3D stereoscopic technology intensifies and heightens the viewer s experience by adding an extra dimension to the viewing of visual content. However, with expansion of this technology to the commercial market concerns have been expressed about the potential negative effects on the visual system, producing viewer discomfort. The visual stimulus provided by a 3D stereoscopic display differs from that of the real world, and so it is important to understand whether these differences may pose a health hazard. The aim of this thesis is to investigate the effect of 3D stereoscopic stimulation on visual discomfort. To that end, four experimental studies were conducted. In the first study two hypotheses were tested. The first hypothesis was that the viewing of 3D stereoscopic stimuli, which are located geometrically beyond the screen on which the images are displayed, would induce adaptation changes in the resting position of the eyes (exophoric heterophoria changes). The second hypothesis was that participants whose heterophoria changed as a consequence of adaptation during the viewing of the stereoscopic stimuli would experience less visual discomfort than those people whose heterophoria did not adapt. In the experiment an increase of visual discomfort change in the 3D condition in comparison with the 2D condition was found. Also, there were statistically significant changes in heterophoria under 3D conditions as compared with 2D conditions. However, there was appreciable variability in the magnitude of this adaptation among individuals, and no correlation between the amount of heterophoria change and visual discomfort change was observed. In the second experiment the two hypotheses tested were based on the vergence-accommodation mismatch theory, and the visual-vestibular mismatch theory. The vergence-accommodation mismatch theory predicts that a greater mismatch between the stimuli to accommodation and to vergence would produce greater symptoms in visual discomfort when viewing in 3D conditions than when viewing in 2D conditions. An increase of visual discomfort change in the 3D condition in comparison with the 2D condition was indeed found; however the magnitude of visual discomfort reported did not correlate with the mismatch present during the watching of 3D stereoscopic stimuli. The visual-vestibular mismatch theory predicts that viewing a stimulus stereoscopically will produce a greater sense of vection than viewing it in 2D. This will increase the conflict between the signals from the visual and vestibular systems, producing greater VIMS (Visually- Induced Motion Sickness) symptoms. Participants did indeed report an increase in motion sickness symptoms in the 3D condition. Furthermore, participants with closer seating positions reported more VIMS than participants sitting farther away whilst viewing 3D stimuli. This suggests that the amount of visual field stimulated during 3D presentation affects VIMS, and is an important factor in terms of viewing comfort. In the study more younger viewers (21 to 39 years old) than older viewers (40 years old and older) reported a greater change in visual discomfort during the 3D condition than the 2D condition. This suggests that the visual system s response to a stimulus, rather than the stimulus itself, is a reason for discomfort. No influence of gender on viewing comfort was found. In the next experiment participants fusion capability, as measured by their fusional reserves, was examined to determine whether this component has an impact on reported discomfort during the watching of movies in the 3D condition versus the 2D condition. It was hypothesised that participants with limited fusional range would experience more visual discomfort than participants with a wide fusion range. The hypothesis was confirmed but only in the case of convergent and not divergent eye movement. This observation illustrates that participants capability to convergence has a significant impact on visual comfort. The aim of the last experiment was to examine responses of the accommodation system to changes in 3D stimulus position and to determine whether discrepancies in these responses (i.e. accommodation overshoot, accommodation undershoot) could account for visual discomfort experienced during 3D stereoscopic viewing. It was found that accommodation discrepancy was larger for perceived forwards movement than for perceived backwards movement. The discrepancy was slightly higher in the group susceptible to visual discomfort than in the group not susceptible to visual discomfort, but this difference was not statistically significant. When considering the research findings as a whole it was apparent that not all participants experienced more discomfort whilst watching 3D stereoscopic stimuli than whilst watching 2D stimuli. More visual discomfort in the 3D condition than in the 2D condition was reported by 35% of the participants, whilst 24% of the participants reported more headaches and 17% of the participants reported more VIMS. The research indicates that multiple causative factors have an impact on reported symptoms. The analysis of the data suggests that discomfort experienced by people during 3D stereoscopic stimulation may reveal binocular vision problems. This observation suggests that 3D technology could be used as a screening method to diagnose un-treated binocular vision disorder. Additionally, this work shows that 3D stereoscopic technology can be easily adopted to binocular vision measurement. The conclusion of this thesis is that many people do not suffer adverse symptoms when viewing 3D stereoscopic displays, but that if adverse symptoms are present they can be caused either by the conflict in the stimulus, or by the heightened experience of self-motion which leads to Visually-Induced Motion Sickness (VIMS).

