US20040199052A1 - Endoscopic imaging system - Google Patents

Abstract

An endoscopic imaging system includes a reusable control cabinet having a number of actuators that control the orientation of a lightweight endoscope that is connectable thereto. The endoscope is used with a single patient and is then disposed. The endoscope includes an illumination mechanism, an image sensor and an elongate shaft having one or more lumens located therein. A polymeric articulation joint at the distal end of the endoscope allows the distal end to be oriented by the control cabinet. The endoscope is coated with a hydrophilic coating that reduces its coefficient of friction and because it is lightweight, requires less force to advance it to a desired location within a patient.

Description

FIELD OF THE INVENTION
• The present invention relates to medical devices in general and therapeutic and diagnostic endoscopes in particular.[0001]
BACKGROUND OF THE INVENTION
• As an aid to the early detection of disease, it has become well established that there are major public health benefits from regular endoscopic examinations of internal structures such as the esophagus, lungs, colon, uterus, and other organ systems. A conventional imaging endoscope used for such procedures comprises a flexible tube with a fiber optic light guide that directs illuminating light from an external light source through a lens at the distal end of the endoscope which focuses the illumination on the tissue to be examined. An objective lens and fiber optic imaging light guide communicating with a camera at the proximal end of the scope, or an imaging camera chip at the distal tip, transmit an image to the examiner. In addition, most endoscopes include one or more working channels through which medical devices such as biopsy forceps, snares, fulguration probes, and other tools may be passed.[0002]
• Navigation of the endoscope through complex and tortuous paths is critical to success of the examination with minimum pain, side effects, risk or sedation to the patient. To this end, modern endoscopes include means for deflecting the distal tip of the scope to follow the pathway of the structure under examination, with minimum deflection or friction force upon the surrounding tissue. Control cables similar to puppet strings are carried within the endoscope body and connect a flexible portion of the distal end to a set of control knobs at the proximal endoscope handle. By manipulating the control knobs, the examiner is usually able to steer the endoscope during insertion and direct it to the region of interest, in spite of the limitations of such traditional control systems, which are clumsy, non-intuitive, and friction-limited. Common operator complaints about traditional endoscopes include their limited flexibility, limited column strength, and limited operator control of stiffness along the scope length.[0003]
• Conventional endoscopes are expensive medical devices costing in the range of $25,000 for an endoscope, and much more for the associated operator console. Because of the expense, these endoscopes are built to withstand repeated disinfections and use upon many patients. Conventional endoscopes are generally built of sturdy materials, which decreases the flexibility of the scope and thus can decrease patient comfort. Furthermore, conventional endoscopes are complex and fragile instruments which can frequently need expensive repair as a result of damage during use or during a disinfection procedure. To overcome these and other problems, there is a need for a low cost imaging endoscope that can be used for a single procedure and thrown away. The scope should have better navigation and tracking, a superior interface with the operator, improved access by reduced frictional forces upon the lumenal tissue, increased patient comfort, and greater clinical productivity and patient throughput than those that are currently available.[0004]
SUMMARY OF THE INVENTION
• To address these and other problems in the prior art, the present invention is an endoscopic video imaging system. The system includes a motion control cabinet that includes a number of actuators that control the orientation of an endoscope and an imaging system to produce images of tissue collected by an image sensor at the distal end of the endoscope. A single use endoscope is connectable with the control cabinet and used to examine a patient. After the examination procedure, the endoscope is disconnected and disposed of.[0005]
• The endoscope of the present invention includes a flexible elongate tube or shaft and an illumination source that directs light onto a tissue sample. An image sensor and objective lens at or adjacent the distal end of the endoscope captures reflected light to produce an image of the illuminated tissue. Images produced by the sensor are transmitted to a display device to be viewed by an examiner. In one embodiment, the illumination source comprises one or more light emitting diodes (LEDs) and the image sensor comprises a CMOS solid state image sensor.[0006]
• The endoscope of the present invention also includes a steering mechanism such as a number of tensile control cables, which allow the distal end of the endoscope to be deflected in a desired direction. In one embodiment of the invention, a proximal end of the tensile control cables communicates with actuators within the control cabinet. A freestanding joystick controller generates electrical control signals which the control cabinet uses to compute signals to drive the actuators that orient the distal end of the endoscope in the direction desired by the examiner. In another embodiment of the invention, the distal end of the endoscope is automatically steered, or provided to the examiner, based on analysis of images from the image sensor.[0007]
• In one embodiment of the invention, the endoscope includes a polymeric articulation joint adjacent its distal end that aids in bending the distal end of the scope in a desired direction. The articulation joint is constructed as a number of live hinges integrated into a unified structure of the required overall properties and dimensions. Tension of the control cables causes the live hinges of the articulation joint to deflect, thereby bending the distal tip of the endoscope. In one embodiment of the invention, the articulation joint exerts a restoring force such that upon release of a tensioning force, the distal end of the scope will straighten.[0008]
• In an alternative embodiment, the articulation joint comprises a number of stacked discs that rotate with respect to one another. Control cables pass through the discs and pull adjacent discs together to turn the distal end of the endoscope.[0009]
• In another embodiment of the invention, the endoscope has a variation in stiffness along its length that allows the distal end to be relatively flexible while the more proximal regions of the scope have increased column strength and torque fidelity so that a physician can twist and advance the endoscope with greater ease and accuracy and with fewer false advances (“loops”). Variation in stiffness along the length can be provided by varying the durometer of materials that comprise a shaft of the endoscope. Operator-controlled, variable stiffness can be provided by control cables that can be tightened or loosened to adjust the stiffness of the shaft. In yet another embodiment, the spacing between the live hinges of the articulation joint is selected to provide a variation in stiffness along the length of the articulation joint.[0010]
• In yet another embodiment of the invention, the endoscope is covered with a retractable sleeve that uncovers the distal end of the scope during use and extends over the distal end after the scope is removed from a patient.[0011]
• In another embodiment of the invention, the scope is coated with a hydrophilic coating to reduce its coefficient of friction.[0012]
• In another embodiment of the invention, the scope is retractable in a longitudinal direction. The distal end of the scope is extendable using a spring, pull wires, bellows or the like to allow a physician to move the distal tip without having to alter the position of the shaft of the endoscope.[0013]
• In yet another embodiment of the invention, the endoscope includes a heat dissipating mechanism for removing heat produced by the illumination source and image sensor.[0014]
BRIEF DESCRIPTION OF THE DRAWINGS
• The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:[0015]
• FIGS. 1A and 1B illustrate two possible embodiments of an endoscopic video imaging system in accordance with the present invention;[0016]
• FIG. 2 illustrates further detail of an endoscope used in the imaging system shown in FIG. 1A;[0017]
• FIG. 3A is a block diagram of a motion control cabinet that interfaces with an imaging endoscope in accordance with one embodiment of the present invention;[0018]
• FIG. 3B is a block diagram of a motion control cabinet that interfaces with an imaging endoscope in accordance with another embodiment of the present invention;[0019]
