SYSTEM AND METHOD FOR SELECTIVE MEASUREMENT OF FIBER OPTIC INSTRUMENT SENSORS
An instrument system that includes an elongate body, an optical fiber, and a controller is provided. The optical fiber is operatively coupled to the elongate body and has a plurality of strain sensors provided on the optical fiber. The controller is operatively coupled to the optical fiber and adapted to obtain signals from one of the plurality of strain sensors more frequently than from another of the plurality of strain sensors and to determine a position of the elongate body based on the obtained signals from the one of the plurality of strain sensors.
1 . An instrument system, comprising:
an elongate body;
an optical fiber operatively coupled to the elongate body and having a plurality of strain sensors provided on the optical fiber; and
a controller operatively coupled to the optical fiber and adapted to:
obtain signals from one of the plurality of strain sensors more frequently than from another of the plurality of strain sensors; and
determine a position of the elongate body based on the obtained signals from the one of the plurality of strain sensors.
2 . The instrument system of claim 1 , wherein the optical fiber comprises a proximal portion. and a distal portion, and wherein the one of the plurality of strain sensors is located on the distal portion and the another of the plurality of strain sensors is located on the proximal portion.
3 . The instrument system of claim 1 , wherein the controller is adapted to obtain the signals by selecting, based on movement of the elongate body, the one of the plurality of strain sensors to be sampled more frequently.
4 . The instrument system of claim 1 , wherein the optical fiber comprises a first proximal portion and a second proximal portion, wherein the second proximal portion is more proximal than the first proximal portion, and wherein the controller is adapted to select, based on an increase in signal amplitude of signals from the first proximal portion relative to signals from the second proximal portion, the first proximal portion to be sampled more frequently.
5 . The instrument system of claim 1 , wherein the plurality of strain sensors comprise a plurality of axially-spaced Bragg gratings.
6 . The instrument system of claim 5 , wherein the plurality of axially-spaced Bragg gratings are substantially continuous along the optical fiber.
7 . An instrument system, comprising:
an elongate body;
an optical fiber operatively coupled to the elongate body and having a plurality of strain sensors provided on the optical fiber; and
a controller operatively coupled to the optical fiber and adapted to:
select a reference strain sensor from among the plurality of strain sensors;
receive signals from the plurality of optical fibers; and
determine, based on the signals received from the plurality of strain sensors, a position of the elongate body relative to a position of reference strain sensor.
8 . The instrument system of claim 7 , wherein one of the plurality of strain sensors is most proximal to the controller, and wherein the selected reference strain sensor is not the one of the plurality of strain sensors.
9 . The instrument system of claim 8 , wherein the selected reference strain sensor is adjacent to the one of the plurality of strain sensors.
10 . The instrument system of claim 7 , wherein the reference strain sensor is a first strain sensor, and wherein the controller is adapted to select a second reference strain sensor from among the plurality of strain sensors.
11 . The instrument system of claim 10 , wherein the controller is adapted to determine a position of the first strain sensor relative to a position of the second reference strain sensor.
12 . The instrument system of claim 7 , further comprising a localization sensor operatively coupled to the elongate body, wherein the controller is adapted to determine a position of the reference strain sensor relative to a position of the localization sensor.
13 . The instrument system of claim 7 , wherein the instrument system is adapted to prevent the reference strain sensor from moving.
14 . The instrument system of claim 7 , wherein the plurality of strain sensors comprises a plurality of Bragg gratings that are substantially continuous or overlapping.
15 . An instrument system, comprising:
an elongate body;
an optical fiber operatively coupled to the elongate body and having a plurality strain sensors provided on the optical fiber; and
a controller operatively coupled to the optical fiber and adapted to:
select a measurement strain sensor from among the plurality of strain sensors;
receive a signal from the measurement strain sensor; and
determine, based on the signal, a position of a portion of the elongate body at which the measurement strain sensor is located.
16 . The instrument system of claim 15 , wherein the measurement strain sensor comprises a Braga grating, and wherein the controller is configured to receive the signal by measuring only a portion of the Bragg grating, Wherein a length of the portion of the Braga grating is less than a length of the Bragg grating.
17 . The instrument system of claim 16 , wherein the plurality of Bragg gratings are overlapping.
18 . The instrument system of claim 15 , wherein the controller is further configured to select a reference strain sensor from among the plurality of strain sensors, and wherein the controller is configured to determine the position of the portion of the elongate body relative to a position of the reference strain sensor.
19 . The instrument system of claim 18 , wherein the selected reference strain sensor is adjacent to the selected measurement strain sensor.
20 . The instrument system of claim 15 , wherein one of the plurality of strain sensors is most proximal to the controller, and wherein the selected measurement strain sensor is not the one of the plurality of strain sensors.