Intravenous set flow control device
First Claim
1. A flow control device for use with an intravenous set comprising a drip chamber, a volumetric chamber having a predetermined volume connected to the drip chamber, and externally actuated means for selectively interrupting fluid flow into the volumetric chamber, said flow control device comprising:
- means for measuring a drop rate indicative of the rate of drop formation in the drip chamber;
means for designating a selected volumetric flow rate;
means for designating a selected drop rate;
means for storing the selected volumetric flow rate;
means for automatically controlling fluid flow out of the drip chamber to cause the measured drop rate in the drip chamber to approach the selected drop rate;
means for automatically actuating the interrupting means to cause the volumetric chamber to fill and empty repeatedly such that said volumetric chamber repeatedly dispenses said predetermined volume; and
means for automatically and repeatedly measuring the rate at which the volumetric chamber empties to determine a parameter indicative of the volumetric flow rate of fluid out of the volumetric chamber and for automatically modifying the selected drop rate in response to said parameter to cause the volumetric flow rate of fluid out of the drip chamber to approach the selected volumetric flow rate.
2 Assignments
0 Petitions
Accused Products
Abstract
A controller for an intravenous set is disclosed which operates both to maintain the instantaneous drip rate through a drip chamber included in the IV set at a desired value, and to modify this value repeatedly during the course of an infusion. The desired drip value is modified in accordance with the measured volumetric flow rate through the intravenous set such that if a particular infusion fluid produces abnormally small volume drops in the drip chamber, then the controller automatically increases the drip rate to compensate. In this way, extremely accurate control of the fluid flow rate is obtained without the need for complex infusion pumps. A disclosed embodiment operates to provide separate alarms for open line errors, air in line errors, and occlusion errors.
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Citations
23 Claims
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1. A flow control device for use with an intravenous set comprising a drip chamber, a volumetric chamber having a predetermined volume connected to the drip chamber, and externally actuated means for selectively interrupting fluid flow into the volumetric chamber, said flow control device comprising:
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means for measuring a drop rate indicative of the rate of drop formation in the drip chamber; means for designating a selected volumetric flow rate; means for designating a selected drop rate; means for storing the selected volumetric flow rate; means for automatically controlling fluid flow out of the drip chamber to cause the measured drop rate in the drip chamber to approach the selected drop rate; means for automatically actuating the interrupting means to cause the volumetric chamber to fill and empty repeatedly such that said volumetric chamber repeatedly dispenses said predetermined volume; and means for automatically and repeatedly measuring the rate at which the volumetric chamber empties to determine a parameter indicative of the volumetric flow rate of fluid out of the volumetric chamber and for automatically modifying the selected drop rate in response to said parameter to cause the volumetric flow rate of fluid out of the drip chamber to approach the selected volumetric flow rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 15)
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8. A flow control device for use with an intravenous set comprising a drip chamber, a volumetric chamber connected to the drip chamber, and externally actuated means for selectively interrupting fluid flow into the volumetric chamber, said flow control device comprising:
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a frame; means for mounting the drip chamber, the volumetic chamber, and the interrupting means to the frame; means for controlling the fluid flow out of the drip chamber; means for detecting drops formed in the drip chamber; means for determining when the fluid level in the volumetric chamber fails to a lower level; means for determining when the fluid level in the volumetric chamber rises to an upper level; means for actuating the interrupting means; a computer coupled to the controlling means, the detecting means, the lower level determining means, the upper level determining means, and the actuating means; means, included in the computer, for storing a requested flow rate; means, included in the computer, for controlling the actuating means to fill the volumetric chamber to the upper level; means, included in the computer, for causing the means for controlling fluid flow out of the drip chamber to establish a first drop rate selected to provide a first approximation of the requested flow rate; means, included in the computer, for counting the drops detected as the fluid level in the volumetric chamber falls from the upper level to the lower level to determine a parameter indicative of the actual flow rate; and means, included in the computer, for causing the means for controlling fluid flow out of the drip chamber to establish a second drop rate which differs from the first drop rate in correspondence to the discrepancy between the actual flow rate and the requested flow rate to provide a second approximation of the requested flow rate which is closer to the requested flow rate than is the first approximation of the requested flow rate. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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16. A flow control device for use with an intravenous set comprising a drip chamber, a volumetric chamber connected to the drip chamber, and externally actuated means for selectively interrupting fluid flow into the volumetric chamber, said flow control device comprising:
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a frame; means for mounting the drip chamber, the volumetric chamber, and the interrupting means to the frame; means for controlling fluid flow out of the drip chamber; means for detecting drops formed in the drip chamber; means for determining when the fluid level in the volumetric chamber falls to a lower level; means for determining when the fluid level in the volumetric chamber rises to an upper level; means for actuating the interrupting means; a computer coupled to the controlling means, the detecting means, the lower level determining means, the upper level determining means, and the actuating means; means, included in the computer, for storing a requested flow rate; means, included in the computer, for causing the controlling means to establish a first drop rate selected to provide a first approximation of the requested flow rate; means, included in the computer, for determining the rate at which the fluid level in the volumetric chamber falls from the upper level to the lower level to determine a parameter indicative of the actual flow rate; and means, included in the computer, for causing the controlling means to establish a second drop rate which differs from the first drop rate in correspondence to the discrepancy between the actual flow rate and the requested flow rate to provide a second approximation of the requested flow rate which is closer to the requested flow rate than is the first approximation of the requested flow rate. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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Specification