Steerable segmented endoscope and method of insertion Number:7,087,013 from the United States Patent and Trademark Office (PTO) owispatent A steerable endoscope has an elongated body with a selectively steerable distal portion and an automatically controlled proximal portion. The endoscope body is inserted into a patient and the selectively steerable distal portion is used to select a desired path within the patient's body. When the endoscope body is advanced, an electronic motion controller operates the automatically controlled proximal portion to assume the selected curve of the selectively steerable distal portion. Another desired path is selected with the selectively steerable distal portion and the endoscope body is advanced again. As the endoscope body is further advanced, the selected curves propagate proximally along the endoscope body, and when the endoscope body is withdrawn proximally, the selected curves propagate distally along the endoscope body. This creates a serpentine motion in the endoscope body allowing it to negotiate tortuous curves along a desired path through or around and between organs within the body.<H insertion, endoscope, Steerable, segme, 7087013.html, Patent, pto, 7087013

Title: Steerable segmented endoscope and method of insertion

Abstract: A steerable endoscope has an elongated body with a selectively steerable distal portion and an automatically controlled proximal portion. The endoscope body is inserted into a patient and the selectively steerable distal portion is used to select a desired path within the patient's body. When the endoscope body is advanced, an electronic motion controller operates the automatically controlled proximal portion to assume the selected curve of the selectively steerable distal portion. Another desired path is selected with the selectively steerable distal portion and the endoscope body is advanced again. As the endoscope body is further advanced, the selected curves propagate proximally along the endoscope body, and when the endoscope body is withdrawn proximally, the selected curves propagate distally along the endoscope body. This creates a serpentine motion in the endoscope body allowing it to negotiate tortuous curves along a desired path through or around and between organs within the body.

Patent Number: 7,087,013 Issued on 08/08/2006 to Belson, et al.

Inventors: Belson; Amir (Cupertino, CA), Frey; Paul DeWitt (Redwood City, CA), McElhaney; Christine Wei Hsien (San Carlos, CA), Milroy; James Craig (Palo Alto, CA), Ohline; Robert Matthew (Redwood City, CA), Tartaglia; Joseph M. (Morgan Hill, CA)
Assignee: NeoGuide Systems, Inc. (Los Gatos, CA)

Appl. No.: 10/402,599

Filed: March 27, 2003

Related U.S. Patent Documents


Application Number	Filing Date	Patent Number	Issue Date
09969927	Oct., 2001	6610007
09790204	Feb., 2001	6468203
60194140	Apr., 2000

Current U.S. Class: 600/145 ; 600/117; 600/146

Current International Class: A61B 1/00 (20060101)

Field of Search: 600/145,146,117,150,151,152,143,144 604/95.01 901/1

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Primary Examiner: Flanagan; Beverly M.
Attorney, Agent or Firm: Wilson Sonsini Goodrich & Rosati

Parent Case Text

CROSS-REFERENCE TO OTHER APPLICATIONS

The present application is a continuation of U.S. patent application Ser. No. 09/969,927 entitled "Steerable Segmented Endoscope and Method of Insertion" filed Oct. 2, 2001, now U.S. Pat. No 6,610,007 which is a continuation-in-part of U.S. patent application Ser. No. 09/790,204 entitled "Steerable Endoscope and Improved Method of Insertion" filed Feb. 20, 2001, U.S. Pat. No. 6,468,203 which claims priority of U.S. Provisional Patent Application No. 60/194,140 filed Apr. 3, 2000, each of the above applications is incoporated herein by reference for all purposes.

Claims

We claim:

1. An apparatus comprising: an elongated instrument body having a multiplicity of controllable sections, including at least a first section, a second section and a third section; and an electronic motion controller configured for controlling each of the first section, the second section, and the third section to assume first, second, and third portions, respectively, of an arbitrary curve when the elongated instrument body is in an initial position, and configured to, when the elongated instrument advances distally from the initial position, control the second section to assume the first portion of the arbitrary curve and the third section to assume the second portion of the arbitrary curve by propagating at least one measured length of at least one side of the second section to at least one side of the third section.

2. The apparatus of claim 1, wherein the electronic motion controller is further configured to, when the elongated instrument withdraws proximally a distance of approximately one unit of length from the initial position, control the first section to assume the second portion of the arbitrary curve and the second section to assume the third portion of the arbitrary curve.

