Implantable, modular tissue stimulator

Abstract

The implantable, electrically operated tissue stimulator system comprises a master controller module having a micro-controller, a telemetry circuit, a power module, non-volatile memory, a real time clock and a bi-directional bus, and a plurality of Input/Output modules (I/O modules) which are connected to said bi-directional bus. Each I/O module 16 comprises (1) a control logic, (2) a programmable DC/DC Converter, (3) a capacitor multiplexer, (4) two or more electrodes (channels), (5) one amplitude holding capacitor per electrode, including circuitry for isolating the holding capacitor from other holding capacitors, and a switching network used for isolating the main power source from the electrodes during delivery of the stimulation pulses. Each I/O module can be used to (I) deliver stimulus pulses to two or more preselected channels, each channel being capable of being programmed to deliver pulses having a different amplitude, pulse width and rate, and each channel being capable of being programmed to stimulate either, in isolation from other channels or in combination with other channels, (II) learn and record into non-volatile memory the morphology of a biological signal, compare the prerecorded morphology against that of freshly acquired signals, and, upon a positive comparison, respond by either, initiating or terminating a preselected stimulation schedule, modifying the on-going stimulation schedule, or up-linking a command to another external medical device to initiate delivery of medical therapy, (III) write into non-volatile memory the time and date when adjustments are made to any of the stimulation parameters along with the new stimulation value (adjustments data base), and (IV) on a periodic basis or upon command, measure and write into non-volatile memory electrode impedance values along with the time and date when the adjustments are made (impedance data base).