Charging system providing adjustable transmitted power to improve power efficiency within an implanted device

• US 9,833,629 B2
• Filed: 11/09/2016
• Issued: 12/05/2017
• Est. Priority Date: 01/06/2016
• Status: Active Grant

• Current Assignee: Shiratronics, Inc.
• Original Assignee: Syntilla Medical LLC
• Inventors: Dellamano, Harry, Griffith, Paul, Menezes, Francis M.
• Primary Examiner(s): VOORHEES, CATHERINE M
• Application Number:
  US15/347,745
• Publication Number:
  US 20170189697A1
• Time in Patent Office: 391 Days
• CPC Class Codes: A61N 1/0526 Head electrodes A61N1/0551 takes precedence
• CPC Class Codes: A61N 1/0529 Electrodes for brain stimulation
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36075 Headache or migraine
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• 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 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• 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 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• 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: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A system for transferring power to, and communicating with, at least one body-implantable active device includes an external power transfer system associated with an external device disposed outside of a body, operable to transfer power through a dermis layer to each body-implantable active device, and communicate data to and from each body-implantable active device, and also includes a power receiving system associated with each body-implantable active device, operable to receive power transferred from the external power transfer system, and communicate data to and from the external power transfer system. The body-implantable active device may include an implantable neurostimulation system.

Claims

1. A system for transferring power from an external power transfer system (EPTS) to at least one body-implantable active device (BIAD) through a dermis layer, said system comprising:

an EPTS for being disposed external to a dermis layer of a body; and

a BIAD for being disposed beneath the dermis layer of the body;

the EPTS including;

a transmit coil;

a variable voltage generator circuit operable to generate on an output thereof a variable DC voltage; and

a resonant driver circuit coupled to the variable DC voltage output, and operable to drive the transmit coil with a resonant current at a resonant frequency;

the BIAD including;

a receive coil tuned to the resonant frequency of the transmit coil and operable to inductively receive power therefrom when in proximity thereto; and

a power receiving circuit coupled to the receive coil and operable to deliver the received power to circuitry within the BIAD;

wherein the EPTS is operable to adjust the variable DC voltage to modulate energy stored in the resonant driver circuit each resonant cycle and to modulate available transmitted power that is receivable by the BIAD.

2. The system as in claim 1 wherein:

the EPTS further comprises a back telemetry receive circuit for receiving back telemetry information from the BIAD; and

the EPTS is further operable to control the variable voltage generator circuit in response to back telemetry information received from the BIAD.

3. The system as in claim 1 wherein:

the EPTS further comprises a current sensing circuit for detecting a change in transmitted power received by the BIAD; and

the EPTS is further operable to control the variable voltage generator circuit in response to detecting a change in transmitted power received by the BIAD.

4. The system as in claim 1 wherein:

the variable voltage generator circuit comprises a buck/boost circuit operable to generate the variable DC voltage output having a magnitude controllable over a range extending above and below a battery voltage powering the variable voltage generator circuit.

5. The system as in claim 1 wherein:

the resonant driver circuit further comprises an excitation input operable to pump energy into the resonant driver circuit each resonant cycle.

6. The system as in claim 5 wherein the resonant driver circuit comprises:

an excitation coil and a switch device coupled in series between an upper power supply node and a lower power supply node, wherein the switch device is operable, responsive to a control input thereof, to substantially impress the variable DC voltage across the excitation coil during a portion of each resonant cycle to thereby store in the excitation coil an amount of energy that varies in accordance with the variable DC voltage, and to decouple the excitation coil from the lower power supply node during a remaining portion of each resonant cycle to thereby deliver the stored energy to the transmit coil.

7. The system as in claim 6 wherein the resonant driver circuit further comprises:

a capacitor coupled between a first node and an output node of the resonant driver circuit, said first node disposed between the excitation coil and the switch device.

8. The system as in claim 6 wherein the resonant driver circuit further comprises:

a buffer circuit having an output coupled to the switch device control input, wherein the buffer circuit includes a boosted supply greater than a battery voltage powering the EPTS.

9. The system as in claim 8 wherein:

the buffer circuit comprises an input coupled to the excitation input of the resonant driver circuit.

