Device and method for ultrasound treatment of biological tissue

A medical device for applying heat-based tissue treatment to an individual's body part, the device comprising:

• an applicator defining an interface surface region for attachment with the body part and carrying the following:
• a treatment circuitry configured and operable to perform a treatment session on biological tissue in a region of interest in the body part to provide a desired treatment effect, by generating heating radiation and delivering said heating radiation towards the region of interest via said interface surface region;
• a control circuitry configured and operable to monitor a temperature of the region of interest, the control circuitry comprising first and second opposing ultrasound transducer-assemblies adapted to transmit ultrasound radiation from one of the first and second transducer assemblies to be received by the other of the first and second transducer assemblies via, respectively, first and second opposing portions of the interface region of the applicator, providing measured data corresponding to the ultrasound radiation being received, said measured data being indicative of time-of-flight data of the ultrasound radiation between the first and second opposing transducer-assemblies and therefore indicative of a temperature of the tissue in the region of interest engaged between the first and second opposing portions of the interface region, thereby enabling real time extraction, from the time-of-flight data, of an average temperature of said region of interest being a deep region with respect to the interface region.