Fully Actuated Body-Mounted Robotic System for MRI-Guided Lower Back Pain Injections: Initial Phantom and Cadaver Studies

Abstract

This paper reports the improved design, system integration, and initial experimental evaluation of a fully actuated body-mounted robotic system for real-time MRI-guided lower back pain injections. The 6-DOF robot is composed of a 4-DOF needle alignment module and a 2-DOF remotely actuated needle driver module, which together provide a fully actuated manipulator that can operate inside the scanner bore during imaging. The system minimizes the need to move the patient in and out of the scanner during a procedure, and thus may shorten the procedure time and streamline the clinical workflow. The robot is devised with a compact and lightweight structure that can be attached directly to the patient's lower back via straps. This approach minimizes the effect of patient motion by allowing the robot to move with the patient. The robot is integrated with an image-based surgical planning module. A dedicated clinical workflow is proposed for robot-assisted lower back pain injections under real-time MRI guidance. Targeting accuracy of the system was evaluated with a real-time MRI-guided phantom study, demonstrating the mean absolute errors (MAE) of the tip position to be 1.50±0.68mm and of the needle angle to be 1.56±0.93°. An initial cadaver study was performed to validate the feasibility of the clinical workflow, indicating the maximum error of the position to be less than 1.90mm and of the angle to be less than 3.14°.

Body-Mounted Robotics for Interventional MRI Procedures

“…In addition, the needle driver can be manipulated in the motorized or manual mode by engaging or disengaging the gears transmission of the actuation unit; Therefore, it can increase the safety if the motors fail, and facilitate the learning curve because the clinicians can place the needle manually as they do in conventional clinical practice. A detailed description of the mechanical design was reported in [9], [10].…”

“…The first robot is a 4 DOF (degree of freedom) system called ArthroBot for shoulder arthrography in pediatric patients [8]. The second robot is a 6 DOF system called PainBot for perineural injections used to treat pain in adult and pediatric patients [9], [10]. The major contributions of this paper include: 1) development of a unified robotic framework to support the clinical workflow of interventional MRI procedures with modular design principles, 2) creation of a dedicated clinical workflow for MRI-guided musculoskeletal procedures using body-mounted robots, and 3) verification of the feasibility of the framework and validation of the clinical workflow with initial cadaver torso studies using both ArthroBot and PainBot.…”

Current State of Robotics in Interventional Radiology

“…In addition to the MRI-guided robotic systems mentioned here, there are numerous other robotic systems that have or are currently undergoing further testing in different interventions, such as for prostate biopsies [ 67 , 68 ], breast biopsy [ 69 – 71 ], lumbar spine injections [ 72 ], shoulder arthrography [ 73 , 74 ], and neuroablation [ 75 ].…”

State of the Art and Future Opportunities in MRI-Guided Robot-Assisted Surgery and Interventions

“…Although ultrasound is free of ionizing radiation, it is userdependent, and good nerve visualization can be technically difficult, especially for nerves in and around the bony structures of the spine and deep nerves, such as those in the pelvis. Our research groups at the Children's National Hospital and the Johns Hopkins University have developed an MRI-compatible body-mounted robot to allow interventional radiologists to position and manipulate the needle, while the patient is in the bore of the magnet [48], [49], as shown in Fig. 3(a).…”

“…The targeting accuracy of the system was evaluated with a real-time MRIguided phantom study, demonstrating the mean absolute errors of the tip position to be 1.50 ± 0.68 mm and the needle angle to be 1.56 ± 0.93 • . An initial cadaver study was performed to validate the feasibility of the clinical workflow, indicating the maximum error of the position to be less than 1.90 mm and the angle to be less than 3.14 • [49].…”