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The Accuracy of Dual Photon Absorptiometry Measurements of Soft Tissue CompositionGordon, Christopher L. 04 1900 (has links)
During routine measurements of body composition using a 153Gd
based dual photon densitometer, it was observed that negative
values were being obtained for the body fat fraction in some
adults, in children and in small animals. In these three groups,
there appears to be a body size dependent error whereby the
measured fat fraction becomes increasingly negative as subject size
becomes smaller.
The fat fraction is derived from relating the measured mass
attenuation coefficient of soft tissue to an internal calibration
based on the use of water and lard as substitutes for muscle and
fat. To investigate whether this procedure for instrument
calibration is the cause of the fat fraction errors, soft tissue
phantoms which contained known amounts of fat, water and protein
were prepared. Over the range of fat fractions used, accurate
results were obtained.
By using prepared soft tissue and water phantoms it was
established that the measured fat fraction incorrectly became
progressively smaller as object thickness decreased and incorrectly
increased with object thickness. However, accurate measurements
were obtained if the equivalent tissue thickness is greater than
9 em and less tnan 16 em of water. Equally reproducible
measurements are obtained at all thicknesses investigated.
When dual photon measurements of body composition in 13 adolescent females were compared with measurements obtained from
skinfold thicknesses or bioimpedance, there was good agreement
between techniques but dual photon results demonstrated a broader
range of variation with body size. Comparisons between dual photon
absorptiometry derived body composition measurements of 52 male
athletes with results obtained from under water weighing allowed
for derivation of a simple correction factor for the accuracy
errors due to body size. / Thesis / Master of Science (MSc)
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Acute Effects of Sound Assisted Soft Tissue Mobilization (SASTM) on Lower Extremity Flexibility, Isokinetic and Isometric StrengthBeer, Jeffrey Allen 07 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / SASTMTM is a myofascial technique used to mobilize soft tissue and aid in the elongation of soft tissue and create physiological change. The purpose of the study was to determine the acute effects of Sound Assisted Soft Tissue Mobilization (SASTMTM) on lower extremity hamstring strength (isokinetic & isometric) and flexibility. Thirty division III male athletes with limited ROM of ≤ 90o of knee extension with 90o of hip flexion while lying supine consented to volunteer. Each subject was treated and measured through a double-blinded experimental design where the subjects and tester were unaware of the real treatment being administered and measured. The research consisted of 4 visits (familiarization/baseline, and 3 data collection session). Testing sessions were conducted a week after the baseline session, followed by two sessions, 2 days and a week after the 1st session. Three different modalities (SASTMTM, Therapeutic Ultrasound and “The Stick”) were performed on a treatment leg, and the opposite leg served as a control. Data collection consisted of a warm-up on a cycle ergometer followed by one randomly chosen modality on the treatment leg. Data collection was conducted using a Cybex 300-isokinetic device and a digital goniometer. Isokinetic strength testing was performed at 60, 180 and 240o/s. Isometric testing was collected at 45o of knee flexion. Repeated two-way ANOVA’s (3-Treatment x 3-Time) were used for statistical analyses to determine the effects of interventions and the time on strength and flexibility. The statistical analyses resulted in no significant results (p≤.05) for acute effects for either strength or flexibility with respect to time, treatment or treatment and time interactions.
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Measurement of soft tissue profile changes as a result of placement of orthodontic bracketsKebert, Michele 12 March 2008 (has links)
ABSTRACT
This research report quantifies the soft tissue profile changes that occur as a result of
the placement of orthodontic brackets. It also assesses whether patients are able to
perceive any changes in their own profiles immediately post bonding.
Using a standardised photographic technique, profile photographs were taken of a
group of patients both before and immediately after the placement of orthodontic
brackets. A series of angular and linear measurements were made each on the
photographic images using a computer software program. The data obtained from the
‘before’ and ‘after’ photographs were then compared.
Patients were also asked several standard questions about their ‘before’ and ‘after’
photographs.
