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This PDF file contains the front matter associated with SPIE Proceedings Volume 8218, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.
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The present study focuses on the theoretical and practical infrared radiation propagation properties of tapered silver /
silver iodide coated Hollow Glass Waveguides (HGWs). Tapered HGWs with inner diameters ranging from 300 μm to
650 μm with a linear taper increasing at an approximate rate of 1.5 μm/cm were fabricated and optimized for low-loss
transmission of CO2 laser radiation at of 10.6 μm. The theoretical losses in these tapered silver / silver iodide coated
HGWs are calculated for light transmitted from the big to the small and vice versa. Theoretical calculations used in this
study are based on ray-optics. Experimental loss measurements are likewise presented, along with the calculated and
measured output beam divergence. The experimental bending losses of the tapered HGWs are studied and compared
with those measured and for those for non-tapered, straight bore sizes from 300 to 700 μm. Experimental losses for
tapered Ag/AgI HGWs ranged from 0.732 - 1.340 dB/m depending on configuration and bending radius.
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Ophthalmic surgery may benefit from the use of more precise fiber delivery systems for laser surgery. In this study,
chains of sapphire microspheres integrated into the distal tip of a hollow waveguide are used for preliminary mid-infrared,
Erbium:YAG laser ablation studies in contact mode with ophthalmic tissues, ex vivo. The combination of the
Er:YAG laser's short optical penetration depth and small spot diameters achieved with this novel fiber probe may
provide more precise tissue removal. One, three, and five microsphere chain structures were assembled and compared,
resulting in spot diameters of 67, 32, and 30 μm, respectively. Single laser pulses of 0.1 mJ energy and 75 μs duration
produced craters with average widths of 44, 30, and 17 μm and depths of 26, 10, and 8 μm, for one, three, and five
sphere structures, respectively. Chains of microspheres produced spatial filtering of the multimode Er:YAG laser
beam and fiber, thus providing spot diameters not otherwise available for precise tissue ablation using conventional
fiber delivery systems. With further probe development, this novel approach to mid-IR laser ablation may provide an
alternative to mechanical tools for ultra-precise surgical dissection and removal of ophthalmic tissues.
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Flexible 100-μm-bore hollow fibers were developed for Er:YAG laser delivery. The hollow
fiber was inner coated with silver and dielectric layer to enhance the reflection rate at an objective
wavelength band. A dielectric layer is formed by using the liquid-phase coating technique. Micro tube
pump with an inner diameter of 300-μm is newly used to flow polymer solution through the ultra-thin
silver hollow fiber with a constant speed. Fabrication process and transmission properties of the ultra
thin polymer-coated silver hollow fiber were discussed. The loss for the 100-μm-bore size,
10-cm-length polymer-coated silver hollow fiber was 1.7 dB at the wavelength of 2.94 μm.
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In this work we present the fabrication of silica hollow core photonic crystal fibres (HC-PCF) with guidance at 2.94μm.
As light is confined inside the hollow core with a very small overlap of the guided E-M wave with the fibre material, the
high intrinsic loss of silica at these mid-infrared wavelengths can be overcome. The band gap effect is achieved by a
periodic structure made out of air and fused silica. As silica is bio-inert, chemically stable and mechanically robust, these
fibres have potential advantages over other multi-component, non-silica optical fibres designed to guide in this
wavelength regime. These fibres have a relatively small diameter, low bend sensitivity and single-mode like guidance
which are ideal conditions for delivering laser light down a highly flexible fibre. Consequently they provide a potential
alternative to existing surgical laser delivery methods such as articulated arms and lend themselves to endoscopy and
other minimally invasive surgical procedures. In particular, we present the characterisation and performance of these
fibres at 2.94 μm, the wavelength of an Er:YAG laser. This laser is widely used in surgery since the wavelength overlaps
with an absorption band of water which results in clean, non-cauterised cuts. However, the practical implementation of
these types of fibres for surgical applications is a significant challenge. Therefore we also report on progress made in
developing hermetically sealed end tips for these hollow core fibres to avoid contamination. This work ultimately
prepares the route towards a robust, practical delivery system for this wavelength.
