Patent Description:
Surgical robotic systems are frequently used during surgical interventions, in order to assist a surgeon. The surgical robotic system may guide the positioning and orienting of a surgical tool for the surgeon.

The surgical robotic system comprises a surgical robotic arm, comprising an end effector holding a tool guide. The tool guide is to be placed with a given position and orientation relative to a surgical target. The surgeon can couple a surgical tool to the tool guide so that once the tool guide is placed relative to the surgical target, the surgical robotic system assists the surgeon in the guiding of the tool. Thus, the surgeon may maneuver the surgical tool with the right position and orientation relative to the surgical target during the surgery.

The surgeon may use the surgical robotic system in order to drill one or several holes into one or several bones of a patient, and then to implant a screw into each respective drilled hole. The surgical target corresponds to a specific position and orientation of the hole to be drilled on a bone such as a vertebra, or a fractured bone of the patient. For example, in spine surgery, several surgical targets may be located on several vertebrae of the patient.

The tool guide maintains the tool in a specific position and orientation relative to the surgical target in order to precisely guide the surgeon into drilling the hole and then implanting the screw. Thus, the surgical robotic system assists the surgeon in drilling the hole and then implanting the screw into the drilled hole.

However, a problem may occur during the guiding of the tool by the tool guide of the surgical robotic system. For example, a misalignment can exist or appear between the tool and the surgical target, such that the surgical target and the tool are not coaxial, and/or are not correctly positioned relative to each other. Such a misalignment may occur because of mechanical inaccuracies, movements of the bone during drilling or screwing or between drilling and screwing, etc. Such a misalignment can negatively impact the surgical procedure and possibly the final result of the surgical procedure.

For example, when the surgical robotic system assists the surgeon in implanting a screw into a drilled hole, the screw may not be perfectly coaxial with the drilled hole due to such misalignments. The misalignment between the screw and the surgical target may cause an undesirable locking to occur between the screwdriver and the screw engaged in the drilled hole, in a manner which makes it difficult to decouple the screw and screwdriver from each other. Another problem caused by such misalignment may be the difficulty for the surgeon to easily find the hole with the screw.

Document <CIT> discloses a guiding system comprising a coupling link for coupling a guide bush and a cutter. Document <CIT> discloses a guiding system comprising a coupling link for coupling a tool and a mount. Document <CIT> discloses a guiding system comprising a coupling link for coupling a tool and a drive. Document <CIT> discloses a guiding system comprising a coupling link for coupling a tool and a track. Document <CIT> discloses a guiding system comprising a coupling link for coupling a tool and a tool guide.

A general aim of the invention is to propose a guiding system allowing an improved guiding of a surgical robotic system.

According to a first aspect, the invention is directed towards a guiding system for a surgical robotic system, comprising a tool guide extending substantially around a tool guide axis, a tool extending substantially around a tool axis, an intermediate part mounted on the tool so that the tool and the intermediate part are integral in translation and so that the tool is mobile relative to the intermediate part in rotation around the tool axis, and first and second coupling links adapted to couple the intermediate part and the tool guide, wherein the guiding system presents:.

Some preferred but not limitative features of the guiding system described above are the following, taken individually or in combination:.

According to a second aspect, the invention is directed towards a surgical robotic system, comprising a robotic arm comprising the guiding system according to the first aspect, a tracking system configured to determine a position and orientation of the tool guide and/or the tool relative to a surgical target, a control unit coupled to the tracking system and configured to control the robotic arm to align the tool with the surgical target, and a display unit adapted to configure a guiding of the tool guide and/or the tool.

A third, no-claimed, aspect is directed towards a method for guiding a tool with a surgical robotic system according to the second aspect relative to a surgical target, wherein the surgical target comprises a surgical target channel directed along a surgical target axis, wherein the method comprises the following steps:.

Some preferred but not limitative features of the method described above are the following, taken individually or in combination:.

Other features and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting and must be considered with respect to the appended figures in which:.

<FIG> are perspective views of guiding systems for a surgical robotic system according to different embodiment of the invention, wherein the tool and the intermediate part are adapted to be at least partially inserted substantially radially inside the tool guide.

A guiding system for a surgical robotic system is illustrated by way of a non-limiting example in <FIG>. The guiding system comprises a tool guide <NUM> extending substantially around a tool guide axis X, a tool <NUM> extending substantially around a tool axis T, an intermediate part <NUM> mounted on the tool <NUM> so that the tool <NUM> and the intermediate part <NUM> are integral in translation and so that the tool <NUM> is mobile relative to the intermediate part <NUM> in rotation around the tool axis T, and first and second coupling links <NUM>, <NUM> adapted to couple the tool <NUM> and the tool guide <NUM>.

The guiding system may be used during surgical interventions, in order to assist a surgeon in guiding the positioning and orienting of the intermediate part <NUM> coupled to the tool guide <NUM>, thus of the tool <NUM>, relative to a surgical target <NUM>.

