Medtronic Autosonix™ Ultrasonic Coagulation System. A system of electromechanical components designed to ultrasonically transect and coagulate a broad range of soft tissue. The system includes a generator that produces a 55.5 kHz electrical signal and feeds that signal via the patient cable to a piezoelectric crystal stack mounted in the autoclavable transducer. The crystal stack converts the electrical signal to mechanical vibration at that same frequency. This ultrasonic vibration is amplified as it traverses the length of the titanium probe within the disposable instrument to levels which will permit tissue ablation, cauterization or cutting. Uses ultrasound, or sound waves, for fragmentation of soft tissues. Unlike standard cutting or electrosurgical systems, this system offers precise control of tissue ablation due to the controlled ultrasonic field generated. This precise control allows the surgeon to perform atraumatic transection and coagulation with minimal disturbance to surrounding tissue structure. The generator unit (power supply) feeds a 55.5 kHz (55,500 cycles per second ) electrical signal to piezoelectric crystals mounted in the transducer. The active elements of the transducer then vibrate at that same 55.5 kHz frequency. When placed in a liquid, the vibrating ball tip causes microscopic bubbles to grow and then collapse with great energy intensity, thus causing the tissue directly in front of the probe to be liquefied or fragmented. The blade tip allows cutting and coagulation of tissue by causing shear forces to be developed in the tissue. These shearing forces separate tissue and heat the surrounding tissue to a level which permits coagulation and sealing of blood vessels, without the burning associated with electrocautery.