1.Compact Fundus Imaging System Using Shack-Hartmann Wavefront Sensing for High-speed Auto-focus
Zhe-Kai LIN ; Long CHEN ; Geng-Yong ZHENG ; Jin-Tian HUANG ; Jia-Xin DONG ; Shang-Pan YANG ; Wen-Zheng DING ; Ding-An HAN ; Xue-Hua WANG ; Ya-Guang ZENG
Progress in Biochemistry and Biophysics 2026;53(4):1076-1086
ObjectiveThe widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF) technologies. Image-based methods relying on sharpness evaluation require iterative searches, resulting in slow convergence, while projection-based techniques are susceptible to optical artifacts and calibration errors. To address these challenges, this study introduces a novel AF system based on direct wavefront sensing, designed to deliver simultaneous high speed, high precision, and operational robustness within the compact form factor essential for portable ophthalmic devices. MethodsOur approach fundamentally reimagines the AF process by directly measuring the ocular wavefront aberration. We developed a custom portable fundus camera integrating a miniaturized Shack-Hartmann wavefront sensor (SHWS) into the optical path. An 850 nm laser diode projects a point source onto the retina via oblique illumination to minimize corneal reflections. Light scattered from this spot carries the eye’s refractive error through the imaging optics and is directed to the SHWS, positioned at a plane optically conjugate to the primary color CMOS imaging sensor. A microlens array within the SHWS samples the incident wavefront, generating a pattern of focal spots on a CCD. Real-time centroid analysis of these spots provides a map of local wavefront slopes. These measurements are processed through a singular value decomposition (SVD) algorithm to fit a Zernike polynomial basis set, enabling real-time reconstruction of the wavefront phase. The defocus component (S) is extracted from the second-order Zernike coefficients, providing a direct, quantitative measure of the refractive error in diopters. This value serves as a precise error signal in a closed-loop control system, which commands a voice-coil actuated focusing lens to its null position in a single, deterministic step, eliminating the need for iterative search algorithms. ResultsComprehensive evaluation demonstrated the system’s high performance. Testing on a calibrated model eye (OEMI-7) established a highly linear relationship between the computed defocus S and the focusing lens position across a ±20 Diopter (D) compensation range, achievable within a 5 mm mechanical travel. The system achieved a focusing precision of 0.08 D, corresponding to an 18-fold improvement over a conventional projection spot-size method tested under identical conditions. The total focus acquisition time, encompassing wavefront measurement, computation, and lens actuation, averaged under 0.5 s. Clinical validation with 25 human volunteers (50 eyes, refractive range -15 D to +10 D) confirmed practical efficacy. The wavefront-sensing AF succeeded in 92% of attempts with a mean time of 0.5 s, substantially outperforming a projection-based benchmark which achieved only a 32% success rate with an average time of 4.25 s. The system provided instantaneous directional guidance and maintained stability during minor ocular movements. Objective assessment of image quality, via amplitude contrast of retinal vasculature, showed consistent and significant enhancement following AF correction across the entire tested diopter range. ConclusionThis work successfully implements and validates a direct wavefront-sensing autofocus paradigm for portable fundus cameras. By directly quantifying and compensating for the optical defocus aberration, this method bypasses the fundamental limitations of image-processing and projection-based techniques, enabling rapid, precise, and deterministic diopter compensation. The developed system delivers an exceptional combination of a wide operational range (±20 D), high accuracy (0.08 D), fast convergence (0.5 s), and a compact physical footprint. This technology provides a practical and high-performance focusing solution capable of enhancing the reliability, throughput, and diagnostic utility of portable retinal imaging in large-scale screening applications. Future efforts will be directed towards system cost optimization and performance adaptation for diverse ocular conditions.
2.Physical fitness status and its association with lifestyle behaviors among secondary vocational school students
LIU Zhihao, ZOU Xiaojun, XUE Jianhua, YANG Xiaofang, XU Huaping, KONG Junfeng, LU Jinkui, CHEN Yajun
Chinese Journal of School Health 2026;47(6):784-788
Objective:
To analyze the compliance status of physical fitness indicator and lifestyle characteristics among secondary vocational school students, as well as their associations, so as to provide a reference for physical fitness promotion among secondary vocational school students.