The surgical target <NUM>, as illustrated by way of a non-limiting example in <FIG>, <FIG>, may be defined by a surgical target <NUM> position and/or a surgical target axis S. More specifically, the surgical target <NUM> may be a surgical target channel <NUM> oriented along the surgical target axis S and having a first end and a second end located opposite the first end, the surgical target <NUM> position corresponding to the position of the first end of the surgical target <NUM>. The first end of the surgical target channel <NUM> may correspond to an entry point of the tool <NUM> into a bone <NUM> of a patient <NUM>.

The terms proximal and distal are used in relation to a position along the surgical target axis S, so that during the surgical procedure, the distal end of an element is located closer to the surgical target <NUM>, considering a distance along the surgical target axis S, than the proximal end of the same element.

The tool guide <NUM> extends substantially around the tool guide axis X. The tool guide <NUM> may be a tool guide channel, the tool guide <NUM> forming a substantially cylindrical sleeve around the tool guide axis X. The tool guide <NUM> is adapted to receive the first coupling link <NUM>, <NUM> and/or the second coupling link <NUM>. The tool guide <NUM> may also be adapted to receive the tool <NUM> and/or the intermediate part <NUM>. The tool guide <NUM>, more particularly the tool guide channel <NUM>, may comprise a distal end and a proximal end located opposite the distal end.

The intermediate part <NUM> may extend around at least part of the tool <NUM>, more particularly around at least part of a tool shaft <NUM> of the tool <NUM>. The intermediate part <NUM> may extend substantially along the tool axis T. The intermediate part <NUM> may present a substantially hollow cylindrical shape configured to be arranged around the tool <NUM>, more particularly around the tool shaft <NUM> of the tool <NUM>, the tool shaft <NUM> passing through the intermediate part <NUM>.

The tool <NUM> and the intermediate part <NUM> are mobile relative to each other only in rotation around the tool axis T, and are rigidly secured to each other in all the other degrees of freedom. In other words, the tool <NUM> can be rotated around the tool axis T inside the intermediate part <NUM>, whatever the guiding configuration of the guiding system. Thus, for example when the tool <NUM> is a screwdriver, the screwdriver can be rotated around the screwdriver axis at any step of the surgical operation. However, the intermediate part <NUM> and the tool <NUM> are moved together in any translation, more particularly in translation along the tool guide axis X or in a plane perpendicular to the tool guide axis X, and in inclination relative to the tool guide axis X. Translating the tool <NUM> results in an identical translation of the intermediate part <NUM>, and inclining the tool <NUM> relative to the tool guide axis X results in an identical inclination of the intermediate part <NUM>.

In the first guiding configuration, the tool <NUM>, the intermediate part <NUM> and the tool guide <NUM> may be substantially parallel to each other, located at a distance from each other, the tool guide axis X and the tool axis T being substantially parallel. Alternatively, the tool <NUM>, the intermediate part <NUM> and the tool guide <NUM> may be substantially coaxial, the tool guide axis X and the tool axis T coinciding substantially. When the tool <NUM>, the intermediate part <NUM> and the tool guide <NUM> are parallel, the tool guide <NUM> may be positioned by the surgical robotic system taking into account the distance between the tool guide <NUM> and the tool <NUM>, in order to align the tool axis T with the surgical target axis S.

The surgeon may for example use the surgical robotic system in order to drill one or several holes into one or several bones <NUM> of the patient <NUM>, and then to implant a screw <NUM> into each respective drilled hole.

First, the guiding system assists the surgeon in drilling the hole. The tool <NUM> is a drill. The surgeon can insert the drill into the tool guide <NUM> of the guiding system, or mount the drill outside the tool guide <NUM>. The tool guide <NUM> allows positioning and orienting of the drill relative to the hole to be drilled, and guiding of the drill at the desired position and orientation during the drilling of the hole in the bone <NUM>. Therefore, the guiding system assists the surgeon in drilling a hole intended to receive the screw <NUM> at the desired hole position, which corresponds to the position of the surgical target <NUM>, and along the desired hole orientation, which corresponds to the orientation of the surgical target axis S.

Second, after the drilling is carried out, the guiding system assists the surgeon in implanting a screw <NUM> into the drilled hole. The tool <NUM> is a screwdriver. The screwdriver has a handle <NUM>, and a shaft <NUM> extending from the handle <NUM>. A screw <NUM> may be removably mounted to the tip of the shaft <NUM> of the screwdriver. The surgeon can insert the screwdriver into the tool guide <NUM> of the guiding system, or mount the screwdriver outside the tool guide <NUM>. The tool guide <NUM> allows positioning of the screwdriver and screw <NUM> relative to the hole drilled in the bone <NUM>, so that the surgeon can insert and screw the screw <NUM> into the hole. Therefore, the guiding system assists the surgeon in implanting the screw <NUM> in the drilled hole. The position and orientation of the surgical target <NUM> corresponds to the position and orientation of the hole drilled in the bone <NUM>.

The first and second coupling links <NUM>, <NUM> adapted to couple the intermediate part <NUM> and the tool guide <NUM> are mechanical linkages allowing certain movements of the intermediate part <NUM>, thus of the tool <NUM>, relative to the tool guide <NUM> and preventing other movements of the intermediate part <NUM>, thus of the tool <NUM>, relative to the tool guide <NUM>.

The first guiding configuration and second guiding configuration allow to the guiding system to minimize the workload of the surgeon while efficiently assisting the surgeon, in order to optimize the guiding and the final result of the surgical procedure.

