Syringe pump control systems using a light sensor

1. A medication pump comprising:

a cartridge chamber for receiving a medication cartridge, the chamber comprising a first open end for receiving the medication cartridge, a second end defining a drive rod opening, and a cartridge chamber wall extending from the first open end to the second end; wherein the cartridge chamber wall is generally cyclindrical;

a motor;

a drive rod comprising an interface end, wherein the interface end of the drive rod extends into the cartridge chamber through the drive rod opening, wherein the drive rod is configured to be axially moved by the motor; and

a light sensor positioned near the second end of the cartridge chamber configured to detect whether the medication cartridge is located within the cartridge chamber near the second end of the cartridge chamber, wherein the light sensor comprises an emitter and a detector, wherein the emitter and the detector are positioned on the cylindrical cartridge chamber wall at opposite ends of chord through the cartridge chamber, wherein the chord connects two points on the cylindrical cartridge chamber wall.

2. The medication pump of claim 1 , further comprising a processor operably connected to the light sensor.

3. The medication pump of claim 2 , wherein the processor is configured to notify a user of whether or not the cartridge is within the cartridge chamber near the second end.

4. The medication pump of claim 1 , wherein the emitter and detector are located outside of the cartridge chamber, wherein the detector is configured to detect light emitted by the emitter when there is no medication cartridge in the cartridge chamber.

5. The medication pump of claim 4 , wherein the cartridge chamber wall is constructed to allow a detectable level of light to pass from the emitter to the detector.

6. The medication pump of claim 1 wherein the chord passes through the medication cartridge when the medication cartridge is in the chamber.

7. The medication pump of claim 6 wherein the chord does not pass through the drive rod.

8. The medication pump of claim 1 , wherein the interface end of the drive rod is configured to attach to a plunger within the medication cartridge, so that the drive rod can advance and retract the plunger.

9. The medication pump of claim 1 , further comprising a medication cartridge comprising:

a barrel wall comprising an open end and a closed end, wherein the closed end defines an orifice;

a ridge defined on an interior face of the barrel wall, wherein the banel wall is more opaque in the region extending from the ridge to the open end than in at least a portion of a remainder of the barrel wall.

10. The medication pump of claim 1 , wherein the cartridge chamber has a central axis extending from the first open end to the second end of the cartridge chamber, wherein the chord is located in a plane perpendicular to the axis.

11. A medication pump system comprising:

a medication cartridge comprising:

a cylindrical barrel wall comprising an open end and a closed end, wherein the closed end defines an orifice; and

a plunger slidably received within the barrel wall; and

a medication pump comprising:

a cartridge chamber for receiving the medication cartridge, the chamber comprising a first open end for receiving the medication cartridge and a second end defining a drive rod opening;

a motor;

a drive rod comprising an interface end, wherein the interface end of the drive rod extends into the cartridge chamber through the drive rod opening, wherein the drive rod is configured to be axially moved by the motor, wherein the interface end is configured to attach to the plunger so that the drive rod can retract or advance the plunger; and

a light sensor positioned near the second end of the cartridge chamber configured to detect whether the medication cartridge is located within the cartridge chamber near the second end of the cartridge chamber;

wherein the cartridge chamber further comprises a cylindrical cartridge chamber wall extending from the first open end to the second end, wherein the light sensor comprises an emitter and a detector, wherein the emitter and the detector are positioned on the cylindrical cartridge chamber wall at opposite ends of a chord through the cartridge chamber, wherein the chord connects two points on the cylindrical cartridge chamber wall.

12. The medication pump system of claim 11 , wherein the chord passes through the cylindrical barrel wall of the medication cartridge twice when the medication cartridge is located in the cartridge chamber.

13. The medication pump system of claim 12 , wherein the chord does not pass through the drive rod.

14. The medication pump system of claim 11 , wherein the cylindrical barrel wall comprises a ridge defined on an interior face of the barrel wall, wherein the barrel wall is more opaque in the region extending from the ridge to the open end than in at least a portion of the remainder of the barrel wall.

15. The medication pump system of claim 11 , further comprising a processor operably connected to the light sensor and configured to notify a user of whether or not the cartridge is within the cartridge chamber near the second end.

16. The medication pump system of claim 11 , wherein the emitter and detector are located outside of the cartridge chamber, wherein the detector is configured to detect light emitted by the emitter when there is no medication cartridge in the cartridge chamber.

17. The medication pump of claim 11 , wherein the cartridge chamber has a central axis extending from the first open end to the second end of the cartridge chamber, wherein the chord is located in a plane perpendicular to the axis.

18. A medication pump comprising:

a cartridge chamber for receiving a medication cartridge, the chamber comprising a first open end for receiving the medication cartridge, a second end defining a drive rod opening, and a cylindrical cartridge chamber wall extending between the first open end and the second end;

a motor;

a drive rod comprising an interface end, wherein the interface end of the drive rod extends into the cartridge chamber through the drive rod opening, wherein the drive rod is configured to be axially moved by the motor wherein; and

a light sensor including an emitter and a detector, the emitter and the detector are positioned on the cylinder cartridge chamber wall at opposite ends of a chord through the cartridge chamber, wherein the chord passes through a portion of the medication cartridge when the medication cartridge is in the cartridge chamber, wherein the chord does not pass through the drive rod, and wherein the chord connects two points on the cylindrical cartridge chamber wall.

19. The medication pump of claim 18 wherein the emitter and detector are located outside of the cartridge chamber.

20. The medication pump of claim 18 , wherein interface end of the drive rod is configured to attach to a plunger within the medication cartridge to retract or advance the plunger.

21. The medication pump of claim 18 , further comprising a processor operably connected to the light sensor, wherein the processor is configured to notify a user of whether or not the cartridge is within the cartridge chamber near the second end.

22. The medication pump of claim 18 , further comprising a medication cartridge comprising:

a barrel wall comprising an open end and a closed end, wherein the closed end defines an orifice;

a ridge defined on an interior face of the barrel wall, wherein the baffel wall is more opaque in the region extending from the ridge to the open end than in at least a portion of a remainder of the barrel wall.

23. The medication pump of claim 18 , wherein the cartridge chamber has a central axis extending from the first open end to the second end of the cartridge chamber, wherein the chord is located in a plane perpendicular to the axis.