| 摘要 |
<p>PUMP APPARATUS A pump apparatus for transferring precise amounts of fluid from a container to a patient. The pump apparatus has a defined volume pump chamber divided by a diaphragm into a first chamber volume and a second chamber volume. The first chamber volume receives and exhausts pumped fluid in response to a decrease or increase in the volume of the first chamber volume in response to an increased pressure of a pumping fluid in the second chamber volume. The diaphragm and the pump chamber provide accurate per cycle pumping volumes. The pumping fluid pressure is varied by periodically electrically heating a ribbon filament in a heating chamber interconnected to the second chamber volume of the pump chamber thereby increasing the temperature and hence the pressure and/or volume of the pumping fluid. The pumped fluid enters the first chamber volume through a one-way valve as the pumped fluid portion volume expands and is exhausted through a second one-way valve as the volume of the first chamber volume contracts. Control circuitry is provided to allow variations in the pulse repetition rate and pulse width to control the pumping rate. A feedback control loop may also be provided by sensing, for example, the fluid flow rate, pressure, temperature or other dependent variable and generating an error signal therefrom to control the pulse repetition rate or pulse width.</p> |
