Following lower-limb amputation, patients suffer from sensory loss within the prosthesis/residuum complex leading to diminished proprioception and balance. Artificial sensory systems have the potential to improve rehabilitation outcomes including better functional usage of lower-limb prostheses to achieve a higher quality of life for the prosthetic users. The purpose of this work was to develop and test the e fficacy of a vibrotactile feedback system for lower-limb amputees that may augment feedback during complex balance and movement tasks. Responses to different vibrotactile stimuli frequencies, locations, and physical conditions were assessed. Key outcome measures for this work were the response time and response accuracy of the subjects to the different stimulator configurations. Frequencies closer to 250 Hz applied to the anterior portion of the thigh resulted in the quickest reaction times. When multitasking, reaction times increased. These preliminary results indicate that vibrotactile sensory feedback may be viable to use by lower-limb amputees.

Submitted by Fernanda Rodrigues de Lima (fernanda.rlima@ufpe.br) on 2018-09-28T22:24:37Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vicente Júlio Barbosa de Lima.pdf: 3260180 bytes, checksum: 266a84db735351f521f495c4e7ab12d3 (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-11-23T18:36:26Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vicente Júlio Barbosa de Lima.pdf: 3260180 bytes, checksum: 266a84db735351f521f495c4e7ab12d3 (MD5) / Made available in DSpace on 2018-11-23T18:36:26Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Vicente Júlio Barbosa de Lima.pdf: 3260180 bytes, checksum: 266a84db735351f521f495c4e7ab12d3 (MD5) Previous issue date: 2016-08-25 / A cirurgia de amputação de membros é considerada o procedimento cirúrgico mais antigo da humanidade. Nas últimas décadas têm aumentado consideravelmente o número de pacientes jovens ativos que sofrem amputação e que necessitam de prótese como substituto do membro perdido. Esse estudo realizou análise comparativa entre a prótese passiva mais utilizada e a prótese ativa microprocessada. O objetivo da pesquisa consistiu em oferecer critérios técnicos para a modelagem de joelhos protéticos ativos, com uso de microprocessadores. Considerando a dimensão e as mudanças na vida de um jovem que é submetido a amputação, a pesquisa contribui para o desenvolvimento de novos estudos nessa área. Desta forma foi realizado mapeamento sistemático e revisão da literatura, antropometria com a avaliação do eixo anatômico e mecânico dos membros inferiores, avaliação cinemática e dinâmica com testes de circuito baseado no protocolo de teste da Ottobock®; cinética da marcha e comportamento do centro de pressão e centro de massa com utilização de baropodômetro. Assim, realizou-se uma descrição detalhada do mapeamento e da avaliação cinemática e dinâmica com elaboração de tabelas e imagens das forças de pressão e centro de massa. Observou-se melhor desempenho de função e mobilidade da prótese microprocessada em relação a prótese mecânica: menor alteração do eixo anatômico em relação ao eixo de carga; melhor equilíbrio do corpo, melhor resposta a mudanças espaciais e obstáculos, melhor a juste e controle do paciente sobre a prótese; menor força de atuação do solo sobre o coto; menor alteração entre o centro de gravidade do corpo e o centro de pressão do pé protético. Foram estabelecidos critérios técnicos biomecânicos para a modelagem de joelho protético e oferecido subsídio para futuros trabalhos para o desenvolvimento de joelhos protéticos ativos de baixo custo. / The limb amputation surgery is considered the oldest surgical procedure of humanity. In recent decades have greatly increased the number of active young patients suffering amputation and who need prosthesis as a substitute for the missing limb. This study was conducted comparative analysis of the most widely used passive prosthesis and microprocessor active prosthesis. The research objective was to provide technical criteria for modeling active prosthetic knees, using microprocessors. Given the size and the changes in the life of a young man who undergoes amputation, research contributes to the development of new studies in this area. Thus it was carried out systematic mapping and review of the literature, anthropometry with the assessment of the anatomical axis and mechanical lower limbs, kinematic and dynamic evaluation with circuit testing based on the test protocol Ottobock; kinetic gait and center of pressure behavior and mass center using baropodometry. Thus, there was a detailed description of the mapping and kinematic and dynamic evaluation with drafting tables and images of pressure forces and center of mass. There was better performance function and mobility microprocessor prosthesis in relation to mechanical prosthesis: minor change to the anatomical axis in relation to the load axis; body better balance, better response to spatial changes and obstacles, the better the juste and patient control over the prosthesis; lower ground actuation force on the stump; minor variation between the center of gravity of the body and the center of pressure of the prosthetic foot. Biomechanical were established technical criteria for knee prosthetic modeling and offered allowance for future work for the development of prosthetic knees low cost assets.

