measures of improving the accuracy of HIFU focal spot

                                         measures of improving the accuracy of HIFU focal spot

High focus piezo is a high-tech products,there are many factors to affect high precision piezo focal spot , such as phase and amplitude difference of the single probe , human tissue and blood flow and so on. Which involves areas of a number of piezo disciplines and some the complex mechanism ,it is one of the hotspots of HIFU piezo in technology research. This paper only introduces the research and exploration of the piezo focal spot precision from the focal point of the probe during the development of the device.During the development process of equipment, it begin to solve the problem focusing precision of multi-probe, the treatment of head means swing each time, the piezo probe change every time and it will cause changes of focal spot. , it is found that the acoustic axis of the single-probe sound field does not coincide with the geometric axis by detecting the sound field of a single probe, which is mainly to solve one of our aspects and contact with the manufacturer of piezoelectric ceramic, high performance and good stability of the piezoelectric ceramic; it need to take appropriate improvement measure based on piezo tube datasheet chip. Initially probe consider the adjustable direction of the structure by in the fixed way of focusing, but the regulation needs to be carried out on the equipment, waste of time of valuable equipment.The adjustment process requires the sound field test, time-consuming and laborious, and high intensity high focus piezoelectric ceramic is a wearing parts, a lot of trouble for the user , so we did not use this program; Finally,using screening method of piezoelectric ceramic, improving precision grade, manufacturing multiple probe parts, put into the use of piezoelectric ceramic, the sound field detection, out of substandard ceramic. In the development process, in order to save time and cost, designed a set of auxiliary sound field detection tool, the use of the device itself, the three-dimensional motion positioning function for sound field measurement. Sound field measurement using a slice method, in the vicinity of a certain range of focal spots, along the geometric axis of the probe at a certain distance from the interval of a number of vertical cross-section of the cross-section, each slice at a certain interval to arrange a number of points, And other strong lines, to find the coordinates of the center of the sound field, and then the center of the sound field coordinates to be integrated into the piezoelectric probe acoustic axis.