A DSP-based design method for detecting fetal heart rate signals / 中国医疗器械杂志

The paper presents the development and design of an ultrasonic Doppler fetal heart rate monitoring system based on DSP, and explains the realization of a algorithm for detecting fetal heart rate. Clinical practice has proved that this system is able to pick up the real-time fetal heart rate correctly and rapidly.

A novel approach of low-frequency ultrasonic naked plasmid gene delivery and its assessment / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To deliver the naked genes into cells through the bioeffects of cell membrane porous produced by low-frequency ultrasound (US) and to investigate the safety by determining the threshold of cell damage and membrane permeability.</p><p><b>METHODS</b>The suspension of red cells from chickens, rabbits, rats, and S180 cells was exposed to calibrated US field with different parameters in still and flowing state. Laser scanning confocal microscopy, fluorescent microscopy, scanning electron microscopy, flow cytometry and spectrophotometry were used to examine cell morphology, membrane permeability, enzymes, free radicals, naked gene expression efficiency, threshold of cell damage and cell viability.</p><p><b>RESULTS</b>The plasmid of green fluorescent protein (GFP) as a reporter gene was delivered into S180 cells under optimal conditions without cell damage and cytotoxicity. The transfection rate was (35.83 +/- 2.53)% (n = 6) in viable cells, and the cell viability was (90.17 +/- 1.47)% (n = 6). Also, malondialdehyde, hydroxyl free radical, alkaline phosphatase, and acid phosphatase showed a S-shaped growth model (r = 0.98 +/- 0.01) in response to the permeability change and alteration of cell morphology. The constant E of energy accumulation in US delivery at 90% cell viability was an optimal control factor, and at 80% cell viability was the damage threshold.</p><p><b>CONCLUSION</b>US under optimal conditions is a versatile gene therapy tool. The intensity of GFP expression in US group has a higher fluorescent peak than that in AVV-GFP group and control group (P < 0.001). The optimal gene uptakes, expression of gene and safety depend on E, which can be applied to control gene delivery efficiency in combination with other parameters. The results are helpful for development of a novel clinical naked gene therapeutic system and non-hyperthermia cancer therapeutic system.</p>

A study on medical image fusion / 中国医疗器械杂志

Five algorithms with its advantages and disadvantage for medical image fusion are analyzed. Four kinds of quantitative evaluation criteria for the quality of image fusion algorithms are proposed and these will give us some guidance for future research.

A multifrequency phase-controlled driving system for ultrasound therapy / 中国医疗器械杂志

Ultrasound therapy is a new type of therapy technology, there are hyperthermia and high intensity focused ultrasound surgery (HIFUS). Compared with a single frequency system, mutiple frequency system has an additional function to combine power patterns of different frequencies. This function increases the availability of power patterns to treat tumors of various shapes and depths. Therefore, we have in this article proposed a system with the ability to drive ultrasonic phased arrays of multiple resonant frequencies for ultrasound hyperthermia and HIFUS. The results show that this system is able to (1) drive multi-element applicators or phased arrays of a single resonant frequency through the multichannel power amplifiers, (2) concurrently drive transducer with different resonant frequencies, (3) adjust the relative phase and output power of each channel for the scanning ultrasonic focus, and (4) operate each channel with good output stability.