WO2011108018A1

WO2011108018A1 - Instrument for controlling and moving laparoscopic instruments and to drive precision biopsies under ecographic or fluoroscopic guidance

Info

Publication number: WO2011108018A1
Application number: PCT/IT2011/000056
Authority: WO
Inventors: Guido Danieli; Domenico Mundo; Michele Perreli
Original assignee: Danieli, Giovanna; Gozzi, Francesca; Villa, Federica; Pace, Calogero; Caruso, Pasquale; Perrotta, Paolo; Aulicino, Edoardo; Lecce, Albenzio; Nudo, Paola; Lopresti, Ivano; Vitelli, Emiliano; Cosco, Francesco, Igino
Priority date: 2010-03-02
Filing date: 2011-03-02
Publication date: 2011-09-09
Also published as: ITCS20100006A1

Abstract

The basic structure is formed by three to five self balanced arms, of which at least three bear six Degrees of Freedom (DOF) arms, while the two optional bear 5 DOF. The central arm and the two 5 DOF are passive, convertible into active, the first being dedicated to moving and reorienting the endoscope, while the remaining two will be five DOF arms, which can be used as active arms to help the doctor during the surgery. Passing to the last 6 DOF arms, the first DOF are passive and lockable, while the sixth is integral part of the position control system of the laparoscopic instrument, that allows also rotating the instrument's sheet about an axis perpendicular to the 6th DOF, and perpendicular to the sheet itself, maintaining fixed the point of insertion in the patient's skin. Moreover this system allows rotating the instrument with respect to the sheet, changing its depth of penetration into the body, and finally actuating the instrument, every movement being controlled by the doctor sitting at the console, using the manual instrumentation present in the hospitals. The presence of a quasi - haptic interface able to inform the doctor on the level of forces exerted is also foreseen. The description of a new multi-use instrument for laparoscopy able to open the blades symmetrically and to tilt the head in two mutually perpendicular directions, is given. Finally two more end effectors are presented, able to guide precision biopsies under ecographic or fluoroscopic control.

Description

INSTRUMENT FOR CONTROLLING AND MOVING LAPAROSCOPIC INSTRUMENTS AND TO DRIVE PRECISION BIOPSIES UNDER ECOGRAPHIC OR FLUOROSCOPIC GUIDANCE

Navi-Robot has been initially conceived for usage in the orthopedic surgical room. However its three self balanced arms structure is suitable to a series of other biomedical applications, among which the reduction of ionized radiation absorption for the patient, but, even more importantly, for the doctors. For instance Navi-Robot may be used to guide fracture reduction in augmented reality, as shown in patent EP0977514, or to drive the elimination of an osteoid osteoma on the base of only two fluoroscopies, or to drive the insertion of a distal screw in an endo-medullar nail. To this end it is necessary to use stereophotogrammetry in conjunction with a special end-effector, bearing 4 radio-opaque spheres in known position, acting as a guide for the drill. But this application gave the idea of using Navi-Robot under both fluoroscopic and ecographic guidance, as will be described in the following. On the other hand, in 2005 a PCT was presented, then transformed into European patent application EP05778903.4 of title "Robotized System of control and micrometric actuation of an endoscope", system suitable to be applied to the side arms of Navi-Robot, while the central arm, in active mode, may drive the endoscopic camera according to the operator's request. In order to do the Navi-Robot structure has been modified with respect to the patent EP1843876, both on the prismatic joint used for vertical motion, replaced by a simpler four parallel bar link, and for moving the sixth joint so that its axis crosses those of the fourth and fifth in the same point, so as to realize a spherical joint, with the advantage that, if the last link is also balanced, the entire structure is fully self balanced, and can assume any configuration staying balanced. Finally the sixth joint of the lateral arms has been turned into an active / passive one, so that the system of control of the surgical instrument needs one degree of freedom less than what was previously foreseen in the case of laparoscopic application. But a new mechanism to control the position and actuate the traditional instrument, that simplifies enormously instrument control. Finally, just in order to overcome the limitations of the traditional instrument with respect to the ones utilized by da Vinci (US 6,206,901, US 6,246,200, US 6,312,435, etc), top expression of robotic laparoscopy, a new multi-use instrument has been studied allowing the same motion permitted by da Vinci instrumentation. This allows the . application of Navi-Robot without limitations to mini-invasive surgery, with all advantages that this brings, without taking into account the possibility of using very small diameter instruments, thing that is impossible with da Vinci, increasing strongly the possibilities of applications of an equipment, already extremely versatile.

