Structured light scanner

结构光扫描仪
  • 文章类型: Journal Article
    这项研究评估了使用3D光扫描仪进行颅面测量的准确性和可重复性,特别是EINSTAR扫描仪,与用于面部人体测量的传统卡尺测量相比。两名考官对11名志愿者进行了评估,一个有经验,一个没有经验,他们使用扫描仪进行直接卡尺测量和间接测量。结果显示卡尺和扫描仪结果之间的差异最小,相关系数证明了整体的高准确性和可靠性。尽管扫描时间稍长,3D成像的好处,包括详细的表面映射和虚拟建模,证明其融入临床实践的合理性,特别是在颌面外科和颅面评估。使用EINSTAR扫描仪获得的颅面测量显示出出色的可靠性和准确性,这使该方法具有临床和科学用途的资格。
    This study evaluates the accuracy and repeatability of craniofacial measurements with a 3D light scanner, specifically the EINSTAR scanner, in comparison to traditional caliper measurements for facial anthropometry. Eleven volunteers were assessed by two examiners, one experienced and one inexperienced, who performed direct caliper measurements and indirect measurements using the scanner. Results indicated minimal differences between caliper and scanner results, with overall high accuracy and reliability demonstrated by correlation coefficients. Despite the slightly longer scanning time, the benefits of 3D imaging, including detailed surface mapping and virtual modeling, justify its integration into clinical practice, particularly in maxillofacial surgery and craniofacial assessment. Craniofacial measurements obtained with the EINSTAR scanner showed excellent reliability and accuracy, which qualifies this method for clinical and scientific use.
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  • 文章类型: Journal Article
    UNASSIGNED: Geometric morphometrics is a powerful approach to capture and quantify morphological shape variation. Both 3D digitizer arms and structured light surface scanners are portable, easy to use, and relatively cheap, which makes these two capturing devices obvious choices for geometric morphometrics. While digitizer arms have been the \"gold standard\", benefits of having full 3D models are manifold. We assessed the measurement error and investigate bias associated with the use of an open-source, high-resolution structured light scanner called SeeMaLab against the popular Microscribe 3D digitizer arm.
    UNASSIGNED: The analyses were based on 22 grey seal (Halichoerus grypus) skulls. 31 fixed anatomical landmarks were annotated both directly using a Microscribe 3D digitizer and on reconstructed 3D digital models created from structured light surface scans. Each skull was scanned twice. Two operators annotated the landmarks, each twice on all the skulls and 3D models, allowing for the investigation of multiple sources of measurement error. We performed multiple Procrustes ANOVAs to compare the two devices in terms of within- and between-operator error, to quantify the measurement error induced by device, to compare between-device error with other sources of variation, and to assess the level of scanning-related error. We investigated the presence of general shape bias due to device and operator.
    UNASSIGNED: Similar precision was obtained with both devices. If landmarks that were identified as less clearly defined and thus harder to place were omitted, the scanner pipeline would achieve higher precision than the digitizer. Between-operator error was biased and seemed to be smaller when using the scanner pipeline. There were systematic differences between devices, which was mainly driven by landmarks less clearly defined. The factors device, operator and landmark replica were all statistically significant and of similar size, but were minor sources of total shape variation, compared to the biological variation among grey seal skulls. The scanning-related error was small compared to all other error sources.
    UNASSIGNED: As the scanner showed precision similar to the digitizer, a scanner should be used if the advantages of obtaining detailed 3D models of a specimen are desired. To obtain high precision, a pre-study should be conducted to identify difficult landmarks. Due to the observed bias, data from different devices and/or operators should not be combined when the expected biological variation is small, without testing the landmarks for repeatability across platforms and operators. For any study necessitating the combination of landmark measurements from different operators, the scanner pipeline will be better suited. The small scanning-related error indicates that by following the same scanning protocol, different operators can be involved in the scanning process without introducing significant error.
