Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “computational design”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1988

The ergonomics of computer aided design within advanced manufacturing technology.

Many manufacturing companies have now awakened to the significance of computer aided design (CAD), although the majority of them have only been able to purchase computerised draughting systems of which only a subset produce direct manufacturing data. Such companies are moving steadily towards the concept of computer integrated manufacture (CIM), and this demands CAD to address more than draughting. CAD architects are thus having to rethink the basic specification of such systems, although they typically suffer from an insufficient understanding of the design task and have consequently been working with inadequate specifications. It is at this fundamental level that ergonomics has much to offer, making its contribution by encouraging user-centred design. The discussion considers the relationships between CAD and: the design task; the organisation and people; creativity; and artificial intelligence. It finishes with a summary of the contribution of ergonomics.

Journal Article↗
PubMed2004

[The computer-aided design and manufacture of unilateral orbital defect restoration].

OBJECTIVE: By reverse engineering and rapid prototyping techniques to found a new design method of maxillofacial restoration. METHODS: By laser scanning apparatus the plaster face model was scanned and the primitive face point data were acquired. With the reverse engineering software, the point data were reconstructed to one smooth face surface image and the defect orbital tissue shape data was obtained from the normal contralateral tissue data in the software. The model designed the three-dimensional data of defect part and the rapid prototyping technique made the resin orbital restoration. RESULTS: The laser scanning apparatus acquired the distinct and precise model data of the plaster face-model. The Digisurface retrograde engineer software succeeded to fulfill the unilateral orbital defect computer-aided design. The orbital restoration inosculated the plaster model tightly and symmetrically. CONCLUSION: The reverse engineering software and rapid prototyping technique could finish the computer-aided design and manufacture of the unilateral orbital defect restoration smoothly and satisfactorily.

Computer-Aided Design↗
PubMed2002

Computational drug design accommodating receptor flexibility: the relaxed complex scheme.

A novel computational methodology for drug design that accommodates receptor flexibility is described. This "relaxed-complex" method recognizes that ligand may bind to conformations that occur only rarely in the dynamics of the receptor. We have shown that the ligand-enzyme binding modes are very sensitive to the enzyme conformations, and our approach is capable of finding the best ligand-enzyme complexes. This new method serves as the computational analog of the experimental "SAR by NMR" and "tether" methods, which permit a building block approach for constructing a very potent drug.

Algorithms↗
PubMed2000

A computer-aided design mammography screening system for detection and classification of microcalcifications.

This paper presents a prototype of a computer-aided design (CAD) diagnostic system for mammography screening to automatically detect and classify microcalcifications (MCCs) in mammograms. It comprises four modules. The first module, called the Mammogram Preprocessing Module, inputs and digitizes mammograms into 8-bit images of size 2048x2048, extracts the breast region from the background, enhances the extracted breast and stores the processed mammograms in a data base. Since only clustered MCCs are of interest in providing a sign of breast cancer, the second module, called the MCCs Finder Module, finds and locates suspicious areas of clustered MCCs, called regions of interest (ROIs). The third module, called the MCCs Detection Module, is a real time computer automated MCCs detection system that takes as inputs the ROIs provided by the MCCs Finder Module. It uses two different window sizes to automatically extract the microcalcifications from the ROIs. It begins with a large window of size 64x64 to quickly screen mammograms to find large calcified areas, this is followed by a smaller window of size 8x8 to extract tiny, isolated microcalcifications. Finally, the fourth module, called the MCCs Classification Module, classifies the detected clustered microcalcifications into five categories according to BI-RADS (Breast Imaging Reporting and Data System) format recommended by the American College of Radiology. One advantage of the designed system is that each module is a separate component that can be individually upgraded to improve the whole system. Despite that it is still is a prototype system a preliminary clinical evaluation at TaiChung Veterans General Hospital (TCVGH) has shown that the system is very flexible and can be integrated with the existing Picture Archiving and Communications System (PACS) currently implemented in the Department of Radiology at TCVGH.

