Medical liquid injection system and method

• US 6,520,928 B1
• Filed: 08/19/1999
• Issued: 02/18/2003
• Est. Priority Date: 08/19/1999
• Status: Expired due to Term

• Current Assignee: Alceu Meibach Rosa Junior
• Original Assignee: Alceu Meibach Rosa Junior
• Inventors: Junior, Alceu Meibach Rosa
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US09/377,470
• Time in Patent Office: 1,279 Days
• Field of Search: 604/30, 604/67, 604/150-153, 604/131, 604/140, 604/181, 604/182, 604/245
• US Class Current: 604/30
• CPC Class Codes: A61M 2202/0241 Anaesthetics; Analgesics
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/1456 with a replaceable reservoir comprising a piston rod to be moved into the reservoir, e.g. the piston rod is part of the removable reservoir

Abstract

A novel device and method for the efficient, regular and highly maneuverability administration of medical liquids, especially anesthetics. The system of the present invention includes a light-weight, hand-held injection device which is connected to an operating pedal and a control unit. The control unit stores a number of preprogrammed injection procedures having specific injection flow rates and volumes, and provides the user with the ability to create and store a plurality of user-defined procedures. The control unit and injector allow precise selection, control and monitoring of the injection flow rate and volume. The operating pedal provides “hands-free” control of the procedures, as well as a means to select various sub-procedures, such as an Aspiration mode, Introduction mode, or Preparation mode, in addition to the Injection mode.

Claims

1. A medical liquid injection system, comprising:

a hand-held injection device having a motor, a cartridge case for holding a medical liquid cartridge, a needle, and means, connected to said motor, for expelling liquid from said cartridge through said needle;

a foot-operable pedal connected to said injection device for controlling the operation of said motor;

a control unit connected to said foot-operable pedal for selecting or programming injection procedures;

said injection system having a preparation mode for calibration of said cartridge, an introduction mode for advancing said needle to a desired location, an aspiration mode for detecting and preventing intravenous injection of the medical liquid, and an injection mode for delivering the medical liquid to the desired location;

said preparation, introduction, aspiration, and injection modes being independently selectable by depressing said foot-operated pedal in discrete directions. operable during a continuous depression of said foot-operable pedal in a predetermined direction and ceasing upon release of said foot-operable pedal.

2. A medical liquid injection system as in claim 1, wherein during said preparation, introduction, aspiration and injection modes, said control unit displays a textual or graphical current mode message indicating to the user the current mode in operation.

3. A medical liquid injection system as in claim 1, wherein, in said preparation mode, said motor operates in a direction to expel liquid from said cartridge at a predetermined relatively low flow rate, said preparation mode being operable during a continuous depression of said foot-operable pedal in a predetermined direction and ceasing upon release of said foot-operable pedal.

4. A medical liquid injection system as in claim 1, wherein in said introduction mode:

said motor operates in a direction to expel liquid from said cartridge;

said motor operates at a first, relatively high rate, for a first predetermined period of time and operates at a second, relative d predetermined period of time;

said control unit emits a sonorous signal during said operation of said motor at said second rate;

said motion alternates between said first and second rates for the duration of the introduction mode to deliver an optimal amount of the medical liquid at an optimal rate thereby allowing the liquid to penetrate the tissue surrounding the needle without stressing the nerves, to avoid pain without causing undesirable numbness, or over dosage.

5. A medical liquid injection system as in claim 4, wherein during operation of said motor at said second rate during said introduction mode, said control unit displays a warning message suitable to direct the user to cease advancing said needle.

6. A medical liquid injection system as in claim 4, wherein said introduction mode continues during depression of said foot-operable pedal in a predetermined direction and ceases upon release of said foot-operable pedal.

7. A medical liquid injection system as in claim 1, wherein, in said aspiration mode:

said motor operates in a direction to withdraw a predetermined amount of liquid into said cartridge, at a relatively low rate, pauses for a predetermined period, and then operates in an opposite direction, to expel an amount of liquid from said cartridge equal to said predetermined amount withdrawn, so the injection process can be continued.

8. A medical liquid injection system as in claim 7, wherein said aspiration mode is activated by transient depression of said foot-operable pedal in a predetermined direction.

9. A medical liquid injection system as in claim 8, wherein said foot-operable pedal need not be operated for the duration of said aspiration mode.

10. A medical liquid injection system as in claim 7, wherein, during said aspiration mode, said control unit emits a sonorous warning signal.

11. A medical liquid injection system as in claim 10, wherein, during said aspiration mode, said control unit displays a warning message suitable to direct the user to cease advancing the needle.

12. A medical liquid injection system as in claim 1, wherein, in said injection mode, said motor operates in a direction to expel liquid from said cartridge and said control unit emits a sonorous signal after each of a predetermined volume of liquid is ejected from said cartridge.

