Project Summary/Abstract
Cerebrovascular disease is the 2nd leading cause of mortality in the world showing 17.2% in 2019. Approximately
795,000 strokes occur in the US every year, which are projected to expand to 1.25 million cases by 2025. Current
approaches to treat intracranial blood vessels include medical, surgical, and endovascular methods. Among
them, endovascular technologies with clot retriever thrombectomy devices, flow diverters, and embolization coils,
etc. have been widely used to treat cerebrovascular disease since they are less invasive, more effective, and
less risky. The typical endovascular sequence uses a micro guidewire to access target lesions, followed by
tracking a catheter over the wire. However, even skilled interventionalists often encounter difficulties in
translating proximal catheter/guidewire movements into anticipated movements at its distal end due mainly to
unpredictable jerky and whipping motions of the pre-bent guidewire tip, particularly while navigating narrow and
winding pathways. These issues cause prolonged operational procedures that increase the risk to expose
interventionalists and patients to a high level of harmful X-ray radiation. To mitigate these issues in the current
endovascular procedures, automated steering methods of guidewires have been introduced. As of today,
however, a clinically practical solution for an ultra-low profile, simple, remotely controlled, automated steerable
guidewire for neurointerventional procedures, which does not need to alter the materials or increase the overall
dimensions in commercial endovascular products, is lacking.
In this project, we will develop an innovative Robot-guided system that allows for easy and rapid delivery of
guidewires in challenging tortuous and complex neurovascular anatomy. The proposed Robot is based on
acoustic streaming that generates sufficient forces to steer guidewires three dimensionally and can be easily
integrated to the distal tip of existing commercial guidewires. Steering the proposed Robot guidewires can be
achieved by simply switching the frequency and amplitude of acoustic waves from a static, compact, remote
acoustic source (similar to the clinically well-proven ultrasound imaging probe), not requiring any bulky actuator
or robotic arm. Thus, the overall system is ultra-low profile, cost-effective, and safe to the human body, being
expected to allow for full robotic/telerobotic neurovascular interventions substantially reducing the total procedure
time and thus minimizing the exposure to harmful X-ray radiation. To materialize the proposed innovated
concept, task plans are established (1) to determine design parameters in Robot guidewires using a commercial
CFD (computational fluid dynamics) package, (2) to fabricate Robot prototypes utilizing a 2-photon
polymerization-based 3-D printer, (3) to integrate fabricated Robot prototypes to commercial guidewires and
characterize their steering motions, and (4) to assess the maneuverability performance of the Robot guidewire
using a preclinical in vitro test platform that accurately replicates complex human cerebral artery environments.
