Introduction

Measuring techniques for the ultrasonic radiation conductance of ultrasonic transducers, in particular the High Intensity Focused Ultrasound (HIFU) type, using a periodic electrical signal and a submersible load cell.

Technical features

The measuring system is based on a submersible load cell, i.e. a force transducer that converts a force into an electrical signal, based on strain gauge technology. This measurement system allows the output signal from the force sensor to be directly available, avoiding delayed mass reading introducing by the balance scaling, thus reducing the insonation time. By exploiting the FFT of the transducer input signal transducer and the load cell output, it is possible to perform primary measurement of the power emitted by ultrasonic transducer in less than 5 s, avoiding target damages, that can occur in HIFU (High Intensity Focused Ultrasound) measurements. The system based on submersible load cell, compared to the actual primary measurement systems, permits in situ evaluation of the efficiency of the biomedical ultrasound equipments [TRL 8].

Possible Applications

• in situ evaluation of the ultrasonic power emitted by biomedical equipment, for diagnosis and therapy;
• Ultrasonic radiation conductance measurement of  ultrasound transducers operating in the frequencies range 1 MHz – 15 MHz.

Advantages

• Reduced measurement time;
• Reduced mechanical set-up;
• Technology appropriate for portable measuring systems;
• Low development cost.