US 6,321,118 B1 · Method and apparatus for power link detection with implantable medical devices

Abstract

A dual directional coupler is placed in the forward power-delivery path of an external transmitter adapted to transmit power to a receiver of an implantable medical device. The dual directional coupler monitors both the forward and reflected (or reverse) power being sent to, and being reflected from, the implantable device. When a valid power link is established between the external transmitter and the implantable medical device, the reflected power falls below a prescribed threshold. When a valid power link does not exist, or when a previously-established power link is broken, then the reflected power rises above the prescribed threshold. The presence of a valid power link is established by monitoring whether the reflected power is above or below the prescribed threshold. The dual directional coupler may be realized using passive discrete circuit components, such as capacitors and inductors; or alternatively using a pair of small transformers, each having a primary and secondary winding wound on a magnetic toroidal core.

Claims16

Dependent claims

Transmitting apparatus usable for transmitting power to an implantable medical device that determines whether a power link has been established with the implantable medical device, comprising:

an RF oscillator that generates an RF signal;
a headpiece having a transmitting coil;
a power amplifier that amplifies the RF signal to produce an RF power signal;
an output power path that connects the RF power signal with the transmitting coil;
a directional coupler connected in-line with the output power path between the power amplifier and the transmitting coil, the directional coupler having a reflected power port on which a reflected power signal appears having a magnitude proportional to reflected power present on the output power path;
and
a comparator circuit that compares the reflected power signal to a threshold reference signal and that generates a power link status signal as a function of whether the reflected power signal exceeds the threshold reference signal;
wherein the power link status signal provides a LINK or NO-LINK indication of whether a power link is established with the implantable medical device.

5 more elements

Apparatus that determines whether a power link is established with an implantable medical device, comprising:

means generating a power signal;
a transmitter that transmits the power signal to the implantable medical device over an output power path;
means for monitoring reflected power present on the output power path;
comparison means for comparing the reflected power to a threshold reference signal;
and
means for generating a power link status signal as a function of the comparison to the threshold reference signal.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for power link detection with implantable medical devices

Life of this patent

Method and apparatus for power link detection with implantable medical devices

Life of this patent

Abstract

Claims16