Optical coherence tomography (OCT) is a relatively new imaging technology which can produce high resolution images of three-dimensional structures. OCT has been mainly used for medical applications such as for ophthal...Optical coherence tomography (OCT) is a relatively new imaging technology which can produce high resolution images of three-dimensional structures. OCT has been mainly used for medical applications such as for ophthalmology and dermatology. In this study we demonstrate its capability in providing much more reliable biometry identification of fingerprints than conventional methods. We prove that OCT can serve secure control of genuine fingerprints as it can detect if extra layers are placed above the finger. This can prevent with a high probability, intruders to a secure area trying to foul standard systems based on imaging the finger surface. En-Face OCT method is employed and recommended for its capability of providing not only the axial succession of layers in depth, but the en-face image that allows the traditional pattern identification. Another reason for using such OCT technology is that it is compatible with dynamic focus and therefore can provide enhanced transversal resolution and sensitivity. Two En-Face OCT systems are used to evaluate the need for high resolution and conclusions are drawn in terms of the most potential commercial route to ex- ploitation.展开更多
In this paper, the dynamic analysis of mental sweating for sound stimulus of a few tens of eccrine sweat glands is performed by the time-sequential piled-up en-face optical coherence tomography (OCT) images with the f...In this paper, the dynamic analysis of mental sweating for sound stimulus of a few tens of eccrine sweat glands is performed by the time-sequential piled-up en-face optical coherence tomography (OCT) images with the frame spacing of 3.3 sec. In the experiment, the amount of excess sweat can be evaluated simultaneously for a few tens of sweat glands by piling up of all the en-face OCT images. Strong non-uniformity is observed in mental sweating where the amount of sweat in response to sound stimulus is different for each sweat gland. Furthermore, the amount of sweat is significantly increased in proportion to the strength of the stimulus.展开更多
Background:Optical coherence tomography angiography(OCTA)is a novel non-invasive angiography technology that has recently been extensively studied for its utility in anterior segment imaging.In this study,we compared ...Background:Optical coherence tomography angiography(OCTA)is a novel non-invasive angiography technology that has recently been extensively studied for its utility in anterior segment imaging.In this study,we compared a split-spectrum amplitude decorrelation angiography(SSADA)OCTA and an optical micro-angiography(OMAG SD)OCTA system to current angiographic technique,indocyanine green angiography(ICGA),to assess corneal vascularisation in an animal model.Methods:We imaged 16 rabbits,(one eye per animal)with corneal vascularisation using SSADA OCTA(AngioVue;Optovue Inc.,USA),OMAG OCTA(Angioscan;RS-3000 Nidek Co.Ltd.,Japan)and ICGA in the same region of interest of the cornea at successive time-points.We then analysed all scanned images for vessel density measurements and used paired t-tests and Bland-Altman plots to examine for significant differences.The en-face segmentation images from each of the OCTA scans were also extracted and were matched at every 50μm segmentation to be compared for vessel density at the respective depths.Results:Bland-Altman plots revealed a good agreement between all three imaging techniques(P>0.05)for all vessel density measurements computed,and the ranges of 95%limit of agreement were acceptable from a clinical perspective.No significant difference was reported,with ICGA(μ=16.52±8.94%)being more comparable to the OMAG OCTA(μ=16.23±9.51%;p=0.50)than the SSADA OCTA(μ=17.09±7.34%;p=0.33)system.Also,a good correlation value(r>0.9)was obtained when comparing the vessel density measurements of the en-face segmentations between the OCTA systems.Conclusions:Comparable vessel density quantification between the two OCTA systems,and with ICGA was obtained.Segmentation analysis of the vasculature at different depths showed varied performance in the two OCTA systems relative to each other.The implications of the study may help to aid in the development of better OCTA algorithms for the anterior segment and its use in clinical translational research.展开更多