In the first guiding configuration, the intermediate part 60and the tool guide <NUM> are mobile relative to each other according to a first degree of freedom corresponding to a translation along the tool guide axis X. Thus, in the first guiding configuration, the intermediate part <NUM>, thus the tool <NUM>, may be translated along the tool guide axis X while the tool guide <NUM> remains at a fixed position along the tool guide axis X, or vice versa the tool guide <NUM> may be translated along the tool guide axis X while the intermediate part <NUM>, thus the tool <NUM>, remains at a fixed position along the tool guide axis X. Additionally or alternatively, the intermediate part <NUM>, thus the tool <NUM>, and the tool guide <NUM>, may each simultaneously be translated along the tool guide axis X, in opposite directions or in a same direction but along different distances, so that the relative position of the intermediate part 60and the tool guide <NUM> along the tool guide axis X varies.

In the first guiding configuration, the first degree of freedom is a unique first degree of freedom. Thus, the intermediate part 60and the tool guide <NUM> cannot be moved relative to each other in any other direction or orientation than in translation along the tool guide axis X. The tool <NUM> can therefore only be moved relative to the tool guide according to two degrees of freedom, that is to say in translation along the tool guide axis X, which corresponds to the first degree of freedom, and also in rotation around the tool axis T. For example, an orientation of the intermediate part <NUM>, thus of the tool <NUM> relative to the tool guide <NUM>, cannot be modified, and a position of the intermediate part <NUM>, thus of the tool <NUM>, relative to the tool guide <NUM> in a direction other than the direction of the tool guide axis X cannot be modified. The first guiding configuration thus offers a rigid guiding of the intermediate part <NUM>, thus of the tool <NUM>.

During a surgical intervention, the tool <NUM> may be placed in a predetermined position and orientation relative to the surgical target <NUM> according to the operation to perform. Then, the guiding system in the first guiding configuration rigidly guides the intermediate part <NUM>, thus the tool <NUM>. For example, the guiding system rigidly guides the drill into the bone <NUM> so as to drill a hole in the bone <NUM>, or rigidly guides the screwdriver so as to implant the screw <NUM> into the drilled hole. In the first guiding configuration, the intermediate part <NUM> and the tool guide <NUM> are mobile relative to each other only in translation along the tool guide axis X, that is to say according to the unique first degree of freedom. The tool <NUM>, for example the drill or the screwdriver, is also mobile in rotation around the tool axis T relative to the tool guide <NUM>.

Thus, in the first guiding configuration, the workload of the surgeon is minimized, as the position and inclination of the tool <NUM> relative to the tool guide <NUM> is managed by the guiding system, the surgeon having leeway to influence only one degree of freedom.

In the second guiding configuration, the intermediate part <NUM>, thus the tool <NUM> and the tool guide <NUM> are also mobile relative to each other according to at least one additional degree of freedom. Thus, the intermediate part <NUM>, thus the tool <NUM>, and the tool guide <NUM>, may be moved relative to each other in translation along the tool guide axis X, and may also be moved relative to each other according to at least one other degree of freedom, for example in orientation or in translation along a direction other than the direction of the tool guide axis X.

Thus, the second guiding configuration offers a more flexible guiding of the intermediate part <NUM>, thus of the tool <NUM>. The guiding system thus allows the surgeon to maintain some leeway in the guiding of the tool <NUM>, in position and/or orientation, relative to the tool guide <NUM>, more specifically in at least one position and/or orientation other than the translation along the tool guide axis X and rotation around the tool axis T.

A more flexible guiding allows to prevent problems during the guiding of the tool <NUM> by the guiding system. Especially, it may be necessary for the surgeon to adjust a position and orientation of the tool <NUM> relative to the tool guide <NUM> in order to align the tool <NUM> in position and/or orientation relative to the surgical target <NUM>. For example, if a misalignment may exist or appear between the tool <NUM> and the surgical target <NUM>, such that the surgical target <NUM> and the tool <NUM> are not coaxial and/or are not correctly positioned relative to each other. Such a misalignment may occur because of mechanical inaccuracies, movements of the bone <NUM> during drilling or screwing or between drilling and screwing, etc..

A relatively flexible guiding, as allowed by the second guiding configuration, allows the surgeon to rectify such a misalignment, that is to say to adjust a position and/or orientation of the tool <NUM> relative to the tool guide <NUM> in order to align the tool <NUM> in position and/or orientation relative to the surgical target <NUM>.

For example, when the surgical robotic system assists the surgeon in implanting a screw <NUM> in a drilled hole, the drilled hole and the screw <NUM> may not be perfectly coaxial due to misalignments. This may cause an undesirable locking to occur between the screwdriver and the screw <NUM> engaged in the drilled hole, in a manner which makes it difficult to decouple the screw <NUM> and the screwdriver from each other.

