Compared to traditional identification technology, biometric technology has attracted a lot of attention because it highlights the special physiological characteristics and behavioural patterns of the human body. Among many biometric technologies, finger vein recognition technology is highly resistant to forgery, reliable, and unaffected by changes in skin surface conditions. In this study, a specially designed 128-ring array fast photoacoustic imaging system is used to accurately capture finger vein, muscle and skin images for information acquisition. The image segmentation algorithm in deep learning was used to remove the noise from the images, and then using the uniqueness of finger veins and muscle structures between individuals, the features of each image were automatically extracted using a 2D convolutional neural network to produce the classification results for each image, which were then ensemble to produce the identification results for each subject.
Breast cancer has a high morbidity and mortality rate worldwide. The overexpression of HSP70 (Heat Shock Protein 70) has associated with the occurrence, development, treatment, prognosis and drug resistance in breast cancer, and may become a new target for anti-tumor therapy. In this paper, triple-negative breast cancer cells MDA-MB-231 were used to investigate the effects of HS (Heat Shock) and HSP70 inhibitor VER-155008 treatments on mitochondrial morphology and membrane potential by laser scanning confocal microscopy. Meanwhile, the cell proliferation was studied by MTT method. We observed that mitochondrial networks were broken and the mitochondrial membrane potentials were decreased with the HSP70 function inhibition, and its pro-apoptotic effects can be alleviated when VER-155008 treatment was combined with HS. These results were the same as the effects of HS and HSP70 inhibitor on MCF-7, ER-positive breast cancer cells, we had reported. In addition, the proliferation of MDA-MB-231 and MCF-7 after different treatments indicated that HS treatment promoted proliferation in MCF-7, but not in MDA-MB-231.
KEYWORDS: Optical coherence tomography, Image processing, Data processing, Data acquisition, Data conversion, Spectral data processing, Computing systems, Signal processing, Image restoration
Optical Coherence Tomography(OCT) system is a non-contact imaging modality based on low-coherence optical interferometry, used for imaging turbid scattering media. They excel in rendering depth-resolved images of internal structures with micrometer-scale resolution. Previous OCT systems have some defects in image reconstruction, which are limited by complex signal processing and mathematical computation, slow image processing speed, difficult to realize real-time imaging, and high equipment cost. This paper proposes an OCT image reconstruction algorithm acceleration scheme based on the combination of FPGA (Field-Programmable Gate Array) and Python, aiming at accelerating and simplifying the image acquisition and processing of the OCT system through Python, so as to enhance the efficiency of medical diagnosis and biological research. Using Python as the upper computer control software, provide user-friendly graphical interface, output spectral waveform and then realize the Fourier transform, de-direct current and autocorrelation terms and other algorithmic steps to generate OCT images, to realize the real-time data transmission and processing. Python not only has a powerful data visualization ability, but also has the advantages of simple operation, easy to develop the program to ensure that the system operates efficiently.
Photoacoustic Tomography (PAT) combines the advantages of optical imaging and ultrasound imaging, playing an indispensable role in biomedical research and clinical investigations. However, current advanced PAT systems are large in size and expensive, limiting their widespread adoption. Despite attempts to reduce costs by using low-cost light sources, research on sensor driving and data acquisition optimization remains lacking. Therefore, we present a low-cost and high-speed PAT system consisting of a 20Hz pulse frequency PhotoSonus-YAG laser, ultrasound array transducer, a multi-channel high-speed data acquisition system, and computer.This study designs a multi-channel high-speed data acquisition system (DAS) based on FPGA. The system, with FPGA as the core, DDR III SDRAM as the storage device, and a 14-bit high-performance ADC as the core analogto- digital conversion chip, utilizes a USB-based high-speed data acquisition card solution. To meet the demand for synchronous processing of multi-channel signals, the system employs high-end FPGA chips from Xilinx’s ZYNQ7000 series and Texas Instruments’ AFE5816 chips from the ultrasonic AFE series. These components are interconnected via Low Voltage Differential Signaling (LVDS) interfaces to ensure high-speed and highly reliable digital signal transmission. The designed high-speed data acquisition system achieves a collection of 65MSPS × 14 Bit × 16 channels, with a maximum data acquisition speed of 1000 frames per second. This design not only significantly reduces the volume and cost of the PAT system but also ensures the quality of image preservation through real-time data acquisition and processing.
