Automated means for withdrawing a syringe plunger

• US 20040103951A1
• Filed: 06/05/2003
• Published: 06/03/2004
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Baxter Corporation Englewood (Baxter International Inc.)
• Original Assignee: Forhealth Technologies Incorporated (Baxter International Inc.)
• Inventors: Osborne, Joel A., Tribble, Dennis, Aven, William C.
• Granted Patent: US 6,877,530 B2
• Time in Patent Office: Days
• US Class Current: 141/27
• CPC Class Codes: A61M 2005/3114 Filling or refilling
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 2209/045 for filling, e.g. for filling reservoirs
• CPC Class Codes: B65B 3/003 Filling medical containers such as ampoules, vials, syringes or the like
• CPC Class Codes: B65B 7/2821 applying plugs or threadless stoppers for bottles or jars B67B1/04

Abstract

In one exemplary embodiment, an automated means for withdrawing a syringe plunger a method for just-in-time extension of the plunger to permit filling the syringe with a prescribed dose of medication are provided. The method includes the steps of: (1) inputting a desired volume of the prescribed dose of medication; (2) inputting syringe identifying information; (3) calculating a distance that the plunger is to be extended based on the inputted desired volume and syringe identifying information; (4) calculating drive parameters for a controllable drive that causes extension of the plunger when actuated and ensures that the plunger is extended the desired distance; and (5) controlling the drive in view of the calculated drive parameters to cause the plunger to be extended the desired distance.

Claims

1. An automated device for extending a plunger of a syringe a defined distance within a syringe barrel based upon inputted syringe information, the device comprising:

a housing;

an adjustable plunger extension mechanism that includes a movable component that intimately engages the plunger so that movement of the component is translated into extension of the plunger, the component including a controllable drive that moves the component the defined distance; and

a controller that receives the inputted syringe information and calculates the defined distance that the plunger is moved based on the inputted syringe information and instructs the controllable drive to move the plunger the defined distance.

2. The automated device of claim 1, further including:

a sensor device that signals a controller when the component reaches one end of its permitted path of travel, the controller in communication with the controllable drive to instruct the drive to cease moving the component in a specific direction when the component reaches one end of its permitted path of travel.

3. The automated device of claim 1, wherein the adjustable plunger extension mechanism includes a support frame, a carrier that moves linearly therealong and includes a pair of arms that engage the plunger.

4. The automated device of claim 1, wherein the controllable drive comprises a servo motor and a screw drive mechanism that is operatively coupled to the carrier so that actuation of the servo motor is translated into movement of a drive spindle of the screw drive mechanism which in turn causes movement of the component.

5. The automated device of claim 4, wherein the servo motor rotates in a first direction and in a second opposite direction such that rotation in the first direction causes the component to move linearly in a first direction and rotation in the second direction causes the component to move linearly in a second direction.

6. The automated device of claim 1, wherein the controllable drive comprises a servo motor whose actuation causes the servo motor to go through a predetermined number of steps.

7. The automated device of claim 6, wherein the controller is operatively connected to the servo motor and sends a control signal to the servo motor to instruct the servo motor to go through a predetermined number of steps, wherein there is a correlation between the number of steps and the defined distance that the component is driven which in turn represents the defined distance that the plunger is extended creating a volume within the syringe to accept a prescribed volume of medication.

8. The automated device of claim 7, wherein the inputted syringe information includes a syringe type, a barrel diameter, and a desired dose volume of medication to be filled into the syringe, wherein the controller calculates the defined distance that the plunger needs to be extended based upon the inputted syringe information and then calculates the number of steps that the servo motor is driven through in order to extend the plunger the defined distance.

9. The automated device of claim 1, wherein the component includes first and second verticals walls that one connected at end thereof, the vertical walls being parallel to one another and spaced apart from one another, wherein other ends of the vertical walls include features for intimately engaging the plunger to cause the extension thereof when the component is moved linearly.

10. The automated device of claim 9, wherein the features comprise a pair of flange members disposed at the other ends of the vertical walls, each flange member extending beyond the vertical wall and into a space between the two parallel vertical walls so as to overhang the vertical wall, wherein a diameter of the plunger is less than a distance between the two spaced vertical walls but greater than a distance between the flange members so that the flange members grip and engage a lip of the plunger and cause the extension of the plunger.

