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7. Towards an in-process inspection system for advanced composites manufacture

Author

Crowley, Dennis Michael

Subjects
620.1
Abstract

The manufacture of advanced composites components is a complex and multi-stage process. However, the properties of advanced composite materials are attractive for a number of applications, particularly those where lower weight components are required . Historically advanced composite raw materials, such as carbon fibres, have been costly, which limited them to high-performance applications where cost was not the prime driver, such as military aerospace and motorsport. More recently, however, their applications have grown to include civil aerospace in secondary structures and in high-performance and luxury automotive applications. The composites industry is expected to see a period of relatively high growth over the next decade, with flagship projects such as the Boeing 787 Dreamliner and Airbus A350XWB aircraft .also incorporating carbon fibre materials into their fuselage structures. The BMW i3 electric megacity car also uses a carbon-fibre chassis and is expected to be produced at rates which are an order of magnitude higher than previous automotive applications. This need to make more components at a higher production rate and lower cost is the main motivation for this study. Quality control and scrap form a large source of the cost of advanced composites components. It is felt that by introducing in-process inspection, over and above the current quality control practices, that the cost reductions necessary to ensure the future growth and attractiveness of advanced composites can be achieved. This work has determined that for an in-process inspection system to be successful a more holistic approach is necessary; thus process documentation, traceability and the human-in-the-loop were also considered along with measurement. The human-in-the-loop was investigated through a series of semi-structured interviews using prevalent motivation theories as a framework. The process documentation was reviewed and led to the development of a digital, on-line tool for organising acceptance criteria and defect reporting. The measurement system was developed through experiments and led to a prototype meas~rement system and a metric for the identification of bridging, a common in-process defect. The framework for an in-process inspection, developed during this research, includes a laser stripe scanner for 2 and 3D surface measurement, an on-line acceptance criteria tool which gives quality traceability and facilitates two-way communication, and a suggested management framework established from the semi-structured interviews. These would be used as part of a knowledge system which has the potential to improve design for manufacture in the early stages of product development, compounding the potential cost savings and productivity improvements realised by the in-process inspection system.

Published
2015

24. Intermediate results after complete repair of tetralogy of Fallot in neonates

Author

Hennein, Hani A., Mosca, Ralph S., Urcelay, Gonzalo, Crowley, Dennis C., and Bove, Edward L.

Subjects
Infants (Newborn), Tetralogy of Fallot, Valves, Safety regulations, Health
Abstract

