scholarly journals An Electro-Thermal Actuation Method for Resonance Vibration of a Miniaturized Optical-Fiber Scanner for Future Scanning Fiber Endoscope Design

Actuators ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 21 ◽  
Author(s):  
Aydin Aghajanzadeh Ahrabi ◽  
Mandeep Kaur ◽  
Yasong Li ◽  
Pierre Lane ◽  
Carlo Menon
Keyword(s):  
Optical Fiber ◽  
Single Mode ◽  
The Body ◽  
Tube Diameter ◽  
Experimental Results ◽  
Thermal Excitation ◽  
Transthoracic Needle Biopsy ◽  
Scanning Fiber Endoscope ◽  
Scanning Fiber ◽  
Insertion Tube

Medical professionals increasingly rely on endoscopes to carry out many minimally invasive procedures on patients to safely examine, diagnose, and treat a large variety of conditions. However, their insertion tube diameter dictates which passages of the body they can be inserted into and, consequently, what organs they can access. For inaccessible areas and organs, patients often undergo invasive and risky procedures—diagnostic confirmation of peripheral lung nodules via transthoracic needle biopsy is one example from oncology. Hence, this work sets out to present an optical-fiber scanner for a scanning fiber endoscope design that has an insertion tube diameter of about 0.5 mm, small enough to be inserted into the smallest airways of the lung. To attain this goal, a novel approach based on resonance thermal excitation of a single-mode 0.01-mm-diameter fiber-optic cantilever oscillating at 2–4 kHz is proposed. The small size of the electro-thermal actuator enables miniaturization of the insertion tube. Lateral free-end deflection of the cantilever is used as a benchmark for evaluating performance. Experimental results show that the cantilever can achieve over 0.2 mm of displacement at its free end. The experimental results also support finite element simulation models which can be used for future design iterations of the endoscope.

scholarly journals Multiple Light Coupling and Routing via a Microspherical Resonator Integrated in a T-Shaped Optical Fiber Configuration System

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 521 ◽  
Author(s):  
Georgia Konstantinou ◽  
Karolina Milenko ◽  
Kyriaki Kosma ◽  
Stavros Pissadakis
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Single Mode ◽  
Equatorial Region ◽  
Experimental Results ◽  
Glass Microsphere ◽  
Single Mode Optical Fiber ◽  
Light Coupling ◽  
Fiber Taper ◽  
Optical Fiber Taper

We demonstrate a three-port, light guiding and routing T-shaped configuration based on the combination of whispering gallery modes (WGMs) and micro-structured optical fibers (MOFs). This system includes a single mode optical fiber taper (SOFT), a slightly tapered MOF and a BaTiO3 microsphere for efficient light coupling and routing between these two optical fibers. The BaTiO3 glass microsphere is semi-immersed into one of the hollow capillaries of the MOF taper, while the single mode optical fiber taper is placed perpendicularly to the latter and in contact with the equatorial region of the microsphere. Experimental results are presented for different excitation and reading conditions through the WGM microspherical resonator, namely, through single mode optical fiber taper or the MOF. The experimental results indicate that light coupling between the MOF and the single mode optical fiber taper is facilitated at specific wavelengths, supported by the light localization characteristics of the BaTiO3 glass microsphere, with spectral Q-factors varying between 4.5 × 103 and 6.1 × 103, depending on the port and parity excitation.

scholarly journals Optical Fiber Sensor Experimental Research Based on the Theory of Bending Loss Applied to Monitoring Differential Settlement at the Earth-Rock Junction

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Jianchun Qiu ◽  
Dongjian Zheng ◽  
Kai Zhu ◽  
Bin Fang ◽  
Lin Cheng
Keyword(s):  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Single Mode ◽  
Differential Settlement ◽  
The Body ◽  
Fiber Sensor ◽  
Monitoring Device ◽  
The Earth ◽  
Bending Loss ◽  
Sensor Monitoring

Considering the differential settlement in the junction between the structure perpendicular to the dike and the body and foundation of dike (called the earth-rock junction in this paper) during runtime, an experimental investigation of optical fiber sensor monitoring was conducted. Based on the sensing mechanism of single-mode optical fiber bending loss, the experiment focused on the influence of the bending radius of an optical fiber on the bending loss. In view of the characteristics of the differential settlement in the earth-rock junction, we designed a butterfly-type optical fiber sensor and composite optical fiber sensor for monitoring device in monitoring the differential settlement to enlarge the monitoring range and improve the sensibility of optical fiber sensor. Based on the research on the working principle and bending properties of the composite optical fiber monitoring device, we conducted experiments on the bending of the composite optical fiber sensor monitoring device and the use of the device for monitoring the differential settlement. These experiments verified the feasibility of the composite optical fiber sensor monitoring device at monitoring the differential settlement in the earth-rock junction.