Algorithms↗
PubMedDate not supplied

Fabrication of total-contact burn masks by use of human body topography and computer-aided design and manufacturing.

Total-contact burn masks are used to treat scar tissue hypertrophy of the face. The mask should conform very closely to the contours of the face and provide evenly distributed pressure. The mask is worn continually throughout wound maturation. Lack of fit because of an inability to obtain exact facial contours by use of an alginate material diminishes the effectiveness of the mask. A multidisciplinary team representing physical therapy, CAD/CAM (computer-aided design and computer-aided manufacturing), biomedical engineering, and prosthetics has advanced the method of developing total-contact burn masks by use of human body electronic imaging, computer graphics, and numerically controlled milling processes. High-resolution surface scanning and CAD/CAM have been used successfully to accurately fabricate three such masks. The methodology and preliminary results from use of these state-of-the-art techniques are described in this article.

Burns↗
PubMed1996

Can children with autism be taught to understand false belief using computers?

A specially designed computer version of the Sally-Anne false task belief task was used to teach understanding of false belief to three groups: children with autism, children with Down's Syndrome and young normal children. In an initial assessment children were selected for teaching only if they failed four false belief tasks: the dolls version of the Sally-Anne task (close transfer task) and three other false belief tasks involving different scenarios (distant transfer tasks). Following teaching, all three groups were able to pass the Sally-Anne task, but the children with autism alone were unable to pass the distant transfer tasks. The possibility that the children with autism had developed an alternative strategy in order to pass the instruction task is discussed.

Autistic Disorder↗
PubMedDate not supplied

A system for computer-assisted design of stent-grafts for aortic aneurysms using 3-D morphological models.

A three-dimensional model was constructed from helical CT images for abdominal aortic aneurysm (AAA) and thoracic aortic aneurysm (TAA). A stent-graft was designed and positioned endoluminally on the computer. One hundred and nine stent-grafts for 101 patients were designed by this method and deployed well in all patients. The design time was reduced from 4 to 0.5 hr.

Adult↗
PubMed1984

A computer-aided design for orthognathic surgery.

An interactive on-line computer system is described with application in orthognathic surgery. Both the hardware and software of the system are discussed. The application of the system is outlined under the various features of the system's software. The general software collects, stores and analyses graphic data such as from cephalometric radiographs and facial and dental photographs. The specific software handles the planning requirements of orthognathic surgery--diagnosis, treatment planning and prediction of post-operative soft-tissue profile.

Cephalometry↗
PubMed1996

Interactive simulation of cranial surgery in a computer aided design environment.

Accurate pre-surgical planning is a prerequisite for successful craniofacial surgery. This paper introduces a simulation system developed in a computer aided design (CAD) environment, where a 3-D mathematical model of the skull is entered. The architecture of the program yields a flexible and easy-to-use system that allows the simulation of surgery on the wire frame image of the model. Possible actions simulated are osteotomy, bending, rotation, translation and removal. Numerical values for anatomical distances and the intracranial volume are easily calculated. Information on the techniques used and the numerical data resulting from the simulation can be stored. Plots of intermediate steps of the simulation or of contours of separate pieces permit feed-back to the operating theatre.

Computer Simulation↗
PubMed2002

Virtual reality modeling and computer-aided design in pediatric surgery: applications in laparoscopic pyloromyotomy.

As a test of the applicability of modern bioengineering tools to pediatric surgery, we developed by computer-aided design (CAD) methods and evaluated a virtual reality (VR) model of laparoscopic pyloromyotomy (LP) and created a set of retractable hook instruments, called Pylorohooks. Our VR model of LP incorporated the infant's body wall, stomach, and hypertrophied pylorus as well as laparoscopic cannulas and two Pylorohooks. CAD software was used to design the 3-mm-diameter, retractable, double-pronged, minimally-traumatic hook instrument. A rapid prototype processor was employed to create a plastic model of the instrument. Surgical-grade stainless-steel prototypes were then manufactured and used in actual LPs. A working VR model was achieved. Following an initial correction in the angulation of the hooks, the instruments were successfully employed in nine consecutive LPs in infants weighing from 3.4 to 5.7 kg. VR and CAD thus proved instrumental in the development of a new LP approach. Because of increasing pressure to limit human and animal experimentation, computer-based bioengineering methods offer promising alternatives that are clearly applicable to pediatric surgery.

