US 12,127,972 B2
Cannulas for ophthalmic procedures
Ashish Sinha, Irvine, CA (US); and Robert Jeffrey Heng, Lake Forest, CA (US)
Assigned to Alcon Inc., Fribourg (CH)
Filed by Alcon Inc., Fribourg (CH)
Filed on Jun. 8, 2022, as Appl. No. 17/805,896.
Claims priority of provisional application 63/223,645, filed on Jul. 20, 2021.
Prior Publication US 2023/0022895 A1, Jan. 26, 2023
Int. Cl. A61F 9/00 (2006.01); A61F 9/007 (2006.01)
CPC A61F 9/0008 (2013.01) [A61F 9/007 (2013.01); A61B 2217/007 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A cannula device system for a surgical procedure comprising:
a valved cannula comprising a hub, a shaft, and a cannula transition between the hub and the shaft;
a viscous fluid control (VFC) cannula, comprising:
a proximal segment comprising a first inner diameter (ID), a first proximal end, and a first distal end; and
a distal segment comprising a second ID smaller than the first ID, a second proximal end, and a second distal end terminating inside the hub of the valved cannula, wherein a gap is formed between the distal segment and the hub sufficient to allow injected fluid to backflow out of the valved cannula when a pressure in an eye is higher than a pressure exerted on the injected fluid;
wherein the proximal segment and the distal segment have a common central axis disposed through a center of the VFC cannula;
wherein a first transition connecting the proximal segment and the distal segment via the first distal end and the second proximal end comprises a first concave fillet and a second convex fillet;
wherein a ratio of a length of the distal segment to a total length of the VFC cannula is approximately in a range of 0.2 to 0.4; and
wherein a positional angle between the central axis and a tangential line through a midpoint of the first concave fillet is approximately in a range of 20 and 40 degrees.