Fluid infusion pumping apparatus
First Claim
1. In an infusion pumping apparatus having a motor for driving a pumping member to expel liquid, from a pumping chamber having an input from a single source of said liquid, at a rate as determined by a preset motor output rate, ramping control means for initiating the pumping of said liquid by operating the motor at a plurality of starting fractional rates for predetermined periods of time until the preset rate is obtained, each starting fractional rate being less than the preset rate and successive starting fractional rates increasing the motor rate, maintaining said preset rate for a selected period of time and means for stopping the motor after a predetermined quantity of said liquid has been delivered, said ramping control means also operating the motor at a plurality of stopping fractional rates for predetermined periods of time prior to the stopping of the motor, each stopping fractional rate being less than the preset rate and successive stopping fractional rates decreasing the motor speed.
1 Assignment
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Accused Products
Abstract
A fluid infusion positive displacement pump includes a plunger driven by a stepping motor which is operated by a motor control system. The control system advances the plunger to expel liquid in a series of incremental steps at a user-set pumping rate and until a preset total dosage has been delivered with the pumping rate being determined by the waiting time between each step. In order to minimize shock to the patient, the pump is operated at a plurality of increasing fractional rates during the start of pumping and at a plurality of decreasing fractional rates at the termination of pumping with the user-set (maximum) pumping rate occurring between such fractional rate pumping periods.
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Citations
13 Claims
- 1. In an infusion pumping apparatus having a motor for driving a pumping member to expel liquid, from a pumping chamber having an input from a single source of said liquid, at a rate as determined by a preset motor output rate, ramping control means for initiating the pumping of said liquid by operating the motor at a plurality of starting fractional rates for predetermined periods of time until the preset rate is obtained, each starting fractional rate being less than the preset rate and successive starting fractional rates increasing the motor rate, maintaining said preset rate for a selected period of time and means for stopping the motor after a predetermined quantity of said liquid has been delivered, said ramping control means also operating the motor at a plurality of stopping fractional rates for predetermined periods of time prior to the stopping of the motor, each stopping fractional rate being less than the preset rate and successive stopping fractional rates decreasing the motor speed.
- 7. An infusion pumping apparatus comprising a motor, a pumping chamber having an input from a single source of liquid, a pumping member operatively connected to said motor and arranged to expel said liquid from the pumping chamber at a rate as determined by a preset motor output rate, means for initiating the operation of said motor, ramping control means operative upon the initiation of said last named means for operating the motor at a plurality of starting fractional rates for predetermined periods of time until the preset rate is obtained, each starting fractional rate being less than the preset rate and successive starting fractional rates increasing the motor speed, maintaining said preset rate for a selected period of time, and means for stopping the motor after a predetermined quantity of said liquid has been delivered, said ramping control means also operating the motor at a plurality of stopping fractional rates for predetermined periods of time prior to the stopping of the motor, each stopping fractional rate being less than the preset rate and successive stopping fractional rates decreasing the motor speed.
Specification