1.Processing History and Modern Research of Bile-processed Coptidis Rhizoma: A Review
Zhaowei DONG ; Jing YANG ; Qinwan HUANG ; Jin WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):269-278
Bile-processed Coptidis Rhizoma(B-pCR), first documented in Shengji Zonglu, is a unique processed products of Coptidis Rhizoma(CR) characterized by "mutual enhancement processing" and "enhancing the cold property of cold-natured herbs". Pig bile can enhance the bitter and cold properties of CR, yielding potent effects in purging excess fire from the liver and gallbladder. The processing increases the dissolution of alkaloids such as berberine, coptisine, and palmatine, while introducing bile acids from pig bile, including taurine-type and glycine-type cholic acids. This enhances its pharmacological effects, such as antipyretic activity, regulation of glucose and lipid metabolism disorders, and intestinal absorption. Traditional processing techniques and quality standards for B-pCR are outlined in the Shanghai Traditional Chinese Medicine(TCM) Decoction Pieces Processing Standard and the Gansu TCM Processing Standard. However, incomplete specifications for critical process parameters and quality criteria significantly impact its production and clinical application. A review of research over the past two decades on the processing history, process optimization, quality evaluation, material basis, and changes in pharmacological effects and properties of B-pCR reveals that the pretreatment method and dosage of pig bile, and processing temperature are key factors influencing its quality. Furthermore, current quality standards lack specific indicators. Additionally, the enhancement of the cold property and medicinal efficacy direction of B-pCR is not only associated with changes in alkaloid groups but also depend on the synergistic effects of bile acids. This review can provide insights for improving the quality evaluation system of B-pCR.
2.Mechanisms of Huanglian Jiedutang and Its Major Active Constituents in Inhibiting LPS-induced M1 Polarisation of BV2 Microglia
Haojia ZHANG ; Kai WANG ; Kunjing LIU ; Xin LAN ; Zijin SUN ; Chunyu WANG ; Wenyuan MA ; Wei SHAO ; Jinhua HAN ; Liyang DONG ; Changxiang LI ; Xueqian WANG ; Youxiang CUI ; Fafeng CHENG ; Qingguo WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(11):44-55
ObjectiveTo investigate whether Huanglian Jiedutang (HLJD) and its major active constituents (geniposide, baicalin, and berberine) can inhibit the inflammatory response of BV2 cells under lipopolysaccharide (LPS) stimulation via the high-mobility group protein B1 (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway, and to explore differences in therapeutic efficacy among the three monomers, their combined formula, and HLJD under equal content ratios. MethodsBV2 microglial cells were used as the primary experimental model. Cell viability was assessed using the cell counting kit-8 (CCK-8) method to examine the effects of different concentrations of dimethyl sulfoxide (DMSO, 0.8%, 0.4%, 0.2%, 0.1%, and 0.05%) on cell viability. IncuCyte was employed to monitor the growth of cells under different concentrations of HLJD (200, 100, 50, 25, 12.5, 6.25 mg·L-1). Nitric oxide (NO) assay was used to screen the optimal HLJD concentration. High-performance liquid chromatography (HPLC) determined the content of geniposide, baicalin, and berberine in HLJD, and experimental groups were subsequently established according to the relative proportions of these constituents. CCK-8 assay evaluated cell viability under different treatments. Enzyme-linked immunosorbent assay (ELISA) measured levels of inflammatory factors (TNF-α, IL-1β, IL-6, IL-10) in the supernatant. Flow cytometry assessed the effects of treatments on M1-type polarization of BV2 cells. Western blot determined the expression levels of HMGB1, TLR4, and NF-κB-related proteins. ResultsCompared with the blank group, DMSO at concentrations ≤0.2% did not affect cell viability within 48 h. BV2 cell growth plateaued at 24 h after treatment with 200 mg·L-1 HLJD. Under stimulation with 2 mg·L-1 LPS, this concentration of HLJD effectively reduced NO release, and 6 h pre-treatment had a stronger inhibitory effect on NO than direct administration. HPLC results showed that 1 mg of HLJD freeze-dried powder contained approximately 24 μg of geniposide, 15 μg of baicalin, and 30 μg of berberine. Based on these ratios, experimental groups were blank, LPS (2 mg·L-1), HLJD (200 mg·L-1), monomer combination, geniposide (4.8 mg·L-1), baicalin (3 mg·L-1), and berberine (6 