巨噬细胞样细胞(macrophage-like cells, MLC)指起源、功能与巨噬细胞类似的免疫细胞,包括小胶质细胞、玻璃体细胞及巨噬细胞。将en face OCT显示层面设置在视网膜表明即可观测到视网膜表明的MLC(epiretinal MLC, eMLC),随后利用Image ...巨噬细胞样细胞(macrophage-like cells, MLC)指起源、功能与巨噬细胞类似的免疫细胞,包括小胶质细胞、玻璃体细胞及巨噬细胞。将en face OCT显示层面设置在视网膜表明即可观测到视网膜表明的MLC(epiretinal MLC, eMLC),随后利用Image J软件即可对细胞进行提取和量化。研究表明,eMLC在炎症情况下均可出现细胞募集及活化现象,但在不同眼底病中各具特点。在糖尿病视网膜病变、视网膜静脉阻塞等视网膜缺血缺氧性疾病中,eMLC密度越高,黄斑水肿可能越严重。此外,eMLC密度更高的视网膜静脉阻塞患者抗VEGF疗效更差,视力预后不佳,提示基于en face OCT的eMLC不仅可用于评估视网膜炎症情况,而且还能充当提示疾病疗效及预后的标志物。在葡萄膜炎等免疫炎症性疾病中,en face OCT亦可观测到eMLC密度、形态等改变。白塞病葡萄膜炎患者视网膜血管渗漏程度与eMLC密度相关性强,故eMLC密度可充当无创评估视网膜血管渗漏程度的新指标。然而,目前提取和量化eMLC的方法及标准不统一,降低了各研究间的可比性。因此,亟需制定统一的操作规范和评估标准。此外eMLC所代表的具体细胞类型及功能仍需进一步探究。未来,研究者可以利用en face OCT对眼底炎症地进行无创评估。基于en face OCT的eMLC还能作为基础研究与临床研究之间的桥梁,为揭示疾病的致病机制提供重要参考。展开更多
针对中国FACE（FreeAir CO2 Enrichment）平台的镇籼96、扬稻8号、II优084和扬两优6号四种水稻品种，采用新一代高通量测序技术，研究了水稻根系内生菌的整体微生物群落对未来大气CO2浓度升高的响应。结果表明，水稻内生菌群落中，Y-变...针对中国FACE（FreeAir CO2 Enrichment）平台的镇籼96、扬稻8号、II优084和扬两优6号四种水稻品种，采用新一代高通量测序技术，研究了水稻根系内生菌的整体微生物群落对未来大气CO2浓度升高的响应。结果表明，水稻内生菌群落中，Y-变形菌纲的肠杆菌科相对丰度最高，占整体微生物群落的30．8％～59．8％。对于镇籼96、扬稻8号和II优084三种水稻品种，大气CO2浓度升高可能抑制了数量上占优势的微生物菌群（优势菌群）生长，而促进了数量上不占优势的微生物菌群（稀少菌群）繁殖。例如，对于II优084品种，相对丰度高于14．6％的4种水稻内生菌为肠杆菌科、假单胞菌科、黄单胞菌科和气单胞菌科，大气CO2浓度升高，这些优势菌群的相对丰度之和由74．8％降为67．2％；相反，稀少菌群主要由鞘脂杆菌科、丛毛单胞菌科、黄杆菌科及草酸杆菌科组成，其相对丰度之和则由4．13％增至16．9％，其中，与对照相比，鞘脂杆菌科相对丰度增加比例高达344倍，是大气CO2浓度升高的最敏感微生物类群。但对于水稻品种扬两优6号，根系内生菌对大气CO2浓度升高的响应模式与其他三种品种不完全一致。这些研究结果表明，微生物的相对丰度可能是影响水稻根系内生菌对大气CO2浓度升高响应的重要因素，为研究全球变化下整体微生物结构与功能的演变规律提供了一定的依据。展开更多
We developed high-speed time-domain (TD) en face optical coherence tomography (OCT) system using KTN optical beam deflector. The KTN optical beam deflector operates at a high repetition rate of 200 kHz with a fairly l...We developed high-speed time-domain (TD) en face optical coherence tomography (OCT) system using KTN optical beam deflector. The KTN optical beam deflector operates at a high repetition rate of 200 kHz with a fairly large beam deflection angle. We proposed a high-speed en face OCT system that used a KTN optical deflector as the sample beam scanning. In the experiment, we obtained en face OCT images of human fingerprint with a frame rate of 800 fps, which is the fastest speed obtained by a TD-OCT imaging. Furthermore, a 3D-OCT image was also obtained at 0.2 s (=5 volumes/s) by our imaging system.展开更多
Objectives To develop a simple, accurate and reproducible method, which combines macro and histopathological techniques for determining the degree of lipid deposition in genetically modified mice. Method The entire a...Objectives To develop a simple, accurate and reproducible method, which combines macro and histopathological techniques for determining the degree of lipid deposition in genetically modified mice. Method The entire aortas from C57BL/6, ldlr-/- and apoE-/- mice were stained with Sudan IV using either in vivo perfusion or traditional in vitro enface staining techniques. Histological sections of aortic root and hearts were embedded in tissue freezing medium and cut with a cryostat, then stained with Oil Red O. The calculated aortic root area based on the aortic root circumference was used to reduce measurement errors. Results The in vitro en face staining can stain all fat, which include the adventitial tissue around aorta. However the in vivo perfusion staining can specifically stain the fatty deposition inside of aorta. Both entire aorta and aortic root section staining showed that there was a highly significant increase in fatty deposition in the aortas of the genetic modified mice. Although all mice genetic background was same, the apoE-/- mice had larger atherosclerotic lesions than ldlr-/- mice. Conclusions The new in vivo peffusion method is more accurate than the in vitro en face method. The combination of these macro and microscopic techniques overcomes the shortcomings of the earlier published methods which are generally limited to the measurement of fatty red staining areas only, neglecting non-specific adventitial fat staining around aorta and aortic root section tissue distortion.展开更多
