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- Front Matter: Volume 7845
- Multimodal Biomedical Imaging
- Optical Methods for Biomedical Applications
- Advanced Optical Techniques for Diagnosis
- Biomedical Imaging and Analysis
- Diffuse Optical Imaging and Scattering Analysis
- Spectroscopy and Tissue Diagnosis
- Multiphoton Microscopy and Applications
- Optical Interactions with Tissues and Cells
- Nano-/Biophotonics
- Photo-thermal Interaction and Calculations
- Optical Techniques: Advances in Research
- Mechanisms and Techniques in Photodynamic Therapy
- Advanced Biomedical and Clinical Systems
- Poster Session
Front Matter: Volume 7845
Front Matter: Volume 7845
Show abstract
This PDF file contains the front matter associated with SPIE Proceedings volume 7845, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.
Multimodal Biomedical Imaging
Quantitative phase microscopy of red blood cells with slightly-off-axis interference
Show abstract
Microscopic interferometry is a noncontact technique for quantitative phase imaging of live cells. The method combines
the principles of single-shot slightly-off-axis interferometry and confocal microscopy and is characterized by real-time
acquisition capabilities and optimized spatial resolution. However, slightly-off-axis interferometry requires less detector
bandwidth than traditional off-axis interferometry and fewer phase-shifted steps than on-axis interferometry. Meanwhile,
confocal microscopy allows microstructure magnification imaging. To validate the utility of this technique, experimental
and theoretical comparisons are given. The potential of the technique for phase microcopy is demonstrated by
experiments on red blood cells. This study will set the basis for interferometric phase measurements of dynamic
processes with fine spatial details, especially for observing live biological cell dynamics.
Elimination of the twist distortion in IVUS and CAG image fusion based on the Frenet-Serret formulas
Show abstract
Cardiovascular disease can be diagnosed at higher accuracy by the fusion of IVUS (Intravascular Ultrasound) and
CAG (Coronary Angiography) data. In the IVUS images acquisition process, pull-back path of the ultrasonic probe
will twist due to intravascular blood flow and friction with vascular wall, which causes image distortion in the
fusion of such IVUS images. In this paper, a new method used for reducing the twist between adjacent frames of
IVUS is presented. First, we establish a rough perspective projection imaging model from the crossing information
of two almost perpendicular projective angiography images. Then we use a discrete approximation of the
Frenet-Serret formulas to calculate IVUS frames' relative twist by sequential triangulation method and correct the
twist. Finally, coronary lumen data extracted from the corrected IVUS images are added to 3D transducer paths
which are reconstructed by the model mentioned above. Reconstruction of the coronary artery which contains the
lumen information of IVUS removes blind spots in CAG and provides a full view of artery which is absent in
IVUS images.
Optical Methods for Biomedical Applications
Depletion kinetics of circulating prostate cancer cells studied by in vivo flow cytometer
Guangda Liu,
Jin Guo,
Yan Li,
et al.
Show abstract
Prostate cancer is the most common malignancy in American men and the second leading cause of deaths from cancer,
after lung cancer. The tumor usually grows slowly and remains confined to the gland for many years. During this time,
the tumor produces little or no symptoms or outward signs. As the cancer advances, however, it can metastasize
throughout other areas of the body, such as the bones, lungs, and liver. Surgical resection, hormonal therapy,
chemotherapy and radiation therapy are the foundation of current prostate cancer therapies. Treatments for prostate cause
both short- and long-term side effects that may be difficult to accept. Molecular mechanisms of prostate cancer
metastasis need to be understood better and new therapies must be developed to selectively target to unique
characteristics of cancer cell growth and metastasis. We have developed the "in vivo microscopy" to study the
mechanisms that govern prostate cancer cell spread through the microenvironment in vivo in real-time confocal nearinfrared
fluorescence imaging. A recently developed "in vivo flow cytometer" and optical imaging are used to assess
prostate cancer cell spreading and the circulation kinetics of prostate cancer cells. A real- time quantitative monitoring of
circulating prostate cancer cells by the in vivo flow cytometer will be useful to assess the effectiveness of the potential
therapeutic interventions.
Evaluation of whole blood coagulation process by optical coherence tomography
Xiangqun Xu,
Jia Lin
Show abstract
This study was to investigate the feasibility of using optical coherence tomography (OCT) to evaluate whole blood
coagulation process. Attenuation coefficients and 1/e light penetration depth (D1/e) against time of human whole blood
during in vitro clot formation under static were measured from the OCT profiles of reflectance vs depth. The results
obtained clearly showed that the optical parameters are able to identify three stages during the in vitro blood clotting
process. It is concluded that D1/e measured by OCT is a potential parameter to quantify and follow the liquid-gel
transition of blood during clotting.
Dynamic temperature monitoring and control with fully distributed fiber Bragg grating sensor
Show abstract
In this paper, fiber Bragg grating (FBG) is used as a fully distributed sensor to monitor tissue dynamic temperature
changes during laser-induced interstitial thermotherapy (LITT). This work is mainly realized by the correlative single
particle (CSP) algorithm, which is a rapid algorithm for spectrum reconstruction. Experimental LITT treatment was set
up by using 532nm laser applicator on a piece of fresh liver tissue. In the experiments, the dynamic temperature profile
was successfully demodulated with a refreshing speed of 11 seconds. With the aid of dynamic feedback, the
thermotherapy boundary temperature was well controlled around 35°C during the treatment by adjusting the laser output
power in real-time. Therefore, with this method, it is promising to precisely control the tissue temperature in vivo and
improve the safety of the LITT remarkably.
Effects of the optical transfer function on velocity estimation with optical coherence tomography
Show abstract
Doppler optical coherence tomography (DOCT) is an extension of optical coherence tomography (OCT) for measuring
blood flow dynamics simultaneously with the microscopic structures at high spatial and velocity resolution. In this paper,
we analyze the effects of parameters of the DOCT system on the optical transfer function (OTF) which finally affects the
accuracy of the velocity estimation. Experimental data are given to show the effects. The methods of overcoming the
effects are also pointed out.
Advanced Optical Techniques for Diagnosis
Single-detector polarization-sensitive OCT for biological tissue imaging
Show abstract
In this paper, we built up a single-detector PS-OCT system using only one detector. It displays interference light
oscillation caused by tissue birefringence as grey image, eliminating the time-comsuming calculation in conventional
two-detector PS-OCT. The periodicity of grey scale indicates the birefringence distribution of tissue, which is far more
straightforward than Muller matrix or Stokes vector in conventional two-detector PS-OCT. The the imaging theory and
setup of single-detector PS-OCT is discussed in detail, and experiment with bovine cartilage proved its ability of
detecting tissue birefringence.
Monitoring collagen remodeling on opto-thermal response of photoaged skin irradiated by Er:YAG laser with optical coherence tomography
Show abstract
The Optical Coherence Tomography technology was used to perform noninvasive cross-sectional imaging of
internal structures in photoaged mouse skin irradiated by Er:YAG laser. The mice were irradiated chronically with a
steady dose of ultraviolet irradiation. Various laser light doses were irradiated on the back skins of the photoaged mouse.
An OCT was used to observe the process of the collagen remodeling in dermis. The relationship between optical
characteristic parameter such as attenuation coefficient and light dose was discovered. The total attenuation coefficient
increased when the light dose increased. Our findings showed that Er:YAG laser could be used for the symptoms of the
photoaged skin with some degree of thermal damage in the dermis, and the OCT could image the progress of collagen
remodeling in photoaged mouse dermis. The OCT may be a useful tool for the determination of optimal parameters for
laser skin treatment.
Biomedical Imaging and Analysis
Performance of hybrid system for fluorescence and micro-computed tomography in synchronous mode
Show abstract
Fluorescence diffuse optical tomography (FDOT) plays an important role in studying physiological and pathological
processes of small animals in vivo. The low spatial resolution, however, limits the ability of FDOT in resolving the biodistributions
of fluorescent markers. The anatomical information provided by X-ray computed tomography (CT) can be
used to improve the image quality of FDOT. However, in most hybrid FDOT/CT systems, the projection data sets of
optics and X-ray are acquired sequentially, which increases the acquisition time and bring in the unwanted soft tissue
displacement. In this paper, we evaluate the performance of a synchronous FDOT/CT system, which allows for faster
and concurrent imaging. Compared with previous FDOT/CT systems, the two subsystems (FDOT and CT) acquire
projection images in synchronous mode, so the body position can keep consistent in the same projection data acquired by
both subsystems. The experimental results of phantom and in vivo experiments suggest that the reconstruction quality of
FDOT can be significantly improved when structural a priori information is utilized to constrain the reconstruction
process. On the other hand, the synchronous FDOT/CT system decreases the imaging time.
Effect of electrode configurations on the focal spot of x-ray tube
Show abstract
The grating-based x-ray phase-contrast imaging have more advantages over the conventional
x-ray imaging techniques based on the attenuation of x-rays in soft tissues in the medical
diagnosis. However, until now the phase contrast imaging technique have not been put into
practical uses, one of the reasons is that there is no compact x-ray source suitable for phase
signal detection. The x-ray tube that can be used as the source of phase contrast imaging system
is becoming the focus of research, the key issues of which could be the shape and the uniformity
of focal spot. This paper provided and studied one kind of x-ray tube based on the electron
impinging target. According to the system design of the phase contrast imaging, an x-ray tube
with square focal spot of 0.8 mm side length was needed. An electrode structure which could
form a planar electric field distribution was so designed that the emitted electrons from filament
could move to target along straight paths. For comparison, an axis-symmetry field x-ray tube
was designed too. The electron trajectories were simulated following the computation of the
electric potential distributions in the two cases of electrode structure, respectively. The
simulation results show that the x-ray tube of planar field structure may lend more regular
square shape to focus spot than the axis-symmetry field structures.
