Self-Test of Air-Coupled Probe for Sensitivity Map Production Using Parabolic Reflector.

The spatial distribution of a transduction efficiency over the air-coupled probe surface was proposed as a convenient tool for the probe integrity inspection. In this research, a parabolic reflector is used for passive focusing of the acoustic wave on the surface of inspected probe. Therefore, no additional transducer is required for inspection: probe is used for self-inspection.

The Assessment of Calcium and Bleomycin Cytotoxic Efficiency in Relation to Cavitation Dosimetry.

Microbubble (MB)- and ultrasound (US)-facilitated intracellular Ca delivery, known as sonoporation (SP), is a promising anticancer treatment modality, since it allows a spatio-temporally controllable and side-effect-free alternative to conventional chemotherapy. The current study provides extensive evidence that a 5 mM concentration of Ca in combination with US alone or US and Sonovue MBs can be an alternative to the conventional 20 nM concentration of the anticancer drug bleomycin (BLM). Ca application together with SP induces a similar level of death in Chinese hamster ovary cells to the combination of BLM and SP but does not cause systemic toxicity, as is inherent to conventional anticancer drugs.

Ultrasonic needle hydrophone calibration in air by a parabolic off-axis mirror focused beam using three-transducer reciprocity.

An acoustic field distribution investigation in air requires a small receiving sensor. Needle hydrophones seem to be an attractive solution, and it has previously been demonstrated that needle hydrophones designed for use in water can be used in air. The metrology problem is that an absolute sensitivity calibration is needed, because needle hydrophones are not characterized in air, especially for frequencies below 1 MHz, which is of interest for air-coupled ultrasound.

Miniature Ferroelectret Microphone Design and Performance Evaluation Using Laser Excitation.

Miniature microphones suitable for measurements of ultrasonic wave field scans in air are expensive or lack sensitivity or do not cover the range beyond 100 kHz. It is essential that they are too large for such fields measurements. The use of a ferroelectret (FE) film is proposed to construct a miniature, needle-style 0.

Air-Coupled Ultrasonic Probe Integrity Test Using a Focused Transducer with Similar Frequency and Limited Aperture for Contrast Enhancement.

Air-coupled ultrasonic probes require a special design approach and handling due to the significant mismatch to the air. Outer matching layers have to be soft so can be easily damaged and excitation voltages might cause the degradation of electrodes or bonding between the layers. Integrity inspection is desired during design, manufacturing, and exploitation.

Half bridge topology 500 V pulser for ultrasonic transducer excitation.

Application of half bridge topology for ultrasonic transducer excitation using long pulse trains is presented. The novelty of the approach is the high speed solution for a high side drive. A commercially available high speed digital isolator and a high speed MOSFET driver were combined to give the possibility to deliver fast driving signals to a high side N-channel MOSFET.

Efficient high voltage pulser for piezoelectric air coupled transducer.

The design of high voltage pulser for air coupled ultrasound imaging is presented. It is dedicated for air-coupled ultrasound applications when piezoelectric transducer design is used. Two identical N-channel MOSFETs are used together with 1200V high and low side driver IC.