Transmission-Reflectance Swappable Raman Probe for Physiological Detections

• US 20150208957A1
• Filed: 07/09/2014
• Published: 07/30/2015
• Est. Priority Date: 01/29/2014
• Status: Active Grant

• Current Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Original Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Inventors: ZHANG, Chun, KWOK, Ka Cheung, LEUNG, Lydia Lap Wai
• Granted Patent: US 9,295,420 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: G01J 3/0202 Mechanical elements; Supports for optical elements
• CPC Class Codes: G01J 3/0216 using light concentrators or collectors or condensers
• CPC Class Codes: G01J 3/0227 using notch filters
• CPC Class Codes: G01J 3/0237 Adjustable, e.g. focussing
• CPC Class Codes: G01J 3/06 Scanning arrangements arrangements for order-selection
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 21/63 optically excited
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers

Abstract

A transmission-reflectance swappable Raman device and a method thereof are disclosed. The excitation light is selectively directed to the sample in one direction for generating the transmission Raman signal in transmission mode or in another direction for generating the reflectance Raman signal in reflectance mode. The content of an analyte in a sample can be determined by analyzing transmission and reflectance Raman signal.

Claims

1. An optical signal detection device, comprising:

a) a frame;

b) an excitation light source coupled to said frame and configured to generate an excitation light;

c) a sample space disposed within said frame and adapted to receive a sample during operation;

d) a detector coupled to said frame and configured to capture transmission optical signal and reflectance optical signal generated by said sample when said excitation light is directed to said sample during operation; and

e) an optical component coupled to said frame and positioned between said sample space and said detector for reflecting said excitation light and transmitting said transmission optical signal and said reflectance optical signal;

wherein said device is switchable between a transmission mode and a reflectance mode of operation;

wherein in said transmission mode said excitation light source is positioned to direct said excitation light to said sample in a first direction for generating said transmission optical signal during operation;

wherein in said reflectance mode said frame is configured to direct said excitation light to said optical component;

said optical component reflecting said excitation light to said sample along a signal axis in a second direction opposite to said first direction for generating said reflectance optical signal.

2. The optical signal detection device of claim 1, wherein said first direction and said second direction are substantially parallel to each other.

3. The optical signal detection device of claim 1, wherein said transmission optical signal and said reflectance optical signal are directed to said detector along said signal axis.

4. The optical signal detection device of claim 1, wherein said optical component is selected from a group consisting of a notch filter, a long-pass filter, a band-pass filter and a dichroic mirror.

5. The optical signal detection device of claim 1, wherein the center of said optical component aligns with said signal axis and said optical component is disposed at an angle with respect to said signal axis.

6. The optical signal detection device of claim 1, wherein said transmission optical signal and said reflectance optical signal are Raman signals.

7. The optical signal detection device of claim 5, wherein the wavelength of said excitation light is in a range of 900-1300 nm.

8. The optical signal detection device of claim 1, wherein said frame further comprises a rotatable stage configured to rotate using the center of said optical component as the center of rotation and said excitation light source is mounted on said rotatable stage of said frame;

thereby when said device switches from said transmission mode to said reflectance mode, said rotatable stage rotates from zero degree to no more than ninety degrees with respect to said signal axis so that said excitation light is directed to said optical component.

9. The optical signal detection device of claim 1, wherein said frame further comprises a rotatable stage configured to rotate using the center of said optical component as the center of rotation;

wherein said sample space, said optical component and said detector are mounted on said rotatable stage of said frame;

thereby when said device switches from said transmission mode to said reflectance mode, said rotatable stage rotates from zero degree to no more than ninety degrees with respect to said light source so that said excitation light is directed to said optical component.

10. The optical signal detection device of claim 1, wherein said frame further comprises a translatable and rotatable stage and said excitation light source is mounted on said translatable and rotatable stage of said frame;

wherein in said transmission mode, said translatable and rotatable stage positions said excitation light source to align with said signal axis and in said reflectance mode, said translatable and rotatable stage positions said excitation light source to a predefined position such that said excitation light source directs said excitation light to said optical component at an angle of no more than ninety degrees with respect to said signal axis.

