3D Imaging Measurements Research Articles

Controlled, Parametric, Individualized, 2D, and 3D Imaging Measurements of Aerosol Deposition in the Respiratory Tract of Healthy Human Subjects: Preliminary Comparisons with Simulations

Preliminary comparisons of simulation results from existing extrathoracic (ET) models and a lung deposition model with individualized, two-dimensional and three-dimensional (3D) imaging measurements of aerosol deposition in the respiratory tract of healthy human subjects have been presented. In general, the ET models did not correspond well with each individual's experimental data. However, there is rather good agreement between simulated and experimental results for regional lung deposition comparable to those previously found in the literature. Comparisons of generational distributions are relatively poor. These preliminary results suggest not only the need for further developments in deposition modeling, but also the need for better methods for analyzing experimentally determined 3D deposition distributions for comparison to simulated results. Copyright 2013 American Association for Aerosol Research

Development of 3D Image Measurement System and Stereo-matching Method, and Its Archeological Measurement

The three dimensional measurement & modeling system with digital cameras on PC is now making progress and its need and hope is increasingly felt in terrestrial (close-range) photogrammetry for such sectors as cultural heritage preservation, architecture, civil engineering, manufacturing, measurement etc. Therefore, we have developed a system to improve the accuracy of stereo-matching, which is the very core of 3D measurement. As for stereo-matching method, in order to minimize the mismatching and to be robust in geometric distortions, occlusion, as well as brightness change, we invented Coarse-to-Fine Strategy Method by integrating OCM (Orientation Code Matching) with LSM (Least Squares Matching). Thus this system could attain the accuracy of 0.26mm, when we experimented on a mannequin. And when we actually experimented on the archeological ruins in Greece and Turkey, the accuracy was within the range of 1cm, compared with their blue-print plan. Besides, formally workers used to take at least 1.5 month for this kind of survey operation with the existing method, but now workers need only 3 or 4 days. Thus, its practicality and efficiency was confirmed.This paper demonstrates our new system of 3D measurement and stereo-matching with some concrete examples as its practical application.

Measuring the anterior cruciate ligament’s footprints by three-dimensional magnetic resonance imaging

The purpose of this study was to compare 3D MR imaging and open cadaveric measurements of the ACL's footprints to see whether 3D MR imaging measurements are accurate enough to be used for preoperative templating in anatomic ACL reconstruction. Eight formalin-injected cadaveric knees were scanned by rapid acquisition isotropic 3D MR imaging. The femoral and tibial footprints were measured on MR imaging and compared with cadaveric dissection. Bland-Altman plots were used to assess the level of agreement. The AM and PL bundles were clearly appreciated in each specimen by 3D MR imaging and cadaveric dissection. The average paired difference in the femoral and tibial footprint measurements was 2, 1, 2, and 2 mm for the femoral footprint length, femoral footprint width, tibial footprint length, and tibial footprint width, respectively. The individual paired measurements were all within the mean difference ± two standard deviations of the difference in the Bland-Altman plot showing strong agreement. Measuring the ACL's footprint by 3D MR imaging or open cadaveric dissection has strong agreement and can be used interchangeably. 3D MR imaging has the potential to allow surgeons to: (1) tailor ACL reconstruction technique or graft choice based on ACL footprint size, (2) plan for selective bundle ACL reconstruction for partial tears, and (3) preoperatively template tunnel position according to the patient's individual anatomy.

Automatic inspection system for dimensional measurements of the saw blade milling cutter

The demand for measuring equipments of automatic optical inspection has grown rapidly, because of its benefits of promoted efficiency and higher precision. Instead of manual projection measurements, measurement performance and efficiency can be obviously enhanced by the image measurement system. In this investigation, digital image processing and geometrical measurement principles have been integrated to develop a dynamic measurement system for the dimensional measurements of a saw blade milling cutter. The repeatability of the measurement system has been analyzed and its accuracy has been verified by using commercial 3D image measurement system. The analysis results show that the dimensional precision of 25μm and the angular precision of 0.21° can be realized by the self-developed measurement system. Between the results of the developed system and reference standard system, there are 25μm deviation in dimensional measurement and 0.26° in angular measurement. That measuring performances can meet the industrial requirement and the higher measurement efficiency can be achieved.