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We report an ultracompact Mach-Zehnder index sensor with a device length of 438.6 μm using two micro-abrupt-tapers
in a cladding-reduced strongly-guiding fiber based on a focused CO2 laser beam. The cladding of strongly-guiding fiber
is chemically etched before irradiated by a focused CO2 laser beam. The index sensitivity is 600 nm/refractive index unit
respectively at around 1.37 μm wavelength with a volume of 31.2 picoliter optical liquid trapping at one micro-abrupt-taper.
A 72 picoliter glucose liquid with concentration of 200 mg/dL can lead to a red-shift of 0.8 nm at 1.3 μm.
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Flexible fiber bundles for image transmission are fabricated by use of hollow optical fiber. The fiber bundle was
fabricated by the well-known stack-and-draw technique, and coated silver film as reflection layer on the inner surface.
In this report, we describe the result of Raman spectral imaging using fabricated bundle.
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This study involves the optimization of thin silver coated Hollow Glass Waveguides (HGWs) for low-loss delivery of
laser radiation at visible wavelengths and discusses preliminary work in the development of polystyrene dielectric thin
films in silver coated HGWs for low-loss radiation delivery at near and far infrared wavelengths. The optimization of the
silver thin film deposition procedure in HGWs for reduced transmission losses at λ = 500 - 1050 nm is presented along
with experimental results. Such low-loss hollow waveguides are capable of delivering high power / high energy laser
light with no functional damage. The benefits and use of novel polystyrene thin films in HGWs is likewise presented and
preliminary experimental results are discussed along with potential applications of said polystyrene coated waveguides.
Polystyrene is an attractive material for use as a dielectric thin film in HGWs due to its relatively low refractive index
nearing the optimal refractive index of n = 1.414 for use as a single dielectric thin film in HGWs. Furthermore, its nontoxicity,
low cost, and chemical inertness add to its beneficial use as a transparent thin film at visible and infrared
wavelengths ranging from λ = 500 - 3,000 nm and λ > 50 μm. Its broadband transparency additionally allows for its
simultaneous use as a dielectric film in HGWs at infrared and visible wavelengths. Preliminary results in the
development of polystyrene coated HGWs optimized for transmission at short and long wavelengths are presented,
primarily through FTIR spectroscopic methods. The design for the optimization of deposited polystyrene thin films in
HGWs based on desired transmission wavelength range is discussed.
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Near-UV laser light is used for soft tissue treatment for several years now. In first applications the light was delivered
directly from the laser, but for in vivo treatment more flexibility was needed. Multi-mode fibers can be used to achieve a
high output power coupled from multi-mode lasers. If fiber bundles are used the power can be increased additionally.
But the power density on the treated tissue does not rise proportionally, because of the larger spot. A better ablation can
be achieved with a Gaussian beam profile coming from a single-mode fiber. Higher beam quality and higher intensity
from a small single-mode core produce power densities in the order of kW/cm2 in a focus spot smaller than 100 μm. If
the laser therapy is used with the scanning fiber endoscope, treatment in between imaging spirals can be employed and
only a single fiber is required. 405 nm laser-induced fluorescence may be able to produce both wide-field fluorescence
imaging and laser therapy in a single laser. However additional wavelengths combiners and dual-clad couplers are
necessary for multi-wavelength reflectance imaging requiring increased input power to compensate for the losses of
these devices. This leads to very high intensities at the fiber coupler and damage will occur at this interface. Differences
in damage rate due to differently treated fiber end-faces will be discussed. We suggest a new loss mechanism which is
basal for the end-face damage and show miscellaneous methods to reduce the occurring damage and enhance the system
lifetime.