The results indicate that the placement of orthodontic brackets can cause changes in
the soft tissue profile of patients. Statistically significant changes were found for four
of the ten profile measurements that were investigated, namely the Nasolabial Angle,
the Maxillo-Mandibular Contour, the Interlabial Angle and the Lower Lip Projection.
It was also found that patients are able to perceive changes in their profiles brought
about by the placement of orthodontic brackets, and that most are able to correctly
recognise which photograph was taken after bracket placement. The majority of
patients prefer the photographs of their profiles taken before bracket placement.
This study was conducted using a standardised orthodontic bracket. Future research
may be carried out to compare profile changes occurring with other bracket systems.
This may assist manufacturers in designing brackets that are more comfortable and
acceptable for patients.
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Simulation numérique du comportement dynamique des organes pelviens / Numerical simulation of dynamic behavior of pelvic organsChen, Zhuo-Wei 27 June 2013 (has links)
Le prolapsus des organes pelviens (vessie, rectum, utérus, vagin) est un problème de santé qui touche de plus en plus de femmes. Ce trouble, dont la fréquence augmente avec le vieillissement de la population, altère inévitablement la qualité de vie des malades. Pour autant, les causes de cette pathologie sont mal connues et les pratiques chirurgicales demeurent mal évaluées. La réalisation d’un simulateur du comportement dynamique des organes pelviens permettant au chirurgien d’estimer l’impact fonctionnel de son geste avant sa réalisation est donc un besoin identifié. Ce travail concerne ainsi le développement, par la méthode des éléments finis, d’un modèle numérique du mouvement des organes pelviens et de leurs interactions. Un modèle est construit à partir d’une segmentation de l’IRM des patiente, permettant de générer la géométrie des organes pelviens. Des lois hyperélastiques sont ensuite adoptées pour modéliser le comportement mécanique des organes. Des résultats qualitatifs sont obtenus, permettant de comprendre les causes de certaines formes de prolapsus et d’estimer l’effet virtuel des interactions entre les organes. / Pelvic organ prolapse is a health problem that occurs only in women and becomes more common. These disorders whose frequency increases with the aging of the population affect the patients’ quality of life. However, the causes of these diseases are poorly understood and the surgical practices remain poorly evaluated. The realization of a simulator will allow surgeon to estimate the functional impact of his actions before implementation, to perform the surgery in a more controlled and reliable way. This work concerns the development of a numerical model of pelvic organs’ movement and their interactions based on the finite element methods. A first model is constructed from patients MRI images, allowing the generation of the organ geometries. Hyperelastic modeling of the organs behaviors were considered. Qualitative results could help to understand the reasons for the prolapse and to estimate the potential effect of organs interactions.
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Prognostic factors in desmoid tumors.Kotilingam, Dhanasekaran. Douglas, Tommy C., Ford, Charles Erwin, Rodin, Andrei S., January 2008 (has links)
Source: Masters Abstracts International, Volume: 47-02, page: 0949. Adviser: Tommy Douglas. Includes bibliographical references.
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Natural History and Prognostic Factors in Soft Tissue Injuries of the Shoulder: A Prospective Cohort Pilot StudyCARPENTER, JENN 31 August 2009 (has links)
Introduction: Soft Tissue Injuries (STIs) of the shoulder are common presentations to the Emergency Department but very little is known about the natural history, long-term disability or prognostic factors associated with these injuries. The goals of this pilot study are to describe the three-month outcome of these injuries, to begin to identify prognostic factors associated with poor outcome and to determine the feasibility of a future study aimed at predicting poor outcome.
Methods: A cohort of 117 working-age adults presenting to the Emergency Department with acute STIs of the shoulder were prospectively recruited. Patients were interviewed by phone at one week, one month and three months. During the calls, patients completed the Disabilities of the Arm and Shoulder (DASH) questionnaire and provided information about treatments and follow-up that had occurred.
Results: Of the 117 subjects, 72.3% had pain and disability above the population norm at one month and that number only decreased to 38.7% at three months. A substantial effect was also seen on Work and Leisure activities. The following prognostic factors were identified as having some association with poor three-month outcome: age, mechanism of injury, ability to rotate arm and abduct arm in ED, pain at one week, whether the injury was work-related, visit with family physician in first week and DASH score (disability) at one week.
