Three-dimensional Scanner for Multipath Fading Measurement

Our aim was to evaluate the effect of a vacuum bell (VB) combined with a three-dimensional (3D) scanner for the noninvasive treatment of pectus excavatum (PE). A VB was used to create a vacuum at the anterior chest wall with a patient-activated hand pump, and it should be applied regularly for more than 2h each day at home. Eighty-two patients required to be followed up every three months were included in this retrospective study and distributed into four stages (stage 1: treated for 3months, stage 2: treated for 6months, stage 3: treated for 9months, and stage 4: treated for 12months). In addition, the deformity in the chest wall was scanned by a 3D scanner at the clinic, and the 3D depth (3D-DE) and 3D Haller index (3D-HI) of PE were calculated through Geomagic studio 2013 software. Eighty-two patients (12/2017-12/2019) met the criteria at the clinic, and 24 patients (29.3%) achieved excellent correction (3D-DE ≤ 3mm). When comparing the improvement in 3D-DE and 3D-HI of PE to the patient's treatment time, a statistically significant difference was observed between stages 2 and 1 (3D-DE p<0.01, 3D-HI p<0.01), stages 3 and 2 (3D-DE p<0.01, 3D-HI p<0.01) and stages 4 and 3 (3D-DE p<0.01, 3D-HI p<0.01). There was a statistically significant difference in sternum elevation between patients aged <10years and those aged ≥ 10years (3D-DE p = 0.006, 3D-HI p = 0.045) and patients with symmetrical and asymmetric PE (3D-DE p = 0.042, 3D-HI p = 0.032). However, there was no statistically significant difference in sternal elevation between males and females (3D-DE p = 0.27, 3D-HI p = 0.495). The main side effects were moderate subcutaneous hematoma, petechial bleeding, thoracalgia and chest tightness. With controllable side effects, noninvasive treatment for PE with a VB combined with a 3D scanner is safe, objective and radiation free, and the initial results to date are encouraging. Patients aged <10years, with symmetrical PE and treated for over 12months may achieve a better outcome.

Background: 3D scanners are used to obtain three-dimensional (3D) shapes of body parts, offering an alternative to conventional techniques such as casting and a variety of potential advantages. However, 3D scanners are usually very expensive and not affordable and accessible for most orthotists and prosthetists, especially in developing countries. Therefore, this study aimed to evaluate the validity and reliability of a low-cost handheld and affordable 3D scanner (3Dsystems, ‘sense’) for use in orthotics and prosthetics. Methods: The validity and reliability of the 3D Sense scanner were assessed through repeated scanning and measurement of the predefined circumferences of the stumps of four transtibial amputees and 8 body cast models. Two assessors performed digital scanning and tape measurement on two different days, each consisting of three trials per condition/day. The reliability of the 3D sense scanner was assessed by investigating between trials, the assessors, and day reliability using Intraclass Correlation Coefficients. The standard error of measurement (SEM) was also calculated to assess measurement error. The validity of the 3D sense scanner was assessed using correlation analysis, mean percentage error (the mean differences between scanner and tape measure), and Bland-Altman statistics. Results: The 3D Sense scanner provides stumps and body cast model measurements with similar reliability to the tape measure. Reliability coefficients for the 3D scanner are relatively high (ICC). The ICCs all are near 1.0 and SEMs all range from 0.06 to 0.10. The 3D Sense scanner demonstrated excellent validity. There was a significant positive correlation between the 3D scanner and tape measure for both stumps and body cast models measurements (r > 0.850; p < 0.0001). The measurement error between the 3D scanner and tape measure is very low as indicated by mean differences close to zero. Conclusions: This study introduces a low-cost handheld and affordable 3D scanner, which has proven to be a valid and reliable clinical tool in orthotics and prosthetics. This 3D scanner would have extensive and powerful clinical applicability resulting in valid and reliable digital information of body segments for computer-aided design (CAD) of orthotics and prosthetics.

Background: Three-dimensional (3D) scanners have made it possible to measure and display body surface and shape with high precision. These are fast measurements with minimum discomfort, which is especially useful when children are involved. The objective was to assess the reliability and validity of a 3D-scanner for measuring unconventional torso parameters in children and adolescents. Methods: This is a sub-sample of the SAYCARE study, an observational multicentre research effort being conducted in six South American countries, aimed at developing methods to collect data on cardiovascular health biomarkers, lifestyles, and environmental, social and family risk factors. Images were captured using a portable scanner (iSense, Cubify, USA) attached to a Tablet 128Gb with OSX (Ipad-Air Apple, USA). Images were reshaped to exclude head, hair, arms and legs; area and volume were measured using 3D design software ((Rhinoceros for OSX, v5.02, USA). Results: The sub-sample for our study comprised 54 girls and 46 boys, aged 6 to 17 years old, from two private schools in Lima, Peru. Out of 100 participants, 82 were scanned twice. There was strong reliability (rho_c&gt; 0.80) between first and second measurements of area and volume in boys of every age group. In girls, the reliability coefficient was moderate (rho_c&gt; 0.70) only for area comparison in adolescents older than 10 years of age. The mean torso area was 0.55 m2 (SD 0.08) in girls and 0.63 m2 (SD 0.13) in boys. The overall mean torso volume was 24.4 l (SD 5.33) in girls and 31.47 l (SD 10.14) in boys. Area under ROC curve oscillates between 0.5707 and 0.6383 when volume/area ratio was compared to the selected “gold standard” (waist to height ratio &gt; 0.5). Conclusion: Use of portable and low cost 3D-scanners provides a reliable but inaccurate alternative for area and volume torso measurements in children and adolescents.

