Cardiovascular Engineering and Technology最新文献

{"title":"Quantification of Mechanical Characteristics of Conventional Steerable Ablation Catheters for Treatment of Atrial Fibrillation Using a Heart Phantom.","authors":"Jacob Miller,&nbsp;Alykhan Sewani,&nbsp;Jeffrey Rezazada,&nbsp;Yara Alawneh,&nbsp;Pedram Kazemian,&nbsp;Maria Terricabras,&nbsp;Graham Wright,&nbsp;M Ali Tavallaei","doi":"10.1007/s13239-023-00662-6","DOIUrl":"https://doi.org/10.1007/s13239-023-00662-6","url":null,"abstract":"<p><strong>Purpose: </strong>Accurate and reliable catheter navigation is important in formation of adequate lesions during radiofrequency cardiac catheter ablation. To inform future device design efforts and to characterize the limitations of conventional devices, the focus of this study is to assess and quantify the mechanical performance of manual ablation catheters for pulmonary vein isolation procedures within a phantom heart model.</p><p><strong>Methods: </strong>We measured three important metrics: accuracy of catheter tip navigation to target anatomical landmarks at the pulmonary veins (PVs), orientation of the catheter relative to the tissue at the targets, and the delivered force values and their stability and variations at those targets. A stereovision system was used for navigational guidance and to measure the catheter's tip position and orientation relative to the targets. To measure force, piezoelectric sensors were used which were integrated at the targets, whereby operators were instructed to stabilize the catheter to achieve a chosen reference force value.</p><p><strong>Results: </strong>An overall positioning accuracy of 1.57 ± 1.71 mm was achieved for all targets. No statistical significance was observed in position accuracy between the right and left PVs (p = 0.5138). The orientation of the catheter relative to tissue surface was 41° ± 21° with no statistical significance between targets. The overall force stability was 41 ± 6 g with higher difficulty in force stabilization in the right compared to the left PV (40 ± 8 vs. 43 ± 2 g, p < 0.0001).</p><p><strong>Conclusion: </strong>Based on our results, future improvements to manual catheter navigation for ablation should focus on improving device performance in orientation control and improved force stability.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10029128","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":"The Comparative Method Based on Coronary Computed Tomography Angiography for Assessing the Hemodynamic Significance of Coronary Artery Stenosis.","authors":"Zbigniew Małota,&nbsp;Wojciech Sadowski,&nbsp;Konrad Pieszko,&nbsp;Rafał Zimoląg,&nbsp;Filip Czekała,&nbsp;Renata Malinowska,&nbsp;Jarosław Hiczkiewicz","doi":"10.1007/s13239-023-00658-2","DOIUrl":"https://doi.org/10.1007/s13239-023-00658-2","url":null,"abstract":"<p><strong>Purpose: </strong>An important aspect in the prevention and treatment of coronary artery disease is the functional evaluation of narrowed blood vessels. Medical image-based Computational Fluid Dynamic methods are currently increasingly being used in the clinical setting for flow studies of cardio vascular system. The aim of our study was to confirm the feasibility and functionality of a non-invasive computational method providing information about hemodynamic significance of coronary stenosis.</p><p><strong>Methods: </strong>A comparative method was used to simulate the flow energy losses in real (stenotic) and reconstructed models without (reference) stenosis of the coronary arteries under stress test conditions, i.e. for maximum blood flow and minimal, constant vascular resistance. In addition to the absolute pressure drop in the stenotic arteries (FFR_sten) and in the reconstructed arteries (FFR_rec), a new energy flow reference index (EFR) was also defined, which expresses the total pressure changes caused by stenosis in relation to the pressure changes in normal coronary arteries, which also allows a separate assessment of the haemodynamic significance of the atherosclerotic lesion itself. The article presents the results obtained from flow simulations in coronary arteries, reconstructed on the basis of 3D segmentation of cardiac CT images of 25 patients from retrospective data collection, with different degrees of stenoses and different areas of their occurrence.</p><p><strong>Results: </strong>The greater the degree of narrowing of the vessel, the greater drop of flow energy. Each parameter introduces an additional diagnostic value. In contrast to FFR_sten, the EFR indices that are calculated on the basis of a comparison of stenosed and reconstructed models, are associated directly with localization, shape and geometry of stenosis only. Both FFR_sten and EFR showed very significant positive correlation (P < 0.0001) with coronary CT angiography-derived FFR, with a correlation coefficient of 0.8805 and 0.9011 respectively.</p><p><strong>Conclusion: </strong>The study presented promising results of non-invasive, comparative test to support of prevention of coronary disease and functional evaluation of stenosed vessels.