APPARATUS AND METHODS FOR AUTOMATED
SEQUENTIAL MOVEMENT CONTROL FOR
OPERATION OF A REMOTE NAVIGATION
CROSS-REFERENCE TO RELATED
 This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/702,482, filed Jul. 26, 2005, the entire disclosure of which is incorporated herein by reference.
 The present invention relates to remote navigation systems that remotely actuate medical devices, and in particular to methods of automation of sequential device movements in the operation of remote navigation systems.
 Remote navigation systems which remotely orient the distal end of an elongate medical device in a selected direction are making medical navigation through the body faster and easier, and are allowing physicians to reach locations that could not be reached with conventional manual devices. These remote navigation systems also allow for the automation of navigation, which is useful in a number of diagnostic and therapeutic procedures, including mapping.
 Medical procedures such as minimally interventional diagnosis and treatment of cardiac arrhythmias in electrophysiology often involve steering a localized medical device such as a catheter within anatomical regions in order to create a geometrical representation or map of the anatomical chamber of interest. In such a procedure, a localized catheter is steered to various sites within the anatomical chamber, and the three dimensional coordinates at each such location are recorded by a localization system after confirming that the device is indeed in contact with an internal wall, thereby providing data for the creation of a geometric map of the internal surface of the chamber. Wall contact confirmation is provided, for instance, from intra-cardiac ECG data, for which purpose the catheter is also equipped with ECG recording electrodes. An example of a system that helps create such a map is the CARTOTM EP Mapping system manufactured by Biosense Webster Inc., wherein the system renders a continuous interpolated surface given a discrete set of "visited" interior or internal surface points as input.
 This type of procedure is commonly performed "by hand" with a manually steered catheter, and so it can be a laborious process; a typical map can have in excess of 80 or 100 points. With the recent advent of remote navigation systems such as the Niobe® Magnetic Navigation System manufactured by Stereotaxis, Inc. of St. Louis, Mo., it is possible to automate the navigation process needed to create a map, or a portion of a map, providing a significant increase in procedural efficiency for the physician.
 There are several types of remote navigation systems. Each typically includes an orientation system for orienting the distal end of a medical device and a positioning system which advances and retracts the medical device. One
such system is a magnetic navigation system which uses one or more external magnets (electromagnets or compound permanent magnets). To project a field into the operating region in a subject to act on magnetically responsive elements in the distal end of the medical device to orient the distal end in a selected direction. A device positioning system advances and retracts the medical device.
 Another remote navigation system is a mechanical navigation system which uses a guide which is mechanically operated (with push wires, pull wires, gears, other mechanical elements) to a selected direction. A positioning system advances and retracts a medical device through the guide in a selected direction. Although not nearly as capable as magnetic navigation systems, such systems can be developed by Stereotaxis, Inc. and others.
 Other remote navigation systems under development include electrostrictive, magnetostrictive and fluid pressure systems for remotely orienting the distal end of a medical device.
 Efforts are being continually made to improve the ability to control remote navigation systems, and in particular to facilitate communication between the physician and the system.
 This invention, in one aspect, is directed to a method of controlling automated operation of a remote navigation system including an orientation system and a positioning system. A sequence of automated movement "building blocks" or primitives are defined on the system by a user in order to execute a series of sequential device movements of a medical device within a patient anatomy in automated fashion. Some embodiments of the present invention provide methods of, and graphics user interfaces and controllers for, operating remote navigation systems.
 According to one aspect of this invention, methods of operating remote navigation systems which have orientation and positioning systems are provided that can implement one or more of the following:
 1. Setting a retraction limit for the positioning system to ensure that the medical device is not inadvertently withdrawn from a location (e.g. a chamber of the heart) during automated movements.
 2. Advancing the positioning system to an absolute length. Based on a calibrated device length, the positioning system is operated to advance or retract the device until a desired length is achieved. This is useful at the start of a series of movements to ensure that the movement pattern is starting from a known position.
 3. Moving a relative amount. The positioning system is advanced or retracted a specified length (preferably in mm). This is useful in implementing drag operations (dragging the distal end of the device on an anatomical surface as is done in certain mapping and ablation procedures) and could be combined with orientation changes to create multistep motions.
 4. Setting orientation. This operates the orientation system to orient the distal end of the device in a selected orientation. In the case of a magnetic navigation system this