Patent Publication Number: US-11020197-B2

Title: Control unit for a medical device

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/911,467, filed on Feb. 11, 2016, which is a National Phase of PCT Patent Application No. PCT/IL2014/050781 having International Filing Date of Sep. 1, 2014, which claims the benefit of priority under 35 USC § 119(e) of U.S. Provisional Patent Application Nos. 61/972,528 filed on Mar. 31, 2014 and 61/872,727 filed on Sep. 1, 2013. 
    
    
     The contents of the above applications are all incorporated by reference as if fully set forth herein in their entirety. 
     FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates to a control unit for a medical device and, more particularly, to a control unit and integrated user interface which enable translation of natural hand movements to an attached medical tool such as a laparoscopic tool to thereby enable precise and fine control over the position and function of the medical device. 
     Medical devices such as endoscopes and catheters are widely used in minimally invasive surgery for viewing or treating organs, cavities, passageways, and tissues. Generally, such devices include an elongated device body which is designed for delivering and positioning a distally-mounted instrument (e.g. scalpel, grasper or camera/camera lens) within a body cavity, vessel or tissue. 
     Since such devices are delivered through a delivery port which is positioned through a small incision made in the tissue wall (e.g. abdominal wall), and are utilized in an anatomically constrained space, it is desirable that the medical device or at least a portion thereof be steerable, or maneuverable inside the body using controls positioned outside the body (at the proximal end of the medical device). Such steering enables an operator to guide the device within the body and accurately position the distally-mounted instrument at an anatomical landmark. 
     Various interfaces for endoscopic instruments have been described in the prior art, see, for example, U.S. Patent Application Nos. 2008/0255420 and 2012/0041450 and U.S. Pat. No. 7,572,253. 
     However, there remains a need for a medical device control unit having an interface that allows the surgeon to intuitively maneuver a surgical tool inside the body while allowing precise control through a wide range of device and effector-end movements. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention there is provided a control unit for a medical device, the control unit comprising a user interface including (a) a first interface being mounted on a pivotal support attached to a housing of the control unit, the first interface being engageable by a palm of a hand; (b) a restraint being pivotally attached to the first interface and having an element capable of elastically deforming to apply a restraining force to a back of the hand when the palm is engaged with the first interface; and (c) a second interface being pivotally attached to the first interface and being engageable by one or more fingers of the hand. 
     According to further features in preferred embodiments of the invention described below, the pivotal support is gimbaled. 
     According to still further features in the described preferred embodiments the control unit further comprises a housing including a drive unit. 
     According to still further features in the described preferred embodiments the second interface includes levers are sequentially or simultaneously operable via thumb and index finger of the hand. 
     According to still further features in the described preferred embodiments the first interface can be tilted with respect to the pivotal support. 
     According to still further features in the described preferred embodiments tilting of the first interface deflects a steerable portion of the medical device. 
     According to still further features in the described preferred embodiments the levers operate an effector end of the medical device. 
     According to still further features in the described preferred embodiments the second interface can be tilted with respect to the first interface. 
     According to still further features in the described preferred embodiments tilting of the second interface deflects an effector end of the medical device. 
     According to still further features in the described preferred embodiments the drive unit includes at least one motor and control wires for operating the medical device. 
     According to another aspect of the present invention there is provided control unit for a minimally invasive surgical tool, the control unit comprising a user interface including: (a) a first interface control being engageable by a back of a hand of a user and being for controlling an angle and height of the minimally invasive surgical tool with respect to a tissue access site; (b) a second interface control being engageable by a palm of the hand of the user and being for controlling a deflection of a steerable portion of the minimally invasive surgical tool; and (c) a third interface control being engageable by one or more fingers of the user and being for controlling a tissue manipulating end of the minimally invasive surgical tool. 
     According to still further features in the described preferred embodiments the control unit further comprises a housing including a drive unit. 
     According to still further features in the described preferred embodiments the second interface control is gimbaled. 
     According to still further features in the described preferred embodiments the first interface control includes an arm hingedly connected to a dorsum pad. 
     According to still further features in the described preferred embodiments the control unit further comprises a knob for rotating the housing with respect to the first, second and third interface controls. 
     According to still further features in the described preferred embodiments the third interface control includes a pair of finger holds operable via a thumb and index finger. 
     According to still further features in the described preferred embodiments the third interface control includes a ball rotatable around at least two perpendicular axis. 
     According to still further features in the described preferred embodiments a user can simultaneously operate the first, second and third interface controls via a single hand. 
     According to still further features in the described preferred embodiments the drive unit includes at least one motor for operating the minimally invasive laparoscopic tool. 
     According to still further features in the described preferred embodiments the control unit further comprises a strap or clamp for securing the hand of the user to the first interface control. 
     The present invention successfully addresses the shortcomings of the presently known configurations by providing a control unit for a surgical tool such a laparoscope. The control unit includes a user interface that enables a user to simultaneously control the movement and actuation of an attached surgical tool such as a laparoscope using a single hand. 
     Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. 
       In the drawings: 
         FIGS. 1 a -1 c    illustrate one embodiment of the control unit of the present invention attached to a laparoscope.  FIG. 1 a    is a general view of motorized laparoscopic tool and the surgeon interface,  FIG. 1 b    illustrates positioning of the surgeon&#39;s hand within the surgeon interface.  FIG. 1 c    shows the laparoscopic tool without the motor pack cover. 
         FIGS. 2 a -2 b    illustrate the interface portion of the interface ( FIG. 2 a   ) and a user&#39;s hand mounted thereon. 
         FIGS. 3 a -3 d    illustrate the dorsum interface portion of the present invention. 
         FIGS. 4 a -4 g    illustrate the palm interface portion and the palm interface mechanical components including an exemplary joystick component ( FIG. 4 g   ) of the present invention. 
         FIGS. 5 a -5 e    illustrate the movements of the palm interface and the corresponded movements of the articulation 
         FIGS. 6 a -6 b    illustrate one embodiment of the finger interface portion of the present invention. 
         FIGS. 7 a -7 b    illustrate the surgeon options for ergonomic adjustments of the finger interface portion of the present invention. 
         FIGS. 8 a -8 d    illustrate the finger interface portion of the present invention and related components. 
         FIGS. 9 a -9 i    illustrate jaws open-close modes enabled by the finger interface portion of the present invention. 
         FIGS. 10 a -10 b    illustrate jaw rotational modes enabled by the finger interface portion of the present invention. 
         FIG. 10 c    is a sensor utilizable by the finger interface of the present control unit. 
         FIGS. 11 a -11 b    illustrate an embodiment of the present invention which enables simultaneous control over two steerable portion of an attached laparoscope.  FIG. 11 a    is a cut-away view of the interface, showing a sensor for enabling control of a second steerable portion.  FIG. 11 b    illustrates articulation with 2 independent steerable portions. 
         FIGS. 12 a -12 e    illustrate the operation of a second portion of the interface that controls a second steerable portion enabled by rotating the finger interface portion with respect to the palm interface portion of the present invention. 
         FIGS. 13 a -13 h    illustrate interface controls over two independent steerable portions. 
         FIGS. 14 a -14 b   ,  FIG. 15  and  FIG. 16  illustrate a motorized drive unit embodiment of the control unit of the present invention. 
         FIG. 17  illustrates how user interface (UI) movements translate into activation signals in control unit and movement of a laparoscopic tool attached thereto. 
         FIG. 18  illustrates various operational modes of the control unit of the present invention. 
         FIGS. 19-20  illustrate a prototype control unit constructed in accordance with the teachings of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is of a control unit and interface which can be used to control the movement, position and function of an attached medical device. Specifically, the present invention can be used to control a surgical tool such a laparoscope using natural hand movements. 
     The principles and operation of the present invention may be better understood with reference to the drawings and accompanying descriptions. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     In laparoscopic surgery, a surgeon has to position the distal end portion (including the tissue manipulating end, e.g., grasper) of the laparoscope within a body cavity (e.g. abdominal cavity) and adjacent to treated tissue. In order to correctly position the laparoscope, the surgeon has to spatially orient the entire laparoscope while controlling deflection of the steerable portion and actuating the tissue manipulating end. 
     A surgeon typically uses an interface (handle) of a surgical tool for positioning, maneuvering, holding and operating the device and effector end at the tissue site of interest. While presently used device interfaces can provide such functionality, they can be limited by a tradeoff between maneuverability and operability of the entire device and its effector end (instrument mounted on a distal end of a laparoscope shaft) thus requiring considerable time and effort on the part of the surgeon to complete a minimally invasive treatment procedure. 
     Experiments performed using various prototypes of the laparoscopic tool interface described herein have led to the development of a control unit and interface that can provide a surgeon with more natural and complete control over the operation of a medical device such as a laparoscope. 
     Thus, according to one aspect of the present invention there is provided a control unit for a medical device. 
     The control unit includes a drive unit and attached user interface. As is further described hereinunder, the interface is operated by a single hand of a user and actuates motors and control wires within the control unit to thereby control positioning, movement and operation of a medical device attached to the control unit. 
     The control unit includes a user interface which has separate control for device positioning, movement and effector end positioning and operation. The user interface includes a first interface which is mounted on a pivotal support attached to a housing of the control unit. The first interface is engageable by a palm of a hand and enables the user to control deflection of a steerable portion of the medical device as well as rotation and tilting (with respect to tissue access site) of the entire device. 
     To maintain the palm of a user against the first interface through tilting, rotation and angulation, the control unit further includes a restraint which is pivotally attached to the first interface and includes an element that is capable of elastically deforming to apply a restraining force to a back of the hand (dorsum) when the palm is engaged with the first interface. When this restraint engages the back of the hand, the element elastically deforms and applies a downward force to the back of the hand thus maintaining the hand against the first interface and enabling precise control of this interface, as well as, enabling the user to pull up on the medical device. 
