Patent Publication Number: US-2021186558-A1

Title: Imaging cannula with a hinged tip

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of U.S. Provisional Application 62/552,014 filed Aug. 30, 2017, which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure is directed to systems utilized in medical procedures and operational methods used during those procedures. More particularly, the present disclosure is directed to a surgical tool and methods of utilizing the surgical tool during a medical procedure. 
     BACKGROUND 
     Medical robotic systems such as teleoperational systems used in performing minimally invasive surgical procedures offer many benefits over traditional open surgery techniques, including less pain, shorter hospital stays, quicker return to normal activities, minimal scarring, reduced recovery time, and less injury to tissue. Consequently, demand for such medical teleoperational systems is strong and growing. 
     Examples of medical teleoperational systems include the da Vinci® Surgical System and the da Vinci® S™ Surgical System from Intuitive Surgical, Inc., of Sunnyvale, Calif. Each of these systems includes a health care provider&#39;s console, a patient-side cart, a high performance three-dimensional (“3-D”) vision system, and Intuitive Surgical&#39;s proprietary EndoWrist® articulating instruments, which are modeled after the human wrist. When added to the motions of manipulators holding the surgical instruments, these articulating instruments allow at least six degrees of freedom of motion to their end effectors, which is comparable to or even greater than the natural motions of open surgery. 
     Minimally invasive surgical procedures performed by teleoperational systems provide many advantages over conventional surgery, however as the size of access points are reduced, so is visualization of the surgical site. Even with advances in surgical access, health care providers still need to see the surgical area in which they work. Conventional minimally invasive surgical procedures are performed using endoscopes introduced through cannulas that carry a camera to capture images that may be displayed to the health care provider. Other cannulas are used to introduce other surgical tools. Accordingly, minimally invasive procedures may require an extra incision through which the endoscope extends. 
     To reduce the number of incisions in a patient, it would be desirable to provide a cannula having an associated camera thereon that may also be used to introduce other surgical tools. 
     SUMMARY 
     In general, the present disclosure is directed to a cannula through which a medical function may be carried out, with the cannula having a hinged tip containing a camera. Certain implementations include the tip and camera in a first position while being advanced through tissue to provide an image to a health care provider, with the tip pivotable about the hinge to move the tip from the cannula opening and to cause the camera to be in a second position during the procedure. Other certain implementations include a first camera and a second camera disposed in the hinged tip. The tip and cameras may be in a first position while the cannula is advanced through tissue, and the tip may pivot about the hinge to a second position away from the cannula opening. The first camera may capture distal images when in the first position and the second camera may capture distal images when the tip is in the second position. Additional certain embodiments of the invention are best summarized by the claims that follow the description. 
     Some exemplary aspects of the present disclosure are directed to a surgical instrument that includes a cannula having a proximal end, a distal end, and a lumen therethrough. The surgical instrument also includes a camera disposed at the distal end of the cannula to permit visualization of tissue at the distal end of the cannula, and also includes a hinge pivotably coupling the camera to the cannula. The hinge may permit the camera to pivot from a first position where the camera faces a distal direction at the distal end of the cannula to a second position where the camera faces a proximal direction at the distal end of the cannula. 
     Additional exemplary aspects of the present disclosure are directed to a surgical instrument that includes a cannula having a proximal end, a distal end, and a lumen therethrough. A first camera may be disposed at the distal end of the cannula to permit visualization of tissue at the distal end of the cannula. The surgical instrument also may include a second camera and a displaceable tip carrying the first camera and the second camera. The displaceable tip may be pivotably connected by a hinge to the cannula to pivot between a first position and a second position and carry the first and the second cameras between the first and second positions. The first camera may be disposed to have a field of view in a distal direction when the displaceable tip is in the first position and the second camera disposed to have a field of view in the distal direction when the displaceable tip is in the second position. 
     Additional exemplary aspects of the present disclosure are directed to a surgical instrument including a cannula having a proximal end, a distal end, and a lumen therethrough, and having a first camera disposed on the cannula and facing in a first direction to permit visualization of tissue in the first direction. The first camera may be arranged to capture images of tissue adjacent the distal end of the cannula. A second camera may be disposed on the cannula and may face in a second direction different than the first direction. In some aspects, a hinge may connect the first and the second cameras to the cannula such that the first camera is disposed to face in a distal direction when the first and the second cameras are in a first position and the second camera is disposed to face in the distal direction when the first and the second cameras are in a second position. 
     Yet additional exemplary aspects of the present disclosure are directed to methods of visualizing tissue during a medical procedure. Some methods may include capturing images of tissue with a camera carried by a tip attached at a distal end of a cannula while introducing the cannula into a patient, and pivoting the tip and camera from a first position in-line with the cannula to a second position out of line with the cannula to open the cannula. A surgical tool may then be introduced through the cannula. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic view of a teleoperated medical system in a surgical frame of reference, in accordance with an embodiment of the present disclosure. 