3. The apparatus of claim 1, wherein the elongated instrument body further comprises a selectively steerable distal portion.

4. The apparatus of claim 1, further comprising an axial motion transducer for measuring axial motion of the elongated instrument body.

5. The apparatus of claim 1, further comprising an imaging system for transmitting an image from a distal end to a proximal end of the elongated instrument body.

6. The apparatus of claim 5, wherein the imaging system comprises a fiberoptic imaging bundle extending from the distal end to the proximal end of the elongated instrument body.

7. The apparatus of claim 1, further comprising an imaging system for transmitting an image from a distal end of the elongated instrument body to a video monitor.

8. The apparatus of claim 1, wherein the elongated instrument body is configured as an endoscope for insertion into a patient's body.

9. The apparatus of claim 1, wherein the elongated instrument body is configured as a colonoscope for insertion into a patient's colon.

Description

FIELD OF THE INVENTION

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.

BACKGROUND OF THE INVENTION

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.

Steerable endoscopes, catheters and insertion devices for medical examination or treatment of internal body structures are described in the following U.S. patents, the disclosures of which are hereby incorporated by reference in their entirety: U.S. Pat. Nos. 4,753,223; 5,337,732; 5,662,587; 4,543,090; 5,383,852; 5,487,757 and 5,337,733.

SUMMARY OF THE INVENTION

In keeping with the foregoing discussion, the present invention takes the form of a steerable endoscope for negotiating tortuous paths through a patient's body. The steerable endoscope can be used for a variety of different diagnostic and interventional procedures, including colonoscopy, upper endoscopy, bronchoscopy, thoracoscopy, laparoscopy and video endoscopy. The steerable endoscope is particularly well suited for negotiating the tortuous curves encountered when performing a colonoscopy procedure.

The steerable endoscope has an elongated body with a manually or selectively steerable distal portion and an automatically controlled proximal portion. The selectively steerable distal portion can be selectively steered or bent up to a full 180 degree bend in any direction. A fiberoptic imaging bundle and one or more illumination fibers extend through the body from the proximal end to the distal end. Alternatively, the endoscope can be configured as a video endoscope with a miniaturized video camera, such as a CCD camera, which transmits images to a video monitor by a transmission cable or by wireless transmission, or alternatively through the use of CMOS imaging technology. Optionally, the endoscope may include one or two instrument channels that may also be used for insufflation or irrigation, air and water channels, and vacuum channels.

A proximal handle attached to the elongate body includes an ocular for direct viewing and/or for connection to a video camera, a connection to an illumination source and one or more luer lock fittings that are connected to the instrument channels. The handle is connected to a steering control for selectively steering or bending the selectively steerable distal portion in the desired direction and to an electronic motion controller for controlling the automatically controlled proximal portion of the endoscope. An axial motion transducer is provided to measure the axial motion of the endoscope body as it is advanced and withdrawn. Optionally, the endoscope may include a motor or linear actuator for both automatically advancing and withdrawing the endoscope, or for automatically advancing and passively withdrawing the endoscope.

One preferable embodiment of the endoscope includes a segmented endoscopic embodiment having multiple independently controllable segments which may be individually motorized and interconnected by joints. Each of the individual adjacent segments may be pivotable about two independent axes to offer a range of motion during endoscope insertion into a patient.

This particular embodiment, as mentioned, may have individual motors, e.g., small brushed DC motors, to actuate each individual segment. Furthermore, each segment preferably has a backbone segment which defines a lumen therethrough to allow a continuous lumen to pass through the entire endoscopic instrument to provide an access channel through which wires, optical fibers, air and/or water channels, various endoscopic tools, or any variety of devices and wires may be routed. The entire assembly, i.e., motors, backbone, cables, etc., may be encased or covered in a biocompatible material, e.g., a polymer, which is also preferably lubricious to allow for minimal frictional resistance during endoscope insertion and advancement into a patient. This biocompatible cover may be removable from the endoscopic body to expose the motors and backbone assembly to allow for direct access to the components. This may also allow for the cover to be easily replaced and disposed after use in a patient.

