International Journal of Artificial Organs最新文献

{"title":"Analysis of fluid forces impacting on the impeller of a mixed flow blood pump with computational fluid dynamics.","authors":"Abdoulaye Billo Diallo, Hasan Çınar, Rafet Yapıcı","doi":"10.1177/03913988241293003","DOIUrl":"10.1177/03913988241293003","url":null,"abstract":"<p><p>This study presents four different impeller designs to compare hydrodynamic forces. Numerical simulation studies are performed via computational fluid dynamics to specify and investigate the hydraulic forces impacting the impeller of the mixed-flow blood pump with a volute. The design point of this pump is that the flow rate is 5 L/min, the rotational speed is 8000 rpm, and the manometric head is 100 mmHg. The designed impellers are placed in the same volute and simulation studies are performed with the same mesh size (17.3 million cells) of the pumps. The simulation studies have been conducted in setting 1050 kg/m³ blood density, 35 cP fluid viscosity, and SST-kω turbulence model. Additionally, this study examines the changes in hydraulic forces and hydraulic efficiency with fluid viscosity. As a result of experimental simulation studies, the highest hydraulic efficiencies of 40.87% and 39.5% are achieved in the case of the shaftless-grooveless and shafted-grooveless impeller, respectively. The maximum axial forces are obtained from the pump with the shaftless-grooveless impeller. Whereas radial forces, maximum values are calculated in the pump with the shaftless-outer groove impeller for all flow rates. Finally, the wall shear stresses, which are important for blood pump designs, are evaluated and the maximum value of 227 Pa is observed in the pump impeller with a shaftless-grooved.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"894-907"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11613519/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Donnan equilibrium is still valid in high-volume HDF.","authors":"Malte Gross, Alfred Gagel, Andreas Maierhofer","doi":"10.1177/03913988241296699","DOIUrl":"10.1177/03913988241296699","url":null,"abstract":"<p><p>Clinical studies have shown that hemodiafiltration reduces morbidity and mortality of dialysis patients compared to hemodialysis alone. This is attributed to its superior middle molecule clearance compared to standard hemodialysis. However, doubts arose as to whether a high convective flux through the dialyzer membrane has an influence on the equilibrium concentration of small ions, especially that of sodium. Due to the presence of negatively charged impermeable proteins on the blood side, the Gibbs-Donnan effect leads to an asymmetric distribution of membrane permeable ions on both sides of the membrane. In thermodynamic equilibrium, the concentrations of those ions can easily be calculated. However, the convective fluid flow leads to deviations from thermodynamic equilibrium. In this article, the effect of a convective flow on the ion distribution across a semipermeable membrane is analyzed in a theoretical model. Starting from the extended Nernst-Planck equation, including diffusive, convective, and electrostatic effects, a set of differential equations is derived. An approximate solution for flow speeds up to 0.1 ms^-1 as well as a numerical solution are given. The results show that in any practical dialysis setting the convective flow has negligible influence on the electrolyte concentrations.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"867-875"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11613633/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142619695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of eye phantom for optical coherence tomography angiography study.","authors":"B Abira Bright, Vani Damodaran, Thiruvengadam Jayanthi","doi":"10.1177/03913988241289847","DOIUrl":"10.1177/03913988241289847","url":null,"abstract":"<p><p>Tissue phantoms play an important role in validating biomedical imaging techniques. For optical imaging systems such as optical coherence tomography, creating layers of phantoms with different refractive indices is important. This paper explored various phantom materials to create eye-mimicking phantoms. The phantom also included microfluidic channels to mimic vasculature. To verify the optical properties of the created phantom, the transmission and reflection spectroscopy was performed using a photoluminescent spectrometer studying the complete visible and near infrared spectrum. We created a 3D model to house multiple layers that mimicked the retina at one end and the contact lens at the other, representing the anterior segment of the eye. A realistic retinal layer-mimicking, which, among other things, may pave the way for new combined imaging modalities.