• FIGS. 4A-4D illustrate one mechanism for connecting the vision endoscope to a motion control cabinet;[0020]
• FIG. 5 is a detailed view of one embodiment of a handheld controller for controlling an imaging endoscope;[0021]
• FIG. 6 illustrates one embodiment of a distal tip of an imaging endoscope in accordance with the present invention;[0022]
• FIG. 7 illustrates one mechanism for terminating a number of control cables in a distal tip of an imaging endoscope;[0023]
• FIG. 8 illustrates an imaging endoscope having control cables routed through lumens in the walls of an endoscope shaft;[0024]
• FIGS. 9A and 9B illustrate a transition guide that routes control cables from a central lumen of an endoscope shaft to lumens in an articulation joint;[0025]
• FIGS. 10A and 10B illustrate the construction of a shaft portion of an endoscope in accordance with one embodiment of the present invention;[0026]
• FIG. 1I illustrates one mechanism for providing a shaft having a varying stiffness along its length;[0027]
• FIGS. 12A and 12B illustrate an extrusion used to make an articulation joint in accordance with one embodiment of the present invention;[0028]
• FIG. 13 illustrates an articulation joint in accordance with one embodiment of the present invention;[0029]
• FIGS. 14 and 15 illustrate an extrusion having areas of a different durometer that is used to form an articulation joint in accordance with another embodiment of the present invention;[0030]
• FIGS. 16A and 16B illustrate another embodiment of an articulation joint including a number of ball and socket sections;[0031]
• FIGS. 17A-17D illustrate various possible configurations of ball and socket sections used to construct an articulation joint;[0032]
• FIGS. 18A-18B illustrate an articulation joint formed of a number of stacked discs in accordance with another embodiment of the present invention;[0033]
• FIGS. 19A-19B illustrate a disc used to form an articulation joint in accordance with another embodiment of the present invention;[0034]
• FIGS. 20A-20B illustrate a disc used to form an articulation joint in accordance with another embodiment of the present invention;[0035]
• FIGS. 21A-21B illustrate a non-circular segment used to form an articulation joint in accordance with another embodiment of the present invention;[0036]
• FIG. 22 illustrates an endoscope having a braided member as an articulation joint in accordance with another embodiment of the present invention;[0037]
• FIG. 23 illustrates one possible technique for securing the ends of a control wire to a braided articulation joint;[0038]
• FIG. 24 illustrates a shaft having one or more memory reducing wraps in accordance with another embodiment of the present invention;[0039]
• FIG. 25 illustrates a shaft including longitudinal stripes of a high durometer material in accordance with another embodiment of the present invention;[0040]
• FIGS. 26-29 illustrate alternative embodiments of a gripping mechanism that rotates an imaging endoscope shaft in accordance with the present invention;[0041]
• FIGS. 30A and 30B illustrate a retractable sleeve used with another embodiment of the present invention;[0042]
• FIG. 31 illustrates one embodiment of a heat dissipating distal tip of an endoscope in accordance with the present invention; and[0043]
• FIGS. 32 and 33 illustrate alternative embodiments of a heat dissipating distal tip in accordance with the present invention.[0044]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• As indicated above, the present invention is an endoscopic video imaging system that allows a physician to view internal body cavities of a patient as well as to insert surgical instruments into the patient's body. An imaging endoscope used with the present invention is sufficiently inexpensive to manufacture such that the endoscope can be considered a disposable item.[0045]
• As shown in FIG. 1A, an endoscopic[0046]video imaging system10 according to one embodiment of the present invention includes animaging endoscope20, amotion control cabinet50 and ahandheld controller80. Theimaging endoscope20 has adistal tip22 that is advanced into a patient's body cavity and aproximal end24 that is connected to themotion control cabinet50. As will be explained in further detail below, themotion control cabinet50 includes a number of actuators that control a steering mechanism within the endoscope in order to change the orientation of thedistal tip22. A physician or their assistant uses thehandheld controller80 to input control signals that move thedistal tip22 of theimaging endoscope20. In addition, themotion control cabinet50 may include connections to sources of air/gas and a flushing liquid such as water for clearing the imaging endoscope. Themotion control cabinet50 also includes imaging electronics to create and/or transfer images received from an image sensor to a video display for viewing by a physician or technician.
• In the embodiment shown, the[0047]imaging endoscope20 also includes abreakout box26 that is positioned approximately midway along the length of the endoscope. Thebreakout box26 provides an attachment point for avacuum bottle40 that collects liquids from a lumen within the imaging endoscope. Thevacuum bottle40 is controlled by a vacuum valve28 that is positioned on thebreakout box26. Alternatively, the valve can be positioned within themotion control cabinet50 and controlled from thehandheld controller80.
• If desired, the[0048]handheld controller80 can be secured to thebreakout box26 such that the two units can be moved as one if desired. Upon completion of a patient examination procedure, theimaging endoscope20 is disconnected from themotion control cabinet50 and disposed of. Anew imaging endoscope20 is then connected to themotion control cabinet50 for the next examination procedure to be performed.
• The embodiment shown in FIG. 1A is a “parallel” configuration whereby the[0049]endoscope20 andhandheld controller80 are separately plugged into different connectors of themotion control cabinet50. This parallel configuration allows one operator to handle the endoscope while another operator can handle thehandheld controller80. Alternatively, thehandheld controller80 may be secured to theendoscope20 such that a single operator can control both. FIG. 1B illustrates a “serial” configuration of the invention. Here, theimaging endoscope20 is connected to themotion control cabinet50 through thehandheld controller80.
• FIG. 2 shows further detail of one embodiment of the[0050]imaging endoscope20. At the proximal end of the endoscope is alow torque shaft24 and aconnector34 that connects theendoscope20 to themotion control cabinet50. Distal to thebreakout box26 is a higher torque shaft. At the distal end of theendoscope20 is thedistal tip22 that includes a light illumination port, an image sensor, an entrance to a working lumen and a flushing lumen (not shown). Proximal to thedistal tip22 is an articulation joint30 that provides sufficient flexibility to the distal section of the shaft such that thedistal tip22 can be directed over an angle of 180 degrees by the steering mechanism.
• As discussed above, the[0051]endoscope20 in accordance with one embodiment of the invention, has a higher torque shaft at the distal section of the endoscope and a lower torque shaft at its proximal end. Thebreakout box26 positioned along the length of the endoscope shaft can be used as a handle or gripper to impart rotation of the distal end of the endoscope during a medical examination procedure. The higher torque portion of the shaft transfers rotational motion that is imparted at a location proximal to the distal tip in order to guide the distal tip of the imaging catheter. The low torque shaft portion of the imaging catheter does not transfer torque as well and can twist when rotational motion is applied.
• In use, the physician can insert a medical device such as a biopsy forceps, snare, etc., into a[0052]connector32 found on thebreakout box26 that leads to a working channel lumen in the endoscope. In alternate embodiments, the entrance to the working channel lumen may be positioned further towards the proximal end of the endoscope.
• FIG. 3A is a block diagram of the major components included within one embodiment of the[0053]motion control cabinet50. The motion control cabinet is preferably positioned on a cart that is wheeled near a patient prior to an examination procedure. The motion control cabinet is connected to a source of electrical power, either A.C. mains or a battery, as well as to a source of insufflation gas and irrigation liquid. Inside themotion control cabinet50 is acontroller interface52 that is connected to thehandheld controller80 and receives control signals therefrom. To change the orientation of the distal tip of the imaging endoscope, the control signals are received from a directional switch in thehandheld controller80. The control signals are supplied to a servo motor controller54 that in turn controls a number of actuators, such as servo motors56a,56b,56c,56d. Each of the servo motors56a-56dis connected to one or more control cables within the imaging endoscope. Motion of the servo motors56a-56dpulls or releases the control cables in order to change the orientation of thedistal tip22 of theimaging endoscope20. Although the embodiment shown in FIG. 3A shows four servo motors and control cables, it will be appreciated that fewer or more servo motors and corresponding control cables could be used to move the distal tip. For example, some imaging endoscopes may use three control cables and three associated servo motors.
