OpenUCT :: Browsing by Subject "Human Biology"

Browsing by Subject "Human Biology"

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Open Access
3D cine DENSE MRI: ventricular segmentation and myocardial stratin analysis
(2013) Auger, Daniel A; Spottiswoode, Bruce S
Includes abstract. Includes bibliographical references.
Open Access
A sleep behaviour intervention to improve cardiometabolic health in adults with overweight and obesity
(2020) Henst, Rob HP; Rae, Dale E; Roden, Laura C
Rob Henricus Petrus Henst was born on the 12th of March in Schaijk, the Netherlands. He graduated from pre-vocational secondary education (VMBO) in 2005 and continued to study process and laboratory technology at an intermediate vocational educational (MBO) institution. In 2009, Rob started with a Bachelor of Science degree, majoring in Life Science with a minor in Exercise Science. For his undergraduate thesis in 2012, he moved to South Africa where he was introduced to chronobiology in exercise science. In 2013, Rob continued to study in South Africa for his Master of Science (Exercise Science) degree and published his first peer-reviewed article in the Journal of Biological Rhythms. He then developed an interest in sleep and cardiometabolic health, specifically in the context of public health. In 2015, these interests were combined and lead to his current PhD thesis on a sleep behaviour intervention for the betterment of cardiometabolic health. In this year, he also co-founded the business unit Sleep Science within the Sports Science Institute of South Africa to help individuals sleep better. In 2019, Rob moved back to the Netherlands to write the final pages of his PhD thesis.
Open Access
Aetiology of fatigue during maximal and supramaximal exercise
(2003) Nobbs, Les; Noakes, Tim; Gibson, A St Clair; Rauch, L H
The aim of this thesis was to investigate the extent of peripheral and central components in the development of fatigue during maximal exercise. Fatigue during maximal and supramaximal excercise has traditionally been modelled from the peripheral context of an inadequate capacity to supply metabolic substrate to the contracting muscles to meet the increased energy demand.
Open Access
An investigation into variations in the venous drainage pattern in brains of adolescents and adults
(2020) du Toit, Francesca; Louw, Graham J
It is well established that the brain changes dramatically in appearance during gestation and even after birth. Due to the multi-channelled origins and the number of developmental options, the adult venous system is characterised by a higher incidence of anatomical variations than the arterial system. Limited information is available on anatomical variation of the complete cerebral venous system. It is important to have an understanding of the usual drainage pattern the cerebral venous system and its anatomical variations to provide a foundation for future studies on anomalous venous structures. The extent to which fetal drainage patterns persist postnatally has yet to be established. The goal of the current study was to accurately describe the cerebral venous drainage patterns, including persistence of fetal drainage patterns in children, adolescents and adults in order to understand anatomical variations and the clinical impact during cerebrovascular interventions. For the current study 302 magnetic resonance images with contrast medium from the Groote Schuur and Red Cross Children's War Memorial Hospitals were retrospectively reviewed. The volumes of the dural venous sinuses were traced using a novel approach developed for the study. The approach included constructing 3D models of the dural venous sinuses and using the tracings for statistical and morphological analyses. No images of children met the inclusion criteria and therefore further analyses of the subset was not possible. Statistical analyses were performed to determine if there are any associations between venous sinus volume and sex, age, cerebral dominance and/or variations. Significant differences were noted for sex, dominance and variations of the cerebral venous system. The confluence of sinuses (CS) showed the most abundant number of variations. Although many studies and classifications have been made regarding the variations of these structures, there is a lack of a comprehensive classification that includes all variations. The goal of the current study was to determine the anatomical variations more comprehensively particularly at the level of the superior sagittal sinus (SSS) and confluence of sinuses. The study improved on the current literature by using contrast enhanced images as opposed to nonenhanced images or results obtained at autopsy. It is also the first study to establish a tracing protocol for venous volume to determine cerebral dominance and describe variations of the dural venous sinuses.
