Northrop Grumman Systems Corporation

Imed Corporation

Robert A Bramble

Stephen Bollish

Michael Scott Andrews

Michael P Johnson

Eric L Firing

A radio-frequency (RF) transmitter power amplifier circuit provides for practically linear performance by predistorting the amplifier input signals to compensate for amplifier distortion at high power levels, and provides a fine degree of control of amplifier power needed to handle complex modulation schemes with widely and rapidly varying power requirements. A predistortion database () contains gain and phase corrections for various transmission types and a separate automatic gain control database () contains fine amplifier gain corrections. A real-time processor () combines the two types of corrections and applies them to the amplifier input signals, and a background processor () continually updates both databases in accordance with a programmable priority scheme. Integration of predistortion and amplifier power control is achieved in a manner that minimizes adverse effects of one type of control on the other. One feature of the invention provides for rapid convergence of the predistortion correction.

Efficient method and means for integration of power control and predistortion in a transmitter

An apparatus for infusing TPN fluids to a patient includes a source of fluid, a pump for infusing fluid from the source to the patient, and a computer for controlling the operation of the pump. During the operation of the apparatus the infusion rate of the pump is varied according to an infusion regimen that is based on the volume of fluid to be infused and the time during which the fluid is to be infused. This regimen is characterized by a trifurcated ramp up region having interrelated incremental rates of infusion which transition the pump from a zero rate of infusion to a steady state rate of infusion. The infusion regimen is also characterized by a period of steady state infusion which follows the ramp up region, and a ramp down region in which the infusion rate is decremented from the steady state rate based on the remaining volume of fluid to be infused to the patient and the remaining time for infusing this remaining volume of fluid. Infusion rate changes in both the ramp up and ramp down regions is accomplished in steps. Depending on the calculated steady state infusion rate, the step sizes may be either 5 ml/hr or 1 ml/hr. The different time intervals between steps in the ramp up region are related to each other and to the total time for infusing fluids to the patient and the time intervals between steps in the ramp down region are controlled by the computer.

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San Diego, CA, United States of America

Robert A Bramble