External charger with adjustable alignment indicator

• US 9,227,075 B2
• Filed: 11/13/2009
• Issued: 01/05/2016
• Est. Priority Date: 12/03/2008
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Aghassian, Daniel, Freidin, Lev, Chen, Joey
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): KIMBALL, JEREMIAH T
• Application Number:
  US12/618,637
• Publication Number:
  US 20100137948A1
• Time in Patent Office: 2,244 Days
• Field of Search: 607/60, 607/61, 607/46, 607/33
• US Class Current: 1/1
• CPC Class Codes: A61B 2018/205545 Arrangements for particular spot shape, e.g. square or annular
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• 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 1/37258 Alerting the patient
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• 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 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• 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 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

Electrical energy is transcutaneously transmitted at a plurality of different frequencies to an implanted medical device. The magnitude of the transmitted electrical energy respectively measured at the plurality of frequencies. One of the frequencies is selected based on the measured magnitude of the electrical energy (e.g., the frequency at which the measured magnitude of the electrical energy is the greatest). A depth level at which the medical device is implanted within the patient is determined based on the selected frequency. For example, the depth level may be determined to be relatively shallow if the selected frequency is relatively high, and relatively deep if the selected frequency is relative low. A charge strength threshold at which a charge strength indicator generates a user-discernible signal can then be set based on the determined depth level.

Claims

1. A method of controlling the charging of a medical device implanted within a patient, comprising:

transcutaneously transmitting electrical energy at a plurality of different frequencies to the implanted medical device;

measuring the magnitude of the transmitted electrical energy respectively at the plurality of frequencies;

selecting one of the frequencies based on the measured magnitude of the electrical energy;

consulting data correlating frequencies with charge strength threshold values to select a charge strength threshold using the selected frequency; and

setting a charge strength threshold at which a charge strength indicator generates a user-discernible signal to the selected charge strength threshold.

2. The method of claim 1, wherein the selected frequency is the frequency at which the measured magnitude of the electrical energy is the greatest.

3. The method of claim 1, wherein the charge strength threshold is set incrementally higher as the selected frequency incrementally decreases, and the charge strength threshold is set incrementally lower as the selected frequency incrementally increases.

4. The method of claim 1, wherein the data further correlates frequencies with depth levels at which the medical device is implanted, and wherein the data is consulted to select a depth using the selected frequency, and the selected depth is used to select the charge strength threshold.

5. The method of claim 4, wherein the selected depth is determined to be relatively shallow if the selected frequency is relatively high, and the selected depth is determined to be relatively deep if the selected frequency is relative low.

6. The method of claim 4, wherein selecting the depth comprises estimating a depth value based on the selected frequency using the data.

7. The method of claim 6, wherein the depth value is estimated by comparing the selected frequency to a pre-calibrated frequency/depth curve in the data.

8. The method of claim 1, wherein measuring the magnitude of the electrical energy comprises measuring the magnitude of a current within the electrical energy.

9. The method of claim 8, wherein the electrical energy is transcutaneously transmitted from an external charger, and the current within the electrical energy is the electrical current delivered into a primary coil of the external charger.

10. The method of claim 1, wherein the electrical energy is transcutaneously transmitted from an external charger, and the magnitude of electrical energy is measured at a single relative location between the external charger and the implanted medical device.

11. The method of claim 1, wherein the electrical energy is transcutaneously transmitted from an external charger, and the magnitude of electrical energy is measured at multiple relative locations between the external charger and the implanted medical device.

12. An implantable medical system, comprising:

an implantable medical device;

an external charger configured for transcutaneously transmitting electrical energy at a plurality of different frequencies to the implanted medical device;

a charge strength indicator configured for generating a user-discernible signal;

a detector configured for measuring the magnitude of the transmitted electrical energy respectively at the plurality of frequencies;

memory configured for storing a charge strength threshold at which the charge strength indicator generates the user-discernible signal; and

a processor configured to select one of the frequencies based on the measured magnitude of the electrical energy,

consult stored data correlating frequencies with charge strength threshold values to select the charge strength threshold using the selected frequency, and

store the selected charge strength threshold in the memory.

13. The system of claim 12, wherein the selected frequency is the frequency at which the measured magnitude of the electrical energy is the greatest.

14. The system of claim 12, wherein the processor is configured to store incrementally higher values for the selected charge strength threshold as the selected frequency incrementally decreases, and store incrementally lower values for the selected charge strength threshold as the selected frequency incrementally increases.

15. The system of claim 12, wherein the processor is further configured to determine a depth at which the medical device is implanted within a patient based on the selected frequency, and to select the charge strength threshold based on the determined depth.

16. The system of claim 15, wherein the processor is configured to determine the depth to be relatively shallow if the selected frequency is relatively high, and relatively deep if the selected frequency is relative low.

17. The system of claim 15, wherein the processor is configured to determine the depth by estimating a depth value based on the selected frequency by consulting stored data correlating frequencies with depth values.

18. The system of claim 17, wherein the data correlating frequencies with depth values is stored in the memory.

19. The system of claim 12, wherein the data correlating frequencies with charge strength threshold values is stored in the memory.

20. The system of claim 12, wherein the detector is configured for measuring the magnitude of the electrical energy by measuring the magnitude of a current within the electrical energy.

21. The system of claim 20, wherein the current within the electrical energy is the electrical current delivered into a primary coil of the external charger.

22. The system of claim 12, wherein the charge strength indicator, detector, memory, and processor are contained within the external charger.

23. An external charger for an implantable medical device, comprising:

a source of electrical power;

an alternating current (AC) coil configured for transcutaneously transmitting electrical energy at a plurality of different frequencies from the electrical power source to the implanted medical device;

a charge strength indicator configured for generating a user-discernible signal;

a detector configured for measuring the magnitude of the transmitted electrical energy respectively at the plurality of frequencies;

memory configured for storing a charge strength threshold at which the charge strength indicator generates a user-discernible signal; and

a processor configured to

select one of the frequencies based on the measured magnitude of the electrical energy,

consult stored data correlating frequencies with charge strength threshold values to select the charge strength threshold using the selected frequency, and

store the selected charge strength threshold in the memory.

24. The external charger of claim 23, wherein the selected frequency is the frequency at which the measured magnitude of the electrical energy is the greatest.

25. The external charger of claim 23, wherein the processor is configured to store incrementally higher values for the selected charge strength threshold as the selected frequency incrementally decreases, and store incrementally lower values for the selected charge strength threshold as the selected frequency incrementally increases.

26. The external charger of claim 23, wherein the processor is further configured to determine a depth at which the medical device is implanted within a patient based on the selected frequency, and to select charge strength threshold based on the determined depth.

27. The external charger of claim 26, wherein the processor is configured to determine the depth to be relatively shallow if the selected frequency is relatively high, and relatively deep if the selected frequency is relative low.

28. The external charger of claim 26, wherein the processor is configured to determine the depth by estimating a depth value based on the selected frequency by consulting stored data correlating frequencies with depth values.

29. The external charger of claim 28, wherein the data correlating frequencies with depth values is stored in the memory.

30. The external charger of claim 23, wherein the data correlating frequencies with charge strength threshold values is stored in the memory.

31. The external charger of claim 23, wherein the detector is configured for measuring the magnitude of the electrical energy by measuring the magnitude of a current within the electrical energy.

32. The external charger of claim 31, wherein the current within the electrical energy is the electrical current delivered into the AC coil.

33. The external charger of claim 23, further comprising a portable housing containing the electrical power source, AC coil, charge strength indicator, detector, memory, and processor.