Geomagic Design Research Articles

Fabrication of malleable three-dimensional-printed customized bolus using three-dimensional scanner.

A three-dimensional (3D)-printed customized bolus (3D bolus) can be used for radiotherapy application to irregular surfaces. However, bolus fabrication based on computed tomography (CT) scans is complicated and also delivers unwanted irradiation. Consequently, we fabricated a bolus using a 3D scanner and evaluated its efficacy. The head of an Alderson Rando phantom was scanned with a 3D scanner. The 3D surface data were exported and reconstructed with Geomagic Design X software. A 3D bolus of 5-mm thickness designed to fit onto the nose was printed with the use of rubber-like printing material, and a radiotherapy plan was developed. We successfully fabricated the customized 3D bolus, and further, a CT simulation indicated an acceptable fit of the 3D bolus to the nose. There was no air gap between the bolus and the phantom surface. The percent depth dose (PDD) curve of the phantom with the 3D bolus showed an enhanced surface dose when compared with that of the phantom without the bolus. The PDD of the 3D bolus was comparable with that of a commercial superflab bolus. The radiotherapy plan considering the 3D bolus showed improved target coverage when compared with that without the bolus. Thus, we successfully fabricated a customized 3D bolus for an irregular surface using a 3D scanner instead of a CT scanner.

Sex Determination of Human Crania Using 3D Surface Scanning of the Mastoid Process

Historically, sex determination of human skulls has been dependent on visual examination and qualitative scoring of sexually dimorphic features such as the mastoid process. The accuracy of this method relies heavily on observer experience. We report a new method for sex determination based on quantitative analysis of the mastoid process. A Polhemus FastScan 3D laser scanner is employed to capture cranial surface morphology. The scan protocol generates 2 mesh models that are imported and aligned using Geomagic Design X64 software to create a single digital model per cranium. From the model, the mastoid process is isolated and its volume measured. Total cranial volume is also estimated from the model, allowing computation of a mastoid ratio (mastoid volume:cranial volume) for each specimen. A pilot study was performed utilizing a small sample of crania from known-sex Medieval Nubian individuals. Results demonstrate little overlap in the range of male vs female absolute mastoid volume. Intra-observer measurement error is low. A t-test shows significant differences (p < 0.05) between male and female mastoid ratios, demonstrating the utility of this method for sex determination. Moreover, the new method is advantageous because the scan protocol is quick; it captures a permanent record of each specimen; and unlike qualitative scoring, it can be executed consistently with minimal training. Future work will focus on evaluating inter-observer error, testing the method across population samples, and devising protocols for other dimorphic features, with the goal of developing a comprehensive multivariate method for sexing skulls based on 3D surface scanning.

3차원 인체 측정을 이용한 청소년기 여성의 유방 발육 변화 추이 및 특성 연구 - 만 13~18세를 중심으로 -

The purpose of this study was to analyze the breast growth variation trends and characteristics of Korean adolescent girls based on 3D body measurements. Subjects were 174 girls aged between 13 and 18. 3D body scanning data were collected and the data were measured by Geomagic Design X program. The total of 18 anthropometric measurements and 4 index items were analyzed. The main results of this study are as follows: 1) Overall, the breast growth of adolescent girls got out of children`s body shapes at the age of 14 and the adult`s body shapes appeared remarkably at the age of 18. Before the age of 15, the adolescent girls` breast enlarged. 2) The surface lengths of upper body, which means the breast volume, showed significant growth above B cup groups rather than under A cup groups. The demand of B cup size (32.2%) was higher than A cup size (25.9%). And 35.6% of subjects` brassiere band size was 70. 3) The thorax grew evenly in the circumference, depth and breadth. The thoracic development related to the breast volume as well as the whole upper body`s development. These results reveal that it is necessary to develop adolescent girls` brassiere reflecting on adolescent girls` breast growth variation trends and characteristics by age, breast size and thoracic development.

Author response to: Brough et al. in response to the recently published article: Lottering, N., MacGregor, D.M., Barry, M.D., Reynolds, M.S., Gregory, L.S., 2014. Introducing standardized protocols for anthropological measurement of virtual sub-adult crania using computed tomography 2(1), 34–38

Firstly, we would like to thank Ms. Alison Brough and her colleagues for their positive commentary on our published work [1] and their appraisal of our utility of the “off-set plane” protocol for anthropometric analysis. The standardized protocols described in our manuscript have wide applications, ranging from forensic anthropology and paleodemographic research to clinical settings such as paediatric practice and orthopaedic surgical design. We affirm that the use of geometrically based reference tools commonly found in computer aided design (CAD) programs such as Geomagic Design X® are imperative for more automated and precise measurement protocols for quantitative skeletal analysis. Therefore we stand by our recommendation of the use of software such as Amira and Geomagic Design X® in the contexts described in our manuscript...

Introducing standardized protocols for anthropological measurement of virtual subadult crania using computed tomography

Objectives This study introduces and assesses the precision of a standardized protocol for anthropometric measurement of the juvenile cranium using three-dimensional surface rendered models, for implementation in forensic investigation or paleodemographic research. Materials and methods A subset of multi-slice computed tomography (MSCT) DICOM datasets (n=10) of modern Australian subadults (birth—10 years) was accessed from the “Skeletal Biology and Forensic Anthropology Virtual Osteological Database” (n>1200), obtained from retrospective clinical scans taken at Brisbane children hospitals (2009–2013). The capabilities of Geomagic Design X™ form the basis of this study; introducing standardized protocols using triangle surface mesh models to (i) ascertain linear dimensions using reference plane networks and (ii) calculate the area of complex regions of interest on the cranium. Results The protocols described in this paper demonstrate high levels of repeatability between five observers of varying anatomical expertise and software experience. Intra- and inter-observer error was indiscernible with total technical error of measurement (TEM) values ≤0.56 mm, constituting <0.33% relative error (rTEM) for linear measurements; and a TEM value of ≤12.89 mm2, equating to <1.18% (rTEM) of the total area of the anterior fontanelle and contiguous sutures. Conclusions Exploiting the advances of MSCT in routine clinical assessment, this paper assesses the application of this virtual approach to acquire highly reproducible morphometric data in a non-invasive manner for human identification and population studies in growth and development. The protocols and precision testing presented are imperative for the advancement of “virtual anthropology” into routine Australian medico-legal death investigation.