An magnetic resonance conditional robot for lumbar spinal injection: Development and preliminary validation

PurposeThis work presents the design and preliminary validation of a Magnetic Resonance (MR) conditional robot for lumbar injection for the treatment of lower back pain.MethodsThis is a 4-degree-of-freedom (DOF) robot that is 200 x 230 x 130 mm3 in volume and has a mass of 0.8 kg. Its lightweight and compact features allow it to be directly affixed to patient's back, establishing a rigid connection, thus reducing positional errors caused by patient movements during treatment.ResultsTo validate the positioning accuracy of the needle by the robot, an electromagnetic (EM) tracking system and a needle with an EM sensor embedded in the tip were used for the free space evaluation with position accuracy of 0.88 +/- 0.46 mm and phantom mock insertions using the Loop-X CBCT scanner with target position accuracy of 3.62 +/- 0.92 mm.ConclusionPreliminary experiments demonstrated that the proposed robot showed improvements and benefits in its rotation range, flexible needle adjustment, and sensor protection compared with previous and existing systems, offering broader clinical applications.