Open Access
Anabolic-androgenic steroids : knowledge, attitudes, ethical dilemmas and review for primary care physicians
(2002) Ebrahim, F A; Lambert, Mike; Schwellnus, Martin
Includes bibliographical references.
Restricted
The anti-cancer activity of a novel palladacycle, BTC2, in oestrogen receptor positive and triple negative breast cancers
(2017) Irene, Ikponmwosa; Prince, Sharon; Kimani, Serah
Breast cancer remains the leading cause of cancer death among women worldwide. This is in part due to late diagnosis, high recurrence rate and the development of drug resistance. Indeed, even though oestrogen receptor-positive breast cancers are known to respond to hormonal therapy, drug resistance is a common occurrence. Furthermore, triple negative breast cancers lack a specific therapeutic target, which has led to poor treatment outcomes. Hence, there is a critical need for new therapeutic approaches. Our laboratory previously identified a novel palladium-based compound, AJ-5, that exhibit potent anti-cancer activity in triple negative and oestrogen receptor-positive breast cancer cells. However, AJ-5 is poorly soluble, therefore, a series of water soluble AJ-5-based compounds were synthesized. The aim of this study was to test and characterise the anti-cancer activity of one of these AJ-5 analogues, BTC2, in triple negative (MDA-MB-231) and oestrogen receptor-positive (MCF7) breast cancer cell lines. Cytotoxicity assays were performed and BTC2 was shown to inhibit the proliferative rates of breast cancer cells with calculated IC50 values of 0.49μM in MCF7 cells and 0.58μM in MDA-MB-231 cells. BTC2 did not display considerable selectivity to breast cancer cells as the calculated IC50 value for the normal fibroblast cell line (FG0) was found to be 0.85μM and thus the selectivity index was less than 2 in both cell lines. Clonogenic assays were performed and BTC2 was shown to inhibit the long term (10 to 21 days) survival of MCF7 and MDA-MB-231 cells as it reduced their colony forming ability. Western blot analyses and immunofluorescence with an antibody to ƴH2AX, a robust marker of DNA double strand breaks, indicated that BTC2 acts by inducing DNA damage as the levels of this protein increased in drug treated cells. Light microscopy revealed that BTC2 induced morphological features of apoptosis (membrane blebbing and cell shrinkage) and autophagy (vacuoles reminiscent of autophagosomes). To further characterise the molecular mechanism underpinning the cytotoxic effects of BTC2, western blotting was performed with antibodies against key protein markers of stress signalling, cell cycle, apoptosis and autophagy. The results indicated that BTC2 activated the p38 MAP kinase signalling pathway and the p53 response in MCF7 cells. It is worth noting that MDA-MB-231 cells have a mutant p53 but that the p53 target protein, p21, was upregulated in both MCF7 and MDA-MB-231 cells. This suggests that p21 is regulated by a p53-independent mechanism in the MDA-MB-231 cells. BTC2 was shown to induce apoptosis and autophagy in both breast cancer cell lines as demonstrated by increased levels of cleaved PARP and LC3-II respectively. Apoptosis was confirmed by Annexin V-FITC/ propidium iodide double staining using flow cytometry. Taken together, data from this study suggest that BTC2 represents a promising anti-cancer drug for the treatment of triple negative and oestrogen receptor-positive breast cancer cells.
