Patent Publication Number: US-2023157529-A1

Title: Camera positioning method and apparatus for capturing images during a medical procedure

Description:
BACKGROUND 
     1. Field 
     This disclosure relates generally to positioning a camera for imaging and more particularly to positioning a camera inside a body cavity of a patient for capturing images during a medical procedure. 
     2. Description of Related Art 
     Miniaturized cameras are used during investigative medical procedures and surgical procedures such as laparoscopic surgery and computer assisted robotic surgery to produce images of a site of the procedure within a body cavity of the patient. The camera generally includes an illumination source for illuminating the site of the procedure. 
     SUMMARY 
     In accordance with one disclosed aspect there is provided an apparatus for positioning a camera to capture images inside a body cavity of a patient during a medical procedure. The apparatus includes an insertion tube, a plurality of connected linkages extending from a distal end of the insertion tube, each linkage having a threaded actuator received on a threaded end of a drive shaft extending between the threaded actuator and a proximal end of the insertion tube. The apparatus also includes a camera disposed at a distal end of the plurality of connected linkages. Each connected linkage has at least one associated movement actuated by movement of the threaded actuator in response to rotation of the drive shaft, the associated movements of the connected linkages together operable to facilitate positioning of the camera within the body cavity of the patient. 
     Each drive shaft may include a drive coupler at the proximal end of the drive shaft, the drive coupler operable to receive a drive torque for causing rotation of the drive shaft. 
     The drive couplers may be housed within a drive interface operably configured to removably couple to a driver unit, the driver unit being operable to provide the respective drive torques. 
     Each drive coupler may include a rotational coupler for transmitting torque to each drive shaft, the rotational coupler being operably configured to receive the proximal end of the drive shaft and to transmit the drive torque to the drive shaft while accommodating linear movement of the proximal end due to resulting movements of the camera. 
     The rotational coupler may include a tubular body for receiving the proximal end of drive shaft, the tubular body having a slotted portion that engages a pin extending through the proximal end of the drive shaft for coupling to the tubular body. 
     Each rotational coupler may include a moveable detent coupled to the proximal end of the drive shaft and operable to resiliently engage a fixed detent in the drive interface corresponding to a startup position for each of the proximal ends of the respective drive shafts, the startup positions of the drive shafts defining an insertion position of the camera. 
     The interface may be removably received on the drive unit, and wherein when received the moveable and fixed detents may be disengaged to permit movement of the camera away from the insertion position. Prior to removal of the interface, the drive unit is operably configured to place the camera in the insertion position causing the moveable and fixed detents to be aligned. When removed, the moveable and fixed detents are engaged to retain the rotational couplers in the startup position. 
     In the insertion position the camera may be positioned generally in line with a longitudinal axis extending outwardly from the insertion tube. 
     The plurality of connected linkages may include at least a panning linkage for producing side-to-side motion of the camera, an elevating linkage for moving the camera away from the longitudinal axis, and a tilt linkage for tilting the camera forward and backward with respect to the longitudinal axis. 
     The panning linkage may be connected to the distal end of the insertion tube, the elevating linkage is connected to the panning linkage and the tilt linkage is connected to the elevating linkage, and the camera may be attached to the tilt linkage. 
     At least one of the drive shafts may include a compliant portion facilitating bending of the shaft in response to movements of the camera while continuing to permit rotation of the at least one drive shaft. 
     Each linkage may include a revolute joint constrained to permit motion in a single degree of freedom corresponding to the associated movement of the linkage and the threaded actuator may be coupled to the linkage to cause motion about the revolute joint. 
     In accordance with another disclosed aspect there is provided a method for positioning a camera to capture images inside a body cavity of a patient during a medical procedure, the camera being disposed at a distal end of a plurality of connected linkages extending from a distal end of an insertion tube, each linkage having a threaded actuator received on a threaded end of a drive shaft extending between the threaded actuator and a proximal end of the insertion tub. The method involves selectively causing rotation of the respective drive shafts to cause movement of the respective threaded actuators, the movement of the respective threaded actuators causing associated movements of the connected linkages to positioning of the camera within the body cavity of the patient. 
     Selectively causing rotation of the respective drive shafts may involve causing the respective drive shafts to position the camera in an insertion position prior to removal from the body cavity of a patient. 
     Causing the respective drive shafts to position the camera in an insertion position may involve causing the camera to be positioned generally in line with a longitudinal axis of the insertion tube. 
