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Control of human walking is not thoroughly understood, which has implications in developing suitable strategies for the retraining of a functional gait following neurological injuries such as spinal cord injury (SCI). Bipedal robots allow simple elements of the complex nervous system to be analysed to quantify their contribution to motor control. RunBot is a bipedal robot which has been developed to operate through reflexes without using central pattern generators or trajectory planning algorithms. Switches in the feet identify ground contact and are used to activate motors in the legs, generating a gait cycle visually similar to that of humans. If a causal relationship can be established between foot contact information and muscle activity in humans during walking, rather than developing a complicated biologically realistic neural system to control stepping, the model used in the control of the RunBot robot could instead be simplified using this relationship and the associated filter functions transferring the sensory data into motor actions. By recording foot contact information and muscle activity (EMG) during human walking, both on a treadmill and overground, a relationship between heel contact and peaks in the muscle activity related to hip and knee joint actions was identified. Adaptive filtering was then used as a computational device to model the relationship between the recorded foot contact information and muscle activity data. Using these transfer functions, a minimal, linear, analogue control system for controlling walking could be created, based on the controller used in the RunBot robot. The human walking transfer functions were then applied to RunBot to analyse the produced gait. It was found that the gait cycle was stable and controlled, which is a positive indication that the control system has potential for use in controlling assistive devices for the retraining of an efficient and effective gait, with potential applications in SCI rehabilitation.

This thesis presents the creation of a novel tissue diagnosis probe based on the measurement of stiffness and force during mechanical tool-tissue interactions. The probe using force and vision sensing modalities was created to be used for tissue diagnosis in medical applications, especially for robot-assisted minimallyinvasive surgery (MIS) to provide the necessary sensing modalities to allow for haptic feedback. By employing the developed prototypes, estimations of the mechanical properties of ex-vivo human prostate tissues were conducted using the finite element analysis (FEA) method and the Newton-Raphson algorithm. A clinical study of prostate tumour identification has been carried out on ex-vivo prostate samples and a study onrobotic palpation using a second prototype developed as part of this projectand comparing it to manual palpation was conducted. With the aim of measuring the indentation depth and the corresponding tissue reaction force simultaneously to obtain stiffness information,aprototype of a stiffness probe was constructedconsisting of a commercial digitalcamera and a force sensor. The effectiveness and sensitivityof the designedprobe was validatedthrough experiments on silicone phantomsand animal organs. The results showed that the probe could perform stiffness measurementsand localize tissue abnormalitieswhen indenting or sliding over the target surfaces. In order to investigate the mechanical properties of ex-vivo human prostate using the developed probe, a portable sliding indenter robot integrating the probe and the Phantom Omni device was created. Based on force-displacement measurements of the probe-soft tissue interaction, inversefinite element analysis (FEA)andthegeneralised Newton-Raphson algorithm were used to estimateunknown parameters including the shear modulus ofthe ex-vivo human prostate. The prostate was modelled as a nonlinear hyperelastic material (utilizing Arruda-Boyce model) inthe finite element modelling software package, ABAQUS 6.8-1. The results indicated that the proposed model can estimate the mechanical properties ofthe ex-vivo human prostate effectively. With the aim of identifying the stiffness of normal and cancerous prostate tissue, the prostates of 26 male patients were examinedusing the developed sliding indenter robot. Threedimensional (3D) stiffness maps of ex-vivo human prostate were created. The stiffness maps were correlatedwith other clinical examinations including Magnetic Resonance Imaging (MRI), Digital Rectal Examination (DRE), histology and Ultrosound-guided biopsy. The proposedprobe proved to be a promising platform to distinguish between cancerous and healthy tissue in prostate andto discriminate pathological tissue variations. In addition, the results provided quantitative information for the diagnosis and localization of prostate cancer. To ensure the proposed probe is suitable for MIS applications, a furtherprototype of the stiffness probebased on optic-fibreforce sensing replacing the commercial available force sensor was created. A study on robotic palpation using the developed probe and comparing it tomanual palpation was conducted. The results indicated that robotic palpation was more effective than manual palpation conducted by experienced surgeons.