Open Access
Application and development of indirect measures of free-living energy expenditure
(2004) Keytel, Lara; Lambert, Vicki
The aims of this thesis were to explore the accuracy in measuring free-living total daily energy expenditure (TDEE), by examining existing indirect measures of energy expenditure (EE) measurement and further, developing new techniques, for improved accuracy and application, in population-based studies. In a number of the studies, the research focus is the heart rate (HR) monitoring technique, for TDEE estimation as a result of its low cost and ease of implementation in large population-based studies. This thesis represents a progression from the application of the HR monitoring technique for estimating EE in response to training, or as a means to validate a physical activity recall instrument. However, what is highlighted are the limitations of the existing methodology for estimated TDEE in this way. Therefore, this thesis introduces a novel concept in the HR monitoring technique, incorporating group-based EE equations, and further, by including the effects of the previous minutes HR response on the estimation of EE from HR. Finally, this thesis validates these modifications, using a respiration chamber, purpose-built as a part of this dissertation. It should be noted, however, that in some instances, the thesis was constrained by opportunistic sampling, or the fact that in the case of Chapter 4, the study sample was part of a larger study designed for another purpose. Nevertheless, the outcomes of this research, in particular, the group-based HR-EE prediction equations, have important implications for large population-based epidemiological research concerning physical activity dose-response. Bibliography: p. 227-253.
Open Access
The application of clinical gait analysis to running injuries
(2005) Arendse, Regan Emile; Schwellnus, Martin; Gibson, Alan St Clair
Clinical evaluation of the injured runner requires identification and correction of the multiple factors commonly implicated in running injury. Effective management of running injuries requires that the concerned health professional identify all implicated factors. In this regard it is essential that the relationship between running style and injury he determined, because if there is an association between the gait analysis variables descriptive of running style and injury, these would be important in the management of the injured runner. The Gait Analysis Laboratory at the Sports Science institute of South Africa and the University of Cape Town with its three-dimensional Vicon 370 motion analysis system and Advanced Medical Technology industry® strain gauge force platform is appropriate for collecting data to study running style. These data include the movement patterns and estimated mechanical power and work required to effect the observed movement of the ankle and knee. The forces applied by the supporting surfaces on the runners were collected. The data captured with the Workstation® programme (Oxford Metric, Oxford, England), was processed with GaitLab® (Kiboho Publishers, Cape Town, South Africa), collated in Excel ® (Microsoft Corporation, Redmond, USA) and statistically analysed (StatSoft, Inc. (2000). STATISTICA for Windows [Computer program manual]. Tulsa, OK, USA). In this thesis a series of studies are presented with the aim of determining the relevance of running style to the assessment of the injured runner and the conventional treatment methods used to treat common running injuries.
Open Access
An assessment of the health status by non-specific stress indicators in early farming populations from central and southern Africa
(2006) Dlamini, Nonhlanhla; Morris, Alan
The adoption of an agricultural lifestyle had profound implications for nutritional ecology, health and behaviour of human populations. The goal of this project was to generate information about the health status and disease patterns of early farming populations from central and southern Africa. Skeletal material was obtained from various 'Iron Age' sites in South Africa, Ingombe Ilede from Zambia, and Sanga and Katoto from the Democratic Republic of Congo. Palaeopathological analyses was done through the examination of non-specific stress indicators that included cribra orbitalia/porotic hyperostosis, Harris lines, linear enamel hypoplasias, subperiosteal bone lesions and dental diseases. The evidence from palaeopathology indicated that the environments played a major role in causing differences observed at micro-scale level. It is suggested that the health problems of these agricultural peoples are a result of their sedentary lifestyle and aggregation, which promoted maintenance and spread of infectious diseases; as well as high carbohydrate diets and dependence on a few main foodstuffs that affected their iron levels. The individuals from the forest region were less healthy than those in the dry or wet savanna zones. Also, the impact of the stress experienced by these societies was not sufficient to cause stunted growth and thus did not affect their terminal heights. The complex relationship between the environment, socio-cultural factors and biology has shown that subsistence economy only influences a fraction of human behaviour, health and well being. The results of this study argue that generalisations about prehistoric farming peoples cannot be made, until further research work is done.
