Systems and methods for measuring the frequency of signals generated by high frequency medical devices

Patent metadata

Field	Value
Publication number	US-10073125-B2
Application number	US-201615377740-A
Country	US
Kind code	B2
Filing date	Dec 13, 2016
Priority date	Jun 29, 2012
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A digital measurement system includes an oscillator, a mixer, and a controller coupled to each other. The oscillator provides a reference signal having a second frequency. The mixer generates a down-converted signal based on the output signal and the reference signal. The controller then determines a characteristic of the output signal (e.g., frequency or phase) based on the down-converted signal. An analog measurement system includes a filter having a center frequency, a rectifier, and a controller. The filter filters the output signal and the rectifier rectifies the filtered signal. The controller samples the rectified signal and determines a characteristic of the output signal based on the level of the rectified signal. The reference signal controller may adjust a characteristic of the output signal based on the determined frequency and/or phase of the output signal.

First claim

What is claimed is:

1. A generator comprising:
a first oscillator configured to generate an output signal having a first frequency;
a second oscillator configured to generate a reference signal having a second frequency;
a first mixer coupled to the first oscillator and the second oscillator and configured to generate a down-converted signal based on the output signal and the reference signal;
a controller configured to determine an actual frequency of the output signal based on the down-converted signal;
an amplifier configured to amplify the output signal and generate an amplified output signal; and
a second mixer configured to generate a second, down-converted signal based on the amplified output signal and the reference signal, wherein the controller is further configured to:
operate at a clock frequency that is lower than the first frequency; and
determine a phase of the amplified output signal based on the second, down-converted signal.

2. The generator according to claim 1 , wherein the output signal is a digital signal or an analog signal.

3. The generator according to claim 1 , wherein the controller is further configured to control the output signal based on the actual frequency of the output signal.

4. The generator according to claim 1 , wherein the second frequency is a fixed frequency or a variable frequency.

5. The generator according to claim 1 , wherein the second frequency is set to a frequency such that the difference between the first frequency and the second frequency is less than a clock frequency of the generator.

6. The generator according to claim 1 , wherein the second frequency is adjustable and is set to be the same as the first frequency.

7. The generator according to claim 1 , wherein the second frequency is adjustable and is set to be different from the first frequency.

8. The generator according to claim 1 , further comprising a sensor coupled to an output of the amplifier, the sensor configured to sense the amplified output signal and transmit a sensed, amplified output signal to the second mixer.

9. A generator, comprising:
an oscillator configured to generate an output signal;
a first filter having a first center frequency and configured to filter the output signal to generate a first filtered signal;
a first rectifier configured to rectify the first filtered signal to generate a first rectified signal;
an amplifier configured to amplify the output signal to generate an amplified output signal;
a second filter having a second center frequency and configured to filter the amplified output signal to generate a second filtered signal;
a second rectifier configured to rectify the second filtered signal to generate a second rectified signal; and
a microprocessor configured to:
sample the first rectified signal;
determine a frequency of the output signal based on an amplitude of the first rectified signal;
sample the second rectified signal; and
determine a phase of the amplified output signal based on an amplitude of the second rectified signal.

10. The generator according to claim 9 , wherein the first filter is one of a notch filter or a band-pass filter.

11. The generator according to claim 9 , wherein the first filter is configured to attenuate the output signal as the frequency of the output signal shifts from the first center frequency.

12. The generator according to claim 9 , wherein the output signal is a digital signal or an analog signal.

Assignees

• Covidien Lp

Inventors

• Moul Wayne L
• Behnke Ii Robert J
• Frushour Scott E M
• Jensen Jeffrey L

Classifications

• G01R25/00

  Arrangements for measuring phase angle between a voltage and a current or between voltages or currents · CPC title

• G01R23/02 Primary

  Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage · CPC title

• A61B18/1206 Primary

  Generators therefor · CPC title

• G01R25/02

  in circuits having distributed constants · CPC title

• G01R23/145

  by heterodyning or by beat-frequency comparison with the harmonic of an oscillator · CPC title