Methods:
Using a convenience sampling method, a questionnaire survey and physical fitness tests were conducted from September to December 2024 among 5 141 secondary vocational school students recruited from 16 secondary vocational schools across 8 provinces/municipalities in China, including Fujian, Chongqing, Guangdong, Guangxi, Hubei, Jiangxi, Shanghai and Zhejiang. Data on lifestyle factors were collected using a self designed questionnaire combined with standardized scales, including dietary habits, unhealthy behaviors, and 24 hour behaviors (physical activity, screen time, and sleep behavior). Multivariable Logistic regression model was used to analyze the associations of individual lifestyle behaviors and clustering of unhealthy lifestyle behaviors with non-compliance in physical fitness indicators among secondary vocational school students.
Results:
The compliance rates for waist circumference, vital capacity, grip strength, standing long jump, 30 second sit ups, 20 meter shuttle run, 50 meter dash, sit and reach, 20 second side steps among secondary vocational school students were 55.9%, 89.6%, 81.8%, 79.4%, 77.8%, 61.4%, 87.0%, 12.6%, and 63.5%, respectively, with a non-overweight/obesity rate of 78.9%. The reporting rates of daily breakfast consumption, milk consumption, and vegetable consumption were 58.9%, 18.3%, and 37.5%, respectively. The reporting rates of frequent takeout consumption, frequent sugar sweetened beverage consumption, smoking, alcohol drinking, insufficient moderate to vigorous physical activity (MVPA), excessive screen time, and insufficient sleep were 30.0%, 43.8%, 8.4%, 15.8%, 42.9%, 90.8%, and 42.6%, respectively. Multivariable Logistic regression analysis showed that secondary vocational school students with insufficient MVPA had higher risks of non-compliance in vital capacity, grip strength, standing long jump, 30 second sit ups, 20 meter shuttle run, 50 meter dash, and 20 second side steps ( OR =1.22- 1.60 ); secondary vocational school students who consumed breakfast daily had lower risks of non-compliance in vital capacity and overweight/obesity ( OR =0.81, 0.85); daily vegetable consumption was associated with a lower risk of vital capacity non-compliance ( OR =0.72); frequent takeout consumption was associated with an increased risk of non-compliance in the sit and reach test ( OR =1.28); smoking was associated with increased risks of non-compliance in the 20 meter shuttle run and 20 second side steps ( OR =1.38, 1.58) (all P <0.05). Regarding the clustering of unhealthy behaviors, secondary vocational school students with 4- 5 clustered unhealthy behaviors had higher risks of non-compliance in waist circumference and standing long jump; those with≥6 clustered behaviors had higher risks of non-compliance in standing long jump, 20 meter shuttle run, and 20 second side step ( OR = 1.17-1.36, all P <0.05).
Conclusions
The clustering of unhealthy behaviors is negatively associated with physical fitness status among secondary vocational school students. Secondary vocational schools should prioritize the promotion of comprehensive lifestyle management to improve the physical fitness levels of secondary vocational school students.
4.Rapid Video Analysis for Contraction Synchrony of Human Induced Pluripotent Stem Cells-Derived Cardiac Tissues
Yuqing JIANG ; Mingcheng XUE ; Lu OU ; Huiquan WU ; Jianhui YANG ; Wangzihan ZHANG ; Zhuomin ZHOU ; Qiang GAO ; Bin LIN ; Weiwei KONG ; Songyue CHEN ; Daoheng SUN
Tissue Engineering and Regenerative Medicine 2025;22(2):211-224
BACKGROUND:
The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time.
METHODS:
We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed.
RESULTS:
Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results.
CONCLUSION
This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.
5.Molecular biological research and molecular homologous modeling of Bw.03 subgroup
Li WANG ; Yongkui KONG ; Huifang JIN ; Xin LIU ; Ying XIE ; Xue LIU ; Yanli CHANG ; Yafang WANG ; Shumiao YANG ; Di ZHU ; Qiankun YANG
Chinese Journal of Blood Transfusion 2025;38(1):112-115
[Objective] To study the molecular biological mechanism for a case of ABO blood group B subtype, and perform three-dimensional modeling of the mutant enzyme. [Methods] The ABO phenotype was identified by the tube method and microcolumn gel method; the ABO gene of the proband was detected by sequence-specific primer polymerase chain reaction (PCR-SSP), and the exon 6 and 7 of the ABO gene were sequenced and analyzed. Homologous modeling of Bw.03 glycosyltransferase (GT) was carried out by Modeller and analyzed by PyMOL2.5.0 software. [Results] The weakening B antigen was detected in the proband sample by forward typing, and anti-B antibody was detected by reverse typing. PCR-SSP detection showed B, O gene, and the sequencing results showed c.721 C>T mutation in exon 7 of the B gene, resulting in p. Arg 241 Trp. Compared with the wild type, the structure of Bw.03GT was partially changed, and the intermolecular force analysis showed that the original three hydrogen bonds at 241 position disappeared. [Conclusion] Blood group molecular biology examination is helpful for the accurate identification of ambiguous blood group. Homologous modeling more intuitively shows the key site for the weakening of Bw.03 GT activity. The intermolecular force analysis can explain the root cause of enzyme activity weakening.