Ma thèse a pour objectifs d’étudier et d’améliorer le confort d’un coussin d’assise dans le cas d’un fauteuil roulant pour handicapé, afin de limiter au mieux, l’apparition des escarres.Mes travaux ont pour principal objectif de modéliser et de simuler numériquement un coussin de type nid d’abeille de marque ‘‘Stimulite® Honeycomb Cushion’’ en contact avec un fessier afin de pouvoir (i) modéliser le comportement mécanique de contact, (ii) d’évaluer la pression ainsi que la distribution des contraintes à l’interface coussin/fessier, et (iii) d’intégrer les échanges thermomécaniques.Par ailleurs, des essais expérimentaux ont été effectués pour quantifier les lois de comportement des matériaux constituants le coussin nid d’abeille. J’ai également utilisé une nappe permettant de mesurer la pression à l’interface coussin/fessier. Parallèlement, une caméra infrarouge a été utilisée pour mesurer la répartition de la température sur le coussin et le fessier pour une personne assise pendant une durée variable. / The aim of this thesis is to study and improve the comfort of a wheelchair cushion for handicapped, to reduce the appearance of pressure ulcers.In the study, the main objective is to model and simulate numerically a type of cushion, namely ‘‘Stimulite® Honeycomb Cushion Classis’’, in contact with a buttocks-tissue in order to (i) model the mechanical behavior of contact, (ii) evaluate the pressure and the stress distribution at the interface cushion/buttock-tissue, and (iii) integrate thermo-mechanical exchanges.Moreover, the experimental tests were carried out to quantify the law of behavior of material constituent of the honeycomb cushion. I also used a pressure-mapping sensor TexiMat® to measure the pressure at the interface cushion/buttocks-tissue.Meanwhile, an infrared camera was used to measure the temperature distribution on the cushion and buttocks-tissue of a person sitting during variable periods.

Charles University in Prague, Czech Republic Faculty of Pharmacy in Hradec Kralove Dept. of Social and Clinical Pharmacy Author: Kristýna Tumová, DiS. Tutor: PhDr. Eva Švarcová, Ph.D. Thesis: Psychosocial workload of Pharmacists II. Background: My work is focused on pharmacy professionals in terms of their daily mental stress. Aim of study: To characterize the profession of a pharmacist from a historical perspective, their role in society, and the legislative definitions. Describe concepts related to mental health and mental hygiene focusing on stress, fatigue, and burnout. In the practical part, analyse the identified subjective feelings of fatigue of pharmacists and pharmaceutical assistants while comparing these two interviewed groups and evaluating the impact of the pharmacy location (city, village). Methods: Questionnaire survey through the Subjective Symptoms of Fatigue (SSF) questionnaire and the scale of Mental Fatigue. Respondents - pharmacists and pharmaceutical assistants in the same proportion of representation concerning the expertise and location of the pharmacy. A total of 200 respondents, 100 respondents from villages and 100 from cities. Each of the 100 respondents is represented by 50 pharmacists and 50 pharmaceutical assistants. Processing of results - Microsoft Excel program....

Charles University, Faculty of Pharmacy in Hradec Králové Department Department of Social and Clinical Pharmacy Candidate Barbora Čavajdová Consultant PhDr. Eva Švarcová, Ph.D. Thesis Title Psychosocial Work Burden of Pharmacists I. Introduction: Practicing a pharmacy as a pharmacist can cause stress and strain. The main task is to dispense medicines, where a lot of attention and responsibility is needed. With the induced stress and the action of stressors, there are feelings of fatigue, which disappear after rest. Working conditions are an important factor that affect the overall mental and physical condition of the pharmacist. Objective: The aim of the work was to evaluate the degree of fatigue of pharmacists by analyzing working conditions and based on the results to recommend proposals for improving health and working conditions. Methods: The method was based on a questionnaire survey, where pharmacists responded to the degree of fatigue in the area of subjective feelings of fatigue, vision problems and problems associated with the musculoskeletal system. Questionnaires were filled in by pharmacists from chain and independent pharmacies, and the results were then compared. Out of 200 questionnaires, 160 fully completed questions were returned to me and the results were evaluated in Microsoft...

