{"title":"使用稳定流速近似分析颅内动脉瘤的流动不稳定性和振动。","authors":"","doi":"10.1016/j.jbiomech.2024.112237","DOIUrl":null,"url":null,"abstract":"<div><p>Recent computational and experimental studies of intracranial aneurysms have revealed potential mechanisms of aneurysm bruits and murmurs, driven by flow instabilities rather than by stable pulsatile flow. Some of these studies have been conducted under the assumption of constant flow rate (steady flow); however the validity of this assumption has not been evaluated for high-frequency flow instability, or vibrations from fluid-structure interaction (FSI) simulations. We evaluated the time-averaged wall shear stress, flow instability and vibration amplitude of steady flow simulations, performed at both cycle-averaged and peak-systolic flow rates, and compared these to recent pulsatile FSI simulations. Wall shear stress fields of pulsatile flow (time-averaged and peak values) were well-approximated by the respective steady-flow FSI simulations, and the spatial distribution and frequency content of flow instability and vibrations were reasonably approximated by the steady flow simulations at peak-systolic flow rates. However, the level of flow instability and vibration was generally over-predicted by the steady flow simulations at peak-systolic flow rates as flow remained unstable for longer than in the pulsatile simulation, while no flow instability was detected for steady flow at cycle-averaged flow rates. Additionally, the amplitude of flow instability and vibration fluctuated considerably in the steady flow simulations, while the pulsatile simulations exhibited consistent vibration amplitudes (less than 10 % variation at peak systole between cycles). Finally, steady flow simulations at peak-systolic conditions required 2-3x <em>more</em> compute time than the pulsatile simulations for the same time duration. Therefore, we recommend using pulsatile flow simulations when investigating vibrations and flow instabilities.</p></div>","PeriodicalId":15168,"journal":{"name":"Journal of biomechanics","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On the use of steady flow rates for approximating flow instabilities and vibrations in intracranial aneurysms\",\"authors\":\"\",\"doi\":\"10.1016/j.jbiomech.2024.112237\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Recent computational and experimental studies of intracranial aneurysms have revealed potential mechanisms of aneurysm bruits and murmurs, driven by flow instabilities rather than by stable pulsatile flow. Some of these studies have been conducted under the assumption of constant flow rate (steady flow); however the validity of this assumption has not been evaluated for high-frequency flow instability, or vibrations from fluid-structure interaction (FSI) simulations. We evaluated the time-averaged wall shear stress, flow instability and vibration amplitude of steady flow simulations, performed at both cycle-averaged and peak-systolic flow rates, and compared these to recent pulsatile FSI simulations. Wall shear stress fields of pulsatile flow (time-averaged and peak values) were well-approximated by the respective steady-flow FSI simulations, and the spatial distribution and frequency content of flow instability and vibrations were reasonably approximated by the steady flow simulations at peak-systolic flow rates. However, the level of flow instability and vibration was generally over-predicted by the steady flow simulations at peak-systolic flow rates as flow remained unstable for longer than in the pulsatile simulation, while no flow instability was detected for steady flow at cycle-averaged flow rates. Additionally, the amplitude of flow instability and vibration fluctuated considerably in the steady flow simulations, while the pulsatile simulations exhibited consistent vibration amplitudes (less than 10 % variation at peak systole between cycles). Finally, steady flow simulations at peak-systolic conditions required 2-3x <em>more</em> compute time than the pulsatile simulations for the same time duration. Therefore, we recommend using pulsatile flow simulations when investigating vibrations and flow instabilities.</p></div>\",\"PeriodicalId\":15168,\"journal\":{\"name\":\"Journal of biomechanics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.4000,\"publicationDate\":\"2024-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of biomechanics\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0021929024003154\",\"RegionNum\":3,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"BIOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of biomechanics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0021929024003154","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOPHYSICS","Score":null,"Total":0}
On the use of steady flow rates for approximating flow instabilities and vibrations in intracranial aneurysms
Recent computational and experimental studies of intracranial aneurysms have revealed potential mechanisms of aneurysm bruits and murmurs, driven by flow instabilities rather than by stable pulsatile flow. Some of these studies have been conducted under the assumption of constant flow rate (steady flow); however the validity of this assumption has not been evaluated for high-frequency flow instability, or vibrations from fluid-structure interaction (FSI) simulations. We evaluated the time-averaged wall shear stress, flow instability and vibration amplitude of steady flow simulations, performed at both cycle-averaged and peak-systolic flow rates, and compared these to recent pulsatile FSI simulations. Wall shear stress fields of pulsatile flow (time-averaged and peak values) were well-approximated by the respective steady-flow FSI simulations, and the spatial distribution and frequency content of flow instability and vibrations were reasonably approximated by the steady flow simulations at peak-systolic flow rates. However, the level of flow instability and vibration was generally over-predicted by the steady flow simulations at peak-systolic flow rates as flow remained unstable for longer than in the pulsatile simulation, while no flow instability was detected for steady flow at cycle-averaged flow rates. Additionally, the amplitude of flow instability and vibration fluctuated considerably in the steady flow simulations, while the pulsatile simulations exhibited consistent vibration amplitudes (less than 10 % variation at peak systole between cycles). Finally, steady flow simulations at peak-systolic conditions required 2-3x more compute time than the pulsatile simulations for the same time duration. Therefore, we recommend using pulsatile flow simulations when investigating vibrations and flow instabilities.
期刊介绍:
The Journal of Biomechanics publishes reports of original and substantial findings using the principles of mechanics to explore biological problems. Analytical, as well as experimental papers may be submitted, and the journal accepts original articles, surveys and perspective articles (usually by Editorial invitation only), book reviews and letters to the Editor. The criteria for acceptance of manuscripts include excellence, novelty, significance, clarity, conciseness and interest to the readership.
Papers published in the journal may cover a wide range of topics in biomechanics, including, but not limited to:
-Fundamental Topics - Biomechanics of the musculoskeletal, cardiovascular, and respiratory systems, mechanics of hard and soft tissues, biofluid mechanics, mechanics of prostheses and implant-tissue interfaces, mechanics of cells.
-Cardiovascular and Respiratory Biomechanics - Mechanics of blood-flow, air-flow, mechanics of the soft tissues, flow-tissue or flow-prosthesis interactions.
-Cell Biomechanics - Biomechanic analyses of cells, membranes and sub-cellular structures; the relationship of the mechanical environment to cell and tissue response.
-Dental Biomechanics - Design and analysis of dental tissues and prostheses, mechanics of chewing.
-Functional Tissue Engineering - The role of biomechanical factors in engineered tissue replacements and regenerative medicine.
-Injury Biomechanics - Mechanics of impact and trauma, dynamics of man-machine interaction.
-Molecular Biomechanics - Mechanical analyses of biomolecules.
-Orthopedic Biomechanics - Mechanics of fracture and fracture fixation, mechanics of implants and implant fixation, mechanics of bones and joints, wear of natural and artificial joints.
-Rehabilitation Biomechanics - Analyses of gait, mechanics of prosthetics and orthotics.
-Sports Biomechanics - Mechanical analyses of sports performance.