Objective To improve HIFU focal spot accuracy.Methods Combining with actual production,the influencing factors of ultrasound spot accuracy were analyzed from the aspect of mechanical equipment.In order to ensure the first focal accuracy,suitable piezoelectric ceramics flakes were selected by measuring single probe acoustic field.Reasonable designing projection planning was used to ensure the second focal accuracy.Results By means of general positioning of H7h6 clearance fit,focal spot accuracy error of ?66mm probe was kept under 0.05mm.If(?+?)was kept under 0.12?,the focal spot accuracy could be controlled under 0.5mm.Conclusion During the development of HIFU,focal spot accuracy can be improved by taking effective measures to ensure two focal accuracies.[Chinese Medical Equipment Journal,2008,29(2):28-30]

To evaluate the curative effect of antisense telomerase ODN on malignant glioma cells. The activity of telomerase in 16 fresh malignant gliomas was detected positive by PCR ELISA method. After covered with lipofectin, the 5?mol/L telomerase ODN was incubated with cultured gliomas cells. PCNA, TUNEL positive rate and the phase of cell cycle were detected by FcM per 24h. The results showed: Anti sense ODN inhibited telomerase activity after being applied for 48 hours, and inhibition was complete at 72 hours, The ODN inhibited proliferation of malignant gliomas and promoted their apoptosis markedly at 72 hours. After 96 hours, most transfected glioma cells were stopped to grow at G 2/M phase, and the number of apoptosis cells increased as time went on. The results suggested that anti sense telomerase ODN could inhibit the telomerase activity, and in turn promote aptoptosis of glioma cells and inhibit the growth of the tumor.

To establish the proliferation and apoptosis index(P/AI), and to explore its relationship to the malignant degree of gliomas. Specimens of normal brain tissues obtained from 8 patients undergoing decompression operation for head injury, and 69 paraffin-embedded specimens and 26 fresh specimens of the glioma were studied. Immunohistochemical staining of proliferation cell nuclear antigen (PCNA) and terminal deoxynucleotidyl transferase mediated dUTP DIG nick end labeling(TUNEL) were used to determine the proliferation and apoptosis rates of the glioma. Grading was defined by the ratio between PCNA positive rate and TUNEL positive rate (P/AI). An increase in P/AI denoted an increase in malignancy. It was found that P/AI of normal brain tissue was 0.2-1.5. In 85.1% of grades Ⅰ and Ⅱ gliomas, P/AI was lower than 2.5 and while in 91.7% of grades Ⅲ and Ⅳ gliomas P/AI was 2.5. There were significant differences between normal group, grades Ⅰ and Ⅱ and grades Ⅲ and Ⅳ over gliomas (P

Objective To study the clinical effect of homemade rapamycin-eluting stent on acute myocardial infarction(AMI).Methods A total of 116 AMI patients who received emergency PCI were divided into two groups,the Cypher group(n=52)and the Partner group(n=64).There was no obvious difference in ages,female ratio,smoking,hypertension,hyperlipidema and diabetes between the two groups.The MACE and the restenosis were the targets we wanted to observe.Results The emergency PCI were all successful.Fifty-five Cypher stents and sixty-four Partner stents were planted.The MACE was 0 during in-hospital and the follow-up.Eleven patients in Cypher group(21.15%)and eighteen patients in Partner group(28.13%)underwent coronary angiography re-examination at the 6 months' post-stenting,the restenosis both being 0.Conclusion The homemade rapamycin-eluting stent is safe and effective in AMI.

Bioradar is based on the integration of theory of radar and bio-medical engineering,which can detect the life-parameters in farther distance.It is new concept radar presented by foreign experts.The technology can be widely used in detection of lifeform signal and non-contact clinical monitoring.Biomedical signal processing method is the premise that the technology can be realized.The signals can be interfered by the environmental factors,breath motion and so on,especially the influences of breath motion which can not be solved by average methods.A large number of signal processing methods are used in various aspects of the technology.This review introduces the progress of bioradar technology and the application of the current signal processing methods in the field.

To separate the biological radar echo signals in different breathing modes. Echo signals of bioradar-based vital signs monitoring system were acquired in different breathing modes, and an improved signal separa-tion algorithm was used to obtain respiratory and heartbeat signals as well as their parameters. Under two breath-ing modes, the center frequencies of the signals from the self-adaptive filter were kept consistent with those of heartbeat signals, and the signals with other frequencies were suppressed effectively. The algorithm can be used to sep-arate heartbeat signals while suppress other interference signals effectively. ZHANG Jing and LIU Qian are the first au-thors who contributed equally to the article.

This paper introduces the means and characteristics of signal acquisition of the non-contact life parameters detection system as well as the design of preprocessor circuit.The results show that the preprocessor is designed reasonably,which can provide the computer with high quality signals.

Strong clutters are produced by the echo waves from the debris when the life detector based on radar locates the living human subject under the debris, which makes the life detector work abnormally because the amplifier is saturate. A canceling technology for the strong clutters is provided to solve the problems discussed above in this paper. The canceling technology for the strong clutters can provide methods and theories in practice by constructing and simulating the mathematic model in the computer, analyzing and discussing the results.

This article refers to constructing process of non-contact life parameter detecting system by twin-antenna. The technology above proves feasible through pilot study of restraining environmental interference by donkey antenna. A new method for solving the problem of environmental interference of non-contact life parameter detecting system is also presented.

The effect of hydrazine on blue membrane was investigated by the UV/VIS absorption spectrum technique and the flash photolysis technique, the results show that: hydrazine can convert blue membrane to purple membrane and the photocycle returns, but the rate of decay of photcycle intermediate(M412) quickens, this phenomenon is not seen when metal cations are added to blue omembrane solution(the rate of decay of photcycle intermediate slowers). At the same time , the effect of pH and temperature on the interaction between hydrazine and blue membrane was investigated. When hydrazine was added to blue membrane solution, the sensitivity of the reaction is pH and temperature dependent. Over the pH range(2～4.8), the sensitivity of the reaction lowers with the increase of the acidity. Over the temperature range(20～40℃), the sensitivity of the reaction lowers with the increase of the temperature.