Ultrasound-guide prostate biopsy robot and calibration based on dynamic kinematic error model with POE formula.

In the transrectal ultrasound-guided transperineal prostate biopsy, the application of robots can effectively reduce the interference of low-quality ultrasound images on the physician to determine the biopsy route and improve the positive detection rate. In this paper, an 8-degree-of-freedom (DOF) prostate biopsy robot for clinical is developed to realize the operation of ultrasonic probe scanning, the inserting point and target lesion point positioning, and the needle insertion. Considering the dynamic errors caused by different motions of robot joints, a dynamic product-of-exponentials (POE) based kinematic model that can reflect non-geometric errors is proposed by integrating the errors into each joint. Moreover, the parameters in the model are identified by linearizing the dynamic POE-based kinematic model. Finally, the experiment shows the maximum errors can be limited to 0.60 and 1.16 mm for inserting point and needle endpoint after compensation, and the maximum inserting angle error is limited to 1.381°. It proves the feasibility of the kinematic model proposed in this paper and indicates that the robot system can meet the requirements of clinical biopsy.