Medical equipment has become increasingly sophisticated with technological progress, with the result that sterilization is often more difficult to achieve. Much modern equipment is intricate, delicate and thermolabile. For the purposes of this research, fibre-optic endoscopes were chosen as important examples of this type of equipment. Because of their expense, individual instruments may be required more than once during a surgical list. There is thus a need for a rapid, simple, cold method of sterilizing such equipment but there are no suitable methods currently available. Physical sterilization methods and gaseous chemicals cannot be used and the sporicidal liquids available for the treatment of heat labile surgical equipment require contact periods of several hours. Previous research showed that a mixture of methanol and sodium hypochlorite had appreciable sporicidal properties. The main aim of this work was therefore the investigation of alcohol-hypochlorite mixtures and the development of a cold, quick-acting sporicidal liquid suitable for treating thermolabile instruments and other equipment. The physical, chemical and biological properties of several mixtures of sodium hypochlorite and an alcohol were studied and some were shown to be sporicidal within two minutes. The effect of changing the pH of these mixtures and of hypochlorite solution alone was investigated. The uses of such solutions were considered. Disinfection methods currently used for endoscopes in two hospitals were studied and shown to be ineffective. Following successful treatment of a laboratory contaminated fibre-optic endoscope a solution of sodium hypochlorite buffered to pH 7.6 was suggested for use with thermolabile medical equipment.

Ischaemia-reperfusion injury (IRI) following prolonged hypothermic storage contributes to the occurrence of delayed graft function and progression of end-stage graft failure. The objective of my thesis is to evaluate xenon in preventing graft ischaemia-reperfusion injury in a rat model of kidney transplantation. The ultimate aim is to improve the long-term transplant outcome through preserving the graft quality. I have demonstrated that exposure of human proximal tubular cells (HK-2) to xenon activated IGF-1, HIF-1a, VEGF, HO-1, Bcl-2 and HSP-70. Xenon treatment prior to, or after, hypothermia-hypoxia challenge conferred protection against cell injury. In the Lewis to Lewis rat syngeneic renal grafts, xenon exposure before graft retrieval from donors or after engraftment in recipients decreased caspase-3 expression, and prevented TLR-4/NF-kB activation. The serum level of pro-inflammatory cytokines IL-1?, IL-6 and TNF-a was reduced and renal function was preserved. In the Brown-Norway to Lewis rat allogeneic renal grafts, xenon donor pre-treatment and recipient post-treatment decreased the renal tubular cell death, tubular inflammation and tubular MHC II expression. This in turn improved early graft function. T cell mediated alloresponse was therefore reduced. In combination with cyclosporine A, both xenon pre-treatment and xenon post-treatment prolonged the renal graft survival. In the Fischer-to-Lewis rat allogeneic grafts, xenon exposure to donors before graft retrieval or to recipients after engraftment enhanced tubular cell proliferation, decreased tubular cell death and graft inflammation associated with IRI. T cell infiltration and fibrosis were significantly suppressed with xenon treatment, chronic allograft nephropathy was attenuated. In summary, my thesis shows that either xenon donor pre-treatment or recipient post-treatment protected the renal graft against IRI, which in turn reduced acute immune rejection and attenuated chronic allograft nephropathy. This novel approach against IRI could be translated into clinical practice leading to considerable increase in viable organ availability and improvement in the long-term graft survival.

No description available.

