An orientation module (RCM) is added between the support arm and the needle driver (PAKY) for the purpose of changing the orientation of the needle. The entire system is manually placed with the ARM so that the point of the needle is located at the skin entry point. The RCM module can orient the needle in two directions (R1 and R2) while maintaining the fixed location of the needle point (RCM Point). Needle insertion is performed with PAKY (T).

ARM + RCM + PAKY

Safety is ensured by the decoupling of the orientation and insertion mechanisms so that PAKY and RCM may not be simultaneously enabled. This guarantees that insertion is not performed while orienting and orientation is locked while inserting the needle. In addition needle orientation is only performed while the needle is outside the body, so that the system may not inadvertently cause injury to any structure outside the needle’s trajectory.

Under joystick control the system tested with better than 2 mm targeting accuracy and it was subsequently used in a clinical study for percutaneous nephrolithotomy. This study included 46 patients and compared percutaneous access achieved by the robot to conventional, manual access gaining techniques. When comparing PAKY-RCM with standard manual techniques, the mean number of attempts was 2.2±1.6 vs. 3.2±2.5 (P=0.14), time to access was 10.4±6.5 minutes vs. 15.1±8.8 minutes (P=0.06), estimated blood loss score was 1.3±0.49 vs. 1.7±0.66 (P=0.14), and color of effluent urine following access was 2.0±0.90 vs. 2.1±0.7 (P=0.82). The study showed that the number of attempts and time to access were slightly better with the robot than those of standard percutaneous access techniques.