System and method for detecting abnormalities in intravascular infusion
First Claim
1. A system for detecting abnormalities in infusion of parenteral fluid from a parenteral fluid delivery system to a patient comprising:
- a) infusion means for producing a perturbation of said fluid flow by varying the rate of fluid flow from an equilibrium flow rate with a specific volume of fluid;
b) sensor means for measuring pressure of said fluid over a period of time and adapted to generate a signal representing a pressure response of said fluid to said perturbation and a signal representing an equilibrium pressure level;
c) first integrator means operatively connected to said sensor means for determining a first integral of the difference between said equilibrium pressure signal and said pressure response signal over time, and for generating a signal representing said first integral;
d) means for determining resistance to said infusion of fluid from the delivery system adapted to scale said first integral signal according to said specific volume, and for producing a signal representing the resistance to fluid flow;
e) second integrator means for determining a second integral by multiplying the difference between said pressure response signal over time and said equilibrium pressure signal by a value representing said time, and integrating the resultant product with respect to said time, and adapted to generate a signal representing said second integral determined; and
f) means responsive to said first and second integrator means for determining compliance of said fluid delivery system by dividing said second integral signal by said first integral signal to produce a signal representing an effective time constant, and by scaling said effective time constant by said previously determined resistance to produce a signal representing compliance of said fluid delivery system.
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Accused Products
Abstract
The system and method for detecting abnormalities in infusion of parenteral fluid involves producing perturbation of fluid flow by varying the flow rate of the fluid with respect to an equilibrium flow rate, measuring the pressure level, and measuring the pressure of the fluid over a period of time, to determine equilibrium pressure and a pressure response of the fluid to the perturbation, determining an integral of the difference between the equilibrium pressure and the pressure response, determining resistance to fluid flow, determining a second integral of the difference between the pressure response and equilibrium pressure multiplied by time, and determining compliance by dividing the second integral by the first integral. Resistance and compliance values are displayed, and an alarm is generated when the resistance or compliance parameters fall outside of reference ranges.
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Citations
47 Claims
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1. A system for detecting abnormalities in infusion of parenteral fluid from a parenteral fluid delivery system to a patient comprising:
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a) infusion means for producing a perturbation of said fluid flow by varying the rate of fluid flow from an equilibrium flow rate with a specific volume of fluid; b) sensor means for measuring pressure of said fluid over a period of time and adapted to generate a signal representing a pressure response of said fluid to said perturbation and a signal representing an equilibrium pressure level; c) first integrator means operatively connected to said sensor means for determining a first integral of the difference between said equilibrium pressure signal and said pressure response signal over time, and for generating a signal representing said first integral; d) means for determining resistance to said infusion of fluid from the delivery system adapted to scale said first integral signal according to said specific volume, and for producing a signal representing the resistance to fluid flow; e) second integrator means for determining a second integral by multiplying the difference between said pressure response signal over time and said equilibrium pressure signal by a value representing said time, and integrating the resultant product with respect to said time, and adapted to generate a signal representing said second integral determined; and f) means responsive to said first and second integrator means for determining compliance of said fluid delivery system by dividing said second integral signal by said first integral signal to produce a signal representing an effective time constant, and by scaling said effective time constant by said previously determined resistance to produce a signal representing compliance of said fluid delivery system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. The method of detecting abnormalities in infusion of parenteral fluid from a parenteral fluid delivery system to a patient, the delivery system having an equilibrium flow rate, comprising the steps of:
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a) producing a perturbation of said fluid flow by varying the rate of fluid flow from an equilibrium flow rate with a specific volume of fluid; b) measuring the pressure of said fluid over a period of time, generating a signal representing an equilibrium pressure level, and generating a signal representing a pressure response of said fluid to said perturbation; c) determining a first integral of the difference between said equilibrium pressure signal and said pressure response signal over time, and generating a signal representing said first integral; d) determining resistance to fluid flow in the delivery system by scaling said first integral according to said specific volume, and generating a signal representing resistance to fluid flow; e) determining a second integral by multiplying the difference between said pressure response signal over time and said equilibrium pressure signal by a value representing said time, and integrating the resultant product with respect to said time, and generating a signal representing said second integral; and f) determining compliance of the fluid delivery system by dividing said second integral signal by said first integral signal to produce a signal representing an effective time constant of said fluid delivery system and scaling said time constant signal by said previously determined resistance to produce a signal representing compliance of said fluid delivery system. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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38. A system for determining compliance in infusion of a fluid to a patient by a fluid delivery system, the fluid delivery system having an equilibrium flow rate, comprising:
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a) an infusion pump for producing a perturbation in said fluid flow by varying the rate of fluid flow from the equilibrium flow rate with a specific volume of fluid; b) a pressure sensor for measuring the pressure of the fluid in the fluid delivery system over a period of time and adapted to provide a perturbation pressure signal representing the pressure response of said fluid to said perturbation and an equilibrium pressure signal representing an equilibrium fluid pressure; c) a resistance calculator for determining the resistance to the infusion of fluid and providing a resistance signal representative thereof; d) a first integrator which receives the perturbation pressure signal and the equilibrium pressure signal and determines a first integral of the difference between said equilibrium pressure signal and said perturbation pressure signal over time, and for providing a pressure difference signal representative thereof; and e) a compliance calculator which receives the perturbation pressure signal and the equilibrium pressure signal and determines a second integral by multiplying the difference between the perturbation pressure signal and said equilibrium pressure signal over time by a value representing said time, and integrating the resultant product with respect to said time, and adapted to provide a compliance signal representing said second integral divided by said first integral, the quotient of which is divided by the resistance signal. - View Dependent Claims (39, 40, 41, 42, 43)
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44. A system for detecting abnormalities in infusion of fluid to a patient from a fluid delivery system, the fluid delivery system having an equilibrium flow rate, comprising:
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a) an infusion pump for producing a perturbation in said fluid flow by varying the rate of fluid flow from the equilibrium flow rate with a specific volume of fluid; b) a pressure sensor for measuring the pressure of the fluid in the fluid delivery system over a period of time and adapted to provide a perturbation pressure signal representing the pressure response of said fluid to said perturbation and an equilibrium pressure signal representing an equilibrium fluid pressure; c) a resistance calculator for determining the resistance to the infusion of fluid and providing a resistance signal representative thereof; d) a first integrator which receives the perturbation pressure signal and the equilibrium pressure signal and determines a first integral of the difference between said equilibrium pressure signal and said perturbation pressure signal over time, and for providing a pressure difference signal representative thereof; e) a compliance calculator which receives the perturbation pressure signal and the equilibrium pressure signal and determines a second integral by multiplying the difference between the perturbation pressure signal and said equilibrium pressure signal over time by a value representing said time, and integrating the resultant product with respect to said time, and adapted to provide a compliance signal representing said second integral divided by said first integral, from the quotient of which is subtracted a flow factor which is proportional to the time of flow perturbation of the specific volume of fluid, all of which is divided by the resistance signal; and f) an alarm comparator which receives the resistance signal and compares it to a threshold value and provides an alarm based on the comparison and receives the compliance signal and compares it to a threshold value and provides an alarm signal based on the comparison. - View Dependent Claims (45, 46, 47)
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Specification