The objective of this thesis is to develop the computational methodologies for investigating the musculoskeletal system performance during human standing and walking, which can lead to a better understanding of the musculoskeletal functions in standing balance and locomotion, and hence to improve clinical diagnosis, treatments and also rehabilitation interventions. Firstly, an improved Hill-type muscle model was developed to describe the dynamic response of a musculotendon unit subjected to neural excitation by considering more physiological characteristics of skeletal muscles. The dynamic process from neural input through to muscular force generation was represented using two processes: neural excitation dynamics and muscle activation dynamics. The improved muscle model has been used throughout the thesis for musculoskeletal analysis. An inverted pendulum model driven by a pair of antagonistic muscles was developed to stimulate human standing in the sagittal plane. A set of dynamic simulations has been used to investigate the effect of muscle intrinsic properties on system stability. It is found that the force-velocity relationship of the muscle contractile element has the most significant impact on the dynamic stability of the musculoskeletal system. Thereafter, a musculoskeletal model with six ankle flexor and extensor muscles, which was combined with a multi-objective optimization scheme had been constructed to investigate the interplay between energy cost and body stability during standing balance. The simulation results suggest that there is a very strong dependence between energy expenditure and body stability during standing postural control, and energy expenditure appears to be a primary consideration in standing balance. To simulate human walking biomechanics, a three-dimensional musculoskeletal model with 13 body segments and 98 muscle groups was constructed using OpenSim software. The gait measurement database provided by Grant Challenge Competition was used to support the modelling. A set of bone scaling and inverse kinematics procedures was used to refine the model to fit the subject-specific anthropometric and kinematic dataset. The refined model generated reasonable muscle moment arm and net muscle moment data over a complete walking cycle. Finally, a novel computational framework has been developed to evaluate the mechanical loadings at each individual skeletal muscle group during human walking by integrating a forward dynamics formulation of the muscle contraction dynamics into an inverse dynamics based static optimization scheme. The experimental validation against the measured force sensor data suggested that the approach proposed here provided more accurate estimation of the muscular loadings than the conventional static optimization method and also the OpenSim software.

A shift in the global chronic wound care market from traditional wound dressings to advanced bio-derived products has demonstrated the demand for the 1st generation of skin substitute products. Although these demonstrated the proof-of-concept for tissue engineering, the manufacturing processes were mainly laboratory based, labour intensive and not amenable to scale-up. The aim of this thesis was to carry out a technical and economical evaluation of alternative manufacturing options for the next generation of cell-derived wound healing products delivered in an amorphous gel format. Experimental work was carried out to demonstrate the feasibility of an alternative manufacturing process culturing human dermal fibroblasts (HuFFs) to generate extracellular matrix. A microcarrier-based process was selected and results showed the HuFFs proliferated well on both Cytodex 2 and biodegradeable Vicryl discs. Limitations with both approaches are discussed. Economic feasibility of the microcarrier based processes was evaluated, and this was compared to the conventional manual and automated roller bottle processing route. Impact of manufacturing options on the cost of goods and net present value were assessed. Deterministic analysis indicated that the key process economic drivers are the cell density and the ratio of cells to extracellular matrix. Additionally, stochastic analysis was applied to rank each process options in terms of risk-reward characteristics and this showed sensitivity to the production capacity required. Further process economics analysis evaluated the feasibility behind recombinant growth factor production using both E.coli and yeast processing routes, and the analysis highlighted critical titre levels required for this option to be feasible. The work in this thesis demonstrates the use of simulation tools and risk analysis to support the quality of decision making to enable a cost effective manufacture of advanced wound healing products.

