41 research outputs found

    Developing Optical Coherence Tomography for the Quantitative Study of Erosive and Carious Lesions in Dental Enamel in vitro

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    PhDOptical Coherence Tomography (OCT) is an imaging technique that uses near infra-red light to non-invasively form cross-sectional images of specimens, in a similar way to ultrasound and RADAR. A number of research groups have used OCT to study natural and artificial carious lesions and to some extent erosive lesions. For this, a variety of in vitro models have been used. However, the exact mechanism by which these demineralised enamel lesions affect the OCT measurements is not fully understood. This remains a barrier to its adoption as both an analytical laboratory tool and a widespread technique in clinical dentistry. Therefore, the aim of this thesis was to develop an understanding of how different demineralised enamel lesions manifest in OCT measurements. This is necessary for the technique to become useful as an in vivo clinical measurement and imaging system. Consequently, this study was carried out in a controlled laboratory environment for which a novel specimen holder was designed. This mitigated against specimen movement and maintained specimen hydration, which can be a source of uncertainty in the measurements. A custom-built OCT microscope was used for this work, which enabled automation of experiments and continuous time-lapse OCT imaging over time periods of hours to several days. This enabled bovine enamel demineralisation dynamics to be captured during in vitro caries and erosion formation. The stability of the system also enabled direct comparison between the OCT measurements of the optical properties of different demineralisation models. To achieve these measurements, the OCT system was carefully characterised and compared to established profilometry measurements. Interestingly, this revealed that the experimental protocol used to obtain lesions for profilometry was not to be representative of the lesions formed and measured by OCT. This is an important point when interpreting OCT data in light of other techniques. A novel method of analysis was developed that uses longitudinal OCT image correlation to quantify early stage surface softening during erosion. By using OCT volumetric data, this technique was able to measure sub-resolution changes at the specimen surface. Early results also indicate sensitivity to remineralisation. This thesis shows that OCT is sensitive to different demineralisation models produced and measured under controlled conditions. New method of handling the data can observe changes not previously seen in OCT. However, further work is still required to understand the underlying physical changes that lead to this sensitivity in OCT.BBSRC and GSK - BBSRC Industrial CASE award BB/K501190/1)

    Optical Methods in Sensing and Imaging for Medical and Biological Applications

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    The recent advances in optical sources and detectors have opened up new opportunities for sensing and imaging techniques which can be successfully used in biomedical and healthcare applications. This book, entitled ‘Optical Methods in Sensing and Imaging for Medical and Biological Applications’, focuses on various aspects of the research and development related to these areas. The book will be a valuable source of information presenting the recent advances in optical methods and novel techniques, as well as their applications in the fields of biomedicine and healthcare, to anyone interested in this subject

    Health and disease in Chalcolithic Cyprus : a problem-oriented palaeopathological study of the human remains

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    PhD ThesisPoor preservation of the human skeletal remains on Cyprus has, in the past, limited palaeopathological analyses conducted. The research presented here has two main aims: (1) to explore the possibility of deriving useful information from the poorly preserved human remains from Chalcolithic Cyprus and the methodological adjustments required to do so, and (2) to discuss the health status of the human Chalcolithic populations in Southwest Cyprus, determining patterns in the expression of pathologies related to age, sex or burial location which, if present, may further elucidate aspects of lifeways within and amongst the living populations. These aims are achieved through a macroscopic and microscopic analysis of the pathological lesions on the human skeletal remains from the Souskiou-Laona cemetery, the Lemba-Lakkous and Kissonerga-Mosphilia settlement sites which all date to the Middle Chalcolithic period. This research presents one of the first comprehensive palaeopathological studies for the Chalcolithic period in Cyprus with multi-site data. Lesions arising from osteoarthritic processes, non-specific diseases and disorders as well as trauma, dental pathologies and congenital defects are recorded, analysed and discussed within the archaeological context. The results presented in this thesis show that information regarding prehistoric peoples can be drawn from poorly preserved remains and it goes further to explore the limitations to the interpretations which can be postulated. The analyses of the research indicate that there are moderate to low prevalence of pathological lesions observed on the Chalcolithic skeletal remains. There is differential expression between males and females in the joints affected by osteoarthritic changes and the types of dental pathologies suffered by each sex. This research contributes to the overall historiography of health and disease in Cyprus, by filling a lacuna for the Chalcolithic period. Additionally, it provides an illustration of some methodological modifications, such as qualitative discussion, needed when dealing with poorly preserved and commingled material in a palaeopathological study.Wellcome Trust Northern Centre for the History of Medicine, Newcastle University Overseas Research Studentshi

