Real-time Image Display Research Articles

Video-rate endocavity photoacoustic/harmonic ultrasound imaging with miniaturized light delivery.

Endocavity ultrasound (US) imaging is a frequently employed diagnostic technique in gynecology and urology for the assessment of male and female genital diseases that present challenges for conventional transabdominal imaging. The integration of photoacoustic (PA) imaging with clinical US imaging has displayed promising outcomes in clinical research. Nonetheless, its application has been constrained due to size limitations, restricting it to spatially confined locations such as vaginal or rectal canals. This study presents the development of a video-rate (20Hz) endocavity PA/harmonic US imaging (EPAUSI) system. The approach incorporates a commercially available endocavity US probe with a miniaturized laser delivery unit, comprised of a single large-core fiber and a line beamshaping engineered diffuser. The system facilitates real-time image display and subsequent processing, including angular energy density correction and spectral unmixing, in offline mode. The spatial resolutions of the concurrently acquired PA and harmonic US images were measured at and in the radial direction, respectively, and 1.22deg and 1.50deg in the angular direction, respectively. Furthermore, the system demonstrated its capability in multispectral PA imaging by successfully distinguishing two clinical dyes in a tissue-mimicking phantom. Its rapid temporal resolution enabled the capture of kinetic dye perfusion into an ex vivo porcine ovary through the depth of porcine uterine tissue. EPAUSI proved its clinical viability by detecting pulsating hemodynamics in the male rat's prostate in vivo and accurately classifying human blood vessels into arteries and veins based on measurements. Our proposed EPAUSI system holds the potential to unveil previously overlooked indicators of vascular alterations in genital cancers or endometriosis, addressing pressing requirements in the fields of gynecology and urology.

Development of Chest X-ray Image Evaluation Software Using the Deep Learning Techniques

Although the widespread use of digital imaging has enabled real-time image display, images in chest X-ray examinations can be confirmed by the radiologist’s eyes. Considering the development of deep learning (DL) technology, its application will make it possible to immediately determine the need for a retake, which is expected to further improve examination throughput. In this study, we developed software for evaluating chest X-ray images to determine whether a repeat radiographic examination is necessary, based on the combined application of DL technologies, and evaluated its accuracy. The target population was 4809 chest images from a public database. Three classification models (CLMs) for lung field defects, obstacle shadows, and the location of obstacle shadows and a semantic segmentation model (SSM) for the lung field regions were developed using a fivefold cross validation. The CLM was evaluated using the overall accuracy in the confusion matrix, the SSM was evaluated using the mean intersection over union (mIoU), and the DL technology-combined software was evaluated using the total response time on this software (RT) per image for each model. The results of each CLM with respect to lung field defects, obstacle shadows, and obstacle shadow location were 89.8%, 91.7%, and 91.2%, respectively. The mIoU of the SSM was 0.920, and the software RT was 3.64 × 10−2 s. These results indicate that the software can immediately and accurately determine whether a chest image needs to be re-scanned.

Meta-optics empowered vector visual cryptography for high security and rapid decryption

Optical encryption is a promising approach to protecting secret information owing to the advantages of low-power consumption, parallel, high-speed, and multi-dimensional processing capabilities. Nevertheless, conventional strategies generally suffer from bulky system volume, relatively low security level, redundant measurement, and/or requirement of digital decryption algorithms. Here, we propose a general optical security strategy dubbed meta-optics-empowered vector visual cryptography, which fully exploits the abundant degrees of freedom of light as well as the spatial dislocation as key parameters, significantly upgrading the security level. We also demonstrate a decryption meta-camera that can implement the reversal coding procedure for real-time imaging display of hidden information, avoiding redundant measurement and digital post-processing. Our strategy features the merits of a compact footprint, high security, and rapid decryption, which may open an avenue for optical information security and anti-counterfeiting.

Predictive side decoding for human-centered multiple description image coding

Multiple description coding (MDC) provides a favorable solution for human-centered image communication, which takes into account people’s varying watching situations as well as people’s demand for real-time image display. As an effective technique for MDC, three-description lattice vector quantization (3D-LVQ) is considered for image coding in this paper. Based on intra- and inter-correlation in the 3D-LVQ index assignment as well as wavelet intra-subband correlation, a novel predictive decoding method for 3D-LVQ-based image coding is proposed to enhance side decoding performance, which attempts to predict lost descriptions (sublattice points) in a good way for better reconstructions of wavelet vectors (fine lattice points) in the side decoding. Experimental results validate effectiveness of the proposed decoding scheme in terms of rate-distortion performance.

