Seyyed Mostafa Mousavi Janbeh Sarayi

Bio: Seyyed Mostafa Mousavi Janbeh Sarayi is an academic researcher from State University of New York System. The author has contributed to research in topics: Vibration & Circulant matrix. The author has an hindex of 3, co-authored 8 publications receiving 21 citations. Previous affiliations of Seyyed Mostafa Mousavi Janbeh Sarayi include University at Buffalo & University of Tehran.

Free vibration and wave power reflection in Mindlin rectangular plates via exact wave propagation approach

Abstract: Reflection, propagation and energy analysis are crucially important in designing structures, especially plates. A thick plate is considered based on first order shear deformation theory. Wave Propagation Method (WPM) is employed to exactly derive resonant frequencies and wave power reflection from different classical boundary conditions. Firstly, the frequency results are compared with other literature to validate the exact proposed wave solution in the present work. Then, wave analysis and benchmark results for natural frequencies are presented for six different combinations of boundary conditions. The results indicate that the wave power reflection of thick rectangular plates is quite complicated and an incident wave of a specific type gives rise to other types of waves except for simply supported boundary conditions where the reflected wave power does not depend on the system parameters.

Revascularization Outcome Prediction for A Direct Aspiration-First Pass Technique (ADAPT) from Pre-Treatment Imaging and Machine Learning

Abstract: A direct aspiration-first pass technique (ADAPT) has recently gained popularity for the treatment of large vessel ischemic stroke. Here, we sought to create a machine learning-based model that uses pre-treatment imaging metrics to predict successful outcomes for ADAPT in middle cerebral artery (MCA) stroke cases. In 119 MCA strokes treated by ADAPT, we calculated four imaging parameters—clot length, perviousness, distance from the internal carotid artery (ICA) and angle of interaction (AOI) between clot/catheter. We determined treatment success by first pass effect (FPE), and performed univariate analyses. We further built and validated multivariate machine learning models in a random train-test split (75%:25%) of our data. To test model stability, we repeated the machine learning procedure over 100 randomizations, and reported the average performances. Our results show that perviousness (p = 0.002) and AOI (p = 0.031) were significantly higher and clot length (p = 0.007) was significantly lower in ADAPT cases with FPE. A logistic regression model achieved the highest accuracy (74.2%) in the testing cohort, with an AUC = 0.769. The models had similar performance over the 100 train-test randomizations (average testing AUC = 0.768 ± 0.026). This study provides feasibility of multivariate imaging-based predictors for stroke treatment outcome. Such models may help operators select the most adequate thrombectomy approach.

A Nonlinear Mechanics-based Virtual Coiling Method For Intracranial Aneurysm

Abstract: Enodvascular coils treat intracranial aneurysms (IAs) by causing them to occlude by thrombosis. Ideally, coiled IAs eventually occlude in the long-term. However, 20.8% are found incompletely occluded at treatment follow-up. Computer simulations of coiling and its effect on aneurysmal flow could help clinicians predict treatment outcomes a priori, but it requires accurate modeling of coils and their deployment procedure. In addition to being accurate, coiling simulations must be efficient to be used as a bedside tool. To date, several virtual coiling techniques have been developed, but they lack either accuracy or efficiency. For example, finite-element-based virtual coiling methods model the mechanics of coiling and are highly accurate, at the expense of high computational cost (and thus low efficiency). Geometric-rule-based coiling techniques ignore the mechanics and therefore are computationally efficient, but may produce unrealistic coil deployments. In order to develop a virtual coiling method that combines accuracy and efficiency, we propose a novel virtual coiling algorithm that models coil deployment with nonlinear mechanics and nonlinear contact. Our approach is potentially more accurate than existing "simple" techniques because we model coil mechanics. It is also potentially faster than finite-element techniques because it models the most time-consuming part of these algorithms-namely contact resolution-with a novel formulation that resolves contact faster with exponential functions. Moreover, we model the coil's pre-shape as well as coil packaging into the catheter, both of which are important to model but are lacking from most existing techniques.

An Analytical Approach for Preliminary Response-Based Design of Semi Rigid Moment Resisting Frames

Abstract: In many cases, beam to column connections in structural frames are semi rigid, but they are considered to be ideally rigid or pinned due to their computational complexity and shortage of designing methods. In this paper, connections are considered as linear rotational springs with variable stiffness. Moreover, the main contribution of the present study is a preliminary design method of moment resisting frames, considering semi rigid behavior of connections, by means of presented diagrams for different frames. These diagrams relate three features of a frame together; stiffness of frames connections, geometrical properties of frames elements, and its lateral displacement. These diagrams can be used when the required stiffness of frames connections is needed while the desired response of the frame, dimensions of the frame and the ratio of second moment of inertia of its elements are known. On the other hand, they could be used to obtain the ratio of beams length to columns length and the ratio of second moment of inertia of beams to columns alongside the stiffness of frames connections while the only known data is the number of frames grids in X and Y directions and its desired response.

Mechanics of Continua

Abstract: So far we have treated only point-like particles; an exception was the treatment of the rigid body in Chap. 8. In this chapter we will investigate deformable bodies, for a twofold reason: (1) If a body is not rigid but deformable, it has its own internal dynamics, which is independent of its state of motion (disregarding inertial forces), as was investigated, e.g., in Chap. 8. (2) The continuum mechanics is a first example of a field theory. A more detailed treatment of a field theory is the subject of the Maxwell theory of the electromagnetic fields.2