Adjustable cannula systems and devices

Abstract

Various adjustable cannula systems are provided. The systems can include an adjustable cannula capable of expansion and/or contraction having an elongate body with a distal end and a proximal end. The adjustable cannula can be coupled to an upper housing and a lower housing such that rotation of the upper housing results in expansion or contraction of the adjustable cannula. The adjustable cannula can also have a proximal end having a lumen larger than a distal end lumen. A plurality of flanges can be formed in the elongate body by a plurality of slits that span a majority of a length of the cannula, including along or proximate to its proximal end and distal end.

1 - 32 . (canceled) 
     
     
         33 . A cannula system configured to be anchored in the pars plana of an eyeball, the system comprising an expandable member that increases upon application of electrical energy having a first polarity to the expandable member, and that decreases upon application of electrical energy having a second polarity to the expandable member, the second polarity opposite the first polarity. 
     
     
         34 . The cannula system of  claim 33 , wherein a proximal end of the expandable member is coupled to an electrical energy source, and wherein the expandable member increases or decreases from one gauge to another when electrical energy is applied by the electrical energy source. 
     
     
         35 . The cannula system of  claim 34 , comprising the electrical energy source. 
     
     
         36 . The cannula system of  claim 33 , further comprising an insulating layer configured to inhibit the electrical energy from injuring surrounding tissue. 
     
     
         37 . An adjustable cannula system comprising:
 a housing;   an expandable member coupled to the housing, the expandable member including a proximal portion and a distal portion, wherein the proximal portion has a larger cross-sectional area than the distal portion in an unexpanded state; and   a plurality of folds extending along a portion of the expandable member such that the folds form a plurality of edge points, wherein the folds are configured to accommodate expansion of the expandable member.   
     
     
         38 . The adjustable cannula system of  claim 37 , wherein the distal end of the expandable member comprises outer edge points and inner edge points. 
     
     
         38 . The adjustable cannula system of  claim 37 , wherein, upon expansion of the expandable member, the expandable member has a substantially smooth surface.