Characterization of photoacoustic signal using wavelet analysis
Show abstract
In this paper, we present the continuous wavelet analysis for extract the information of photoacoutical signal sampled
with a focoused transducer. The results demonstrate that wavelet transform of photoacoustic signals with 1 time
averaging could reconstruct the localization and the size of absorbers, and it greatly reduced the data acquisition time. In
addition, the results indicate that the localization and the size of absorbers could be recovered as the value of
signal-to-noise ratio (SNR) is in the range from 0.3 to1.
Multispectral colour analysis for quantitative evaluation of pseudoisochromatic color deficiency tests
Show abstract
Multispectral color analysis was used for spectral scanning of Ishihara and Rabkin color deficiency test book images. It
was done using tunable liquid-crystal LC filters built in the Nuance II analyzer. Multispectral analysis keeps both,
information on spatial content of tests and on spectral content. Images were taken in the range of 420-720nm with a
10nm step. We calculated retina neural activity charts taking into account cone sensitivity functions, and processed
charts in order to find the visibility of latent symbols in color deficiency plates using cross-correlation technique. In such
way the quantitative measure is found for each of diagnostics plate for three different color deficiency carrier types -
protanopes, deutanopes and tritanopes. Multispectral color analysis allows to determine the CIE xyz color coordinates of
pseudoisochromatic plate design elements and to perform statistical analysis of these data to compare the color quality of
available color deficiency test books.
Diffuse Optical Imaging and Scattering Analysis
Quantitative analysis of dehydration in porcine skin caused by optical clearing agents
Show abstract
Dehydration is supposed to be one of mechanisms of optical clearing, but current studies merely gave some qualitative
descriptions. Here an analysis method was established to evaluate the water content of skin with PLS method based on
the measurements of near-infrared reflectance spectroscopy and weight of porcine skin. Furthermore, a commercial
spectrometer with integrating sphere was used to measure the reflectance and transmittance after treatment with different
agents. Then the established method was used to evaluate the water content, while the Inverse Adding-Double algorithm
was used to calculate the reduced scattering coefficients. The results show that both the water contents and reduced
scattering coefficients decrease during the optical clearing process, and there is direct relationship between the optical
clearing efficacy and dehydration. With the treating time last, the relative change in reduced scattering coefficient is
larger than that in dehydration of skin, and the difference between the changes depends on the agents. Therefore, we
conclude that dehydration is the main mechanism of skin optical clearing during the 60 min treatment of the agents, but
for some OCAs, i.e., PEG400, glycerol, or D-sorbitol, there might be some other mechanisms contributing to the optical
clearing efficacy.
Study on the backscattering Mueller matrix of the sphere-cylinder scattering model of anisotropic tissues
Show abstract
Most biological tissues are anisotropic turbid media containing fibrous structures,
such as collagen fibers, axons, or myofibrils. Tests using both unpolarized and
polarized lights indicate that the anisotropic tissues can be approximated to a
scattering medium containing cylindrical and spherical scatterers. Mueller matrix, as a
representative measurement to examine polarization properties, can be used to analyze
some important information of turbid media. In this paper, we measure the two
dimensional backscattering Mueller matrix of a microsphere-silk phantom composed
of a slab of well aligned silk fibers submerged in microsphere solution. We also use a
polarization sensitive Monte Carlo simulation program to analyze the Mueller matrix
of sphere-cylinder scattering media, such as the microsphere-silk sample. We present
systematic analysis about the relationship between the characteristic features in all the
Mueller matrix elements and the important parameters of the sphere-cylinder
scattering medium approximating biological tissues, such as the sphere-cylinder ratio,
direction of the cylinders, diameters of both types of scatterers, etc. These
experimental and simulation results confirm the practicability of backscattered
Mueller matrix characterizing such anisotropic scattering media like biological
tissues.
The influence of molecules adsorbed on surface enhanced Raman scattering
Show abstract
The relationship between the SERS signal intensity properties and the soaking times in a given concentration of
4-aminothiophenol (4-ATP) solution is experimentally investigated. The results show that the relationship depends on
the specific position of the SERS excitation wavelength within the LSPR spectrum of the SERS substrates. In the case of
LSPR peak wavelength of the SERS substrate located at the right side of ideal excitation wavelength arrangement, the
SERS intensity no longer increases monotonically with the soaking time, which is different from the previous result
reported.
Spectroscopy and Tissue Diagnosis
Feasibility study for rapid determination of alanine aminotransferase concentration in whole blood by using visible and near infrared spectroscopy
Show abstract
Visible and Near infrared spectroscopy was applied for the fast determination of alanine
aminotransferase with whole blood. First, spectra of different thickness (0.5mm, 1mm, 2mm, 4mm
) were investigated to explore Optimal Optical Path for determination. The results show that the whole
blood sample with 0.5mm thickness is more suitable for spectral analysis. And then Near infrared
spectroscopy of 176 samples were collected. Multiplicative scatter correction and second-order
differential method have been used to spectral pretreatment. Stepwise multiple linear regression
method and partial least squares regression method have been employed to establish quantitative
detection model to predict content of alanine aminotransferase in whole blood. The alanine
aminotransferase measured presents best result in calibration and prediction by Near-Infrared
Spectroscopy with partial least squares regression calibration model, and the calibration correlation
coefficient, the standard error of calibration and the standard error of prediction are 0.98, 2.42 and
7.22 respectively.
Discriminant analysis for classification of colonic tissue autofluorescence spectra
Show abstract
This study evaluates the potential of a discriminant analysis to classify colonic mucosa from
autofluorescence spectral characteristics. With 337 nm excitation, the autofluorescence spectra of colonic
tissues were measured using a FLS920 spectrofluorimeter. Principal component analysis (PCA) combined
with Fisher's discriminant analysis was performed for tissue classification. As a result, the sensitivity and
specificity of the discriminant analysis is 92.3% and 90.5%, respectively. The results suggest the relative
concentrations of collagen and nicotinamide adenine dinucleotide (NADH) are the potential diagnostic
biomarkers for colonic tissue classification using autofluorescence spectroscopy, and the discriminant
analysis based on PCA is useful to differentiate adenocarcinoma from normal tissue.
Raman micro-spectroscopy for classification of nasopharyngeal tissue in vitro
Show abstract
Nasopharyngeal carcinoma is one of the most serious diseases which is mostly found in Asia, especially in South China.
Early detection and diagnosis is crucial to effective treatment and can greatly improve survival rate. Recent
developments in tissue spectroscopy may significantly expand our ability to diagnose this tumor rapidly and accurately.
In this work, Raman spectra of nasopharyngeal tissue in vitro were acquired and analyzed with principal component
analysis. Consistent spectral differences appear to exist between normal and cancerous tissue, mainly in five bands
located at 853cm-1, 937cm-1, 1094cm-1, 1260-1340cm-1, 1530-1580 cm-1, respectively. Statistical analysis was performed
using PCA which can easily divide the samples to two groups with a high sensitivity and specificity. The results
presented here demonstrate Raman spectroscopy has the potential ability to detect and diagnose cancerous tissue nondestructively
and rapidly which may be a very helpful diagnosis tool in the future.
Multiphoton Microscopy and Applications
The analysis of aging skin based on multiphoton microscopy
Show abstract
Aging is a very important issue not only in dermatology, but also in cosmetic science. Cutaneous aging
involves both chronological and photoaging aging process. The chronological aging is induced with the
passage of time. And the photoaging skin is the extrinsic aging caused by sun exposure. The aim of this study
is to use multiphoton microscopy (MPM) in vivo to assess intrinsic-age-related and photo-age-related
difference. The changes of dermal collagen are measured in quantitively. The algorithm that we used
automatically produced the transversal dermal map from MPM. Others, the texture of dermis are analyzed by
Fourier transform and Gray Level Co-occurrence Matrix. And the object extraction in textured images is
proposed based on the method in object edge extraction, and the aim of it is to detect the object hidden in the
skin texture in difference aging skin. The result demonstrates that the approach is effective in detecting the
object in epidermis and dermis textured image in different aging skin. It could help to further understand the
aging mechanism.
Cell flow analysis with a two-photon fluorescence fiber probe
Show abstract
We report the use of a sensitive double-clad fiber (DCF) probe for in situ cell flow velocity measurements and cell
analysis by means of two-photon excited fluorescence correlation spectroscopy (FCS). We have demonstrated the
feasibility to use this fiber probe for in vivo two-photon flow cytometry previously. However, because of the viscosity of
blood and the non-uniform flow nature in vivo, it is problematic to use the detected cell numbers to estimate the sampled
blood volume. To precisely calibrate the sampled blood volume, it is necessary to conduct real time flow velocity
measurement. We propose to use FCS technique to measure the flow velocity. The ability to measure the flow velocities
of labeled cells in whole blood has been demonstrated. Our two-photon fluorescence fiber probe has the ability to
monitor multiple fluorescent biomarkers simultaneously. We demonstrate that we can distinguish differently labeled
cells by their distinct features on the correlation curves. The ability to conduct in situ cell flow analysis using the fiber
probe may be useful in disease diagnosis or further comprehension of the circulation system.