文摘Optical coherence tomography (OCT) is a relatively new imaging technology which can produce high resolution images of three-dimensional structures. OCT has been mainly used for medical applications such as for ophthalmology and dermatology. In this study we demonstrate its capability in providing much more reliable biometry identification of fingerprints than conventional methods. We prove that OCT can serve secure control of genuine fingerprints as it can detect if extra layers are placed above the finger. This can prevent with a high probability, intruders to a secure area trying to foul standard systems based on imaging the finger surface. En-Face OCT method is employed and recommended for its capability of providing not only the axial succession of layers in depth, but the en-face image that allows the traditional pattern identification. Another reason for using such OCT technology is that it is compatible with dynamic focus and therefore can provide enhanced transversal resolution and sensitivity. Two En-Face OCT systems are used to evaluate the need for high resolution and conclusions are drawn in terms of the most potential commercial route to ex- ploitation.
文摘In this paper, the dynamic analysis of mental sweating for sound stimulus of a few tens of eccrine sweat glands is performed by the time-sequential piled-up en-face optical coherence tomography (OCT) images with the frame spacing of 3.3 sec. In the experiment, the amount of excess sweat can be evaluated simultaneously for a few tens of sweat glands by piling up of all the en-face OCT images. Strong non-uniformity is observed in mental sweating where the amount of sweat in response to sound stimulus is different for each sweat gland. Furthermore, the amount of sweat is significantly increased in proportion to the strength of the stimulus.
文摘Background:Optical coherence tomography angiography(OCTA)is a novel non-invasive angiography technology that has recently been extensively studied for its utility in anterior segment imaging.In this study,we compared a split-spectrum amplitude decorrelation angiography(SSADA)OCTA and an optical micro-angiography(OMAG SD)OCTA system to current angiographic technique,indocyanine green angiography(ICGA),to assess corneal vascularisation in an animal model.Methods:We imaged 16 rabbits,(one eye per animal)with corneal vascularisation using SSADA OCTA(AngioVue;Optovue Inc.,USA),OMAG OCTA(Angioscan;RS-3000 Nidek Co.Ltd.,Japan)and ICGA in the same region of interest of the cornea at successive time-points.We then analysed all scanned images for vessel density measurements and used paired t-tests and Bland-Altman plots to examine for significant differences.The en-face segmentation images from each of the OCTA scans were also extracted and were matched at every 50μm segmentation to be compared for vessel density at the respective depths.Results:Bland-Altman plots revealed a good agreement between all three imaging techniques(P>0.05)for all vessel density measurements computed,and the ranges of 95%limit of agreement were acceptable from a clinical perspective.No significant difference was reported,with ICGA(μ=16.52±8.94%)being more comparable to the OMAG OCTA(μ=16.23±9.51%;p=0.50)than the SSADA OCTA(μ=17.09±7.34%;p=0.33)system.Also,a good correlation value(r>0.9)was obtained when comparing the vessel density measurements of the en-face segmentations between the OCTA systems.Conclusions:Comparable vessel density quantification between the two OCTA systems,and with ICGA was obtained.Segmentation analysis of the vasculature at different depths showed varied performance in the two OCTA systems relative to each other.The implications of the study may help to aid in the development of better OCTA algorithms for the anterior segment and its use in clinical translational research.