     The control unit also includes a second interface which is pivotally attached to the first interface and is engageable by one or more fingers of the hand. 
     The user interface of the present invention is suitable for use with any medical device used for viewing or manipulating tissue at a site of treatment in or on the body of a mammal (e.g. human subject). 
     The medical device of the present invention is preferably used in minimally invasive surgery wherein a steerable distal portion thereof positioned within a body of a subject is controlled from a proximal end positioned outside the body (extra corporeally) via, for example, control wires. The medical device can be used for viewing or for manipulating tissues within any body cavity. Examples of medical devices that can benefit from the present invention include an endoscope (e.g. laparoscope or thorascope), a catheter, a surgical holder and the like. 
     The user interface of the present invention is particularly suitable for use with a laparoscopic device having a steerable distal portion and a distally-mounted instrument such as a grasper or cutter. 
     Laparoscopes are widely used in minimally invasive surgery for viewing or treating organs, cavities, passageways, and tissues. Generally, such devices include an elongated device body which is designed for delivering and positioning a distally-mounted instrument (e.g. scalpel, grasper or camera/camera lens) within a body cavity, vessel or tissue. 
     Since such devices are delivered though a delivery port which is positioned through a small incision made in the tissue wall (e.g. abdominal wall), and are utilized in an anatomically constrained space (within, for example, the abdominal cavity), it is desirable that the medical device or at least a portion thereof be steerable, or maneuverable inside the body using controls positioned outside the body (at the proximal end of the medical device). Such steering enables an operator to guide the device within the body and accurately position the distally-mounted instrument at an anatomical landmark. 
     Numerous examples of steerable devices are known in the art, see for example, U.S. Pat. Nos. 2,498,692; 4,753,223; 6,126,649; 5,873,842; 7,481,793; 6,817,974; 7,682,307 and U.S. Patent Application Publication No. 20090259141. 
     Deflection of the steerable portion is typically effected via one or more control wires which run along the shaft of the device to the distal end of the steerable portion. 
     The proximal end of each control wire is connected to the control unit; pulling of the wire applies forces that deflect the steerable portion with relation to the pulled wire. 
     The device effector end (distally-mounted instrument) is controlled via one or more additional wires which are similarly connected to the control unit and actuated by the user interface. Thus, the user interface and control unit of a steerable device such as a steerable laparoscope provides three separate functions, positioning of the device shaft with respect to the tissue access site (up/down, angle), deflection of the steerable portion, and actuation of the distally mounted instrument. 
     The user interface of the present invention provides these three functions via movement of three separate limb joint and muscle groups. 
     (i) The shaft of the device is moved up and down and side to side with respect to the tissue access site by arm movement (primarily about the elbow and/or shoulder joints). 
     (ii) The steerable portion of the device shaft is deflected via hand movement (primarily about the wrist joint). This is achieved by tilting the first interface. 
     (iii) The distally mounted instrument is actuated via finger movement (primarily about the inter-phalangeal joints and the metacarpal-phalangeal joints). Finger movement can also be used to deflect the device shaft around a second deflection region. 
     The present interface provides several advantages when used to position and operate a surgical tool such as a steerable laparoscope: 
     (i) greater and more natural maneuverability—a laparoscope can be operated using less effort and without requiring extreme maneuvering of body and limbs; 
     (ii) simultaneous control over the three functions—the laparoscope can be positioned while being steered and actuated; 
     (iii) single handed operation—all movements are controlled via a single hand using three interface regions, the dorsum, the palm and the fingers; 
     (iv) single handed operation of multiple steerable portions—all movements are controlled via a single hand operating simultaneously three interface regions, the dorsum, the palm and the fingers; 
     (v) compact interface fits in the palm of a hand, instinctive operation shortens learning curve; and 
     (vi) can be used to control any attached/integrated surgical instrument. 
     The control unit and interface of the present invention are described in more detail below with reference to  FIGS. 1 a   - 13   h.    
       FIGS. 1 a -1 b    illustrate control unit  10  attached to surgical tool  12 . For illustrative purposes control unit  10  is shown attached to a laparoscope  12  in  FIG. 1 a    with a hand  100  of a user engaged with user interface  80  of control unit  10  ( FIG. 1 b   ). It will be understood however, that control unit  10  (or only interface  80  thereof) can be attached to, or integrated with, any surgical instrument that can benefit from the present invention. 
     Control unit  10  includes a housing  14  which contains a drive unit  16  circuitry  15  shown in  FIG. 1 c    and an interface  80  which is mounted on a proximal end  20  of housing  14 . Housing  14  and interface  80  can be fabricated from a polymer and/or alloy using machining, 3D printing and/or casting/molding fabrication approaches. Housing  14  can be 40-60 mm in diameter and about 60-120 mm in height. 