The second guiding configuration may be used for example after the screwdriver has been translated along a certain distance, especially once the screw <NUM> is at least partially inserted into the hole, the guiding system being in the first guiding configuration in order to partially insert the screw <NUM> into the hole. Once the guiding system is in the second guiding configuration, the surgeon may thus manipulate the screwdriver with ease according to the at least one additional degree of freedom when the screwdriver moves inwards so as to continue to implant the screw <NUM> in the drilled hole. Thus, the surgeon may correct a potential misalignment between the screw <NUM> and the drilled hole, therefore preventing the undesirable locking between the screwdriver and the screw <NUM> engaged in the drilled hole.

If the guiding system is in the first guiding configuration and the surgeon notices a misalignment or a risk of undesirable locking between the screw <NUM> and the screwdriver, the surgeon may move the guiding system to the second guiding configuration. Then, the surgeon may adjust a position and/or orientation of the tool <NUM> relative to the tool guide <NUM> so as to align to the tool <NUM> with the surgical target <NUM>. Alternatively, the guiding system may automatically be transitioned from the first guiding configuration to the second guiding configuration after the tool <NUM> has been moved along a certain distance towards the surgical target <NUM> along the tool guide axis X.

The at least one additional degree of freedom may comprise an inclination of the intermediate part <NUM>, thus of the tool <NUM>, relative to the tool guide axis X.

Thus, the tool <NUM> and the tool guide <NUM> in the second configuration are mobile relative to each other in translation along the tool guide axis X, in rotation around the tool axis T, and in angular inclination relative to the tool guide axis X. The tool <NUM> may be inclined with respect to the tool guide axis X so as to form an inclination angle relative to the tool guide axis X, the tool <NUM> thus having an orientation which differs from the orientation of the tool guide <NUM>. A non-limiting example of a tool <NUM> having a non-zero angular inclination, or orientation, relative to the tool guide <NUM>, is illustrated in <FIG>. The axis labelled S' in <FIG> corresponds to an axis which is parallel to the surgical target axis S.

Therefore, if the tool <NUM> is not coaxial with the surgical target <NUM> while the guiding system is in the second guiding configuration, that is to say when the tool axis T forms a non-zero inclination angle with respect to the surgical target axis S, the orientation of the tool <NUM> may be modified so as to align the tool axis T with the surgical target axis S. For example, the orientation of the drill may be adjusted if the drill is not coaxial with the hole to be drilled. Similarly, the orientation of the screwdriver may be adjusted if the screwdriver is not coaxial with the drilled hole into which the screw <NUM> is to be inserted.

In addition, or alternatively, the at least one additional degree of freedom may comprise a translation of the intermediate part <NUM>, thus of the tool <NUM>, in the plane perpendicular to the tool guide axis X, for example a translation of the intermediate part <NUM>, thus of the tool <NUM> along at least one direction of the plane perpendicular to the tool guide axis X.

Thus, if the tool <NUM> does not face the surgical target <NUM>, for example if the tool <NUM> is spaced apart with respect to the surgical target <NUM> in a direction perpendicular to the tool guide axis X, then a position of the tool <NUM> may be adjusted so that the tool <NUM> faces the surgical target <NUM>, for example so that a tip of the tool <NUM> is only separated from the first end of the surgical target <NUM> by a predetermined distance along the tool guide axis X. For example, the position of the tool <NUM> may be adjusted so that the tool <NUM> is substantially coaxial with the surgical target <NUM>, the tool axis T and the surgical target axis S being substantially coaxial.

Such a second coupling link <NUM> allows to compensate a misalignment in position and/or orientation, between the tool <NUM> and the surgical target <NUM>.

The first coupling link <NUM>, <NUM> and/or the second coupling link <NUM> may include a slide link, wherein the slide link is directed along the tool axis T, the tool axis T corresponding to the tool guide axis X in the first guiding configuration. The slide link may allow a cylindrical contact with the tool guide <NUM>, so as to allow a translation along the tool guide axis X. The first coupling link <NUM>, <NUM> and/or the second coupling link <NUM> is thus slidable inside the tool guide channel <NUM>.

The first coupling link <NUM>, <NUM> and/or the second coupling link <NUM> may include a ball joint. The ball joint may allow a spherical connection with the tool guide <NUM>, so as to allow a rotation around the tool guide axis X, and preferably further rotation around one or more supplementary axes of rotation so as to allow inclination of the tool <NUM> relative to the tool guide axis X.

The first coupling link <NUM>, <NUM> and/or the second coupling link <NUM> may be rigidly secured to each other so as to be moved together.

The first coupling link <NUM>, <NUM> may comprise at least one slide link. For example, the first coupling link <NUM>, <NUM> may comprise two slide links substantially arranged along the tool guide axis X, as illustrated by way of a non-limiting example in <FIG>. At least one slide link of the first coupling link <NUM>, <NUM> has an outer diameter which corresponds substantially to an inner diameter of the tool guide channel <NUM>. Therefore, the first coupling link <NUM>, <NUM> can only be moved inside the tool guide channel <NUM> according to the first degree of freedom, that is to say in translation along the tool guide axis X. Thus, the two slide links of the first coupling link <NUM>, <NUM> ensure the first guiding configuration of the guiding system.

