Abstract:
A micro-robotic platform and a method for deploying the platform in a body cavity for performing endoluminal surgical interventions in a fully bimanual fashion. The platform comprises a first ( 1 ) and a second ( 2 ) surgical robot each provided with a surgical tool ( 5, 6 ) and being configured to be attached to the body cavity wall. The first and the second surgical robot each comprises a first ( 11 ) and a second ( 12 ) snake-like robotic unit, the first snake-like robotic unit ( 11 ) comprising a first central unit ( 13 ) and first articulated attachment means ( 7   a, b;    8   a, b;    9 ) extending from said first central unit ( 13 ) for attaching the first central unit to the body cavity wall. The second snake-like robotic unit ( 12 ) comprises a second central unit ( 14 ), second articulated attachment means ( 7   c;    8   c;    9 ) for attaching the second central unit to the body cavity wall and an articulated arm ( 3, 4 ) bearing the surgical tool ( 5, 6 ), the second articulated attachment means and the articulated arm extending from the second central unit. Releasable connection means ( 15 ) are provided on the first and second central units ( 13, 14 ) to connect the first central unit to the second central unit releasably to form each of the first and second surgical robot within the body cavity deployed in such a way to allow a surgical procedure to be performed in a true bimanual way.

Description:
FIELD OF THE INVENTION  
       [0001]    The present invention generally relates to the field of endoluminal surgery and more particularly relates to an endoluminal bimanual micro-robotic platform and a method for deploying the micro-robotic platform in a body cavity such as the gastric cavity. 
       BACKGROUND OF THE INVENTION 
       [0002]    In traditional open surgery, physical and rigid links exist between the surgeon and the patient&#39;s organs. The instruments are hand-held and operated under direct binocular vision. 
         [0003]    With the introduction of laparoscopic techniques, the direct physical links between the surgeon and the patient&#39;s organs are represented by the trocars, which are used for the insertion of different instruments, energised dissection devices and staplers, all having a remote end-effector and proximal actuation i.e., the surgeon&#39;s hand. 
         [0004]    Surgical tele-operated robots, such as the Da Vinci® system, are considered an important on-going evolution in minimally invasive surgery because, whilst the main features of surgical execution are retained, the actuation of bimanual tools is remote from the patient and is performed by the surgeon operating from a console. The Da Vinci® wrist is remotely driven by actuators at the proximal end of the tool module through cable drives. 
         [0005]    Recent examples of autonomous surgical robots include the inchworm-type devices. Self-propelled robotic endoscopes have been developed for navigation in tubular organs [K. Ikuta et al.,  Hyper - redundant active endoscope for minimum invasive surgery , Proc. First Int. Symp. on Medical Robotics and Computer Assisted Surgery, Pittsburg, Pa., 1994; A. B. Slatkin et al.,  The development of a robotic endoscope , Intelligent Robots and Systems 95. ‘Human Robot Interaction and Cooperative Robots’, Proceedings. 1995 IEEE/RSJ International Conference, vol. 2, pp. 162-171, 5-9 Aug. 1995; A. Menciassi et al.,  Robotic solutions and mechanisms for a semi-autonomous endoscope , Intelligent Robots and System, 2002. IEEE/RSJ International Conference, vol. 2, pp. 1379-1384, 2002]. 
         [0006]    Hyper-redundant robotic structures, essentially snake-like structures, improve manipulation performance in complex and highly constrained environments. They have been used in several fields of industry as well as bimanual haptic interfaces and have been also proposed for design of endoscopic robots. Existing hyper-redundant robotic structures, also for surgery, are generally cable actuated from external driving systems and thus are mechanically connected with the outside world. 
         [0007]    In flexible interventional endoscopy, the rigid link between the surgeon and the organs becomes progressively weaker as the mechanical constraints are transferred from outside the body (e.g. the hand held device, the instruments inside the trocar, etc.) to lumen of an internal hollow organ. Mechanically, as exemplified by the autonomous colonoscopes, the rigid transmission from outside is removed. A surgical robotic system for flexible endoscopy is disclosed in WO2007/111571. A pair of robotic arms ending with surgical tools extend from the distal end of a flexible endoscope. US2005/096502 discloses a surgical device for use in laparoscopy or surgical endoscopy comprising an elongated body with a plurality of arms carrying surgical tools extending from the distal end. 
