Syringe plunger driver system

• US 20030229311A1
• Filed: 06/05/2002
• Published: 12/11/2003
• Est. Priority Date: 06/05/2002
• Status: Active Grant

• Current Assignee: Carefusion 303 Incorporated (Becton, Dickinson & Co)
• Original Assignee: Cardinal Health 303 Incorporated (Cardinal Health, Inc.)
• Inventors: G. Morris, Matthew, Kasvikis, Spyros, Schwartz, Donald F.
• Granted Patent: US 7,150,724 B2
• Time in Patent Office: Days
• US Class Current: 604/151
• CPC Class Codes: A61M 2202/0007 introduced into the body
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• 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
• CPC Class Codes: A61M 5/1458 Means for capture of the plunger flange
• CPC Class Codes: Y10T 29/49769 Using optical instrument [excludes mere human eyeballing]
• CPC Class Codes: Y10T 29/49771 Quantitative measuring or gauging
• CPC Class Codes: Y10T 29/49776 Pressure, force, or weight determining
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A syringe plunger driver system capable of capturing syringes of widely varying sizes comprises a pair of asymmetric plunger retainer arms pivotally mounted to a plunger driver. The system includes a low profile driver having a length that exceeds its width so that it may be mounted adjacent control modules and other operational modules. The arms are biased toward each other and one arm is longer than the other with a notch on an inside edge to receive the tip of the shorter arm when capturing small syringe flanges. A rotation knob mounted to the front surface of the low profile driver forces the arms apart when rotated to a first rotation position. A force sensor is mounted in the driver to detect occlusions in the fluid line. A processor monitors the force sensed by the force sensor and provides an alarm if the force exceeds a threshold. The driver includes a force concentrator that defines a pushing surface adapted to press against a plunger flange so that the force applied to the plunger flange is concentrated at a defined location for more accurate measurement.

Claims

1. A syringe plunger driver system for engaging syringe plungers of different sizes, each plunger having a plunger piston, a plunger flange, and a plunger stem interconnecting the piston with the flange, and each plunger forming a part of a syringe, each syringe having a barrel in which the plunger moves, each plunger flange having an inner side facing the syringe barrel and an outer side, the syringe plunger driver system having a plunger driver adapted to move the syringe plunger into the syringe barrel in an operation mode, the syringe plunger driver system comprising:

a pushing surface located on the plunger driver adapted to press against the outer side of the plunger flange to move the flange toward the barrel during the operation mode;

a plunger retainer located on the plunger driver adapted to capture the plunger of the syringe, the plunger retainer comprising;

a first arm mounted on the plunger driver; and

a second arm mounted on the plunger driver at a location spaced-apart from the first arm, said first and second arms being asymmetric; and

a bias device connected with the first and second arms to bias the arms toward each other to capture the plunger flange between the first and second arms.

2. The syringe plunger driver system of claim 1 wherein the first and second arms have inside edges facing each other and the first arm comprises a notch on its inside edge for receiving a tip of the second arm.

3. The syringe plunger driver system of claim 2 wherein the arms are pivotally mounted to the plunger driver in selected locations such that the bias device will move the tip of the second arm into the notch of the first arm when no flange is present between the first and second arms.

4. The syringe plunger driver system of claim 3 wherein the first arm has a first length and the second arm has a second length, the second length being shorter than the first length, and wherein the first and second arms are pivotally mounted to the plunger driver such that when a flange is properly positioned at the plunger driver in preparation for the operation mode the arms will be equidistantly spaced from the flange on either side of the flange.

5. The syringe plunger driver system of claim 4 wherein the inside edge of each of the first and second arms comprises an anti-siphon ledge configured to engage the inner side of the plunger flange to restrain the plunger flange from movement toward the syringe barrel.

6. The syringe plunger driver system of claim 1 wherein the first and second arms are pivotally mounted to the plunger driver at positions that are equidistant from a location where a syringe plunger flange would be properly mounted to the plunger driver in the operation mode, the first and second arms having different lengths with the longer arm having a notch formed on its inside edge for receiving a tip of the shorter arm when the first and second arms are brought toward each other by the bias device.

7. The syringe plunger driver system of claim 6 wherein the first and second arms are curved inwardly, whereby the first and second arms are adapted to capture syringe plunger flanges of different sizes.

8. The syringe plunger driver system of claim 1 wherein the plunger driver has a rear surface that is mounted to a guide device that controls the movement of the plunger driver to be parallel with the plunger stem, the plunger driver having a front surface opposite the rear surface and defining a length of the plunger driver between the front and rear surfaces, and two lateral surfaces located between the front and rear surfaces, the lateral surfaces defining a width of the plunger driver, the length of the plunger driver being longer than the width.

