In conventionally used bulls eye and triangulation techniques, the exact depth of penetration and the angle of trajectory to be employed cannot be predicted and hence it usually causes over or under insertion of the needle leading to potential complications. The Rawandales Percutaneous Access Trigonometry System (PATS) is useful for achieving a successful initial puncture and decreasing the learning curve of initial puncture since the linear distance Y to be traversed in millimetres by the needle to reach the calyx is indicated by the scale on Part D-m.. By using this device a safe, fast, efficient and cost effective successful renal puncture can be safely created and successful percutaneous surgery performed. Procedure for using the The Rawandales Percutaneous Access Trigonometry System (PATS) 1. Patient under anaesthesia is placed in prone position 2. The Rawandales Percutaneous Access Trigonometry System (PATS) is fixed to the operating table as in fig 1. The PATS is adjusted just above the back of the patient. 3. With the fluoroscopy in the postero anterior (vertical or 0 degrees) position zero degree guide point is aligned on the target site, till the radio opaque marker is over the target calyx and just touching the skin. This is done by adjusting limbs A-f, B and C using the adjusting knobs. 4. The rotation angle of the parts of the thirty degree guide is adjusted at 30�. The fluoroscopy is then positioned 30 degrees towards the operating surgeon and limb D used to align thirty degrees guide point over the target site, using the adjusting knobs, but without moving the zero degree guide from its set position. 5. A stab incision is then taken over the skin corresponding to thirty degrees guide point 6. The linear distance Y to be traversed in millimetres by the needle to reach the calyx is then indicated by the scale on Part D-w. The reference table is based on the principles of trignometry for a right angled triangle. (Formula, 7. The needle is then inserted t