The first coupling link <NUM>, <NUM> may comprise at least one ball joint. For example, the first coupling link <NUM>, <NUM> may comprise two ball joints substantially arranged along the tool guide axis X, as illustrated by way of a non-limiting example in <FIG>, <FIG> and <FIG>. At least one of the ball joints of the first coupling link <NUM>, <NUM> has an outer diameter which corresponds substantially to an inner diameter of the tool guide channel <NUM>. Therefore, the ball joints of the first coupling link <NUM>, <NUM> can only be moved inside the tool guide channel <NUM> according to the first degree of freedom, that is to say in translation along the tool guide axis X. Thus, the two ball joints of the first coupling link <NUM>, <NUM> ensure the first guiding configuration of the guiding system.

The first coupling link <NUM>, <NUM> may comprise a ball joint and a slide link, as illustrated by way of a non-limiting example in <FIG>, <FIG>, <FIG>. At least one of the ball joint or the slide link has an outer diameter which corresponds substantially to an inner diameter of the tool guide channel <NUM>, so as to allow movement of the first coupling link <NUM>, <NUM> inside the tool guide channel <NUM> only in translation along the tool guide axis X, thus ensuring the first guiding configuration of the guiding system.

The second coupling link <NUM> may have an outer dimension which is smaller than an inner dimension of the tool guide <NUM>, so as to form a gap between the second coupling link <NUM> and the tool guide <NUM> when the second coupling link <NUM> is inserted into the tool guide <NUM>. Thus, in the second guiding configuration, that is to say when the second coupling link <NUM> couples the intermediate part <NUM> and the tool guide <NUM>, the intermediate part <NUM>, thus the tool <NUM>, may be translated along the tool guide axis X, and may also be translated in the plane perpendicular to the tool guide axis X along a distance corresponding to the gap formed between the second coupling link <NUM> and the tool guide <NUM>. Thus, a small misalignment in position between the surgical target <NUM> and the tool <NUM> may be rectified.

More particularly, the second coupling link <NUM> may comprise a ball joint having a diameter smaller than a diameter of the tool guide channel <NUM>, as illustrated by way of a non-limiting example in <FIG>. Such a second coupling link <NUM> authorizes an inclination of the tool <NUM> relative to the tool guide axis X and a translation of the tool <NUM> in a plane perpendicular to the tool guide <NUM>, in addition to the translation of the tool <NUM> and/or the tool guide <NUM> along the tool guide axis X, thus ensuring the second guiding configuration of the guiding system.

Alternatively, the second coupling link <NUM> is at least partially made of an elastic material, such that a deformation of said elastic material of the second coupling link <NUM> allows said translation of the intermediate part <NUM>, thus of the tool <NUM> in the plane perpendicular to the tool guide axis. The elastic properties of the elastic material allow, via the elastic deformation of the elastic material, a translation of the second coupling link <NUM>, thus of the tool <NUM>, in the plane perpendicular to the tool guide axis X, along a distance corresponding to a maximum deformation of the second coupling link <NUM> in the corresponding direction. The second coupling link <NUM> may be entirely made of said elastic material. The elastic material may be silicon.

More specifically, the second coupling link <NUM> may be a slide link or a ball joint at least partially made of an elastic material. The slide link or the ball joint has an outer diameter which corresponds substantially to an inner diameter of the tool guide channel <NUM>. The slide link or the ball joint may comprise a core made of a non-elastic material such as steel, and an outer envelope made of silicon, or may be entirely made of silicon.

Alternatively, or in addition, the second coupling link <NUM> may comprise a slide link having a diameter smaller than a diameter of the tool guide channel <NUM>. Such a second coupling link <NUM> authorizes a translation of the intermediate part <NUM>, thus of the tool <NUM>, in a plane perpendicular to the tool guide <NUM>, in addition to the translation of the tool <NUM> and/or the tool guide <NUM> along the tool guide axis X thus ensuring the second guiding configuration of the guiding system, but does not authorize an inclination of the intermediate part <NUM>, thus of the tool <NUM>, relative to the tool guide axis X.

Alternatively, a dimension of the second coupling link <NUM> may correspond substantially to a dimension of the tool guide channel <NUM>. For example, the second coupling link <NUM> may be a ball joint having a diameter corresponding substantially to a diameter of the tool guide channel <NUM>. Thus, the second coupling link <NUM> authorizes an inclination of the tool <NUM> relative to the tool guide axis X, in addition to the translation of the tool <NUM> and/or the tool guide <NUM> along the tool guide axis X, thus ensuring the second guiding configuration of the guiding system.

The first and second coupling links <NUM>, <NUM> may be arranged around the intermediate part <NUM> and/or may be rigidly secured to the intermediate part <NUM>. For example, when the first and second coupling links <NUM>, <NUM> include a slide link, said slide link may present a substantially hollow cylindrical shape configured to be arranged around the intermediate part <NUM>, the intermediate part <NUM> extending through said slide link.

In a first example of realization, the first coupling link <NUM>, <NUM> may include the second coupling link <NUM> and an additional coupling link. Therefore, the number of coupling links of the guiding system is minimized and the guiding system is thus simplified. For example, the second coupling link <NUM> may be a slide link or a ball joint, and the first coupling link <NUM>, <NUM> may include the slide link or ball joint of the second coupling link <NUM>, and an additional coupling link such as an additional slide link <NUM> or an additional ball joint <NUM>.

