Infusion device with optical sensor

• US 6,110,153 A
• Filed: 12/14/1998
• Issued: 08/29/2000
• Est. Priority Date: 07/25/1996
• Status: Expired due to Term

• Current Assignee: Carefusion 303 Incorporated (Becton, Dickinson & Co)
• Original Assignee: ALARIS Medical Systems, Inc. (Becton, Dickinson & Co)
• Inventors: Davis, David L., Hatch, Richard F., Brasier, Robert E.
• Primary Examiner(s): Stright, Ronald
• Assistant Examiner(s): Thissell, Jeremy
• Application Number:
  US09/211,223
• Time in Patent Office: 624 Days
• Field of Search: 604/65, 604/67, 604/151, 604/153, 604/154, 604/131, 604/122, 604/123, 128/DIG. 12, 128/DIG. 13, 250/577, 250/574
• US Class Current: 604/245
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

An infusion device with a disposable administration set which is inexpensive to manufacture. In the preferred embodiment of the present invention the disposable administration set has a plurality of elongated cam followers connected to a plate assembly, wherein the cam followers are displace in a predetermined sequence and forced against a delivery tube by cam means driven by rotary drive means. The device also includes an optical occlusion sensor which is synchronized to operate in phase with the movement of the cam followers to measure pressure within the delivery tube at one pump phase, thereby sensing downstream occlusions, and to measure vacuum within the delivery tube at a second pump phase, thereby sensing upstream occlusions. The occlusion sensor is optical, and measures the degree of total internal reflection at the interface of the tube and the plate assembly, occlusion in the tubing.

Claims

1. A system for detecting deviations in the flow of fluid through a flexible tube, the flexible tube providing fluid communication between a fluid source and a patient, the system comprising:

a transparent plate in contact with the flexible tube;

a light source configured to project light onto the transparent plate in the direction of the flexible tube; and

an optical sensor disposed such that it is directed at the transparent plate and the tube and is configured to measure reflected light; and

wherein said transparent plate mounts the flexible tube such that when the flexible tube is in a normal flow condition, it is in contact with the transparent plate and when the flexible tube is exposed to an upstream occlusion condition, the tube has decreased contact with the transparent plate.

2. The system of claim 1 further comprising:

an infusion pump which provides the flow of fluid through the tube.

3. The system of claim 2 wherein the infusion pump has a housing which holds the transparent plate, the light source and the optical sensor.

4. The system of claim 1 wherein the transparent plate mounts the flexible tube such that the flexible tube has a first level of contact with the transparent plate when under a normal condition at which the tube experiences pressure exerted by the flow of fluid through the tube and a second level of contact with the transparent plate when under an expanded state at which the tube experiences increased pressure caused by a downstream blockage of the flow, wherein the second level of contact with the transparent plate when in the expanded state is a greater level of contact with the transparent plate.

5. The system of claim 1 wherein the transparent plate has an index of refraction which differs from the index of refraction of the flexible tube, such that increased contact between the tube and the transparent plate cause a decrease in the amount of light reflected in a critical angle.

6. The system of claim 5 wherein the optical sensor is positioned to measure the amount of light reflected at the critical angle.

9. The system of claim 1 wherein the determining means is further capable of identifying an air bubble in the flexible tube.

7. A system for detecting deviations in the flow of fluid through a flexible tube, the flexible tube providing fluid communication between a fluid source and a patient, the system comprising:

a transparent plate in contact with the flexible tube;

a light source configured to project light onto the transparent plate in the direction of the flexible tube;

an optical sensor disposed such that it is directed at the transparent plate and the tube and is configured to measure reflected light;

wherein the transparent plate has s first surface and a second surface, the second surface having a first recess which forms a lens configured to direct light emitted form the light source onto the first surface, and a second recess which forms a lens configured to direct light reflected from the first surface into the optical sensor; and

means for determining whether the measurements received from the optical sensor indicate either an upstream or downstream blockage in the flow through the tube.