11. The automated device of claim 10, wherein the component travels from a starting position in which the component is in a raised position and a lowered position where the component has traveled away from the raised position, the plunger being received within the space between the vertical walls in the starting position with the lip of the plunger being proximate to or seated against the flange members and wherein movement of the component from the starting position to the lowered position extends the plunger the desired defined distance prior to the syringe being removed from the automated device.

12. The automated device of claim 2, wherein the sensor device includes a first sensor fixed at a first location at one end of the permitted length of travel for the component and a second sensor fixed to a second location at the other end of the permitted length of travel, the sensors being constructed so that they detect the presence of the movable component.

13. The automated device of claim 12, wherein each of the first and second sensors comprises a U-shaped bracket sensor that emits a beam across two arms thereof with a section of the movable component being received between the two arms so as to impinge the beam and trigger the sensor device to send a control signal to a controller that is operatively coupled to the controllable drive.

14. The automated device of claim 13, wherein the section of the movable component that is received between the two arms is a flag that is coupled to the component and extends outwardly therefrom.

15. The automated device of claim 13, wherein the first and second sensors are linearly aligned and spaced apart from one another, the first sensor representing an upper limit of the path of travel of the component, the second sensor representing a lower limit of the path of travel of the component.

16. An automated syringe preparation mechanism for an automated medication preparation system, the mechanism comprising:

a first automated gripping means for removing a tip cap from a barrel of one syringe and placing the removed tip cap at a first location;

an automated device for delivering a prescribed dosage amount of medication to the syringe by injecting the medication through the uncapped barrel in a just-in-time for use manner; and

a second automated gripping means for replacing the removed tip cap on the syringe barrel after the medication is injected therein.

17. The automated syringe preparation mechanism of claim 16, wherein the first automated gripping means is a robotic device having first and second gripping arms that are spaced apart from one another in a first position and are moved toward one another to a second position so as to securely capture and hold the tip cap between the first and second gripping arms.

18. The automated syringe preparation mechanism of claim 16, wherein the robotic device is movable at least along an x axis and a y axis.

19. The automated syringe preparation mechanism of claim 16, wherein the first location is proximate to a location where the syringe barrel is held and is radially inward from the associated syringe.

20. The automated syringe preparation mechanism of claim 16, further including:

an automated device for extending a plunger of the syringe barrel.

21. The automated syringe preparation mechanism of claim 20, wherein the automated device is operatively connected to a control unit which instructs the automated device to extend the plunger a defined distance based in part on the prescribed amount of medication to be injected into the barrel.

22. The automated syringe preparation mechanism of claim 16, wherein the automated medication preparation system includes an automated rotary device that is indexed to advance the syringe from one station to another station, the rotary device having a first feature formed as part thereof for releasably retaining the syringe and a second feature for holding the removed tip cap as the syringe is advanced from one station to the next.

23. The automated syringe preparation mechanism of claim 16, wherein the automated device for delivering a prescribed dosage amount of medication to the syringe comprises a robotic device having a pivotable arm that includes a platform section having a first face and an opposing second face, a cannula extending through the platform away from the first face for receiving the medication from a supply, the cannula being operatively connected to an apparatus that draws the medication from the supply into the cannula when actuated.

24. The automated syringe preparation mechanism of claim 23, wherein the cannula is coupled to a flexible conduit that extends outwardly from the second face of the platform and is operatively connected to the apparatus.

25. The automated syringe preparation mechanism of claim 23, wherein the apparatus comprises an aspirating device that applies negative pressure to an interior of the cannula to cause the medication to be drawn from the supply to the cannula.

26. The automated syringe preparation mechanism of claim 23, further including:

a sensor for detecting when the cannula is aligned with the uncapped syringe body to ensure that the cannula is received cleanly within an interior of the syringe barrel.

27. A method for just-in-time removal of a tip cap from a syringe barrel, filling the syringe with a prescribed dose of medication and replacing the tip cap on the syringe barrel, the method including the steps of:

securing the syringe barrel to a device of an automated preparation system;

gripping and removing the tip cap from the syringe barrel to open up an interior of the syringe barrel and placing the removed tip cap at a first location;

extending a plunger a defined distance within the syringe barrel based in part upon a volume of the prescribed dose;

delivering the prescribed dose to the interior of the syringe barrel through the open syringe barrel;

gripping the removed tip cap at the first location and moving it to the syringe barrel containing the prescribed dose; and

replacing the tip cap on the syringe barrel.