Open Access
Best medical care practices in sport: investigating the barriers to the implementation in the developing countries. Uganda as a case study
(2020) Lubega, Samuelsaul; Lambert, Mike
The dissertation consists of four separate studies that have focused on different aspects of the relationship between the management of sports related injuries and utilisation of best practices before sports, during sports and after sports-related injuries. Background: Participation in sports has an associated risk of injury which is defined by the type of sport and level of participation. Any injury affects the athletes‘ health status. To mitigate this risk, international sporting organizations provide guidelines, and mandates the proper evaluation and care for athletes before, during and after training or participation in competition. Despite the availability of guidelines describing best medical care practices for managing athletes, inappropriate management practices are reported globally. The barriers to best medical practice vary. While these barriers have been investigated in a variety of sports in developed countries, similar investigations have not been extensively conducted in developing countries, where the demands are different. Therefore, the overall aim of this thesis was to explore barriers to best medical practices in a variety of sports in Uganda. Methodology: The research was conducted as four studies. The first study used a descriptive case study approach. The data were collected on a sample of injured athletes (n=75) from four sports in Uganda (football/soccer, athletics, basketball and rugby) to describe the medical care practices of the sports resource providers. The current prevention, emergency care, intermediate treatment, rehabilitation services and return-to-sports strategies were all documented in a period of six months. The gaps in best practices were observed, and further investigated in the next three studies. Firstly, a validated questionnaire was used to establish the level of knowledge and practices of various components/themes of athletes‘ well-being and best practices among the stakeholders. Secondly, the current standards of the sports arenas and medical and high-performance facilities were examined using a validated checklist. The last study was a semi-structured interview which assessed the available national health care policies to support sports best practice strategies in Uganda Findings: The overall results of the first study showed there was a significant lack of compliance to best medical care practices in all the phases of athletes‘ health care. The barriers to best practice were confirmed as: (i) the lack of adequate knowledge and awareness on various best practice strategies, (ii) the sports and health facilities were below the required standards and, (iii) there were no national health sports care policies to support and facilitate the implementation of best practices in Uganda. Conclusion: (i) A holistic approach may be required to address the best medical care practice barriers in Uganda to improve on the health and safety of athletes. (ii) The knowledge of stakeholders should be improved and awareness created about best medical practices in sports in Uganda. (iii) There is a critical need to develop a national sports health care policy. (iv) The facilities for sports and health care of athletes urgently need improvement and supported.
Open Access
Black River Cemetery: An anthropological study of the human remains exhumed from a historic Cape Town burial ground
(2020) Pütter, Christie; Friedling, Jacqui; Patrick, Mary
The Black River Cemetery, located in modern day Athlone (a suburb of Cape Town), was open for burials from 1867 - 1951, serving three Anglican Churches. The recent (2017) excavation of the historic site allowed for the analysis of the exhumed skeletal remains. The outcome of the skeletal analysis is valuable as the lives documented on the skeleton of a past group of people can write the story of individuals and communities that may have otherwise been omitted from the history books. The aim of this study is to describe demography, lifestyle and disease for a group of people living at the Cape between the 18th and early 20th centuries. The excavation of the cemetery yielded 1,305 graves of which 1,050 contained skeletal remains. Skeletal preservation was varied due to taphonomic influences, but overall it was poor with high fragmentation and taphonomic loss of skeletal material. The skeletal analysis performed utilised several well-established methodologies used in bioarchaeological and forensic anthropological disciplines and produced a body of information encompassing the demographics for this historic skeletal sample. Historical research on the Colonial Cape, coupled with the Black River Cemetery history and burial registers was employed to provide the context to the results of the skeletal analysis. The historic research suggests that the community and people buried there were most likely hardworking people of the poorer communities at the Cape in the 18th and 19th century with a division of labour between men and women. In the period of time that the cemetery was receiving burials, multiple social, political and economic changes occurred including; the bubonic (black) plague, Spanish influenza epidemic, the Boer War, the First World War and the Diamond Rush. It also saw the beginnings of racially segregated living and forced relocations. This backdrop provides an interesting landscape on which to view the skeletal analysis. The data analyses showed that the mortality profiles were skewed from the normal profiles determined by Weiss (1973). The sex ratio was skewed toward males indicating a greater mortality risk for men while the age mortality profiles showed a higher child and juvenile mortality and lower old adult mortality than is typically expected in a cemetery assemblage. This is an indicator of the effects of the epidemics and other factors reducing survivability of individuals. The low frequencies of periosteal reactions also may point to the poor survival capability as individuals may have succumbed to infections before the effect would be exhibited on the skeletal material. Pathological and stress indicators also show a sexually dimorphic trend with males exhibiting greater frequencies of degenerative joint disease, fractures, osteophytic growths and rates of dental attrition. Stature analysis showed a sexually homogenous group of people suggesting a lower health status and likely malnourishment or undernutrition. The social environment in which people lived likely contributed to a weakened immune system, and the generally poor health status of the people. The experience of the people living in Black River and the surrounding areas appears to be one of hard, repetitive labour and nutritional stress within an everchanging urban setting.
