Implant charging field control through radio link

• US 9,155,901 B2
• Filed: 01/09/2015
• Issued: 10/13/2015
• 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., Shelton, Brian M., Wolfe, James H.
• Primary Examiner(s): Rodas, Richard Isla
• Assistant Examiner(s): PELTON, NATHANIEL R
• Application Number:
  US14/593,807
• Publication Number:
  US 20150142081A1
• Time in Patent Office: 277 Days
• Field of Search: 320/108, 607/60, 607/61
• US Class Current: 1/1
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: G01R 19/12 Measuring rate of change
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• 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: H02J 7/0042 characterised by the mechanical construction

Abstract

A charger that evaluates the effectiveness of the charging field generated by the charger at an implantable device. The charger includes a charging coil, a communication module, and a processor. The processor can include instructions to determine the effectiveness of the charging field based on one or several signals or communications received from the implantable device. The charger can use the determination of the effectiveness of the charging field to vary the strength of the charging field and/or to prompt the user to move the charger with respect to the implantable device.

Claims

1. A portable charger device for transcutaneous charging of an implantable neurostimulator in a patient, the charger device comprising:

a housing having an external surface that is configured to at least partially engage a skin surface of the patient and be positioned at least partially over the implantable neurostimulator;

an antenna disposed within the housing;

a charging coil disposed within the housing and configured to magnetically couple with a corresponding receiving coil of the implantable neurostimulator,

an indicator disposed on the housing and configured to identify an effectiveness of a charging field created between the charging coil of the charger device and the corresponding receiving coil of the implantable neurostimulator; and

a processor disposed within the housing and configured to;

set a power of the charging coil of the charger device to a first level;

generate and send a request to establish communication via the antenna;

activate the indicator to identify the effectiveness of the charging field;

increase the power of the charging coil of the charger device to a second level;

determine if the power of the charging coil at the second level is at a maximum level;

receive a first signal from the implantable neurostimulator at a first time;

determine if the charging field generated by the charging coil of the charger device at the second level is detectable at the corresponding receiving coil of the implantable neurostimulator;

determine a current flowing through a shunt circuit of the implantable neurostimulator, wherein the current flowing through the shunt circuit is excess current generated by the charging field at the corresponding receiving coil of the implantable neurostimulator;

adjust the power of the charging coil of the charger device to a third level based in part on if the charging field is detectable at the corresponding receiving coil of the implantable neurostimulator and the determined current flowing through the shunt circuit;

receive a second signal from the implantable neurostimulator at a second time;

determine a change in the voltage induced by the charging field from the first time to the second time based on the first and second signals; and

control the indicator to indicate the change in the voltage induced by the charging field from the first time to the second time.

2. The portable charger device of claim 1, wherein it is determined if the charging field generated by the charging coil at the second level is detectable based on data contained in the first signal.

3. The portable charger device of claim 2, wherein determining if the power of the charging coil at the second level is at the maximum level comprises:

comparing the second level to the maximum level; and

identifying that the power of the charging coil at the second level is at the maximum level if the second level is greater than or equal to the maximum level.

4. The portable charger device of claim 3, wherein the processor is further configured to determine based on the received signal if the charging field is at an acceptable strength level if the charging field is detectable at the corresponding receiving coil of the implantable neurostimulator.

5. The portable charger device of claim 4, wherein determining if the charging field is at an acceptable strength level comprises determining at least one of:

if the voltage induced by the charging field is adequate to charge the implantable neurostimulator within a time range, and if a current flowing through the shunt circuit exceeds a threshold value.

6. The portable charger device of claim 5, wherein the processor is further configured to control the indicator to indicate repositioning of the charger device.

7. The portable charger device of claim 6, wherein adjusting the level of the charge field to a third level comprises at least one of:

increasing the strength of the charging field if the voltage induced by the charging field is inadequate to charge the implantable neurostimulator within the time range; and

decreasing the strength of the charging field if the current flowing through the shunt circuit exceeds the threshold value.

8. The portable charger device of claim 7, wherein the processor is further configured to determine a change in the current induced by the charging field from the first time to the second time based on the first and second signals if the voltage induced by the charging field does not change from the first time to the second time;

and control the indicator to indicate the change in the current induced by the charging field from the first time to the second time.

9. The portable charger device of claim 8, wherein the first level of the power of the charging coil is a zero-level.

10. A method of controlling transcutaneous charging of an implantable neurostimulator in a patient with a charger device, wherein the charger device at least partially engages a skin surface of the patient and is positioned at least partially over the implantable neurostimulator, the charger device comprising an antenna and a charging coil configured to magnetically couple with a corresponding receiving coil of the implantable neurostimulator, the method comprising:

setting a power of the charging coil of the charger device to a first level;

generating and sending a request to establish communication via the antenna;

activating an indicator of the charger device to identify an effectiveness of a charging field created between the charging coil of the charger device and the corresponding receiving coil of the implantable neurostimulator, wherein the indicator is configured to identify the effectiveness of the charging field;

increasing the power of the charging coil to a second level;

determining if the power of the charging coil at the second level is at a maximum level;

receiving a first signal from the implantable neurostimulator at a first time;

determining if the charging field generated by the charging coil at the second level is detectable at the corresponding receiving coil of the implantable neurostimulator;

determining a current flowing through a shunt circuit of the implantable neurostimulator;

adjusting the level of the charge field to a third level based in part on if the charging field is detectable at the corresponding receiving coil of the implantable neurostimulator and the determined current flowing through the shunt circuit;

receiving a second signal from the implantable neurostimulator at a second time;

determining a change in the voltage induced by the charging field from the first time to the second time based on the first and second signals; and

controlling the indicator to indicate the change in the voltage induced by the charging field from the first time to the second time.

11. The method of claim 10, wherein it is determined if the charging field generated by the charging coil at the second level is detectable based on data contained in the first signal.

12. The method of claim 11, wherein determining if the power of the charging coil at the second level is at the maximum level comprises:

comparing the second level to the maximum level; and

identifying that the power of the charging coil at the second level is at the maximum level if the second level is greater than or equal to the maximum level.

13. The method of claim 12, further comprising determining based on the received signal if the charging field is at an acceptable strength level if the charging field is detectable at the corresponding receiving coil of the implantable neurostimulator.

14. The method of claim 13, wherein determining if the charging field is at an acceptable strength level comprises determining one of:

if the voltage induced by the charging field is adequate to charge the implantable neurostimulator within a time range, and if a current flowing through the shunt circuit exceeds a threshold value.

15. The method of claim 14, wherein adjusting the level of the charge field to a third level comprises one of:

increasing the strength of the charging field if the voltage induced by the charging field is inadequate to charge the implantable neurostimulator within the time range; and

decreasing the strength of the charging field if the current flowing through the shunt circuit exceeds the threshold value.

16. The method of claim 15, further comprising determining a change in the current induced by the charging field from the first time to the second time based on the first and second signals if the voltage induced by the charging field does not change from the first time to the second time;

and controlling the indicator to indicate the change in the current induced by the charging field from the first time to the second time.

17. The method of claim 16, wherein the first level of the power of the charging coil is a zero-level.

18. The method of claim 17, wherein the generating and the sending of the request to establish communication is independent of charging.