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10412489/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10404119","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":"In Silico Evaluation of a Self-powered Venous Ejector Pump for Fontan Patients.","authors":"Reza Rasooli,&nbsp;Knut Erik Teigen Giljarhus,&nbsp;Aksel Hiorth,&nbsp;Ingunn Westvik Jolma,&nbsp;Jan Ludvig Vinningland,&nbsp;Charlotte de Lange,&nbsp;Henrik Brun,&nbsp;Henrik Holmstrom","doi":"10.1007/s13239-023-00663-5","DOIUrl":"https://doi.org/10.1007/s13239-023-00663-5","url":null,"abstract":"<p><strong>Purpose: </strong>The Fontan circulation carries a dismal prognosis in the long term due to its peculiar physiology and lack of a subpulmonic ventricle. Although it is multifactorial, elevated IVC pressure is accepted to be the primary cause of Fontan's high mortality and morbidity. This study presents a self-powered venous ejector pump (VEP) that can be used to lower the high IVC venous pressure in single-ventricle patients.</p><p><strong>Methods: </strong>A self-powered venous assist device that exploits the high-energy aortic flow to lower IVC pressure is designed. The proposed design is clinically feasible, simple in structure, and is powered intracorporeally. The device's performance in reducing IVC pressure is assessed by conducting comprehensive computational fluid dynamics simulations in idealized total cavopulmonary connections with different offsets. The device was finally applied to complex 3D reconstructed patient-specific TCPC models to validate its performance.</p><p><strong>Results: </strong>The assist device provided a significant IVC pressure drop of more than 3.2 mm Hg in both idealized and patient-specific geometries, while maintaining a high systemic oxygen saturation of more than 90%. The simulations revealed no significant caval pressure rise (< 0.1 mm Hg) and sufficient systemic oxygen saturation (> 84%) in the event of device failure, demonstrating its fail-safe feature.</p><p><strong>Conclusions: </strong>A self-powered venous assist with promising in silico performance in improving Fontan hemodynamics is proposed. Due to its passive nature, the device has the potential to provide palliation for the growing population of patients with failing Fontan.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10412470/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10385096","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":"An IMU-Based Wearable System for Respiratory Rate Estimation in Static and Dynamic Conditions.","authors":"Alessandra Angelucci,&nbsp;Andrea Aliverti","doi":"10.1007/s13239-023-00657-3","DOIUrl":"https://doi.org/10.1007/s13239-023-00657-3","url":null,"abstract":"<p><strong>Purpose: </strong>Breathing parameters change with activity and posture, but currently available solutions can perform measurements only during static conditions.</p><p><strong>Methods: </strong>This article presents an innovative wearable sensor system constituted by three inertial measurement units to simultaneously estimate respiratory rate (RR) in static and dynamic conditions and perform human activity recognition (HAR) with the same sensing principle. Two units are aimed at detecting chest wall breathing-related movements (one on the thorax, one on the abdomen); the third is on the lower back. All units compute the quaternions describing the subject's movement and send data continuously with the ANT transmission protocol to an app. The 20 healthy subjects involved in the research (9 men, 11 women) were between 23 and 54 years old, with mean age 26.8, mean height 172.5 cm and mean weight 66.9 kg. Data from these subjects during different postures or activities were collected and analyzed to extract RR.</p><p><strong>Results: </strong>Statistically significant differences between dynamic activities (\"walking slow\", \"walking fast\", \"running\" and \"cycling\") and static postures were detected (p < 0.05), confirming the obtained measurements are in line with physiology even during dynamic activities. Data from the reference unit only and from all three units were used as inputs to artificial intelligence methods for HAR. When the data from the reference unit were used, the Gated Recurrent Unit was the best performing method (97% accuracy). With three units, a 1D Convolutional Neural Network was the best performing (99% accuracy).</p><p><strong>Conclusion: </strong>Overall, the proposed solution shows it is possible to perform simultaneous HAR and RR measurements in static and dynamic conditions with the same sensor system.