The application of estimation and control techniques in 2 modes of exercise for the spinal cord injured

A spinal cord injury (SCI) can result in a loss of sensory and motor capacity, dysfunction of the autonomic nervous system and also in a number of secondary health conditions including muscular atrophy, cardiovascular disease and osteoporosis. The impact of these secondary health conditions may be reduced through exercise which loads the muscles, skeleton and central cardiovascular system. A number of new exercise methods are emerging in the field of rehabilitation. Functional electrical stimulation (FES) is a technique for inducing artificial muscular contractions that has been applied to facilitate cycling amongst adults with a spinal cord injury. Preliminary data has demonstrated the feasibility of FES cycling in the paediatric SCI population. The use of an electric motor to provide torque assistance where required allows the exercise to continue for longer periods and over a wider range of cadences. In this thesis, a feedback control system is devised whereby the cadence can be automatically controlled to reference levels using such a motor, and tested during FES cycling of children with an SCI. The use of robot-assisted body weight supported devices is gaining popularity in the rehabilitation world. Their application has thus far been focused on rehabilitation of gait via neural re-learning. However, robot-assisted gait can also elicit a significant cardiovascular response and thus has potential as a tool for exercise training and testing. In this thesis, a method for estimating the work rate contributed by an exercising subject is developed and then incorporated into a feedback control scheme where the objective is to regulate the work rate to reference values. This enables specific work rate profiles to be performed during robot-assisted gait as is often required for standard exercise tests and training. In addition to controlling the mechanical variables during exercise, it is also possible to control some of the physiological variables. A feedback system whose goal is to control the rate of oxygen uptake rate is developed which also incorporates the work rate control method. This allows a predetermined level of physiological response to be achieved so that the training is of sufficient intensity to promote improvements in physical capacity and fitness. This thesis examines the application of estimation and control techniques in two exercise modes for the spinal cord injured. The ultimate aim of the exercise is to reduce the severity of the secondary health conditions that spinal cord injured people face. The estimation and control algorithms allow the exercise to be regulated with respect to speed and intensity and therefore have utility in both training and testing applications

Dimensionless Quantification of Small Radial Turbine Transient Performance

Turbochargers are inherently dynamic devices, comprising internal flow volumes, mechanical inertias and thermal masses. When operating under transient conditions within an engine system, these dynamics need to be better understood. In this paper, a new non-dimensional modelling approach to characterise the turbocharger is proposed. Two new dimensionless quantities are defined with respect to mechanical and thermal transient behaviour, which are used in conjunction with the Strouhal number for flow transients. The modelling approach is applied to a small wastegated turbocharger and validated against experimental results. The model is used to simulate the turbocharger mass flow rate, turbine housing temperature and shaft speed responses to different excitation frequencies for different sizes of turbine. The results highlight the influence of turbocharger size on the dynamic behaviour of the system, which is particularly marked for the turbine housing temperature. At certain frequency ranges, the system behaviour is quasi-steady, allowing modelling through static maps in these operating regions. Outside these ranges, however, transient elements play a more important role. The simulation study shows that the proposed dimensionless parameters can be used to normalise the influence of turbine size on the dynamic response characteristics of the system. The model and corresponding dimensionless parameters can be applied in future simulation studies as well as for turbocharger matching in industry.</p

A Neuromuscular Model for Symbiotic Man-Machine Exoskeleton Control Accounting for Patient Impairment Specificity

Millions of people worldwide live with impaired locomotion. The degree of impairment is highly variable and the causes are multiple. This variation necessitates the design of a new generation of exoskeleton controllers for personalised, symbiotic man-machine interaction. One of the characteristics of such a controller is the ability to realistically include the characteristics of both normal and neurologically impaired human locomotion. The information can be used to recover only the relevant missing features of locomotion. In this paper, we describe the main characterisation tools used to describe human movement and discuss possible ways to include the resulting information in a neuromuscular model in order to create a personalised controller for a wearable exoskeleton

Emerging Infectious Disease leads to Rapid Population Decline of Common British Birds

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period

Emergence of a Novel Avian Pox Disease in British Tit Species

Avian pox is a viral disease with a wide host range. In Great Britain, avian pox in birds of the Paridae family was first diagnosed in a great tit (Parus major) from south-east England in 2006. An increasing number of avian pox incidents in Paridae have been reported each year since, indicative of an emergent infection. Here, we utilise a database of opportunistic reports of garden bird mortality and morbidity to analyse spatial and temporal patterns of suspected avian pox throughout Great Britain, 2006–2010. Reports of affected Paridae (211 incidents) outnumbered reports in non-Paridae (91 incidents). The majority (90%) of Paridae incidents involved great tits. Paridae pox incidents were more likely to involve multiple individuals (77.3%) than were incidents in non-Paridae hosts (31.9%). Unlike the small wart-like lesions usually seen in non-Paridae with avian pox in Great Britain, lesions in Paridae were frequently large, often with an ulcerated surface and caseous core. Spatial analyses revealed strong clustering of suspected avian pox incidents involving Paridae hosts, but only weak, inconsistent clustering of incidents involving non-Paridae hosts. There was no spatial association between Paridae and non-Paridae incidents. We documented significant spatial spread of Paridae pox from an origin in south-east England; no spatial spread was evident for non-Paridae pox. For both host clades, there was an annual peak of reports in August/September. Sequencing of the avian poxvirus 4b core protein produced an identical viral sequence from each of 20 great tits tested from Great Britain. This sequence was identical to that from great tits from central Europe and Scandinavia. In contrast, sequence variation was evident amongst virus tested from 17 non-Paridae hosts of 5 species. Our findings show Paridae pox to be an emerging infectious disease in wild birds in Great Britain, apparently originating from viral incursion from central Europe or Scandinavia