Process Online Monitoring on Cold Extrusion of Internal Thread in High-strength Steel

In order to solve the problems of data collection, data storage, artificial neural networks, real-time display of images, real-time monitoring of current status and recurrence of historical data, online monitoring system of cold extrusion of internal thread process is designed by LabVIEW8.5. The time-domain analysis and time-frequency-domain analysis are carried out for the torque signal, temperature signal, vibration signal, acoustic emission signal and transmitted signal. The research shows that: this online monitoring system can forecast processing status accurately, raise real-time alarm to replace or re-install the thread forming tap, accordingly avoids effectively the wreckage of thread forming tap and the scrap of work pieces; the fault recognition rate reaches 97%. And the practical model of online monitoring system for cold extrusion of internal thread process can be used to monitor working process.

A study of dense-medium cyclone inner-wall abrasion based on ultrasonic phased array technology

Directing at the problem that dense-medium cyclone is abraded by materials while conventional detection method can’t make real-time and highly efficient detection of defects, this paper introduced working process and imaging principle of ultrasonic phased array technology in details. And then through experimental research of dense-medium cyclone model, it drew the conclusion that ultrasonic phased array technology could conduct real-time imaging display of dense-medium cyclone inner-wall abrasion defects and the error was within 8%.

Ultrasound Imaging with Microbubbles [Life Sciences

Medical ultrasound (US) imaging, also known as echography, is one of the most frequently used front-line clinical imaging modalities and is characterized by its safety, affordability, accessibility, and real-time image display. Sound pulses, typically in the megahertz range, are sent into the body and the backscattered echoes are used to create a tomographic image. The contrast of an US image arises from local variations in the physical properties of the tissues, primarily density and elasticity, revealing tissue structures at depth.

Full-view photoacoustic tomography using asymmetric distributed sensors optimized with compressed sensing method

Abstract Photoacoustic tomography (PAT) is an effective optical biomedical imaging method characterized with non-ionizing and noninvasive, presenting good soft tissue contrast and excellent spatial resolution. To build a full-view photoacoustic (PA) image, numbers of ultrasound sensors are needed to assure the image quality, which will bring difficulties to data acquisition and real-time image display. Compressed sensing (CS) theory breaks the restriction of Nyquist sampling theorem and is capable to rebuild signals with less measurements. In this contribution, we proposed an optimization method to increase image quality of full-view PAT with less ultrasound sensors, which combines the theory of CS and a circularly distributing asymmetric data acquisition frame. The hardware cost can be saved and time efficiency of PAT can be raised without sacrificing the image quality. The feasibility of our proposed method is verified in simulation experiments which yield expected results. Our study might be helpful for clinical medical imaging such as early stage breast cancer detection, endoscopic imaging and in vivo monitoring.

Design of a shift-and-add based hardware accelerator for color space conversion

In this paper, a Nios II processor based hardware/software co-design architecture with high expandability and development flexibility is proposed. The architecture integrates a pipelined color space converter (CSC), hardware accelerator (HA), and a LCD touch module (LTM) HA, which facilitates a high-speed implementation of RGB to YCbCr color space conversion with a real-time image display. To avoid the inefficiency of CSC circuit architecture due to massive floating-point multiplication operations in the conversion formulae, a GA-based evolutionary technique is used to realize the fast multiplierless CSC hardware architecture. Meanwhile, a pipeline design method is further applied to enhance the maximum operating frequency in circuit design. As compared to the commonly used floating-point based CSC architecture, the pipelined CSC HA in this paper has excellent advantages of low-complexity and high speed. After the mechanism is integrated into a system-on-a-programmable-chip (SOPC), the maximum operating frequency reached 168.12 MHz. That is, in every 0.11 s, the color space conversion can process a 512 × 512 image. This excellent result is practical to the fast development of different kind of image/video processing systems.

Ultrasound in the Austere Environment: A Review of the History, Indications, and Specifications

In the last 10 years, the use of ultrasound has expanded because of its portability, safety, real-time image display, and rapid data collection. Simultaneously, more people are going into the backcountry for enjoyment and employment. Increased deployment for the military and demand for remote medicine services have led to innovative use and study of ultrasound in extreme and austere environments. Ultrasound is effective to rapidly assess patients during triage and evacuation decision making. It is clinically useful for assessment of pneumothorax, pericardial effusion, blunt abdominal trauma, musculoskeletal trauma, high-altitude pulmonary edema, ocular injury, and obstetrics, whereas acute mountain sickness and stroke are perhaps still best evaluated on clinical grounds. Ultrasound performs well in the diverse environments of space, swamp, jungle, mountain, and desert. Although some training is necessary to capture and interpret images, real-time evaluation with video streaming is expected to get easier and cheaper as global communications improve. Although ultrasound is not useful in every situation, it can be a worthwhile tool in the austere or deployed environment.