Background/Aims: Rubella can be devastating to a foetus if maternally acquired in early pregnancy. A single rubella vaccine (SRV), given to prepubertal girls was replaced by the MMR immunisation in infancy for both sexes in 1988. Women born before 1983 probably received the SRV and had contact with circulating rubella, whilst women born after 1982 probably received the MMR vaccine and had little contact with circulating rubella. When immunity levels fall, outbreaks can occur, as seen in the last 10 years. The rubella status of antenatal women in the Cwm Taf (South) Health Board area and post-partum vaccine uptake in the rubella susceptible women was explored. Method: Data of 14,519 antenatal rubella tests (2005-2010) and questionnaire data from 111 rubella susceptible women (2009-2011) were analysed. Self-reported immunisation status and post-partum vaccine uptake were validated by examination of childhood immunisation records and medical records. Data for probable SRV recipients and probable MMR vaccine recipients were compared. Key Results: The overall rubella susceptibility rate increased from 3.8% (88/2312) in 2005 to 4.6% (116/2536) in 2010. First pregnancy data showed a statistically significant increase in susceptibility from 6.4% (49/760) in 2005 to 8.9% (71/798) in 2010 (c²=6.860, df=1, p=0.009) and women born after 1982 were five times more likely to be rubella susceptible than those born earlier (odds ratio=5.05, 95% CI from 3.46 to 7.35). Those aged < 20 years had a mean susceptibility rate of 21.3% (236/1107) Average antibody titres for rubella immune women differed significantly by year of birth; those born earlier had a stable average of 58 IU/ml whilst those born later (following a period of steady decline) averaged 20 IU/ml. Of rubella susceptible women in the questionnaire study, 62.8% had received two or more doses of a rubella containing vaccine. Examination of medical records showed that over 36% (39/107) of rubella susceptible women in the study did not receive post-partum immunisation. Conclusion: The results suggest that immunity is waning, and that a third dose of MMR vaccine in adolescence is required to ensure protection during pregnancy. The study also demonstrates that reliance on Child Health Records to assess need for immunisation is flawed. Post-partum MMR uptake also needs to be addressed if national targets are to be met.

One of the many challenges in the development of neural prosthetic devices is the choice of electrode material. Electrodes must be biocompatible, and at the same time, they must be able to sustain repetitive current injections in a highly corrosive physiological environment. We investigated the suitability of carbon nanotube (CNT) electrodes for retinal prosthetics by studying prolonged exposure to retinal tissue and repetitive electrical stimulation of retinal ganglion cells (RGCs). Experiments were performed on retinal wholemounts isolated from the Cone rod homeobox (CRX) knockout mouse, a model of Leber congenital amaurosis. Retinas were interfaced at the vitreo-retinal juncture with CNT assemblies and maintained in physiological conditions for up to three days to investigate any anatomical (immunohistochemistry and electron microscopy) and electrophysiological changes (multielectrode array stimulation and recordings; electrodes were made of CNTs or commercial titanium nitride). Anatomical characterisation of the inner retina, including RGCs, astrocytes and Müller cells as well as cellular matrix and inner retinal vasculature, provide strong evidence of a gradual remodelling of the retina to incorporate CNT assemblies, with very little indication of an immune response. Prolonged electrophysiological recordings, performed over the course of three days, demonstrate a gradual increase in signal amplitudes, lowering of stimulation thresholds and an increase in cellular recruitment for RGCs interfaced with CNT electrodes, but not with titanium nitride electrodes. These results provide for the first time electrophysiological, ultrastructural and cellular evidence of the time-dependent formation of strong and viable bio-hybrids between the RGC layer and CNT arrays in intact retinas. We conclude that CNTs are a promising material for inclusion in retinal prosthetic devices.