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970135/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10031336","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":"Electrocardiogram to Determine Mitral and Aortic Valve Opening and Closure.","authors":"M Rifqi Aufan,&nbsp;Zachary T Jost,&nbsp;Neal J Miller,&nbsp;Oleg F Sharifov,&nbsp;Himanshu Gupta,&nbsp;Gilbert J Perry,&nbsp;J Michael Wells,&nbsp;Thomas S Denney,&nbsp;Steven G Lloyd","doi":"10.1007/s13239-023-00664-4","DOIUrl":"https://doi.org/10.1007/s13239-023-00664-4","url":null,"abstract":"<p><strong>Purpose: </strong>Knowledge of the timing of cardiac valve opening and closing is important in cardiac physiology. The relationship between valve motion and electrocardiogram (ECG) is often assumed, however is not clearly defined. Here we investigate the accuracy of cardiac valve timing estimated using only the ECG, compared to Doppler echocardiography (DE) flow imaging as the gold standard.</p><p><strong>Methods: </strong>DE was obtained in 37 patients with simultaneous ECG recording. ECG was digitally processed and identifiable features (QRS, T, P waves) were examined as potential reference points to determine opening and closure of aortic and mitral valves, as compared to DE outflow and inflow measurement. Timing offset of the cardiac valves opening and closure between ECG features and DE was measured from derivation set (n = 19). The obtained mean offset in combination with the ECG features model was then evaluated on a validation set (n = 18). Using the same approach, additional measurement was also done for the right sided valves.</p><p><strong>Results: </strong>From the derivation set, we found a fixed offset of 22 ± 9 ms, 2 ± 13 ms, 90 ± 26 ms, and - 2 ± - 27 ms when comparing S to aortic valve opening, T_end to aortic valve closure, T_end to mitral valve opening, and R to mitral valve closure respectively. Application of this model to the validation set showed good estimation of aortic and mitral valve opening and closure timing value, with low model absolute error (median of the mean absolute error of the four events = 19 ms compared to the gold standard DE measurement). For the right-sided (tricuspid and pulmonic) valves in our patient set, there was considerably higher median of the mean absolute error of 42 ms for the model.</p><p><strong>Conclusion: </strong>ECG features can be used to estimate aortic and mitral valve timings with good accuracy as compared to DE, allowing useful hemodynamic information to be derived from this easily available test.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10404132","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":"Acute Mechanical Consequences of Vessel-Specific Coronary Bypass Combinations.","authors":"Colton J Kostelnik,&nbsp;Mary K Gale,&nbsp;Kiersten J Crouse,&nbsp;Tarek Shazly,&nbsp;John F Eberth","doi":"10.1007/s13239-023-00661-7","DOIUrl":"https://doi.org/10.1007/s13239-023-00661-7","url":null,"abstract":"<p><strong>Purpose: </strong>Premature coronary artery bypass graft (CABG) failure has been linked to geometric, mechanical, and compositional discrepancies between host and graft tissues. Acute hemodynamic disturbances and the introduction of wall stress gradients trigger a myriad of mechanobiological processes at the anastomosis that can be associated with restenosis and graft failure. Although the origins of coronary artery disease dictate the anastomotic target, an opportunity exists for graft-vessel optimization through rationale graft selection.</p><p><strong>Methods: </strong>Here we explored the four distinct regions of the left (L) and right (R) ITA (1 = proximal, 2 = submuscular, 3 = middle, 4 = distal), and four common target vessels in the coronary circulation including the proximal and distal left anterior descending (PLAD & DLAD), right coronary (RCA), and left circumflex (LCX) arteries. Benchtop biaxial mechanical data was used to acquire constitutive model parameters of these tissues and enable vessel-specific computational models to elucidate the mechanical consequences of 32 unique graft-target combinations.</p><p><strong>Results: </strong>Simulations revealed the maximum principal wall stresses for the PLAD, RCA, and LCX occurred when anastomosed with LITA₁, and the maximum flow-induced shear stress occurred with LITA₄. The DLAD, on the other hand, reached stress maximums when anastomosed to LITA₄. Using a normalized objective function of simulation output variables, we found LITA₂ to be the best graft choice for both LADs, RITA₃ for the RCA, and LITA₃ for the LCX.</p><p><strong>Conclusion: </strong>Although mechanical compatibility is just one of many factors determining bypass graft outcomes, our data suggests improvements can be made to the grafting process through vessel-specific regional optimization.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10029129","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":"Optimization of 4D Flow MRI Spatial and Temporal Resolution for Examining Complex Hemodynamics in the Carotid Artery Bifurcation.","authors":"Retta El Sayed,&nbsp;Alireza Sharifi,&nbsp;Charlie C Park,&nbsp;Diogo C Haussen,&nbsp;Jason W Allen,&nbsp;John N Oshinski","doi":"10.1007/s13239-023-00667-1","DOIUrl":"10.1007/s13239-023-00667-1","url":null,"abstract":"<p><strong>Background: </strong>Three-dimensional, ECG-gated, time-resolved, three-directional, velocity-encoded phase-contrast MRI (4D flow MRI) has been applied extensively to measure blood velocity in great vessels but has been much less used in diseased carotid arteries. Carotid artery webs (CaW) are non-inflammatory intraluminal shelf-like projections into the internal carotid artery (ICA) bulb that are associated with complex flow and cryptogenic stroke.