The method of the present invention involves inserting the distal end of the endoscope body into a patient, either through a natural orifice or through an incision, and steering the selectively steerable distal portion to select a desired path. When the endoscope body is advanced or inserted further into the patient's body, the electronic motion controller operates the automatically controlled proximal portion of the body to assume the selected curve of the selectively steerable distal portion. This process is repeated by selecting another desired path with the selectively steerable distal portion and advancing the endoscope body again. As the endoscope body is further advanced, the selected curves propagate proximally along the endoscope body. Similarly, when the endoscope body is withdrawn proximally, the selected curves propagate distally along the endoscope body, either automatically or passively. This creates a sort of serpentine motion in the endoscope body that allows it to negotiate tortuous curves along a desired path through or around and between organs within the body.

The method can be used for performing colonoscopy or other endoscopic procedures, such as bronchoscopy, thoracoscopy, laparoscopy and video endoscopy. In addition, the apparatus and methods of the present invention can be used for inserting other types of instruments, such as surgical instruments, catheters or introducers, along a desired path within the body.

BRIEF DESCRIPTION OF THE DRAWINGS

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. 4 shows a third embodiment of the steerable endoscope of the present invention.

FIG. 5 shows a fourth embodiment of the steerable endoscope of the present invention.

FIG. 6 shows a wire frame model of a section of the body of the endoscope in a neutral or straight position.

FIG. 7 shows the wire frame model of the endoscope body shown in FIG. 6 passing through a curve in a patient's colon.

FIG. 8 shows a representative portion of an alternative endoscopic body embodiment having multiple segments interconnected by joints.

FIG. 9 shows a partial schematic representation of the embodiment of FIG. 8 showing two segments being pivotable about two independent axes.

FIG. 10 shows a preferable endoscope embodiment having motorized segmented joints.

FIGS. 11A-11B show exploded isometric assembly views of two adjacent segments and an individual segment, respectively, from the embodiment shown in FIG. 10.

FIGS. 12-17 show the endoscope of the present invention being employed for a colonoscopic examination of a patient's colon.

FIGS. 18-20 show an endoscope being advanced through a patient's colon while a datum measures the distance advanced into the patient.

FIG. 21 shows a schematic representation of one embodiment of a control system which may be used to control and command the individual segments of a segmented endoscopic device of the type shown in FIGS. 8-11B.

FIG. 22 shows a flow chart embodiment for the master controller algorithm which may be used to control the overall function during endoscope insertion into a patient.

FIG. 23 shows a flowchart embodiment of the segment controller algorithm.

FIGS. 24-26 shows a non-contact method of measurement and tracking of an endoscope using an external navigational system such as a global positioning system.

DETAILED DESCRIPTION OF THE 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.

The handle 120 is connected to an electronic motion controller 140 by way of a controller cable 136. A steering control 122 is connected to the electronic motion controller 140 by way of a second cable 13 M. The steering control 122 allows the user to selectively steer or bend the selectively steerable distal portion 104 of the body 102 in the desired direction. The steering control 122 may be a joystick controller as shown, or other known steering control mechanism. The electronic motion controller 140 controls the motion of the automatically controlled proximal portion 106 of the body 102. The electronic motion controller 140 may be implemented using a motion control program running on a microcomputer or using an application-specific motion controller. Alternatively, the electronic motion controller 140 may be implemented using, a neural network controller.

An axial motion transducer 150 is provided to measure the axial motion of the endoscope body 102 as it is advanced and withdrawn. The axial motion transducer 150 can be made in many possible configurations. By way of example, the axial motion transducer 150 in FIG. 2 is configured as a ring 152 that surrounds the body 102 of the endoscope 100. The axial motion transducer 150 is attached to a fixed point of reference, such as the surgical table or the insertion point for the endoscope 100 on the patient's body. As the body 102 of the endoscope 100 slides through the axial motion transducer 150, it produces a signal indicative of the axial position of the endoscope body 102 with respect to the fixed point of reference and sends a signal to the electronic motion controller 140 by telemetry or by a cable (not shown). The axial motion transducer 150 may use optical, electronic or mechanical means to measure the axial position of the endoscope body 102. Other possible configurations for the axial motion transducer 150 are described below.