6.Gut microbiota-derived tryptophan metabolites regulated by Wuji Wan to attenuate colitis through AhR signaling activation.
Wanghui JING ; Sijing DONG ; Yinyue XU ; Jingjing LIU ; Jiawei REN ; Xue LIU ; Min ZHU ; Menggai ZHANG ; Hehe SHI ; Na LI ; Peng XIA ; Haitao LU ; Sicen WANG
Acta Pharmaceutica Sinica B 2025;15(1):205-223
Disruption of the intestinal mucosal barrier caused by gut dysbiosis and metabolic imbalance is the underlying pathology of inflammatory bowel disease (IBD). Traditional Chinese medicine Wuji Wan (WJW) is commonly used to treat digestive system disorders and showed therapeutic potential for IBD. In this interdisciplinary study, we aim to investigate the pharmacological effects of WJW against experimental colitis by combining functional metabolomics and gut-microbiota sequencing techniques. Treatment with WJW altered the profile of the intestinal microbiota and notably increased the abundance of Lactobacillus, thereby facilitating the conversion of tryptophan into indole-3-acetic acid (IAA) and indoleacrylic acid (IA). These indole derivatives activated the aryl hydrocarbon receptor (AhR) pathway, which reduced colonic inflammation and restored the expression of intestinal barrier proteins. Interestingly, the beneficial effects of WJW on gut barrier function improvement and tryptophan metabolism were disappeared in the absence of gut microbiota. Finally, pre-treatment with the AhR antagonist CH-223191 confirmed the essential role of IAA-mediated AhR activation in the therapeutic effects of WJW. Overall, WJW enhanced intestinal barrier function and reduced colonic inflammation in a murine colitis model by modulating Lactobacillus-IAA-AhR signaling pathway. This study provides novel insights into colitis pathogenesis and presents an effective therapeutic and preventive approach against IBD.
8.Rapid Video Analysis for Contraction Synchrony of Human Induced Pluripotent Stem Cells-Derived Cardiac Tissues
Yuqing JIANG ; Mingcheng XUE ; Lu OU ; Huiquan WU ; Jianhui YANG ; Wangzihan ZHANG ; Zhuomin ZHOU ; Qiang GAO ; Bin LIN ; Weiwei KONG ; Songyue CHEN ; Daoheng SUN
Tissue Engineering and Regenerative Medicine 2025;22(2):211-224
BACKGROUND:
The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time.
METHODS:
We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed.
RESULTS:
Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results.
CONCLUSION
This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.
9.Rapid Video Analysis for Contraction Synchrony of Human Induced Pluripotent Stem Cells-Derived Cardiac Tissues
Yuqing JIANG ; Mingcheng XUE ; Lu OU ; Huiquan WU ; Jianhui YANG ; Wangzihan ZHANG ; Zhuomin ZHOU ; Qiang GAO ; Bin LIN ; Weiwei KONG ; Songyue CHEN ; Daoheng SUN
Tissue Engineering and Regenerative Medicine 2025;22(2):211-224
BACKGROUND:
The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time.
METHODS:
We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed.
RESULTS:
Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results.
CONCLUSION
This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.
10.Rapid Video Analysis for Contraction Synchrony of Human Induced Pluripotent Stem Cells-Derived Cardiac Tissues
Yuqing JIANG ; Mingcheng XUE ; Lu OU ; Huiquan WU ; Jianhui YANG ; Wangzihan ZHANG ; Zhuomin ZHOU ; Qiang GAO ; Bin LIN ; Weiwei KONG ; Songyue CHEN ; Daoheng SUN
Tissue Engineering and Regenerative Medicine 2025;22(2):211-224
BACKGROUND:
The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time.
METHODS:
We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed.
RESULTS:
Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results.
CONCLUSION
This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.


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