• in situ bioprinting
• motion compensation
• robotics
• python
• linuxcnc
• computer vision

The purpose of the thesis is to design and develop a robotic system capable of compensating a patient generic movement, such as a beating heart, breath-induced thoracic cavity motion or sudden and unexpected motions, caused by pain, tremor or other diseases during an In Situ Bioprinting process. Based on the previous work conducted on the IMAGObot platform (a 5-D.o.F. robotic manipulator), the aim is to print on moving and non-planar surfaces, following the trajectory of a fiducial marker placed onto the patient, inside the robot workspace. To do this, a monocular vision system (featured by a webcam and fiducial markers positioned on the robot workspace) and a software interface between it and the robot controller were developed. It was entirely programmed on Python environment using the OpenCV library for markers pose estimation, and used to update the robot trajectory with respect to the detected marker motion on LinuxCNC software. Moreover, in order to mimic the physiological displacement of a patient’s rib cage due to breathing, a moving 3D-printed platform and a silicone chest phantom were produced. The work was conducted at the Research Center “E. Piaggio” of the University of Pisa.