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.Clinical application of minimally invasive mitral valvuloplasty in patients with infective endocarditis complicated with mitral valve insufficiency
Yubin ZHONG ; Yunqing SHI ; Quanlin YANG ; Songyi QIAN ; Limin XIA ; Kai SONG ; Sun PAN
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2026;33(05):778-783
Objective To investigate the clinical efficacy of minimally invasive mitral valvuloplasty (MVP) in the treatment of infective endocarditis (IE) with mitral regurgitation (MR). Methods A retrospective analysis was conducted on the clinical data of patients who underwent MVP for IE with MR at the Department of Cardiovascular Surgery in Zhongshan Hospital, Fudan University from 2016 to 2020. Patients were divided into two groups based on the surgical incision: those with a right mini-thoracotomy were classified as a minimally invasive surgery (MIS) group, and those with a median sternotomy (MS) were classified as an MS group. All patients had isolated mitral valve involvement. Perioperative data were analyzed, and mid- to long-term outcomes were compared between the two groups. Results A total of 86 patients were included, with 40 in the MIS group [22 males and 18 females, with a mean age of (39.78±15.36) years ranging from 14 to 75 years] and 46 in the MS group [27 males and 19 females, with a mean age of (49.94±16.13) years ranging from 14 to 71 years]. The patients in the MIS group were relatively younger (P=0.004) with better preoperative cardiac function (P=0.004). There was no statistical difference in preoperative fever, gender, or comorbidities between the two groups (P>0.05). The MIS group had shorter postoperative ventilation times, less postoperative 24-hour drainage, less blood transfusion, and shorter total hospital stays compared to the MS group (P<0.05). There was no statistical difference in cardiopulmonary bypass times or ICU stays between the two groups (P>0.05). The perioperative complication rates and mortality rates were not significantly different between the two groups (P>0.05). Follow-up was conducted for 11-92 months, with a mean duration of (49±19) months and an overall follow-up rate of 91.9%. During the follow-up, 3 patients in each group required reoperation for mitral valve issues, with no statistical difference in incidence (7.5% vs. 6.5%, P=0.691). There were no warfarin-related complications, recurrences, or deaths in either group during follow-up. Multivariate regression analysis identified age, preoperative cardiac function, and surgeon experience as influencing factors for the choice of surgical approach. Conclusion Minimally invasive MVP for IE with MR is relatively safe in the perioperative period and shows significant efficacy, with clear mid- to long-term outcomes. It is recommended for younger patients with better preoperative cardiac function and when performed by surgeons with extensive experience in mitral valvuloplasty.
3.Comparison of Embolization Coils and Patent Ductus Arteriosus Occluders for Coronary Artery Fistula Transcatheter Closure: A Single Centre Experience
Peijian WEI ; Yihang LI ; Liang XU ; Junyi WAN ; Fengwen ZHANG ; Gary TSE ; Jeffrey Shi Kai CHAN ; Shouzheng WANG ; Wenbin OUYANG ; Gejun ZHANG ; Fang FANG ; Xiangbin PAN
Korean Circulation Journal 2025;55(3):199-212
Background and Objectives:
There is no dedicated occlusive device for closing coronary artery fistulas (CAFs), and specific efficacy and safety data of various off-label occlusive devices for CAFs closure are scarce.
Methods:
Patients undergoing transcatheter closure of CAFs from January 2011 to December 2022 were included in the single-center retrospective study. The study population was divided into 2 groups: coils group (n=35) and patent ductus arteriosus (PDA) occluders group (n=66).
Results:
No significant intergroup differences were observed in demographic characteristics except age. The presence of multiple CAF origins (54.3% vs. 4.5%, p<0.001) and multiple draining sites (51.4% vs. 3.0%, p<0.001) were more common in the coils group. In contrast, the presence of aneurysm (72.7% vs. 14.3%, p<0.001), and large fistula (75.8% vs. 37.1%, p<0.001) were more prevalent in the PDA occluders group. The acute procedural success rate of the PDA occluders group was higher compared to that of the coils group (87.9% vs.62.9%, adjusted odds ratio [OR], 7.20; 95% confidence interval, 1.59–32.64; p=0.01).In addition, no significant intergroup differences were noted in both the recanalization rate (7.8% vs. 20%, p=0.107) and the reintervention rate (3.1% vs. 8.6%, p=0.342).