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Bile duct cancers are increasing in frequency while being difficult to diagnose. Currently available endoscopic imaging
devices used in the biliary tree are low resolution with poor image quality, leading to inadequate evaluation of
indeterminate biliary strictures. However, a new ultrathin and flexible cholangioscope system has been successfully
demonstrated in a human subject. This mini-cholangioscope system uses a scanning fiber endoscope (SFE) as a
forward-imaging guidewire, dimensions of 1.2-mm diameter and 3-m length. Full color video (500-line resolution at
30Hz) is the standard SFE imaging mode using spiral scanning of red, green, and blue laser light at low power. Image-guided
operation of the biopsy forceps was demonstrated in healthy human bile ducts with and without saline flushing.
The laser-based video imaging can be switched to various modes to enhance tissue markers of disease, such as widefield
fluorescence and enhanced spectral imaging. In parallel work, biochemical discrimination of tissue health in pig
bile duct has been accomplished using fiberoptic delivery of pulsed UV illumination and time-resolved autofluorescence
spectroscopic measurements. Implementation of time-resolved fluorescence spectroscopy for biochemical
assessment of the bile duct wall is being done through a secondary endoscopic channel. Preliminary results indicate that
adequate SNR levels (> 30 dB) can be achieved through a 50 micron fiber, which could serve as an optical biopsy
probe. The SFE is an ideal mini-cholangioscope for integration of both tissue and molecular specific image contrast in
the future. This will provide the physician with unprecedented abilities to target biopsy locations and perform
endoscopically-guided therapies.
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A spectral imaging system based on a bundle of hollow optical fibers transmitting infrared radiation image is
constructed. The system consists of an FT-IR spectrometer and a high-speed infrared camera and infrared transmission
spectra are obtained by carefully processing multiple interferograms. It is shown that infrared spectral images of a variety
of samples are measured by the system. By mapping transmission of the specific wavelengths in the spectrum, existence
maps of oil and fat of biological samples are obtained.
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The objective of this study is to validate a method for the measurement of tissue oxygen saturation level via a
thermal imaging bundle in-vitro and in-vivo. The method consists of a thermal imaging system and an algorithm
which estimates the compound concentration according to the temperature rise of the tissue. A temperature rise
is obtained by illuminating the tissue in the NIR range and is measured using a thermal camera and a coherent
thermal imaging bundle for non-invasive transendoscopic use. The system was validated using agar phantoms of
varying concentrations of Methylene Blue and ICG as well as blood samples. The algorithm estimated the
Methylene Blue relative amount and the results were compared to the real relative amount. The calculated RMS
of the error was 5.12%, a satisfying value for this stage. In the blood samples, for oxygenation levels higher than
50% the RMS of the error was 5.79%. Once the system was verified a portable system was built for clinical use,
this system was also evaluated on agar phantoms and the RMS of the error was 10.64%. As a result of the
encouraging experiments in-vivo, animal trials were performed. The oxygenation levels of mice were decreased
and were estimated respectively using our system. The system determined a small decrease in the tissue oxygen
saturation of the mice. These results verify the algorithm's and bundle's suitability for the use in a non-invasive
system. They provide motivation for performing more complex in-vitro experiments and moving on to clinical
trials.
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We have fabricated hollow waveguides based on a silver-clad stainless steel tube for delivery of infrared (IR) laser light
such as Er-YAG and CO2 laser light. The silver-clad layer's inner wall was polished to a mirror-smooth state. A thin
silver iodide (AgI) layer was formed by iodination of the layer's inner surface to enhance reflection of the propagating
IR light at the inner wall of the hollow waveguide. The waveguide's inner and outer diameters are 0.4 and 0.6 mm,
respectively. Since this type of metallic hollow waveguide has high mechanical strength and heat resistance, it seldom
fractures or melts. Moreover, it has such a small diameter that it can be bent flexibly. We have experimentally fabricated
a 1-m-long hollow waveguide with a 0.24 μm thick inner AgI layer, which is optimum thickness for Er-YAG laser light
transmission. The transmissions of Er-YAG laser light were 64% and 60% under a straight condition and a 90° bend
with a 7.5-cm radius condition, respectively. By optimizing the thickness of the inner AgI layer according to the
propagating light's wavelength, CO2 laser light can also be transmitted effectively though the hollow waveguide.
