Optical signal channel selector

• US 5,204,922 A
• Filed: 10/22/1991
• Issued: 04/20/1993
• Est. Priority Date: 10/22/1991
• Status: Expired due to Fees

• Current Assignee: Puritan Bennett Corp. (Medtronic Plc)
• Original Assignee: Puritan Bennett Corp. (Medtronic Plc)
• Inventors: Weise, Karl H., Weir, Charles S.
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): BARNS, STEPHEN
• Application Number:
  US07/780,477
• Time in Patent Office: 546 Days
• Field of Search: 385/18, 385/19, 385/22, 385/25, 356/406, 356/416, 356/419
• US Class Current: 385/18
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 2021/7786 Fluorescence
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 21/80 Indicating pH value
• CPC Class Codes: G02B 26/0816 by means of one or more reflecting elements
• CPC Class Codes: G02B 6/29362 Serial cascade of filters or filtering operations, e.g. for a large number of channels
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35

Abstract

The optical signal channel selector apparatus includes one or more first optical channels, and a plurality of a secondary optical channels for carrying an optical signal. A parabolic mirror is rotatable to provide optical communication between a first optical channel and any one of the secondary optical channels. A position encoded stepper motor is coupled to the parabolic mirror for controlling the position of the mirror. Solid state optical interface blocks having one or more filters receive the optical signal and transmit output optical signals with filtered wavelength ranges in the secondary optical channels. The rotation of the mirror by a position encoded stepper motor allows selection of a desired secondary channel, and automatically shutters the remaining channels closed.

Claims

1. An optical signal channel selector apparatus for an optical signal transmission and detection system having multiple optical channels for communicating at least one optical signal comprising:

a) at least one first optical channel means for carrying an optical signal;

b) a plurality of a second optical channel means for carrying an optical signal, each said second optical channel means including a solid-state optical fiber block having at least one filter means for receiving said optical signal and transmitting an output optical signal with a limited wavelength range;

c) movable selector means adapted to be in optical communication with any one of said first optical channel means and movable to be in optical communication with any one of said second optical channel means for providing optical communication between one of said first optical channel means and a selected second optical channel means; and

d) means for moving said selector means to provide optical communication between one of said first optical channel means and a different one of said second optical channel means.

2. The apparatus of claim 1, wherein said movable selector means includes mirror means having a reflective surface rotatable about an axis for reflecting said optical signal between said first and second optical channel means.

3. The apparatus of claim 1, wherein said mirror means comprises a parabolic focusing mirror.

4. The apparatus of claim 1, wherein said second optical channel means includes a plurality of optical fiber channels for carrying a source optical signal received from said first optical channel means to each of said optical interface block to generate an output optical signal with a limited wavelength range, said plurality of optical fiber channels being disposed about said mirror means in a plane normal to the axis of rotation of said mirror means for receiving said source optical signal reflected from said mirror means, whereby said mirror means is adapted to communicate said optical signal between said first optical channel means and sequential ones of said second optical channel means.

5. The apparatus of claim 1, wherein said selector means comprises mirror means rotatable about an axis and said means for moving said selector means includes means for controlling a rotational position about said axis to communicate said optical signal between said first optical channel means and sequential ones of said second optical channel means.

6. The apparatus of claim 5, wherein said means for moving said selector means includes a stepper motor having a rotatably driven shaft coaxial with the rotational axis of said mirror means and connected to said mirror means for aligning said mirror means with said sequential ones of said second optical channel means.

7. The apparatus of claim 5, wherein said means for controlling said rotational position includes position encoding means for generating an encoded signal representing the rotational position of said mirror means about said axis.

8. The apparatus of claim 6, wherein said means for moving said selector means includes position encoding means for generating an encoded position signal representing the rotational position of said mirror means about said axis, and computer means in electrical communication with said position encoding means and said stepper motor for receiving said encoded position to monitor the rotational position of said mirror means and to control the stepper motor responsive to said encoded position signal.

9. The apparatus of claim 1, wherein said first optical channel means comprises a broad spectrum light source for generating a source optical signal.

10. The apparatus of claim 9, wherein said first optical channel means comprises lens means for collimating or focusing said source optical signal.

11. The apparatus of claim 1, wherein said first optical channel means comprises an optical fiber for carrying said optical signal.

12. The apparatus of claim 1, wherein said second optical channel means comprises an optical fiber for carrying said optical signal.

13. The apparatus of claim 1, wherein said second optical channel means includes optical signal detector means for measuring intensity of said output signal.

14. The apparatus of claim 1, wherein said second optical channel means includes an oxygen sensor for receiving said output optical signal and generating at least one return optical signal representing an oxygen partial pressure in a sample.

15. The apparatus of claim 1, wherein said second optical channel means includes a carbon dioxide sensor for receiving said output optical signal and generating at least one return optical signal representing a carbon dioxide pressure in a sample.

16. The apparatus of claim 1, wherein said second optical channel means includes a pH sensor for receiving said output optical signal and generating at least one return optical signal representing pH of a sample.

17. The apparatus of claim 1, wherein said second optical channel means includes a plurality of return channels in optical communication with said optical interface block for carrying return optical signals, and signal detector means in optical communication with said optical interface block for measuring intensity of said return optical signals.

