Abstract:
A motorized surgical instrument that may be held by the surgeon or be attached to the surgeon&#39;s limb by means of a special adapter that includes an interface between the surgeon and the surgical tool. The motorized surgical instrument includes mechanism, motors, gears, interface and power source that enable the surgeon to easily control the motorized surgical tools in order perform the surgical procedure. The system differs from prior art systems in that the surgeon operates the tools by using the natural hand motions he would use if he were performing direct manual surgery on the subject. The described motorized surgical tool has a wider range of movement and reach than commonly used surgical tools. These new properties increase the possibilities of tool maneuvering by the surgeon, while allowing the surgeon to operate the motorized surgical tool segments easily while maintaining a comfortable posture.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the field of remotely manipulated surgical tools, generally for laparoscopic surgery, especially such tools having motorized motions in several degrees of freedom. 
       BACKGROUND OF THE INVENTION 
       [0002]    In laparoscopic surgery, the surgeon performs the operation through small incisions made in the patient&#39;s body cavity, using long instruments and observing the internal anatomy and the progress of the surgical procedure with an endoscope camera. Such surgical tools are conventionally held manually by the surgeon, often using both hands, and the instruments are generally activated by the power of the surgeon&#39;s bare hands, in much the same way as regular surgical instruments used for conventional surgery, are operated. 
         [0003]    To overcome these problems, several surgical tools have been developed, But these technologies are often uncomfortable to use, may limit the dexterity of the surgeon and Relatively to the required action. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention seeks to present a novel surgical tool mechanism and interface for activating surgical instruments, useful for performing laproscopic surgical procedures on a patient&#39;s body. The system incorporates a surgical tool or effector having both articulated joints and rotations, and differs from prior art instruments in that the actuation is powered by means of electric motors driving combinations of gears and actuating mechanisms. The system is constructed to simulate the motions that would be made by a manually-held, equivalently functional tool. The system comprises a body that includes motors, gears and a power source; mechanisms which enable change of the spatial position of the surgical tool&#39;s component parts; and a mechanism which enables control of the surgical tool end effector. The motion is preferably transmitted by means of rotation of small diameter concentric hollow tubes, connected at their proximal ends to a gear housing, and connected at their distal ends to either an end effector, or to a second set of articulately joined concentric hollow tubes. According to one embodiment, the connections between two tubes sets enables transmitting rotation power from one set of tubes to the other simultaneously. Other connections between the tube sets enable transmitting angular moments from one set of tubes to the other simultaneously. The end effector is connected at the distal part of the last set of tubes. The motorized surgical body may be held by the surgeon in various ways—either by directly holding the motorized surgical tool body, or by means of an adapter that enables the surgeon to connect the motorized surgical tool to his limbs or other parts of his body. 
         [0005]    The use of motorization in the present invention reduces muscular fatigue in the surgeons hands or arms, since the tool motions are performed under power. Prior art robotic surgical tools overcome the problem of muscular fatigue, but the motions required by the surgeon at the operating interface are often unnatural compared with the tactile feeling when using an equivalent manual tool. Furthermore, prior art robotic systems are generally based on full size anthropomorphic robots, which are generally of such a size that the surgeon cannot get sufficiently close to the patient to view the operation from close-up. The arrangement of the present invention, and in particular, its small physical dimensions, allows close personal contact of the surgeon with the patient. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: 
           [0007]      FIG. 1  illustrates schematically a surgeon performing a laparoscopic procedure on a patient in the operating room, using a first preferred embodiment of the system of the present invention; 
           [0008]      FIG. 2  is a close-up schematic view of the set of motorized surgical tools shown in  FIG. 1 ; 
           [0009]      FIG. 3  is a close up schematic view of the motorized surgical tool, according to another preferred embodiment of the present invention, held in the surgeon&#39;s right hand of  FIGS. 1 and 2 ; 
           [0010]      FIG. 4  shows a first kind of motorized surgical tool and its degrees of freedom 
           [0011]      FIG. 5  illustrates a motorized surgical tool, similar to that shown in  FIG. 4 , but equipped with a grip handle and a battery cavity; 
           [0012]      FIG. 6  illustrates schematically a preferred interface for the motorized surgical tool of  FIG. 4 , showing the positions of the controls for each degree of freedom; 
           [0013]      FIG. 7  illustrates schematically, an internal view of the gear box of the tool of  FIGS. 3 to 5 ; 
           [0014]      FIG. 8  shows a concentric system of Cardan joints allowing simultaneous power transmission through the articulated arm of the tool of  FIGS. 2 to 7 ; 
