| 摘要 |
<p>An energy delivery system and method control the frequency of the power driving an ultrasonic device (24) to achieve more efficient power delivery. During operation of the ultrasonic device to deliver power to a patient site (16), the system and method automatically sweep the drive power through a frequency range, locate the series and parallel resonance frequencies, calculate the average of those frequencies and lock the power generator at that average frequency to drive the crystal. This frequency sweep procedure occurs automatically when the ultrasonic crystal is located at the patient site and the power generator operator presses the power-on switch to apply power. The method of tuning the power generator thus occurs when the crystal is at the site temperature and is transparent to the operator. The application of an external bio-layer to the crystal increases its bandwidth and its robustness. Mounting a temperature sensor (28) or sensors at the crystal permits monitoring of the crystal temperature and allows drive level control over the power generator to control the temperature at the crystal.</p> |
