Figure 8. Evaluation of the steering and navigational performance of the telerobotically controlled magnetic guidewire in comparison with the conventional neurovascular guidewire based on manual manipulation by a neurointerventionalist.

(A) Neurointerventionalist manually manipulating a conventional neurovascular guidewire with pre-bent distal tip for twist-based steering under real-time x-ray fluoroscopy. (B) Defined navigational task for the performance comparison from the left internal carotid artery (ICA) to the inferior M2 segment of the middle cerebral artery (MCA). (C) Conventional neurovascular guidewire (Synchro 2, Stryker) with an outer diameter of 0.014 inches (360 μm) and pre-bent (shapeable) distal tip. (D) Comparison of the procedural time for the trained neurointerventionalist to complete the defined navigational task using the manually controlled passive guidewire and the telerobotically controlled magnetic guidewire over 10 consecutive trials for each experiment. The interventionalist has +4 years of training and experiences in endovascular neurointervention based on conventional guidewire manipulation and was trained with the telerobotic manipulation system for less than 1 hour (see Novice 3 in fig. S16). (E) The number of incidents with undesirable guidewire behavior such as the distal tip colliding with or looping inside aneurysms or falling into undesired branches during the given navigational task. (F) The pre-bent tip of the conventional guidewire tended to undergo unpredictable and undesirable motion while making frequent contact with the aneurysms present along the path due to the limited steering capability based on twisting maneuver. (G) The magnetic guidewire demonstrated smooth navigation in the narrow and tortuous pathways without any unintended distal tip movements or contact with the aneurysms along the navigated path due to its active steering capability. Videos for comparison of the steering and navigational performance are available in movies S7 and S8.