Design of high-intensity ultrasonic sound intensity measurement based on narrow pulse method
The research on high-intensity ultrasonic has taken the delectable achievement in the treatment of cancer and the detection of internal structure for the dam. The rapid and accurate sound intensity measurement of high-intensity ultrasonic transducer is necessary for its application and generalization. The paper introduces the principle of sound intensity measurement, proposes measurement scheme on the basis of the narrow pulse method and also discusses the design of hardware circuit and software.
An Experimental Study on Acoustic Field Measurement of New Phased-array Focused Ultrasound
Objective:Phased-array focused ultrasound is a hot point of researches in thermal physics therapy,of which the acoustic field investigation is the most important section in technology.This paper analyzes the simulation and the experimental results in the acoustic field of new phased-array focused ultrasound.Methods:An acoustic filed measurement system was developed under LabVIEW virtual instruments platform,which is used to measure the acoustic pressure field distributions of the phased-array focused ultrasound in one single focal mode by scanning the acoustic field with a probe hydrophone.Meanwhile,the acoustic field distribution in a single focal mode is simulated with MATLAB toolbox.Results:The experimental result is approximately consistent with theoretical one.Conclusions:The paper demonstrated the correctness of the theoretical model and feasibility and validity of the measurement system.
Changes in biologic characteristics of breast cancer treated with high-intensity focused ultrasound.
Proliferation, invasion, immortalization and metastasis are the main malignant characteristics of cancer. Previous studies have shown that high-intensity focused ultrasound (US), or HIFU, can induce irreversible damage both to breast cancer cells and to tumor blood vessels. However, light microscopy alone may not always show this clearly. In this study, molecular biologic techniques were used to examine any changes in molecular markers associated with malignant behavior after exposure to HIFU. A total of 48 women with breast cancer were randomized to a control group (mastectomy) and a HIFU group (HIFU followed by mastectomy). Immunohistochemical staining, messenger RNA (mRNA) in situ hybridization and telomere-repeat amplification protocol-enzyme-linked immunosorbent assay (TRAP-ELISA) techniques were used to detect tumor expression of proliferating cell nuclear antigen (PCNA), cell adhesion molecule CD44v6, matrix metalloproteinase-9 (MMP-9), erbB2 mRNA, and to measure telomerase activity in both groups. The results demonstrated that there were significant alterations in expression of PCNA, CD44v6, MMP-9, erbB2 mRNA, and a dramatic decrease in telomerase activity in the HIFU group. It is concluded that malignant tumor characteristics are arrested by HIFU, and that biologic factors are potential markers for assessing HIFU efficacy.