     In accordance with another disclosed aspect there is provided an apparatus for positioning a camera to capture images inside a body cavity of a patient during a medical procedure. The apparatus includes an articulated arm includes a plurality of connected moveable linkages, a camera disposed at a distal end of the plurality of connected linkages, the camera including a camera housing enclosing image capture optics, an image sensor, and image capture electronic circuitry operable to produce image data representing images captured by the image sensor, and data transmission electrical circuitry operable to generate and transmit data signals encoding the image data to a host system, the data transmission electrical circuitry being housed within in one of the moveable linkages and coupled to the image capture electronic circuitry via a flexible interconnect. 
     Other aspects and features will become apparent to those ordinarily skilled in the art upon review of the following description of specific disclosed embodiments in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In drawings which illustrate disclosed embodiments, 
         FIG.  1    is a perspective view of a robotic surgical apparatus; 
         FIG.  2    is a perspective view of a drive unit and camera of the robotic surgical apparatus shown in  FIG.  1   ; 
         FIG.  3    is a perspective view of an insertion tube, linkages, and the camera shown in  FIG.  2   ; 
         FIG.  4    is a further enlarged perspective view of the linkages and camera shown in  FIG.  3   ; 
         FIG.  5    is a rear perspective view of the linkages and camera in a deployed state; 
         FIG.  6    is a rear perspective view of a drive interface shown in  FIG.  3   ; and 
         FIG.  7    is a front perspective view of the linkages and camera in a deployed state. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG.  1   , a robotic surgical apparatus is shown generally at  100 . The surgical apparatus  100  includes a cart  102  that supports an articulated boom  104  that carries a drive unit  106  having a camera  108  mounted on the drive unit. The cart  102  may be wheeled up to a patient (not shown) and the articulated boom  104  deployed to maneuver the drive unit  106  and camera  108  into a location for accessing a body cavity of the patient and positioning a camera to capture images inside the body cavity of a patient during a medical procedure. The surgical apparatus  100  may be controlled by a workstation console (not shown) connected to the surgical apparatus via a cable  110  that carries signals for controlling the drive unit  106  and camera  108 . 
     Referring to  FIG.  2   , the drive unit  106  and camera  108  are shown in front view. The camera  108  is mounted at a distal end of a plurality of connected linkages  120  extending from a distal end  122  of an insertion tube  124 . The insertion tube  124  extends outwardly from a drive interface  126  that is removably received on the drive unit  106 . 
     The camera  108 , insertion tube  124 , and drive interface  126  are shown in greater detail in  FIG.  3   . Referring to  FIG.  3   , in the embodiment shown the plurality of connected linkages  120  include a panning linkage  130 , an elevating linkage  132 , and a tilt linkage  134 . The panning linkage  130  is connected by a revolute joint  136  to the distal end  122  of the insertion tube  124 , which constrains the panning linkage to side-to-side motion in the direction indicated by the arrow  138 . The elevating linkage  132  is connected to the panning linkage  130  by a revolute joint  140 , which constrains the linkage to movement away from a longitudinal axis  142  in the direction indicated by the arrow  144 . The tilt linkage  134  is connected to the elevating linkage  132  by a revolute joint  148 , which constrains the linkage to movement for tilting the camera  108  forward and backward with respect to the longitudinal axis  142  in the direction indicated by the arrow  150 . 
     In the embodiment shown the panning linkage  130  is thus connected to the distal end  122  of the insertion tube  124 , the elevating linkage  132  is connected to the panning linkage  130  and the tilt linkage  134  is connected to the elevating linkage  132 . The camera  108  is disposed at a distal end of the plurality of connected linkages  120 , in this case connected to the tilt linkage  134 . In other embodiments the plurality of connected linkages  120  may be otherwise arranged and one or more of the linkages may be omitted. 
     The connected linkages  120  are shown in enlarged detail in  FIG.  4    with a distal cap  152  (shown in  FIG.  3   ) on the insertion tube  124  removed. Referring to  FIG.  4   , the panning linkage  130  has a threaded actuator  180  received on a threaded end  182  of a drive shaft  184 . The elevating linkage  132  has a threaded actuator  188  received on a threaded end  190  of a drive shaft  192 . The tilt linkage  134  has a threaded actuator  194  received on a threaded end  196  of a drive shaft  198 . Each of the drive shafts  184 ,  192  and  198  extend between the respective threaded actuators  180 ,  188 , and  194  and a proximal end  186  (shown in  FIG.  3   ) of the insertion tube  124 . The drive shafts  184 ,  192  and  198  are routed through respective bores  170 ,  172 , and  174  extending through the insertion tube  124  (only shown in part in  FIG.  4   ). The bores  170 ,  172 , and  174  are sized and configured such that each drive shaft  184 ,  192  and  198  is freely rotatable within the bores as indicated by the arrows shown in  FIG.  4   . 
