EP0248632A2
Expired / Lapsed
EP
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Intravenous fluid flow monitor
Assignee: Ivac Medical Systems Inc
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Filing: 1987-06-02
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Granted: —
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Expires: 2007-06-02
Abstract
Abstract An improved system for monitoring the fluid flow through a fluid delivery system to a patient wherein the fluid flow rate is varied in a predetermined sequential manner. Corresponding changes in pressure in the line (14) connecting the vein of a patient (16) and the pump (12) are detected and are used to derive signals indicative of the resistance or impedance in the line, which in turn can be used to determine whether the vein is normal, whether it is phlebitic, whether it is occluded, whether infiltration of the cannula into the patient's soft tissue has occurred, or whether the continuity of tubing to the vein has been interrupted.
Inventors
- 👤 James H. Philip
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 05:07
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/14; A61M5/168; A61M5/16831; A61M5/16854; A61M5/16859
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
106 words
A system for monitoring the flow of parenteral fluid through a fluid delivery system to a patient comprising; a) means for supplying parenteral fluid at controllable flow rate through the fluid delivery system to a patient; b) means for monitoring fluid pressure in the fluid delivery system supplying parenteral fluid to a patient; c) means for controlling the fluid flow rate in a predetermined manner; d) means responsive to the sensed pressure and to the fluid flow rate, for determining the resistance to flow in the fluid delivery system; and e) means for comparing the resistance to predetermined limits and for generating output signals responsive thereto.
Claim 2
Independent Claim
106 words
A system for monitoring the flow of parenteral fluid through a fluid delivery system to a patient comprising; a) means for supplying parenteral fluid at controllable flow rate through the fluid delivery system to a patient; b) means for monitoring fluid pressure in the fluid delivery system supplying parenteral fluid to a patient; c) means for controlling the fluid flow rate in a predetermined manner; d) means responsive to the sensed pressure and to the fluid flow rate, for determining the resistance to flow in the fluid delivery system; and e) means for comparing the resistance to predetermined limits and for generating output signals responsive thereto.
Claim 3
Dependent Claim
30 words
The system of claim 1, wherein the means for calculating the resistance in the fluid delivery system and the means for comparing the resistance to predetermined limits is a microprocessor.
Claim 4
Dependent Claim
35 words
The system of claim 2, wherein the microprocessor further comprises means for monitoring the time rate of change of pressure in fluid delivery system which is responsive to changes in flow rate of the fluid.
Claim 5
Dependent Claim
36 words
The system of claim 3 wherein the microprocessor analyzes the time rate change of pressure in the fluid delivery system and calculates the mean transit time of pulsatile changes in the flow rate of the fluid.
Claim 6
Dependent Claim
46 words
The system of the claim 3 wherein the microprocessor analyzes the time rate of change of pressure in the fluid delivery system and calculates a time constant for changes in the pressure which is responsive to changes in the flow rate in the fluid delivery system.
Claim 7
Dependent Claim
51 words
The system of claim 1 or claim 2, wherein the means for monitoring the pressure in the fluid delivery system is a pressure transducer outputting an analog signal, and the system further comprises analog-to-digital converter means for conversion of the analog signal to a digital signal for supply to the microprocessor.
Claim 8
Dependent Claim
26 words
The system of claim 2, wherein the microprocessor determines the changes in pressure with respect to the changes in flow rate, to provide a resistance value.
Claim 9
Dependent Claim
20 words
The monitor of claim 7, wherein the microprocessor further comprises means for monitoring the time rate of change of pressure.
Claim 10
Dependent Claim
13 words
The system of claim 1 wherein the resistance to flow is an impedance.
Claim 11
Dependent Claim
27 words
The system of claim 2, wherein the microprocessor further comprises means for monitoring impedance responsive to variations in flow rates, the variations having a predetermined frequency spectrum.
Claim 12
Dependent Claim
30 words
The system of claim 10, wherein the microprocessor comprises means for taking the Fourier transform of variations in the pressure which are responsive to the variations in the flow rate.
Claim 13
Dependent Claim
21 words
The system of claim 10, wherein said microprocessor further comprises means for calculating the time derivative of changes in the pressure.
Claim 14
Dependent Claim
61 words
The system of claim 9, wherein the means for supplying parenteral fluid at controllable flow rates comprises means for causing the flow rates to be varied in a manner having a defined frequency component, and wherein the means for determining the impedance to flow comprises means for analyzing the variations in pressure which are responsive to the variations in flow rates.
Claim 15
Independent Claim
96 words
A method for monitoring the flow of parenteral fluid through a fluid delivery system to a patient comprising: a) supplying parenteral fluid at controllable flow rate through a fluid delivery system to a patient; b) monitoring fluid pressure in the fluid delivery system supplying parenteral fluid to a patient; c) controlling the fluid flow rate in a predetermined manner; d) determining the resistance to flow in the fluid delivery system in response to the sensed pressure and to the fluid flow rate; and e) comparing the resistance to predetermined limits and generating output signals responsive thereto.
Claim 16
Independent Claim
96 words
A method for monitoring the flow of parenteral fluid through a fluid delivery system to a patient comprising: a) supplying parenteral fluid at controllable flow rate through a fluid delivery system to a patient; b) monitoring fluid pressure in the fluid delivery system supplying parenteral fluid to a patient; c) controlling the fluid flow rate in a predetermined manner; d) determining the resistance to flow in the fluid delivery system in response to the sensed pressure and to the fluid flow rate; and e) comparing the resistance to predetermined limits and generating output signals responsive thereto.
Claim 17
Dependent Claim
31 words
The method of claim 14, wherein the time rate of change of pressure in the fluid delivery system which is responsive to changes in flow rate of the fluid is monitored.
Claim 18
Dependent Claim
37 words
The method of claim 15 wherein the time rate of change of pressure in the fluid delivery system is analyzed and the mean transit time of pulsatile changes in the flow rate of the fluid is calculated.
Claim 19
Dependent Claim
45 words
The method of claim 15, wherein the time rate of change of pressure in the fluid delivery system is analyzed and a time constant for changes in the pressure which is responsive to changes in the flow rate in the fluid delivery system is calculated.
Claim 20
Dependent Claim
36 words
The method of claim 15, wherein the pressure in the fluid delivery system is monitored by a pressure transducer outputting an analog signal, and the method further comprises converting the analog signal to a digital signal.
Claim 21
Dependent Claim
27 words
The method of claim 15 wherein the changes in pressure with respect to the changes in flow rate are determined in order to determine a resistance value.
Claim 22
Dependent Claim
15 words
The method of claim 19, wherein the time rate of change of pressure is monitored.
Claim 23
Dependent Claim
14 words
The the method of claim 14, wherein the resistance calculated is an impedance value.
Claim 24
Dependent Claim
22 words
The method of claim 21, wherein impedance response to variations in flow rates is monitored, the variations having a predetermined frequency spectrum.
Claim 25
Dependent Claim
24 words
The method of claim 22, including determining the Fourier transforms of variations in the pressure which are responsive to variations in the flow rate.
Claim 26
Dependent Claim
16 words
The method of claim 23, wherein the time derivative of changes in the pressure is calculated.
Claim 27
Dependent Claim
48 words
The method of claim 22, wherein the parenteral fluid is supplied at controllable flow rates which are varied in a manner having a defined frequency content, and the impedance to flow is determined by analyzing the variations in pressure which are responsive to the variations in flow rates.
References Cited (Backward Citations)
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