Abstract:
Disclosed is a mechanical telemanipulator handle to control surgical instruments with articulated end-effectors, such as dissectors, scissors or graspers, enhancing a surgeon&#39;s performance during various surgical procedures. These surgical instruments may be inserted into surgical incisions in a body of a patient and the articulated end-effector is mounted on the distal extremity of the instrument shaft, comprising a plurality of links interconnected by a plurality of joints, whose movements are remotely controlled at the telemanipulator&#39;s proximal handle. This remote actuation is accomplished through mechanical transmission, optimally along flexible elements, which are able to kinematically connect the end-effector with the handle such that the movements applied on the handle are reproduced by the end-effector at a predetermined scaled ratio. The articulated handle further comprises one or more movement-amplification systems that amplify the movements generated at the handle so that the gripping force at the instrument&#39;s end-effector can be increased and the surgeon&#39;s ergonomy improved.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the field of remotely actuated mechanical systems, more particularly to endoscopic mechanisms, and most particularly to remotely actuated endoscopic surgical instruments. More specifically, this invention relates to articulated handle mechanisms used to control surgical instruments such as graspers, dissectors, and scissors, wherein the orientation of end-effectors in relation to the instrument shaft is able to be controlled. This mechanism is also adapted for any suitable remote actuated application requiring dexterous manipulation with high stiffness and precision such as, but in no way limited to, assembly manipulation, manipulation in narrow places, manipulation in dangerous or difficult environments, and manipulation in contaminated or sterile environments. 
       BACKGROUND OF THE INVENTION 
       [0002]    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 through a long incision in the abdomen, through which traditional surgical tools are inserted. However, due to the long incision, this approach is extremely invasive for the patients, resulting in substantial blood loss during the surgery and long and painful recovery periods at the hospital. 
         [0003]    In order to reduce the invasiveness of open surgery, laparoscopy, a minimally invasive technique, was developed. Instead of a single long incision, four to five small incisions are made in the patient through which appropriately sized surgical instruments and endoscopic cameras are inserted. Because of the low invasiveness, this technique reduces blood loss and shortens hospital stays and pain. When performed by experienced surgeons, this technique can attain clinical outcomes similar to open surgery. However, despite the above-mentioned advantages, laparoscopy requires extremely advanced surgical skills to manipulate the rigid and long instrumentation. The entry incision acts as a point of rotation, decreasing the surgeon&#39;s freedom for positioning and orientating the instruments inside the patient. The movements of the surgeon&#39;s hand about this incision are inverted and scaled-up relative to the instrument tip (“fulcrum effect”), which removes dexterity, sensibility and magnifies the tremors of the surgeon&#39;s hands. In addition, these long and straight instruments force surgeons to work in a uncomfortable posture, which can be tremendously tiring during several hours of operation and result in stress and discomfort for hands, arms and body. Therefore, due to these drawbacks of laparoscopic instrumentation, these minimally invasive techniques are mainly limited to use in simple surgeries, while only a small minority of surgeons is able to use them in complex procedures. 
         [0004]    To overcome these limitations, surgical robotic systems were developed to provide an easier-to-use approach to complex minimally invasive surgeries. By means of a computerized robotic interface, these systems enable the performance of remote laparoscopy wherein the surgeon sits at a console manipulating two master manipulators to perform the operation through several small incisions. Like laparoscopy, the robotic approach is also minimally invasive, bringing several advantages over open surgery in terms of reduced pain, blood loss, and recovery time. In addition, it also offers better ergonomy for the surgeon compared to open and laparoscopic techniques. However, although being technically easier, robotic surgery brings several negative aspects. A major disadvantage of these systems is related to the extremely high complexity of existing robotic devices, which are composed of complex mechanical and electronic systems, leading to huge costs of acquisition and maintenance, which are not affordable for the majority of surgical departments worldwide. Another drawback of these systems comes from the fact that current surgical robots are very large, competing for precious space within the operating room environment and significantly increasing preparation time. Access to the patient is thus impaired, which, together with a lack of force-feedback, raises safety concerns. 
