Omar Al Assad
General Electric
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Publication
Featured researches published by Omar Al Assad.
Proceedings of SPIE | 2015
David Allen Langan; Bernhard Erich Hermann Claus; Omar Al Assad; Yves Trousset; Cyril Riddell; Gregoire Avignon; Stephen B. Solomon; Hao Lai; Xin Wang
As percutaneous endovascular procedures address more complex and broader disease states, there is an increasing need for intra-procedure 3D vascular imaging. In this paper, we investigate C-Arm 2-axis tomosynthesis (“Tomo”) as an alternative to C-Arm Cone Beam Computed Tomography (CBCT) for workflow situations in which the CBCT acquisition may be inconvenient or prohibited. We report on our experience in performing tomosynthesis acquisitions with a digital angiographic imaging system (GE Healthcare Innova 4100 Angiographic Imaging System, Milwaukee, WI). During a tomo acquisition the detector and tube each orbit on a plane above and below the table respectively. The tomo orbit may be circular or elliptical, and the tomographic half-angle in our studies varied from approximately 16 to 28 degrees as a function of orbit period. The trajectory, geometric calibration, and gantry performance are presented. We overview a multi-resolution iterative reconstruction employing compressed sensing techniques to mitigate artifacts associated with incomplete data reconstructions. In this work, we focus on the reconstruction of small high contrast objects such as iodinated vasculature and interventional devices. We evaluate the overall performance of the acquisition and reconstruction through phantom acquisitions and a swine study. Both tomo and comparable CBCT acquisitions were performed during the swine study thereby enabling the use of CBCT as a reference in the evaluation of tomo vascular imaging. We close with a discussion of potential clinical applications for tomo, reflecting on the imaging and workflow results achieved.
Proceedings of SPIE | 2015
Bernhard Erich Hermann Claus; David Allen Langan; Omar Al Assad; Xin Wang
There is a clinical need to improve cerebral perfusion assessment during the treatment of ischemic stroke in the interventional suite. The clinician is able to determine whether the arterial blockage was successfully opened but is unable to sufficiently assess blood flow through the parenchyma. C-arm spin acquisitions can image the cerebral blood volume (CBV) but are challenged to capture the temporal dynamics of the iodinated contrast bolus, which is required to derive, e.g., cerebral blood flow (CBF) and mean transit time (MTT). Here we propose to utilize a circular tomosynthesis acquisition on the C-arm to achieve the necessary temporal sampling of the volume at the cost of incomplete data. We address the incomplete data problem by using tools from compressed sensing and incorporate temporal interpolation to improve our temporal resolution. A CT neuro perfusion data set is utilized for generating a dynamic (4D) volumetric model from which simulated tomo projections are generated. The 4D model is also used as a ground truth reference for performance evaluation. The performance that may be achieved with the tomo acquisition and 4D reconstruction (under simulation conditions, i.e., without considering data fidelity limitations due to imaging physics and imaging chain) is evaluated. In the considered scenario, good agreement between the ground truth and the tomo reconstruction in the parenchyma was achieved.
international conference on intelligent autonomous systems | 2016
Huan Tan; Shiraj Sen; Arpit Jain; Shuai Li; Viktor Holovashchenko; Ghulam Ali Baloch; Omar Al Assad; Romano Patrick; Douglas Roy Forman; Yonatan Gefen; Pramod Sharma; Frederick Wilson Wheeler; Charles Burton Theurer; Balajee Kannan
Current operations in rail yards are dangerous and limited by the operational capabilities of humans being able to perform safely in harsh conditions while maintain high productivity. Such issues call out the need for robust and capable autonomous systems. In this paper, we outline one such autonomous solution for the railroad domain, capable of performing the brake bleeding inspection task in a hump yard. Towards that, we integrated a large form factor mobile robot (the Clearpath Grizzly) with an industrial manipulator arm (Yasakawa Motoman SIA20F) to effectively detect, identify and subsequently manipulate the brake lever under harsh outdoor environments. In this paper, we focus on the system design and the core algorithms necessary for reliable and repeatable system execution. To test our developed solution, we performed extensive field tests in a fully operational rail yard with randomly picked rail cars under day and night-time conditions. The results from the testing are promising and validate the feasibility of deploying an autonomous brake bleeding solution for railyards.
Archive | 2014
Omar Al Assad; David Allen Langan; Bernhard Erich Hermann Claus; Jeffrey Wayne Eberhard; Michel F. Grimaud
Archive | 2014
Bernhard Erich Hermann Claus; David Allen Langan; Omar Al Assad
Archive | 2016
David Allen Langan; Bernhard Erich Hermann Claus; Omar Al Assad; Gregoire Avignon
Archive | 2017
Huan Tan; John Michael Lizzi; Douglas Roy Forman; Charles Burton Theurer; Omar Al Assad; Romano Patrick; Viktor Holovashchenko; Balajee Kannan; Yonatan Gefen
Archive | 2014
Bernhard Erich Hermann Claus; David Allen Langan; Omar Al Assad
Archive | 2012
Bernard Bouvier; Romain Moulin; Jean-Michel Marteau; Vincent Croulard; Omar Al Assad; Bruno Galloni; Stephane Graziani; Gilles Robin
Archive | 2017
Huan Tan; John Michael Lizzi; Douglas Roy Forman; Charles Burton Theurer; Omar Al Assad; Mauricio Castillo-Effen; Romano Patrick; Balajee Kannan; Yonatan Gefen