scholarly journals Computational Simulations of the Anterior Vertebral Surface for Optimal Surgical Instrumentation Design

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Francisco Casesnoves
Keyword(s):  
Vertebral Body ◽  
Design Method ◽  
Computational Design ◽  
Human Bone ◽  
Mechanical Forces ◽  
Grid Data ◽  
Statistical Parameters ◽  
Surgical Instrumentation ◽  
The Individual ◽  
Fitting Model

The engineering design of surgical instrumentation to apply mechanical forces and linear moments on the human bones during the operations constitutes a rather difficult task. This is due both to the natural and pathological irregularities of the human bone morphology and surfaces and also to the individual variations from one patient to another. Usually, the forces are applied by the surgeon only on a determined part of the bone surfaces. This paper describes an innovative computational design method to digitalize, simulate, and fit mathematically the anterior vertebral body facet. We used real experimental data from 17 human cadaveric specimens to get and store a large amount of numerical surface digital values. The complete anterior vertebral body side was visualized and analyzed with grid data Subroutine, which was also used first to select the so-called natural regions of interest (ROIs). These ROIs correspond to those parts of the surface in contact with the surgical instrumentation, where the mechanical forces are applied. Subsequently, a numerical mathematical fitting-model was implemented for these ROIs. This was carried out with the development of a 3D geometrical least-squares optimization algorithm and appropriate software designed according to the proper numerical method selected. In doing so, the 3D superficies equations of the anterior vertebral body (L3, L4, L5, and S1) were determined after these fittings were mathematically checked as appropriate. Statistical parameters and determination coefficients that define the error boundaries and the goodness of this optimal fitting-model were calculated and NURBS error data in similar studies were commented. It was proven that the principal source of error was the micro- and macro-irregularities of human bone facets. The final surface equations, and their geodesics, were used to obtain accurate data for the spinal surgery instrumentation manufacturing. The industrial bioengineering result was the application of these equations for the design of a new spinal vertebral surgical distractor. This innovative distractor separates two adjacent vertebrae while keeping them parallel. That is, at their natural inclination, avoiding hammering the vertebrae to make the intervertebral space wider. The device mechanics also minimizes the necessary force to be carried out by the surgeon during the operation.

Computational Simulations of Vertebral Body for Optimal Instrumentation Design

2012 ◽  
Vol 6 (2) ◽  
Author(s):  
F. Casesnoves
Keyword(s):  
Experimental Data ◽  
Engineering Design ◽  
Vertebral Body ◽  
Technical Difficulty ◽  
Regions Of Interest ◽  
Computational Method ◽  
Mechanical Forces ◽  
Computational Simulations ◽  
Large Sets ◽  
Fitting Model

The engineering design of surgical instrumentation to exert forces and torques/moments on bones during operations constitutes a rather difficult task. This technical difficulty is caused mainly by the natural, pathological, and individual irregularities of the human bone morphologies and surfaces. Usually, mechanical forces are applied on determined parts of bone surfaces, so-called regions of interest (ROIs). We describe a computational method (CAD) to digitalize, simulate, and fit mathematically the anterior vertebral body morphometric. Based on experimental data from 17 cadaveric specimens, large sets of surface digital points were generated. Complete anterior vertebral body morphologies were visualized and analyzed with subroutines, which are initially used to select these natural ROIs. Subsequently, an optimized fitting model was implemented for the ROIs. 3D surface equations of the anterior vertebral body (L3, L4, L5, and S1) were determined. Statistics and determination coefficients which define the error boundaries and goodness of the model, were calculated and mathematically analyzed. A bioengineering application is the use of these equations for the industrial design of an innovative vertebral distractor. The device separates two adjacent vertebrae in parallel, and minimizes the force to carry out the surgical maneuver.