Efficient reduction of speckle noise in Optical Coherence Tomography

Speckle pattern, which is inherent in coherence imaging, influences significantly axial and transversal resolution of Optical Coherence Tomography (OCT) instruments. The well known speckle removal techniques are either sensitive to sample motion, require sophisticated and expensive sample tracking systems, or involve sophisticated numerical procedures. As a result, their applicability to in vivo real-time imaging is limited. In this work, we propose to average multiple A-scans collected in a fully controlled way to reduce the speckle contrast. This procedure involves non-coherent averaging of OCT A-scans acquired from adjacent locations on the sample. The technique exploits scanning protocol with fast beam deflection in the direction perpendicular to lateral dimension of the cross-sectional image. Such scanning protocol reduces the time interval between A-scans to be averaged to the repetition time of the acquisition system. Consequently, the averaging algorithm is immune to bulk motion of an investigated sample, does not require any sophisticated data processing to align cross-sectional images, and allows for precise control of lateral shift of the scanning beam on the object. The technique is tested with standard Spectral OCT system with an extra resonant scanner used for rapid beam deflection in the lateral direction. Ultrahigh speed CMOS camera serves as a detector and acquires 200,000 spectra per second. A dedicated A-scan generation algorithm allows for real-time display of images with reduced speckle contrast at 6 frames/second. This technique is applied to in vivo imaging of anterior and posterior segments of the human eye and human skin.

Applications of ultrasound in paediatric anaesthesia

Ultrasound (US) scanning during the placement of major regional nerve blocks or intravascular catheters allows a non-invasive real-time image display of tissue planes, neurovascular structures and needles. Advances in scanner technology have allowed anaesthetists to accurately target needle placement, which enhances the success and safety of these procedures. This review will summarise the use of US for regional blockade and vascular cannulation in paediatric anaesthetic practice.

Advanced Surgical Guidance Technology: A Review

To maximize the outcome of implant placement, the use of advanced radiographic procedures such as computerized tomography, along with fabrication of surgical guides, has been advocated to inform surgeons of ideal implant location. More recently, simulation computer software has been introduced to view radiographic images and test potential implant locations. Yet, surgical guides are processed based on ideal tooth position, with little consideration for underlying anatomical limitations, which creates a disconnection between diagnostic planning and surgical restrictions. In response to this "missing link," computer-assisted design and computer-assisted manufacturing, as well as real-time surgical navigation were recently developed to obtain fully integrated surgical and prosthetic planning. Today, there are several technologies available, but, to our knowledge, a systematic assessment of surgical guidance has not yet been performed. Therefore, the aims of this review are to introduce advanced radiographic and software modalities, and present a detailed assessment of computer-assisted design and computer-assisted manufacturing methods and surgical navigation.

Endoscopic fluorescence imaging and point spectroscopy system for the detection of gastro-intestinal cancers

We describe a combined endoscopic fluorescence imaging and spectroscopy system for the detection of gastro-intestinal cancers, utilizing the fluorescence from aminolaevulinic acid-induced protoporphyrin IX. Both the imaging and spectroscopy systems are controlled by a single desktop PC, which also carries out image processing and stores spectral data, enabling real-time display of images and spectra on one monitor. These systems have been tested in vivo and the results illustrate the potential of both systems in the detection of early cancers. Preliminary testing of the combined system using a foam model has shown that the combined system may better facilitate cancer detection than the use of either system individually.

A VXI-based high speed X-ray CCD detector

For time-resolved X-ray scattering, one ideally wants a high speed detector that also is capable of giving position sensitive information. Charge Coupled Devices (CCDs) have been used successfully as X-ray detectors. Unfortunately, they are inherently slow because of the serial readout. EEV has developed a CCD that has eight channels of parallel readout, thus increasing the speed eightfold. Using state-of-the-art VXI electronics, we have developed a readout system that could read the entire array in 2.5 ms using a 20-MHz readout clock. For testing and characterization, the device was clocked at a significantly slower speed of 30 kHz. The data are preamplified, and all eight channels of output are simultaneously digitized to 12 bits and stored in buffer memory. The system is controlled by a 486-based PC through an MXI bus and VXI controller using commercially available software. The system is also capable of real-time image display and manipulation.

Development of a high resolution PET

A high-resolution positron emission tomograph (PET) for brain studies has been developed. It consists of five detector rings (240 BGOs/ring). New multisegment photomultiplier tubes (PMTs) were adopted for the system with 5-mm-wide BGOs. The system is designed to examine a patient sitting or lying down on a chair/bed couch. The functions of PMT auto gain control and real-time image display are implemented in the system. The physical performance of the system was evaluated: the spatial resolution is 3.5 mm in the transaxial plane and 5.7 mm in the axial direction, and the total system sensitivity is 109 kcps/ mu Ci/ml for a uniform phantom 20 cm in diameter with a pulse height threshold of 350 keV.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>