Method for controlling fluid accuracy and backflow compensation

Patent metadata

Field	Value
Publication number	US-2018296993-A1
Application number	US-201816013050-A
Country	US
Kind code	A1
Filing date	Jun 20, 2018
Priority date	Mar 13, 2013
Publication date	Oct 18, 2018
Grant date	—

Abstract

A method for controlling fluid ratio accuracy during a dual flow injection with a powered injection system is described. The method includes predicting a first capacitance volume of a first syringe comprising a first medical fluid and a second capacitance volume of a second syringe comprising a second medical fluid with a first capacitance correction factor and a second capacitance correction factor, respectively, selecting a ratio of the first medical fluid and the second medical fluid to be administered to a patient in the dual flow injection, determining a relative acceleration ratio of a first piston of the first syringe and a second piston of a second syringe based on the predicted first capacitance volume and the predicted second capacitance volume, wherein the relative acceleration ratio is selected to maintain the selected ratio of the first medical fluid and the second medical fluid during the dual flow injection, and injecting a mixture of a first medical fluid and a second medical fluid having the selected ratio with the powered injection system.

First claim

We claim:

1 . A method for controlling fluid ratio accuracy during a dual flow injection with a powered injection system, the method comprising:
predicting a first capacitance volume of a first syringe comprising a first medical fluid and a second capacitance volume of a second syringe comprising a second medical fluid with a first capacitance correction factor and a second capacitance correction factor, respectively; selecting a ratio of the first medical fluid and the second medical fluid to be administered to a patient in the dual flow injection; determining a relative acceleration ratio of a first piston of the first syringe and a second piston of a second syringe based on the predicted first capacitance volume and the predicted second capacitance volume, wherein the relative acceleration ratio is selected to maintain the selected ratio of the first medical fluid and the second medical fluid during the dual flow injection; and injecting a mixture of a first medical fluid and a second medical fluid having the selected ratio with the powered injection system.

2 . The method of claim 1 , wherein the first medical fluid has a different viscosity than the second medical fluid.

3 . The method of claim 2 , wherein the first medical fluid has a higher viscosity than the second medical fluid.

4 . The method of claim 3 , wherein the first medical fluid is an imaging contrast agent and the second medical fluid is saline.

5 . The method of claim 4 , wherein the ratio ranges from 10:90 to 90:10 imaging contrast agent to saline.

6 . The method of claim 1 , wherein the piston of the first syringe is accelerated at an acceleration value A 1 , where the acceleration value A 1 is determined by equation (1),
A 1 =A 2 /( c ·( V 1 /V 2 ))  (1)
wherein A 2 is an acceleration value for the second syringe, c is a scalar correction factor derived from the first capacitance correction factor and the second capacitance correction factor, V 1 is a velocity of the first piston, and V 2 is a velocity of the second piston.

7 . The method of claim 6 , wherein A 2 is the maximum acceleration value of the second piston.

8 . The method of claim 1 , wherein the injection system further comprises a first tubing set connected to a distal end of the first syringe and a second tubing set connected to a distal end of the second syringe.

9 . The method of claim 8 , wherein the backflow volume of the first medical fluid into the second tubing set is less than 0.5 mL.

10 . A flow mixing device configured for use within a fluid path between a fluid injector and a fluid line connected to a patient, the flow mixing device comprising:
a housing having a proximal end opposite a distal end, the housing comprising a first portion and a second portion; a first fluid port provided at the proximal end for receiving a first injection fluid; a second fluid port provided at the proximal end for receiving a second injection fluid; a first orifice at the distal end of the first fluid port and a second orifice at the distal end of the second fluid port, wherein the first orifice has a reduced cross section relative to the second orifice; a mixing chamber disposed within the housing between the proximal end and the distal end for mixing the first and second injection fluids, the mixing chamber being in fluid communication with the first and second fluid ports, by way of the first orifice and second orifice, respectively; and a third fluid port provided at the distal end and in fluid communication with the mixing chamber for discharging a mixed solution of the first and second injection fluids.

11 . The flow mixing device of claim 10 , wherein the first injection fluid has a Reynolds number of greater than 4000 after passing through the first orifice.

12 . The flow mixing device of claim 11 , wherein the first injection fluid has a laminar flow before passing through the first orifice and has a turbulent flow after passing through the first orifice.

13 . The flow mixing device of claim 11 , wherein the second injection fluid has a laminar flow after passing through the second orifice.

14 . The flow mixing device of claim 10 , wherein the reduced cross section of the first orifice offsets any backflow of the first injection fluid when injecting a ratio of fluid having more than 50% of the second injection fluid that is more viscous than the first injection fluid.

15 . The flow mixing device of claim 10 , wherein the mixing chamber is adapted to eliminate zones of stagnant fluid flow.

16 . The flow mixing device of claim 10 , wherein the first portion and a second portion of the housing are joined together at a seam extending around an outer perimeter of lateral sides of the first portion and the second portion.

17 . The flow mixing device of claim 10 , further comprising a turbulent flow inducing member disposed within the mixing chamber for promoting turbulent mixing of the first and second injection fluids.

18 . The flow mixing device of claim 10 , wherein the flow mixing device is formed from a medical-grade plastic material having sufficient rigidity to prevent expansion of the housing during an injection procedure.

19 . The flow mixing device of claim 18 , wherein the housing retains its shape without appreciable expansion at an injection pressure of 1200 psi.

20 . The flow mixing device of claim 10 , wherein the first fluid port and the second fluid port are angled relative to the longitudinal axis of the flow mixing device so the fluid flow of the first injection fluid and the second injection fluid converges or diverges relative to the longitudinal axis.

Assignees

• Bayer Healthcare Llc

Inventors

• Schriver Ralph H
• Maihoefer Andreas
• Dedig James A
• Spohn Michael A
• Grubic Herbert M
• Swantner Michael J
• Caruso Adam

Classifications

• A61M2206/16

  Rotating swirling helical flow, e.g. by tangential inflows · CPC title

• B01F2215/0468

  Numerical pressure values · CPC title

• A61M2039/0027

  for mixing several substances from different containers · CPC title

• A61M5/16827

  controlling delivery of multiple fluids, e.g. sequencing, mixing or via separate flow-paths (infusion of multiple fluids without using a controller A61M5/1407) · CPC title

• A61M2206/14

  Static flow deviators in tubes disturbing laminar flow in tubes, e.g. archimedes screws · CPC title