           [0015]      FIGS. 9   a  and  9   b  illustrate schematically an arrangement for converting the rotary motion shown in  FIG. 8  into a linear motion required to actuate the jaws of the grasper: 
           [0016]      FIG. 10  is a close up schematic view of the motorized surgical tool, according to a further preferred embodiment of the present invention, held in the surgeon&#39;s left hand in  FIGS. 1 and 2 ; 
           [0017]      FIG. 11  is an external schematic view of the motor/gear housing of the preferred motorized tool shown in  FIG. 10 ; 
           [0018]      FIG. 12  is an internal view of the motor/gear housing of  FIG. 11 ; 
           [0019]      FIG. 13  is an internal view of a planetary gear cluster preferably used within the motor/gear housing of the embodiment of  FIGS. 11 and 12 ; 
           [0020]      FIG. 14  shows the distal part of the motor/gear housing showing a screw mechanism for converting the rotary motor motion to linear motion; 
           [0021]      FIGS. 15   a ,  15   b  and  15   c  show more details of the screw mechanism of  FIG. 14 , for converting the rotary motor motion to linear motion; 
           [0022]      FIG. 16  shows the main parts of the linear mechanism that enables the opening and closing the jaws of the grasper of the tool of  FIGS. 10 to 15   c ; and 
           [0023]      FIG. 17  is an overall view of the system from the surgeon&#39;s stance, showing the interface motions required for effecting the four separate motions enabled by the embodiment of the tool shown in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0024]    Reference is now made to  FIG. 1 , which illustrates schematically a surgeon  10  performing a laparoscopic procedure on a patient  11  in the operating room, using a first preferred embodiment of the system of the present invention. The system is characterized in that the surgeon&#39;s hands  12 ,  13 , are able to grip and manipulate the robotic interface handles in a manner close to the way in which manually held instruments performing the same procedure would be gripped and manipulated by the surgeon. The interface of the tools of the present system thus imitates the motion of the hands of the surgeon, and uses similar, if not the same, motions and muscles. The system can preferably utilize several different tools for different functions, which can be readily changed during the surgical procedure with change in the surgical tasks to be performed. Alternatively and preferably, the basic tool motion transmission mechanism can be standardized, and different heads used for different motion or actuation functions. 
         [0025]    Reference is now made to  FIG. 2 , which is a close up schematic view of the set of motorized surgical tools shown in  FIG. 1 , held in the surgeon&#39;s hands  12 ,  13  by operating arms  28 ,  29 . The tool  20  in the surgeon&#39;s left hand is a grasper  21 . In this embodiment, three degrees of freedom (DOF) of motion are available, namely the rotation  22  of the grasper, its opening and closing action  23 , and the linear motion  24  of the actuating rod  26  along the direction of the length of the tool. The first two motions are power-implemented by the tool&#39;s motors and gears, housed in the motor casing  25 , while the third, linear motion is implemented by the surgeon&#39;s own manual moving of the whole tool using motion of his hand. It is to be understood that further degrees of motion are also possible, such as angular tilt in any direction, since the tool is held in the surgeon&#39;s hand, which can move freely in space. However, such further degrees of freedom are likely to be largely limited in practice by the constrained surgical environment in which the tool is being used. Further details of the operation of this tool are given hereinbelow in  FIGS. 10 to 16 , and associated description. 
         [0026]    Reference is now made to  FIG. 3 , which is a close up schematic view of the motorized surgical tool, according to another preferred embodiment of the present invention, held in the surgeon&#39;s right hand  12  of  FIGS. 1 and 2 . This tool  30  also has a grasper at its extremity, but in this case includes an articulated arm, such that unlike the embodiment in  FIG. 2 , it has 4 degrees of freedom. 
         [0027]    Reference is now made to  FIG. 4 , which is a view of the tool  30  of  FIG. 3 , showing the motions provided by this embodiment. The motions originate in the gear box  40 , which contains the motors and transmission gears for generating the movements needed for the tool functions. The first DOF,  41 , designated DF 1 , is a rotationary motion of the upper arm  42  of the tool. The second DOF  43 , designated DF 2 , is a bending motion between the upper arm  42  of the tool and the lower arm  44 . The third DOF  45 , designated DF 3 , is a rotationary motion of the lower arm  44  of the tool. The final DOF  46 , designated DF 4 , is the actuation of the opening and closing of the grasper end effector  47 . A combination of all of these motions enables a high level of flexibility to be achieved with this tool, even without taking into account any additional movement or orientation supplied by manual motion of the surgeon&#39;s hand. The operation of the motion actuators of the tool of the embodiment of  FIG. 4  is further explained in  FIGS. 6 to 9B . 
         [0028]    Reference is now made to  FIG. 5 , which illustrates schematically a motorized surgical tool  50 , similar to that shown in  FIG. 4 , but equipped with a grip handle  51  and a battery cavity  52 , such that it can be directly hand-held by the surgeon and used as an independent tool. It is to be understood that this option can be applied to any of the motorized surgical tool preferred embodiments described herewithin. 