Cardiovascular disease (CVD) is the world’s biggest killer, globally accounting for over 17,5 million deaths annually. Almost half of these deaths are caused by acute myocardial infarction. It is an umbrella term that encompasses several medical conditions associated with the heart and the circulatory system. It is important to detect patients with high risk of acute myocardial infarction quickly. This can help in cutting costs by screening the hospital admissions process and focusing resources to those that are specifically at risk. Biomarkers and biosensors are playing a crucial role in the diagnostic revolution of cardiovascular disease. Although significant studies have been done on electrochemically transduced biosensors for detecting CVDs, of late they have had limited commercial success. However, advances in interrelated research areas have made it possible for faster, accurate, portable and environmentally friendly electrochemical diagnostic devices to be made. This project aims to: • Develop Immunoassays for two cardiac biomarkers which are CRP and cardiac troponin T • Integrate the immunoassays on to screen-printed gold electrodes (SPGE) to make electrochemical immunosensors. • Optimise the immunosensors to produce rapid, sensitive and specific devices • Evaluate the performance of the optimised immunosensors compared to other alternative detection devices. Some aspects of the fabrication process of screen-printed gold electrodes were investigated particularly ink compositions and curing techniques. It was found that the quality of the carbon ink affects the performance of the electrodes and that curing electrodes with conventional oven drying gave better performance to high throughput infra-red drying. Initially a plate based ELISA assay for CRP was developed before the assay was transferred onto screen-printed gold electrodes. Antibodies were immobilised using passive adsorption and after optimisation of the screen-printed immunosensor, it managed to detect CRP with a limit of detection of 0.52 µg mL-1 with a linear range up to 20 µg mL-1 in spiked serum. This was within diagnostically relevant range. Comparison of the assay with a commercial alternative gave good correlation (R2 value of 0.99). A second immunosensor was developed for cardiac Troponin T (cTnT) using similar screen-printed gold electrodes. In this immunosensor, the use of self-assembled monolayers (SAMs) was employed to assist in covalent immobilisation, orientation and preservation of the capture antibody. A method for depositing the 11-mercaptoundecanoic acid (11-MUA) SAMs on the gold working electrode without compromising functionality of the other electrodes was developed. It was found that the use of self-assembled monolayers increased the sensitivity of the assay enabling it to decrease the limit of detection on the immunosensor from 2.12 ng mL-1 (passive adsorption) to 1.14 ng mL-1 (SAM assisted covalent immobilisation). It was also found that the use of SAMs enhanced the shelf life of the immobilised antibody compared to those passively adsorbed. The use of gold nanoparticles to amplify the immunosensor signal was explored .This further improved the sensitivity of the cTnT assay. The final immunosensor setup comprising the use of 11-MUA self-assembled monolayers and 60 nm conjugated gold nanoparticles enabled the detection of cTnT with a limit of detection of 0.51ng mL-1 in buffer and 0.58 ng mL-1 in 75% serum samples. This assay was benchmarked against a hospital analyser and a quartz crystal microbalance biosensor (QCM-1). It gave comparable results with correlation values of 0.99 and 0.95. The two developed immunosensors for CRP and cTnT can easily be integrated onto an electrochemical analyser to make a multi-marker electrochemical immunosensor for detecting cardiovascular diseases.