         FIG. 1B  is a perspective view of patient side systems, according to one example of principles described herein. 
         FIG. 2  is a simplified illustration of a cannula with a displaceable tip according to some embodiments. 
         FIG. 3A  is a simplified illustration of a cannula with a tip in a first position for the insertion through tissue of a patient according to some embodiments. 
         FIG. 3B  is a simplified illustration of a cannula with a tip in a second position accommodating the passage of surgical tools therethrough according to some embodiments. 
         FIG. 4A  is a simplified illustration of a cannula with a tip in a first position for the insertion through tissue of a patient according to some embodiments. 
         FIG. 4B  is a simplified illustration of a cannula with a tip in a second position accommodating the passage of surgical tools therethrough according to some embodiments. 
         FIG. 5A  is a simplified illustration of a cannula with a tip in a first position for the insertion through tissue of a patient according to some embodiments. 
         FIG. 5B  is a simplified illustration of a cannula with a tip in a second position accommodating the passage of surgical tools therethrough according to some embodiments. 
         FIG. 6  is a simplified flow diagram of a method of imaging tissue during a medical procedure according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. In the following detailed description of the aspects of the invention, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, it will be obvious to one skilled in the art that the embodiments of this disclosure may be practiced without these specific details. In other instances well known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments of the invention. 
     Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. In addition, dimensions provided herein are for specific examples and it is contemplated that different sizes, dimensions, and/or ratios may be utilized to implement the concepts of the present disclosure. To avoid needless descriptive repetition, one or more components or actions described in accordance with one illustrative embodiment can be used or omitted as applicable from other illustrative embodiments. For the sake of brevity, the numerous iterations of these combinations will not be described separately. For simplicity, in some instances the same reference numbers are used throughout the drawings to refer to the same or like parts. 
     The embodiments below will describe various instruments and portions of instruments in terms of their state in three-dimensional space. As used herein, the term “position” refers to the location of an object or a portion of an object in a three-dimensional space (e.g., three degrees of translational freedom along Cartesian X, Y, Z coordinates). As used herein, the term “orientation” refers to the rotational placement of an object or a portion of an object (three degrees of rotational freedom . . . e.g., roll, pitch, and yaw). As used herein, the term “pose” refers to the position of an object or a portion of an object in at least one degree of translational freedom and to the orientation of that object or portion of the object in at least one degree of rotational freedom (up to six total degrees of freedom). As used herein, the term “shape” refers to a set of poses, positions, or orientations measured along an object. 
     Referring to  FIG. 1A  of the drawings, a teleoperated medical system for use in, for example, medical procedures including diagnostic, therapeutic, or surgical procedures, is generally indicated by the reference numeral  10  and operates within a surgical environment having a surgical frame of reference coordinate system, XS, YS, ZS. As will be described, the teleoperated medical systems of this disclosure are under the teleoperated control of a health care provider. In alternative embodiments, a teleoperated medical system may be under the partial control of a computer programmed to perform the procedure or sub-procedure. In still other alternative embodiments, a fully automated medical system, under the full control of a computer programmed to perform the procedure or sub-procedure, may be used to perform procedures or sub-procedures. As shown in  FIG. 1A , the teleoperated medical system  10  generally includes a teleoperated assembly  12  mounted to or near an operating table O on which a patient P is positioned. The teleoperated assembly  12  may be referred to as a patient side cart. A medical instrument system  14  and an endoscopic imaging system  15  are operably coupled to the teleoperated assembly  12 . An operator input system  16  allows a health care provider or other type of health care provider S to view images of or representing the surgical site and to control the operation of the medical instrument system  14  and/or the endoscopic imaging system  15 . A supplemental imaging system  90  including an image processing controller  92  and a minimally invasive imaging cannula  94  may be used with the medical instrument system  14  and endoscopic imaging system  15  as will be described below. Together with the patient side cart, the supplemental imaging system  90  may be known as or may form a part of a patient side system. The endoscopic imaging system  15  provides images of the external surfaces of anatomic structures within the surgical environment. The supplemental imaging system  90  may be an internal imaging system capable of imaging beyond the external surface of the anatomical structures. 
