano-TiO2 and nano-ZnO nanoparticulate suspension supernatants indicated minimal toxicity. Nano-ZnO coated samples did not elicit LDH release with an increase in proliferation and viability of cells was observed. Scanning electron microscopy (SEM) and optical microscopy indicated that all cell types used (mesenchymal stem cells and osteoblast-like cells) were able to maintain their normal morphological state when adhered to the surface of the nano-coated material. Further studies as regards to patterned coated samples showed an exclusive adhesion selection by osteoblast-like cells to nZnO patterned regions that needs to be further investigated. Conclusion: ZnO NPs provide an antimicrobial and biocompatible coating material for medical and dental bone implants.
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Investigation of head-neck tapers in modular hip prosthesesRaji, Halimat-Shaddiya Yewande January 2018 (has links)
Corrosion at the head-neck junction of total hip replacements is a poorly understood phenomenon with an incidence of 1 - 2 %. Concerns around taper junction corrosion have focused on design factors including changes in taper surface topography and geometry as well as operating conditions such as high bearing surface friction and fluid ingress-egress at the taper junction. Hence, this thesis considered 3 aspects of the head taper junction namely: (1) frictional torque at the bearing surface and below the taper junction for varying head sizes and bearing material combinations, (2) Cobalt and Chromium ion release from CoCr/Ti taper junctions, (3) FE analysis of tapers utilising variables including taper length, material, angle, and clearance under loading conditions representative of walking, hip simulator profiles and stair climb. Bearing friction and the torque about the taper axis beneath the taper junction were positively correlated with the head size (R2 = 0.57 bearing friction, R2 = 0.88 torque) and average surface roughness (Ra) (R2 = 0.66 bearing friction, R2=0.79 torque) of the femoral head. Torque generated on large MoP bearings (0.93 ± 0.2 Nm) was found to be comparable to MoM (0.81 Nm). The median cumulative Cr release rate was at least 2 times greater than that of Co (0.0220 ppb/cycle Cr relative to 0.0109 ppb/cycle Co) due to the acidic environment utilised in the accelerated tests. No statistically significant difference in ion release was found, between the trunnions of different surface finishes. Finite element analyses showed that the largest gaps generated at the mouth of the taper, were associated with smaller taper contact areas. Clearances within ±0.1° enabled the tapers to engage over comparable lengths and therefore did not show differences in taper opening, showing this was influenced by the taper engagement length rather than location (proximal or distal) of contact. Stair climb loading generated the largest taper gaps (80 m) and surface stresses on the head taper (1200 MPa); these were greatest on the shortest trunnion. Although the stair climb loading condition is not currently mandated in testing THR devices, its use could provide a more accurate prediction of taper performance in vivo and may be beneficial to 'beyond compliance' initiatives to improve implant performance.
