Mcdonnell Douglas Corporation

Other

Koninklijke Philips Corporation N.V.

Blue Road Research

The Boeing Company

Han Sen Medical, Inc.

Wicor Holding Ag

Eric Udd

Richard F Cahill

Robert G Younge

Bhaskar S Ramamurthy

Neal A Tanner

Randall L Schlesinger

John P Theriault

Whitten Lee Schulz

Keith H Wanser

Ronald J Michal

Michael M Morrell

Timothy E Clark

Jeffrey A Eck

Gerald L Schwantz

Raymond E Wagoner

Philip A Turek

Vasilii V Spirin

Mikhail G Shlyagin

Sean G Calvert

Eric David Haugse

Peter F Snawerdt, Iii

Angela Trego

Stuart E Higley

George W Finch

Andreas Weisshaar

W Marley Kunzler

Steven F Watanabe

M Wesley Kunzler

Philip M Gretzkowski

A sensor comprising an optical fiber that includes a Bragg grating and a longitudinal-strain-inducing (LSI) jacket for inducing longitudinal strain into the optical fiber as a function of a transverse load, i.e., pressure or force. As the LSI jacket induces strain into the optical fiber, the fiber grating deforms, thereby changing the character of light reflected from the grating. The changes in character of the reflected light can be measured using suitable optical instrumentation. Additional physical characteristics that can be measured/sensed using an LSI-jacket-based sensor include moisture content/presence, chemical content/presence, and temperature. A transverse-load-sensing sensor can include transverse-load-applying structures that compress the LSI jacket under transverse load, causing the jacket to controllably elongate and thereby induce longitudinal strain into the optical fiber. Chemical and moisture LSI jackets can comprise materials that swell in the presence of the chemical or moisture.

Fiber-grating sensors having longitudinal-strain-inducing jackets and sensor systems and structures including such sensors

A fiber grating sensor system is used to measure key parameters that include pressure, strain and temperature at specific locations and at high speed. The system relies on spectral properties associated with the fiber grating sensors, the light source and the optical detection system to provide these capabilities. The system has been successfully applied to measurement of pressures up to 1,200,000 psi and by increasing the spectral width of the light source extensions of pressure measurements to 4,000,000 psi and higher are possible. Temperature change measurements have been made of 400 degrees C. over a period of 25 micro-seconds limited by the physical response of the fiber sensors and the output detector bandwidth both of which can be greatly improved by reducing fiber sizes and with improved detectors. Novel methods have been devised to lower cost and enable measurements with spatial location, speed and accuracy that have been very difficult or not yet achieved.

Fiber grating sensor system for measuring key parameters during high speed

Systems and methods comprise or involve optical fibers having Bragg gratings. The optical fibers can be assembled in a parallel manner into a fiber sensor configuration. Bragg gratings can be written onto different cores of optical fibers. Bragg gratings may be written at a same or nearly same axial position for all optical fibers in the configuration and may be written at the same time and may have a substantially equal index of refraction variation and unequal lengths. Spaced Bragg gratings may also have characteristic sidelobe spectrums for tagging the respective gratings. Gratings can also be written at different wavelengths and over another grating at the same location.

Optical fiber grating sensors and methods of manufacture

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. Each of the plurality of strain sensors has a reflectivity, wherein one of the plurality of strain sensors has a different reflectivity than another one of the plurality of strain sensors. The controller is operatively coupled to the optical fiber and adapted to: receive one or more signals from the plurality of strain sensors; and determine a position of the elongate body based on the one or more signals.

Fiber optic instrument shape sensing system and method

An instrument system that includes an elongate body and an optical fiber is provided. The elongate body has a longitudinal axis and capable of being twisted about the longitudinal axis. The optical fiber is operatively coupled with the elongate body and having a strain sensor provided thereon. The strain sensor is configured to indicate twist of the elongate body.

Optical fiber instrument system for detecting twist of elongated instruments

A method for measuring bending is provided. The method includes receiving a reflected signal from a strain sensor provided on an optical fiber; determining a spectral profile of the reflected signal; and determining bending of the optical fiber based on a comparison of the spectral profile of the reflected signal with a predetermined spectral profile.