文摘巨噬细胞样细胞(macrophage-like cells, MLC)指起源、功能与巨噬细胞类似的免疫细胞,包括小胶质细胞、玻璃体细胞及巨噬细胞。将en face OCT显示层面设置在视网膜表明即可观测到视网膜表明的MLC(epiretinal MLC, eMLC),随后利用Image J软件即可对细胞进行提取和量化。研究表明,eMLC在炎症情况下均可出现细胞募集及活化现象,但在不同眼底病中各具特点。在糖尿病视网膜病变、视网膜静脉阻塞等视网膜缺血缺氧性疾病中,eMLC密度越高,黄斑水肿可能越严重。此外,eMLC密度更高的视网膜静脉阻塞患者抗VEGF疗效更差,视力预后不佳,提示基于en face OCT的eMLC不仅可用于评估视网膜炎症情况,而且还能充当提示疾病疗效及预后的标志物。在葡萄膜炎等免疫炎症性疾病中,en face OCT亦可观测到eMLC密度、形态等改变。白塞病葡萄膜炎患者视网膜血管渗漏程度与eMLC密度相关性强,故eMLC密度可充当无创评估视网膜血管渗漏程度的新指标。然而,目前提取和量化eMLC的方法及标准不统一,降低了各研究间的可比性。因此,亟需制定统一的操作规范和评估标准。此外eMLC所代表的具体细胞类型及功能仍需进一步探究。未来,研究者可以利用en face OCT对眼底炎症地进行无创评估。基于en face OCT的eMLC还能作为基础研究与临床研究之间的桥梁,为揭示疾病的致病机制提供重要参考。
文摘针对中国FACE（FreeAir CO2 Enrichment）平台的镇籼96、扬稻8号、II优084和扬两优6号四种水稻品种，采用新一代高通量测序技术，研究了水稻根系内生菌的整体微生物群落对未来大气CO2浓度升高的响应。结果表明，水稻内生菌群落中，Y-变形菌纲的肠杆菌科相对丰度最高，占整体微生物群落的30．8％～59．8％。对于镇籼96、扬稻8号和II优084三种水稻品种，大气CO2浓度升高可能抑制了数量上占优势的微生物菌群（优势菌群）生长，而促进了数量上不占优势的微生物菌群（稀少菌群）繁殖。例如，对于II优084品种，相对丰度高于14．6％的4种水稻内生菌为肠杆菌科、假单胞菌科、黄单胞菌科和气单胞菌科，大气CO2浓度升高，这些优势菌群的相对丰度之和由74．8％降为67．2％；相反，稀少菌群主要由鞘脂杆菌科、丛毛单胞菌科、黄杆菌科及草酸杆菌科组成，其相对丰度之和则由4．13％增至16．9％，其中，与对照相比，鞘脂杆菌科相对丰度增加比例高达344倍，是大气CO2浓度升高的最敏感微生物类群。但对于水稻品种扬两优6号，根系内生菌对大气CO2浓度升高的响应模式与其他三种品种不完全一致。这些研究结果表明，微生物的相对丰度可能是影响水稻根系内生菌对大气CO2浓度升高响应的重要因素，为研究全球变化下整体微生物结构与功能的演变规律提供了一定的依据。
文摘We developed high-speed time-domain (TD) en face optical coherence tomography (OCT) system using KTN optical beam deflector. The KTN optical beam deflector operates at a high repetition rate of 200 kHz with a fairly large beam deflection angle. We proposed a high-speed en face OCT system that used a KTN optical deflector as the sample beam scanning. In the experiment, we obtained en face OCT images of human fingerprint with a frame rate of 800 fps, which is the fastest speed obtained by a TD-OCT imaging. Furthermore, a 3D-OCT image was also obtained at 0.2 s (=5 volumes/s) by our imaging system.
基金supported by the Hong Kong WangKuan Cheng Foundation GrantBritish Heart Foundation
文摘Objectives To develop a simple, accurate and reproducible method, which combines macro and histopathological techniques for determining the degree of lipid deposition in genetically modified mice. Method The entire aortas from C57BL/6, ldlr-/- and apoE-/- mice were stained with Sudan IV using either in vivo perfusion or traditional in vitro enface staining techniques. Histological sections of aortic root and hearts were embedded in tissue freezing medium and cut with a cryostat, then stained with Oil Red O. The calculated aortic root area based on the aortic root circumference was used to reduce measurement errors. Results The in vitro en face staining can stain all fat, which include the adventitial tissue around aorta. However the in vivo perfusion staining can specifically stain the fatty deposition inside of aorta. Both entire aorta and aortic root section staining showed that there was a highly significant increase in fatty deposition in the aortas of the genetic modified mice. Although all mice genetic background was same, the apoE-/- mice had larger atherosclerotic lesions than ldlr-/- mice. Conclusions The new in vivo peffusion method is more accurate than the in vitro en face method. The combination of these macro and microscopic techniques overcomes the shortcomings of the earlier published methods which are generally limited to the measurement of fatty red staining areas only, neglecting non-specific adventitial fat staining around aorta and aortic root section tissue distortion.