         [0005]    WO9743942, WO9825666 and US2010011900 disclose a robotic tele-operated surgical instrument, designed to replicate a surgeon&#39;s hand movements inside the patient&#39;s body. By means of a computerized, robotic interface, it enables the performance of remote laparoscopy wherein the surgeon sits at a console manipulating two joysticks to perform the operation through several small incisions. However, this system does not have autonomy or artificial intelligence, being essentially a sophisticated tool fully controlled by the surgeon. The control commands are transmitted between the robotic master and robotic slave by a complex computer-controlled mechatronic system, which is extremely costly to produce and maintain and difficult to use for the hospital staff. 
         [0006]    WO2013014621 describes a mechanical telemanipulator for remote manipulation with a master-slave configuration, comprising a slave manipulator driven by a kinematically equivalent master manipulator and a mechanical transmission system such that each part of the slave manipulator mirrors the movement of each corresponding part of the master manipulator. Therefore, this system allows surgeons to perform surgical procedures by directly manipulating a control handle in the proximal part of the mechanical telemanipulator while their movements are replicated (scaled down or not) by an articulated instrument that can reach the abdominal cavity of the patient through small incisions or trocars. Although the mechanical transmission system is well adapted to the device, the kinematic model and transmission topology of the handle were not optimized, forcing surgeons to move their hands in non-ergonomic ranges of motion and limiting the amount of gripping force that can be generated at the instrument&#39;s end-effector. 
         [0007]    Accordingly, an aim of the present invention is to provide a mechanical telemanipulator handle mechanism with a new configuration, which is able to deliver higher gripping forces to the instrument&#39;s end-effector. 
         [0008]    Another aim of the present invention is to provide a mechanical telemanipulator handle mechanism with a more ergonomic range of motion for the surgeon&#39;s hands. 
       SUMMARY OF THE INVENTION 
       [0009]    Theses aims and other advantages are achieved by a new articulated handle mechanism, designed to be used at the proximal extremity of a mechanical telemanipulator. This mechanical telemanipulator is intended to control surgical instruments, in the form of, for example, a dissector, scissor or grasper, with articulated distal end-effectors. These distal articulations of the end-effectors are able to (1) operate the surgical instrument in order to accomplish its “open/close” function (for example, grasping or cutting) and (2) provide orientation motions between the end effector and the instrument shaft. The handle corresponds to the distal degrees-of-freedom of the master manipulator and the end-effector corresponds to the distal degrees-of-freedom of the slave manipulator. The mechanical telemanipulator further comprises a mechanical transmission system arranged to kinematically connect all the master degrees-of-freedom to the equivalent end-effector degrees-of-freedom such that the end-effector replicates the movements of the handle. 
         [0010]    In order to deliver higher gripping forces to the instrument&#39;s end-effector and to provide a more ergonomic range of motion for the surgeon&#39;s hands, the handle comprises an amplification system configured to act on the two distal degrees-of-freedom. With this amplification system, the angular relation between master and slave degrees-of-freedom is changed in some degrees of freedom. While for general degrees-of-freedom of the mechanical telemanipulator there is a “1 to 1” angular relation between a master joint and the equivalent slave joint, the angular relation between the two distal articulations of the handle and the two distal articulations of the end-effector is modified only for the “open/close” function, while the angular relation for orientation motions remains “1 to 1”. For the “open/close” function, the angular relation can be linearly amplified (for instance, “2 to 1” or “3 to 1”) or non-linearly amplified, depending on the invention&#39;s embodiment. 
