With the development of hardware technology, the interest in wearable devices is increasing. Among the associated technology, ear-related wearable devices provide an efficient communication ...experience for auditory-verbal interaction while the user is moving. Since wearable devices are attached to the body, a sense of fitness is an important element. Therefore, this study aims to improve wearability of ear-related wearable devices by analyzing and categorizing ear shapes of Koreans and Caucasians based on 3D ear data. To do so, first, the external ear was measured through a 3D scanner. Next, descriptive statistics and correlation analyses were performed for each anthropometric measurement. The ear measurements were then compared by race, gender, and age group through an independent two-sample t-test and one-way analysis of variance. Then, an exploratory factor analysis was performed to determine the major factors that characterize the ear shape. Finally, categorization of ear shapes according to race was conducted through a hierarchical cluster analysis. From this, the major factors affecting ear shapes were found to be related to upper ear height, concha width, lower ear height, and ear protrusion. From the extracted factors, ear shapes were categorized into four groups: round, rectangular, triangular, and inverted triangular. Resultingly, these four ear shapes should be considered in improving the wearability of the ear-related wearable device. Ultimately, these findings inform applications in the ear-related wearable device industry.
Stroke patients suffer from ankle joint deformities due to spastic ankle muscles. This study evaluated the viability of using 3D scanned surface images of the feet of stroke victims to visually ...assess the deformities of a hemiparetic foot and investigated the influences of deformed ankle joints on gait kinematics.
A total of 30 subjects with stroke-induced hemiparesis and 11 age-matched healthy controls completed the clinical assessments. We analyzed their feet's morphometric characteristics using a 3D scanner, identified convenient anthropometric measurements, and conducted gait trials on even and uneven terrains. The 3D foot morphometric characteristics were evaluated using the geometric morphometrics method (GMM).
Results showed that there were significant differences in bilateral foot shapes between the chronic stroke patients and healthy controls and between the paretic and non-paretic sides in the chronic stroke patients. In stroke patients, those with the smaller medial malleoli's vertical tilt angles showed significantly different ankle ranges of motion of dorsi-/plantar flexion during gaits on uneven terrains (
= 0.009). In addition, those with the greater medial malleoli's vertical tilt angles showed significantly different ankle ranges of motion of inversion/eversion during gaits on even and uneven terrains (
< 0.05).
Using 3D scanning technology, bilateral morphometric changes in the feet of chronic stroke patients were shown by GMM and the simple anthropometric measurements identified its shape deformities in the feet. Their possible effects on gait kinematics while walking on uneven terrains were investigated. Current methodology can be potentially useful in applying conventional productions of clinically manufactured, patient-fitted ankle-foot-orthosis in orthotics and prosthetics, and in detecting various unidentified pathological deformities in the feet.
AbstractModular construction can improve construction performance (i.e., cost, schedule, and safety) by prefabricating modules at an off-site facility and installing them at a construction site. ...However, when defects of modules are not easily repairable on the construction site, they cause additional cost overruns and delays due to long lead times of refabrication and reshipment. Thus, quality assessment of modular components at the fabrication facility before shipment is very important. The current inspection practices rely on manual measurement, which can be imprecise, labor-intensive, and time-consuming. To address this issue, some research efforts are made on the module inspection techniques (e.g., estimates of geometric properties and surface quality) using laser-scanned data. The accuracy of these techniques relies on the quality (i.e., coverage and resolution) of the scan data. However, ensuring the consistent quality of data is a major challenge as there is little to no research on optimal scan planning for modular components. Therefore, this paper proposes a model-based 3D scan planning method for modular components that ensures user-specified scan quality. Given a 3D computer-aided design (CAD) or building information modeling (BIM) model, scanner property, and user’s quality requirement, this method automatically computes the input parameters for the laser scanner (i.e., angular step and field of view) and optimal scan positions. It also predicts the scan quality and shows the areas that will not meet the user requirement due to geometric constraints (i.e., self-occluded surfaces). This study was validated through two case studies using two modular-sized structures in a fabrication facility. The results showed that the scan planner is able to accurately predict the scanning quality and ensure that the output scan will meet the user quality requirement.
