Resolution Target Research Articles

Single-shot quantitative differential phase contrast imaging combined with programmable polarization multiplexing illumination.

We propose a single-shot quantitative differential phase contrast method with polarization multiplexing illumination. In the illumination module of our system, a programmable LED array is divided into four quadrants and covered with polarizing films of four different polarization angles. We use a polarization camera with polarizers before the pixels in the imaging module. By matching the polarization angle between the polarizing films over the custom LED array and the polarizers in the camera, two sets of asymmetric illumination acquisition images can be calculated from a single-shot acquisition image. Combined with the phase transfer function, we can calculate the quantitative phase of the sample. We present the design, implementation, and experimental image data demonstrating the ability of our method to obtain quantitative phase images of a phase resolution target, as well as Hela cells.

Multimodal laparoscopic coincidence gamma imaging system for near-infrared fluorescence guided surgery: a preclinical study.

Minimally invasive surgery has advantages in terms of quality of life and patient outcomes. Recently, near-infrared (NIR) fluorescence guided surgery has widely used for preclinical and clinical trials. However, NIR fluorescence has a maximum penetration capability of 10mm. Radiographic imaging can be a solution to overcome the depth issue of NIR fluorescence. For this reason, the performance of the multimodal imaging system, which integrates annihilation gamma (511keV) rays, NIR fluorescence, and color images, was evaluated. The multimodal imaging system consisted of a laparoscopic module, containing an internal detector for annihilation gamma events and cameras for optical imaging, and a flat module for coincidence detection with the internal detector. The acquired images were integrated by an algorithm with post image processing and registration. To evaluate the performance of the proposed multimodal imaging system, the images of a resolution target, a square bar target filled with a fluorescence dye, and a sodium-22 point source were analyzed. A preclinical test for axillary sentinel lymph node (SLN) biopsy with a rat model was conducted. The spatial resolution of color images was equivalent to 4 lp/mm. The modulation transfer function of NIR fluorescence at 1 lp/mm was 0.83. The 511keV gamma sensitivity and spatial resolution of the point source were 0.54cps/kBq and 2.1mm, respectively. The image of 511keV gamma rays showed almost the same intensity regardless of the thickness of the tissue phantom. In the preclinical test, an integrated image of the SLN sample of the rat model was obtained with the proposed multimodal imaging system. With the proposed laparoscopic system, a merged image of the sample was obtained with the rat model. The annihilation gamma rays showed penetration capability with the tissue-mimicking phantom superior to that of NIR fluorescence.

Correcting spatial-spectral crosstalk and chromatic aberrations in broadband line-scan spectral-domain OCT images.

Digital correction of optical aberrations allows for high-resolution imaging across the full depth range in optical coherence tomography (OCT). Many digital aberration correction (DAC) methods have been proposed in the past to evaluate and correct monochromatic error in OCT images. However, other factors that deteriorate the image quality have not been fully investigated. Specifically, in a broadband line-scan spectral-domain OCT system (LS-SD-OCT), photons with different wavelengths scattered from the same transverse location and in the imaged object will be projected onto different spatial coordinates onto the 2D camera sensor, which in this work is defined as spatial-spectral crosstalk. In addition, chromatic aberrations in both axial and lateral directions are not negligible for broad spectral bandwidths. Here we present a novel approach to digital recovery of the spatial resolution in images acquired with a broadband LS-SD-OCT, which addresses these two main factors that limit the effectiveness of DAC for restoring diffraction-limited resolution in LS-SD-OCT images. In the proposed approach, spatial-spectral crosstalk and chromatic aberrations are suppressed by the registration of monochromatic sub-band tomograms that are digitally corrected for aberrations. The new method was validated by imaging a standard resolution target, a microspheres phantom, and different biological tissues. LS-SD-OCT technology combined with the proposed novel image reconstruction method could be a valuable research tool for various biomedical and clinical applications.