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Discrete choice analysis of preferences for dental prosthesesZhang, Shanshan January 2014 (has links)
Background: Tooth loss has a negative impact on patients’ general health and wellbeing. Dental prostheses can restore oral function, aesthetics and improve oral health related quality of life. Preferences for dental prostheses cannot be fully captured using existing clinical studies and questionnaires. Discrete choice experiment (DCE) is a novel method in health economics to elicit people’s preference for treatments and it allows the researcher to integrate all aspects relevant to treatment into evaluation and measurement of interrelationship between factors. The aim of this PhD thesis is to use a mixed method of DCE and qualitative interviews to analyse dentists and patient’s preferences for dental prosthesis choices in replacing missing teeth. Methods: Discrete choice experiment questionnaires were developed, describing dental prosthdontic treatments in multi-dimensions, including outcome, process and economic factors. Survey and analysis using the questionnaires were conducted with dentists and patients in Edinburgh. Qualitative interviews with Edinburgh dentists and patients were carried out to derive factors to aid the DCE questionnaire design and provide in-depth understanding of DCE results. Systematic reviews were performed to summarise existing evidence on prosthesis evaluation in traditional quantitative studies and perception of prostheses in qualitative interviews. The current application of DCEs in dentistry was also systematically reviewed. Results: Treatment longevity was identified as the most important factor for dentists and patients’ treatment decisions of anterior missing tooth replacements, followed by appearance and chewing function. Dentists put more value on fixation/comfort and treatment procedure than patients. Patients cared about cost of treatment whereas dentists were relatively insensitive. Gender, age and treatment experience significantly influenced patients’ preference for treatment characteristics. Dental implant supported crown was preferred by dentists, whereas patients gave higher utility to traditional prosthodontic treatments. The monetary benefit of fixed dental prostheses ranged from £1856 -£3848 for patients, far exceeding their willingness-to-pay (WTP), which was £120 - £240. Dentists were willing to pay £600-£3000, more than the perceived benefit £503 to £1649. Qualitative study identified the above factors and provided interpretation of DCE results. Problems in the dental care system related to referral and training for dental implant treatments were raised. Discussion: This thesis is the first DCE application in dentistry evaluating and comparing dentists and patients preferences for missing tooth replacements. Dentists and patients’ preferences were elicited qualitatively and qualitatively integrating multidimensional factors. Patients’ preference for treatments, monetary benefit and WTP were demonstrated to be different from dentists’. Treatment benefits exceeded patients WTP for fixed dental prostheses.
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Análise de fadiga em próteses odontológicas implanto-suportada sob carregamento multiaxiais. / Analysis of failure in implanto-supported odontological prostheses under multiaxial loading.Henry Figueredo Losada 13 November 2018 (has links)
Próteses odontológicas são estruturas que restituem a função mastigatória e substituem componentes dentários danificados. A maioria dos estudos em próteses odontológicas que envolve métodos analíticos clássicos de análise de estrutura são inviáveis e situações nas quais a experimentação é dificultosa. Estas próteses, sob condições reais de carregamentos cíclicos (mastigação), são repetidamente sujeitas à estados de tensões multiaxiais cíclicas. Neste sentido, a natureza cíclica do carregamento, a qual os componentes das próteses são submetidos, sugere que o modo de falha por fadiga possui maior relevância neste tipo de estrutura. O desenvolvimento da computação eo aumento das capacidades de processamentos tem permitido maior implementação dos métodos numéricos, como o Métodos de Elementos Finitos (MEF). Através deste método (MEF) se realiza a modelagem do comportamento mecânico ajustadas à realidade física dos fatores biomecânicos envolvidos. Em uma revisão bibliográfica, verificou-se que a maioria dos livros e artigos encontrados não apresentam informação detalhadas sobre a previsão da vida baseado em análises de fadiga multiaxial que utilizem o MEF para cálculo das próteses odontológicas. O objetivo deste trabalho foi propor um modelo numérico computacional utilizando o MEF para avaliar a vida à fadiga em próteses odontológicas submetidas a carregamentos multiaxiais. Para isso, foi empregada a manipulação de imagens adquiridas, ensaios experimentais normativos, Análise por Elemento Finitos (FEA) na previsão de vida à fadiga aplicada tanto em carregamento uniaxial ou multiaxial, a contabilização do dano por fadiga em carregamento multiaxial de amplitude variáveis, otimização e implementação de subrotina para as interfaces APDL -MATLAB. Os resultados mostraram que, através das técnicas de aquisição de dados de imagens (Micro-CT) e medições mecânicas combinadas com métodos numéricos consegue-se modelar uma estrutura complexa como uma prótese dental. / Dental prostheses are structures that restore the masticatory function and replace damaged dental components. Most studies on dental prostheses involve that classical analytical methods of structure analysis are infeasible and situations in which experimentation is difficult. These prostheses, under real conditions of cyclic loading (chewing), are repeatedly subjected to cyclic multiaxial stress states. In this sense, the cyclical nature of the loading, to which the components of the prosthesis are submitted, suggests that the fatigue failure mode has greater relevance in this type of structure. The development of computation and the increase of processing capacities have allowed greater implementation of numerical methods, such as Finite Element Methods (FEM). Through this method (FEM) it is performed the modeling of the mechanical behavior which is adjusted to the physical reality of the involved biomechanical factors. In a bibliographical review, it was verified that most of the books and articles found do not present detailed information about the prediction of life based on analyzes of multiaxial fatigue that use the FEM to calculate the dental prostheses. The objective of this research was to propose a computational numerical model using the FEM to evaluate the life to the fatigue in dental prostheses submitted to multiaxial loads. For this, we used the manipulation of acquired images, normative experimental tests, Finite Element analysis (FEA) in the prediction of life to the fatigue applied in either uniaxial or multiaxial loading, the counting of the fatigue damage in multiaxial amplitude variable loading, optimization and implementation of the subroutine for the APDL -MATLAB interfaces. The results showed that, through the techniques of image data acquisition (Micro-CT) and mechanical measurements combined with numerical methods, it is possible to model a complex structure such as a dental prostheses.