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Large core silica optical fibers are often used for delivering high power laser for medical applications. It has been
observed that optical fibers that are transmitting high power laser light may fracture when bent and that the polymer
cladding or coating of the fiber plays a significant part in determining the fiber strength. In this work, we examine the
fiber performance in bending under high laser power after the fiber is treated at high humidity and high temperature, a
condition encountered commonly in medical applications, such as in an autoclave.
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In this study, a metal assisted guide mode resonance device for bioanalytical applications is proposed. The particular
spectrum inversion property and its resonance mechanism are discussed. The metal assisted guided mode resonance
eliminates evanescent wave distributed in substrate and provides a strongly asymmetric modal profile; the evanescent
wave is one fold enhanced in top medium. The intrinsic bulk sensitivity achieves 337.5 in a fundamental TM mode
resonating at 800nm with 1st diffraction angle.
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Hollow Glass Waveguides (HGWs) incorporating single dielectric thin film designs deposited on silver coated silica
hollow waveguides have been used for low-loss transmission of infrared radiation in the 2 - 14 micrometer region. Silver
iodide has traditionally been the material of choice as a dielectric thin film in HGWs, with other dielectric thin film
materials such as cadmium sulfide and lead sulfide being used as well. The incorporation of multilayer stacks of
alternating low and high refractive index dielectric thin films in HGWs has been theoretically shown to further reduce
the optical attenuation. Theoretically, lower losses are achieved when the refractive index contrast of the two thin film
materials used is high and the number of films incorporated in the HGW film structure increases. Theoretically, such
multilayer dielectric stack designs can give rise to the appearance of 1-D photonic bandgap structures with
omnidirectional reflection properties as long as critical design parameters are met and scattering contributions due to
surface roughness and similar defects are sufficiently low. This study involves the practical design of multilayer
dielectric stacks in HGWs, with lead sulfide as a high refractive index material and cadmium sulfide as low refractive
index material. The design, optimization, and processing methodology for achieving low-loss multilayer dielectric stacks
in HGWs at desired infrared wavelengths is discussed. Characterization of multilayer dielectric coated HGWs includes
FTIR spectroscopy for determining the optical response and infrared laser measurements for determining the optical
attenuation properties of said multilayer dielectric stack coated HGWs. The experimental loss dependency of dielectric
coated HGWs incorporating such metal chalcogenide materials on the particular thin film materials used and number of
dielectric layers incorporated is presented and challenges in the current fabrication methodology are discussed.
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The flexible fiber optic probe for laser trapping Raman spectroscopy is developed to analyze single bio-particles in vivo.
The probe consists of the hollow optical fiber and TiO2 micro-lens. Red blood cell and yeast are stably trapped by the
fabricated probe. The Raman measurement of PMMA particle having 10 μm diameters is also demonstrated.
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Transmission characteristics at terahertz (THz) frequencies are numerically analyzed for elliptical dielectric-coated
metallic hollow fibers. Effective refractive indices of the two polarizations of the HE11 mode, the modal power fraction
in the air core and the birefringence of the fiber are presented. The impact of the metallic layer on the field confinement
is investigated by comparing the modal profiles of the dielectric-coated metallic hollow fiber (DMHF) to that of the
polymer tube (PT). Effects of dielectric absorption on the transmission properties are demonstrated. Total transmission
loss of about 2 dB/m and birefringence in the order of 10-2 are predicted. Owing to the high reflectivity of the inner
coatings, more than 99% of the fundamental mode power is confined in the air core.
