Failure modes and effects analysis of mechanical thrombectomy for stroke discovered in human brains

2021 ◽  
pp. 1-8
Author(s):  
Yang Liu ◽  
Daniel Gebrezgiabhier ◽  
Adithya S. Reddy ◽  
Evan Davis ◽  
Yihao Zheng ◽  
...  
Keyword(s):  
Failure Modes ◽  
Mode Analysis ◽  
Vessel Occlusion ◽  
Neurological Outcomes ◽  
Tensile Forces ◽  
Failure Mode Analysis ◽  
Stent Retrievers ◽  
Human Brains ◽  
The Impact ◽  
Perforating Arteries

OBJECTIVE Despite advancement of thrombectomy technologies for large-vessel occlusion (LVO) stroke and increased user experience, complete recanalization rates linger around 50%, and one-third of patients who have undergone successful recanalization still experience poor neurological outcomes. To enhance the understanding of the biomechanics and failure modes, the authors conducted an experimental analysis of the interaction of emboli/artery/devices in the first human brain test platform for LVO stroke described to date. METHODS In 12 fresh human brains, 105 LVOs were recreated by embolizing engineered emboli analogs and recanalization was attempted using aspiration catheters and/or stent retrievers. The complex mechanical interaction between diverse emboli (elastic, stiff, and fragment prone), arteries (anterior and posterior circulation), and thrombectomy devices were observed, analyzed, and categorized. The authors systematically evaluated the recanalization process through failure modes and effects analysis, and they identified where and how thrombectomy devices fail and the impact of device failure. RESULTS The first-pass effect (34%), successful (71%), and complete (60%) recanalization rates in this model were consistent with those in the literature. Failure mode analysis of 184 passes with thrombectomy devices revealed the following. 1) Devices loaded the emboli with tensile forces leading to elongation and intravascular fragmentation. 2) In the presence of anterograde flow, small fragments embolize to the microcirculation and large fragments result in recurrent vessel occlusion. 3) Multiple passes are required due to recurrent (15%) and residual (73%) occlusions, or both (12%). 4) Residual emboli remained in small branching and perforating arteries in cases of alleged complete recanalization (28%). 5) Vacuum caused arterial collapse at physiological pressures (27%). 6) Device withdrawal caused arterial traction (41%), and severe traction provoked avulsion of perforating and small branching arteries. CONCLUSIONS Biomechanically superior thrombectomy technologies should prevent unrestrained tensional load on emboli, minimize intraluminal embolus fragmentation and release, improve device/embolus integration, recanalize small branching and perforating arteries, prevent arterial collapse, and minimize traction.

Abstract P507: Clot Ingestion Leads to the Highest First Pass Complete Recanalization Rates in a Human Brain Model of Large Vessel Occlusion Stroke

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Luis Savastano ◽  
Yang Liu ◽  
Daniel Gebrezgiabhier ◽  
Adithya Reddy ◽  
Evan Davis ◽  
...  
Keyword(s):  
Large Vessel ◽  
Large Vessel Occlusion ◽  
Test Bed ◽  
En Bloc ◽  
Vessel Occlusion ◽  
First Pass ◽  
Tensile Forces ◽  
Stent Retrievers ◽  
Hybrid Test ◽  
Human Brains

Introduction: Suction catheters and stent retrievers are based on the classical paradigm of “en bloc” removal of emboli by generation of tensile forces by vacuum or device withdrawal. However, in this process emboli elongate and fracture leading to fragmentation. Fragments can migrate downstream or remain impacted in the arterial wall resulting in a residual occlusion. Hypothesis: Clot ingestion is biomechanically superior to “en bloc” removal and leads to higher recanalization rates with less complications. Methods: To test this hypothesis, we present a hybrid test bed consisting of pressurized human brains which was developed and validated for large vessel occlusion (LVO) and revascularization. We fabricated 3 types of representative embolus analogs (EAs) (elastic, fragment-prone and stiff) and recreated 105 LVO in twenty-four fresh human brains with the vasculature connected to an hydraulic system to mimic physiological flow and pressures. Recanalization was attempted in 61 LVO cases by Direct Aspiration (DA) using an 068 catheter and in 44 LVO cases combining Stent Retriever with Aspiration (SR+A). Rates of successful recanalization (SR, Grade 2b or higher) and complete recanalization (CR, Grade 2c or higher) were measured. Up to 4 attempts were done before declaring a failure (Grade 2a or lower). Results: DA resulted in 90% of SR, 79% of CR, 61% of first pass SR and 49% of first pass CR. SR+A resulted in 34% of SR, 34% of CR, 23% of first pass SR and 14% of first pass CR. Elastic EA were associated with 88% of SR, 85% of CR, 61% of first pass SR and 52% of first pass CR. Stiff EAs were associated with 64% of SR, 64% of CR, 36% of first pass SR and 36% of first pass CR. Fragment-prone EAs were associated with 64% of SR, 40% of CR, 38% of first pass SR and 21% of first pass CR. Conclusion: Clot ingestion is biomechanically superior to “en bloc” removal and leads to the highest rates of SR, CR and first pass recanalization. DA achieves higher recanalization rates than SR+A. Elastic clots are associated with the highest rates or recanalization, followed by stiff clots and finally by fragment-prone clots.