<FIG>, <FIG> and <FIG> illustrate non-limiting examples in which the second coupling link <NUM> is a ball joint and the first coupling link <NUM>, <NUM> comprises the ball joint of the second coupling link <NUM> and an additional coupling link in the form of an additional ball joint <NUM>. <FIG>, <FIG>, <FIG> illustrate non-limiting examples in which the second coupling link <NUM> is a ball joint and the first coupling link <NUM>, <NUM> comprises the ball joint of the second coupling link <NUM> and an additional coupling link in the form of an additional slide link <NUM>. <FIG> illustrates a non-limiting example in which the second coupling link <NUM> is a slide link and the first coupling link <NUM>, <NUM> comprises the slide link of the second coupling link <NUM> and an additional coupling link in the form of an additional slide link <NUM>.

The first coupling link <NUM>, <NUM> may be adapted to be located inside the tool guide <NUM> in the first guiding configuration, both the second coupling link <NUM> and the additional coupling link <NUM> of the first coupling link <NUM>, <NUM> being located inside the tool guide <NUM>. The first coupling link <NUM>, <NUM> may be adapted to be located at least partially outside the tool guide <NUM> in the second guiding configuration, only the second coupling link <NUM> being located inside the tool guide <NUM>, the additional coupling link <NUM> of the first coupling link <NUM>, <NUM> being located outside the tool guide <NUM>. Thus, the first guiding configuration provides a rigid guiding while the second guiding configuration allows for a more flexible guiding.

In a second example of realization, the first coupling link <NUM>, <NUM> and the second coupling link <NUM> are distinct coupling links. The first coupling link <NUM>, <NUM> may be adapted to be located inside the tool guide <NUM> in the first guiding configuration, and to be located outside the tool guide <NUM> in the second guiding configuration.

In the first example of realization or in the second example of realization, the first and second coupling links <NUM>, <NUM> may be configured so that a transition between the first guiding configuration and the second guiding configuration is achieved by translating the first and second coupling links <NUM>, <NUM> relative to the tool guide <NUM> along the tool guide axis X.

Thus, the user may easily change a guiding configuration of the guiding system by a simple translation of the first and second coupling links <NUM>, <NUM> along the tool guide axis X, therefore easily adapting the guiding configuration according to the guiding needs.

The translation may be of a few millimeters or a few centimeters along the tool guide axis X. For example, the surgeon can move the tool guide <NUM> a few centimeters away from the surgical target <NUM> so as to transition the guiding system from the first guiding configuration to the second guiding configuration. Once the guiding system is in the second guiding configuration, the surgeon may adjust a position and/or orientation of the tool <NUM> relative to the tool guide <NUM> so as to align to the tool <NUM> with the surgical target <NUM>. Once the tool <NUM> is aligned with the surgical target <NUM>, the surgeon may then move the tool guide <NUM> back a few centimeters along the tool guide axis X, in order to transition the guiding system from the second configuration to the first configuration.

More specifically, the first coupling link <NUM>, <NUM> may be located closer to the distal end of the tool guide <NUM> than the second coupling link. When the first coupling link <NUM>, <NUM> comprises the second coupling link <NUM> and an additional coupling link, the additional coupling link may be located closer to the distal end of the tool guide <NUM> than the second coupling link. Thus, when the tool <NUM>, thus the intermediate part <NUM>, is translated along the tool guide axis X towards the distal end of the tool guide <NUM> and/or when the tool guide <NUM> is translated in an opposite direction, the first coupling link <NUM>, <NUM> or the additional coupling link of the first coupling link <NUM>, <NUM> exits the tool guide channel <NUM> while the second coupling link <NUM> is still inside the tool guide channel <NUM>, thus the system transitions from the first guiding configuration to the second guiding configuration.

The first and/or second coupling links <NUM>, <NUM> and the intermediate part <NUM> may be rigidly secured to each other so as to be moved together.

Thus, a translation of the tool <NUM>, thus of the intermediate part <NUM>, along the tool guide axis X may correspondingly translate the first and/or second coupling links <NUM>, <NUM> along the tool guide axis X, therefore achieving a transition between the first guiding configuration and the second guiding configuration. The transition between the first guiding configuration and the second guiding configuration is therefore even more easily achieved by the user.

The translation of the tool <NUM>, thus of the intermediate part <NUM>, and/or of the tool guide <NUM> relative to each other may be performed manually by the user of the guiding system, and/or automatically by the guiding system.

For example, a translation of the tool <NUM>, thus of the intermediate part <NUM>, along the tool guide axis X towards the surgical target <NUM> may cause the first coupling link <NUM>, <NUM> or the additional coupling link of the first coupling link <NUM>, <NUM> to exit the tool guide <NUM>, thus transitioning the guiding system from the first guiding configuration to the second guiding configuration. A translation of the tool <NUM>, thus of the intermediate part <NUM>, along the tool guide axis X away from the surgical target <NUM> may cause the first coupling link <NUM>, <NUM> or the additional coupling link of the first coupling link <NUM>, <NUM> to enter the tool guide <NUM>, thus transitioning the guiding system from the second guiding configuration to the first guiding configuration. Similarly, a translation of the tool guide <NUM> towards the surgical target <NUM> may cause the guiding system to transition from the second guiding configuration to the first guiding configuration, while a translation of the tool guide <NUM> relative to the tool <NUM>, thus to the intermediate part <NUM>, away from the surgical target <NUM> may cause the guiding system to transition from the first guiding configuration to the second guiding configuration. A simultaneous translation of the tool guide <NUM> and the tool <NUM>, thus the intermediate part <NUM>, in opposite directions along the tool guide axis X may cause the guiding system to transition between the first guiding configuration and the second guiding configuration.

