Imaging with an optical incoherent synthetic aperture (SA) means that the incoherent light from observed objects is processed over time from various points of view to obtain a resolution equivalent to single-shot imag...Imaging with an optical incoherent synthetic aperture (SA) means that the incoherent light from observed objects is processed over time from various points of view to obtain a resolution equivalent to single-shot imaging by the SA larger than the actual physical aperture. The operation of such systems has always been based on two-wave interference where the beams propagate through two separate channels. This limitation of two channels at a time is removed in the present study with the proposed SA where the two beams pass through the same single channel at any given time. The system is based on a newly developed self-interference technique named coded aperture correlation holography. At any given time,the recorded intensity is obtained from interference between two waves co-propagating through the same physical channel. One wave oriented in a particular polarization is modulated by a pseudorandom coded phase mask and the other one oriented orthogonally passes through an open subaperture. Both subapertures are multiplexed at the same physical window. The system is calibrated by a point spread hologram synthesized from the responses of a guide star. All the measurements are digitally processed to achieve a final image with a resolution higher than that obtained by the limited physical aperture. This unique configuration can offer alternatives for the current cumbersome systems composed of far apart optical channels in the large optical astronomical interferometers. Furthermore,the proposed concept paves the way to an SA system with a single less-expensive compact light collector in an incoherent optical regime that may be utilized for future ground-based or space telescopes.展开更多
Holographic imaging offers a reliable and fast method to capture the complete three-dimensional （3D） information of the scene from a single perspective. We review our recently proposed single-channel optical system ...Holographic imaging offers a reliable and fast method to capture the complete three-dimensional （3D） information of the scene from a single perspective. We review our recently proposed single-channel optical system for generating digital Fresnel holograms of 3D real-existing objects illuminated by incoherent light. In this motionless holographic technique, light is reflected, or emitted from a 3D object, propagates through a spatial light modulator （SLM）, and is recorded by a digital camera. The SLM is used as a beamsplitter of the single-channel incoherent interferometer, such that each spherical beam originated from each object point is split into two spherical beams with two different curve radii. Incoherent sum of the entire interferences between all the couples of spherical beams creates the Fresnel hologram of the observed 3D object. When this hologram is reconstructed in the computer, the 3D properties of the object are revealed.展开更多
Coded aperture imaging(CAI)is a technique to image three-dimensional scenes with special controlled abilities.In this review,we survey several recently proposed techniques to control the parameters of CAI by engineeri...Coded aperture imaging(CAI)is a technique to image three-dimensional scenes with special controlled abilities.In this review,we survey several recently proposed techniques to control the parameters of CAI by engineering the aperture of the system.The prime architectures of these indirect methods of imaging are reviewed.For each design,we mention the relevant application of the CAI recorders and summarize this overview with a general perspective on this research topic.展开更多
Millions of people around the globe suffer peripheral nerve injuries caused by trauma and medical disorders.However,medical school curricula are profoundly deficient in peripheral nerve education.This lack of knowledg...Millions of people around the globe suffer peripheral nerve injuries caused by trauma and medical disorders.However,medical school curricula are profoundly deficient in peripheral nerve education.This lack of knowledge within the healthcare profession may cause inadequate patient care.We developed the Virtual Peripheral Nerve Academy(VPNA)as a reusable virtual learning environment to provide medical students with detailed education on the peripheral nervous system(PNS).Students are introduced to the PNS through virtual 3D rendering of the human body,wherein they visualize individual nerves through dissection and observe normal motor and sensory function associated with each nerve.PNS structures that are absent from traditional texts are included in this visualization,ranging from the innervation of joints to the normal anatomic variation required for differential diagnosis of pain after an injury.Detailed modules on peripheral nerve disorders allow students to observe pathophysiological mechanisms,associated symptomatology,and appropriate treatments.Students are briefed on a patient clinical case,then interact with a patient avatar to learn the appropriate diagnostics,including physical exam maneuvers and electrodiagnostic testing.Interactive modules on peripheral nerve surgeries detail surgical techniques.The VPNA data and analytics dashboards allow medical students and course instructors to assess skill improvement and identify specific learning needs.The built-in learner management system and availability on both computer-based and virtual reality platforms facilitate integration into any existing medical school curricula.Ultimately,this immersive technology enables every medical student to learn about the peripheral nervous system and gain competency in treating real-life nerve pathologies.展开更多