13. A medical liquid injection system as in claim 12, wherein, after each predetermined volume of liquid is ejected from said cartridge, said control unit displays a visual signal.

14. A medical liquid injection system as in claim 1, wherein:

said medical liquid injection system has a fully operational mode wherein said control unit is connected to said foot-operable pedal and wherein a plurality of injection rates and injection volumes are independently selectable through said control unit; and

said medical liquid injection system has a limited operational mode wherein said foot-operable pedal is solely used to operate said injection system and wherein only discrete, matched pairs of injection rates and injection volumes are selectable through said foot-operable pedal.

15. A medical liquid injection system as in claim 14, wherein, in said limited operation mode, said discrete, matched pairs of injection rates and injection volumes are selectable by depressing said foot-operable pedal in discrete directions.

16. The medical liquid injection system of claim 1, wherein:

said injection system having an injection mode where said control unit emits sonorous signals after predetermined increments of said liquid are expelled from said needle.

17. A medical liquid injection system as in claim 16, wherein said control unit includes a display which displays a total current injected volume expelled from said needle.

18. A medical liquid injection system as in claim 17, wherein said control unit displays a textual or graphic final dosage message when a total injected volume reaches a predetermined desired total injected volume.

19. A medical liquid injection system as in claim 1, wherein:

said injection device includes a piston for ejecting the medical liquid from said cartridge and means for sensing a velocity of said piston; and

said foot-operable pedal includes means for monitoring said velocity of said piston and for altering a rate of rotation of said motor to achieve and maintain a desired injection rate.

20. A medical liquid injection system as in claim 19, wherein said means to monitor the velocity of said piston comprises means to detect a rate of rotation of said motor.

21. A medical liquid injection system as in claim 20, wherein said means to detect the rate of rotation of said motor comprises:

a wheel connected to said motor, said wheel including a plurality of regularly angularly-spaced apertures; and

an optical sensor for detecting passage of said apertures.

22. A medical liquid injection system as in claim 21, wherein aid optical sensor is connected to said means, in said foot-operable pedal, for monitoring said velocity and position of said piston and for altering said rate of rotation of said motor, thereby providing for monitoring and adjustment of an injection rate and a total injected volume.

23. A medical liquid injection system as in claim 1, wherein:

said hand-held liquid injection device has a body portion;

said liquid injector device includes means to rotate said cartridge case, said needle and said cartridge, independently of said body portion of said injection device, to allow desired orientation of said inclined tip of said needle without movement of said body portion of said injection device.

24. A medical liquid injection system as in claim 1, wherein said foot-operable pedal for controlling certain aspects of an injection procedure comprises:

a base;

a foot pad for engaging a foot of a user;

said foot pad being pivotally connected to said base and being pivotal about two substantially orthogonal axes;

means to detect pivoting said foot pad about each of said two substantially orthogonal axes;

means to transmit control signals to an injection device responsive to pivoting of said foot pad.

25. A medical liquid injection system as in claim 24, wherein said means to detect pivoting of said foot pad about said two substantially orthogonal axes comprises two pairs of opposed motion sensors located below said foot pad, each motion sensor being located opposite said pivotal connection between said foot pad and said base with respect an associated motion sensor, and each pair of motion sensors being aligned along one of said substantially orthogonal axes.

26. A medical liquid injection system as in claim 1, further comprising:

a harpoon for threading into a stopper of said medical liquid cartridge, said harpoon having a threaded end and a shaft having a non-circular cross section;

an assembly device for attaching said harpoon to the stopper of the medical liquid cartridge, said assembly device including;

a harpoon seat having a tubular first end and having a recess in said first end, said recess having a non-circular cross section and being sized and shaped for closely receiving said shaft of said harpoon;

a cartridge support having a through opening with first and second tubular portions, said first tubular portion being sized and shaped to closely receive said first tubular end of said harpoon seat, said second tubular portion having a diameter less than a diameter of said first tubular portion forming an abutment wall there between; and

whereby said harpoon can be reliably fixedly engaged with the stopper of the cartridge by inserting said shaft of said harpoon into said recess of said harpoon seat, inserting said first tubular end of said harpoon seat into said first tubular end of said cartridge support until said harpoon seat engages said abutment wall, inserting the cartridge into said cartridge support until the rubber stopper thereof contacts said threaded end of said harpoon, and rotating said cartridge and said cartridge support relative to said harpoon seat while applying compressive pressure.

27. A medical liquid injection system as in claim 26, wherein said harpoon includes a collar between said shaft and said threaded end to limit an amount by which said harpoon can be threaded into the rubber stopper.

28. A medical liquid injection system as in claim 1, wherein said injection device has thermal and hydraulic sealing components permitting the injector to be cleaned and sterilized in a convention manner.