Melanoma is a highly malignant cutaneous tumor, and its early recognition is critical for improving treatment outcomes and patient survival. Related to this is melanocytic nevus, a common skin lesion whose association with melanoma has been of great interest. Photoacoustic microscopy, one of the most promising techniques in skin imaging, has many features applicable to in vivo imaging of dermatologic conditions, such as imaging of cutaneous microvascular and pigmented lesions. It has the advantages of high spatial resolution, nondestructiveness, and relatively large penetration depth for imaging oxygen and deoxyhemoglobin (HbO2 and HbR) as well as melanin. The aim of this study is to explore melanocytic nevi in depth by photoacoustic microscopy and to provide new technical support for the prevention and early diagnosis of melanoma.
With the advancement of technology and increasing security demands, the exploration and extraction of new internal fingertip features have become a significant trend. In traditional fingerprint recognition systems, enhancing anti-spoofing capabilities is crucial. Conventional fingerprints are typically obtained through surface imaging, making their texture features easily susceptible to theft. Optical coherence tomography (OCT) technology offers non-invasive, high-resolution, and live tissue detection advantages, providing micron-level resolution images of biological tissues within a millimeter depth range. This enables the capture of more secure and stable internal biometric features such as internal fingerprints, sweat pores, and sweat glands. Subcutaneous fingerprints are stable, difficult to alter, and possess strong anti-spoofing characteristics. Consequently, subcutaneous fingerprint recognition promises higher security and reliability, addressing the shortcomings of currently prevalent fingerprint recognition systems. This paper presents a subcutaneous fingerprint recognition scheme based on an embedded system. The scheme utilizes Xilinx's Zynq, an all-programmable System on Chip (SoC), and employs OCT technology for fingerprint capture to meet the reliability demands of fingerprint recognition. It addresses issues in traditional OCT capture systems, such as large size, high power consumption, and poor scalability. By using image processing algorithms such as Gray level Co-occurrence Matrix(GLCM), the system extracts features from subcutaneous fingerprint images, achieving low-cost, real-time subcutaneous fingerprint image capture and recognition.
Blood vessels are not only the channel of tumor growth and metastasis, but also the channel of tumor drug therapy. With the development of laser technology, laser treatment of tumor has attracted more and more attention. The changes of blood vessels and tumor parenchyma during photothermal therapy directly reflect the effect of photothermal therapy on tumor. In this paper, speckle variance OCT was used to monitor the dynamic changes of blood vessels and tumor parenchyma in laser photothermal therapy. Specifically, taking the mouse ear as an animal model, the spectral domain OCT combined with speckle variance algorithm was used to monitor the changes of blood vessels and tissues in real time during tissue 830nm continuous laser irradiation. At the same time, the infrared thermal imager is used to monitor the temperature change in the process. To establish the correlation between temperature and the damage of tissue and blood vessels under laser irradiation. The results will provide an effective evaluation method for photothermal therapy and an auxiliary method for tumor treatment monitoring
Tissue local temperature information is necessary for guiding treatment parameters in photothermal therapy. Therefore, a temperature monitoring method suitable for the treatment process is needed for monitoring tissue temperature in real time. In this study, a temperature monitoring system based on PID on the photothermal effect of graphene oxide on tissue was proposed. Graphene Oxide (GO) has high photothermal conversion performance and low cytotoxicity under near infrared laser irradiation at 808nm. The photoacoustic imaging system and infrared thermal imager were employed to monitor the effect of GO as a photothermal agent on the photoacoustic signal and temperature of tissues. Firstly, the relationship between the intensity of photoacoustic signal and the temperature of tissues under the action of GO was established. Then, the PID feedback algorithm was applied to monitor and regulate the temperature change of tissues by the intensity of photoacoustic signal, so as to achieve the purpose of photothermal treatment. The results show that GO can enhance the photoacoustic signal of the tissue under laser irradiation and improve the temperature of the irradiated tissue. The system can effectively monitor and regulate the tissue temperature to achieve the therapeutic effect of tumor with little effect on normal tissue.