     
    
     
       BRIEF DESCRIPTION OF FIGURES 
         [0011]    The invention will be better understood according to the following detailed description of several embodiments with reference to the attached drawings, in which: 
           [0012]      FIG. 1  shows a perspective view of a mechanical telemanipulator according to an embodiment of the current invention; 
           [0013]      FIG. 2  shows a schematic view of a mechanical telemanipulator according to an embodiment of the invention disclosed in WO2013014621; 
           [0014]      FIG. 3  shows a perspective view of a mechanical telemanipulator comprising an articulated end-effector and an articulated handle according to an embodiment of the invention disclosed in WO2013014621; 
           [0015]      FIG. 4  shows a perspective view of a distal end-effector of the mechanical telemanipulator according to an embodiment of the current invention and the invention disclosed in WO2013014621; 
           [0016]      FIG. 5  shows a distal end-effector of the perspective of  FIG. 4  in a first active position; 
           [0017]      FIG. 6  shows a distal end-effector of the perspective of  FIG. 4  in a second active position; 
           [0018]      FIG. 7  shows a distal end-effector of the perspective of  FIG. 4  in a third active position; 
           [0019]      FIG. 8  shows a distal end-effector of the perspective of  FIG. 4  in a fourth active position; 
           [0020]      FIG. 9  shows a distal end-effector of the perspective of  FIG. 4  in a fifth active position; 
           [0021]      FIG. 10  shows a perspective views of two distal end-effector links; 
           [0022]      FIG. 11  shows the transmission topology for the two distal end-effector links, during an “opened” configuration, according to an embodiment of the invention disclosed in WO2013014621; 
           [0023]      FIG. 12  shows the transmission topology for the two distal end-effector links, during an “closed” configuration, according to an embodiment of the invention disclosed in WO2013014621; 
           [0024]      FIG. 13  shows the transmission topology for the two distal end-effector links, during an “force-applying” configuration, according to an embodiment of the invention disclosed in WO2013014621; 
           [0025]      FIG. 14  shows the transmission topology for a first distal end-effector link, according to an embodiment of the current invention; 
           [0026]      FIG. 15  shows the transmission topology for a second distal end-effector link, according to an embodiment of the current invention; 
           [0027]      FIG. 16  shows a schematic side view of an articulated handle, according to an embodiment of the current invention; 
           [0028]      FIG. 17  shows the transmission topology for two distal end-effector links, during an “opened” configuration, according to an embodiment of the current invention; 
           [0029]      FIG. 18  shows the transmission topology for two distal end-effector links, during an “closed” configuration, according to an embodiment of the current invention; 
           [0030]      FIG. 19  shows the transmission topology for two distal end-effector links, during an “force-applying” configuration, according to an embodiment of the current invention; 
           [0031]      FIG. 20  shows the transmission topology for two distal end-effector links, during an “laterally oriented” configuration, according to an embodiment of the current invention; 
           [0032]      FIG. 21  shows a first perspective view of an articulated handle, according to an embodiment of the current invention; 
           [0033]      FIG. 22  shows a second perspective view of an articulated handle, according to an embodiment of the current invention; 
           [0034]      FIG. 23  shows a third perspective view of an articulated handle, according to an embodiment of the current invention; 
           [0035]      FIG. 24  shows a fourth perspective view of an articulated handle, according to an embodiment of the current invention; 
           [0036]      FIG. 25  shows the transmission topology for two distal end-effector links, during an “closed” configuration, according to an embodiment of the current invention; 
           [0037]      FIG. 26  shows a schematic side view of an articulated handle, according to an embodiment of the current invention; 
           [0038]      FIG. 27  shows the transmission topology for two distal end-effector links, during an “opened” configuration, according to an embodiment of the current invention; 
           [0039]      FIGS. 28 through 35  show motion transmission from first to the second amplification pulleys by various mechanical means according to various embodiments of the current invention. 
           [0040]      FIGS. 36 and 37  show a schematic view of a different mechanical telemanipulator kinematics where embodiments of the current invention can be applied. 
           [0041]      FIG. 38  shows the kinematics of a mechanical telemanipulator found in a hand-held embodiment of the present invention. 
           [0042]      FIG. 39  displays the kinematics of a single cable loop embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0043]    The articulated handle  2 , according to an embodiment of the present invention, is intended to be used in a mechanical telemanipulator  1 , like the one shown in  FIG. 1 . 
         [0044]    One of the key features of this type 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 end-effector  3  on a remote location. 
         [0045]    According to  FIG. 2 , the mechanical telemanipulator  1  (according to an embodiment of the current invention and the invention disclosed in WO2013014621) may comprise: 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 . 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 , may be substantially 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 . 
         [0046]    Referring still to  FIG. 2 , 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 . 
         [0047]    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.  FIG. 3  shows a close-up view of the proximal handle  2  and the distal end-effector  3 , with their respective moving links (according to an embodiment of the invention disclosed in WO2013014621). 