Computer-Aided Design↗
PubMed2002

A new brain-computer interface design using fuzzy ARTMAP.

This paper proposes a new brain-computer interface (BCI) design using fuzzy ARTMAP (FA) neural network, as well as an application of the design. The objective of this BCI-FA design is to classify the best three of the five available mental tasks for each subject using power spectral density (PSD) values of electroencephalogram (EEG) signals. These PSD values are extracted using the Wiener-Khinchine and autoregressive methods. Ten experiments employing different triplets of mental tasks are studied for each subject. The findings show that the average BCI-FA outputs for four subjects gave less than 6% of error using the best triplets of mental tasks identified from the classification performances of FA. This implies that the BCI-FA can be successfully used with a tri-state switching device. As an application, a proposed tri-state Morse code scheme could be utilized to translate the outputs of this BCI-FA design into English letters. In this scheme, the three BCI-FA outputs correspond to a dot and a dash, which are the two basic Morse code alphabets and a space to denote the end (or beginning) of a dot or a dash. The construction of English letters using this tri-state Morse code scheme is determined only by the sequence of mental tasks and is independent of the time duration of each mental task. This is especially useful for constructing letters that are represented as multiple dots or dashes. This combination of BCI-FA design and the tri-state Morse code scheme could be developed as a communication system for paralyzed patients.

Brain↗
PubMed1995

[The rational computer-aided design of new drugs: a review of the methods].

Progress in computer science over recent 10 years has sharply reduced both the cost and the time spent on designing new drugs. Various concepts in solving this problem are now integrated into one approach--computer-assisted rational drug design. It consists of two groups of methods: 1) computer-assisted analysis of chemical structure-biological activity relationships by QSAR, OSMR, 3D QSAR and CoMFA; 2) computer modelling of the interaction of a ligand (a small drug molecule) with its target--a biological macromolecule, which is generally a protein. The findings of new ligands, which would selectively bind to the well-known protein can be done by screening the small molecules listed in some computer data bases. These new chemical structures can be used as a basis for drug designing.

Computer Simulation↗
PubMed2005

A computer-aided design system for revision of segmentation errors.

Automatic image segmentation methods often involve errors, requiring the assistance of the user to correct them. In this paper, a computer-aided design system is introduced for correcting such errors. The proposed system approximates each 3-D region by a parametric surface. Region voxels are first parametrized spherically using a coarse-to-fine subdivision method. By using the voxel positions and their parameter coordinates, control points of a rational Gaussian surface are determined through a least-squares method to approximate the region. Finally, this surface is overlaid with the volumetric image and by locally pulling or pushing it with the mouse while viewing image information, the surface is revised as needed. Typically, a few minutes are sufficient to correct errors in a region.

Algorithms↗
PubMed2000

Three-dimensional morphological analysis of the proximal femoral canal, using computer-aided design system, in Japanese patients with osteoarthrosis of the hip.

An accurate three-dimensional morphological analysis of the femur is required to produce well fitting uncemented femoral implants. A computer-aided design system made it possible to produce three-dimensional femoral models and to accurately measure certain parameters with planes standardized for all subjects. The study subjects were Japanese; there were 89 patients (113 hips) with osteoarthrosis (OA) and 18 volunteers (36 hips) free of hip joint complaints and with no abnormal radiological findings (normal; N). The femoral canal was classified into three types, A-I, A-II, and B-II, based on the shape in the frontal and sagittal planes. Either triangular (type T) or circular (type C) shapes were identified at the proximal cross section. Type A-II, which is considered the standard type, accounted for 89% of the N hips, and 42% of the OA hips. Type A-I, with a posterior canal plane strongly inclined toward the anterior, accounted for 26% of the OA hips and 6% of the N hips; 96% of type A-I hips were triangular. Type B-II, which had a steep medial canal plane, accounted for 29% of the OA hips and 6% of the N hips; 63% of type B-II hips were circular.

