Optical detection system for determining neural activity in brain based on water concentration

• US 10,420,469 B2
• Filed: 12/15/2017
• Issued: 09/24/2019
• Est. Priority Date: 11/22/2017
• Status: Active Grant

• Current Assignee: Hi LLC (Cybin, Inc.)
• Original Assignee: Hi LLC (Cybin, Inc.)
• Inventors: Sobek, Daniel, Yang, Changhuei, Marblestone, Adam, Alford, Jamu
• Primary Examiner(s): Santos Rodriguez, Joseph M
• Application Number:
  US15/844,411
• Publication Number:
  US 20190150745A1
• Time in Patent Office: 648 Days
• CPC Class Codes: A61B 2562/04 Arrangements of multiple sensors of the same type
• CPC Class Codes: A61B 2576/026 for the brain
• CPC Class Codes: A61B 5/0042 for the brain
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0097 by applying acoustic waves and detecting light, i.e. acoustooptic measurements
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: G01B 9/02002 using two or more frequencies
• CPC Class Codes: G01B 9/0201 using temporal phase variation
• CPC Class Codes: G01B 9/02031 With non-optical systems, e.g. tactile
• CPC Class Codes: G01N 2021/1706 in solids
• CPC Class Codes: G01N 2021/3129 Determining multicomponents by multiwavelength light
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 21/45 using interferometric methods; using Schlieren methods
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G01N 29/2418 : using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046
• CPC Class Codes: G16H 30/40 : for processing medical images, e.g. editing

Abstract

A non-invasive system and method. Sample light is delivered into an anatomical structure, such that a portion of the sample light passes through a target voxel comprising brain matter in the head and is scattered by the head as signal light. The signal light is detected, changes in the level of water concentration or relative water concentration of the target voxel are detected based on the detected signal light, and a level of neural activity is determined within the target voxel based on the determined changes level of the water concentration or relative water concentration of the target voxel.

Claims

1. A non-invasive detection system, comprising:

an optical source configured for delivering sample light into a head, such that a portion of the sample light passes through a target voxel comprising brain matter in the head and is scattered by the head as signal light, wherein the wavelength of the sample light is in the range of 950-1080 nanometers, such that the signal light is encoded with a time-varying optical absorption of the target voxel;

at least one detector configured for detecting the signal light; and

a processor configured for determining changes in the level of water concentration or relative water concentration of the target voxel based on the time-varying optical absorption of the target voxel encoded within the detected signal light, and determining whether or not neural activity exists within the target voxel based on the determined changes level of the water concentration or relative water concentration of the target voxel.

2. The system of claim 1, wherein another portion of the sample light not passing through the target voxel is scattered by the brain matter as background light that combines with the signal light to create a sample light pattern, the system further comprising an interferometer comprising the optical source, the interferometer configured for combining reference light with the sample light pattern to generate an interference light pattern, wherein the at least one detector is configured for detecting the signal light within the interference light pattern.

3. The system of claim 2, further comprising an acoustic assembly configured for delivering ultrasound into the target voxel in the brain matter, such that the signal light is frequency shifted by the ultrasound.

4. The system of claim 3, further comprising a controller configured for operating the acoustic assembly and the interferometer to pulse the ultrasound and the sample light in synchrony, such that only the signal light is frequency shifted by the ultrasound.

5. The system of claim 4, wherein the controller is further configured for operating the interferometer to sequentially modulate the interference light pattern to generate a plurality of different interference light patterns, wherein the at least one detector is configured for detecting the different interference light patterns, and the processor is configured for determining changes in the level of water concentration or relative water concentration of the brain matter based on the detected interference light patterns.

6. The system of claim 5, wherein the at least one detector comprises an array of detectors configured for detecting spatial components of each different interference light pattern, wherein the processor is configured for determining the changes in the level of water concentration or relative water concentration of the target voxel based on the detected spatial components.

7. The system of claim 6, wherein each detector is configured for respectively storing a plurality of values in a plurality of data storing bins representative of the respective spatial components of the interference light patterns, wherein the processor is configured for determining the changes in the level of water concentration or relative water concentration of the target voxel based on the plurality of values stored in the data storing bins of each detector.

8. The system of claim 5, wherein the interferometer is configured for sequentially modulating the interference light pattern by phase modulating the interference light pattern.

9. The system of claim 4, wherein the controller is configured for operating the acoustic assembly and the interferometer to pulse the ultrasound and the sample light in synchrony, such that only a single pulse of the sample light is delivered into the head for each pulse of the ultrasound delivered into the target voxel.