Collagen alteration as quantitative optical biomarker of epithelial tumor progression
Show abstract
Collagen plays an important role during epithelial tumor progression. Visualizing collagen alteration may become an
intrinsic indicator for evaluating epithelial tumor progression. In this work, we demonstrate that collagen alteration can
be used as quantitative optical biomarker of epithelial tumor progression by use of second harmonic generation
microscopy.
Optical Interactions with Tissues and Cells
A role for Nrf2 in UVA-mediated heme oxygenase induction and protection from membrane damage in human skin fibroblasts
Show abstract
Our previous study has shown that Ultraviolet-A (UVA) irradiation induces heme oxygenase 1 (HO-1) expression in
cultured human primary skin fibroblasts FEK4. In the present study, we demonstrate a coordinated induction of HO-1
and NF-E2-related factor 2 (Nrf2) following UVA irradiation or hemin treatment. The induction of HO-1 by either UVA
irradiation or hemin treatment was largely abolished by down-regulation of Nrf2 with its targeted short interfering RNA
(siNrf2). The study further reveals that knockdown of Nrf2 protein increased UVA-induced cell death measured by MTS
assay. These findings together indicate that Nrf2-mediated induction of HO-1 expression may provide a cytoprotection
for human skin cells from oxidative damage.
Photonic homeostatics
Show abstract
Photonic homeostatics is a discipline to study the establishment, maintenance, decay, upgrading and representation
of function-specific homoestasis (FSH) by using photonics. FSH is a negative-feedback response of a biosystem to
maintain the function-specific fluctuations inside the biosystem so that the function is perfectly performed. A stress may
increase sirtuin 1 (SIRT1) activities above FSH-specific SIRT1 activity to induce a function far from its FSH. On the one
hand, low level laser irradiation or monochromatic light (LLL) can not modulate a function in its FSH or a stress in its
stress-specific homeostasis (StSH), but modulate a function far from its FSH or a stress far from its StSH. On the other
hand, the biophotons from a biosystem with its function in its FSH should be less than the one from the biosystem with
its function far from its FSH. The non-resonant interaction of low intensity laser irradiation or monochromatic light (LIL)
and a kind of membrane protein can be amplified by all the membrane proteins if the function is far from its FSH. This
amplification might hold for biophoton emission of the membrane protein so that the photonic spectroscopy can be used
to represent the function far from its FSH, which is called photonomics.
Light induced heme oxygenase 1 is suppressed by Bach1 in human skin keratinocytes
Show abstract
Ultraviolet A (UVA) radiation is an oxidizing agent that strongly induces the heme oxygenase 1(HO-1) expression in
cultured human skin fibroblasts, but weakly induces it in skin keratinocytes. Here, we report that low basal levels of HO-
1 and much higher basal levels of HO-2 protein were observed in keratinocytes compared with fibroblasts. Silencing of
Bach1 strongly increased HO-1 levels in HaCaT transformed keratinocytes and these HO-1 levels were not further
increased by either UVA irradiation or silencing of HO-2. This is consistent with the conclusion that high constitutive
levels of HO-2 expression in keratinocytes are responsible for the resistance of these cells to HO-1 induction by UVA
radiation and that Bach1 plays a predominant role in influencing the lack of HO-1 expression in keratinocytes. Bach1
inhibition reduced the 500 kJ/m2 UVA-induced cell damage by LDH membrane integrity and MTS viability assays.
These results suggest that Bach1 inhibition protect against high dose of UVA irradiation induced damage in
keratinocytes.
The effect of 630-nm light stimulation on the sEMG signal of forearm muscle
Dan D. Yang,
W. Sheng Hou,
Xiao Y. Wu,
et al.
Show abstract
This study aimed to explore if the red light irradiation can affect the electrophysiology performance of flexor digitorum
superficialis (FDS) and fatigue recovery. Four healthy volunteers were randomly divided into two groups. In the designed
force-tracking tasks, all subjects performed the four fingertip isometric force production except thumb with a load of
30% of the maximum voluntary contraction (MVC) force until exhaustion. Subsequently, for the red light group, red
light irradiation (640 nm wavelength, 0.23J/cm2, 20 min) was used on the right forearm; for the control group, the
subjects relaxed without red light irradiation. Then subjects were required to perform fatigue trail again, and sEMG
signal was collected simultaneously from FDS during finger force production. Average rectified value (ARV) and
median frequency (MF) of sEMG were calculated. Compared to the control group, the red light irradiation induced more
smoother value of ARV between 30% and 40%, and the value of MF was obviously large and smooth. The above
electrophysiological markers indicated that recovery from muscle fatigue may be positively affected by the red light
irradiation, suggesting that sEMG would become a power tool for exploring the effect of red light irradiation on local
muscle fatigue.
Brain lesion induced by 1319nm laser radiation
Show abstract
The laser-tissue interaction has not been well defined at the 1319 nm wavelength for brain exposure. The goal of this
research effort was to identify the behavioral and histological changes of brain lesion induced by 1319 nm laser. The
experiment was performed on China Kunming mice. Unilateral brain lesions were created with a continuous-wave
Nd:YAG laser (1319nm). The brain lesions were identified through behavioral observation and histological haematoxylin
and eosin (H&E) staining method. The behavior change was observed for a radiant exposure range of 97~773 J/cm2. The
histology of the recovery process was identified for radiant exposure of 580 J/cm2. Subjects were sacrificed 1 hour, 1
week, 2 weeks, 3 months, 7 months and 13 months after laser irradiation. Results showed that after laser exposure,
behavioral deficits, including kyphosis, tail entasia, or whole body paralysis could be noted right after the animals
recovered from anesthesia while gradually disappeared within several days and never recurred again. Histologically, the
laser lesion showed a typical architecture dependent on the interval following laser treatment. The central zone of
coagulation necrosis is not apparent right after exposure but becomes obvious within several days. The nerotic tissue
though may persist for a long time, will finally be completely resorbed. No carbonization granules formed under our
exposure condition.
Nano-/Biophotonics
Fluoroimmunoassay for antigen based on fluorescence quenching between quantum dots and gold nanoparticles
Peng Huang,
Kan Wang,
Omar Pandoli,
et al.
Show abstract
A unique, sensitive, and highly specific fluoroimmunoassay system for antigen detection using gold and quantum dot
nanoparticles has been developed. The assay is based on the fluorescence quenching of quantum dots caused by gold
nanoparticles coated with antibody. To demonstrate its analytical capabilities, the CdTe quantum dots were coated with
anti-HBsAg monoclonal antibodies (QDs-MAb1) and gold nanoparticles coated with another anti-HBsAg monoclonal
antibodies (GNPs-MAb2) which specifically bound with HBsAg could sandwich the HBsAg captured by the
immunoreactions. The sandwich-type immunocomplex was formed and the fluorescence intensity of quantum dots was
measured. The results showed that the fluorescence intensity of quantum dots at 570 nm was negative linear proportional
to the HBsAg concentration logarithm, and the limit of detection of the HBsAg was 0.928 ng/mL. This new system can
be extended to detect target molecules with matched antibodies and has broad potential applications in immunoassay and
disease diagnosis.
The effects of Ce3+ and Ce4+ on the stability of fibroblast growth factor-2
Show abstract
The interaction between tri or tetravalent cerium ions and basic fibroblast growth factor (FGF-2) at 0.1-6: 1 molar ratio
under physiological condition was studied by fluorescence and CD spectrum. The different spectra alterations of FGF-2
induced by Ce3+ and Ce4+ showed that Ce3+ and Ce4+ caused different conformational changes of FGF-2 respectively,
though both of them destabilized the protein. The instability of FGF-2 in the presence of Ce3+ is involved in the oxidation
of its free cystein of protein, but that this treatment nearly does not affect the biological activity. As to Ce4+, it not only
induced the conformational changes of protein but also inhibits its activity in a dose-dependent manner, which could be
relative to the electrostatic repulsion between Ce4+ and its basic amino acid residues (pI=9.6) or the specific binding of
Ce4+ to deprotonated amino acid residues. The interesting results would be helpful to investigate the problem of the
stability of proteins.
Photo-thermal Interaction and Calculations
Effects of MTZs parameters during non-ablative fractional photothermolysis treatments: a numerical study
Show abstract
The novel method of non-ablative FP is acknowledged as an effective technique by offering significant clinical
improvement while minimal risk of complications. A new time-dependent mathematical model was built up to
investigate the photo-thermal interactions during FP treatments. With this model, effects of treatment-affecting
parameters, such as diameter, density and energy of the micro laser beam as well as skin cooling, were numerically
investigated. Different photo-thermal behaviors with various treatment parameters were particularly discussed, based on
which, a novel concept of programmable treatment procedure (PTP) was proposed. With this technique, desired
therapeutic outcomes may be obtained from personalized treatments.
A numerical investigation of photo-thermal interactions during laser sebaceous gland treatment
Show abstract
Aberrations of sebaceous follicles usually cause great mental suffering and unconfidence to the patients. A new
time-dependent mathematical model was built up to investigate the photo-thermal interactions during laser sebaceous
gland treatment. With this model, effects of treatment-affecting parameters, such as diameter and depth of the sebaceous
gland, laser energy density, pulse repetition, and especially cooling methods, were numerically investigated. The
simulated results showed that skin cooling is essentially necessary for achieving ideal therapeutical outcomes in laser
sebaceous gland treatment, and CSC is the most effective cooling method. A simple but valid method to improve the
therapeutical outcomes of laser sebaceous gland treatment, named as adaptive temperature control (ATC), was proposed.
