National Taiwan University

Other

Chow-Shing Shin

Chia-Chin Chiang

Chun-Pin Lin

Shien-Kuei Liaw

Zheng-Cheng Lin

Uei-Ming Li

Yu-Chang Tseng

Hsuan-Chen Chen

Kin-Man Yip

Chiu-Hao Lin

A system for evaluating cutting efficiency of root canal rotary instruments is provided. The system includes a root canal rotary instrument, a driving unit, a cutting object, a prestressing force providing unit and a feeding unit. The root canal rotary instrument is attached on the driving unit, and driven thereby. The cutting object is pressed by the prestressing force providing unit to contact the root canal rotary instrument. The feeding unit feeds the cutting object to the root canal rotary instrument, and the root canal rotary instrument cuts an uncut surface of the cutting object.

System for evaluating cutting efficiency of root canal rotary instruments

The invention provides a fiber-optic sensing system for measuring a curvature in a small and elongated cavity of an object. The system includes a light source, an optical fiber and a light signal reflecting device disposed at a distal end of the optical fiber. The optical source emits a light signal into the optical fiber. The distal section of the optical fiber is inserted into the cavity of the object which curvature is to be measured. The curvature of the cavity bends the distal section of the optical fiber so that attenuation of light signal transmitting through the distal section occurs. This attenuated signal is reflected by a reflecting device and coupled into a measuring device. Thereby the curvature is deduced in accordance with the amount of energy attenuation in the reflected light signal.

Fiber-optic sensing system for measuring curvature

The invention provides a fiber-optic sensing system, utilizing a fiber-grating-based sensor, for a physical parameter, e.g., a pressure or a temperature. Different kinds of fiber-grating-based sensors may be used for this purpose but in-fiber gratings such as Fiber Bragg Grating, Long Period Grating and Surface Corrugated Long Period Fiber Grating are particularly suitable. Due to the small size of the optical fiber and the fact that same fiber acts as the sensing element as well as the signal conducting medium, it is possible to install the sensor in a small diameter needle which is commonly used for medical diagnosis and treatment. As a result, when the fiber-optic sensing system of the invention is used for in-vivo measurement of a biological parameter, such a sensing needle can be used for different in-vivo pressure or temperature sensing applications without causing too much harm and discomfort to the subject tested.

Fiber-optic sensing system

A device and a method of temperature compensating are disclosed. The device and method are employed for temperature compensation of a section of optical fiber. The device and method are useful for limiting any change in optical properties of the section of optical fiber or optical structures that can be corrected by changing the linear dimension accordingly. Such optical properties include the characteristic wavelengths of FBGs, Fabry-Perot cavities, and the like. The device includes a composite plate comprising plural fiber laminae, each of which has a designed orientation, and having a specific temperature-dependent characteristic in a direction for compensating an optical component positioned thereon having a temperature-dependent deformation, wherein said specific temperature-dependent characteristic is determined by said designed orientations of said plural fiber laminae.

Device and method of temperature compensating optical component

This invention relates to a new technique of interrogating fiber grating sensors employed for measuring physical quantities such as temperature and force. The technique involves the edge filtering of transmitted light that occurs when a narrow bandwidth light of suitable wavelength from a laser source is passed through a Long Period Fiber Grating (LPFG). When the characteristics attenuation spectrum of the LPFG is shifting, an energy modulation effect will be achieved when one measures the intensity of the transmitted narrow bandwidth light. The narrow bandwidth strong light is best obtained by the reflection of a broad band light from a fiber Bragg gratings (FBGs). If the reflected narrow band spectrum from the FBGs is kept constant while the LPFG is subjected to temperature changes, applied loading or other type of suitable physical quantity changes, the characteristic transmission spectrum of the LPFG will shift according to the applied physical quantity, thus modulating the eventual transmitted light intensity. By transforming this intensity into a voltage signal, the variation of the physical quantity concerned can be deduced. Conversely, if the attenuation spectrum of the LPFG is kept constant and the FBG is subjected to temperature changes, applied loading or other type of suitable physical quantity changes, the same modulation effect will be achieved and the physical quantity concerned can likewise be monitored.

Growing community of inventors

Taipei, Taiwan

Chow-Shing Shin