Transradial coronary intervention (TRI) lowers bleeding and mortality compared with transfemoral coronary intervention (TFI). There are limited data on outcomes as TFI operators transition to a default TRI practice. The aim of this study was to assess TFI and TRI outcomes before, during, and after the year TRI was first learned by femoral operators. Patients undergoing percutaneous coronary intervention (PCI) at a Veterans Affairs Medical Center from 2006 to 2012 were included. In 2009, TRI was learned by all operators and then used as the default PCI approach from 2010 to 2012. Baseline characteristics and outcomes were collected. Predictors of major bleeding, major adverse cardiovascular events (MACE), and mortality were determined by multivariable analysis; 1192 veterans were included. TRI rates were 9% (2006-2008), 65% (2009), and 90% (2010-2012). Incidence of 1-year MACE and mortality was 5.4% and 3.9%, respectively, in 2009, and 5.6% and 3%, respectively, during 2010 to 2012. Major bleeding remained at <1%. Age, glycoprotein IIb/IIIa inhibitors, and ST-elevation myocardial infarction were independently associated with major bleeding, whereas TRI was protective. Transition to default TRI is feasible over a short time period and associated with low rates of MACE and mortality and very low rate of major bleeding.

An alternative method of conventional prosthesis is  osseointegrated transfemoral implant, in where the prosthesis is fixated directly to the bone. The benefits with this system is increased range of motion, sensory feedback and reduced soft tissue problem. One of the drawbacks of this method is the effect of stress shielding, which could in long term lead to bone loss and bone resorption. The aim of this study is to investigate how the length of the fixture (60, 80 and 100 mm) of OPRA system (Osseointegrated Prosthesis for the Rehabilitation of Amputees) affects the stress distribution in femoral bone and implant during short walk by using Finite Element Methods.  The finite element model used in this study was constructed of three major parts: THUMS model (Total Human Model of Safety) of left thigh, implant and bone graft. The analysis was performed through the software LS-DYNA, with an implicit solver. The loading of the total gait cycle was applied in the distal end of the implant, whereas the proximal end of the thigh was fixed.  The FE simulation revealed lower stress distribution in the distal end of femoral bone, and higher in the proximal end. Implant 60 had lowest effect of stress shielding. The highest stress distribution in OPRA implant was shown in the abutment shaft, in the interface with bone graft. The length of the fixture did not have any impact on the stress distribution in the implant.

Die transfemorale Aortenklappenimplantation stellt für ältere Patienten mit einer symptomatischen, hochgradigen Aortenklappenstenose und einem erhöhten perioperativen Letalitätsrisiko eine Alternative zum konventionell-chirurgischen Aortenklappenersatz dar. In der vorliegenden Arbeit wurden die beiden aktuell in Europa zugelassenen transfemoralen Systeme in Bezug auf deren prozedurale Sicherheit, den klinischen Nutzen, die 1-Jahres-Letalitätsrate und die langfristige Klappenfunktionalität unter Anwendung der Kriterien zur standardisierten Komplikationsanalyse des Valve Academic Research Consortiums (VARC) verglichen. Jeweils 100 konsekutive Patienten, bei denen eine transfemorale Aortenklappenimplantation mit den Edwards SAPIEN™/SAPIEN XT™ Transcatheter Heart Valves bzw. dem Medtronic CoreValve ReValving™ System durchgeführt wurde, wurden in die Analyse eingeschlossen. Dies stellt das größte bisher publizierte Patientenkollektiv für den Vergleich der beiden Aortenklappenimplantationssysteme in einem Zentrum über den femoralen Zugangsweg dar. Es wurden mit beiden Systemen ähnlich gute postinterventionelle hämodynamische und klinische Ergebnisse erreicht. Ein signifikanter Unterschied bezüglich der prozeduralen Sicherheit und der 1-Jahres-Letalitätsrate zwischen den beiden Systemen konnte trotz signifikanter Unterschiede in Bezug auf bestimmte periinterventionelle Risiken nicht nachgewiesen werden. Die langfristige Klappenfunktion beider Systeme war exzellent.

