A research group from the Suzhou Institute of Biomedical Engineering and Technology (SIBET) of the Chinese Academy of Sciences has developed a dual-mode magnetic intravascular ultrasound (IVUS) robot with both small size and high flexibility. 

IVUS uses guidewire technology to deliver a miniature ultrasound probe into the blood vessel, which can provide cross-sectional vascular ultrasound images. Its clinical value has been recognized worldwide. However, the miniature single-element ultrasound probe of conventional IVUS is driven by an external motor through a long flexible shaft, and faces challenges in imaging in complex vascular regions, such as inflexible manipulation and non-uniform rotation distortion. 

Therefore, research on a novel IVUS catheter with flexible manipulation and stable imaging in complex vascular areas is necessary for accurate diagnosis and treatment of cardiovascular and cerebrovascular diseases. 

The dual-mode magnetic IVUS robot developed by the SIBET team consists of a front tip and a rear catheter. The design eliminates the long flexible shaft structure, giving the robot small size and high manipulation flexibility.  

In the navigation mode, the robot performed controlled bending under the actuation of static magnetic fields and actively entered the target branch at the bifurcated blood vessel. In the imaging mode, it performed stable acoustic beam scanning under the actuation of dynamic magnetic fields, providing high-resolution ultrasound images. 

"The dual-mode magnetic IVUS robot improves both operational flexibility and imaging stability during the interventional procedure, providing a potential solution for the visualization of complex vascular structures," said CUI Yaoyao of SIBET, leading researcher of the study. 

The study entitled "Development and Control of a Dual-Mode Magnetic Intravascular Ultrasound Robot for Imaging in Tortuous Blood Vessels" was published in IEEE/ASME Transactions on Mechatronics. 

Schematic diagram of the magnetic IVUS robot. (Image by SIBET)

Prototype IVUS robot and its imaging result. (Image by SIBET)