Three Dimensional Electrical Impedance Tomography

The electrical resistivity of mammalian tissues varies widely and is correlated with physiological function. Electrical impedance tomography (EIT) can be used to probe such variations in vivo, and offers a non-invasive means of imaging the internal conductivity distribution of the human body. But the computational complexity of EIT has severe practical limitations, and previous work has been restricted to considering image reconstruction as an essentially two-dimensional problem. This simplification can limit significantly the imaging capabilities of EIT, as the electric currents used to determine the conductivity variations will not in general be confined to a two-dimensional plane. A few studies have attempted three-dimensional EIT image reconstruction, but have not yet succeeded in generating images of a quality suitable for clinical applications. Here we report the development of a three-dimensional EIT system with greatly improved imaging capabilities, which combines our 64-electrode data-collection apparatus with customized matrix inversion techniques. Our results demonstrate the practical potential of EIT for clinical applications, such as lung or brain imaging and diagnostic screening

Targeting "open and distance" learning in Namibia : a study, comparing opinions of the service provider and the users on how the program responds to the needs of "young" learners

Abstract Access to Education and Training has become one of the rapidly increasing demands in many countries of the world and Namibia is no exception. As a developing young Nation, it has realised that the provision of Alternative Secondary Education is the only realistic means of expanding educational opportunities to the out-of-school population, including many young formal school push-outs. One of the principle means of delivery for this education is through the recently introduced mode of study, called Open . For many out-of-school learners, this form of education brought about relieve in that it increased access and flexibility, with a high emphasize on independent learning. However, same can not be said for the young and inexperienced school push outs. For them, this could mean a change from obedient child to adult and equal in this highly demanding and challenging world of self-directed learning. Against this scenario, the present study aimed at exploring differences in opinions of Management as policy developers and Learners on how the Open program responds to the diverse educational needs of young learners. It followed a qualitative interview method, with selected groups of informants from both Management and Learners. The sample consists of 6 informants from both groups and mainly targeted learners between the ages 16 and 17 years. Opinions were first analysed individually, then within the particular group and lastly between the two groups. The study discovered that there are indeed differences in opinions of the two groups. It further identified challenges faced by the program in effective and efficient delivery systems towards these young and inexperienced users. Emanating from the findings, the study recommends full-fletched needs analysis amongst its users. It also recommends sensitisation towards Special Needs Education amongst all its Stakeholders, as well as an effective training intervention for all Full-time and Part-time staff employed by the program