Conclusions: At the present time, the emergency physician must treat patients with STIs of the shoulder without any substantial knowledge of the morbidity that these injuries cause, which patients are at high risk of poor outcome or what would constitute optimum management. This study has determined that poor outcome is common and it has begun to identify factors that can help predict which patients will have a more complicated course. As it is now felt that the transition from acute to chronic pain begins well before three months, it will be important for future studies to develop a method of early identification of patients at high risk of poor outcome and to determine effective management in an attempt to prevent that transition. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2009-08-31 12:12:22.113
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Modeling and Control of A Flexible Needle in Soft TissueBoroomand, Arefeh Unknown Date
No description available.
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Gait analysis methods to minimise soft tissue artefact and evaluate techniques to locate the hip joint centrePeters, Alana Victoria January 2010 (has links)
The purpose of this thesis was to investigate gait analysis methods used to minimise soft tissue artefact (STA) when measuring the kinematics and kinetics of human gait. STA affects all gait analysis methods and is considered to be one of the major sources of error in clinical motion analysis. A systematic review was initially performed to quantify the magnitude of STA for different areas of the lower limbs during gait analysis. Despite the high quality of the existing literature, the results of the review were inconclusive regarding the exact magnitude of STA during human gait analysis. Previously, there were no methods used consistently throughout the reviewed studies to assess STA. The primary aim of this thesis was to determine the most valid method for minimising STA during human gait analysis. / Whilst the systematic review provided equivocal results on the magnitude of STA, it was able to confirm that STA at the tibia is less than for the femur segment. As a result, the tibial segment was investigated to determine marker locations that are least susceptible to STA. Twenty unimpaired young adults were included in the study and were instrumented with 36 markers, including 10 markers on each shank segment. The markers were well spread across the tibial segment in order to assess as many locations as possible. Four markers located on the tibia were less susceptible to STA. These were the proximal and distal anterior tibial crest markers as well as the medial and lateral malleolar markers. These markers were rigid to one another thus were rigid to the underlying bone. / In order to assess the modelling methods proposed in the literature a gold standard comparison was required. A potential new gold standard method was identified as 3-D freehand ultrasound (3-DUS). This was believed to be a non-invasive and cost effective method for locating internal bony structures. A validation of the new method (3-DUS) against MRI was performed to ensure the new gold standard was a valid methodology. The two methods, 3-DUS and MRI were compared for their accuracy in determining the location of the HJC within the pelvis segment. Twenty unimpaired participants were included in this study. The participants were of variable ages and physical composition. The difference between 3-DUS and MRI determined distance between the left and right HJC was 4.0 ± 2.3mm. It was determined that the results from 3-DUS were clinically not significantly different to MRI. The results of this investigation indicated that 3-DUS could be used as a gold standard measurement for three dimensional gait analysis (3-DGA) research. / The new gold standard method was used to validate existing 3-DGA modelling methods to determine which obtained the most accurate location of the HJC. To date, the greatest clinical application for gait analysis is as a test for people with central nervous system disorders associated with spasticity, especially children with cerebral palsy (CP) (Simon 2004). For this reason, 53 patients with gait abnormalities who had been referred to the Royal Children’s Hospital gait laboratory for a 3-DGA were tested. The participant sample represented patients who were referred to the Hugh Williamson Gait Analysis Laboratory (HWGAL). This was apparent because from 2008-2009 69% of patients at HWGAL had a diagnosis of CP, of the sample included in this study, 67% had a CP diagnosis. / Patients underwent a 3-DGA in addition to a 3-DUS of their left and right femoral heads. Resultant ultrasounds were assessed for the quality of the images and 46 patients were included for data analysis. Seven different methods were investigated for the determination of the HJC and four of these were analysed in two different ways, as such there were 11 models compared to 3-DUS. The Harrington et al method obtained the most accurate and repeatable results where the 3-D location error was 14.3 ± 8.0mm. That method considerably outperformed the functional techniques that had previously been proposed in the literature. This highlighted the importance of testing research techniques in target populations. / To conclude, this thesis has identified locations on the tibia which are most rigid to the underlying bone as well as a new gold standard measurement tool suitable for use in 3-D gait analysis research. The thesis has also demonstrated the validity of using functional methods for determining the HJC in pathological populations. Limitations of previous research were identified, including a lack of translation of research findings into clinical practice. Future work following on from this thesis should aim to address this issue.
