Abstract:
A docking system for a mechanical telemaniplator is provided, optionally to be used with a mechanical telemanipulator with a master-slave configuration. The docking system is configured to allow for safe and secure immobilization of a handle or master manipulator of a mechanical telemanipulator with a master-slave configuration so as to prevent movement of a slave manipulator or instrument. While the docking element can be deployed on any mechanical telemanipulator, it can advantageously be used on a surgical platform comprising a mechanical telemanipulator with a master-slave configuration. In this context, the docking system can be used to secure the handle portion or master manipulator of the surgical platform to safely prevent undesirable movement of a slave manipulator or surgical instrument.

Description:
FIELD OF THE INVENTION 
       [0001]    A docking system for a mechanical telemanipulator is provided. More particularly, a docking system is provided for a mechanical telemanipulator with a master-slave configuration wherein the movements of one or more master manipulators is reproduced in the movements of one or more slave manipulators. Even more particularly, it may be desirable for the operator of a mechanical telemanipulator with a master-slave configuration to dock or secure a master manipulator so as to temporarily prevent movement of a slave manipulator. Accordingly, the present invention is related to a docking system for a mechanical telemanipulator with a master-slave configuration that allows a user to safely secure the master manipulator or handle portion to prevent unwanted movements. Thus, the present invention is further related to a method of safely securing the handle or master manipulator of a mechanical telemanipulator with a master-slave configuration. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present docking system can be provided in connection with any mechanical telemanipulator, particularly those comprising a master-slave configuration. Optionally, the inventive docking system can be advantageously provided on a surgical platform comprising a mechanical telemanipulator with a master-slave configuration. In the surgical context, it is crucial that the operator of the mechanical telemanipulator (e.g., a telemanipulator designed to be used in minimally invasive surgery) be able to secure or dock the one or more handles or master manipulators of the mechanical telemanipulator so as to prevent movement of the slave manipulator. In the surgical context, the operator needs to have confidence that only desired movements of the slave manipulator will take place, particularly when portions of the slave manipulator are disposed within a patient&#39;s body. For example, the operator may need to dock the master manipulator to temporarily attend to other tasks in the operating room or to assess progress in the surgery before continuing. 
         [0003]    Open surgery is still the standard technique for most surgical procedures. It has been used by the medical community for several decades and consists of performing the surgical tasks by a long incision in the abdomen or other body cavity, through which traditional surgical tools are inserted. However, due to the long incision, this approach is extremely invasive for the patient, resulting in substantial blood loss during the surgery and long and painful recovery periods in an in-patient setting. 
         [0004]    In order to reduce the invasiveness of open surgery, laparoscopy, a minimally invasive technique, was developed. Instead of a single long incision, one or more smaller incisions are made in the patient through which appropriately sized surgical instruments and endoscopic cameras are inserted. Because of the low degree of invasiveness, laparoscopic techniques reduce blood loss and pain while also shortening hospital stays. When performed by experienced surgeons, these techniques can attain clinical outcomes similar to open surgery. However, despite the above-mentioned advantages, laparoscopy requires advanced surgical skills to manipulate the generally rigid and long instrumentation through small incisions in the patient. 
         [0005]    Traditionally, laparoscopic instruments, such as graspers, dissectors, scissors and other tools, have been mounted on straight shafts. These shafts are inserted through small incisions into the patient&#39;s body and, because of that, their range of motion inside the body is reduced. The entry incision acts as a point of rotation, decreasing the surgeon&#39;s freedom for positioning and orientating the instruments inside the patient. Therefore, due to the drawbacks of currently available instrumentation, laparoscopic procedures are mainly limited to use in simple surgeries, while only a small minority of surgeons is able to use them in complex procedures. 
         [0006]    In the context of laparoscopic surgery, and perhaps particularly in the context of laparoscopic surgeries where multiple surgical instruments may be attached and detached from a surgical platform with a master-slave configuration, it can be critical to be able to safely secure the master manipulator portion of the surgical platform such that instruments can safely be changed at the slave manipulator portion. In addition, laparoscopic procedures can be lengthy and complex, thus giving rise to circumstances where a surgeon may simply need to take a break or pause the surgery to attend to other tasks in the operating room. In such circumstances, it can be desirable to have a docking capability available so that the master manipulator can be safely secured, resulting in immobilization of the slave manipulator. This is particularly the case when surgical instruments are actually deployed in the surgical field (e.g., when a surgical instrument is positioned inside an incision in a patient) and a pause is necessary without re-positioning the surgical instrument. 
