Since the first version in 1997 the system has undergone various changes.
The major versions are
  • 2008 - Stable single channel MeCFES.
    • Main processor: ADSP2183 @8MHz + Flash + 10 bit DAC + 12 bit ADC
    • Fast recovery amplifier
    • Stimulator based upon the patented voltage controlled current source
    • Switch mode power supply for generating high voltage rails for the stimulator
    • Multiplexer front end for inversion of the stimulation pulse.
    • Schematics and description is found here
  • 2000 - First attempt on a four channel MeCFES changing platform to ADSP2183.
    • The issue was to create a sufficiently balanced stimulation circuit. The naive approach was to create a bridge of current mirrorsStim_Ver2001.jpg
    • The problem was that they were not accurate enough
  • 1997 - First working mono channel MeCFES based upon the TMS320 microprocessor.