     Laparoscope  12  includes a shaft  13  having a steerable portion  22  and a distally mounted instrument (grasper  24  shown). Laparoscope can be fabricated using materials and approaches well known in the art. 
     Shaft  13  includes a plurality of wire guides (not shown) disposed along its length for routing one or more control wires (not shown) from drive unit  14  to an end of the steerable portion and one or more actuation wires from drive unit  14  to grasper  24 . In the case of a device which includes two or more separately steerable portions (e.g. enabling zigzag-shaped deflection), each control wire is routed to an end of a respective steerable portion. 
     Shaft  13  can be 20-40 cm in length and 3-12 mm in diameter and can be hollow or solid. A hollow shaft  13  enables internal routing of wires, in a solid configuration of shaft  13 , wires can be routed on the external surface of shaft  13  through dedicated guides. 
     The steerable portion of shaft  13  can be fabricated from a tube having cutouts (e.g. such as those shown in U.S. Pat. No. 4,911,148) or from links (e.g. U.S. Pat. Nos. 7,682,307, 6,817,974) with control wires running through guides formed in the tube or links. Alternatively, the steerable portion can be fabricated as described in U.S. Provisional Patent Application No. 61/765,745 to the present inventor, the teachings of which are fully incorporated herein. 
     Proximal end  30  of shaft  13  is attached to a distal end  32  of housing  14 , and control and actuation wires/rods of shaft  13  run through housing  32  and attach to drive unit  16 . Drive unit  16  can include levers and gears for translating movements of user interface  80  to pulling of control and/or actuation wires. Such transfer can be mechanical (manual) or motorized. A motorized embodiment of drive unit  16  is shown in  FIG. 1 c    and  FIGS. 14 a -14 b    and  15 - 16 . 
       FIG. 1 b    illustrates engagement between hand  100  of a user and interface  80 . The surgeon&#39;s hand  100  is placed in such a manner where the back of the user&#39;s hand (herein dorsum  101 ) is positioned under restraint  33  (of dorsum interface  30 ) while three of the user&#39;s fingers are free to grasp first interface  40  (also referred to herein as palm interface  40 ), the thumb and index fingers engage a second interface  60  (also referred to herein as finger interface  60 ). 
       FIG. 1 c    illustrates control unit  10  with housing cover removed showing drive unit and associated components. Drive unit  16  includes a motor pack, battery  11 , the electrical circuits of controller  15  and base  41  of palm interface  40 . Diathermia plug  17  is shown connected to the device body. 
       FIG. 2 a    illustrates the three control interfaces of user interface  80  in greater detail; dorsum interface  30 , palm interface  40  and finger interface  60 . 
     Dorsum interface  30  includes two arc-shaped elements  32  and  33  that are interconnected at their ends. Element  33  engages dorsum  101  and is elastically deformable to conform to dorsum  101  while applying a downward force thereto. Element  32  is preferably rigid but can have some elasticity. Dorsum interface  30  is connected to palm interface  40  at  31 . Dorsum interface  30  may be immovably attached to base  41  or it may freely rotate with respect to base  41  thereby adjusting to the manner in which a user&#39;s hand fits against (on top of) palm interface  42 . 
     Palm interface  40  is pivotally attached to a base  41  which includes sensors for measuring the spatial orientation of the user&#39;s hand, by measuring the orientation of palm surface  42  with respect to base  41 . 
     Finger interface  60  is connected to palm interface  40  via shaft  91 . Shaft  91  form a part of a ball joint  90  (not visible) that allows shaft  91  to spatially rotate with respect to palm interface  40 . The movement of shaft  91  allows the user to adjust the orientation of finger interface  60  in order to achieve optimal ergonomics. 
     Knob  92  allows the user to adjust the frictional force on ball joint  90 , allowing to fixate finger interface  60  with respect to palm interface  40  or to enable the user to change the orientation of finger interface  60  at any time. 
     Finger interface  60  is used to control an effector end (e.g. surgical tool such as grasper) of the device. Finger interface  60  can simultaneously determine the distance between the user&#39;s fingers and their orientation via sensors attached to the levers of this interface. 
       FIG. 2 b    typical engagement between interface  80  and hand  100  of the user. The palm of the user rests against palm surface  42  of palm interface  40 , dorsum  101  is positioned underneath dorsum interface  30  (and is forced downward by the elastic deformation of element  33 ), three of the user&#39;s fingers grasp the circumference of palm surface  42  and the other two fingers (thumb and index finger) engage (pinch) levers  62  of finger interface  60 . While holding interface  80 , the user can tilt palm surface  42 , and open/close or rotate levers  62  of finger interface  60 . While performing these movements, sensors locate at interface  40  and  60  measure the movement. The sensors measurements are sampled by controller  15 . Controller  15  compares the orientation of palm surface  42  to the orientation of articulation  22  ( FIG. 5 e   ). If there is a difference the controller sends commands to the motors in order to change the orientation of articulation  22  to match that of the user&#39;s hand. 