A Framework for Component Layout and Geometry Design of Mechanical Systems: Configuration Network and its Viewing Control

1995 ◽  
Author(s):  
Kikuo Fujita ◽  
Shinsuke Akagi
Keyword(s):  
Design Method ◽  
Mechanical Systems ◽  
Optimization Procedure ◽  
Computational Design ◽  
Object Oriented Programming ◽  
Design System ◽  
Air Conditioner ◽  
Programming Technique ◽  
Geometry Design ◽  
Component Layout

Abstract A Framework of computational design method and model is proposed for layout and geometry design of complicated mechanical systems, which is named “configuration network and its viewing control”. In the method, a design object is represented with a set of declarative relationships among various elements of a system, that is, configurations, which is gradually extended from schematic structure to exact layout and geometry through design process. Since a whole of such configurations forms a too complicated network to compute all together, how to view subparts is controlled based on levels of granularity and width of scope range. Such a configuration network is made to grow and refined through embodying geometry and layout corresponding to a focused subpart with a numerical optimization procedure. The framework has also an ability to flexibly integrate with engineering analysis. Moreover, a design system is implemented with an object-oriented programming technique, and it is applied to a design problem of air conditioner units in order to show the validity and effectiveness of the framework.

Computational Design for Digitally Fabricated 3D Inductive Power Transfer Coils

2022 ◽  
pp. 1-28
Author(s):  
Jun Xu ◽  
Eugeni L. Doubrovski ◽  
Jo Geraedts ◽  
Yu Song
Keyword(s):  
Design Method ◽  
Computational Design ◽  
Future Research ◽  
Receiver Coil ◽  
Power Transfer ◽  
Coil Design ◽  
Optimal Position ◽  
Inductive Power Transfer ◽  
Transmitter Coil ◽  
Inductive Power

Abstract The geometric shapes and the relative position of coils influence the performance of a three-dimensional (3D) inductive power transfer system. In this paper, we propose a coil design method for specifying the positions and the shapes of a pair of coils to transmit the desired power in 3D. Given region of interests (ROIs) for designing the transmitter and the receiver coils on two surfaces, the transmitter coil is generated around the center of its ROI first. The center of the receiver coil is estimated as a random seed position in the corresponding 3D surface. At this position, we use the heatmap method with electromagnetic constraints to iteratively extend the coil until the desired power can be transferred via the set of coils. In each step, the shape of the extension, i.e. a new turn of the receiver coil, is found as a spiral curve based on the convex hulls of adjacent turns in the 2D projection plane along their normal direction. Then, the optimal position of the receiver coil is found by maximizing the efficiency of the system. In the next step, the position and the shape of the transmitter coil are optimized based on the fixed receiver coil using the same method. This zig-zag optimization process iterates until an optimum is reached. Simulations and experiments with digitally fabricated prototypes were conducted and the effectiveness of the proposed 3D coil design method was verified. Possible future research directions are highlighted well.

Defining the Individual

2010 ◽  
Author(s):  
Niall Sharples
Keyword(s):  
Iron Age ◽  
Soil Layer ◽  
Human Remains ◽  
Human Bone ◽  
Cultural Tradition ◽  
Left Femur ◽  
Southern England ◽  
Socially Constructed ◽  
Definition Of ◽  
The Individual

During the 1985 excavation at Maiden Castle (Sharples 1991a), a large grain storage pit cut into the back of the rampart of the Early Iron Age hillfort was excavated. About half way down the fill of that pit the left femur of a mature adult was exposed. This bone was lying in a relatively sterile soil layer and it was not marked by any special finds or careful constructions; in many respects it could easily be dismissed as a discovery with little significance. Fifty years ago such bones would have been regarded as accidental losses, simply rubbish conveniently disposed of in a handy receptacle. It could be an indication that excarnation was the general means of disposal and that this occurred close to or actually inside settlements, but it might also indicate the accidental disturbance of human remains in graves located at the hillfort. In recent years we have come to understand that these deposits are much more significant. A number of archaeologists (Whimster 1981; C. Wilson 1981; Cunliffe 1992) came to realize that the presence of human remains on Iron Age settlements was a distinct cultural tradition characteristic of central southern England. The work of J. D. Hill (1995b) has enhanced our understanding of this phenomenon by emphasizing that the deposition of human remains is part of a complex suite of actions which involves the arrangement of different categories of material in carefully placed deposits. The process of deposition was clearly intimately involved in the definition of social relationships in the Iron Age of central southern England. It is difficult to imagine that if we, as archaeologists, could immediately recognize a human bone, our ancient pit diggers could not. The placement of this bone was a deliberate act, and the location of this deposit was carefully chosen. Hill (1995b) has shown that these pit deposits were carefully structured. Human remains are normally found in layers that are largely sterile, but a pit chosen for the deposition of human bone will normally have fills containing other carefully selected deposits. These mark the pit as a bank of socially constructed material.