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A new concept for exciting whispering gallery modes (WGMs) using small core microstructured optical fibers (MOFs)
is presented. Here a 10 μm spherical dye doped micro resonator was positioned onto the tip of the MOF, and the
application of this device for refractive index sensing applications is presented. With this configuration, both the
excitation and collection efficiency of the WGM modulated fluorescence spectra of the dye are found to be greatly
improved compared to the more traditional excitation scheme in which the resonator is attached to a glass slide and
excited using a confocal microscope. This novel MOF-tip configuration provides a more compact and robust architecture
for in vivo/vitro biosensing applications. It is also shown that the same architecture can be used to operate the dye doped
resonator beyond its lasing threshold, resulting in improved performances.
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The realization of a DNA biosensor based on Double Tilted Fiber Bragg Grating (DTFBG) for label-free detection has
been demonstrated. To our knowledge this is the first time that a biosensor has been realized with such kind of device.
The surface of the optical fiber has been functionalized with peptide nucleic acid (PNA) in order to capture DNA
strands. The changes of the interference fringes visibility of the grating, due to the PNA-DNA binding, proved the
occurred fiber hybridization. The re-use of the fiber for multiple measurements and the selectivity of the sensor have
been also investigated.
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Vitreoretinal surgery requires delicate manipulation of retinal tissue. However, tool-to-tissue interaction forces in the order
of sub-millinewton are usually below the human sensory threshold. A surgical force sensor (FS) compatible with
conventional surgical tools may significantly improve the surgery outcome by preventing tissue damage. We have
designed and built a miniature FS for vitreoretinal surgery using a fiber-optic common-path phase-sensitive optical
coherence tomography (OCT) system where the distal end of the fiber probe forms a low-finesse Fabry-Pérot (FP) cavity
between the cleaved tip of the lead-in single mode fiber and the polished back surface of a stainless steel surgical tool tip.
To accurately measure the change of the FP cavity length, the cavity is interrogated by the fiber-optic common-path
phase-sensitive OCT. The FP cavity was illuminated with a broadband light source, and the interferometric signal was
detected using a broadband spectrometer. The phase of the interferometric signal, which is proportional to the cavity
length change as well as the exerted force, was extracted. We have conducted calibration experiments to characterize our
one dimensional FS. Our result shows that the FS responses linearly to force in axial direction with force sensitivity better
than 0.25 millinewton.
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Dispersive Fourier Transform (DFT) is a powerful technique for real-time and high-speed spectroscopy. In DFT, the
spectral information of an optical pulse is mapped into time using group velocity dispersion (GVD) in the dispersive
fibers with an ultrafast real-time spectral acquisition rate (>10 MHz). Typically, multi-mode fiber (MMF) is not
recommended for performing DFT because the modal dispersion, which occurs simultaneously with GVD, introduces
the ambiguity in the wavelength-to-time mapping during DFT. Nevertheless, we here demonstrate that a clear
wavelength-to-time mapping in DFT can be achieved by using the few-mode fibers (FMFs) which, instead of having
hundreds of propagation modes, support only a few modes. FMF-based DFT becomes appealing when it operates at the
shorter wavelengths e.g. 1-μm range, a favorable spectral window for biomedical diagnostics, where low-cost single
mode fibers (SMFs) and high-performance dispersion-engineered fibers are not readily available for DFT. By employing
the telecommunication SMFs (e.g. SMF28), which are in effect FMFs in the 1-μm range as their cut-off wavelength is
~1260 nm, we observe that a 3nm wide spectrum can be clearly mapped into time with a GVD as high as -72ps/nm and a
loss of 5 dB/km at a spectral acquisition rate of 20 MHz. Moreover, its larger core size than the high-cost 1-μm SMFs
renders FMFs to exhibit less nonlinearity, especially high-power amplification is implemented during DFT to enhance
the detection sensitivity without compromising the speed. Hence, FMF-based DFT represents a cost-effective approach
to realize high-speed DFT-based spectroscopy particularly in the biomedical diagnostics spectral window.
