Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331381
Maria Margarida Dias Soares Quinas Guerra, Rui D. M. Travasso
A simulation of a hybrid multi-scale phase-field model which describes the dynamics of the interface that divides the new capillaries and the stroma was performed. Four equations model the behaviour of proliferating endothelial cells (ECs) in response to a gradient of a pro-angiogenic factor (T), leading to the growth and time evolution of a tree of vascular vessels from sprouts emerging from the original capillar. New sprouts are pulled by activated tip cells and move with a velocity proportional to the gradient of angiogenic factors. The sources of pro-angiogenic factor are hypoxic cells. This factor diffuses throughout a three-dimensional system and is consumed by the ECs whose proliferation is governed by an order parameter (φ). Higher values of chemotactic response led to an increase of the number of ramifications in the vessels, which were thinner; higher values of proliferation rate to thicker vessels and a more ramified network and an increase in the number of hypoxic cells led to a higher number of branches, higher angiogenic factor consumption, longer and internally more proliferative vessels.
{"title":"Novel approach to vascular network modeling in 3D","authors":"Maria Margarida Dias Soares Quinas Guerra, Rui D. M. Travasso","doi":"10.1109/ENBENG.2012.6331381","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331381","url":null,"abstract":"A simulation of a hybrid multi-scale phase-field model which describes the dynamics of the interface that divides the new capillaries and the stroma was performed. Four equations model the behaviour of proliferating endothelial cells (ECs) in response to a gradient of a pro-angiogenic factor (T), leading to the growth and time evolution of a tree of vascular vessels from sprouts emerging from the original capillar. New sprouts are pulled by activated tip cells and move with a velocity proportional to the gradient of angiogenic factors. The sources of pro-angiogenic factor are hypoxic cells. This factor diffuses throughout a three-dimensional system and is consumed by the ECs whose proliferation is governed by an order parameter (φ). Higher values of chemotactic response led to an increase of the number of ramifications in the vessels, which were thinner; higher values of proliferation rate to thicker vessels and a more ramified network and an increase in the number of hypoxic cells led to a higher number of branches, higher angiogenic factor consumption, longer and internally more proliferative vessels.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121178769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331361
B. Tomé, R. Rodrigues, G. Ferreira
The general objective of this project is to develop an acoustic biosensor platform to study protein-DNA binding and its application to the study of DNA transcription factors. An impedance analysis methodology enables the calculation of the acoustic energy dissipation per unit mass observed upon DNA binding, providing quantitative information on the size and shape of the tethered molecules. The rationale of the project rely on the fact that the conformational changes and bending of DNA upon protein binding increase the rigidity of DNA films immobilized at the surface of an acoustic sensor. As a result less acoustic energy is dissipated what is signaled by a decrease of the variation of the acoustic motional resistance. Such experimental approach, together with the associated mathematical signal processing and physical modeling, will provide quantitative information on sequence and conformation DNA sequences recognized by specific transcriptional factors as well as affinity and kinetic constants.
{"title":"Biosensor platform for transcription factor DNA binding activity detection","authors":"B. Tomé, R. Rodrigues, G. Ferreira","doi":"10.1109/ENBENG.2012.6331361","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331361","url":null,"abstract":"The general objective of this project is to develop an acoustic biosensor platform to study protein-DNA binding and its application to the study of DNA transcription factors. An impedance analysis methodology enables the calculation of the acoustic energy dissipation per unit mass observed upon DNA binding, providing quantitative information on the size and shape of the tethered molecules. The rationale of the project rely on the fact that the conformational changes and bending of DNA upon protein binding increase the rigidity of DNA films immobilized at the surface of an acoustic sensor. As a result less acoustic energy is dissipated what is signaled by a decrease of the variation of the acoustic motional resistance. Such experimental approach, together with the associated mathematical signal processing and physical modeling, will provide quantitative information on sequence and conformation DNA sequences recognized by specific transcriptional factors as well as affinity and kinetic constants.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116471824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331355
C. Tavares, R. Martins, M. Oliveira, S. Laranjo, I. Rocha
Heart rate variability is a classical method to quantify the autonomic outflow to the cardiovascular system. The current methods in frequency and time-frequency domains have shown some limitations in resolution. In this paper, we propose a modified Hilbert-Huang algorithm to the assessment of autonomic activity in heart rate signals. These approaches are evaluated while analyzing both simulated signals and experimental data from tachograms associated with cardiac autonomic blockade of patients with paroxysmal atrial fibrillation.