Cranial shapes of Japanese preterm infants at one month of age using a three-dimensional scanner

Three-Dimensional scanning is a method to convert various distances set into object visualization in 3-dimensional form. Developing a 3D scanner has various methods and techniques depending on the 3d scanner's purpose and the size of the object target. This research aims to build a prototype of a 3D scanner scanning small objects with dimensions maximum(10x7x23)cm. The study applied an a-three dimensional(3D) scanner using infrared and a motor to move the infrared upward to get Z-ordinate. The infrared is used to scan an object and visualize the result based on distance measurement by infrared. At the same time, the motor for rotating objects gets the (X, Y) ordinates. The object was placed in the center of the scanner, and the maximum distance of the object from infrared was 20cm. The model uses infrared to measure the object's distance, collect the result for each object's height, and visualize it in the graphic user interface. In this research, we tested the scanner with the distance between the object and infrared were 7 cm, 10 cm, 15 cm, and 20 cm. The best result was 80% accurate, with the distance between the object and the infrared being 10cm. The best result was obtained when the scanner was used on a cylindrical object and an object made of a non-glossy material. The design of this study is not recommended for objects with edge points and metal material.

Indoor localization can provide a number of different services such as location-aware advertisement, indoor navigation and automating different appliances based on the user location. A number of different techniques such as time-difference- of-arrival, angle-of-arrival, time-of-flight, and received signal strength indicator (RSSI) have been used to provide Location Based Services (LBS). RSSI is one of the widely used methods as it is cost efficient and easy to implement. However, RSSI's performance is limited by multipath fading and indoor noise. Particle Filter (PF) is an accurate Bayesian Filtering algorithm that can improve the performance of RSSI-based indoor localization. However, PF is not able to satisfy the high accuracy requirement (possibly 10cm) of indoor localization. In this paper, we present Particle Filter-Extended Kalman Filter (PFEKF) cascaded algorithm that combines PF and EKF in series to reduce the impact of multipath effects and noise on the RSSI. Our experimental results show that PFEKF improves the localization accuracy by 31.3% and 33.9% in 3D and 2D environments respectively when compared with using only a PF.

It is estimated that approximately 40% of the population suffers from abnormal foot posture, specifically high arched or low arched feet. While the evaluation of foot posture can involve many aspects, it commonly requires the measurement of basic dimensions of the foot. Clinicians and researchers often rely on the use of specialized devices or three-dimensional (3D) scanners to evaluate specific aspects of a patient's foot posture. However, current technologies are extremely expensive, therefore highlighting the need for a cost-effective device to be used in rural and clinical settings. As a result, the purpose of this study was to develop an inexpensive system to measure total foot length, truncated length, dorsum height, navicular height, and foot width. Bland-Altman plots showed significant differences between this measurement system and a 3D scanner for total foot length, truncated length, and navicular height (p < 0.001) and significant differences when assessing the repeatability of dorsum height (p = 0.022). However, the magnitudes of these differences were minimal compared to the overall measurement. Additionally, interclass correlation coefficients revealed that this system had excellent validity when compared to a 3D scanner (interclass correlation coefficients = 0.908-0.994), and good to excellent repeatability when compared between days (interclass correlation coefficients = 0.867-0.996). These results demonstrate that it is possible to design an inexpensive, valid, and repeatable system that can be used in clinical, research, and rural settings to successfully evaluate basic dimensions of the foot that can be used for the determination of foot type.

The aim of this paper is to evaluate the use of three‐dimensional (3D) scanning technologies for design and engineering courses. This paper will provide a comparative discussion of the current 3D scanning technologies; and then describes three experimental studies in engineering, transport design and fashion design. Using 3D scanner technology the experiments tested the transferral of a variety of different data from scanned organic 3D shapes to 3D CAD packages for learning and teaching in undergraduate education. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 17: 263–271, 2009; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20213

