Capacitor failure detection

• US 8,128,549 B2
• Filed: 02/20/2007
• Issued: 03/06/2012
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: Neuronetics, Inc.
• Original Assignee: Neuronetics, Inc.
• Inventors: Testani, Anthony, Riehl, Mark Edward, Klingshirn, Frank C.
• Primary Examiner(s): LACYK, JOHN P
• Application Number:
  US11/676,571
• Publication Number:
  US 20080200748A1
• Time in Patent Office: 1,841 Days
• Field of Search: 600 9- 15
• US Class Current: 600/13
• CPC Class Codes: A61N 2/004 specially adapted for a specific therapy
• CPC Class Codes: A61N 2/006 for magnetic stimulation of nerve tissue
• 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: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G01R 31/64 Testing of capacitors
• CPC Class Codes: H03K 3/53 by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback H03K3/335 takes precedence

Abstract

The inventive technique includes methods, devices and computer-readable media for monitoring a magnetic device. One such device includes a magnetic core for generating a magnetic field, a power supply and a capacitor bank that is charged by the power supply and is for pulsing the magnetic core. The device also includes a processor that measures a charging response of the capacitor bank during charging and determines whether the measured charging response is within a predetermined tolerance of a predetermined charging response.

Claims

1. A method for monitoring a magnetic device, the method comprising:

detecting a charging of a capacitor bank in a magnetic device, wherein the capacitor bank is adapted to pulse a magnetic core to generate a magnetic field;

measuring a charging response of the capacitor bank during said detected charging;

comparing the measured charging response to a predetermined charging response;

determining whether the measured charging response is within a predetermined tolerance of the predetermined charging response; and

in response to whether the measured charging response is within a predetermined tolerance of the predetermined charging response, starting, modifying, continuing, or stopping operation of the magnetic device.

2. The method of claim 1, further comprising:

measuring a discharging response of the capacitor bank during a discharging period;

comparing the measured discharging response to a predetermined discharging response; and

determining whether the measured discharging response is within a predetermined tolerance of the predetermined discharging response.

3. The method of claim 2, further comprising discharging the capacitor bank through one of a test capacitor and the magnetic core.

4. The method of claim 1, further comprising:

measuring a voltage droop of the capacitor bank during an inactive period;

comparing the measured voltage droop to a predetermined voltage droop; and

determining whether the measured voltage droop is within a predetermined tolerance of the predetermined voltage droop.

5. The method of claim 1, further comprising providing an alert to a user if said determination is that the measured charging response is not within the predetermined tolerance of the predetermined charging response.

6. The method of claim 2, wherein providing said alert comprises providing an option to modify a power characteristic such that the magnetic field generated by the magnetic core is substantially equivalent to a desired magnetic field.

7. The method of claim 6, wherein the option is to increase a power input to the capacitor bank.

8. The method of claim 7, wherein the increase in power is proportional to a difference between the measured charging response and the predetermined charging response.

9. The method of claim 2, further comprising sending a message indicating that the measured charging response of the capacitor bank is out of the predetermined tolerance of the predetermined charging response.

10. The method of claim 9, wherein the message includes an identification of the magnetic device and an indication of the charging response of the capacitor bank.

11. The method of claim 9, wherein the message is an email message.

12. The method of claim 1, further comprising preventing the capacitor bank from pulsing the magnetic circuit if said determination is that the measured charging response is not within the predetermined tolerance of the predetermined charging response.

13. The method of claim 1, further comprising, if the measured charging response is not within the predetermined tolerance of the predetermined charging response, determining an adjustment to make to the operation of the capacitor bank to pulse the magnetic core to generate a magnetic pulse having a desired characteristic.

14. The method of claim 13, wherein the adjustment is increasing a charging voltage during charging of the capacitor bank.

15. The method of claim 1, further comprising permitting the capacitor bank to pulse the magnetic core if said determination is that the measured charging response is within the predetermined threshold of the predetermined charging response.

16. The method of claim 1, wherein said detecting comprises detecting when a dV/dt of the capacitor bank reaches a predetermined value.

17. The method of claim 1, wherein said measuring comprises measuring a dV/dt of the capacitor bank during said charging.

18. The method of claim 17, wherein said determining comprises comparing the measured dV/dt to a predetermined dV/dt for the capacitor bank.

19. The method of claim 17, further comprising calculating a capacitance value from the measured dV/dt and a voltage used to charge the capacitor bank, and wherein said determining comprises determining whether the calculated capacitance value is within a predetermined tolerance of a predetermined capacitance value.

20. The method of claim 1, wherein the predetermined charging response is determined during manufacturing of the magnetic device.

21. The method of claim 1, wherein said measuring comprises calculating an average of a plurality of measurements.

22. The method of claim 1, further comprising charging the capacitor bank.

23. A magnetic stimulation device, comprising:

a magnetic core for generating a magnetic field;

a power supply;

a capacitor bank for pulsing the magnetic core, wherein the capacitor bank is charged by the power supply; and

a processor that measures a charging response of the capacitor bank during charging and determines whether the measured charging response is within a predetermined tolerance of a predetermined charging response.