The results and conclusions are useful for optimizing laser sebaceous gland treatments and for designing new treatment
procedures.
Monte Carlo simulation of non-invasive glucose measurement based on FMCW LIDAR
Show abstract
Continuous non-invasive glucose monitoring is a powerful tool for the treatment and management of diabetes. A glucose
measurement method, with the potential advantage of miniaturizability with no moving parts, based on the frequency
modulated continuous wave (FMCW) LIDAR technology is proposed and investigated. The system mainly consists of an
integrated near-infrared tunable semiconductor laser and a detector, using heterodyne technology to convert the signal
from time-domain to frequency-domain. To investigate the feasibility of the method, Monte Carlo simulations have been
performed on tissue phantoms with optical parameters similar to those of human interstitial fluid. The simulation showed
that the sensitivity of the FMCW LIDAR system to glucose concentration can reach 0.2mM. Our analysis suggests that
the FMCW LIDAR technique has good potential for noninvasive blood glucose monitoring.
Optical Techniques: Advances in Research
A simple method to fulfill particle trapping by optical tweezers array
Show abstract
We adopt double-plate sheering interferometers to perform an optical tweezers array system. In the optical tweezers
array system, the reflecting mirror is replaced by an optical scanner to be a beam translator. The optical scanner is driven
by an input signal to control the interference strips movement. However, if the interference strips move periodically, the
trapped particles would move along with the strips with the same regulation. So, the particles could not be separated
from the other particles. We use an external modulating device to be a shutter to control the laser beam. Then the trapped
particles would continue moving because of inertia during the laser beam is blocked, and be trapped again after the
shutter opens. If the moving speed of liquid is limited properly, the particles can be separated continuingly and collected.
At the end of this article, we illustrate the result of conducting the novel method and characteristics of the system.
Fast confocal endomicroscopy based on multi-fiber parallel scanning
Show abstract
Confocal endomicroscopy has been developed very quickly for its high resolution and high sensitivity. It could be used
for early diagnoses of disease, such as cancer. In existing confocal endomicroscopy, fiber bundle or single fiber was used
for transferring exciting laser and excited fluorescence signal. Neither of these technologies had high resolution nor high
imaging speed. In this paper, a fast confocal endomicroscopy(FCM) is presented. In the FCM, a multi-fiber array with 9
fibers is used for light signal transferring, including exciting laser and excited fluorescence. In the distal end of the
endomicroscopy, the fibers are arranged in two dimension and form a 3X3 area array. The fibers are not arrayed closely,
but with space. Under driving of a MEMS scanner, the fibers move and scan tissue in parallel. Each fiber takes charge of
1/9 of the whole diagnoses field. Then the whole field is scanned and image is acquired. In the other end, the fibers are
arranged in linear array. Exciting laser is coupled into the linear fiber array and transferred to the distal end of the area
fiber array. Fluorophore molecules in tissue are excited and emit fluorescence. The fluorescence is collected into the 3X3
area fiber array and transferred to the linear array end. An imaging objective lens couples the fluorescence from the fiber
end to a CCD, which converts the light intensity into electrical signal. Image of tissue is reconstructed from the electrical
signal. By parallel scanning, the imaging speed of confocal endomicroscope is improved by several times, which is
associated with the number of fibers in the array.
Noninvasive evaluation system of fractured bone based on speckle interferometry
Show abstract
This paper presents a noninvasive evaluation system of fractured bone based on speckle interferometry using a modified
evaluation index for higher performance, and the experiments are carried out to examine the feasibility in evaluating
bone fracture healing and the influence of some system parameters on the performance. From experimental results, it is
shown that the presence of fractured part of bone and the state of bone fracture healing are successfully estimated by
observing fine speckle fringes on the object surface. The proposed evaluation index also can successfully express the
difference between the cases with cut and without it. Since most system parameters are found not to affect the
performance of the present technique, the present technique is expected to be applied to various patients that have
considerable individual variability.
Mechanisms and Techniques in Photodynamic Therapy
Kinetic analysis of singlet oxygen generation in a living cell using Singlet Oxygen Sensor Green
Show abstract
Singlet oxygen (1O2) can be generated in a living cell upon focused laser irradiation of an intracellular photosensitizer. In
this study, 1O2 generation from the plasma membrane-targeted protoporphyrin IX (PpIX) in human nasopharyngeal
carcinoma CNE2 cells was monitored indirectly by using the fluorescence probe Singlet Oxygen Sensor Green agent
(SOSG). The confocal images indicate that the fluorescence of SOSG in the vicinity of the cells that incubated with PpIX
was dramatically enhanced with the increased irradiation time, while there is no significant enhancement for the control
cells. Moreover, the fluorescence of SOSG is dramatically enhanced with the increase of the intracellular PpIX in CNE2
cells for the same photoirradiation time. These observations imply that the 1O2 generated from the plasma
membrane-targeted PpIX in the CNE2 cells can be escaped into the extracellular medium and to react with the SOSG to
produce SOSG-EP, and the fluorescence enhancement of SOSG around the cells mainly depends on the intracellular
PpIX. Our findings may be useful for further monitored the 1O2 that can be escaping from the living cells.
Photodynamic therapy for port wine stains assisted by a novel robotic system
Show abstract
Port wine stains (PWS) is a vascular malformation consisting of dilated capillaries in the superficial dermis.
Photodynamic therapy (PDT) is an effective approach in the treatment of PWS. However, the procedure of treatment is a
low efficient and hard work, as the doctor need to hold laser fiber to irradiate for 20 min to 50 min per lesion. So an
assisted novel robotic system was developed to instead part of doctor's work. The robotic system consisted of 7 degrees
of freedom, in which there were 5 passive joints and 2 active joints. Binocular surveillance system was used as guidance
for the robot. Clinical trial compared 20 patients (38 lesions) treated by the robotic system with another 20 patients (38
lesions) treated by a doctor. The patients in both groups were injected intravenously with photosensitizer (PSD-007,
4-5mg/kg) and irradiated with 532 nm laser (100mW/cm2, 120-300J/cm2) immediately. Both groups had same good
therapeutic results. The robotic system is helpful in the PWS-PDT and hopefully would become a part of PWS therapy
machine in the future.
Effect of concentration on photobleaching of hematoporphrin monomethyl ether (HMME) in solutions
Show abstract
To analyze the effect of concentration on the photobleaching of HMME, the loss of HMME absorption in simplex
solution (PBS) and complex solution (albumin buffer) was monitored using steady-state absorption spectra during
532nm laser irradiation. Three concentrations (4, 10, 80μmol/L) were set for each type solution. Photobleaching curves
at each concentration were drawn according to the concentration and time during irradiation. Photobleaching rate
coefficients (k) at each concentration were calculated with a mathematical model for singlet oxygen-mediated
photobleaching reaction. Then the photobleaching of HMME under different concentrations were compared using the
photobleaching rate coefficients (k) and the slope of photobleaching curves. Finally, the effect of concentration on
HMME photobleaching was analyzed combining the existence state of HMME at each concentration. The results showed
that in both PBS and albumin buffer, the photobleaching rate coefficient of HMME was the largest at 4μmol/L, smaller at
10μmol/L, and the smallest at 80μmol/L. In conclusion, there is a concentration-dependent relationship in the
photobleaching rate of HMME, photobleaching will be inhibited when the concentration of HMME increased above
certain level at which HMME aggregates formed.
Determination of singlet oxygen quantum yield of HiPorfin using Singlet Oxygen Sensor Green
Show abstract
Singlet oxygen (1O2) is widely considered to be the predominant cytotoxic agent for photodynamic therapy (PDT), and
the 1O2 quantum yield is a key characteristic for the newly developed photosensitizers. In this study, 1O2 generation from
the HiPorfin is monitored indirectly by using the fluorescence probe Singlet Oxygen Sensor Green (SOSG). The good
linear relationship between the concentration of HiPorfin and the initial reaction rate of SOSG is observed, and the 1O2
quantum yield of HiPorfin is determined to be 0.124 ± 0.001, as compared to the standard reference of Rose Bengal. The
results suggest that SOSG can be useful for 1O2 quantum yield determination for the potential photosensitizers in PDT.
Advanced Biomedical and Clinical Systems
Confocal fluorescence microendoscopy using a digital micro-mirror device
Show abstract
A design of confocal fluorescence microendoscopy utilizing a digital micro-mirror device (DMD) is described. Laser
beams of the microendoscope are coupled into the body through a telescopic optics system, rather than through
fibers or fiber bundles which are widely used in existing microendoscopes. Each micro-mirror of the DMD is used
as a confocal pinhole. The DMD not only couples the laser beams into the body by a random time-varying speckle
pattern and performs the scanning mechanism of the body tissue with different positions, but also couples the
fluorescent signal emitted from the markers out to the CCD camera. Because of the CCD's integration feature and
DMD's rapid parallel scanning feature, a complete predetermined depth tomography image accumulated by different
scanning patterns of DMD can be acquired through only one CCD exposure procedure. The objective lens to realize
high resolution and high sensitivity fluorescence imaging is the other function of the telescopic optics, with a
numerical aperture of 0.35. The resolution of confocal microendoscope is superior to 228 lp/mm determined by
1951USAF resolution test target. Images of a tendon specimen are also shown to demonstrate practical application
of the design. The confocal microendoscope using a DMD permits the acquisition of high-resolution real-time
confocal images of epithelial tissue in vivo organ and realizes the aim of non-invasive diagnosis and treatment.