Byline: Hani A. Hennein, Ralph S. Mosca, Gonzalo Urcelay, Dennis C. Crowley, Edward L. Bove Abstract: From July 1988 through September 1993, 30 neonates with symptomatic tetralogy of Fallot underwent complete repair. Sixteen patients had tetralogy and pulmonary stenosis, 9 had pulmonary atresia, 3 had nonconfluent pulmonary arteries, and 2 had both pulmonary atresia and nonconfluent pulmonary arteries. The median age at operation was 11 days (mean [+ or -] standard error of the mean, 12.6 [+ or -] 2.9 days), with a mean weight of 3.1 [+ or -] 0.1 kg (range 1.5 to 4.4 kg). Preoperatively, 14 patients were receiving an infusion of prostaglandin, 13 were mechanically ventilated, and 6 required inotropic support. Right ventricular outflow tract obstruction was managed by a limited transannular patch in 25 patients, infundibular muscle division with limited resection in 15, and insertion of a right ventricle-pulmonary artery valved aortic homograft conduit in 5 patients. Follow-up was complete at a median interval of 24 months (range 1 to 62 months). There were no hospital deaths and two late deaths, for 1-month, 1-year, and 5-year actuarial survivals of 100%, 93%, and 93%, respectively. The hazard function for death had a rapidly declining single phase that approached zero by 6 months after the operation. Both late deaths occurred in patients with tetralogy of Fallot and pulmonary atresia who had undergone aortic homograft conduit reconstruction, so that the only independent risk factor for death was the use of a valved homograft conduit (p [less than or equal to] 0.005). Eight patients required reoperation, resulting in 1-month, 1-year, and 5-year freedom from reoperation rates of 100%, 93%, and 66%, respectively. Indications for reoperation were branch left pulmonary artery stenosis in 5 patients, residual right ventricular outflow tract obstruction in 2 patients, and severe pulmonary insufficiency in 1 patient. Independent risk factors for reoperation included an intraoperative pressure ratio between the right and left ventricles of 0.75 or greater (p = 0.01), Doppler residual left pulmonary artery stenosis of 15 mm Hg or more, or Doppler right ventricular outflow tract obstruction gradient of 40 mm Hg or more at hospital discharge (p = 0.002 and 0.02, respectively). This series demonstrates the safety of early hemodynamic repair of symptomatic tetralogy of Fallot in neonates. It also emphasizes the importance of relieving all sources of right ventricular outflow tract obstruction at the initial operation, particularly that located at the site of insertion of the ductus arteriosus, which may be difficult to diagnose in the neonate before ductal closure occurs. The safety and efficacy of valved aortic homograft conduits in neonates requires further investigation. (J T horac C ardiovasc S urg 1995;109:332-44) Author Affiliation: Ann Arbor, Mich Article Note: (footnote) [star] From the Section of Thoracic Surgery, Department of Surgery,a and the Division of Pediatric Cardiology, Department of Pediatrics,b C.S. Mott Children's Hospital, The University of Michigan School of Medicine, Ann Arbor, Mich., [star][star] Read at the Seventy-fourth Annual Meeting of The American Association for Thoracic Surgery, New York, N.Y., April 24-27, 1994., a Address for reprints: Edward L. Bove, MD, Section of Thoracic Surgery, Department of Surgery, The University of Michigan Medical Center, Taubman Health Care Center, 1500 E. Medical Center Ave., Ann Arbor, MI 48109., aa 0022-5223/95 $3.00 + 0 12/6/60636

Published
1995

25. Late follow-up of balloon angioplasty in children with a native coarctation of the aorta

Author

Mendelsohn, Alan M., Lloyd, Thomas R., Crowley, Dennis C., Sandhu, Sainder, K., Kocis, Keith C., and Beekman, Robert H., III

Subjects
Transluminal angioplasty -- Evaluation, Aortic coarctation -- Care and treatment, Cardiac catheterization in children -- Health aspects, Health
Abstract

Between May 1984 and April 1993, 59 children underwent balloon angioplasty of a native coarctation at our institution. The follow-up protocol included a cardiac catheterization 1 to 2 years after angioplasty, which was performed in 90% of patients with [greater than or equal to] 2 years follow-up. Angioplasty caused an acute decrease in peak systolic gradient from 46 [+ or -] 2 to 15 [+ or -] 2 mm Hg, without early aneurysm or emergent surgical intervention in any patient. Based on follow-up data, a satisfactory result was obtained in 38 patients (64%; 70% confidence limit 58% to 71%), defined as a residual systolic gradient 12 months.

Published
1994

26. Digitisation of manual composite layup task knowledge using gaming technology

Author

Prabhu, Vinayak A., Elkington, Michael, Crowley, Dennis, Tiwari, Ashutosh, and Ward, Carwyn

Subjects
Human skill capture, Mechanics of Materials, Manufacturing informatics, Mechanical Engineering, Digitisation of task knowledge, Ceramics and Composites, Composite hand layup, Industrial and Manufacturing Engineering
Abstract

Increased market demand for composite products and shortage of expert laminators is compelling the\ud composite industry to explore ways to acquire layup skills from experts and transfer them to novices and\ud eventually to machines. There is a lack of holistic methods in literature for capturing composite layup\ud skills especially involving complex moulds. This research aims to develop an informatics-based method,\ud enabled by consumer-grade gaming technology and machine learning, to capture and digitise\ud manufacturing task knowledge from skill-intensive hand layup. The digitisation is underpinned by the\ud proposed human-workpiece interaction theory and implemented to automatically extract and decode\ud key knowledge constituents such as layup strategies, ply manipulation techniques, motion mechanics\ud and problem-solving during hand layup, collectively categorised as layup skills. The significance of this\ud research is its potential to facilitate cost-effective transfer of skills from experts to novices, real-time\ud automated supervision of hand layup and automation of layup tasks in the future.

