چكيده به لاتين
Today, the birth rate of premature infants and their mortality has increased. It is very important to understand the neurobiological mechanism of development of brain after the birth of a premature baby. imaging of brain can provide a solution to this problem. Existing high-resolution imaging such as X-ray computer tomography and magnetic resonance imaging are expensive, and since the goal of the project is focus on telemedicine applications, it is generally non-portable. In addition, X-ray ionizing agents are unacceptable for structural and functional imaging of the brain in premature infants. The ultrasound imaging method for the neonatal brain is portable, however, it is mainly morphological (eg, bleeding, edema, cyst, etc.) and provides limited practical information (for example, measurement of blood flow by Doppler ultrasound). Therefore, the system designed and used in this project is a developed non-invasive photoconductive tomography imaging system for the brain in premature infants. photoacoustic tomography provides high-resolution images of the cerebrospinal fluid, as well as blood and tissue and oxygen. The first objective in this project is 3D reconstruction of photoacoustic images using compressed sensing of extracted raw signals from Transducers at the surface of a hemispherical configuration. In the theory of compressed sensing, the expected signal is recovered with a very limited number of samples. Due to limited examples of signal for reconstruction in compressed sensing, the precision in signal reconstruction is important. In fact, raw photo-acoustic signals have important information that retaining each part of them in their recovery is important and key. One of the most important methods of compressed sensing is Bayesian compressed sensing, which has a good reconstruction time and error. In the proposed method of this project, first, the photoacoustic signal is compressed and recovered using the compressed sensing method, then a 3D image reconstruct of its. This approach ,3d reconstruct using compressed and recovered signals, which is against of the compressed imaging. In this method, 3D reconstruction of images compare to the compressed imaging method, where the 3D image is split into two-dimensional frames, and after compressing and recovered frames by a two-dimensional compressed sensing method, frames made three-dimensional image. this method is more suitable for tele_medicine applications.