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Efeito de cargas compressivas oblíquas e da simulação de ciclos mastigatório sobre pilares para implantes cone morse / Effects of oblique compressive load and simulated chewing cycles on internal tapered implant-abutment connectionsMoris, Izabela Cristina Mauricio 15 December 2011 (has links)
A literatura relata que a união osso/implante é extremamente confiável, porém limitações clínicas em relação à prótese ainda ocorrem. Recentemente foi proposto um pilar para implantes cone morse cujo desenho permite a escolha entre coroas cimentadas ou parafusadas, adicionalmente, este pilar também é apresentado em dois tamanhos, o convencional (ø 4,8 mm) e reduzido (ø 3,8 mm). O objetivo deste estudo foi avaliar a resistência à deformação dos pilares protéticos, a resistência de cimentação das coroas e os efeitos da simulação de ciclos mastigatórios sobre: adaptação marginal, perda de torque nos parafusos das coroas e perda de torque dos dois diferentes pilares. Para avaliar a resistência à deformação, 20 implantes/pilares com diâmetro de 4.8 e 3.8 foram submetidos à carga compressiva oblíqua. Para avaliar as outras situações, 40 implantes/pilares foram divididos nos seguintes grupos (N=10): G4.8P- pilar de 4.8 e coroas parafusadas; G4.8C-pilar de 4.8 e coroas cimentadas; G3.8P- pilar de 3.8 e coroas parafusadas; G3.8C- pilar de 3.8 e coroas cimentadas. Todas as coroas foram avaliadas em relação à adaptação marginal antes e após a simulação de ciclos mastigatórios e as coroas cimentadas foram submetidas ao teste de resistência à tração previamente ao ensaio. Os conjuntos foram submetidos a 300.000 ciclos de simulação de movimentos mastigatórios. A perda de torque das coroas parafusadas e de todos os pilares foi analisada antes a após o ensaio. Não houve diferenças significantes para a resistência à deformação entre os pilares; para a resistência de cimentação houve diferenças significantes entre os dois pilares (p≤0,05). Para a adaptação marginal houve diferenças significantes antes e após a simulação dos ciclos mastigatórios entre os grupos G3.8P (p=0,037) e G3.8C (p≤0,05); para a comparação da adaptação das coroas entre os pilares houve diferenças antes da simulação dos ciclos mastigatórios quando comparado os grupos 3.8C com 3.8P e antes e após da simulação quando comparado os grupos 4.8C com 4.8P, para as demais comparações não houve diferença. Quanto à perda de torque nos parafusos das coroas houve diferenças significantes antes e após a simulação dos ciclos mastigatórios para ambos os pilares, quanto às comparações entre os diferentes grupos antes e após a simulação de ciclos mastigatórios houve diferença apenas após (p=0,008) a simulação. Quanto à perda de torque para os pilares houve diferenças significantes apenas para o grupo 3.8C (p≤0,05) antes e após a simulação dos ciclos mastigatórios. Considerando as limitações deste estudo, conclui-se que em relação à resistência à deformação os pilares apresentaram valores próximos; quanto a retenção das coroas, cimentadas e parafusadas, os pilares de 4.8 foram estatisticamente superiores aos pilares de 3.8; a simulação de ciclos mastigatórios teve influência sobre a adaptação marginal das coroas e em relação a perda de torque dos pilares não foram encontradas diferenças estatísticas. / Reports in the literature have stated that the bone/implant interface is extremely reliable. However, clinical limitations in relation to the prosthesis still occur. A Morse taper implant-abutment design that allows choosing between cemented or screwed crowns has been recently proposed. The abutment is presented in two different diameter sizes (conventional (ø 4.8 mm) and narrow (ø 3.8 mm). The aim of this study was to evaluate the resistance to deformation of the implant/abutment