• Also included in the[0054]motion control cabinet50 is apower source58 that provides electrical power to a light source such as a number of light emitting diodes (LEDs) at thedistal end22 of the imaging endoscope. Alternatively, if the imaging catheter utilizes an external light source, then the motion control cabinet can include a high intensity light source such as a laser or Xenon white light source that supplies light to a fiber optic illumination guide within theimaging endoscope20 in order to illuminate an internal body organ. Thepower source58 may be controlled by control signals received from thehandheld controller80 when the user desires to activate the light source.
• An[0055]imaging electronics board60 captures images received from an image sensor (not shown) at the distal end of the imaging endoscope. Theimaging electronics board60 can enhance the images received or can provide video effects such as zoom, color changes, highlighting, etc., prior to display of the images on a video display (not shown). Images of the tissue may also be analyzed by theimaging electronics board60 to produce control signals that are supplied to the servo motor controller54 in order to automatically steer the distal tip of the endoscope as will be discussed in further detail below. Images produced by theimaging electronics board60 may also be printed on a digital printer, saved to a computer readable media such as a floppy disk, CD, DVD, etc., or a video tape for later retrieval and analysis by a physician.
• Finally, the[0056]motion control cabinet50 includesvalves70 that control the delivery of insufflation air/gas to insufflate a patient's body cavity and an irrigation liquid to flush out a body cavity and/or clean the imaging light source and image sensor at the distal end of the endoscope. The insufflation air/gas and irrigation liquid are connected to the imaging catheter via aconnector38 that connects to an irrigation/insufflation lumen of theimaging endoscope20. In one embodiment of the invention, the irrigation and insufflation lumen are the same lumen in the imaging catheter. However, it will be appreciated that separate irrigation and insufflation lumens could be provided if desired and if space in the endoscope permits.
• FIG. 3B illustrates another embodiment of a motion control cabinet[0057]50A that is similar to the cabinet shown in FIG. 3A. The motion control cabinet50A includes avacuum valve71 that controls vacuum delivered to avacuum collection bottle40. Avacuum line73 connects to a vacuum lumen within theimaging endoscope20. Thevacuum valve71 is controlled from thehandheld controller80.
• FIGS. 4A-4D illustrate one mechanism for securing the proximal end of the imaging endoscope to the[0058]control cabinet50 prior to performing an endoscopic examination. Thecontrol cabinet50 includes a connector34A having a number ofshafts57 that are driven by the servo motors56 shown in FIGS. 3A and 3B. Eachshaft57 is shaped to be received in a corresponding spool on which the control cables are wound. Also included in the connector34A are connections to the insufflation andirrigation valves70 andvacuum valve71 to provide air, water and vacuum to the endoscope.
• FIGS. 4A and 4B illustrate one[0059]possible connector34 found at the proximal end of theendoscope20 for securing the endoscope to themotion control cabinet50. Theconnector34 includes a number ofthumbscrews77 or other quick release mechanisms that allow theconnector34 to be easily secured to the connector34A on the motion control cabinet. As shown in FIG. 4C, the connector34A includes a number ofspools79 about which the control cables are wound. Each spool is preferably threaded or grooved to prevent the control cables from binding on the spool during use. A cover may surround a portion of the spool to keep the control cables against the spool and to aid in supporting the spool within theconnector34. In one embodiment of the invention, the spools are prevented from rotating when the connector is not engaged with themotion control cabinet50 bybrakes81 having pins that fit within corresponding slots in the spool. Once theconnector34 is mounted to themotion control cabinet50, thebrakes81 are disengaged from the spool such that the spool can be moved by the servo motors. Electrical connections for the light source and image sensor as well as connections to the air and water valves can be found on the sides of the connector or on the rear face of theconnector34 to engage the valves, as shown in FIG. 4A.
• FIG. 4D illustrates a cross-sectional view of a[0060]shaft57 fitted within aspool79. Theshaft57 is supported by acylinder59 having aspring61 therein such that theshaft57 is free to move within thecylinder59. Thecylinder59 is directly coupled to the servo motors within the motion control cabinet. Thespring61 allows theshaft57 to float such that the shaft can more easily align and engage the mating surface of thespool79.
• Upon insertion of the[0061]shaft57 into thespool79, thebrake81 is released, thereby allowing thespool79 to be moved by rotation of thecylinder59. In some instances, thebrake81 may be omitted, thereby allowing thespools79 to freely rotate when theconnector34 is not engaged with themotion control cabinet50.
• FIG. 5 illustrates various controls located on the[0062]handheld controller80 in accordance with one embodiment of the invention. Thehandheld controller80 includes acontroller body82 that, in the parallel embodiment of the invention, is coupled to themotion control cabinet50 by anelectrical cord84, a wireless radio frequency channel, an infrared or other optical link. If the connection is made with an electrical cord, a strain relief86 is positioned at the junction of theelectrical cord84 and thebody82 of the controller to limit the bending of the electrical wires within theelectrical cord84. In the serial embodiment of the invention, the connection of thehandheld controller80 to themotion control cabinet50 is made with a conductor that includes both the wires to transmit signals to the motion controllers and imaging systems, as well as a lumens to carry the insufflation air/gas and irrigation liquid. In addition, the control cables of the endoscope engage cables connected to the actuators in the motion control cabinet through thehandheld controller80.
• Positioned in an ergonomic arrangement on the[0063]handheld controller80 are a number of electrical switches. Anarticulation joystick88 or other multi-positional device can be moved in a number of positions to allow the physician to orient the distal tip of the imaging endoscope in a desired direction. In order to guide the imaging endoscope manually, the physician moves thejoystick88 while watching an image on a video monitor or by viewing the position of the distal tip with another medial imaging technique such as fluoroscopy. As the distal tip of the endoscope is steered by moving thejoystick88 in the desired direction, the physician can push, pull and/or twist the endoscope to guide the distal tip in the desired direction.
• A camera button[0064]90 is provided to capture an image of an internal body cavity or organ in which theimaging endoscope20 is placed. The images collected may be still images or video images. The images may be adjusted for contrast or otherwise enhanced prior to display or storage on a recordable media.
• An irrigation button[0065]92 activates an irrigation source to supply a liquid such as water through an irrigation lumen of the imaging endoscope. The liquid serves to clean an image sensor and the light source at the distal end of the endoscope as well as an area of the body cavity. Aninsufflation button94 is provided to activate the insufflation source within themotion control cabinet50 to supply air/gas through a lumen of the catheter. The supply of the insufflation gas expands portions of the body cavity around the distal tip of the endoscope so that the physician can more easily advance the endoscope or better see the tissue in front of the endoscope.
• In one embodiment of the invention, the[0066]handle82 also includes athumb screw96 for securing thehandheld controller80 to thebreakout box26 as indicated above. A corresponding set of threads on abreakout box26 receive thethumb screw96 in order to join the two parts together. One or moreadditional buttons98 may also be provided to activate additional functions such as recording or printing images, adjusting light intensity, activating a vacuum control valve, etc., if desired.