9. The syringe plunger driver system of claim 8 further comprising a control device mounted to the rear surface of the plunger driver and interconnected with the first and second arms, the control device having a first position at which it moves the first and second arms outwardly into a syringe plunger non-engagement position in opposition to the bias device to permit easy loading of the syringe plunger flange to the plunger driver, and a second position at which the control device permits the first and second arms to capture the syringe plunger flange.

10. The syringe plunger driver system of claim 9 wherein the control device comprises a rotation knob having a first rotation position at which it moves the first and second arms outwardly into the syringe plunger non-engagement position in opposition to the first bias device, and a second rotation position at which the rotation knob does not prevent the first and second arms from capturing the syringe plunger flange.

11. The syringe plunger driver system of claim 1 wherein the bias device comprises a spring connected with the plunger retainer that biases the arms pivotally inward towards each other, the spring having enough force to retain a plunger flange in between the arms during the operation mode.

12. The syringe plunger driver system of claim 1 further comprising a force detector located in the plunger driver and adapted to sense force exerted by the pushing surface against the plunger flange, the force detector outputting a force signal representative of the force exerted against the plunger flange.

13. The syringe plunger driver system of claim 12 wherein the force detector is in contact with the pushing surface.

14. The syringe plunger driver system of claim 13 wherein the pushing surface comprises a movable flange contact plate.

15. The syringe plunger driver system of claim 14 wherein the movable flange contact plate is pivotally mounted.

16. The syringe plunger driver system of claim 12 further comprising a processor in communication with the force signal that compares the force signal against a threshold and provides an alarm signal if the force signal exceeds the threshold.

17. The syringe plunger driver system of claim 12 wherein the plunger driver includes a force concentrator that defines the pushing surface, whereby the force exerted against the plunger flange is concentrated on the pushing surface of the force concentrator so that the force detector can accurately sense the force exerted.

18. A syringe plunger driver system for accurately detecting force exerted against a syringe plunger, each plunger having a plunger piston, a plunger flange, and a plunger stem interconnecting the piston with the flange, and each plunger forming a part of a syringe, each syringe having a barrel in which the plunger moves, each plunger flange having an inner side facing the syringe barrel and an outer side, the syringe plunger driver system having a plunger driver adapted to move the syringe plunger into the syringe barrel in an operation mode, the syringe plunger driver system comprising:

a force concentrator located on the plunger driver that defines a pushing surface adapted to press against the outer side of the plunger flange to move the flange toward the barrel during the operation mode, whereby the force exerted against the plunger flange in operation mode is concentrated at the pushing surface of the force concentrator so that the force may be accurately detected;

a force detector located in the plunger driver and adapted to sense force exerted by the pushing surface against the plunger flange, the force detector outputting a force signal representative of the force exerted against the plunger flange;

a plunger retainer located on the plunger driver adapted to capture the plunger of the syringe; and

a bias device connected with the plunger retainer to bias the plunger retainer into contact with the plunger flange.

19. The syringe plunger driver system of claim 18 wherein the force concentrator is located on a movable flange contact plate.

20. The syringe plunger driver system of claim 19 wherein the movable flange contact plate is pivotally mounted.

21. The syringe plunger driver system of claim 18 further comprising a processor in communication with the force signal that compares the force signal against a threshold and provides an alarm signal if the force signal exceeds the threshold.

22. A method for capturing syringe plungers of different sizes at a plunger driver, each plunger having a plunger piston, a plunger flange, and a plunger stem interconnecting the piston with the flange, wherein each plunger forms a part of a syringe, each syringe having a barrel in which the plunger moves, each plunger flange having an inner side facing the syringe barrel and an outer side, the plunger driver adapted to move the syringe plunger into the syringe barrel in an operation mode, the method comprising the steps of:

opening first and second asymmetric arms mounted to the plunger driver away from each other far enough to permit easy loading of a syringe plunger to the plunger driver; and

after a syringe plunger has been properly positioned in relation to the plunger driver, closing the first and second arms inward toward each other to capture the syringe plunger flange between the first and second arms.

23. The method of claim 22 wherein the step of closing the arms comprises the step of closing the first and second arms inward toward each other such that a tip of one of the arms moves into a notch on an inside edge of the other of the arms so that a syringe plunger flange of a relatively small size may be captured by the first and second arms.

24. The method of claim 22 wherein the step of opening first and second asymmetric arms further comprises the step of rotating a rotation knob interconnected with the first and second arms to a first rotation position at which the rotation knob pivotally moves the first and second arms outward into a syringe plunger non-engagement position whereby easy loading of a syringe plunger in relation to the plunger driver is facilitated.

25. The method of claim 24 wherein the step of closing the first and second arms inward toward each other comprises the steps of:

applying a biasing force to the first and second arms to bias them inward toward each other; and

moving the rotation knob to a second rotation position at which the rotation knob does not apply force opposing the biasing devices on the first and second arms so that the arms may move toward each other to capture a syringe plunger.