FIG. 3 shows a second embodiment of the endoscope 100 of the present invention. As in the embodiment of FIG. 2, the endoscope 100 has an elongate body 102 with a selectively steerable distal portion 104 and an automatically controlled proximal portion 106. The steering control 122 is integrated into proximal handle 120 in the form or one or two dials for selectively steering, the selectively steerable distal portion 104 of the endoscope 100. Optionally, the electronic motion controller 140 may be miniaturized and integrated into proximal handle 120, as well. In this embodiment, the axial motion transducer 150 is configured with a base 154 that is attachable to a fixed point of reference, such as the surgical table. A first roller 156 and a second roller 158 contact the exterior of the endoscope body 102. A multi-turn potentiometer 160 or other motion transducer is connected to the first roller 156 to measure the axial motion of the endoscope body 102 and to produce a signal indicative of the axial position.

The endoscope 100 may be manually advanced or withdrawn by the user by grasping the body 102 distal to the axial motion transducer 150. Alternatively, the first roller 156 and/or second roller 158 may be connected to at least one motor, e.g., motor 162, for automatically advancing and withdrawing the body 102 of the endoscope 100.

FIG. 4 shows a third embodiment of the endoscope 100 of the present invention, which utilizes an elongated housing 170 to organize and contain the endoscope 100. The housing 170 has a base 172 with a linear track 174 to guide the body 102 of the endoscope 100. The housing 170 may have an axial motion transducer 150' that is configured as a linear motion transducer integrated into the linear track 174. Alternatively, the housing, 170 may have an axial motion transducer 150'' configured similarly to the axial motion transducer 150 in FIG. 2 or 3. The endoscope 100 may be manually advanced or withdrawn by the user by grasping the body 102 distal to the housing 170. Alternatively, the housing 170 may include a motor 176 or other linear motion actuator for automatically advancing and withdrawing the body 102 of the endoscope 100. In another alternative configuration, a motor with friction wheels, similar to that described above in connection with FIG. 3, may be integrated into the axial motion transducer 150''.

FIG. 5 shows a fourth embodiment of the endoscope 100 of the present invention, which utilizes a rotary housing 180 to organize and contain the endoscope 100. The housing 180 has a base 182 with a rotating drum 184 to guide the body 102 of the endoscope 100. The housing 180 may have an axial motion transducer 150''' that is configured as a potentiometer connected to the pivot axis 186 of the rotating drum 184. Alternatively, the housing 180 may have an axial motion transducer 150'' configured similarly to the axial motion transducer 150 in FIG. 2 or 3. The endoscope 100 may be manually advanced or withdrawn by the user by grasping the body 102 distal to the housing 180. Alternatively, the housing 180 may include a motor 188 connected to the rotating drum 184 for automatically advancing and withdrawing the body 102 of the endoscope 100. In another alternative configuration, a motor with friction wheels, similar to that described above in connection with FIG. 3, may be integrated into the axial motion transducer 150'.

FIG. 6 shows a wire frame model of a section of the body 102 of the endoscope 100 in a neutral or straight position. Most of the internal structure of the endoscope body 102 has been eliminated in this drawing for the sake of clarity. The endoscope body 102 is divided up into sections 1, 2, 3 . . . 10, etc. The geometry of each section is defined by four length measurements along the a, b, c and d axes. For example, the geometry of section 1 is defined by the four length measurements l.sub.1a, l.sub.1b, l.sub.1c, l.sub.1d, and the geometry of section 2 is defined by the four length measurements l.sub.2a, l.sub.2b, l.sub.2c, l.sub.2d, etc. Preferably, each of the length measurements is individually controlled by a linear actuator (not shown). The linear actuators may utilize one of several different operating principles. For example, each of the linear actuators may be a self-heating NiTi alloy linear actuator or an clectrorheological plastic actuator, or other known mechanical, pneumatic, hydraulic or electromechanical actuator. The geometry of each section may be altered using the linear actuators to change the four length measurements along the a, b, c and d axes. Preferably, the length measurements are changed in complementary pairs to selectively bend the endoscope body 102 in a desired direction. For example, to bend the endoscope body 102 in the direction of the a axis, the measurements l.sub.1a, l.sub.2a, l.sub.3a . . . l.sub.10a would be shortened and the measurements l.sub.1b, l.sub.2b, l.sub.3b . . . l.sub.10b would be lengthened an equal amount. The amount by which these measurements are changed determines the radius of the resultant curve.

In the selectively steerable distal portion 104 of the endoscope body 102, the linear actuators that control the a, b, c and d axis measurements of each section are selectively controlled by the user through the steering control 122. Thus, by appropriate control of the a, b, c and d axis measurements, the selectively steerable distal portion 104 of the endoscope body 102 can be selectively steered or bent up to a full 180 degrees in any direction.

