A sensor system includes a radiation source, an optical fiber, and a detection device. The radiation source is arranged to emit pulses of radiation. The optical fiber comprises a first end and a core. The first end is arranged to receive pulses of radiation output from the radiation source such that, in use, the pulses of radiation are coupled into the fiber. The core is arranged to support propagation of the pulses of radiation along the fiber. The core includes a plurality of reflectors each comprising a portion of the core having a refractive index which is different to the refractive index of adjacent regions of the core. Reflections of a pulse of radiation from adjacent reflectors output at the first end of the fiber are resolvable from each other in the time domain. The detection device is arranged to measure radiation output from the first end of the fiber and resolve radiation reflected at different locations in the core of the fiber.

There is provided an OTDR method of assisting a user in finding a temporary event along an optical fiber link using an Optical Time Domain Reflectometer (OTDR). The method comprises: performing at least one OTDR acquisition toward the optical fiber link to obtain a baseline OTDR trace, wherein each OTDR acquisition is performed by propagating in the optical fiber link under test, a pulsed test signal and detecting corresponding return light from the optical fiber link so as to obtain an OTDR trace representing backscattered and reflected light as a function of distance in the optical fiber link; repeating OTDR acquisitions in real-time to obtain real-time OTDR traces; and for each new OTDR acquisition, comparing the corresponding real-time OTDR trace to the baseline OTDR trace to detect a temporary deformation of the OTDR trace using at least one of a difference between the baseline OTDR trace and the real-time OTDR trace and a derivative thereof, said temporary deformation being indicative of the presence of the temporary event along the optical fiber link.

A fluid measurement system and method for determining distributed measurement of a fluid type and a fluid velocity in a wellbore, pipeline or other conduit in which fluid is moving. Measurement is made by immersing one or more cables having sequential sampling sections in the fluid and monitoring a cooling effect across a cable on the sampling sections and the response to injection of a high frequency pulse each sampling section. A probabilistic model is then used to determine the distributed velocity and fluid types along the conduit.

A method and system of compensating for body deformation during image acquisition or external beam treatment includes acquiring image data of a body and peak wavelength data from a plurality of fiber Bragg gratings (FBGs) disposed on the body aligned along a predetermined coordinate system on the body, such as a cartesian coordinate system. The method further comprises detecting effective shifts of the Bragg wavelengths of the FBGs caused by body deformation during image acquisition, and controlling the movement of the body through a cavity in a scanning device and controlling the acquisition of the image data or external beam treatment during body deformation based on the effective shifts of the Bragg wavelengths of the FBGs.

A method for compensating for dynamic changes in a body of a patient during a controlled interaction with the body includes acquiring data from at least one sensing device disposed on the body and detecting a change along at least one optical fiber of the sensing device caused by dynamic changes associated with the body during the controlled interaction. A respiratory gating signal is generated based on the change along the at least one optical fiber of the sensing device measured over time. The method further comprises controlling relative movement between the body and an interactive device in response to the respiratory gating signal to compensate for the dynamic changes associated with the body during the controlled interaction.

A sensing device (10) for a high voltage disconnecting switch (20). The sensing device (10) comprises: a first optical fiber (110) configured to receive light from an optical source (100) and configured to guide the light; an optical collimator (120) coupled to the first optical fiber (110) to receive the light guided in the first optical fiber (110) and configured to collimate the light into a collimated light beam; a bendable optical component (130) coupled to the optical collimator (120) to receive the collimated light beam and configured to guide the collimated light beam, wherein the bendable optical component (130) is configured and arranged to bend depending on a switching state of the high voltage disconnecting switch (20), thereby influencing the collimated light beam; and a deriving unit (160) configured to derive information about the switching state of the high voltage disconnecting switch (20) based on the collimated light beam.

A method for compensating for dynamic changes in a body of a patient during a controlled interaction with the body includes acquiring data from at least one sensing device disposed on the body and detecting a change along at least one optical fiber of the sensing device caused by dynamic changes associated with the body during the controlled interaction. A respiratory gating signal is generated based on the change along the at least one optical fiber of the sensing device measured over time. The method further comprises controlling relative movement between the body and an interactive device in response to the respiratory gating signal to compensate for the dynamic changes associated with the body during the controlled interaction.

A spectral interrogation device, including: an optical source for emitting a light signal, a measurement optical fibre comprising a series of successive Bragg gratings for reflecting the light signal in different wavelength bands, a reflective optical fibre comprising a total reflection element, a wavelength detector, and an optical switch for switching between a sequence of three operating modes. In a first mode, the light signal emitted by a given optical source is guided from the optical source to a corresponding measurement optical fibre. In a second mode, the light signal is guided to make a predetermined number of return trips in a line formed by a coupling between the measurement optical fibre and a corresponding reflective optical fibre, generating a predetermined delay between the successive gratings. In a third mode, the light signal is guided to a corresponding detector to successively measure the wavelength bands associated with the gratings.

A method for compensating for dynamic changes in a body of a patient during a controlled interaction with the body includes acquiring data from at least one sensing device disposed on the body and detecting a change along at least one optical fiber of the sensing device caused by dynamic changes associated with the body during the controlled interaction. A respiratory gating signal is generated based on the change along the at least one optical fiber of the sensing device measured over time. The method further comprises controlling relative movement between the body and an interactive device in response to the respiratory gating signal to compensate for the dynamic changes associated with the body during the controlled interaction.