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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design and Prototype Validation of a Laterally Mounted Powered Hip Joint for Hip Disarticulation Prostheses

Mroz, Sarah 26 May 2023 (has links)
Powered prostheses are at the forefront of prosthetic technology, improving functionality by providing positive power to joints in the absence of native anatomy. Currently, there is no commercially available powered solution for hip-level amputees, and most hip prostheses are mounted to the front of the prosthetic socket. This thesis designed, fabricated, and tested a novel Laterally Mounted Powered Hip Joint (LMPHJ) that augments user gait to promote improved walking patterns. The LMPHJ attaches to the lateral side of the prosthetic socket, locating the hip centre of rotation closer to the anatomical location while ensuring user safety and stability. The new design locates the motor and all electronics in the thigh area, thereby maintaining a low profile while transmitting the required hip moments to the joint centre of rotation. A prototype was designed and manufactured to evaluate LMPHJ performance. Mechanical testing followed the ISO 15032:2000 standard and successfully demonstrated the joint's resistance to everyday loading conditions. Functional testing involved integrating the LMPHJ, Ossur Rheo Knee, and Ossur Pro-Flex XC with a prosthesis simulator that allowed three able-bodied participants to walk with the powered prosthesis successfully. This validated the mechanical design for walking over level ground and demonstrated that the LMPHJ is ready for next phase evaluation with hip disarticulation amputee participants.
2

Biomechanical adaptations involved in ramp descent: Impact of microprocessor-controlled ankle-foot prothesis. Kinetic and kinematic responses to using microprocessor-controlled ankle-foot prosthesis in unilateral trans-tibial amputees during ramp descent

Struckovs, Vasilijs January 2017 (has links)
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
3

Gait termination on a declined surface in trans-femoral amputees: Impact of using microprocessor-controlled limb system

Abdulhasan, Zahraa M., Scally, Andy J., Buckley, John 30 May 2018 (has links)
Yes / Walking down ramps is a demanding task for transfemoral-amputees and terminating gait on ramps is even more challenging because of the requirement to maintain a stable limb so that it can do the necessary negative mechanical work on the centre-of-mass in order to arrest (dissipate) forward/downward velocity. We determined how the use of a microprocessor-controlled limb system (simultaneous control over hydraulic resistances at ankle and knee) affected the negative mechanical work done by each limb when transfemoral-amputees terminated gait during ramp descent. Methods: Eight transfemoral-amputees completed planned gait terminations (stopping on prosthesis) on a 5-degree ramp from slow and customary walking speeds, with the limb's microprocessor active or inactive. When active the limb operated in its ‘ramp-descent’ mode and when inactive the knee and ankle devices functioned at constant default levels. Negative limb work, determined as the integral of the negative mechanical (external) limb power during the braking phase, was compared across speeds and microprocessor conditions. Findings: Negative work done by each limb increased with speed (p < 0.001), and on the prosthetic limb it was greater when the microprocessor was active compared to inactive (p = 0.004). There was no change in work done across microprocessor conditions on the intact limb (p = 0.35). Interpretation: Greater involvement of the prosthetic limb when the limb system was active indicates its ramp-descent mode effectively altered the hydraulic resistances at the ankle and knee. Findings highlight participants became more assured using their prosthetic limb to arrest centre-of-mass velocity. / ZA is funded by the Higher Committee of Education Development in IRAQ (HCED student number D13 626).
4

Impact of combined microprocessor control of the prosthetic knee and ankle on gait termination in unilateral trans-femoral amputees. Limb mechanical work performed on centre of mass to terminate gait on a declined surface using linx prosthetic device