• The endoscope of the present invention may also be steered automatically. Images received by the[0067]imaging electronics60 are analyzed by a programmed processor to determine a desired direction or orientation of the distal tip of the endoscope. In the case of a colonoscopy, where the endoscope is advanced to the cecum, the processor controls the delivery of insufflation air/gas to inflate the colon, the processor then analyzes the image of the colon for a dark spot that generally marks the direction in which the scope is to be advanced. The processor then supplies control instructions to the servo controller54 such that the distal tip is oriented in the direction of the dark spot located.
• In other modes, a processor in the motion control cabinet causes the distal tip of the endoscope to move in a predefined pattern. For example, as the scope is being withdrawn, the distal tip may be caused to move in a search pattern such that all areas of a body cavity are scanned for the presence of disease. By using the automatic control of the distal tip, a physician only has to advance or retract the scope to perform an examination.[0068]
• As will be described in further detail below, the[0069]imaging endoscope20 generally comprises a hollow shaft having one or more lumens formed of polyethylene tubes which terminate at thedistal tip22. As shown in FIG. 6, one embodiment of adistal tip110 comprises a cylinder having adistal section112 and aproximal section114. Theproximal section114 has a smaller diameter than the diameter of thedistal section112 in order to form a stepped shoulder region. The diameter of the shoulder is selected that shaft walls of the endoscope can seat on the shoulder region to form a smooth outer surface with thedistal section112. The distal face of thedistal tip110 includes a number of ports, including a camera port116, one or more illumination ports118, an access port or workingchannel lumen120, and a directionalflush port122.
• Fitted within the camera port[0070]116 is an image sensor (not shown) that preferably comprises a CMOS imaging sensor or other solid state device and one or more glass or polymeric lenses that produce electronic signals representative of an image of the tissue in front of the camera port116. The image sensor is preferably a low light sensitive, low noise video VGA, CMOS, color imager or higher resolution sensor such as SVGA, SXGA, or XGA. The video output of the sensor may be in any conventional format including PAL, NTSC or high definition video format.
• The illumination port[0071]118 houses one or more lenses and one or more light emitting diodes (LEDs) (not shown). The LEDs may be high intensity white light sources or may comprise colored light sources such as red, green and blue LEDs. With colored LEDs, images in different spectral bands may be obtained due to illumination with any-one or more individual colors. White light images may be obtained by the simultaneous or sequential illumination of the colored LEDs and combining individual color images. As an alternative to LEDs, the light source may be external to the endoscope and the illumination light delivered to the illumination port with a fiber optic bundle.
• The[0072]access port120 is the termination point of the working channel or lumen of theendoscope20. In the embodiment described above, the proximal end of the working channel terminates at thebreakout box26 as shown in FIG. 2. However, the working channel could terminate nearer the proximal end of the imaging catheter.
• The directional[0073]flush port122 includes a cap124 that directs liquid supplied through an irrigation and insufflation lumen across the front face of thedistal tip110 in the direction of the camera port116 and/or the illumination port118. The cap124 thereby serves to clean the camera port116 and the illumination port118 for a better view of the internal body cavity in which the imaging catheter is placed. In addition, the flushing liquid cleans an area of tissue surrounding the distal end of the endoscope.
• FIG. 7 shows further detail of one embodiment of a[0074]distal tip110 of the imaging endoscope. In this embodiment, thetip section110 includes a number of counterbored holes126 that are positioned around the circumference of thedistal tip110. The counter boredholes126 receive swaged or flanged ends of the control cables that orient the distal tip. Tension on the control cables pull thedistal tip110 in the direction of the tensioning force.
• FIG. 8 is a lengthwise, cross-sectional view of an[0075]imaging endoscope20 in accordance with one embodiment of the present invention. Thedistal tip110 is adhesively secured, welded or otherwise bonded within a center lumen at the distal end of the articulation joint30. Secured to the proximal end of the articulation joint30 is a distal end of ashaft128. As discussed above, theshaft128 is preferably stiffer or better able to transmit torque towards the distal end of the endoscope than at the proximal end of the endoscope.
• The[0076]control cables130 that move the distal tip of the endoscope are preferably made of a non-stretching material such as stainless steel or a highly oriented polyethylene-theralate (PET) string. The control cables may be routed within a center lumen of theshaft128 or, as shown in FIG. 8, may be routed through lumens formed within the walls of the shaft. Thecontrol cables130 extend through guides within the walls of articulation joint30 and terminate either at the distal end of the articulation joint30 or in thedistal tip section110.
• If the control cables are routed through the center lumen of the[0077]shaft128, the cables are preferably carried in stainless steel or plastic spiral wrapped lumens to prevent binding and atransition guide140 such as that as shown in FIGS. 9A and 9B may be used to guide the control cables into the proximal end of the articulation joint. Thetransition guide140 has aproximal end142 that is secured within a lumen of the distal end of the shaft. Acentral body portion144 of thetransition guide140 has a diameter equal to the outer diameter of the imaging endoscope. In addition, thebody portion144 includes a number ofdiagonal lumens148 that extend from a center lumen of theproximal end142 to an outer surface of a steppeddistal end146 of the transition guide. Thedistal end146 is secured within a proximal end of the articulation joint30. Control cables in the diagonally extendinglumens148 are therefore guided to the outer edge of the catheter where they extend through the guides or control cable lumens of the articulation joint30.
• FIGS. 10A, 10B illustrate one embodiment of a shaft that comprises the[0078]imaging endoscope20. Theshaft160 has acover162 that may include a wire orother braid164 embedded therein. Thebraid164, if present, allows the torque characteristics of the shaft to be adjusted. Thecover162 may be formed by placing a sleeve over a mandrel. Thebraid164 is placed over the sleeve and the mandrel is dipped into or sprayed with a coating material. Preferably the sleeve and coating material are made of polyurethane or other biocompatible materials such as polyethylene, polypropylene or polyvinyl alcohol. In addition, the interior lumen(s) and exterior of the shaft can be coated with a extrudable, hydrophilic, lubricious coating such as the HYDROPASS™ hydrophilic coating available from Boston Scientific, of Natick, Mass., and described in U.S. Pat. Nos. 5,702,754 and 6,048,620 which are herein incorporated by reference.
• A[0079]plastic spiral wrap166 such as spiral wire wrap available from Panduit Inc. is inserted into a lumen of thecover162. Thespiral wrap166 prevents theshaft160 from crushing as it is bent around a patient's anatomy.
• In one embodiment of the[0080]shaft160, the spiral wrap has a thickness of 0.060 inches and a pitch of {fraction (3/16)} inch. However, it will be appreciated that other thicknesses of spiral wrap with a different pitch could be used to provide the desired column strength and bend modulus as well as to prevent kinking.
• FIG. 11 shows one method of altering the torque fidelity of the distal and proximal portions of the shaft. The[0081]shaft160 has aflexible section170 that is proximal to the break out box and astiffer section172 that is distal to the break out box. The portion of the scope that is distal to the break out box has an increasing flexibility toward the distal tip and conversely a higher torque fidelity and column strength proximally. To increase the torque fidelity characteristics of thedistal section172 of the shaft, abraid164 in that section includes two or more wires that are wound in opposite directions. In one embodiment, the wire braid has a pitch of 14-16 pik. However, the number of wires and their spacing can be adjusted as needed in order to tailor the torque fidelity of the shaft.
• The[0082]proximal end170 of theshaft160 has a single spiral ofwire176 that is preferably wound in the same direction as theplastic spiral wrap166 in the center lumen of theshaft160. Again, the torque fidelity of the proximal end of theshaft170 can be adjusted by adjusting the pitch and/or direction of thewire176 and its flexibility.
