Hip disarticulations and hemipelvectomies are the highest level of lower limb amputations. As such, these amputations create ambulation difficulties and current prosthetic solutions are limited. Powered prosthetic joints have successfully improved lower limb amputee gait; however, no powered hip joints are available on the market. This thesis presents the design and evaluation of a microprocessor-controlled powered hip joint for hip-level amputees. A rope and pulley system was used to transmit power from an actuator located at the prosthetic thigh to rotate the prosthetic leg around an anteriorly-located prosthetic hip joint. The pulley system features an innovative tensioning system using multiple keyways, allowing the system to be tensioned without external tensioning devices. The powered hip prosthesis passed ISO 15032:2000 mechanical strength tests that simulated 100 kg user loads. The joint was also tested by able-bodied individuals using a hip disarticulation simulator to walk with the powered hip-knee-ankle-foot prosthesis. Though the participants had asymmetrical gait with shorter intact-side swing time, the device successfully allowed the participants to ambulate. The final device weighed 3.9 kg and respected geometric design constraints to fit comfortably under pants. Future work is needed to implement a gait control system, resolve a rope slack issue, and test the device with hip-level amputees.

Yes / If a prosthetic foot creates resistance to forwards shank rotation as it deforms during loading, it will exert a braking effect on centre of mass progression. The present study determines whether the centre of mass braking effect exerted by an amputee's habitual rigid ‘ankle’ foot was reduced when they switched to using an ‘Echelon’ hydraulic ankle–foot device. Nineteen lower limb amputees (eight trans-femoral, eleven trans-tibial) walked overground using their habitual dynamic-response foot with rigid ‘ankle’ or ‘Echelon’ hydraulic ankle–foot device. Analysis determined changes in how the centre of mass was transferred onto and above the prosthetic-foot, freely chosen walking speed, and spatio-temporal parameters of gait. When using the hydraulic device both groups had a smoother/more rapid progression of the centre of pressure beneath the prosthetic hindfoot (p ≤ 0.001), and a smaller reduction in centre of mass velocity during prosthetic-stance (p < 0.001). As a result freely chosen walking speed was higher in both groups when using the device (p ≤ 0.005). In both groups stance and swing times and cadence were unaffected by foot condition whereas step length tended (p < 0.07) to increase bilaterally when using the hydraulic device. Effect size differences between foot types were comparable across groups. Use of a hydraulic ankle–foot device reduced the foot's braking effect for both amputee groups. Findings suggest that attenuation of the braking effect from the foot in early stance may be more important to prosthetic-foot function than its ability to return energy in late stance.

Bakgrund: Protesen har existerat sedan forntida egypten. Att leva med en protes kan ha både negativ och positiv påverkan hos protesbäraren. Omställningen bidrar till en ny livsstil där varje individ kan påverkas i olika utsträckning både psykiskt och fysiskt. Sjuksköterskan behöver ha kunskap om protesbärarens upplevelser för att kunna hjälpa protesbäraren att anpassa sig till livet med en protes. Syfte: Syftet med studien var att belysa upplevelser av att leva med en protes för nedre extremitet. Metod: Allmän litteraturstudie bestående av tio resultatartiklar som söktes fram i databaserna CINAHL, PubMed, PsycINFO samt Sage Journals. Artiklarna analyserades med hjälp av en guide för kvalitativ forskning gjord av Popenoe et al. (2021). Resultat: Det framkom fem kategorier och dessa var: rörlighet, komfort och funktion, samhällets inverkan, utbildning, jobb och ekonomi och socialt stöd. Alla kategorier belyste hur det kan vara att leva med en protes för nedre extremitet. Konklusion: Protesen kan medföra en känsla av självständighet samtidigt som den kan upplevas som en begränsning med smärtor och problem med passform. Stöd från anhöriga och vårdpersonal var viktigt för återhämtningen. Att vårdpersonal gav god och tillräcklig information var också väsentligt. Ytterligare forskning behövs om protesbärares upplevelser av att leva med en protes för nedre extremitet där sjuksköterskor får den kunskap som krävs för att ge en god omvårdnad. / Background: The prosthesis has existed since ancient Egypt. Living with a prosthesis can have both negative and positive effects on the prosthesis user. The transition contributes to a new lifestyle where each individual can be affected to different extents both psychologically and physically. The nurse needs to have knowledge about the experiences of a prosthesis user in order to be able to help the prosthesis user adapt to life with a prosthesis. Aim: The aim of the study was to illustrate experiences of living with a lower extremity prosthesis. Method: The general literature review study included ten result articles that were searched in the databases CINAHL, PubMed, PsycINFO and Sage Journals. The articles were analyzed using a guide for qualitative research made by Popenoe et al. (2021). Results: Five categories emerged and these were: mobility, comfort and function, impact from the society, education, jobs and finances and social support. All categories highlighted what it can be like to live with a prosthesis for the lower limb. Conclusion: The prosthesis can bring a sense of independence as well as a limitation that includes pain and problems with the fitting of the prosthesis. Support from relatives and healthcare professionals was important for the recovery. It was also essential that healthcare staff provided good and sufficient information to the patient. Further research is needed on prosthesis users’ experiences of living with a lower extremity prosthesis where nurses gain the knowledge required to provide good nursing care.

