Method for pumping fluid from a flexible, variable geometry reservoir
First Claim
1. A method of infusing a fluid from a variable geometry reservoir into a patient using a pump having a chamber with initial volume greater than the reservoir, the chamber capable of containing the reservoir, the chamber having reducible volume which in turn reduces the volume of the reservoir, the chamber also having a means for reducing its volume and a programmable controller for controlling the volume reducing means, the controller having a memory, the method comprising the steps of:
- (a) electronically determining in the controller the volume of the chamber to be reduced according todσ
=dV·
S94 where dV is the incremental reservoir volume reduction associated with incremental chamber volume reduction dσ
at chamber volume σ
, and S.sub.σ
is the previously determined relationship of reservoir volume reduction to chamber volume reduction at chamber position σ
, wherein the controller determines dσ
of the chamber volume by determinations from values of dV and Sσ
in the memory; and
(b) electronically actuating the volume reducing means according to the determinations of the controller.
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Accused Products
Abstract
A method of pumping fluid from an IV bag with a volumereducible chamber capable of holding the bag. The method includes the steps of placing the bag in the chamber and reducing the volume of the chamber according to calculations from known values in the controller memory to compensate for the nonlinear relationship between the reduction of bag volume corresponding to reduction in chamber volume. The next step is actuating the motor which controls the volume to reduce the volume of the chamber according to the calculations. A method of pumping from a flexible bag also is contemplated where the controller also or alternatively controls the rate of the reduction of the chamber rather than the volume.
179 Citations
20 Claims
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1. A method of infusing a fluid from a variable geometry reservoir into a patient using a pump having a chamber with initial volume greater than the reservoir, the chamber capable of containing the reservoir, the chamber having reducible volume which in turn reduces the volume of the reservoir, the chamber also having a means for reducing its volume and a programmable controller for controlling the volume reducing means, the controller having a memory, the method comprising the steps of:
-
(a) electronically determining in the controller the volume of the chamber to be reduced according to dσ
=dV·
S94where dV is the incremental reservoir volume reduction associated with incremental chamber volume reduction dσ
at chamber volume σ
, and S.sub.σ
is the previously determined relationship of reservoir volume reduction to chamber volume reduction at chamber position σ
, wherein the controller determines dσ
of the chamber volume by determinations from values of dV and Sσ
in the memory; and(b) electronically actuating the volume reducing means according to the determinations of the controller. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
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11. A method of infusing a fluid from a variable geometry reservoir into a patient using a pump having a chamber with initial volume greater than the reservoir, the chamber capable of containing the reservoir, the chamber having reducible volume which in turn reduces the volume of the reservoir, the chamber also having a means for reducing its volume and a programmable controller for controlling the volume reducing means, the controller having a memory, the method comprising the steps of:
-
(a) electronically determining in the controller the rate and volume the chamber is to be reduced according to ##EQU7## where Ri is the incremental rate of intravenous fluid delivered to the patient associated with incremental chamber volume reduction dσ and
the time interval dt at chamber volume σ
, and SR is the previously determined relationship of rate of fluid flow from the reservoir to rate of chamber volume reduction at chamber volume σ
, wherein the controller determines dσ
/dt of the chamber volume rate reduction by determinations from values Ri and SR is the previously determined relationship of rate of fluid flow from the reservoir to rate of chamber volume reduction at chamber volume σ
, wherein the controller determines dσ
/dt of the chamber volume rate reduction by determinations from values Ri and SR in the controller memory; and(b) electronically actuating the volume reducing means according to the determinations of the controller. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification