High-Power Gallium Nitride HIFU Transmitter With Integrated Real-Time Current and Voltage Measurement

Review of the design of power ultrasonic generator for piezoelectric transducer

The power ultrasonic generator (PUG) is the core device of power ultrasonic technology (PUT), and its performance determines the application of this technology in biomedicine, semiconductor, aerospace, and other fields. With the high demand for sensitive and accurate dynamic response in power ultrasonic applications, the design of PUG has become a hot topic in academic and industry. However, the previous reviews cannot be used as a universal technical manual for industrial applications. There are many technical difficulties in establishing a mature production system, which hinder the large-scale application of PUG for piezoelectric transducers. To enhance the performance of the dynamic matching and power control of PUG, the studies in various PUT applications have been reviewed in this article. Initially, the demand design covering the piezoelectric transducer application and parameter requirements for ultrasonic and electrical signals is overall summarized, and these parameter requirements have been recommended as the technical indicators of developing the new PUG. Then the factors affecting the power conversion circuit design are analyzed systematically to realize the foundational performance improvement of PUG. Furthermore, advantages and limitations of key control technologies have been summarized to provide some different ideas on how to realize automatic resonance tracking and adaptive power adjustment, and to optimize the power control and dynamic matching control. Finally, several research directions of PUG in the future have been prospected.

Efficacy and safety of HIFU in combination with TACE in unresectable pediatric HB: A randomized, controlled, single-center clinical trial

BACKGROUND

Hepatoblastoma (HB) is the most common liver tumor in children, and the main treatment for HB is currently surgery. Studies have shown that transcatheter arterial chemoembolization (TACE) combined with high intensity focused ultrasound (HIFU) has significant efficacy, but there are relatively few studies on TACE combined with HIFU in China.

OBJECTIVE

To investigate the effect of using HIFU combined with TACE on patients' liver function impairment and immune function in pediatric HB patients and to analyze the effectiveness and safety.

MATERIALS AND METHODS

The clinical data of 110 unresectable pediatric HB patients treated in our hospital from December 2019 to December 2021 were selected as the subjects and divided into 2 groups. The comparison group was treated with TACE, and the combination group was treated with HIFU on the basis of the comparison group. The differences in immune function, survival, treatment side effects and clinical efficacy between the 2 groups were observed.

RESULTS

In the combined group, the 1-year survival rate was 100%, the 3-year survival rate was 84.0%, the 5-year survival rate was 16.0%; while in comparison group, it was 82%, 16%, 0%, respectively. The ratio of CD4+/CD8+ in the combined group were significantly higher than in the comparison group after treatment (P < .05). Granulocytopenia, mucositis, thrombocytopenia, and cardiac and renal toxicity were significantly lower in the combined group than in the comparison group, and the effective rate of the combined group was 98.00% which was significantly higher than that of the control group (76.00%) (P < .05).

CONCLUSION

Comparative study of HB in children treated with HIFU combined with TACE is more effective, effectively improving the immune level of patients, significantly increasing the remission rate, which can improve the tumor necrosis and improve the survival quality of patients, and is a better choice for HB in children.

An automated system for nucleic acid extraction from formalin-fixed paraffin-embedded samples using high intensity focused ultrasound technology

Formalin-fixed paraffin-embedded (FFPE) tissue samples are routinely used in prospective and retrospective studies. It is crucial to obtain high-quality nucleic acid (NA) from FFPE samples for downstream molecular analysis, such as quantitative polymerase chain reaction (PCR), Sanger sequencing, next-generation sequencing, and microarray, in both clinical diagnosis and basic research. The current NA extraction methods from FFPE samples using chemical solvent are tedious, environmentally unfriendly, and unamenable to automation or field deployment. We present a tool for NA extraction from FFPE samples using a high-intensity focused ultrasound (HIFU) technology. A cartridge strip containing reagents for FFPE sample deparaffinization and NA extraction and purification is operated by an automation tool consisting of a HIFU module, a liquid handling robot unit, and accessories including a thermal block and magnets. The HIFU module is a single concaved piezoelectric ceramic plate driven by a current-mode class-D power amplifier. Based on the ultrasonic cavitation effects, the HIFU module provides highly concentrated energy introducing paraffin emulsification and disintegration. The high quantity and quality of NA extracted using the reported system are evaluated by PCR and compared with the quantity and quality of NA extracted using the current standard methods.