Ratiometric air-in-line detector

• US 4,857,050 A
• Filed: 09/23/1987
• Issued: 08/15/1989
• Est. Priority Date: 09/23/1987
• Status: Expired due to Fees

• Current Assignee: ALARIS Medical Systems, Inc. (Becton, Dickinson & Co)
• Original Assignee: Fisher Scientific Co. (Thermo Fisher Scientific Incorporated)
• Inventors: Deckert, Curt, Lentz, David, Wilson, Larry
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Daley, Kathleen A.
• Application Number:
  US07/100,218
• Time in Patent Office: 692 Days
• Field of Search: 604/65, 604/66, 604/253, 604/122, 604/123, 604/67, 250/577, 73/55, 128/DIG. 13
• US Class Current: 604/67
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: G01F 23/2921 for discrete levels
• CPC Class Codes: G01P 13/0086 with photo-electric detection
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

An air-in-line detector for use with an IV administration system comprises a light emitter positioned relative to a plurality of light sensors for receiving an IV tube therebetween. A comparator is connected with the light sensors to determine the relative intensity of light respectively incident on each sensor. Means connected with the comparator generates signals in accordance with the relative intensities to indicate whether an IV tube is present and, if so, whether there is fluid or air in the tube.

Claims

1. An IV tube air-in-line detector comprising:

a first light emitter;

a receiver having juxtaposed first and second sensor means for independently sensing the intensity of light from said emitter respectively incident thereon;

means for holding said emitter and said receiver with said tube therebetween;

a first comparator electronically connected with said first and second sensor means to indicate an air-in-line condition when the intensity of light incident on said first sensor means is more than the intensity of light incident on said second sensor means and to indicate a fluid-in-line condition when the intensity of light incident on said second sensor means is more than the intensity of light incident on said first sensor means;

a second emitter mounted on said holding means to transmit light from said second emitter to said first sensor means; and

a strobe means electrically connected to said first and second light emitters to alternatingly cause light emissions from said first and second light emitters.

2. An IV tube air-in-line detector as cited in claim I further comprising means electrically connected with said first sensor means to determine whether said first sensor means receives light from said second light emitter.

3. An IV tube air-in-line detector as cited in claim 2 wherein said second light emitter is juxtaposed with said receiver to place said first sensor means between said second light emitter and said second sensor means;

and further comprising means positioned on said holding means to reflect light from said second light emitter onto said first sensor means.

4. An IV tube air-in-line detector as cited in claim 3 wherein light from said light emitter is collimated light.

5. An Iv tube air-in-line detector as cited in claim 4 wherein said light emitter is not diametrically opposed from said receiver relative to said tube.

6. An IV tube air-in-line detector as cited in claim 5 wherein said holding means is formed with a channel for receiving said tube therein.

7. An Iv tube air-in-line detector as cited in claim 6 wherein light from said light emitter is infra-red light.

8. An IV tube air-in-line detect as cited in claim 7 wherein said IV tube is transparent.

9. An IV tube air-in-line detector as cited in claim 8 further comprising a second comparator for indicating a fluid-in-line condition when the sum of the intensities of said first and said second sensing means is below a predetermined level.

10. An IV tube air-in-line detector comprising:

a first light emitter;

a first light sensor for receiving light from said emitter;

a second light sensor juxtaposed with said first light sensor for independently receiving light from said emitter;

means of hold said tube between said emitter and said first and second sensors; and

means for determining the ratio of the intensity of light received by said first sensor to the intensity of light received by said second light sensor to indicate an air-in-line condition when the ratio of intensities is substantially greater than unity, and to indicate a fluid-in-line condition when the ratio is substantially less than unity or the sum of the intensities is below a predetermined level;

a second emitter mounted on said molding means to transmit light from said second emitter to said first sensor means; and

a strobe means electrically connected to said first and second light emitters to alternatingly cause light emissions from said first and second light emitters.

11. An IV tube air-in-line detector as cited in claim 10 further comprising means electrically connected with said first sensor means to determine whether said first sensor means receives light from said second light emitter.

12. An IV tube air-in-line detector as cited in claim 11 wherein said second light emitter is juxtaposed with said receiver to place said first sensor means between said second light emitter and said second sensor means;

and further comprising means positioned on said holding means to reflect light from said second light emitter onto said first sensor means.

13. Iv tube air-in-line detector as cited in claim 12 wherein light from said light first emitter is collimated.

14. An IV tube air-in-line detector as cited in claim 13 wherein said light emitter and said juxtaposed first and second light sensor are to diametrically disposed relative to said tube.

15. An IV tube air-in-line detector as cited in claim 14 wherein said holding means if formed with a channel for receiving said tube therein.

16. An IV tube air-in-line detector as cited in claim 15 wherein light from said first light emitter is infra-red.

17. An IV tube air-in-line detector as cited in claim 16 wherein said IV tube is transparent.

18. A method for indicating an air-in-line condition for an IV tube comprising the steps of:

holding said tube in the path of collimated light between a strobed light emitter and a pair of juxtaposed light sensors;

ratioing the intensity of light incident on said light sensors;

indicating an air-in-line condition when the ratio is within a predetermined range;

disregarding the ratio and indicating a fluid-in-line condition whenever the sum of intensities from said light sensors falls below a predetermined level; and

aiming light from a second strobed light emitter in alternation with said strobed light at one of said pair of light sensors to check operation of said ratioing step.