     The operator input system  16  may be located at a health care provider&#39;s console which is usually located in the same room as operating table O. It should be understood, however, that the health care provider S can be located in a different room or a completely different building from the patient P. The health care provider&#39;s operator input system  16  includes left and right eye displays for presenting the health care provider S with a coordinated stereo view of the surgical site that enables depth perception. The operator input system  16  further includes one or more input control devices which cause the teleoperated assembly  12  to manipulate one or more instruments or the endoscopic imaging system. The input control devices can provide the same degrees of freedom as their associated instruments  14  to provide the health care provider S with telepresence, or the perception that the input control devices are integral with the instruments  14  so that the health care provider has a strong sense of directly controlling the instruments  14 . To this end, position, force, and tactile feedback sensors (not shown) may be employed to transmit position, force, and tactile sensations from the instruments  14  back to the health care provider&#39;s hands through the input control devices. The control device(s) may include one or more of any number of a variety of input devices, such as hand grips, joysticks, trackballs, data gloves, trigger-guns, hand-operated controllers, voice recognition devices, touch screens, body motion or presence sensors, and the like. In some embodiments, the control device(s) will be provided with the same degrees of freedom as the medical instruments of the teleoperated assembly to provide the health care provider with telepresence, the perception that the control device(s) are integral with the instruments so that the health care provider has a strong sense of directly controlling instruments as if present at the surgical site. In other embodiments, the control device(s) may have more or fewer degrees of freedom than the associated medical instruments and still provide the health care provider with telepresence. In some embodiments, the control device(s) are manual input devices which move with six degrees of freedom, and which may also include an actuatable handle for actuating instruments (for example, for closing grasping jaws, applying an electrical potential to an electrode, delivering a medicinal treatment, and the like). 
     The teleoperated assembly  12  supports and manipulates the medical instrument system  14  while the health care provider S views the surgical site through the console  16 . An image of the surgical site can be obtained by the endoscopic imaging system  15 , such as a stereoscopic endoscope, which can be manipulated by the teleoperated assembly  12  to orient the endoscope  15 . An electronics cart  18  can be used to process the images of the surgical site for subsequent display to the health care provider S through the health care provider&#39;s console  16 . The number of medical instrument systems  14  used at one time will generally depend on the diagnostic or surgical procedure and the space constraints within the operating room among other factors. The teleoperated assembly  12  may include a kinematic structure of one or more non-servo controlled links (e.g., one or more links that may be manually positioned and locked in place, generally referred to as a set-up structure) and a teleoperated manipulator. The teleoperated assembly  12  includes a plurality of motors that drive inputs on the medical instrument system  14 . These motors move in response to commands from the control system (e.g., control system  20 ). The motors include drive systems which when coupled to the medical instrument system  14  may advance the medical instrument into a naturally or surgically created anatomical orifice. Other motorized drive systems may move the distal end of the medical instrument in multiple degrees of freedom, which may include three degrees of linear motion (e.g., linear motion along the X, Y, Z Cartesian axes) and in three degrees of rotational motion (e.g., rotation about the X, Y, Z Cartesian axes). Additionally, the motors can be used to actuate an articulable end effector of the instrument for grasping tissue in the jaws of a biopsy device or the like. 
     The teleoperated medical system  10  also includes a control system  20 . The control system  20  includes at least one memory and at least one processor (not shown), and typically a plurality of processors, for effecting control between the medical instrument system  14 , the endoscopic system  15 , the operator input system  16 , and monitors on the electronics cart  18 . The control system  20  may also receive and process images from the supplemental imaging system  90 . The electronics cart  18  may house components of the endoscopic imaging system  15 , the supplemental imaging system  90 , the control system  20  as well as monitors and processors for processing and displaying captured images. 
     Some examples of processors may include non-transient, tangible, machine readable media that include executable code that when run by one or more processors may cause the one or more processors to perform the processes of method  600 . Some common forms of machine readable media that may include the processes of method  600  are, for example, floppy disk, flexible disk, hard disk, magnetic tape, any other magnetic medium, CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, RAM, PROM, EPROM, FLASH-EPROM, any other memory chip or cartridge, and/or any other medium from which a processor or computer is adapted to read. 
     The control system  20  also includes programmed instructions (e.g., a computer-readable medium storing the instructions) to implement some or all of the methods described in accordance with aspects disclosed herein. While control system  20  is shown as a single block in the simplified schematic of  FIG. 1A , the system may include two or more data processing circuits with one portion of the processing optionally being performed on or adjacent the teleoperated assembly  12 , another portion of the processing being performed at the operator input system  16 , and the like. Any of a wide variety of centralized or distributed data processing architectures may be employed. Similarly, the programmed instructions may be implemented as a number of separate programs or subroutines, or they may be integrated into a number of other aspects of the teleoperated systems described herein. In one embodiment, control system  20  supports wireless communication protocols such as Bluetooth, IrDA, HomeRF, IEEE 802.11, DECT and Wireless Telemetry. 
     In some embodiments, control system  20  may include one or more servo controllers that receive force and/or torque feedback from the medical instrument system  14 . Responsive to the feedback, the servo controllers transmit signals to the operator input system  16 . The servo controller(s) may also transmit signals instructing teleoperated assembly  12  to move the medical instrument system(s)  14  and/or endoscopic imaging system  15  which extend into an internal surgical site within the patient&#39;s body via openings in the body. Any suitable conventional or specialized servo controller may be used. A servo controller may be separate from, or integrated with, teleoperated assembly  12 . In some embodiments, the servo controller and teleoperated assembly are provided as part of a teleoperated arm cart positioned adjacent to the patient&#39;s body. 