Photoacoustic Imaging (PAI) is a non-invasive imaging technology. It breaks through the limitation of shallow imaging depth of traditional optical imaging and low imaging contrast of acoustic imaging. It has a potential wide application in early cancer detection. PAI combined with endoscopy has great significance in the early diagnosis of gastric tumors. However, imaging just obtains the local location information. It cannot obtain the information of any location visually, especially in the process of photothermal therapy. In this paper, COMSOL was employed to simulate the visual model of photoacoustic photothermal imaging of gastric tissue and tumor. The physical processes of photoacoustic imaging such as photothermal strain-ultrasound generated by pulsed laser in stomach were simulated. A complete photoacoustic model was established through the coupling of each physical field. Firstly, a simplified gastric tissue model was constructed, and physical parameters were set for grid division. Then several physical field modules in COMSOL were coupled. The light distribution, temperature change and photoacoustic signal generated by thermal expansion during the propagation of light in biological tissues were obtained by simulation. The simulation results showed that the distribution of light in gastric tumor was significantly lower than that around the stomach. The tumor absorbs more light energy, resulting in a significantly higher temperature than surrounding stomach tissue. The photoacoustic signal of thermal expansion caused by laser irradiation of biological tissue was obtained. This study is helpful to understand the propagation and interaction of light in normal tissues and gastric tumors. It also provides a certain reference for the research and application of photoacoustic imaging in gastric cancer.
Photoacoustic imaging is an imaging technology which combines the advantages of high-resolution optical imaging and deep detection depth of acoustic imaging. Photoacoustic imaging combined with hysteroscopy may be a new diagnostic technique for endometrial cancer. However, the energy loss after pulsed laser passing through the hysteroscope is very large. Therefore, the energy of pulsed laser after hysteroscopy based on photoacoustic imaging is worth further discussion. A coupling Program of pulsed laser and hysteroscope based on the optical path of pulsed laser and hysteroscope was designed in this paper. The Program was optimized by ZEMAX simulation, and then the optimal effect of pulsed laser observation through hysteroscopy was verified by phantom experiment. The results show that the pulsed laser can obtain better photoacoustic signals after passing through our coupling module. This method is expected to be applied to the detection of endometrial diseases in clinic.
Endometrial carcinoma is an epithelial malignant tumor o the endometrium. At present, the conventional methods for endometrial carcinoma detection are cytologial smear and hysteroscopic endometrial biopsy. The hysteroscopic biopsy is a minimally invasive diagnostic and treatment technique in gynecology. However, it can only obtain the lesion of upper mucosa of the uterus by hysteroscopic endometrial biopsy, but cannot detect the infiltration depth of the lesions. Photoacoustic imagining is an imagining technique combining optical and ultrasound. It has both the high resolution of optical imaging and the deep detection depth of ultrasonic imaging. In our study, hysteroscopy-based photoacoustic imaging techniques were proposed to discuss the effect of pigeon intracavitary imaging. The results show that the detectable depth reaches 2.5 cm in our ultrasonic probe with hysteroscopy in vitro. And the longitudinal resolution is 0.5mm. So the system can effectively detect subcutaneous lesions in the cavity. The system is expected to play an important role in the early diagnosis and treatment monitoring of the uterine lesions.
hotothermal therapy (PTT) is an alternative to surgery, which is commonly used to treat tumors in intracavitary organs. PTT involves heating the diseased tissue with radiation energy, resulting in tumor necrosis. In order to improve the safety and effectiveness of PT, it is necessary to monitor the tissue temperature in real time and regulate the laser power during PTT. Photoacoustic imaging (PAI) is a non-invasive and non-ionizing imaging method with high resolution and high accuracy. Due to the dependence of the thermal expansion coefficient on temperature, the Grüneisen parameter is linearly proportional to temperature, and the variation of the amplitude of the photoacoustic signal is related to the variation of the Grüneisen parameter. In this study, we propose a system for laser dose regulation with photoacoustic signal temperature feedback based on PID algorithm. The pulsed laser is irradiated on the sample surface, the ultrasonic probe receives the photoacoustic signal generated by the sample, and the photoacoustic signal is collected by the oscilloscope and transmitted to the computer, which generates the corresponding command to the heating laser according to the signal and changes the output power of the heating laser. The experimental results show that this method can effectively control the photothermal damage range.
