In the context of the rapid development of the research in the biosystem structure materials domain, a representative direction shows the analysis of the behavior of these materials. This direction of research requires the use of various means and methods for theoretical and experimental measuring and evaluating. PhD thesis "Methods and means for analyzing the behavior of biosystems structure materials" shall be given precedence in this area of research, aimed at studying the behavior of polymeric materials and composites biosystems structure and in particular the skeletal structure biosystem. Therefore, it is developed a specific method of research based on the development of theoretical models for the prediction of the mechanical, thermal and machinability properties of these materials. There are used Moldflow, Solidworks and Ansys software types. In order to validate the theoretical research were designed and conducted experimental research on the mechanical properties and the behavior of the polymeric biomaterials represented by ABS, UHMWPE, HDPE, PA, PC, PET, PP, PP_GF-30% and composite materials with polymeric thermoplastic matrixes from the skeletal biosystem¿s structure. In order to analyze the theoretical and experimental correlations, the experimental data were processed using the statistical analysis software programs SPSS v17, v8 Origin, Palisade Decision Tools. In conclusion, the thesis represents a technic, scientific and efficient support for analyzing the behavior of the new polymeric and composite materials from the biosystem structure. / Mitu, LG. (2014). Methods and techniques for bio-system's materials behaviour analysis [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/35445

Yes / Background Disruptions to the progress of the centre-of-pressure trajectory beneath prosthetic feet have been reported previously. These disruptions reflect how body weight is transferred over the prosthetic limb and are governed by the compliance of the prosthetic foot device and its ability to simulate ankle function. This study investigated whether using an articulating hydraulic ankle attachment attenuates centre-of-pressure trajectory fluctuations under the prosthetic foot compared to a fixed attachment. Methods Twenty active unilateral trans-tibial amputees completed walking trials at their freely-selected, comfortable walking speed using both their habitual foot with either a rigid or elastic articulating attachment and a foot with a hydraulic ankle attachment. Centre-of-pressure displacement and velocity fluctuations beneath the prosthetic foot, prosthetic shank angular velocity during stance, and walking speed were compared between foot conditions. Findings Use of the hydraulic device eliminated or reduced the magnitude of posteriorly directed centre-of-pressure displacements, reduced centre-of-pressure velocity variability across single-support, increased mean forward angular velocity of the shank during early stance, and increased freely chosen comfortable walking speed (P ≤ 0.002). Interpretation The attenuation of centre-of-pressure trajectory fluctuations when using the hydraulic device indicated bodyweight was transferred onto the prosthetic limb in a smoother, less faltering manner which allowed the centre of mass to translate more quickly over the foot.