Failure Mode Analysis of Bedding Rock Slope Affected by Rock Mass Structural Plane

2014 ◽  
Vol 602-605 ◽  
pp. 594-597 ◽  
Author(s):  
En An Chi ◽  
Tie Jun Tao ◽  
Ming Sheng Zhao ◽  
Qiang Kang
Keyword(s):  
Rock Mass ◽  
Slope Failure ◽  
Failure Modes ◽  
Shear Stiffness ◽  
Mode Analysis ◽  
Structural Plane ◽  
Plane Failure ◽  
Failure Mode Analysis ◽  
Dip Angle ◽  
The Impact

Based on the discrete element numerical simulation, the change of failure modes of slope influenced by parameters of rock mass structural plane is studied. It is shown the failure modes shift gradually from the bedding sliding failure modes to the sliding-bending failure modes with the increase of the strength of the rock mass structural plane; The slope failure modes are mainly sliding failure modes with the increasing of the normal and shear stiffness and spacing of rock structural plane. Failure modes shift from shearing slip failure modes to shearing slip and buckling failure modes and finally to the tilting failure modes with the increase of the rock structural plane dip angle. The impact of the rock structural plane cohesion to the slope stability is the greatest, and the stiffness is the least.

Case Study and Fault Modeling for Wrong Redundancy Evaluation on DRAM Devices

2007 ◽  
Author(s):  
Martin Versen ◽  
Dorina Diaconescu ◽  
Jerome Touzel
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Fault Modeling ◽  
Mode Analysis ◽  
Root Cause ◽  
Failure Mode Analysis

Abstract The characterization of failure modes of DRAM is often straight forward if array related hard failures with specific addresses for localization are concerned. The paper presents a case study of a bitline oriented failure mode connected to a redundancy evaluation in the DRAM periphery. The failure mode analysis and fault modeling focus both on the root-cause and on the test aspects of the problem.

STATISTICAL FAILURE MODE ANALYSIS OF SUBMARINE PIPELINE ACCIDENTS

1983 ◽  
Vol 1983 (1) ◽  
pp. 361-365 ◽  
Author(s):  
William K. Olender
Keyword(s):  
Gulf Of Mexico ◽  
Failure Modes ◽  
Oil And Gas ◽  
Third Party ◽  
Mode Analysis ◽  
Operational Experience ◽  
Submarine Pipeline ◽  
Oil Pipeline ◽  
Failure Mode Analysis ◽  
System Variables

ABSTRACT This study was conducted to investigate the appropriate exposure and system variables that affect the frequencies of submarine pipeline accidents and spills, the relationships among these variables, and the principal failure modes for individual pipeline classes. Available data on accidents, spills, pipeline inventory, and operational experience were used to compute annual and (diameter adjusted) mean accident rates, standard deviations, and confidence limits. Combined data for three dissimilar maritime regions indicate that a failure rate for oil and gas submarine pipelines of between one and ten incidents per 1,000 kilometers (km) per year probably represents a conservative estimate; however, the number of accidents in two of these regions was too small to provide statistically meaningful results. A more detailed analysis of Gulf of Mexico data recorded in the 1969-1980 period revealed that, while external factors such as severe weather and third party (man-made) activity accounted for nearly half of all pipeline incidents in that maritime region, corrosion has accounted for about half of all oil pipeline failures since 1975. Failure rates derived for Gulf of Mexico pipelines, however, are believed to overestimate pipeline vulnerability by a substantial margin owing to the exclusion of all but offshore Texas and Louisiana pipelines from the database.