     The teleoperated medical system  10  may further include optional operation and support systems (not shown) such as illumination systems, steering control systems, irrigation systems, and/or suction systems. In alternative embodiments, the teleoperated system may include more than one teleoperated assembly and/or more than one operator input system. The exact number of manipulator assemblies will depend on the surgical procedure and the space constraints within the operating room, among other factors. The operator input systems may be collocated, or they may be positioned in separate locations. 
       FIG. 1B  is a perspective view of one embodiment of a teleoperated assembly  12  and a block diagram of a supplemental imaging system  90 . The teleoperated assembly  12  shown provides for the manipulation of three surgical tools  26  (e.g., instrument systems  14 ) and an imaging device  28  (e.g., endoscopic imaging system  15 ), such as a stereoscopic endoscope used for the capture of images of the site of the procedure. As used herein, the term capture or captured images is intended to include still shots, video, and streaming. The imaging device may transmit signals over a cable  56  to the electronics cart  18 . Manipulation is provided by teleoperative mechanisms having a number of joints. The imaging device  28  and the surgical tools  26  can be positioned and manipulated through incisions or natural orifices in the patient so that a kinematic remote center is maintained at the incision to minimize the size of the incision. Images of the surgical site can include images of the distal ends of the surgical tools  26  when they are positioned within the field-of-view of the imaging device  28 . 
     The teleoperated assembly  12  includes a drivable base  58 . The drivable base  58  is connected to a telescoping column  57 , which allows for adjustment of the height of the arms  54 . The arms  54  may include a rotating joint  55  that both rotates and moves up and down. Each of the arms  54  may be connected to an orienting platform  53 . The orienting platform  53  may be capable of 360 degrees of rotation. The teleoperated assembly  12  may also include a telescoping horizontal cantilever  52  for moving the orienting platform  53  in a horizontal direction. 
     In the present example, each of the arms  54  connects to a manipulator arm  51 . The manipulator arms  51  may connect directly to surgical tools  26 . The manipulator arms  51  may be teleoperable. In some examples, the arms  54  connecting to the orienting platform are not teleoperable. Rather, such arms  54  are positioned as desired before the health care provider begins operation with the teleoperative components. 
     The supplemental imaging system  90  may provide imaging functionality that augments and/or complements the functionalities provided by surgical tools  26 . The supplemental imaging system  90  includes the image processing controller  92  and the imaging cannula  94  to provide the additional imaging functionality. The imaging cannula  94  may be a minimally invasive instrument sized for insertion into the surgical environment. The supplemental imaging system  90  and the imaging cannula  94  are discussed in greater detail below with reference to  FIGS. 2 and 3A-5B . 
     Endoscopic imaging systems (e.g., systems  15 ,  90 , and/or  28 ) may be provided in a variety of configurations including rigid or flexible endoscopes. Rigid endoscopes include a rigid tube housing a relay lens system for transmitting an image from a distal end to a proximal end of the endoscope. Flexible endoscopes transmit images using one or more flexible optical fibers. Digital image based endoscopes have a “chip on the tip” camera design in which a distal digital sensor such as a one or more charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device acquire image data. Endoscopic imaging systems may provide two- or three-dimensional images of the endoscopic field of view (i.e. the imaging area) to the viewer. Two-dimensional images may provide limited depth perception. Three-dimensional stereo endoscopic images may provide the viewer with more accurate depth perception. Stereo endoscopic instruments employ stereo cameras to capture stereo images of the field of view of the patient anatomy. An endoscopic instrument may be a fully sterilizable assembly with the endoscope cable, handle and shaft all rigidly coupled and hermetically sealed. 
       FIG. 2  is a simplified illustration of the supplemental imaging system  90  including the image processing controller  92  and the image cannula  94 . As indicated above, the supplemental imaging system  90  may be incorporated into a teleoperational medical system such as the teleoperated medical system  10  shown in  FIGS. 1A and 1B . In other implementations, the supplemental imaging system  90  may be used independently of the teleoperated medical system depicted in  FIGS. 1A and 1B . For example, the supplemental imaging system  90  may be used in standalone and/or manually operated applications. 
     The imaging cannula  94  includes a main body  102 , a displaceable tip  104 , an optional hub  106 , and a displaceable member, described herein as a hinge  130 . 