• As will be appreciated, the[0083]single wire spiral176 provides some torque fidelity but does have the same torque fidelity as the dual wire braid in the distal section of the shaft. Thesingle wire spiral176 may be omitted from the proximal portion of the shaft if even less torque fidelity is desired.
• In order to facilitate steering the distal tip of imaging endoscope, the endoscope includes an articulation joint that allows the distal tip to be turned back on itself, i.e., over an arc of 180 degrees, by the control cables. As shown FIG. 12A,[0084]12B[,?] an articulation joint200 is formed from a cylinder of a plastically deformable material having acentral lumen202, and a number ofcontrol wire lumens204 located in the walls of the articulation joint. If desired, the space between the control wire lumens in the cylinder wall may be thinner such that the control wire lumens form bosses that extend into the central lumen of the cylinder. Thecontrol cable lumens204 are preferably oriented at 120° apart if three control cables are used or 90° apart if four control cables are used.
• To facilitate bending of the articulation joint, the cylinder includes a number of[0085]live hinges220 formed along its length. As can be seen in FIG. 13, eachlive hinge220 comprises a pair of opposing V-shapedcuts230 on either side of the cylinder and are separated by aflexible web232 that forms the bendable portion of the hinge. In the embodiment designed for four control cables, each live hinge is oriented at 90 degrees with respect to an adjacent hinge.
• Upon retraction of a control cable, those live[0086]hinges having webs232 that are in line with the retracting control cable do not bend. Those live hinges having webs that are not in line with the control cable will be closed, thereby bending the articulation joint in the direction of the control cable under tension.
• Another advantage of the articulation joint shown in FIG. 13 is that the distal end of the scope can be retracted by pulling all the control cables simultaneously. This allows the physician to maneuver the distal tip in the body without having to move the remaining length of the endoscope. This may be useful when performing surgical procedures such as obtaining a biopsy or snaring polyps.[0087]
• The articulation joint can be formed by extruding a cylinder with the central and control cable lumens in place and cutting the cylinder tube with a knife, laser, water jet, or other material removal mechanism to form the live hinges. Alternatively, the articulation joint can be molded with the live hinge joints in place. As will be appreciated, the angles of the V-shaped cuts that form the hinges may be uniform or may vary along the length of the articulation joint. Similarly, the distance between adjacent live hinges may be uniform or may vary in order to tailor the bending and torque fidelity characteristics of the articulation joint. In one embodiment of the invention, each live hinge has a closing angle of 30° so that six hinges are required to provide 180° of movement. The distal end of the articulation joint[0088]200 may be counter-bored to receive thedistal tip section110 of the endoscope, as discussed above. Similarly, the proximal end of the articulation joint200 is adapted to receive the distal end of the shaft of the endoscope. In the embodiment shown in FIG. 13, thecontrol cable lumens204 are aligned with the widest spacing of the live hinges and with the web portion of each hinge. However, it may be desirable to offset thecontrol cable lumens204 with respect to the hinges in order to lessen potential binding of the control cables in the hinge. As indicated above, the articulation joint should be made of a biocompatible material that will bend but will not collapse. Suitable materials include polyurethane, polyethylene, polypropylene, or other biocompatible polymers.
• To prevent wear by the control cables as they are pulled by the actuation mechanism in the motion control cabinet, it may be desirable to produce the articulation joint from a material having areas of different durometers. As shown in FIGS. 14 and 15, a cylinder formed from an extruded[0089]tube240 has alternating bands of ahigh durometer material242 and alower durometer material244 around its circumference. Thelumens246 used to route the control cables are formed in the high durometer material to resist abrasion as the control cables are tensioned and released. In addition, the high durometer material also reduces friction between the control cables and the surrounding lumen. FIG. 15 illustrates an articulation joint where the control cable lumens are offset with respect to the orientation of the web portions248 of the live hinges so that the control cables do not pass through the web portion of the hinge.
• FIGS. 16A, 16B illustrate an alternative embodiment of an articulation joint. In this embodiment, the joint comprises a series of ball and socket connectors that are linked together. As shown in FIG. 16A, each connector includes a[0090]socket section290 and aball section292. Theball section292 fits in asocket section290 of an adjacent connector. Alumen294 extends axially through theball section292 to allow for passage of the wires that connect to the light source and the image sensor and tubes that carry irrigation fluids and insufflation gases. The ball and socket sections are preferably molded of a biocompatible polymer.
• Each socket section can be formed with a fully formed ball section such as ball section[0091]300 shown in FIG. 17A. Alternatively, a partial ball section such as ball section304 can be formed on a socket section306 as shown in FIG. 17B. To provide room for the control cables to move, the ball section can include slot308 as shown in FIGS. 17A, 17B that cuts through the middle and sides of the ball section. Alternatively, a number of smaller slots310 can be positioned around the circumference of the ball section as shown in FIGS. 17C and 17D. The slots allow the control cables to be shortened under tension. A number of holes312 at the interface of the ball section and socket section allows passage of the control cables from the socket section into the ball section as shown in FIG. 17D.
• In another embodiment of an articulation joint, the joint is made of a series of stacked discs that are positioned adjacent one another and move with respect to each other. As shown in FIG. 18A, a[0092]disc350 comprises anannular ring352 having a pair of rearward facing rocker surfaces orcams354 and a pair of forward facing rocker surfaces orcams356. Thecams354 are positioned 180° apart on the rear surface of theannular ring352, while theforward facing cams356 are positioned 180 degrees apart on the forward face of theannular ring352. In the embodiment shown, theforward cams356 are oriented at 90° with respect to therear cams354. Opposite each cam on the other side of the annular ring is a flat land section so that the cams of an adjacent disc may engage with and rock on the flat section.Holes360 are drilled through the annular ring and through the cams for passage of the control cables. Upon tension of the control cables, the discs will rock on the surface of thecams354,356 thereby bending the articulation joint in the desired direction.
• FIG. 18B shows an articulation joint made up of a series of stacked discs[0093]350a,350b,350c. . . engaged with one another to form an articulation joint. A number ofcontrol cables370a,370b,370c,370d, pass through the discs and are used to pull the discs on the cam surfaces to move the joint in the desired direction.
• FIGS. 19A and 19B show an alternative embodiment of the articulation joint shown in FIGS. 18A and 18B. In this embodiment, an articulation joint comprises a series of stacked[0094]discs380, each comprising an annular ring having a pair ofconcave pockets382 on its rear surface and a pair of correspondingly shapedconvex cams384 on its front surface. Theconcave pockets382 are oriented at 90° with respect to theconvex cams384 so that adjacent discs may be stacked such that the cams of a disc fit within the pockets of the adjacent disc. The corresponding shapedcams384 andpockets382 help prevent the discs from rotating with respect to one another. Holes orlumens386 are formed through theannular ring380 for passage of a number ofcontrol cables390a,390b,390c,390d, as shown in FIG. 19B. The holes orlumens386 may be positioned at the center of the cams and pockets. However, the holes for the control cables may be offset from the position of the cams and pockets, if desired. Preferablydiscs380 are molded from a biocompatible polymer having a relatively slick surface, such as polyurethane, polypropylene, or polyethylene, that reduces friction between adjacent cams and pockets.