     Each connected linkage  120  thus has at least one associated movement actuated by movement of the respective threaded actuators  180 ,  188 , and  194  in response to rotation of the respective drive shafts  184 ,  192  and  198 . The associated movements of the connected linkages  120  are together operable to facilitate positioning of the camera  108  within the body cavity of the patient. For example, rotation of the shaft  184  causes the threaded actuator  180  to move either forwardly or rearwardly in a direction aligned with the longitudinal axis  142  causing the panning linkage  130  to pan about the revolute joint  136  moving the camera  108  from side to side. In the embodiment shown, each of the linkages  120  thus includes a revolute joint ( 136 ,  140 ,  148 ) constrained to permit motion in a single degree of freedom corresponding to the associated movement of the linkage and a threaded actuator ( 180 ,  188 , and  194 ) coupled to the linkage to cause motion about the revolute joint. 
     Referring to  FIG.  5   , the camera  108  is shown in rear view in a deployed state with the drive shafts  184 ,  192  and  198  omitted for clarity. The threaded actuator  180  terminates in a ball and socket joint  200  on the rear of the panning linkage  130  which facilitates pivoting at the joint during movement. Similarly the threaded actuator  188  terminates in a ball and socket joint  202  on a strut  204  of the elevating linkage  132 . A proximal end threaded actuator  188  is received in a hinged block  206  and rotation of the drive shaft  192  causes the elevating linkage  132  to raise or lower with respect to the longitudinal axis  142 . Finally, the threaded actuator  194  is mounted in a first swivel block  208  on the elevating linkage  132  and has a distal end that is clamped to a second swivel block on the tilt linkage  134 . Rotation of the drive shaft  198  causes the camera  108  to tilt up or down about the revolute joint  148 . 
     When the drive shafts  184 ,  192  and  198  are rotated to cause the camera  108  to be deployed, the linkages  120  are displaced from the longitudinal axis  142  causing portions of the drive shafts  192  and  198  running through the panning linkage  130  and elevating linkage  132  to be bent through an angle. The drive shafts  192  and  198  thus have at least a compliant portion within the linkages to facilitating bending of the shaft in response to movements of the camera  108 . The compliant portion permits the drive shaft  192  and  198  to be bent through the necessary angle while continuing to permit rotation of the drive shafts for actuating the respective linkages. In some embodiments the drive shafts may be fabricated entirely from a compliant material, while in other embodiments the drive shafts may have some rigid portions and some compliant portions. In one embodiment at least a portion of drive shafts may be fabricated from a hollow stainless steel tube. 
     Referring back to  FIG.  3   , the camera  108  and plurality of connected linkages  120  are generally aligned along the longitudinal axis  142  extending outwardly from the insertion tube, which may define an insertion position for inserting the camera  108 , linkages  120  and insertion tube  124  into the body cavity of the patient. Once inserted the drive shafts  184 ,  192  and  198  may be rotated to deploy the camera  108  as shown in  FIG.  5   . Referring to  FIGS.  3  and  4   , in the embodiment shown the insertion tube  124  includes at least one bore  154  for receiving an instrument for performing surgical operations within the body cavity of the patient. The instrument may be a dexterous surgical instrument such as described in commonly owned PCT Patent Application PCT/CA2013/001076 entitled ARTICULATED TOOL POSITIONER AND SYSTEM EMPLOYING SAME and PCT Patent Application PCT/CA2015/000098 entitled ACTUATOR AND DRIVE FOR MANIPULATING A TOOL, both of which are incorporated herein in their entirety. 