Bakgrund: Transfemoralt amputerade har nedsatt balans och ökad fallrisk, men väldigt lite forskning är gjord om detta. Inverted pendulum model (IPM) är en balansmodell för icke-amputerade som bygger på ett känt samband mellan Center of Pressure (CoP) och Center of Mass (CoM). Syftet med denna studie är att kinetiskt validera den inverterade pendelmodellen för transfemoralt amputerade. Metod: I studien deltog amputerade (n=5) och en matchande kontrollgrupp (n=5). Man samlade in data genom att deltagarna fick stå stilla på två stycken kraftplattor under tre styckern villkor; öppna ögon, stängda ögon och weight-bearing feedback. Man undersökte sedan korrelationen mellan avståndet från CoM till CoP och CoMacc i både anterioposterior (A/P) riktning samt medio-lateral (M/L) riktning och analyserade datan med trevägsvariansanalys (ANOVA). Resultat: Resultatet visade att det fanns en signifikant interaktionseffekt mellan villkor och position i M/L-riktning. I A/P-riktning fanns det en signifikant interaktionseffekt mellan grupp och position samt villkor och position. Slutsats: Resultatet innebär att IPM är kinetiskt validerat i A/P-riktning sett till hela kroppen men inte på den amputerade sidan. Hur det intakta benet förhåller sig till IPM för amputerade är tvivelaktigt. / Background: It is known that transfemoral prosthesis users lack normal balance control and are more likely to fall. Research on this topic is insufficient. The Inverted Pendulum Model (IPM) is a commonly used biomechanical model for assessment of balance and postural control for healthy individuals based on an assumption that Center of Pressure (CoP) and Center of Mass (CoM) are inter-dependent. The aim of the study is to validate IPM kinetically for transfemoral prosthesis users. Method: Amputees (n=5) and a control group (n=5) participated. During data collection, participants stood on two force plates with eyes open, eyes closed and with weight-bearing feedback. Correlation of the distance CoP-CoM and CoMacc were calculated for anteroposterior and mediolateral directions and evaluated with three-way ANOVA. Result: Results showed significant interaction effects between condition and position plus group and position in anteroposterior direction and condition and group in mediolateral direction. Conclusion: Results indicate kinetic validity of IPM for transfemoral amputees when looking at the whole body but not at the amputated side in the A/P direction. Kinetic validity of IPM for the intact leg is questionable.

Die vorliegende Arbeit beschäftigt sich mit der altersabhängigen Inzidenz und den Risikofaktoren für das Auftreten von lokalen Gefäßkomplikationen nach Herzkathetern über den femoralen Zugang. Diese sind die häufigsten Komplikationen nach Herzkatheteruntersuchungen überhaupt. Besonders berücksichtigt wurden multimorbide und sehr alte Patienten. Durch den demographischen Wandel und eine stetig wachsende Zahl an durchgeführten Herzkatheterprozeduren wird das Aufkommen solcher Patienten in der Zukunft weiter ansteigen. Der Zugang über die Leistengefäße stellt vielerorts noch immer den meistgenutzten dar. Frühere Studien konnten bereits diverse Risikofaktoren für das Auftreten von lokalen Gefäßkomplikationen nach Herzkathetern ermitteln, unter anderem hohes Alter und typische Alterskrankheiten. In den untersuchten teils sehr kleinen Kohorten wurden oft außerordentlich hohe Komplikationsraten ermittelt. Um zu verhindern, dass alten Patienten aus Sorge um mögliche Komplikationen potentiell lebensrettende invasive Maßnahmen vorenthalten werden, ist eine stetige Risikoevaluation notwendig. In dieser Studie wurden 42.628 Prozeduren bei Patienten, die am Herzzentrum Leipzig zwischen 2005 und 2009 einen diagnostischen Herzkatheter oder eine perkutane Koronarintervention (PCI) erhielten, ausgewertet. Ziel der Arbeit war es, die altersabhängigen Komplikationsraten sowie Prädiktoren für das Auftreten von Komplikationen zu ermitteln. Dazu wurden für drei Altersgruppen (Patienten unter 65, zwischen 65 und 79 sowie über 80 Jahre) jeweils prozedurale und klinische Parameter analysiert. Es wurde ein moderater Anstieg der Komplikationsraten festgestellt. Dies zeigt, dass Herzkatheter über einen Leistenzugang bis ins hohe Alter ein sicheres Verfahren sind. Die ermittelten Prädiktoren können einer klinischen Risikostratifizierung dienen.