Ramp descent is a demanding task for trans-tibial amputees, due to the difficulty in controlling body weight progression over the prosthetic foot. A deeper understanding of the impact of foot function on ramp descent biomechanics is required to make recommendations for rehabilitation programs and prosthetic developments for lower-limb amputees. The thesis aim was to determine the biomechanical adaptations made by active unilateral trans-tibial amputees (TT) using a microprocessor-controlled ankle-foot prosthesis in active (MC-AF) compared to non-active mode (nonMC-AF) or elastically articulated ankle-foot device. A secondary aim was to determine the biomechanical adaptation made by able-bodied individuals when ankle motion was restricted using a custom made ankle-foot-orthosis and provide further insight into the importance of ankle dynamics when walking on ramps. Kinetic and kinematic data were recorded from nine TT’s and twenty able-bodied individuals. Able-bodied participants, ankle restriction, led to an increase in involved limb loading response knee flexion that is accompanied by the increased knee power generation during the single-limb-support phase that correlates to TTs results. TT’s use of an MC-AF reduced the ‘plantar-flexion’ resistance following foot contact allowing foot-flat to be attained more quickly. Followed by the increased ‘dorsi-flexion’ resistance which reduced the shank/pylon rotation velocity over the support foot, leading to an increase in negative work done by the prosthesis. These findings highlight the importance of having controlled ankle motion in ramp descent. Use of an MC-AF can provide TTs controlled motion for descending ramps and hence provide biomechanical benefits over using more conventional types of ankle-foot devices. / Engineering and Physical Science Research Council (EPSRC) via Doctoral Training Account (DTA) (EP/P504821/1) Chas. A. Blatchford and Sons Ltd., Basingstoke, UK provided the prosthetic hardware, prosthetist support, and facilitated the attendance of the TT participants for this study

No description available.

No description available.

No description available.

Osteoarthritis and cartilage deterioration are favored by meniscetomy, which is the ablation of the meniscus from the knee joint. Meniscectomy can be partial or total. This procedure is performed when meniscus lesions and tears or the degeneration of the meniscus caused by its natural dehydration occur. There is a peak of meniscal lesions observed between 20 and 29 years old. Alternative methods such as sutures fail in that they present a short term solution which is ideal for a less active, older generation. A long term solution is needed for a younger population to reduce the number of surgical procedures over the lifetime of this active group. There is a crucial need for a functional implant designed in the image of the native meniscus. Blends of poly (vinyl alcohol) PVA and poly (vinyl pyrrolidone) (PVP) present a potential solution. PVA has shown similar characteristics to soft tissues. PVP further stabilizes the hydrogel network. This work is the mechanical characterization of PVA/PVP (99:1) hydrogels under physiological conditions. Equilibrium swelling in a medium replicating the ionic and the osmotic content of the synovial fluid was investigated during 35 days. The mass retention of hydrogels was characterized using data obtained from the swelling study and was examined as a function of the cross link density and the polymer content. The modulus of hydrogels was obtained in unconfined compression, first at a strain rate slow enough to ignore fluid flow in and out of the gels, and subsequently at a physiological strain rate of walking. Results indicate that PVA/PVP hydrogels volume swelling ratio and weight swelling ratio show no significant difference for most formulations by the 14th day of immersion. A few hydrogels would reach equilibrium by day 21. Additionally, percentage polymer mass retention increases with the cross link density. However, there is no consistent trend with the polymer content. All formulations with 10% wt of polymer show the highest mass retention while 15% wt show the lowest. Interestingly, the mechanical characterization of hydrogels at 100%/min strain rate shows that 15% wt is the only formulation whose compressive modulus falls within the targeted range whereas 10% wt proves to not be stiff enough. 20% wt and 25% wt are always too stiff. Results obtained from unconfined compression at the physiological strain rate, that is 1920%/min, are rather inconclusive. There is not enough consistency in the literature to narrow the results down to one successful candidate formulation. The modulus range obtained at physiological strain rate encompasses the range obtained at 100%/min strain rate. The highest modulus value obtained is 10 times higher at physiological strain rate than the modulus of a real human meniscus obtained at 100%/min strain rate. It is not reasonable at this time to make a choice of a formulation at physiological strain rate due to high variability of the modulus of a human meniscus as a result of its intrinsic anisotropy. All formulations tested would be considered successful candidates, which is irrational considering the difference in their stiffness. / Mechanical Engineering

