Fiber optic position and/or shape sensing based on rayleigh scatter
AssigneeLuna Innnovations Incorporated
InventorsMark E. Froggatt, Roger G. Duncan
Life of this patent
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Abstract
A fiber optic position and/or shape sensing device includes an optical fiber with either two or more single core optical fibers or a multi-core optical fiber having two or more fiber cores. In either case, the fiber cores are spaced apart so that mode coupling between the fiber cores is reduced, and preferably, minimized. The optical fiber is physically associated with an object. Strain on at least a portion of the optical fiber where it is associated with the object is determined by an OFDR using one or more Rayleigh scatter patterns for that portion of the optical fiber. The determined strain is used to determine a position and/or a shape of the object.
Claims35
A fiber optic sensing device comprising:
- an optical fiber including at least two fiber cores spaced apart so that mode coupling between the fiber cores is reduced;
- wherein each fiber core has an associated Rayleigh scatter signature and different segments of each fiber core correspond to a portion of the associated Rayleigh scatter signature;
- a frequency domain reflectometer coupled to the optical fiber configured to obtain a Rayleigh scatter pattern associated with each of multiple fiber segments from each core;
- and
- a computing device configured to determine a spectral shift of the Rayleigh scatter pattern associated with each of multiple fiber segments from each core and to use the determined spectral shift for the Rayleigh scatter pattern associated with each of multiple fiber segments from each core in determining a strain parameter for each of the multiple fiber segments from each core and in determining a position and/or shape of a portion of the fiber based on the determined strain parameters.
A fiber optic method, comprising:
- coupling a frequency domain reflectometer to an optical fiber having at least two fiber cores spaced apart so that mode coupling between the fiber cores is reduced, wherein each fiber core has an associated Rayleigh scatter signature and different segments of each fiber core correspond to a portion of the associated Rayleigh scatter signature;
- physically associating the optical fiber with a position and/or shape of an object;
- using the frequency domain reflectometer to obtain a Rayleigh scatter pattern associated with each of multiple fiber segments from each core;
- determining a spectral shift of the Rayleigh scatter pattern associated with each of multiple fiber segments from each core;
- using the determined spectral shift for the Rayleigh scatter pattern associated with each of multiple fiber segments from each core in determining a strain parameter for each of the multiple fiber segments from each core;
- and
- determining a position and/or shape of the object based on the determined strain parameters.
A medical instrument system, comprising:
- a medical instrument;
- an optical fiber conforming at least in part to at least a portion of a shape of the medical instrument and including at least two fiber cores spaced apart so that mode coupling between the fiber cores is reduced;
- wherein each fiber core has an associated Rayleigh scatter signature and different segments of each fiber core correspond to a portion of the associated Rayleigh scatter signature;
- a frequency domain reflectometer coupled to the optical fiber configured to obtain a Rayleigh scatter pattern associated with each of multiple fiber segments from each core that is associated with the portion of the shape of the medical instrument;
- and
- a computing device configured to determine a spectral shift of the Rayleigh scatter pattern associated with each of multiple fiber segments from each core and to use the determined spectral shift for the Rayleigh scatter pattern associated with each of multiple fiber segments from each core in determining a strain parameter for each of the multiple fiber segments from each core and in determining a position and/or a shape of the portion of the medical instrument based on the determined strain parameters.
Dependencies are inferred from the claim text.