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"920-927"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142563621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing small diameter tissue engineered vascular grafts with heparin and hepatocyte growth factor: A promising approach.","authors":"Zhiwen Cai, Zhengli Tan, Ran Tian, Peng Miao, Xin Chen, Chenliang Yao, Zhengya Yu","doi":"10.1177/03913988241293011","DOIUrl":"https://doi.org/10.1177/03913988241293011","url":null,"abstract":"<p><p>Currently, there is often a lack of suitable small-caliber graft vessels for treating cardiovascular diseases because of thrombosis and intimal hyperplasia. Tissue engineered vascular grafts (TEVGs) promise a potential solution to this issue. Acellular vascular matrix with good mechanical properties and biocompatibility is commonly used as a tissue engineered scaffold. In this study, acellular rat aortas were preloaded with heparin and hepatocyte growth factor (HGF) to fabricate small diameter TEVGs. In terms of the biomechanical properties, this scaffold was similar to native rat aortas. We implanted this scaffold into a rat abdominal aorta, and the acellular aorta with heparin only was used as control. The patency at 6 months of the two groups was 100%. At 1 month, a complete layer of endothelial cells could be seen on the surface of the vascular lumen of the scaffold with heparin and HGF. The results also showed that the intimal thickness was significantly reduced in the grafts coated with HGF compared to the control grafts. In conclusion, the small-diameter TEVGs constructed by acellular vascular scaffolds coated with heparin and HGF have a promising clinical application prospect.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":"47 12","pages":"928-938"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142768479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Risk factors for acute kidney injury in patients with severe acute pancreatitis: A systematic review and meta-analysis.","authors":"Min Liu, Yuqiong Xiao, Anqiao Wang","doi":"10.1177/03913988241289070","DOIUrl":"10.1177/03913988241289070","url":null,"abstract":"<p><strong>Objective: </strong>This systematic review and meta-analysis aimed to identify the risk factors for acute kidney injury (AKI) in patients with severe acute pancreatitis (SAP).</p><p><strong>Methods: </strong>A comprehensive literature search was conducted using the PubMed, Embase and Cochrane Library databases for case-control studies comparing the clinical characteristics of patients with SAP with and without AKI. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS). Pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated using fixed- or random-effects models, based on heterogeneity.</p><p><strong>Results: </strong>Five studies involving 795 patients with SAP were included, of whom 173 (21.8 %) developed AKI. All studies were of high quality according to the NOS. Among the 17 potential risk factors that were analysed, a history of alcohol consumption (OR = 2.36, 95% CI = 0.54-10.43, <i>p</i> < 0.001), elevated serum amylase (OR = 4.50, 95% CI = 1.77-11.43, <i>p</i> = 0.002) and Acute Physiology and Chronic Health Evaluation II (APACHE II) score (OR = 1.57, 95% CI = 0.49-2.64, <i>p</i> = 0.004) were significantly associated with an increased risk of AKI. However, hypertension (OR = 1.14, 95% CI = 0.60-2.16, <i>p</i> = 0.69) and diabetes (OR = 1.88, 95% CI = 0.51-6.95, <i>p</i> = 0.34) were not significantly associated with AKI risk. Based on funnel plots, no obvious publication bias was detected.</p><p><strong>Conclusions: </strong>A history of alcohol consumption, elevated serum amylase and APACHE II score are significant risk factors for AKI in patients with SAP. For early intervention, clinical physicians should be vigilant about the risk of AKI in patients with SAP with these factors. More high-quality studies are needed to validate these findings and explore other potential risk factors.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"876-884"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic modeling of variable speed left ventricular assist devices coupled to the cardiovascular system.","authors":"Chengxuan Su, Shulei Li, Xingmin Gui, Donghai Jin, Guangmao Liu","doi":"10.1177/03913988241291678","DOIUrl":"10.1177/03913988241291678","url":null,"abstract":"<p><strong>Background: </strong>Most of the modeling of the Left Ventricular Assist Devices (LVADs) coupled with the cardiovascular system is based on the assumption of constant rotational speed. Compared with the traditional inertial model, the validated hysteresis model can take into account the unsteady characteristics of LVADs, but it fails to work under the condition of variable speed modulation.</p><p><strong>Method: </strong>This study takes into consideration the impact of speed variations on the unsteady hysteresis effects. The time constant in the hysteresis model is treated as a time-varying parameter, thereby developing a new model applicable to variable speed modulation. Under sinusoidal speed modulation at various phases, a comparative analysis was undertaken among the steady-state model, inertial model, and the new model. Transient Computational Fluid Dynamics (CFD) simulations and existing experimental results are used for validation.