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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

An automatic electrically controlled leg brace for knee joint instability

Chen, David Yu-hung January 1972 (has links)
No description available.
2

Design and development of a soft brace for active correction of spine scoliosis.

Ali, Athar 27 March 2023 (has links)
Scoliosis is an abnormality of the spinal curvature that severely affects the musculoskeletal, respiratory, and nervous systems. Conventionally, it is treated using rigid spinal braces. These braces are static, rigid, and passive in nature, and they (largely) limit the mobility of the spine, resulting in other spinal complexities. Moreover, these braces do not have precise control over how much force is being applied by them. Over-exertion of force may deteriorate the spinal condition. This research presents a novel active soft brace that allows mobility to the spine while applying controlled corrective forces. The brace uses elastic bands to apply forces in the form of elastic resistance. These forces are regulated by varying the tensions in elastic bands using low-power, lightweight, twisted string actuators (TSAs). Use of TSAs and the elastic bands significantly reduces the weight and power consumption of the device. This results in higher comfortability and longer wear time. To realize the brace concept a finite element analysis was carried out. A FE model of the patient’s trunk was created and validated with in-vitro study from literature. The brace model was installed on the simulated trunk to evaluate in-brace correction in both sagittal and coronal planes. The brace was evaluated under various load cases by simulating the actuator action. The research also focused on the protype development which include the actuator and contact forces modeling of the active soft brace (ASB). The actuator modeling is required to translate the twisting of string in terms of contraction of the string’s length, whereas the contact force modeling helps in estimating the net resultant force exerted by the band on the body using single point pressure/force sensors. The actuators (TSAs) are modeled as helix geometry and numerical estimation was validated using a laser position sensor. The results showed that the model effectively tracked the position (contraction in length) with root mean square error (RMSE) of 1.7386 mm. The contact force is modeled using the belt and pulley contact model and validated by building a custom testbed. The actuator module is able to regulate the pressure in the range 0–6 Kpa, which is comparable to 0–8 Kpa pressure regulated in rigid braces. This makes it possible to verify and demonstrate the working principle of the proposed active soft brace. The use of stretch sensor to measure the stretch(tension) in the elastic bands is a crucial part of the brace. It is used as feedback to control the tension in the elastic bands using twisted string actuators. A few, fabric and silicon-based stretch sensors are analyzed to pick a suitable candidate for the active soft brace application. Two control modes were designed to control the amount of force being exerted by the brace. One using pressure sensors as feedback to keep the contact pressure at desired setpoint. Second mode using the stretch sensor to keep the tension in the bands at a desired setpoint. The active soft brace modules (TSA actuator, bands and stretch sensors, controller) were integrated and validated on the mannequin. This research concludes the preliminary part of conceptual design, construction, and validation of the demonstrator prototype, before going into the clinical trials. Clinical trials take longer duration to evaluate the effectiveness of the brace on real patients and were out of the scope of the project.
3

Design and Evaluation of the Kingston Brace

JONES, SIMON 18 February 2010 (has links)
Lisfranc injuries affect at least 1 out of every 55,000 people each year. Although they are rare foot injuries, their effects can be devastating. 20-40% of Lisfranc injuries are missed upon first presentation. This increases the number of poor outcomes, resulting in a disproportionate number of malpractice lawsuits and compensation claims. The Kingston Brace was designed to support an injured foot during a CT scan with the goal of providing the diagnosing physician with the best diagnostic information possible. A prototype was designed and built to support a variety of foot orientations in order to determine which orientation is optimal for Lisfranc joint CT scanning. Three fresh frozen cadaver feet were put through several experiments with the Brace. The 2D diagnostic quality of CT scans taken using the Kingston Brace was compared against that of CT scans using the existing protocol. The Kingston Brace allows for a greater visualization of the injured Lisfranc joint than the existing CT protocol. Lisfranc joint spreading was used as a measure of potential pain in injured patients. The joint spreading was minimal, suggesting that injured patients would not feel as much additional pain during imaging. Also, the adoption of the Kingston Brace resulted in no change in the morphological parameters resulting from more advanced 3D analysis. The experimentally determined optimal Kingston Brace orientation was found to be 9◦ of plantarflexion and 13◦ of eversion. These orientations can be incorporated into the next generation of Kingston Brace design. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-07-06 15:01:57.866
4