         [0008]    The current robotic solutions for gastric surgical procedures are based on bulky robotic units and still require several incisions in the patient&#39;s abdomen. On the other hand, current endoluminal procedures for gastrointestinal tract surgery (a subset of NOTES—Natural Orifice Transluminal Endoscopic Surgery—procedures) are still not effective, since they are usually performed by a single flexible instrument, having external cable actuation. Furthermore, this approach has not yet exploited the benefits of robotics. Significant advance is expected with the integration of computer-assisted surgery, flexible endoscopy and tele-operated laparoscopy to access the abdominal cavity through natural orifices 
         [0009]    Micro-robots introduced into the peritoneal cavity in pigs through a standard 12 mm laparoscopic trocar after gas insufflation have been reported recently as an adjunct to laparoscopic surgery [D. Oleynikov et al.,  Miniature robots can assist in laparoscopic cholecystectomy , Surg Endosc., vol. 19, pp. 473-476, DOI: 10.1007/s00464-004-8918-6, 2005]. On this subject see also WO2007/149559, relating to a robotic surgical device insertable in the patient&#39;s body and positionable within the patient&#39;s body using an external magnet. A pair of arms extend from a body housing magnets interacting with an outer magnetic handle for controlling the positioning of the device. Each arm ends with a surgical tool and is connected to the body through a shoulder joint with two degrees of freedom. Each arm comprises two arm portions connected to one another through an elbow joint with one degree of freedom. 
         [0010]    The robotic device according to WO2007/149559, as well those proposed for flexible endoscopy cited above, is unable to perform true bimanual operation due to the fact that the arms bearing the surgical tool extend from a common origin and, despite the degrees of freedom of the arms, their possibility of co-operation is limited by dimensional and spatial factors and the workspace results quite limited. Moreover, the single arms extend from a point which is fixed to the abdominal cavity by magnetic means. All the forces exerted by the arms must be supported by the same force which maintains the common origin in contact with the abdominal wall. This limits the range of force that can be exerted by the tools. In addition to that, a threshold between the working space (proportional to the number of links, thus to the length, of each arm) and the maximum force (limited by the maximum torque that the magnetic link can support, thus inversely proportional to the arm length) must be fixed. 
         [0011]    Furthermore, existing research has shown that there is a pressing need for developing a novel surgical approach based on micro-robotics instead of attempting instrumental technologies for the existing operating flexible endoscopes. The multi-capsule robotic device disclosed by Menciassi et al., Biomedical Robotics and Biomechatronics, 2008, BIOROB 2008, 2nd IEEE RAS&amp;EMBS INT. CONF. ON, IEEE, Piscataway, N.J., USA, 238-243, Oct. 19, 2008, follows this trend, but, like the device disclosed in WO2007/149559, cannot work in a bimanual way and hence is affected by the same drawbacks. Moreover, a local self-assembling technique of the device from the single component capsules swallowed by the patient is foreseen which is very difficult to carry out with the required precision and velocity. 
       SUMMARY OF THE INVENTION 
       [0012]    The object of the present invention is to provide a micro-robotic platform for advanced endoluminal surgery insertable for deployment in a body cavity to perform surgical procedures with a true bimanual robotic operation. 
         [0013]    A particular object of the present invention is to provide an endoluminal micro-robotic platform of the above mentioned type formed by at least two deployable surgical robots capable of being coupled in a body cavity. 
         [0014]    A further object of the present invention is to provide an endoluminal micro-robotic platform of the above mentioned type in which the surgical robots have an higher number of degrees of freedom and an increased stability, are able to withstand to higher forces and have better manipulation performances than the prior art similar devices. 
         [0015]    It is still another object of the present invention to provide a method for deploying the endoluminal micro-robotic platform of the above mentioned type in a body cavity such as the gastric cavity. 