mg·L-1). The monomer combination group consisted of all three active constituents dissolved together. LPS and HLJD or its active constituents did not affect cell viability compared with the blank group. LPS significantly increased TNF-α, IL-1β, IL-6, and IL-10 in the supernatant (P<0.01). HLJD and its active constituents significantly reduced pro-inflammatory factors TNF-α, IL-1β, and IL-6 (P<0.05, P<0.01) while upregulating anti-inflammatory IL-10 (P<0.01), with the monomer combination showing the strongest effect (P<0.05, P<0.01). Compared with the blank group, LPS significantly increased the proportion of CD80⁺CD86⁺ (M1-type) BV2 cells (P<0.01). HLJD and its constituents partially inhibited M1 polarization (P<0.05, P<0.01), with the monomer combination exhibiting the most pronounced effect (P<0.05, P<0.01). Compared with the blank group, LPS upregulated HMGB1, TLR4, and NF-κB-related proteins (P<0.01), whereas HLJD and its active constituents significantly reduced their expression (P<0.05, P<0.01), with the monomer combination having the strongest regulatory effect (P<0.05, P<0.01). ConclusionHLJD and its major active constituents (geniposide, baicalin, berberine) can inhibit LPS-induced inflammatory responses in BV2 cells. The combination of the three active constituents demonstrates the most potent anti-inflammatory effect, significantly attenuating M1-type polarization of BV2 cells via the HMGB1/TLR4/NF-κB signaling pathway.
3.Huanglian Jiedutang Against Acute Ischemic Stroke: A Review
Liyang DONG ; Qinyuan ZHANG ; Yiping WU ; Yingping HE ; Wei SHAO ; Haojia ZHANG ; Xueqian WANG ; Changxiang LI ; Youxiang CUI ; Fafeng CHENG ; Qingguo WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(11):77-86
Huanglian Jiedutang (HLJDT), as a classical formula for clearing heat and removing toxins, has been widely applied in the treatment of various clinical diseases in recent years, particularly during the fire-heat stage of stroke, where it has attracted considerable attention. Based on previous studies, this paper systematically elaborates on the research progress on the active components of HLJDT, its clinical application in ischemic stroke, and advances in studies on its mechanisms of action. Modern pharmacological studies have demonstrated that HLJDT contains multiple active components, including baicalin, geniposide, and berberine. In the treatment of ischemic stroke, these components exert therapeutic effects through multi-target, multi-pathway, and multi-level mechanisms. Clinical studies have shown that HLJDT can increase cerebral blood flow, reduce cerebral infarct volume, and improve post-stroke physical dysfunction in patients with ischemic stroke. Experimental studies have indicated that HLJDT can improve neurological function scores and increase cerebral perfusion in experimental stroke models. In addition, the mechanisms underlying the anti-ischemic stroke effects of HLJDT may be related to anti-inflammatory and antioxidant activities, promotion of angiogenesis, and regulation of amino acid and energy metabolism. Although existing studies have confirmed that HLJDT exhibits multi-target and multi-pathway synergistic therapeutic characteristics, further large-sample randomized controlled trials are still needed to verify its long-term efficacy and to further elucidate the dynamic interaction network among components, targets, and pathways. Combined with network pharmacology and molecular docking analyses, this study further clarifies the synergistic targets of the core components (berberine, baicalin, and geniposide), providing a theoretical basis for in-depth research and clinical translation of HLJDT in the treatment of ischemic stroke.
4.Meta analysis of the efficacy of digital psychological therapies on depressive symptoms among adolescents
YANG Xuan, YANG Dong, CAI Rui, TANG Yuping, YE Sheng, LUO Yaoyue
Chinese Journal of School Health 2026;47(4):531-537
Objective:
To systematically evaluate the therapeutic efficacy and maintenance effects of digital psychological therapies on depressive symptoms among adolescents, so as to provide a reference for clinical practice.
Methods:
Randomized controlled trial(RCT) investigating digital psychological therapies to improve depressive symptoms among adolescents were searched across databases, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang database, VIP database, and SinoMed, from database inception to November 20, 2025. Following literature screening, quality assessment, and data extraction, a Meta analysis was performed using Stata 18.0 software.