Bakgrund: Ortopedingenjören har som uppgift att med sin kompetens och erfarenhet tillhandahålla en ortopedteknisk lösning som motsvarar patientens behov och önskemål. Handlingsutrymmet är det utrymme som en ortopedingenjör har till att ta självständiga beslut i sin yrkesutövning och är därmed summan av kompetens, bedömningar och rutiner inom verksamhetens ramar.  Syfte: Syftet med examensarbetet är att öka kunskapen om ortopedingenjörens upplevda handlingsutrymme i Sverige och Norge i relation till förskrivningsregler för protes på nedre extremiteter.  Metod: Examensarbetet baserades på en enkätundersökning med frågor gällande ortopedingenjörens upplevda handlingsutrymme utifrån mixed method. Enkäten publicerades via SOIF, Facebook gruppen Ortopedteknik i Sverige och NITO ortopedi.  Resultat: Faktorer som formade handlingsutrymmet, i situationer när ortopedingenjören upplevde stort inflytande, var främst patientrelaterade. De faktorer som beskrevs forma handlingsutrymmet vid upplevelsen av mindre inflytande var främst ekonomi och lagar/riktlinjer. Majoriteten av ortopedingenjörerna upplevde att de ofta kunde uppfylla patientens önskemål med avseende på sitt handlingsutrymme. Det förekom en delad mening om en förändring i förskrivningsprocessen behövde ske eller ej. En stor del av ortopedingenjörerna upplevde att de alltid haft möjlighet att påverka ett beslut vid förskrivning av en protes eller proteskomponent, medan ett mindre antal ortopedingenjörer har upplevt en eller flera situationer där beslutet inte kunnat påverkats. Slutsats: Ortopedingenjörer har varierande upplevelser gällande sitt handlingsutrymme, faktorer som formar handlingsutrymmet och möjligheten att påverka handlingsutrymmet vid förskrivning av proteser för nedre extremiteter. / Background: The task of the prosthetist is to provide an orthopaedic solution that meets the patient´s needs and wishes with expertise and experience. The discretion of action is the space that a prosthetist must make independent decisions in his professional practice and are thus the sum of skills, assessments and procedures within the discretion of the business. Purpose: The purpose of the study was to increase knowledge of the prosthetist perceived discretion in Sweden and Norway in relation to the prescription rules for lower limb prosthetics.  Method: The study was based on a survey that addressed questions regarding prosthetist perceived discretion for action through a mixed method. The survey was published via SOIF, the Facebook group Orthopaedics in Sweden and NITO orthopaedics. Results: Factors that affected the action of discretion, in situations when the prosthetist experienced great influence, were mainly related to the patient. In opposite, when the prosthetist experienced less influence, the main factors that affected a decision regarding a prosthetic where economy and laws/guidelines. The majority of prosthetists felt that they were often able to fulfil the patient’s request regarding to their discretion of action. In consideration to if the prescription process were in need of change or not, the opinion was divided. Many of the prosthetists have always experienced that they’re in charge of decision making or at least have been able to affect the decision. While a small number of prosthetists have experienced one or multiple situations where they could not affect the decision.  Conclusion: Prosthetists have varying experiences regarding their discretion, factors that shape the discretion and the ability to influence the discretion when prescribing prosthetics for lower limb.

Over one million amputees are living in the United States with major lower limb loss (Ziegler-Graham et al. 2008). Lower limb amputation leads to the functional loss of the ankle plantar flexor muscles, which are important contributors to body support, forward propulsion, and leg swing initiation during walking (Neptune et al. 2001; Liu et al. 2006). Effective prosthetic component design is essential for successful rehabilitation of amputees to return to an active lifestyle by partially replacing the functional role of the ankle muscles. The series of experimental and computer simulation studies presented in this research showed that design characteristics of energy storage and return prosthetic ankles, specifically the elastic stiffness, significantly influence residual and intact leg ground reaction forces, knee joint moments, and muscle activity, thus affecting muscle output. These findings highlight the importance of proper prosthetic foot stiffness prescription for amputees to assure effective rehabilitation outcomes. The research also showed that the ankle muscles serve to stabilize the body during turning the center of mass. When amputees turn while supported by their prosthetic components, they rely more on gravity to redirect the center of mass than active muscle generation. This mechanism increases the risks of falling and identifies a need for prosthetic components and rehabilitation focused on increasing amputee stability during turning. A proper understanding of the effects of prosthetic components on amputee walking mechanics is critical to decreasing complications and risks that are prevalent among lower-limb amputees. The presented research is an important step towards reaching this goal. / text

