EP0248633A2
Expired / Lapsed
EP
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Detection of fluid flow faults in the parenteral administration of fluids
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 This invention is directed to a method and system for evaluating the fluid communication between a parenteral fluid delivery system and a patient's blood vessel. In accordance with the invention, one or more fluid flow pulses are applied to the fluid within the delivery system. Both positive and negative fluid flow pulses may be applied. The pressure response to the pulses under conditions of normal, unimpeded fluid flow is significantly different than the pressure response to such pulses when an infiltration or other fluid flow fault has occurred and this difference is used to detect fluid faults.
Inventors
- 👤 Robert D. Butterfield
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 12:55
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/14; A61M5/168; A61M5/16831; A61M5/16854; A61M5/16859; A61M2205/00; A61M2205/70; A61M2205/702; Y; Y10; Y10S; Y10S128/00; Y10S128/13
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
149 words
A system for monitoring the flow of parenteral fluid from a parenteral fluid delivery system to a patient comprising: a) means to apply a fluid flow pulse to fluid in the fluid delivery system; b) means to sense the pressure response of fluid in the delivery system to the applied pulse and generate a signal representing the response or characteristic thereof; c) means to generate a reference signal representing a pressure response or characteristic thereof of fluid in the delivery system to a fluid flow pulse of a magnitude and duration equivalent to the fluid flow pulse applied in a) above when fault-free fluid flow conditions exist; d) means to compare the signal representing the sensed pressure response or characteristic thereof with the signal representing the reference pressure response or characteristic thereof to detect a difference therebetween; and e) means responsive to the difference to generate an alarm signal.
Claim 2
Independent Claim
149 words
A system for monitoring the flow of parenteral fluid from a parenteral fluid delivery system to a patient comprising: a) means to apply a fluid flow pulse to fluid in the fluid delivery system; b) means to sense the pressure response of fluid in the delivery system to the applied pulse and generate a signal representing the response or characteristic thereof; c) means to generate a reference signal representing a pressure response or characteristic thereof of fluid in the delivery system to a fluid flow pulse of a magnitude and duration equivalent to the fluid flow pulse applied in a) above when fault-free fluid flow conditions exist; d) means to compare the signal representing the sensed pressure response or characteristic thereof with the signal representing the reference pressure response or characteristic thereof to detect a difference therebetween; and e) means responsive to the difference to generate an alarm signal.
Claim 3
Dependent Claim
50 words
The system of claim 1 wherein means responsive to the difference is actuated when the difference between the sensed pressure response signal and the reference pressure response signal exceeds a predetermined amount, the predetermined difference therebetween selected to indicate improper fluid communication between the fluid delivery system and the patient.
Claim 4
Dependent Claim
49 words
The system of claim 1 or 2 wherein means are provided to determine the differences between a first pressure-time curve representing the sensed pressure response and a second pressure-time curve representing the reference pressure response, the differences representing a numerical integration of the area between the two pressure-time curves.
Claim 5
Dependent Claim
12 words
The system of claim 3 wherein the differences are summed absolute values.
Claim 6
Dependent Claim
38 words
The system of claim 4 wherein the differences are determined from the equation wherein S(t) is the value of the sensed pressure response at time t; R(t) is the value of the reference pressure response at time t.
Claim 7
Independent Claim
39 words
The system of any one of claims 1 to 5 wherein the reference pressure response is determined by the application of a fluid flow pulse to the fluid when the fluid flow through the fluid delivery system is fault-free.
Claim 8
Independent Claim
34 words
The system of any one of claims 1 to 6 wherein means to apply a fluid flow pulse include means to generate a negative fluid flow pulse to fluid in the fluid delivery system.
Claim 9
Independent Claim
30 words
The system of any one of claims 1 to 7 wherein the fluid delivery system includes a pulsatile pump to pump parenteral fluid through the delivery system to the patient.
Claim 10
Independent Claim
40 words
The system of any one of claims 1 to 8 wherein means to apply a fluid flow pulse to the fluid delivery system includes means to generate positive and negative fluid flow pulses to fluid in the fluid delivery system.
Claim 11
Dependent Claim
33 words
The system of claim 5 including means to determine the short-term fluid pressure variations, identified as noise, of fluid in the fluid delivery system prior to the application of the fluid flow pulse.
Claim 12
Dependent Claim
52 words
The system of claim 10 including means to calculate a factor representing a measure of infiltration (MOI) from the equation: wherein: SMOE is the subtractive measure of error as calculated in claim 5; Noise is the short-term fluid pressure variations as determined in claim 10, and K is a constant or zero.
Claim 13
Dependent Claim
11 words
The system of claim 11 wherein the constant K is 1.
Claim 14
Independent Claim
159 words
A method of evaluating the fluid communication between a parenteral fluid delivery system and a patient, comprising: a) applying a fluid flow excitation pulse of predetermined magnitude and duration to fluid in the fluid delivery system; b) sensing the pressure response to the applied excitation pulse and generating a signal representing the pressure response sensed or characteristic thereof; c) developing a reference signal representing a pressure response or characteristic thereof of fluid in the fluid delivery system having fault-free communication with the patient to a fluid flow pulse equivalent in magnitude and duration to the fluid flow pulse applied in a) above; d) comparing the signal representing the sensed response to the signal representing the reference response to determine a difference therebetween; and e) generating an alarm signal when the sensed response signal differs by a predetermined amount from the reference response signal, the predetermined difference therebetween indicating improper fluid communication between the fluid delivery system and the patient.
Claim 15
Independent Claim
159 words
A method of evaluating the fluid communication between a parenteral fluid delivery system and a patient, comprising: a) applying a fluid flow excitation pulse of predetermined magnitude and duration to fluid in the fluid delivery system; b) sensing the pressure response to the applied excitation pulse and generating a signal representing the pressure response sensed or characteristic thereof; c) developing a reference signal representing a pressure response or characteristic thereof of fluid in the fluid delivery system having fault-free communication with the patient to a fluid flow pulse equivalent in magnitude and duration to the fluid flow pulse applied in a) above; d) comparing the signal representing the sensed response to the signal representing the reference response to determine a difference therebetween; and e) generating an alarm signal when the sensed response signal differs by a predetermined amount from the reference response signal, the predetermined difference therebetween indicating improper fluid communication between the fluid delivery system and the patient.
Claim 16
Dependent Claim
42 words
The method of claim 13 wherein the transient pressure response to an applied pulse of the same magnitude as the test pulse under normal fluid flow conditions is calculated from a mathematical model of the fluid delivery system and the injection site.
Claim 17
Independent Claim
34 words
The method of claims 13 or 14 wherein the test pulse is applied to the fluid in the fluid delivery system by adjusting the fluid flow rate therein to a higher or lower level.
Claim 18
Independent Claim
41 words
The method of claims 13, 14 or 15, wherein the test pulse applied to the fluid in the fluid delivery system is in a direction opposite to the direction of the normal fluid flow through the delivery system to the patient.
Claim 19
Independent Claim
26 words
The method of any one of claims 13 to 16 wherein the fluid flow through the fluid delivery system is a series of fluid flow pulses.
Claim 20
Independent Claim
33 words
The method of any one of claims 13 to 17 wherein the test pulse is a series of positive and negative fluid flow pulses which form a fluid flow pattern which is sinusoidal.
References Cited (Backward Citations)
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