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Biomedical subjects

T Zhuang

Publications and source records attributed to T Zhuang.

13 recordsLinked to original sources
PubMed2001

Realizations of fast 2-D/3-D image filtering and enhancement.

This paper proposes a novel algorithm for multidimensional image enhancement based on a fuzzy domain enhancement method, and an implementation of a recursive and separable low-pass filter. Considering a smoothed image as a fuzzy data set, each pixel in an image is processed independently, using fuzzy domain transformation and enhancement of both the dynamic range and the local gray level variations. The algorithm has the advantages of being fast and adaptive, so it can be used in real-time image processing applications and for multidimensional data with low computational cost. It also has the ability to reduce noise and unwanted background that may affect the visualization quality of two-dimensional (2-D)/three-dimensional (3-D) data. Examples for the applications of the algorithm are given for mammograms, ultrasound 3-D images, and photographic images.

Algorithms↗
PubMed2001

[Application of time-frequency analysis on medical signal processing].

The frequency content of many biomedical signals can change rapidly with time. Conventional Fourier spectral analysis techniques are insufficient for analyzing the time-varying spectral content of these signals. By mapping a one-dimensional function of time(or frequency), the time-frequency representation can localize the signal energy in both the time and frequency directions. It has been shown that many biomedical signal problems may benefit from time-frequency analysis. The basic method of time-frequency analysis and its application in biomedical signals processing are introduced.

Algorithms↗
PubMed2000

Identification of a novel isoform of poly(A) polymerase, TPAP, specifically present in the cytoplasm of spermatogenic cells.

We have identified cDNA clones encoding a testis-specific poly(A) polymerase, termed TPAP, a candidate molecule responsible for cytoplasmic polyadenylation of preexisting mRNAs in male haploid germ cells. The TPAP gene was most abundantly expressed coincident with the additional elongation of mRNA poly(A) tails in round spermatids. The amino acid sequence of TPAP contained 642 residues, and shared a high degree of identity (86%) with that of a nuclear poly(A) polymerase, PAP II. Despite the sequence conservation of functional elements, including three catalytic Asp residues, an ATP-binding site, and an RNA-binding domain, TPAP lacked an approximately 100-residue C-terminal sequence carrying one of two bipartite-type nuclear localization signals, and part of a Ser/Thr-rich domain found in PAP II. Recombinant TPAP produced by an in vitro transcription/translation system was capable of incorporating the AMP moiety from ATP into an oligo(A)(12) RNA primer in the presence of MnCl(2). Moreover, an affinity-purified antibody against the 12-residue C-terminal sequence of TPAP recognized a 70-kDa protein in the cytoplasm of spermatogenic cells. These results suggest that TPAP may participate in the additional extension of mRNA poly(A) tails in the cytoplasm of male germ cells, and may play an important role in spermiogenesis, probably through the stabilization of mRNAs.

Amino Acid Sequence↗
PubMed1998

[Computer assisted ENT surgery system].

This paper describes a novel computer assisted ENT surgery system which is based on high-performanced 3D optical localizer and the combinational registration method for matching between pre-operative and intra-operative information. Preliminary results on cadaver specimen show the system is suited for clinical ENT surgery.

Equipment Design↗
PubMed1998

[Interactive 2D/3D image processing, registration and display system].

This paper presents an integrated system for interactive 2D/3D image processing, registration and display. The main image processing algorithm in the system is image filtering, enhancement, adaptive B-snake model, image registration, pseudo color representation and 3D volume rendering. The system provides good visulization interface and image tool.

Humans↗
PubMed1998

[The method and development of computer-assisted surgery].

The methodology and the state of the art of Computer-Assisted Surgery (CAS) are introduced in this paper. Computer-assisted surgery is a new high technology which uses computer science, biomedical engineering, mechanism, mathematics, surgery, and so on. Its objective is to help surgeons use multimodal data, such as CT, MRI, DSA, PET, et al. in a rational and quantitative way in order to plan and perform medical intervention. Stereotactic localization method and registration are two cruxes in computer-assisted surgery. There are several methods for localization and registration. In recent ten years, computer-assisted surgery has been a cynosure of scientists. Some computer-assisted surgery systems have been used in clinical practice.

General Surgery↗
PubMed1997

[The study of a frameless stereotactic localization method using DSA].

A frameless stereotactic localization method with DSA is introduced in this paper. A locating plate and four head marks are used in the method. Using two projection images of DSA, the three dimension coordinate of any point can be calculated referring to the reference locating coordinate system. The method is the theoretic basis of locating brain structure such as the blood vessel using DSA.

Algorithms↗
PubMed1997

[Experimental study on direct volume reconstruction].

Application of DVR is investigated with the X-ray equipment under single circle imaging geometry. A real volume model that consists of aluminum bar, lucite and air bar is designed. A prototype imaging system that includes X-ray cone-beams ource, rotating system, fluorescent screen, image intensifier, TV camera, image acquisitor and microcomputer is constructed. The experimental results show that DVR with the current simple X-ray equipment is of interests and values.

Image Processing, Computer-Assisted↗
PubMed1997

[Description of finger shape in the process of growing during infancy].

In this paper, a new method of estimating bone age is reported that is based on the use of spatial description parameters and fourier frequential descriptors, which presents the boundary shapes detected in finger bones X-ray films of 0-, 3-, 6-, 9-month baby according to their bone shape changes in different stages.

Age Determination by Skeleton↗
PubMedDate not supplied

MRI brain image segmentation by multi-resolution edge detection and region selection.

Combining both spatial and intensity information in image, we present an MRI brain image segmentation approach based on multi-resolution edge detection, region selection, and intensity threshold methods. The detection of white matter structure in brain is emphasized in this paper. First, a multi-resolution brain image representation and segmentation procedure based on a multi-scale image filtering method is presented. Given the nature of the structural connectivity and intensity homogeneity of brain tissues, region-based methods such as region growing and subtraction to segment the brain tissue structure from the multi-resolution images are utilized. From the segmented structure, the region-of-interest (ROI) image in the structure region is derived, and then a modified segmentation of the ROI based on an automatic threshold method using our threshold selection criterion is presented. Examples on both T1 and T2 weighted MRI brain image segmentation is presented, showing finer brain tissue structures.

Brain↗