Optically monitoring brain activities using 3D-aware head-probe
A flexible head probe and modular head probe system that includes an optical functional near-infrared spectroscopy (fNIRS) system and integrated position sensor. The head probe and modular head probe system determines physiological data based upon the optical information gathered by the fNIRS system and gathers motion and position data from the position sensor. The physiological data and motion and position data are combined to permit topographical and tomographic analyses of a user's brain tissue.
1. A head probe comprising:
plural flexible modules, each module comprising:
a communication port configured to temporarily physically interface one of the plural modules with another of the plural modules to create an inter-connected system of modules;
a flexible base configured to conform to a section of a user's head surface;
a first light source, on a surface of the base facing the user's head, that propagates light through a user's head tissue;
a first photodetector, on the surface of the flexible base facing the user's head, that detects light from the first light source after the light traverses the user's head tissue; and
a position sensor that gathers positioning and motion data of the head probe, the positioning and motion data representative of locations and spatial arrangement of the first light source and the first photodetector.
2. The head probe of claim 1 wherein the position sensor includes a 3-axis accelerometer and a gyroscope.
3. The head probe of claim 1 wherein the light propagated is near-infrared light with a wavelength between 600-2500 nm.
4. The head probe of claim 1 wherein the first photodetector detects light on a first flexible module from a light source on an interfaced second flexible module after the light traverses the user's head tissue.
5. The head probe of claim 1 further comprising a wireless transceiver.
6. The head probe of claim 1 wherein the flexible base is diamond shaped, composed of two triangles connected along one edge.
7. The head probe of claim 1 wherein the plural flexible modules each further comprises a second photodetector, on the surface of the flexible base facing the user's head, located farther from the first light source than the first photodetector that detects the light from the first light source after the light traverses the user's head tissue.
8. The head probe of claim 7 wherein the plural flexible modules each further comprises:
a second light source, on the surface of the flexible base facing the user's head, that propagates additional light through the user's head tissue; and
wherein the first and the second photodetectors detect the light emitted by the first light source and the additional light emitted by the second light source after the light and the additional light traverse the user's head tissue.
9. A modular head probe system comprising:
plural flexible modules, each comprising:
a communication port configured to temporarily interface with another of the plural modules to create an inter-connected system of modules;
a light source, on a surface facing a user's head, that propagates light from the light source through a user's head tissue;
a light detector, on the surface of the given module facing the user's head, that detects the light from the light source after the light traverses the user's head tissue; and
a position sensor; and
a master module comprising a controller, the controller configured to determine physiological data of the user's head tissue based upon light detected by the photodetectors of the plural flexible modules, the controller further configured to use the motion and positioning data gathered by the position sensors of the plural flexible modules to recover locations and spatial arrangements of the light detectors and the light sources of the plural flexible modules.
10. The modular head probe system of claim 9 wherein the plural flexible modules and the control unit are configured to be connected, disconnected, and reconnected in multiple layout configurations.
11. The modular head probe system of claim 9 wherein the physiological data comprises hemodynamics.
12. The modular head probe system of claim 9 wherein the controller is further configured to use the locations and the spatial arrangements of the light detectors and the light sources of the plural flexible modules to perform at least one of the following: data cleaning, data processing, data correction, data pruning, and detection of data artifacts on the physiological data.
13. The modular head probe system of claim 9 wherein the plural modules are further configured to be connected using inter-integrated circuit protocol.
14. The modular head probe system of claim 9 wherein the master module includes a wireless transceiver and an external power source connection.
15. The modular head probe system of claim 9 wherein the physiological data is determine, and wherein the motion and positioning data is gathered in real time during user activity.
16. The modular head probe system of claim 9 further comprising a backend computer configured to determine all connection routes between the plural flexible modules and the master module and further configured to determine an optimized module layout.
17. The modular head probe system of claim 16 wherein the optimized module layout is defined as maximizing an average brain sensitivity.
18. The modular head probe system of claim 9 further comprising a computer configured to use the locations and the spatial arrangements of the light detectors and the light sources of the plural flexible modules to map the physiological data to a tomographic reconstruction of the user's head tissue.