     The main body  102  is formed as a hollow tube having a distal end  110  and a proximal end  112 , and having a lumen  116  passing therethrough from the distal end  110  to the proximal end  112 . In the implementation shown, the main body  102  is formed as a cylinder defining and extending along an axis  114 . The main body  102  may be insertable into the body of the patient for the delivery or removal of fluid, gathering of data, or providing access to instruments or surgical tools inserted through the lumen  116 . Although the diameter of the main body  102  may vary, some implementations include a range of about 14 to 24 gauge. Other sizes are contemplated. In addition, the main body  102  may have any length sufficient to provide access to the desired region of the patient. In some implementations, the length of the main body may be within a range of about 1 inch to 12 inches, although other lengths, both larger and smaller, are contemplated. 
     The hub  106  may be disposed at the proximal end  112  of the main body  102 . The hub  106  may be a flange or collar having a diameter greater than the diameter of the main body  102 . In some implementations, the hub  106  may act as a mechanical stop that prevents the imaging cannula  94  from moving distally further into a patient. In some implementations, the hub  106  may be disposed a specific or known distance from the distal end  110  of the main body so that a health care provider is immediately aware of a depth of the distal end  110  of the main body  102  when the hub  106  abuts against the patient&#39;s body or other mechanical stop. In some implementations, the hub  106  may be a connector connectable to tubes or other components or systems usable during the surgery. 
     The tip  104  is disposed at the distal end  110  of the main body  102 . The tip  104  may include a pointed leading end  120  and a trailing end  122 . The outer diameter of the tip  104  may be sized to substantially match the circular outer diameter of the main body  102 . In embodiments where the outer profile of a cross-section of the main body  102  is a shape other than a circle, the outer profile of the tip  104  may be shaped to match that of the outer profile of the main body  102 . For example, if the main body  102  had a substantially square cross-section, the outer peripheral edge of the tip  104  may also have a substantially square cross-section. Other cross-sectional shapes are contemplated. The pointed leading end  120  may be sized and arranged to pierce patient tissue when the imaging cannula  94  is introduced into a patient. For example, the tip  104  may be pointed in the manner of a trocar needle in order to puncture the patient&#39;s body and pass through tissue to provide access to a region of interest within the patient&#39;s body. The trailing end  122  may be sized and arranged to abut against the distal end  110  of the main body  102 , and the tip  104  may be sized to cover the lumen  116  of the main body  102 . 
     The tip  104  also may include one or more imaging components, such as a camera  124  to enable the imaging cannula  94  to capture images of tissue, a body cavity, a surgical site which may include surgical tools at a surgical site, or other area of interest within a patient&#39;s body. In some implementations, the camera may be used to image tissue through which the imaging cannula  94  passes when introduced to the patient&#39;s body. Some implementations include a single camera  124  in the tip  104 , while other implementations include two or more cameras as described below. In some implementations, the camera  124  in the tip  104  may be configured to capture still images or a video stream. In some implementations, a live video stream may be transmitted from the camera  124  in the tip  104  to the image processing controller  92  forming a portion of the supplemental imaging system  90 . In some implementations, a portion or the entire tip  104  may be formed of a transparent material through which images may be captured. In some implementations, the tip  104 , or portions of the tip  104 , may be formed of transparent polymers including acrylics poly-carbonates, polyethylenes, polyethylene, composite plastics, including polymer nano-composites, or other materials. 
     In some implementations, the outer surface of the tip  104  may comprise a lens for the camera  124  disposed in or forming the tip  104 . For example, the pointed leading end  120  may have a particular shape that provides focused light by means of refraction to the camera  124  in a manner processable by the image processing controller  92  to generate an image, which may be stored or presented to the health care provider at the operator input system  16 . In some instances, the trailing end  122  also has a particular shape to form a lens. For example, the trailing end  122  may include a lens that focuses light into the camera  124  of the tip  104 . In other implementations, the trailing end  122  is a flat plane through which the camera  124  may capture images without focus distortion. In such systems, the camera  124  may include lenses independent of the trailing end  122  of the tip  104 . Naturally, any convex shape of the trailing end  122  may be less pronounced than the curved shape of the leading end  120 . 
     The tip  104  may be connected to the main body  102  by a displacing element shown and described herein as a hinge  130 . In this embodiment, the hinge is disposed at the distal end  110  of the main body  102  connecting the main body  102  to the tip  104 . In some implementations, the hinge  130  permits the tip  104  to pivot from a first position where the pointed leading end  120  of the tip  104  faces in the distal direction indicated by the arrow  140  to a second position where the pointed leading end  120  of the tip  104  faces a proximal direction indicated by the arrow  142 . These positions may be generally referred to as a closed position where the tip is in line with the lumen  116  and the pointed leading end extends in the distal direction  140  and as an open position where the tip  104  is out of alignment with the lumen  116 . The purpose of this displaceable tip  104  will become apparent in accordance with the further description below. 
     The hinge  130  may be any type of hinge suitable for pivoting the tip  104  from the closed position to the open position. In some implementations, the hinge  130  includes a pivot hinge acting as a mechanical bearing connecting the tip  104  to the main body  102 . In some implementations, the hinge provides a fixed axis of rotation about which the tip  104  pivots to move from the closed position covering the lumen  116  of the main body  102  to the open position where the lumen  116  is open or accessible. 