Description of the preferred embodiment.

Let's start with the structural modifications of Navi-Robot intended as base instrument. As previously quoted, two are the structural modifications with respect to what already patented, the use of the four parallel bar link to replace the vertical prismatic joint previously considered, and the displacement of the sixth joint in order to produce a spherical hinge. In particular Figure 1 shows the comparison between the old system configuration (la) and the new one (lb). Naturally the entire system may use step motors, as is done now, but also other types of motors. Further general modification, the introduction of the passive / active joint on the sixth joint of the lateral arms. Finally, always in general theme, the end effector for drill driving and guiding needles of screws, that connecting to the intermediate end effector of the central arm, allows the introduction in direction and position pre-established of what is desired. This particular end effector (Fig. 2) must also be provided with a certain number of radio-opaque spheres, in order to allow identify its position in the frame of reference of the fluoroscope, that must be previously calibrated in order to determine its intrinsic parameters. As far as the working principle is concerned, the idea is to take two images in which both the region of interest and end effector (that must be still) are visible, while connecting the fluoroscope to one of the passive Navi-Robot arms. Once this is done, is possible, marking with the mouse the point of interest and the spheres in each image, through the principles of stereophotogrammetry, compute both the initial position of the end effector and the position that this must assume to perform the precision biopsy. At this point, the central arm, that knows the position of the end effector in its system of reference, is able to move in the required position to allow the precision biopsy. But, as previously mentioned, the system allows this process also in conjunction with an ultrasound device. In this case the probe must be connected directly to the Navi- Robot as end effector. The doctor, thanks to the automatic balancing of the system, may perform as usual the ultrasound analysis, connecting also the ultrasound equipment to the Navi-Robot PC, that automatically couples the ultrasound information's to the position in which these were detected, supplying a kind of ultrasound CAT with zero radiation. At this point, once the doctor has indicated on the screen where to take the biopsy, and since Navi-Robot knows through a previous calibration both the ultrasound probe geometry and that of the end effector, it is possible to compute the new position the Navi-Robot may assume with its end effector, and conclude the operation. Passing to the laparoscopic application, the system is essentially composed by three basic elements, a positioning system, a fine position control and actuation of the traditional laparoscopic instrument, and a command console. Obviously the global positioning system is Navi-Robot itself, of which we just discussed, with the modifications with respect to patent EP1843876. Once fixed to this the control and actuation system, the doctor may freely move it, thanks to automatic balancing, toward the working position, connect the endoscopic instrument to the robotic equipment, already positioned, lock the arm or require the robot mode for the central arm, of whose final actuator we will discuss later, and will be ready for the surgery. This is the basic configuration of each of the lateral arms, while for the central is possible to use as it is or a possible modification will be shown later. Finally, two possible auxiliary arms could have a configuration self balanced but lockable, without measuring devices, or be even true active/ passive arms. As far as the control system of the surgical instrument, this is a further 4 degrees of freedom system, including the actuator, while a first degree of freedom is supplied by the last joint of the Navi-Robot arm. This motorized hinge, together with the first degree of freedom of the control system acting on the double four parallel bar link of figure 3, allows rotating the surgical

80 instrument, about its point of insertion in the patient's skin. A further degree of freedom allows controlling axial penetration of the instrument with respect to the sheet, a third degree controls rotation of the instrument, again with respect to the sheet, while the fourth is dedicated to the actuation of the instrument, scissors, forceps or whatever it is. All this is shown in fig. 3, where with 1, 2, 3 and 4 are identified the various degrees of freedom of the control system. In particular,

85 notice that, differently from what was previously proposed, the control system of the first degree of freedom is based on the use of a double four parallel bar link, that allows the point where the axis of the first hinge (the one of the sixth joint of Navi-Robot) crosses the axis passing through the centers of the hinges of the third adjustable bar (a) of the second four parallel bar link, to stay fixed, even mclining the bars initially vertical. Assembling then the laparoscopic instrument and

90 relative slide, that allows changing penetration, inclined with respect to the axis of said bar (a), and passing through the point of intersection between axes previously mentioned, we obtain the invariance of the point of penetration into the patient's tissue. Finally the control system for penetration and actuation are provided with force sensors, to evaluate forces required in the various operations in order to supply the surgeon an indication on possible problems. Such indications

95 could be both of force and visible, such a led column increasing in eight proportionally to the force registered, so that it is easily perceived and valued. Naturally, it is possible to use both methods in one time for redundancy.

