Shape sensing with multi-core fiber sensor
AssigneeIntuitive Surgical Operations, Inc.
InventorsEric E. Sanborn, Mark E. Froggatt, Dawn K. Gifford, Jeffrey T. LaCroix, Patrick Roye, Alexander K. Sang
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Abstract
Shape sensing with a multi-core fiber can achieve high accuracy as well as accommodate small bend radii by measuring signals with peripheral waveguide cores placed at multiple different radial distances from the center axis of the fiber, and computing strain metrics from signals of cores selected based on the respective radial distances and a determination of whether the waveguide cores have strained out of range.
Claims20
A shape-sensing system comprising:
- a multi-core optical fiber having embedded therein:
- a central waveguide core placed along a center axis of the optical fiber;
- and
- at least four helically wound peripheral waveguide cores placed at fixed radial distances from the center axis, a value of a first radial distance of the fixed radial distances differing from a value of at least a second radial distance of the fixed radial distances;
- and
- a plurality of interrogators coupled to the central and peripheral waveguide cores;
- at an output of the plurality of interrogators, acquisition electronics configured to measure signals resulting at least in part from light reflected in the central and peripheral waveguide cores;
- and
- a processing facility configured to compute, for each of a plurality of positions along the fiber, one or more strain metrics from the signals associated with the central waveguide core and at least three peripheral waveguide cores selected among the at least four peripheral waveguide cores based on the fixed radial distances of the waveguide cores from the center axis in conjunction with a determination of whether the waveguide cores have strained out of range.
A method comprising:
- measuring optical signals resulting from interrogation of a multi-core optical fiber including a central waveguide core and at least four helically wound peripheral waveguide cores, the peripheral waveguide cores being placed at respective fixed radial distances from a center axis, a value of a first radial distance of the fixed radial distances differing from a value of at least a second radial distance of the fixed radial distances;
- and
- using a processing facility to determine, for each of a plurality of positions along the fiber, which of the at least four peripheral waveguide cores are useful for strain measurements, and to select, among the peripheral waveguide cores determined to be useful for strain measurements, at least three peripheral waveguide cores based on the respective fixed radial distances of the peripheral waveguide cores from the center axis, giving preference to peripheral waveguide cores with greater fixed radial distances;
- and
- using the processing facility to compute a strain profile for the optical fiber from strain metrics evaluated, for each of the positions along the fiber, based on the optical signals associated with the central waveguide core and the selected peripheral waveguide cores.
A non-transitory computer-readable medium storing instructions for controlling the operation of one or more hardware processors to compute a strain profile of a multi-core optical fiber from optical signals measured for a central waveguide core and at least four helically wound peripheral waveguide cores of the optical fiber, the peripheral waveguide cores being placed at fixed radial distances from the center axis, the instructions, when executed, causing the one or more hardware processors to:
- determine, for each of a plurality of positions along the fiber, which of the peripheral waveguide cores are useful for strain measurements, and select, among the peripheral waveguide cores determined to be useful for strain measurements, at least three peripheral waveguide cores based on respective radial distances of the peripheral waveguide cores from the center axis, giving preference to peripheral waveguide cores with greater distances;
- and
- compute the strain profile for the optical fiber from strain metrics evaluated, for each of the positions along the fiber, based on the signals measured for the central waveguide core and the selected peripheral waveguide cores.
Dependencies are inferred from the claim text.