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  • 文章类型: Journal Article
    目的:骨赘是骨性关节炎的常见影像学标志。然而,使用常规成像无法准确描绘它们,从而阻碍了依赖于术前图像的手术干预。研究表明,超声(US)在检测骨赘和监测骨关节炎的进展方面很有前途。此外,三维(3D)超声重建可以提供量化骨赘的手段。这项研究的目的是比较3DUS和常规计算机断层扫描(CT)之间膝关节骨赘描绘的准确性。
    方法:对11个人类尸体膝盖进行了骨赘的预筛查。选择了三个骨关节炎膝盖,然后,获得了3DUS和CT图像,分段,并以3D进行数字重建。解剖后,获得了关节表面的高分辨率结构光扫描仪(SLS)图像。进行了表面匹配和表面距离的均方根(RMS)误差分析,以评估每种模式捕获骨赘的准确性。比较了3DUS之间的RMS误差,CT和SLS模型。
    结果:3DUS与SLS以及CT与SLS模型的平均RMS误差比较分别为0.87mm±0.33mm(平均值±标准偏差)和0.95mm±0.32mm,分别。3DUS和CT之间没有发现统计学差异。成像方式的比较观察表明,与CT相比,3DUS更好地描绘了具有软骨和纤维软骨组织特征的骨赘。
    结论:与CT相比,使用3DUS可以改善对软骨部分骨赘的描绘。它还可以提供有关骨赘的存在和程度的有用信息。虽然需要对US的自动分割和配准进行算法改进,以提供更可靠的骨赘描绘准确性研究,这项研究提出了3DUS在骨关节炎的常规诊断评估和术前计划中的潜在应用.
    OBJECTIVE: Osteophytes are common radiographic markers of osteoarthritis. However, they are not accurately depicted using conventional imaging, thus hampering surgical interventions that rely on pre-operative images. Studies have shown that ultrasound (US) is promising at detecting osteophytes and monitoring the progression of osteoarthritis. Furthermore, three-dimensional (3D) ultrasound reconstructions may offer a means to quantify osteophytes. The purpose of this study was to compare the accuracy of osteophyte depiction in the knee joint between 3D US and conventional computed tomography (CT).
    METHODS: Eleven human cadaveric knees were pre-screened for the presence of osteophytes. Three osteoarthritic knees were selected, and then, 3D US and CT images were obtained, segmented, and digitally reconstructed in 3D. After dissection, high-resolution structured light scanner (SLS) images of the joint surfaces were obtained. Surface matching and root mean square (RMS) error analyses of surface distances were performed to assess the accuracy of each modality in capturing osteophytes. The RMS errors were compared between 3D US, CT and SLS models.
    RESULTS: Average RMS error comparisons for 3D US versus SLS and CT versus SLS models were 0.87 mm ± 0.33 mm (average ± standard deviation) and 0.95 mm ± 0.32 mm, respectively. No statistical difference was found between 3D US and CT. Comparative observations of imaging modalities suggested that 3D US better depicted osteophytes with cartilage and fibrocartilage tissue characteristics compared to CT.
    CONCLUSIONS: Using 3D US can improve the depiction of osteophytes with a cartilaginous portion compared to CT. It can also provide useful information about the presence and extent of osteophytes. Whilst algorithm improvements for automatic segmentation and registration of US are needed to provide a more robust investigation of osteophyte depiction accuracy, this investigation puts forward the potential application for 3D US in routine diagnostic evaluations and pre-operative planning of osteoarthritis.
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  • 文章类型: Journal Article
    Foot impression evidence recovered from crime scenes can be available in the form of barefoot prints, sock-clad footprints, or as impressions within footwear. In some cases, suspects leave their footwear at the scene of the crime, and the insoles from the footwear can be important in linking a person to the footwear. The application of 3D data-collecting technology is becoming more and more popular within forensic science and has been used to recover footwear impression evidence. The present study is a feasibility study to discover if 3D data capturing devices can be applied to insoles; to capture the footprint impression for measurement using the Gunn method (a method used in forensic podiatry casework). Three different methods of data capture were conducted; Adobe Photoshop, MeshLab, and calipers used directly on the insole. Paired t-tests and Intraclass Correlation Coefficient (ICC) were conducted for all three data capture methods. Seven measurements used in this study were significantly different across all three methods. ICC scores were moderate to excellent for the Photoshop method, poor to good for the 3D method, and moderate to excellent for the Direct method.