10. The system of claim 4, wherein the controller is configured for operating the acoustic assembly and the interferometer to pulse the ultrasound and the sample light in synchrony, such that a duration of each pulse of the ultrasound delivered into the target voxel is within a decorrelation time of the target voxel, and multiple pulses of the sample light are delivered into the head for each pulse of the ultrasound delivered into the target voxel.

11. The system of claim 2, wherein the interferometer is configured for combining the reference light with the signal light using a homodyne technique.

12. The system of claim 11, wherein the interferometer is further configured for frequency shifting the sample light by the frequency of the ultrasound, such that the reference light is combined with the signal light using the homodyne technique.

13. The system of claim 2, wherein each of the interference light patterns comprises a speckle light pattern.

14. The system of claim 7, wherein the array of detectors is configured for respectively detecting spatial components of each different interference light pattern, and storing the plurality of values for all of the interference patterns in the plurality of data storing bins within 10 milliseconds.

15. The system of claim 7, wherein the array of detectors is configured for respectively detecting spatial components of each different interference light pattern, and storing the plurality of values for all of the interference patterns in the plurality of data storing bins within 1 microsecond to 1 millisecond.

16. The system of claim 7, wherein the processor is configured for reconstructing the amplitude of the signal light using the plurality of values stored in each of the data storing bins, and determining the changes in the level of water concentration or relative water concentration of the target voxel based on the reconstructed amplitude of the signal light.

17. The system of claim 16, wherein each value respectively stored in each of the data storing bins is an intensity of the spatial component of the respective interference light pattern, the processor is configured for using the plurality of values stored in each of the data storing bins to extract a product of the amplitude of the signal light and a known amplitude of the reference light, and determining the amplitude of the signal light from the extracted product.

18. The system of claim 7, further comprising a lock-in camera that includes the array of detectors and the corresponding data storing bins.

29. The system of claim 1, wherein the processor is configured for identifying fast signals in the target voxel based on the determined changes level of the water concentration or relative water concentration of the target voxel, wherein whether or not neural activity exists within the target voxel is determined based on identified fast signals in the target voxel.

19. A non-invasive method comprising:

delivering sample light into a head, such that a portion of the sample light passes through a target voxel comprising brain tissue in the head and is scattered by the head as signal light, the target voxel comprising brain matter, wherein the wavelength of the sample light is in the range of 950-1080 nanometers, such that the signal light is encoded with a time-varying optical absorption of the target voxel;

detecting the signal light;

determining changes in the level of water concentration or relative water concentration of the target voxel based on the time-varying optical absorption of the target voxel encoded within the detected signal light; and

determining whether or not neural activity exists within the target voxel based on the determined changes of the level of water concentration or relative water concentration of the target voxel.

20. The method of claim 19, wherein another portion of the sample light not passing through the target voxel is scattered by the biological tissue as background light that combines with the signal light to create a sample light pattern, the method further comprising combining reference light with the sample light pattern to generate an interference light pattern, wherein the signal light is detected within the interference light pattern.

21. The method of claim 19, further comprising delivering ultrasound into the target voxel, such that the signal light is frequency shifted by the ultrasound.

22. The method of claim 21, further comprising pulsing the ultrasound and the sample light in synchrony, such that only the signal light is frequency shifted by the ultrasound.

23. The method of claim 22, further comprising:

sequentially modulating the interference light pattern to generate a plurality of different interference light patterns; and

detecting the different interference light patterns, wherein the changes in the level of water concentration or relative water concentration of the brain matter are determined based on the detected interference light patterns.

24. The method of claim 22, wherein the ultrasound and the sample light are pulsed in synchrony, such that only a single pulse of the sample light is delivered into the head for each pulse of the ultrasound delivered into the head.

25. The method of claim 22, wherein the ultrasound and the sample light are pulsed in synchrony, such that a duration of each pulse of the ultrasound delivered into the target voxel is within a decorrelation time of the target voxel, and multiple pulses of the sample light are delivered into the head for each pulse of the ultrasound delivered into the head.

26. The method of claim 20, further comprising combining the reference light with the signal light using a homodyne technique.

27. The method of claim 26, further comprising frequency shifting the sample light by the frequency of the ultrasound, such that the reference light is combined with the signal light using the homodyne technique.

28. The method of claim 20, further comprising generating source light, and splitting the source light into the sample light and the reference light.

30. The method of claim 23, identifying fast signals in the target voxel based on the determined changes level of the water concentration or relative water concentration of the target voxel, wherein whether or not neural activity exists within the target voxel is determined based on identified fast signals in the target voxel.