Alveolar Mitochondrial Quality Control During Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a leading cause of respiratory failure and death in patients in the intensive care unit. Experimentally, acute lung injury resolution depends on the repair of mitochondrial oxidant damage by the mitochondrial quality control (MQC) pathways, mitochondrial biogenesis, and mitophagy, but nothing is known about this in the human lung. In a case–control autopsy study, we compared the lungs of subjects dying of ARDS (n = 8; cases) and age-/gender-matched subjects dying of nonpulmonary causes (n = 7; controls). Slides were examined by light microscopy and immunofluorescence confocal microscopy, randomly probing for co-localization of citrate synthase with markers of oxidant stress, mitochondrial DNA damage, mitophagy, and mitochondrial biogenesis. ARDS lungs showed diffuse alveolar damage with edema, hyaline membranes, and neutrophils. Compared with controls, a high degree of mitochondrial oxidant damage was seen in type 2 epithelial (AT2) cells and alveolar macrophages by 8-hydroxydeoxyguanosine and malondialdehyde co-staining with citrate synthase. In ARDS, antioxidant protein heme oxygenase-1 and DNA repair enzyme N-glycosylase/DNA lyase (Ogg1) were found in alveolar macrophages but not in AT2 cells. Moreover, MAP1 light chain-3 (LC3) and serine/threonine-protein kinase (Pink1) staining were absent in AT2 cells, suggesting a mitophagy failure. Nuclear respiratory factor-1 staining was missing in the alveolar region, suggesting impaired mitochondrial biogenesis. Widespread hyperproliferation of AT2 cells in ARDS could suggest defective differentiation into type 1 cells. ARDS lungs show profuse mitochondrial oxidant DNA damage but little evidence of MQC activity in AT2 epithelium. Because these pathways are important for acute lung injury resolution, our findings support MQC as a novel pharmacologic target for ARDS resolution.

Tracking of Multiple Static and Dynamic Targets for 4D Automotive Millimeter-Wave Radar Point Cloud in Urban Environments

This paper presents a target tracking algorithm based on 4D millimeter-wave radar point cloud information for autonomous driving applications, which addresses the limitations of traditional 2 + 1D radar systems by using higher resolution target point cloud information that enables more accurate motion state estimation and target contour information. The proposed algorithm includes several steps, starting with the estimation of the ego vehicle’s velocity information using the radial velocity information of the millimeter-wave radar point cloud. Different clustering suggestions are then obtained using a density-based clustering method, and correlation regions of the targets are obtained based on these clustering suggestions. The binary Bayesian filtering method is then used to determine whether the targets are dynamic or static targets based on their distribution characteristics. For dynamic targets, Kalman filtering is used to estimate and update the state of the target using trajectory and velocity information, while for static targets, the rolling ball method is used to estimate and update the shape contour boundary of the target. Unassociated measurements are estimated for the contour and initialized for the trajectory, and unassociated trajectory targets are selectively retained and deleted. The effectiveness of the proposed method is verified using real data. Overall, the proposed target tracking algorithm based on 4D millimeter-wave radar point cloud information has the potential to improve the accuracy and reliability of target tracking in autonomous driving applications, providing more comprehensive motion state and target contour information for better decision making.

Phase-based reconstruction optimization method for digital holographic measurement of microstructures.

Digital holography has transformative potential in measuring stacked-chip microstructures due to its noninvasive, single-shot, full-field characteristics. However, uncertainties in reconstruction distance inevitably lead to resolving blur and reconstruction distortion. Herein, we propose a phase-based reconstruction optimization method that consists of a phase-evaluation function and a structured surface-characterization model. Our proposed method involves setting a reconstruction distance range, obtaining phase information using sliced numerical reconstruction, and optimizing the reconstruction distance by finding the extreme value of the function, which identifies the focal plane of the reconstructed image. The structure of the surface topography is then characterized using the characterization model. We perform simulations of the recording, reconstruction, and characterization to verify the effectiveness of the proposed method. To further demonstrate the approach, a simple holographic recording system is constructed to measure a standard resolution target, and the measurement results are compared with a commercial instrument. The simulation and experiment demonstrate, respectively, 31.16% and 34.41% improvement in step-height characterization accuracy.

P‐89: Digital Holography Microscope with liquid crystal phase modulator

We proposed a DHM system with improved resolution property by using liquid crystal (LC) phase modulator. The LC phase modulator can stably control the phase modulation characteristics of the interference pattern and implements the four‐step phase shifting scheme. The proposed DHM system showed a four‐fold improvement in resolution compared to the conventional DHM with polarized camera. Finally, it was confirmed that the modulation transfer function (MTF) value was improved 2 times at the resolution target of 105 lines/mm.