         [0007]    The present applicants are unaware of any prior docking system that allows for safe and secure immobilization of a master manipulator in a mechanical telemanipulator with a master-slave configuration so as to prevent unwanted motion at the slave manipulator. Haptic devices with docking capabilities for the haptic arm are known, such as the Omni® line of devices by Sensable, but these do not include use of docking capabilities provided on a mechanical telemanipulator with a master-slave configuration. In particular, the present applicants are unaware of any similar docking system being provided in the context of surgical platforms including telemanipulators. While other surgical platforms are known, their movements are often controlled through electronic means whereby a computer dictates movement (or non-movement) of effectors. In certain such platforms, the system freezes by electronic control if the operator removes his hands from the controls or if his head moves away from an associated vision system. Such a configuration does not correspond to mechanical immobilization of a master manipulator so as to prevent movement of a slave manipulator in a mechanical telemanipulator comprising a master-slave configuration. 
         [0008]    Accordingly, an aim of the present invention is to overcome a deficiency in the known art by providing a docking system for a mechanical telemanipulator. An additional aim is for the docking system to allow for secure immobilization of a master manipulator portion of the mechanical telemanipulator such that movement of a slave portion of the mechanical telemanipulator is prevented. An additional aim is to provide an operator of a mechanical telemanipulator with a method for securing the handle or master manipulator portion so as to prevent movement of the slave manipulator portion. 
       SUMMARY OF THE INVENTION 
       [0009]    These aims and other advantages are realized in a new docking system for safely securing a master manipulator or handle of a mechanical telemanipulator. In one embodiment, the docking system can be used in the context of a master-slave-configured surgical platform wherein the operator wishes to secure the handle or master manipulator to prevent movement of the slave manipulator or surgical instrument. The docking system can be configured and deployed to allow for securing the system while changing surgical instruments or pausing use of the telemanipulator during a surgical procedure. 
         [0010]    In various embodiments, the docking system is deployed in a method for securing a master manipulator or handle of a mechanical telemanipulator. In particular embodiments, the docking system may be deployed in a method for securing the handle or master manipulator of a surgical platform comprising a master-slave configuration to prevent movement of a slave manipulator or surgical instrument. 
         [0011]    The docking system of the present invention can take on a number of physical configurations allowing for easy and secure docking of a master manipulator of a mechanical telemanipulator to a fixed element so as to temporarily prevent movement of a slave manipulator. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0012]      FIG. 1  shows a docking system disposed on a mechanical telemanipulator according to an embodiment of the present invention with close up views of a docking element disposed on a master manipulator and of a slave manipulator represented by a surgical instrument. 
           [0013]      FIGS. 2 through 6  show the kinematics of a mechanical telemanipulator with various embodiments of a docking element according to the present invention. 
           [0014]      FIG. 7  shows close up views of various aspects of a docking element disposed on a mechanical telemanipulator according to an embodiment of the present invention. 
           [0015]      FIG. 8  shows perspective views of various aspects of a docking element according to an embodiment of the present invention. 
           [0016]      FIG. 9  shows perspective views of further aspects of a docking element according to an embodiment of the present invention. 
           [0017]      FIGS. 10 through 14  show various possible configurations of a docking element according to various embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    A docking system, according to an embodiment of the present invention, is intended to be used as an element of or in conjunction with a mechanical telemanipulator  1 , like the one shown in  FIG. 1 . One of the key features of this kind of mechanical telemanipulator  1  lies in its master-slave architecture, which enables a natural replication of the user hand movements, on a proximal handle  2 , by a distal instrument  3 , on a remote location. 
         [0019]    According to  FIG. 2 , this mechanical telemanipulator  1  comprises: i) a master manipulator  4  having a corresponding number of master links  21 ,  22 ,  23 ,  24 ,  25 ,  26  interconnected by a plurality of master joints  9 ,  10 ,  11 ,  12 ,  13 ,  14 , a ii) a handle  2  for operating the mechanical telemanipulator  1 , connected to the distal end of the master manipulator  4 , iii) a slave manipulator  5  having a number of slave links  27 ,  28 ,  29 ,  30 ,  31 ,  32  interconnected by a plurality of slave joints  15 ,  16 ,  17 ,  18 ,  19 ,  20 ; and iv) an end-effector  3  (instrument/tool or a gripper/holder) connected to the distal end of the slave manipulator  5 . The configuration of the mechanical telemanipulator can also be described by considering the end-effector  3  to be part of the slave manipulator  5  and the handle  2  to be part of the master manipulator  4 . In a broader sense, the links and joints composing the end-effector can be considered distal slave links and joints, while the links and joints composing the handle can be considered distal master links and joints. 
