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The manuscript concerns the optical design and the development of a non-invasive new imaging system for the early diagnosis of skin pathologies. Indeed, an early diagnosis can make the difference between malignant and benign skin lesion in order to minimize unnecessary surgical procedure.Furthermore, prognosis for the year 2015 was that more than t...
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... recently, a new medical imaging technique appeared, the photo-acoustic tomog- raphy (PAT) or photo-acoustic microscopy (PAM) for high resolution [14]. PAT/PAM is related to the photo-acoustic physical effect [15]. This effect occurs inside the sample by a thermoelastic expansion due to the absorption of a electromagnetic field (optical, radio-frequency or micro waves) and therefore, a temperature rise, typically in the millikelvin range. During the thermal relaxation process, pressure is induced leading to the generation of a mechanical wave -i.e., a high frequency acoustic wave. The time delay of the detected ultrasonic wave yields a depth information of the object position. Two or three dimensional surface scans offer a two or three dimensional lateral information about the photo-acoustic source and thus, a tomographic image [16]. Figure 9 shows the scheme of the photo-acoustic microscopy principle. The spatial resolution of PAT is related to the emitting photo-acoustic signal -i.e., higher is the frequency, better is the spatial resolution of the imaging system. For example, a high-frequency photo-acoustic signal with 50 MHz central frequency, results approx- imately in a 40 µm resolution with 3 mm imaging depth -i.e., as for high frequency ultrasound technique - [17]. PAM provides better resolution than PAT because of the focused electromagnetic wave into a small size volume through a microscope ...
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... in the plane s=0 The measurement procedure starts with the recording of through-focus slices according to the method described in the previous section. In addition, in order to retrieve low- frequency wavefront information, five derived intensity planes exponentially-spaced along the optical axis are kept [198,199]. Then, the IPR algorithm is applied and pro- cessed as in Fig. 3.9. The NA of the microlens to be tested is limited by the one of the microscope objective, as well as the sampling of the imaging system. The latter depends onto the detector pixel size ∆x, the wavelength λ, the magnification of the imaging sys-tem γ and the Nyquist sampling Q [200]. It is given by the ...
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Citations
... Nuclear imaging is a medical imaging technique that has a wide range of clinical applications in medicine. Some typical applications: Figure 6: Ultrasound Imaging Principle [28] Nuclear imaging is used in a variety of applications to evaluate different parts of the body. One of the main uses of nuclear imaging is cardiac imaging, where it can be used to evaluate blood flow to the heart and detect any blockages or abnormalities, such as coronary artery disease or heart failure. ...
... A diagram of the ultrasound imaging method's basic principles can be found in Figure 5 [28]. It gives depth information that is then used to create a two-or three-dimensional image of the sample based on the measurement of the time delay between the red-coloured ultrasound wave that is being emitted and the blue-coloured waves that are being reflected back from each layer of the sample. ...
The diagnosis and treatment of various diseases had been expedited with the help of medical imaging. Different medical imaging modalities, including X-ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Nuclear Imaging, Ultrasound, Electrical Impedance Tomography (EIT), and Emerging Technologies for in vivo imaging are widely used in today’s healthcare throughout the world. A review of medical imaging modalities is presented in this chapter, in addition to these modalities, some advanced techniques such as contrast-enhanced MRI, MR approaches for osteoarthritis, Cardiovascular Imaging, and Medical Imaging data mining and search. Despite its important role and potential effectiveness as a diagnostic tool, reading and interpreting medical images by radiologists is often tedious and difficult due to the large heterogeneity of diseases and the limitation of image quality or resolution. Besides the introduction and discussion of the basic principles, typical clinical applications, advantages, and limitations of each modality used in current clinical practice, this chapter also highlights the importance of emerging technologies in medical imaging and the role of data mining and search aiming to support translational clinical research, improve patient care, and increase the efficiency of the healthcare system.
... Nuclear imaging is a medical imaging technique that has a wide range of clinical applications in medicine. Some typical applications: Figure 6: Ultrasound Imaging Principle [25] Nuclear imaging is used in a variety of applications to evaluate different parts of the body. One of the main uses of nuclear imaging is cardiac imaging, where it can be used to evaluate blood flow to the heart and detect any blockages or abnormalities, such as coronary artery disease or heart failure. ...
... A diagram of the ultrasound imaging method's basic principles can be found in Figure 5 [25]. It gives depth information that is then used to create a two-or three-dimensional image of the sample based on the measurement of the time delay between the red-coloured ultrasound wave that is being emitted and the blue-coloured waves that are being reflected back from each layer of the sample. ...
