Anyone heard of the 'Wheel of Consent'?

The thing I found intriguing about the Conscious Connections workshop description I recently mentioned was the idea of the 'wheel of consent'.

Some googling shows this is derived from something conceived by Betty Martin.

I have never had any sort of sexual/sensual/intimate experiences where anything like it has ever, to my awareness, consciously played a part.

Who here knows about it, and understands how it fits into a bigger picture of sex and sexuality?