</p><p><strong>Results: </strong>The new model provides a more accurate method for the predicting the characteristics of LVAD in the coupled model under varying pump speeds, and exhibits higher linearity in the work done by the left ventricle and the blood pump, and <math><mrow><msup><mi>R</mi><mn>2</mn></msup><mo>=</mo><mn>0</mn><mo>.</mo><mn>9998</mn></mrow></math>, which is aligning closely with the experimental results. This enhancement renders it applicable for proactive control predictions and passive control validations.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"908-919"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142499875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation between circulating dephosphorylated uncarboxylated matrix Gla protein and vascular calcification in peritoneal dialysis patients.","authors":"Liman Mao, Haole Huang, Meiyang Zhou, Canxin Zhou","doi":"10.1177/03913988241293980","DOIUrl":"10.1177/03913988241293980","url":null,"abstract":"<p><strong>Introduction: </strong>To explore the association between serum Dephosphorylated uncarboxylated matrix Gla protein (dp-ucMGP) and abdominal aortic calcification (AAC) in peritoneal dialysis (PD) patients.</p><p><strong>Methods: </strong>A total 128 PD patients and 120 healthy controls were enrolled into the study. Serum dp-ucMGP was measured by enzyme-linked immunosorbent assay. Abdominal lateral plain radiography was used to evaluate the abdominal aortic calcification score (AACS). PD patients were divided into two groups according to the presence or absence of AAC. The relationships between dp-ucMGP levels and AACS were assessed by Spearman analysis and the value of dp-ucMGP in predicting AAC was evaluated by receiver operating characteristic (ROC).</p><p><strong>Results: </strong>Serum dp-ucMGP in PD patients were significantly higher than controls (<i>p</i> < 0.05). And PD patients with AAC had higher serum dp-ucMGP than that of PD patients without AAC (<i>p</i> < 0.05). The serum dp-ucMGP levels was positively associated with AACS (<i>r</i> = 0.794, <i>p</i> < 0.0001) in PD patients. The multivariate logistic regression analyses showed that serum dp-ucMGP was independent factors of AAC in PD patients (OR = 2.555, 95% CI = 1.415-4.609). The area under ROC curve of dp-ucMGP was 0.9227, the corresponding sensitivity was 0.86, and the specificity was 0.92.</p><p><strong>Conclusion: </strong>Serum dp-ucMGP levels were positively associated with the AACS in PD patients. Higher serum dp-ucMGP level is independently associated with AAC in PD patients.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"885-893"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11613520/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142557796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absolute blood volume and long-term survival in chronic hemodialysis patients.","authors":"Joachim Kron, Stefanie Broszeit, Til Leimbach, Susanne Kron","doi":"10.1177/03913988241296405","DOIUrl":"10.1177/03913988241296405","url":null,"abstract":"<p><p>Current online hemodiafiltration devices can be used to determine the absolute blood volume in clinical practice using the dialysate bolus method. Most of publications on this method have focused on preventing intradialytic complications. The influence of absolute blood volume on long-term prognosis has not been reported yet. A total of 79 participants in a previous study about absolute blood volume were followed for 5 years. Patients with a specific blood volume above (<i>n</i> = 45) and below 75 ml/kg (<i>n</i> = 34) respectively were compared with regard to survival using Kaplan-Meier analysis. Patients with a specific blood volume below 75 ml/kg had a significantly higher overall 5-year survival rate than patients above 75 ml/kg (70% vs 39%, <i>p</i> = 0.0233). In patients without cardiac dysfunction, there were no significant differences in 5-year survival between a specific blood volume below or above 75 ml/kg (66% vs 51%). A specific blood volume above 75 ml/kg was associated with an increased mortality in patients with mildly impaired left-ventricular systolic ejection fraction of 40%-59%, whereas in patients with normal blood volume this cardiac impairment did not impact mortality (22% vs 90% 5-year survival, <i>p</i> = 0.0036). This demonstrates the significance of optimum volume control for long-term survival particularly in cases of reduced cardiac function.