Method and apparatus for supplying energy to a medical device

• US 8,825,173 B2
• Filed: 10/10/2008
• Issued: 09/02/2014
• Est. Priority Date: 10/16/2007
• Status: Active Grant

• Current Assignee: Kirk Promotion Ltd.
• Original Assignee: Kirk Promotion Ltd.
• Inventors: Forsell, Peter
• Primary Examiner(s): Patel, Niketa
• Assistant Examiner(s): Hankins, Lindsey G
• Application Number:
  US12/682,477
• Publication Number:
  US 20100211133A1
• Time in Patent Office: 2,153 Days
• Field of Search: 607/1, 607/2, 607/9, 607 30- 34, 607/61
• US Class Current: 607/61
• 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: 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 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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: H04B 5/79 for data transfer in combination with power transfer

Abstract

For supplying energy to a medical implant (100) in a patient'"'"'s body a receiver (102) cooperates with an external energizer (104) so that energy is wirelessly transferred. A feedback communication system (109) sends feedback information from the receiver to the energizer, the feedback information being related to the transfer of energy to the receiver. The feedback communication system communicates using the patient'"'"'s body as an electrical signal line. In particular, the communication path between the receiver and the external energizer can be established using a capacitive coupling, i.e. the feedback information can be capacitively transferred over a capacitor having parts outside and inside the patient'"'"'s body. An energy balance between the amount of energy received in the receiver and the energy used by the medical implant can be followed over time, and then the feedback information is related to the energy balance.

Claims

1. Apparatus configured to supply energy to a medical implant, comprising:

a receiver adapted to be implanted in a mammal patient'"'"'s body,

an external energizer adapted to wirelessly transfer energy to the receiver, and

a feedback communication system configured to send feedback information from the receiver to the external energizer, the feedback information being related to the transfer of energy to the receiver, wherein the feedback communication system is adapted to communicate the feed back information using the patient'"'"'s body as an electrical capacitive conducting signal line,

two capacitive capacitor plates, one capacitor plate being adapted configured to contact the inside of the mammal patient'"'"'s body, the other capacitor plate is configured to be the outside of the mammal patient'"'"'s body, each capacitor plate being divided so as to comprise a first dividing plate or portion and a second dividing plate or portion in order to improve the total capacitive coupling between the two capacitor plates, wherein the two dividing plates or portions on a sending side are adapted to be provided with signals which are the inverse of each other, when transmitting a signal through the capacitor, such that the first dividing plate or portion is configured to be provided with a direct signal and the second dividing plate is configured to be provided with an inverted signal, and

an inverter circuit for the inversion of signals communicating with the outside capacitor plate, one dividing plate or portion of the external capacitor plate being provided with the direct signal and the other dividing plate or portion being provided with the inverted signal.

2. The apparatus according to claim 1, wherein

a first energy balance between the amount of energy received in the receiver and the energy used by the medical implant is followed over time, and

the feedback communication system sends information related to the first energy balance.

3. The apparatus according to claim 1, wherein

a second energy balance between the amount of energy received in the receiver and the amount of wireless energy transmitted from the external energizer is followed over time,

information related to the received amount of energy is sent via the feedback communication system from the patient'"'"'s body, and

the external energizer is adapted to be moved along the patients skin to reach a position where the second energy balance is optimized for a maximum energy transfer to the receiver.

4. The apparatus according to claim 1, wherein the communication path between the receiver and the energizer via the patient'"'"'s body has a relatively high electrical resistance to reduce the electrical current flowing in the communication path through the patient'"'"'s body.

5. The apparatus according to claim 4, wherein the communication path between the receiver and the external energizer is established using a capacitive coupling, so that the feedback communication system communicates using the capacitive coupling.

6. The apparatus according to claim 5, wherein

the feedback communication system has an external communication unit that is connected to the external energizer and comprises a part of a capacitive energy storage, and

the feedback information, transmitted using the capacitive coupling, is represented by electrical currents injected into or drawn from the capacitive energy storage.

7. The apparatus according to claim 5, wherein

the feedback communication system has an internal communication unit that is connected to the receiver energizer and comprises a part of a capacitive energy storage, and

the feedback information, transmitted using the capacitive coupling, is represented by electrical currents injected into or drawn from the capacitive energy storage.

8. The apparatus according to claim 5, wherein

the feedback communication system has an external communication unit that is connected to the external energizer and comprises a first part of a capacitive energy storage, and

the feedback communication system has an internal communication unit that is connected to the receiver energizer and comprises a second part of a capacitive energy storage, and

the feedback information, transmitted using the capacitive coupling, is represented by electrical currents injected into or drawn from the capacitive energy storage.

9. The apparatus according to claim 6, wherein the feedback information is in a digital form and is represented by variations of the derivative of the voltage over the capacitive energy storage.

10. The apparatus according to claim 5, wherein

at least one of the external communication unit and the internal communication unit comprises a comparator configured to compare at least two different received frequencies,

at least the other of the external communication unit or the internal communication unit configured to send out at least two different frequencies, and

a communication path is established in digital form between the external communication unit and the internal communication unit using the different frequencies and said comparator placed at the other end of the communication path.

11. The apparatus according to claim 1, wherein said receiver comprises an internal coil.

12. The apparatus according to claim 1, wherein the energizer comprises an external coil.

13. The apparatus according to claim 12, wherein the second energy balance is related to the coupling factor between the internal and external coil.

14. The apparatus according to claim 12, further comprising a display unit for showing the energy balance during a movement of the energizer.

15. A method of supplying energy to a medical implant using an apparatus according to claim 1, the method comprising the steps of:

wirelessly transferring energy from an external energizer to a receiver implanted in a mammal patient'"'"'s body,

sending feedback information from the receiver to the external energizer, the feedback information being related to the transfer of energy to the receiver, the feedback communication system being adapted to communicate the feed back information using the patient'"'"'s body as an electrical capacitive conducting signal line,

providing the two dividing plates or portions on the sending side with signals which are the inverse of each other, when transmitting a signal through the capacitor, such that the first dividing plate or portion can be provided with a direct signal and the second dividing plate can be provided with an inverted signal, and

inverting the signals supplied by the inverter circuit for the communicating with the outside capacitor plate, one dividing plate or portion of the external capacitor plate being provided with the direct signal and the other dividing plate or portion being provided with the inverted signal.

16. The method according to claim 15, further comprising

following over time a first energy balance between the amount of energy transferred to the receiver and the energy used by the medical implant,

in the step of sending the feedback information, sending information related to the first energy balance.

17. The method according to claim 15, further comprising

following over time a second energy balance between the amount of energy received in the receiver and the amount of wireless energy transmitted from the external energizer,

in the step of sending the feedback information, sending information related to the transferred amount of energy, and

moving the external energizer along the patient'"'"'s skin to reach a position where the second energy balance is optimized for a maximum energy transfer to the receiver.

18. The method according to claim 15, wherein, in sending the feedback information, a communication path is established between the receiver and the energizer using a capacitive coupling, so that the feedback information is sent using the capacitive coupling.

19. The method according to claim 15, wherein

the energizer comprises a feedback receiver in turn comprising a capacitive energy storage, and

the feedback information, transmitted using the capacitive coupling, is represented by electrical currents injected into or drawn from the capacitive energy storage.