M
Hi Once Again, 
We are presently developing an active therapeutic device, and would like to know what the MDD classification would be.
So, to the MDD 93/42/EEC, Annex IX we go...
And for our device the determining rule is Rule 9 (3.1) which states:
"All active therapeutic devices intended to administer or exchange energy are in Class IIa unless their characteristics are such that they may administer or exchange energy to or from the human body in a potentially hazardous way, taking account of the nature, the density and site of application of the energy, in which case they are in Class IIb."
So, then, the question is what constitutes "potentially hazardous"? I presume the interpretation of this would be left to an NB?
It is frustrating that this is so vague. It may explain why my research into similar existing devices on the market seem to show no consistent classification of either IIa or IIb (different NB's interpreting differently?).
Are the "nature, the density and site of application" referring only to intended use and non-fault conditions? If so, our preliminary risk analysis and assessment indicates that the current delivered is sufficiently low that electrical-hazards are mitigated. Also, the energy delivered is only intended for peripheral limbs, and is intended to be delivered transcutaneously only.
Is this sufficient arguement to argue in favor of a Class IIa classification?
Anyone out there have any experience with the interpretation of this particular classification rule?
Thanks in advance,
MM.

We are presently developing an active therapeutic device, and would like to know what the MDD classification would be.
So, to the MDD 93/42/EEC, Annex IX we go...
And for our device the determining rule is Rule 9 (3.1) which states:
"All active therapeutic devices intended to administer or exchange energy are in Class IIa unless their characteristics are such that they may administer or exchange energy to or from the human body in a potentially hazardous way, taking account of the nature, the density and site of application of the energy, in which case they are in Class IIb."
So, then, the question is what constitutes "potentially hazardous"? I presume the interpretation of this would be left to an NB?
It is frustrating that this is so vague. It may explain why my research into similar existing devices on the market seem to show no consistent classification of either IIa or IIb (different NB's interpreting differently?).
Are the "nature, the density and site of application" referring only to intended use and non-fault conditions? If so, our preliminary risk analysis and assessment indicates that the current delivered is sufficiently low that electrical-hazards are mitigated. Also, the energy delivered is only intended for peripheral limbs, and is intended to be delivered transcutaneously only.
Is this sufficient arguement to argue in favor of a Class IIa classification?
Anyone out there have any experience with the interpretation of this particular classification rule?
Thanks in advance,
MM.