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"939-942"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11613524/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>N</i>-succinyl chitosan-oxidized hyaluronic acid-calcium chloride hydrogel as hemostatic agent.","authors":"Prihartini Widiyanti, Wahyu Addin Pratama","doi":"10.1177/03913988241280202","DOIUrl":"10.1177/03913988241280202","url":null,"abstract":"<p><p>This study aims to develop an effective hemostatic agent in the management of irregular and deep wounds that can accelerate the hemostatic process. The background revealed the importance of rapid treatment of bleeding, with data showing a significant risk of death from blood loss. Current treatments use conventional hemostatic dressings, but they are less effective on irregular surgical wounds. Several studies have developed chitosan, hyaluronic acid, and CaCl₂-based hydrogels that have hemostatic, regenerative, and antibacterial potential. However, there is still a need to develop hydrogels that are thermally stable, biocompatible, and able to accelerate the hemostatic process. This research will synthesize self-healing hydrogels by modifying the structure of chitosan and hyaluronic acid, using a certain ratio of ingredients. The research procedure was carried out with the preparation of <i>N</i>-succinyl chitosan (NSC) and oxidized hyaluronic acid (OHA) as the main ingredients which were then added with CaCl₂ to produce self-healing injectable hydrogel. First, NSC and OHA were dissolved in phosphate buffer solution (pH = 7.4 PBS) to obtain 60 mg/mL NSC and OHA solution respectively. Calcium chloride was then dissolved in water to obtain 120 mg/mL CaCl₂ solution. Then NSC-OHA-CaCl₂-based hydrogels were synthesized through rapid and full solution mixing above room temperature with the composition of (1-1-0.1; 1-1-0.2; and 1-1-0.3). The targeted findings of this research are sample characterization results that explain and prove the best NSC-OHA-CaCl₂ composition variation that can be used as a hemostatic agent for irregular and deep wounds. The results of the analysis obtained FTIR test data with the formation of C = N functional groups in the four samples; blood clotting time test for sample K0, K1, K2, and K3 with time 4.6, 3.33, 2.66, and 1 s; MTT assay with cell viability percentage of 77.82% for sample K0, 84.18% for sample K1, 89.30% for sample K2, and 89.50% for sample K3; hemolysis index percentage of 0.373% for sample K0, 0.555% for sample K1, 0.625% for sample K2, and 0.201% for sample K3; Viscosity test obtained data of 13 dPa s for sample K0, 15 dPa s for sample K1, 16 dPa s for sample K2, and 18 dPa. The injectability test yielded an injectability percentage of 96.84% for sample K0, 95.03% for sample K1, 94.78% dPa s for sample K2, and 94.61% for sample K3; the DSC test results of the four samples obtained a transition peak at the exothermic peak of 62.27°C for sample K0, 70.23°C for sample K1, 73.77°C for sample K2, and 74.49°C for sample K3; and the characteristic graph of the TGA test results, the weight profile of the hydrogel during heating which showed a mass change of 21.64 mg in sample K0, 16.89 mg in sample K1, 15.37 mg in sample K2, and 11.43 mg in sample K3 (°C).</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"847-857"},"PeriodicalIF":16.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142365166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of statins on incidence of gastrointestinal bleeding events among patients with continuous-flow left ventricular assist devices.","authors":"Hala Halawi, Jesse E Harris, Duc T Nguyen, Edward A Graviss, David Putney, Mahwash Kassi","doi":"10.1177/03913988241286437","DOIUrl":"10.1177/03913988241286437","url":null,"abstract":"<p><strong>Background: </strong>Patients with continuous flow left ventricular assist devices (CF-LVADs) are at increased risk of gastrointestinal bleeding (GIB). Statins are commonly prescribed in LVAD patients for cardiovascular disease prevention. However, their impact on GIB events is controversial. Importantly, literature regarding statins impact on GIB in CF-LVAD patients is lacking.</p><p><strong>Methods: </strong>A single-center, retrospective review of adult patients who underwent CF-LVAD implantation between May 2016 and January 2020 was performed. Patients were categorized based on statin use throughout the study period. The primary outcome was the composite of arteriovenous malformation confirmed GIB and major GIB events for up to 1-year post-LVAD implantation.</p><p><strong>Results: </strong>Of 123 patients included in the final analysis, 66 (54%) received statin therapy during the study period. No difference was observed in the primary outcome between the statin and control groups (RR: 1.73; 95% CI: 0.75-3.98; <i>p</i>=0.20). Multivariable Cox regression revealed that older age and higher baseline creatinine were associated with an increased risk of GIB within 1-year of CF-LVAD implantation.</p><p><strong>Conclusion: </strong>Among patients with CF-LVADs, there was no significant difference in the incidence of major GIB events associated with the use of statin therapy. Further studies are needed to assess whether a true association exists.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":" ","pages":"826-835"},"PeriodicalIF":16.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142464547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}