PAKY is a new robotic surgical device developed in 1996 at the Johns Hopkins University for Percutaneous Access to the KidneY.

Unlike traditional open surgery, percutaneous (through the skin) needle access procedures offer several advantages, including reduction of patient pain, recovery time, and morbidity. Successful percutaneous procedures require enormous skill --- the surgeon must manually insert a needle to a desired point in a patients's body, guided only by feel and by grainy fluoroscopic x-ray images, all while avoiding collateral injury.

Our goal was to develop a system to improve the accuracy and precision during percutaneous renal access. To achieve this we focused on:

needle placement accuracy,
procedure duration,
patient safety,
sterility, and

surgeon radiation exposure.

The result is a robotic surgical device called PAKY (for Percutaneous Access to the KidneY). PAKY mimics the urologist's manual procedure yet increases its safety, speed, and accuracy. The key advantages of this approach are that it employs a proven radiological needle alignment procedure, improves accuracy in comparison to purely manual placement, and enables lateral fluoroscopic monitoring of the needle.

The image to the right shows PAKY mounted in position in the operating room. PAKY is mounted directly on the operating room table. The fluoroscopic x-ray arm (called a "C-arm") used by the surgeon is visible in this image.

This is a typical fluoroscopic X-Ray image of PAKY in use. The spine is visible on the right of the image. The outline of PAKY's radiolucent plastic disk can bee seen to the left of center of the image. The surgeon's percutaneous needle is positioned normal to the viewing plane and is seen as a light dot just to the left of center.
This is a "side-view" fluoroscopic X-Ray image of PAKY taken from a 45 degree angle with respect to the needle axis. Note the following: (1) the difficulty with which the kidney is seen on this X-ray; (2) the needle entering the image from the lower-left, with tip terminating in the caelix of the kidney; and (3) a catheter entering the image from the bottom has been inserted into the kidney.

PAKY will soon begin clinical trials.

JHU is has recently filed for patents on this device, and will be licensing it to a major medical instrument manufacturer.

References

Dan Stoianovici and Jefferey A. Cadeddu and Roger D. Demaree and Stephen A. Basile and Russell H. Taylor and Louis L. Whitcomb and William N. Sharpe nd Louis R. Kavoussi. An Efficient Needle Injection Technique and Radiological Guidance Method for Percutaneous Procedures. In Proceedings of the FirstJoint Conference of Computer Vision, Virtual reality, and Robotics II (CVRMed II) and Medical Robotics and Computer Assisted Surgery III (MRCAS III)", March 1997, Grenoble, France. (Accepted, to appear).
Dan Stoianovici and Jefferey A. Cadeddu and Roger D. Demaree and Stephen A. Basile and Russell H. Taylor and Louis L. Whitcomb and William N. Sharpe and Louis R. Kavoussi. A Novel Mechanical Transmission Applied to Percutaneous Renal Access. In Proceedings of the 1997 ASME Winter Annual Meeting (Under Review).