interface, the tensile strength of the cemented crowns and the effects of simulated chewing cycles on: marginal fit, crown-screw torque loss and torque loss of the two different abutments. To evaluate the resistance to deformation, 20 abutments with diameter of 4.8 and 3.8 were subjected to compressive oblique load. To evaluate the other situations, 40 implants/abutments were divided into the following groups (N = 10): G4.8P-abutment 4.8 with screwed crowns; G4.8C-abutment 4.8 with cemented crowns; G3.8P abutment 3.8 with screwed crows; G3.8C-abutment 3.8 with cemented crowns. All crowns were evaluated for marginal fit before and after simulation of the chewing cycles. The cemented crowns were subjected to tensile strength test before the simulated chewing cycles. The specimens were subjected to 300,000 cycles that simulated the chewing movements. The torque loss of the screwed crowns and all abutments were analyzed before and after the cycling tests. No significant differences were found for the deformation resistance between the abutments. No significant differences were found in the tensile strength of the cemented crowns between the two abutments (p≤0.05). The marginal fit of the crowns found no significant differences before and after the simulation of the chewing cycles between groups G3.8P (p = 0.037) and G3.8C (p≤0.05). No differences were found in crown misfit between the abutments before simulating the chewing cycles when compared between groups 3.8C 3.8P. No differences were found between groups 4.8C and 4.8P before and after the chewing simulation. Torque loss of the screwed crowns was not significantly different before and after the simulation of the chewing cycles for both abutments. Comparisons between the different groups before and after simulation found significant differences after the simulation of the chewing cycles (p = 0.008). Group 3.8C was the only group that presented significant differences (p≤0.05) before and after the simulation cycles. Within the limitations of this study, it can be concluded that the resistance to deformation between both abutments was similar. Retention of cemented and screwed crowns was statistically higher for the 4.8 abutments when compared to the 3.8 abutments. The simulation of chewing cycles significantly influenced the marginal fit of the crowns. No differences statistically significant in torque loss were found between the two abutments.
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Evolución de las terminaciones en las preparaciones dentarias en Rehabilitación OralKawashima Matamoros, Luciana Sachie 14 December 2018 (has links)
El objetivo de esta revisión es reportar las técnicas paso a paso para realizar terminaciones dentarias correctas según el material para la confección de las prótesis fijas. / The aim of this review is to report on the techniques to perform corrected dental terminations according to the preparation material of fixed prostheses. / Tesis
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Post-mastectomy self-perceptions and breast restoration decision- making in women who wear external breast prostheses and women who have had breast reconstructions : implications for health professionalsLewis Reaby, Linda, n/a January 1996 (has links)
Women diagnosed with breast cancer and who have the disease surgically treated by
mastectomy experience a health crisis. This thesis focused on the behaviours, feelings
and attitudes of women during their breast cancer and mastectomy experiences. The
overall purpose was to identify therapeutic factors that can be used by health
professionals to improve the psychological and physiological well-being of women with
this disease. The conceptual scaffolding for the thesis was drawn from the fields of
perceptual psychology and decision-making.