Conclusions
Transcatheter closure of CAFs using PDA occluders was associated with significantly higher acute procedural success rates compared to coil embolization with comparable late outcomes.
4.Comparison of Embolization Coils and Patent Ductus Arteriosus Occluders for Coronary Artery Fistula Transcatheter Closure: A Single Centre Experience
Peijian WEI ; Yihang LI ; Liang XU ; Junyi WAN ; Fengwen ZHANG ; Gary TSE ; Jeffrey Shi Kai CHAN ; Shouzheng WANG ; Wenbin OUYANG ; Gejun ZHANG ; Fang FANG ; Xiangbin PAN
Korean Circulation Journal 2025;55(3):199-212
Background and Objectives:
There is no dedicated occlusive device for closing coronary artery fistulas (CAFs), and specific efficacy and safety data of various off-label occlusive devices for CAFs closure are scarce.
Methods:
Patients undergoing transcatheter closure of CAFs from January 2011 to December 2022 were included in the single-center retrospective study. The study population was divided into 2 groups: coils group (n=35) and patent ductus arteriosus (PDA) occluders group (n=66).
Results:
No significant intergroup differences were observed in demographic characteristics except age. The presence of multiple CAF origins (54.3% vs. 4.5%, p<0.001) and multiple draining sites (51.4% vs. 3.0%, p<0.001) were more common in the coils group. In contrast, the presence of aneurysm (72.7% vs. 14.3%, p<0.001), and large fistula (75.8% vs. 37.1%, p<0.001) were more prevalent in the PDA occluders group. The acute procedural success rate of the PDA occluders group was higher compared to that of the coils group (87.9% vs.62.9%, adjusted odds ratio [OR], 7.20; 95% confidence interval, 1.59–32.64; p=0.01).In addition, no significant intergroup differences were noted in both the recanalization rate (7.8% vs. 20%, p=0.107) and the reintervention rate (3.1% vs. 8.6%, p=0.342).
Conclusions
Transcatheter closure of CAFs using PDA occluders was associated with significantly higher acute procedural success rates compared to coil embolization with comparable late outcomes.
5.Analysis of risk factors for mid- and long-term residual after arterial switch operation
Kai LUO ; Xiaoyang ZHANG ; Xiaomin HE ; Yanjun PAN ; Xinrong LIU ; Guocheng SHI ; Zhongqun ZHU ; Jinghao ZHENG ; Wei ZHANG
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(12):1696-1701
Objective To analyze the risk factors and re-intervention strategies for mid- and long-term residual after arterial switch operation (ASO). Methods The clinical data of children with complex congenital heart disease who underwent ASO surgery in Shanghai Children’s Medical Center from January 2006 to June 2022 were retrospectively collected, and the risk factors for mid- and long-term residual after ASO were analyzed. Results A total of 952 children undergoing ASO were enrolled in this study, including 654 males and 298 females with an average age of (102.9±90.1) d and weight of (4.6±1.6) kg. There were 421 patients with D-transposition of the great arteries with intact ventricular septum (D-TGA/IVS), 357 patients with D-transposition of the great arteries with ventricular septal defect (D-TGA/VSD), and 174 patients with right ventricle double outlet combined with subpulmonary ventricular septal defect (Taussig-Bing malformation). Eighty-nine patients died early after the surgery, the mortality rate was 9.3%. The 746 surviving children were regularly followed up after the surgery (follow-up rate 86.4%), with a median follow-up time of 79.4 (12.0-188.0) months. During the follow-up, 53 children underwent surgical re-intervention due to residual, including 33 males and 20 females, with a median age of 62.5 (17.0-214.0) months. The median surgical weight was 19.0 (8.2-86.0) kg, and the mean time of re-intervention was 28.0-170.0 (77.5±45.4) months after the ASO. Residual problems included common trunk and branch stenosis of the pulmonary artery in 23 patients, right ventricular outflow tract (RVOT) obstruction in 11 patients, left ventricular outflow tract obstruction in 6 patients, aortic arch restenosis in 5 patients, aortic insufficiency in 5 patients, residual shunt of ventricular septal defect in 2 patients, and tricuspid valve insufficiency in 1 patient. The early postoperative mortality rate was 3.8% (2/53), with the causes of death being acute myocardial infarction due to coronary artery injury and acute left heart failure, respectively. The mean follow-up time of the surviving children was (52.4±28.6) months, and no mid- and long-term death occurred. Two patients underwent the third operations due to pulmonary restenosis. The multivariate analysis result showed that combined aortic arch surgery and early postoperative RVOT velocity>3 m/s were independent risk factors for mid- and long-term residual after ASO. Conclusion ASO is an ideal procedure for the treatment of D-TGA/IVS, D-TGA/VSD and Taussig-Bing malformations. Combined aortic arch surgery and early postoperative RVOT velocity>3 m/s are independent risk factors for mid- and long-term residual after ASO.