     Depending on the implementation, the hinge  130  may be a standard hinge having two leaves, each with at least one knuckle, and with a pin extending through the knuckles and defining a pivot axis about which the leaves rotate. Particularly, the knuckles may extend from the leaves and wrap around the pin. Other types of hinges may be used. For example, some implementations of the imaging cannula  94  include concealed hinges embedded in the distal edge of the main body  102  and the trailing end  122  of the tip  104 . Such a concealed hinge ensures that the tip  104  may properly abut against the distal end  110  of the main body  102  in a manner that maintains the hinge  130  at a position within the outer boundary of the main body  102 . So doing may ensure that the hinge  130  is not exposed to rub against, tear, or introduce additional trauma to tissue as the cannula  94  is introduced through tissue into the patient. 
     In some cases, the hinge  130  may be a biased hinge that may bias the tip  104  toward the closed position where the pointed leading end  120  of the tip  104  faces in the distal direction indicated by the arrow  140 . In other cases, the hinge  130  may be a biased hinge that may bias the tip  104  toward the open position where the pointed leading end  120  of the tip  104  faces the proximal direction indicated by the arrow  142 . In yet other cases, the hinge  130  may be arranged to be biased toward both the closed position and the open position. In such cases, the hinge  130  may require a relatively higher applied force to move the tip  104  away from the closed position toward the open position, but as the tip  104  approaches the open position, the biasing force takes over and snaps the tip  104  to the open position. Likewise, the same biasing force toward the open position would need to be overcome in order to move the tip to the closed position. As the tip  104  approaches the closed position, the biasing force toward the closed position may snap the tip  104  toward the closed position. 
     In some instances, the hinge  130  may be a spring hinge biasing the tip as described. That is, depending on the implementation, the spring hinge may include a spring biasing the tip  104  to a position away from the distal end  110  of the main body  102 , to a position toward the distal end  110  of the main body, or both. Accordingly, the tip  104  may be biased to an open position, a closed position, or biased toward at least two discrete positions. 
     In some embodiments, the hinge is a flexure hinge formed as a compliant mechanism. The flexure hinge may be formed of the same material as the tip  104  or may be attached to the tip  104  and the main body  102  using an adhesive, screws, ultrasonic welding, or other attachment mechanism. In some implementations, the flexure hinge may bias the tip  104  toward one, two, or more positions. For example, in some implementations, the flexure hinge biases the tip  104  toward the closed position and also biases the tip  104  toward the open position. 
     In implementations where the hinge  130  biases the tip  104  to discreet positions that correspond with the closed position and the open position, the discrete positions may be established to be those that direct the camera  124  carried in the tip  104  to provide a desired field of view. In some implementations, the discrete positions are first and open positions arranged to be 180 degrees from each other as will be described with reference to  FIGS. 3A and 3B . Other implementations have discrete positions at 90 degrees from each other, at 120 degrees from each other, or at other angles. 
     In the implementation shown, the cannula  94  is connected to the image processing controller  92  via a cable  132 . The cable  132  may extend to the camera  124 , and may be arranged to carry data signals from the camera  124  to the image processing controller  92 . As indicated above, the image processing controller  92  may be in communication with or may form a part of the control system  20  of the teleoperated medical system  10 . In some implementations, the image processing controller  92  may be disposed in the tip  104  with the camera  124 . In one implementation, the camera  124  includes a light detector or image sensor, while the image processing occurs at the image processing controller  92 . In other implementations, the camera  124  includes the light detector or image sensor and the processor and memory functions to enable the camera to capture images. The cable  132  may also carry commands to the camera  124 . For example, if the camera  124  is capable of an optical zoom, then control signals from the health care provider to the camera may be carried by the cable  132 . In some implementations, the cable  132  may extend down the lumen  116  of the main body  102 , may be embedded in the wall of the main body  102 , or may be otherwise situated to physically connect the camera  124  to the image processing controller  92 . In some implementations, the camera  124  includes or is in communication with a wireless transmitter or transceiver that may transmit or stream signals of captured images to the image processing controller  92  for storage or display to the health care provider. 
       FIGS. 3A and 3B  show a side view of the imaging cannula  94 . In  FIG. 3A , the tip  104  is disposed in a closed position, with the tip  104  in-line with the main body  102  and covering its lumen  116  (shown in  FIG. 2 ). In  FIG. 3B , the tip  104  is disposed in a open position, with the tip  104  disposed out of line with the lumen  116 . In this implementation, the tip  104  is disposed adjacent the side or exterior surface of the main body  102 . In the open position, a health care provider or the teleoperated assembly  12  may introduce surgical tools  26  ( FIG. 1B ) through the lumen  116  of the imaging cannula  94  to perform a medical task or procedure. Accordingly, in the implementation shown, the tip  104  pivots 180° about the hinge  130  from the closed position shown in  FIG. 3A  to the open position shown in  FIG. 3B . 