Laser-induced hard tissue ablation by assisted with a liquid film on target tissue surface
Show abstract
The objective of this study was to investigate the influence of an applied water film on bone hard tissue ablation by pulse
CO2 laser. Fresh bovine shank bone in vitro used in the experiment were put on a PC-controlled motorized linear drive
stage and moved repeatedly through focused beam of laser without and with a water film of 0.4 mm and 1 mm on target
tissue. The wavelength of pulse CO2 laser was 10.64 μm, pulse repetition rate was 60 Hz, the energy density was 18-84
J/cm2 and the beam diameter of about 400 μm. The moving speed of stage was 12 mm/s, scanning times was 5. The
surface morphology and microstructure of ablation grooves were examined by stereomicroscope and scanning electron
microscope (SEM) respectively. The geometry of the groove was measured with optical coherence tomography (OCT),
and the thermal injury was examined by histology. It shows that water film on the target tissue surface plays an
important role during the ablation process. A proper thickness of water film applied to target tissue surface could
improve the regular of cut shape, smooth the cut surface, produce the same or even larger ablation rate and efficiency,
and reduce the thermal injury around the groove by compared with dry ablation condition. Moreover, the addition of
water could alter the microstructure of bone sample.
Poster Session
Research on laser induced pain effect
Show abstract
To study 1.06μm laser causing pain in human skin. The skin of human dorsum hand was irradiated by a Nd: YAG laser.
The energy of each pulse and whether the subjects felt a painful sensation after each stimulus were recorded. The pain
threshold was defined as the laser dose at which the subjects reported a painful sensation to 50% of stimulus deliveries.
The pain thresholds were determined under 3 different beam diameter and pulse duration conditions. The influence of
skin temperature on the pain caused by laser stimulus was also explored. As the temperature of skin was about 30°C, the
pain thresholds were 394mJ/mm2, 36.4mJ/mm2 and 8.92mJ/mm2 respectively under the stimulating condition of 1.20mm
beam diameter and 85μs pulse duration, 1.20mm beam diameter and 20ns pulse duration and 2.56mm beam diameter and
20ns pulse duration. Under the first condition, when skin temperature was 25°C and radiant exposure was 383mJ/mm2,
the probability of laser stimulus causing pain was 16.7%; when skin temperature was 39°C and radiant exposure was
361mJ/mm2, the probability was 56.7%. The threshold of 1.06μm laser stimulus causing pain decreases with decreasing
pulse duration, increasing beam diameter and skin temperature.
Uniform mesoporous dye-doped silica nanoparticles as a multifunctional drug carrier for in vivo early tumor diagnosis
Show abstract
In this report, we synthesized multifunctional dye-doped mesoporous silica nanoparticles(MSNs) by encapsulating
near-infrared dyes into the nanoparticles. In order to enhance the targeting property, the surface was modified with amino
group for further conjugation of targeted ligands. In addition, we explored the influence of the synthetic temperature on
the particle morphology. The optical properties, morphology and structure of the as-prepared dye-doped silica
nanoparticles were characterized. Results indicated the dye-doped silica nanoparticles can be used as a good probe for
early tumor diagnosis and have the potential to serve as a targeted carrier for antitumor drugs.
The influence of laser pulse on time resolved reflectance and transmittance in slab media
Show abstract
In this paper, the mathematical equation of the flatheaded Gauss laser pulse is given. Based on the Diffusion equation, by
using the Gauss laser pulses in different pulse width and shapes for the incident light sources, we get the simulations of
the time-resolved reflectance, transmittance and their pulse shapes in the boundary condition of homogeneous slab. The
simulation results show that the ultra short Gauss laser pulse is widened by the diffusive scattering, in addition, the
various medium parameters have different influence on the reflected and transmitted intensity of the laser pulse. In the
boundary condition of homogeneous slab media, the interactions between the absorption coefficient, the scattering
coefficient, the anisotropy coefficient, the pulse width and the pulse shape of the incident laser pulse all have been
investigated. This study is useful for the optical noninvasive measurement of the optical properties of tissue.
Optical trapping gold nanoparticles by a pulse laser
Show abstract
Gold nanoparticles are widely employed in nanomaterials, nanobiotechnology and health care, but generally they are
considered difficult to trap stably. Compared with the continuous laser which is popular to the optical trapping, pulse
laser has a relatively larger power in its work pulse, which is useful for trap particles. So this paper comprehensively
analyzes the forces (the radiation forces, the gravitation, and the Brownian motion) on the gold nanoparticles in the
optical tweezers formed by a pulse laser, through building up a mathematical model. Finally gets the dependence relation
between the characteristics of the pulse laser and that of the gold nanoparticles.
Fluorescence lifetime imaging using multi-dimension time-correlated single photon counting method
Show abstract
The key technology of fluorescence lifetime imaging is introduced in this article. Time-correlated single photon counting
(TCSPC) in Time-domain method is adopted to record fluorescence lifetime . The principle of TCSPC and the
Multi-wavelength imaging method are introduced in the paper. The counting efficiency and the amount of information in
the data can be increased by recording the fluorescence in several wavelength channels simultaneously.
Multi-wavelength imaging was also successfully used to separate different chromophores in stead-state images.
An analytic scheme for time-domain diffuse fluorescence tomography in circular geometry: methodology and validation
Show abstract
Near-infrared fluorescence diffuse optical tomography has proven to be an efficient tool for visualizing the
bio-distributions of fluorescent markers in tissue. We present a two-dimensional image reconstruction method for
time-domain fluorescence diffuse optical tomography on a turbid medium of circular domain. The methodology is based
on a linear generalized pulse spectrum technique that employs the analytical solution to the Laplace-transformed
time-domain photon-diffusion equation to construct a Born normalized inverse model. A pair of real domain
transform-factors is introduced to simultaneously reconstruct the fluorescent yield and lifetime images and the resultant
linear inversions are solved using an algebraic reconstruction technique. The algorithm is validated using simulated data,
and the spatial resolution, noise-robustness and so on are assessed. The experimental validation is performed using a
multi-channel time-correlated single-photon-counting system and a cylinder phantom that embeds a fluorescent target
made from 1%-Intralipid solution and Cy5.5 agent. The results show that the approach retrieves the position and shape of
the target with a reasonable accuracy.
Development of a novel spectrometer for tongue coating analyzer based on volume holography transmissive grating
Show abstract
Tongue diagnosis (TD) is an important diagnostic methods in the traditional Chinese medicine (TCM). According to the
viewpoint of TCM, the changes of the tongue coating (TC) can reflect the pathological state of the patient. And the
nature or severity of diseasec can be determined by observing the TC. Over the years, TD is mostly depended on the
subjective experience of the Chinese physician. And the diagnostic results will be impacted by.some factors, e.g. the
different light sources or environmental brightness. Recently years, the method of digital image processing has been used
into the TD. But its application is limited by the complicated algorithm, time-consuming and big error, etc. Therefore, a
novel tongue coating analyzer(TCA) is designed in this paper. Meanwhile, a novel spectrometer for TCA based on the
volume holography transmissive (VHT) grating is developed. In this spectrometer, since the VHT grating doesn't
produce the stray-light due to the absence of the grooves of classical surface-embossed gratings, the VHT grating is used
as the diffraction grating instead of the classical plane or concave grating. Experimental results show that the
performances of the spectrometer for TCA have been improved by using the VHT grating, optimizing the light-path
structure and software algorithm, etc. Compared with the others, this spectrometer for TCA has many advantages, such
as, less diffraction, wider spectrum range, higher efficiency and resolution, etc. The spectrum range of the spectrometer
for TCA can reach 300-1000nm, its resolution can reach 1nm and the optical density is larger than 3.
Improvement of the frequency-domain inverse Monte Carlo simulation
Show abstract
This article aims at the optical property (absorption coefficient and scatter coefficient) reconstruction from the
frequency-domain (FD) near-infrared diffuse measurement on small tissues, such as a cervix, for which inverse Monte
Carlo (MC) simulation is the suitable choice. To achieve the fast and accurate reconstruction based on the inverse Monte
Carlo simulation, following techniques were adopted. First, in the forward calculation, a database, which include the
frequency-domain information calculated from MC simulation for a series of optical parameters of tissue, were
established with fast methods. Then, in the reconstruction procedure, Levenberg-Marquardt (L-M) optimization was
adopted and Multiple Polynomial Regression (MPR) method was used to rapidly get the FD information at any optical
properties by best fitting the curved surface formed by the above database. At Last, in the reconstruction, to eliminate the
influence of the initial guess of optical properties on the reconstruction accuracy, cluster analysis method was introduced
into L-M reconstruction algorithm to determine the region of the initial guess. The reconstruction algorithm was
demonstrated with simulation data. The results showed that it takes less than 0.5s to reconstruction one set of optical
properties. The average relative error from the reconstruction algorithm joined with cluster analysis is 10% lower than
that without cluster analysis.