         [0048]    Referring to  FIG. 4 , the end-effector  3  is connected to the distal extremity of the slave link  29  by a proximal joint, which allows the rotation of the proximal end-effector link  30  by the proximal axis  34  in such a manner that the orientation of the proximal end-effector link  30  with respect to the main axis  33  of the slave link  29  can be changed. The distal end-effector links  31 ,  32  are pivotally connected to the proximal end-effector link  30  by two distal joints, having coincident axes of rotation, which are represented by the distal axis  35 . This distal axis  35  is substantially perpendicular and non-intersecting with the proximal axis  34  and substantially intersects the main axis  33  of the slave link  29 .  FIGS. 5 to 7  show the end-effector  3  with different angular displacements at the proximal end-effector link  30 . 
         [0049]    By actuating the two distal joints, the two distal end-effector links  31 ,  32  can be angulated over the distal axis  35 , with respect to the plane containing the main axis  33  and the distal axis  35 , by the angles θ 31 , θ 32 . Consequently, by the combination of rotations θ 31 , θ 32 , it is possible to operate the surgical instrument, in order to provide orientation motions between the end effector and the slave link  29  ( FIG. 8 ) and to accomplish its “open/close” function ( FIG. 9 ). 
         [0050]    The mechanical telemanipulator  1  further comprises mechanical transmission systems arranged to kinematically connect the slave manipulator  5  with the master manipulator  4  such that the movement (angle of joint) applied on each master joint of the master manipulator  4  is reproduced by the corresponding slave joint of the slave manipulator  5 . 
         [0051]    For each degree of freedom of the mechanical telemanipulator  1 , different types of mechanical transmissions can be used. In order to minimize the system&#39;s overall friction and inertia, while increasing “back-drivability” and stiffness, the mechanical transmission between the majority of the master and slave joints is essentially in the form of pulley-routed flexible elements, where each driven pulley of the slave joint is connected to the respective driving pulley of the master joint, by a multi-stage closed cable loop transmission. As can be seen in  FIG. 4 , the distal end-effector members  31 ,  32  are operatively connected to flexible members so that they can be independently rotated in both directions along the distal axis  35 . The contact between the flexible elements and the distal end-effector elements is made in the circular grooved surfaces  31   a ,  31   b ,  32   a ,  32   b  ( FIG. 10 ), which have a pulley-like geometry, forming the pulleys p 31  and p 32 . 
         [0052]      FIG. 11  shows the working principle of this actuation for the case of transmitting the rotations θ 25 , θ 26  from the driving pulleys p 25  (shaded in  FIG. 11 ) and p 26  (not visible in  FIG. 11 ) around the axis  37 , on the proximal handle  2 , to the rotations θ 31 , θ 32  of the driven pulleys p 31  (shaded in  FIG. 11 ) and p 32  (not visible in  FIG. 11 ) around the axis  35 , on the end-effector  3 . The flexible element  36  is composed by two different segments,  36   a ,  36   b , which form a closed cable loop between the driven pulley p 31  of the end-effector link  31  and the driving pulley p 25  of the handle link  25 . The flexible element  37  (coincident with flexible element  36  in  FIG. 11 ) is composed by two different segments  37   a ,  37   b , which form a closed cable loop between the driven pulley p 32  end-effector link  32  (dashed in  FIG. 11 ) and the driving pulley p 26  of the handle link  26  (dashed in  FIG. 11 ). These flexible elements  36 ,  37  connect the driving pulley  25   p  to the driven pulley  31   p  and the driving pulley  26   p  to the driven pulley  32   p  so that θ 31 =θ 25  and θ 32 =θ 26 . 
         [0053]      FIG. 12  show the configuration where θ 25 =θ 26 =0. In this case, θ 31 =θ 32 =0, and the end-effector remains closed while no gripping force is being applied between the end-effector links  31  and  32 . To increase the gripping force of the end-effector  3 , the handle links  25  and  26 , which are parallel but separated by an offset o ( FIG. 12 ), need to be further moved towards each other, by the angles θ 25 , θ 26  ( FIG. 13 ). These further movements stretch the segments  36   a  and  37   b , which increases the force of the end-effector link  31  against the end-effector link  32 . However, as can be seen in  FIG. 13 , the amount of griping force that can be achieved in this configuration, which is related to the rotation angles θ 25 , θ 26 , is geometrically limited by the physical collision between the handle links  25  and  26 . 