     The position of the camera  124  in the tip  104  is also apparent in these Figures. In  FIG. 3A , the tip  104  includes two cameras  124 , disposed back to back. For explanatory purposes,  FIG. 3A  refers to a first camera  124   a  and a second camera  124   b . Since the tip  104  is formed of a clear or transparent material, the cameras  124   a ,  124   b  are able to image through the material of the tip  104  and capture images. 
       FIG. 3A  shows the cannula  94  ready for insertion through skin and tissue of the patient to a cavity undergoing examination or treatment. Accordingly, with the tip  104  disposed in-line with the axis  114  (or in a closed position), the field-of-view  140   a  from the camera  124   a  appears in the distal direction  140  in front of the tip  104 . Accordingly, as the cannula  94  is inserted into the patient, the camera  124   a  can image the tissues that come in contact with the tip  104 . This may enable a healthcare provider to determine what tissues are being transected by the imaging cannula  94 . In addition, this may enable the user to determine when the distal tip  104  has reached the interior of the patient&#39;s body. For example, it may become visually apparent to a health care provider when the distal tip  104  enters a cavity to undergo treatment. 
       FIG. 3B  shows the cannula  94  in position to perform a surgical task to provide access to the interior of the patient. Here, the tip  104  is rotated 180° about the hinge  130 . Accordingly, the camera  124   a , and the leading end  120  of the tip  104  are pivoted about the hinge  130  to face the proximal direction  142 . Here, the camera  124   b  has also pivoted from a position facing the proximal direction  142  to a position facing the distal direction  140 . Accordingly, the camera  124   b  provides a field-of-view  140   b  facing the distal direction  140 . Because of this arrangement, the camera  124   b  may provide visualization to a health care provider of a surgical site, including visualization of surgical tools that may be inserted through the imaging cannula  94 . In some implementations, the tip  104  may be biased toward the discrete positions shown in the manner described herein. In this implementation, one discrete position may be the pivoted position in  FIG. 3B  with the tip  104  rotated 180°. In implementations with a hinge having two discrete positions, a first discrete position may be the position shown in  FIG. 3A  and a second discrete position may be the position shown in  FIG. 3B . In some implementations, the tip  104  may be rotated by a surgical tool introduced through the lumen  116  ( FIG. 2 ) to abut against and displace the tip  104  about the hinge  130 . 
     Alternative implementations may include discrete positions that are not 180° apart. As one example, a first discrete position of the tip  104  may be the position shown in  FIG. 3A , and a second discrete position of the tip  104  may be a position rotated 90° from the position shown in  FIG. 3A . In this instance, where two cameras are used, the camera  124   b  also may be pivoted by 90 degrees so as to provide a field-of-view facing in the distal direction  140 . 
     In one example using a spring hinge, the tip  104  may be biased to the position shown in  FIG. 3B  and not biased to the position shown in  FIG. 3A . In such an implementation, a healthcare provider may prepare for surgery by manually aligning the tip  104  in the position shown in  FIG. 3A  and placing the tip  104  against the patient&#39;s tissue so that the tissue resistance is greater than the spring force of the hinge  130 . In such a condition, the tissue itself may maintain the tip  104  in the closed position shown in  FIG. 3A  during the time period that the cannula  94  is being advanced through the patient tissue. Accordingly, the health care provider could view the tissue being transected by the cannula. When the tip  104  enters a cavity in the patient, the resistance to the spring force of the hinge  130  may be decreased, and the spring hinge may rotate or pivot the tip  104  to the position shown in  FIG. 3B . As such, the cannula  94  may be self-opening. 
       FIGS. 3A and 3B  show the cannula  94  using two cameras  124   a ,  124   b  to capture images with field of views in the distal direction  140 . In some implementations, both cameras  124   a  and  124   b  continuously stream images to the image processing controller  92 , which may form a part of the control system  20 . The control system  20  may then stream images to the operator input system  16  for live viewing by the health care provider S ( FIG. 1 .). In some implementations, the operator input system  16  may be arranged to receive inputs from a healthcare provider to command the control system  20  to switch viewpoints to change the display between images captured by the first camera  124   a  and images captured by the second camera  124   b . In other implementations, the operator input system may be arranged to activate or stream from one camera at a time. 
       FIGS. 4A and 4B  show another imaging cannula  200  with a single camera  202  facing one direction. The imaging cannula  200  differs from the cannula  94  only in that the tip  104  includes a single camera  202 . Accordingly, for simplicity, other portions of the imaging cannula  200  will not be re-described. The camera  202  has a field-of-view  140   a  facing in the distal direction  140  in  FIG. 4A . However, with the tip  104  pivoted about the hinge  130  in  FIG. 4B , the field-of-view is now facing in the proximal direction  142 . Accordingly, the cannula  200  may be unable to image the surgical site during the surgical procedure. 