In a first example embodiment illustrated in <FIG>, <FIG>, the tool <NUM> and the intermediate part <NUM> are adapted to be at least partially inserted substantially radially inside the tool guide <NUM>, the first and second coupling links <NUM>, <NUM> being arranged on the intermediate part <NUM>, for example around the intermediate part <NUM>. The tool guide <NUM> is configured to receive the first and second coupling links <NUM>, <NUM>, the intermediate part <NUM> and the tool <NUM>, the tool <NUM> being inserted inside the tool guide <NUM> by the user. The tool guide <NUM> maintains the tool <NUM> in the desired position and orientation during the surgery in order to allow guiding of the tool <NUM> by the surgical robotic system. In the first guiding configuration, the tool axis T and the tool guide axis X substantially coincide. The first and second coupling links <NUM>, <NUM> may be rigidly secured to the intermediate part <NUM>, so that the first and second coupling links <NUM>, <NUM> are moved together with the intermediate part <NUM>.

In a second example embodiment illustrated in <FIG>, <FIG>, and <FIG>, the tool <NUM> is adapted to be mounted radially outside the tool guide <NUM>, the first and second coupling links <NUM>, <NUM> being at least partially inserted in sliding engagement within the tool guide <NUM> and comprising a connecting section <NUM> extending radially outwardly to mechanically connect the first and second coupling links <NUM>, <NUM> to the intermediate part <NUM>. The tool <NUM> and the intermediate part <NUM> are thus located outside the tool guide <NUM>, that is to say radially outwardly relative to the tool guide <NUM>, and the first and second coupling links <NUM>, <NUM> are located at least partially inside the tool guide <NUM>. The tool guide <NUM> maintains the intermediate part <NUM>, thus the tool <NUM>, in the desired position and orientation during the surgery in order to allow guiding of the tool <NUM> by the surgical robotic system. In the first guiding configuration, the tool axis T and the tool guide axis X are substantially parallel, the tool axis T being spaced apart outwardly with respect to the tool guide axis X by the connecting section <NUM>. The connecting section <NUM> may rigidly fix the intermediate part <NUM> to the first and second coupling links <NUM>, <NUM>, so that the first and second coupling links <NUM>, <NUM> are moved together with the intermediate part <NUM>.

The guiding system may further comprise blocking means <NUM> adapted to prevent a rotation of the intermediate part <NUM> relative to the tool guide <NUM> around the tool axis T. The blocking means <NUM> may comprise a pin or rib and a groove or slot, the pin or rib <NUM> being configured to cooperate with the groove or slot so as to block a rotation of the intermediate part <NUM> relative to the tool guide <NUM>.

The groove or slot and the pin or rib <NUM> are configured so that when the intermediate part <NUM>, the first and second coupling links <NUM>, <NUM> and the tool <NUM> are located inside the tool guide <NUM>, the pin or rib <NUM> cooperate with the groove or slot, the pin or rib <NUM> being able to translate in the groove or slot along the tool guide axis X while the groove or slot prevents a rotation of the pin or rib <NUM> around the tool guide axis X.

The pin or rib <NUM> may extend mainly along a main direction, a length of the pin or rib <NUM> corresponding to a dimension of the pin or rib <NUM> along the main dimension. The pin or rib <NUM> may be mounted on the intermediate part <NUM>, on the first coupling link <NUM>, <NUM>, or on the second coupling link <NUM>. The pin or rib <NUM> is configured so as to extend radially outwardly away from the element on which it is mounted, substantially in the main direction.

The groove or slot may be formed in the tool guide <NUM>, more particularly in an inner face of the tool guide channel <NUM>.

The groove or slot has a length corresponding to a dimension along the tool guide axis X of the groove or slot, which corresponds to a main dimension of the groove or slot. The length of the groove is less than the length of the tool guide channel <NUM>, and the groove does not extend at the distal end of the tool guide <NUM>, that is to say does not open at the distal end of the tool guide <NUM>. The length of the slot is less than or equal to the length of the tool guide channel <NUM>, and the slot extends at the distal end of the tool guide <NUM>, that is to say opens at the distal end of the tool guide <NUM>.

The groove or slot has a depth corresponding to a radial dimension of the groove or slot. The depth or the groove or slot may be substantially equal to the main dimension of the pin or rib <NUM>, so that the groove or slot allows only a translation of the pin or rib <NUM> along the tool guide axis X. The depth or the groove or slot may be greater than the main dimension of the pin or rib <NUM>, so that the groove or slot allows a translation of the pin or rib <NUM> along the tool guide axis X and also allows movement of the intermediate part <NUM> relative to the tool guide <NUM> according to the at least one additional degree of freedom, for example so as to allow an inclination of the intermediate part <NUM> compared to the tool guide axis X and/or a translation of the intermediate part <NUM> in the plane normal to the tool guide axis X.

