1.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.
2.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.
3.The mechanism of Laggerae Herba in improving chronic heart failure by inhibiting ferroptosis through the Nrf2/SLC7A11/GPX4 signaling pathway
Jinling XIAO ; Kai HUANG ; Xiaoqi WEI ; Xinyi FAN ; Wangjing CHAI ; Jing HAN ; Kuo GAO ; Xue YU ; Fanghe LI ; Shuzhen GUO
Journal of Beijing University of Traditional Chinese Medicine 2025;48(3):343-353
Objective:
To investigate the role and mechanism of the heat-clearing and detoxifying drug Laggerae Herba in regulating the nuclear factor-erythroid 2-related factor-2(Nrf2)/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway to inhibit ferroptosis and improve chronic heart failure induced by transverse aortic arch constriction in mice.
Methods:
Twenty-four male ICR mice were divided into the sham (n=6) and transverse aortic arch constriction groups (n=18) according to the random number table method. The transverse aortic arch constriction group underwent transverse aortic constriction surgery to establish models. After modeling, the transverse aortic arch constriction group was further divided into the model, captopril, and Laggerae Herba groups according to the random number table method, with six mice per group. The captopril (15 mg/kg) and Laggerae Herba groups (1.95 g/kg) received the corresponding drugs by gavage, whereas the sham operation and model groups were administered the same volume of ultrapure water by gavage once a day for four consecutive weeks. After treatment, the cardiac function indexes of mice in each group were detected using ultrasound. The heart mass and tibia length were measured to calculate the ratio of heart weight to tibia length. Hematoxylin and eosin staining were used to observe the pathological changes in myocardial tissue. Masson staining was used to observe the degree of myocardial fibrosis. Wheat germ agglutinin staining was used to observe the degree of myocardial cell hypertrophy. Prussian blue staining was used to observe the iron deposition in myocardial tissue. An enzyme-linked immunosorbent assay was used to detect the amino-terminal pro-brain natriuretic peptide (NT-proBNP) and glutathione (GSH) contents in mice serum. Colorimetry was used to detect the malondialdehyde (MDA) content in mice serum. Western blotting was used to detect the Nrf2, GPX4, SLC7A11, and ferritin heavy chain 1 (FTH1) protein expressions in mice cardiac tissue.
Results:
Compared with the sham group, in the model group, the ejection fraction (EF) and fractional shortening (FS) of mice decreased, the left ventricular end-systolic volume (LVESV) and left ventricular end-systolic diameter (LVESD) increased, the left ventricular anterior wall end-systolic thickness (LVAWs) and left ventricular posterior wall end-systolic thickness (LVPWs) decreased, the ratio of heart weight to tibia length increased, the myocardial tissue morphology changed, myocardial fibrosis increased, the cross-sectional area of myocardial cells increased, iron deposition appeared in myocardial tissue, the serum NT-proBNP and MDA levels increased, the GSH level decreased, and Nrf2, GPX4, SLC7A11, and FTH1 protein expressions in cardiac tissue decreased (P<0.05). Compared with the model group, in the captopril and Laggerae Herba groups, the EF, FS, and LVAWs increased, the LVESV and LVESD decreased, the ratio of heart weight to tibia length decreased, the myocardial cells were arranged neatly, the degree of myocardial fibrosis decreased, the cross-sectional area of myocardial cells decreased, the serum NT-proBNP level decreased, and the GSH level increased. Compared with the model group, the LVPWs increased, the iron deposition in myocardial tissue decreased, the serum MDA level decreased, and Nrf2, GPX4, SLC7A11, and FTH1 protein expressions in cardiac tissue increased (P<0.05) in the Laggerae Herba group.
Conclusion
Laggerae Herba improves the cardiac function of mice with chronic heart failure caused by transverse aortic arch constriction, reduces the pathological remodeling of the heart, and reduces fibrosis. Its mechanism may be related to Nrf2/SLC7A11/GPX4 pathway-mediated ferroptosis.
4.Combination of CT/MRI LI-RADS With Second-Line Contrast-Enhanced Ultrasound Using Sulfur Hexafluoride or Perfluorobutane for Diagnosing Hepatocellular Carcinoma in High-Risk Patients
Yu LI ; Sheng LI ; Qing LI ; Kai LI ; Jing HAN ; Siyue MAO ; Xiaohong XU ; Zhongzhen SU ; Yanling ZUO ; Shousong XIE ; Hong WEN ; Xuebin ZOU ; Jingxian SHEN ; Lingling LI ; Jianhua ZHOU
Korean Journal of Radiology 2025;26(4):346-359
Objective:
The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB).