       FIGS. 5A and 5B  show another imaging cannula  210  with a single camera  212  facing the direction opposite that shown in  FIGS. 4A and 4B . The imaging cannula  210  differs from the cannula  200  only in that the tip  104  includes the single camera  212  facing the direction opposite that shown in  FIGS. 4A and 4B . Again, for simplicity, other portions of the imaging cannula will not be re-described. The camera  212  has a field-of-view  140   b  facing in the distal direction  140  only when the tip  104  is pivoted to an open position where the cannula  210  is open. 
       FIG. 6  is a simplified diagram of a method  600  for imaging tissue of a patient during a surgical procedure. According to some embodiments, the method  600  may be performed using, for example, the teleoperated medical system  10  as described herein. The method may begin at  602  by preparing the patient for the surgical procedure. At  604 , the method includes creating an incision and introducing the cannula with a pivotable tip in a closed position. As used herein, the closed position is a position where the tip covers the lumen of the cannula. Creating the incision may include cutting tissue to create an opening through which the cannula may pass, or may include piercing the skin and tissue with the pointed tip of the cannula. Introducing the cannula to the patient with the tip in the closed position may include simply advancing the tip into patient tissue when the tip is biased to the closed position. Alternatively, it may include orienting the tip against a biasing force, such a biasing force of the hinge, to be in the closed position, and then placing the tip against the patient in order to maintain the tip in the dosed position while the tip is introduced to the patient. Accordingly in such instances, the force of patient tissue on the tip may be greater than the biasing force to maintain the tip of the closed position. 
     At  606 , the imaging cannula may capture or stream images from a camera in the tip as it advances through the patient tissue. The tip may include one, two, or more cameras arranged to capture images of portions of the surgical procedure. In some implementations, two cameras are arranged back to back in the cannula tip. These cameras may have different lens arrangements that may include or cooperate with the shape of the tip surfaces to provide images useful to the health care provider. Some implementations include a camera arranged to capture clear images of tissue in contact with the tip taking into account the angled surfaces forming the pointed leading end of the tip. Some implementations include a first camera arranged to clearly capture images of tissue in contact with the tip and a second camera arranged to clearly capture images of tissue or instruments spaced from the tip. At  606 , the imaging cannula may image tissues that come in contact with the tip. In so doing, the user may be able to determine what tissues are being transected by the cannula as well as determine when the cannula reaches a desired location at the interior of the patient&#39;s body. 
     At  608 , the tip may penetrate a body cavity or otherwise arrive at a desired location. In some implementations, entry into the body cavity may be visible and apparent based on images from the camera in the tip of the cannula. 
     At  610 , the camera tip may pivot from the closed position to an open position. As described herein, the open position may be a position where the tip is not aligned with the lumen of the cannula. In some implementations, the open position may be a position where the tip is pivoted 180° and is adjacent to and/or in contact with an exterior surface of a main body of the cannula. In some implementations, the tip may pivot in response to a surgical tool introduced from a proximal end of the cannula through the cannula to make contact against a proximally facing portion of the tip when the tip is in the closed position. Additional application of force may pivot the tip from its closed position in-line with the lumen of the cannula to an open position not in-line with the lumen of the cannula. As described herein, some hinges bias the tip to discrete positions. Accordingly, applying a force with a surgical tool against the tip may displace the tip from the lumen of the cannula, and the biasing hinge may continue to apply a biasing force to pivot the tip to a pre-established discrete position. In some implementations, this discrete position may be a position 180° about a pivot axis from the closed position to an open position. 
     In embodiments having a camera that faces the proximal direction when the tip is in the closed position, 180° pivoting may move the camera to face the distal direction. In this position, the camera may capture images distal of the distal end of imaging cannula. 
     At  612 , the imaging cannula may capture or stream images with a camera while the tip is in the open position. This may provide a distally facing field-of-view allowing imaging of an interior of a body cavity. This may also allow a user to guide and observe the entry of other cannulae or instruments. 
     Upon completion of a surgical procedure, at  614 , the cannula may be withdrawn from the patient. Because of the pivotable nature of the tip, tissue may cause the tip to pivot from the open position to a position at least partially aligned with the lumen of the cannula. The cannula and tip may then be withdrawn from the patient. 
     Any reference to surgical instruments and surgical methods is non-limiting as the instruments and methods described herein may be used for animals, human cadavers, animal cadavers, portions of human or animal anatomy, non-surgical diagnosis, industrial systems, and general robotic or teleoperational systems. 
     Although illustrative embodiments have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the embodiments may be employed without a corresponding use of other features. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. Thus, the scope of the invention should be limited only by the following claims, and it is appropriate that the claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.