The thesis was supported by a study that examined specific areas concerning the breast
cancer and mastectomy experience. These areas were self-perceptions, the
psychological milieu resulting from a breast cancer diagnosis, and post-mastectomy
breast restoration decision-making. The population included: a prosthesis group of 64
women who had mastectomies and wore external breast prostheses, a reconstruction
group of 31 women who had mastectomies and underwent breast reconstructions, a
control A group of 75 women who had not experienced mastectomy, and a control B
group of 65 women who also had not experienced mastectomy.
Self-perceptions:
The perceptions of the prosthesis, reconstruction and control A groups regarding their
body-image, self-concept, total self-image, and self-esteem were compared by using
Polivy's (1977) Body-Image Scale and Rosenberg's (1965) Self-Esteem Scale. The
body-image, total self-image, and self-esteem mean scores indicated that the prosthesis
and reconstruction groups had more positive feelings regarding their bodies than did the
control group. There were no significant differences in self-concept among the three
groups. These findings challenge a common assumption that mastectomy automatically
results in psychiatric morbidity caused by an altered body-image and suggest that health
professionals should not make assumptions about how a woman will psychologically
respond to mastectomy.
Quality of life perceptions were compared among the prosthesis, reconstruction and
control B groups using the Ferrans and Powers (1985) Quality of Life Index. The mean
scores of the prosthesis and reconstruction groups were higher than the control group's
scores, with higher scores indicating more positive quality of life perceptions. The
findings suggest that the women in the mastectomy samples had found ways to cope
with their health crises. Over time, they learned not to define all existence in terms of a
cancer diagnosis and had gained or maintained a positive perspective on life.
Post-mastectomy attitudes in the prosthesis and the reconstruction groups were
compared. Using the Mastectomy Attitude Scale the results indicated that both groups
were satisfied with their bodies, had a positive outlook towards their lives, implied that
sexuality entailed more than having breasts, and felt that mastectomy treatment was
necessary to save their lives. Neither group concealed that they had a mastectomy, nor
were the women prone to discuss their mastectomy experiences. The findings from the
study indicate that the women post-mastectomy already had or developed positive
attitudes towards themselves and life in general and the method chosen for breast
restoration had no apparent impact on these attitudes.
The self-perception data indicated that women do adjust and cope with breast cancer
surgically treated by mastectomy. These women should be encouraged by health
professionals to develop a helping relationship with other women who are newly
diagnosed with the disease. This alliance could engender hope in those women who are
beginning their journey along a similar road to survival. More hope for these women
and less fatalism would decrease their sense of crisis and facilitate their abilities to take
an active part in the decision-making processes relating to their treatment.
Psychological Milieu:
The women in the prosthesis and the reconstruction groups were interviewed about their
breast cancer and mastectomy experiences. The findings supported the premise that
receiving a diagnosis of breast cancer plunged the women into a health crisis and caused
an instant disruption to their lives. The women found that they had to suddenly deal
with several complex issues all at the same time, such as what must be done in the
immediate future to treat the cancer, as well as the more frightening issues of the
meaning of the illness on their ultimate life expectancy. All of this turmoil played
havoc with their ability to make informed decisions regarding their breast cancer
treatment alternatives. This finding suggests the need for more individualised
interventions and support for women when they are making decisions during this
stressful period. Health professionals need to keep in mind that simply hearing the
word "cancer" often prevents a person from assimilating the complete diagnosis,
indicated treatments, and possible prognosis. Therefore, care-givers must be prepared
to repeat and elaborate upon information previously given to the affected individual and
the family.