         [0020]    More particularly, the kinematic chain formed by the plurality of articulated slave links  27 ,  28 ,  29 ,  30 ,  31 ,  32  and corresponding slave joints  15 ,  16 ,  17 ,  18 ,  19 ,  20  of the slave manipulator  5 , is identical to the kinematic chain formed by the plurality of articulated master links  21 ,  22 ,  23 ,  24 ,  25 ,  26  and corresponding master joints  9 ,  10 ,  11 ,  12 ,  13 ,  14  of the master manipulator  4 . 
         [0021]    The end-effector  3  might optionally be adapted to be releasable from the proximal part of the slave manipulator  5 . The master manipulator  4  and the slave manipulator  5  are connected to each other by a connecting link  6 . This connecting link  6  is connected to a ground  7  by a first telemanipulator joint  8 . This first telemanipulator joint  8  can be decomposed in a master joint  8   m  and slave joint  8   s , which can respectively be considered as the first proximal joints of the master manipulator  4  and the slave manipulator  5 . In the same way, the connecting link  6  can be decomposed in a master link  6   m  and slave link  6   s , which can respectively be considered as the first proximal links of the master manipulator  4  and the slave manipulator  5 . 
         [0022]    With this kinematic model, the mechanical telemanipulator  1  has 7 independent degrees-of-freedom, (DOF), which enable the end-effector  3  to replicate handle  2  translations (3DOF), orientations (3DOF) and actuation (1DOF) in the vicinity of the remote manipulation area. 
         [0023]    The mechanical telemanipulator device further comprises mechanical transmission systems arranged to kinematically connect the slave manipulator  5  with the master manipulator  4  such that the movement (angle or orientation of joint) applied on each master joint of the master manipulator  4  is reproduced by the corresponding slave joint of the slave manipulator  5 . In order to improve the precision of the device, the replication of translational movements between handle  2  and end-effector  3  can be scaled down with a predetermined scaled ratio, which can advantageously be in the order of 2:1 or 3:1, if each master link is respectively, by way of example, two or three times longer than the corresponding slave link. 
         [0024]    In order to allow the user to temporarily and safely release or dock the handle  2 , in some embodiments of the current invention, the mechanical telemanipulator  1  can be provided with a docking system, being composed by at least one docking element  34  where at least one master link  25 ,  26  can be anchored ( FIG. 3 ). In a general manner, the docking element can be attached to a reference body with a certain level of mobility and the docked point (where the master link is anchored to the docking point) might also be located not on the distal master links  25 ,  26  but on a more proximal link. As a result, all the master links from the proximal link to the link where the docked point is located, are able to move with the same mobility as the reference body. On the other hand, the links that are distal to the link where the docked point is located are not blocked. Due to the nature and design of the transmission system, the equivalent links of the slave manipulator  5  will also have the same mobility. 
         [0025]    In the embodiment shown in  FIG. 3 , the reference element is a fixed ground  33 . Therefore, this docking system enables the mechanical telemanipulator  1  to be completely blocked by attaching the handle links  25 ,  26  to a docking element  34 . In this way, and given the fact that in this particular embodiment the telemanipulator  1  has non-redundant kinematics, the entire master manipulator  4  becomes blocked. As a consequence, due to the mechanical transmission system that connects the slave manipulator  5  to the master manipulator  4 , all the links composing the mechanical telemanipulator  1  (from the master links  25 ,  26  to the slave links  31  and  32 ) become blocked, which completely avoids any unwanted movement of the end-effector in the vicinity of the remote manipulation area. In the context of a surgical platform, this would avoid any unwanted movement of end-effectors (surgical instruments) in the vicinity of the surgical field. 
