Miniaturization of MR Safe Pneumatic Rotational Stepper Motors Pneumatic rotational stepper motors can be used to actuate MR (magnetic resonance) safe robotic systems. This paper describes novel techniques to minimize the volumetric size andor step size of such motors in order to cope with the limited space requirements while still delivering high precision. Three designs are presented: the R10 measures 1.0 cm3, has step size 12.9xc2xb0 and torque 1.2 N mm. The R40 measures 25.6 cm3, has step size 1.01xc2xb0 and torque 470 N mm. The R54 measures 46.7 cm3, has step size 1.01 mxc2xb0 and torque 240 N mm. The particularly small step size in the R54 motor is achieved by using a highreduction planetary gear.These three motors demonstrate that smallscale rotational stepper motors with a wide range of step sizes and good torque characteristics can be constructed that surpass stateofart designs by a considerable margin. This allows the advancement of MR safe robotics towards more compact and versatile designs, and also overcome certain existing limitations by combining multiple motors with different specifications.

Toward a Versatile Robotic Platform for Fluoroscopy and MRIGuided Endovascular Interventions: A PreClinical Study Cardiovascular diseases remain as the most common cause of death worldwide. Remotely manipulated robotic systems are utilized to perform minimally invasive endovascular interventions. The main benefits of this methodology include reduced recovery time, improvement of clinical skills and procedural facilitation. Currently, robotic assistance, precision, and stability of instrument manipulation are compensated by the lack of haptic feedback and an excessive amount of radiation to the patient. This paper proposes a novel masterslave robotic platform that aims to bring the haptic feedback benefit on the master side, providing an intuitive user interface, and clinical familiar workflow. The slave robot is capable of manipulating conventional catheters and guidewires in multimodal imaging environments. The system has been initially tested in a phantom cannulation study under fluoroscopic guidance, evaluating its reliability and procedural protocol. As the slave robot has been entirely produced by additive manufacturing and using pneumatic actuation, MR compatibility is enabled and was evaluated in a preliminary study. Results of both studies strongly support the applicability of the robot in different imaging environments and prospective clinical translation.