Recharge of implanted medical devices

• US 10,707,692 B2
• Filed: 01/26/2017
• Issued: 07/07/2020
• Est. Priority Date: 01/26/2017
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Schmidt, Craig L., Munns, Gordon O.
• Primary Examiner(s): Wu, Eugene T
• Application Number:
  US15/416,655
• Publication Number:
  US 20180212451A1
• Time in Patent Office: 1,258 Days
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/00 Measuring for diagnostic purposes radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00; Identification of persons
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/68 Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 1/3962 in combination with another heart therapy
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• 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 50/12 : of the resonant type
• CPC Class Codes: H02J 50/402 : the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• 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: H02J 7/00309 : Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0047 : with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/02 : for charging batteries from ac mains by converters

Abstract

Systems, devices and methods are disclosed that allow recharging a power source located in an implanted medical device implanted in a patient, the recharging device comprising first and second pairs of electrical coils configured to generate first and second uniform magnetic fields in overlapping first and second cylindrical regions located between the respective pairs of electrical coils.

Claims

1. A method for recharging a power source located in an implantable medical device, the method comprising:

generating, by a signal generator, an electrical signal having a varying voltage waveform;

applying, by a first driver circuit, the electrical signal to a first pair of electrical coils, the first pair of electrical coils having a first central axis, the first pair of coils configured to generate a first uniform magnetic field in a first cylindrical region located between the first pair of coils when the first pair of coils is electrically energized;

applying, by a second driver circuit, the electrical signal to a second pair of electrical coils, the second pair of electrical coils having a second central axis, the second pair of coils configured to generate a second uniform magnetic field in a second cylindrical region located between the second pair of coils when the second pair of coils is electrically energized,

wherein the first uniform magnetic field and the second uniform magnetic field form a resultant magnetic field within an area common to both the first cylindrical region and the second cylindrical region within an area common to both the first cylindrical region and the second cylindrical region, the resultant magnetic field operable to provide a charging energy to at least one receiving antenna of the implantable medical device located within the resultant magnetic field when the first pair of coils and the second pair of coils are electrically energized; and

rotating, by a position controller and a motor controlled by the position controller, the second pair of coils around the first central axis so that when rotated, the second central axis remains perpendicular to the first central axis.

2. The method of claim 1, further comprising:

receiving, by communication circuitry, a feedback signal indicating a level of coupling between the resultant magnetic field and a receiving antenna of the implantable medical device located within the resultant magnetic field;

determining, by processing circuitry coupled to the communication circuitry, a final position for the second pair of coils as the second pair of coils is being rotated around the first central axis based on the feedback signal; and

positioning, by the positioning circuitry and the motor, the second pair of coils at the final position.

3. The method of claim 1, wherein the first pair of coils are separated from each other by a first distance and the second pair of coils are separated from each other by a second distance such that at least a portion of a patient including the implantable medical device may be disposed in the area common to both the first cylindrical region and the second cylindrical region between the first pair of coils and the second pair of coils.

4. A system for recharging an implantable medical device, the system comprising:

a first pair of electrical coils having a first central axis, the first pair of coils configured to provide a first uniform magnetic field in a first cylindrical region located between the first pair of coils when the first pair of coils is electrically energized;

a second pair of electrical coils and having a second central axis, the second pair of coils configured to provide a second uniform magnetic field in a second cylindrical region located between the second pair of coils when the second pair of coils is electrically energized; and

a source of electrical energy coupled to the first pair of coils and to the second pair of coils, the source configured to provide electrical energy to energize the first pair of electrical coils and to energize the second pair of electrical coils;

wherein the first uniform magnetic field and the second uniform magnetic field form a resultant magnetic field within an area common to both the first cylindrical region and the second cylindrical region, the resultant magnetic field operable to provide a charging energy to at least one receiving antenna of the implantable medical device located within the resultant magnetic field when the first pair of coils and the second pair of coils are electrically energized, and

wherein the second pair of coils is configured to be rotated around the first central axis of the first pair of coils while keeping the second uniform magnetic field of the second pair of coils orthogonal to the first uniform magnetic field of the first pair of coils.

5. The system of claim 4, wherein the system further comprises:

a motor coupled to a position control circuit, the motor mechanically coupled to the second pair of coils and configured to provide a force configured to rotate the second pair of coils around the first central axis of the first pair of coils under the control of the positioning control circuit.

6. The system of claim 4, the system further comprising:

a communication circuitry, the communication circuitry coupled to the position control circuit and configured to receive a feedback signal indicative of variations in the strength of a resultant magnetic field being generated by the first pair of coils and the second pair of coils within the area common to both the first cylindrical region and the second cylindrical region, and to provide the feedback signal or information derived from the feedback signal to the position control circuitry, and

wherein the position control circuitry is configured control the motor to rotate the second set of coils to a final position based at least in part on the feedback signal or the information derived from the feedback signal.