Results:
A total of 20 studies involving 2 042 adolescents aged 11-19 were included. The Meta analysis revealed that digital psychological therapies significantly alleviated depressive symptoms in adolescents ( SMD =-0.59, 95% CI =-0.85 to -0.32, P <0.01). The therapeutic effect was sustained at long term follow up ( SMD =-0.21, 95% CI =-0.34 to -0.09, P <0.01). Furthermore, depression scores in the intervention group showed a continued decrease from post intervention to long term follow up ( SMD =-0.28, 95% CI =-0.41 to -0.14, P <0.01). Egger s linear regression test indicated possible publication bias (Kendall s tall=0.28, P <0.01).
Conclusions
Digital psychological therapies can effectively improve depressive symptoms among adolescents, with stable long term efficacy. However, current evidence remains limited and exhibits substantial heterogeneity. Therefore, further large sample, high quality RCTs are warranted to validate the effectiveness of this intervention.
5.Correlation of mitochondrial genetic differentiation and spatial variables of Oncomelania hupensis robertsoni in Yunnan Province
Yuanyuan ZHANG ; Jing SONG ; Yuwan HAO ; Zaogai YANG ; Xinping SHI ; Siqi NING ; Hongqiong WANG ; Chunhong DU ; Jihua ZHOU ; Zongya ZHANG ; Kai LI ; Shizhu LI ; Yi DONG
Chinese Journal of Schistosomiasis Control 2026;38(1):54-59
Objective Objective To analyze the potential spatial factors affecting the genetic differentiation of Oncomelania hupensis robertsoni in Yunnan Province. Methods A total of 13 administrative villages were selected from schistosomiasis-endemic areas of Yunnan Province as O. hupensis snail sampling sites. At least 200 snails were collected in each site, and the spatial variable data of each site were recorded, including longitude, latitude and altitude. Thirty active and Schistosoma japonicum uninfected O. hupensis snails were selected from each sampling site by means of the crawling method and the cercarial shedding method. Genomic DNA was extracted from O. hupensis snails. Following PCR amplification, purification of PCR amplification products and sequencing, the gene sequences of O. hupensis snail samples were spliced and edited using the DNAstar software and the NCBI database to yield the complete mitochondrial sequences of O. hupensis snails at each sampling site, and the mitochondrial genetic distance matrix of O. hupensis robertsoni was calculated at each sampling site. The geographical coordinates of each sampling site were marked using the software ArcGIS 10.2, and the straight-line geographical distance between each sampling site was calculated. The altitude difference, longitude difference and latitude difference between each sampling site were calculated using the Excel software, and the correlation between the mitochondrial genetic distance matrix of O. hupensis robertsoni and each spatial variable matrix was examined by using the Mantel test at 13 sampling sites in Yunnan Province. Results Among the 13 O. hupensis snail sampling sites in Yunnan Province, the largest mitochondrial genetic distance of O. hupensis robertsoni snail populations was seen between Anding Village, Nanjian Yi Autonomous County and Caizhuang Village, Midu County (26.244 2), and the largest geographical distance was seen between Dongyuan Village, Gucheng District and Cangling Village, Chuxiong County (272.64 km). The highest altitude difference was seen between Anding Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1 086.10 m), and the largest longitude difference was found between Qiandian Village, Eryuan County and Cangling Village, Chuxiong County (1.86°), while the largest latitude difference was measured between Leqiu Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1.81°). In addition, the mitochondrial genetic distance of O. hupensis robertsoni snail populations was positively correlated with altitude at 13 snail sampling sites in Yunnan Province (r = 0.542 8, P < 0.001), and showed no significant correlations with geographical distance (r = 0.093 4, P > 0.05), longitude (r = −0.199 5, P > 0.05) or latitude (r = 0.205 7, P > 0.05). Conclusion Altitude may be a potential spatial factor affecting the genetic differentiation of O. hupensis robertsoni in Yunnan Province.
