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A brain computer interface (BCI) allows the user to communicate with a computer using only brain signals. In this way, the conventional neural pathways of peripheral nerves and muscles are bypassed, thereby enabling control of a computer by a person with no motor control. The brain signals, known as electroencephalographs (EEGs), are recorded by electrodes placed on the surface of the scalp. A requirement for a successful BCI is that interfering artifacts are removed from the EEGs, so that thereby the important cognitive information is revealed. Two systems based on second order blind source separation (BSS) are therefore proposed. The first system, is based on developing a gradient based BSS algorithm, within which a constraint is incorporated such that the effect of eye blinking artifacts are mitigated from the constituent independent components (ICs). The second method is based on reconstructing the EEGs such that the effect of eye blinking artifacts are removed. The EEGs are separated using an unconstrained BSS algorithm, based on the principles of second order blind identification. Certain characteristics describing eye blinking artifacts are used to identify the related ICs. Then the remaining ICs are used to reconstruct the artifact free EEGs. Both methods yield significantly better results than standard techniques. The degree to which the artifacts are removed is shown and compared with standard methods, both subjectively and objectively. The proposed BCI systems are based on extracting the sources related to finger movement and tracking the movement of the corresponding signal sources. The first proposed system explicitly localises the sources over successive temporal windows of ICs using the least squares (LS) method and characterises the trajectories of the sources. A constrained BSS algorithm is then developed to separate the EEGs while mitigating the eye blinking artifacts. Another approach is based on inferring causal relationships between electrode signals. Directed transfer functions (DTFs) are also applied to short temporal windows of EEGs, from which a time-frequency map of causality is constructed. Additionally, the distribution of beta band power for the IC related to finger movement is combined with the DTF approach to form part of a robust classification system. Finally, a new modality for BCI is introduced based on space-time-frequency masking. Here the sources are assumed to be disjoint in space, time and frequency. The method is based on multi-way analysis of the EEGs and extraction of components related to finger movements. The components are localised in space-time-frequency and compared with the original EEGs in order to quantify the motion of the extracted component.

This investigation concerned the design and development of a novel measurement system that incorporates bilayer sensors for monitoring applications in the biomedical and automotive industry. The bilayer sensors are made primarily from a configuration of soft magnetic material on a non magnetic substrate that is used to enhance the changes in the relative permeability of the material, caused by tensile or compressive stresses. Three modulation techniques were examined as a method for convening the sensor signal information this is the first use of the phase (PM) and frequency (FM) modulation methods in conjunction with bilayer sensors. The measurement system incorporated, in software code, a range of mathematical concepts used for extracting and processing the sensor information signal. The use of simulated and acquired modulation signals allowed the comparison of the modulation techniques. Optimisation of the bilayer sensor was considered by studying the effects of the bilayer sensor physical dimensions and parameters on its performance. Also the thermal stability of the bilayer sensor and FM system was examined. Physiological measurements for the detection and monitoring of cardio respiratory activities were conducted. A bilayer sensor measurement system was used for the first time not only to detect but also to map the normal heartbeat rate through the hemo-dynamics of the carotid artery. The system was used to monitor a range of respiratory activities such as normal respiration, deep inhalation/exhalation and apnoea. The application of the sensor is a non-invasive and a non-disturbing method for monitoring biomedical activities related to skin curvature changes. The bilayer sensor measurement system was used for monitoring of airflow in turbulent conditions. Measurements were conducted for a variety of airflows and at a range of distances from the centre of the tube, were the flow is at maximum. Furthermore the effect of substrate thickness and material choice was investigated on the performance of the sensor. This investigation led to the design and construction of a novel measurement system than can successfully detect and quantify displacements in the micron range. The application of this system to biomedical and automotive applications showed the universality and adaptability of the bilayer sensors and its measurement method.