The Effects of Wearing Prophylatic Knee Sleeves/Braces on Selected Isokinetic Measures During a Velocity Spectrum Knee Extension Test

Call, Michael H. IV 10 December 1998 (has links)
Twenty Virginia Tech varsity football players, age 18-24, volunteered as subjects to examine the effects of wearing prophylatic knee sleeves/ braces on selected isokinetic measures (i.e. strength, power and endurance). Each subject performed the Biodex (Multi-Joint System 2AP) knee extension test in each of three experimental conditions: sleeved with the Don Joy Knee support (S-DJ); braced with the McDavid lateral knee support (B-MD); and the control, unsupported condition (C-UN). The order of experimental conditions and the specific knee tested were randomized. The subjects were administered a Biodex knee extension test at 60 deg/sec, 210 deg/sec, and 450 deg/sec. The test protocol consisted of five maximal repetitions at 60 deg/sec, twenty maximal repetitions at 210 deg/sec and thirty maximal repetitions at 450 deg/sec. The following isokinetic measures were recorded: (1) peak torque to body weight ratio at 60 deg/sec. (2) work to fatigue ratio at 210º and 450 deg/sec. (3) average power at 210º and 450 deg/sec, and (4) range of motion at 60º, 210º, and 450 deg/sec. One way repeated measures analysis of variance revealed significant difference ( p > .03 ) in peak torque to body weight ratio treatment groups; work to fatique ratio, average power and range of motion revealed no significant diference among the three experimental conditions. The investigator concluded that prophylatic knee sleeves/braces effects peak torque to body weight ratio; the effect of different levels of condition does not depend on what level of speed is present for work to fatigue, average power and range of motion. / Master of Science
5

Investigation of Inflection Points as Brace Points in Multi-Span Purlin Roof Systems

Bryant, Michael R. 26 June 1999 (has links)
An experimental and analytical investigation was conducted to evaluate the behavior of inflection points as brace points in multi-span purlin roof systems. Seven tests were conducted using "C" and "Z" purlins attached to standing seam and through fastened panels. These tests were subjected to uniform gravity loading by means of a vacuum chamber. The experimental results were compared with analytical predictions based on the 1996 AISI Specifications with and without the inflection point considered a brace point. Finite element modeling of through fastened "C" and "Z" purlin tests were conducted and compared to experimental through fastened results. Conclusions were drawn on the status of the inflection point and on the design of multi-span purlin roof systems with current AISI Specifications. / Master of Science
6

The Biomechanical Effects of an Externally Applied Orthosis on Medial Compartment Knee Osteoarthritis

Conrad, Janet 06 December 2011 (has links)
This thesis examined the immediate biomechanical effects of valgus unloader brace application in participants with moderate medial compartment knee osteoarthritis during gait. Thirty-three individuals were prescribed a valgus unloader brace. 3D knee moments and angles were calculated during walking with and without the brace. Principal Component Analysis identified amplitude and temporal changes of the moment and angle waveforms during gait. Three groups were identified based on the change in knee adduction moment magnitude with brace application. Two-Way ANOVA tested for differences among groups and conditions in principal component scores, as well as discrete varus thrust values. There existed three subgroups of participants identified by different gait adaptations to brace application. The brace had temporal and magnitude effects on 3D kinetics and kinematics for the participant group. This study showed that the brace does not provide a consistent change to knee joint mechanics. These results have implications for brace prescription.
7