Brain-computer interfaces (BCIs) provide direct access to the brain, serving crucial roles in treating neurological disorders and developing neural prostheses. Recent clinical successes include diagnosing and treating epilepsy and advancing prosthesis for visual and limb impairments. Achieving high spatial and temporal resolution is essential for accurately localizing seizures, mapping brain functions, and controlling neuronal activity. However, existing solutions have substantial form factors, necessitating large-size craniotomy, permanent removal of a part of the skull, or wires running through the body, which limits real-world applicability and complicates post-surgery recovery. We present a minimally invasive, high-bandwidth, and fully wireless brain-machine interface platform that addresses these challenges through a combination of an implantable application-specific integrated circuit (ASIC) chip and a wearable relay station. The platform supports an aggregate sampling rate of 8.68 MSPS at 10-bit resolution and a 108.48/54.24 Mbps data rate using impulse radio ultra-wideband (IR-UWB). A high-density microelectrode array (HD-MEA) with configurable electrode options is integrated into the ASIC implant, enabling simultaneous readout of 1024/256 channels at 8.48/33.9 KSPS. By reducing the ASIC implant to a thickness of 25 µm, the total volume of the implant is only 3.6 mm³, making it thinner than a strand of human hair and occupying less than a third of the volume of a grain of rice. We conducted in-vivo experiments in the cortices of pigs and monkeys and successfully achieved ultra-high resolution receptive field mapping. This work sets a new standard for volumetric efficiency in implantable brain-computer interfaces.

En Perú los tipos de diabetes que presentan mayor incidencia en pacientes son: Diabetes mellitus tipo 1, Diabetes mellitus tipo 2 y diabetes gestacional. De acuerdo con el registro en la situación de diabetes según datos del sistema de vigilancia en el Perú (Ministerio de salud) desde el 2018 hasta el 2021 el tipo de diabetes con mayor predominio y casos registrados es la DM tipo 2 con un 96.7%, siguiendo la DM tipo 1 con 2.1%, la diabetes gestacional con 0.9% y en la región Lambayeque el 5% de personas padece diabetes. La DM tipo 2 tiene mayor preponderancia y causante principal de amputaciones en los miembros inferiores, con un 19% en personas masculinas y el 28.3% en personas femeninas con riesgo muy elevado debido al pie diabético, afectando de manera drástica el estilo de vida al ciudadano ya que deben continuar con el uso de muletas o en silla de ruedas, limitándolos a actividades físicas en su vida diaria. En la actualidad se debe tener en cuenta la ergonomía, el adecuado diseño y para prótesis que utilizarán personas con diabetes los materiales utilizados deben ser adecuados para no generar contusiones, irritabilidad, alergia, inflamación en el muñón de la persona amputada de manera transfemoral. La presente tesis tiene por objetivo diseñar una prótesis transfemoral, utilizando la matriz morfológica, seleccionando materiales, mediante el software SolidWorks realizando el análisis estático lineal, verificando que el diseño sea seguro con la finalidad de permitir la marcha normal de la persona, mejorando su estilo de vida. / In Peru, the types of diabetes that have the highest incidence in patients are Diabetes mellitus type 1, Diabetes mellitus type 2 and gestational diabetes. According to data from the surveillance system in Peru (Ministry of Health), from 2018 to 2021, the type of diabetes with the highest prevalence and recorded cases is type 2 DM with 96.7%, followed by type 1 DM with 2.1%, gestational diabetes with 0.9% and in the Lambayeque region 5% of people suffer from diabetes. Type 2 DM is more prevalent and the main cause of amputations in the lower limbs, with 19% in males and 28.3% in females with a very high risk due to diabetic foot, drastically affecting the lifestyle of the citizen since they must continue to use crutches or wheelchairs, limiting them to physical activities in their lives. daily. At present, ergonomics must be taken into account, the appropriate design and for prostheses to be used by people with diabetes, the materials used must be suitable to avoid causing contusions, irritability, allergy, inflammation in the stump of the transfemoral amputee. This thesis aims to design a transfemoral prosthesis, using the morphological matrix, selecting materials, using SolidWorks software, performing linear static analysis, verifying that the design is safe in order to allow the normal walking of the person, improving their lifestyle.