• FIGS. 20A and 20B show yet another alternative embodiment of an articulation joint. In this embodiment, the articulation joint is formed of a stack of discs, each of which comprises an annular ring. The annular ring has cams having an[0095]arcuate slot392 molded therein that allows a control cable to move more freely in the cam as the disc is moved relative to an adjacent disc. As best shown in FIG. 20B, theslot392 tapers from awidest point394 at the outer edge of the cam to anarrow point396 where the slot forms acylindrical hole398 that extends to the opposite edge of theannular ring380. A control wire390bis free to bend within the widened portion of thearcuate slot392 as an adjacent disc is rotated.
• Although the discs of the articulation joints shown in FIGS. 18-20 are generally circular in shape, it will be appreciated that other shapes could be used. FIGS. 21A and 21B show an articulation joint formed from a number of sections having a generally square outer shape. As shown in FIG. 21A, a section[0096]400 is a square band having a pair ofpins402 that extend outwardly on opposite sides of the rear surface of the square section. On the opposite sides of the front surface are a pair of opposingcircular recesses404 that are sized to receive the round pins402 of an adjacent section. The embodiment shown, the control cables are routed through holes or lumens in corner blocks406 that are found in each corner of the square section400. FIG. 21B shows two adjacent square sections400a,400bsecured together. As can be seen, the section400bcan rotate up or down on its pins with respect to the adjacent section400a. Although circular and square articulation sections have been shown, it will be appreciated that other segment shapes such as triangular or pentagonal, etc., could also be used to form an articulation joint.
• In some environments, a full 180° turning radius of the distal tip of the imaging endoscope may not be necessary. In those environments, the articulation joint may be replaced with a flexible member such as a braided stent. FIG. 22 shows an[0097]imaging endoscope425 having abraided stent430 as the articulation joint. The braided stent extends between a distal tip432 and aconnector434 that joins the proximal end of thestent430 with the distal end of aflexible shaft436. Acover438 extends over theflexible shaft436 and thebraided stent430. Control cables (not shown) extend through a lumen offlexible shaft436 and are used to pull thestent430 such that the distal tip432 is oriented in the desired direction. In addition, pulling all the control cables simultaneously allows the distal tip of the endoscope to be retracted.
• FIG. 23 shows one method of securing the distal ends of the control cables to a[0098]braided stent430. Thecontrol cables440a,440b,440c,440dcan be woven through the wires of thestent430 and terminated by forming loops around the wires that comprise the stent. Alternatively, the ends of the cables440 can be soldered or adhesively secured to the wires of the stent.
• In some embodiments, the articulation joint is designed to exert a restoring force so that imaging endoscope will tend to straighten upon the release of tension from the control cables. In other cases, it may be desirable to maintain the position of the distal tip in a certain direction. In that case, a construction as shown in FIG. 24 can be used. Here, the shaft of the imaging endoscope includes an[0099]inner sleeve450 that is overlaid with two or more plastic spiral wraps452,454, and456.Wrap452 is wound in the clockwise direction whilewrap454 is wound in the counter-clockwise direction over thewrap452 and the wrap456 is wound in the same direction as thefirst wrap452. The wraps are formed of a relatively coarse plastic material such that friction is created between the alternatingly wound layers of the wrap. A suitable material for the plastic wrap includes a braided polyester or polyurethane ribbon. Upon tension of the imaging endoscope by any of the control cables, the plastic spiral wraps will move with respect to each other and the friction between the overlapping wraps will tend to maintain the orientation of the imaging endoscope in the desired direction. The endoscope will remain in the desired direction until it is pulled in a different direction by the control cables. Covering the alternatingly wound spiral wraps452,454, and456 is abraid458. The braid is formed of one or more plastic or wire threads wound in alternate directions. Anouter sleeve460 covers thebraid458 to complete the shaft.
• FIG. 25 shows another alternative embodiment of a shaft construction used in an imaging endoscope according to the present invention. The shaft includes a[0100]cover sheath470 having bands of ahigh durometer material472 and alow durometer material474 that alternate around the circumference of thesheath470. The high durometer material and low durometer materials form longitudinal strips that extend along the length of the shaft. Within thesheath470 is aplastic spiral wrap474 that prevents theshaft470 from crushing as it is bent in a patient's anatomy. The high durometer materials add to the torque fidelity characteristics of the shaft. The width of the high durometer material strips compared to the low durometer material may be adjusted in accordance with the torque fidelity characteristics desired.
• During examination with the imaging endoscope, the physician may need to twist the scope in order to guide it in the desired direction. Because the outer surface of the scope is preferably coated with a lubricant and it is round, it can be difficult for the physician to maintain an adequate purchase on the shaft in order to rotate it. As such, the imaging endoscope of the present invention may include a gripper mechanism that aids the physician in grasping the shaft for either rotating it or moving the shaft longitudinally. One embodiment of a shaft gripping device is shown in FIG. 26. Here, a[0101]gripper500 comprises a unshaped member having a pair oflegs502,504 that are aligned with the longitudinal axis of animaging endoscope20. At the distal end of thelegs502,504 are two 90° bends506,508. Thegripper500 includes ahole505 positioned at the curved bent portion of the gripper that joins the legs as well as holes in each of the 90°sections506,508. The imaging endoscope passes through the holes such that thegripper500 is slideable along the length of the shaft portion of the endoscope. The spring nature of the material used to fashion the gripper causes thelegs502,504 to be biased away from the shaft of the endoscope. Only the friction of the opposing holes at thebent portions506,508 prevent thegripper500 from freely sliding along the length of the shaft. On the inner surface of thelegs502,504 are a pair oftouch pads510,512, having an inner surface that is shaped to match the outer circumference of the shaft portion of the endoscope. When the physician squeezes thelegs502,504 radially inward, thetouch pads510,512 engage the shaft such that the physician can push or pull the endoscope or rotate it. Upon release of thelegs502,504, thetouch pads510,512 release from the surface of the shaft and thegripper500 can be moved along the length of the shaft to another location if desired.
• FIG. 27 shows a gripper similar to that of FIG. 26 with like parts being identified with the same reference numbers. In this embodiment, the gripper includes two[0102]hemispherical discs520,522, positioned on the outside surface of thelegs502,504. Thehemispherical surfaces520,522 are designed to fit within the hand of the physician and increase the radial distance from the gripper to the shaft such that it is easier to twist the shaft, if desired.
• FIG. 28 shows yet another alternative embodiment of a shaft gripper. In this example, a[0103]gripper550 comprises a u-shaped member having a pair oflegs552,554, that are oriented perpendicularly to the longitudinal axis of theimaging endoscope20. Thelegs552,554 include a recessedsection556,558 that is shaped to receive the outer diameter of the shaft portion of the endoscope. Athumbscrew560 is positioned at the distal end of the legs such that the legs can be drawn together and cause thelegs554,556 to securely engage the shaft of the endoscope. Upon release of thethumbscrew560, thelegs554,552 are biased away from the shaft such that thegripper550 can be moved. The shaft can be twisted by rotating thelegs552,554, with respect to the longitudinal axis of the shaft.
• FIG. 29 shows an alternative embodiment of the[0104]gripper550 shown in FIG. 28. In this example, thegripper580 includes a u-shaped member having a pair oflegs582,584. At the distal end of each leg is arecess586,588 that is shaped to receive the outer diameter of the shaft. The shaft is placed in therecesses586,588, and a thumbscrew is positioned between the ends of thelegs582,584, and the u-shaped bend in thegripper580. By tightening thethumbscrew590, the legs are compressed against the shaft of theimaging endoscope20, thereby allowing the physician to rotate the endoscope by moving thegripper580.
• In one embodiment of the invention the endoscope has a movable sleeve that operates to keep the distal end of the endoscope clean prior to use and covers the end of the scope that was in contact with a patient after the scope has been used.[0105]
