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High content screening (HCS) plays an important role in biological applications, and drug development. Existing techniques fail to simultaneously meet multiple needs of throughput, efficiency in sample and chemical consumption, real-time imaging of a large view at high resolution. Leveraging advances in microfluidics and imaging technology, we setup a new paradigm of large-scale, high-content drug screening solutions for rapid biological processes, like cardiotoxicity. The designed microfluidic chips enable 10 types of drugs each with 5 concentrations to be assayed simultaneously. The imaging system RUSH has 30 Hz video rate for a centimeter filed-of-view at 0.8 m resolution. Using the HCS system, we assayed 12 small molecules through their effects on the Ca2+ ion signal of cardiomyocytes. Experimental results demonstrated the unparallelized capability of the system in revealing the spatiotemporal patterns of Ca2+ imaging of cardiomyocytes, and validated the cardiotoxicity of certain molecules. We envision this new HCS paradigm and cutting-edge platform as the most advanced alternative to well-plate based methods.

After over 30 years of advances, multiphoton microscopy (MPM) is now instrumental in a wide range of in vivo biological imaging applications. However, it has, until recently, remained not achievable or affordable to meet the unmet need for fast monitoring of biological dynamics and large-scale examination of biological heterogeneity. Only within the past few years have new strategies emerged to empower MPM at a speed that was once inconceivable, notably at kilohertz two-dimensional (2D) frame rate, and 3D rate or beyond. This Review highlights the latest high-speed innovations and discusses the potential of their synergism with other advanced, but less speed-centric MPM toolboxes. Recognizing these prospects and challenges could inspire new approaches for reprioritizing imaging speed in future MPM developments. This Review summarizes the latest state-of-the-art technologies for high-speed multiphoton (fluorescence) microscopy, especially at kilohertz 2D frame rate, and 3D video rate or beyond—a speed regime that was generally inconceivable until very recently, as well as the prospects and challenges of these emerging technologies.

A scene-level two-pass video rate controller for high efficiency video coding (HEVC) standard is proposed in this paper. The proposed rate controller is suitable for many pre-recorded applications in which encoded videos are transferred later on through a communication channel with limited bandwidth and buffering constraint. This rate controller operates in two passes. In the first pass, the video sequence is compressed and relevant information is collected. In the second pass, an optimal base quantization parameter (QP) for each video scene is calculated by simplifying the λ-domain rate-distortion model. Then, using the optimal base QP and the known QP cascading technique, a QP is computed for each picture in the scene. In this way, the quality of the compressed video is kept relatively constant during a scene and thus it provides a high-level perceptual quality for the compressed video. The base QP may be slightly modified during the second pass encoding by a fuzzy controller according to the second pass encoding results and the buffer status. The proposed rate controller has been implemented on H.265/HEVC standard reference software. Experimental results show that in comparison with the constant QP encoding and three known rate control algorithms the proposed algorithm provides a high-level quality for tested video sequences while the required buffering delay is low and the available bandwidth is fully used.

In this article, we propose a time-sequential switching light-field (LF) camera for an alternative image capture of the high-resolution two-dimensional (2-D) images and three-dimensional (3-D) LF elemental images as additional functionalities. For image data acquisitions of both the 2-D and 3-D LF imaging of moving objects at a video frame rate (or even higher frame rate up to approximately 1000 f/s), a polarization-dependent-switching microlens array (MLA) is implemented in the LF camera system instead of a conventional passive-type MLA. By controlling the incident polarization conditions using an electrically fast-switching liquid crystal layer, the imaging mode can be time-sequentially switched quite rapidly (switching times of approximately 220 and 290 μ s for the mode conversions from the 3-D LF to the 2-D mode, and the reversal mode change, respectively). Using the elemental image sets sampled from the alternating time-sequential imaging results, either the directional-view images or depth-refocused images can be reconstructed and provided at a moving picture frame rate. The depth-refocused images are possible for a wide depth range from 25 to 350 cm. Directional views of 22 × 22 and 9 × 9 in portions can be reconstructed for the single-shot image capture and the time-sequential video-rate image capture, respectively.

This paper surveys the recent advances on the modeling and control of hysteresis of piezoelectric actuators (PTAs) in the context of high precision applications of atomic force microscopes (AFMs). The current states, findings, and outcomes on hysteresis modeling and control in terms of achievable bandwidth and accuracy are discussed in detailed. Future challenges and the scope of possible research are presented to pave the way to video rate atomic force microscopy.

International audience; A fast image deconvolution algorithm is used to demonstrate the resolution enhancement of video rate camera acquired Terahertz images. Our algorithm is based on variable splitting technique with the use of a family of sparsity inducing regularizers for the first time in an image deconvolution application, it is also suitable for practical applications in industry with computationally constrained conditions. The results of the proposed process provide substantial enhancement on the quality and resolution of THz images.

