Development of a 6 DOF MR Compatible Robot for Gross Body Motion of an Anthropomorphic Fetal MRI Phantom

In the US, birth defects result in over 139,000 hospitalizations, costing $2.6B and leaving the patient with lifelong treatments, disabilities, illness, or even death, which can largely impact the individual and their family’s life. MRI anthropomorphic phantoms can accelerate and enhance the development of sequences and image processing algorithms, improving diagnostic and treatment efficacies. Our lab has evaluated the existing fetal MRI phantoms, revealing that 7% include physiological motion. In response to this, we have developed a 6 DOF robot to integrate physiological motion for a fetal phantom used in the gravid abdomen. This robot has been tested to have a positioning accuracy of ±2.1 mm (SD 0.87 mm) and orientation accuracy of ±1.7° (SD 2.9°). After acquiring MR images, the robot has been shown to degrade image SNR less than 2% with a maximum B0 variation of 1 ppm, supporting its MR compatibility and minimal impact on images.<p></p>