Robotic system for dental subtraction radiography

Dental subtraction radiography requires accurate repositioning of the patient and X-ray source in order to correctly diagnose decay, movement, or bone loss. Present mechanical repositioning systems do not allow the imaging of the teeth in the back of the mouth, and are uncomfortable for the patient. A new repositioning system that utilizes a six-degree-of-freedom position sensor and a robot arm with an X-ray source is proposed. A model for the system is given, and an error analysis is performed to determine the influence of sensor and robot errors. Experiments performed to determine sensor noise and accuracy are described. Further tests showed that there is no adverse effect due to the presence of metal work in the patient´s mouth