10. The system as in claim 9 further comprising:

a triggerable oscillator circuit having an input coupled to receive a trigger signal, and operable to generate an excitation signal on an output thereof which is coupled to the excitation input of the resonant driver circuit.

11. The system as in claim 10 wherein the triggerable oscillator circuit is operable to cause the excitation signal to oscillate, at a self-oscillation frequency, in the absence of periodic assertions of the trigger signal.

12. The system as in claim 1 wherein:

the BIAD comprises a head-locatable neurostimulation system;

the EPTS is disposed within a headset charging and control device operable to charge and communicate with the head-locatable neurostimulation system; and

the transmit coil is co-locatable with the receive coil.

13. The system as in claim 12 wherein:

the resonant driver circuit comprises a Class E inverter circuit having an excitation coil coupled between a first node and a first power supply node conveying the variable DC voltage, having a switch device coupled between the first node and a reference power supply node, and having a capacitor coupled between the first node and an output node thereof; and

the power receiving circuit comprises a Class E resonant rectifier circuit;

wherein said Class E inverter circuit and said Class E resonant rectifier circuit are together operable as an isolated Class E DC-DC converter circuit at the resonant frequency.

14. A system for transferring power from an external power transfer system (EPTS) to at least one body-implantable active device (BIAD) through a dermis layer, said system comprising:

an EPTS for being disposed external to a dermis layer of a body; and

a BIAD for being disposed beneath the dermis layer of the body;

the EPTS including;

a transmit coil;

a variable voltage generator circuit operable to generate on an output thereof a variable DC voltage responsive to a voltage control signal received on an input thereof; and

a resonant driver circuit operable to drive the transmit coil with a resonant current at a resonant frequency, said resonant driver circuit having an upper power supply node coupled to the variable DC voltage output, and having a lower power supply node coupled to a reference power supply voltage;

the BIAD including;

a receive coil tuned to the resonant frequency of the transmit coil and operable to inductively receive power therefrom when in proximity thereto; and

a power receiving circuit coupled to the receive coil and operable to deliver the received power to circuitry within the BIAD;

wherein the EPTS is operable to adjust the variable DC voltage to modulate energy stored in the resonant driver circuit each resonant cycle and to thereby modulate available transmitted power that is receivable by the BIAD.

15. The system as in claim 14 wherein:

the EPTS further comprises a back telemetry receive circuit for receiving back telemetry information from the BIAD; and

the EPTS is further operable to control the variable voltage generator circuit in response to back telemetry information received from the BIAD.

16. The system as in claim 14:

wherein the variable voltage generator circuit comprises a buck/boost circuit operable to generate the variable DC voltage output having a magnitude controllable over a range extending above and below a battery voltage powering the variable voltage generator circuit; and

wherein the resonant driver circuit further comprises;

an excitation coil and a switch device coupled in series between the upper power supply node and the lower power supply node, wherein the switch device is operable, responsive to a control input thereof, to substantially impress the variable DC voltage across the excitation coil during a portion of each resonant cycle to thereby store in the excitation coil an amount of energy that varies in accordance with the variable DC voltage; and

a capacitor coupled between a first node and an output node of the resonant driver circuit, said first node disposed between the excitation coil and the switch device.

17. The system as in claim 16 wherein the resonant driver circuit further comprises:

a buffer circuit having an input coupled to an excitation input of the resonant driver circuit, having an output coupled to the switch device control input, and having a boosted local power supply greater in magnitude than a battery voltage powering the EPTS.

18. The system as in claim 16 wherein:

the resonant driver circuit comprises a Class E inverter circuit; and

the power receiving circuit comprises a Class E resonant rectifier circuit;

wherein said Class E inverter circuit and said Class E resonant rectifier circuit are together operable as an isolated Class E DC-DC converter circuit at the resonant frequency.

19. The system as in claim 16 further comprising at least a second BIAD, and wherein:

the EPTS includes a series-connected plurality of transmit coils, each corresponding to a respective BIAD; and

the resonant driver circuit is operable to drive the series-connected plurality of transmit coils with the resonant current at the resonant frequency.

20. The system as in claim 19 wherein:

each respective BIAD comprises a respective head-locatable neurostimulation system;

the EPTS is disposed within a headset charging and control device operable to charge and communicate with each respective head-locatable neurostimulation system; and

each transmit coil is co-locatable with the corresponding receive coil.