US Patent 10045764 Minimally invasive implantable neurostimulation system

An external medical device generates a drive signal inductively coupled to an implantable coil from an external coil. A regulator module coupled to the implantable coil generates an output signal in response to the inductively coupled signal and a feedback signal correlated to an amplitude of the inductively coupled signal. A signal generator receives the output signal for generating a therapeutic electrical stimulation signal. The control module adjusts the drive signal in response to the feedback signal to control the electrical stimulation signal.