Malignant tumor is a serious threat to human health. With the development of medical technology, a variety of treatment methods appear in clinic. As a non-invasive treatment, laser photothermal therapy is a treatment that kills cancer cells by converting light energy into heat energy through laser irradiation. Its advantage is protecting normal tissue while destroying cancerous tissue. However, it’s still not clear that the effect of heat generated by laser on tissue and temperature changes during photothermal treatment process. Optical coherence tomography (OCT) is a non-contract, real-time optical imaging technology. OCT has been widely used in clinical treatment and scientific research based on fast imaging speed and high detection sensitivity. In our study, breast cancer of mice was chosen as the research object. Combined infrared thermography and OCT were applied to monitor the dynamic changes of tumor tissue. The effect of photothermal from OCT image and temperature were obtained and analyzed. Specifically, we investigated the structural change characteristics and temperature distribution of tumor tissue with increasing laser power. And then, the temperature change of tumors of different sizes at power of 3W were further analyzed. The results show that combined with OCT images and temperature can be well used to guide the photothermal treatment process. It can serve as a basis for the method with safely, consistently and effectively.
Near-infrared photoimmunotherapy (NIR-PIT) is an emerging cancer therapy based on conjugating monoclonal antibody (mAb) with a NIR phthalocyanine dye conjugate. Direct tumor necrosis and immunogenic cell death occur during NIR irradiation. We applied a multi-modal optical imaging approach including high-resolution optical coherence tomography (OCT) and high-sensitivity fluorescence mesoscopic tomography, to provide 3D tumor micro-structure and micro-distribution of mAb-IR700 in the tumor simultaneously during and after NIR-PIT in situ and in vivo. Moreover, label-free speckle variance algorithm combined OCT was applied to monitor the change of blood vessels and the alterations of the blood volume inside the blood vessels during and NIR-PIT treatment.
Microvascular network distributes all around the body. Blood vessel is the main channel of tumor development and metastasis, and it is also the channel of drug therapy. So, the tumor vessel feature is very important for characterizing the tumor progress. In our study, OCT was applied on capturing the structure of normal and tumor tissue. Speckle variance algorithm was used to deduce vessel information. And then, vessel character, such as measurable diameters of lumen in blood vessels, vessels tortuosity index and vessel density of vascular between normal vessel and tumor vessel were displayed quantitatively. The result could uncover the difference between the normal and tumor vessel and will help to understand tumor angiogenesis.
Photoacoustic Blood Pressure Recognition Based on Deep LearningXiaoman Zhang, Huaqin Wu, Biying Yu, Sulian Wu, Weijie Wu,Jianyong Cai*and Hui Li* Key Laboratory of OptoElectronicScience and Technology for Medicine of Ministry of Education,Fujian Provincial Key Laboratory of Photonics Technology,College of Photonic and Electronic Engineering, Fujian Normal University Ministry of Education, Fuzhou 350007, P.R. ChinaABSTRACTContinuous and non-invasive real-time measurement of human blood pressure is of great importance for health care and clinical diagnosis.Photoacoustic imaging allows absorption-based high-resolution spectroscopyin vivo imaging with a depth beyond that of optical microscopy. In this study,a novel photoacoustic imaging systemis usedfor monitoring and imaging of vesselpulsation,whichcan realize simple, non-invasive and continuous measurement and recognition of blood pressure. Combined with deep learning method, a model is established to effectively evaluate the dependence of blood vessel elasticity on theblood pressure.These results can quickly and accurately identify the photoacoustic signals of blood vessels under different pressures.