24. The device of claim 23, further comprising a test resistor, and wherein the processor measures a discharging response of the capacitor bank during discharging of the capacitor bank through the test resistor and determines whether the measured discharging response is within a predetermined tolerance of a predetermined discharging response.

25. The device of claim 23, wherein the processor measures a voltage droop of the capacitor bank during an inactive period and determines whether the measured voltage droop is within a predetermined tolerance of the predetermined voltage droop.

26. The device of claim 23, further comprising a display that provides an alert to a user if said determination is that the measured charging response is not within the predetermined tolerance of the predetermined charging response.

27. The device of claim 24, wherein the display provides an option to modify a power characteristic such that the magnetic field generated by the magnetic core is substantially equivalent to a desired magnetic field.

28. The device of claim 27, wherein the option is to increase a power input to the capacitor bank.

29. The device of claim 28, wherein the increase in power is proportional to a difference between the measured charging response and the predetermined charging response.

30. The device of claim 24, further comprising a communication interface that is operatively coupled to the processor, wherein the communication interface sends a message indicating that the measured charging response of the capacitor bank is out of the predetermined tolerance of the predetermined charging response.

31. The device of claim 30, wherein the communication interface is one of a modem and cable modem.

32. The device of claim 30, wherein the message includes an identification of the magnetic device and an indication of the charging response of the capacitor bank.

33. The device of claim 30, wherein the message is an email message.

34. The device of claim 23, wherein, if the measured charging response is not within the predetermined tolerance of the predetermined charging response, the processor determines an adjustment to make to the operation of the capacitor bank to pulse the magnetic core to generate a magnetic pulse having a desired characteristic.

35. The device of claim 34, wherein the adjustment is increasing a charging voltage during charging of the capacitor bank.

36. The device of claim 23, wherein the processor further permits the capacitor bank to pulse the magnetic core if the processor determined that the measured charging response is within the predetermined threshold of the predetermined charging response.

37. The device of claim 23, wherein the processor measures a dV/dt of the capacitor bank during said charging.

38. The device of claim 37, further comprising a memory that stores a predetermined dV/dt for the capacitor bank, and wherein the processor determines whether the measured charging response is within a predetermined tolerance of a predetermined charging response by comparing the measured dV/dt to the predetermined dV/dt.

39. The device of claim 23, wherein the predetermined charging response is determined during manufacturing of the magnetic device.

40. The device of claim 23, wherein the processor obtains a plurality of measurements and calculates an average of the plurality of measurements.

41. The device of claim 23, further comprising a backup capacitor bank and a switch, wherein the switch is adapted to disconnect the capacitor bank and connect the backup capacitor bank to pulse the magnetic core if the processor determines that the measured charging response is within a predetermined tolerance of a predetermined charging response.

42. A method for monitoring a magnetic device, the method comprising:

measuring a discharging response of a capacitor bank in a magnetic device during a discharging period, wherein the capacitor bank is adapted to pulse a magnetic core to generate a magnetic field;

comparing the measured discharging response to a predetermined discharging response;

determining whether the measured discharging response is within a predetermined tolerance of the predetermined discharging response; and

in response to whether the measured discharging response is within a predetermined tolerance of the predetermined discharging response, starting, modifying, continuing, or stopping operation of the magnetic device.

43. The method of claim 42, further comprising discharging the capacitor bank through one of a test capacitor and the magnetic core.

44. A method for monitoring a magnetic device, the method comprising:

measuring a voltage droop of a capacitor bank in a magnetic device during an inactive period, wherein the capacitor bank is adapted to pulse a magnetic core to generate a magnetic field;

comparing the measured voltage droop to a predetermined voltage droop;

determining whether the measured voltage droop is within a predetermined tolerance of the predetermined voltage droop; and

in response to whether the measured voltage droop is within a predetermined tolerance of the predetermined voltage droop, starting, modifying, continuing, or stopping operation of the magnetic device.

45. A magnetic stimulation device, comprising:

a magnetic core for generating a magnetic field;

a power supply;

a capacitor bank for pulsing the magnetic core, wherein the capacitor bank is charged by the power supply;

a test resistor; and

a processor that measures a discharging response of the capacitor bank during discharging of the capacitor bank through the test resistor and determines whether the measured discharging response is within a predetermined tolerance of a predetermined discharging response.

46. A magnetic stimulation device, comprising:

a magnetic core for generating a magnetic field;

a power supply;

a capacitor bank for pulsing the magnetic core, wherein the capacitor bank is charged by the power supply; and

a processor that measures a voltage droop of the capacitor bank during an inactive period and determines whether the measured voltage droop is within a predetermined tolerance of the predetermined voltage droop.