An optimization method to reconstruct the object profile is performed by using a flexible laser plane and bi-planar references. The bi-planar references are considered as flexible benchmarks to realize the transforms among two world coordinate systems on the bi-planar references, the camera coordinate system and the image coordinate system. The laser plane is confirmed by the intersection points between the bi-planar references and laser plane. The 3D camera coordinates of the intersection points between the laser plane and a measured object are initially reconstructed by the image coordinates of the intersection points, the intrinsic parameter matrix and the laser plane. Meanwhile, an optimization function is designed by the parameterized differences of the reconstruction distances with the help of a target with eight markers, and the parameterized reprojection errors of feature points on the bi-planar references. The reconstruction method with the bi-planar references is evaluated by the difference comparisons between true distances and standard distances. The mean of the reconstruction errors of the initial method is 1.01 mm. Moreover, the mean of the reconstruction errors of the optimization method is 0.93 mm. Therefore, the optimization method with the bi-planar references has great application prospects in the profile reconstruction.
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http://dx.doi.org/10.1038/s41598-018-19928-4 | DOI Listing |
Sci Rep
March 2024
Health Engineering Innovation Center, Khalifa University, Abu Dhabi, UAE.
There is a growing interest in the research and development of Cable Driven Rehabilitation Devices (CDRDs) due to multiple inherent features attractive to clinical applications, including low inertia, lightweight, high payload-to-weight ratio, large workspace, and modular design. However, previous CDRDs have mainly focused on modifying motor impairment in the sagittal plane, despite the fact that neurological disorders, such as stroke, often involve postural control and gait impairment in multiple planes. To address this gap, this work introduces a novel framework for designing a cable-driven lower limb rehabilitation exoskeleton which can assist with bi-planar impaired posture and gait.
View Article and Find Full Text PDFInt Orthop
May 2023
Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246, Hamburg, Germany.
Purpose: Calibration of radiographs is a critical step in digital templating for hip arthroplasty. Calibration errors of > 1.5% lead to over- or undersizing of the templated implants and may affect logistics and patient safety.
View Article and Find Full Text PDFSensors (Basel)
February 2023
Healthcare Engineering Innovation Center, Khalifa University of Science Technology & Research, Abu Dhabi P.O. Box 127788, United Arab Emirates.
Although Cable-driven rehabilitation devices (CDRDs) have several advantages over traditional link-driven devices, including their light weight, ease of reconfiguration, and remote actuation, the majority of existing lower-limb CDRDs are limited to rehabilitation in the sagittal plane. In this work, we proposed a novel three degrees of freedom (DOF) lower limb model which accommodates hip abduction/adduction motion in the frontal plane, as well as knee and hip flexion/extension in the sagittal plane. The proposed model was employed to investigate the feasibility of using bi-planar cable routing to track a bi-planar reference healthy trajectory.
View Article and Find Full Text PDFBMC Musculoskelet Disord
September 2022
Department of Orthopaedics, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, No.31 Xinjiekou East Street, Xicheng District, Beijing, China.
Background: Three-dimensional computed tomography (3D CT) reconstruction is the reference standard for measuring component orientation. However, functional cup orientation in standing position is preferable compared with supine position. The low-dose bi-planar radiographs can be used to analyze standing cup component orientation.
View Article and Find Full Text PDFJ Arthroplasty
December 2022
Young Adult Hip Service, Department of Trauma and Orthopaedics, Addenbrooke's - Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.
Background: Total hip arthroplasty (THA) carries a substantial litigative burden. THA may introduce leg length discrepancy (LLD), necessitating a valid and reliable technique for LLD measurement. This study investigates the reliability and validity of techniques quantitively measuring LLD in both pre- and post-THA.
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