Materials and Methods:
This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB.
Results:
In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%).
Conclusion
The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.
5.Combination of CT/MRI LI-RADS With Second-Line Contrast-Enhanced Ultrasound Using Sulfur Hexafluoride or Perfluorobutane for Diagnosing Hepatocellular Carcinoma in High-Risk Patients
Yu LI ; Sheng LI ; Qing LI ; Kai LI ; Jing HAN ; Siyue MAO ; Xiaohong XU ; Zhongzhen SU ; Yanling ZUO ; Shousong XIE ; Hong WEN ; Xuebin ZOU ; Jingxian SHEN ; Lingling LI ; Jianhua ZHOU
Korean Journal of Radiology 2025;26(4):346-359
Objective:
The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB).
Materials and Methods:
This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB.
Results:
In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%).
Conclusion
The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.
6.Combination of CT/MRI LI-RADS With Second-Line Contrast-Enhanced Ultrasound Using Sulfur Hexafluoride or Perfluorobutane for Diagnosing Hepatocellular Carcinoma in High-Risk Patients
Yu LI ; Sheng LI ; Qing LI ; Kai LI ; Jing HAN ; Siyue MAO ; Xiaohong XU ; Zhongzhen SU ; Yanling ZUO ; Shousong XIE ; Hong WEN ; Xuebin ZOU ; Jingxian SHEN ; Lingling LI ; Jianhua ZHOU
Korean Journal of Radiology 2025;26(4):346-359
Objective:
The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB).
Materials and Methods:
This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB.
Results:
In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%).
Conclusion
The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.
7.Advances in deep learning algorithms for brain age prediction
Jianhao LIAO ; Kai WU ; Jiayuan HUANG ; Rui HAN ; Runlin PENG ; Jing ZHOU
Chinese Journal of Medical Physics 2025;42(1):122-127
Brain age prediction is of great significance to the in-depth understanding of individual neurodevelopment,early diagnosis of neuropsychiatric disorders,and formulation of personalized treatment plans. With the continuous advancement of deep learning,more and more researches focus on using such algorithms to predict brain age. Compared with traditional regression algorithms,deep learning which has the advantages of complex pattern learning,end-to-end learning and high adaptability can more accurately reveal the neuropathological mechanisms of neuropsychiatric disorders,and provide more precise tools for clinical assessment,assisted diagnosis and prognosis prediction. Herein the study reviews the recent advances in the application of deep learning algorithms in brain age prediction,introduces the achievements in deep learning model optimization,multimodal data inputs and interpretability studies for brain age prediction,discusses the methods for the establishment of integrated deep learning architectures and the future challenges of developing unified benchmarking,and provides an outlook on the application of deep learning in brain age prediction.
8.Expert consensus on integrated diagnosis and treatment techniques for oropharyngeal squamous cell carcinoma
Wei SHANG ; Haoyue XU ; Zongxuan HE ; Xiaoying LI ; Haijun LU ; Xiaohong ZHAN ; Dapeng HAO ; Yan SUN ; Wei GUO ; Zhangui TANG ; Guoxin REN ; Zhijun SUN ; Jian MENG ; Jie ZHANG ; Jichen LI ; Yue HE ; Chunjie LI ; Jianhua WEI ; Lizheng QIN ; Yaowu YANG ; Qing XI ; Wei WU ; Kai YANG ; Bing HAN ; Lingxue BU ; Shuangyi WANG ; Kai SONG ; Jiaqi ZHU ; Hongyu HAN ; Yu KONG ; Jieying LI ; Man HU ; Mingjin XU ; Moyi SUN
Journal of Practical Stomatology 2025;41(6):725-736
In recent decades,the incidence of human papillomavirus(HPV)-associated oropharyngeal squamous cell carcinoma(OPSCC)has shown a marked increase.Significant changes have also occurred in the OPSCC diagnosis and treatment paradigm.Deter-mining HPV status prior to treatment is now essential,and radiotherapy/chemotherapy,immunotherapy,and minimally invasive surgical techniques have progressively emerged as key modalities for managing OPSCC.However,alongside these paradigm shifts,a comprehen-sive technical consensus guiding the entire diagnostic and therapeutic process for OPSCC patients is currently lacking.Given China's large population base and the rising incidence of OPSCC,an expert panel convened to develop a clinical technical consensus on OPSCC diagno-sis and management tailored to China's specific context.This consensus aims to further enhance and standardize understanding of OPSCC management techniques among relevant healthcare professionals.
