Abstract: An electrical stimulation apparatus including a medical device. The medical device includes: a housing component having at least one electrically conductive area. The medical device includes a plurality of conductors configured to be electrically coupled to a distal electrode array. The electrode array are implantable in a human body. The medical device includes a stimulation circuit positioned inside the housing component. The stimulation circuit includes a plurality of controllable stimulation channels. A first subset of the stimulation channels is electrically coupled to the conductors. A second subset of the stimulation channels is electrically coupled to the electrically conductive area of the housing component. The stimulation circuit is operable to simultaneously create a first stimulation path in the electrode array and a second stimulation path that extends from the electrode array to the housing component.

Abstract: The present disclosure provides a medical stimulation system that includes a plurality of implantable channels each operable to obtain a voltage signal from a designated area of a body tissue. The medical stimulation system includes an impedance measurement device. The impedance measurement device includes a plurality of attenuators each coupled to a respective one of the channels. The attenuators are each operable to attenuate an amplitude of the voltage signal received from its respectively-coupled channel. The impedance measurement device includes a multiplexing component that receives the amplitude-attenuated voltage signals from each of the attenuators. The multiplexing component selectively outputs two of the amplitude-attenuated voltage signals. The impedance measurement device includes a differential amplifier that receives the two amplitude-attenuated voltage signals outputted from the multiplexing component as a differential input signal.

Abstract: The present disclosure provides a medical device that includes a neurostimulator. The neurostimulator includes one or more channels. Each channel includes a digitally-controlled switch coupled to a voltage source. The switch is in one of an “on” state and an “off” state in response to a first control signal. Each channel also includes a digitally-controlled current sink coupled to the switch. The current sink is coupled between the switch and the voltage source. The current sink draws a variable amount of electrical current in response to a second control signal. Each channel further includes a conductor coupled to the switch and the current sink. The conductor is configured to be coupled to an electrode that is operable to deliver the electrical current drawn by the current sink to a target tissue area.