Search results for " three-dimensional"
showing 10 items of 323 documents
A microscope configuration for nanometer 3-D movement monitoring accuracy.
2011
In this paper we present a new microscopy configuration based upon temporal tracking of a secondary reflected speckle by imaging the speckle through properly defocused optics. The configuration is used to monitor three-dimensional (3-D) spontaneous contraction of rat cardiac muscle cells while achieving nanometer tracking accuracy at a rate of 30 frames per second (fps) without using interferometric recording. Estimation of the change in the optical path of accuracy of 50 nm in the transverse direction and of 200 nm in the axial direction was achieved.
Handheld and cost-effective Fourier lightfield microscope
2022
In this work, the design, building, and testing of the most portable, easy-to-build, robust, handheld, and cost-effective Fourier Lightfield Microscope (FLMic) to date is reported. The FLMic is built by means of a surveillance camera lens and additional off-the-shelf optical elements, resulting in a cost-effective FLMic exhibiting all the regular sought features in lightfield microscopy, such as refocusing and gathering 3D information of samples by means of a single-shot approach. The proposed FLMic features reduced dimensions and light weight, which, combined with its low cost, turn the presented FLMic into a strong candidate for in-field application where 3D imaging capabilities are pursu…
Design of a Three-Dimensional-Printed Surgical Glove for Minimal-Incision Podiatric Surgery.
2019
Background: Precision in minimal-incision surgery allows surgeons to achieve accurate osteotomies and patients to avoid risks. Herein, a surgical guide for the foot is designed and validated in vitro using resin foot models for hallux abducto valgus surgery. Methods: Three individuals with different experience levels (an undergraduate student, a master's student, and an experienced podiatric physician) performed an Akin osteotomy, a Reverdin osteotomy, and a basal osteotomy of the first metatarsal. Results: The average measurements of each osteotomy and the angle of the basal osteotomy do not reveal significant differences among the three surgeons. A shorter deviation from the planned meas…
Development of software in the study of carotid artery in the neck.
2001
The aim of this work was to develop and employ software for the study of the common carotid artery and its branches in the neck. We first constructed geometric models of anatomic components, for the building of knowledge bases to be used in automatic feature extraction techniques from images. Then, we developed a software system characterised by three-dimensional visualisation, image processing functions, knowledge base and a programming language to describe classification processing by means of fuzzy logic. The software system was used to perform automatic reconstruction of three-dimensional models of carotid arteries from contiguous CT scans of the neck. These findings suggest that such s…
Multicolor 3D Printing of Complex Intracranial Tumors in Neurosurgery.
2020
Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. The model can be used for planning and simulating critical steps of a surgical approach. Therefore, it is important that anatomical structures such as blood vessels inside a tumor can be printed to be colored not only on their surface, but throughout their whole volume. During simulation this allows for the removal of certain parts (e.g., with a high-speed drill) and revealing internally located structures of a different color. Thus, diagnostic information from various imaging modalities (e.g., CT, MRI) can be combined in a single compact …
Direct measurement of left ventricular outflow tract by transthoracic real-time 3D-echocardiography increases accuracy in assessment of aortic valve …
2007
Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter.We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from …
Calculation of bone graft volume using 3D reconstruction system.
2010
Objectives: To obtain bone ?bioreplicas? for determining precisely the amount of biomaterial required for bone regeneration procedure. Study design: A case-control comparison with a total sample size of 20 cases, 10 control and 10 test samples. ?Bioreplicas? were generated from helical CAT scans with 0.5 mm slices, without 3D reconstruction or image filters. Bone defects in premolar and molar areas were treated with titanium mesh and xenograft (MP3) combined with resorbable carriers. Time taken to carry out procedures with and without the use of ?bioreplicas? (in minutes), discrepancies between the grafts performed with and without ?bioreplicas? and bone defects (mm), and postoperative comp…
Morphology of the Physiological Foramen: I. Maxillary and Mandibular Molars
2004
Information concerning the anatomy of the physiological foramen is limited. The aim of this study was to investigate the distance between the physiological and anatomical apex, accessory foramina frequency, and the shape and diameter of the physiological foramen in maxillary and mandibular molars. The apical anatomy of 523 maxillary and 574 mandibular molars from an Egyptian population was investigated by means of a computer-aided stereomicroscope (40 x magnification). The following results were obtained:
3D printed fluidic platform with in-situ covalently immobilized polymer monolithic column for automatic solid-phase extraction
2020
Abstract In this work, 3D stereolithographic printing is proposed for the first time for the fabrication of fluidic devices aimed at in-situ covalent immobilization of polymer monolithic columns. Integration in advanced flow injection systems capitalized upon programmable flow was realized for fully automatic solid-phase extraction (SPE) and clean-up procedures as a ‘front-end’ to on-line liquid chromatography. The as-fabricated 3D-printed extraction column devices were designed to tolerate the pressure drop of forward-flow fluidic systems when handling large sample volumes as demonstrated by the determination of anti-microbial agents, plastic additives and monomers as models of emerging co…
Isolation of the left atrial surface from cardiac multi-detector CT images based on marker controlled watershed segmentation
2006
The delineation of left atrium (LA) and pulmonary veins (PVs) anatomy from high resolution images holds importance for atrial fibrillation (AF) investigation and treatment. In this study, a semiautomatic segmentation procedure for LA and PVs inner surface from contrast enhanced CT data was developed. The procedure consists of a three dimensional marker controlled watershed segmentation applied to the external morphological gradient, followed by variable threshold surface extraction from the original intensity image. A preliminary anisotropic non-linear filtering was implemented to improve the S/N ratio of CT images. The performance of segmentation was evaluated on cardiac CT scans of 12 AF …