Wireless energy transfer with variable size resonators for medical applications

A power source for wirelessly providing power to a wireless receiver of an electrically powered implantable medical device, the power source comprising:

• a power supply, the power supply configured to supply power at a rate sufficient to charge the implantable medical device;
• and
• a first electromagnetic resonator coupled to the power supply and having a mode with a resonant frequency ω1, an intrinsic loss rate Γ1, and a first Q-factor Q1=ω1/2Γ1;
• wherein the first electromagnetic resonator is configured to be wirelessly coupled to a second electromagnetic resonator integrated with the implantable medical device or a load associated with the implantable medical device to provide non-radiative wireless power to the second electromagnetic resonator, the second electromagnetic resonator having a mode with a resonant frequency ω2, an intrinsic loss rate Γ2, and a second Q-factor Q2=ω2/2Γ2;
• wherein the first electromagnetic resonator has an associated lossy object, and the first electromagnetic resonator is configured to tailor electromagnetic fields with respect to the lossy object;
• and
• wherein the square root of the product of the respective Q factors is greater than 100.

A medical device wireless power system, comprising:

• a power supply, the power supply configured to supply power at a rate sufficient to charge an implantable medical device;
• a first electromagnetic resonator coupled to the power supply and having a mode with a resonant frequency ω1, an intrinsic loss rate Γ1, and a first Q-factor Q1=ω1/2Γ1, the first electromagnetic resonator having an associated first lossy object, and the first electromagnetic resonator comprising a magnetic shield to reduce a strength of generated magnetic fields in a specific direction and create a non-symmetric active area with respect to the first lossy object;
• a load configured to power the implantable medical device using electrical power, wherein the load has an associated second lossy object;
• and
• a second electromagnetic resonator associated with the implantable medical device and configured to be coupled to the load, the second electromagnetic resonator having a mode with a resonant frequency ω2, an intrinsic loss rate Γ2, and a second Q-factor Q2=ω2/2Γ2;
• wherein the first electromagnetic resonator is configured to be wirelessly coupled to the second electromagnetic resonator associated with the implantable medical device to provide non-radiative wireless power to the second electromagnetic resonator;
• wherein the second electromagnetic resonator is configured to tailor electromagnetic fields with respect to the second lossy object;
• and
• wherein the square root of the product of the respective Q factors is greater than 100.