Purpose: To develop a lightweight and portable 6-degree-of-freedom (6DoF) robotic image guided positioning system with a real-time image guided feedback for ensuring correct patient position for canine FLASH trials.
Methods: The goal of this project is a physical treatment platform design that incorporates a lightweight and portable form factor that can be moved by a single person. A simulated model for this 6DoF robotic treatment platform was constructed using Matlab. An experimental 6DoF robotic Stewart platform was designed and built using linear actuators, an embedded (microcontroller) system with dedicated firmware, motor control electronics, and a single board computer. Investigations on different 3D surface image tracking systems such as Vision RT and Microsoft's Azure-Kinect are currently underway. Since treatment sites in this project are located near the surface (dog limbs), the above-mentioned tracking technologies are expected to perform well; they are capable of tracking targets that are near or rigidly connected to the skin surface.
Results: The 6DoF platform simulation reported a motion (leg length) range of ±20 mm, which can generate ±12 mm translations (along the x, y, and z axes), and ±5 degree rotations (pitch, roll, and yaw). Additional modeling is currently underway to quantify load-dependent parameters. Several tests of the experimental prototype have reported spatial resolutions of 3.9 x 10⁻⁵ mm, 25 mm/s velocities, and 2-5 mm/s² accelerations. Additional development is required to maximize motor efficiency and communication speeds.
Conclusion: The work carried out has shown promising results for future use with a real-time image guided device for sub-millimeter positional corrections for FLASH delivery. The overall system will require the fabrication of electronic circuit boards and the design and manufacture of parts specific to the 6DoF robotic platform. Additional development will be required for an efficient closed feedback system between surface tracking measurements and positional corrections.