A method for estimating a steady state response of a drill string in a borehole includes calculating a first displacement of the drill string in a frequency domain for a first excitation force frequency and a number of multiples of this frequency using an equation of motion of the drill string. The semiconductor integrated circuit device comprises: a first power supply circuit including an output circuit and providing a first series regulator in cooperation with the output external transistor; and a plurality of terminals. Automatic capture verification during bipolar stimulation is recommended only if anodal stimulation is not detected at a working stimulation output. The first and second difference signals are received by a programmable timing element having a user programmable device and a signal limiting device for limiting the duration of the first or second difference signals provided at respective first or second outputs of the programmable timing element to a user programmable maximum value. The system includes an electrical signal generator and an endovascular module with electrode units for transiently being disposed in the internal and external carotid arteries, adjacent a carotid body.