Automatic on-off charger for an implantable medical device

摘要

An external charger for an implantable medical device is disclosed which can automatically detect an implant and generate a charging field. The technique uses circuitry typically present in an external charger, such as control circuitry, a Load Shift Keying (LSK) demodulator, and a coupling detector. An algorithm in the control circuitry periodically issues charging fields of short duration in a standby mode. If the coupling detector detects the presence of a conductive material, the algorithm issues a listening window during which a charging field is generated. If an LSK reply signal is received at the LSK demodulator, the external charger can charge the implant in a normal fashion. If a movement signature is detected at the LSK demodulator indicative of a predetermined user movement of the external charger, a charging field is issued for a set timing period, to at least partially charge the IPG battery to restore LSK communications.

主权项

1. An external charger for charging a battery in an implantable medical device, comprising:
a coil; and control circuitry configured to automatically energize the coil to generate a charging field without initiation by a user, wherein the control circuitry comprises circuitry to:
periodically energize the coil to generate a first field;evaluate a voltage across the coil or a current through the coil to determine if the external charger is possibly proximate to the implantable medical device during the generation of the first field; andenergize the coil to generate the charging field when it is determined that the external charger is possibly proximate to the implantable medical device.