In the last decade, the healthcare delivery model for many diseases has been changing from a disease centred approach to a patient centred approach, where healthcare provision is tailored around an individual patient's needs. This is leading to a situation where many diseases are now being treated by multidisciplinary teams of healthcare professionals working across the three care sectors: primary, secondary and tertiary. This is known as an integrated care approach. Cancer is recognised by the National Service Frameworks as a key model of the integrated care approach. This has meant that the information systems supporting the care process need to evolve to reflect these changes. Particularly, all members of the cancer care team, including GPs, should work together seamlessly and communicate in a timely and effective manner to maintain the continuity of cancer patient care and ensure it is delivered without unnecessary delay. This thesis investigates the current situation in Wales against this changing scenario in order to identify the problems hindering the communication between GPs and other members of cancer care teams. It then specifies a new system to overcome these problems, and support the integrated care approach with a particular emphasis on the role of GPs in the care domain. This proposed system provides a common Electronic Patient Record System with the aim of supplying required information to all care sectors according to the needs and working practices of the clinicians in each care sector. It is demonstrated that this new system will give better support in the future to the team members than the current systems.

A messenger role for carbon monoxide has been identified for the cardiovascular system and also possibly for neurological effects through activation of soluble guanylate cyclise (SGC) and consequent production of intracellular cyclic guanosine monophosphate (cGMP). Chronic exposure to carbon monoxide associated with indoor heating may affect this important mechanism. Therefore the differential effects upon cGMP in blood platelets for people residing in homes with different types of heating were investigated. A differential in ambient concentrations of benzene and nitrogen dioxide has also been hypothesized for residential areas of differing urbanicity in particular with respect to traffic flows. Therefore the differential in urinary biomarker of benzene exposure, s phenylmercaptuirc acid (sPMA) as well as in environmental concentrations of nitrogen dioxide was investigated in people residing in urban and less urban microenvironments. Environmental concentrations of carbon monoxide indoors were measured in real-time over a period of one week and integrated measurements of benzene and nitrogen dioxide concentrations outdoors were obtained over a period of one month. cGMP was measured in the blood platelets of subjects and sPMA in their urine. Environmental concentrations of carbon monoxide indoors were low but despite this in homes heated by liquid petroleum gas (LPG) the concentration of cGMP in subjects' blood platelets were twice those in subjects using other types of heating. Further, for the LPG group the difference between paired measurements for the winter and summer seasons were 91%. Substantial differences between mean concentrations of benzene (37%) and nitrogen dioxide (65%) were observed between urban and less urban areas but this differential was not reflected by any difference in toxic uptake as measured by sPMA in urine. Exposure to emissions from LPG heating substantially affected cGMP concentrations in blood platelets but this is very unlikely to be caused by the low levels of carbon monoxide measured. We hypothesize that Nitric oxide may be responsible for the differences observed in cGMP. Substantial differences in outdoor benzene and nitrogen dioxide concentrations exist within the city of Cardiff but sPMA is not sufficiently sensitive to be used as a biomarker of exposure.

The main goal of the current study was to investigate the capabilities of the indirect three-dimensional printing (3DP) process when used in combination with bioceramic Apatite-Wollastonite (A-W) powders and to evaluate the mechanical properties of the printed parts. A-W glass ceramic is a bioactive material that is used clinically for bone substitutes due to its suitable mechanical properties. Additive manufacturing approaches, especially 3DP, have been shown to produce 3D complex structures via computer aided design. A-W with weight % of 4.6 MgO, 44.7 CaO, 34 SiO2, 16.2 P2O5 and 0.5 CaF2 was used in the present study. The approach taken to indirect 3DP was: (i) blending of the A-W with maltodextrin (MD) powder; (ii) using a Z Corp Z310plus 3D printer to selectively print binder into sequentially deposited thin layers of the blended powders in order to build up a 3D structure; (iii) heat treating the 3D printed parts to 1150°C to burn off the MD and sinter the A-W to create a consolidated 3D structure. Phosphate glass infiltration was used to fill the porosities and increase the mechanical strength of the sintered parts. Bioactive phosphate glass with weight % of 6.22 Na2O, 71.29 P2O5, and 22.49 CaO was used because it can dissolve faster than A-W. The flexural strength, Young’s modulus, porosity and shrinkage were measured on various samples printed from the seven powder blends (PBs). PBs with 30% MD and zb®60 binder were required for the parts to develop sufficient strength. PBs 1, 4, and 5 develop the highest strength after sintering. PB1 contains A-W particle sizes in the range of 53-90 μm, PB4 contains A-W particle sizes in the range of 0-53 μm and PB5 contains mixed particle size ranges (78.5% in the range of 53-90 μm with 21.5% in the range of 0-53 μm). Average flexural strengths of 23.65 MPa, 35.64 MPa, and 25.68 MPa were achieved for PB1, PB4, and PB5, respectively. The average strength of PB5 increased to 31.34 MPa after glass infiltration. In all cases, the increase in strength is a result of the increased consolidation during sintering, as indicated by the observed reduced porosity. Indirect 3D printing of A-W structures can be used to create strong, highly porous structures, but care must be taken to appropriately select binder and processing parameters. Moreover, this is a promising approach for fabrication in bone tissue engineering.

