Abstract: Medical devices and methods of using medical devices are disclosed. An example tissue retraction device includes a first engagement member having a first end and a second end, a second engagement member having a first end and a second end, a first elastic member attached to the second end of the first engagement member, and a first alignment member having a first end, a second end and a lumen extending therethrough. Further, the tissue retraction device has a first length, the first alignment member has a second length, the first elastic member extends within the lumen of the first alignment member and the second length of the first alignment member is less than or equal to the first length of the tissue retraction device.

Abstract: A method that provides increased flexibility to measure dynamic range of a rotating system is provided. The method includes the steps of: providing a first rotating member; providing a second rotating member suitably engaged to the first rotating member; providing a set of sensors disposed to sense variations in characteristics along a circumference of the first member and the second member respectively; providing a controller for receiving information sensed by the sensors; determining a rate of rotation of the rotating members; selectively using the sensed information thereby at different rate of rotation different amount of the sensed information is used.