Pressure injuries cause pain both physically and financially. By creating a comfortable pressure mapping system, pressure injuries can more easily be prevented, and a large expenditure avoided. Nano composite piezo-responsive foam (NCPF) is an inexpensive foam that can be used to measure a static load while still providing a comfortable interface. As NCPF compresses, the impedance changes, correlating to a change in pressure. Optimizing electrode geometry is needed to take full advantage of the impedance change NCPF incurs upon deformation. To optimize electrode geometry, a design of experiment was performed which concluded that a one square inch area of interlaced finger electrodes provides the largest change in impedance with a finger gap of 1.5 mm. The optimized electrode geometry is utilized in several demonstrations including a modular design allowing a wide range of surfaces to be mapped using the same hardware. By building a phenomenological model, NCPF output voltage is converted to pressure readings with an RMSE of 8.02%. This model provides evidence that using NCPF as a pressure sensor is a viable path to creating smart objects that an individual interacts with daily. In addition to the modular design, this technology is demonstrated in pressure sensing gloves and pressure plates, highlighting the feasibility of NCPF as a pressure sensing medium. Each system developed with NCPF is outfitted with an iOS application which allows for real time system feedback as well as record keeping capabilities.

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SAMMANFATTNING   Bakgrund: Trycksår är en lokal skada i huden och i underliggande vävnad som kan uppkomma i samband med sjukdom, vård och behandling. Trycksår betraktas idag som en vårdskada och ska anmälas som en avvikelse. För individen innebär det stort lidande och ger höga kostnader för samhället, större omvårdnadsbehov och förlängda vårdtider. Studier visar att kunskap om trycksårsprevention hos sjuksköterskor och undersköterskor i Sverige inte är tillräckligt hög. Ett trycksensorsystem (MAP-system) finns nu tillgängligt som ger omedelbar feedback av patientens tryckpunkter som ett hjälpmedel vid trycksårsprevention. Syfte: Att utvärdera effekten av MAP- systemet avseende förekomst av trycksår hos äldre patienter under vårdtiden på en geriatrisk avdelning på sjukhus. Metod: En randomiserad, kontrollerad studiedesign valdes. En geriatrisk vårdavdelning valdes ut med en MAP-grupp (n=91) och en kontrollgrupp (n=99). Ett studieprotokoll användes med uppgifter om: demografisk data, hudinspektion (trycksårsklassificering kategori 1-4), Modifierad Nortonbedömning, komfort, maxtryck samt preventiva åtgärder. Insamlad data behandlades i SPSS och signifikansberäkning, standardavvikelse och medeltal räknades ut. Resultat: Användande av MAP-systemet gav ingen signifikant skillnad i andelen patienter med trycksår mellan MAP- och kontrollgruppen. Andel patienter med trycksår i MAP-gruppen dag ett var 24,2 % och dag 14, 28,2 %. I kontrollgruppen var andelen dag ett 18,2 % och dag 14, 23,8 %. Vanligaste lokalisationen av trycksår var hälar därefter sakrum och glutealt. Patienter med trycksår fick signifikant fler trycksårsförebyggande åtgärder. Slutsats: Studien visar ingen signifikant skillnad mellan andelen patienter med trycksår i MAP- och kontrollgruppen. Preventiva åtgärder prioriterades främst till patienter med trycksår. Genomförandet av studien antas ha medfört ökat fokus på trycksårsprevention samt påverkat prevalensen av trycksår positivt på den aktuella avdelningen. / ABSTRACT   Background: Pressure ulcers consist of local damage to the skin and underlying tissue and can occur in relation to illness, care and treatment. Pressure ulcers are today considered as an adverse event and are to be reported as a deviation from care routines. For the individual it can be the source of great suffering. It also generates large costs for the community, increased needs of nursing as well as prolonged periods of hospitalization. Studies show that the level of knowledge among registered nurses and assistant nurses in Sweden is insufficient. A pressure mapping system (MAP system) is now available, and can provide immediate feedback about the patient´s pressure points as a tool for pressure ulcer prevention. Aim: To study the effect of the MAP system regarding the presence of pressure ulcers in elderly hospitalized patients on a geriatric ward. Method: A randomized, controlled study design was chosen. A geriatric ward was selected with a MAP group (n=91) and a control group (n=99). A study protocol containing demographic data, systematic skin inspection (with classification of pressure ulcers category 1-4), Modified Norton scale, comfort, maximum pressure and preventive measures was used. Data was processed in SPSS; generating mean, standard deviation and level of significance. Results: No significant difference in the prevalence of pressure ulcers was shown between the MAP- group and the control group. The prevalence of pressure ulcers in the MAP-group was 24,2 % on day one and 28,2 % on day 14. In the control group the corresponding numbers were 18,2 % and 23,8 %. The most common localization of pressure ulcers were heels, followed by the sacral and gluteal regions. Patients with pressure ulcers received significantly more preventive measure compared to patients without pressure ulcers. Conclusion: The study shows no significant differences between the groups regarding the prevalence of patients with pressure ulcers. Preventive measures were prioritized mostly for patients with existing pressure ulcers. The study is assumed to have increased the focus on pressure ulcer prevention thus affecting the prevalence of pressure ulcers in a positive way on the present ward.

