Li Zhangyong

Modeling the electrical characteristics of the stomach and reconstructing image

Currently, stomach functional detection has a great demand. It is a challenging job. The electrical impedance tomography study can be applied to explore a new method of gastric motility detection. In accordance with a color image of human sectional anatomy, the boundaries of the human body contours of the real body of stomach can be required. Simulate on dynamic electrical impedance tomography algorithm base on back-projection technique. Results show that the model can reflect different kinds of distribution of electrical conductivity. Basing on the back-projection techniques, the algorithm has a certain degree of precise location and identification. Electrical impedance tomography of gastric motility is feasible and reliable.

Using an Electrical Bio-Impedance Method to Detect and Evaluate Gastric Motility for Erosive Gastritis Patients

In order to investigate the complex course of electricity and mechanism of erosive gastritis (EG), including its rhythm, transmission, gastric empty course and the influences of them, it is necessary to extract gastric motility feature indexes. Methods: According the clinic standardization, 30 volunteers of erosive gastritis were selected. The signal processing device was designed by Chongqing University of Posts and Telecommunications. Both signals impedance gastric motility (IGM) and EGG collected from body surface are decomposed by Multi-resolution Analysis (MRA). Wavelet transform is addressed to separate the IGM signal from breathing and blood flowing impedance signals. By the means of energy and frequency spectrum analysis technic, the signals can be classify according to the dominant power and dominant frequency. Some indexes such as frequency of EGG and IGM, signal power spectrum and dynamic spectrum, the rates of rhythm and power for the normal EGG and IGM and so on can also be calculated. Results: The experiments of gastric motility measurement and evaluation are executed including before teating and after a week. The parameters have changed significantly between health adult and patient (P 0.05). The results of the experiments show that the method based on the synchronous measurement of EGG and IGM can provide a non-invasive way to investigate and evaluate gastric motility situation correspond ing gastrointestinal physiology and pathology conditions.

Design Multiparameter Anaesthesia Depth Monitor System

A Multiparameter system was designed to monitor depth of anaesthesia for children surgical intervention. Heart rate variability (HRV) come from ECG signal, Pressure of End-Tidal Carbon Dioxide and Oxygen Saturation were used to evaluate depth of anaesthesia. Some physiological parameters were obtained in real time through continuous monitor. Pressure of End-Tidal Carbon Dioxide and Respiratory Rate could be measured from End-Tidal Carbon Dioxide signal. Heart rate and kinds of HRV parameters were got from electrocardiogram (ECG) signal with 300Hz sampling rate. Pulse Oxygen Saturation and pulse could be obtained from pulse oxygen saturation signal. Depth of anaesthesia could be estimated base on the information. The structure of the system and each part were introduced in detail in this paper. Both microcontroller and personal computer (PC) software design was also analysed in the paper. The microcontroller program is responsible for signal extracting and pre-processing. The PC program is responsible for data further process, result display and human-machine interface design. The simulation signal recording expressed that the system was fit the expect object. In the future, the volunteers need be employed to do some experiment to check this system.