Utility
Subclass Subgroup Patent
A61K 8/21 09808406
B01D 17/0205 09808741
C12Q 1/6886 09809859
E21B 47/124 09810058
F16L 11/133 09810351
  59/029 09810366
F17C 9/02 09810376
G05F 1/10 09811099
H02M 1/36 09812948
H04R 3/005 09813811