         [0016]    These objects are achieved with the endoluminal micro-robotic platform and the method for its deployment in a body cavity according to the invention, the main features of which are stated in the independent claims  1  and  10 . Further important features are set forth in the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The features and the advantages of the endoluminal micro-robotic platform and the method for its deployment in a body cavity according to the invention will be apparent from the following description of an embodiment thereof given by way of a non-limiting example with reference to the attached drawings, in which 
           [0018]      FIG. 1  is a schematic overall view of the endoluminal micro-robotic platform according to the invention operatively deployed in a body cavity; 
           [0019]      FIG. 2  is a perspective view of an assembled deployable surgical robot; 
           [0020]      FIG. 3  is a perspective view of a snake-like robotic unit; 
           [0021]      FIG. 4  is a perspective view of an arm of the robotic unit of  FIG. 3 ; 
           [0022]      FIG. 5  is a longitudinal view of the arm of  FIG. 4  in an extended condition; 
           [0023]      FIG. 6  is another longitudinal view of the arm of  FIG. 4 , axially rotated by 90° relative to  FIG. 5 ; 
           [0024]      FIG. 7  is a cross sectional view of the arm of the robotic unit taken along lines VII-VII of  FIG. 6 ; 
           [0025]      FIG. 8  is a longitudinal sectional view of the arm of the robotic unit taken along lines VIII-VIII of  FIG. 6 ; 
           [0026]      FIGS. 9 to 19  illustrate the steps of the method for deploying the robotic platform in a body cavity such as the stomach. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    As used in the present specification the term “robotic platform” is meant as a robotic framework or a set of robotic components when assembled and deployed in a body cavity to perform a surgical procedure. Likewise, the term “bimanual” is meant as having two surgical tools capable of being operated in the same way as the hands of the surgeon, with substantially the same degrees of freedom. A “snake-like robot” is defined as a flexible or articulated robotic functional unit, as in  FIG. 3 , which can be inserted into human body cavities through natural orifices thanks to its cylindrical shape. A single “snake-like robot” may connect with one or more similar “snake-like robots” to form a surgical robot, as shown in  FIG. 2 . 
         [0028]    With reference to  FIGS. 1 to 4 , the endoluminal micro-robotic platform according to the invention comprises a first and a second deployable surgical robot, generally indicated as  1  and  2 , each being equipped with an operating arm  3  and  4 , bearing a surgical tool  5  and  6  (either an operative tool or an assistive tool or a monitoring sensor) at the respective free ends, and with three attachment legs  7   a, b, c,  and  8   a, b, c  respectively configured to permit a stable hold of the surgical robots to the wall of a body cavity, for example the stomach S, as shown in the figures. In particular, the attachment legs  7   a, b, c  and  8   a, b, c  are equipped with an attachment device  9  at their free ends, through which they are connected to the wall of the body cavity. By way of example, the attachment device  9  may be a mucho-adhesive polymer layer or an air suction device or a magnetic device in combination with external or internal magnets. The operative arms  3  and  4  and the attachment legs  7   a, b, c  and  8   a, b, c  of each surgical robot, extend from a respective body  10  connected to a cable  18  for energy supply and data transmission that passes through an inserting port to be connected to an external unit placed out of the patient&#39;s body. 
         [0029]    As shown in  FIG. 2 , each surgical robot  1  and  2  is formed by a first and a second snake-like robotic unit  11 ,  12 . The first snake-like robotic unit comprises a central unit  13  and two attachment legs  7   a, b  (or  8   a, b ) extending therefrom. The second snake-like robotic unit  12  comprises a central unit  14 , the attachment leg  7   c  ( 8   c ) and the operating arm  3  ( 4 ), both extending from the central unit  13  ( 14 ). The central units  13  and  14  embed a local electronic control circuitry and an electro-mechanical connector  15  to connect reversibly the central unit  13  of the first snake-like robotic unit  11  to the central unit  14  of the second snake-like robotic unit  12  to form the body  10  of the surgical robot  1  ( 2 ). The connection surface can have connectors, for energy or data transmission between the central units  13  and  14 . 
