Pearson D.G.,Mayo Clinic Arizona |
American Journal of Surgery | Year: 2016
Background Traditional retrorectus techniques for ventral hernia repair often produce abdominal wall pain related to transfascial suture placement. This report details results of a retrorectus mesh herniorrhaphy technique avoiding transfascial suture fixation. Methods A retrospective review of 90 patients who underwent retrorectus ventral hernia repair between 2009 and 2015 was performed. All were treated with primary posterior rectus fascial closure and retrorectus mesh placement. Standard weight polypropylene mesh was used with polypropylene tacking sutures to the posterior rectus sheath with medialization of the rectus muscles and primary closure of the anterior rectus sheath over the mesh repair. Results The overall complication rate was 19.6%. Hernia recurrence occurred in 2 patients (2.2%) with mean follow-up of 3.0 years. There were 4 cases of superficial infection (4.3%). Two patients (2.2%) developed hematomas and 2 patients developed seromas (2.2%). Late abdominal pain occurred in 6 (6.5%) patients, eventually resolving in all but 2. Conclusions Retrorectus ventral hernia repair avoiding transfascial suture placement produces a functional repair with minimal chronic pain and a low rate of complications. © 2016 Elsevier Inc. All rights reserved.
JBIS - Journal of the British Interplanetary Society | Year: 2015
Project Icarus is a theoretical design study for an interstellar probe based on the landmark Project Daedalus study completed in 1978. The Project Icarus Terms of Reference  (ToR) specify that the probe should achieve at least some deceleration at the target system. Magnetic sails were initially proposed by Andrews and Zubrin  in 1988 as a potential aid to interstellar deceleration, and several papers have since been written on the subject. This paper presents the complete calculations for a magsail and evaluates suitability of the various approximations used to simplify the math. The resulting calculations are then used to model full deceleration of a magsail-equipped vessel vs. one that uses only a fusion engine. This paper is a submission of the Project Icarus Study Group.
CAMX 2015 - Composites and Advanced Materials Expo | Year: 2015
Optical measurements are becoming critical for modern design, manufacturing and test. As computer aided design, modeling and simulation are critical for product design and development, the test world now uses full-field optical measurements to better understand the holistic response of their materials, structures and completed designs. This full-field measurement and response allows engineers to more fully understand their parts and their interactions, improving the quality of the designs. This new methodology is the ideal tool for materials measurements, including complex measurements of forming limit curves and flow curves, to get more accurate materials measurements, full-scale article tests and crash tests. An image is worth 1000 strain gauges. These greatly improved data sets provide thousands of measurement points, rather than the traditional, couple of measurement points from strain gauges, LVDTs or accelerometers. This full-field data also traverses material transitions, allowing precise monitoring of real boundary conditions. With these improved data, computer model iteration is much easier and more real. And, precise model validation can be performed on a greater variety of conditions, allowing the models to more accurately predict real design behavior. This paper will review advances in optical measurements throughout the design cycle, and discuss how this data can greatly enhance design quality and consistency. Copyright 2015 by John Tyson II. Published by CAMX-The Composites and Advanced Materials Expo with permission.
Proceedings of the ASME Design Engineering Technical Conference | Year: 2015
Function Generation is a long standing linkage design problem. It is possible to design a planar four bar linkage whose input and output links will pass through seven coordinated positions. This paper discloses the first graphical solution to this problem. The approach is to consider the constraints imposed by the target positions on the linkage through the poles and rotation angles. This approach enables the designer to explore the range of possible solutions when fewer than seven positions are specified by dragging a fixed or moving pivot in the plane. The selection of free choices is made at the end of the process and the complete mechanism is visible when the choices are made. The constraints only need to be made once which eliminates the repetitive construction required by previous methods to consider multiple pivot locations. Since it is so easy to consider multiple pivot locations and the solution mechanism is visible, the required design time is greatly reduced. A corresponding analytical solution is also developed and solved based on the same constraints. This is a new analytical solution and is defined by a system of 20 nonlinear equations with 20 unknowns. Copyright © 2015 by ASME.
Burris A.C.,II |
Boura J.A.,William Beaumont Hospital |
Raff G.L.,William Beaumont Hospital |
Chinnaiyan K.M.,William Beaumont Hospital
JACC: Cardiovascular Imaging | Year: 2015
Objectives This study sought to evaluate the diagnostic yield of triple rule out (TRO) versus coronary computed tomography angiography (CTA) scanning in patients with acute chest pain enrolled in a large statewide registry. Background Although TRO scans provide simultaneous evaluation of coronary artery disease (CAD), pulmonary embolism (PE), and aortic disease (AD), their use is not well defined. Methods Patients undergoing TRO or coronary CTA at 53 Michigan institutions for acute chest pain (in the emergency department or inpatient setting) in the ACIC (Advanced Cardiovascular Imaging Consortium) were included. Demographic characteristics, scan findings, and image quality parameters were compared between coronary CTA and TRO scans. The primary outcome was diagnostic yield, defined as obstructive CAD (>50% stenosis), PE, or AD; secondary outcomes were radiation dose, contrast volume, and image quality. Results From July 2007 to September 2013, 12,834 patients underwent computed tomography scanning (TRO, n = 1,555; coronary CTA, n = 11,279). The TRO group had more women (57.1% vs. 47.8%, p < 0.001). Diagnostic yield was similar (TRO, 17.4% vs. coronary CTA, 18.3%; p = 0.37), driven by CAD (15.5% vs. 17.2%, p = 0.093); PE and AD were 1.1% and 0.4% (p = 0.004) and 1.7% and 1.1% (p = 0.046). TRO had higher median radiation (9.1 mSv vs. 6.2 mSv; p < 0.0001) and mean contrast (113 ± 6 ml vs. 89 ± 17 ml; p < 0.0001) doses. Nondiagnostic images were frequent in TRO (9.4% vs. 6.5%; p < 0.0001). In emergency department patients, PE and AD were more often detected on TRO. Among inpatients, there were no differences in overall yield or in that of PE, AD, or CAD. Conclusions TRO was associated with slightly higher yield of PE and AD, specifically in the emergency department. This benefit comes with higher nondiagnostic image quality, radiation, and contrast doses. Although TRO may be of value in selected patients, its indiscriminate use is not warranted. The appropriate use of TRO needs to be further defined. (Advanced Cardiovascular Imaging Consortium [ACIC]; NCT00640068). © 2015 American College of Cardiology Foundation.