A medical device allows movement control of a distal end portion of the medical device and is adapted for one-handed operation. The medical device is capable of omni-directional control of the distal end portion of the device. The device has an elongated member including a deflectable portion at a distal end portion of the elongated member. The device also has a control portion disposed on the elongated member. This control portion can be a handle for one-handed use by an operator of the medical device. The control portion comprises an elastic element and a flexible element. Angular movement of a first portion of the control portion with respect to a second portion of the control portion results in amplification of that angular movement in the deflectable portion of the device.