Self-Contained Image Recalibration in a Scanning Fiber Endoscope Using Piezoelectric Sensing

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
I. L. Yeoh ◽  
P. G. Reinhall ◽  
M. C. Berg ◽  
E. J. Seibel
Keyword(s):  
Image Quality ◽  
Optical Fiber ◽  
Base Station ◽  
Major Step ◽  
Imaging Device ◽  
Calibration Chamber ◽  
Scanning Fiber Endoscope ◽  
The Cost ◽  
Optical Calibration ◽  
Scanning Fiber

The scanning fiber endoscope (SFE) is a new ultrathin (1.2 mm diameter) medical imaging device that utilizes a unique mechanical scanning technique to image large (120 deg) fields of view (FOVs). A single 80 μm optical fiber is circularly vibrated by a piezo-electric tube to illuminate a field while the reflected light is collected to construct an image pixel-by-pixel. Accurate scanning of the optical fiber is paramount to image quality. Previously, an optical calibration chamber in the base station was used to calibrate the scanning of the optical fiber. This analytical and experimental work eliminates the use of the calibration chamber by implementing a new piezoelectric sensing approach enabling self-contained recalibration to maintain high-image quality during long medical procedures and also reducing the cost, size, and power consumption of the SFE. This work provides a major step toward self-calibration through adaptive control without additional sensors.

Method to Achieve High Frame Rates in a Scanning Fiber Endoscope

2011 ◽  
Vol 5 (3) ◽  
Author(s):  
Matthew J. Kundrat ◽  
Per G. Reinhall ◽  
Eric J. Seibel
Keyword(s):  
Flexible Endoscopy ◽  
Initial Position ◽  
The Body ◽  
Target Area ◽  
Imaging Device ◽  
Velocity Imaging ◽  
Time To Build ◽  
Image Center ◽  
Scanning Fiber Endoscope ◽  
Scanning Fiber

A new and miniature imaging device is being developed to allow flexible endoscopy in regions of the body that are difficult to reach. The scanning fiber endoscope employs a single scanning optical fiber to illuminate a target area, while backscattered light is detected one pixel at a time to build a complete image. During each imaging cycle the fiber is driven outward in a spiral pattern from its resting state at the image center to the outer fringe of the image. At this point, the fiber is quickly driven back to its initial position before acquiring a subsequent frame. This work shortens the time between successive images to achieve higher overall frame rates by applying a carefully timed input, which counteracts the tip motion of the scanning fiber, quickly forcing the scanning fiber to the image center. This input is called motion braking and is a square wave function dependent upon the damped natural frequency of the scanning fiber and the instantaneous tip displacement and velocity. Imaging efficiency of the scanning fiber endoscope was increased from 75–89% with this implementation.

scholarly journals DESIGNING A TEMPORARY COLD PROTECTIVE GEAR CONSTRUCTED BY FOLDING NEWSPRINT PAPER CONSIDERING HEAT-RETAINING PROPERTY AND RIGIDITY

2021 ◽  
Vol 1 ◽  
pp. 1123-1132
Author(s):  
Tatsuya Oda ◽  
Shigeru Wesugi
Keyword(s):  
Natural Disaster ◽  
Cold Season ◽  
Apex Angle ◽  
The Body ◽  
Experimental Results ◽  
Protective Gear ◽  
Significant Difference ◽  
Body Shapes

AbstractDuring the cold season, the cold protective products are often short during evacuation life after a natural disaster. If evacuees can make and wear simple cold protective gears by using materials obtainable on site, it will reduce the burden on the evacuees in emergent situation. Therefore, we investigated the structure constructed by folding newsprint paper, which can improve the heat retention effect and be applied to various body shapes. Focusing on the glide reflection structure repeating a smaller chamber, the basic size was determined by experiments with reference to the accordion shape, and the experimental results indicated that the heat retention effect was significantly greater than that of a mere air layer and those of ordinary fabrics. Next, it was found that the apex angle of structure had no significant difference in the heat retention effect. Then, the dimensions of the structure were determined to maintain the air layer under the pressure of the clothes by simulation of structural analyses. Finally, we made a temporary cold protective gear that can practically cover the trunk of the body and found that the heat retention effect was significantly higher than that of unprocessed newsprint and that of accordion shape.

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