Published
2016

27. LayupRITE: Manufacturing Support Tools for the Composites Industry.

Author

Crowley, Dennis, Shakspeare, Paul, Rider, Leah, Thornton, Brian, Edwards, Stuart, and Ward, Carwyn

Subjects
TOOL manufacturing, AGILE software development, INDUSTRIAL research, MANUFACTURING industry equipment, TOOLS
Abstract

The vast majority of composite components are manufactured using some form of manual labour. This is especially true for components with any degree of geometrical complexity that requires some form of drape of cloth(s) to a mould surface. Most academic research and industrial manufacturing effort recently appear to have been dedicated more towards methods of automation, rather than supporting human operator(s) in the layup environment. Such automation has its place, but given the likelihood that some form of reliance on the human operating system in manufacturing is always required, it seems folly to entirely ignore the human aspects? This paper seeks to redress the balance somewhat, introducing an extremely agile and new layup know-how system titled 'LayupRITE'. Underpinned by significant volumes of research at the University of Bristol, LayupRITE is a series of software, hardware, quality, design for manufacturing (DFM), and training platforms that have been combined and deployed under the one capability. It is a system of augmenting technologies intending to develop layup competencies, with an overall intention of de-risking the hand layup process; increasing reliability and quality. In this paper we will introduce the system, its technologies and capabilities, and show examples of its successful application in training and production environments. [ABSTRACT FROM AUTHOR]

Published
2019

28. Hypercholesterolemia after cardiac transplantation in children

Author

Uzark, Karen, Crowley, Dennis, Callow, Louise, and Bove, Edward

Subjects
Transplantation of organs, tissues, etc. -- Complications, Hypercholesterolemia in children -- Physiological aspects, Heart -- Transplantation, Atherosclerosis in children -- Causes of, Hypercholesterolemia in children -- Drug therapy, Hyperlipidemia in children -- Physiological aspects, Hyperlipidemia in children -- Care and treatment, Health
Abstract

During the past decade, a steadily increasing number of children have undergone heart transplantation. The leading causes of death in the period immediately following transplant are graft rejection and complications of treatments given to suppress this immune reaction. In the ensuing years, death can result from atherosclerosis, which is much more prevalent in transplant patients, both children and adults, than in the general population. (Atherosclerosis is the build-up of fatty material inside coronary arteries and results in diminished blood flow to the heart.) This condition may result from a variety of factors; one explanation implicates hyperlipidemia (high blood levels of fats and cholesterol). To assess the rate of hyperlipidemia among young heart transplant patients, 14 children between 6 months and 16 years of age were evaluated before and after transplantation. Within 12 months of surgery, 12 of 14 children (86 percent) developed hypercholesterolemia. The results indicate that this was not the result of treatment with anti-inflammatory agents or other drugs administered to prevent graft rejection; there was no correlation between cholesterol levels and blood levels of corticosteroids or cyclosporine. In addition, there was no correlation between cholesterol levels and the dosages of these drugs. Niacin therapy was instituted in five patients with particularly high cholesterol levels, and resulted in a significant decrease in hypercholesterolemia. Excessive levels of cholesterol have been linked to the development of atherosclerosis. Hyperlipidemia, particularly hypercholesterolemia, is a common problem in children following heart transplantation, and should be evaluated within two months of transplant surgery, and periodically thereafter. Elevated cholesterol should be treated, either with cholesterol-lowering drugs or other therapies. (Consumer Summary produced by Reliance Medical Information, Inc.)

