Peut être couvert par l'un ou plusieurs des brevets américains suivants :
4,797,916
5,426,690
5,660,269
5,663,981
5,787,356
5,794,152
5,929,598
5,930,720
6,253,088
6,314,278
6,788,920
6,788,953
6,953,118
7,023,176
Autres brevets en instance.
5,491,745
5,493,605
5,671,248
5,717,312
5,801,466
5,825,161
5,960,358
5,987,330
6,321,068
6,418,209
6,839,550
6,889,184
7,030,819
7,146,160
5,533,010
5,574,727
5,732,355
5,754,407
5,864,619
5,893,034
6,044,281
6,070,082
6,618,015
6,671,315
6,901,271
6,907,094
7,203,307
7,206,403
5,581,598
5,650,790
5,758,289
5,768,345
5,912,968
5,915,227
6,076,052
6,125,277
6,714,630
6,782,098
6,914,940
6,940,867