Automated means for withdrawing a syringe plunger

• US 6,877,530 B2
• Filed: 06/05/2003
• Issued: 04/12/2005
• Est. Priority Date: 12/03/2002
• Status: Expired due to Fees

• 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.
• Primary Examiner(s): MAUST, TIMOTHY LEWIS
• Application Number:
  US10/457,066
• Publication Number:
  US 20040103951A1
• Time in Patent Office: 677 Days
• Field of Search: 141/2, 141/18, 141/21, 141/25, 141/27, 141/94, 141/95, 141/192, 141/198, 141/391, 141/330, 604/416
• 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;

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; and

a sensor device for monitoring a length of travel of the movable component, the sensor device being independent and stationary relative to the movable component.

2. The automated device of claim 1, wherein the sensor device signals the 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 are 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. 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;

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; and

a sensor device that signals the 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, 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 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, wherein the inputted syringe information includes a variable fluid volume overfill value that factors into the calculation of the defined distance.

17. The automated device of claim 16, 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.

18. The automated device of claim 16, 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.

19. 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, wherein the inputted syringe information includes an overdraw value that is added to an inputted dose volume to form a total fluid volume that is used as a basis for calculating the defined distance.

20. The automated device of claim 19, wherein the overdraw value comprises a volume of an air gap to be added to the syringe barrel to assist in filling of the syringe barrel.