Comparison between radiation forces on gold nanoparticles and on polystyrene nanobeads
Show abstract
Gold nanoparticles have found broad applications in nanomaterials and nanobiotechnology and health care. They are
considered to be superior handles or probes relative to polystyrene beads for their own specific physical characteristics.
But unfortunately they are considered difficult to trap stably by optical tweezers still owing to their specific physical
characteristics. In this paper, numerical studies are carried out to show that how the radiation forces on the gold particles
dependant on the parameters of the lasers and of the particles. The results show that a stable trap for gold particles needs
a more strictly choice of lasers than polystyrene nanobeads for given particle size and other conditions.
Signal and noise analysis of optical coherence tomography in highly scattering material at 1550nm
Show abstract
The signal and noise properties of standard time domain optical coherence tomography system are analyzed in
near-infrared region based on extended Huygens-Fresnel principle. The signal-to-noise ratio and maximum probing
depth are estimated for scattering media with discontinuity plane inside. In numerical simulation, the relationship
between coherent signal and scattering coefficients, and depth dependence SNR are calculated. The difference between
specular and diffuse reflection is given out and analyzed. Numerical result is verified by well established experiment
with different concentration mixture solution of IntralipidTM, from 1% to 15%. The OCT system consists of fiber
Michelson interferometer and 1550 nm ASE optical source with coherent length of 14μm. Both numerical and
experimental results show that multiple scattering events are the main reason for decreasing of signal-to-noise ratio.
According to the research, wavelength at 1550 nm is also suitable for imaging of biomedical tissue because of lower
scattering coefficients. More than 2 mm penetration depth is obtained in experiment for 10% IntralipidTM which has
scattering coefficient similar to skin tissue.
Imaging model of optical sectioning of thick specimen
Show abstract
Based on the cartesian coordinate system, a coaxial couple cartesian coordinate system is designed whose z-axis is
coaxial but z-axis coordinate is independent, and its xy plane is different but coordinate is the same. The object
space and the image space are set in the two sub-cartesian coordinates respectively. In the coaxial couple cartesian
coordinate system, according to the principle of optical imaging, a form of the optical microscope's imaging model
of optical sectioning biological thick specimen is derived. The model form show that if a biological thick specimen
is expressed as a pile of slices with tiny interval, and a slice among the slices is put in microscope's focal plane, then
the thick specimen's image in image plane is the superposition of the focal plane image and all of the defocus images.
In the model form, thick specimen's image is simply sorted into focal plane image and defocus image to make it
easy to look insight, so the model clearly reflects the imaging relationship between the slice of thick specimen, and it
is conducive to the analysis of the microscope's imaging characteristics for thick specimen. And the stack of optical
section according to the model is equivalent to the mathematical model of three-dimensional imaging of thick
specimen.
A method for determining optical properties of human tissues by measuring diffuse reflectance with CCD
Show abstract
It is important to measure optical properties noninvasively, quickly and accurately in vivo for disease diagnostics and
medical therapeutics. In this study, we measured the absorption coefficient and the reduced scattering coefficient of
human tissues by measuring diffuse reflectance with CCD, examined the techniques involved, such as quantization of
diffusion approximation theory, effective reverse fitting algorithm, and the data selection and processing method, and
finally concluded about the accuracy of this method. The experimental results indicate that the error is less than or equal
to 8% using the diffusion theory, under the condition that the reduced scattering coefficient is one order of magnitude
greater than the absorption coefficient. The stability and precision of optical property measurements are significantly
improved by using the multi-step iterative fitting method and using the ring areas to determine the diffuse reflectance
center. The efficiency of reverse algorithm is greatly enhanced by selecting a one-dimensional array on the straight line
crossing both the entry point and the diffusion center for fitting. The error of measured absorption coefficient and
scattering coefficient of the Intralipid solution and human forearm tissues are less than 5% with our method. These
results can provide important technical information for application of the diffusion theory.
Surfaced-enhanced Raman spectroscopy of nasopharyngeal carcinoma cell using gol nanoparticles
Show abstract
The surface-enhanced Raman scattering (SERS) spectroscopy and normal Raman spectroscopy of single living human
nasopharyngeal carcinoma cells(CNE-1) were tested and analyzed by gold nanoparticles incubation into cells. The
characteristic Raman bands in the SERS spectra of living cells were tentatively assigned. Six obvious Raman bands
(718, 1001, 1123, 1336, 1446, 1660 cm-1) were observed in the normal Raman spectroscopy of living CNE-1 cells.
Colloidal gold nanoparticles that were introduced inside cells resulted in strongly enhanced Raman signals of the native
chemical constituents of the cells, and over twenty SERS Raman bands were observed in the SERS spectroscopy of
living CNE-1 cells. Four vibrations of the DNA backbone (1026, 1097, 1336 and 1585 cm-1) confirmed that some gold
nanoparticles were able to enter the nucleus. The results showed that, based on colloidal gold, the SERS spectroscopy
might provide a sensitive and structurally selective detecting method for native chemicals inside a cell, such as DNA and
phenylalanine.
New optical method for noninvasive blood glucose measurement by optical ultrasonic modulation
Show abstract
A new optical technique for continuous, noninvasive monitoring of blood glucose levels based on ultrasonic modulation
of scattering light is proposed. The ultrasound-modulated scattered light has an accurate separation of scattering and
absorption changes in tissue. And the optical scattering and absorbing coefficient of tissue depend on the concentration
of glucose in the extracellular fluid. As the glucose induced to scattering and absorption changes, the ultrasoundmodulated
light also changes. In this paper, a correlation is observed between ultrasound-modulated light intensity as
well as its modulation depth and blood glucose concentration in phantom experiments. In addition, some researches
about ultrasound-modulated signal affected by the temperature of glucose aqueous solution are done. Preliminary
experiments find that this method is a promising noninvasive blood glucose measurement.
Marginal characteristics of skin scarred dermis quantitatively extracted from multiphoton microscopic imaging
Show abstract
Multiphoton microscopy based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) was
applied to examine the marginal regions at dermis of normal, atrophic and keloid scars. High-contrast, high-resolution
image showed an obvious boundary at scar margin and different morphological patterns of collagen or elastin on the two
sides. Since the degree of the morphological alteration between the two sides of boundary at scar margin was varied
among different types of scars, alteration degree of SHG-to-TPEF index was defined as a quantitative indicator for
discrimination. It will help to determine the most appropriate clinical treatment strategy for different types of scars and
potentially monitor therapy in vivo.
A processing technology of two-photon microscopic image of nasopharyngeal cancer cells
Show abstract
Nasopharyngeal carcinoma (NPC) is one of the most common malignancies in china, with a deep and hidden
localization. Recently, methods for early diagnosis of NPC has become one of the most important research topics in
medical field. Early monitoring of morphological change of NPC cells during the carcinogenesis is of great importance,
and early information extracted from the NPC cells during the initial stage of NPC is critical for diagnosis and treatment.
In this paper, image processing methods for two-photon microscopic image of NPC cells was investigated with the
purpose of providing useful information for early diagnosis and treatment of NPC.
There is abundant information in a two-photon microscopic image of NPC cells, which can be analyzed and processed
by means of computer and image pattern processing algorithm. In this paper, firstly, a mathematical method of transform
of Bottom-hat based on Matlab platform was employed to enhance the image of NPC cells, making the image easier to
distinguish; Then, several classical edge detection algorithms were compared and discussed, for example, Roberts
operator, Prewitt operator, and Canny operator etc. According to the inherent characteristics of two-photon microscopic
image of NPC cells, corrosion algorithm was used to define the edge of NPC cells. Furthermore, the article gets the
iterative threshold segmentation after noise denoising, on the other hand, improved discriminant analysis was adopted for
threshold segmentation of NPC cells, better results were obtained.
Radiation force on a chiral sphere by a Gaussian beam
Show abstract
Based on the generalized Lorenz-Mie theory (GLMT), the incident Gaussian beam and scattered fields of the chiral
sphere are expressed in terms of the spherical vector wave functions. An expression of the radiation force on the chiral
sphere in a Gaussian beam is derived from the theory of electromagnetic momentum. The influence of the chiral
parameter, the beam waist radius and the radius of the chiral sphere on radiation force is discussed numerically.
A novel nasopharyngeal cancer detection based on plasma SERS combined with PCA-LDA statistical analysis
Show abstract
In order to develop a novel and simple blood test for non-invasive nasopharyngeal cancer detection, a surface-enhanced
Raman spectroscopy (SERS) method was presented for blood plasma biochemical analysis. High quality SERS spectrum
from human plasma-Ag NP mixture can be obtained using a confocal Raman system. SERS measurements were
performed on normal and cancer groups of plasma samples. The measured SERS spectra revealed some specific
biomolecular differences in nasopharyngeal cancer plasma. Principal component analysis of the measured SERS spectra
separated the spectral features of the two groups into two distinct clusters with little overlaps. Linear discriminate
analysis based on the PCA generated features differentiated the nasopharyngeal cancer SERS spectra from normal SERS
spectra with high sensitivity (97.7%) and specificity (100%). The results from this exploratory study illustrated great
promising for developing SERS human plasma analysis into a clinical tool for non-invasive detection of nasopharyngeal
cancers.
