REDUCING CYLINDER WEAR IN A DRUG PUMP

• US 20080286132A1
• Filed: 05/16/2007
• Published: 11/20/2008
• Est. Priority Date: 05/16/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Mezera, Ronald L., Haase, James M., Whitehead, Nicholas R.
• Granted Patent: US 7,798,789 B2
• Time in Patent Office: Days
• US Class Current: 417/413.1
• CPC Class Codes: A61M 2205/103 rotating
• CPC Class Codes: A61M 2205/106 reciprocating
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: F04B 17/048 the fluid flowing around the moving part of the motor

Abstract

The present invention relates to a method and related apparatus for rotating a piston of a drug pump during the pumping stroke to reduce drug pump wear. The actuator may move a piston that pumps fluid through a pumping channel. In the present invention, the armature includes one or more openings or shapes that cause the actuator, including the armature and the piston, to rotate about a longitudinal axis of the piston during the pumping stroke. Rotation of the actuator member may help to reduce wear to the actuator member and the pump itself caused by repetitive pumping motions.

Claims

1. An actuator member for a fluid pumping device comprising:

an armature portion;

a piston portion operably connected to the armature portion; and

one or more openings formed through the armature portion at an angle whereby when a fluid flows through the openings the actuator member rotates about an axis represented by the piston.

2. The apparatus of claim 1 wherein the openings are generally circular.

3. The apparatus of claim 1 wherein the openings are ovoid.

4. The apparatus of claim 1 wherein armature portion further comprises a number of different blades.

5. The apparatus of claim 1 wherein actuator is made of an material with a high magnetic permeability.

6. The apparatus of claim 1 wherein the actuator is generally rigid.

7. The apparatus of claim 1 wherein the actuator is formed of one or more of ferrous materials or ferritic stainless steel.

8. An actuator for delivering fluid through a piston channel from an inlet to an outlet, the actuator comprising:

an armature configured to move between a first position and a second position, the armature including one or more contours formed in the armature; and

a piston coupled to the armature and moveable within the piston channel,

whereby movement of the armature and piston from the first position to the second position causes the actuator to rotate around a longitudinal axis of the piston.

9. The apparatus of claim 8 wherein the contours are formed in a bottom surface of the armature.

10. The apparatus of claim 8 wherein the contours are formed along the outer edge of the armature.

11. The apparatus of claim 8 wherein armature portion further comprises a number of different blades.

12. The apparatus of claim 8 wherein actuator is made of a material with a high magnetic permeability.

13. The apparatus of claim 8 wherein the actuator is generally rigid.

14. The apparatus of claim 8 wherein the actuator is formed of one or more of ferrous materials or ferritic stainless steel.

15. An apparatus for delivering a fluid, the apparatus comprising:

a housing;

an inlet in the housing for receiving the fluid;

an outlet in the housing for discharging the fluid;

a piston channel within the housing through which the fluid flows from the inlet to the outlet; and

an actuator positioned within the housing and moveable between a first position and a second position, the actuator defining a piston chamber for storing fluid received through the inlet when the actuator is in the retracted position, the actuator driving the fluid stored in the piston chamber toward the outlet when the actuator transitions from the retracted position to the forward position, the actuator comprising;

an armature including one or more openings therethrough; and

a piston coupled to the armature and moveable within the piston channel,

whereby when the fluid flows through the openings of the armature the actuator is caused to rotate around an axis.

16. The apparatus of claim 15 wherein the openings are formed through the armature on a pre-selected path to effectuate the rotation of the actuator when fluid passes therethrough.

17. The apparatus of claim 15 wherein the openings are generally circular in shape.

18. The apparatus of claim 15 wherein the openings through the armature or more than one shape.

19. The apparatus of claim 15 wherein the axis is longitudinally through the piston.