A Comparative Study On The Nonlinear Behavior Of Chevron And Suspended Zipper Braced Steel Frames

Ozcelik, Ahmet Yigit 01 July 2010 (has links) (PDF)
Chevron braced steel frames require large beams to redistribute the unbalanced vertical forces exerted on the beams after brace buckling. A new frame configuration similar to chevron brace was proposed in literature, where zipper columns were attached between mid-spans of the beams from second to top story. During severe ground motion, the unbalanced vertical forces caused by buckling of lower story braces are in this case redistributed to the upper story braces by these zipper columns. Consequently, all story braces buckle successively from first to top story brace instead of concentration of inelastic action in one story. This system has been improved recently by adding an elastic hat truss between the top two stories to prevent formation of a full zipper mechanism and to prevent collapse. Two-phase numerical study is undertaken in this study to evaluate the response of chevron and suspended zipper braced frames, where the objective of the first phase is to observe the change in the performance of the configurations for different sets of initial imperfection and rotational spring stiffness values. Rotational springs are added at the end nodes of the braces to represent the effects of gusset plates and initial imperfection is assigned to the mid-length of the braces to achieve proper buckling behavior. The objective of the second phase is to compare the response of chevron and suspended zipper brace frames. For this purpose, three, nine and twenty-story buildings are designed for both brace configurations. The designed buildings are analyzed under static and dynamic loadings.
8

Συγκριτική πολυπαραγοντική μελέτη των ψυχολογικών συνεπειών της ιδιοπαθούς εφηβικής σκολίωσης και κύφωσης Scheuermann σε εφήβους που αντιμετωπίστηκαν με εφαρμογή κορμικού κηδεμόνα

