Time-of-flight optical measurement and decoding of fast-optical signals

Patent metadata

Field	Value
Publication number	US-11412930-B2
Application number	US-201916533133-A
Country	US
Kind code	B2
Filing date	Aug 6, 2019
Priority date	Aug 23, 2018
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

An optical measurement system comprising an optical source configured for delivering sample light in an anatomical structure, such that the sample light is scattered by the anatomical structure, resulting in physiological-encoded signal light that exits the anatomical structure, an optical detector configured for detecting the physiological-encoded signal light, and a processor configured for acquiring a TOF profile derived from the physiological-encoded signal light, the initial TOF profile having an initial contrast-to-noise ratio (CNR) between a plurality of states of a physiological activity in the anatomical structure. The processor is further configured for applying one or more weighting functions to the initial TOF profile to generate a weighted TOF profile having a subsequent CNR greater than the initial CNR between the plurality of states of the physiological activity. The processor is further configured for processing the weighted TOF profile, and identifying one of the plurality of states of the physiological activity.

First claim

What is claimed is:

1. An optical measurement system, comprising:
an optical source configured for delivering sample light in an anatomical structure, such that the sample light is scattered and absorbed by the anatomical structure, resulting in physiological-encoded signal light that exits the anatomical structure;
an optical detector configured for detecting the physiological-encoded signal light; and
a processor configured for acquiring an initial time-of-flight (TOF) profile derived from the physiological-encoded signal light, the initial TOF profile having an initial contrast-to-noise ratio (CNR) between a plurality states of a physiological activity in the anatomical structure, the processor further configured for applying one or more weighting functions comprising a fractional power to the initial TOF profile to generate a weighted TOF profile having a subsequent CNR greater than the initial CNR between the plurality of states of the physiological activity, the processor further configured for processing the weighted TOF profile by reducing the weighted TOF profile to a single index value by computing an area of the weighted TOF profile, the single index value being indicative of one of the plurality of states of the physiological activity, the processor further configured for identifying the one state of the physiological activity based on the single index value.

2. The optical measurement system of claim 1 , wherein the plurality of states of the physiological activity comprises an active state and an inactive state.

3. The optical measurement system of claim 1 , wherein the plurality of states of the physiological activity comprises at least two different active states.

4. The optical measurement system of claim 1 , wherein the fractional power is ½.

5. The optical measurement system of claim 1 , wherein the one or more weighting functions further comprises a ramp function.

6. The optical measurement system of claim 1 , wherein the one or more weighting functions comprises a change in intensity between a plurality of reference TOF profiles respectively corresponding to the plurality of states of the physiological activity.

7. The optical measurement system of claim 1 , wherein the optical detector is configured for deriving the initial TOF profile from the physiological-encoded signal light by directly detecting the initial TOF profile of the physiological-encoded signal light, and wherein at least a portion of the processor comprises:
an analog circuit configured for applying the one or more weighting functions to the initial TOF profile to generate the weighted TOF profile, and reducing the weighted TOF profile to the single index value; and
a digitizer configured for digitizing the single index value;
wherein at least another portion of the processor is configured for identifying the one state of the physiological activity based on the single digitized index value.

8. The optical measurement system of claim 1 , wherein the sample light comprises a single pulse.

9. The optical measurement system of claim 8 , wherein the single pulse has an optical pulse width of less than 1 ns.

10. The optical measurement system of claim 8 , wherein the single pulse has an optical pulse width of less than 100 ps.

11. The optical measurement system of claim 8 , wherein the optical detector comprises a photodiode configured for detecting the physiological-encoded signal light.

12. The optical measurement system of claim 11 , wherein the photodiode is one of a metal-semiconductor-metal (MSM) photodiode and a PIN diode.

13. The optical measurement system of claim 1 , wherein the optical detector is configured for detecting a frequency domain representation of the physiological-encoded signal light, wherein the processor is configured for deriving the initial TOF profile from the physiological-encoded signal light by transforming the frequency domain representation of the physiological-encoded signal light into the initial TOF profile.

14. The optical measurement system of claim 1 , wherein the anatomical structure is a brain, and wherein the physiological activity is a fast-optical signal.

15. An optical measurement method, comprising:
delivering sample light in an anatomical structure, such that the sample light is scattered by the anatomical structure, resulting in physiological-encoded signal light that exits the anatomical structure;
detecting the physiological-encoded signal light;
acquiring an initial time-of-flight (TOF) profile derived from the detected physiological-encoded signal light, the initial TOF profile having an initial contrast-to-noise ratio (CNR) between a plurality of states of a physiological activity in the anatomical structure;
applying one or more weighting functions comprising a fractional power to the initial TOF profile to generate a weighted TOF profile having a subsequent CNR greater than the initial CNR between the plurality of states of the physiological activity;
processing the weighted TOF profile by reducing the weighted TOF profile to a single index value by computing an area of the weighted TOF profile, the single index value being indicative of one of the plurality of states of the physiological activity;
identifying the one state of the physiological activity based on the single index value.

16. The optical measurement method of claim 15 , wherein the fractional power is ½.

17. The optical measurement method of claim 15 , wherein the one or more weighting functions further comprises a ramp function.

18. An optical measurement system, comprising:
an optical source configured for delivering sample light in an anatomical structure, such that the sample light is scattered and absorbed by the anatomical structure, resulting in physiological-encoded signal light that exits the anatomical structure;
an optical detector configured for detecting the physiological-encoded signal light; and
a processor configured for acquiring an initial time-of-flight (TOF) profile derived from the physiological-encoded signal light, the initial TOF profile having an initial contrast-to-noise ratio (CNR) between a plurality states of a physiological activity in the anatomical structure, the processor further configured for applying one or more weighting functions to the initial TOF profile to generate a weighted TOF profile having a subsequent CNR greater than the initial CNR between the plurality of states of the physiological activity, the processor further configured for processing the weighted TOF profile by computing an area of the weighted TOF profile to reduce the weighted TOF profile to a single index value indicative of one of the plurality of states of the physiological activity, and identifying the one state of the physiological activity based on the single index value.

19. The optical measurement system of claim 18 , wherein the plurality of states of the physiological activity comprises an active state and an inactive state.

20. The optical measurement system of claim 18 , wherein the plurality of states of the physiological activity comprises at least two different active states.

21. The optical measurement system of claim 18 , wherein the one or more weighting functions comprises a fractional power.

22. The optical measurement system of claim 21 , wherein the fractional power is ½.

23. The optical measurement system of claim 21 , wherein the one or more weighting functions further comprises a ramp function.

24.

Assignees

• Hi Llc

Inventors

• Alford Jamu
• Marblestone Adam
• Vellekoop Ivo
• Sobek Daniel
• Henninger Michael
• Robinson Brian
• Shen Yuecheng
• Horstmeyer Roarke

Classifications

• A61B5/0004 Primary

  characterised by the type of physiological signal transmitted · CPC title

• A61B5/0261

  using optical means, e.g. infrared light · CPC title

• A61B5/0084

  for introduction into the body, e.g. by catheters (A61B5/1459 takes precedence) · CPC title

• A61B5/0066

  Optical coherence imaging · CPC title