The following figure 4 shows a possible kit of motion control of an existing endoscopic instrument. Note that the lower gear (1), fixed to the instrument's body, allows rotating it by 360° 100 about its axis. Meanwhile the upper gear, if rotated by an angle different from that of the lower gear, activates the opening and closing of the instrument, through a second pair of bevel gears commanding two bars that together with the instrument's handle, form a planar four bar link. The following figure 5 shows how the above mentioned kit is actuated by two other spur gear positioned on the sides, themselves actuated by bevel gears that are commanded directly by 105 motors.

Moreover, the control system, knowing the relative position of the surgical instruments and of the endoscopic camera, will move the instruments coupling the motor's actions of the first degree of freedom of the system and of the last degree of freedom of Navi-Robot, so that the operator, moving laterally the joy-stick, will always obtain a variation in depth, while moving it back and 110 forth, will obtain a motion parallel to the plane of observation. Note that the entire kit must be sterilizable, and commanded by motors positioned on the slide of the 4 degrees of f eedom system, the motion being transmitted through sterile shafts, while force sensors will be positioned between motor and frame.

Passing to the central arm, that must hold the endoscope and relative video-cameras for 115 laparoscopic applications, we must detach the fifth link and whatever is connected, and substitute it with an horizontal link fixed to the previous, holding on the other side only the endoscope support mounted after an universal joint, with encoders on the cross axes, whose base may be turned by the actuator of the fourth link of Navi-Robot through a simple belt. This way the first three degrees of freedom allow moving in space the center of the universal joint cross, while the skin supplies a 120 fixed point to univocally determine the position of the endoscope, that can be also rotated through the fourth actuator, being the full thing controlled via pedals. Figure 6 shows the new geometry of the central arm.

However, as previously mentioned a new multi-use instrument for laparoscopy has been designed, able to incline the cutting and grasping elements up to 90° in two directions, in order to allow the 125 range of motion up to now permitted up to now only by da Vinci. Figure 7 shows this instrument and relative actuation system, on which act four independent motors, mounted on a new slide, to be substituted to that for traditional instruments.

Let's start to examine the tip of the same instrument. As can be seen, the two elements of the scissors/forceps open in a symmetric fashion, and this thanks to the use of five spur gears, of which

130 1 and 3 are keyed to the same shaft. Moreover the distance between axes 1-2 and 3-5 are identical, while gear 4 is used only to reverse the motion, and finally the cutting and grasping elements are fixed to gears 2 and 5. Motion to gear 1 is given by gear 6, that, as can be noted is partly spur and partly bevel, and actuated by gear 7, sector of bevel gear. In parallel, another sector of bevel gear, 8, act on the bevel portion of gear 9 that, with its spur portion, moves gear 10, fixed to the frame

135 holding gears 1-5.

Rotating gear 6 by 20° we obtain the opening of the forceps in straight configuration by 40°, rotating in the same direction and of the same quantity gears 6 and 9, we obtain configuration d with closed forceps, further rotating gear 6 the forceps opens, even if inclined by 90°.

Gear 7 is actuated by gear 11 in configuration e, while 12 acts on 10 through 8 and 9. To obtain 140 the configuration b is necessary to act on all gears from 11 to 13, and taming further 11 we obtain forceps opening. Motion transmission between the gears on the tip and those at the bottom is through micro-rods. Finally the entire thing is actuated through gears, placed in parallel to the instrument axis, that are actuated through bevel gears and motors placed on the slide, as shown in figure 7e.

