Abstract: An image guided surgery system to enable a surgeon to move a surgical tool into a desired position relative to a body part is provided. The system works by accurately superimposing representations of the tool being used in the surgical field over images of the body part such that real-time tool position feedback is provided to the surgeon. The system uses a fluoroscopic x-ray device to generate two-dimensional body part images, a localizing device to determine the poses of surgical tools and the x-ray device, mathematical modeling of the imaging chain of the x-ray device, and a means for displaying the images of the body part superimposed with representations of the surgical tools. A related feature is the use of a digital flat-panel x-ray imager that employs a regular array of sensors to convert incident x-ray energy to a computer readable image, thereby permitting the fluoroscopic x-ray device to be used in any orientation without being affected by distortions due to local magnetic fields.

Abstract: In a procedure for the treatment of carpal tunnel syndrome, the carpal ligament is spread by use of a cutting device passing through the interior of a cannula inserted into the carpal tunnel through an incision in the patient's wrist, the cannula containing an inflatable balloon at its distal end to secure the position of the cutting device against the carpal ligament, and the cutting device comprising a blade whose position is remotely controlled from the proximal end of the device. Other features of the procedure are the use of a blunt-tipped hypodermic needle and exchange wire to establish a path to the site under the carpal ligament, an endoscope or other visualization device to be inserted through the cannula with the cutting device, and a removable sheath over the cannula to contain the inflatable balloon until inflation is desired.