Fluid path impedance assessment for improving fluid delivery performance

Patent metadata

Field	Value
Publication number	US-2022047816-A1
Application number	US-202117449122-A
Country	US
Kind code	A1
Filing date	Sep 28, 2021
Priority date	Aug 31, 2017
Publication date	Feb 17, 2022
Grant date	—

Abstract

A fluid injector system for delivering a multi-phase fluid injection to a patient and methods of fluid delivery is disclosed. Methods of creating and using a multi-aspect fluid path impedance model of the injector system are used. Modeling and adjustment of factors that affect impedance and prevent or reduce backflow, reduce the likelihood of fluid flow rate spikes and provide more accurate flow rates and mixing ratios of fluids may be repeated or happen essentially continuously during an injection. The adjustments may be determined before the injection or determined and/or adjusted during the injection. The determination may include sensor feedback commonly used in injectors such as pressure and position feedback as well as other sensors. In all cases, the user can be notified of adjustments through on-screen notices and/or through the recordation of the injection data by a control device of the injector at the conclusion of the injection.

First claim

1 .- 20 . (canceled)

21 . A fluid delivery method, comprising:
providing a fluid delivery system for a multiphase fluid injection comprising at least a first syringe containing a first fluid, at least a second syringe containing a second fluid, a fluid conduit for conducting fluid from the first syringe and the second syringe to a patient, and an injector comprising at least a first piston for expelling fluid from the first syringe and at least a second piston for expelling fluid from the second syringe; advancing the first piston to expel fluid from the first syringe into the conduit during a first phase of the injection; measuring one or more parameter of the injection during the first phase of the injection; calculating a retraction distance for the second piston based on the one or more measured parameter and a desired fluid flow rate; retracting the second piston by the calculated retraction distance to a retracted position; and performing a second phase of the injection by advancing the second piston from the retracted position through at least a portion of the second syringe to expel fluid from the second syringe and into the conduit.

22 . The method of claim 21 , wherein the one or more parameter are temperature, viscosity, pressure, bulk modulus, concentration, catheter size, hydraulic resistance, actual flow rate, system capacitance, system impedance, and factors that affect system capacitance, impedance and hydraulic resistance.

23 . The method of claim 21 , further comprising calculating a new flow rate for the second phase of the injection based on the one or more measured parameter and performing the second phase of the injection at the new flow rate.

24 . The method of claim 21 , wherein advancing the first piston comprising advancing the first piston from an initial position to an extended position to deliver a first pre-determined volume of fluid from the first syringe to a downstream location.

25 . The method of claim 24 , wherein advancing the first piston further comprises advancing the first piston to an over-travel position to deliver a second pre-determined volume of fluid from the first syringe to the downstream location.

26 . The method of claim 25 , wherein a delivery distance between the extended position and the over-travel position is selected such that the second pre-determined volume of fluid compensates for under-delivery of fluid as a result of the capacitance swelling of the first syringe during a transition from the initial position to the extended position.

27 . The method of claim 25 , further comprising:
retracting the first piston from the over-travel position to a retracted position to relieve pressure in the fluid delivery system.

28 . The method of claim 21 , wherein a distance between the over-travel position and the retracted position is the same as a distance between the over-travel position and the extended position.

29 . The method of claim 21 , further comprising:
calculating a retraction distance for the first piston based on the one or more measured parameter and a desired fluid flow rate; and retracting the first piston by the calculated retraction distance to a retracted position.

30 . A method of delivering multiple fluids to a patient via a multi-phase injection with a fluid injector, comprising:
injecting a first fluid during a first phase of the injection with a first pressure limit, wherein the first fluid has a first viscosity; and injecting a second fluid during a second phase of the injection with a second pressure limit, wherein the second fluid has a second viscosity, wherein the first viscosity is greater than the second viscosity, and wherein the second pressure limit is less than the first pressure limit to minimize a flow rate fluctuation in a fluid path at a transition from the first phase to the second phase.

31 . The method of claim 30 , wherein the second pressure limit is derived from at least one of a table or an equation or pressure measured during the second phase.

32 . The method of claim 30 , wherein the injecting the second fluid during the second phase of the injection with the second pressure limit comprises injecting the second fluid at the second pressure limit for a duration of the second phase.

33 . The method of claim 30 , wherein the second pressure limit is based upon at least one parameter of the fluid delivery system, wherein the at least one parameter is selected from a group comprising fluid type, fluid viscosity, catheter size, desired flow rate, system capacitance, and system impedance.

34 . The method of claim 30 wherein the second pressure limit is determined based on a position of a piston within a syringe containing the second fluid.

35 . The method of claim 30 , further comprising:
determining a flow rate for the second fluid based on the second pressure limit.

36 . The method of claim 30 , further comprising:
pre-pressurizing the a second syringe containing the second fluid prior to injecting the second fluid.

37 . The method of claim 30 , further comprising:
applying the second pressure limit while injecting an initial amount of the second fluid; and applying the first pressure limit while injecting a remaining amount of the second fluid.

38 . The method of claim 30 , further comprising deriving a third pressure limit from at least one of a table or an equation or pressure measured during the first phase that is different from the first pressure limit and second pressure limit and then applying the second pressure limit while injecting an initial amount of the second fluid; and applying the third pressure limit while injecting a remaining amount of the second fluid.

39 . The method claim 38 , wherein the third pressure limit is based upon at least one parameter of the fluid delivery system, wherein the at least one parameter is selected from a group comprising fluid type, fluid viscosity, catheter size, desired flow rate, system capacitance, and system impedance.

40 . The method of claim 30 , further comprising:
gradually transitioning from the first pressure limit to the second pressure limit during a transition from the first phase to the second phase over a pre-determined transition time.

Assignees

• Bayer Healthcare Llc

Inventors

• Uber Iii Arthur
• Marsh Chelsea
• Barone William
• Mcdermott Michael
• Newing Timothy
• Spohn Michael
• Delbrugge Vince
• Schriver Ralph
• Cowan Kevin
• Griffiths David

Classifications

• A61M2205/3341

  stabilising pressure or flow to avoid excessive variation · CPC title

• G16H20/17

  delivered via infusion or injection · CPC title

• A61M2205/3334

  Measuring or controlling the flow rate · CPC title

• A61M5/16886

  for measuring fluid flow rate, i.e. flowmeters · CPC title

• A61M5/3221

  Constructional features thereof, e.g. to improve manipulation or functioning · CPC title