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  • 文章类型: Journal Article
    During craniotomies, a portion of the calvarium or skull is removed to gain access to the intracranial space. When it is not possible to re-implant the flap, surgeons may repair the defect intraoperatively or at a later date. With larger defects being more difficult to repair intraoperatively, we investigated a method for the creation of patient-specific moulds for ad hoc bone flap reconstruction using rapid prototyping. Patient-specific moulds were created based on light scanned models of the defect, using custom software and rapid prototyping. Polymethylmethacrylate bone implants were created for three retrospective craniotomy cases and evaluated based on original flap and skull reconstruction accuracy. Bone implants created using our moulding method reconstruct the original flap and skull with an average reconstruction accuracy of 0.82 and 1.3 mm, respectively. Average skull reconstruction accuracy obtained by surgeons performing freehand implant reconstruction was 1.49 mm. Time needed to generate moulds was between 2 h and 45 min and 6 h and 20 min. Improvements to current printing technology will make this procedure technically feasible for future cranial procedures.
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  • 文章类型: Journal Article
    OBJECTIVE: Structured light scanning is a promising inexpensive and accurate intraoperative imaging modality. Integration of these scanners in surgical workflows has the potential to enable rapid registration and augment preoperative imaging, in a practical and timely manner in the operating theatre. Previously, we have demonstrated the intraoperative feasibility of such scanners to capture anatomical surface information with high accuracy. The purpose of this study was to investigate the feasibility of automatically characterizing anatomical tissues from textural and spatial information captured by such scanners using machine learning. Assisted or automatic identification of relevant components of a captured scan is essential for effective integration of the technology in surgical workflow.
    METHODS: During a clinical study, 3D surface scans for seven total knee arthroplasty patients were collected, and textural and spatial features for cartilage, bone, and ligament tissue were collected and annotated. These features were used to train and evaluate machine learning models. As part of our preliminary preparation, three fresh-frozen knee cadaver specimens were also used where 3D surface scans with texture information were collected during different dissection stages. The resulting models were manually segmented to isolate texture information for muscles, tendon, cartilage, and bone. This information, and detailed labels from dissections, provided an in-depth, finely annotated dataset for building machine learning classifiers.
    RESULTS: For characterizing bone, cartilage, and ligament in the intraoperative surface models, random forest and neural network-based models achieved an accuracy of close to 80%, whereas an accuracy of close to 90% was obtained when only characterizing bone and cartilage. Average accuracy of 76-82% was reached for cadaver data in two-, three-, and four-class tissue separation.
    CONCLUSIONS: The results of this project demonstrate the feasibility of machine learning methods to accurately classify multiple types of anatomical tissue. The ability to automatically characterize tissues in intraoperatively collected surface models would streamline the surgical workflow of using structured light scanners-paving the way to applications such as 3D documentation of surgery in addition to rapid registration and augmentation of preoperative imaging.
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  • 文章类型: Journal Article
    BACKGROUND: To evaluate the three-dimensional (3D) changes after mandibular setback surgery (MSS) in skeletal Class III malocclusion using cone-beam computed tomography (CBCT) and a structured light-based scanner.
    METHODS: Twenty-eight adult Korean patients with skeletal Class III malocclusion treated by MSS were evaluated. CBCT and facial scan images were recorded one week before and six months after surgery. To use an identical 3D coordinate system, superimposition was performed, and nine skeletal and 18 soft tissue landmarks were identified. Changes in the landmarks and correlation coefficients and ratios between hard and soft tissue changes were evaluated. Paired t test and Pearson\'s correlation test were performed.
    RESULTS: After MSS, the amount of transverse correction was 2.45 mm; mandibular setback, 5.80 mm; and vertical reduction, 1.64 mm at the menton, on average. In the transverse axis, there were significant changes and correlations in the lips and chin and an increasing gradient of ratios from the lower lip to the chin. In the anteroposterior axis, the lower lip and chin moved backward significantly and showed notable correlation with hard tissue movement. In the vertical axis, significant upward movement was observed in the landmarks related to the chin, but only lower facial height was significantly decreased.