High-resolution single pulse LA-ICP-MS mapping via 2D sub-pixel oversampling on orthogonal and hexagonal ablation grids – A computational assessment

Laser beam profiles in analytical laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) instruments are in general homogenized to produce a flat-top beam profile. However, in practice, they are mostly super-Gaussian in nature, and for small laser beam sizes (<5 μm) they even approach a Gaussian profile. This implies that the amount of surface material sampled by the laser (=ablation volume) directly depends on the beam profile and ablation grid. By contraction of the ablation grid (=sub-pixel mapping) not only more accurate surface sampling is realized, but also a higher pixel density, an improved spatial resolution, and a better signal-to-noise ratio. Although LA sampling is predominantly performed on an orthogonal grid, hexagonal or staggered/interleaved sampling may further improve the image quality as regular hexagons are more compact than squares (=lower perimeter/area) and suffer less from orientation bias (=lower anisotropy). Due to the current limitations of LA stages in executing precise hexagonal sampling with small beam sizes, computational protocols were employed to simulate LA-ICP-MS mapping. Simulation was performed by discrete convolution using the crater profile as the kernel, followed by the application/addition of Poisson/Flicker noise related to the local concentration and instrumental sensitivity/noise. A freely accessible online app was developed (https://laicpms-apps.ki.si/webapps/home/) to study the effect of sampling grid contraction (orthogonal and hexagonal) on the image map quality (spatial resolution and signal-to-noise ratio) by virtual ablation of phantoms. Comparison of experimental LA-ICP-MS maps obtained through orthogonal and hexagonal sampling methods could only be performed using a beam size of 150 μm and a macroscale inkjet-printed resolution target. This was due to the unavailability of precise hexagonal sampling stages and microscale resolution targets, which prevented the use of smaller beam sizes.

Abstract 554: Monocyte Toll-like Receptor 4 (tlr4) Signaling Is Essential For Post Thrombotic Upa Expression

Background: Leukocyte expression of Toll-like receptor 4 (TLR4) increases with transformation to chronic deep venous thrombosis (DVT) &amp; in non-resolving thrombi, but TLR4 function during thrombus clearance is unclear. We hypothesized TLR4 signaling to regulate expression of fibrinolytic factors in monocytes &amp; macrophages (MO/MFs) for VT resolution. Methods: Small interfering RNA (siRNA) knockdown (KD) of TLR4 &amp; disruption of Myd88-dependent/independent pathways occurred in immortalized MFs (RAW264.7), with quantitative real-time PCR (qRT-PCR) for a panel of fibrinolytic factors &amp; immunoblotting for urokinase (uPA). Tlr4-/- mice &amp; wild-type controls underwent IVC stasis/ligation, yielding VT at 2h, 2d, &amp; 8d. Murine/chronic human thrombi underwent immunofluorescent staining for indicated targets &amp; murine thrombi weight-length ratios were found. Splenic &amp; Bone marrow-derived MFs from Tlr4 Cre mice were immunoblotted for uPA. Results: TLR4 silencing in RAW264.7 cells yielded suppression of uPA mRNA (Fig 1B) &amp; protein levels (not shown). TRIF KD yielded decreased uPA mRNA (Fig 1C) &amp; protein levels (not shown), implicating Myd88-independent signaling in MO/MF uPA production. Human (not shown) &amp; murine chronic thrombi staining saw TLR4 co-localization with MF marker CCR2 (Fig 1D). Global knockout (KO) of murine TLR4 did not affect early thrombogenesis (Fig 1E left), with delayed VT resolution seen from 2d (Fig 1E right). Decreased uPA protein levels were observed in Tlr4 KO mice (Fig 1F). Conclusions: TLR4 signaling stimulates in vivo VT resolution. Expression of fibrinolytic factor uPA is enforced in MO/MFs by TLR4-Myd88-independent signaling, a potential target for VT resolution.