28. The method of claim 27, wherein the step of securing the syringe barrel comprises the step of:

releasably holding the syringe barrel about a rotary device that advances the syringe from one station to a next station.

29. The method of claim 27, wherein the step of delivering the prescribed dose comprises the steps of:

providing a robotic device having an arm that is positioned between first and second positions, wherein the arm has a section including a cannula;

connecting the cannula to an apparatus that draws the prescribed dose from a medication supply to the cannula when the apparatus is actuated and the arm is in the first position;

moving the robotic arm to the second position; and

injecting the prescribed dose into the syringe body through an entrance port created when the tip cap is removed.

30. The method of claim 29, wherein in the first position, the cannula extends upwardly away from the arm and in the second position, the cannula extends downwardly away from the arm.

31. The method of claim 29, wherein the apparatus aspirates the prescribed dose from the medication supply.

32. A method for just-in-time extension of a plunger of a syringe to permit filling the syringe with a prescribed dose of medication, the method including the steps of:

inputting a desired volume of the prescribed dose of medication;

inputting syringe identifying information;

calculating a distance that the plunger is to be extended based on the inputted desired volume and syringe identifying information;

calculating drive parameters for a controllable drive that causes extension of the plunger when actuated and ensures that the plunger is extended the desired distance; and

controlling the drive in view of the calculated drive parameters to cause the plunger to be extended the desired distance.

33. The method of claim 32, wherein the syringe identifying information includes a barrel diameter of the syringe.

34. The method of claim 32, wherein the syringe identifying information includes make and model information a selected syringe.

35. The method of claim 32, wherein the step of calculating the distance that the plunger is extended includes the steps of:

determining the volume of a medication receiving space formed in a syringe barrel as the plunger is extended; and

calculating based upon a diameter of the syringe barrel the distance that the plunger is to be extended so that the volume of the medication receiving space at least equals the inputted desired volume of the dose of medication.

36. The method of claim 32, wherein the controllable drive comprises a servo motor and the step of calculating drive parameters includes the step of:

calculating a number of steps through which the drive is to be driven to cause the plunger to be extended the calculated distance, wherein there is a correlation between the number of steps through which the drive is driven and the distance that the plunger is extended.

37. The method of claim 36, wherein the servo motor is operatively connected to a component by a screw drive mechanism, the component engaging the plunger and whose movement is translated into extension of the plunger.

38. The method of claim 32, further including the steps of:

inputting an overfill volume amount that is added to the desired volume of the prescribed dose of medication to yield a modified volume dosage;

calculating a distance that the plunger is to be extended based on the modified volume dosage;

calculating drive parameters for a controllable drive that causes extension of the plunger when actuated and ensures that the plunger is extended the calculated distance; and

controlling the drive in view of the calculated drive parameters to cause the plunger to be extended the calculated distance which includes an overdraw volume so that contents do not splash out of the syringe when filling.

39. An automated device for extending a plunger of a syringe a defined distance within a syringe barrel, the device comprising:

a housing;

an adjustable plunger extension mechanism that includes a movable component that intimately engages the plunger so that movement of the component is translated into extension of the plunger; and

an input for inputting syringe specific information that is used in part to calculate the defined distance the plunger is extended; and

a controller that receives the inputted syringe information and calculates the defined distance that the plunger is moved based on the inputted syringe information and determines drive parameters that are delivered to a drive that is operatively connected to the movable component to cause the plunger to be moved the defined distance.

40. The automated device of claim 39, wherein the drive comprises a servo motor and one of the drive parameters is a number of steps through which the servo motor is to be driven to cause the plunger to be extended the defined distance, wherein there is a correlation between the number of steps through which the drive is driven and the distance that the plunger is extended.

41. The automated device of claim 39, wherein the controller calculates the defined distance based in part upon a volume of the prescribed dose and a diameter of the syringe barrel so that the plunger is extended sufficiently to form a space that has a volume that at least equals the volume of the prescribed dose of medication.