Abdulhasan, Zahraa M. January 2018 (has links)
The major objective of this thesis was to investigate how the use of a recently developed microprocessor-controlled limb system altered the negative mechanical work done by the intact and prosthetic limb when trans-femoral amputees terminated gait. Participants terminated gait on a level surface from their self-selected walking speed and on declined surface from slow and customary speeds, using limb system prosthesis with microprocessor active or inactive. Limb negative work, determined as the integral of the negative mechanical (external) limb power during the braking phase, was compared across surface, speed and microprocessor conditions. Halting gait was achieved predominantly from negative work done by the trailing/intact. Trailing versus leading limb mechanical work imbalance was similar to how able body individuals halted gait. Importantly, the negative limb work performed on the prosthetic side when terminating gait on declined surface was increased when the microprocessor was active for both slow and customary speeds (no difference on level surface) but no change on intact limb. This indicates the limb system’s ‘ramp-descent mode’ effectively/dynamically altered the hydraulic resistances at the respective joints with evidence indicating changes at the ankle were the key factor for increasing the prosthetic limb negative work contribution. Findings suggest that trans-femoral amputees became more assured using their prosthetic limb to arrest body centre of mass velocity when the limb system’s microprocessor was active. More generally findings suggest, trans-femoral amputees should obtain clinically significant biomechanical benefits from using a limb system prosthesis for locomotion involving adapting to their everyday walking where adaptations to an endlessly changing environment are required. / Higher Committee of Education Development in IRAQ (HCED)
5

Knäkomponenters inverkan på livskvalité : En studie på individer med transfemoral amputation / The impact of knee components on quality of life : A study of individuals with a transfemoral amputation

Karlsson, Ellinor, Medlöw, Ellen January 2017 (has links)
Syfte: Syftet  med  studien var  att undersöka  om  det  finns  en skillnad  i  livskvalité mellan  individer  med  transfemoral  amputation  som använder  mikroprocesstyrd knäkomponent (MPK) respektive mekanisk knäkomponent (Mek.). Design: Tvärsnittsstudie Försökspersoner: 14 protesbrukare  med unilateral transfemoral amputation (10 män, 4 kvinnor; 4 Mek., 10 MPK), amputerade på grund av trauma, kongenital orsak, infektion eller tumör och som använt sig av samma typ av knäled i minst ett år. Metod: För  att  studera  livskvalité  i  målpopulationen  genomfördes  en enkätundersökning bestående av RAND-36 samt kompletterande frågor. Deltagarna fördelades i två grupper med avseende på knäkomponent för att möjliggöra analys av resultaten. Resultat: Ingen signifikant  skillnad  i livskvalité uppmättes mellan  grupperna. De största  skillnaderna observerades  dock  i  den fysiska-  (Mek.:  0 MPK:  50) och emotionella (Mek.: 41,75 MPK: 100) rollfunktionen. Slutsats: Resultatet  i  studien  visade  ingen  signifikant  skillnad i  livskvalité mellan grupperna. Vidare  bör  mer  specifika  mätinstrument,  inriktade  mot  individer  med amputation, användas för att undersöka livskvalité i målpopulationen. / Purpose: The purpose of the study was to investigate if there is a difference in qualityof  life  (QoL)  between  individuals  with  a  transfemoral  amputation  usingmicroprocessor-controlled  knee  components  (MPK)  versus  mechanical  kneecomponents (Mech.). Design: Cross-sectional study Subjects: 14 prosthesis users with a unilateral transfemoral amputation  (10 men, 4women; 4 Mech., 10 MPK), amputated due to trauma, congenital reasons, infection ortumor and used the same prosthetic knee for at least one year. Method: To study QoL in the  population concerned a questionnaire was carriedout, including the RAND-36 and supplementary questions. The  participants  were divided into two groups with regard to the knee component to enable the results to be analyzed. Results: No significant difference in QoL were found between the groups. The largest differences were observed in physical (Mech.: 0 MPK: 50) and emotional (Mech.: 41.75MPK: 100) role function. Conclusion: The result of the study showed no significant difference in QoL between the groups. Furthermore, specific measuring instruments targeting individuals with amputation should be used to investigate quality of life in the population concerned.
6

Regulace provozu autonomních solárních systémů / Control system used in autonomous solar system

Slezák, Pavel January 2008 (has links)
This thesis dealing with description and of autonomous solar systems and algorithms for control of decision-making mechanism. Optimal set of these machanism has effeect in raise of efficiency in hole autonomous system. In practical purposes propose create one by using microprocesor ATMEGA8, which measure all electrical data in system and control all decisions of implemented algorithm.

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