Spatiotemporal Evolution of Orbital Angular Momentum (OAM) Beams Based on a Uniform Circular Frequency Diverse Array (UC-FDA)

Radar imaging based on orbital angular momentum (OAM) beams has become a significant approach to realize high resolution and multidimensional target detection. The irradiation of a target area with OAM beams with different modes has been proven to be a feasible solution to improve the azimuthal resolution of the target. This article is the first to propose and validate novel spatiotemporal OAM beams generated by a uniform circular frequency diverse array (UC-FDA). Unlike the conventional uniform circular array (UCA), signals with frequency intervals need to be fed to the antennas in the UC-FDA structure. The mode of the spatiotemporal OAM beam can be switched automatically with spatial transmission, which enhances the flexibility of mode switching and reduces the switching time. The evolution characteristics of the OAM beam are fully demonstrated. Meanwhile, the intrinsic spatiotemporal evolution rules and influence parameters are analyzed and summarized. Furthermore, an optimized dynamic decomposition (DMD) algorithm is proposed and used to implement mode detection. Finally, the spatiotemporal evolution of OAM beams is applied to a rudimentary exploration of radar imaging. The measured results indicate that azimuth imaging of targets can be successfully accomplished. Spatiotemporal OAM beams may unlock promising potential for new-tech radar scenarios.

Programmable Aperture Light‐Field Microscopy

AbstractA computational three‐dimensional (3D) microscopy technique, termed programmable aperture light‐field microscopy (PALFM), for motion‐free, high‐resolution volumetric imaging of fluorescent or self‐luminous samples is proposed. The well‐known Fourier slice theorem is extended to incoherent tomographic imaging, which states that a detected image under an ideal aperture corresponds to a central slice in the 3D object spectrum, so the spectrum coverage can be accomplished based on the motion‐free aperture modulation. When further considering frequency extension and coverage, a hybrid aperture modulation scheme is designed consisting of non‐centrosymmetric circular and annular apertures for high‐efficiency, non‐ambiguous depth discrimination. A PALFM system with an easy‐to‐build programmable aperture module attached to an off‐the‐shelf inverted fluorescence microscope is constructed, where annular apertures can manipulate Bessel‐like beams for spectrum modulation. Experimental results on near‐diffraction‐limited imaging of a resolution target across a large depth range and high‐resolution, multi‐color 3D imaging of a mouse kidney section verify the validity and effectiveness of PALFM. High‐speed, long‐term time‐lapse volumetric imaging of HeLa cells in vitro further demonstrates that PALFM is a promising tomographic imaging tool for studying dynamic cellular processes and events without requiring complicated sample rotation or beam scanning.

Multiplexed superresolution phase microscopy with transport of intensity equation

Resolving power in imaging systems, optical microscopy in particular, is limited by several factors being diffraction probably the most important one. Digital holographic microscopy (DHM) allows diffraction-limited quantitative phase imaging (QPI) with high accuracy by retrieving complex fields using interferometric recording, and a bunch of superresolution (SR) techniques have been widely reported through the past. However, there are additional ways to retrieve the complex amplitude distribution (such as the transport of intensity equation – TIE), having additional advantages over interferometric recording. We present how to increase the resolution limit in low/medium numerical aperture (NA) microscope objectives by using time and angular multiplexing while providing quantitative phase imaging (QPI) retrieved by TIE algorithm. This is, to the best of our knowledge, the first time that the resolution limit is experimentally improved in combination with TIE for phase retrieval in QPI. The proposed approach is validated in a real microscope embodiment (Olympus IX81) using resolution targets for quantitative resolution analysis and verifying a resolution gain factor of 2 from an experimental point of view.

Single-shot super-resolution quantitative phase imaging allowed by coherence gate shaping

Biomedical and metasurface researchers repeatedly reach for quantitative phase imaging (QPI) as their primary imaging technique due to its high-throughput, label-free, quantitative nature. So far, very little progress has been made toward achieving super-resolution in QPI. However, the possible super-resolving QPI would satisfy the need for quantitative observation of previously unresolved biological specimen features and allow unprecedented throughputs in the imaging of dielectric metasurfaces. Here we present a method capable of real-time super-resolution QPI, which we achieve by shaping the coherence gate in the holographic microscope with partially coherent illumination. Our approach is based on the fact that the point spread function (PSF) of such a system is a product of the diffraction-limited spot and the coherence-gating function, which is shaped similarly to the superoscillatory hotspot. The product simultaneously produces the PSF with a super-resolution central peak and minimizes sidelobe effects commonly devaluating the superoscillatory imaging. The minimization of sidelobes and resolution improvement co-occur in the entire field of view. Therefore, for the first time, we achieve a single-shot widefield super-resolution QPI. We demonstrate here resolution improvement on simulated as well as experimental data. A phase resolution target image shows a resolving power improvement of 19%. Finally, we show the practical feasibility by applying the proposed method to the imaging of biological specimens.