Die transfemorale Aortenklappenimplantation stellt für ältere Patienten mit einer symptomatischen, hochgradigen Aortenklappenstenose und einem erhöhten perioperativen Letalitätsrisiko eine Alternative zum konventionell-chirurgischen Aortenklappenersatz dar. In der vorliegenden Arbeit wurden die beiden aktuell in Europa zugelassenen transfemoralen Systeme in Bezug auf deren prozedurale Sicherheit, den klinischen Nutzen, die 1-Jahres-Letalitätsrate und die langfristige Klappenfunktionalität unter Anwendung der Kriterien zur standardisierten Komplikationsanalyse des Valve Academic Research Consortiums (VARC) verglichen. Jeweils 100 konsekutive Patienten, bei denen eine transfemorale Aortenklappenimplantation mit den Edwards SAPIEN™/SAPIEN XT™ Transcatheter Heart Valves bzw. dem Medtronic CoreValve ReValving™ System durchgeführt wurde, wurden in die Analyse eingeschlossen. Dies stellt das größte bisher publizierte Patientenkollektiv für den Vergleich der beiden Aortenklappenimplantationssysteme in einem Zentrum über den femoralen Zugangsweg dar. Es wurden mit beiden Systemen ähnlich gute postinterventionelle hämodynamische und klinische Ergebnisse erreicht. Ein signifikanter Unterschied bezüglich der prozeduralen Sicherheit und der 1-Jahres-Letalitätsrate zwischen den beiden Systemen konnte trotz signifikanter Unterschiede in Bezug auf bestimmte periinterventionelle Risiken nicht nachgewiesen werden. Die langfristige Klappenfunktion beider Systeme war exzellent.

Although sitting is a large part of everyday life is the influence of the sitting positions and chair design on pressure and load distribution as well as comfort for transfemoral amputees quite unexplored. The aim of this study was therefore to examine this further. Two transfemorally amputated females (49 and 57 years old) participated in the study. Three positions were examined for each subject; sitting without foot support and sitting with the knee joints flexed 90◦ and 105◦. The pressure inside the socket was measured by two pressure sensors, placed distally and proximally on the posterior wall inside the socket. The lengthwise pressure distribution and the sidewise load distribution between the socket and the underlying material was measured by a pressure mat. In addition to this, the subjects answered a questionnaire regarding the subjective comfort for each position.  The result showed that the pressure underneath the socket were higher distally than proximally without foot support. The pressure transferred proximally as the knee became more flexed. The most even load distribution sidewise was found when the subjects sat with their knees flexed 105 degrees. Sitting with the knees flexed 90◦ was ranked as the most comfortable position. No conclusion could be made regarding the pressure inside of the socket. Additionally, according to this study the level of comfort does not have any clear relation with the sidewise load distribution or the longitudinal pressure distribution. / En stor del av livet spenderas sittandes, men den påverkan som sittposition och stoldesign har på tryckfördelning och komfort för transfemoralt amputerade är ganska outforskat. Studien ämnar därför undersöka detta. Två transfemoralt amputerade kvinnor (49 och 57 år) medverkade i studien. Tre sittpositioner undersöktes för varje testperson; sittande utan fotstöd samt sittande med knäleden i 90◦ respektive 105◦ flexion. Trycket inuti hylsan mättes med hjälp av två trycksensorer, som placerades distalt och proximalt på den bakre hylsväggen. Tryckfördelningen i längsriktningen och lastfördelningen i sidled mellan hylsan och underlaget mättes med en tryckmatta. Förutom detta svarade testpersonerna även på ett frågeformulär angående den subjektiva komforten för varje position. Resultatet visade att trycket under hylsan var högre distalt än proximalt när inget fotstöd användes. Trycket förflyttades proximalt då knät böjdes. Den mest jämna lastfördelningen mellan sidorna påträffades när knät var flekterat 105◦. Enligt frågeformuläret var den mest bekväma positionen den med 90◦ i knäleden. Ingen slutsats kunde göras angående trycket inuit hylsan. Ingen tydlig relation kunde heller inte hittas mellan den subjektiva komforten och tryck- eller lastfördelningen.

