Design of Intravascular Ultrasound-enhanced Thrombolysis Excitation System Based on FPGA / 中国医疗器械杂志

An intravascular ultrasound-enhanced thrombolysis excitation system with adjustable frequency, amplitude and duty cycle was designed based on FPGA (ZYNQ-7Z020). Firstly, the FPGA generated waveform amplitude binary data based on direct digital frequency synthesis (DDS) technology, and then the data was converted into burst signal through an external daughter card, which included D/A conversion circuit, active low-pass filter, power amplifier circuit and impedance matching circuit. The test results demonstrated that the output waveform reached the target with advantages of simple implementation and flexible control, the peak negative pressure generated from ultrasound transducer was doubled by means of an electrical impedance matching network. In vitro thrombus models were applied to verify the excitation system, it turned out that ultrasound cavitation effect generated could accelerate the penetration of urokinase and increase the thrombolysis rate by about 20%.

Technology of ultrasound-enhanced supercritical extraction for magnolol and honokiol / 中草药

Objective: To explore the enhanced role of ultrasound on supercritical fluid extraction. Methods: With stability parameters of supercritical fluid extraction of Magnoliae Officinalis Cortex, taking magnolol and honokiol contents and extraction rate as the reference indicators, the extraction effect between ultrasonic and supercritical fluid and ultrasound-enhanced supercritical fluid was compared. Rusults: Ultrasound-enhanced supercritical fluid extraction is superior to the others. Conclusion: Ultrasound could strengthen the supercritical fluid extraction of active ingredients from Magnoliae Officinalis Cortex.