The hands are essential for our ability to complete tasks. Quantifying the many forces acting on the entire hand is important to improve our understanding of hand function and hand-related musculoskeletal disorders. Biomechanical models of the hand used to compute internal tissue loads typically simplify the applied forces into a single point of force applied at the centre of mass of the distal phalanx. Accounting for the distributed loads across the hands and fingers is a needed step in understanding the loads acting on and inside the body. Therefore, the purpose of this thesis was to use a pressure mapping system to examine the effects of distributed loads on net joint moments and muscle activations in the hands during common tasks. Twenty-three right-handed participants completed a series of finger presses, power grips, and pinch tasks. A pressure mapping system measured pressure on 17 regions of the hand. Three- dimensional hand kinematics was collected using a 72-marker setup. Forces were also measured with a six degrees of freedom force transducer to ensure participants matched specified exertion levels. Pressure distribution, kinematics, and kinetics were used to calculate internal net joint moments at the fingers (distal phalangeal flexion, proximal phalangeal flexion, metacarpal flexion, metacarpal abduction) and muscle activations for 22 forearm and hand muscles using an OpenSim model. External loads were represented in three manners: (1) Centre of Mass Model (COM) distributed the forces over segments that contributed to the force production and placed loads at the centre of mass; (2) Centre of Pressure Model (COP) distributed the forces over segments that contributed to the force production and placed loads at the centre of pressure; (3) Single Point Model (SP) placed a single load at the distal phalanx or the centre of mass of the hand. Results of equivalence tests indicate differences in all net joint moments between COM-SP and COP-SP comparisons. There were no differences between COM and COP. COM and COP moments during all tasks were larger in digits with a larger percentage of total force compared to SP. Due to the larger moments in those conditions, COM and COP calculated larger muscle activities compared to SP. Both internal net joint moments and muscle activations were most affected by the pressure distribution and hand posture. Overall, these findings indicate that representing external forces using distributed loads provide increased fidelity of forces at the hand and fingers. Distributed loads provide more information on internal loads of the hand and digits, and in turn, quantify individual differences that can lead to injury in occupational settings. / Thesis / Master of Science in Kinesiology

One of the major obstacles to pressure ulcer research is the difficulty in accurately measuring mechanical loading of specific anatomical sites. A human motion analysis system capable of automatically segmenting a patient's body into high-risk areas can greatly improve the ability of researchers and clinicians to understand how pressure ulcers develop in a hospital environment. This project has developed automated computational methods and algorithms to analyze pressure images acquired in a hospital setting. The algorithm achieved 99% overall accuracy for the classification of pressure images into three pose classes (left lateral, supine, and right lateral). An applied kinematic model estimated the overall pose of the patient. The algorithm accuracy depended on the body site, with the sacrum, left trochanter, and right trochanter achieving an accuracy of 87-93%. This project reliably segments pressure images into high-risk regions of interest.