     Finger interface  60  measures a distance between the thumb and index fingers engaging the levers, by measuring for example the angles of finger levers  62  of this interface. Controller  15  calculates the difference between the distance of the fingers and the distance between, for example, the jaws of a grasper effector end, and sends commands to the motor that operates the jaws open-close mechanism in order to match jaw opening to finger distance. 
     Rotational (twist) measurement is enabled via a rotation sensor (not shown) that measures the angle between finger interface  60  and shaft  91 . Controller  15  calculates the difference between the angle of the fingers and the angle between the jaws and the shaft. If there is a difference between the measurements, controller  15  sends commands to the motor that operates the jaws rotation mechanism in order to match jaw rotation to finger angulation. 
     Some of the measurements sampled by controller  15  may be scaled in order to maintain optimal ergonomics. For example, the movement of a user&#39;s hand can be scaled up in order to provide large changes in shaft deflection via relatively small palm movements, or alternatively, movement of the user&#39;s hand can be scaled dawn to increase accuracy of movement. 
     As is described hereinabove, each of these interface elements serves a different control function and all three can be operated simultaneously to enable precise and intuitive control over laparoscopic tool  12 , steerable portion  22  and effector end  24  (e.g. grasper). 
     In addition to the above, user interface  80  can also include buttons (on interface  40  or  60 , or on housing of control unit  10 ) for operating a light source, diathermia device, camera and the like positioned within control unit  10 , on shaft of the medical device (e.g., in the steerable portion, or at effector end  24 ). 
     Each of these interface elements is described hereinunder starting with dorsum interface  30 . 
     Dorsum Interface 
       FIGS. 3 a -3 b    illustrate one embodiment of a dorsum interface  30  constructed in accordance with the teachings of the present invention. Dorsum interface  30  includes an arced shaped restraint  32  which is pivotally connected to the body of the palm interface  40  through hinge  31 . 
     Hinge  31  may rotate freely or may be lockable and enables setting of an angle between handle  32  and palm interface distal end  42 . 
     Element  33  serves as the elastic/deformable connection between dorsum interface and the back of the human hand (dorsum). 
     Dorsum interface  30  allows the user to control the spatial position and orientation of the device. When the user disengages from palm surface  42  and finger interface  60  as is shown in  FIGS. 3 c -3 d   , element  33  of dorsum interface  30  enables the user to change the height, angle and rotation of a medical device attached to control unit  10  with respect to the tissue access site. Such control is achieved by hand movements around the elbow and shoulder joints and to a lesser degree by torso movements without a need to actually grasp the palm surface  42 . Dorsum interface  30  also allows the user to release the finger hold on palm interface  40 , thereby providing rest for the operating hand while still being engaged to interface  80 . 
     Palm Interface 
     Palm interface  40  measures the orientation of a user&#39;s arm with respect to the device attached to control unit  10 . 
       FIGS. 4 a -4 e    illustrate the main components of palm interface  40 . Base  41  is the connection between housing  14  and palm surface  42 . Base  41  serves as the housing for motor  49 . Motor  49  controls the position of spherical brake  43 . Inner spherical body  48  shown in  FIG. 4 c    is fixed without moving to base  41  and contains joy stick sensor  50 . Hemi-spherical parts  44  and  45  are connected to each other and contain inner spherical body  48  thus forming a ball joint/gimbal. Cylinder  51  connects rod  53  with top surface of part  45 . When assembled, parts  44  and  45  can rotate around part  48  thereby rotating rod  53  of joy stick sensor  50 . Pin  56  is connected to inner spherical body  48  and placed in slot  57 . This configuration prevents parts  44  and  45  of the ball joint from undesired twist around a third axis of inner ball  48 . Beam  47  connects the ball joint (formed from parts  44  and  45 ) and palm surface  42 . 
     Palm surface  42  is shaped as a hemisphere and can include electrical switches for controlling desired functions of the medical device. Switch  53  serves as a panic button. If a user senses that the medical device is not functioning as desired, actuation of the panic button immediately arrests the motors and prevents any function of the medical device. 
     Switch  52  controls a brake mechanism within the ball joint which can be activated by the user to “freeze” articulation at a desired orientation. When switch  52  is actuated, a spherical brake  43  engages part  44  ( FIG. 4 e   ) to apply friction thereto and prevent it from rotating with respect to part  50 . 
     A second actuation of switch  52  actuates motor  49  which moves brake  43  away from part  44  ( FIG. 4 d   ). Switch  52  can also be used to set various operation modes of control unit  10  as is further described hereinbelow with reference to  FIG. 18 . 