         [0030]    Each attachment leg  7   a, b, c  and  8   a, b, c  and each operating arm  3  and  4  has four degrees of freedom. In particular, as shown in detail in  FIGS. 3 and 4 , each attachment leg  7   a  and  7   b  (the same applies to attachment legs  7   c  and  8   a, b, c  and to operating arms  3  and  4 )) is formed by a proximal leg portion  16   a  and  16   b  respectively extending from opposite parts of the central unit  13  and a distal leg portion  17   a  and  17   b  respectively extending from the free ends of the proximal leg portions  16   a  and  16   b.  An attachment device  9  is placed at the free ends of each of the distal leg portions  16   b ,  17   b . The proximal leg portion  16   a  ( 16   b ) is connected for axial rotation about its longitudinal axis X 1  to the central unit  13 . The distal leg portion  17   a  ( 17   b ) is connected for bending about a transverse axis X 2  to the proximal leg portion  16   a  ( 16   b ). Moreover, the distal leg portion  17   a  ( 17   b ) is connected for axial rotation about its longitudinal axis X 3  to the proximal leg portion  16   a  ( 16   b ). Finally, the attachment device  9  is connected for rotation about a transverse axis X 4  to the free end of the distal leg portion  17   a  ( 17   b ). All the angular displacements of the different leg portions and the attachment devices are carried out by tre relevant motors under external control, as will be explained below. 
         [0031]    In the present embodiment the connection between the two “snake-like” robotic units  11  and  12  of each surgical robot  1  and  2  is carried out in such a way that the portions of proximal legs  16   a  and  16   b  of the unit  11  are coplanar to the corresponding portions of proximal legs  16   a  and  16   b  of the unit  12  as shown in  FIG. 2 . 
         [0032]    It is clear from the foregoing that, once the surgical robot  1  or  2  is secured to the body cavity wall through the attachment legs  7   a, b, c  or  8   a, b, c,  the relative positions of the central bodies  10  of the surgical robots  1  and  2  can be varied in a wide range. This results in a far greater number of relative positions and orientations the surgical tools  5  and  6  are able to take on as compared to the prior art devices, such as those according to WO2007/149559 or WO2007/111571, in which the arms bearing the surgical tools extend from a common supporting means having a fixed spatial positioning. Furthermore, since the central bodies  10  are supported by three legs  7   a, b, c  and  8   a, b, c  respectively, the arms  3  and  4  bearing the surgical tools  5  and  6  can have better performances in term of force torque and reliability as compared to the prior art. 
         [0033]      FIGS. 5 to 8  illustrate a possible constructional embodiment for an attachment leg of a surgical robot of the invention, the same technical solution applying to an operating arm  3  or  4 . The proximal leg portion  16   a  is connected to the central unit  13  and rotates using a gear transmission formed by a spur gear  20  connected to a motor  21 , housed in the proximal leg portion  16   a , and engaging with a spur gear  22  integral to the central unit  13 . The proximal leg portion  16   a  and the distal leg portion  17   a  are connected by a joint  23  allowing their relative bending about transverse axis X 2 . A worm  24  extends from a motor  25  housed in the proximal leg portion  16   a  and is engaged with a worm gear  26 . The worm gear  26  is fixed to the joint  23 , whereby relative bending is enabled once the motor  25  is started. The distal leg portion  17   a  is connected to the joint  23  and rotates using a gear transmission formed by a spur gear  27  connected to a motor  28 , housed in the distal leg portion  17   a , and engaging with a spur gear  29  integral to the joint  23 . The distal leg portion  17   a  and the attachment device  9  are connected by a joint  30  allowing the attachment device  9  to rotate about transverse axis X 4 . A worm  31  extends from a motor  32  housed in the distal leg portion  17   a  and is engaged with a worm gear  33  fixed to the joint  30 , whereby the attachment device  9  is enabled to rotate relative to the distal leg portion  17   a.    
         [0034]    The motors  21 ,  25 ,  28  and  32  can be DC brushless motor and can also be equipped with an encoder, in order to have closed loop control of the motion. 
         [0035]    It is worth noting that the various proximal and distal leg portions, as well as the various proximal and distal operative arm portions, are structurally equal, i.e. the attachment legs and the operative arms have a modular structure. This greatly simplifies their production and assembling. 