Complex optically computed phase microscopy for label-free sub-cellular imaging.

In this study, we investigated a complex optically computed phase microscopy (complex-OCPM) technology. Based on a low coherence interferometer and an innovative optical computation approach, the complex-OCPM imaging system achieves depth resolved quantitative phase measurement. Particularly, the complex-OCPM imaging system directly measures the complex amplitude of the optical field emerging from the sample, extracts the phase as the argument of a complex signal, and achieves a high spatial resolution in phase imaging. We evaluated the performance of complex-OCPM imaging using resolution targets and live cells. Our results show that the complex-OCPM system achieves quantitative phase imaging with sub-cellular resolution on label-free cells.

Auto-Focusing in Digital Holographic Microscopy Using Differential Cosine Score

Accurately estimating the reconstruction distance of samples is very important for digital holographic microscopy, various auto-focusing algorithms have been proposed. These algorithms determine focus position by finding the global peak or valley of the evaluation curve. However, the discrete step size is small in precise autofocus process, which causes that the function values around peak or valley are not much different. As a result, the sensitivity of the peak and valley values of the evaluation curve is low, and the focusing accuracy is also susceptible to noise. In this paper, an autofocusing method using differential cosine score (DCS) is proposed to improve the accuracy and sensitivity of evaluation curve. In this method, two virtual detectors are placed on both sides of the real detector at the same distance. Two ordinary focusing curves and one DCS curve can be obtained by using the cosine score function. Therefore, the focal plane can be automatically identified by searching the zero-crossing of DCS curve, which avoids the problem of low sensitivity of peak and valley values by traditional methods. We illustrate the validity of the proposed method with measurements on USAF resolution target, blood smear and Hela cell.

Implementing a Care Plan System in a Community Hospital Electronic Health Record.

Nursing care plans, the result of the nursing process, are important because they guide quality patient care, define the nurse's role in patient treatment, and support patient specific nursing interventions. Nurse leaders at a community hospital identified that 70% of hospitalized patients shared the same three nursing problems and three-day resolution target dates. This quality improvement project involved the implementation of a nursing care plan system within the organization's existing electronic health record platform that supported the development of individualized plans. The implementation included a) integration of care plan activities into the nursing workflow, b) adoption of a standardized nursing language to provide structure nursing care plan data capture and reporting, c) configuration of the electronic health record to recommend patient data-driven care plan problems based on nursing assessment documentation; and d) trended care plan data to identify problem patterns within the patient population. A postimplementation audit indicated a 130% improvement in achieving individualized care plans within 24 hours of admission.

Testing specialized pro-resolving mediators on bacteria-derived inflammation in chronic rhinosinusitis

Background and Hypothesis:Chronic rhinosinusitis (CRS) is defined by chronic tissue inflammation, and prior work in the field implicates activation of the NFκb pathway. This pathway is activated by pattern recognition receptors (PRRs), which recognize molecules associated with pathogens and cellular damage. In CRS subjects, particularly those with nasal polyps, dysregulated pro-resolving processes have been documented. Specialized pro-resolving lipid mediators (SPMs), including lipoxin A4 and the resolvins, are prime targets for active resolution of the chronic tissue inflammation that defines the disease. We hypothesize that exaggerated pro-inflammatory responses to CRS tissues could be mitigated by application of SPMs in vitro. Project Methods:CRS polyp tissue was collected from surgical specimens, and submerged in cell culture conditions with 10 ug/ml lipopolysaccharide (LPS) or lipoteichoic acid (LTA) to mimic bacterial pathogens commonly observed in CRS (i.e., P. aeruginosa or S.aureus). Tissues were treated with 50 nM of SPMs, either lipoxin A4, resolvin D1, or resolvin D2. RNA was isolated from treated tissues. RNA was analyzed with Taqman Microarray NF-kB human pathway RT-PCR panel to evaluate expression of NF-kB-associated genes. In tandem, supernatant was collected for analysis of cytokine and chemokine signaling proteins. Protein assays were performed using the Luminex Multiplex Assay to observe modulation of pro-inflammatory immune signaling molecules Results:LPS and LTA exposures demonstrated robust and different pro-inflammatory responses in ex vivo nasal polyp tissue. Treatment with SPMs was able to at least partially reduce NF-kB activation and the associated inflammatory response at a molecular level. Conclusion:Inflammation is a complex, temporally precise physiologic process. In chronic inflammatory mucosal diseases such as CRS, repeated acute insults may lead to chronic tissue inflammation. A novel treatment approach leveraging endogenous tissue resolving processes, i.e., SPMs was tested here in vitro and demonstrates potential promise for CRS with nasal polyps.