Habilitacijos procedūrai teikiamoje mokslo darbų apžvalgoje apibendrinama Vilniaus universiteto Širdies ir kraujagyslių ligų klinikos Širdies chirurgijos centro patirtis, pakartotinai operuojant ligonius po širdies vožtuvų protezavimo. Įvertintas mažai trombogeniškų protezų efektyvumas. Nustatyta, kad labai sunkių ligonių su infekuotais protezais mirštamumas nemažėja, nors pastaraisiais metais daugiau operuojame III funkcinės klasės ligonių ir jų operacijų rezultatai puikūs. Dėl pasiūlyto radikalesnio triburio vožtuvo nesandarumo gydymo pirminių operacijų metu, efektyviai mažėja pakartotinių šio vožtuvo operacijų. Įteisinta planinė seno rutulinio protezo pakeitimo operacija. Įdiegti nauji širdies pjūviai, įdiegtos krūtinės ląstos pjūvių atlikimo metodikos, farmakologiniai ir nefarmakologiniai perioperacinio kraujavimo stabdymo būdai efektyviai sumažina kraujavimo pavojų. Pasiūlytas originalus kairio skilvelio drenavimo būdas per atskira torakotominį pjūvį padeda sumažinti pooperacinį širdies nepakankamumą. Šiame darbe remiuosi kartu su bendradarbiais atliktų operacijų rezultatais. Šiuo metu kaip skyriaus, kuriame gydomi ligoniai su vožtuvų patologija, vadovas atlieku daugiau kaip pusę pakartotinių operacijų. Moksliniai pranešimai apie pakartotinių operacijų rezultatus buvo daryti Lietuvos, Pasaulio ir Europos kongresuose ir suvažiavimuose. / The review of scientific work presented for habilitation procedure summarizes the experience of redo operations of patients after replacement of heart valves accumulated at the Heart Surgery Centre of Vilnius University Clinic of Angiology and Cardiology. The efficacy of low thrombogenicity valve prostheses was evaluated. It was found out that the mortality rate of very severely ill patients with infected did not decrease; however the larger number of patients in functional class III were being operated during the period of recent years and the results of these operations were excellent. The rate of redo tricuspid valve operations had decreased effectively because of more radical surgery treatment of this valve during the primary operation. The operation of replacement of old ball prosthesis has been validated. The new incisions of the heart were introduced as well as new methods of performance of chest box incisions and pharmacologic and non-pharmacologic methods of perioperative hemostasis; the methods mentioned above effectively reduced the risk of bleeding. The original method of the left ventricle venting via separate thoracotomy incision enabled to reduce postoperative heart failure. This work is based on the results of operations performed in cooperation with co-workers. As a chief of the department where the patients with pathology of heart valves are treated, I am performing more than a half of redo operations. The scientific presentations concerning the results of... [to full text]

We have designed and examined a compliant knee mechanism that may offer solutions to problems that exist for infants and toddlers who are just learning to walk. Pediatric prosthetic knees on the market today are not well designed for infants and toddlers for various reasons. Children at this age need a prosthetic that is light in weight, durable, and stable during stance. Of the eleven knees on the market for children, all but three are polycentric or four-bar knees, meaning they have multiple points of movement. Polycentric knees are popular designs because they offer the added benefit of stable stance control and increased toe clearance, unfortunately this type of knee is often too heavy for young children to wear comfortably and is not well suited for harsh environments such as sand or water, common places children like to play. The remaining three knees do not offer a stance control feature and are equally vulnerable to harsh environments due to ball bearing hinges. Compliant mechanisms offer several design advantages that may make them suitable in pediatric prosthetic knees -- light weight, less susceptible to harsh environments, polycentric capable, low part count, etc. Unfortunately, they present new challenges that must be dealt with individually. For example compliant mechanisms are typically not well suited in applications that need adjustability. This problem was solved by mixing compliant mechanism design with traditional mechanism design methods. This paper presents a preliminary design concept for a compliant pediatric prosthetic knee. The carbon fiber composite spring steel design was first built and then evaluated using Finite Element Analysis. The prototype's instant center was plotted using the graphical method. From our analysis position, force and stress information was gathered for a deflection up to 120 degrees. The instant centers that were plotted indicate that the knee has good potential in offering adequate stability during stance.

No description available.

My thesis focuses on the perceptive afflictions caused by alteration of the normal biological functioning of sight and memory. These afflictions are related to the redefinition and disgregation of the classical and postclassical cinematographic characters, and affect cinematographic language, establishing a dialectical relation with the filmic image that contaminates our spectatorial perception. In the first chapter I propose a different reading of a few moments in film history, turning points in which a modification of the ordinary sensorial patterns has been introduced. From the German Expressionism to the late authorial experiments of the 60s, there is a sort of hidden history of film that passes through the continuous redefinition of the audience sensory activity. The different perspective upon broadly studied topics leads to the analysis of contemporary cinema: my thesis tries to investigate the reasons that led cinema to continually increase the representation of perceptive afflictions during the last years, and theses “affected” narratives of afflictions and dysfunctions have interesting effects upon so called “normal” perception of the reality surrounding us. The chapters 2 and 3 respectively analyze memory disorders and different dysfunctions of sight: these elements determine alterations in the ‘normal’ and ‘sensory’ perception of reality. They work as narrative factors changing the visual filmic instruments and redefining the role of the subject (and his/her uncertain definition of identity) in contemporary narratives that show how new technologies are profoundly transforming (and enhancing) the perceptive mechanisms involved in our spectatorial activity. In this work I analyze those films that are mostly committed to a clear and readable narration. My study primarily concentrates on American cinema of the last 30 years – with particular attention to popular Hollywood productions – because Hollywood has become the privileged ‘laboratory’ for the negotiation of gaze and images in the contemporary mediascape, while during the classical era experimental and avant-garde cinema were the “place” in which audience experienced the most important redefinitions of the boundaries between different types of mediated perception.