    How has the morphology of the human mandible varied in response to the dietary changes that have occurred in Britain between the Neolithic and Post-Medieval periods?

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    Unlike cranial morphology, human mandibular morphology has been found to be influenced primarily by environmental as opposed to genetic factors. Previous research has demonstrated that significant morphological changes have occurred in the mandible during the Agricultural and Industrial Revolutions when widespread dietary changes occurred, and diet became softer. During this time the size of the mandible decreased, and mandible morphology became more gracile. This research however has typically focussed on comparisons between two time periods associated with a large dietary transition. For this reason, it is not known if the reported changes in mandible morphology represent a consistent reduction in mandibular robusticity or rather fluctuation between periods associated with dietary variability. Furthermore, it is unclear how susceptible the mandible is to smaller dietary changes. The aim of this thesis is to investigate how responsive mandible morphology is to the dietary changes that have occurred in Britain from the Neolithic through to the Post-Medieval periods. It is hypothesised that mandible morphology is responsive enough to mechanical stimuli that more minor dietary changes will also result in morphological variation. Results indicated that in general mandible morphology became increasingly gracile over time, while more pronounced morphological changes are associated with major dietary transitions such as the intensification of agriculture and the Industrial Revolution. Moreover, significant increases in gracilisation occurred between the Anglo-Saxon and Medieval period, potentially indicating that the dietary changes that occurred during the Industrial Revolution were more gradual than previous research has indicated. In addition to the more prominent morphological changes, smaller morphological fluctuations occurred such as during the Roman occupation. It is concluded that the mandible is more responsive to smaller dietary changes than demonstrated by previous research and the morphological variation associated with these major dietary transitions may not have been as simple or rapid as previously assumed

    Health and disease in Chalcolithic Cyprus : a problem-oriented palaeopathological study of the human remains

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    Poor preservation of the human skeletal remains on Cyprus has, in the past, limited palaeopathological analyses conducted. The research presented here has two main aims: (1) to explore the possibility of deriving useful information from the poorly preserved human remains from Chalcolithic Cyprus and the methodological adjustments required to do so, and (2) to discuss the health status of the human Chalcolithic populations in Southwest Cyprus, determining patterns in the expression of pathologies related to age, sex or burial location which, if present, may further elucidate aspects of lifeways within and amongst the living populations. These aims are achieved through a macroscopic and microscopic analysis of the pathological lesions on the human skeletal remains from the Souskiou-Laona cemetery, the Lemba-Lakkous and Kissonerga-Mosphilia settlement sites which all date to the Middle Chalcolithic period. This research presents one of the first comprehensive palaeopathological studies for the Chalcolithic period in Cyprus with multi-site data. Lesions arising from osteoarthritic processes, non-specific diseases and disorders as well as trauma, dental pathologies and congenital defects are recorded, analysed and discussed within the archaeological context. The results presented in this thesis show that information regarding prehistoric peoples can be drawn from poorly preserved remains and it goes further to explore the limitations to the interpretations which can be postulated. The analyses of the research indicate that there are moderate to low prevalence of pathological lesions observed on the Chalcolithic skeletal remains. There is differential expression between males and females in the joints affected by osteoarthritic changes and the types of dental pathologies suffered by each sex. This research contributes to the overall historiography of health and disease in Cyprus, by filling a lacuna for the Chalcolithic period. Additionally, it provides an illustration of some methodological modifications, such as qualitative discussion, needed when dealing with poorly preserved and commingled material in a palaeopathological study.EThOS - Electronic Theses Online ServiceWellcome Trust Northern Centre for the History of MedicineNewcastle University Overseas Research StudentshipGBUnited Kingdo

