China
Africa
Explore chapters and articles related to this topic
Using the Transmission Matrix to Image Disordered Media
Published in Lingyan Shi, Robert R. Alfano, Deep Imaging in Tissue and Biomedical Materials, 2017
Davy Matthieu, Gigan Sylvain, Azriel Z. Genack
Control of scattered waves was demonstrated in acoustic [13–15] and microwave [16, 17] experiments in which a pulse emerging from a random sample is time reversed and refocused on a source within a scattering medium. In recent years, there has been a surge of interest in the TM because of the possibility of controlling optical transmission by manipulating the incident waveform with use of a spatial light modulator (SLM) [18–29]. The possibilities for biomedical applications abound.
Wavefront sensors
Published in Pablo Artal, Handbook of Visual Optics, 2017
“Countermeasures” to subaperture violation can be software or hardware based. Software-based methods are usually more time consuming. One of the hardware-based ways is to switch the subapertures on and off, so that a definite assignment of the spots to their subapertures is possible. Yoon et al. [112] proposed the blocking of adjacent lenslets using translatable plates. Instead of mechanical switching, Lindlein et al. [56] used spatial light modulators in front of the microlenses of the sensor to switch on and off the subapertures. It was done with a coding algorithm that allows a definite assignment of the spots to their subapertures. With relaxation time 50 ms for liquid crystal modulators and 50 ms readout time for CCD device, a five-time switching and reading will result in at least 500 ms for measurement.
The application of advanced imaging techniques in glaucoma
Published in Expert Review of Ophthalmology, 2022
Su Ling Young, Nikhil Jain, Andrew J Tatham
Adaptive optics scanning laser ophthalmoscopy utilizes wavefront sensors that measures aberrations in ocular optics and a deformable mirrors or spatial light modulators to compensate for aberrations in human eyes, which enables detailed imaging of individual retinal nerve fiber layer microstructures previously not possible with conventional scanning laser ophthalmoscopy, including retinal ganglion cells despite advanced RNFL thinning [77]. To date case-control studies [77,78] have identified microcystic changes arising from small hyper-reflective structures the inner nuclear layer and progressive expansion of retinal nerve fiber bundle narrowing over a period ranging from 4 months to over a year. Whilst further research is required, these changes may be potential biomarkers for glaucoma progression.
Super-resolution imaging and quantification of megakaryocytes and platelets
Published in Platelets, 2020
Abdullah O. Khan, Jeremy A. Pike
Since this early implementation, an array of alternative strategies for projecting patterned light onto the sample have been utilized - including spatial light modulators, digital mirrors, and electro- and acousto-optic devices [16,17]. These approaches, combined with the efficiency of modern cameras, have led to progressively faster SIM, and as a result, live cell applications have become increasingly commonplace [18]. Moreover, multiplexed imaging is easier with these modern implementations as diffraction gratings do not to be switched. However, at present simultaneous multi-color imaging does normally require multiple cameras.