Sonotrode

A device suitable for treating subcutaneous adipose tissue, comprising:

• a. an ultrasonic transducer for generation of ultrasonic vibrations having a proximal face and a distal face;
• and
• b. a sonotrode including a narrower proximal stem portion defining a sonotrode axis and a broader distal cap portion
• wherein said stem portion has a distal end and bears a proximal face of said sonotrode, said sonotrode acoustically coupled to said distal face of said ultrasonic transducer through said proximal face of said sonotrode,
• wherein said cap portion has a proximally-facing back side, a distal working face of said sonotrode and a periphery,
• wherein said distal end of said stem portion meets said back side of said cap portion,
• wherein where said distal end of said stem portion meets said back side of said cap portion a cross sectional area of said cap portion perpendicular to said sonotrode axis is not less than 4 times greater than a cross sectional area of said distal end of said stem portion perpendicular to said sonotrode axis;
• and
• wherein said sonotrode is configured as an acoustic amplitude transformer for a selected ultrasonic frequency,
• wherein said cap portion is thin, being not less than than 2 mm and not more than 10 mm thick,
• wherein not less than 70% of both said working face and said back side of said cap portion are planar and perpendicular to said sonotrode axis, and
• wherein a periphery of said cap portion when viewed from the side is a straight line parallel to said sonotrode axis.