Published
1990

33. HAND LAY-UP OF COMPLEX GEOMETRIES - PREDICTION, CAPTURE AND FEEDBACK.

Author

Crowley, Dennis M., Elkington, Michael, Ward, Carwyn, and Potter, Kevin

Subjects
GEOMETRIC analysis, MOLDING (Founding), DIFFERENCES, INDUSTRIAL productivity, STOCHASTIC learning models
Abstract

This paper presents a process improvement framework built on previous research activities at the University of Bristol. The work focusses on hand lay-up and seeks to reduce variability, improve productivity and increase manufacturability of future designs. The framework is based on a double-loop learning model which incorporates prediction, capture and feedback. The predictive method employed uses a kinematic drape model as part of an expert system. The expert is needed to translate the model outputs into a more realistic set of drape instructions. The lay-up is captured by video analysis and quality data captured using an on-line tool. This data is then fed back to the user to facilitate decision making. [ABSTRACT FROM AUTHOR]

Published
2016

34. DevTrack 6.0

Author

Crowley, Dennis

Subjects
Microsoft Corp., Computer software industry, Computer programmers
Abstract

AS A PROGRAMMER, IT'S AS HARD TO BE excited about bug databases as it is about source control ... or your text editor. Bug- and issue-tracking just isn't sexy. [ILLUSTRATION […]

Published
2006

35. High Dynamic Range Imaging

Author

Crowley, Dennis

Subjects
High Dynamic Range Imaging: Acquisition, Display, and Image-Based Lighting (Book) -- Book reviews, Books -- Book reviews
Abstract

"HDRI" HAS LATELY BECOME MORE and more of a buzzword in our industry (we'll uncover what it means in a moment). Valve has begun to implement this technology in its […]

Published
2006

38. Neonatal Cardiac Catheterization: A 10-Year Transition from Diagnosis to Therapy

Author

Division of Pediatric Cardiology, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, MI, USA, US, Division of Pediatric Cardiology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA, US, Ann Arbor, Shim, David, Beekman III, Robert H., Lloyd, Thomas R., Crowley, Dennis C., Division of Pediatric Cardiology, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, MI, USA, US, Division of Pediatric Cardiology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA, US, Ann Arbor, Shim, David, Beekman III, Robert H., Lloyd, Thomas R., and Crowley, Dennis C.

Abstract

To assess the changing role of cardiac catheterization in the care of the neonate, a retrospective review of all catheterizations between January 1984 to December 1985 (group I) and January 1994 to December 1995 (group II) at C.S. Mott Children's Hospital was performed. Neonatal cardiac catheterization was performed more frequently (p = 0.02) in group I, comprising 14% (110 of 772) of all catheterizations versus 11% (93 of 880) in group II. Access was performed by cutdown in 15 patients (13 venous and 2 arterial), all in group I. In group I, 20 of 110 patients (18%) had balloon atrial septostomies; no other catheter interventions were performed. Interventions were more frequent (p = 0.003) and varied in group II, including 15 septostomies, 17 balloon valvuloplasties (13 pulmonary and 4 aortic), 2 coil embolizations of collaterals, and 1 cardiac biopsy. Despite the higher prevalence and complexity of interventions in group II, fluoroscopy times (median; range: 16 min; 2???55 vs 16 min; 1???107) were similar in both groups (p = not significant) as well as the prevalence of complications. Neonatal cardiac catheterizations are performed less frequently than they were a decade ago at our institution, and therapeutic interventions have become more common. Despite these changes, fluoroscopy time and the rate of complications have not increased.

Published
2006

39. Pressure-Regulated Volume Control vs Volume Control Ventilation in Infants After Surgery for Congenital Heart Disease

Author

Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109, USA, US, Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA, US, Department of Pediatrics and Surgery, University of Southern California School of Medicine, Los Angeles, CA 90027, USA, US, Ann Arbor, Crowley, Dennis C., Bove, Edward L., Kulik, Thomas J., Rosen, H.K., Bandy, Kenneth P., Dekeon, M.K., Kocis, Keith C., Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109, USA, US, Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA, US, Department of Pediatrics and Surgery, University of Southern California School of Medicine, Los Angeles, CA 90027, USA, US, Ann Arbor, Crowley, Dennis C., Bove, Edward L., Kulik, Thomas J., Rosen, H.K., Bandy, Kenneth P., Dekeon, M.K., and Kocis, Keith C.