6.Clinical efficacy of right midaxillary straight incision in the treatment of doubly committed subarterial ventricular septal defect: A retrospective cohort study
Bozhong SHI ; Xiaomin HE ; Jinghao ZHENG ; Kai LUO ; Guocheng SHI ; Yanjun, PAN ; Zhongqun ZHU
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(12):1702-1707
Objective To analyze the clinical efficacy of right midaxillary straight incision surgery in the treatment of doubly committed subarterial ventricular septal defect. Methods The clinical data of children with doubly committed subarterial ventricular septal defect who received surgeries in our hospital from August 2020 to July 2023 were analyzed retrospectively. All the children underwent surgical repair and were divided into two groups according to the incision position, including a right midaxillary straight incision group and a median incision group. The outcomes were compared between the two groups. Results A total of 187 patients were enrolled. There were 102 patients in the right midaxillary straight incision group, including 55 males and 47 females with a median age of 26.0 (5.0, 127.0) months and a median weight of 12.5 (5.1, 32.8) kg at surgery. There were 85 patients in the median incision group, including 37 males and 48 females with a median age of 4.0 (2.0, 168.0) months and a median weight of 6.7 (4.8, 53.9) kg at surgery. No mortality occurred in the study. There was no statistical difference between the two groups in the cardiopulmonary bypass time [(50.0±18.4) min vs. (46.1±15.7) min] or aortic cross-clamping time [(31.3±18.6) min vs. (26.3±17.5) min] (P>0.05). Compared to the median incision group, the time from the end of cardiopulmonary bypass to the closure of chest [(22.3±15.6) min vs. (37.1±13.4) min, P<0.001], postoperative hospital stay [(6.9±3.9) d vs. (8.6±3.6) d, P=0.002], the length of incision [(4.3±2.7) cm vs. (8.5±3.2) cm, P<0.001], drainage volume [(79.0±32.2) mL vs. (100.2±43.1) mL, P<0.001], and the pain score on the 2nd and the 3rd day after the operation were statistically better in the right midaxillary straight incision group (P<0.05). The medical experience and incision satisfaction scores at discharge of the right midaxillary straight incision group were higher (P<0.05). During the follow-up of 21.0 (1.0, 35.0) months, no residual shunt was detected and all patients in both groups had a normal cardiac function and mild or less valve regurgitation. Conclusion Compared to the median incision, minimally invasive right midaxillary straight incision for the repair of doubly committed subarterial ventricular septal defect offers comparable efficacy and reliability, with the added advantages of being minimally invasive, cosmetically superior, and promoting faster postoperative recovery.
