METHOD AND APPARATUS FOR INJECTING FLUID INTO THE VASCULAR SYSTEM

• US 3,631,847 A
• Filed: 03/25/1969
• Issued: 01/04/1972
• Est. Priority Date: 03/04/1966
• Status: Expired due to Term

• Current Assignee: James C. Hobbs II
• Original Assignee: James C. Hobbs II
• Inventors: Hobbs, James C. II
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US04/810,292
• Time in Patent Office: 1,015 Days
• Field of Search: 128/2,2.05,218A,218.2,218P,236,273 222/59
• US Class Current: 600/432
• CPC Class Codes: A61B 5/02755 Radioactive tracers
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/16854 by monitoring line pressure

Abstract

A method for use in the study and diagnosis of vascular systems in which liquids of a wide range of viscosities and for various purposes may be injected into such a system at constant predetermined rates and volumes. Apparatus to inject radiopaque fluid into a vascular system comprising a syringe, a plunger in the syringe, a catheter connecting the syringe to the vascular system, means to move the plunger in the syringe, and means to measure and control the speed of the plunger in the syringe throughout the period of injection.

Claims

1. The method of injecting radiopaque fluids into the vascular system of a human being which comprises the steps of:

a. placing a quantity of a radiopaque fluid in a syringe having a plunger, b. connecting one end of the syringe to a catheter to receive fluid expelled from the syringe, c. inserting the other end of the catheter into the vascular system of a human being, d. exerting sufficient force on the plunger to expel the fluid through said catheter and inject the fluid into said vascular system, and e. maintaining a preselected constant rate of injection by continuously monitoring and maintaining constant the speed of the plunger advance in the syringe during the time of injection of fluid, said monitoring being the result of a signal automatically generated by control means connected to said syringe.

2. The method set out in claim 1 in which said rate is continued for a predetermined period of time.

3. The method set out in claim 1 in which a predetermined volume of the fluid is expelled.

4. The method set out in claim 1 in which the force is repeatedly applied and interrupted so that the flow of the fluid is pulsating.

5. The method set out in claim 1 in which a signal corresponding to the predetermined rate of injection is generated and a feedback signal corresponding to the actual rate of injection is generated and the two signals are maintained in balance.

6. Apparatus for injecting radiopaque fluids into the vascular system of a mammal comprising:

a. a syringe assembly including a cylinder to contain a radiopaque fluid, a plunger movable endwise therein to expel said fluids, b. a frame assembly supporting said syringe assembly, c. a power cylinder assembly operatively connected to said frame assembly and to said plunger, d. a motive power assembly including a motor operatively connected to said power cylinder assembly for moving said plunger at a constant predetermined speed, and e. means operatively connected to said motive power assembly to generate a plunger speed-indicating signal to control the speed of the motor whereby the discharge rate of said fluid is maintained constant independently of fluid pressure variations in the syringe assembly.

7. The combination of elements set forth in claim 6 in which the power cylinder assembly includes a cylinder, a threaded rod in and connected to said cylinder and connected at one end to said motive power assembly.

8. The combination of elements set forth in claim 6 in which a stop nut is adjustably screw threaded on said plunger to limit the endwise movement of said plunger in one direction.

9. The combination of elements in claim 6 in which the frame assembly includes at least two rods on opposite sides of said syringe and having the centerlines thereof parallel to and in the same plane as the centerline of syringe to support the syringe assembly and a nut on each rod to engage and clamp the syringe assembly in place.

10. The combination of elements set forth in claim 6 in which the motive power assembly includes a variable speed direct current motor and means for controlling the speed of the said motor.

11. Apparatus for injecting fluid into a mammular vascular system comprising:

a. a syringe assembly including a cylinder to contain a fluid to be injected, a plunger therein, and an endwise movable stem connected to said plunger, b. a source of electric power, c. an electric motor operatively connected to said source and said stem, d. means operatively connected to said motor to monitor and control the speed of said motor aT a constant preselected speed while injecting said fluid by continuously varying the power supplied to the motor to maintain a predetermined rate of discharge of said fluid, e. a manually operated switch to start said motor, and f. an automatically operated switch to stop said motor.

12. The combination of elements set forth in claim 11 in which said automatically operated switch is adjustable as to location.

13. The combination of elements set forth in claim 11 in which the said automatically operated switch is a relay switch that opens when an undesirable electrical hazard is detected.

14. The combination of elements set forth in claim 11 in which said manually operated switch is connected to and energizes an auxiliary circuit for apparatus to record the distribution of said fluid in said vascular system.

15. The method of injecting radiopaque liquids into the vascular system of a human being which comprises the steps of a. exerting sufficient force on a plunger in a syringe to expel radiopaque liquid from said syringe and into such a vascular system, and b. maintaining a predetermined constant rate of injection of the liquid by continuously monitoring the forward speed of the plunger to maintain constant the speed of the plunger advance in the syringe during the time of injection of the liquid, said monitoring being the result of a signal automatically generated by control means connected to said syringe.

16. The method set out in claim 15 in which said rate is continued for a predetermined period of time.

17. The method set out in claim 15 in which a predetermined volume of the liquid is expelled.

18. The method set out in claim 15 in which the force is repeatedly applied and interrupted so that the flow of the fluid is pulsating.

19. The method set out in claim 15 in which a signal corresponding to the predetermined rate of injection is generated and a feedback signal corresponding to the actual rate of injection is generated and the two signals are maintained in balance.

20. The method of injecting radiopaque fluids into the human vascular system which comprises the steps of:

a. placing a quantity of radiopaque fluid in a motor driven syringe having a plunger, b. connecting one end of the syringe to a catheter to receive fluid expelled from the syringe, c. inserting the other end of the catheter into the human vascular system, d. generating a first signal corresponding to the desired rate of flow of said radiopaque fluid out of said syringe, e. generating a feedback signal corresponding to the actual rate of flow of said fluid, and f. combining the two said signals, said combination of signals serving to operate the motor of said motor driven syringe so that said radiopaque fluid is injected into the vascular system at a constant rate of flow.

21. The method as in claim 20 wherein said feedback signal is derived by continuously monitoring the forward plunger speed.

22. Apparatus for injecting radiopaque fluids into the vascular system of a mammal comprising:

a. a syringe assembly including a cylinder to contain a radiopaque fluid, a plunger movable endwise therein to expel said fluids, b. a casing assembly supporting said syringe assembly, c. a power cylinder assembly operatively connected to said casing assembly and to said plunger, d. a motive power assembly including a motor, operatively connected to said power cylinder assembly for moving said plunger at a constant predetermined speed, and e. means operatively connected to said power assembly to generate a plunger speed-indicating signal to control the speed of the motor whereby the discharge rate of said fluid is maintained constant independently of fluid pressure variations in the syringe assembly.

23. The apparatus as in claim 22 wherein said signal-generating means is a tachometer-generator.

24. Apparatus for injecting fluid into a mammular vascular system comprising:

a. a syringE assembly including a cylinder to contain a fluid to be injected, a plunger therein, and an endwise movable stem connected to the plunger, b. an electric motor operatively connected to said stem and adapted to be connected to a source of electricity, c. means operatively connected to said motor to monitor and control the speed of said motor at a constant preselected speed while injecting said fluid by continuously varying the power supplied to the motor to maintain a predetermined rate of discharge of said fluid, and d. means operatively connected to the motor to automatically terminate the injection when a condition dangerous to the patient exist within said apparatus.