Chapter 61 - Designing aircraft seats to fit the human body contour

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Interfacing anatomically conformal electronic components, such as sensors, with biology is central to the creation of next-generation wearable systems for health care and human augmentation applications. Thus, there is a need to establish computer-aided design and manufacturing methods for producing personalized anatomically conformal systems, such as wearable devices and human-machine interfaces (HMIs). Here, we show that a three-dimensional (3D) scanning and 3D printing process enabled the design and fabrication of a sensor-integrated anatomical human-machine interface (AHMI) in the form of personalized prosthetic hands that contain anatomically conformal electrode arrays for children affected by amniotic band syndrome, a common birth defect. A methodology for identifying optimal scanning parameters was identified based on local and global metrics of registered point cloud data quality. This method identified an optimal rotational angle step size between adjacent 3D scans. The sensitivity of the optimization process to variations in organic shape (i.e., geometry) was examined by testing other anatomical structures, including a foot, an ear, and a porcine kidney. We found that personalization of the prosthetic interface increased the tissue-prosthesis contact area by 408% relative to the non-personalized devices. Conformal 3D printing of carbon nanotube-based polymer inks across the personalized AHMI facilitated the integration of electronic components, specifically, conformal sensor arrays for measuring the pressure distribution across the AHMI (i.e., the tissue-prosthesis interface). We found that the pressure across the AHMI exhibited a non-uniform distribution and became redistributed upon activation of the prosthetic hand’s grasping action. Overall, this work shows that the integration of 3D scanning and 3D printing processes offers the ability to design and fabricate wearable systems that contain sensor-integrated AHMIs.

BackgroundThe dual-plane technique has been widely used in augmentation mammaplasty procedures. However, there are some concerns about aesthetic contour maintenance for long time after muscle releasing. This study aims to track and analyze breast dynamic morphological changes after dual-plane breast augmentation with three-dimensional (3D) scanning technique.MethodsThirteen dual-plane anatomic implant augmentation patients underwent 3D scanning preoperatively (pre-OP) and postoperatively in four time points (1 month: post-1M, 3 months: post-3M, 6 months: post-6M and 12 months: post-12M). The linear distance, breast projection, nipple position, breast volume and breast surface area were measured and analyzed on the 3D models over time.ResultsCompared with post-12M, no significant differences were found in distances of nipple to midline, nipple to inframammary fold and sternal notch to the level of inframammary fold after 6 months in both straight-line distance and its projection on surface. The distances between sternal notch and nipple had no significant difference after post-1M. Breast volume changes had no significant difference after post-3M. The volume and area percentage of upper pole decreased while the lower pole’s increased gradually. The surface showed no significant changes after post-1M. The changes of breast projection had no significance after post-1M either. The nipple moved 1.0±0.6 cm laterally(X axis), 0.6±0.7 cm upward(Y axis) and 2.3±1.1 cm anteriorly (Z axis) at post-12M, and the differences were not significant after post-1M.Conclusions3D scanning technique provides an objective and effective way to evaluate breast morphological changes after augmentation mammaplasty over time. Dual-plane augmentation optimizes breast shape especially in the lower pole and maintains stable aesthetic outcome during the 12 months follow-up. Most of the contour changes and the interadaptation with the implant have completed 6 months after operation. Therefore, 6 months could be chosen as a relatively stable observing period in the assessment of postoperative outcomes of dual-plane breast augmentation.

Reverse modelling of natural rock joints using 3D scanning and 3D printing

In order to analyse the buckling behaviour of existing bow-string arch bridges, it is necessary to deal with the imperfections that influence the global stability of their superstructures. Direct quantification of the material imperfections represents an extremely difficult task for this type of structure. On the other hand, the geometrical imperfections can be measured in more detail by using special scanners or high-accuracy surveying instruments. This contribution represents a beginning part of the research activities focusing on the real values of geometric imperfections of existing steel arch bridges using three-dimensional (3D) scanning. The possibility of using these data for further theoretical and numerical analysis based on the finite element method (FEM) and for further creating the building information modelling (BIM) of the bridges is proposed. When verifying the stability of bow-string arch bridges, much higher attention has to be paid to the out-of-plane stability of the arches. The numerical models of an existing bridge superstructure were developed to execute a nonlinear analysis with geometrical imperfections included. Both the theoretical and actual imperfections obtained by 3D scanning were taken into account. The obtained data, their comparison and the applicability of the presented method are finally discussed.

Nowadays, location awareness becomes the key to numerous Internet of Things (IoT) applications. Among the various methods for indoor localisation, received signal strength indicator (RSSI)-based fingerprinting attracts massive attention. However, the RSSI fingerprinting method is susceptible to lower accuracies because of the disturbance triggered by various factors from the indoors that influence the link quality of radio signals. Localisation using body-mounted wearable devices introduces an additional source of error when calculating the RSSI, leading to the deterioration of localisation performance. The broad aim of this study is to mitigate the user’s body shadowing effect on RSSI to improve localisation accuracy. Firstly, this study examines the effect of the user’s body on RSSI. Then, an angle estimation method is proposed by leveraging the concept of landmark. For precise identification of landmarks, an inertial measurement unit (IMU)-aided decision tree-based motion mode classifier is implemented. After that, a compensation model is proposed to correct the RSSI. Finally, the unknown location is estimated using the nearest neighbour method. Results demonstrated that the proposed system can significantly improve the localisation accuracy, where a median localisation accuracy of 1.46 m is achieved after compensating the body effect, which is 2.68 m before the compensation using the classical K-nearest neighbour method. Moreover, the proposed system noticeably outperformed others when comparing its performance with two other related works. The median accuracy is further improved to 0.74 m by applying a proposed weighted K-nearest neighbour algorithm.