Ζαχαράτος, Σπυρίδων 27 April 2009 (has links)
Η εφαρμογή κηδεμόνα αποτελεί την πιο αποτελεσματική, μη χειρουργική, μέθοδο αντιμετώπισης μετρίων παραμορφώσεων της σπονδυλικής στήλης στους εφήβους. Φαίνεται όμως να έχει σημαντικές επιπτώσεις στην καθημερινή δραστηριότητα των εφήβων. Με την παρούσα μελέτη διερευνήθηκε η αυτοεκτίμηση της κατάστασης της υγείας των εφήβων με τις δύο πιο κοινές παραμορφώσεις της σπονδυλικής στήλης, οι οποίες αντιμετωπίστηκαν με την χρήση κηδεμόνα. Σε εβδομήντα εννέα εφήβους με παραμόρφωση σπονδυλικής στήλης ( ιδιοπαθής σκολίωση, θωρακική κύφωση Scheuermann ) και εξήντα δύο εφήβους χωρίς παραμόρφωση της σπονδυλικής στήλης (ομάδα ελέγχου) τους ζητήθηκε και συμπλήρωσαν το ερωτηματολόγιο Quality Of Life Profile for Spine Deformities. Η παρούσα μελέτη έδειξε ότι οι έφηβοι με παραμόρφωση της σπονδυλικής στήλης είναι, στατιστικώς σημαντικά, λιγότερο πιθανόν να έχουν πόνο στην ράχη όταν αθλούνται σε σχέση με την ομάδα ελέγχου αλλά περισσότερο πιθανό να έχουν δυσκολίες τόσο όταν σκύβουν όσο και στις καθημερινές δραστηριότητές τους και ενώ φορούν τον κηδεμόνα. Οι έφηβοι αυτοί ( με την παραμόρφωση) παραπονούνται ότι ξυπνούν εξ’ αιτίας πόνου στην ράχη και εκνευρίζονται με την εξωτερική τους εμφάνιση. Οι ασθενείς αυτοί αντιμετωπίζουν, συχνά, προβλήματα στις σχέσεις με τους φίλους τους ενώ αναφέρουν δυσκολίες κατά την έγερσή τους από το κρεβάτι αλλά και στον ύπνο κατά τη διάρκεια της νύχτας, συγκριτικά με τους εφήβους χωρίς παραμόρφωση. Επιπλέον καθώς μεγαλώνουν ηλικιακά αισθάνονται μεγαλύτερη ντροπή για το σώμα τους και ανησυχούν για το μελλοντικό αποτέλεσμα της παραμόρφωσης. Όσο δε ο συνολικός χρόνος 56 εφαρμογής του κηδεμόνα αυξάνεται οι έφηβοι με παραμόρφωση έχουν περισσότερες πιθανότητες να εμφανίσουν μειωμένο πόνο στην οσφύ σε σχέση με τους εφήβους της ομάδας ελέγχου. Τα κορίτσια συγκρινόμενα με τα αγόρια, στις ομάδες με παραμόρφωση, έχουν περισσότερες πιθανότητες να εμφανίσουν πόνο στην οσφύ μετά από τις καθημερινές δραστηριότητες στο σπίτι ή μετά από την γυμναστική. Οι ασθενείς με τα μεγαλύτερα κυρτώματα δυσκολεύονται πιο πολύ στο να σκύψουν ενώ πονούν πιο συχνά στην ράχη. Οι ψυχολογικές επιπτώσεις από τη εφαρμογή του κηδεμόνα στους εφήβους με παραμόρφωση της σπονδυλικής τους στήλης σχετίζονται κυρίως με τις συναναστροφές των παιδιών στο χώρο του σχολείου και σε συνδυασμό με τον πόνο στην ράχη αποτελούν τις κυριότερες αιτίες χαμηλής συμμόρφωσης. Λεπτομερείς συστάσεις και ψυχολογική υποστήριξη απαιτείται για όλους τους ασθενείς που υποβάλλονται σε θεραπεία με κηδεμόνα ενώ κρίνεται απαραίτητη και η σωματική άσκηση, ιδιαίτερα για τα μεγαλύτερης ηλικίας κορίτσια και όλα αυτά με σκοπό να επιτευχθεί η καλύτερη δυνατή συμμόρφωση στην θεραπεία. / Bracing is the most effective non-operative treatment for mild progressive spinal deformities in adolescence but it has shown a considerable impact on several aspects of adolescents’ functioning. This cross-sectional study investigated the self-perceived health status of adolescents with the two most common deformities, treated with body orthosis. Seventy-nine adolescents with spinal deformities (idiopathic adolescent scoliosis, thoracic Scheuermann kyphosis) and 62 adolescents without spinal deformities were asked to complete the Quality of Life profile for Spine Deformities Instrument. This study showed that adolescents with deformities are significantly less likely to have back pain in training than controls, but more likely to have difficulty in forward bending, and in the most common daily activities while in brace. These individuals claim they wake up because of back pain and feel quite nervous with the external appearance of their body. These patients face often problems with their relations with friends, while they reported difficulties in getting up from bed and sleep at night more often than their counterparts without deformities. As they grow older, patients feel increasing ashamed of their body, as they are more concerned about the future effect of the deformity on their body. As the bracing time increases, patients have much more probability than controls to get low back pain. Girls with deformity have a higher probability than boys to get low back pain while working in the house and while training. Individuals 57 with larger spinal curvatures have more difficulties in bending and increased incidence of back pain than their counterparts with smaller curvatures. Psychological reasons associated mainly with relations at school and back pain are the main causes for low compliance in adolescents with spinal deformities treated with body orthosis. Careful instructions for all individuals who will undergo brace therapy, psychological support for all patients who develop psychological reactions and physical training particularly for older girls should be recommended to increase bracing compliance
9

Strengthening T-Joints of Rectangular Hollow Steel Sections Using Through-Wall Bolts and Externally Bonded FRP Plates

