Method and apparatus for supplying energy to a medical device

• US 9,789,323 B2
• Filed: 05/04/2015
• Issued: 10/17/2017
• Est. Priority Date: 10/16/2007
• Status: Active Grant

• Current Assignee: Peter Forsell
• Original Assignee: Peter Forsell
• Inventors: Forsell, Peter
• Primary Examiner(s): Wehrheim, Lindsey G
• Application Number:
  US14/702,871
• Publication Number:
  US 20160023004A1
• Time in Patent Office: 897 Days
• CPC Class Codes: A61B 17/12 for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord specially adapted for vas deferens or fallopian tubes A61F6/20; materials for ligaturing blood vessels A61L17/00
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61F 2250/0001 Means for transferring electromagnetic energy to implants
• CPC Class Codes: A61N 1/08 Arrangements or circuits for monitoring, protecting, controlling or indicating for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

In a method and apparatus for supplying wireless energy to a medical device (100) implanted in a patient, wireless energy is transmitted from an external energy source (104) located outside a patient and is received by an internal energy receiver (102) located inside the patient, for directly or indirectly supplying received energy to the medical device. An energy balance is determined between the energy received by the internal energy receiver and the energy used for the medical device, and the transmission of wireless energy is then controlled based on the determined energy balance. The energy balance thus provides an accurate indication of the correct amount of energy needed, which is sufficient to operate the medical device properly, but without causing undue temperature rise.

Claims

1. An apparatus configured to control inductive transmission of wireless energy supplied to an electrically operable medical device adapted to be implanted in a mammal patient, comprising:

an external energy source adapted to be located outside the patient, comprising a primary coil adapted to transmit wireless energy,

an internal energy receiver located inside the patient, comprising;

a secondary coil adapted to receive the wireless energy inductively, the internal energy receiver being connected or configured to be connected to the electrically operable medical device configured to directly or indirectly supplying the wirelessly received energy thereto, and

at least one stabilizing unit to stabilize the wirelessly received energy in the electrically operable medical device,

wherein the electrically operable medical device as adapted to transfer feedback control information to the external energy source,

wherein the feedback control information is related to an energy for operating the medical device, said feedback control information being adapted to be used to control the transmission of wireless energy from the external energy source, and

wherein the electrically operable medical device is adapted to consume, store or consume and store the wirelessly received energy after it has been stabilized in the at least one stabilizing unit of the electrically operable medical device,

wherein the apparatus is configured to;

first transmit the wireless energy with a predetermined energy rate and second transmit the wireless energy based on an energy balance, adapted to be determined by detecting a direction and rate of change in a current amount of accumulated energy in the at least one stabilizing unit, wherein the rate of change is a speed of change of the energy balance, measured as accumulated energy in the stabilizing unit,

wherein the apparatus is adapted to repeatedly detect the direction and speed of change in the current amount of accumulated energy in the at least one stabilizing unit, intermittently at certain intervals during ongoing energy transfer executed on a continuous basis during the transmission of wireless energy, and

wherein the feedback control information is further related to the direction and speed of change in the current amount of accumulated energy in the at least one energy stabilizing unit.

2. The apparatus according to claim 1 wherein the apparatus is adapted to determine an energy balance, during the transmission of wireless energy, between the energy received by the internal energy receiver and energy used for the medical device by at least one of:

an internal control unit or an external control unit, said feedback control information being related to the determined energy balance, and wherein the apparatus is adapted to control the transmission of wireless energy from the external energy source based on the determined energy balance using said feedback control information.

3. The apparatus according to claim 2 wherein the apparatus is adapted to detect at least one of:

a change in said energy balance, such that the transmission of wireless energy is then controlled based on said detected energy balance change, and a difference between energy received by said internal energy receiver and energy used for the medical device, such that the apparatus is adapted to control transmission of wireless energy based on said detected energy difference.

