Peut être couvert par l'un des brevets américains suivants :
4,797,916
5,426,690
5,650,790
5,660,269
5,754,407
5,758,289
5,893,034
5,912,968
6,070,082
6,125,277
6,782,098
6,788,920
6,953,118
7,023,176
Autres brevets en instance.
5,434,905
5,491,745
5,661,780
5,663,981
5,768,345
5,787,356
5,915,227
5,929,598
6,253,088
6,314,278
6,788,953
6,839,550
7,203,307
7,206,403
5,493,605
5,533,010
5,671,248
5,696,471
5,794,152
5,801,466
5,930,720
5,960,358
6,418,209
6,618,015
6,889,184
6,901,271
66
5,574,727
5,581,598
5,717,312
5,732,355
5,825,161
5,864,619
5,987,330
6,044,281
6,671,315
6,714,630
6,907,094
6,914,940