O objetivo deste trabalho é avaliar a distribuição de pressão, no assento e no encosto, relacionada à variação do ângulo de tilt da cadeira de rodas e contribuir para uma melhor prescrição de sistemas de adequação postural na posição sentada. Para tanto, estruturou-se uma pesquisa descritiva composta por procedimentos tipo estudos de casos. A pesquisa foi direcionada a usuários com diagnóstico de Paralisia Cerebral, nível motor IV e V (GMFCS) e que necessitam de um melhor posicionamento no sentar. Para as análises, foram utilizadas as almofadas pré-fabricadas que acompanham a cadeira em conjunto com as técnicas de mapeamento de pressão e termografia. As principais variáveis analisadas foram a distribuição de pressão e de temperatura, por meio de diagramas, bem como foram avaliados estatisticamente os respectivos valores médios. Os resultados demonstraram que nenhum dos 15 usuários avaliados apresentou postura adequada no sistema de assento e encosto padrão da cadeira de rodas. A distribuição da pressão mostrou-se inadequada, em geral, com picos importantes atribuídos à falta de estabilidade da pelve e do tronco. A utilização de cadeira de rodas com tilt é indicada, porém, faz-se necessária uma cuidadosa análise desse ângulo, bem como dos suportes de apoio ajustáveis às necessidades individuais. Recomenda-se a personalização das almofadas de assento, de encosto e de apoio de cabeça, através da moldagem do corpo do usuário. Destaca-se que os dados obtidos neste estudo podem auxiliar na identificação das necessidades dos usuários e, consequentemente, no projeto de assentos para cadeira de rodas, proporcionando maior qualidade de vida aos usuários. / The objective of this study is to evaluate the pressure distribution on the seat and backrest related to the angle variations of the wheelchair tilt-in-space. It also aims to contribute to a more suitable prescription of positioning systems. In order to do that, the descriptive research was structured by using case studies. The survey was targeted to users that had been diagnosed with cerebral palsy, gross motor function (GMFCS) IV and V who are need of a more appropriate wheelchair seating. Furthermore, for the analysis, the prefabricated chair cushions, the pressure mapping techniques and thermography had been used. The main variables analyzed were the distribution of pressure and temperature, through diagrams, which were statistically evaluated mean values. The results showed that none of the 15 members evaluated had an adequate posture in the standard seating system. The pressure distribution proved inadequate in general with important peaks attributed to the lack of stability of the pelvis and trunk. The use of the tilting wheelchair is recommended. However, it is required a more careful analysis of this angle, as well as the adjustable support brackets to individual needs. It is recommended to customize the seat cushions, backrest and headrest, through the user's body contour. It is noteworthy that the data obtained in this study can help identify the needs of users and consequently the seat design for a wheelchair, providing a higher quality of life to the users.

Pressure ulcers and related skin integrity threats are a significant problem in current transfer/transport systems used for spinal cord injury patients. To understand this problem twenty-three different slings with varying type, material, and features were analyzed in hopes to identify at-risk areas for skin integrity threats such as pressure ulcers. Population samples included non-disabled (otherwise referred to as "healthy") volunteers as well as SCI patients from the James A. Haley Veterans Hospital. High resolution pressure interface mapping was utilized to directly measure the interface pressures between the patient and sling interface. Overall results provide relevant feedback on the systems used and to suggest a particular type of sling that might reduce and possibly minimize skin integrity threats as well as extend safe patient handling guidelines with sling use. It was found that the highest interface pressures convened along the seams of the sling, regardless of manufacturer or type.

O objetivo deste trabalho é avaliar a distribuição de pressão, no assento e no encosto, relacionada à variação do ângulo de tilt da cadeira de rodas e contribuir para uma melhor prescrição de sistemas de adequação postural na posição sentada. Para tanto, estruturou-se uma pesquisa descritiva composta por procedimentos tipo estudos de casos. A pesquisa foi direcionada a usuários com diagnóstico de Paralisia Cerebral, nível motor IV e V (GMFCS) e que necessitam de um melhor posicionamento no sentar. Para as análises, foram utilizadas as almofadas pré-fabricadas que acompanham a cadeira em conjunto com as técnicas de mapeamento de pressão e termografia. As principais variáveis analisadas foram a distribuição de pressão e de temperatura, por meio de diagramas, bem como foram avaliados estatisticamente os respectivos valores médios. Os resultados demonstraram que nenhum dos 15 usuários avaliados apresentou postura adequada no sistema de assento e encosto padrão da cadeira de rodas. A distribuição da pressão mostrou-se inadequada, em geral, com picos importantes atribuídos à falta de estabilidade da pelve e do tronco. A utilização de cadeira de rodas com tilt é indicada, porém, faz-se necessária uma cuidadosa análise desse ângulo, bem como dos suportes de apoio ajustáveis às necessidades individuais. Recomenda-se a personalização das almofadas de assento, de encosto e de apoio de cabeça, através da moldagem do corpo do usuário. Destaca-se que os dados obtidos neste estudo podem auxiliar na identificação das necessidades dos usuários e, consequentemente, no projeto de assentos para cadeira de rodas, proporcionando maior qualidade de vida aos usuários. / The objective of this study is to evaluate the pressure distribution on the seat and backrest related to the angle variations of the wheelchair tilt-in-space. It also aims to contribute to a more suitable prescription of positioning systems. In order to do that, the descriptive research was structured by using case studies. The survey was targeted to users that had been diagnosed with cerebral palsy, gross motor function (GMFCS) IV and V who are need of a more appropriate wheelchair seating. Furthermore, for the analysis, the prefabricated chair cushions, the pressure mapping techniques and thermography had been used. The main variables analyzed were the distribution of pressure and temperature, through diagrams, which were statistically evaluated mean values. The results showed that none of the 15 members evaluated had an adequate posture in the standard seating system. The pressure distribution proved inadequate in general with important peaks attributed to the lack of stability of the pelvis and trunk. The use of the tilting wheelchair is recommended. However, it is required a more careful analysis of this angle, as well as the adjustable support brackets to individual needs. It is recommended to customize the seat cushions, backrest and headrest, through the user's body contour. It is noteworthy that the data obtained in this study can help identify the needs of users and consequently the seat design for a wheelchair, providing a higher quality of life to the users.