         [0029]    Reference is now made to  FIG. 6 , which illustrates schematically, according to a further preferred embodiment of the present invention, an interface  60  for the motorized surgical tool of  FIG. 4 , showing the positions of the controls for each degree of freedom. The interface is held in the surgeon&#39;s hand, such that simple access to each of the motion controls can be obtained. Rotation of the upper arm is achieved by rotation of the finger control marked DF 1 . Rotation of the lower arm is achieved by rotation of the knob marked DF 3 . Bending of the arm joint is accomplished by backward and forward motion of the thumb hook marked DF 2 . Closing of the grasper is achieved by pressure on the trigger marked DF 4 , preferably using the base of the palm of the hand. Each of the interface controls is preferably connected to a rotary or sliding potentiometer, whose output signal is used for controlling the motor responsible for that particular motion. If the grasper is a two-position tool, i.e. either open or closed, the trigger DF 4  will preferably operate a microswitch to open or close the grasper. If the grasper&#39;s jaws can be continuously adjusted between open and closed, then a potentiometer type of input control is preferably used at the interface. It is to be understood that the control interface shown in  FIG. 6  is only one possible embodiment, and that the invention is not meant to be limited by the particular combination shown in  FIG. 6 . 
         [0030]    Reference is now made to  FIG. 7 , which illustrates schematically, according to a further preferred embodiment of the present invention, an inside view of the gear box  40  of the tool of  FIGS. 3 to 5 , showing a preferred arrangement of the motors and transmission gears for generating the movements needed for the tool functions. Motion DF 1 , rotation of the upper arm, is transmitted to the upper arm outer tube  42 , by means of the belt drive  71 , driven by shaft  72 , which receives its drive from electric motor  73  through gear train  74 . Bending motion DF 2  of the articulated arm is provided from motor  75  though the gear train  76 , which transmits the motion down the inside of the upper arm outer tube  42 . Motion DF 3 , rotation of the lower arm, is generated by motor  77 , and transmitted through gear train  78  to a shaft running inside of the upper arm outer tube  42 , to rotate the lower arm. Transfer of this inner rotation through the articulated arm joint is achieved using a double Cardan joint, which will be described in  FIG. 8  hereinbelow. Finally, motion DF 4  for operating the grasper jaws is obtained from motor  79  through gear train  70  to the innermost shaft within the upper arm outer shaft. 
         [0031]    Reference is now made to  FIG. 8 , which illustrates schematically, according to a further preferred embodiment of the present invention, an arrangement for transmitting the rotary motion DF 3  for operating the lower arm rotation, and the rotary motion DF 4  for operating the grasper, through the joint of the articulated arm of the tool. A concentric double Cardan joint is used, the inner joint being of conventional design using a double yoke  80 , and the outer joint using a ring  81  with the orthogonal hinges  82 ,  83 , attached thereto to avoid interfering with the inner joint. Although a Cardan joint does not provide a smooth angular transfer of motion when the angle between the input and output shafts is large, since unlike other types of flexible joints such as a constant-velocity joints, it can be simply constructed in a concentric design, it becomes the joint of choice for application in the tools of the present invention. 
         [0032]    The rotary motion transmitted down the centermost drive channel of the tool arms, used for operating the grasper at the end of the lower arm, has to be converted to linear motion in order to actuate the grasper. The actuating power is preferably originated as rotary motion because of the ease of production of rotary motion by means of a motor, and is also transmitted as rotary motion because of the ease with which it can traverse the joint in the articulated arm, using the concentric Cardan joint shown in  FIG. 8 . 
         [0033]    Reference is now made to  FIGS. 9   a  and  9   b , which illustrate schematically, according to a further preferred embodiment of the present invention, an arrangement for converting this rotary motion into the linear motion required to actuate the grasper. In  FIG. 9   a , there is shown an overall view of the internal motion actuating components within the lower arm. After traversing the articulated joint, the motion is converted from rotary  90  to linear  91  preferably in a screw motion converter  92 , whose action is shown in detail in  FIG. 9   b  hereinbelow. The linear motion  91  actuates the grasper jaws to open or close them,  93 . The lower arm is not shown in  FIG. 9   a , but is understood to enclose the motion rod  94  and screw converter  92  shown therein, such that when the lower rod is rotated, the grasper also rotates. 