{"title":"A modified Hilbert-Huang algorithm to the assessment of heart rate variability","authors":"C. Tavares, R. Martins, M. Oliveira, S. Laranjo, I. Rocha","doi":"10.1109/ENBENG.2012.6331355","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331355","url":null,"abstract":"Heart rate variability is a classical method to quantify the autonomic outflow to the cardiovascular system. The current methods in frequency and time-frequency domains have shown some limitations in resolution. In this paper, we propose a modified Hilbert-Huang algorithm to the assessment of autonomic activity in heart rate signals. These approaches are evaluated while analyzing both simulated signals and experimental data from tachograms associated with cardiac autonomic blockade of patients with paroxysmal atrial fibrillation.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116141797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331350
A. Batista, C. Loureiro, J. Domingues, J. S. Silva, M. Morgado
We intend to develop an efficient method of measuring respiratory function of the cornea. With this purpose, we resorted to fluorescence lifetime imaging microscopy (FLIM) to monitor the metabolic co-factor flavin adenine dinucleotide (FAD). FAD and nicotinamide adenine dinucleotide (NADH) are co-factors of the electron transport chain. Therefore alterations in amount of these molecules reflect alterations in the metabolism. For assessing the potential of FLIM for metabolic imaging of the cornea, we performed a series of experiments using a time-correlated single photon counting (TCSPC) fluorescence lifetime microscope (Picoquant to MicroTime 100 coupled to an Olympus BX51 Microscope). In this technique, the acquired signal is the convolution between the instrument response function (IRF) and the fluorescence signal from the sample. IRF was acquired using an Erythrosin B solution. In this work we show that it is possible to acquire fluorescence lifetime images of rat and bovine corneas using FAD autofluorescence.
我们打算发展一种有效的测量角膜呼吸功能的方法。为此，我们采用荧光寿命成像显微镜(FLIM)监测代谢辅助因子黄素腺嘌呤二核苷酸(FAD)。FAD和烟酰胺腺嘌呤二核苷酸(NADH)是电子传递链的辅助因子。因此，这些分子数量的变化反映了代谢的变化。为了评估FLIM在角膜代谢成像中的潜力，我们使用时间相关单光子计数(TCSPC)荧光寿命显微镜(Picoquant to MicroTime 100与Olympus BX51显微镜耦合)进行了一系列实验。在该技术中，采集的信号是仪器响应函数(IRF)与样品荧光信号之间的卷积。IRF用红素B溶液获得。在这项工作中，我们表明，它是可能获得荧光寿命图像的大鼠和牛角膜使用FAD自体荧光。
{"title":"FLIM as a tool for metabolic imaging of the cornea","authors":"A. Batista, C. Loureiro, J. Domingues, J. S. Silva, M. Morgado","doi":"10.1109/ENBENG.2012.6331350","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331350","url":null,"abstract":"We intend to develop an efficient method of measuring respiratory function of the cornea. With this purpose, we resorted to fluorescence lifetime imaging microscopy (FLIM) to monitor the metabolic co-factor flavin adenine dinucleotide (FAD). FAD and nicotinamide adenine dinucleotide (NADH) are co-factors of the electron transport chain. Therefore alterations in amount of these molecules reflect alterations in the metabolism. For assessing the potential of FLIM for metabolic imaging of the cornea, we performed a series of experiments using a time-correlated single photon counting (TCSPC) fluorescence lifetime microscope (Picoquant to MicroTime 100 coupled to an Olympus BX51 Microscope). In this technique, the acquired signal is the convolution between the instrument response function (IRF) and the fluorescence signal from the sample. IRF was acquired using an Erythrosin B solution. In this work we show that it is possible to acquire fluorescence lifetime images of rat and bovine corneas using FAD autofluorescence.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"160 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115969989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331362
S. Ghithan, H. Simões, F. Alves, S. Carmo, M. Cunha, R. Marques, F. Fraga, M. Pinto, P. Crespo