Linear poly(amidoamine) (PAA) cationic polymers complexed with DNA have potential as non-viral nucleic acid delivery systems. However, they have poor in vivo biodistribution and a tendency to aggregate. PEGylation polymers are a potential solution for these problems but previous work shows that they do not always form compact complexes. This might be overcome by using mixtures of homopolymer and PEGylated copolymer to form complexes. However, the complexes are unstable in the presence of serum. Therefore, the aim of this study was to improve stability and to allow release of DNA by incorporating a novel cross-linking system. A disulphide-based cross-linker was suggested for this work. Formulation and screening studies for the best homopolymer to copolymer ratio of cross-linked (XL) DNA delivery systems in comparison to non-cross-linked (non- XL) complexes were investigated. The formation of cross-linked complexes was carried out using mixtures of homopolymer (HP) and triblock copolymer (CP), based on the most promising P AA candidate from these aforementioned studies. In this study, we have used three different molecular weights of PEG (655, 1700 and 4600 Da). HP:CP at 1: 1 ratio proved to have the best collective physicochemical characteristics among all of the investigated ratios. The findings from biological evaluation of PEG655-PAA systems revealed that transfection efficiency of cross-linked and non-cross-linked complexes at all HP:CP ratios was similar to PAA in serum-free medium. Transfection of cross- linked complexes at 1: 1 HP:CP ratio did not show a significant difference in serum-free and serum-supplemented media, the transfection of all other formulations, lipofectAMINE and P AA were remarkably reduced in the presence of serum. The results also showed the ability of PEG 1700-P AA-XL complexes to improve the transfection 100 times relative to non-cross-linked complexes. Again, no significant difference could be observed for the gene expression of PEG 1700- P AA systems at 1: 1 HP:CP ratio, whereas the transfection of other systems dramatically reduced in the presence of 10% serum. The same pattern was seen with PEG4600-PAA systems. In vivo assessment of the cross-linked complexes showed that PEG655-PAA-XL complexes provided strikingly higher luciferase activity in the liver, whereas PEG4600-PAA-XL complexes showed the best transfection in non-reticuloendothelial system organs expected to benefit from a longer circulation time. PEG 1700-P AA-XL complexes showed similar transfection in all organs. Therefore, the disulphide-based cross-link was validated as a suitable DNA delivery system for in vivo application.

This work seeks to identify those factors that have influenced the development of the professional group of workers associated with medical laboratory sciences. It has also examined the features that have both encouraged and impeded the trend towards European harmonisation within the profession. The study concentrates on the evolution of this occupational category with respect to four European Nations – the UK, Germany, Greece and Sweden. These countries have been selected on the basis that they have different financial systems for the delivery of health care. The thesis begins with an assessment of the significance of emergent medical sciences during the Renaissance and their impact on diagnostic pathology. This is followed by a consideration of the contribution of Twentieth Century medical advances, set against the background of the Industrial Revolution and the demands emanating from global conflict. The role of scientific and technological developments are seen as the most significant influences in forging European harmonisation within those professions concerned with biomedical sciences. The next consideration concerns the attitude of medical laboratory technologists towards the notion of “profession", together with their ability to identify the characteristics of such a concept. Results indicate that the ability of practitioners in such respect is not significantly different from that of other members of the professions allied to medicine, or the learned professions. The influence of health care systems on medical laboratory sciences is examined by identifying the political, economic, social and technological factors shaping health care delivery in the above countries. In all cases, diagnostic pathology services are financed by a mixture of public and private provision. The thesis also assesses the relationship between the various professional bodies and licensing authorities. Although practitioners in all four countries require some form of licensure (i.e. ate "regulated professions"), only those in the UK undergo State Registration on an annual basis. The views of practitioners towards the mutual recognition of European professional qualifications has been sought using semi-structured interviews. There is some support for such a principle, but in practice little activity is taking place. A comparison has also been made of the views of undergraduates and tutors towards European exchange schemes such as SOCRATES. This is achieved using questionnaires aimed at assessing participation rates, identification of barriers to student mobility, levels of awareness regarding European current affairs, and language competencies. Student participation is relatively low and the main barrier to study in other European countries has been identified as lack of finance. Comparisons have been made with respect to curriculum content, student assessment strategies, course fees and other aspects of education. There is a requirement to increase levels of provision with respect to European studies and students need to be better informed regarding opportunities available to them. The influence of European Union policy on academic and professional harmonisation is assessed by considering aspects of student and staff exchange schemes, together with the possible affects of the Sorbonne and Bologna Declarations. The work concludes with some recommendations for increasing the role of education and training with respect to achieving closer European integration. These include a re-assessment of the affects of replacing Inter-University Collaborative Programmes with Institutional Contracts. There is also a need for greater tutor advocacy and further EU investment in student grant aid.