A measurement system for assisting in guiding an elongated medical device in a body is described. The measurement system comprises a multicore fiber for insertion into an elongated medical device such that a position of the tip of the multicore fiber corresponds with a position near the tip of the elongated medical device, the multicore fiber comprising a plurality of cores, and a measurement device being adapted for determining, based on the optical signals measured from the multicore fiber, a known shape applied to the multicore fiber, and for deriving based thereon, a length of the portion of the multicore fiber that has been introduced in the body or a position of the multicore fiber in the body.

Distributions of a Brillouin frequency shift and a Rayleigh frequency shift in optical fibers set up in a material are measured from scattered waves of pulse laser light entered into the optical fibers, and distributions of pressure, temperature, and strain of the material along the optical fibers at a measurement time point are analyzed using coefficients that are inherent to the set up optical fibers and correlate pressure, temperature, and strain of material with the Brillouin frequency shift and the Rayleigh frequency shift.

A strain detector 1 includes: a metal plate 4 that is fixed to a first end 210 of a first tube 21 and a second end 220 of a second tube 22 while the metal plate 4 straddles a weld 3 between the first end 210 and the second end 220, the first tube 21 and the second tube 22 forming part of a boiler tube 2; and an optical fiber 5 that is fixed to a top of the metal plate 4 and that extends in an axial direction (a first direction D1) of the first tube 21 and the second tube 22. In this manner, the metal plate 4 is fixed to the first tube 21 and the second tube 22 while straddling the weld 3, and the optical fiber 5 is fixed to the top of the metal plate 4, which enables the strain detector 1 to accurately detect a strain in the weld 3 of the boiler tube 2.

A cable tie having a strain sensing device incorporated therein. In one embodiment, the strain sensing device is a fiber Bragg grating (FBG), which is preferably molded within the strap. In this case, the cable tie further includes a socket in optical communication with the fiber Bragg grating for coupling of the cable tie to an external light source. In another embodiment, the strain sensing device is a mechanical fuse that activates in the presence of a predetermined amount of strain on the cable tie. The mechanical fuse is preferably disposed on the strap and is made of a fuse material having a mechanical strength lower than a mechanical strength of the material of the strap so that the mechanical fuse will fracture or deform earlier than the material of the underlying strap when both the fuse and the strap experience the same increasing strain.

An apparatus comprising at least one sensor to detect the position and/or orientation of a body portion of a subject, the sensor in communication with a computing device to process sensor data and optionally a transmitter to transmit sensor data between the sensor and the computing device and/or one or more computing devices.

The present invention relates to an optical shape sensing system, comprising an optical fiber sensor comprising an optical fiber having embedded therein a number of at least four fiber cores (1 to 6) arranged spaced apart from a longitudinal center axis (0) of the optical fiber, the fiber cores each having a resonance wavelength in response to light introduced into the fiber cores (1 to 6) in an unstrained state thereof. The system further comprises an optical interrogation unit (21) configured to interrogate the fiber cores (1 to 6) with light in a scan wavelength range including the resonance wavelengths of the fiber cores in an unstrained state of the fiber cores (1 to 6). The scan wavelength range is set such that a center wavelength of the scan wavelength range is decentered with respect to the resonance wavelength of at least one of the fiber cores (1 to 6).

There is described a method for interrogating optical fiber comprising fiber Bragg gratings (“FBGs”), using an optical fiber interrogator. The method comprises (a) generating an initial light pulse from phase coherent light emitted from a light source, wherein the initial light pulse is generated by modulating the intensity of the light; (b) splitting the initial light pulse into a pair of light pulses; (c) causing one of the light pulses to be delayed relative to the other of the light pulses; (d) transmitting the light pulses along the optical fiber; (e) receiving reflections of the light pulses off the FBGs; and (f) determining whether an optical path length between the FBGs has changed from an interference pattern resulting from the reflections of the light pulses.

A system for determining the position and orientation of a cutter module relative to a frame of a highwall miner is provided. The cutter module is attached to the highwall miner by a string of push beams and moveable relative to the highwall miner. A reel is rotatably mounted to the highwall miner frame and configured to feed out a hose chain that supplies fluid to the cutter module. A fiber optic shape sensing system is associated with the cutter module is configured to receive strain information from the fiber bundle and compute the location of at least one position of the fiber bundle that is associated with the cutter module relative to the reference frame.

The invention provides a dynamically swept tunable laser system and method for measuring sensor characteristics obtained from an array of optical sensors comprising means for dividing the total wavelength sweep of the laser into different regions in any particular order where each region contains single or multiple contiguous sweep segments and where each sweep segment is referenced by a start and a stop reference and can have different lengths compared to the other sweep segments. The sensor characteristics are determined from each region swept by the tunable laser. The invention provides for the tunable laser to be adapted to operate in a quasi-continuous mode to select segments in any order. The relative sweep rates of regions can be changed such that some regions can be swept more times than other regions.

The present invention relates to an FBG sensor for measuring a maximum strain of an object being measured, a method for manufacturing the sensor, and a method of using the sensor. To this end, provided is the FBG sensor for measuring a maximum strain, comprising: an optical fiber (130) having an FBG sensor (150) therein; a first metallic foil (120) contacting the optical fiber (130) on one surface thereof; a second metallic foil (120) which comes into surface-contact with the one surface; an adhesive layer (140) provided between the first and second metallic foils (100, 120); a means for measuring a residual strain of the first and second metallic foils (100, 120) through the FBG sensor (150); and a means for calculating a maximum strain on the basis of the measured residual strain and a sensitivity coefficient (Csen) obtained through experimentation.