Applied for in US.
Patent application number 20070224684
First granted in US.
Patent number 6,949,069
First granted in US.
Patent Number 6,679,839
First granted in US.
Patent Number 6,530,882
First granted in US.
Patent Number 6,496,309
First granted in US.
Patent Number 6,450,949
First granted in the UK
Patent number GB2323679
First granted in the UK.
Patent Number GB2323680
First granted in the UK.
Patent number GB2323681
First granted in the UK.
US patent number 4,015,235