Questionnaires were administered, before, during and after hospitalisation, to the parents of 49 children (aged 3.4-11.4 years) undergoing ENT surgery. Nurses also completed a measure of child behavioural upset during each child's admission. Although there was little evidence from the questionnaires that hospitalisation had adversely affected the children's behaviour (rs = .67 p < .0001), the experience heightened the perception, especially in parents of younger children, about their child's general vulnerability to illness (pr (45) = -.40, p < .005). The data also showed that when parents reported previous hospital contact for what they at that time had considered serious child health concerns, the parents were more anxious at the pre-hospital ENT appointment (z = 1.92, p < .05). Parents' ratings of their children's behaviour problems and parents' perceptions about their children's general vulnerability to illness, both measured before admission, were positively associated with parents' ratings of their children's distress during the hospitalisation (rs (46) = .50, p < .0005; rs (46) = .58, p < .0001, respectively). However, the agreement between parents and nurses about children's behavioural distress during the hospitalisation was very modest (rs (43) = .3 p < .05). These findings have implications for examining and improving the quality of service provision. Almost half of the families were also interviewed two weeks after discharge, about their hospital experience. Qualitative analysis of the interview material identified six significant issues; the inadequacy of information supplied by the hospital; the diversity of information sources accessed by families; the implicit rather than negotiated involvement of parents in the care of their hospitalised child; the attitude and responsiveness of the hospital staff; the adequacy of hospital facilities and unexpected psychological trauma. These themes provide a rich source of information about the experience of parents of hospitalised children and identify areas for service quality improvement.

No description available.

Most sarcomas of the bone occur in patients of a relatively young age including skeletally immature patients. Approximately 50 child sarcomas are treated with limb salvage surgery per year in the United Kingdom. These children need an extendible implant that can be lengthened periodically to keep pace with the growth in the opposite limb. Surgically, invasive devices have been used for the past thirty years with intrinsic problems of infection and long-term recurrent trauma to the patient. To eliminate problems associated with the invasive device I have attempted to develop a non invasive extendible prosthesis by utilising a magnetically coupled drive. The aims of this study were to ascertain the clinical requirements of an electro-mechanical design, evaluate the performance of the proposed design, validate the design by in vitro tests and conclude its effectiveness by conducting an in vivo clinical trial. The final aim was to develop a similar concept for the distraction of juvenile spinal scoliosis. The drive technology used in this device is an induction motor with a gear driven telescoping prosthesis. In very young patients the potential loss of growth in the resected bone usually exceeds the amount of extension that could be built into the prosthesis. Therefore, maximisation of the growth potential was the prime objective of the prospective design. A previously designed two-stage epicyclic gearbox was tested and improvements were made to provide a load carrying capacity identified by in vivo measurements conducted in over 30 patients. In this design the motor configuration is in two parts: a rotor which fits inside the prosthesis and a stator which is an external device used to extend the prosthesis remotely. A compact external drive was developed with focused magnetic flux which required no cooling and operated on a single-phase power supply. The effect of the magnetic rotor on the diagnostic imaging was tested and the findings are reported in this thesis. A number of patients were treated with this new device and the clinical outcome is presented. A different version of the device for use with a spinal rod system was developed for the treatment of juvenile scoliosis.