18. The apparatus of claim 1, wherein said second optical channel means includes signal detector means in optical communication with said optical interface block for measuring intensity of said output optical signal.

19. The apparatus of claim 1, wherein said optical interface block includes a plurality of filter means for receiving said optical signal and transmitting a plurality of output optical signals with different wavelength ranges, and means for combining said plurality of output optical signals.

20. The apparatus of claim 19, wherein said means for combining includes dichroic mirror means.

21. The apparatus of claim 19, wherein said second optical channel means includes a return channel in optical communication with said optical interface block for carrying a return optical signal, and signal detector means in optical communication with said optical interface block for measuring intensity of said return optical signal.

22. The apparatus of claim 19, wherein said optical interface block is in optical communication with an output channel for carrying said combined output optical signals, and includes lens means for focusing said plurality of output optical signals on said output channel means.

23. An optomechanical switching apparatus for use in a system utilizing optical signals, comprising:

an light source for producing an optical signal;

rotatable mirror means for directing said optical signal from said light source to a plurality of points located about said mirror means;

means for controlling the rotational position of the mirror means;

a plurality of optical fiber channels disposed at said plurality of points about said mirror means adapted to be in optical communication with said mirror means such that as the mirror means is rotated said mirror means is in optical communication with a selected optical fiber channel and the mirror means is not in optical communication with the remaining optical fiber channels; and

each optical fiber channel being connected to a solid state optical interface block having at least one filter means for receiving said optical signal and transmitting an output optical signal with a limited wavelength range.

24. The apparatus of claim 23 wherein said mirror means is a parabolic mirror for focusing the optical signal onto said selected optical fiber channel.

25. The apparatus of claim 23 wherein said mirror means has an axis of rotation which is normal to a plane in which optical fiber channels are disposed.

26. The apparatus of claim 25 wherein said light source is disposed in the axis of rotation of the mirror.

27. The apparatus of claim 23 wherein said light source is a flashlamp.

28. A method for measuring the concentration of at least one analyte in a sample utilizing an optical signal transmission and detection system having optical fiber analyte sensor means adapted to receive at least one optical excitation signal and adapted to generate at least one output detection signal which is a function of the corresponding analyte concentration in the sample, said analyte sensor means being optically connected through a plurality of corresponding optical channels to an optical signal channel selector apparatus having multiple optical channels for sequentially communicating at least one optical signal, said optical signal channel selector apparatus including at least one first optical channel means for carrying a source optical signal;

a plurality of a second optical channel means for carrying said source optical signal, each said second optical channel means including a solid-state optical fiber block having at least one filter means for receiving said source optical signal and transmitting an excitation optical signal with a limited wavelength range to said sensor means;

movable selector means adapted to be in optical communication with any one of said first optical channel means and movable to be in optical communication with any one of said second optical channel means for providing optical communication between one of said first optical channel means and a selected second optical channel means; and

means for moving said selector means to provide optical communication between one of said first optical channel means and a different one of said second optical channel means, said method comprising the steps of;

a) exposing said optical sensor means to said sample;

b) generating a source optical signal and transmitting said source optical signal from said first optical channel means through said movable selector means to a first one of said second optical channel means to transmit one said excitation optical signal with a limited wavelength range to said sensor means;

c) generating a first said output detection signal responsive to said excitation optical signal;

d) measuring said first output detection signal from said optical sensor means;

e) moving said selector means to transmit said source optical signal from said first optical channel means to a second one of said second optical channel means to transmit a second said excitation optical signal with a limited wavelength range to said optical sensor means;

f) generating a second said output detection signal responsive to said second excitation optical signal;

g) measuring said second output detection signal from said optical sensor means; and

h) determining the concentration of at least one analyte in said sample based upon at least one of said first and second output detection signals.

29. The method of claim 28, wherein said selector means comprises mirror means rotatable about an axis and further including the step of controlling a rotational position about said axis to communicate said optical signal between said first optical channel means and sequential ones of said second optical channel means.

30. The method of claim 29, wherein said means for moving said selector means includes a stepper motor having a rotatably driven shaft coaxial with the rotational axis of said mirror means and connected to said mirror means for aligning said mirror means with said sequential ones of said second optical channel means, and said step of controlling said rotational position includes generating an encoded signal representing the rotational position of said mirror means about said axis.

31. The method of claim 28, wherein said optical sensor means comprises a dual emission sensor, and said step of generating at least one output detection signal comprises generating two different output detection signals representing the concentration of the analyte to be measured in the sample.

32. The method of claim 31, wherein said dual emission sensor is an oxygen sensor, and said step of generating at least one output detection signal comprises generating two different output detection signals representing the partial pressure of oxygen in the sample.

33. The method of claim 28, wherein said optical sensor means comprises a dual excitation sensor, and said step of generating an output detection signal comprises generating at least one output detection signal representing the concentration of the analyte to be measured in the sample.

34. The method of claim 33, wherein said dual excitation sensor is a carbon dioxide sensor, and said step of generating an output detection signal comprises generating at least one output detection signal representing a carbon dioxide pressure in the sample.

35. The method of claim 33, wherein said dual excitation sensor is a pH sensor, and said step of generating an output detection signal comprises generating at least one output detection signal representing pH of the sample.