         [0034]    Since the grasper operates directly on the patient&#39;s tissue, it is important that excessive clamping pressure is not applied thereto. In order to avoid such a situation, according to further preferred embodiments of this invention, one or more clutches are added to the rotary motion train before the screw converter, in order to limit the torque which can be applied, and hence the closure force of the grasper jaws. Additionally and preferably, in order to provide more tactile sensitivity for the surgeon, a force feedback loop can be applied to the grasper control, using a torque sensor, such that the surgeon can feel the apparent force being applied to grasp the tissue. 
         [0035]    Reference is now made to  FIG. 9   b , which illustrates schematically a preferred internal construction of the screw motion converter shown in  FIG. 9   a . The actuating nut of the converter is an internal thread formed in the converter housing  92 . As the converter housing is rotated, the screw  93  moves up or down depending on the direction of rotation. A ball  94  connected to the end of the actuator rod  95  of the grasper, is held captive but free to move within a cavity in the screw structure, and as the screw structure moves up and down, it pulls the ball with it, and hence the actuator rod  95 . The rod can be prevented from turning with rotation of the converter housing by clamping the connector flange  96  in a housing which allows it to move up and down but not to rotate. Such an embodiment is shown in more detail in  FIGS. 15   a  to  15   c  hereinbelow. Alternatively and preferably, instead of a ball  94  at the top end of the actuator rod, a shape such as a hexagon or square may be used to prevent the rod and screw from turning with rotation of the converter housing. 
         [0036]    Reference is now made to  FIG. 10 , which is a close up schematic view of the motorized surgical tool, according to a preferred embodiment of the present invention, held in the surgeon&#39;s left hand  12  of  FIGS. 1 and 2 . The operation of the tool has been described in  FIG. 2  hereinabove. In  FIG. 10 , the rotary motion DF 1  and the grasper jaw actuation motion DF 2  are shown. 
         [0037]      FIG. 11  is an external schematic view of the motor/gear housing  25  of the preferred motorized tool shown in  FIG. 10 , showing the actuating rod  26  projecting from its distal end. 
         [0038]      FIG. 12  is an internal view of the motor/gear housing  25  of  FIG. 11 , with the lower part of the outer casing removed, showing at its distal end, the motor  120  for providing the DF 2  motion for the gripper, and at its proximal end, the motor  121  for providing the DF 1  rotary motion of the tool. 
         [0039]    Reference is now made to  FIG. 13 , which is an internal view of a planetary gear cluster  130  preferably used within the motor/gear housing of  FIGS. 11 and 12 , for increasing the torque and reducing the rotational speed of the motor  121  which provides the tool with the rotation motion DF 1 . The ring gear  131  acts as the output shaft of the planetary gear cluster, and is attached to the lower part of the motor/gear housing  25 , to which is attached the actuating arm  26 . 
         [0040]      FIG. 14  shows the distal part of the motor/gear housing  25 , showing the screw mechanism for converting the rotary motor  120  motion to linear motion for actuating the grasper jaw motion DF 2 . The rotary motion applied to the screw  140  causes the nut  141  to move up and down within its cavity in the end plate  142  of the motor/gear housing, since it is constrained from turning by the flaps on its periphery. 
         [0041]      FIGS. 15   a, b, c  show more details of the screw mechanism of  FIG. 14 , for converting the rotary motor  120  motion to linear motion.  FIG. 15   a  shows how the nut  141  is held stationary within the end plate of the motor/gear housing by its flaps  145 .  FIG. 15   b  is an X-ray view of the nut  141 .  FIG. 15   c  is a view of the distal end of the nut showing the cavity  146  for containing a ball at the proximal ends of the actuating rod, similar to the embodiment described in  FIG. 9   b.    
         [0042]      FIG. 16  shows the main parts of the linear mechanism that enables the opening and closing the jaws of grasper, from the nut  141 , via the ball headed actuating rod  160  to the jaw actuating arms, providing the grasping motion DF 2 . 
         [0043]    Reference is now made to  FIG. 17 , which is an overall view of the system from the surgeon&#39;s stance, showing the four separate motions enabled by the embodiment of the tool shown in  FIG. 4 . The interface controls shown are an alternative embodiment from those shown in  FIG. 6  hereinabove, but the operating principles remain the same. In the embodiment of  FIG. 17 , the surgeon&#39;s right hand  12  is holding the tool by the operating arm  28 . The control for actuating the motion DF 4  of the grasper jaws  170  comprises two, preferably thumb-operated, triggers  171 ,  172 , for opening and closing the jaws. The rotation DF 3  of the lower arm of the tool is accomplished in the preferred embodiment of  FIG. 17  by rotation of the hand held triggers, those which actuate the jaw motion DF 4 . The bending motion DF 2  of the articulated arm is accomplished by rotation of the operating arm  28  around its axis. 
         [0044]    It is appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of various features described hereinabove as well as variations and modifications thereto which would occur to a person of skill in the art upon reading the above description and which are not in the prior art.