Multi-locus analysis resolves the epidemic finch strain of Trichomonas gallinae and suggests introgression from divergent trichomonads

In Europe, Trichomonas gallinae recently emerged as a cause of epidemic disease in songbirds. A highly virulent and clonal strain of the parasite, first found in the UK, has become the predominant strain there and spread to continental Europe. Discriminating this epidemic strain of T. gallinae from other strains necessitated development of multi-locus sequence typing (MLST). Development of the MLST was facilitated by the assembly and annotation of a 54.7 Mb draft genome of a cloned stabilate of the A1 European finch epidemic strain (isolated from Greenfinch, Carduelis chloris, XT-1081/07 in 2007) containing 21,924 protein coding genes. This enabled construction of a robust 19 locus MLST based on existing typing loci for Trichomonas vaginalis and T. gallinae. Our MLST has the sensitivity to discriminate strains within existing genotypes confidently, and resolves the American finch A1 genotype from the epidemic European finch A1 genotype. Interestingly, one isolate we obtained from a captive black-naped fruit dove Ptilinopsus melanospilus, was not truly T. ¬¬¬gallinae but a hybrid of T. gallinae with a distant trichomonad lineage. Phylogenetic analysis of the individual loci in this fruit dove provides evidence of gene flow between distant trichomonad lineages at two of the 19 loci examined and may provide precedence for the emergence of other hybrid trichomonad genomes including T. vaginalis

Body Weight Support Devices for Overground Gait and Balance Training

Regaining the ability to walk overground, to climb stairs and to perform other functional tasks such as standing up and sitting down are important rehabilitation goals following neurological injury or disease. However, these activities are often difficult to practice safely for patients with severe impairments due to the risk of injury, not only to the patient but also to therapists. The emergence of various technologies that provide a degree of body weight support can play a role in rehabilitation focused on recovering overground gait and balance functions. These can greatly reduce the risk of falls and thus allow more intense and longer training sessions. Therefore, the systems empower individuals with the ability to practice the types of activities and functions they need in order to return home and to be reintegrated into the community as much as possible. This chapter explores the origin of body weight supported devices and considers which groups could derive benefit from the training. An overview of the main training platforms available today—which comprise both robotic and non-robotic technologies—is then provided, followed by a discussion regarding outcomes of the devices thus far and possible future directions of the technology.</p

Body Weight Support Devices for Overground Gait and Balance Training

Regaining the ability to walk overground, to climb stairs and to perform other functional tasks such as standing up and sitting down are important rehabilitation goals following neurological injury or disease. However, these activities are often difficult to practice safely for patients with severe impairments due to the risk of injury, not only to the patient but also to therapists. The emergence of various technologies that provide a degree of body weight support can play a role in rehabilitation focused on recovering overground gait and balance functions. These can greatly reduce the risk of falls and thus allow more intense and longer training sessions. Therefore, the systems empower individuals with the ability to practice the types of activities and functions they need in order to return home and to be reintegrated into the community as much as possible. This chapter explores the origin of body weight supported devices and considers which groups could derive benefit from the training. An overview of the main training platforms available today—which comprise both robotic and non-robotic technologies—is then provided, followed by a discussion regarding outcomes of the devices thus far and possible future directions of the technology.</p

A preliminary study into the effects of pelvic rotations on upper body lateral translation

An understanding concerning the roles of the various degrees of freedom of the human body during functions such as walking is crucial to the design of robotic devices for rehabilitation. However, the function of the three rotational degrees of freedom of the pelvis during walking remains uncertain. Theories have been previously presented postulating a role of pelvic obliquity in reducing vertical movements of the body's centre of mass, and therefore in minimising energy expenditure, but these are not fully supported by empirical evidence. In this paper, an alterative role of pelvic obliquity in reducing lateral movements of the upper body is proposed. Through the application of a robotic orthosis platform, a variety of walking conditions are tested with different levels of pelvic rotation and lateral movement of the upper body. The presence of the robotic device significantly reduces the degree of pelvic obliquity. Though the data show no significant relationship between the pelvic angles and lateral movement, a trend for decreasing upper body movement with increasing pelvic obliquity is apparent