Fig. 5: Biopsy introducer robot actuated by MRI-compatible electromagnetic servomotor.

a Schematic of single degree-of-freedom biopsy introducer robot prior to introducer insertion. b Schematic showing maximum insertion depth. Sheath holder allows introducer sheath position to be maintained during removal of cutting stylet. c Photograph of biopsy introducer robot with MRI-compatible servomotor. d Zoomed in photograph showing Vernier scale on a linear slide with 0.1 mm increments. This Vernier scale is used for system calibration when the robot is first powered on. e Photograph of biopsy robot in the MRI scanner where introducer was replaced with a mock introducer and a tip marker that can be imaged with MRI. Servomotor was used to advance the mock introducer in a controlled manner during continuous imaging at 5 frames per second. Simultaneously acquired coronal images showing movement of tip marker are shown at 1 s increments during actuation in (f–j).