       FIG. 4 f    is a cut-away view of palm interface  40 . Motor  49  is connected to base  41 . Nut  58  is fixed to axis  55  of motor  49  and is threaded to the base of brake  43 ; when axis  55  rotates, nut  58  rotates. Brake  43  is not able to rotate and translates the rotation of axis  55  to a linear movement. Rotation of axis  55  in a first direction moves brake  43  up and vice versa. 
       FIG. 4 g    illustrates a joy stick sensor which includes a central lever  53  that mechanically rotates 2 orthogonal potentiometers that measure the orientation of the lever at 2 orthogonal planes. 
       FIGS. 5 a -5 e    illustrate the relation between the orientation of the palm interface and the orientation of articulation  22 .  FIGS. 5 a -5 b    show palm interface  40  tilted on right-left plane resulting the articulation  22  to bend accordingly to side a and side b at first plane. 
       FIGS. 5 c -5 d    show palm interface  40  tilted on forward-backward plane resulting the articulation  22  to bend accordingly to side c and side d at a second plane orthogonal to the first plane. Orienting the palm interface in other planes will result equivalent orientation of the articulation. 
     Finger Interface 
     Finger interface  60  enables a user to control  2  main degrees of freedom of an effector end  24  (grasper): jaws open-close and the rotation of jaws. Such control is intuitive and can be effected simultaneously with palm interface  40  and dorsum interface  30 . 
       FIGS. 6 a -6 b    illustrate finger interface  60  of control unit  10 .  FIG. 6 a    illustrates finger interface  60  connected to palm interface  40  via shaft  91 .  FIG. 6 b    illustrates ball joint mechanism  90  which includes shaft  91 . Shaft  91  is capable of rotating with respect to housing  93 . A nut  92  is used to regulate the force on the ball joint and allows the surgeon to fix shaft  91  at a desired orientation with respect to body  92 . The distal end of shaft  91  is rectangular in shape in order to prevent finger interface  60  from rotating around shaft  91 . 
       FIGS. 7 a -7 b    illustrate user options for ergonomic adjustments of finger interface  60 .  FIG. 7 a    illustrates the possible orientations of finger interface  60  with respect to palm surface  42 .  FIG. 7 b    illustrates adjustability of a distance between finger interface  60  and palm surface  42 . 
       FIG. 8 a    illustrates housing  63  inner levers  61  and external levers  62  of finger interface  60 ; fingers (thumb, index) are positionable between inner levers  61  and external levers  62 . Housing  63  is connected to shaft  91  via rectangle base  95  that prevents housing  63  from rotating around shaft  91 . 
     Hinge  64  can be used to modify an angle between inner levers  61  and external; levers  62  in order to achieve an optimal fit with the users fingers. 
       FIGS. 8 b -8 c    are a cut-away view of finger interface  60 . Inner levers  61  are fixed to brackets  66  which rotate around hinge  65 . Pin  69  of central shaft  69  is positioned through elongated holes  67  at the end of brackets  66 . Rotation of brackets  66  by inner levers  61  leads to linear movement of shaft  69  (through pin  67 ). 
     A magnet  70  is fixed to the end of shaft  69  and a magnetic sensor  71  ( FIG. 8 d   ) is positioned parallel to the main plane of shaft  69 . Sensor  71  measures the linear movement of magnet  70 . The measured movement is sampled by controller  15  and is used to control the open-close movement and position of the jaws. 
       FIG. 8 c    illustrates linear movement of magnet  70  resulting from rotation of inner levers  61  out of housing  63 , when a user increases a distance between a thumb and index finger. Magnet  70  moves about 4 mm from an initial position in which inner levers  61  were pressed inward. External levers  62  can be used to open inner levers  61 , or a spring (not shown) can be used in order to maintain inner levers  61  in a normally open position. The angle between inner levers  61  and external levers  62  can be adjusted using hinge  64 . 
       FIGS. 9 a -9 i    illustrate jaws open-close modes of operation enabled by finger interface  60 , corresponding linear travel of magnet  70  over magnetic sensor  71  and positions of the jaws of grasper  24 . 
       FIGS. 10 a -10 c    illustrate rotation modes of the jaws and the mechanism for measuring the degree of rotation. 
     Magnet  70  (mounted on shaft  69 ) has a flat surface that fits within a D shaped opening  74  rotary position sensor  73 . Shaft  69  slides through opening  74  when levers  61  and  62  are rotated by the user. Rotation of levers  61  and  62  rotates housing  79  and shaft  69  with respect to body  63  of finger interface  60 . Rotary position sensor  73  is fixed to body  63 , and as such shaft  69  can rotate inner body  75  of rotary position sensor  73  thus enabling measurement of an angle of rotation between levers  61  and  62  and shaft  91 . Rotary position sensor  73  data is sampled by controller  15  which compares the orientation of finger interface  60  to the orientation of jaws of grasper  24 . If there is a difference controller  15  sends a command to the motors to match orientation of jaws of grasper  24  to the orientation of the user&#39;s fingers. 