Different cyclotron models capable of accelerating protons up to 20MeV have been worldwide installed. Although their purpose is mainly positron emission tomography (PET) radioisotope production, they are equipped with several beam lines suitable for scientific research. Each beam line may typically deliver proton currents up to 150 μA (1×1015 particles/s). Radiobiological and dosimetric studies can be performed using these beam lines, which may contribute to further improve ion therapy and material radiation hardness results, among other applications. We report experimental results aiming at characterizing the proton beam achievable outside a PET cyclotron. In addition, we simulate this experimental setup by using Geant4. We show that simulation is consistent with previous published experimental data and with our first-measured results. These point to a beam angular spreading which may be utilized to establish an irradiation setup within the bunker. We estimate that the dose achievable with such setup may span 4-orders-of-magnitude, useful in radiobiology, ranging from 10mGy to 100 Gy. Finally, we show by simulation that neutron and γ-ray dose on a realistic, in-bunker target is negligible down to at most the 1% level. Further quantification for lower levels is ongoing.
{"title":"Preliminary characterization of the external proton beam from a PET cyclotron for use in neutron and proton radiobiology and other dosimetric studies","authors":"S. Ghithan, H. Simões, F. Alves, S. Carmo, M. Cunha, R. Marques, F. Fraga, M. Pinto, P. Crespo","doi":"10.1109/ENBENG.2012.6331362","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331362","url":null,"abstract":"Different cyclotron models capable of accelerating protons up to 20MeV have been worldwide installed. Although their purpose is mainly positron emission tomography (PET) radioisotope production, they are equipped with several beam lines suitable for scientific research. Each beam line may typically deliver proton currents up to 150 μA (1×1015 particles/s). Radiobiological and dosimetric studies can be performed using these beam lines, which may contribute to further improve ion therapy and material radiation hardness results, among other applications. We report experimental results aiming at characterizing the proton beam achievable outside a PET cyclotron. In addition, we simulate this experimental setup by using Geant4. We show that simulation is consistent with previous published experimental data and with our first-measured results. These point to a beam angular spreading which may be utilized to establish an irradiation setup within the bunker. We estimate that the dose achievable with such setup may span 4-orders-of-magnitude, useful in radiobiology, ranging from 10mGy to 100 Gy. Finally, we show by simulation that neutron and γ-ray dose on a realistic, in-bunker target is negligible down to at most the 1% level. Further quantification for lower levels is ongoing.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122937208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331378
A. R. Bento, S. Baptista, J. Malva, A. P. Silva, F. Agasse
Methamphetamine (METH) is a potent and widely consumed psychostimulant which causes brain functional and structural abnormalities. However, little is known about the effect of METH on adult neurogenic niches and its consequences on the subventricular zone (SVZ). Thus, this work aims to disclose the effects of METH on SVZ neurogenesis. SVZ neurospheres were cultured from early postnatal mice and subjected to increasing concentrations of METH (1 μM to 500 μM). After 24 hours of exposure to METH cell death was triggered by both necrosis and apoptosis. METH exerted toxic effects on stem/progenitor cells expressing SOX2, but not on doublecortin-labeled neuroblasts. METH decreased BrdU incorporation in SVZ cell cultures. Furthermore, METH decreased the number of NeuN-positive neurons, as well as P-JNK-positive growing axons. Altogether, our data demonstrate that METH is toxic to SVZ cells and reduces neuronal differentiation and maturation at non toxic concentrations.