Open Access
Bone health and physical activity through the various life stages
(2003) Micklesfield, Lisa; Lambert, Vicki
The aims of this thesis were to investigate the interaction between physical activity and bone health through various life stages, in order to better understand the determinants of adult bone mass and consequently, osteoporosis. All the studies have been carried out on the various ethnic groups that make up the population of South Africa, with widely divergent economic and sociocultural experiences, and therefore provide us with insight into determinants of bone health within the South African context. In this dissertation, we will explore the relationship and interactions between physical activity, and other lifestyle, physiological and demographic factors, on BMD and bone QUS parameters in the South African population. What sets this thesis apart is that we consider groups that are largely unstudied, groups undergoing demographic and epidemiological transitions, and even groups for whom physical activity may no longer provide protection for bone health.
Open Access
Characterisation and functional analysis of the chicken microphthalmia gene
(2002) Pinder, Karen Elizabeth; Kidson, Sue
Despite the fact that the chicken embryo is a model system for developmental biologists, comparatively little is known about the regulation of avian melanogenesis. There has only been one report of the characterisation of the chicken tyrosinase gene promoter, and only one full-length chicken microphthalmia cDNA (cmi9) has been identified to date.
Open Access
Clinical and imaging features of the lumbar spine in elite male schoolboy cricketers : the effect of a pre-season lumbar stabilisation intervention
(2008) Aginsky, Kerith Dana; Derman, Wayne; Gray, J
Current evidence indicates that schoolboy cricketers are at a high risk of injury to the lumbar spine. This is particularly relevant in the case of fast bowlers who bowl with a high degree of shoulder counter-rotation. There, however, is a lack of evidence in the literature with respect to injury research of all cricketing disciplines, as fast bowlers receive the most attention. After reviewing the literature it was evident that the effect of a cricket-specific lumbar stabilisation exercise intervention in an attempt to reduce lower back pain and alter other physiological variables, had never been studied. Previous interventions in cricketers have focused only on fast bowlers in an attempt to decrease the degree of shoulder counter-rotation. However, these studies either took two years to observe a decrease or were unsuccessful.
Open Access
A control system approach to subject specific prospective respiratory motion correction in cardiac MRI
(2012) Burger, Ian H; Meintjes, Ernesta
Respiratory motion of the heart is a problem for high-resolution cardiac MRI. Diaphragmatic navigator gating with a 5mm acceptance window is most commonly used to address this but has an inherently low respiratory efficiency that is further compromised by respiratory drift. A novel method is presented that uses data from multiple navigators prior to the imaging segment as input for a control system to predict the diaphragm position throughout the imaging segment and correct the slice position in real time.
