Stormram 3: A Magnetic Resonance Imaging-Compatible Robotic System for Breast Biopsy

Stormram 3 is a magnetic resonance imaging (MRI)-compatible robotic system that can perform MR-guided breast biopsies of suspicious lesions. The base of the robot measures 160 # 180 # 90 mm, and it is actuated by five custom pneumatic linear stepper motors, driven by a valve manifold outside the Faraday cage of the MRI scanner. All parts can be rapidly prototyped with three-dimensional (3-D) printing or laser cutting, making the design suitable for other applications, such as actuation in hazardous environments. Based on the choice of materials, the robot (with the exception of the needle) is inherently MR safe. Measurements show that the maximum force of the T-49 actuator is 70 N, at a pressure of 0.3 MPa. The Stormram 3 has an optimized repeatability that is lower than 0.5 mm, and it can achieve a positional accuracy on the order of 2 mm.