{"title":"The effect of methamphetamine on subventricular zone neurogenesis: Cell death, proliferation and differentiation","authors":"A. R. Bento, S. Baptista, J. Malva, A. P. Silva, F. Agasse","doi":"10.1109/ENBENG.2012.6331378","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331378","url":null,"abstract":"Methamphetamine (METH) is a potent and widely consumed psychostimulant which causes brain functional and structural abnormalities. However, little is known about the effect of METH on adult neurogenic niches and its consequences on the subventricular zone (SVZ). Thus, this work aims to disclose the effects of METH on SVZ neurogenesis. SVZ neurospheres were cultured from early postnatal mice and subjected to increasing concentrations of METH (1 μM to 500 μM). After 24 hours of exposure to METH cell death was triggered by both necrosis and apoptosis. METH exerted toxic effects on stem/progenitor cells expressing SOX2, but not on doublecortin-labeled neuroblasts. METH decreased BrdU incorporation in SVZ cell cultures. Furthermore, METH decreased the number of NeuN-positive neurons, as well as P-JNK-positive growing axons. Altogether, our data demonstrate that METH is toxic to SVZ cells and reduces neuronal differentiation and maturation at non toxic concentrations.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129104899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331343
C. Leitão, H. Lima, J. Pinto, L. Bilro, P. Antunes, C. Marques, J. Prata, P. André, R. Nogueira
Cardiovascular diseases are the leading cause of death in the world, arising their early prediction as a key aspect. The analysis of pulse wave propagation characteristics, such as velocity and morphology, can give important data about arterial stiffness, a parameter with growing significance in cardiovascular events prediction. In this paper it is presented a new optical fibre sensor to assess the pressure waveform in the carotid artery. The optical sensor is based on fibre Bragg grating technology, increasingly applied in several fields, including biomedical sensing due to its advantageous features. The Bragg sensor was characterized and tested in human carotids. It is presented a case study showing the great potential of Bragg technology in the assessment of the pressure waveform.
{"title":"Development and characterization of new sensors for hemodynamic evaluation: Fibre Bragg sensor for arterial pulse waveform acquisition","authors":"C. Leitão, H. Lima, J. Pinto, L. Bilro, P. Antunes, C. Marques, J. Prata, P. André, R. Nogueira","doi":"10.1109/ENBENG.2012.6331343","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331343","url":null,"abstract":"Cardiovascular diseases are the leading cause of death in the world, arising their early prediction as a key aspect. The analysis of pulse wave propagation characteristics, such as velocity and morphology, can give important data about arterial stiffness, a parameter with growing significance in cardiovascular events prediction. In this paper it is presented a new optical fibre sensor to assess the pressure waveform in the carotid artery. The optical sensor is based on fibre Bragg grating technology, increasingly applied in several fields, including biomedical sensing due to its advantageous features. The Bragg sensor was characterized and tested in human carotids. It is presented a case study showing the great potential of Bragg technology in the assessment of the pressure waveform.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126661820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331360
F. Nery, J. S. Silva, N. Ferreira, F. Caramelo
The amount of information generated by medical imaging procedures as well as the number of exams performed all over the world is increasing over time. This leads to the need of faster and more efficient ways to deal with the large datasets characteristic of these procedures. Computer-aided diagnostic methods have an important role in this area. This paper presents a fully automatic method for the identification of the lungs in CT images. The lung regions are identified by a threshold operation as a first step. To separate merged lungs, we apply a sequence of morphological operations. Additionally the trachea and large airways are identified and removed in each slice. The proposed approach was tested in several whole-body CT studies presenting positive results.
