SENSING SYSTEM FOR DETECTING A PISTON IN A MEDICAL FLUID CONTAINER

• US 20170246399A1
• Filed: 08/27/2015
• Published: 08/31/2017
• Est. Priority Date: 09/02/2014
• Status: Active Grant

• Current Assignee: Eli Lilly and Company
• Original Assignee: Eli Lilly and Company
• Inventors: Forlani, Christian Fabio, Massari, Rossano Claudio, Mojarrad, Mehran
• Granted Patent: US 10,384,014 B2
• Time in Patent Office: Days
• CPC Class Codes: A61M 2005/3126 Specific display means related to dosing
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3389 Continuous level detection A61M2205/3393 takes precedence
• CPC Class Codes: A61M 2205/587 Lighting arrangements
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/1684 by detecting the amount of infusate remaining, e.g. signalling end of infusion
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/31568 Means keeping track of the total dose administered, e.g. since the cartridge was inserted

Abstract

A sensing system for determining a position of a plunger within a fluid container. The sensing system includes a light source, a light detector and a controller. The light source is configured to emit light into a barrel wall of the fluid container so that the barrel wall serves as a waveguide to guide the light to travel therein in an axial direction. The light detector is positioned to detect reflected light that was emitted by the light source, traveled through the barrel wall serving as the waveguide, and then reflected off a surface of the plunger. The controller is in communication with the light detector to determine an axial position of the plunger surface based on data from the light detector of the detected reflected light.

Claims

1. A sensing system for determining a position of a plunger within a fluid container, the fluid container including a barrel made of a light transmitting material, the barrel extending in an axial direction between a forward outlet end and a rearward end, the plunger having at least one peripheral surface region in fluid tight engagement with an interior surface of a wall of the barrel to seal fluid in the barrel forward of the plunger, the plunger advanceable in the axial direction within the barrel toward the forward outlet end for dispensing the fluid from the fluid container through the forward outlet end, the sensing system comprising:

a light source configured to emit light into the barrel wall so that the barrel wall serves as a waveguide to guide the light to travel therein in the axial direction;

a light detector positioned to detect reflected light that was emitted by the light source, traveled through the barrel wall serving as the waveguide, and then reflected off the at least one peripheral surface region; and

a controller in communication with said light detector to determine an axial position of the at least one peripheral surface region within the fluid container based on data from said light detector of said detected reflected light.

2. The sensing system of claim 1 wherein said light source is configured to direct light into an axial end face of the barrel wall.

3. The sensing system of claim 2 wherein the axial end face of the barrel wall is at the rearward end.

4. The sensing system of claim 3 wherein said light source is positioned to be centered on a thickness of the wall as measured in a radial direction.

5. The sensing system of claim 3 wherein said light source is positioned to be adjacent to the axial end face.

6. The sensing system of claim 3 wherein said light source is a single illuminating element.

7. The sensing system of claim 6 wherein said single illuminating element is a light emitting diode.

8. The sensing system of claim 1 wherein said light detector extends in the axial direction to allow positioning of the barrel therealong, and wherein a light filtering element is positioned to be between said light detector and the barrel wall.

9. The sensing system of claim 1 wherein said light source is configured to direct light into a protuberance integrally formed with the barrel wall and projecting therefrom in a radial direction.

10. The sensing system of claim 9 wherein the protuberance extends continuously around a circumference of the barrel wall.

11. The sensing system of claim 9 wherein the said light source is configured to direct light into the protuberance that projects radially outward from the barrel wall.

12. The sensing system of claim 11 wherein said light source is configured to direct light into the protuberance that comprises a finger grippable flange of the barrel wall.

13. The sensing system of claim 12 wherein the flange extends continuously around a circumference of the barrel wall

14. The sensing system of claim 1 wherein the at least one peripheral surface region comprises first and second peripheral surface regions spaced in the axial direction, and wherein said controller determines a first axial position of the first peripheral surface region and a second axial position of the second peripheral surface region, said controller configured to determine a plunger compression based on the first and second axial positions.

15. The sensing system of claim 1 wherein said light detector is configured to extend around the barrel wall.

16. The sensing system of claim 15 wherein said light detector has a helical configuration.

17. The sensing system of claim 1 wherein said light detector comprises a light transmitting portion located radially of the container barrel and a sensing portion located axially of the container barrel.

18. A medication delivery device comprising:

a housing including a container retainer;

a medication container held within the container retainer, the medication container including a barrel and a plunger, the barrel made of a light transmitting material and extending in an axial direction between a forward outlet end and a rearward end, the plunger having at least one peripheral surface region in fluid tight engagement with an interior surface of a wall of the barrel to seal medication in the barrel forward of the plunger;

an advancing mechanism within said housing operable to advance said plunger within said barrel to dispense medication from the medication container through said forward outlet end;

a light source mounted within said housing to emit light into the barrel wall so that the barrel wall serves as a waveguide to guide the light to travel therein in the axial direction;

a light detector mounted within the container retainer to detect reflected light that was emitted by the light source, traveled through the barrel wall serving as the waveguide, and then reflected off the at least one peripheral surface region; and

a controller mounted within the housing in communication with said light detector to determine an axial position of the at least one peripheral surface region within the medication container based on data from said light detector of said detected reflected light.

19. The medication delivery device of claim 18 wherein said light source is configured to direct light into an axial end face of the barrel wall at the rearward end.

20. The medication delivery device of claim 19 wherein said light source is a single light emitting diode.

21. The medication delivery device of claim 18 further comprising an axially extending light filtering element positioned between said light detector and said barrel wall.

22. The medication delivery device of claim 18 wherein said light source is configured to direct light into a protuberance integrally formed with the barrel wall and projecting therefrom in a radial direction.

23. The medication delivery device of claim 18 further comprising a display in electronic communication with said controller for indicating information determined based on said axial position of said at least one peripheral surface region.

24. The medication delivery device of claim 18 further comprising an actuator accessible externally of the housing and manually operable to control operation of said advancing mechanism.

25. The medication delivery device of claim 18 further comprising a first light polarizing filter and a second light polarizing filter, said first and second light polarizing filters oriented transverse to each other, said first light polarizing filter disposed between said light detector and said container, said second light polarizing filter arranged on said container retainer over said container to restrict ambient light.

26. The medication delivery device of claim 18 wherein said light source emits light into the barrel wall through a fiber optic, light pipe or wave guide disposed therebetween.

27. The medication delivery device of claim 18 wherein said light detector is mounted within the container retainer to detect reflected light that was emitted by the light source, traveled through the barrel wall serving as the waveguide, and then reflected off a neck section of the barrel at the forward outlet end, said detected reflected light associated with said neck section being used by said controller with the determined axial position of the at least one peripheral surface region to calculate an amount of medication remaining in the medication container.