The numbers of patients needing facial prostheses has increased in the last few decades due to improving cancer survival rates. The many limitations of the handmade prostheses together with rapid expansion of prototyping in all directions, particularly in producing human anatomically accurate parts, have raised the question of how to employ this technology for rapid manufacturing of facial soft tissue prostheses. The idea started to grow and the project was implemented based on CAD/CAM principles – additive manufacturing technology, by employing layered fabrication of facial prostheses from starch powder and a water based binder and infiltrated with a silicone polymer (SPIS). The project aimed to produce a facial prosthesis by using 3D colour printing, which would match the patient’s skin shade and have the desirable mechanical properties, through a relatively low cost process that would be accessible to the global patient community. This was achieved by providing a simple system for data capture, design and reproducible method of manufacture with a clinically acceptable material. The prosthesis produced has several advantages and few limitations when compared to existing products/prostheses made from silicone polymer (SP). The mechanical properties and durability were not as good as those of the SP made prosthesis but they were acceptable, although the ideal properties have yet to be identified. Colour reproduction and colour matching were more than acceptable, although the colour of the SPIS parts was less stable than the SP colour under natural and accelerated weathering conditions. However, it is acknowledged that neither of the two methods used represent the natural life use on patients and the deficiencies demonstrated in terms of mechanical properties and colour instability were partially inherent in the methodology used, as the project was still at the developmental stage and it was not possible to apply real life tests on patients. Moreover, deficiencies in mechanical and optical properties were probably caused by the starch present, which was used as a scaffold for the SP. Furthermore, a suitable retention system utilising existing components was designed and added to the prosthesis. This enabled the prosthesis to be retained by implants with no need for the addition of adhesive. This would also help to prolong the durability and life span of the prosthesis. The capability of the printer to produce skin shades was determined and it was found that all the skin colours measured fall within the range of the 3D colour printer and thereby the printer was able to produce all the colours required. Biocompatibility was also acceptable, with a very low rate of toxicity. However, no material is 100% safe and each material has a certain range of toxicity at certain concentrations. At this stage of the project, it can be confirmed that facial prostheses were successfully manufactured by using 3D colour printing to match the patient’s skin shade, using biocompatible materials and having the desirable mechanical properties. Furthermore, the technology used enabled prostheses to be produced in a shorter time frame and at a lower cost than conventional SP prostheses. They are also very lightweight, easier to use and possibly more comfortable for the patients. Moreover, this technology has the capability of producing multiple prostheses at the time of manufacture at reduced extra cost, whilst the data can be saved and can be utilised/modified for producing further copies in the future without having to going through all the steps involved with handmade prostheses. Based on the mechanical properties and colour measurements the prostheses will have a finite service life and the recommendation is that these prostheses will need replacing every 6 to 12 months, depending on how the patient handles and maintains the prostheses and whether the prosthesis is being used as an interim or definitive prosthesis. This was largely comparable to existing prostheses but without the time and cost implications for replacement. However, it is acknowledged that further investigations and clinical case studies are required to investigate the “real life” effect on the prostheses and to get feedback from the patients in order to make appropriate improvements to the mechanical properties and the durability of the prosthesis.

No description available.

No description available.

Advances in surgery have led to marked improvements in patient care, in particular, indexed by minimally invasive surgery (MIS). With the assistance of technology, progressively more complex procedures are undertaken with the aim of diminishing the impact of surgery on the patient. However, this increases demands placed on the surgeon in terms of technical ability. Surgical robotics may overcome this by enhancing surgeon capability through a variety of means. However, it is imperative that novel equipment is scrutinised not only for its performance effects but as to its impact on the user. This is to ensure that not all a surgeon’s resources are devoted to using a new instrument rendering them unable to focus on other aspects of surgery such as dealing with unexpected events e.g. bleeding. Neuroergonomics encompasses the study of the brain and behaviour at work and entails appreciating the cortical correlates of work-related tasks in order to understand both task demands and how the work environment may be modulated to facilitate performance. This paradigm has been applied to safety critical industry such as aviation and air traffic control, and is wholly applicable to surgery especially as the increasing demands placed on surgeons may be more cognitive in nature and as such not be as readily detected with conventional ergonomic tools. This purpose of this thesis is to apply neuroergonomic principles to evaluate brain behaviour associated with complex surgical tasks and how this may be modulated by assistive technology. Using functional near infrared spectroscopy (fNIRS), the cortical substrate for undertaking a complicated navigational task, of the nature likely to benefit from robotic enhancement, is assessed. This establishes firstly, a reliance on cortical regions involved in visuospatial working memory; and secondly demonstrates that experts elicited greater cortical activity than novices. Subsequently, assistive technology known to enhance performance is assessed as to its impact on prefrontal cortical (PFC) activity. A randomised controlled trial across six sessions is then undertaken with the aim of appraising how this technology may affect the learning process in terms of frontoparietal cortical activity. Brain behaviour is assessed in terms of activity and network behaviour determined using graph theory. Finally, a novel tool for aiding collaborative surgery is investigated demonstrating a modulation of search strategy and underlying cortical activity affording subsequent performance improvement. This work sheds light on the neurocognitive aspects of undertaking surgical tasks and how this information can be applied within the paradigm of neuroergonomics to evaluate and assess novel instrumentation in surgery.