Syftet med studien är att undersöka om det finns någon inlärningseffekt på testet Limits of Stability (LoS) för transtibialt amputerade protesbrukare och en kontrollgrupp. Sju transtibialt amputerade protesbrukare och en kontrollgrupp bestående av sju friska vuxna män upprepade testet LoS  fem gånger under fyra testtillfällen. Två kraftplattor och 69 reflexmarkörer användes för att samla in data. Testpersonerna placerades med en fot på varje kraftplatta och blev instruerade att förflytta sin center of pressure genom att luta kroppen från anklarna mot åtta mål som visades på en skärm tillsammans med deras center of pressure. Ordningen på målen var slumpvist utvalda. Datan analyserades med Friedmans test, eftersom den inte var normalfördelad, för att se om det fanns någon skillnad i resultatet mellan upprepningarna av testet och resultatet mellan testtillfällena. Det fanns några signifikanta skillnader mellan upprepningarna och mellan testtillfällena som tyder på att det finns en inlärningseffekt efter första upprepningen och första testtillfället, men resultatet var inte tillräckligt entydigt för att kunna dra några konkreta slutsatser. Vidare studier rekommenderas. / The aim of the study is to examine the learning effect of Limits of Stability (LoS) test concerning transtibially amputated prosthetic users and a healthy control group. Seven transtibially amputated prosthetic users and a control group of seven healthy males repeated the LoS test five times during four sessions, one in the morning and one in the afternoon in two consecutive days. Two forceplates and 69 reflex markers were used to collect the data. The test subjects were placed with on the foot on each forceplate and were instructed to move their center of pressure by leaning the body from the ankles towards eight targets presented on a screen along with their center of pressure. The targets were selected in random order. The data was analyzed with Friedmans test, since the data wasn’t normally distributed, to see if there was any discrepancy between the repetitions and between the sessions. There were some significant discrepancies between repetitions and between sessions mainly involving the first repetition and the first session. However the results weren’t distinct enough to draw any concrete conclusions. Further studies are recommended.

The advancement of technologies that interface with electrically excitable tissues, such as the cortex and muscle, has the potential to lend greater mobility to the disabled, and facilitate the study of the central and peripheral nervous systems. Myoelectric interfaces are currently limited in their signal fidelity, spatial resolution, and interfacial area. Such interfaces are either implanted in muscle or applied to the surface of the muscle or skin. Thus far, the former technology has been limited in its applications due to the stiffness (several orders of magnitude greater than muscle) of its substrates, such as silicon and polyimide, whereas the latter technology suffers from poor spatial resolution and signal quality due to the physical separation between the electrodes and the signal source. We have developed a stretchable microneedle electrode array (sMEA) that can function while stretching and flexing with muscle tissue, thereby enabling multi-site muscle stimulation and electromyography (EMG) measurement across a large interfacial area. The scope of this research encompassed: (i) the development of a stretchable and flexible array of penetrating electrodes for the purposes of stimulating and measuring the electrical activity of excitable tissue, (ii) the characterization of the electrical, mechanical, and biocompatibility properties of this electrode array, (iii) the measurement of regional electrical activity of muscle via the electrode array, (iv) the study of the effect of spatially distributed stimulation of muscle on the fatigue and ripple of muscle contractions, and (v) the assessment of the extent to which the stretch response of electrically stimulated muscle behaves in a physiological manner.