Steerable segmented endoscope and method of insertion

#The present invention relates generally to endoscopes and endoscopic medical procedures. More particularly, it relates to a method and apparatus to facilitate insertion of a flexible endoscope along a tortuous path, such as for colonoscopic examination and treatment.

#An endoscope is a medical instrument for visualizing the interior of a patient's body. Endoscopes can be used for a variety of different diagnostic and interventional procedures, including colonoscopy, bronchoscopy, thoracoscopy, laparoscopy and video endoscopy.

#Colonoscopy is a medical procedure in which a flexible endoscope, or colonoscope, is inserted into a patient's colon for diagnostic examination and/or surgical treatment of the colon. A standard colonoscope is typically 135-185 cm in length and 12-19 mm in diameter, and includes a fiberoptic imaging bundle or a miniature camera located at the instrument's tip, illumination fibers, one or two instrument channels that may also be used for insufflation or irrigation, air and water channels, and vacuum channels. The colonoscope is inserted via the patient's anus and is advanced through the colon, allowing direct visual examination of the colon, the ileocecal valve and portions of the terminal ileum. Insertion of the colonoscope is complicated by the fact that the colon represents a tortuous and convoluted path. Considerable manipulation of the colonoscope is often necessary to advance the colonoscope through the colon, making the procedure more difficult and time consuming and adding to the potential for complications, such as intestinal perforation. Steerable colonoscopes have been devised to facilitate selection of the correct path though the curves of the colon. However, as the colonoscope is inserted farther and farther into the colon, it becomes more difficult to advance the colonoscope along the selected path. At each turn, the wall of the colon must maintain the curve in the colonoscope. The colonoscope rubs against the mucosal surface of the colon along the outside of each turn. Friction and slack in the colonoscope build up at each turn, making it more and more difficult to advance and withdraw the colonoscope. In addition, the force against the wall of the colon increases with the buildup of friction. In cases of extreme tortuosity, it may become impossible to advance the colonoscope all of the way through the colon.

#FIG. 1 shows a prior art colonoscope being employed for a colonoscopic examination of a patient's colon.

#FIG. 2 shows a first embodiment of the steerable endoscope of the present invention.

#FIG. 3 shows a second embodiment of the steerable endoscope of the present invention.

#FIG. 1 shows a prior art colonoscope 500 being employed for a colonoscopic examination of a patient's colon C. The colonoscope 500 has a proximal handle 506 and an elongate body 502 with a steerable distal portion 504. The body 502 of the colonoscope 500 has been lubricated and inserted into the colon C via the patient's anus A. Utilizing the steerable distal portion 504 for guidance, the body 502 of the colonoscope 500 has been maneuvered through several turns in the patient's colon C to the ascending colon G. Typically, this involves a considerable amount of manipulation by pushing, pulling and rotating the colonoscope 500 from the proximal end to advance it through the turns of the colon C. After the steerable distal portion 504 has passed, the wall of the colon C maintains the curve in the flexible body 502 of the colonoscope 500 as it is advanced. Friction develops along the body 502 of the colonoscope 500 as it is inserted, particularly at each turn in the colon C. Because of the friction, when the user attempts to advance the colonoscope 500, the body 502′ tends to move outward at each curve, pushing against the wall of the colon C, which exacerbates the problem by increasing the friction and making it more difficult to advance the colonoscope 500. On the other hand, when the colonoscope 500 is withdrawn, the body “502” tends to move inward at each curve taking up the slack that developed when the colonoscope 500 was advanced. When the patient's colon C is extremely tortuous, the distal end of the body 502 becomes unresponsive to the user's manipulations, and eventually it may become impossible to advance the colonoscope 500 any farther. In addition to the difficulty that it presents to the user, tortuosity of the patient's colon also increases the risk of complications, such as intestinal perforation.

#FIG. 2 shows a first embodiment of the steerable endoscope 100 of the present invention. The endoscope 100 has an elongate body 102 with a manually or selectively steerable distal portion 104 and an automatically controlled proximal portion 106. The selectively steerable distal portion 104 can be selectively steered or bent up to a full 180 degree bend in any direction. A fiberoptic imaging bundle 112 and one or more illumination fibers 114 extend through the body 102 from the proximal end 110 to the distal end 108. Alternatively, the endoscope 100 can be configured as a video endoscope with a miniaturized video camera, such as a CCD camera, positioned at the distal end 108 of the endoscope body 102. The images from the video camera can be transmitted to a video monitor by a transmission cable or by wireless transmission where images may be viewed in real-time or recorded by a recording device onto analog recording medium, e.g., magnetic tape, or digital recording medium, e.g., compact disc, digital tape, etc. Optionally, the body 102 of the endoscope 100 may include one or two instrument channels 116, 118 that may also be used for insufflation or irrigation, air and water channels, and vacuum channels. The body 102 of the endoscope 100 is highly flexible so that it is able to bend around small diameter curves without buckling or kinking while maintaining the various channels intact. When configured for use as a colonoscope, the body 102 of the endoscope 100 is typically from 135 to 185 cm in length and approximately 12-13 mm in diameter. The endoscope 100 can be made in a variety of other sizes and configurations for other medical and industrial applications.

#A proximal handle 120 is attached to the proximal end 110 of the elongate body 102. The handle 120 includes an ocular 124 connected to the fiberoptic imaging bundle 112 for direct viewing and/or for connection to a video camera 126 or a recording device 127. The handle 120 is connected to an illumination source 128 by an illumination cable 134 that is connected to or continuous with the illumination fibers 114. A first luer lock fitting, 130 and a second luer lock fitting 132 on the handle 120 are connected to the instrument channels 116, 118.