Electronic impedance transformer for inductively-coupled load stabilization
US6745077B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 2001 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Nov 13, 2022 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/37223
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A fixed frequency external power source having an external coil is inductively coupled with an implanted coil of an implanted medical device. The implant device has an electronic impedance transformer as part of its load circuit. Such electronic impedance transformer sets a proper voltage and current ratio (impedance) so that the coil set, i.e., the external coil and the implanted coil, are loaded with an optimal load. Such optimal loading, in turn, significantly minimizes any mismatch loss from the inductive link between the external coil and the implant coil, and allows wide ranges in the voltage and load resistance and coil separation, while at the same time maintaining an optimal load condition. The impedance transformer is especially applicable to fully implantable cochlear stimulation systems wherein, during one mode of operation, a relatively large power level must be transferred for charging the implanted power storage element, e.g., a rechargeable battery, but wherein another mode of operation, the implant is operated and powered from an external unit and a relatively small power level is transferred to the implant device. The ratio of these power levels may be large, e.g.…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.