       FIGS. 11 a -11 b    illustrate an embodiment of user interface  80  which can be used to control at least two steerable portions.  FIG. 11 a    is a cut-away view of interface  80  showing an additional sensor  50   b  which enables control of a second steerable portion of a medical device (laparoscope).  FIG. 11 b    illustrates articulation of two independent steerable portions, a proximal steerable portion  102  and a distal steerable portion  103 . 
       FIGS. 12 a -12 e    illustrate operation of a second steerable portion via a finger rotation mechanism of interface  60 . The first steerable portion is controlled via palm interface  40  as described above. 
       FIGS. 13 a -13 h    illustrate the various modes of operation of interface  40  and finger rotation mechanism of interface  60  and the resultant independent deflection of the two steerable portions.  FIG. 13 a    shows the interface at the “home” position. The two independent steerable portions are co-linear as shown in  FIG. 13 b   .  FIG. 13 c    illustrates actuation of interface  40  resulting in deflection of proximal steerable portion  102  only ( FIG. 13 d   ). Actuation of interface  60  and resultant deflection of distal steerable portion  103  only are shown in  FIGS. 13 e -13 f    (respectively), while actuation of both interfaces and resulting deflection of both steerable portions are shown in  FIGS. 13 g -13 h    (respectively). 
       FIGS. 14 a   - 16  illustrate a motorized drive unit  16  embodiment of control unit  10 . As is shown in  FIG. 14 a   , drive unit  16  includes a motor pack  102  and a cable pulley system  104 . 
     Motor pack  102  includes one or more motors  108  (three of five motors shown in  FIG. 14 a   ) which are individually actuated by interface  80 . Motors  108  can be electric motors (e.g. FAULHABER motors  1024  with gear ratios of 1:256 1:64) powered by a battery pack (e.g. 3 AA 1.5V rechargeable batteries not shown) housed in proximal end  130 . Motor pack  102  is positioned between a proximal end  130  of housing  14  and a motor housing floor  112 . 
     In a preferred embodiment of the present invention, control unit  10  includes 5 motors  108 , 3 motors for pulling and releasing control cables, one motor  108  for opening and closing the jaws of grasper  24  and one motor  108  for rotating the jaws. 
     Motors  108  that pull and release the control cables are arranged around a central longitudinal axis point of motor pack  102  offset at 120 degrees from each other. Such an arrangement allows simultaneous operation of three control cables enabling full control of an articulated joint. 
     As is shown in  FIG. 14 a   , drive unit  16  also includes linkage  128  for actuating grasper  24 . Linkage  128  is actuated by a motor  130  which drives a drive gear positioned within proximal end  130 . The motor drive gear meshes with a second gear which is attached directly to a shaft of linkage  128  within proximal end  130 . 
     Proximal end  130  can also include a memory unit and controller chip as well as ports for connecting control unit  10  to a computer to upload firmware, calibrate the operation of motors  108  and the interface elements. 
     Motors  108  are connected to cable pullers  114  through screw housing  116  via a motor-screw coupling  119  ( FIG. 16 ). Screw housing  116  functions in translating rotational movement of a drive shaft of motor  108  to a linear motion (up/down) of cable puller  114  (shown separately in  FIG. 14 b   ). Motor  108  rotates screw housing  116  that is coupled to the motor gear via motor-screw coupling  119  ( FIG. 16 ). The proximal portion of cable puller  114  includes a spiral thread (Shown in  FIG. 14 b   ) that engages a spiral groove in screw housing  116 . Cable puller  114  passes through a semi-circular opening in housing floor  117  which prevents it from rotating and thus forces it to move linearly (up/down) through the opening under rotation of motor  108 . The distal portion of cable puller  114  includes a groove  111  ( FIG. 14 b   ) for coupling to a cable  113  ( FIG. 16 ) attached to cable head  115 . 
     Drive unit  16  also includes a gear cluster  106  (shown in isolated view in  FIG. 15 ) which is positioned between motor pack  102  and cable pulley system  104 . Gear cluster  106  includes drive gears  118  which are mounted around screw housings  116 , and non-drive gears  130  which interconnect drive gears  118  with sensor housing gears  122 . 
       FIG. 16  illustrates the drive relationship between drive gear  118 , non-drive gear  130  and sensor housing gear  122 . 
     Drive gear  118  rotates with rotation of motor  108  to rotate non-drive gear  130  which in turn rotates sensor housing gear  122 . Sensor housing gear  122  rotates sensor housing  123  against a rotation sensor  124 , this provides drive unit  16  with an indication of the extent of rotation and thus the extent of up/down movement of cable puller  114 . Rotation sensor  124  can include a magnetic rotation chip which is located above a magnetic disk  125  which is fixed to housing  123 . The chip can sense the rotation of magnetic disk  125  from a distance of up to 1 mm. 