4. The apparatus according to claim 3, wherein the apparatus is adapted to control the amount of transmitted wireless energy to be at least one of:

decreased, if at least one of;

the detected energy balance change implies that the energy balance is increasing,

the detected energy difference implies that the received energy is greater than the used energy,

the direction of change in the current amount of accumulated energy in the energy stabilizing unit implies that the received energy is greater than the used energy, and

the detected energy balance rate implies that the received energy rate is greater than the used energy rate,

and increased if at least one of;

the detected energy balance change implies that the energy balance is decreasing,

the detected energy difference implies that the received energy is less than the used energy,

the direction of change in the current amount of accumulated energy in the energy stabilizing unit implies that the received energy is greater than the used energy, and

the detected energy rate implies that the received energy is less than the used energy.

5. The apparatus according to claim 4, wherein the decrease/increase of energy transmission corresponds to at least one of:

a detected change rate,

speed of change,

direction of change, and

a magnitude of said detected energy difference.

6. The apparatus according to claim 3, wherein the wirelessly received energy used by the medical device is at least one of:

consumed to operate the medical device,

stored in at least one energy storage device of the medical device and consumed to operate the medical device, and

stored in at least one energy storage device of the medical device.

7. The apparatus according to claim 6, wherein substantially all energy used by the medical device is consumed to operate the medical device.

8. The apparatus according to claim 6, wherein substantially all energy used for the medical device is stored in said at least one energy storage device.

9. The apparatus according to claim 6, wherein the energy used for the medical device is partly consumed to operate the medical device and partly stored in said at least one energy storage device.

10. The apparatus according to claim 6, wherein a capacitor is provided in the at least one stabilizing unit to stabilize the energy received before the energy is supplied directly or indirectly to the medical device.

11. The apparatus according to claim 3, wherein the apparatus is adapted to directly or indirectly measure the difference between the total amount of energy received by the internal energy receiver and the total amount of consumed, stored or consumed and stored energy over time, and to determine the energy balance based on a detected change said total amount difference.

12. The apparatus according to claim 3, wherein said detected difference relates to an integral over time of at least one measured electrical parameter related to said energy balance, wherein said integral of the electrical parameter relates to the energy balance as an accumulated difference between the total amount of energy received by said internal energy receiver and the total amount of consumed and/or stored energy.

13. The apparatus according to claim 1, wherein the apparatus is adapted to determine the energy balance based on a detected change followed over time in the amount of consumed and/or stored energy.

14. The apparatus according to claim 13, wherein the apparatus is adapted to detect the change in the amount of consumed, stored or consumed and stored energy by determining over time a derivative of a measured electrical parameter related to said amount of consumed, stored or consumed and stored energy, a derivative at a first given moment is corresponding to the rate of a change at the first given moment, wherein the rate of change includes the direction and speed of the change.

15. The apparatus according to claim 14, wherein the apparatus is adapted to determine said derivative based on a detected rate of change of the electrical parameter.

16. The apparatus according to claim 13, further adapted to supply the energy with at least one of:

at least two different voltages, including the at least one constant voltage, and

at least two different currents, including said at least one constant current.

17. The apparatus according to claim 1, wherein the apparatus is adapted to supply energy received by the internal energy receiver to the medical device with at least one of:

at least one constant voltage, wherein the constant voltage is created by a constant voltage circuitry comprised in the apparatus, and

at least one constant current, wherein the constant current is created by a constant current circuitry comprised in the apparatus.

18. The apparatus according to claim 1, wherein the apparatus is adapted to use the direction of change to control the transmission of wireless energy in at least one of the following ways:

decreasing the transmitted energy, when direction of change implies that the received energy is greater than the used energy, and

increasing the transmitted energy, when direction of change implies that the used energy is greater than the used received energy.

19. The apparatus according to claim 1, wherein the apparatus is adapted to use a rate of change corresponding to the speed of change to control the transmission of wireless energy in at least one of the following ways:

decreasing the transmitted energy in a small step, when speed of change is smaller, and direction of change implies that the received energy is greater than the used energy,

decreasing the transmitted energy in a larger step, when speed of change is larger, and direction of change implies that the received energy is greater than the used energy,

increasing the transmitted energy in a small step, when speed of change is smaller, and direction of change implies that the used energy is greater than the used received energy, and

increasing the transmitted energy in a larger step of the speed of change is implies a larger speed of, when speed of change is larger, and direction of change implies that the used energy is greater than the used received energy.