3D measurements using a programmable projector and a grating

2005 ◽  
Author(s):  
Kevin Harding ◽  
Russ Demuth ◽  
Robert Tait
Keyword(s):  
3D Measurements

Multipulsed digital holography applied to full 3D measurements of dynamic events

2001 ◽  
Author(s):  
Fernando Mendoza Santoyo ◽  
Giancarlo Pedrini ◽  
Staffan Schedin ◽  
Hans J. Tiziani
Keyword(s):  
Digital Holography ◽  
3D Measurements ◽  
Dynamic Events

scholarly journals Calibration Method for Line-Structured Light Three-Dimensional Measurements Based on a Single Circular Target

2022 ◽  
Vol 12 (2) ◽  
pp. 588
Author(s):  
Jun Wang ◽  
Xuexing Li
Keyword(s):  
Structured Light ◽  
Three Dimensional ◽  
Calibration Method ◽  
Optical Center ◽  
3D Measurements ◽  
Light Plane ◽  
Laser Projector ◽  
Dimensional Measurements ◽  
Intersection Points ◽  
Circular Target

Single circular targets are widely used as calibration objects during line-structured light three-dimensional (3D) measurements because they are versatile and easy to manufacture. This paper proposes a new calibration method for line-structured light 3D measurements based on a single circular target. First, the target is placed in several positions and illuminated by a light beam emitted from a laser projector. A camera captures the resulting images and extracts an elliptic fitting profile of the target and the laser stripe. Second, an elliptical cone equation defined by the elliptic fitting profile and optical center of the camera is established based on the projective geometry. By combining the obtained elliptical cone and the known diameter of the circular target, two possible positions and orientations of the circular target are determined and two groups of 3D intersection points between the light plane and the circular target are identified. Finally, the correct group of 3D intersection points is filtered and the light plane is progressively fitted. The accuracy and effectiveness of the proposed method are verified both theoretically and experimentally. The obtained results indicate that a calibration accuracy of 0.05 mm can be achieved for an 80 mm × 80 mm planar target.

scholarly journals Finite element simulation of the impedance response of a vascular segment as a function of changes in electrode configuration

2020 ◽  
Vol 11 (1) ◽  
pp. 112-131
Author(s):  
M. Amini ◽  
H. Kalvøy ◽  
Ø.G. Martinsen
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Experimental Measurement ◽  
Three Dimensional ◽  
Electrode Configuration ◽  
Element Modeling ◽  
3D Measurements ◽  
Element Simulation ◽  
Vascular Segment ◽  
Set Up

AbstractMonitoring a biological tissue as a three dimensional (3D) model is of high importance. Both the measurement technique and the measuring electrode play substantial roles in providing accurate 3D measurements. Bioimpedance spectroscopy has proven to be a noninvasive method providing the possibility of monitoring a 3D construct in a real time manner. On the other hand, advances in electrode fabrication has made it possible to use flexible electrodes with different configurations, which makes 3D measurements possible. However, designing an experimental measurement set-up for monitoring a 3D construct can be costly and time consuming and would require many tissue models. Finite element modeling methods provide a simple alternative for studying the performance of the electrode and the measurement set-up before starting with the experimental measurements. Therefore, in this study we employed the COMSOL Multiphysics finite element modeling method for simulating the effects of changing the electrode configuration on the impedance spectroscopy measurements of a venous segment. For this purpose, the simulations were performed for models with different electrode configurations. The simulation results provided us with the possibility of finding the optimal electrode configuration including the geometry, number and dimensions of the electrodes, which can be later employed in the experimental measurement set-up.

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