Psoriasis is a common chronic inflammatory skin disease with high prevalence, chronicity, disfiguration, disability. Real-time detection of psoriatic pathological characteristics by optical technology is of great significance for the diagnosis and treatment of psoriasis. We used multiphoton microscopy (MPM) imaging technology based on intrinsic nonlinear optical signals to image the skin of a mouse psoriasis model induced by imiquimod (IMQ). The changes of cells and collagen in psoriasis skin tissue were obtained and analyzed, comparing with the hematoxylin and eosin (H and E) stained image. We found that the MPM technique could clearly observe the differences between normal and psoriasis skin. This is of great significance to the pathogenesis of psoriasis and also provides adjuvant imaging method for the treatment of psoriasis.
To explore the damage range in the photothermal treatment at different temperatures, a temperature-feedback photothermal control system was developed. The system used an infrared thermal imager to noninvasively monitor the temperature .so it could avoid the damage caused by thermocouple measurement and apply the PID controller to achieve the desired temperature(1). the range of damage at the surface and the depth of internal damage were recorded at the different temperatures, which are based on the temperature-feedback photothermal control system. Finally, the recorded data are used to fit the curve by linear regression, and the damage depth was predicted according to the range of external damage at the surface. The technique could be a potential application for monitoring tumor treatment.
Photothermal therapy of tumors has become an important method. In recent years, the method has been widely studied in tumor therapy, and the corresponding results has been obtained well. However, it is still not been solved the effects of the heat on the tumor and its surrounding tissues, and the temperature control in corresponding tissues during the treatment process. In our study, the mouse skin was chosen as the research object. Infrared thermal imager and optical coherence tomography (OCT) were combined to monitor the photothermal therapy in real time in vivo. Temperature and morphological structure were obtained during the photothermal therapy process. The results will provide effective guidance for the photothermal therapy of tissue.
With the development of diagnostic and therapeutic options in gastric cancer, the incidence of gastric cancer is decreasing over the past two decades. However, it is still necessary to improve the early diagnosis technology of gastric cancer to reduce the mortality of gastric cancer. Photoacoustic imaging is a rapidly developing diagnostic modality of cancer which is based on optical excitation and ultrasonic detection. In this paper, photoacoustic imaging is proposed as a visual tool to compound structural and location information for early stage gastric cancer detection by using nanoscale gold rods. The experimental results showed that the nanoscale gold rods can increase penetration depth of tumor in addition to that diagnosing the early gastric cancer with no obvious symptoms.
Resting heart rate (RHR) is considered an important biomedical indicator to evaluate cardiovascular function. High RHR is an important prognostic factor for sudden cardiac death and heart failure in the general population, and especially among patients with known cardiac disease. The imaging photoplethysmography (IPPG) technology is used to achieve the accurate detection of RHR signal, which has the advantages of low cost, simple operation, fast acquisition speed etc. In this paper, we propose a new simple, inexpensive and easy-to-use method to measure the RHR in vivo. The result shows that Fast Fourier Transform with Hamming window filters, band-pass filter gives more accurate results. The color change of the fingertip is enlarged by using the mobile phone camera. From the distribution of color change of the fingertip, the RHR is estimated with the primary calibration result of the relationship between color variation and the blood volume change.
Photo-thermal response is one of the basis processes of laser irradiated tissue, dominating the laser surgical process and depending on the effect of laser treatment. To better investigate the interaction between ablative laser and skin, and more understand the light distribution and temperature distribution during the laser irradiation. Numerical simulation, which based on finite elements method (FEM), was used to solve the bio-heat and the thermal damage equations. Laser parameters can be adjustable during the process of surgery. Optical transmission, scattering coefficient and absorption coefficient in bio-tissue under laser irradiation were carried out to analyze the thermal response, which resulted from the absorbed light energy. And then, optical coherence tomography (OCT) was applied to study the injure in mice skin. The result is consistent to Numerical simulation, which will help to improve the laser therapy.