A Correlation Model Based Failure Mode Analysis Method for Mechatronics Systems

2015 ◽  
Vol 727-728 ◽  
pp. 637-640
Author(s):  
Ying Liu ◽  
Zheng Hu ◽  
Shi Gang Zhang
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Cognitive Map ◽  
Fuzzy Cognitive Map ◽  
Mode Analysis ◽  
Correlation Model ◽  
Analysis Method ◽  
Failure Mode Analysis ◽  
The Relationship ◽  
Reasoning Technique

Failure mode analysis formechatronics systems has many problems in real applications in terms of excessivedependency on experience, lack of uniform description and tedious analysis work. In order to increaseits effectiveness, an automatic failure modes analysis framework is constructedand an extended fuzzy cognitive map is used as a reasoning technique toanalysis the effect of the failures. A function-failure correlation model witha standard description is adopted to describe the relationship between failuremodes and functions, so that designers and engineers from different fields cancomprehend and communicate within the same framework. Functional flows andfailure modes are defined as basic concepts in the fuzzy cognitive map, whichprovides an easy way to carry out an automatic cause and effect reasoning.

Failure Mode Analysis of Mobile Equipment Hydraulic Leaks

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Mahmoud I. Awad ◽  
Ali A. Alkelani
Keyword(s):  
Failure Modes ◽  
Mode Analysis ◽  
Assembly Process ◽  
Impact Reduction ◽  
Different Types ◽  
Failure Mode Analysis ◽  
Potential Improvement ◽  
The Many ◽  
Reduction Cost

Leaks in general and hydraulic leaks in specific are one of the major failure modes for mobile equipment. In-plant leak rates may range from 1% to 25%, while field leaks may range from 1% to 13% depending on the complexity of the system, assembly process, and parts quality. In this paper, the main potential leak causes are discussed and the performance of different types of fittings is compared, including JIC 37 flare fittings, O-ring boss seal, and O-ring face seal. Several potential improvement actions related to assembly process, torque specifications, and quality of manufactured fittings are proposed to reduce leaks. Among the many benefits leak reduction will result in improved customer safety and satisfaction, assembly down time reduction, cost and warranty reduction, and environmental impact reduction.

The Failure Mode Analysis of Open Pit Slope Base on Finite Element Method

2013 ◽  
Vol 405-408 ◽  
pp. 35-39 ◽  
Author(s):  
Hai Dong Meng ◽  
Yan Xu ◽  
Dong Yuan Zang
Keyword(s):  
Finite Element Method ◽  
Slope Failure ◽  
Failure Modes ◽  
Open Pit ◽  
Mode Analysis ◽  
Geological Model ◽  
Failure Model ◽  
Safe Production ◽  
Failure Mode Analysis ◽  
South Slope

This paper is aimed at analysing the slope failure model for an open pit slope. Firstly, The method of engineering geological survey is carried out for the open pit south slope. Then, the appropriate geological model is established. And the slope model of the open pits was established and solved by finite elemen program. The analysis reveals the internal sliding of the open-cut and the failure modes of bottom sliding along the base weak level. It will be an important guiding significance for the safe production of open pit coal mine.

Failure Mode Analysis of Mechanical Systems at Conceptual Design Stage

2006 ◽  
Author(s):  
M. F. Wani ◽  
Muzamil Jan
Keyword(s):  
Failure Mode ◽  
Conceptual Design ◽  
Failure Modes ◽  
Mode Analysis ◽  
Design Stage ◽  
Component Failure ◽  
Conceptual Design Stage ◽  
Failure Mode Analysis ◽  
And Function ◽  
The Given

This paper presents a methodology for determining criticality of failure modes in mechanical system at conceptual design stage on the basis of functional and structural knowledge of the system, using statistical method ‘K-Clustering’. First of all component failure matrix (CF) is derived then its transpose is obtained. Then similarity matrix (SM) is obtained by pre-multiplying component failure matrix (CF) by its transpose. By adding each row corresponding to the given function and arranging the sums in ascending or descending order and selecting a range to determine critical failure modes. Prediction of critical failure modes during conceptual design stage using the component failure matrix (CF) and function component matrix (EC) matrices, the function failure mode matrix can be computed as EF = EC × CF.

Coil Failure Mode Analysis for Fiber Carbon Composite Core Rod Used in Overhead Stranded Wires

2015 ◽  
Vol 723 ◽  
pp. 7-16 ◽  
Author(s):  
Rui Li ◽  
Hong Yun Yu ◽  
Miao Qian ◽  
Min Bo Yu ◽  
Guo Yong Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Theoretical Basis ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Carbon Composite ◽  
Test Method ◽  
Mode Analysis ◽  
Element Simulation ◽  
Failure Mode Analysis ◽  
Core Rod

This paper studies the mechanical performance of fiber carbon composite core rod under coiled condition by finite element simulation and analyzes the failure modes by coiling test, providing technical support and theoretical basis for the manufacture technique, test method, and application of fiber carbon composite core rod.

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