Automatic inspection system for dimensional measurements of the saw blade milling cutter

The demand for measuring equipments of automatic optical inspection has grown rapidly, because of its benefits of promoted efficiency and higher precision. Instead of manual projection measurements, measurement performance and efficiency can be obviously enhanced by the image measurement system. In this investigation, digital image processing and geometrical measurement principles have been integrated to develop a dynamic measurement system for the dimensional measurements of a saw blade milling cutter. The repeatability of the measurement system has been analyzed and its accuracy has been verified by using commercial 3D image measurement system. The analysis results show that the dimensional precision of 25μm and the angular precision of 0.21° can be realized by the self-developed measurement system. Between the results of the developed system and reference standard system, there are 25μm deviation in dimensional measurement and 0.26° in angular measurement. That measuring performances can meet the industrial requirement and the higher measurement efficiency can be achieved.

Quasi multi‐baseline‐stereo method with single camera for reducing occlusion

AbstractA robust 3D image measurement method is proposed in order to suppress occlusion by a quasi multi‐baseline‐stereo method based on a single camera configuration. There is no way to suppress completely the “occlusion problem” in the field of stereo geometry. In order to deal with this problem, the multi‐baseline‐stereo configuration is often adopted and is basically effective. This paper proposes a new configuration for stereo measurement by means of a single camera, a mechanical feeder for the object, image processing for the baseline calibration, and in particular, diagonal feeding of the object in front of the camera. The concept of this method is to realize a pair of stereo geometries in the stereo configuration with a single camera and a mechanical feeder. It is technically noted that the baseline of this single camera stereo was precisely calibrated by an image processing procedure in both the horizontal and vertical directions. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 93(1): 41–49, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10156

A practical 3D measurement system based on projection pattern control techniques

AbstractMost of the recent 3D image measurement methods have employed certain pattern projection techniques because of their higher reliabilities. Especially, the intensity‐modulated technique can detect more stripe addresses by a single projection and therefore is very much expected for its practical use in the near future. The traditional techniques of this type, however, have encountered several serious problems where 3D measurements are difficult in sensitivity, speed and accuracy or fatally impossible for unknown objects. In order to solve these problems, we propose an automatic control technique of angle and space frequency of projection pattern. Furthermore, for security of measurement accuracy and measurement speed, projection pattern intensity control technique and optimal intensity‐modulation projection technique are adopted in the proposal measurement system. By using the proposed technique the automatic 3D measurement intended for the geostationary objects and the swaying objects were realized in experimental results. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(11): 34–41, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10147

Frontiers of Imaging and 3D Image Measurement

Frontiers of Imaging and 3D Image Measurement

Ionization and dissociation of molecular ion beams caused by ultrashort intense laser pulses

Studies of the simplest one-electron molecule, H2+, are the first step towards understanding the interaction of ultrashort intense laser pulses with molecules. We conduct coincidence 3D imaging measurements of H2+ beams following their exposure to intense ultrashort laser pulses. These measurements are compared with our time-dependent calculations as well as a simple model we recently proposed. Our findings include above threshold Coulomb explosion - a surprising structure in the energy spectrum near the ionization appearance intensity; above threshold dissociation (ATD) of the excited electronic states of H2+; and enhanced high-order ATD - involving the net absorption of at least 3 photons - brought about by closing the 2-photon channel.

Lung Volumes in Fetuses with Congenital Diaphragmatic Hernia: Comparison of 3D US and MR Imaging Assessments

To prospectively compare three-dimensional (3D) ultrasonography (US) and magnetic resonance (MR) imaging in the assessment of lung volumes in fetuses with congenital diaphragmatic hernia. Informed consent was obtained for this ethics committee-approved study. Left and right lung volumes were measured by using the 30 degrees virtual organ computer-aided analysis 3D US technique and a transverse multiplanar T2-weighted MR imaging technique in 43 fetuses with isolated congenital diaphragmatic hernia. Regression analysis was used to determine the significance of the association between the two methods. The 43 fetuses were assessed in a total of 78 examinations. Median gestational age at the examinations was 28 weeks (range, 18-38 weeks). In all examinations, it was possible to visualize and measure both the ipsilateral and the contralateral lungs with MR imaging. In contrast, with 3D US, the contralateral lung could be measured in all examinations, but the ipsilateral lung could be measured in only 44 (56%) examinations. For the contralateral lungs, there was a significant association between 3D US and MR imaging measurements (r = 0.86, P < .001). Although the mean lung volume measured with 3D US was 25% lower than that measured with MR imaging, the ratio of observed volume to expected normal mean volume for gestation was not significantly different between the two methods (3D US, 0.48; MR imaging, 0.52). In the 44 examinations in which the ipsilateral lung could be measured with both methods, 3D US volumes were not significantly different from MR imaging volumes, and the association was weaker (r = 0.39, P < .05) in the ipsilateral lungs than in the contralateral lungs. For congenital diaphragmatic hernia, 3D US provides a reliable measurement of the contralateral but not the ipsilateral lung.