• FIGS. 30A and 30B illustrate one embodiment of an[0106]endoscope594 having asponge504 at its distal end. The sponge fits over the endoscope and has a peel off wrapper that may be removed and water or other liquid can be applied to the sponge. The water activates a hydrophilic coating so that the distal end of the endoscope has an increased lubricity. In addition, the sponge functions as a gripper when compressed allowing the physician to pull and/or twist the endoscope.
• A[0107]collapsible sleeve598 is positioned over the distal end of the endoscope and can be retracted to expose the lubricated distal tip of the probe. In one embodiment, thesleeve598 is secured at its distal end to thesponge594 and at its proximal end to the breakout box. Moving the sponge proximally retracts the sleeve so that the endoscope is ready for use. After a procedure, thesponge594 is moved distally to extend the sleeve over the distal end of the endoscope. With the sleeve extended, any contaminants on the probe are less likely to contact the patient, the physician or staff performing the procedure.
• In some instances, it may be desirable to limit the amount of heat that is dissipated at the distal end of the imaging endoscope. If light emitting diodes are used, they generate heat in the process of producing light for illumination. Similarly, the image sensor generates some heat during operation. In order to limit how hot the distal end of the endoscope may become and/or to provide for increased life for these components, it is necessary to dissipate the heat. One technique for doing so is to fashion a heat sink at the distal tip of the imaging endoscope. As shown in FIG. 31, a distal tip[0108]600 includes acap602 and a heat dissipating section604 that is made of a heat dissipating material such as a biocompatible metal. The heat dissipating section604 includes asemicircular opening606 having a relativelyflat base608 that extends approximately along the diameter of the heat dissipating section604. Theflat base608 forms a pad upon which electrical components such as the LEDs and image sensor can be mounted with a thermally conductive adhesive or other thermally conductive material. The heat generating devices will transfer heat generated during operation to the heat dissipating section604. Thedistal cover602 covers the distal end of the heat dissipating section604 in order to prevent the heat dissipating section604 from touching the tissue in the body as well as to protect the body as the imaging catheter is moved in the patient. Prisms, lenses, or other light bending devices may be needed to bend light entering the distal end of the endoscope to any imaging electronics that are secured to the relativelyflat base608 of the heat dissipating section604.
• FIG. 32 shows a heat dissipating distal tip of an endoscope wherein the distal tip does not include a cover but is molded from a single piece of heat dissipating material such as a biocompatible metal. The heat dissipating section[0109]620 again includes a semicircular opening with a relativelyflat surface622 that extends along the diameter of the section and on which heat generating electronic devices can be mounted. With a semicircular opening formed in the distal end of the heat dissipating distal tip620, the illumination mechanism and image sensor are mounted on theflat surface622. The irrigation port is oriented to direct water over the hemispherical cutout in order to clean the illumination mechanism and image sensor or image sensor lenses.
• In yet another embodiment of the invention, the imaging devices at the distal end of the endoscope can be cooled by air or water passed through a lumen to the end of the endoscope and vented outside the body. For example, air under pressure may be vented through an orifice near the imaging electronics. The expansion of the air lowers its temperature where it cools the imaging electronics. The warmed air is then forced to the proximal end of the endoscope through an exhaust lumen. Alternatively, the endoscope may include a water delivery lumen that delivers water to a heat exchanger at the distal tip. Water warmed by the electronic components in the distal tip is removed in a water return lumen.[0110]
• FIG. 33 shows an alternative embodiment of the heat dissipating distal tip shown in FIG. 31. In this example, the heat dissipating[0111]distal tip640 has a number ofscalloped channels642 positioned around the circumference of the distal tip. The scallopedchannels642 increase the surface area of the heat dissipating distal tip, thereby further increasing the ability of the tip to dissipate heat from the illumination and imaging electronic devices.
• Although the present endoscopic imaging system has many uses, it is particularly suited for performing colonoscopic examinations. In one embodiment, a 10-13 mm diameter prototype having a 0.060 inner spiral wrap with a pitch of {fraction (1/4)} inch and coated with a hydrophilic coating was found to have a coefficient of friction of 0.15 compared to 0.85 for conventional endoscopes. In addition, the endoscope of the present invention required 0.5 lbs. of force to push it through a 2-inch U-shaped bend where a conventional endoscope could not pass, through such a tight bend. Therefore, the present invention allows colonoscopes to be made inexpensively and lightweight so that they are more comfortable for the patient due to their lower coefficient of friction and better trackability.[0112]
• In addition to performing colonoscopies, the endoscopic imaging system of the present invention is also useful with a variety of surgical devices including: cannulas, guidewires, sphincterotomes, stone retrieval balloons, retrieval baskets, dilatation balloons, stents, cytology brushes, ligation devices, electrohemostasis devices, sclerotherapy needles, snares and biopsy forceps.[0113]
• Cannulas are used with the endoscopic imaging system to cannulate the sphincter of Odi or papilla to gain access to the bile or pancreatic ducts. Guidewires can be delivered down the working channel of the endoscope and used as a rail to deliver a surgical device to an area of interest. Sphincterotomes are used to open the papilla in order to place a stent or remove a stone from a patient. Stone retrieval balloons are used along with a guidewire to pull a stone out of a bile duct. Retrieval baskets are also used to remove stones from a bile duct. Dilatation balloons are used to open up strictures in the gastrointestinal, urinary or pulmonary tracts. Stents are used to open up strictures in the GI, urinary or pulmonary tracts. Stents can be metal or plastic, self-expanding or mechanically expanded, and are normally delivered from the distal end of a catheter. Cytology brushes are used at the end of guidewires to collect cell samples. Ligation devices are used to ligate varices in the esophagus. Band ligators employ elastic bands to cinch varices. Electrohemostasis devices use electrical current to cauterize bleeding tissue in the GI tract. Sclerotherapy needles are used to inject coagulating or sealing solutions into varices. Snares are used to remove polyps from the GI tract, and biopsy forceps are used to collect tissue samples.[0114]
• Examples of specific surgical procedures that can be treated with the endoscopic imaging system of the present invention include the treatment of gastroesophageal reflux disease (GERD) by the implantation of bulking agents, implants, fundoplication, tissue scarring, suturing, or replacement of valves or other techniques to aid in closure of the lower esophageal sphincter (LES).[0115]
• Another example of a surgical procedure is the treatment of morbid obesity by deploying implants or performing reduction surgery, gastric bypass and plication or creating tissue folds to help patients lose weight.[0116]
• Endoscopic mucosal resection (EMR) involves the removal of sessile polyps or flat lesions by filling them with saline or the like to lift them prior to resection. The endoscope of the present invention can be used to deliver needles, snares and biopsy forceps useful in performing this procedure.[0117]
• In addition, the endoscopic imaging system of the present invention can be used to perform full-thickness resection (FTRD) in which a portion of a GI tract wall is excised and the wounds healed with staplers or fasteners. Finally, the endoscopic imaging system of the present invention can be used to deliver sclerosing agents to kill tissues or drug delivery agents to treat maladies of internal body tissues.[0118]
• While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the scope of the invention. For example, although some of the disclosed embodiments use the pull wires to compress the length of the endoscope, it will be appreciated that other mechanisms such as dedicated wires could be used. Alternatively, a spring can be used to bias the endoscope distally and wires used to compress the spring thereby shortening the length of the endoscope. Therefore, the scope of the invention is to be determined from the following claims and equivalents thereof.[0119]