    CONCLUSIONS: Soft tissue changes according to hard tissue movement after MSS exhibited a distinct pattern of an increasing gradient from the lips to the chin in a transverse aspect.
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  • 文章类型: Clinical Trial
    OBJECTIVE: Structured light scanning is an emerging technology that shows potential in the field of medical imaging and image-guided surgery. The purpose of this study was to investigate the feasibility of applying a hand-held structured light scanner in the operating theatre as an intraoperative image modality and registration tool.
    METHODS: We performed an in vitro study with three fresh frozen knee specimens and a clinical pilot study with three patients (one total knee arthroplasty and two hip replacements). Before the procedure, a CT scan of the affected joint was obtained and isosurface models of the anatomies were created. A conventional surgical exposure was performed, and a hand-held structured light scanner (Artec Group, Palo Alto, USA) was used to scan the exposed anatomy. Using the texture information of the scanned model, bony anatomy was selected and registered to the CT models. Registration RMS errors were documented, and distance maps between the scanned model and the CT model were created.
    RESULTS: For the in vitro trial, the average RMS error was 1.00 mm for the femur and 1.17 mm for the tibia registration. We found comparable results during clinical trials, with an average RMS error of 1.3 mm.
    CONCLUSIONS: The results of this preliminary study indicate that structured light scanning could be applied accurately and safely in a surgical environment. This could result in a variety of applications for these scanners in image-guided interventions as intraoperative imaging and registration tools.
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  • 文章类型: Journal Article
    背景:抗惊厥脸,“鼻子短,宽阔的鼻梁,后背褶皱,大嘴巴,在1970年代描述了在怀孕期间暴露于抗惊厥药物苯妥英和苯巴比妥的儿童。激光扫描可以建立身体特征的三维位置,并更客观地确定怀孕期间暴露于这些抗惊厥药物的儿童面部受影响软组织的大小和形状的变化。
    方法:13个人,在整个怀孕期间暴露于苯妥英作为单一疗法或多疗法,在先前的分析中,根据头颅X光片的测量结果,确定其颅面特征发生了显着变化。这些变化与中面部发育不全和鼻子短有关,抗惊厥脸的特征。“他们面部的软组织已经用激光扫描进行了评估。
    结果:通过激光扫描确定的软组织的显着变化是宽hiltrum(cph-cph),窄嘴(ch-ch),短鼻梁(n-prn),缩短鼻子高度(n-sn),和变平的轨道(轨道突起指数)。
    结论:这项对暴露于苯妥英钠的个体的面部特征的分析,选择是因为颅面骨结构的变化,表明有几个重大变化,其中两个,扩大人脉和小嘴巴,以前没有被描述为这种表型的一部分。
    BACKGROUND: The \"anticonvulsant face,\" with a short nose, broad nasal bridge, epicanthal folds, and wide mouth, was described in the 1970s in children who had been exposed during pregnancy to the anticonvulsant drugs phenytoin and phenobarbital. The laser light scan makes it possible to establish three-dimensional positions of physical features and to determine more objectively the changes in the size and shape of the affected soft tissues of the faces of children exposed to these anticonvulsant drugs during pregnancy.
    METHODS: Thirteen individuals, exposed throughout pregnancy to phenytoin as either monotherapy or polytherapy, were identified in a previous analysis as having significant changes in their craniofacial features based on measurements of cephalometric radiographs. Those changes were associated with midface hypoplasia and a short nose, features of the \"anticonvulsant face.\" The soft tissues of their faces have been evaluated with laser light scans.
    RESULTS: The notable changes in soft tissues identified by laser light scans were a wide philtrum (cph-cph), narrow mouth (ch-ch), short nasal bridge (n-prn), shortened nose height (n-sn), and flattened orbits (orbital protrusion index).
    CONCLUSIONS: This analysis of the facial features of phenytoin-exposed individuals, selected because of changes in their craniofacial bony structures, showed that there were several significant changes, two of which, widening of the philtrum and a small mouth, have not been described previously as part of this phenotype.
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