Abstract: A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients.

Abstract: A biopsy needle has a cylindrical shell outer cannula and a stylet consisting of an inner stylet and outer stylet, both of which are inserted into the cylindrical cannula. The outer stylet has a series of strain relieved slits which provide bending over a deflection region in one direction, and the outer stylet is formed from a material such as a shape memory alloy (SMA) having a superelastic phase. The deflection is generated by an SMA wire spanning a deflection extent and attached to the outer stylet on either side of the deflection extent. The inner stylet, when positioned inside the outer stylet, has one or more actuation fibers which couple optical energy into the SMA wire, causing a deflection of the outer stylet over the deflection extent, with the optical energy provided to the actuation fibers for control of the deflection. Additional fibers may be placed in the inner stylet to measure temperature and to measure deflection.

Abstract: A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients.

Abstract: A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients.

Abstract: A biopsy needle has a central axis and includes one or more sensing regions, each sensing region formed by a plurality of sensing optical fibers located over a particular extent of said central axis and inside the outer shell of the needle. The sensing optical fibers are coupled to a wavelength interrogator. A steerable catheter has a central axis and outer shell, the outer shell coupled to a plurality of optical fibers in sensing regions and actuation regions, the sensing regions formed over particular extents of the central axis by bonding gratings to the inner surface of the outer shell, and the actuation regions formed by coupling optical energy into shape memory alloys bonded to the outer shell.

Abstract: A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients.

Abstract: A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients.

Abstract: A biopsy needle has a cylindrical shell outer cannula and a stylet consisting of an inner stylet and outer stylet, both of which are inserted into the cylindrical cannula. The outer stylet has a series of strain relieved slits which provide bending over a deflection region in one direction, and the outer stylet is formed from a material such as a shape memory alloy (SMA) having a superelastic phase. The deflection is generated by an SMA wire spanning a deflection extent and attached to the outer stylet on either side of the deflection extent. The inner stylet, when positioned inside the outer stylet, has one or more actuation fibers which couple optical energy into the SMA wire, causing a deflection of the outer stylet over the deflection extent, with the optical energy provided to the actuation fibers for control of the deflection.

Abstract: A biopsy needle has a central axis and includes one or more sensing regions, each sensing region formed by a plurality of sensing optical fibers located over a particular extent of said central axis and inside the outer shell of the needle. The sensing optical fibers are coupled to a wavelength interrogator. A steerable catheter has a central axis and outer shell, the outer shell coupled to a plurality of optical fibers in sensing regions and actuation regions, the sensing regions formed over particular extents of the central axis by bonding gratings to the inner surface of the outer shell, and the actuation regions formed by coupling optical energy into shape memory alloys bonded to the outer shell.

Abstract: A biopsy needle has a central axis and includes one or more sensing regions, each sensing region formed by a plurality of sensing optical fibers located over a particular extent of said central axis and inside the outer shell of the needle. The sensing optical fibers are coupled to a wavelength interrogator. A steerable catheter has a central axis and outer shell, the outer shell coupled to a plurality of optical fibers in sensing regions and actuation regions, the sensing regions formed over particular extents of the central axis by bonding gratings to the inner surface of the outer shell, and the actuation regions formed by coupling optical energy into shape memory alloys bonded to the outer shell.

Abstract: A plurality of AWG filters with aliasing responses are selected such that the wavelength range of a fundamental response of the AWG filters results in the aliased range of AWG filters to be adjacent to a fundamental range of the AWG filters. A plurality of optical sources is provided sufficient to cover each fundamental wavelength range and each alias wavelength range of the AWG filters. When a single one of the optical sources is enabled, reflected optical energy from a series string of FBGs coupled to the optical source is applied to the plurality of AWG filters, and the AWG output in combination with the wavelength range of the optical source is used to discriminate reflected wavelength from the FBG sensors.

Abstract: A biopsy needle has a central axis and includes one or more sensing regions, each sensing region formed by a plurality of sensing optical fibers located over a particular extent of said central axis and inside the outer shell of the needle. The sensing optical fibers are coupled to a wavelength interrogator. A steerable catheter has a central axis and outer shell, the outer shell coupled to a plurality of optical fibers in sensing regions and actuation regions, the sensing regions formed over particular extents of the central axis by bonding gratings to the inner surface of the outer shell, and the actuation regions formed by coupling optical energy into shape memory alloys bonded to the outer shell.

Abstract: A wavelength interrogator is coupled to a circulator which couples optical energy from a broadband source to an optical fiber having a plurality of sensors, each sensor reflecting optical energy at a unique wavelength and directing the reflected optical energy to an AWG. The AWG has a detector coupled to each output, and the reflected optical energy from each grating is coupled to the skirt edge response of the AWG such that the adjacent channel responses form a complementary pair response. The complementary pair response is used to convert an AWG skirt response to a wavelength.

Abstract: A biopsy needle has a central axis and includes one or more sensing regions, each sensing region formed by a plurality of sensing optical fibers located over a particular extent of said central axis and inside the outer shell of the needle. The sensing optical fibers are coupled to a wavelength interrogator. A steerable catheter has a central axis and outer shell, the outer shell coupled to a plurality of optical fibers in sensing regions and actuation regions, the sensing regions formed over particular extents of the central axis by bonding gratings to the inner surface of the outer shell, and the actuation regions formed by coupling optical energy into shape memory alloys bonded to the outer shell.

Abstract: An optical add drop multiplexer (OADM) for use in a sensing system has the OADMs arranged either in a cascade or in a ring, with each OADM accepting a source input and generating a source output, and accepting a signal input and generating a signal output, where the source input includes a broadband optical source for use in providing optical power to a plurality of sensor gratings arranged in a series string, each sensor grating responsive to a physical parameter at a unique wavelength. The series string of sensors is excited by optical power coupled from the broadband source port, and returns optical signal response to a sensor port of the OADM, which optical energy is added to optical energy at the signal input port to form the signal output port. In another embodiment for a ring topology, the source ports and signal ports include a clockwise and counterclockwise set of source and sensor signals, and the sensor signals for CW and CCW each include a primary and secondary signal.

Abstract: A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.

Abstract: A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.