8. The system for detecting deviations in the flow of fluid through a flexible tube, the flexible tube providing fluid communication between a fluid source and a patient, the system comprising:

a transparent plate in contact with the flexible tube;

a light source configured to project light onto the transparent plate in the direction of the flexible tube;

an optical sensor disposed such that it is directed at the transparent plate and the tube and is configured to measure reflected light; and

means for determining whether the measurements received from the optical sensor indicate either an upstream or downstream blockage in the flow through the tube, wherein the determining means is capable of distinguishing between upstream occlusions and downstream occlusions.

10. The system for detecting deviations in the flow of fluid through a flexible tube, the flexible tube providing fluid communication between a fluid source and a patient, the system comprising:

a transparent plate in contact with the flexible tube and providing a mounting of the flexible tube wherein the flexible tube has a reference state when under the pressure exerted by the desired rate of flow and a contracted state when under a vacuum exerted by an upstream blockage of the flow, wherein the contracted state has decreased contact with the transparent plate;

a light source configured to project light onto the transparent plate in the direction of the flexible tube;

an optical sensor disposed such that it is directed at the transparent plate and the tube and is configured to measure reflected light; and

means for determining whether the measurements received from the optical sensor indicate either an upstream or downstream blockage in the flow through the tube.

11. A system for detecting deviations in the flow of fluid through a flexible tube, the flexible tube providing fluid communication between a fluid source and a patient, the system comprising:

a transparent plate mounting the flexible tube at a first surface of the transparent plate, the plate mounting the tube such that the tube has a first level of contact with the first surface when in a normal condition during which fluid is flowing through the tube, a second level of contact with the first surface which is greater than the first level of contact when there exists a downstream blockage of the fluid, and no contact with the first surface when there exists an upstream blockage of the fluid;

a light source disposed for projecting light onto a second surface of the plate in the direction of the first surface and the mounted tube, the second surface spaced from the first surface;

an optical sensor disposed such that it is directed at the second surface of the transparent plate and at the first surface and the tube and is configured to measure reflected light; and

means for determining whether measurements of reflected light received from the optical sensor indicate an upstream blockage in flow through the tube or a downstream blockage.

12. The system of claim 11 wherein the means for determining includes an electronic synchronizer.

13. The system of claim 12 wherein the electronic synchronizer further comprises:

an analog to digital signal converter connected to the optical sensor;

a set of reference values stored electronically; and

a comparator which receives digital signals from the signal converter and receives the stored reference values.

14. The system of claim 11 further comprising:

an alarm configured to activate in response to adverse indications from the means for determining.

15. The system of claim 11 wherein the second surface of the transparent plate has a first recess which forms a lens configured to direct light emitted from the light source onto the first surface, and the second surface of the transparent plate has a second recess which forms a lens configured to direct light reflected from the first surface into the optical sensor.

16. A system for detecting deviations in the flow of fluid through a flexible tube, the flexible tube providing fluid communication between a fluid source and a patient, the system comprising:

a transparent plate in contact with the tube;

a light source for projecting light onto the plate; and

an optical sensor directed at the transparent plate for measuring reflected light;

wherein the said plate having a first recess at which the light source is directed and a second recess at which the optical sensor is directed, each recess having a lens for directing light.

17. A system for detecting blockages in the flow through a tube comprising:

a flexible tube providing fluid communication between a fluid source and a patient, said tube defining a first diameter under a reference state due to a uniform rate of flow through the tube;

a transparent plate in contact with the tube while the tube is in the reference state; and

a light source configured to project light onto the transparent plate; and

an optical sensor configured to measure the light reflected from the transparent plate.

18. The system of claim 17 further comprising:

an electronic comparator configured to receive signals from the optical sensor and determine whether the tube has deviated from the reference state.

19. The system of claim 18 wherein the electronic comparator determines whether the tube is in an expanded state due to a downstream blockage or a contracted state due to an upstream blockage.

20. The system of claim 18 wherein the electronic comparator further determines the presence of an air bubble in the tube.