文摘Imaging with an optical incoherent synthetic aperture (SA) means that the incoherent light from observed objects is processed over time from various points of view to obtain a resolution equivalent to single-shot imaging by the SA larger than the actual physical aperture. The operation of such systems has always been based on two-wave interference where the beams propagate through two separate channels. This limitation of two channels at a time is removed in the present study with the proposed SA where the two beams pass through the same single channel at any given time. The system is based on a newly developed self-interference technique named coded aperture correlation holography. At any given time,the recorded intensity is obtained from interference between two waves co-propagating through the same physical channel. One wave oriented in a particular polarization is modulated by a pseudorandom coded phase mask and the other one oriented orthogonally passes through an open subaperture. Both subapertures are multiplexed at the same physical window. The system is calibrated by a point spread hologram synthesized from the responses of a guide star. All the measurements are digitally processed to achieve a final image with a resolution higher than that obtained by the limited physical aperture. This unique configuration can offer alternatives for the current cumbersome systems composed of far apart optical channels in the large optical astronomical interferometers. Furthermore,the proposed concept paves the way to an SA system with a single less-expensive compact light collector in an incoherent optical regime that may be utilized for future ground-based or space telescopes.
文摘Holographic imaging offers a reliable and fast method to capture the complete three-dimensional （3D） information of the scene from a single perspective. We review our recently proposed single-channel optical system for generating digital Fresnel holograms of 3D real-existing objects illuminated by incoherent light. In this motionless holographic technique, light is reflected, or emitted from a 3D object, propagates through a spatial light modulator （SLM）, and is recorded by a digital camera. The SLM is used as a beamsplitter of the single-channel incoherent interferometer, such that each spherical beam originated from each object point is split into two spherical beams with two different curve radii. Incoherent sum of the entire interferences between all the couples of spherical beams creates the Fresnel hologram of the observed 3D object. When this hologram is reconstructed in the computer, the 3D properties of the object are revealed.
基金Australian Research Council(LP190100505).European Union's Horizon 2020 research and innovation programme under grant agreement No.857627(CIPHR).
文摘Coded aperture imaging(CAI)is a technique to image three-dimensional scenes with special controlled abilities.In this review,we survey several recently proposed techniques to control the parameters of CAI by engineering the aperture of the system.The prime architectures of these indirect methods of imaging are reviewed.For each design,we mention the relevant application of the CAI recorders and summarize this overview with a general perspective on this research topic.
文摘Millions of people around the globe suffer peripheral nerve injuries caused by trauma and medical disorders.However,medical school curricula are profoundly deficient in peripheral nerve education.This lack of knowledge within the healthcare profession may cause inadequate patient care.We developed the Virtual Peripheral Nerve Academy(VPNA)as a reusable virtual learning environment to provide medical students with detailed education on the peripheral nervous system(PNS).Students are introduced to the PNS through virtual 3D rendering of the human body,wherein they visualize individual nerves through dissection and observe normal motor and sensory function associated with each nerve.PNS structures that are absent from traditional texts are included in this visualization,ranging from the innervation of joints to the normal anatomic variation required for differential diagnosis of pain after an injury.Detailed modules on peripheral nerve disorders allow students to observe pathophysiological mechanisms,associated symptomatology,and appropriate treatments.Students are briefed on a patient clinical case,then interact with a patient avatar to learn the appropriate diagnostics,including physical exam maneuvers and electrodiagnostic testing.Interactive modules on peripheral nerve surgeries detail surgical techniques.The VPNA data and analytics dashboards allow medical students and course instructors to assess skill improvement and identify specific learning needs.The built-in learner management system and availability on both computer-based and virtual reality platforms facilitate integration into any existing medical school curricula.Ultimately,this immersive technology enables every medical student to learn about the peripheral nervous system and gain competency in treating real-life nerve pathologies.
