Power control loop for implantable tissue stimulator

A cochlear stimulating system comprising:

• an external wearable processor (WP), including a speech processor, a battery, a microphone, and an antenna coil;
• the microphone being connected to the speech processor, the speech processor including means for converting sounds sensed through the microphone to RF electrical signals indicative of a desired cochlea stimulation pattern, the antenna coil being coupled to the receive RF electrical signals from the speech processor, the battery being coupled to the speech processor to provide operating power thereto;
• and
• an implantable cochlear stimulator (ICS) including an implanted antenna, a receiver, a power monitoring circuit, an electrode array, a current generator, and a telemetry coil;
• the implanted antenna being coupled with the antenna coil of the WP so as to receive the RF electrical signal;
• the receiver being coupled to the implanted coil and including means for extracting data and power from the received RF electrical signal, wherein the power extracted from the received RF electrical signal provides operating power for the ICS;
• the power monitoring circuit being coupled to the power output of the receiver so as to monitor the power consumption of the ICS, and including means for generating a back telemetry signal indicative of the monitored power consumption and applying the back telemetry signal to the telemetry coil;
• and the current generator including means for generating a series of electrical stimulation pulses that are applied to the electrode array as a function of the data extracted from the received RF electrical signal;
• and wherein
• the WP further includes means for receiving the back telemetry signal from the telemetry coil of the ICS and means for adjusting the power level of the RF electrical signal sent to the ICS through the antenna coil as a function of the back telemetry signal so as to compensate for variations in the power consumption of the ICS;
• whereby the power coupled to the ICS from the WP automatically tracks the power consumed within the ICS.

A method for conserving power within a tissue stimulating system having an external part and an implantable part;

• the external part having a power source therein for providing operating power for the system, including means for supplying power to the implantable part;
• the implantable part having electrode means and means for stimulating tissue adjacent the electrode means with electrical power derived from the power transmitted to the implantable part from the external part;
• the method comprising the steps of:
• monitoring power consumption within the implantable part;
• generating a power consumption signal indicative of changes in the consumed power within the implantable part;
• transmitting the power consumption signal to the external part;
• adjusting the amount of power supplied to the implantable part as a function of the power consumption signal so that the amount of power transmitted to the implantable part automatically tracks the power consumed within the implantable part.