Charles University, Faculty of Pharmacy in Hradec Králové Department Department of Social and Clinical Pharmacy Candidate Barbora Čavajdová Consultant PhDr. Eva Švarcová, Ph.D. Thesis Title Pharmacists' health aspects of stress Introduction: Pharmacists working in pharmacies may be subject to some strain and stress. The main task of this profession is the dispensing of medicines when you need to be very attentive and responsible. With the action of stressors and the consequent stress there are manifestations of fatigue which disappear with rest. Working conditions are an important factor that affect the overall mental and physical condition of the pharmacist. Objective: The aim of the thesis was to evaluate the degree of fatigue of pharmacists by analysing working conditions and based on the results to recommend proposals for improving health and working conditions in pharmacies. Methods: The method was based on a questionnaire survey, where pharmacists responded to the degree of fatigue in the area of subjective feelings of fatigue, vision problems and problems associated with the musculoskeletal system. Questionnaires were filled in by pharmacists from chain (Benu and Dr.Max) and other pharmacies, then the results were compared. Out of 200 questionnaires, 160 fully completed questions were...

Vocal fatigue is a frequent symptom and a debilitating condition affecting individuals with voice disorders. In spite of the various attempts to define and quantify vocal fatigue, this complex trait has not been well understood. Mokken scaling was performed on the Vocal Fatigue Index (VFI) to develop a hierarchical understanding of the latent trait of vocal fatigue. Two hundred nine patients with voice disorders completed the VFI and provided the item responses necessary to complete the Mokken scaling. Results revealed a moderately strong Mokken scale and that the VFI presents a hierarchical structure to the underlying trait of vocal fatigue. Mokken scaling contributes to the ongoing investigation to the underlying construct of vocal fatigue and may provide additional information about specific complaints within the population of those with voice disorders.

Dry eye syndrome has been associated with the lack of phospholipids in the tear film, leading to disruption of the tear film and subsequent irritation. Characterization of the transport and release of phospholipids from a silicone hydrogel contact lens is required to assess the possible use of these lenses for phospholipid delivery to increase patient comfort. This thesis examines the use of silicone hydrogel contact lenses as phospholipid delivery devices. Contact lenses of silicone hydrogel composition were loaded with varying amounts of radiolabeled 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) from a solution of n-propanol. These lenses were eluted at 35°C into artificial tear fluid (ATF) or ATFcontaining varying amounts of DMPC. The amount of DMPC loaded into a lens is a linear function of the time of exposure to the DMPC/propanol solution. The initial rate of elution into ATF appears to be diffusion controlled for at least 10 hrs and is proportional to the amount of DMPC loaded. The ease of loading and the controllable release of DMPC from silicone hydrogels present the possibility of using such lenses to counter eye discomfort caused by inherently low levels of phospholipid in tears. To reduce manufacturing steps and concern for residual n-propanol in the lens, it is beneficial to incorporate the DMPC into the monomer formulation and then photopolymerize the lens. Results showed that using this process, DMPC can be placed in the lens and then eluted at faster rates than when it was loaded from n-propanol.

This study examines how a user-centered approach can influence product design to reduce physical discomfort when using in-ear true wireless. The given study is a collaboration with the consumer electronics company Zound Industries. The purpose has been to understand the origins of why physical discomfort can arise when using in-ear true wireless headphones and to what extent the user behaviour plays in it all. Previous studies have shown how physical discomfort in the form of eczema, itching and soreness has been caused by the use of in-ear true wireless. Based on user-centered methods such as expert interviews, cultural probes, user interviews, focus groups, this study has been able to identify not only how, but why physical discomfort can occur when using in-ear true wireless. Furthermore, the study has also been able to identify behavioural patterns among users that reveal how headphones are used for purposes other than what they are intended for. It has been possible to show how users use their headphones like an earplug without music to block out sound in order to be able focus or to communicate they don’t want to be disturbed to avoid social interactions. The conducted knowledge and insights provide a better understanding of how design can be used to enhance the experience of using in-ear true wireless headphones. Applying design strategies within design for behavioural change, an adjustable headphone has been developed that allows the user to use the headphone according to the needs of the user. The study provides a basis for how design can be better utilised in future in-ear true wireless headphones.

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