         [0026]    In other embodiments of the current invention, such as the one shown in  FIG. 4 , the reference element is the proximal master link  6 , where the docking element  35  is attached and the docked point  36  is located on the non-distal master link  23 . Therefore, all the master links from the proximal master link  6  to the master link  23  are able to move with the same mobility as the proximal master link  6 , which consists of 1 DOF around the proximal joint  8 . The same level of mobility is archived by the equivalent links of the slave manipulator  5 . On the other hand, the master links  24 ,  25 ,  26  that are distal to the master link  23  attachment to the docked point  36  remain free to move. Due to the transmission system, the equivalent links  30 ,  31 ,  32  of the slave manipulator  5  will also be unblocked. 
         [0027]    In another embodiment of this invention, shown in  FIG. 5 , the mechanical telemanipulator  1  comprises an additional DOF, compared to the mechanical telemanipulator  1  of the embodiment shown in  FIGS. 1 to 4 , with new master and slave links  37 ,  38  and new master and slave joints  39 ,  40 , thus providing a total of 8 DOF. It further comprises a mechanical constraint system  41  which is configured to ensure that one master link  23  of the master manipulator  4  is guided or constrained to translate along and rotate about a fixed point  42 , so that the corresponding slave link  29  of the slave manipulator  5  always translates along and rotates about a virtual point  43  in the vicinity of the remote manipulation area. This virtual point is also known as a remote-centre-of-motion, RCM. In this embodiment, the reference element is the mechanical constraint system  41 , where the docking element  44  is attached. The docked point  45  is located on the non-distal master link  23 . Therefore, all the master links from link  6  to link  23  are able to move with the same mobility as the mechanical constraint system  41 , which consists of 2 DOF around the fixed point  42 . The same level of mobility is achieved by the equivalent links of the slave manipulator  5 , which have 2DOF around the RCM  43 . On the other hand, the handle links  24 ,  25 ,  26  remain free to move. Due to the transmission system, the equivalent links  30 ,  31 ,  32  of the end-effector  3  will also be free. 
         [0028]      FIG. 6  shows the embodiment of  FIG. 5  being used during a minimally invasive surgical procedure, where the end-effector  3  is inserted inside the patient&#39;s body through a trocar  46 . The RCM is brought to the incision point. When the telemanipulator  1  is docked, the distance dl between the docked point  45  and the fixed point  42  can be set so that the end-effector  3  remains inside the trocar, and therefore in a safe position configuration to not allow for any involuntary movements of the end effector in the surgical field. 
         [0029]      FIG. 7  shows a possible design implementation of the embodiment of  FIGS. 5 and 6 . The docket point  45  comprises an axisymmetric component  45   a , which is attached to the master link  23 , while the docking system is mainly composed of a flexible blade  44   a , attached to the constraint system  41 , and a docking hook  44   b.    
         [0030]    In order to dock the mechanical telemanipulator  1 , the master link  23  needs to slide upwards through the constraint system  41 , causing at a certain point contact between the wedge surfaces  45   a ′ and  44   b ′ of the axisymmetric component  45   a  and the docking hook  44   b . Then, the flexible blade  44   a  is deflected outwards until the wedge surfaces  45   a ′ and  44   b ′ are not in contact any more. In this position the mechanical telemanipulator is considered to be docked (upwards by gravity and downwards by the geometry of the axisymmetric component  45   a  and the docking hook  44   b ). In order to be undocked, the system master link  23  has to be twisted so that the docking hook  44   b  and the groove  45   a ″ are aligned, as shown in  FIG. 9 . 
         [0031]    In other embodiments of the present invention, the docking system  44  and docked point  45  can take different shapes and solutions in other to guarantee the docking of the mechanical telemanipulator  1 . In these embodiments, there are varied configurations in which the docking element is attached to the master link. For instance,  FIG. 10  shows an embodiment wherein the attachment is made by a system with two magnets  46 .  FIG. 11  shows an embodiment were the attachment is made by friction forces.  FIG. 12  shows an embodiment where the attachment is made by two Velcro surfaces  47 .  FIG. 13  shows an embodiment where the attachment is made by two matching geometries.  FIG. 14  shows an embodiment were the docking system  44  takes the shape of a wire-like component where the docked point  45  can be hooked. 
         [0032]    While this invention has been shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Solely by way of example, one of skill in the art will understand that numerous shapes and solutions for the docking element and docked point of the inventive docking system are possible and that several exemplary embodiments have been presented herein.