Image Scanning Microscopy to Investigate Polycomb Protein Colocalization onto Chromatin

Super-resolution microscopy has been recently applied to understand the 3D topology of chromatin at an intermediated genomic scale (kilobases to a few megabases), as this corresponds to a sub-diffraction spatial scale crucial for the regulation of gene transcription. In this context, polycomb proteins are very renowned gene repressors that organize into the multiprotein complexes Polycomb Repressor Complex 1 (PRC1) and 2 (PRC2). PRC1 and PRC2 operate onto the chromatin according to a complex mechanism, which was recently recapitulated into a working model. Here, we present a functional colocalization study at 100–140 nm spatial resolution targeting PRC1 and PRC2 as well as the histone mark H3K27me3 by Image Scanning Microscopy (ISM). ISM offers a more flexible alternative to diffraction-unlimited SRMs such as STORM and STED, and it is perfectly suited to investigate the mesoscale of PRC assembly. Our data suggest a partially simultaneous effort of PRC1 and PRC2 in locally shaping the chromatin topology.

Using symmetric illumination and color camera to achieve high throughput Fourier ptychographic microscopy.

This study aims to develop a high throughput Fourier ptychographic microscopy (FPM) technique based on symmetric illumination and a color detector, which is able to accelerate image acquisition by up to 12 times. As an emerging technology, the efficiency of FPM is limited by its data acquisition process, especially for color microscope image reconstruction. To overcome this, we built an FPM prototype equipped with a color camera and a 4×/0.13 NA objective lens. During the image acquisition, two symmetric LEDs illuminate the sample simultaneously using white light, which doubles the light intensity and reduces the total captured raw patterns by half. A standard USAF 1951 resolution target was used to measure the system's modulation transfer function (MTF) curve, and the H&E-stained ovarian cancer samples were then imaged to assess the feature qualities depicted on the reconstructed images. The results showed that the measured MTF curves of red, green, and blue channels are generally comparable to the corresponding curves generated by conventional FPM, while symmetric illumination FPM preserves more tissue details, which is superior to the results captured by conventional 20×/0.4 NA objective lens. This investigation initially verified the feasibility of symmetric illumination based color FPM.

Detection and Recognition Algorithm of Arbitrary-Oriented Oil Replenishment Target in Remote Sensing Image

In view of the fact that the aerial images of UAVs are usually taken from a top-down perspective, there are large changes in spatial resolution and small targets to be detected, and the detection method of natural scenes is not effective in detecting under the arbitrary arrangement of remote sensing image direction, which is difficult to apply to the detection demand scenario of road technology status assessment, this paper proposes a lightweight network architecture algorithm based on MobileNetv3-YOLOv5s (MR-YOLO). First, the MobileNetv3 structure is introduced to replace part of the backbone network of YOLOv5s for feature extraction so as to reduce the network model size and computation and improve the detection speed of the target; meanwhile, the CSPNet cross-stage local network is introduced to ensure the accuracy while reducing the computation. The focal loss function is improved to improve the localization accuracy while increasing the speed of the bounding box regression. Finally, by improving the YOLOv5 target detection network from the prior frame design and the bounding box regression formula, the rotation angle method is added to make it suitable for the detection demand scenario of road technology status assessment. After a large number of algorithm comparisons and data ablation experiments, the feasibility of the algorithm was verified on the Xinjiang Altay highway dataset, and the accuracy of the MR-YOLO algorithm was as high as 91.1%, the average accuracy was as high as 92.4%, and the detection speed reached 96.8 FPS. Compared with YOLOv5s, the p-value and mAP values of the proposed algorithm were effectively improved. It can be seen that the proposed algorithm improves the detection accuracy and detection speed while greatly reducing the number of model parameters and computation.