The Intensity™ Micro Combo is the microcurrent device you have been looking for. This unit has 2 waveforms: Microcurrent and Tens. There are 4 modes of Tens and the microcurrent is adjustable from 0 to 700uA.
Wave Form: Tens - Monophasic Square, Microcurrent - Monophasic Square•Pulse Rate: Tens - 1-150 Hz, Microcurrent - 1-150 Hz
Pulse Width: Tens - 50-300us, Microcurrent - 2-200mS•Output Voltage: Tens - Constant Current, Microcurrent - Constant Current
Current: Tens - 0-100mA, Microcurrent - 0-700ua•Modes: Tens - 4, Microcurrent - 3
Timer: Tens - 1-60 Constant, Microcurrent - 1-60 Constant
Caution: This is a Class II Medical device and Federal law Restricts this device to sale by or on the order of a licensed health care professional.