     Referring back to  FIG.  3   , the drive interface  126  includes a housing  158  having a front cover  160  and a rear cover  162 . Referring to  FIG.  6   , the drive interface  126  is shown with the front cover  160  omitted and the rear cover  162  removed to reveal the drive components. The drive shafts  184 ,  192  and  198  are routed back through the respective bores  172 ,  174 , and  176  in the insertion tube  124  and are bent upwardly within the housing  158  and have proximal ends  260 ,  262 , and  264  that terminate in respective drive couplers  266 ,  268 , and  270 . The drive couplers  266 ,  268 , and  270  are identical and the drive coupler  270  will be further described herein. The drive coupler  270  includes a bevel gear assembly  272  that receives a drive torque from the drive unit  106  (shown in  FIG.  2   ) at a drive hub  274  when the drive interface  126  is engaged on the drive unit. The bevel gear assembly  272  rotates in the direction indicated by the arrow and the rotating motion is coupled through the gears via a shaft  276  to a rotational coupler  278 . The rotational coupler  278  is generally operable to receive the proximal end  264  of the drive shaft  198  and to transmit the drive torque to the drive shaft while accommodating linear movement of the proximal end due to resulting movements of the camera  108 . When the plurality of connected linkages  120  move, the drive shafts  184 ,  192  and  198  extend or retract with the motion, which must be accommodated. In the embodiment shown, the rotational coupler  278  has a tubular body  280  for receiving the proximal end  264  of drive shaft  198 . The tubular body  280  has a slotted portion  282  that engages a pin  284  extending through the proximal end of the drive shaft for coupling to the tubular body. The pin  284  couples the rotational torque to the proximal end  264  of the drive shaft  198  while permitting the proximal end and pin to slide within the slotted portion  282  of the tubular body  280 , thus accommodating extension or retraction of the drive shaft. 
     In the embodiment shown the drive coupler  270  also includes a moveable detent mechanism  290 , which is coupled to move with the proximal end  264  of the drive shaft  198 . The moveable detent  290  has a pin  292  operable to resiliently engage a rear side of a fixed detent plate  294  on the rear cover  162 . The fixed detent plate  294  has an opening  296  sized to accommodate a head of the pin  292 , the opening being positioned to define a startup position for the proximal end  264  of the drive shaft  198  that places the camera  108  in the insertion position aligned with the longitudinal axis  142 , as shown in  FIG.  3   . In one embodiment, the drive interface  126  is removably received on the drive unit  106  and when received, the pin  292  on the moveable detent mechanism  290  is disengaged to permit movement of the camera  108  away from the insertion position. Prior to removal of the interface  126  from the drive unit  106 , the drive unit is operably configured to return the camera  108  to the insertion position causing the pin  292  and the opening  296  on the fixed detent plate  294  to be aligned but not yet engaged. When the drive interface  126  is removed from the drive unit  106 , the pin  292  and the opening  296  engage and retain the rotational coupler  278  in the startup position. The drive couplers  266  and  268  have similar moveable and fixed detent mechanisms that operate in the same way. Advantageously, the detent mechanism locks the drive interface  126  in the insertion position when not received on the drive unit  106  preventing movement of the drive hub  274  and other drive hubs which would at least partially deploy the camera  108 . The plurality of connected linkages  120  and camera  108  thus remain in the insertion position while being cleaned and sterilized, and when re-used will be in a known orientation. 
     The camera  108  shown in the above embodiments will general be miniaturized to improve access to the body cavity of the patient and to reduce the size of incision needed to provide access for the camera in surgical procedures. In some embodiments, the camera may include one or more high definition image sensors (not shown), where a pair of image sensors are capable of producing stereoscopic 3D views within the body cavity. The image sensors include sensor electronic circuitry that generates image data representing the captured images. The captured image data must be transmitted back to the drive unit  106 , which requires additional data transmission circuitry. The image capture electronic circuitry and data transmission electrical circuitry may generate significant heat within the housing of the camera  108 . Referring to  FIG.  7   , in one embodiment the camera  108  houses the image sensors and image capture electronic circuitry. A data transmission printed circuit board  300  carries the data transmission electrical circuitry and is housed within the elevating linkage  132 . The image capture electronic circuitry and data transmission electrical circuitry may be coupled via a flexible interconnect (not shown) that permits the  108  to be tilted by the tilt linkage  134 . Advantageously, the separation of electrical circuitry places a significant source of heat in the linkage away from the housing of the camera  108 , thus spreading the heat load over a larger area. 
     In accordance with another disclosed aspect there is provided an apparatus for positioning a camera to capture images inside a body cavity of a patient during a medical procedure. The apparatus includes an articulated arm that includes a plurality of connected moveable linkages, a camera disposed at a distal end of the plurality of connected linkages, the camera including a camera housing enclosing image capture optics, an image sensor, and image capture electronic circuitry operable to produce image data representing images captured by the image sensor, and data transmission electrical circuitry operable to generate and transmit data signals encoding the image data to a host system, the data transmission electrical circuitry being housed within in one of the moveable linkages and coupled to the image capture electronic circuitry via a flexible interconnect. 
     While specific embodiments have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.