The diagnosis and treatment of various diseases had been expedited with the help of medical imaging. Different medical imaging modalities, including X-ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Nuclear Imaging, Ultrasound, Electrical Impedance Tomography (EIT), and Emerging Technologies for in vivo imaging modalities is presented in this chapter, in addition to these modalities, some advanced techniques such as contrast-enhanced MRI, MR approaches for osteoarthritis, Cardiovascular Imaging, and Medical Imaging data mining and search. Despite its important role and potential effectiveness as a diagnostic tool, reading and interpreting medical images by radiologists is often tedious and difficult due to the large heterogeneity of diseases and the limitation of image quality or resolution. Besides the introduction and discussion of the basic principles, typical clinical applications, advantages, and limitations of each modality used in current clinical practice, this chapter also highlights the importance of emerging technologies in medical imaging and the role of data mining and search aiming to support translational clinical research, improve patient care, and increase the efficiency of the healthcare system.
... De nombreuses variantes et améliorations ont été développées, parmi lesquelles la tomographie par cohérence optique dans le domaine spectral (Leitgeb et al. 2003 ;Perrin 2016) et la tomographie par cohérence optique plein champ (Beaurepaire et al. 1998 ;Dubois et al. 2004). Contrairement aux techniques classiques d'OCT, l'OCT plein champ a pour particularité l'utilisation d'un détecteur 2D (type caméra CCD, CMOS, etc.) permettant d'acquérir, en une série d'acquisitions, une image plein champ d'OCT. ...
L’imagerie optique des systèmes biologiques a connu ces dernières années des développements spectaculaires, délivrant une quantité et une qualité d’informations qui, il y a une vingtaine d’années encore, relevaient du rêve pour les physiciens, les biologistes ou les médecins.Les systèmes d’imageries non conventionnelles permettent d’accéder à des grandeurs physiques (opacité, phase, indice optique, propriété de polarisation d’une onde ou composition chimique d’un objet) non accessibles aux systèmes de mesure conventionnels. Pour cela, ces systèmes utilisent des montages optiques particuliers et des traitements numériques spécifiques des images permettant la reconstruction de grandeurs physiques. On parle également d’imagerie computationnelle.Cet ouvrage présente diverses modalités d’imageries non conventionnelles développées pour le domaine biomédical : imagerie par analyse de front d’onde, holographie/tomographie numérique, nanoscopie optique, endoscopie et imagerie monodétecteur. Pour chaque modalité, les montages et les algorithmes de reconstruction sont présentés.
Interference microscopy uses the phenomenon of interference between two waves to indirectly recover depth information. The coherence of light defines the ability of two waves to interfere with each other. It is determined by two coherence phenomena, which are temporal coherence when the two waves are temporally separated and spatial coherence when they are spatially separated. Interferometry is useful for metrology because the height information is contained in fringe intensity distribution. There are two main families of algorithms to quantify the fringes: phase-shifting microscopy and coherence scanning interferometry. In interferometric profilometry, three types of interference objectives are mainly used: Michelson objective; Mirau objective; and Linnik configuration. As with any measurement system, interference microscopy has its own limitations. These are lateral resolution and axial resolution, field of view and measurement dynamics. Data acquisition and analysis methods most often use fringe scanning and phase-shifting information to achieve sub-nanometer noise levels over large height ranges.
At present, with the rapid development of computer and communication technology and people's demand for medical technology services, telemedicine virtual reality technology has become a high‐tech hot spot in the information age and a new trend in the development of the medical industry. However, my country's high‐quality medical resources are mainly concentrated in large and medium‐sized cities, and there is an urgent need to improve the fairness of medical services. Telemedicine virtual reality technology has received more and more attention from people, has been widely used worldwide, and has become an important part of hospital information engineering. This article first introduces the basic concepts of telemedicine virtual reality technology, the latest development of telemedicine virtual reality technology and related technologies, and then introduces the system in detail. The system is functionally divided into two parts: consulting management and system management. Consulting management includes all remote business consulting processes; system management includes management of medical resources and user data, and then detailed description and visualization of the development and use of disease model libraries. Telemedicine completely separates the rehabilitation area of skin patients from the hospital, and patients can complete relief and rehabilitation outdoors or even when they are discharged from the hospital. As a remote access device, telemedicine virtual reality technology has been popularized to a certain extent. The general patient group represented by patients with stable skin conditions has improved their understanding of telemedicine technology, which is beneficial to the development of telemedicine virtual reality technology. The utilization rate, safety, rehabilitation effect and completion rate of telemedicine virtual reality technology are as high as 85%, 92%, and 96%, respectively, saving a lot of time and medical expenses. Therefore, telemedicine virtual reality technology is also the direction of my country's next medical reform, and it can also be used in other aspects of continuing education of telemedicine virtual reality technology.
OCT instruments permit fast and non-invasive 3D optical biopsies of biological tissues. However, they are bulky and expensive, making them only affordable at the hospital and thus, not sufficiently used as an early diagnostic tool. Significant reduction of system cost and size is achieved by implementation of MOEMS technologies. We propose an active array of 4x4 Mirau microinterferometers where the reference micro-mirrors are carried by a vertical comb-drive microactuator, enabling the implementation of the phase-shifting technique that improves the sensitivity and eliminates unwanted interferometric terms. We focus on the design of the imaging system, the microfabrication and the assembly of the Mirau microinterferometer, and the swept-source OCT imaging.
