Self-tuning external device for wirelessly recharging implantable medical devices
US9744368B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 16, 2012 |
| Grant date | Aug 29, 2017 |
| Priority date | — |
| Expiry date | May 16, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J2310/23
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
External device circuitry self-tunes so that current is being driven through a coil at a resonant frequency of the tank circuit including the coil. The self-tuning nature of the driver circuitry enables adaptation within a cycle to changes in the resonant frequency such as those due to changing loads on the coil from environmental factors. The self-tuning circuitry monitors the direction of current flow in the tank circuit so that during a non-driven phase of a two-phase cycle, the circuitry detects the current naturally changing directions and then activates the driver circuitry to drive current into the tank circuit in phase with the natural direction of current flow. Unity power factor is approximated while driving the coil despite changes in resonance. Power being driven into the tank circuit may then be measured at the approximation of unity power factor to control the amount of power being applied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.