    Health and disease in Chalcolithic Cyprus : a problem-oriented palaeopathological study of the human remains

    Get PDF
    Poor preservation of the human skeletal remains on Cyprus has, in the past, limited palaeopathological analyses conducted. The research presented here has two main aims: (1) to explore the possibility of deriving useful information from the poorly preserved human remains from Chalcolithic Cyprus and the methodological adjustments required to do so, and (2) to discuss the health status of the human Chalcolithic populations in Southwest Cyprus, determining patterns in the expression of pathologies related to age, sex or burial location which, if present, may further elucidate aspects of lifeways within and amongst the living populations. These aims are achieved through a macroscopic and microscopic analysis of the pathological lesions on the human skeletal remains from the Souskiou-Laona cemetery, the Lemba-Lakkous and Kissonerga-Mosphilia settlement sites which all date to the Middle Chalcolithic period. This research presents one of the first comprehensive palaeopathological studies for the Chalcolithic period in Cyprus with multi-site data. Lesions arising from osteoarthritic processes, non-specific diseases and disorders as well as trauma, dental pathologies and congenital defects are recorded, analysed and discussed within the archaeological context. The results presented in this thesis show that information regarding prehistoric peoples can be drawn from poorly preserved remains and it goes further to explore the limitations to the interpretations which can be postulated. The analyses of the research indicate that there are moderate to low prevalence of pathological lesions observed on the Chalcolithic skeletal remains. There is differential expression between males and females in the joints affected by osteoarthritic changes and the types of dental pathologies suffered by each sex. This research contributes to the overall historiography of health and disease in Cyprus, by filling a lacuna for the Chalcolithic period. Additionally, it provides an illustration of some methodological modifications, such as qualitative discussion, needed when dealing with poorly preserved and commingled material in a palaeopathological study.EThOS - Electronic Theses Online ServiceWellcome Trust Northern Centre for the History of MedicineNewcastle University Overseas Research StudentshipGBUnited Kingdo

    Classification of breast malignancy using optimised advanced diffusion-weighted imaging : and surgical planning for breast tumour resection using MR-guided focused ultrasound

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    Intravoxel Incoherent Motion Imaging (IVIM) is a non-invasive MR-imaging technique that enables the measurement of cellularity and vascularity using diffusion-weighted (DW)-imaging. IVIM has been applied to various cancer types including breast cancer, and is becoming more popular but lacks standardisation. The quantitative parameters; diffusion, D, perfusion fraction, f, and pseudo micro capillary diffusion, D* are thought to be correlated with tumour physiognomies such as proliferation, angiogenesis and heterogeneity.In Part 1 of this thesis, an optimised clinical b-value protocol is produced using a robust statistical method. This optimised protocol and various fitting methodologies are investigated in healthy volunteers, and then the most precise approach is applied in a clinical trial in patients following diagnosis of breast cancer, before treatment, to correlate IVIM parameters with breast cancer grade, histological type and molecular subtype with statistically significant results supporting IVIM’s potential as a non-invasive biomarker for malignancy. Monte Carlo simulations support this clinical application, where real data mean squared errors due to SNR limitations lie within simulated errors. A computed DW-imaging program is also presented to produce better quality images than acquired high b-value images as an adjunct to the optimised IVIM protocol.In Part 2 of this thesis, MR-guided Focused Ultrasound (MRgFUS) is explored as a means to create a pre-surgical template of thermally induced palpable markers to enable a surgeon to resect occult lesions and potentially reduce positive tumour margin status and local recurrence after breast conserving surgery. A surrogate animal model with pseudo lesion is presented, as well as a clinical tool to plan spot markers around a lesion as seen on MRI
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