         [0054]    An articulated handle  2  able to overcome the above mentioned limitation is shown, inter alia, in  FIGS. 14 to 27 , according to different embodiments of the present invention. It comprises an amplification system that is introduced at the handle  2  level so that i) the rotations θ 25 , θ 26  are not physically limited (or the limitation allows for broader ranges of θ 25  and θ 26 ) and ii) there is an amplification factor α between the rotation of the handle links  25  and  26  and the end-effector links  31  and  32 , so that, when the end-effector links  31  and  32  are already in contact, the same movement of the handle links  25  and  26  will create a higher stretch on the segments  36   a  and  37   b , which therefore increases the gripping force at the end-effector (compared with the handle mechanisms shown in  FIGS. 11 to 13 ). 
         [0055]    Just like in the previous systems shown in  FIGS. 11 to 13  (embodiments of WO2013014621), the driven pulley p 32  is connected to the driving pulley p 26  by the flexible element  37 . However, in this solution, instead of being rigidly attached to the handle link  26 , the driving pulley p 26  is rigidly attached to a first amplification pulley p 26   a , which is connected to a second amplification pulley p 26   b  by a handle flexible element  126 . This second amplification pulley p 26   b  is able to rotate around a second axis  40  and is rigidly attached to the replacement handle link  26 ′, which replaces the handle link  26  from the system shown in  FIGS. 11 to 13 . The ratio between the diameters of second amplification pulley p 26   b  and the first amplification pulley p 26   a  correspond to the amplification factor α of the handle  2 , which corresponds also to the ratio between the angle θ 32  of the end-effector link  32  and the angle θ 26 ′ of the replacement handle link  26 ′ (θ 32 /θ 26 ′=Øp 26   b /Øp 26   a =α). 
         [0056]      FIG. 15  shows the previously described system applied to the actuation of the end-effector link  31 . Just like in the previous systems shown in  FIGS. 11 to 13 , the driven pulley p 31  is connected to the driving pulley p 25  by the flexible element  36 . However, in this solution, instead of being rigidly attached to the handle link  25 , the driving pulley p 25  is rigidly attached to a first amplification pulley p 25   a , which is connected to a second amplification pulley p 25   b  by a handle flexible element  125 . This second amplification pulley p 25   b  is able to rotate around a second axis  40  and is rigidly attached to the replacement handle link  25 ′, which replaces the handle link  25  from the system shown in  FIGS. 13 to 15 . The ratio between the diameters of second amplification pulley p 25   b  and the first amplification pulley p 25   a  correspond to the amplification factor α of the handle  2 , which corresponds also to the ratio between the angle θ 31  of the end-effector link  31  and the angle θ 25 ′ of the replacement handle link  25 ′ (θ 31 /θ 25 ′=Øp 25   b /Øp 25   a =α=θ 32 /θ 26 ′=Øp 26   b /Øp 26   a ). 
         [0057]      FIG. 16  shows the side view of an embodiment of the current invention where the replacement handle link  25 ′ and replacement handle link  26 ′ are merged in a single replacement handle link  38  and the second amplification pulley p 25   b  and the second amplification pulley p 26   b  are merged in a single second amplification pulley  39 . As can be seen in  FIG. 17 , this solution enables to simultaneously trigger the actuation to both the end-effector link  31  and end-effector link  32 , with an amplification factor α (θ 38 .α=θ 25 =θ 26 ). 
         [0058]      FIG. 18  shows the configuration where θ 38 =0. In this case, θ 31 =θ 32 =0, the end-effector remains closed while no gripping force is being applied between the end-effector links  31  and  32 . To increase the gripping force of the end-effector  3 , the replacement handle link  38  needs to be further moved towards the closing direction, by an angle θ 38  ( FIG. 19 ). This movement stretches the segments  36   a  and  37   b  and therefore increases the force of the end-effector link  31  against the end-effector link  32 . This stretching of the cables (and consequent increase in gripping force) is higher than in the configuration shown in  FIG. 13 , due to the amplification factor α and by the fact that the two handle links  25 ,  26  are not physical colliding between them. 