{"title":"3D automatic lung segmentation in low-dose CT","authors":"F. Nery, J. S. Silva, N. Ferreira, F. Caramelo","doi":"10.1109/ENBENG.2012.6331360","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331360","url":null,"abstract":"The amount of information generated by medical imaging procedures as well as the number of exams performed all over the world is increasing over time. This leads to the need of faster and more efficient ways to deal with the large datasets characteristic of these procedures. Computer-aided diagnostic methods have an important role in this area. This paper presents a fully automatic method for the identification of the lungs in CT images. The lung regions are identified by a threshold operation as a first step. To separate merged lungs, we apply a sequence of morphological operations. Additionally the trachea and large airways are identified and removed in each slice. The proposed approach was tested in several whole-body CT studies presenting positive results.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131829972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331340
S. Pimenta, G. Minas, F. Soares
The research team is working in the development of automatic and miniaturized devices for medical applications. An example of this work is the development of a miniaturized, low cost, portable and automatic system to blood typing in emergency situations, based on a spectrophotometric approach and in the presence of agglutination (interaction between red blood cells' surface and specific reagents). The application of a simple and fast experimental protocol allows determining blood typing and enables the design of an electronic automatic system. This system will be useful to reduce some limitations of the existing systems and methods to blood typing.
{"title":"Spectrophotometric approach for automatic human blood typing","authors":"S. Pimenta, G. Minas, F. Soares","doi":"10.1109/ENBENG.2012.6331340","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331340","url":null,"abstract":"The research team is working in the development of automatic and miniaturized devices for medical applications. An example of this work is the development of a miniaturized, low cost, portable and automatic system to blood typing in emergency situations, based on a spectrophotometric approach and in the presence of agglutination (interaction between red blood cells' surface and specific reagents). The application of a simple and fast experimental protocol allows determining blood typing and enables the design of an electronic automatic system. This system will be useful to reduce some limitations of the existing systems and methods to blood typing.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134200398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-18DOI: 10.1109/ENBENG.2012.6331352
S. Nascimento, H. T. Correia, Sandra Franco, Jose Manuel Borges de Ameida
Retinal imaging capable of resolving individual photoreceptors cannot be obtained with conventional ophthalmoscopy but requires compensation of the individual optical aberrations that blur the optical image from the fundus. This optical compensation is normally accomplished by adaptive optics. We built a retinal imaging system based on adaptive optics can image individual cone photoreceptors. The system uses infrared radiation from a superluminescent diode (SLD) and a Hartman-Shack wavefront sensor to measure eye aberrations. An ophthalmoscope channel with a digital camera is integrated with the system to visualize the retina. A deformable mirror is used to partially compensate the aberrations of the light from the eye thereby improving the image quality and optical resolution. Images from the fundus were obtained from one healthy retina at about 0.5-1.0 deg eccentricity. The cone photoreceptor mosaic is visible and individual photoreceptors can be inspected.
{"title":"Retinal imaging with photoreceptor resolution","authors":"S. Nascimento, H. T. Correia, Sandra Franco, Jose Manuel Borges de Ameida","doi":"10.1109/ENBENG.2012.6331352","DOIUrl":"https://doi.org/10.1109/ENBENG.2012.6331352","url":null,"abstract":"Retinal imaging capable of resolving individual photoreceptors cannot be obtained with conventional ophthalmoscopy but requires compensation of the individual optical aberrations that blur the optical image from the fundus. This optical compensation is normally accomplished by adaptive optics. We built a retinal imaging system based on adaptive optics can image individual cone photoreceptors. The system uses infrared radiation from a superluminescent diode (SLD) and a Hartman-Shack wavefront sensor to measure eye aberrations. An ophthalmoscope channel with a digital camera is integrated with the system to visualize the retina. A deformable mirror is used to partially compensate the aberrations of the light from the eye thereby improving the image quality and optical resolution. Images from the fundus were obtained from one healthy retina at about 0.5-1.0 deg eccentricity. The cone photoreceptor mosaic is visible and individual photoreceptors can be inspected.","PeriodicalId":399131,"journal":{"name":"2012 IEEE 2nd Portuguese Meeting in Bioengineering (ENBENG)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132982364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：