Patent ID: 7641658

Claim:
A cutting device comprising: a blade pivotally connected to the distal end of a flexible shaft; a locking sleeve surrounding at least part of the flexible shaft; a sheath having a beveled distal end and surrounding at least part of the flexible shaft; where the cutting device can be inserted into a material to be cut after accessing the material through a channel comprising a substantially straight proximal section having a long axis and distal section having a long axis; and where the long axis of the distal section is curved, or where the long axis of the distal section is substantially straight but varies at least about 10° off of the long axis of the proximal section; where the blade pivots at least about 90° with respect to a long axis of the distal end of the flexible shaft from a first, insertion position to a second, cutting position; where the blade has one or more than one notch; where the locking sleeve can be advanced distally and retracted proximally; where advancement distally causes the locking sleeve to engage with the one or more than one notch, thereby locking the blade into the cutting position, and retraction proximally causes the locking sleeve to disengage from the one or more than one notch, thereby unlocking the blade from the cutting position; where the flexible shaft can be advanced distally and retracted proximally relative to the sheath; and where retraction proximally of the flexible shaft causes the blade to disengage from the locking sleeve and pivot to the insertion position.