7. The system of claim 4, wherein at least one of the first pair of electrical coils and the second pair of electrical coils comprises a pair of coils arranged as a Helmholtz coil.

8. The system of claim 4, further comprising:

a sensor positioned at a location within the area common to both the first cylindrical region and the second cylindrical region and configured to sense a strength of a magnetic field being generated within the area common to both the first cylindrical region and the second cylindrical region, and

processing circuitry configured to provide a reduction of the electrical energy being provided by the source to the first pair of coils and to the second pair of electrical coils if the strength of the magnetic field sensed by the sensor exceeds a threshold value.

9. The system of claim 4, further comprising:

a processor and a memory coupled to the processor, the memory storing a profile comprising a set of values for levels of electrical energy to be provided to at least the first pair of electrical coils and the second pair of electrical coils over a duration of a recharging process, the profile configured so that when executed by the processor, the levels of electrical energy provided to each of the first pair of electrical coils and the second pair of electrical coils is set and/or varied over the duration of the recharging process based on a set of values stored in profile.

10. The system of claim 4, further comprising feedback signal processing to tune the resultant magnetic field intensity modulation frequency and direction to maximize the wireless power transfer.

11. The system of claim 4, wherein the source is configured to provide electrical energy comprising a sinusoidal waveform to both the first pair of coils and to the second pair of electrical coils.

12. The system of claim 4, wherein the source is configured to provide electrical energy to the first pair of coils and to the second pair of coils at a level of energy so that a strength of the resultant magnetic field generated within the area common to both the first cylindrical region and the second cylindrical region does not exceed 1,500 A/m.

13. A recharging system for recharging a power source located in an implantable medical device, the recharging system comprising:

a first pair of electrical coils having a first central axis, the first pair of coils configured to generate a first uniform magnetic field in a first cylindrical region located between the first pair of coils when the first pair of coils is electrically energized; and

a second pair of electrical coils having a second central axis perpendicular to the first central axis, the second pair of electrical coils configured to generate a second uniform magnetic field in a second cylindrical region located between the second pair of coils when the second pair of coils is electrically energized;

wherein the first uniform magnetic field and the second uniform magnetic field form a resultant magnetic field within an area common to both the first cylindrical region and the second cylindrical region, the resultant magnetic field operable to provide a charging energy to at least one receiving antenna of the implantable medical device located within the resultant magnetic field when the first pair of coils and the second pair of coils are electrically energized, and

wherein the second pair of coils is configured to be rotated around the first central axis so that when rotated, the second central axis remains perpendicular to the first central axis.

14. The system of claim 13, further comprising processing circuitry configured to receive a feedback signal indicating a level of coupling between the resultant magnetic field and the at least one receiving antenna of the implantable medical device, and determine a final position of the second pair of coils when rotated around the first central axis based on the feedback signal.

15. The system of claim 13, further comprising processing circuitry configured to receive a feedback signal indicating a variation in a strength of the resultant magnetic field being provided in the area common to both the first cylindrical region and the second cylindrical region as the second pair of coils is rotated, and determine a final position of the second pair of coils when rotated around the first central axis based on the feedback signal.

16. The system of claim 13, further comprising processing circuitry configured to receive a feedback signal indicating level of coupling between the implantable medical device and the resultant magnetic field as the relative excitation currents are tuned, and determine a final ratio of currents relative to the first and the second pairs of coils based on the feedback signal.

17. The system of claim 13, wherein the first pair of coils are separated from each other by a first distance and the second pair of coils are separated from each other by a second distance such that at least a portion of a patient including the implantable medical device may be disposed in the resultant magnetic field between the first pair of coils and the second pair of coils.

18. The system of claim 13, wherein a radius for each of the coils of the first pair of coils and the second pair of coils is in a range of 10 to 30 inches.

19. The system of claim 13, wherein at least one of the first pair of electrical coils and the second pair of electrical coils comprises a pair of coils arranged as a Helmholtz coil.

20. The system of claim 13, wherein a first and second coils of the first pair of coils are coupled by a first electric conductor in a series coupling arrangement so that a first electric current provided to the first coil of the first pair of coils flows through the second coil of the first pair of coils, and a third and fourth coil of the second pair of coil are coupled by a second electrical conductor in a series coupling arrangement so that a second current provided to the third coil of the second pair of coils flow through the fourth coil of the second pair of coils.

21. The system of claim 13, wherein at least one of the first pair of coils and the second pair of coils comprise a winding comprising an electrical conductor that is flat-planar wound on a first support structure and on a second support structure to form a set of coils comprising the first pair of coils or the second pair of coils.

22. The system of claim 13, wherein at least one of the first pair of coils and the second pair of coils comprise a winding comprising an electrical conductor that is spiral wound on a first support structure and on a second support structure to form a set of coils comprising the first pair of coils or the second pair of coils.