Open Access
Critical analysis of techniques for normalising electromyographic data : from laboratory to clinical research
(2008) Albertus, Yumna; Lambert, Mike; Derman, Wayne; Tucker, Ross; Noakes, Tim
Measurements of muscle activity derived from surface EMG electrodes are variable due to both intrinsic and extrinsic factors. The intrinsic factors are endogenous in nature (features within the body) and include muscle fiber type, muscle fiber diameter and length, the amount of tissue between muscle and electrode, and depth and location of muscle with respect to the placement of electrodes (24). These biological factors vary between subjects and cannot be controlled. The extrinsic factors are experimental variables which are influenced by the researcher and can be controlled to some extent. Examples of extrinsic factors include the location, area, orientation, shape of electrodes and the distance between electrodes (interelectrode distance). In order to measure biological variation in the EMG signal, which is important in studies where surface EMG is used to gain understanding of physiological regulation, it is important to minimise the variation caused by these factors. This is in part achieved through the appropriate method of normalisation. The isometric maximal voluntary contraction (MVC) has been used as a standardmethod of normalisation for both static and dynamic exercises. However, researchers have recently improved the methods of normalisation by developing alternative techniques for the measurement of EMG during dynamic activities. By using the same type of movement for normalisation as during the trial, experimental errors can be reduced. The appropriate method of normalisation is defined as a method that is capable of showing repeatability, reliability (low intra-subject variation) and sensitivity to changes in EMG amplitude that is due to biological change and not the contribution of experimental factors. The aim of this thesis was to critically analyse alternative methods of EMG normalisation during dynamic exercise. The data should provide possible guidelines to researchers who are planning studies involving measurement of EMG activity during cycling, running and in clinical populations. Furthermore, the thesis aimed to illustrate that decisions regarding the most appropriate method of normalisation should be based on the study design, research question (absolute muscle activity or changes in muscle pattern) and the muscles being investigated.
Open Access
Dental pathology and macrowear: a biocultural analysis of southern African holocene hunter-gatherers and hunter-herders
(2023) Olszewski, Judyta; Gibbon, Victoria
Dental macrowear quantity, direction, and oral pathology were assessed against demographic factors in southern African Holocene hunter-gatherers and -herders (sAHGH). This is the first study to investigate inter-related implications of diet, health, and behaviour across time and space using only teeth on a large sAHGH sample. This aim was accomplished through a systematic assessment of macroscopic dental examinations, particularly including direction, a method not yet addressed for sAHGH teeth. Data were obtained using a multimethod approach on 369 individuals and 6271 teeth and statistically analysed using R (version 4.1.3) and IBM© SPSS. The results showed a need for an adaptation of the Brabant index; therefore, I created a novel adaption to the method inclusive of a visual guide. Individuals were better preserved from coastal regions (n = 313) and young/middle-ages (n = 71), and sex and temporal divisions were similarly distributed, with fewer individuals dating to the earlier Holocene (n = 50). Wear quantity advanced rapidly, with increased odds in anterior teeth (OR=18, p≤0.01) and first molars (OR=4.6, p≤0.01). Horizontal and plane wear directions frequently occurred (n = 8321 teeth), and combined wear results reflected a plant-based diet and using teeth as tools. Tool use was further demonstrated by non-masticatory wear (n = 22) and microchipping (n = 55), elucidating behaviours such as occupational tasks and dental hygiene. Generally, the teeth demonstrated good health; however, the first molar was affected most frequently with antemortem tooth loss (OR=13.6, p≤0.01), infections (OR=4.4, p≤0.01), and caries (OR=28.7, p≤0.01). Overall, pathological lesions post-2000 BP reduced, suggesting health improvements. Notably, incidence rates for enamel hypoplasia on the first molars (n = 26) alluded to increased infant stress possibly related to herding. Interestingly, amelogenesis imperfecta was found, demonstrating a hereditary condition associated with comorbidities. Despite increasing oral pathology and wear into old age, good survival rates suggest biological resilience. The results of this study support resource-sharing practices regardless of developmental stage between sexes, as sAHGH retained homogeneous diets and labour-based contributions from childhood. This research contributes to holistic inferences on health and behaviour through the direct analyses of sAHGH, integrating biology with the environment, and elaborates on the discussion of the role of dental wear and behaviours contributing to pathology susceptibility. A macroscopic, multimethod approach proved effective in analysing the interplay of masticatory mechanisms and systematic assessments using non-destructive methods. These results demonstrated how hunter-gatherer groups thrived over millennia, and that sAHGH are a good adaptive representation of dental analyses for precontact populations