         [0036]    Each snake-like robotic unit is equipped with means for energy and data transmission and with a set of sensors to perceive the robot position in a tri-dimensional space and to monitor in real time its performance. On board battery  34  and a control board  35  can also by mounted on each leg portion. 
         [0037]    A laser fibre can also be mounted on the operating arm  3  or  4  and the laser fibre can be passed through the insertion port. 
         [0038]    One or more robotic cameras  36  are also inserted in the body cavity and attached to the body cavity wall in the same way as the attachment legs. In particular, a robotic camera  36  comprises an attachment device  9 , an active (motorized) joint  37  with one or two degrees of freedom, a CMOS or CCD camera, a lens system, an illumination module and means for energy and data transmission. 
         [0039]    The endoluminal micro-robotic platform according to the invention is used in the following way. 
         [0040]    A semi-rigid gastro-esophageal insertion port  40  is introduced through the mouth into the gastric cavity of a sedated or anesthetized patient. The main functions of this port are to allow an easy and fast introduction of the different modules of the robotic platform and to maintain the stomach in an insufflated condition. See  FIG. 9 . 
         [0041]    A flexible and externally steerable introducer  41  is used to deploy the different parts of the platform in the desired positions. To that end an auxiliary pipe to be inserted through a flexible endoscope can also be used. First a sealing element  42  to close the gastro-duodenal junction is introduced, thus allowing the required stable insufflation of the stomach. The sealing element  42  is basically an inflatable balloon, shown in  FIG. 10 , before placement and insufflation, and in  FIG. 11 , after placement and insufflation. 
         [0042]    After the sealing element  42  has been placed, a set of deployable robotic cameras  36  is introduced, as shown in  FIGS. 12 and 13 . In the following the introduction of two robotic cameras in devised. In general the number of cameras depends on the specific surgical needs. 
         [0043]    Then the first snake-like robotic unit  11  composing a first deployable surgical robot  1  is introduced, as shown in  FIG. 13 . The distal attachment device  9  is guided, under external control, to a first desired attachment position. Once the distal attachment device of the first snake-like robotic unit composing a first deployable surgical robot touches the gastric wall in the desired position, it sticks to the tissue, as shown in  FIG. 14 . Then the introducer can be withdrawn and the first snake-like robotic unit composing the first deployable surgical robot moves, under external control, in order to guide the other attachment device to a second desired attachment position on the gastric wall. When both the terminal attachment devices adhere to the gastric wall, as shown in  FIG. 15 , and the first snake-like robotic unit reaches a stable position. 
         [0044]    Once the first snake-like robotic unit composing the first deployable surgical robot holds a stable position, as shown in  FIG. 15 , the second snake-like robotic unit  12  composing a first deployable surgical robot  1  is introduced, as shown in  FIG. 16 , and positioned so that the central units of the two snake-like robotic units  11  and  12  can easily link together through the electro-mechanical linking mechanism. Once a proper connection of the two units is occurred, the introducer is withdrawn, and the attachment devices of the second snake-like robotic unit composing a first deployable surgical robot  1  is moved under external control towards the gastric wall, in order to achieve a stable adhesion. This procedure allows the correct assisted assembly of a first deployable surgical robot  1 , having three legs, equipped with attachment devices at each free end, and an operating arm, equipped with a surgical tool, as shown in  FIG. 17 . 
         [0045]    The same procedure, as shown in  FIGS. 17 and 18 , is followed to assemble a second deployable surgical robot  2 , equipped with a different surgical tool, thus enabling an effective bimanual robotic surgery from inside the gastric cavity, as shown in  FIG. 19 . 
         [0046]    Even if in the above description of the use of the endoluminal robotic platform according to the invention reference has been made to the gastric cavity as a body cavity, it is understood that the invention is not limited to this use and the endoluminal robotic platform of the invention can be deployed in any other body cavity through any other suitable natural or artificial orifice. 
         [0047]    Various modifications and alterations to the invention may be made based on a review of the disclosure. These changes and addition are intended to be within the scope of the invention as set forth in the following claims.