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We report the optimal design for hollow fiber inner-coated with metallic and multi-dielectric layers by using ray-optics
theory. Transmission characteristics of the multilayer hollow fiber are more dependent on the film surface roughness in
infrared region. Comparisons of fibers with smooth and rough films are made and discussed in detail. The optimal design
for film thickness, inner radius, the number of layers and refractive indices is presented. The calculation results are
important for structure design, material selection and further fabrication of metallic multilayer hollow fiber when
considering imperfections in film coating techniques.
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The mid-infrared radiation generated by bulk Dy:PbGa2S4 laser working at room temperature was characterized and for
its delivery the special type of COP/Ag hollow waveguide was used. The optical pumping of Dy:PbGa2S4 laser was
performed by flashlamp pumped Er:YLF laser at 1.73 μm wavelength. The compact 60 mm long Dy:PbGa2S4 laser
oscillator worked in free-running mode with the repetition rate 1.5 Hz. The output energy was 5.1 mJ in 80 μs long pulse
at 4.3 μm wavelength. The spatial beam structure was close to the Gaussian shape.
The goal of the presented study was the preliminary investigation of the mid-infrared Dy:PbGa2S4 radiation delivery
possibility by the cyclic olefin polymer and silver coated hollow glass waveguide. The length of the waveguide was
103 cm and the inner diameter was 700 μm. The thickness of the polymer inner layer was calculated for the optimal
4 μm radiation transmission. Mid-infrared laser radiation was coupled into the waveguide by the CaF2 lens with the focal
length 55 mm. The characterization of delivered 4.3 μm radiation was provided. It was observed that the spatial structure
is changing essentially, which follows from the transmission principle of the hollow waveguide. As conclude the
delivery system for 4.3 μm mid-infrared Dy:PbGa2S4 laser radiation was investigated for the first time.
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A spectral Attenuated Total Reflection (ATR-) sensor with variable path lengths is proposed. Based on a new polymer
cladding material, the numerical aperture and the related maximum propagation angle in Polymer Clad Silica Fiber
(PCSF) have been increased significantly. The penetration depth of the evanescent field into the cladding of step-index
fibers depends strongly on the propagation angle. We found that when removing its cladding, the effective path length in
the interaction section can be adjusted, using meridional rays/modes of different propagation angles. Because the fiber
length is short, the mode conversion in the light-transporting section of the PCSF is negligible.
After measuring the optical properties of the PCSF, the ATR with selected liquids surrounding the light-guiding core is
determined in dependence of wavelength and excitation-angle. Especially, the possibilities to change from low to high
propagation angles including the excitation and detection system will be discussed.
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Polymer claddings with low refractive indices for silica core fibers were developed. Applications include fiber
lasers and transmission of high power lasers in surgery. For many applications, operating fibers under high
temperatures is desirable. In a previous publication, the results of testing polymer cladded silica core fiber at 150°C
for 6400 hours were given, along with 5000 hours of testing polymer films. The results at 150°C were encouraging,
with little additional loss measured. Here we test polymers under more severe conditions, at 270°C, for periods up
to 10 hours. The polymers' cured indices range from 1.374 to 1.397 (at 852 nm). Changes in Young's modulus,
refractive index, yellowing, weight, hardness, strength, and elongation were observed. While these polymers cannot
function at 270°C for extended periods, it is possible to expose them for shorter durations without significant
damage. Some polymer properties actually improved after 4 hours of heating. Fibers clad with such polymers have
been successfully jacketed with extruded materials, and have endured high temperatures for a few minutes. It is
possible that a sensor, fiber laser or other fiber device could function in these temperatures for short periods without
the coating properties changing beyond values required for operation.
