| 摘要 |
<p>This invention relates to improvements in fluid flow control systems for parenteral administration of medical fluids. Prior art control systems are generally adaptable for only a single type of output device and are often deficient in their regulating accurately over a wide range of flow rates. The present invention overcomes these deficiencies by providing a digital system for parenteral administration of medical fluids, wherein a wide variety of different electromechanical output control devices, e.g. a ste ing motor pump or a solenoid actuated I.V. tube pincher, is driven by electrical output pulses of variable frequency and pulse width from a digital pulse generation and control system, the frequency and pulse width of the output pulses being selected and controlled by the system to establish drop flow rates with digital precision over an extremely wide dynamic range. In the preferred embodiment, desired flow rate is achieved, under control of the varying output pulses, by the repetitive unclamping and clamping of the I.V. tubes. Duty cycle limitation, appropriate to the particular operating characteristics of the electromechanical output device utilized, Is implemented to avoid inducing run-way free flow conditions. Appropriate alarms respond to system malfunctions to alert medical personnel.</p> |