The light transmission in biological tissue and the optical properties of biological tissue are important research contents of biomedical photonics. It is of great theoretical and practical significance in medical diagnosis and light therapy of disease. In this paper, the temperature feedback-controller was presented for monitoring photothermal treatment in realtime. Two-dimensional Monte Carlo (MC) and diffuse approximation were compared and analyzed. The results demonstrated that diffuse approximation using extrapolated boundary conditions by finite element method is a good approximation to MC simulation. Then in order to minimize thermal damage, real-time temperature monitoring was appraised by proportional-integral-differential (PID) controller in the process of photothermal treatment.
Aging is a very important issue not only in dermatology, but also cosmetic science. Cutaneous aging involves both chronological and photoaging aging process. The evaluation and classification of aging is an important issue with the medical cosmetology workers nowadays. The purpose of this study is to assess chronological-age-related and photo-age-related of human skin. The texture features of skin surface skin, such as coarseness, contrast were analyzed by Fourier transform and Tamura. And the aim of it is to detect the object hidden in the skin texture in difference aging skin. Then, Support vector machine was applied to train the texture feature. The different age’s states were distinguished by the support vector machine (SVM) classifier. The results help us to further understand the mechanism of different aging skin from texture feature and help us to distinguish the different aging states.
In our study, the skin canceration processes induced by UVB were analyzed from the perspective of tissue spectrum. A home-made Raman spectral system with a millimeter order excitation laser spot size combined with a multivariate statistical analysis for monitoring the skin changed irradiated by UVB was studied and the discrimination were evaluated. Raman scattering signals of the SCC and normal skin were acquired. Spectral differences in Raman spectra were revealed. Linear discriminant analysis (LDA) based on principal component analysis (PCA) were employed to generate diagnostic algorithms for the classification of skin SCC and normal. The results indicated that Raman spectroscopy combined with PCA-LDA demonstrated good potential for improving the diagnosis of skin cancers.
Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the prevalent skin cancers, which have a quite high incidence in the white race. In recent years, however, their incidences have been increasing in the yellow race, resulting in a great threat to the public health. According to researches, chronics UVB irradiation (280nm~320nm) is the major culprit of skin cancer in humans. In our study, the model of UVB induced skin cancer was established firstly. Optical coherence tomography (OCT) combined with the histopathology was exploited to monitor the morphologic and histological changes of the process of UVB induced skin cancer. Meanwhile, this canceration process was systematically studied and analyzed from the perspective of tissue optics. The attenuation coefficient (μt) has a rising trend in the epidermis, but which shows a downward trend in the dermis. The results are conducive to understand the process of UVB-induced skin cancer and further be able to provide a reference for medical researchers.
The incidence rate of the prostatic hyperplasia is increasing in near decade, early
detection is important for preventing the prostatic cancer (PCa). In this study, the images of
prostate and cavernous nerves were carried out using intrinsic fluorescence and scattering
properties of the tissues without any exogenous dye or contrast agent based on nonlinear optical
microscope. The texture feature and optical property of the interfibrillar substance in prostate
tissue were extracted and analyzed for charactering the prostate structure. It will be the feature
parameter to differentiate the normal, the inflammation or cancer of prostate tissue in clinical with
the application of miniature endoscope nonlinear optical microscope in vivo.
Cutaneous aging is a complicated biological process affecting different constituents of
skin, which can be divided into two types: the chronological aging and the photo-aging. The two
cutaneous aging processes often co-exist accompanying with each other. The effects are often
overlapped including changes in epithelium and dermis. The degeneration of collagen is a major
factor in dermal alteration with aging. In this study, multiphoton microscopy (MPM) with its high
resolution imaging and optical coherence tomography (OCT) with its depth resolved imaging were
used to study the anti-aging dermatology in vivo. It was attempted to make the optical parameter
and texture feature to evaluate the process of aging skin using mathematical image processing.
The links among optical parameter, spectrum and texture feature in collagen with aging process
were established to uncover mechanism of aging skin.
Multiphoton microscopy was employed for monitoring the structure changes of mouse dermis collagen in the intrinsic- or the extrinsic-age-related processes in vivo. The characteristics of textures in different aging skins were uncovered by fast Fourier transform in which the orientation index and bundle packing of collagen were quantitatively analyzed. Some significant differences in collagen-related changes are found in different aging skins, which can be good indicators for the statuses of aging skins. The results are valuable to the study of aging skin and also of interest to biomedical photonics.
