A cam portion (22) is attached to a first position (111) on a measurement target (110). A moving portion (24) is attached to a second position (112) on the measurement target (110) and is movable with respect to the cam portion (22) in an expanding/contracting direction of the measurement target (110). A strain portion (25) is attached to the moving portion (24) so as to fit along the measurement target (110), and is pressed against the cam portion (22). A strain of the strain portion (25) changes when the measurement target (110) expands or contracts and the moving portion moves (24) accordingly. An optical fiber sensor (10) has a temperature measurement portion (16) for measuring a temperature, and a strain measurement portion (17) for measuring a strain, and is attached to the strain portion (25).

An optical strain gauge system measures strain on the exterior surface of a pipe to identify areas of wear on the interior surface of the pipe. The optical strain gauge system comprises an optical sensing interrogator and at least one optical fiber. The optical sensing interrogator comprises a light source and a light sensor. The at least one optical fiber includes fiber Bragg gratings along the length of the optical fiber. The optical fiber is arranged on the exterior surface of the pipe with the fiber Bragg gratings forming a two-dimensional array of points at which strain measurements are obtained. The two-dimensional array of strain measurement points provides an accurate assessment of the strains on the exterior of the pipe which can be used to identify areas of wear on the interior surface of the pipe.

An apparatus, and related method, relates generally to a fiber-optic sensing system. In such a system, fiber-optic sensors are in a rosette or rosette-like pattern. An optical circulator is coupled to receive a light signal from a broadband light source, to provide the light signal to the fiber-optic sensors, and to receive a returned optical signal from the fiber-optic sensors. A spectral engine is coupled to the optical circulator to receive the returned optical signal and configured to provide an output signal.

A method of displaying stress distribution on a sample surface includes: step S4 of capturing images of the sample surface before loading, during the loading, and after unloading; step S5 of measuring a first strain amount for each pixel position based on correlation between the image before the loading and the image after the unloading; step S6 of measuring a second strain amount for each pixel position based on correlation between the image before the loading and the image during the loading; step S7 of calculating stress for each pixel position based on the difference between the first strain amount and the second strain amount; and step S8 of displaying the distribution of the calculated stress at each pixel position.

Measurement apparatus (20) includes a garment (24, 26, 140, 160) including an elastic fabric (27) having a predefined pattern (28) extending across a surface thereof and configured to be worn over a part of a body of a subject (22), such that the elastic fabric stretches across the part of the body. A camera (30, 80) is configured to capture images of the pattern while contacting and traversing across the surface of the fabric while the subject wears the garment. At least one processor (32, 36, 60) is configured to process the images captured by the camera at multiple locations on the surface of the fabric so as measure a local deformation of the pattern at the multiple locations due to stretching of the fabric, and to compute a dimension of the part of the body responsively to the measured deformation.

A device and system for enabling calibration of a structure includes at least one elongate strap having a lower temperature coefficient than the structure, and a length sufficient to encompass a circumference of an external surface of the structure, and at least one diffraction grating having a temperature coefficient at least as high as the structure, wherein the diffraction grating is coupled to the strap and is in direct contact with the external surface of the structure. Deformations in the external surface of the structure induce corresponding deformations in the diffraction grating.

A system for calibrating a deformable sensor is provided. The system includes a deformable sensor including a housing, a deformable membrane coupled to an upper portion of the housing, and an enclosure defined by the housing and the deformable member; an imaging sensor configured to capture an image of the deformable membrane of the deformable sensor; and a controller. The enclosure is configured to be filled with a medium. The controller is configured to: receive the image of the deformable membrane of the deformable sensor; determine whether a contour of the deformable membrane in the image of the deformable membrane of the deformable sensor corresponds to a predetermined contour; and adjust a volume of the medium in the enclosure of the deformable sensor in response to the determination that the contour of the deformable membrane is different from the predetermined contour.

Shape-sensing systems and methods for medical devices. The shape-sensing system can include a medical device, an optical interrogator, a console, and a display screen. The medical device can include an integrated optical-fiber stylet having fiber Bragg grating (“FBG”) sensors along at least a distal-end portion thereof. The optical interrogator can be configured to send input optical signals into the optical-fiber stylet and receive FBG sensor-reflected optical signals therefrom. The console can be configured to convert the reflected optical signals with the aid of filtering algorithms of some optical signal-converter algorithms into plottable data for displaying plots thereof on the display screen. The plots can include a plot of curvature vs. time for each FBG sensor of a selection of the FBG sensors for identifying a distinctive change in strain of the optical-fiber stylet as a tip of the medical device is advanced into a superior vena cava of a patient.

The present invention relates to a method for evaluating physical properties of a thin film specimen and a thin film specimen for a tensile test of the present invention, and according to the present invention, reliability of measured physical properties can be increased, and an abnormal damage of a thin film specimen can be suppressed by analyzing the strain rate of a speckle pattern formed on the thin film specimen by using a digital image correlation analysis scheme during a tensile test of the thin film specimen.

A cable comprising: a plurality of optical fiber cores; and one or more optical fiber core wires including one or more of the optical fiber cores. Further, at least one of the optical fiber core wire is fixed at a plurality of positions in a longitudinal direction of the cable so as to achieve substantially no displacement in a cable radial direction, at least a pair of the optical fiber core wires are fixed in a plane perpendicular to the longitudinal direction of the cable so as to achieve substantially no displacement relative to each other, and sensing of a strain profile in the longitudinal direction of at least the pair of the optical fiber core wires leads to achievement of sensing of a shape of the cable in the longitudinal direction.