Large and staghorn renal calculi (kidney stones) are best treated through Percutaneous Nephrolitotomy (PCNL), a minimally invasive procedure that removes the stones via a small percutaneous, usually in the lumbar region or in the flank. As surgeons must avoid critical anatomical structures such as the colon, spleen, liver, and lung, the use of the conventional PCNL rigid and straight tools often results in incomplete stone removal and has a higher associated complication rate. In this vein, we have designed a handheld concentric tube robot dedicated to treating renal calculi minimally invasively.