6.Effect of piercing electroacupuncture on functional ankle instability
Haitao DONG ; Zhenyang CUI ; Qiang GAO ; Jun LI ; Jing LI
Chinese Journal of Rehabilitation Theory and Practice 2026;32(4):437-444
ObjectiveTo explore the effect of piercing electroacupuncture on ankle muscle strength, dynamic balance and subjective stability in patients with functional ankle instability (FAI). MethodsA total of 48 patients with FAI admitted to the Affiliated Hospital of Traditional Chinese Medicine, Shandong Second Medical University from April, 2024 to July, 2025 were enrolled and randomly divided into control group (n = 24) and experimental group (n = 24). The control group received multimodal functional training, while the experimental group received piercing electroacupuncture in addition, for six weeks. Relative peak torque of ankle plantarflexion, dorsiflexion, inversion and eversion were measured with isokinetic muscle strength testing system before and after treatment, while Y-Balance Test (YBT) and Cumberland Ankle Instability Tool (CAIT) were adopted for evaluation. ResultsOne case dropped out in each group. Relative peak torque of ankle plantarflexion, dorsiflexion, inversion and eversion at each angular velocity, the normalized distance in each direction and composite score of YBT, as well as the score of CAIT increased in both groups after treatment (|t| > 2.891, P < 0.01), while all the indicators were better in the experimental group than in the control group (|t| > 2.104, P < 0.05), except dorsiflexion muscle strength. ConclusionCombination of piercing electroacupuncture can further improve perimalleolar muscle strength, dynamic balance and subjective stability in patients with FAI.
7.Heterogeneity of sub-dimensions of satisfaction with the quality of assistive devices from the perspective of self-care ability stratification
Hua JIANG ; Zhuowen PAN ; Mei YAN ; Liquan DONG
Chinese Journal of Rehabilitation Theory and Practice 2026;32(4):473-481
ObjectiveTo explore the differences in attention to the sub-dimensions of satisfaction with the quality of assistive devices among people with different self-care abilities in China, identify the key driving factors, and provide a basis for the precision design and service provision of assistive devices. MethodsBased on the 2023 national survey data, involving 14 030 people with functional impairments, self-care ability was taken as the core independent variable, eight sub-dimensions of satisfaction as dependent variables, and variables such as gender, age, educational level and residential type were controlled. Univariate analysis was performed using Chi-square test with Bonferroni correction, and a binary Logistic regression model was constructed to identify influencing factors. Meanwhile, reliability and validity tests, endogeneity tests (instrumental variable method and propensity score matching) and heterogeneity tests were conducted. ResultsAmong the eight satisfaction sub-dimensions, six presented significant inter-group differences, with Bonferroni correction (threshold = 0.00625). Following binary Logistic regression and endogeneity correction, significant inter-group heterogeneity was confirmed in dimensions such as size and shape. For the affordability dimension, the main effect of self-care ability was not statistically significant, yet prominent urban-rural heterogeneity was observed. Specifically, taking the fully independent (self-care) group as the reference, the fully dependent group attached significantly greater importance to safety (B = 0.253, P < 0.001), comfort (B = 0.153, P = 0.001) and ease of use (B = 0.316, P < 0.001); the partially dependent group showed the highest level of attention to lightweight (B = 0.094, P = 0.027) and durability (B = 0.254, P < 0.001); and the fully independent group demonstrated a relatively stronger preference for aesthetics. ConclusionStratified functional demands, driven by self-care ability, exist in the satisfaction of individuals with functional impairments with assistive devices in China. The policy formulation and product design of assistive devices should shift to a precision-oriented paradigm: prioritize the guarantee of safety, comfort and ease of use for fully dependent groups, optimize lightweight performance and durability for partially dependent groups, enhance aesthetics and social acceptance for fully independent groups, roll out price subsidy policies for urban price-sensitive groups, and strengthen the supply of core functional services for rural groups. This approach will comprehensively improve the adaptation effectiveness of assistive devices and the well-being of users.
8.Applications of Lactoferrin and Its Nanoparticles in Cancer Therapy
Wen-Tian YUE ; Shu-Rong HE ; Qin AN ; Yun-Xia ZOU ; Wen-Wen DONG ; Qing-Yong MENG ; Ya-Li ZHANG
Progress in Biochemistry and Biophysics 2026;53(2):342-355
Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.
9.Applications of Lactoferrin and Its Nanoparticles in Cancer Therapy
Wen-Tian YUE ; Shu-Rong HE ; Qin AN ; Yun-Xia ZOU ; Wen-Wen DONG ; Qing-Yong MENG ; Ya-Li ZHANG
Progress in Biochemistry and Biophysics 2026;53(2):342-355
Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.
10.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.


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