Aguilera, JOSE Jr 28 September 2012 (has links)
T-joints are common in beam-column connections of steel frames, vierendeel girders and at mid-span of N-trusses. Strengthening the members of these structures increases the demand on the joints, which may require joint strengthening. This thesis examines different strengthening techniques of T-joints of RHS members. In Phase I, the effectiveness of through-wall steel bolts is examined. This is accomplished by controlling the web outward buckling of the chord under the brace axial load. The study examined the effect of the number and pattern of bolts, as well as the web height-to-wall thickness (h/t) ratio of the chord, on strengthening effectiveness. Rectangular 203x76x(3.09, 4.5, and 5.92) mm chord members were tested. The 8 mm diameter steel bolts varied from a single bolt to 15 bolts of various distributions. The joint strength increased by 3.1%, 6.2%, and 29% for chords with (h/t) of 34, 45, and 65, respectively. The number and distribution of bolts had little effect on their effectiveness. In Phase II, similar T-joint specimens were strengthened using adhesively bonded GFRP plates, 9.5 mm thick, of different configurations, and 2 mm thick high-modulus CFRP plates of equivalent stiffness. It was shown that strength gain increases significantly, from 9% to 38%, as (h/t) ratio of the HSS chord increases from 34 to 65. In thin-walled HSS (h/t = 65), retrofitting provided significant gains in strength but not in ductility. In thick-walled HSS (h/t = 34), retrofitting provided little strength gain, but enhanced ductility, especially with properly bonded plates extending on the brace. Generally, plates fractured under local bending or delaminated within plate layers while bond was fully intact. In Phase III, selected configurations of the two retrofitting methods were used in additional T-joints with chord (h/t) ratio of 65, to study their effectiveness in presence of axial compression load in the chord. Two sustained load levels were induced in the chord, representing 45% and 80% of its full axial capacity. The transverse brace load was then gradually increased to failure. The through-wall steel bolts increased the joint capacity by 13% to 25%, depending on the chord’s axial load level, while the bonded GFRP plate increased the capacity by 38 to 46%. / Thesis (Master, Civil Engineering) -- Queen's University, 2012-09-28 12:40:44.479
10

Effects of adherence to bracing treatment in children with adolescent idiopathic scoliosis: a preliminary study

Ichinoe, Abraham 08 April 2016 (has links)
OBJECTIVE: The objective of this study is to determine the different biological, psychological, and social factors that affect patient adherence in bracing treatment for adolescent idiopathic scoliosis. By comparing adherent and non-adherent bracing patients, we hope to gain insight into how to improve patient adherence in bracing as a means of primary treatment and to avoid secondary and tertiary treatments such as surgery. METHODS: Of the 19 patients (15 adherent, 4 non-adherent) who were examined for this study, the majority of them completed all psychosocial surveys at one time point in their bracing treatment. Patients answered surveys for multidimensional anxiety, generalized anxiety, pain-related fear and avoidance, pain catastrophizing, and quality of life. Quantitative sensory testing was performed on only 5 of the 19 patients at the time of writing. Sensory testing was conducted to gather information on thermal sensitivities and thresholds. Statistical t-test significance was determined for all surveys distributed to adherent and non-adherent bracing groups, and scaled T-scores were calculated for each survey measure to determine clinical significance. RESULTS: There were no statistically significant differences in any measures examined between adherent and non-adherent bracing patients. The only statistically significant difference was the number of hours of brace wearing, with the adherent group wearing their brace over 11 hours more than the non-adherent group (p < 0.0004). CONCLUSIONS: Because of the underpowered nature of this study, measures for multidimensional anxiety, generalized anxiety, pain-related fear and avoidance, pain catastrophizing, and quality of life should be reexamined for potential differences between adherent and non-adherent bracing patients. Quantitative sensory testing should be included as a measure of possible sensory differences between the two groups. A future study with a larger sample size may provide greater understanding into the motivations for bracing adherence in an effort to help patients avoid more invasive means of intervention in treating adolescent idiopathic scoliosis.

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