Highly precise and low level signal-generating drivers, systems, and methods of use

• US 9,480,854 B2
• Filed: 11/14/2013
• Issued: 11/01/2016
• Est. Priority Date: 07/10/2008
• Status: Active Grant

• Current Assignee: Applied Magnetics, LLC
• Original Assignee: Applied Magnetics, LLC
• Inventors: Von Ohlsen, Jon, Schoonover, Dale, Braswell, Allen Jr.
• Primary Examiner(s): Matthews, Christine H
• Assistant Examiner(s): Lannu, Joshua D
• Application Number:
  US14/079,890
• Publication Number:
  US 20140071576A1
• Time in Patent Office: 1,083 Days
• US Class Current: 1/1
• CPC Class Codes: A61N 2/02 using magnetic fields produced by coils, including single turn loops or electromagnets A61N2/12 takes precedence
• CPC Class Codes: G06F 1/022 Waveform generators, i.e. devices for generating periodical functions of time, e.g. direct digital synthesizers G06F1/025, G06F1/03 take precedence
• CPC Class Codes: H03B 28/00 Generation of oscillations by methods not covered by groups H03B5/00 - H03B27/00, including modification of the waveform to produce sinusoidal oscillations analogue function generators for performing computing operations G06G7/26; use of transformers for conversion of waveform in ac-ac converters H02M5/18
• CPC Class Codes: H03K 3/01 Details

Abstract

Apparatus and method for providing and using a highly precise and low level driver. In one described embodiment, a driver for a magnetic field generating device is provided, the driver including a first digital to analog converter and a second digital to analog converter; a differential amplifier configured to receive a first signal from the first digital to analog converter and receive a second signal from the second digital to analog converter and output a third signal; and an attenuator to configured to receive the third signal from the differential amplifier.

Claims

1. A method of operating a driver for a magnetic field generating device configured to provide treatment to a subject, the method comprising:

receiving at least one calibration factor;

receiving signals from a first digital to analog converter and a second digital to analog converter;

calibrating the driver using the signals and the at least one calibration factor, the driver comprising a hardware driver, the driver comprising the first digital to analog converter and the second digital to analog converter;

receiving a new AC calibration level; and

further calibrating the driver using the new AC calibration level.

2. The method of claim 1, wherein the at least one calibration factor is both an AC calibration factor and a DC calibration factor.

3. The method of claim 2, wherein the AC calibration factor is determined by a method comprising:

receiving the new AC calibration level;

directing the driver to produce an output signal;

measuring the output signal; and

determining the accuracy of the output signal by comparing the output signal to a reference source.

4. The method of claim 1, wherein the at least one calibration factor is an AC calibration factor.

5. The method of claim 1, wherein the at least one calibration factor is a DC calibration factor.

6. The method of claim 5, wherein the DC calibration factor is determined by a method comprising:

receiving a DC calibration level;

directing the driver to produce an output signal;

measuring the output signal; and

determining and storing a DC offset, based at least in part on the measurement of the output signal.

7. The method of claim 1, wherein using the signals and the at least one calibration factor to calibrate the driver comprises:

providing a signal from the driver to an attenuator configured to attenuate the signal and provide an attenuated signal to a dummy load; and

measuring one or more of the voltage or frequency of the signal.

8. The method of claim 7, wherein using the signals and the at least one calibration factor to calibrate the driver comprises determining whether one or more of the voltage or frequency of the signal is within a range of an expected value.

9. A method for AC calibration of a driver for a magnetic field generating device configured to provide treatment to a subject, the method comprising:

receiving an AC calibration level;

directing the driver to produce an output signal, the driver comprising a hardware driver, the driver comprising a digital to analog converter, wherein directing the driver to produce an output signal comprises;

transmitting a signal to an attenuator configured to produce an attenuated signal; and

transmitting the attenuated signal to a dummy load;

measuring the output signal;

comparing the measured output signal to an expected value; and

calibrating the driver using the AC calibration level, the output signal, and the expected value.

10. The method of claim 9, further comprising determining and storing an AC calibration factor.

11. The method of claim 10, wherein the AC calibration factor produces a linearized AC characteristic for the driver.

12. The method of claim 9, further comprising:

receiving a new AC calibration level; and

using the new AC calibration level to further calibrate the driver.

13. The method of claim 12, further comprising determining the new AC calibration level, based at least in part on a sensor signal received from a sensor configured to measure the output signal.

14. The method of claim 9, further comprising determining whether the output signal is within a range of an expected value.

15. A method for DC calibration of a driver for a magnetic field generating device configured to provide treatment to a subject, the method comprising:

receiving DC calibration levels;

directing the driver to produce an output signal, the driver comprising a hardware driver, the driver comprising a digital to analog converter;

measuring the output signal; and

determining and storing an offset, based at least in part on the measurement of the output signal, wherein determining and storing an offset comprises determining and storing more than one offset, and wherein determining each offset comprises setting a first digital to analog converter to minimum output and a second digital to analog converter to full-scale output

wherein the steps of receiving, directing, measuring and determining and storing steps are performed by a processor associated with the driver.

16. The method of claim 15, wherein determining an offset comprises:

setting the first digital to analog converter to produce minimum output;

setting the second digital to analog converter to produce full-scale output and measuring the driver'"'"'s output signal;

setting the second digital to analog converter to produce minimum output and measuring the driver'"'"'s output signal; and

determining an offset based at least in part on the measurements of the driver'"'"'s output signal.

17. The method of claim 16, wherein determining and storing more than one offset comprises determining and storing four offsets.

18. The method of claim 17, further comprising determining a DC calibration factor, wherein determining a DC calibration factor comprises combining the four offsets.

19. The method of claim 15, wherein directing the driver to produce an output signal comprises:

transmitting a signal to an attenuator configured to produce an attenuated signal; and

transmitting the attenuated signal to a dummy load.

20. The method of claim 15, wherein directing the driver to produce an output signal comprises providing a signal from the driver to an attenuator configured to attenuate the signal and provide an attenuated signal to a dummy load.