Hi Humoor,
If your device is also considered implantable under the MDR definition, then the risk profile of the device is likely higher than the lower class devices discussed in replies above. As shimon indicated, the need for a usability study is unique per the device's intended use, performance characteristics, risk controls, etc. You claim that the use is very simple and straight forward... what is the basis for this / would that be true for any user? Can you use this as a justification for why no usability studies are conducted? You say *almost* no training required.. so it makes me think there is some room for error. How does the device compare to the market (i.e. - what is the State of the Art)? If your device is State of the Art, and its use is likely to be well understood by most clinicians, then I can see that a sound justification for not performing usability studies.