7.Analysis of the therapeutic effect of asymmetric T 1 pedicle osteotomy in the treatment of stiff cervical thoracic lateral kyphosis deformity
Zhenhui ZHANG ; Qiangqiang PAN ; Long WANG ; Wentao JIANG ; Kai SU ; Peilin LIU ; Wei MEI ; Qingde WANG
Chinese Journal of Surgery 2025;63(5):406-412
Objective:To analyze the clinical efficacy of asymmetric T 1 transpedicular wedge resection Smith-Petersen osteotomy (T 1 SPO) in the treatment of stiff cervical thoracic lateral kyphosis deformity. Methods:This is a retrospective case series study. The clinical data of nine patients with stiff cervical thoracic kyphosis who underwent asymmetric T 1 SPO corrective treatment from June 2012 to October 2022 were collected. There were 7 males and 2 females, aged 45 to 68 years. The surgery time, intraoperative blood loss, and complications were recorded. The chin brow vertical angle (CBVA), cervical thoracic kyphosis Cobb angle, cervical thoracic scoliosis Cobb angle, and cervical thoracic sagittal axis (C 2-T 1 sagittal vertical axis, SVA) before surgery, after surgery, and at the last follow-up were measured and the correction rates were calculate. Results:All 9 patients successfully completed the surgery. The operation time ranged from 245 to 320 minutes, and the intraoperative blood loss was 1 400 to 2 200 ml. All patients were followed up for 24 to 48 months. The preoperative CBVA was 93.7° to 112.0°, which improved to 25.2° to 31.7° at the last follow-up, with an correction rate of 73.4%. The preoperative cervicothoracic kyphosis Cobb angle was -57.0° to -16.6°, which improved to 10.3° to 18.5° at the last follow-up, with an correction rate of 166.7%. The preoperative scoliosis Cobb angle was 13.0° to 16.5°, which improved to 2.2° to 3.8° at the last follow-up, with an correction rate of 84.9%. The preoperative SVA was 7.8 to 12.5 cm, which improved to 4.5 to 6.8 cm at the last follow-up, with an correction rate of 42.3%. One patient experienced numbness and weakness in the left hand after surgery, which recovered after 3 months. One patient had poor healing of the surgical incision, which healed after symptomatic treatment. During the follow-up, the coronal and sagittal balance of all patients was maintained, and no other neurological complications occurred. There were no cases of screw loosening, broken screws, or broken rods, or other internal fixation failures.Conclusion:The application of asymmetric T 1 SPO technique in the treatment of stiff cervical thoracic lateral kyphosis deformity can achieve relatively satisfactory correction effects.
8.The correlation between carotid plaque parameters of dual-energy CT angiography and the occurrence of acute stroke events
He ZHANG ; Juan LONG ; Dexing ZHOU ; Pan YU ; Xuefu XIA ; Cong SONG ; Yong WANG ; He ZHANG ; Lili ZHU ; Chunfeng HU ; Kai XU ; Yankai MENG
Journal of Practical Radiology 2025;41(6):910-914
Objective To investigate the correlation between dual-energy computed tomography angiography(CTA)parameters of carotid plaques and acute stroke events.Methods A retrospective analysis was conducted on the clinical and imaging data of patients who underwent dual-energy head and neck CTA and brain MRI scans.Utilizing the Siemens workstation(Syngo.Via VB40B),region of interest(ROI)were placed on the thickest slice of the carotid plaque in the axial plane to obtain parameters such as fat fraction(FF),virtual non-contrast(VNC)value,iodine concentration(IC),electron density(Rho),effective atomic number(Zeff),dual energy index(DEI),spectral curve,and corresponding CT values at 40 keV(40 keVHU)and 90 keV(90 keVHU).The slope of the energy spectrum curve(λ)was calculated within the 40 keV-90 keV range.Patients with acute cerebral infarction(ACI)in the ipsilateral anterior circulation territory were classified into the ACI group,while those without were classified into the non-acute cerebral infarction(NACI)(NACI group).Qualitative data were analyzed using the x2 test,and quantitative data were analyzed using the t-test.The predictive performance was assessed using the area under the curve(AUC)of the receiver operating characteristic(ROC)curve,and the differences between different ROC curves were compared using the DeLong test.Results A total of 72 patients were included,with 21 in the ACI group and 51 in the NACI group.The mean values of FF,Zeff,and 40 keVHU in the ACI group were greater than those in the NACI group.Statistically significant differences were observed between the groups for Zeff,DEI,40 keVHU,and λ(P<0.05).40 keVHU demonstrated the highest predictive performance,and the AUC,sensitivity,and specificity was 0.789,81.0%,and 74.5%,respectively.A combined variable constructed through logistic regression analysis yielded an AUC,sensitivity,and specificity of 0.796,85.7%,and 70.6%,respectively,with no significant statistical differences compared to single factor variables.Conclusion Dual-energy CTA parameters of carotid plaques may aid in predicting intraplaque hemorrhage(IPH)and the occurrence of acute stroke events.