Optical fiber shape sensing systems

In certain variations, fiber shape sensing or measuring systems, devices and methods are described herein, which allow for measurement of three dimensional bending as well as twist measurements of various fibers, e.g., optical fibers and fiber optic probes of various sizes. In certain variations, the systems are designed to take advantage of unique light guiding properties of optical fibers and various fiber gratings.

Fiber shape sensing systems and methods

An instrument system that includes an elongate body, an optical fiber, and a detector is provided. The elongate body is capable of being twisted. The optical fiber includes a first portion coupled to the elongate body and a second portion having a curved shape adapted to reduce transfer of twisting or bending from the elongate body to the second portion, the second portion having a strain sensor provided thereon. The detector is coupled to the optical fiber and adapted to receive a signal from the strain sensor.

Optical fiber instrument system for detecting and decoupling twist effects

A medical instrument system includes an elongate instrument body defining a longitudinal axis and capable of being twisted about its longitudinal axis and an optical fiber sensor coupled to the instrument body. A detector is operatively coupled to the optical fiber sensor and configured to detect respective light signals transmitted on the optical fiber sensor. A controller is operatively coupled to the detector and configured to determine a twist of a portion of the instrument body about its longitudinal axis based on an analysis of detected light signals.

A medical instrument system includes an elongate flexible instrument body with an optical fiber substantially encapsulated in a wall of the instrument body, the optical fiber including one or more fiber gratings. A detector is operatively coupled to the optical fiber and configured to detect respective light signals reflected by the one or more fiber gratings. A controller is operatively coupled to the detector, and configured to determine a twist of at least a portion of the instrument body based on detected reflected light signals. The instrument may be a guide catheter and may be robotically or manually controlled.

A fiber grating environmental sensing system is described that has the ability to measure strain, vibration, humidity and water content. Fiber gratings are used to measure axial strain to accomplish these goals. An approach is described that uses matched fiber grating sensors and filters to allow for thermal compensation greatly reducing one of the key performance issues facing these systems. The system may be deployed in such applications as roadways and paved surfaces, bridges, buildings and aircraft and spacecraft. Means are described to implement transducers optimized for specific environmental measurements as well as means to demodulate the fiber grating sensors.

Fiber grating environmental sensing system

A fiber optic sensor, which includes an interference energy analyzer, is used to measure strain and temperature distribution along a test fiber. The sensor includes the following: a plurality of double-Bragg grating elements positioned along a test fiber, a broadband light source which produces a broadband spectral profile that propagates along the test fiber, an optical filter that is able to change the parameters of the broadband spectral profile, an optical reflection detector, a fiber optic beamsplitter, and an interference energy analyzer. Each double-Bragg grating element consists of two weak Bragg gratings, separated by a distance unique to each element. The interference energy analyzer calculates the energies of the interference patterns, which are created by beams reflected from double-Bragg grating elements. The energy of the interference signal changes when the gratings in one element non-uniformly change its parameters due to non-equal temperature or strain influence on two gratings.

Differential fiber optical sensor with interference energy analyzer

Fiber grating environmental measurement systems are comprised of sensors that are configured to respond to changes in moisture or chemical content of the surrounding medium through the action of coatings and plates inducing strain that is measured. These sensors can also be used to monitor the interior of bonds for degradation due to aging, cracking, or chemical attack. Means to multiplex these sensors at high speed and with high sensitivity can be accomplished by using spectral filters placed to correspond to each fiber grating environmental sensor. By forming networks of spectral elements and using wavelength division multiplexing arrays of fiber grating sensors may be processed in a single fiber line allowing distributed high sensitivity, high bandwidth fiber optic grating environmental sensor systems to be realized.

Fiber grating bond joint health monitoring system

The system includes a generally broadband, low coherence length light source that injects light into a fiber beamsplitter that is used to generate counterpropagating light beams in a Sagnac loop. The loop includes two facing fiber beamsplitters connected together at differing length inner legs, with one of the output legs of the second beamsplitter usually being connected to a in place optical fiber that ends with a phase modulator followed by a mirror. Formatted data is transmitted by impressing relative phase differences between the counterpropagating light beams. Optimum performance depends on appropriate choices for critical lengths in the system.

Growing community of inventors

Fairview, OR, United States of America

Eric Udd