In order to improve the operability and accuracy of high-intensity focused ultrasound （HIFU）, an annular focused transducer, whereby a B-ultrasound probe is placed in its center, is used to realize the real time mon...In order to improve the operability and accuracy of high-intensity focused ultrasound （HIFU）, an annular focused transducer, whereby a B-ultrasound probe is placed in its center, is used to realize the real time monitoring and control of the treatment. In this paper, the spheroidal beam equation （SBE） was used to calculate the sound lield by an annular focused transducer with a wide aperture angle to first derive the heat deposition and the Pennes equation was used to calculate the temperature field in multi-layer tissue. We studied the effect of different parameters on the temperature of the tissues. The result shows that the focal length has a significant influence on both maximum liver temperature rise and skin temperature rise, and both increase with the increase in the focal length. When the frequency increases, the temperature rise first undergoes a rapid increase before gradually reaching a maximum, and then finally decreasing. The temperature rise increases while the inner radius decreases or the sound pressure increases. By choosing suitable parameters, the proper temperature rise both on the target tissue and skin via an annular tbcused transducer with a wide aperture angle can be obtained.展开更多
This research has objective to analyze some tools which are used to support decision maker to make a decision in multi stage and systematic way. And also in making decision, there are a qualitative type and quantitati...This research has objective to analyze some tools which are used to support decision maker to make a decision in multi stage and systematic way. And also in making decision, there are a qualitative type and quantitative type. In order to get an optimum decision making, the decision maker needs systematic way. There is the frame work which is based on combination of some existing methods and challenges emerging in organizational activities, including social organizations as well as business organisations. To formulate the framework, this research conducted focus group discussion consisting of some organizational managers as participants. There are five components of proposed frame work： （1） Criteria Identification through Focus Group Discussion （FGD）; （2） Criteria Selection; （3） Focus Group for Criteria Verification; （4） Multicriteria Decision Making based Analytic Hierarchy Process （AHP）; and （5） Impact Analysis. This research resulted in an effective approach of decision making which allows decision maker to have objective and rational reason in each step of its decision-making process. Strength of the proposed framework is to provide rational and objective approach in group decision making. However, it takes longer time to conduct decision making due to more steps and participants involved. As a conclusion, the proposed research has been successful in establishing a multi stage and rational decision-making process.展开更多
基金Project supported by the National Key Research and Development Program,China(Grant No.2016YFF0203000)the National Natural Science Foundation of China(Grant Nos.11774167 and 61571222)+2 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.020414380001)the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant No.SKLA201609)AQSIQ Technology Research and Development Program,China(Grant No.2017QK125)
文摘In order to improve the operability and accuracy of high-intensity focused ultrasound （HIFU）, an annular focused transducer, whereby a B-ultrasound probe is placed in its center, is used to realize the real time monitoring and control of the treatment. In this paper, the spheroidal beam equation （SBE） was used to calculate the sound lield by an annular focused transducer with a wide aperture angle to first derive the heat deposition and the Pennes equation was used to calculate the temperature field in multi-layer tissue. We studied the effect of different parameters on the temperature of the tissues. The result shows that the focal length has a significant influence on both maximum liver temperature rise and skin temperature rise, and both increase with the increase in the focal length. When the frequency increases, the temperature rise first undergoes a rapid increase before gradually reaching a maximum, and then finally decreasing. The temperature rise increases while the inner radius decreases or the sound pressure increases. By choosing suitable parameters, the proper temperature rise both on the target tissue and skin via an annular tbcused transducer with a wide aperture angle can be obtained.
文摘This research has objective to analyze some tools which are used to support decision maker to make a decision in multi stage and systematic way. And also in making decision, there are a qualitative type and quantitative type. In order to get an optimum decision making, the decision maker needs systematic way. There is the frame work which is based on combination of some existing methods and challenges emerging in organizational activities, including social organizations as well as business organisations. To formulate the framework, this research conducted focus group discussion consisting of some organizational managers as participants. There are five components of proposed frame work： （1） Criteria Identification through Focus Group Discussion （FGD）; （2） Criteria Selection; （3） Focus Group for Criteria Verification; （4） Multicriteria Decision Making based Analytic Hierarchy Process （AHP）; and （5） Impact Analysis. This research resulted in an effective approach of decision making which allows decision maker to have objective and rational reason in each step of its decision-making process. Strength of the proposed framework is to provide rational and objective approach in group decision making. However, it takes longer time to conduct decision making due to more steps and participants involved. As a conclusion, the proposed research has been successful in establishing a multi stage and rational decision-making process.