scholarly journals Multistate design of influenza antibodies improves affinity and breadth against seasonal viruses

2019 ◽  
Vol 116 (5) ◽  
pp. 1597-1602 ◽  
Author(s):  
Alexander M. Sevy ◽  
Nicholas C. Wu ◽  
Iuliia M. Gilchuk ◽  
Erica H. Parrish ◽  
Sebastian Burger ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Design Method ◽  
Computational Design ◽  
Surface Proteins ◽  
Antigenic Drift ◽  
Global Public Health ◽  
Large Panels ◽  
Rapid Changes ◽  
Large Panel ◽  
Ha Protein

Influenza is a yearly threat to global public health. Rapid changes in influenza surface proteins resulting from antigenic drift and shift events make it difficult to readily identify antibodies with broadly neutralizing activity against different influenza subtypes with high frequency, specifically antibodies targeting the receptor binding domain (RBD) on influenza HA protein. We developed an optimized computational design method that is able to optimize an antibody for recognition of large panels of antigens. To demonstrate the utility of this multistate design method, we used it to redesign an antiinfluenza antibody against a large panel of more than 500 seasonal HA antigens of the H1 subtype. As a proof of concept, we tested this method on a variety of known antiinfluenza antibodies and identified those that could be improved computationally. We generated redesigned variants of antibody C05 to the HA RBD and experimentally characterized variants that exhibited improved breadth and affinity against our panel. C05 mutants exhibited improved affinity for three of the subtypes used in design by stabilizing the CDRH3 loop and creating favorable electrostatic interactions with the antigen. These mutants possess increased breadth and affinity of binding while maintaining high-affinity binding to existing targets, surpassing a major limitation up to this point.

Designing Optimal Origami Structures by Computational Evolutionary Embryogeny

2014 ◽  
Author(s):  
Wei Li ◽  
Daniel A. McAdams
Keyword(s):  
Design Method ◽  
Center Of Mass ◽  
Computational Design ◽  
Design Methods ◽  
Performance Criteria ◽  
Pattern Design ◽  
Modern Computer ◽  
Evolutionary Operators ◽  
Origami Engineering ◽  
Profile Position

As the advantages of foldable or deployable structures are being discovered, research into origami engineering has attracted more focus from both artists and engineers. With the aid of modern computer techniques, some computational origami design methods have been developed. Most of these methods focus on the problem of origami crease pattern design — the problem of determining a crease pattern to realize a specified origami final shape, but don’t provide computational solutions to actually developing a shape that meets some design performance criteria. This paper presents a design method that includes the computational design of the finished shape as well as the crease pattern. The origami shape will be designed to satisfy geometric, functional, and foldability requirements. This design method is named computational evolutionary embryogeny for optimal origami design (CEEFOOD), which is an extension of the genetic algorithm (GA) and an original computational evolutionary embryogeny (CEE). Unlike existing origami crease pattern design methods that adopt deductive logic, CEEFOOD implements an abductive approach to progressively evolve an optimal design. This paper presents how CEEFOOD — as a member of the GA family — determines the genetic representation (genotype) of candidate solutions, the formulation of the objective function, and the design of evolutionary operators. This paper gives an origami design problem, which has requirements on the folded-state profile, position of center of mass, and number of creases. Several solutions derived by CEEFOOD are listed and compared to highlight the effectiveness of this abductive design method.

scholarly journals Toward the computational design of protein crystals with improved resolution

