Browsing by Author "Milner, Morris"

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    A theoretical study of left ventricular and heart muscle dynamics
    (1973) Hadingham, Paul Trahair; Milner, Morris
    The characteristics of the left ventricle of the human heart considered as a pump have been extensively analysed. Using a new approach relying heavily on the Tensor Calculus, a theoretical model describing the mechanical and dynamical operation of the left ventricle has been developed. This has considerably greater versatility than previously proposed models. In particular the physiological shape, both under normal as well as many abnormal situations, is realistically simulated. Further, the mechanical behaviour of the ventricular wall is synthesised from anatomical data concerning the cardiac muscle fibre structure of the wall. Its mechanical and dynamical properties are then, as in the physiological situation, dependent on those of the muscle fibre. These fibre properties have also been fully investigated and a simple new model for cardiac muscle dynamics, incorporating active state, proposed. This description of the ventricular behaviour in terms of muscle properties represents the first logically structured link between cardiac muscle fibre characteristics and ventricular performance.
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    Electrical restoration of the micturition reflex
    (1974) Naumann, Stephen; Milner, Morris
    Numerous attempts at electrical stimulation of the detrusor muscle of the urinary bladder to evoke contraction and evacuation have been carried out over the past decade. A review of prostheses for the restoration of urinary continence and for effecting bladder evacuation, is given. Problems encountered during detrusor stimulation to effect voiding such as pain and increased urethral resistance are due to current spread to the surrounding pelvic structures. To restrict this current spread, sequentially activated multiple bipolar electrodes are employed. The development of a three-channel vesical stimulator to realize sequential pulsing is described. The inductively coupled device is externally controlled and totally implantable. The system used is believed by the author to be a unique method for transmitting three simultaneous and independent signals successfully to the simple type of receiver used. The good correlation between theoretical and practical results enables the theory developed to be used to predict the performance of coupled coils. The successful clinical trial of the stimulator in an animal and the good current restricting properties of the device indicate that the system used is a feasible method for the treatment of urinary retention following paraplegia.
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    Mathematical modelling studies of human locomotion
    (1973) Hershler, Cecil; Milner, Morris
    This thesis was almost wholly conducted in the confines of the Department of Bio-engineering and Medical Physics, University of Cape Town and the Bio-engineering Unit, Princess Alice Orthopaedic Hospital, Cape Town. It is an interdisciplinary thesis in that an effort has been made to bridge and thus unify the different scientific disciplines of Physics, Biology, Electrical Engineering and Mathematics. Thus the author hopes the work would appeal to as wide an audience as possible. The thesis is directed generally towards a deeper understanding of normal and pathological biped locomotion. It involves theoretical considerations in respect of model building, model testing and practical work concerned with the collection of pertinent data.