</p><p><strong>Purpose: </strong>Optimize 4D flow MRI for measuring the velocity field of complex flow in the carotid artery bifurcation model that contains a CaW.</p><p><strong>Methods: </strong>A 3D printed phantom model created from computed tomography angiography (CTA) of a subject with CaW was placed in a pulsatile flow loop within the MRI scanner. 4D Flow MRI images of the phantom were acquired with five different spatial resolutions (0.50-2.00  mm³) and four different temporal resolutions (23-96 ms) and compared to a computational fluid dynamics (CFD) solution of the flow field as a reference. We examined four planes perpendicular to the vessel centerline, one in the common carotid artery (CCA) and three in the internal carotid artery (ICA) where complex flow was expected. At these four planes pixel-by-pixel velocity values, flow, and time average wall shear stress (TAWSS) were compared between 4D flow MRI and CFD.</p><p><strong>Hypothesis: </strong>An optimized 4D flow MRI protocol will provide a good correlation with CFD velocity and TAWSS values in areas of complex flow within a clinically feasible scan time (~ 10 min).</p><p><strong>Results: </strong>Spatial resolution affected the velocity values, time average flow, and TAWSS measurements. Qualitatively, a spatial resolution of 0.50  mm³ resulted in higher noise, while a lower spatial resolution of 1.50-2.00  mm³ did not adequately resolve the velocity profile. Isotropic spatial resolutions of 0.50-1.00  mm³ showed no significant difference in total flow compared to CFD. Pixel-by-pixel velocity correlation coefficients between 4D flow MRI and CFD were > 0.75 for 0.50-1.00  mm³ but were < 0.5 for 1.50 and 2.00  mm³. Regional TAWSS values determined from 4D flow MRI were generally lower than CFD and decreased at lower spatial resolutions (larger pixel sizes). TAWSS differences between 4D flow and CFD were not statistically significant at spatial resolutions of 0.50-1.00  mm³ but were different at 1.50 and 2.00 mm³. Differences in temporal resolution only affected the flow values when temporal resolution was > 48.4 ms; temporal resolution did not affect TAWSS values.</p><p><strong>Conclusion: </strong>A spatial resolution of 0.74-1.00  mm³ and a temporal resolution of 23-48 ms (1-2 k-space segments) provides a 4D flow MRI protocol capable of imaging velocity and TAWSS in regions of complex flow within the carotid bifurcation at a clini","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10524741/pdf/nihms-1901196.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10028851","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":"An Image-Based Computational Fluid Dynamics Study of Mitral Regurgitation in Presence of Prolapse.","authors":"Lorenzo Bennati,&nbsp;Christian Vergara,&nbsp;Vincenzo Giambruno,&nbsp;Ivan Fumagalli,&nbsp;Antonio Francesco Corno,&nbsp;Alfio Quarteroni,&nbsp;Giovanni Puppini,&nbsp;Giovanni Battista Luciani","doi":"10.1007/s13239-023-00665-3","DOIUrl":"https://doi.org/10.1007/s13239-023-00665-3","url":null,"abstract":"<p><strong>Purpose: </strong>In this work we performed an imaged-based computational study of the systolic fluid dynamics in presence of mitral valve regurgitation (MVR). In particular, we compared healthy and different regurgitant scenarios with the aim of quantifying different hemodynamic quantities.</p><p><strong>Methods: </strong>We performed computational fluid dynamic (CFD) simulations in the left ventricle, left atrium and aortic root, with a resistive immersed method, a turbulence model, and with imposed systolic wall motion reconstructed from Cine-MRI images, which allowed us to segment also the mitral valve. For the regurgitant scenarios we considered an increase of the heart rate and a dilation of the left ventricle.</p><p><strong>Results: </strong>Our results highlighted that MVR gave rise to regurgitant jets through the mitral orifice impinging against the atrial walls and scratching against the mitral valve leading to high values of wall shear stresses (WSSs) with respect to the healthy case.</p><p><strong>Conclusion: </strong>CFD with prescribed wall motion and immersed mitral valve revealed to be an effective tool to quantitatively describe hemodynamics in case of MVR and to compare different regurgitant scenarios. Our findings highlighted in particular the presence of transition to turbulence in the atrium and allowed us to quantify some important cardiac indices such as cardiac output and WSS.