Assessment of the Tomographic Atom Probe Technique for Nanoscale Characterization : Comparison with SIMS Technique

The three dimensional Atom Probe (3D-AP) technique can be considered as the only technique which allows 3D imaging and chemical composition measurements capabilities at the atomic. Since its early developments, 3D Atom Probe has provided major contributions in materials science [1]. Nowadays, the introduction of a femto laser pulsed beam for producing the atom field evaporation has extended the field of investigation of 3D-AP to poor conductive materials [2]. It is now possible due to LASER pulsing to investigate semi-conductor with Tomographic Atom Probe Technique. Therefore, because of the atomic resolution of the technique, Semi-Conductor engineering community has developed a growing interest for the attractive analytical capability of the TAP technique. However, it must be confirmed that the instrument sensitivity and performance will allow to measure dopants distribution in very small structures at the atomic scale resolution.

1P1-M02 高速プロジェクタを用いた3,000フレーム毎秒の三次元画像計測システムの開発(3次元計測/センサフュージョン)

This paper proposes a high frame rate 3D imaging system based on structural light projection using temporally-coded binary patterns. This system consists of a DMD (Digital Micromirror Device) projector and a high-speed camera, both of which operate at over 6,000 frames/s. Introducing image processing algorithms of detecting and tracking the projected light patterns enables frame-by-frame 3D image measurement. Experimental results show that the proposed algorithms worked effectively, and the system achieved 3D imaging at 3,350 frames/s.

Quasi Multi-Baseline-Stereo Method with Single Camera for Reducing Occlusion

In this paper, the robust 3D image measurement method is proposed to suppress the occlusion by proposing a quasi Multi-Baseline-Stereo method based on a single camera configuration. We have no way to suppress completely the “occlusion problem in the field of stereo geometry. In order to cope with this problem, multi-baseline-stereo configuration is often adopted and basically effective. This paper proposes a new configuration of the stereo measurement my means of a single camera, mechanical feeder of the object, image processing for base line calibration, and especially a diagonal feeding of the object in front of the camera. The concept of this method is to realize a pair of stereo geometries on the stereo configuration of a single camera and a mechanical feeder. It is technically noted that the base line of this single camera stereo was precisely calibrated by the image processing procedure in both horizontal and vertical directions.This proposed system with the simple hardware composition could be applicable to several kinds of 3D measurements in several industrial fields.

Digital Camera Calibration and 3D Image Measurement

Digital Camera Calibration and 3D Image Measurement

Routine Evaluation of the Grain Structures of Baked Breads by MRI

We devised a routine evaluation method for the grain structures of baked breads using MRI. A piece of bread was soaked in Fe31 perchlorite-acetone solution, evacuated to remove the air between the grain networks, and used for measurement of MR images. Fe31 concentrations from 8 to 25 mM stained the crumb grain networks well. A plane resolution of 100 μm100 μm and slice thicknesses from 0.25 to 0.4 mm provided images suitable for analysis. A histogram of the PIXELs versus the gray level exhibited a bimodal pattern. The measurement time was shortened to 20 min per image by using the spin-echo 2D-FT method, which is less than one thirtieth the ordinary 3D image measurement time previously reported. MR images of the crumb grain networks and figures obtained by image analysis, i.e. the total-area/pore-area ratio, pore number detected, average pore size, and pore area distribution patterns, characterized the individual breads. The MR image system used in this study can replace a portion of the visual test in a sensory evaluation of bread quality in practical bread making.

Segmentation and measurement based on 3D Voronoi diagram: Application to confocal microscopy

Computational geometry provides many solutions to imaging problems, especially for three-dimensional (3D) image compression, segmentation, and measurement. We present here a new method to partition volume data by Voronoi polyhedra structured in a graph environment. A dynamic construction of the 3D Voronoi diagram is proposed, using image information interactively. The process has been applied to segment and quantitate 3D biological data acquired with a confocal laser scanning microscope (CISM). The discrete volume acquired represents a large mass of data and can be reduced with this particular method, before measurement (processing time) or archiving (memory space). Furthermore, the structure data is a powerful tool to rapidly compute parameters that are characteristic of the volume data.