Quality factor in a contact hearing system
In one embodiment, the present invention is directed to a contact hearing system including: an ear tip including a transmit circuit having a first Q value, wherein the ear tip includes a transmit coil wound on a ferrite core; a contact hearing device including a receive circuit having a second Q value, wherein the first Q value is greater than the second Q value; a receive coil positioned on the contact hearing device, wherein the receive coil includes a core of a non-ferromagnetic material.
1. A contact hearing system comprising:
an ear tip comprising a transmit circuit having a first Q value, wherein the ear tip comprises a transmit coil wound on a ferrite core;
a contact hearing device comprising a receive circuit having a second Q value, wherein the first Q value of the transmit circuit is increased relative to the second Q value of the receive circuit based on winding the transmit coil on the ferrite core; and
a receive coil positioned on the contact hearing device, wherein the receive coil comprises a core of a non-ferromagnetic material, and wherein a distal end of the receive coil is separated from the receive circuit to increase the second Q value of the receive circuit.
2. A contact hearing system according to claim 1 wherein the first Q value is greater than the second Q value by a factor of at least two.
3. A contact hearing system according to claim 2 wherein the receive coil is separated from the receive circuit via a disk provided between the distal end of the receive coil and the receive circuit.
4. A contact hearing system according to claim 3 wherein the disk comprises a ferrite material, and wherein the ferrite disk is configured to shunt magnetic flux entering the receive coil to an outside of the receive coil about the distal end.
5. A contact hearing system according to claim 3 wherein the disk comprises a hole in its central portion.
6. A contact hearing system according to claim 1 wherein the transmit coil is inductively coupled to the receive coil.
7. A contact hearing system according to claim 1 wherein the contact hearing device comprises a diode detector connected to the receive coil.
8. A contact hearing system according to claim 1 wherein the contact hearing device comprises a balanced armature microactuator connected to the receive coil.
9. A contact hearing system according to claim 1 wherein the contact hearing device comprises a platform which supports the receive coil, wherein the platform conforms to the anatomy of the wearers ear canal.
10. A contact hearing system according to claim 1 wherein the contact hearing device comprises a platform which supports the receive coil, wherein the platform is adapted to position the contact hearing device on a wearer's tympanic membrane.
11. A method of inductively coupling an ear tip having a transmit circuit to a contact hearing device having a receive circuit, wherein the transmit circuit has a first Q value greater than a second Q value of the receive circuit, the method comprising the steps of:
exciting a transmit coil in the transmit circuit, the transmit coil being positioned in an ear tip;
radiating an electromagnetic field from the transmit coil to a receive coil;
receiving the radiated electromagnetic field at the receive coil, the receive coil being positioned on a contact hearing device, wherein a distal end of the receive coil is separated from the receive circuit to increase the second Q value of the receive circuit, and wherein the received radiated electromagnetic field is shunted to an outside of the receive coil about the distal end; and
transmitting information from the transmit coil to the receive coil using the electromagnetic field.
12. A method according to claim 11 wherein the first Q value is at least twice as large as the second Q value.
13. A method according to claim 11 wherein the transmit coil comprises a ferrite core.
14. A method according to claim 11 wherein the distal end of the receive coil is separated from the receive circuit by a ferrite disk provided between the receive coil and the receive circuit.
15. A method according to claim 14 wherein the ferrite disk comprises a hole in its central portion.
16. A method according to claim 11 wherein the information is transmitted from the transmit coil to the receive coil using near field radiation.
17. A method according to claim 16 wherein the transmit coil is inductively coupled to the receive coil.
18. A method according to claim 11 wherein the electromagnetic radiation induces a current in the receive coil.
19. A method according to claim 18 wherein the current induced in the receive coil is proportional to a level of magnetic flux passing through the receive coil.
20. A method according to claim 18 wherein a current induced in the receive coil drives a balanced armature microactuator positioned on the contact hearing device.
21. A contact hearing system comprising:
an ear tip comprising a transmit circuit having a first Q value, wherein the ear tip comprises a transmit coil wound on a ferrite core, the first Q value being in a range of between fifty and seventy-five;
a contact hearing device comprising a receive circuit having a second Q value, wherein the second Q value is in the range of between fifteen and twenty-five, and wherein the first Q value is increased relative to the second Q value based on winding the transmit coil on the ferrite core; and
a receive coil positioned on the contact hearing device, wherein the receive coil has a core of non-ferromagnetic material, and wherein a distal end of the receive coil is separated from the receive circuit to increase the second Q value of the receive circuit.
22. A contact hearing system according to claim 21 wherein the receive coil is a component of a receive circuit assembly, the receive circuit assembly comprising a disk at a distal end of the receive coil, wherein the disk comprises a ferrite material and is configured to shunt magnetic flux entering the receive coil to an outside of the receive coil about the distal end.
23. A contact hearing system according to claim 22 wherein the receive coil assembly further comprises a printed circuit board, the printed circuit board being separated from the distal end of the receive coil by the disk.