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Macro-bending fiber optic based heart-rate and pulse pressure shape monitors have been fabricated and tested for
non-invasive measurement. Study of fiber bending loss and its stability and variations are very important
especially for sensor designs based on optical fiber bending. Wavelengths from 1300 nm to 1550 nm have been
used with fabrication based on multimode fiber, single mode fiber, and photonic crystal fiber. The smallest
studied curvature would demand the use of single mode standard fibers. The collected data series show high
quality suitable for random series analysis. Fractal property of optically measured pulse pressure data has been
observed to correlate with physical activity. Correlation to EKG signal suggests that the fabricated monitors are
capable of measuring the differential time delays at wrist and leg locations. The difference in time delay could
be used to formulate a velocity parameter for diagnostics. The pulse shape information collected by the fiber
sensor provides additional parameters for the analysis of the fractal nature of the heart. The application to real
time measurement of blood vessel stiffness with this optical non-invasive fiber sensor is discussed.
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Vitreoretinal surgery is a technically demanding ophthalmologic discipline. One of the main technical challenges in
vitreoretinal surgery is the lack of force sensing since the surgical maneuvers fall below the human sensory threshold.
Previously, a 2-degree-of-freedom (DOF) force sensing instrument with a surgical pick was developed and tested.
However, a more commonly used instrument for vitreoretinal surgery is the forceps, with which a surgeon can easily
grasp and delaminate the scar tissue.
We have designed, fabricated and calibrated a novel 20-gauge (Ga) microsurgical instrument with a 2-DOF force
sensing forceps. Three fiber Bragg grating (FBG) sensors are integrated into the customized AlconTM forceps tip. The
redundant sensor configuration provides good compensation for temperature-related drift. The calibration data show that
the tool can provide a force resolution of 0.25 mN.
In order to test the functionality and performance, the forceps was evaluated in inner shell membrane peeling
experiments with chicken embryos as well as in in-vivo rabbit experiments. The instrument has demonstrated the
capability of being applied in the clinical environment, with consistent force measurements. The force exerted in inner
shell membrane peeling is from 6.07 to 34.65 mN. The development of the 2-DOF force sensing micro-forceps has
shown that the fabrication process is feasible and reliable, and it can be used to develop a future 3-DOF force sensing
tool.
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In this paper, we propose and demonstrate a highly sensitive Microbend Fiber Sensor (MFS) for Ballistocardiogram
(BCG) recording. The MFS based BCG sensor is built into a cushion. It is a portable, small, light and low cost device.
High quality and repeatable BCG signals can be obtained by using this device which allows patients at home to monitor
their cardiovascular health. The measured BCG waveforms closely resemble those in the existing literatures. The BCG
heart beat detection agrees well with one from photo-plethysmography (PPG) signal.
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Chalcogenide glass fiberoptics could underpin new mid-infrared medical endoscopic systems for real-time molecular
sensing, imaging and analysis of tissue and for fiber laser surgery at new mid-infrared wavelengths. Moreover,
chalcogenide glass fiberoptic and waveguide devices and systems could provide the key to new mid-infrared
communications for molecular sensing to inform decision-taking in other sectors as diverse as manufacturing, energy,
the environment and security. The development and deployment of chalcogenide glasses for mid-infrared photonics over
the next decade or so could mirror the complexity and versatility of silica fiber optics developed in the 20th Century for
near-infrared photonics. These ideas are developed in this paper and the current status of chalcogenide glass photonics is
briefly surveyed.
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Minimally-invasive blood glucose monitoring is a very efficient and important way to control blood glucose level of
diabetes. An implantable fiber-optic surface plasmon resonance sensor for minimally-invasive blood glucose monitoring
is presented. As the fiber-optic SPR sensor is sensitive to temperature and moreover the human body temperature drift
plays a great effect on measurement results when the sensor is implanted in human body, long period fiber grating (LPFG)
is utilized for temperature compensation to improve measurement accuracy. The fiber-optic surface plasmon resonance
sensor is theoretically analyzed and the parameters such as the length of sensor, diameter of fiber, thickness of Chrome
and gold are calculated and simulated. The parameters of LPFG is analyzed and simulated, such as length, period and
modulation depth. The structural parameters of the sensor are optimized through the calculation and simulation.
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