The targeted behavior of folate-decorated N-succinyl-N′-octyl chitosan evaluated by NIR system in mouse model
Show abstract
The development of more selective delivery systems for cancer diagnosis and chemotherapy is one of the most
important goals of current anticancer research. The purpose of this study is to construct and evaluate the folate-decorated,
self-assembled nanoparticles as candidates to deliver near infrared fluorescent dyes into tumors and to investigate the
mechanisms underlying the tumor targeting with folate-decorated, self-assembled nanoparticles. Folate-decorated
N-succinyl-N'-octyl chitosan (folate-SOC) were synthesized. The chemical modification chitosan could self-assemble
into stable micelles in aqueous medium. Micelle size determined by size analysis was around 140 nm in a
phosphate-buffered saline (PBS, PH 7.4). Folate-SOC could maintain their structure for up to 15 days in PBS. Near
infrared dye ICG-Der-01 as a mode drug was loaded in the micelles, and the entrapment efficiency (EE) and drug
loading (DL) were investigated. The targeted behavior of folate-SOC was evaluated by near-infrared fluorescence
imaging in vivo on different groups of denuded mice, with A549 or Bel-7402 tumors. The optical imaging results
indicated that folated-decorated SOC showed an excellent tumor specificity in Bel-7402 tumor-bearing mice, and weak
tumor specificity in A549 tumor bearing mice. We believe that this work can provide insight for the engineering of
nanoparticles and be extended to cancer therapy and diagnosis so as to deliver multiple therapeutic agents and imaging
probes at high local concentrations.
Monitoring the process of tissue healing of rat skin in vivo after laser irradiation based on optical coherence tomography
Show abstract
It is imperative to evaluate the tissue wound healing response after laser irradiation so as to develop effective devices for
this clinical indication, and evaluate the thermal damage degree to take appropriate treatment. In our research, we
prepare 6 white rat (approximately 2 months old, weight :28±2g). Each rat was injected intraperitoneally a single dose of
2% pentobarbital sodium. After the rat was anesthetized, the two side of the rats' back were denuded and antisepsised a
standardized. An Er:YAG laser (2940nm, 2.5J/cm2, single spot, 4 times) was irradiated on rat skin in vivo, and the skin
which before irradiated and the process of renovating scathe that irradiated after Er:YAG laser were observed by an
Optical coherence tomography (OCT). The tissue recovery is about a twelve -day period. The results indicate that the
scattering coefficient of post- tissue has changed distinctly. The and flexibility fiber is the chief component of rat dermis
and the collagen is the main scattering material. The normal tissue has a large scattering coefficient, after laser irradiated,
the collagen became concreting and putrescence and caused the structure change. It became more uniform density
distribution, which results in a reduced scattering coefficient. In a word, OCT can noninvasively monitor changes in
collagen structure and the recover process in thermal damage through monitor the tissue scattering coefficient.
Monitoring changes of optical attenuation coefficients of acupuncture points during laser acupuncture by optical coherence tomography
Show abstract
The physical properties of acupuncture point were important to discover the mechanism of acupuncture meridian. In this
paper, we used an optical coherence tomography to monitor in vivo the changes of optical attenuation coefficients of
Hegu acupuncture point and non-acupuncture point during laser irradiation on Yangxi acupuncture point. The optical
attenuation coefficients of Hegu acupuncture point and non-acupuncture point were obtained by fitting the raw data
according to the Beer-Lambert's law. The experimental results showed that the optical attenuation coefficient of Hegu
acupuncture point decreased during the laser acupuncture, in contrast to a barely changed result in that of
non-acupuncture point. The significant change of optical attenuation coefficient of Hegu acupuncture point indicated that
there was a correlation between Hegu and Yangxi acupuncture points to some extent.
Autofluorescence characteristics of human leukemia cells and mononuclear cells
Show abstract
Autofluorescence spectroscopy is a powerful method to identify the endogenous fluorophores in normal and cancerous
cells. The purpose of this study is to characterize the autofluorescence spectra of human normal and leukemia cells.
Autofluorescence measurements of each cell line are performed over a wide range of cell concentrations. All of the
leukemia cells indicate a statistically significant increase in the tryptophan fluorescence relative to that of the normal
cells, while no statistically significant differences are observed in the reduced nicotinamide adenine dinucleotide
(phosphate) (NAD(P)H) and flavin adenine dinucleotide (FAD) fluorescence between the normal and leukemia cells.
The results suggest that the differences in autofluorescence spectra for leukemia cells and mononuclear cells may be
attributed in part to differences in endogenous fluorophores of different cells.
Shear bond strength of a self-etch adhesive to Er:YAG laser-prepared dentin
Show abstract
The purpose of this study was to determine the shear bond strength of a self-etch adhesive to Er:YAG laser-prepared
dentin and evaluate the resin-dentin interface. Extracted sound human molars were sectioned and wet-ground to expose
flat dentin surfaces. These surfaces were subsequently irradiated by an Er:YAG laser with a wavelength of 2.94 μm and
pulse repetition rate of 20 Hz. Energy density was set at 20 J/cm2 and spot size was 2 mm. The conventional bur was
used as a control group. After surface treatments, a self-etch adhesive was bonded to the irradiated dentin surface and
then a resin composite was applied to the dentin surface. Specimens were subjected to shear bond strength test after 24 h
of storage in water. The bonding interface was examined by laser confocal scanning microscope (LCSM) after specimens
were serially sectioned into multiple slices. The results revealed that Er:YAG laser irradiation did not present advantages
compared to the conventional bur.
Wavelength-swept laser around 1300nm based on polygon filter in Littrow telescope-less configuration
Show abstract
A high-speed linear wavelength-swept laser source working at center wavelength of 1309 nm is demonstrated.
Wavelength tuning is performed using a compact polygon filter in Littrow telescope-less configuration. The repetition
frequency of the wavelength-swept laser source is up to 50 kHz with the polygon scanned at a speed of 694 rotations per
second. The turning range is 130 nm and full width at half maximum (FWHM) is 61 nm. The average output power can
reach to 7 mW. The developed swept laser source can be implemented in optical frequency domain imaging, optical
reflectometry, and other test or measurement applications.
Comparison of two linear differential polarization imaging methods in tissue characterization
Show abstract
Linear differential polarization imaging can improve image quality and characterize the polarization properties of
biological tissues. Degree of polarization imaging (DOPI) yields images based on photons backscattered from the
superficial layers, but shows different measurement results for different incident polarization or sample orientations. The
rotating linear polarization imaging (RLPI) method can characterize the anisotropic properties of tissues, by recording
the linear differential polarization as a function of multi-incident and multi-detection polarization angles and gives a set
of new parameters insensitive to incident polarization angles. The physical meanings, dependence on the incident
polarization angles and the imaging depth of the parameters of the rotating linear polarization imaging will be compared
with those of degree of polarization imaging, which indicate the application potential of the two linear differential
polarization imaging methods in tissue imaging and medical diagnosis.
Large format x-ray image detector of high resolution and sensitivity
Show abstract
X-ray phase contrast imaging technique that can be used as a practical diagnostic tool for
medical purposes requires the image detector of higher resolution and sensitivity, and of larger
format as well. The above mentioned parameters cannot be come to their best on one detector at
present, so there is some kind of compromise among these parameters, for example, improving
one parameter may be at the cost of impairing another one. This paper designed an x-ray image
detector composed of a structured scintillation screen, optic taper and CCD camera etc.
Photo-assisted electrochemical etching method was used to make an array of deep holes in the
crystal silicon. The scintillator (CsI:Tl) was molten into the deep holes after the silicon wafer had
been heat-oxidized. When the screen was coupled with CCD camera by optic taper, the detector
fabrication was finished. We use the detector and an x-ray tube of 1mm focal spot to image a test
pattern, the spatial resolution better than 20lp/mm was obtained under the x-ray tube voltage of
45kVp and current of 2mA. The total image pixel of this detector is 2048 x 2048, with the 13.5
micrometer pixel size of the camera. The ratio of the input face size of optic taper to output size
was 2:1. High sensitivity was implemented by the course of x-rays in the scintillator, the longer
the course, the more the x-ray was absorbed, and the higher the sensitivity. In our detector
scintillation screen, the depth of the holes was great than 150 micrometers, with the 1.5
micrometers side length of the square section of a hole.
A sphere-cylinder scattering model for skeletal muscle
Show abstract
We acquired polarized reflectance images and Mueller matrix of fresh bovine skeletal muscle. Using
polarization-dependent Monte Carlo simulations based on a sphere-cylinder scattering model, we are able to reproduce
the characteristic features in the experiment results. We also simulate the changes of reflectance profile during stretching
and rigor process, which are regarded as the changes of cylinders' diameter and the cylinder-sphere ratio in our model.
The good agreement between simulations and experiments indicates that the unique pattern of polarized reflectance of
skeletal muscles can also be due to scattering of well aligned fibrous myofibrils rather than coherent diffraction on the
sarcomeres. It provides another angle to understand the interaction between photons and skeletal muscle and a proper
model which characterizes the microstructure of the skeletal muscle. In addition, we give a parameter K calculated from
the M12 element of Mueller matrix. The K-value is sensitive to different parameters in sphere-cylinder scattering model,
therefore it is expected to use for monitoring the states of the skeletal muscle.
Linear polarization detection of polarization-sensitive optical coherence tomography in the early detection of the application of dental caries
Show abstract
Polarization-Sensitive Optical Coherence Tomography (PS-OCT) is an important
functional OCT. By extracting the polarization properties from PS-OCT signals we can
obtain more information about the structural and optical features of tissues or materials.