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.
KEYWORDS: Skin, Collagen, Second-harmonic generation, Multiphoton microscopy, In vivo imaging, Fourier transforms, Signal detection, Tissues, Animal model studies, Image analysis
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.
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.
Noninvasive measurement technique to obtain tissue optical properties such as the scattering coefficient μs and
the anisotropy factor g using optical coherence tomography (OCT) scattering model which based on the Extended
Huygens-Fresnel principle is developed in our paper. Older and younger mouse-skin are as animal model to compare its
scattering coefficient μs and the anisotropy factor g, the outcome shows that scattering coefficient μs is increased with the
age of mouse-skin. Furthermore, we have made age's mouse-skin into H.E stain slices; the result of its morphology is
consistent with the OCT imaging and OCT-EHF principle. All of that have provided the theoretical basis which to the
research on photo-aging skin and photo-rejuvenation.
Cutaneous photo-thermal damage is the common damages in clinical medicine; it is a complex and dynamic
process that follows an orderly sequence of events. The sequence can be roughly divided into three distinct, yet
sequentially overlapping phases-inflammation, granulation tissue formation, and tissue remodeling. Characteristic
structural changes associated with each phase could provide a basis for photo-thermal damage assessment with imaging
technologies. Monitoring the skin tissue response during the skin after irradiated by laser and tracing the process of skin
remodeling would help to understand the mechanism of photo-thermal. Optical coherence tomography (OCT) and
multiphoton microscopy (MPM) imaging were used to observe the process of the collagen remodeling in mouse dermis
photo-thermal injured which after irradiated by intense pulsed light source (IPLs) in this paper. Our finding showed that
the OCT and MPM techniques can image the process of collagen remodeling in mouse dermis.
With low risk of complications and little down-time, the non-ablative photo-rejuvenation is playing an
increasing role in the therapy of the photo-damaged skin, but the appraisal standard is different. This paper
mainly observed the effect of the mouse skin irradiated by intense pulse light source through two photo
microscopy in sub-micrometer. The spectrum and morphological imaging between pre- and post-irradiated by
Intense Pulse Light (IPL) were obtained from two photon microscopy respectively. The outcome showed that
non-ablative IPL irradiated the aging mouse skin got the better effect, and then have gained the changes of
spectrum intensity and corresponding photon numbers in a rectangular area, these probable achieve the
mechanism of light irradiated skin. The intention of this was offer the theory basis in clinic.
We demonstrated that a simple image statistic, skewness, is able to distinguish the various concentration of
Intralipid solution by using optical coherence tomography. The results showed that the skewness is increased with the
concentration of Intralipid solution. According to Mie theory, the skewness is correlated with the scattering coefficient of
Intralipid solution. And the correlation between skewness and scattering coefficient is explained that the skewness
exploits the characteristic of asymmetry of probability density distribution of image intensity.
The technologies based on Differential Interference Contrast microscopy (DIC), Laser Scanning Confocal Microscopy
(LSCM), Two Photon Emission Laser Scanning Microscopy (TPELSM) and Optical Coherent Tomography (OCT) were
used to study the changes of mouse skin after irradiated by Intense Pulse Light (IPL). The experimental results were
compared and analyzed by different microscopic observation tools. The relations of the epithelial or dermal interaction
with IPL in different energy density were given, and the morphologic changes of mouse skin were observed before and
after days irradiated respectively. The function of dermal collagen during the renovating of the tissue and the key factors
were presented.
KEYWORDS: Skin, Collagen, Digital image correlation, Refractive index, Microscopy, In vivo imaging, Tissue optics, Injuries, Animal model studies, Biopsy
Living cells and transparent specimen can be observed by the Differential Interference Contrast (DIC) microscopy. In this paper, the morphologic changes of mouse skin in vivo treated in several configurations by intense pulse light (IPL) were observed by a DIC microscopy. The differences of the images before and after the IPL irradiation were obtained and the mechanism was analyzed. In addition, the collagen recombination after the irradiation of IPL in skin was acquired.
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