Implantable device for controlling received power by a power receiving unit therein

• US 20060217785A1
• Filed: 03/24/2005
• Published: 09/28/2006
• Est. Priority Date: 03/24/2005
• Status: Active Grant

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Matei, Eusebiu
• Granted Patent: US 7,565,204 B2
• Time in Patent Office: Days
• US Class Current: 607/61
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

An implantable device capable of controlling received power from an external source. The implantable device includes a power receiving unit (PRU) and a control circuit which monitors the voltage across a load and provides a short circuit connection across the PRU when the voltage across the load exceeds a predetermined value.

Claims

1. An implantable device capable of controlling received power from an external source comprising:

a power receiving unit (PRU) adapted to receive power from an external power source by means of magnetic coupling to said external power source;

a load circuit coupled to the PRU and configured to receive power therefrom; and

a switch circuit interconnected between the PRU and the load circuit, the switch adapted to interrupt the transfer of power from the PRU to the load circuit as a function of a load circuit parameter.

2. The implantable device of claim 1 wherein the load circuit parameter is the voltage across the load circuit.

3. The implantable device of claim 2 wherein the load circuit comprises a voltage comparator configured to monitor the voltage across the load circuit wherein the comparator causes the switch circuit to interrupt the transfer of power from the PRU to the load circuit when the voltage across the load circuit exceeds a reference value.

4. The implantable device of claim 3 wherein the switch circuit provides a short circuit connection across the PRU to thereby interrupt power transfer from the PRU to the load circuit.

5. The implantable device of claim 4 wherein the switch circuit comprises a single pull single throw (SPST) switch coupled across the PRU such that in closed position the SPST provides a short circuit connection across the PRU.

6. The implantable device of claim 4 wherein the switch circuit comprises a transistor device coupled across the PRU such that when activated the transistor device provides a short circuit connection across the PRU.

7. The implantable device of claim 4 wherein the PRU comprises a resonant circuit comprising at least a coil and a capacitor and wherein the external power source induces a time varying electrical signal in the coil providing thereby a time varying PRU signal, said time varying electrical signal characterized as having zero crossings,

the implantable device further comprising a full wave rectifier circuit interposed between the PRU and the load circuit to provide full wave rectification of the PRU time varying electrical signal.

8. The implantable device of claim 7 wherein the comparator circuit further comprises a zero crossing detector whereby the comparator circuit interrupts the power transfer from the PRU to the load circuit as a function of a detected zero crossing.

9. The implantable device of claim 8 wherein the comparator circuit interrupts the power transfer from the PRU to the load circuit when a zero crossing is detected and the voltage across the load circuit exceeds a reference value.

10. The implantable device of claim 7 wherein the full wave rectifier circuit comprises at least two transistors arranged to provide rectification of the PRU time varying signal and upon detection of a zero crossing to provide a short circuit connection across the PRU.

11. The implantable device of claim 4 wherein the external source provides a time varying magnetic field at a predetermined frequency and wherein the PRU comprises a tank circuit having a coil and a capacitor, the values of the coil and capacitor selected to provide a tank circuit resonant frequency being substantially equal to the frequency of the time varying magnetic field.