Switched Resonant Ultrasonic Power Amplifier System

• US 20140163431A1
• Filed: 07/16/2013
• Published: 06/12/2014
• Est. Priority Date: 10/30/2003
• Status: Active Grant

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Covidien AG (Medtronic Plc)
• Inventors: Orszulak, James H., McPherson, James W.
• Granted Patent: US 8,966,981 B2
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61N 2007/0056 Beam shaping elements
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• CPC Class Codes: B06B 1/0253 taken directly from the generator circuit
• CPC Class Codes: B06B 1/0261 taken from a transducer or electrode connected to the driving transducer
• CPC Class Codes: B06B 2201/76 Medical, dental
• CPC Class Codes: H10N 30/802 Drive or control circuitry or methods for piezoelectric or electrostrictive devices not otherwise provided for

Abstract

A switched resonant power amplifier system for ultrasonic transducers is disclosed. The system includes an amplifier that receives and processes a driver output signal for generating a drive signal that is provided to an ultrasonic device for controlling output of the ultrasonic device. An output control circuit receives and processes a signal related to a feedback signal generated by the ultrasonic device and a divider reference signal, and generates a compensated clock signal that is adjusted for at least one of phase and frequency differences between the received feedback signal and the divider reference signal. A compensated drive circuit receives and processes the compensated clock signal for generating the divider reference signal, and for generating the driver output signal.

Claims

1. A system for controlling an output of a surgical device, the system comprising:

a driver configured to provide a pair of driver output signals approximately 180°

out of phase with respect to each other;

an amplifier including a pair of switching elements configured to receive and process the pair of driver output signals and produce a respective amplified driver output signal that drives the surgical device and controls the output thereof; and

a wave shaping circuit configured to receive a feedback signal from the surgical instrument and provide a square wave output having a frequency that is substantially identical to a frequency of the feedback signal, the wave shaping circuit configured to provide a reset signal having a substantial identical frequency and 180°

out of phase with respect to the square wave.

2. The system of claim 1, wherein the reset signal is communicated to a compensating circuit for controlling the generation of a compensated reference signal.

3. The system of claim 2, wherein the compensated reference signal is compared to a divider reference signal for producing error signal, wherein the divider reference signal is representative of a compensated clock signal.

4. The system of claim 3, wherein, when a phase difference between the compensated reference signal and the divider signal is at a minimum value, the phase error signal will have a first value.

5. The system of claim 3, wherein, when a phase difference between the compensated reference signal and the divider signal is at a maximum value, the phase error signal will have a second value.

6. The system of claim 3, further including a delay circuit that is configured to control the timing of the compensated clock signal.

7. The system of claim 3, wherein the compensated clock signal is coupled to an input of an input of divider where a frequency of compensated clock signal is stepped-down by the divider to a desired counter output signal.

8. The system of claim 7, wherein the divider is coupled to a flip-flop for splitting the counter output signal into complementary square waves.

9. The system of claim 8, wherein each square wave is substantially 180°

out-of-phase with respect to each other.

10. The system of claim 9, wherein each square wave has a frequency that is substantially one-half of the frequency of the counter output signal.