Breast Restoration Decision-Making:
To evaluate the prosthesis and the reconstruction groups' abilities to undertake
competent breast restoration decision-making, a 5 Stage process was devised, modelled
after Janis and Mann's (1977) seven criteria for competent decision-making. Analysis
of the data revealed that both groups displayed passive information seeking behaviour
in relation to breast restoration alternatives. They had either no knowledge or limited
knowledge regarding the alternatives. Their lack of knowledge was due either to (1)
anxiety about their disease, or (2) deficiencies in the interpersonal skills of individuals
presenting information to them, or (3) the perceptions that they had insufficient time to
gather information, or (4) a combination of these factors.
Because the prosthesis and the reconstruction groups were under stress they used coping
styles to accomplish decision-making. To measure their coping styles five categories
were defined, based on Janis and Mann's (1977) conflict model of emergency decisionmaking
and Simon's (1957) notion of "bounded rationality". Two styles emerged. The
prosthesis group used the "Sideliner" style that allowed the women to make a quick,
conflict-free decision. They were not aware of alternative choices resulting in their
decision-making experience being uncomplicated and effortless. The reconstruction
group used the "Contented" style that also allowed them an uncomplicated and
effortless decision-making experience. The women decided that breast reconstruction
was their only viable option. Many of them did not even think that they had made a
decision about an alternative because of the strong salience towards breast
reconstruction.
A breast restoration decision-making model has been developed and proposed for
women to use when considering their alternatives. This model offers to health
professionals and women a realistic and useable decision-making process that can be
implemented when individuals are experiencing a health crisis. The model can be
modified and used for numerous situations that require decisions regarding treatment
alternatives.
This inquiry has demonstrated that there is a need for a specific health professional to
assist women newly diagnosed with breast cancer. This individual would assume
several roles that include one of advocacy for the women, and the important role of
ensuring that these individuals have the information and knowledge to make competent
decisions regarding their breast cancer treatments.
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Accuracy and precision of a technique to assess residual limb volume with a measuring-tapeJarl, Gustav January 2003 (has links)
Transtibial stump volume can change dramatically postoperatively and jeopardise prosthetic fitting. Differences between individuals make it hard to give general recommendations of when to fit with a definitive prosthesis. Measuring the stump volume on every patient could solve this, but most methods for volume assessments are too complicated for clinical use. The aim of this study was to evaluate accuracy and intra- and interrater precision of a method to estimate stump volume from circumferential measurements. The method approximates the stump as a number of cut cones and the tip as a sphere segment. Accuracy was evaluated theoretically on six scanned stump models in CAPOD software and manually on six stump models. Precision was evaluated by comparing measurements made by four CPOs on eight stumps. Measuring devices were a wooden rule and a metal circumference rule. The errors were estimated with intraclass correlation coefficient (ICC), where 0,85 was considered acceptable, and a clinical criterion that a volume error of ±5% was acceptable (5% corresponds to one stocking). The method was accurate on all models in theory but accurate on only four models in reality. The ICC was 0,95-1,00 for intrarater precision but only 0,76 for interrater precision. Intra- and interrater precision was unsatisfying when using clinical criteria. Variations between estimated tip heights and circumferences were causing the errors. The method needs to be developed and is not suitable for stumps with narrow ends. Using a longer rule (about 30 cm) with a set square end to assess tip heights is recommended to improve precision. Using a flexible measuring-tape (possible to disinfect) with a spring-loaded handle could improve precision of the circumferential measurements.
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Development of a wearable sensor system for real-time control of knee prosthesesAlmeida, Eduardo Carlos Venancio de January 2012 (has links)
It was demonstrated in recent studies that Complementary Limb Motion Estimation (CLME) is robust approach for controlling active knee prostheses. A wearable sensor system is then needed to provide inputs to the controller in a real-time platform. In the present work, a wearable sensor system based on magnetic and inertial measurement units (MIMU) together with a simple calibration procedure were proposed. This sensor system was intended to substitute and extend the capabilities of a previous device based on potentiometers and gyroscopes. The proposed sensor system and calibration were validated with an Optical Tracking System (OTS) in a standard gait lab and first results showed that the proposed solution had a performance comparable to similar studies in the literature.
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