Physicians have often used endoscopes to examine, to biopsy, and to ablate the tissue of patients within lumens such as the esophageous and the bowel. These procedures include esophageal duodenoscopy, (EGD), colonoscopy, and polypectomy. Endoscopes used in these procedures can be several feet long and generally comprise one or more instrument channels and optical fiber bundles. The instrument channels and optical fiber bundles open into the body at the distal end of the endoscope and are generally parallel to the axis of the flexible endoscope. Physicians place flexible instruments through the instrument channels while visualizing and illuminating a site using the optical fiber bundles. The instruments have end-effectors at the distal end for performing useful therapeutic work to tissue. The instruments also provide at their proximal ends operating mechanisms for actuating the end-effectors. Such instruments placed through an instrument channel of an endoscope may include biopsy forceps for tissue sampling, electrical wires for radiofrequency ablation, or tubes used for irrigation, gas transfer, particular matter transfer, and suction.
A physician performing a therapeutic procedure with the use of an endoscope places a long, flexible instrument through the endoscope's instrument channel and then positions the instrument near the site within the body lumen where a therapeutic procedure is to be performed. The physician grasps the endoscope with one hand and introduces the flexible instrument from an entrance at the proximal end of the endoscope with the other. An assistant usually holds the proximal end of the flexible instrument and operates the mechanism at the proximal end of the instrument to actuate the end-effector.
Locating the end-effector within the lumen presents difficulties to the physician. The flexible instrument emerges from the instrument channel of the endoscope in a direction parallel to the axis of the endoscope. Many times work needs to be performed by the instrument at the inner wall of a body lumen, and at an angle to the axis of the endoscope. Much tedious maneuvering of both endoscope and instrument is needed to place the end-effector into a position to perform useful work. The flexible nature of the instrument creates difficulties in locating the end-effector at the needed position on the inner wall of the body lumen. Rotating the endoscope to accommodate the instrument causes the image on the monitor to rotate creating visualization difficulties for the physician.
When the task to be performed is a biopsy, a tissue sample or specimen must be transported away from the work site for collection. To collect the specimen, the physician pulls the entire instrument from the endoscope, removes the specimen, places the specimen into a collection jar, and replaces the instrument into the endoscope. The physician must then manipulate the instrument into a new position to take another specimen.