Adult↗
PubMed1999

Learning to design synergetic computers with an extended symmetric diffusion network.

This article proposes an extended symmetric diffusion network that is applied to the design of synergetic computers. The state of a synergetic computer is translated to that of order parameters whose dynamics is described by a stochastic differential equation. The order parameter converges to the Boltzmann distribution, under some condition on the drift term, derived by the Fokker-Planck equation. The network can learn the dynamics of the order parameters from a nonlinear potential. This property is necessary to design the coefficient values of the synergetic computer. We propose a searching function for the image processing executed by the synergetic computer. It is shown that the image processing with the searching function is superior to the usual image-associative function of synergetic computation. The proposed network can be related, as a special case, to the discrete-state Boltzmann machine by some transformation. Finally, the extended symmetric diffusion network is applied to the estimation problem of an entire density function, as well as the proposed searching function for the image processing.

Artificial Intelligence↗
PubMed1994

Computer-assisted design of an implantable, intrathoracic artificial lung.

A semiempirical mathematical model of convective oxygen transport is used to design a new, low pressure loss, implantable artificial lung that could be used as a bridge to lung transplantation in patients with advanced respiratory failure. The mass transfer and flow friction relations pertinent to the design of a cross-flow hollow fiber membrane lung are described. The artificial lung is designed to transfer over 200 ml/min of oxygen at blood flow rates up to 5 L/min. A compact design and a blood-side pressure loss of < 15 mm Hg allows the device to be implanted in the left chest without the need for a prosthetic blood pump. Surgical implantation of the artificial lung would require the creation of inflow and outflow anastomoses. Oxygen would be supplied via an external source. Blood properties, operating conditions, and empirically determined mass transfer and flow properties are all specified and input into a computer program that numerically solves the design equations. Computer-generated values for the device frontal area, blood path length, and fiber surface area are thereby obtained. The use of this computer-assisted design minimizes the need for extensive trial-and-error testing of prototype devices. Results from in vitro tests of a prototype implantable lung indicate that the mathematical model we describe is an accurate and useful tool in the design of hollow fiber artificial lungs.

Algorithms↗
PubMed2001

[Study on computer aided design system of anterior prosthesis in terms of artificial neural network].

OBJECTIVE: This study was to develop computer aided design system of anterior prosthesis, which can improve information communication among doctors, technicians, patients and raise anterior prosthesis cosmetic effect. METHODS: Digital camera was used for image capture; Space field method, neighboring field average method, midst value filter method, and image average method were used for image pre-process; sample teeth were constructed; anterior prosthesis were automatically designed through tooth feature extraction. RESULTS: 86 patients were prosthetically designed through this CAD system with excellent results. CONCLUSION: This system implemented anterior prosthesis CAD rapidly, guided clinical application and promoted information process in the field of prosthetics.

English Abstract↗
PubMed2001

Towards the design and computational characterization of a membrane protein.

The design of a transmembrane four-helix bundle is described. We start with an idealized four-helix bundle geometry, then use statistical information to build a plausible transmembrane bundle. Appropriate residues are chosen using database knowledge on the sequences of membrane helices and loops, then the packing of the bundle core is optimized, and favorable side chain rotamers from rotamer libraries are selected. Next, we use explicit physical knowledge from biomolecular simulation force fields and molecular dynamics simulations to test whether the designed structure is physically possible. These procedures test whether the designed protein will indeed be alpha-helical, well packed and stable over a time scale of several nanoseconds in a realistic lipid bilayer environment. We then test a modeling approach that does not include sophisticated database knowledge about proteins, but rather relies on applying our knowledge of the physics that governs protein motions. This independent validation of the design is based on simulated annealing and restrained molecular dynamics simulation in vacuo, comparable to procedures used to refine NMR and X-ray structures.

Computer Simulation↗