Dental caries is one of the most prevalent chronic diseases of people worldwide. The
primary caries detection and the structure transformation of the enamel and dentin
between sound and broken teeth are given serious attention by dentists. In this paper,
using our Fourier-domain polarization-sensitive optical coherence tomography
(FD-PS-OCT) setup by three incident linear polarization states and two detection states,
we can get the 9 Mueller matrix elements from M11to M33 of the decay areas of the
artificial caries measured. We also applied our polarized sensitive Monte Carlo
program in the simulation of the PS-OCT detection process. We used a sphere-cylinder
scattering model as an approximation of anisotropic tissues to describe the optical
properties of tooth. By comparing the Mueller matrix elements of both experimental
and simulation results, especially the diagonal elements (M11, M22 and M33), we
reach the point that the main structural change of the caries that affects its scattering
features is the expanded diameter of the enamel rods and dentinal tubules caused by the
acid corrosion due to caries lesion.
Measurements of retinal temperature increase during photodynamic therapy for choroidal neovascularization
Show abstract
To study the risk of retinal thermal injury from 532 nm laser during photodynamic therapy (PDT) for choroidal
neovascularization (CNV) by measuring the retinal temperature increase of rabbit eyes. A microthermocouple technique
was developed to measure retinal temperature increase during PDT in pigmented and non-pigmented rabbit eyes. The
532 nm laser exposures were performed with 100-s duration, 2-mm spot size, and retinal irradiance ranging from 400 to
1600 mW/cm2. A K-type microthermocouple was inserted through the sclerotomy and advanced until the tip reached the
retina at the posterior pole. The thermocouple was connected a computer that recorded and analyzed retinal temperature
data. The results showed that the retinal temperature increase during laser exposure was proportional to retinal irradiance
with a particular spot diameter, exposure duration, wavelength, and fundus pigmentation. And the measured retinal
temperature increases in pigmented rabbits were a little higher than those in albino rabbits under the same radiant
condition. Retinal threshold irradiance required for visible lesions at laser wavelength of 532 nm with 2.0-mm spot size
and 100-s duration was 1657 mW/cm2 in albino and 1003 mW/cm2 in pigmented rabbits, respectively, corresponding to
retinal temperature increase of about 8 °C and 6 °C. The measured temperatures in albino and pigmented rabbit eyes
were both lower than the model predictions, especially in pigmented rabbits. Therefore, further parameter modifying
should be performed to obtain accuracy prediction of retinal temperature.
Sensitivities of the spatial-resolved diffuse reflectance to scattering parameters
Xiao-juan Zhang,
Wei Yang,
Ying Liu
Show abstract
The sensitivity expressions of spatial-resolved diffuse reflectance to first-order, second-order and third-order
scattering parameter are derived in the P3 approximation of transport theory. The influence of first-order scattering
parameter on the P3 approximation and diffusion approximation reflectance are compared, it is demonstrated that the
sensitivity is distinct with that of the diffusion approximation in the region of about two transport mean free paths. The
numerical analysis of second-order and third-order scattering parameter sensitivity expressions are also done. It is found
that the sensitivities change with source-detector separations and reach a maximum in the region of between one
transport mean free path and two transport mean free paths, and are positive in the region of beyond one transport mean
free path. The influence of third-order optical parameter on the diffusing reflectance can be ignored by compared with
the influence of second-order optical parameter.
Minimal invasive treatment using 6.02 micrometer DFG laser for carious dentin
Show abstract
Conventional laser light sources for the treatment of a hard tissue in dental are good for removal of caries. However
these lasers cannot achieve to give a selective treatment effect for caries without a side effect for normal tissue. The
objective of this study is to develop the minimal invasive treatment technique of carious dentin by selective absorption
effect using the laser with a wavelength of 6.02 μm which corresponds to an absorption peak of organic matters called
amide 1 band. Mid-infrared nanosecond pulsed laser by difference-frequency generation was used for the experiment of
selective treatment. A tunable wavelength range, pulse width and repetition rate is from 5.5 to 10 μm, 5 ns and 10 Hz,
respectively. The laser with a wavelength of 6.02 μm and predetermined energy parameters was irradiated to a carious
dentin model. After laser irradiation, the surface and cross-sectional surface of samples were observed. Average power
density about 15 W/cm2 realized to excavate a demineralized region selectively. In the same energy condition, serious
side effect was not observed on the surface of normal dentin. A wavelength of 6.02 μm realizes a selective excavation of
carious dentin. Using 6.02 μm is a novel and promising technique toward to next-generation dental treatment procedure
for realizing minimal intervention.
Finger temperature controller for non-invasive blood glucose measurement
Show abstract
Blood glucose level is an important parameter for doctors to diagnose and treat diabetes. The Near-Infra-Red (NIR)
spectroscopy method is the most promising approach and this involves measurement on the body skin. However it is
noted that the skin temperature does fluctuate with the environmental and physiological conditions and we found that
temperature has important influences on the glucose measurement. In-vitro and in-vivo investigations on the temperature
influence on blood glucose measurement have been carried out. The in-vitro results show that water temperature has
significant influence on water absorption. Since 90% of blood components are water, skin temperature of measurement
site has significant influence on blood glucose measurement. Also the skin temperature is related to the blood volume,
blood volume inside capillary vessels changes with skin temperature. In this paper the relationship of skin temperature
and signal from the skin and inside tissue was studied at different finger temperatures. Our OGTT (oral glucose tolerance
test) trials results show the laser signals follow the skin temperature trend and the correlation of signal and skin
temperature is much stronger than the correlation of signal and glucose concentration. A finger heater device is designed
to heat and maintain the skin temperature of measurement site. The heater is controlled by an electronic circuit according
to the skin temperature sensed by a thermocouple that is put close to the measurement site. In vivo trials were carried out
and the results show that the skin temperature significantly influences the signal fluctuations caused by pulsate blood and
the average signal value.
Electro-acupuncture at different acupoints modulating the relative specific brain functional network
Jiliang Fang,
Xiaoling Wang,
Yin Wang,
et al.
Show abstract
Objective: The specific brain effects of acupoint are important scientific concern in acupuncture. However, previous
acupuncture fMRI studies focused on acupoints in muscle layer on the limb. Therefore, researches on acupoints within
connective tissue at trunk are warranted.
Material and Methods: Brain effects of acupuncture on abdomen at acupoints Guanyuan (CV4) and Zhongwan (CV12)
were tested using fMRI on 21 healthy volunteers. The data acquisition was performed at resting state, during needle
retention, electroacupuncture (EA) and post-EA resting state. Needling sensations were rated after every
electroacupuncture (EA) procedure. The needling sensations and the brain functional activity and connectivity were
compared between CV4 and CV12 using SPSS, SPM2 and the local and remote connectivity maps.
Results and conclusion: EA at CV4 and CV12 induced apparent deactivation effects in the limbic-paralimbic-neocortical
network. The default mode of the brain was modified by needle retention and EA, respectively. The functional brain
network was significantly changed post EA. However, the minor differences existed between these two acupoints. The
results demonstrated similarity between functional brain network mode of acupuncture modulation and functional
circuits of emotional and cognitive regulation. Acupuncture may produce analgesia, anti-anxiety and anti-depression via
the limbic-paralimbic-neocortical network (LPNN).
Study on pathological area of knee by infrared imaging
Show abstract
The application of infrared imaging in biomedical fields has been very broad, but the research results of the lesion of
knee by using of infrared imaging have seldom been reported at present. On the basis of infrared images research, we
present the exploring image analysis and relate the programming optimum entropy algorithm about infrared imaging
analysis. The paper demonstrates the comparative study on the infrared images contrast between the pathological knee
and the reference normal group through the optimum entropy algorithm. The rule of variation between the normal image
and pathological changes of level about knee lesion in patients is gained. The research results provide a kind of methods
for the clinical diagnosis of the pathological knee and also discuss the value of application about the optimum entropy
algorithm in infrared imaging analysis. Contrasting the MRI or CT, the infrared imaging is cheap and harmless. So the
method can be used in health care and prophylactic detection.
Optimization of fiber optic probe distance for biomedical spectroscopy
Bowen Wang,
Yan Tang,
Xiaolei Zhang,
et al.
Show abstract
We present a theoretical model to maximize the illumination and collection efficiency in designing fiber optic probes for
biomedical spectroscopy measurement. This model is in general applicable to probes with single or multiple fibers. We
investigated a number of probe configurations and find that contact measurement is very inefficient for multi-fiber
probes. Contact measurement is a good choice for single-fiber probes, but for multi-fiber probes, there is an optimal
probe distance. By carefully choosing the probe and sample distance, the signal can be enhanced by 5-10 fold.
Experiments demonstrate the distance dependence of collection efficiency in multi-fiber probes.
Diagnosis gynecological tumors based on urine first derivative spectra
Show abstract
We investigate the use of first derivative intrinsic fluorescence spectroscopy as an adjunctive tool for early diagnosis or
screening on gynecological tumors. The first derivative intrinsic fluorescence spectra from limosis morning urine of
gynecologic cancerous patient and the healthy group are measured. And Combining the first order derivative spectra
method and clinic diagnosis standard to cluster analysis the information, we obtained that the diagnostic sensitivity and
specificity are 81% and 75% based on the judgment of setting γ=300, respectively. It may be applied to early diagnose
gynecological tumors using intrinsic urine fluorescence spectra.