O objetivo deste trabalho é avaliar a distribuição de pressão, no assento e no encosto, relacionada à variação do ângulo de tilt da cadeira de rodas e contribuir para uma melhor prescrição de sistemas de adequação postural na posição sentada. Para tanto, estruturou-se uma pesquisa descritiva composta por procedimentos tipo estudos de casos. A pesquisa foi direcionada a usuários com diagnóstico de Paralisia Cerebral, nível motor IV e V (GMFCS) e que necessitam de um melhor posicionamento no sentar. Para as análises, foram utilizadas as almofadas pré-fabricadas que acompanham a cadeira em conjunto com as técnicas de mapeamento de pressão e termografia. As principais variáveis analisadas foram a distribuição de pressão e de temperatura, por meio de diagramas, bem como foram avaliados estatisticamente os respectivos valores médios. Os resultados demonstraram que nenhum dos 15 usuários avaliados apresentou postura adequada no sistema de assento e encosto padrão da cadeira de rodas. A distribuição da pressão mostrou-se inadequada, em geral, com picos importantes atribuídos à falta de estabilidade da pelve e do tronco. A utilização de cadeira de rodas com tilt é indicada, porém, faz-se necessária uma cuidadosa análise desse ângulo, bem como dos suportes de apoio ajustáveis às necessidades individuais. Recomenda-se a personalização das almofadas de assento, de encosto e de apoio de cabeça, através da moldagem do corpo do usuário. Destaca-se que os dados obtidos neste estudo podem auxiliar na identificação das necessidades dos usuários e, consequentemente, no projeto de assentos para cadeira de rodas, proporcionando maior qualidade de vida aos usuários. / The objective of this study is to evaluate the pressure distribution on the seat and backrest related to the angle variations of the wheelchair tilt-in-space. It also aims to contribute to a more suitable prescription of positioning systems. In order to do that, the descriptive research was structured by using case studies. The survey was targeted to users that had been diagnosed with cerebral palsy, gross motor function (GMFCS) IV and V who are need of a more appropriate wheelchair seating. Furthermore, for the analysis, the prefabricated chair cushions, the pressure mapping techniques and thermography had been used. The main variables analyzed were the distribution of pressure and temperature, through diagrams, which were statistically evaluated mean values. The results showed that none of the 15 members evaluated had an adequate posture in the standard seating system. The pressure distribution proved inadequate in general with important peaks attributed to the lack of stability of the pelvis and trunk. The use of the tilting wheelchair is recommended. However, it is required a more careful analysis of this angle, as well as the adjustable support brackets to individual needs. It is recommended to customize the seat cushions, backrest and headrest, through the user's body contour. It is noteworthy that the data obtained in this study can help identify the needs of users and consequently the seat design for a wheelchair, providing a higher quality of life to the users.

Recent experimental achievements in active noise control (ANC) for cooling fans have used near-field error sensors whose locations are determined according to a theoretical condition of minimized sound power. A theoretical point source model, based on the condition previously stated, reveals the location of near-field pressure nulls that may be used to optimize error sensor placement. The actual locations of these near-field pressure nulls for both an axial cooling fan and a monopole loudspeaker were measured over a two-dimensional grid with a linear array of microphones. The achieved global attenuation for each case is measured over a hemisphere located in the acoustic far field of the ANC system. The experimental results are compared to the theoretical pressure null locations in order to determine the efficacy of the point source model. The results closely matched the point source model with a loudspeaker as the primary source, and the sound power reduction was greatly reduced when error sensors were placed in non-ideal locations. A weakness of the current near-field modeling process is that a point monopole source is used to characterize the acoustic noise from an axial cooling fan, which may have multipole characteristics. A more complete characterization of fan noise may be obtained using a procedure based on the work of Martin and Roure [J. Sound Vib. 201 (5), 577--593 (1997)]. Pressure values are obtained over a hemisphere in the far field of a primary source and the contributions from point source distributions up to the second order, centered at the primary source, may be calculated using a multipole expansion. The source information is then used in the aforementioned theoretical near-field calculation of pressure. The error sensors are positioned using the complete fan characterization. The global far-field attenuation for the multipole expansion model of fan noise is compared to that of previous experiments. Results show that the multipole expansion model yields a more accurate representation the near field, but is not successful in achieving greater sound power reductions in the far field.