In the automatically controlled proximal portion 106, however, the a, b, c and d direction measurements of each section are automatically controlled by the electronic motion controller 140, which uses a curve propagation method to control the shape of the endoscope body 102. To explain how the curve propagation method operates, FIG. 7 shows the wire frame model of a part of the automatically controlled proximal portion 106 of the endoscope body 102 shown in FIG. 6 passing, through a curve in a patient's colon C. For simplicity, an example of a two-dimensional curve is shown and only the a and b axes will be considered. In a three-dimensional curve all four of the a, b, c and d axes would be brought into play.

In FIG. 7, the endoscope body 102 has been maneuvered through the curve in the colon C with the benefit of the selectively steerable distal portion 104 (this part of the procedure is explained in more detail below) and now the automatically controlled proximal portion 106 resides in the curve. Sections 1 and 2 are in a relatively straight part of the colon C, therefore l.sub.1a=l.sub.1b and l.sub.2a=l.sub.2b. However, because sections 3-7 are in the S-shaped curved section, l.sub.3a<l.sub.3b, l.sub.4a<l.sub.4b and l.sub.5a<l.sub.5b, but l.sub.6a>l.sub.6b, l.sub.7a>l.sub.7b and l.sub.8a>l.sub.8b. When the endoscope body 102 advanced distally by one unit, section 1 moves into the position marked 1', section 2 moves into the position previously occupied by section 1, section 3 moves into the position previously occupied by section 2, etc. The axial motion transducer 150 produces a signal indicative of the axial position of the endoscope body 102 with respect to a fixed point of reference and sends the signal to the electronic motion controller 140, under control of the electronic motion controller 140, each time the endoscope body 102 advances one unit, each section in the automatically controlled proximal portion 106 is signaled to assume the shape of the section that previously occupied the space that it is now in. Therefore, when the endoscope body 102 is advanced to the position marked 1', l.sub.1a=l.sub.1b, l.sub.2a=l.sub.2b, l.sub.3a=.sub.3b, l.sub.4a<l.sub.4b, l.sub.5a<l.sub.5b, l.sub.6a<l.sub.6b, l.sub.7a>l.sub.7b and l.sub.8a>l.sub.8b, and l.sub.9a>l.sub.9b, when the endoscope body 102 is advanced to the position marked 1'', l.sub.1a=l.sub.1b, l.sub.2a=l.sub.2, l.sub.3a-l.sub.3b, l.sub.4a=l.sub.4b, l.sub.5a<l.sub.5b, l.sub.6a<l.sub.6b, l.sub.7a<l.sub.7b, l.sub.8a>l.sub.8b, l.sub.9a>l.sub.9b, and l.sub.10a >l.sub.10b. Thus, the S-shaped curve propagates proximally along the length of the automatically controlled proximal portion 106 of the endoscope body 102. The S-shaped curve appears to be fixed in space, as the endoscope body 102 advances distally.

Similarly, when the endoscope body 102 is withdrawn proximally, each time the endoscope body 102 is moved proximally by one unit, each section in the automatically controlled proximal portion 106 is signaled to assume the shape of the section that previously occupied the space that it is now in. The S-shaped curve propagates distally along the length of the automatically controlled proximal portion 106 of the endoscope body 102, and the S-shaped curve appears to be fixed in space, as the endoscope body 102 withdraws proximally.

Whenever the endoscope body 102 is advanced or withdrawn, the axial motion transducer 150 detects the change in position and the electronic motion controller 140 propagates the selected curves proximally or distally along the automatically controlled proximal portion 106 of the endoscope body 102 to maintain the curves in a spatially fixed position. This allows the endoscope body 102 to move through tortuous, curves without putting unnecessary force on the wall of the colon C.

FIG. 8 shows a representative portion of an alternative endoscopic body embodiment 190 which has multiple segments 192 interconnected by joints 194. In this embodiment, adjacent segments 192 can be moved or angled relative to one another by a joint 194 having at least one degree-of-freedom, and preferably having multiple degrees-of-freedom, preferably about two axes as shown here. As seen further in FIG. 9, a partial schematic representation 196 of the embodiment 190 is shown where two segments 192 may be rotated about joint 194 about the two indepen