         [0059]    In order to provide orientation motions θ 31 , θ 32  between the end effector  3  and the slave link  29  ( FIG. 8 ), the structural element  46  is rotated by and angle θ 37 , while the replacement handle link  38  remains stationary in relation to the structural element  46  ( FIG. 20 ). This structural element  46  is able to pivot around the handle axis  37  and is where the second amplification pulleys p 25   b,  p 26   b  are mounted to rotate around the axis  40 . This causes the end-effector link  31  and the end-effector link  32  to move θ 31 , θ 32  in the same angle as θ 37 , with no amplification (θ 31 =θ 33 =θ 37 ). However, a second amplification factor α 2  could be used for these degrees of freedom. 
         [0060]      FIGS. 21 to 24  show an embodiment of the handle  2  in different perspective views. A holder  42  may be attached to the handle  2  so that it can be more easily and ergonomically manipulated by the user. 
         [0061]    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. For instance, the replacement handle link  25 ′ and replacement handle link  26 ′ may not be merged ( FIG. 25 ) and the second axis  40 , around which the second amplification pulley p 26   b  is able to rotate, may be perpendicular and non-intersecting with the axis  37  ( FIG. 26 ). In another embodiment, there can be a spring element  43  that can bring the replacement handle link  38  to an opened default position ( FIG. 27 ). 
         [0062]    In other embodiments, the rotation can transmitted from first amplification pulleys p 25   a,  p 26   a  to the second amplification pulleys p 25   b,  p 26   b  by different mechanical solutions ( FIGS. 28 to 33 ). In the previously described embodiments ( FIGS. 14 to 27 ) the motion transmission is made by flexible elements  125   a ,  125   b ,  126   a ,  126   b  whose extremities are fixed to the first and second amplification pulleys p 25   a,  p 26   a,  p 25   b,  p 26   b  in a crossed ( FIG. 28 ) and uncrossed ( FIG. 29 ) configuration. In the embodiment of  FIG. 30 , the motion transmission is made by the friction force between the first amplification pulley p 25   a,  p 26   a  and second amplification pulley p 25   b,  p 26   b . In the embodiment of  FIG. 31 , the motion transmission is made by a contact force (using teeth or other method to increase contact forces). In the embodiment of  FIG. 34 , the motion transmission is made by a push-pull element  44 , which is pivotally connected to the first amplification pulley p 25   a,  p 26   a  and second amplification pulley p 25   b,  p 26   b . In the embodiment of  FIG. 35 , the motion transmission is made by constant-pitch element  45  (which can take the form of a timing belt, a chain or a bead chain) that can engage the first amplification pulley p 25   a,  p 26   a  and second amplification pulley p 25   b,  p 26   b . In still further embodiments, the embodiments previously described ( FIGS. 28 to 33 ) can be used to transmit motion between non-circular first and second amplification pulleys p 25   a,  p 26   a,  p 25   b,  p 26   b  ( FIG. 34 ) or to transmit motion between eccentrically rotating first and second amplification pulleys p 25   a,  p 26   a,  p 25   b,  p 26   b  ( FIG. 35 ). In both the embodiments of  FIGS. 32 and 33 , non-constant amplification factors can be achieved. 
         [0063]    In other embodiments, the mechanical telemanipulator  1  can assume other kinematics, like the ones shown in  FIGS. 36, 37 and 38  (hand-held device). 
         [0064]    In another embodiment of the current invention, instead of having multiple cable loops to actuate each degree-of-freedom, single cable loops  37  and  36  are directly connecting the driven pulleys p 32  and p 31  to the amplification pulley  39  ( FIG. 39 ). In this solution, the driving pulleys p 26  and p 25  are converted into idle pulleys i 26  and i 25  that are able to turn around the axis  37 . In addition, the ratio between the diameters of the idle pulleys i 26 , i 25  and the amplification pulley  39  correspond to the amplification factor α of the handle  2 , which corresponds also to the ratio between the angles θ 32  and  031  of the end-effector link  32  and the angle θ 38  of the replacement handle link  38  (θ 32 /θ 38 =α; θ 31 /θ 38 =α; Øi 26 /Ø 39 =α; Øi 25 /Ø 39 =α).