Open Access
Design and Development of a Portable Multi-user Medical Grade Oxygen Concentrator
(2024) Lowan, Vongani; Sivarasu, Sudesh; Maswime Salome
Introduction: The COVID-19 pandemic has increased the demand for high-flow oxygen concentrators, particularly in resource-limited areas. There is a pressing need for an innovative, high-flow, multi-user oxygen concentrator using local materials to address this healthcare challenge. Methods: The study focused on creating a portable, medical-grade oxygen concentrator using the Skarstrom pressure swing adsorption cycle, incorporating a silica gel drying tank and 13X Zeolite adsorption beds. Critical parameters such as compressor output pressure, heat exchanger efficiency, systemic pressure losses, air separation duration, and peak flow rate of oxygen-enriched air were extensively analysed through experiments and simulations. Results: The concentrator achieved a 21 litres per minute flow rate with over 85% oxygen purity at 100kPa. Cost efficiency was ensured using local components. Enhancements included an orifice in the sieve beds to increase back pressure and equalisation valves to reduce cyclic duration, thus improving efficiency. An internal spacer in the sieve bed was designed to optimise airflow and oxygen production. Discussion: This device addresses the scarcity of oxygen in resource-constrained regions like sub-Saharan Africa. It aims to reduce the cost of oxygen therapy (currently R20.00-R40.00 per patient per day) and should be expanded and implemented in similar settings. Future efforts should focus on integrating advanced functionalities such as remote monitoring for operational efficacy and safety. Conclusion: This multi-user oxygen concentrator represents a significant advancement in medical technology, especially for resource-limited settings. It provides a high oxygen flow rate and concentration at an optimised cost, addressing the oxygen shortage exacerbated by the pandemic. Its innovative design utilises local materials and features that enhance efficiency, offering a cost-effective solution and a model for future healthcare technologies. Future developments should aim to extend this technology's reach, ensure adaptability, and continuously improve its features for enhanced efficacy and safety. This contributes to more equitable medical resource distribution in areas with significant resource constraints.
Open Access
Design and Development of an Autoinjector Tracking Device to Integrate with Emergency Service
(2024) Maqungu, Qhamani; Sivarasu, Sudesh
Anaphylaxis is a life-threatening allergic reaction that requires treatment by prompt injection of epinephrine typically via epinephrine autoinjectors (EAI). An immediate visit to the emergency room (ER) to avoid possible relapse is necessary. Studies have shown that the effectiveness of epinephrine decreases with the prolonged delay of injection after symptoms onset. Many patients get hospitalised or die due to delayed epinephrine injection or unavailability of the EAI devices when it is mostly needed. Some of the reasons for unavailability at the incident site is usually associated with patients forgetting to carry their EAI. Some patients hesitated to administer epinephrine, resulting to a relapse hours later and while some did not seek further monitoring from a trained clinician after administering epinephrine. This study aimed at designing and developing an EAI tracking device to send reminder notifications to patients when they are located ten meters away from their EAI, and to alert emergency medical services (EMS) via SMS, containing location, when the patient is experiencing anaphylaxis. Using Impulse Biomedical's EAI ZibiPen device as a use case, a Bluetooth low energy (BLE) tracking device named GuardAin, was developed and linked to an Android mobile phone application. A pilot case-based study aimed at validating the accuracy of the notification alert algorithm in threedimensional directions was conducted at the Impulse Biomedical offices in the Western Cape. The test conditions were phone in hand and phone in pocket. The distance algorithm was validated using a ttest. The location accuracy from the emergency alert SMS was validated and compared to Google Maps. A total of 80 notification alert tracking tests were conducted. Forty tests were conducted for the horizontal direction test resulting in the detection of ten meters with an average of 10.7 meters. Forty vertical tests resulted in poor detection of a ten-meter distance. However, consistency in detecting three meters was observed with an average of 3.3 meters. The 3.3 meters was the average floor height in the building. Eight locations were selected as the choice of emergency trigger locations. The emergency alert locations were accurately detected within a 50-meter radius. The algorithm was found to be fairly accurate in detecting 10 meters and could serve as a reliable reminder for EAI adherence. However, walking pace determined how far past ten meters the notifications were sent. SMS emergency alerts were found useful to detect EAI usage and accurately relaying patient location to EMS and other emergency contacts. Future works include investigating the usability of the reminder system, and practicality of the emergency services alert system. Additionally, the tracking algorithm to be validated with different Android mobile devices.