9.Expression of epitopes of spike protein of porcine epidemic diarrhea virus and screening of its nanobody
Xiangyun HU ; Shaomei CHEN ; Zeyi XUAN ; Menghe LUO ; Rui PAN ; Kai YANG ; Yulian XI ; Yanhong CAO
Chinese Journal of Veterinary Science 2025;45(5):913-918
This study aims to prepare nanobodies for the epitopes of spike protein(S)of porcine ep-idemic diarrhea virus(PEDV),and verify its reactivity.The expression vector pCZN1-SN was con-structed by the prokaryotic expression system,and SN fragment was expressed in prokaryotic ex-pression and purified by Ni-NTA chromatography column.The SN nanobodies were displayed u-sing phage display technology and screened from the natural nanobody library.The results showed that SN fragments with a size of 26 kDa were obtained by prokaryotic induction,and the specific nanobodies were obtained through three rounds screening by phage display technology.One strain with the best reactivity was selected for prokaryotic expression and purified.The nanobodies were obtained with a size of 14 kDa by Western blot and demonstrated to have a good binding ability to PEDV SN protein.In summary,nanobodies with epitope fragments of PEDV S protein were suc-cessfully screened and prepared based on the phage display technology,which provided a new way for the in-depth application of nanobodies.
10.Analysis of related indicators and interventions in apheresis platelet donors with low ferritin
Jie PAN ; Liang GUAN ; Danhong WANG ; Yunming LIN ; Wanping CHEN ; Kai ZHANG ; Mengsha XIANG
Chinese Journal of Blood Transfusion 2025;38(11):1586-1591
Objective: To analyze characteristics of iron-deficient blood donors, implement targeted interventions, and evaluate their effectiveness, thereby providing a reference for formulating blood donor recruitment and care strategies. Methods: Based on serum ferritin (SF) test results, the apheresis platelet donors were divided into the low SF group (n=90; 45 males and 45 females) and the normal SF group (n=651; 510 males and 141 females). The results of related indicators of the two groups were compared and analyzed. Interventions for the low SF group included extending the blood donation interval to at least 45 days (group A) and oral iron supplementation combined with the extended donation interval implemented in group A (group B). Pre-intervention and post-intervention SF results were compared. Results: For both male and female donors, serum iron levels were significantly lower in the low SF group than those of the normal SF group, while the levels of transferrin, unsaturated iron binding capacity (UIBC) and total iron binding capacity (TIBC) were higher in the low SF group compared to the normal SF group. Some indicators related to red blood cells showed changes, with more evident alterations in females than in males. Twenty-eight donors in group A and 39 donors in group B completed the study after intervention. SF value in group A was (18.32±8.09) μg/L at baseline and (26.21±17.30) μg/L after intervention. Similarly, SF value in group B was (15.87±7.69) μg/L at baseline and (26.24±15.55) μg/L after intervention. In both groups, SF values after intervention were significantly higher than baseline values. However, the magnitude of change did not significantly differ between groups A and B. Conclusion: Other related indicators in blood donors with low ferritin have also experienced some changes, suggesting that some blood donors may have entered the stage of iron-deficient erythropoiesis. Extending blood donation interval facilitates the recovery of iron storage in low-ferritin apheresis platelet donors. Blood stations should develop care strategies for apheresis platelet donors, including, at a minimum, the prolonged blood donation interval for donors with low ferritin.

Result Analysis
Print
Save
E-mail