AbstractThis thesis describes an investigation into the development and performance of vane flowmeter methods for the measurement of air and gas flow. To improve on existing rotating vane anemometer performance, a capacitance change vane sensing technique is investigated. In conjunction with Ower's dynamic equations steady state and step response measurements for a vane flowmeter with analogue and digital readout are presented.
A new form of respiratory anemometer which utilizes the capacitance change transducer has been designed to operate under discontinuous air and gas flow conditions in the presence of water vapour. The performance and calibration techniques for the flowmeter are discussed and comparisons provided with alternative sensor techniques. The design of an electronic respirometer is presented, which enables the respiratory tidal and minute volume of the patient to be continuously monitored under both operative and intensive 'care conditions.
Electronic techniques for the calculation of lung function parameters are investigated and the results obtained using the respiratory flowmeter discussed. An on-line digital computation method for the display and calculation of respiratory parameters is introduced. This technique provides an improved method for pulmonary data analysis and diagnosis, particularly when maximal expiratory flow volume patient curves are required.
The rotating vane instrument is also considered for applications in underground air flow measurement. In particular an intrinsically safe design for use in gassy mines is developed together with a multi-channel tone scanning system for remote monitoring in large mine complexes.
The investigation is concluded by considering further applications for electronic vane flowmeters. This includes a method developed for obtaining flow direction indication, and the design of a closed loop air flow control system for use in sterile enclosures for patients requiring transplant surgery and immunosuppressive drug treatment.
|Date of Award||May 1976|