     Control unit  10  can also include accelerometers and/or gyroscopes for sensing up/down and side-to-side movement of control unit  10 , as well as angular rotation and velocity thereof. Such movement and angular parameters can be used to provide feedback to surgeon with respect to device positioning within the body cavity and/or limit the degree of interface actuation at certain angles of the device. 
     As is described hereinabove, operating a surgical tool attached to control unit  10  is effected by establishing a functional relationship between the orientation of palm interface  40  and direction of articulation movement of finger interface  60  and the action and movement (e.g. rotation) of the end effector.  FIG. 17  illustrates the functional relationship between interface  80  (UI), control unit  10  and an attached laparoscope that enables a user to control a surgical tool via palm and finger movement. 
     Control unit  10  also enables other useful modes of operation. Such operating modes can be initiated via a control switch located at control unit  10 , at a position reachable by a user&#39;s finger when the user&#39;s hand is placed in interface  80 . Activation and (deactivation) can be effected via a specific sequence/duration of click(s) on a control switch. 
     Several modes of operation, each activatable via a specific sequence/duration of clicks are illustrated in  FIG. 18 . Such modes can are facilitated via a braking mechanism of control unit  10  (motor  49  and spherical brake  43  shown in  FIGS. 4 a -4 g    can be used as a braking mechanism). 
     For example, one specific sequence/duration of click(s) can activate a “freeze mode” (locking palm interface  40  and attached tool in a specific position) via motor  49  which moves the braking ring towards hemi-spherical part  44 . Motor  49  is automatically deactivated when control unit  10  detects that sufficient breaking force is applied on hemi-spherical part  44  in order to stop the pivoting maneuvers of the palm interface. 
     Thus, such a “freeze mode” enables the user to lock palm interface  40  and attached tool in a specific orientation. 
     Another specific sequence/duration of click(s) can activate a passive mode. Such a mode enables the user to move the palm interface without moving the attached tool. 
     A “passive joint” mode enables the user to work with a preferred articulation orientation while being free to choose a comfortable hand orientation on palm interface  40 . 
     Another specific sequence/duration of click(s) can activate a “straight articulation” mode which actuate the motors in order to bring the articulation to a straight orientation and then freezes the articulable shaft of the surgical tool in a straight orientation while allowing palm interface  40  to move freely. 
     A “straight articulation” mode is useful for advancing a tool through a trocar; in addition, when in a straight configuration, the tool can mimic traditional laparoscopic tools. 
     In any of the above modes, finger interface  60  is typically not effected, i.e. the user can use this interface to, for example, open/close and rotate the jaws of a grasper, however a scenario in which activation also locks finger interface  60  is also envisaged herein. For example when the surgeon wishes to apply constant force with the jaws or fix the jaws in a preferred angle to each other he can activate these modes by operating the finger levers in a specific sequence/duration of click(s). 
     As used herein the term “about” refers to ±10%. 
     Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting. 
     EXAMPLES 
     Reference is now made to the following example, which together with the above descriptions, illustrates the invention in a non limiting fashion. 
     While working with several types of laparoscopic tools, the present inventor realized that the tool interface is its Achilles heel. In order to hold and operate a free standing laparoscopic tools, one is required to perform unnatural movements with limited degree of control and operability. This is especially true in cases where laparoscope positioning and tool manipulation are effected via a single multi-purpose interface (e.g. the common scissor-like handles that are used for locating the laparoscope and actuating the tissue manipulating end). In order to overcome these deficiencies of prior art interfaces, the present inventor set out to devise an interface that separates the functions of a laparoscope into discrete interface elements and yet enables complete and simultaneous control over such interfaces via a single hand. 
     In reducing the present invention to practice, the present inventor experimented with several prototypes which implement the above interface design philosophy. The solution to the above problem turned out to be an interface that intuitively links the movement of the surgeons hand to that of the laparoscope and utilizes three distinct portions of the hand to operate three distinct interface elements. 
       FIG. 19  illustrates a prototype control unit attached to a laparoscopic shaft.  FIG. 20  illustrates the drive unit portion of the control unit. 
     This prototype includes a motor pack connected to the pulleys of the tool. The motor pack included small motors and transmissions that actuated the 4 degrees of freedom. The size and the weight of the motor pack were small enough to be carried by the surgeon. The interface was connected to the upper side of the motor pack in the same direction of the shaft axis. A joint between the motor pack and the interface allowed the surgeon to change the orientation between the interface and the long axis of the shaft. The motor pack included programmable control circuit that allowed the installing control software. While testing the tool the motor pack used batteries or cellphone Transformer. 
     Operability of the present control unit and interface was tested on a group of novice users using an attached laparoscopic phantom and standard laparoscope control tests. The users completed tasks such as grabbing small objects and moving them into small cups or threading small rubber loops on rods within minutes. The users were also capable of grabbing a surgical needle in the right orientation within minutes. A surgeon that tested the interface demonstrated a first complete suture 10 minutes after a short preliminary introduction to the interface. 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. 
     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.