Highly Precise And Low Level Signal-Generating Drivers, Systems, And Methods Of Use

• US 20100010288A1
• Filed: 07/09/2009
• Published: 01/14/2010
• Est. Priority Date: 07/10/2008
• Status: Active Grant

• Current Assignee: Applied Magnetics, LLC
• Original Assignee: Applied Magnetics, LLC
• Inventors: Schoonover, Dale, Von Ohlsen, Jon, Braswell, Allen JR.
• Granted Patent: US 8,613,695 B2
• Time in Patent Office: Days
• US Class Current: 600/9
• 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 driver for a magnetic field generating device comprising:

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.

2. The driver of claim 1, wherein the first and second signals are used to calibrate the driver.

3. The driver of claim 1, further comprising at least one relay device connected to at least one of the digital to analog converters.

4. The driver of claim 3, further comprising a voltage reference source connected to the at least on relay device.

5. The driver of claim 4, wherein the at least one relay device is used to relay output from the voltage reference source to the second digital to analog converter.

6. The driver of claim 3, further comprising a signal generator connected to the at least one relay device.

7. The driver of claim 6, wherein the at least one relay device is used to relay output from the signal generator to the first digital to analog converter.

8. The driver of claim 1, further comprising a processor.

9. The driver of claim 1, further comprising coils configured to generate a magnetic field.

10. The driver of claim 1, further comprising at least one sensor configured to monitor physical parameters of a subject receiving the magnetic field.

11. The driver of claim 10, wherein the sensor comprises one or more of:

an EKG, an EEG, a heart rate monitor, or a blood pressure monitor.

12. The driver of claim 1, further comprising a magnetometer.

13. The driver of claim 12, wherein the magnetometer is configured to sense an ambient magnetic field.

14. A method of operating a driver for a magnetic field generating device comprising:

receiving at least one calibration factor;

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

using the signals and the at least one calibration factor to calibrate the driver.

15. The method of claim 14, wherein the at least one calibration factor is both an AC calibration factor and a DC calibration factor.

16. The method of claim 14, wherein the at least one calibration factor is an AC calibration factor.

17. The method of claim 14, wherein the at least one calibration factor is a DC calibration factor.

18. The method of claim 15, wherein the AC calibration factor is determined by a method comprising:

receiving an AC calibration level;

directing the driver to produce an output signal;

measuring the output signal; and

determining the accuracy of the output signal.

19. The method of claim 17, 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.

20. A method for AC calibration of a driver for a magnetic field generating device comprising:

receiving an AC calibration level;

directing the driver to produce an output signal;

measuring the output signal; and

comparing the measured output signal to an expected value.

21. The method of claim 20, 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.

22. The method of claim 20, further comprising determining and storing an AC calibration factor.

23. The method of claim 22, wherein the AC calibration factor produces a linearized AC characteristic for the driver.

24. The method of claim 20, further comprising:

receiving a new AC calibration level; and

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

25. The method of claim 24, further comprising determining a new AC calibration level, based at least in part on a sensor signal received from a sensor configured to measure the output signal.

26. A method for DC calibration of a driver for a magnetic field generating device comprising:

receiving DC calibration levels;

directing the driver to produce an output signal;

measuring the output signal; and

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

27. The method of claim 26, wherein determining an offset comprises:

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

setting a 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.

28. The method of claim 26, 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.

29. The method of claim 26, wherein determining and storing an offset comprises determining and storing more than one offset, and wherein determining each offset comprises setting one digital to analog converter to minimum output and another digital to analog converter to full-scale output.

30. The method of claim 29, wherein determining and storing more than one offset comprises determining and storing four offsets.

31. The method of claim 30, wherein determining a DC calibration factor comprises combining the four offsets.