9.Novel Miniature Mobile Integrated Operating Cabin-Theatre: A Clinical Application
Jie ZHANG ; Ming LIANG ; Jingyang SUN ; Xiaozeng WANG ; Yang LI ; Chengfei PENG ; Zhenyang LIANG ; Quanmin JING ; Ning SUN ; Kai XU ; Fei LI ; Yaling HAN
Cardiology Discovery 2025;05(3):202-207
Objective::This study aimed to investigate the feasibility, efficacy, and safety of using a miniature mobile integrated cabin-theatre equipped with angiography and surgical operating room capabilities, and to explore its therapeutic scope, effectiveness, and operational mode.Methods::A miniature mobile integrated operating cabin-theatre was deployed across 15 hospitals in 15 cities or counties in China from April 2012 to November 2024. The interventions and outcomes of interventional and minimally invasive surgical procedures were prospectively observed and evaluated; perioperative complications were documented, and the stability, adaptability, and mobility of the integrated system were assessed.Results::A total of 133 procedures were successfully performed, 130 of which were interventional and 3 minimally invasive. The angiography machine showed good imaging performance without any equipment failures, loosening, or damage, with normal chamber unfolding. One patient experienced a fever the day after laparoscopy, while none of the other patients exhibited perioperative complications such as infection, surgical site bleeding/hematoma, or reperfusion arrhythmia. The instrument was easily manipulated, aligning with the needs of clinical intervention and surgery, and was perceived by patients as being a comfortable environment, with no psychological or other obvious discomfort.Conclusions::The miniature mobile integrated cabin-theatre, comprising an angiography machine and an operating room, allows interventional or minimally invasive surgical procedures to be performed smoothly and safely. It can also provide rapid and efficient on-site treatment of acute and critical illnesses across multiple body systems, including the cardiovascular, cerebrovascular, and gastrointestinal systems.
10.Characterization of a Physiological Mock Circulation System Based on Capillary-Bundle Resistance Element
Dengji LIU ; Xinke CHEN ; Lisha HAN ; Zhen CAO ; Qingzhuo CHI ; Kai YIN ; Ying HE
Journal of Medical Biomechanics 2025;40(5):1256-1264
Objective To investigate the feasibility of parallel capillary bundle arrays for physiomimetic impedance modeling and establish a parametric quantification framework,thereby providing a customizable impedance characterization methodology for diverse in-vitro mock circulation researches.Methods Based on the parallel flow resistance and Poiseuille equation,a tube resistance element with multiple parallel-aligned capillary glass tubes was designed and fabricated.The resistance values of the capillary-bundle and a ball valve were measured through constant flow experiments analogous to electrical resistance measurement method.Moreover,a simple lumped-parameter mock circulation loop was constructed and the pressure and flow rate for each node of the loop were measured under different input flow waveforms.An 0D-Windkessel model corresponding to the experiment was developed.The impedance and compliance were adjusted to match the simulated and experimental pressure and flow waveforms.The accuracy of the capillary bundle impedance in pulsatile experiments was verified by using the computational resistance values.Results The constant-flow impedance calibration experiments revealed that the capillary bundle impedance remained unaffected by flow rate variations over a wide flow range.When the capillary bundle impedance was integrated into the pulsatile circulatory system and the same impedance value obtained from the constant-flow calibration was applied in the computational model,the resulting pressure and flow waveforms showed good agreement with those measured in the pulsatile experiments.However,when the ball valves with nominally identical impedance values were inserted in the pulsatile system,the calculated impedance exhibited a two-fold difference,and significant discrepancies were observed between the simulated and experimental terminal flow waveforms.Conclusions The capillary bundle impedance maintains a constant value regardless of flow rate variations.Once the calibrated resistance value is determined through constant flow experiments,it can be directly applied to pulsatile systems.This approach can provide quantitative pulsatile flow conditions for testing various medical devices.


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