Open Access
Design and Development Towards a Novel Prosthesis for Total Shoulder Arthroplasty to Reduce Aseptic Glenoid Loosening
(2018) Dey, Roopam; Sivarasu, Sudesh; Roche, Stephen
Total shoulder arthroplasty (TSA) is the most common surgical solution, that helps in restoring the structural and functional integrity of a diseased glenohumeral (GH) joint with intact rotator-cuff. A 300% increase in the usage of TSA has been observed since 2007, along with 2.5% increase in revision rate. Aseptic glenoid loosening accounts for 37% of postsurgical failures in TSA. Eccentric loading of the prosthetic glenoid cup, leading to the “rocking horse” effect, is one of the prevalent causes of aseptic glenoid loosening. Current anatomical total shoulder prosthesis (ATSP) geometry does not consider all the GH morphometric features, for example the elliptical shape of the humeral head. Moreover, the morphometric studies leading to the initial ATSP design did not consider the GH morphology of any sub-Saharan population. Hence, there exists a gap in understanding of the implications of certain morphometric features on the functionality of a post-TSA GH joint. This thesis had two primary aims to address this gap in knowledge. Firstly, to study the GH morphometric variations between cohorts representing native European (Swiss) and native sub-Saharan (South African) populations. Secondly, to develop anatomically inspired ATSP design concepts and test them using biomechanical and finite element (FE) models, insilico, under standardised testing protocols. The morphometric analysis suggested that an average Swiss humeral head radius of curvature was larger (P<0.05) than the average South African humeral head. By comparing the biological head sizes, across both the populations, with the dimensions of the commercially available humeral heads, it can be inferred that suitable humeral prostheses are currently not available for individuals with head sizes >28mm or <19mm. Considering both the populations, the inherent shape of an average humeral head was found to be elliptical. The thickest region of the head was found to lie in the posterior region and not at the geometric center. Hertzian contact theory was applied to calculate the GH stresses produced by symmetric and asymmetric elliptical heads. Higher concentric stresses (P<0.001), within the acceptable limit for polyethylene, were observed to be imparted by the asymmetric heads. Population-specific musculoskeletal models were developed to study the post-TSA kinematic variation. When an identical range of motion (RoM) was performed by these models, population-specific variation in muscle moment arms was observed. The novel glenoid designs were not found to alter the post-surgical kinematics. FE models of the biradial, compartmental and pear-shaped glenoid implant designs were subjected to compressive and shear loading according to the American Society for Testing and Materials (ASTM). Using the bi-radial the glenoid cup, with thickened posterior-superior surface, anatomically relevant force distribution patterns could be replicated. Compartmentalising the glenoid prosthesis into concentric and eccentric regions with the gaps, proved to be highly beneficial. When compared to a commercially available glenoid prosthesis, the compartmental prosthesis was able to contain the GH forces to the concentric region for longer, delaying the eccentric loading and therefore potentially reducing the “rocking horse” effect. In the light of the above observations, two conclusions can be drawn from this thesis. Firstly, it would be beneficial if population-specific ATSP were made available for natives of certain geographic locations. Secondly, glenoid prosthesis designs could be compartmentalised to contain the GH joint forces within the concentric regions of the cup which might aid in the reduction of post-TSA complications.

Browsing by Subject "Human Biology"

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