This Thesis presents research on ultra low-power bioelectronics, focusing on purely ana- logue methodologies and techniques stemming from the systematic, in-house developed, transistor-level synthesis framework, termed the “Nonlinear Bernoulli Cell Formalism” (NBCF). The NBCF is capable of converting coupled, nonlinear biological differen- tial equations into coupled, nonlinear electrical differential equations and subsequently into ultra-low power log-domain electrical circuits, or “Cytomimetic Circuits”. The establishment of the aforementioned framework is achieved through the example re- alisation of several, novel, non-linear, multi-dimensional, cytomimetic topologies, that mimic a variety of biological function dynamics. The constructed topologies deal with increased complexity emanating from the high-dimensionality, the highly inter-coupled state variables and parameters, and the multitude of the potentially resulting dynami- cal behaviours. Their effective construction utilises design techniques in weak-inversion, log-domain bioelectronics, specialising in the analysis and synthesis of static and dy- namic translinear circuits. Moreover, statistical fabrication variability Monte Carlo analyses investigate the robustness of the proposed topologies. Subsequent low-level layout, post-layout simulations and fabrication of one of the proposed topologies (mam- malian cell cycle) lead to the production of novel proof-of-concept measured chip results. The measured results validate the feasibility of the NBCF. Further to the establishment of the NBCF and its real-life feasibility, this Thesis serves to suggest area and performance optimisation techniques for widely-used static and dynamic translinear circuits which are pivotal blocks for our cytomimetic designs. Ini- tially, the area optimisation is outlined, by proposing an area minimisation path for the research group’s cochlear implant design. Novel circuit design techniques are imple- mented, in order to reduce the size of log-domain cochlear implant processors. Moreover, performance optimisation is performed by articulating a methodical, step-by-step sym- bolic analysis of a variety of common, static and dynamic, translinear topologies in weak-inversion electronics. The analysis relies upon a simplified EKV-based approxi- mation. The impact of transistor-level design parameters upon performance and ideal behaviour is captured, analysed and discussed in a quantitative and qualitative manner. Finally, optimisation approaches are detailed whereby novel design rules are provided for popular translinear topologies.

In the western world there is an issue in healthcare being created by an increasing number of people who experience disability. Whilst the reasons for these occurring are multiple, the common treatment to aid recovery from this condition is therapy that requires manual stimulation of the musculature form [sic] a therapist. Due to the physical demands that this process places on the therapist it is thought that a possible solution to meeting the increasing future demand for therapy is with developments in robotic technology. This thesis proposes and develops the design of a cable-driven glove to assist patients to grasp, this direction of design was chosen after a consultation with former patients found that this was the activity of upper limb motion that they felt was the most difficult to control after therapy. Their design requirements resulted in the creation of a lightweight glove that maximised the performance of the cable driven system through the use of a vacuum to secure the cable and use the joints of their body to control the flexion. This design resulted in the development of a first generation prototype that was assessed firstly by operating a 3D printed hand to grasp a collection of balls and cubes. After this the prototype was tested by unimpaired volunteers to provide feedback on the comfort and control they have when using the device, which was then compared to the findings from the initial consultation. This showed that the glove was successful in performing the intended motion and was considered comfortable (3.5/5) as well as providing them control (3.83/5). The device was used in a consultation with medical workers as well, who were impressed with the strength of the device, but highlighted improvements that could be made to refine it further.