MICROPROCESSOR CONTROLLED CLASS E DRIVER

• US 20150028806A1
• Filed: 07/29/2014
• Published: 01/29/2015
• Est. Priority Date: 07/29/2013
• Status: Active Grant

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Dearden, Brian R., Wolfe, James H., Khemani, Manish
• Granted Patent: US 9,780,596 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H03C 3/00 Angle modulation H03C5/00, H03C7/00 take precedence
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A charger including a class E power driver, a frequency-shift keying (“FSK”) module, and a processor. The processor can receive data relating to the operation of the class E power driver and can control the class E power driver based on the received data relating to the operation of the class E power driver. The processor can additionally control the FSK module to modulate the natural frequency of the class E power transformer to thereby allow the simultaneous recharging of an implantable device and the transmission of data to the implantable device. The processor can additionally compensate for propagation delays by adjusting switching times.

Claims

1. A charger comprising:

a charging coil, wherein the charging coil is configured to magnetically couple with an implantable device to recharge the implantable device;

a class E driver electrically connected to the charging coil, wherein the class E driver comprises;

a switching circuit, wherein the switching circuit is switched by the application of a first voltage to the switching circuit; and

a current sensor positioned to sense a current passing through the charging coil; and

a processor electrically connected to the class E driver to receive data indicative of the current passing through the charging coil and electrically connected to the class E driver to control the switching circuit via the application of the first voltage to the switching circuit, wherein the processor is configured to receive data indicative of the current passing through the charging coil and control the switching circuit in response to the received data.

2. The charger of claim 1, wherein the switching circuit comprises a transistor.

3. The charger of claim 2, wherein the transistor comprises a MOSFET.

4. The charger of claim 3, wherein the processor is electrically connected to the class E driver to receive data indicative of a second voltage of the switching circuit.

5. The charger of claim 4, wherein the processor is further configured to:

receive data indicative of the second voltage of the switching circuit; and

control the switching circuit in response to the received data indicative of the second voltage of the switching circuit.

6. The charger of claim 4, wherein the second voltage is measured at the drain of the switching circuit and wherein the first voltage is applied to the gate of the switching circuit.

7. The charger of claim 6, wherein the processor is electrically connected to the class E driver via a voltage divider comprising a first resistor and a second resistor.

8. The charger of claim 1, wherein the processor is configured to:

sense a power switching transistor voltage; and

determine whether to adjust a first frequency with which the first voltage is applied to the switching circuit, wherein the adjustment of the first frequency mitigates one or several propagation delays.

9. The charger of claim 8, wherein the processor is configured to retrieve a stored value identifying a second frequency with which the first voltage is applied based on the sensed power switching transistor voltage.

10. The charger of claim 9, wherein the processor is configured to compare the retrieved stored value identifying the second frequency with which the first voltage is applied to one or several frequency limits.

11. The charger of claim 10, wherein the first frequency is set to the second frequency if the second frequency does not exceed the one or several frequency limits.

12. The charger of claim 10, wherein when the second frequency exceeds one of the one or several frequency limits, the first frequency is set to the exceeded one of the one or several frequency limits.

13. A charger comprising:

a charging coil, wherein the charging coil is configured to generate a magnetic field having a frequency and to magnetically couple with an implantable device to recharge the implantable device;

a class E driver electrically connected to the charging coil; and

an FSK module configured to modulate the frequency of the magnetic field among at least three frequencies.

14. The charger of claim 13, wherein the at least three frequencies comprise a first frequency, a second frequency, and a third frequency, and wherein the third frequency is the highest frequency and the second frequency is the lowest frequency.

15. The charger of claim 14, further comprising a processor electrically connected to the FSK module and configured to control the FSK module.

16. The charger of claim 15, wherein the processor is configured to selectively operate the charger in either a data non-transmitting state or in a data transmitting state.

17. The charger of claim 16, wherein a carrier signal has the first frequency when the charger operates in the data non-transmitting state.

18. The charger of claim 16, wherein the processor controls the FSK module to modulate the carrier signal between the second frequency and the third frequency when the charger operates in the data transmitting state.

19. The charger of claim 13, wherein the FSK module comprises two capacitors and two transistors.

20. The charger of claim 19, wherein the two capacitors and the two transistors of the FSK module are electrically connected such that the two capacitors can be selectively included within the circuit by the FSK module.

21. The charger of claim 20, wherein the processor is configured to control the two transistors of the FSK module to selectively include the two capacitors within the circuit by the FSK module.

22. The charger of claim 21, wherein the selective inclusion of the two capacitors within the circuit of the FSK modulates the frequency of the magnetic field between the first, second, and third frequencies.

23. A method of communicating with an implantable device during charging of the implantable device, the method comprising:

generating a charging signal with a charging coil, wherein the charging signal has an initial, first frequency; and

transmitting data by modulating the frequency of the charging signal between a second frequency that is lower than the first frequency and a third frequency that is higher than the first frequency.

24. The method of claim 23, further comprising generating binary transmission data during the charging of the implantable device, wherein the transmission data is the transmitted data.

25. The method of claim 24, wherein modulating the frequency of the charging signal between the second frequency and the third frequency transmits the binary transmission data.

26. The method of claim 23, wherein the frequency of the charging signal is modulated by an FSK module.

27. The method of claim 26, wherein the FSK module comprises two capacitors and two transistors.

28. The method of claim 27, wherein the two capacitors and the two transistors of the FSK module are electrically connected such that the two capacitors can be selectively included within the circuit of by the FSK module to thereby modulate the frequency of the charging signal.

29. A method of controlling a charger comprising:

creating a magnetic coupling between a charger and an implantable device, wherein the magnetic coupling charges the implantable device;

setting an initial frequency of a drive signal, wherein the frequency of the drive signal is set by a processor, and wherein the drive signal controls the opening and closing of a switch;

sensing a voltage at the switch at a first time;

based on the voltage at the switch at the first time, retrieving a value identifying a second frequency; and

changing the frequency of the drive signal.

30. The method of claim 29, wherein changing the frequency of the drive signal comprises changing the frequency of the drive signal from the first frequency to the second frequency.

31. The method of claim 29, comprising retrieving one or several frequency limits, wherein the frequency limits provide an upper and lower bound to a range of acceptable frequencies of the drive signal.

32. The method of claim 31, comprising comparing the second frequency to the one or several frequency limits.

33. The method of claim 32, wherein changing the frequency of the drive signal comprises changing the frequency of the drive signal from the first frequency to the one of the one or several frequency limits if the second frequency exceeds the one of the one or several frequency limits.

34. The method of claim 32, wherein changing the frequency of the drive signal comprises changing the frequency of the drive signal from the first frequency to the second frequency if the second frequency does not exceed the one or several frequency limits.

35. The method of claim 29, wherein the changing of the frequency of the drive signal mitigates an effect of a propagation delay.

36. The method of claim 35, wherein the frequency of the drive signal can be adjusted multiple times to mitigate the effect of the propagation delay.