Claims

1) Robotized system to control and actuate laparoscopic instrumentation and precision guide biopsies, composed by a certain number of 6 degrees of freedom arms, based on the use of Navi-Robot, system characterized by the presence of 3 self balancing 6 degrees of freedom arms, in which vertical motion is obtained with an horizontal axes four parallel bar link, being this the 1^st degree of freedom bearing a counterweight on the opposite side, while motion in a cylindrical space are obtained by two further hinges having vertical axes, being this the 2^nd and 3^rd degree of freedom, a 4^th degree of freedom being formed by a further vertical axis hinge, a 4^th by an horizontal axis hinge intersecting the axis of the 5^th , and a 6^th another hinge with axis perpendicular to that of the 5^th and whose axis crosses also the axis of the 4^th in the same point, generating a spherical hinge, being the two lateral measuring arms for the presence of encoders in each joint, lockable with the help of suitable brakes in any position, and the central also measuring arm but able to convert in active robot blocking with a brake the motor reducer group to the base of the leading link the, while the axis of the same group is fixed to the trailing link, and may be utilized both to drive precision biopsies and to move and control an endoscope, while the traditional laparoscopic tools is controlled substituting the 6^th degree of freedom of a purely passive joint with an active/passive joint on the lateral arms, adding a 4 degrees of freedom control system of which the last is used to actuate of the surgical instrument, whose end portion is entirely sterilizable, by an adaptation and connection kit to the existing instruments, also sterilizable, by a real time control system of the motion of both the surgical tool and of the auxiliary arms by an unique operator, while a new multi-use instrument has also been designed, able to rotate the tip by 90° in order to open the blades of the scissors in every possible direction, moved by a 6 degrees of freedom robotic system in substitution of the previous 4 degrees of freedom, being motion controlled as before, evaluating also forces. Robotized system to control and actuate laparoscopic instrumentation, composed by a certain number of 6 degrees of freedom arms according to claim 1, characterized by the presence of 4 degrees of f eedom system whose the terminal portion is entirely sterilizable, which allows rotating the instrument about two axes perpendicular to the same instrument, the rotation of the same by 360° about its axis, the axial motion of the same about the sheet and the actuation of the surgical tool, is based on the use of a double parallel arms 4 bar link that holds on the third parallel bar a slide inclined by a certain angle in order to leave the instrument's handle the room to be actuated, also keeping constant the point of insertion of the instrument in the patient's belly, located at the intersection between the axis of the external hinge (the last degree of freedom of the lateral arm) and the axis joining the centers of the cited third bar. Robotized system to control and actuate laparoscopic instrumentation, composed by a certain number of 6 degrees of freedom arms according to claim 1, characterized by the fact that the arm supporting the endoscopic camera should be able to be re-directed by the doctor acting as a robot in order to allow correction of the direction of observation, keeping constant the position of the hole of skin insertion.

Robotized system to control and move conventional laparoscopic instruments as per claim 1 in which the central arm is modified eliminating the last two degrees of freedom of the Navi- Robot central arm, extending the third link and connecting with a belt the 4^th joint to a vertical arm holding the video system through an universal joint whose rotations are monitored by encoders, in order to determine the direction of observation

Robotized system to control and move conventional laparoscopic instruments as per claim 1, in which the surgical instrument is a 3 degrees of freedom system, of which one is dedicated to the symmetric opening of the instrument, and the residual two able to incline by 90° the instrument's head in two mutually perpendicular directions through a system of bevel gears and three following pairs of spur gears, of which the last is dedicated to the symmetric opening of scissor' s or forceps, placing in parallel two and three spur gears, while another parallel gear allows rotating the head by 90°, while the first pair of gears allows rotating the head by 90° but in a direction perpendicular to the previous.

Robotized system composed by at least two 6 degrees of freedom arms as per claim 1, used in conjunction with a suitable end effector, of known geometry, uniquely fixed to the Navi-Robot central arm, holding both a cannula to guide biopsy needle insertion and a certain number of radio-opaque spheres in known position, so that, once calibrated the fluoroscope, fixing a measuring arm of the Navi-Robot to the fluoroscope emitter, taking two images in which both are visible and identifiable both the region to examine and the end effector with its spheres, is possible, using the methods of photogrammetry, compute the relative position between end effector and region to be examined, which, once supplied to the controller, allows, turning the arm into active, to orient the cannula in the right direction, supplying also depth of penetration. Robotized system composed by at least two 6 degrees of freedom arms, as per claim 1, to be used in conjunction with a suitable end effector of known geometry, univocally fixable to the central arm of Navi-Robot, holding a cannula to guide biopsy needle insertion, and an ultrasound probe also univocally fixed to an arm of Navi-Robot (may be the central or not), and a special plug interposed between ultrasound equipment and probe, transmitting the information's to the Navi-Robot controller, so that, while the doctor performs the ultrasound exam with the probe univocally fixed to the Navi-Robot arm, this registers the spatial position in which every image is taken, allowing in the following, examining the various images, to find the position of a potentially dangerous nodule, and, substituting the end effector to the probe, be guided in taking the precision biopsy.