Transcutaneous energy transfer primary coil with a high aspect ferrite core

A transcutaneous energy transfer device for transferring energy from an external device located outside of a patient's skin to an internal device implanted below the patient's skin, the transcutaneous energy transfer device comprising:

• an external primary transmitter coil to which energy to be transferred is applied, wherein the external primary transmitter coil has an outer diameter, wherein the external primary transmitter coil comprises at least one wire wrapped around a primary central axis of the external primary transmitter coil into a toroidal shape encircling the primary central axis, the toroid shape having an elliptical cross section rotated about the primary central axis and defining a center gap, and having a primary minimum diameter where the primary surface of the toroid shape is closest to the primary central axis, wherein the toroid shape further defines a primary coil height, wherein the primary coil height is less than the primary minimum diameter;
• an implanted secondary receiver coil comprising at least one wire wrapped around a secondary central axis of the secondary receiver coil into a toroid shape encircling the secondary central axis, wherein the toroid shape of the implanted secondary receiver coil defines an exterior secondary surface defined by an elliptical cross section of the toroid shape rotated about the secondary central axis of the secondary transmitter coil, and further defines a secondary central gap between the secondary surface and the secondary central axis, wherein the implanted secondary coil is configured to be inductively coupled to the external primary transmitter coil when the primary coil is placed adjacent to the skin and the secondary central axis is coaxially aligned with the primary central axis, wherein when the implanted secondary receiver coil is connected to a subcutaneous utilization device, wherein the inductively coupled energy is conducted to the subcutaneous utilization device;
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• a slender cylindrical member centered within the center gap of the external primary transmitter coil member, the slender cylindrical member defining a longitudinal axis coaxially aligned with the primary center axis of the external primary transmitter coil, the slender cylindrical member extending above and below the external primary transmitter coil height and having a uniform outer diameter that is smaller than a diameter of the center gap of the external primary transmitter coil member to define a ring shaped gap between the primary surface of the external primary transmitter coil and the outer diameter of the slender cylindrical member, the slender cylindrical member being formed from a ferrite material, wherein the outer diameter of the slender cylindrical member is less than or equal to one fourth of the outer diameter of the external primary transmitter coil;
• wherein when the longitudinal axis of the slender cylindrical member and the primary central axis and the secondary central axis of both the external primary transmitter coil and the implanted secondary receiver coil are all coaxially aligned on opposite sides of the patient's skin and the external primary transmitter coil is energized, the external primary transmitter coil is configured to generate a toroidal electromagnetic energy field having a generally circular cross section rotated around the primary central axis of the primary transmitter coil and the elliptical cross section of the primary transmitter coil to inductively transfer energy directly to the implanted secondary coil, wherein the elongate member is configured to elongate the circular cross section of the toroidal electromagnetic energy field into an elongated elliptical cross section having an elongated major axis parallel to the longitudinal axis and configured to move the elliptically elongated electromagnetic field farther away from the surface of the external primary transmitter coil, wherein the inductive energy transfer is optimized by the elongation of the toroidal electromagnetic energy field to maximize the power transmission between the internal device and the external device and to maximize the implant depth for operative transfer of energy from the external device to the internal device.

A transcutaneous energy transfer device for inductively coupling energy from an external device to an internal device configured to apply energy to a subcutaneous utilization device, the transcutaneous energy transfer device comprising:

• an external primary transmitter coil to which energy to be transferred is applied, wherein the external primary transmitter coil comprises at least one wire wrapped around a primary central axis of the primary transmitter coil into a toroidal shape encircling the primary central axis, the toroid shape having an elliptical cross section rotated about the primary central axis, and defining a center gap and a primary minimum diameter where the primary surface of the toroid shape is closest to the primary central axis, wherein the external annular primary coil member further defines a primary coil height and the primary coil height is less than the primary minimum diameter;
• a pot core comprising a disk portion and a cylindrical flange, wherein the pot core defines a central axis coaxially aligned with the primary central axis of the primary transmitter coil, wherein the cylindrical flange extends transversely relative to a first face of the disk portion, wherein the cylindrical flange has an inner surface and an outer surface, the pot core further comprising an elongated member, wherein the elongated member extends transversely relative to a first face of the disk portion, wherein the external primary transmitter coil is positioned closer to the inner surface of the cylindrical flange than the external primary transmitter coil is to the elongated member, wherein the elongated member is centered within the circular center gap of the external primary transmitter coil and is formed from a magnetically permeable material, wherein the elongated member defines a longitudinal axis coaxially aligned with the primary central axis of the external primary transmitter coil and the central axis of the pot core, the elongated member having a uniform diameter that is smaller than a diameter of the center gap of the external primary transmitter coil, wherein the elongated member defines a ring shaped center gap between the external primary transmitter coil and the elongated member, wherein the ring shaped center gap between the external primary transmitter coil and the elongated member defines a lateral distance between the external primary transmitter coil and the elongated member, wherein the lateral distance between the external primary transmitter coil and the elongated member is greater than a lateral distance between the external primary transmitter coil and the inner surface of the cylindrical flange, wherein the elongate member is configured to deform a circular cross sectional toroidal electromagnetic field generated by the external primary transmitter coil into an elliptical cross sectional toroidal electromagnetic field, the elliptical cross section of the field having an elongated major axis parallel to the primary central axis of the external primary transmitter coil to thereby move the elliptically elongated electromagnetic field farther away from the surface of the external primary transmitter coil in directions along the major axis;
• an implanted secondary receiver coil comprising at least one wire wrapped around a secondary central axis of the implanted secondary receiver coil into a toroid shape encircling the secondary central axis, wherein the toroid shape of the implanted secondary receiver coil has an exterior secondary surface defined by an elliptical cross section of the toroid shape rotated about the secondary central axis of the implanted secondary receiver coil, wherein the toroid shape defines a secondary central gap between the secondary surface and the secondary central axis;
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• excitation circuitry operatively configured to selectively energize the external primary transmitter coil to create an elliptical toroidal electromagnetic field to inductively couple energy directly from the external primary transmitter coil to the implanted secondary receiver coil when the primary central axis and the secondary central axis of the respective external primary transmitter coil and the implanted secondary receiver coil are coaxially aligned, wherein the inductive energy transfer is optimized by the elongation of the toroidal electromagnetic energy field to maximize the power transmission between the internal device and the external device and to maximize the implant depth for operative transfer of energy from the external device to the internal device.