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MMP family protein expression as prognostic biomarkers in human soft tissue sarcoma of extremitiesAl Gharibi, Khalaf January 2012 (has links)
Soft tissue sarcomas (STS) are rare human malignant neoplasms, arising mostly from stem cells within non-skeletal connective tissues. They account for approximately 1% of all human malignancies. Matrix metalloproteinases (MMPs) are enzymes involved in degradation of the extracellular matrix and their expression by cancer cells allows the cells to penetrate basement membranes and tissue matrix, thereby invading and metastasising. The most studied malignant tumours from the perspective of MMP expression and its relationship to malignant behaviour are epithelial-derived carcinomas. MMPs role in invasion and metastasis of sarcomas has been very little investigated. This is in part because of the difficulty in accumulating sufficient tumour tissue to enable statistically relevant analysis of sufficient tumours. The purpose of this thesis was to examine the expression of key MMPs - MMP-2, MMP-7, MMP-9, and MMP-14 and their inhibitors (TIMP-1 and TIMP-2) at the invasive/subcapsular edge of human malignant and benign connective tissue tumours using immunohistochemistry, a technique that allows a very high level of reaction product localisation within tumours. In three different STS types and appropriate benign equivalents, the expression of MMPs -2, -7, -9, and -14 and their inhibitors (TIMPs -1 and -2) were measured using intensity of staining and the percentage area of staining by image analysis. The results were compared between tumour types and against histological grading that is widely used as a prognostic factor. The findings from this research indicated that metalloproteinases were commonly expressed in STS and benign equivalents. There were differences in expression of some benign versus malignant neoplasms of the same group. No uniform pattern of expression of any of MMPs was observed across the tumours, but some of the data, most notably that for expression of MMP-2 and -9 indicate, a role for MMPs in malignant behaviour and some showed (e.g. MMPs -7 and -14) change in expression with the grade of malignant tumours in the same broad category. There is some evidence of an inverse relationship between MMP and appropriate TIMP expression suggesting that a failure of inhibition, as much as increased expression, is a feature of malignancy.
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Soft tissue facial profile assessment of 15-20 years old Tswana subjectsMzizana, Nondumiso Yvonne Helen 26 August 2010 (has links)
A well balanced and harmonious soft tissue profile is an important consideration in orthodontic diagnosis and treatment planning. The purpose of this study was to determine the soft tissue profile norms in Tswana subjects, compare the results with those of other ethnic groups and develop soft tissue “norms” or standards which may be useful as guides for diagnosis and treatment planning for Tswana orthodontic patients in South Africa. 420 subjects between the ages of 15-20 were randomly selected from their schools at no criteria. 102 Tswana (52 female and 50 male) and 50 non-Tswana subjects (25 female and 25 male) were selected according to criteria. The subjects were selected for excellence of occlusion, balanced facial proportion, complete dentition (third molars disregarded) dental Class I occlusion with normal overbite and overjet, minimal spacing or crowding, no history of orthodontic treatment and no gross caries. Various orthodontic analyses were used to measure and determine soft tissue facial profiles in both Tswana and non-Tswana subjects. Results were analysed statistically to determine the differences in facial profiles between Tswana and non-Tswana subjects and compare these to Caucasian and African-American norms. The results indicate that Tswana subjects had a flatter profile than non-Tswana subjects whose facial profiles were fuller. The study also indicates that the facial profile values established for Caucasian subjects are not applicable to Tswana and African-American subjects. The findings of the present study showed that when planning orthodontic treatment for Tswana subjects it may be useful to perhaps take into account some measurements which may be more appropriate. Copyright / Dissertation (MSc(Odont))--University of Pretoria, 2010. / Orthodontics / unrestricted
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