Abstract

The objective of this investigation was to compare how two modes of positive pressure ventilation affect cardiac output, airway pressures, oxygenation, and carbon dioxide removal in children with congenital heart disease in the immediate postoperative period. The investigation used a one group pretest???post-test study design and was performed in the pediatric cardiac intensive care unit in a university-affiliated children's hospital. Nine infants were enrolled immediately after repair of tetralogy of Fallot (2) or atrioventricular septal defects (7) with mean weight = 5.5 kg (4.2???7.3 kg). Children were admitted to the pediatric cardiothoracic intensive care unit after complete surgical repair of their cardiac defect and stabilized on a Siemen's Servo 300 ventilator in volume control mode (VCV1) (volume-targeted ventilation with a square flow wave pattern). Tidal volume was set at 15 cc/kg (total). Hemodynamic parameters, airway pressures and ventilator settings, and an arterial blood gas were measured. Patients were then changed to pressure-regulated volume control mode (PRVC) (volume-targeted ventilation with decelerating flow wave pattern) with the tidal volume set as before. Measurements were repeated after 30 minutes. Patients were then returned to volume control mode (VCV2) and final measurements made after 30 minutes. The measurements and results are as follows

Published
2006

40. Hemodynamic determinants of exercise-induced ST-Segment depression in children with valvar aortic stenosis

Author

Department of Pediatrics and Communicable Diseases, Section of Pediatric Cardiology, C.S. Mott Children's Hospital, The University of Michigan Medical School, Ann Arbor, Michigan, USA, Kveselis, Daniel A., Rocchini, Albert P., Rosenthal, Amnon, Crowley, Dennis C., Dick, Macdonald II, Snider, A. Rebecca, Moorehead, Catherine P., Department of Pediatrics and Communicable Diseases, Section of Pediatric Cardiology, C.S. Mott Children's Hospital, The University of Michigan Medical School, Ann Arbor, Michigan, USA, Kveselis, Daniel A., Rocchini, Albert P., Rosenthal, Amnon, Crowley, Dennis C., Dick, Macdonald II, Snider, A. Rebecca, and Moorehead, Catherine P.

Abstract

To evaluate the hemodynamic factors associated with treadmill-induced ST-segment depression in children with valvar aortic stenosis, 12 patients (mean age 13 years) with ST-segment depression during treadmill exercise and 5 patients (mean age 13 years) without ST-segment depression during treadmill exercise underwent exercise testing during cardiac catheterization. The left ventricular (LV) systolic pressure and LV outflow tract gradient at rest (177 +/- 25 vs 138 +/- 8 mm Hg and 59 +/- 18 vs 23 +/- 7 mm Hg, respectively) and corresponding pressures during maximal supine exercise (248 +/-37 vs 189 +/- 17 mm Hg and 112 +/- 34 vs 52 +/- 14 mm Hg) were significantly greater (p 2 supply-demand ratio during maximal supine exercise was significantly less (6.4 +/- 2.7 vs 11.8 +/- 0.7; p 2 supply-demand ratio less than 11.0 was 100% sensitive and specific in predicting treadmill-induced ST-segment depression. These results suggest that although the development of ST-segment depression during treadmill exercise is related to LV systolic pressure and LV outflow gradient, its major hemodynamic determinant is the LV-02 supply-demand ratio.