Near-range millimeter wave imaging techniques for persons have been widely used in public security field. To improve the throughput and security as well, a suspicious object detection method is designed for the Walk Through System we built. Simple Online and Realtime Tracking algorithm is applied based on the detection result of YOLOv5 in in each frame. The method can effectively detect objects at a video rate of 10Hz.

Measurement of cellular tractions is important for, for example, engineering of artificial tissue. We propose the use of PSF-engineered localisation microscopy to achieve video rate measurements in large volumes with minimal sample light exposure.

We present a custom fabricated fiber scanning microendoscope with low-cost 3D-printed parts. The procedure of driving the piezotube-based fiber scanner and stability testing is shown. A novel scanning pattern to reduce photobleaching is also proposed.

We present a system for ICG-enhanced fluorescence imaging in the shortwave infrared (SWIR) range. Imaging performance and validation studies performed using an in vivo mouse model, as well as broader clinical outlooks, are discussed.

Imaging dynamic processes in 3D with high temporal resolution is a key challenge in fluorescence microscopy. By combining pupil-plane-engineering with a novel deconvolution algorithm we demonstrate a hybrid method that provides true snapshot volumetric imaging.

Optical nanoscopy is rapidly gaining momentum in the life sciences. Current instruments are, however, often large and expensive, and there is a substantial delay between raw data collection and super-resolved image display. Here, we describe the implementation of a compact, cost-effective, high-speed, structured illumination microscope (SIM), which allows for video-rate super-resolved image reconstructions at imaging rates up to 60 Hz. The instrument is based on a digital micromirror device (DMD) and a global-shutter camera, which enables faster pattern cycles and higher duty cycles than commonly used liquid crystal-based spatial light modulators. In order to utilize a DMD for creating illumination patterns by the coherent superposition of laser beams, we carefully studied its blazed grating effect Through both simulation and experimental determination of system parameters, we identified and optimized its alignment for optimal SIM pattern contrast. Raw image data are collected using inexpensive industry-grade CMOS cameras, while a parallel-computing platform allowed us to reconstruct and visualize living cells in real time. We demonstrate the performance of this system by imaging submicron-sized fluorescent beads diffusing in an aqueous solution, resolving bead-bead interactions in real time. We show that the system is sensitive enough to image intracellular vesicles labeled with fluorescent proteins in fixed cells. We also image dynamic fluctuations of the endoplasmic reticulum (ER), as well as the movement of mitochondria in living osteosarcoma cells, where the cellular organelles are labeled with live cell fluorescent stains.

Correction for ‘Video-rate upconversion display from optimized lanthanide ion doped upconversion nanoparticles’ by Laixu Gao et al., Nanoscale, 2020, DOI: 10.1039/d0nr03076g.

Millimeter wave frequencies has been proven to be able to penetrate clothes and luggage allowing the detection of concealed threats. Previous work showed the high performances of the passive Millimeter wave Imager developed by MC2-Technologies. The system can detect threats through clothes in Real-Time up to 16 images/s with a large field-of-view. This paper introduces a patented scanning technique to simultaneously measure radiated wave from two different scenes while providing high performances and video rate images. The proposed approach is integrated in a global solution so-called SACOP and allows the drastically reduction of the staff and material resources for implementation in real environment. Imaging has been conducted at millimeter-wave frequency with conclusions on the merits. The results demonstrate the potential of the new scanning technique for people screening in a challenging indoor situation.

This talk highlights a novel instrument for real-time video-rate imaging of microcirculation blood flow. The instrument utilizes multi-exposure laser speckle contrast imaging (MELSCI) with a high-speed camera, custom integrated electronics, and machine learning for massive computational bandwidth. This instrument enables, for the first time, continuous in vivo imaging of blood flow at frame rates sufficiently high to track dynamic changes, with perfusion estimates strongly correlated with that of laser Doppler flowmetry (LDF). This is an important step enabling a better understanding of the role of the microcirculation in several cardiovascular diseases. A pilot study on healthy subjects is presented.

We demonstrate three-photon imaging of brain activity in awake mice, achieving 30 frames/s at 512x512 pixels per frame and 620x620 pm field-of-view (FOV) at 750 pm depth.

We report on a highly stable and portable system for quantum imaging with undetected photons in video rate. Our results will pave the way towards extreme light imaging devices for life science.