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10412498/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10029667","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":"Investigation of Cerebral Hemodynamics During Endovascular Aspiration: Development of an Experimental and Numerical Setup.","authors":"C A Luisi,&nbsp;A Amiri,&nbsp;M Büsen,&nbsp;T Sichermann,&nbsp;O Nikoubashman,&nbsp;M Wiesmann,&nbsp;U Steinseifer,&nbsp;M Müller,&nbsp;M Neidlin","doi":"10.1007/s13239-023-00660-8","DOIUrl":"https://doi.org/10.1007/s13239-023-00660-8","url":null,"abstract":"<p><strong>Purpose: </strong>Acute ischemic stroke is a life-threatening emergency caused by an occlusion of a cerebral artery through a blood clot. Aspiration thrombectomy is an endovascular therapy for the removal of vessel occlusions. However, open questions regarding the hemodynamics during the intervention remain, motivating investigations of blood flow within cerebral arteries. In this study, we present a combined experimental and numerical approach to analyze hemodynamics during endovascular aspiration.</p><p><strong>Methods: </strong>We have developed an in vitro setup for investigations of hemodynamic changes during endovascular aspiration within a compliant model of patient-specific cerebral arteries. Pressures, flows, and locally resolved velocities were obtained. In addition, we established a computational fluid dynamics (CFD) model and compared the simulations during physiological conditions and in two aspiration scenarios with different occlusions.</p><p><strong>Results: </strong>Flow redistribution within cerebral arteries after ischemic stroke is strongly dependent on the severity of the occlusion and on the volume flow extracted by endovascular aspiration. Numerical simulations exhibit an excellent correlation of R = 0.92 for flow rates and a good correlation of R = 0.73 for pressures. Further on, the local velocity field inside the basilar artery had a good agreement between CFD model and particle image velocimetry (PIV) data.</p><p><strong>Conclusion: </strong>The presented setup allows for in vitro investigations of artery occlusions and endovascular aspiration techniques on arbitrary patient-specific cerebrovascular anatomies. The in silico model provides consistent predictions of flows and pressures in several aspiration scenarios.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10412675/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10028319","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":"A U-Shaped Network Based on Multi-level Feature and Dual-Attention Coordination Mechanism for Coronary Artery Segmentation of CCTA Images.","authors":"Peng Hong,&nbsp;Yong Du,&nbsp;Dongming Chen,&nbsp;Chengbao Peng,&nbsp;Benqiang Yang,&nbsp;Lisheng Xu","doi":"10.1007/s13239-023-00659-1","DOIUrl":"https://doi.org/10.1007/s13239-023-00659-1","url":null,"abstract":"<p><strong>Purpose: </strong>Computed tomography coronary angiography (CCTA) images provide optimal visualization of coronary arteries to aid in diagnosing coronary heart disease (CHD). With the deep convolutional neural network, this work aims to develop an intelligent and lightweight coronary artery segmentation algorithm that can be deployed in hospital systems to assist clinicians in quantitatively analyzing CHD.</p><p><strong>Methods: </strong>With the multi-level feature fusion, we proposed Dual-Attention Coordination U-Net (DAC-UNet) that achieves automated coronary artery segmentation in 2D CCTA images. The coronary artery occupies a small region, and the foreground and background are extremely unbalanced. For this reason, the more original information can be retained by fusing related features between adjacent layers, which is conducive to recovering the small coronary artery area. The dual-attention coordination mechanism can select valid information and filter redundant information. Moreover, the complementation and coordination of double attention factors can enhance the integrity of features of coronary arteries, reduce the interference of non-coronary arteries, and prevent over-learning. With gradual learning, the balanced character of double attention factors promotes the generalization ability of the model to enhance coronary artery localization and contour detail segmentation.</p><p><strong>Results: </strong>Compared with existing related segmentation methods, our method achieves a certain degree of improvement in 2D CCTA images for the segmentation accuracy of coronary arteries with a mean Dice index of 0.7920. Furthermore, the method can obtain relatively accurate results even in a small sample dataset and is easy to implement and deploy, which is promising. The code is available at: https://github.com/windfly666/Segmentation .</p><p><strong>Conclusion: </strong>Our method can capture the coronary artery structure end-to-end, which can be used as a fundamental means for automatic detection of coronary artery stenosis, blood flow reserve fraction analysis, and assisting clinicians in diagnosing CHD.</p>","PeriodicalId":54322,"journal":{"name":"Cardiovascular Engineering and Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10029135","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}