A caminhada humana é um movimento importante utilizado pelo homem, porém extremamente complexo em relação aos mecanismos energéticos e mecânicos que geram este movimento. O custo energético é maior na caminhada de amputados quando comparada a caminhada de indivíduos sem restrições físicas. Variáveis mecânicas e energéticas de amputados não foram extensivamente estudadas. Nosso objetivo foi avaliar a influência de diferentes velocidades, no recovery, no custo de transporte (C), na eficiência mecânica (Eff), na transdução pendular (Rint), trabalho mecânico, na estabilidade dinâmica, bem como verificar a associação entre a estabilidade dinâmica com recovery, custo de transporte e eficiência mecânica. Participaram do estudo 10 indivíduos amputados transfemurais (com joelho hidráulico e pé em fibra de carbono). Foi realizada cinemetria 3D (quatro câmeras de vídeo) e simultaneamente a análise do consumo de oxigênio. Foram determinadas cinco velocidades de caminhada, após definir a velocidade auto selecionada. Além da velocidade auto selecionada foram definidas duas velocidades acima e abaixo das VAS. Para os dados de Recovery, custo de transporte, eficiência mecânica, transdução pendular, trabalho total, trabalho externo, travalho vertical, trabalho horizontal, trabalho interno e estabilidade dinâmica foram utilizadas rotinas desenvolvidas em Matlab®. A velocidade influencia nos parâmetros mecânicos e energéticos da caminhada de amputados transfemurais. Os maiores valores para: economia de caminhada, Recovery, transdução pendular, eficiência mecânica, trabalho mecânico interno e vertical, e estabilidade dinâmica foram obtidos na máxima velocidade de caminhada dos sujeitos. As correlações entre o coeficiente de variação do comprimento da passada e Recovery, custo de transporte e potência metabólica foram moderadas. Esses resultados são de grande relevância para a área clínica e ponderados durante o processo de reabilitação desses indivíduos. / The human walking is an important movement used by man, but extremely complex in relation to the energetic and mechanical mechanisms that generate this movement. The energy cost of gait is greater in amputees than in normal subjects. Mechanical and energetics variables in amputees have not been extensively studied. Our objective was to assess the influence of speed in recovery, cost of transport (C), mechanical efficiency (Eff), pendular transduction (Rint), mechanic parameters, dynamical stability, well as to verify agreement between dynamical stability with recovery, C, Eff and metabolic power. Materials and Methods: ten transfemoral amputees (with hydraulic knee and carbon fiber foot) were selected in the study. Simultaneously three-dimensional (3D) kinematics data (four cameras) and oxygen consumption were collected at five speeds, two above and two below self-select one. The Recovery, C, Eff, Rint, dynamical stability, were processed using Matlab software. Mechanics and energetics of amputee walking were influenced by speed. In maximal speed of amputee walking were reported greatest values, like: recovery, cost of transport (C), mechanical efficiency (Eff), pendular transduction (Rint), internal and vertical mechanical work and dynamical stability. Pearson correlation between dynamical stability and Recovery, C, Eff and metabolic power were moderate. These results are clinical relevance and should be considered during the rehabilitation of these individuals.