Although personalized polymethylmethacrylate (PMMA) implant production molds for cranioplasty are costly and time-consuming, they allow for better-quality implants. The researchers quantitatively ...tested the contribution of simplified, low-cost techniques to cosmetic improvement.
PMMA prosthesis was placed in a 25-year-old male patient due to osteolysis in the bone flap removed after decompression surgery. A single-sided mold was three-dimensional (3D) printed before the surgery, and the prosthesis was produced during the surgery. In addition, the change in cranial asymmetry was evaluated using a 3D surface scanner after surgery.
The mold took half an hour to design and 5 hours to print. The mold cost about 2 dollars. The root means square (RMS) value measured to determine cranial asymmetry decreased from 5.4 mm to 2.8 mm postoperatively. The patient stated that he was pretty satisfied with the cosmetic result.
Simple design techniques developed can offer low-cost, fast-design alternative solutions with satisfactory cosmetic results for low-income countries and patients.
This work grew out of a desire to investigate the digital surveying process used in phases to define the concept of a morphologically complex product such as an automobile. This investigation was ...conducted by analysing the final steps of the first ten editions of the Specialized Master course in Transportation & Automobile Design at Politecnico di Milano University. In analysing the procedures to create the presentation models starting with clay studio models, four protocols were standardized and compared. Following this, some suggestions and guidelines were summarized to ensure that faithfulness to the design intent during the process would not fail. The ultimate goal of this work is to highlight the critical aspects of a process that is based on a quantitative method (the digital survey), but that requires a qualitative approach to be truly effective.
The foot is a vital organ, as it stabilizes the impact forces between the human skeletal system and the ground. Hence, precise foot dimensions are essential not only for custom footwear design, but ...also for the clinical treatment of foot health. Most existing research on measuring foot dimensions depends on a heavy setup environment, which is costly and ineffective for daily use. In addition, there are several smartphone applications online, but they are not suitable for measuring the exact foot shape for custom footwear, both in clinical practice and public use. In this study, we designed and implemented computer-vision-based smartphone application
that provides the functionality to automatically measure the four essential dimensions (length, width, arch height, and instep girth) of a human foot from images and 3D scans. We present an instep girth measurement algorithm, and we used a pixel per metric algorithm for measurement; these algorithms were accordingly integrated with the application. Afterwards, we evaluated our application using 19 medical-grade silicon foot models (12 males and 7 females) from different age groups. Our experimental evaluation shows that
could measure the length, width, arch height, and instep girth with an accuracy of 95.23%, 96.54%, 89.14%, and 99.52%, respectively. A two-tailed paired
-test was conducted, and only the instep girth dimension showed a significant discrepancy between the manual measurement (MM) and the application-based measurement (AM). We developed a linear regression model to adjust the error. Further, we performed comparative analysis demonstrating that there were no significant errors between MM and AM, and the application offers satisfactory performance as a foot-measuring application. Unlike other applications, the iOS application we developed,
, fulfils the requirements to automatically measure the exact foot dimensions for individually fitted footwear. Therefore, the application can facilitate proper foot measurement and enhance awareness to prevent foot-related problems caused by inappropriate footwear.