Published
2006

41. Results of balloon valvuloplasty in the treatment of congenital valvar pulmonary stenosis in children

Author

Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan, USA, Kveselis, Daniel A., Rocchini, Albert P., Snider, A. Rebecca, Rosenthal, Amnon, Crowley, Dennis C., Dick, Macdonald II, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, Michigan, USA, Kveselis, Daniel A., Rocchini, Albert P., Snider, A. Rebecca, Rosenthal, Amnon, Crowley, Dennis C., and Dick, Macdonald II

Abstract

Transluminal balloon valvuloplasty was used in the treatment of congenital valvar pulmonary stenosis in 19 children, aged 5 months to 18 years. The right ventricular (RV) systolic pressure and RV outflow tract gradient decreased significantly immediately after the procedure (95 +/- 29 vs 59 +/- 14 mm Hg, p <0.01, and 78 +/- 27 vs 38 +/- 13 mm Hg, p <0.01). Seven of these patients were evaluated at cardiac catheterization 1 year after balloon valvuloplasty. No significant change occurred in RV systolic pressure or RV outflow tract gradient at follow-up evaluation compared with measurements immediately after balloon valvuloplasty (60 +/- 5 mm Hg vs 56 +/- 12 mm Hg and 39 +/- 5 vs 38 +/- 10 mm Hg). In addition, follow-up evaluation was performed using noninvasive methods and included electrocardiography (n = 13), vectorcardiography (n = 11) and Doppler echocardiography (n = 11) Doppler echocardiography in 11 patients 15 +/- 9 months after balloon valvuloplasty showed a continued beneficial effect with a mild further decrease in RV outflow tract gradient. Thus, balloon valvuloplasty is effective in the relief of pulmonary stenosis.

Published
2006

43. The social web

Author

Crowley, Dennis, primary, Reas, Casey, additional, Schneider, Michael, additional, and Tiersky, Howard, additional

Published
2005
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46. Aminophylline for the prevention of apnea during prostaglandin [E.sub.1] infusion

Author

Lim, D.S., Kulik, Thomas J., Kim, Dennis W., Charpie, John R., Crowley, Dennis C., and Maher, Kevin O.

Subjects
Prostaglandins -- Physiological aspects, Apnea -- Prevention, Aminophylline -- Testing
Abstract

Background. Apnea is associated with prostaglandin [E.sub.1] infusion (PG[E.sub.1]) used in the palliation of ductal-dependent congenital heart lesions. Hypothesis. Aminophylline is a central respiratory stimulant and will decrease the incidence of PG[E.sub.1]-associated apnea and the need for intubation for apnea in infants with ductal-dependent congenital heart disease. Methods. Informed consent was obtained for all patients. In a prospective, double-blinded, placebo-controlled study, newborn infants with ductal-dependent congenital heart disease were randomized to receive either aminophylline or placebo during initiation and maintenance of PG[E.sub.1], which was started at 0.01 [micro]g/kg/ min and increased to 0.03 [micro]g/kg/min. Aminophylline was given as a bolus dose of 6 mg/kg before or during initiation of PG[E.sub.1], and continued at 2 mg/kg dose every 8 hours for 72 hours. Serum aminophylline levels were checked at 18 and 36 hours. The primary study endpoint was intubation for apnea, with a secondary endpoint of apnea, as defined as acute cessation of breathing with associated hypoxia and bradycardia. Results. The study evaluated 42 infants. The 2 groups were similar for gestational age, weight, hematocrit, and use of sedation. In the aminophylline group, serum levels were 7.6 [+ or -] 1.2 [micro]g/mL. No significant side effects of aminophylline were seen. Infants receiving aminophylline (n = 21) were less likely to have apnea (2 vs 11) or be intubated for apnea (0 vs 6). Length of postoperative stay and survival to discharge were similar between the 2 groups. Conclusions. Aminophylline was effective for the prevention of apnea and intubation for apnea associated with PG[E.sub.1] in infants with ductal-dependent congenital heart disease. Pediatrics 2003;112:e27-e29. URL: http: //www.pediatrics.org/cgi/content/full/112/1/e27; prostaglandin, apnea, congenital heart disease.

Published
2003

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