Biomedical subjects

Daoyin Yu

Publications and source records attributed to Daoyin Yu.

4 recordsLinked to original sources

PubMed2006

[Three-dimensional moston estimation of coronary artery from single-plane cineangiogram sequences].

This paper presents a method for estimating three-dimensional (3D) motion of coronary arteries from single-plane X-ray angiogram sequences on two views. Firstly, original images are preprocessed and two-dimensional (2D) vessel skeletons are extracted. 2D motion estimation is performed along the skeletons in two images. Then geometrical transformation matrix between views is obtained based on perspective projection model for X-ray angiography system, and 3D coordinate of spatial points are calculated. The 3D motion estimation and reconstruction algorithm is applied along the two image sequences to accomplish 3D reconstruction of vessel skeletons and motion vectors between consecutive time instants. Its effectiveness has been demonstrated on clinical single-plane coronary artery angiograms and potential errors are discussed.

Algorithms↗

PubMed2005

Optical phase shifting with acousto-optic devices.

A novel optical phase-shifting method based on a well-known acousto-optic interaction is proposed. By using a pair of acousto-optic modulators (AOMs) and properly aligning them, we construct an optical phase shifter that can directly control the phase of a collimated beam. The proposed phase shifter is insensitive to the polarization of the incident beam when polarization-insensitive AOMs are used, and no calibration is necessary. The proposed approach is confirmed with experimental results.

Journal Article↗

PubMed2005

[Coronary artery motion estimation using X-ray cineangiogram].

This paper presents an approach for estimating the non-rigid motion of coronary arteries using digital angiographic images. Displacement vectors of vessel points are obtained by finding points correspondences in two successive frames. Smoothness of motion field and vessel deformation measurement are considered in matching, and unmatched regions are also dealt with in the fact that the vessel after deformation may have different size with its original station. The search strategy for optimal matching is carried out using dynamic programming (DP) so that computing cost is reduced. Results of this motion estimation method applied to synthetic and clinical images have shown that the method is accurate, with a root mean square error about one pixel for simulated data. For the case of actual X-ray coronary angiographic images, visual inspection of the detected pairs of points shows that the results are very encouraging.

Angiography, Digital Subtraction↗

PubMed2002

New approach for enlargement of medical electronic endoscopic images.

To compensate for the imperfections of the endoscopic mechanical structure and the limitations of working space, a new technology based on the recursive minimum/maximum method is proposed to enlarge images obtained by the medical electronic endoscope. This method can be used repeatedly to obtain image enlargement to 2x by optimizing the neighborhood information of the pixels of interest in adjustable windows. In order to ensure the best evaluation of the pixel, the algorithm criterion is presented to decide whether the new gray value is assigned to the pixel. Experimental results from enlarged endoscopic images are presented that demonstrate that the recursive minimum/maximum method for image enlargement can preserve the fine details with rich edge information and with better visualization.

Algorithms↗