Claims (47)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An imaging endoscope, comprising:

a shaft having a proximal end and a distal end;

an illumination port at the distal end of the shaft for illuminating tissue;

an imaging port at the distal end of the shaft that includes an imaging sensor to produce an image of the tissue;

a plastically deformable articulation joint disposed at the distal end of the shaft comprising a molded or extruded polymeric cylinder having a central lumen and a number of control cable lumens disposed about the circumference of the cylinder;

a number of live hinges formed in the cylinder; and

a number of control cables that are selectively activated to bend the articulation joint in a desired direction.

2. The imaging endoscope ofclaim 1, further comprising a working channel lumen in the shaft through which a medical device may be passed.

3. The imaging endoscope ofclaim 1 wherein each live hinge comprises two or more diametrically opposed angled cutouts in the polymeric cylinder that are joined by flexible webs.

4. The imaging endoscope ofclaim 3, wherein the control cables are aligned with the flexible webs of the live hinges.

5. The imaging endoscope ofclaim 3, wherein the control cables are offset from the flexible webs of the live hinges.

6. The imaging endoscope ofclaim 3, wherein adjacent live hinges along the length of the articulation joint are rotated with respect to each other.

7. The imaging endoscope ofclaim 1, wherein the shaft is coated with a lubricious material.

8. The imaging endoscope ofclaim 1, wherein the shaft includes an insufflation/irrigation lumen.

9. The imaging endoscope ofclaim 1, wherein at least a portion of the shaft includes a spiral wrap.

10. The imaging endoscope ofclaim 9, wherein the spiral wrap is approximately 0.060 inches thick and has a pitch of about {fraction (3/16)} inches.

11. The imaging endoscope ofclaim 1, wherein the articulation joint comprises an extruded cylinder made of two or more materials having different durometers.

12. The imaging endoscope ofclaim 11, wherein the control cable lumens are within a material having a higher durometer.

13. The imaging endoscope ofclaim 1, wherein the shaft is covered by a sleeve that includes wound wrap.

14. The imaging endoscope ofclaim 16, wherein the wrap has a number of threads and a pitch selected to adjust the torque characteristics of the shaft.

15. The imaging endoscope ofclaim 16, wherein the threads of the wound wrap are made of wire.

16. The imaging endoscope ofclaim 16, wherein the wound wrap has two or more threads that are braided.

17. The imaging endoscope ofclaim 1, wherein the articulation joint is longitudinally retractable by tensioning all the control cables.

18. The imaging endoscope ofclaim 1, further comprising a sleeve that selectively exposes the distal end of the endoscope.

19. An imaging endoscope, comprising:

a shaft having a proximal end and a distal end;

an illumination port at the distal end of the shaft for illuminating tissue;

an imaging port at the distal end of the shaft that includes an imaging sensor to produce an image of the tissue;

a plastically deformable articulation joint wherein the articulation joint includes a number of stacked annular disks each having a number of holes through which the control cables pass and camming surfaces that engage an adjacent annular disk in the articulation joint.

20. The imaging endoscope ofclaim 19, wherein the camming surfaces of adjacent annular disks are rotated with respect to each other.

21. An imaging endoscopic system, comprising:

a control cabinet including a number of actuators that operate to control the orientation of an endoscope;

an imaging board for producing images received from an image sensor in an endoscope;

one or more valves to control the delivery of an irrigation fluid and insufflation air/gas to one or more lumens in an endoscope;

a handheld controller including a number of controls that can be activated by a physician to supply commands to the control cabinet; and

a single use endoscope that is connectable to the control cabinet, the endoscope including:

a shaft with a proximal end and a distal end;

an illumination mechanism for illuminating tissue;

an image sensor at the distal end of the endoscope for producing images of tissue;

an articulation joint that permits the distal end of the endoscope to move; and

a number of control cables that are selectively tensioned by the actuators to orient the distal tip of the endoscope.

22. The imaging endoscope system ofclaim 21, wherein the proximal end of the endoscope is connectable to the control cabinet.

23. The imaging endoscopic system ofclaim 21, wherein the endoscope is connected to the control cabinet through the handheld controller.

24. The imaging endoscopic system ofclaim 21, wherein the handheld controller is connected to the control cabinet through a wired link.

25. The imaging endoscopic system ofclaim 21 wherein the handheld controller is connected to the motion control cabinet through a wireless link.

26. A system for obtaining images of a patient's internal body cavity, comprising:

a reusable control cabinet including:

means for controlling the movement of a distal end of an endoscope;

means for controlling the delivery of an irrigation fluid and/or an insufflation air/gas to lumen(s) of the endoscope;

means for producing images of tissue received from signals produced by an image sensor at the distal end of an endoscope;

an input mechanism for supplying signals to control the operation of the control cabinet; and

a disposable endoscope that is connectable to the control cabinet that obtains images of tissue in the body cavity and is controllable by the control cabinet.

27. The system ofclaim 26, wherein the input mechanism comprises a handheld controller connected to the control cabinet with a wired link.

28. The system ofclaim 26, wherein the input mechanism comprises a handheld controller connected to the control cabinet with a wireless link.

29. An endoscope, comprising:

a shaft having a proximal end, a distal end and a central lumen extending therethrough;

an illumination port at the distal end of the shaft;

an imaging port including an image sensor at the distal end of the shaft;

an articulation joint at or adjacent the distal end of the shaft comprising a molded or extruded polymeric cylinder having a number of hinge mechanisms that can be opened and closed to bend the distal end of the shaft; and

a number of control cables that are selectively tensioned to close one or more of the hinge mechanisms of the articulation joint.

30. The endoscope ofclaim 29, wherein the shaft is coated with a hydrophilic coating.

31. The endoscope ofclaim 29, wherein the shaft includes a spiral wrap therein.

32. The endoscope ofclaim 29, wherein the illumination port includes a number of light emitting diodes.

33. The endoscope ofclaim 29, wherein the illumination port includes a number of optical fibers that direct illumination light received from an external source.

34. The endoscope ofclaim 29 wherein the polymeric articulation joint is formed of two or more materials each having a different durometer.

35. The endoscope ofclaim 34, wherein the control cables pass through lumens in the articulation joint that are within a material having a higher durometer.

36. The endoscope ofclaim 29, wherein the hinge mechanisms are equally spaced along the length of the articulation joint.

37. The endoscope ofclaim 29, wherein the hinge mechanisms are not equally spaced along the length of the articulation joint.

38. An imaging endoscope, comprising:

a shaft having a proximal end, a distal end and a working channel lumen therein;

a number of control cables that are connectable to a number of motion controllers to control the orientation of the distal tip;

an articulation joint comprising a braided stent that is moved by the control cables to orient the distal tip of the endoscope;

one or more light emitting diodes at the distal tip to produce illumination light; and

an image sensor at the distal end of the endoscope to produce images of tissue.

39. The imaging endoscope of claims40, further comprising:

means for dissipating heat from the light emitting diodes and image sensor.

40. The imaging endoscope ofclaim 38, further comprising a lumen into which a liquid or gas is delivered and an orifice in the lumen adjacent the light emitting diode and image sensor to direct the air or gas over the light emitting diodes and image sensor to dissipate heat.

41. An endoscope for viewing internal body cavities of a patient, comprising:

a shaft having a central lumen and a braid embedded within a wall of the shaft;

a plastically deformable articulation joint at or adjacent a distal end of the endoscope, the articulation joint including a number of live hinges and lumens through which control cables are passed;

a number of control cables within the lumens of the articulation joint; wherein the distal end of the endoscope may be turned in a desired direction by selectively tightening control cables and the distal tip of the endoscope can be retracted by tightening all the control cables simultaneously.

42. The endoscope ofclaim 45, wherein the control cables are made of metal.

43. The endoscope ofclaim 45, wherein the control cables are made of PET.

44. The endoscope ofclaim 41, wherein the control cables are routed within spiral wrapped lumens within the sleeve.

45. An endoscope for viewing internal body cavities of a patient, comprising:

a shaft having a lumen therein;

an articulation joint at or near the distal end of the shaft for selectively orienting the distal end of the shaft;

an imaging system positioned at or adjacent the distal end of the shaft including a light source and an image sensor for capturing images of the patient's body cavity; and

a retractable sleeve that selectively uncovers the distal end of the shaft for use with a patient and recovers the distal end of the shaft after a patient examination procedure.

46. The endoscope ofclaim 45, wherein the retractable sleeve is connected to a gripper on the shaft that is used to rotate the shaft.

47. The endoscope ofclaim 46, wherein the shaft is coated with a hydrophilic coating and the gripper includes a sponge that can be wetted to activate the hydrophilic coating.

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