2019 ◽  
Vol 75 (11) ◽  
pp. 1015-1027 ◽  
Author(s):  
Jeliazko R. Jeliazkov ◽  
Aaron C. Robinson ◽  
Bertrand García-Moreno E. ◽  
James M. Berger ◽  
Jeffrey J. Gray
Keyword(s):  
Weak Interactions ◽  
Design Method ◽  
Point Mutations ◽  
Computational Design ◽  
Data Bank ◽  
Protein Crystals ◽  
Single Individual ◽  
Space Group ◽  
Protein Backbones ◽  
Crystal Space

Substantial advances have been made in the computational design of protein interfaces over the last 20 years. However, the interfaces targeted by design have typically been stable and high-affinity. Here, we report the development of a generic computational design method to stabilize the weak interactions at crystallographic interfaces. Initially, we analyzed structures reported in the Protein Data Bank to determine whether crystals with more stable interfaces result in higher resolution structures. We found that for 22 variants of a single protein crystallized by a single individual, the Rosetta-calculated `crystal score' correlates with the reported diffraction resolution. We next developed and tested a computational design protocol, seeking to identify point mutations that would improve resolution in a highly stable variant of staphylococcal nuclease (SNase). Using a protocol based on fixed protein backbones, only one of the 11 initial designs crystallized, indicating modeling inaccuracies and forcing us to re-evaluate our strategy. To compensate for slight changes in the local backbone and side-chain environment, we subsequently designed on an ensemble of minimally perturbed protein backbones. Using this strategy, four of the seven designed proteins crystallized. By collecting diffraction data from multiple crystals per design and solving crystal structures, we found that the designed crystals improved the resolution modestly and in unpredictable ways, including altering the crystal space group. Post hoc, in silico analysis of the three observed space groups for SNase showed that the native space group was the lowest scoring for four of six variants (including the wild type), but that resolution did not correlate with crystal score, as it did in the preliminary results. Collectively, our results show that calculated crystal scores can correlate with reported resolution, but that the correlation is absent when the problem is inverted. This outcome suggests that more comprehensive modeling of the crystallographic state is necessary to design high-resolution protein crystals from poorly diffracting crystals.

Study on Statistical Parameters of Resistance of Steel Highway Bridge Reliability Design in China

2010 ◽  
Vol 163-167 ◽  
pp. 3324-3327 ◽  
Author(s):  
Kun Li
Keyword(s):  
Design Method ◽  
Limit State ◽  
Highway Bridges ◽  
Calculation Model ◽  
Highway Bridge ◽  
Statistical Parameters ◽  
Probability Limit ◽  
Reliability Design ◽  
Structure Reliability ◽  
Bridge Reliability

The coming national specification for steel highway bridge will adopt the design method of probability limit state based on the structure reliability theory. Then the statistical parameters of loads and resistance play a key role in this method. Based on the extensive survey and investigation on site, the parameters of resistance are calculated in the study. In the work, three aspects of resistance’s uncertainty which are the uncertainty of materials properties, geometric parameters of members and calculation model are analyzed respectively. Then, the statistical parameters of five typical members of two commonly used steels—Q235q and Q345qD—in steel highway bridges are calculated. The recommended statistical parameters of resistance of steel highway bridge can be a reference for the new specification.

Transmission and Attenuated Total Reflection (ATR) Infrared Spectra of Bone and Collagen

1968 ◽  
Vol 22 (1) ◽  
pp. 23-26 ◽  
Author(s):  
H. Furedi ◽  
A. G. Walton
Keyword(s):  
Infrared Spectra ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Human Bone ◽  
Fair Agreement ◽  
Normal Adult ◽  
Absorption Bands ◽  
Phosphate Absorption ◽  
Adult Human ◽  
The Individual

Transmission and attenuated total reflection (ATR) spectra of collagen and normal, adult human bone have been compared with literature data and band assignments for bone spectra are given. Except for slight shifts in some absorption bands (the amide I band at 1650 cm−1 and some of the phosphate absorption bands), most frequencies of both spectra are in fair agreement with previously reported values for the individual components. An improvement in resolution of some protein bands was achieved with the ATR technique.

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