This paper describes the use of video and digital image processing in investigation of the impact between a rigid hemispherical shape impactor and Hybrid Polyurea-Polyurethane-MWCNTs Nanocomposite ...Coatings. An experimental study was performed for six sample configurations: single aluminum plates (reference test), multilayer plates with 4 types of coatings and double aluminum plates. The impact phenomenon was recorded with a high-speed video camera and the variation of the projectile s velocity during the impact was obtained through digital analysis. Additionally, the test was instrumented using a force sensor specially designed and mounted on the impactor. The video processing was used to draw the velocity curves and to estimate the evolution of the contact forces between the impactor and the multilayer structures, the results obtained being compared with the force sensor data. Some differences between these two types of measurements are observed, so in order to analyze the configurations behavior, a numerical study of the phenomena was performed in LS-DYNA software using a 2D axial symmetric model. The simulations showed that the profile of the force evolution measured with the sensor is affected by the chosen constructive solution and the data obtained based on the video images are more accurate. The deformations were analyzed, the maximum deformation based on image processing and the residual deformation based on 3D Scan post-test. The video technique combined with 3D Scan are precise enough to study the impact at low velocities and the numerical simulations provide results according to reality. The hyperelastic coatings contribute to a better resistance of the aluminum plates.
Mobile 3D scan LiDAR: a literature review Di Stefano, Francesco; Chiappini, Stefano; Gorreja, Alban ...
Geomatics, natural hazards and risk,
01/2021, Letnik:
12, Številka:
1
Journal Article
Recenzirano
Odprti dostop
This paper, by critically reviewing different years (from 2010 to 2020) of research activities performed with Mobile Laser Scanning system, aims to review existing systems and how they are exploited ...in multifaceted domains. To such extent, the work defines five field domains where Mobile Laser Scanning have been used:
Built and urban environment
,
Cultural heritage and Archaeology, Underground environment, Environmental monitoring, Forestry and Agriculture.
Besides, this paper sheds the light on the pros and cons for each domain field, providing useful guidelines for those researchers involved in three-dimensional data collection with innovative systems. To achieve these purposes, research papers, were analysed, mainly considering geosciences related journals. The comparison among them revealed that, despite the incredible potential of Mobile Mapping System, the human intervention is still mandatory, and post-processing actions are needed to achieve the desired results, regardless the domain field. Moreover, our study provides insight into the technical and methodological limitations that raise a general scepticism on Mobile Mapping System for three-dimensional surveying, highlighting that in most of cases
supplementary data
are required to make the final result trustworthy. Such obstacles, hampering Mobile Laser Scanning diffusion, point towards unexplored areas for further investigations, serving as useful guidelines for future research directions.
•An improved DeepLabV3+ network (IDeepLabV3+) for PWS lesion segmentation was developed based on the classic DeepLabV3+ architecture.•The deep learning-based semantic segmentation method can ...automatically segment PWS lesion of different color and shape in texture mapping of 3D images.•Semantic segmentation can be used together with 3D scan for the evaluation of area of facial PWS lesions.
Portwine stain (PWS) birthmarks are congenital vascular malformations. The quantification of PWS area is an important step in lesion classification and treatment evaluation.
The aim of this study was to evaluate the combination of 3D scan with deep learning for automated PWS area quantization.
PWS color was measured using a portable spectrophotometer. PWS patches (29.26–45.82 cm2) of different color and shape were generated for 2D and 3D PWS model. 3D images were acquired by a handheld 3D scanner to create texture maps. For semantic segmentation, an improved DeepLabV3+ network was developed for PWS lesion extraction from texture mapping of 3D images. In order to achieve accurate extraction of lesion regions, the convolutional block attention module (CBAM) and DENSE were introduced and the network was trained under Ranger optimizer. The performance of different backbone networks for PWS lesion extraction were also compared.
IDeepLabV3+ (Xception) showed the best results in PWS lesion extraction and area quantification. Its mean Intersection over Union (MIou) was 0.9797, Mean Pixel Accuracy (MPA) 0.9908, Accuracy 0.9989, Recall 0.9886 and F1-score 0.9897, respectively. In PWS area quantization, the mean value of the area error rate of this scheme was 2.61 ± 2.33.
The new 3D method developed in this study was able to achieve accurate quantification of PWS lesion area and has potentials for clinical applications.
PWS patches of different color and shape were use to create 2D and 3D models. 3D images were acquired by 3D scanner to create corresponding texture maps. Deep learning automatic segmentation using different backbone networks was used to extract PWS lesion from texture mapping of 3D images.
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