Biomedical subjects

Dazong Jiang

Publications and source records attributed to Dazong Jiang.

7 recordsLinked to original sources

PubMed2006

[Computer simulation methods of cardiac electrophysiology].

Computer simulation is one of the powerful protocols to study electrophysiology theoretically. In this paper,the algorithm of Rush and Larsen was used to solve the ordinary differential equations (ODE's) in the Luo-Rudy models of mammalian ventricular cell. The operator splitting and adaptive time step methods were used to solve the partial differential equations (PDE's) in cardiac tissue conduction models. Using these methods we accomplished the simulation programs of single ventricular cell model and two-dimensional (2-D) tissue model. The methods of initiating spiral waves were studied with this software. The data obtained from 2-D simulation can be used for further study on isopotential contour lines, spiral wave tip trajectories, and pseudo-ECG.

Algorithms↗

PubMed2004

[Digital fluoroscopy imaging system with dual energy X-ray image decomposition].

Dual-kilovolt technique was realized in dual energy X-ray imaging system with computer controlled KV adjustment, filter switching and image acquirement. The dual energy images can be obtained in 2-3 seconds to avoid moving artifact. Low energy photons in high energy X-ray beam can be attenuated effectively by a 2 mm Cu filter to separate the spectra of the high and low energy X-rays. A simplified dual energy decomposition method was used to obtain the soft tissue image. An example of chest dual energy radiographs is presented to illustrate the performance of the system.

Humans↗

PubMed2002

[Study of functional magnetic stimulation].

Functional magnetic stimulation (FMS) is a new technique for stimulation on excitable neuromuscular cell and provides extensive applications with many advantages, such as deep stimulation, less pain, non-invasive approach and easy to operate technique. In this paper, the new reports of FMS are introduced including the principle, stimulator, coils, results of experiments and our research on analgesic effect of FMS.

Analgesia↗

PubMed2002

[Synthesis and characteristics of porous hydroxyapatite bioceramics].

The macroporous structure of human bone allows the ingrowth of the soft tissues and organic cells into the bone matrix, profits the development and metabolism of bone tissue, and adapts the bone to the change of load. There is great requirement for artificial biomimic porous bioactive ceramics with the similar structure of bone tissue that can be used clinically for repairing lost bone. Fine hydroxyapatite (HAp) powder produced by wet chemical reaction was mixed with hydrogen peroxide (H2O2), polyvinyl alcohol, methyl cellulose or other pores-making materials to form green cake. After drying at low temperature (below 100 degrees C) and decarbonizing at about 300 degrees C-400 degrees C, the spongy ceramic block was sintered at high temperature, thus, macroporous HAp bioceramic with interconnected pores and reasonable porosity and pore-diameter was manufactured. This kind of porous HAp bioceramics were intrinsically osteoinductive to a certain degree, but its outstanding property was that they can absorb human bone morphogenetic proteins and other bone growth factors to form composites, so that the macroporous HAp bioactive ceramic has appropriate feasibility for clinical application. From the point of biomedical application, the recent developments in synthesis and characteristics investigation of macroporous HAp are reviewed in this paper.

Biocompatible Materials↗

PubMed2002

[5-Aminolevulinic acid esters based photodynamic therapy].

As exogenous ALA (5-aminolevulinic acid) esters can induce the production and accumulation of endogenous photosensitizer PpIX (protoporphyrin IX) in tumor tissues more effectively, they have been the most active photosensitizer prodrug in PDT(photodynamic therapy) field. In this article, along with the procedure of ALA esters based PDT, some primary mechanism and experimental results were considered, which include: first, cellular uptake of ALA esters and its conversion into ALA; second, the production and accumulation of endogenous photosensitizer PpIX induced by eNdogenous ALA esters; last, the photosensitization of PpIX.

Aminolevulinic Acid↗

PubMed2002

[The application and development of artificial intelligence in medical diagnosis systems].

This paper has reviewed the development of artificial intelligence in medical practice and medical diagnostic expert systems, and has summarized the application of artificial neural network. It explains that a source of difficulty in medical diagnostic system is the co-existence of multiple diseases--the potentially inter-related diseases. However, the difficulty of image expert systems is inherent in high-level vision. And it increases the complexity of expert system in medical image. At last, the prospect for the development of artificial intelligence in medical image expert systems is made.

Artificial Intelligence↗

PubMedDate not supplied

Blood cell counting and classification by nonflowing laser light scattering method.

We present a nonflowing laser light scattering method for automatically counting and classifying blood cells. A linear charge-coupled device (CCD) and a silicon photoelectric cell (which is placed behind a pinhole plate on the CCD) form a double-detector structure: the CCD is used to detect the scattered light intensity distribution of the blood cells and the silicon photoelectric cell to complete the focusing process. An isotropic sphere, with relative refractivity near 1, is used to model the blood cell. Mie theory is used to describe the scattering of white blood cells and platelets, and anomalous diffraction, red blood cells. To obtain the size distribution of blood cells from their scattered light intensity distribution, the nonnegative constraint least-squares (NNLS) method combined with the Powell method and the precision punishment method are used. Both numerical simulation and experimental results are presented. This method can be used not only to measure the mean and the distribution of red blood cell size, but also to divide the white blood cells into three classes: lymphocytes, middle-sized cells, and neutrocytes. The experimental results show a linear relationship between the blood cell (both white and red blood cells) concentration and the scattered light intensity, and therefore, the number of blood cells in a unit volume can be determined from this relationship.

Adult↗