pulse generator 32 with pulse delivery circuitry as shown in fig4 in at least one embodiment the pulse delivery circuitry includes a current source i source connected to a capacitor c 1 via a first switch s 1 in one or more embodiments the current source may be a constant current source in at least one embodiment the current source i source may be replaced by a voltage source connected to a capacitor c 1 via the first switch s 1 the voltage source in one or more embodiments provides a voltage and includes an internal resistance that limits the maximum current drawn thus in at least one embodiment the pulse delivery circuitry may generate and deliver electrical pulses that are either current pulses or voltage pulses capacitor c 1 in one or more embodiments may be connected to a first medical device surface electrode 1 such as electrode 16 or 18 at least one embodiment of the invention may include a second switch s 2 that allows fast discharging the capacitor c 1 via electrode 1 and may include an optional resistor r 1 with relatively high ohmic resistance e g 200 k u03c9 that allows slow discharging of capacitor c 1 in order to avoid unintended charge build up according to one or more embodiments in case of data communication when the.