11. The optical signal detection device of claim 1, wherein said device further comprises:

a) an optical apparatus coupled to said frame for switching said device between said transmission mode and said reflectance mode; and

b) a first mirror coupled to said frame at a first predetermined position;

wherein said optical apparatus is configured to direct said excitation light to said sample along said first direction in said transmission mode and direct said excitation light to said first mirror in said reflectance mode;

said first mirror further reflecting said excitation light to said optical component.

12. The optical signal detection device of claim 11, wherein said optical apparatus further comprises:

a) a beamsplitter configured to direct a portion of said excitation light to said sample and direct the other portion of said excitation light to said first mirror;

b) a first shutter positioned along an optical path between said beamsplitter and said sample; and

c) a second shutter positioned along an optical path between said beamsplitter and said first mirror;

wherein said first shutter and said second shutter are interchangeably openable and closable thereby directing said excitation light to said sample when said first shutter is open and said second shutter is close; and

directing said excitation light to said first mirror when said second shutter is open and said first shutter is close.

13. The optical signal detection device of claim 11, wherein said optical apparatus further comprises a second mirror configured to toggle between a first preset position and a second preset position;

wherein when said second mirror is in said first present position, said second mirror reflects said excitation light to said sample and when said second mirror is in said second preset position, said second mirror does not intersect with said excitation light, allowing said excitation light to direct to said first mirror.

14. The optical signal detection device of claim 11, wherein said optical apparatus further comprises a second mirror configured to toggle between a third preset position and a fourth preset position;

wherein when said second mirror is in said third preset position, said second mirror does not intersect with said excitation light, allowing said excitation light to direct to said sample and when said second mirror is in said fourth present position, said second mirror reflects said excitation light to said first mirror.

15. The optical signal detection device of claim 1 further comprising a signal collector aligned between said sample space and said optical component along said signal axis for collecting said transmission optical signal and said reflectance optical signal to said detector.

16. The optical signal detection device of claim 15, wherein said signal collector is selected from a group consisting of compound parabolic concentrator and lens.

17. The optical signal detection device of claim 15, wherein said signal collector is a compound parabolic concentrator and the smaller aperture of said compound parabolic concentrator is positioned proximate to said sample space.

18. A method of analyzing composition of a sample comprising the steps of:

a) providing an excitation light source coupled to a first apparatus;

said first apparatus capable of switching between a transmission mode of operation and a reflectance mode of operation;

b) directing an excitation light from said excitation light source to said sample in a first direction when said first apparatus is in said transmission mode of operation;

thereby generating a transmission optical signal;

c) reflecting said excitation light from said excitation light source to said sample in a second direction when said first apparatus is in said reflectance mode of operation;

thereby generating a reflectance optical signal; and

d) analyzing said transmission optical signal and said reflectance optical signal;

thereby obtaining said composition of said sample;

wherein said first direction and said second direction are substantially parallel to each other but in opposite directions along a signal axis; and

said transmission optical signal and said reflectance optical signal are both directed to a detector along said signal axis.

19. The method of analyzing composition of a sample of claim 18 wherein said first apparatus comprises a rotatable stage in a frame and said excitation light source is mounted on said frame, further comprising the steps of:

a) rotating said rotatable stage to a first position such that said excitation light is directed to said sample in said first direction in said transmission mode of operation; and

b) rotating said rotatable stage to a second position such that said excitation light is directed to an optical component;

said optical component reflecting said excitation light to said sample in said second direction in said reflectance mode of operation;

wherein said rotating steps use the center of said optical component as the center of rotation.

20. The method of analyzing composition of a sample of claim 18 wherein said first apparatus comprises a first mirror coupled to a frame at a first predetermined position and an optical apparatus coupled to said frame;

said optical apparatus further comprising at least one optical component and a controller, further comprising the steps of;

a) commanding said controller to direct said excitation light to said sample in said first direction in said transmission mode; and

b) commanding said controller to direct said excitation light to said first mirror in said reflectance mode;

said first mirror further reflecting said excitation light to an optical component;

said optical component reflecting said excitation light to said sample in said second direction.