Osteoblasts change their intracellular calcium ion concentration in response to mechanical stimuli. Although it has been reported that osteoblasts sense and respond to stretching of a substrate on which osteoblastic cells have adhered, the details of the dynamic characteristics of their calcium signaling response remain unclear. Motion artifacts such as loss of focus during stretch application make it difficult to conduct precise time-course observations of calcium signaling responses. Therefore, in this study, we observed intracellular calcium signaling responses to stretch in a single osteoblastic cell by video rate temporal resolution. Our originally developed cell-stretching microdevice enables in situ observation of a stretched cell without excessive motion artifacts such as focus drift. Residual minor effects of motion artifacts were corrected by the fluorescence ratiometric method with fluorescent calcium indicator Fluo 8H and fluorescent cytoplasm dye calcein red-orange. We succeeded to detect the intracellular calcium signaling response to stretch by video rate temporal resolution. The results revealed a time lag from stretch application to initiation of the intracellular calcium signaling response. We compared two time lags measured at two different cell areas: central and peripheral regions of the cell. The time lag in the central region of the cell was shorter than that in the peripheral region. This result suggests that the osteoblastic calcium signaling response to stretching stimuli initiates around the central region of the cell.

The new High Efficiency Video Coding (HEVC) standard is targeted for high-resolution video contents that are suitable for many high-delay video communications applications, such as video streaming. A few-rate control algorithms (RCAs) have been proposed for the HEVC in the literature. Almost all state-of-the-art RCAs proposed for the HEVC are optimized for constant bit rate low-delay applications. In order to reach a higher visual quality in high-delay applications, such as video streaming, a proportional integral derivative (PID)-fuzzy RCA with the buffering constraint is proposed for the HEVC in this paper. The proposed RCA is designed to minimize fluctuations of quantization parameter (QP) while the buffering constraints are fully obeyed. Unlike conventional fuzzy-PID algorithms that use a PID controller for control and a fuzzy system for tuning the PID parameters, the proposed algorithm uses a fuzzy controller with proportional, integral, and derivative inputs. A base QP is calculated for each group of picture (GOP) by the PID-fuzzy controller and determined QP offsets are added to the base QP to obtain the QP of frames at different temporal layers in the GOP. Experimental results indicate that high rate-distortion performance, fulfilled buffering constraint, and the high visual quality of compressed video are gained simultaneously by the proposed algorithm with low computational complexity.

A wide-field system that can perform video-rate imaging of the entire area of the brain of an awake mouse is aiding the study of neurones, epilepsy and the immune system.

All-optical ultrasound (AOUS) imaging, which uses light to both generate and detect ultrasound, is an emerging alternative to conventional electronic ultrasound imaging. To date, AOUS imaging has been performed using paradigms that either resulted in long acquisition times or employed bench-top imaging systems that were impractical for clinical use. In this work, we present a novel AOUS imaging paradigm where scanning optics are used to rapidly synthesise an imaging aperture. This paradigm enabled the first AOUS system with a flexible, handheld imaging probe, which represents a critical step towards clinical translation. This probe, which provides video-rate imaging and a real-time display, is demonstrated with phantoms and in vivo human tissue., Graphic AbstractFreehand and Video-Rate All-Optical Ultrasound ImagingErwin J Alles, Eleanor C Mackle, Sacha Noimark, Edward Z Zhang, Paul C Beard, Adrien E Desjardins

The seeded iterative demixing strategy, when used in combination with light-field microscopy, enables calcium imaging at single-neuron resolution in the mouse brain at high volumetric imaging rates and depths of up to 380 μm.

Apart from video rate (or requested bitrate), Mean Opinion Score (MOS) has increasingly become a primary term representing Quality of Experience (QoE) in HTTP adaptive streaming (HAS). By monitoring this metric, QoE management can effectively maximize QoE for the users. However, due to various behaviors of particular commercial HAS players, deciding an appropriate monitoring interval has not been fully investigated yet. In this paper, an optimal interval is proposed to be equal to duration of a video chunk in order to aid service managers in early detecting QoE deterioration and limiting the probability of video rate deterioration. The optimal monitoring interval is evaluated by comparing with other values of interval in terms of ratio of video rate deterioration. Furthermore, MOS-based QoE monitoring method which takes into account the proposed interval is thus compared with video rate based monitoring method. The results show that with optimal interval, MOS monitoring guarantees a low ratio of video rate deterioration (around 10% for buffering state and 40% for steady state) and small average CPU Load (about 11.45%).

Optical coherence tomography (OCT) with microscopic resolution is suited for the investigation of dynamic processes on cellular level. Most existing setups for microscopic OCT (mOCT) are able to acquire A-Scans at 100 kHz, hence they are suitable for displaying only B-Scans in real-time. We present an mOCT setup with a new high-speed spectrometer, which is capable of acquiring up to 600.000 A-scans/s. Customized software allows to image mOCT volumes with micrometer resolution at video rate. Therefore, we are able to visualize functional processes on a cellular level in three dimensions over time. Here, we present 2D and 4D data of ex vivo human lung. Recording tens of high-resolution OCT volumes per seconds becomes possible faster than previous setup for OCT with microscopic resolution.