The groove or slot may have a width corresponding substantially to a width of the pin or rib <NUM>, such that the groove or slot prevents the pin or rib <NUM> from being moved in rotation around the tool axis T relative to the tool guide <NUM>. Directions of the width, of the length and of the depth of the groove or slot are perpendicular to one another.

For example, when the pin or rib <NUM> is mounted so that it remains in the groove or slot of the tool guide <NUM> when the guiding system is in the second guiding configuration, the depth of the groove or slot may be slightly greater than the dimension of the pin or rib <NUM> along the main direction, so as to allow movement of the intermediate part <NUM> relative to the tool guide <NUM> according to the at least one additional degree of freedom in the second guiding configuration. Alternatively, when a slot is formed in the tool guide <NUM> and the pin or rib <NUM> is mounted so that it exits the tool guide channel <NUM> when the guiding system is in the second guiding configuration, the depth of the slot may correspond substantially to the dimension of the pin or rib <NUM> along the main direction. Indeed, as the pin or rib <NUM> has exited the tool guide <NUM> in the second guiding configuration, the slot does not risk preventing a movement of the intermediate part <NUM> according to the at least one additional degree of freedom.

<FIG> illustrate non-limiting examples of blocking means <NUM>, in the case when the tool <NUM> and the intermediate part <NUM> are adapted to be at least partially inserted inside the tool guide <NUM>. The pin or rib <NUM> of <FIG> is mounted on the intermediate part <NUM>, between the first and second coupling links <NUM>, <NUM>. The pin or rib <NUM> of <FIG> is mounted on the first coupling link <NUM>.

The tool <NUM> may be a drill adapted to drill a hole for example into a bone <NUM> of a patient <NUM>. The drill can be moved in rotation around the tool axis T whatever the guiding configuration. The drill can also be moved according to the first degree of freedom in the first guiding configuration, or according to the first degree of freedom and/or the additional degree of freedom in the second guiding configuration.

The tool <NUM> may be a screwdriver having a handle <NUM> and a shaft <NUM> extending from the handle <NUM>. The handle <NUM> of the screwdriver is adapted to be grasped by the user so as to move the screwdriver in rotation around the tool axis T whatever the guiding configuration, and also according to the first degree of freedom in the first guiding configuration, or according to the first degree of freedom and/or the additional degree of freedom in the second guiding configuration. The shaft <NUM> of the screwdriver extends substantially along the tool axis T. The intermediate part <NUM> may be mounted around the tool shaft <NUM> between the tool handle <NUM>, which forms a proximal end of the tool <NUM>, and a distal end of the tool <NUM> corresponding to a tip of the shaft <NUM> of the screwdriver, and may extend over at least part of the tool shaft <NUM>.

The guiding system may further comprise a screw <NUM> adapted to be removably mounted on the tip of the shaft <NUM> of the screwdriver. Thus, the surgeon does not need to hold the screwdriver in one hand and the screw <NUM> in the other hand when performing the surgical operation. When the screw <NUM> is mounted on the tip of the shaft <NUM> of the screwdriver, the screw <NUM> extends substantially coaxially with the shaft <NUM> along the tool axis T, the screw <NUM> prolonging the screwdriver, and the screw <NUM> is considered to be part of the tool <NUM>.

The screw <NUM> may be a pedicle screw, a one-piece screw, or a polyaxial screw. A dimension of the screw <NUM> may correspond substantially to a dimension of the surgical target channel <NUM> so that the screw <NUM> may be inserted, partially or substantially fully, inside the surgical target channel <NUM>, as illustrated by way of a non-limiting example in <FIG> and in <FIG>.

The tool guide <NUM> may comprise a tracker, also called tool guide tracker, adapted to be detected by a tracking system in order to determine a position and orientation of the tool guide <NUM> relative to a surgical target <NUM>. The tool guide tracker is positioned and oriented in a fixed relation relative to the tool guide <NUM>. Thus, a position and/or an orientation of the tool guide tracker relative to the tool guide <NUM> is fixed. The tool guide tracker may be mounted on the tool guide <NUM> or on any element of the surgical robotic system, such as a robotic arm <NUM>, more specifically an end effector <NUM> of the robotic arm <NUM>.

The tool guide tracker may be an optical, electromagnetic, ultrasonic, or inertial tracker.

The tracking system may be an optical-based tracking system, for example a camera such as an infrared camera, adapted to detect and localize, in terms of position and/or orientation, the tool guide tracker.

Thus, the relative position and orientation of the tool guide <NUM> and the surgical target <NUM> is known. The relative position and orientation of the tool <NUM> relative to the surgical target <NUM> may be deduced from parameters such as a position and/or orientation of the tool <NUM> relative to the tool guide <NUM>, a dimension of the tool <NUM> along the tool guide axis X, a dimension of the connecting section <NUM>, etc..

The tool guide tracker may be an optical tracker comprising several reflective markers, such as reflective disks or reflective spheres, arranged in at least one tracking pattern. The optical tool guide tracker is adapted to be localized, in terms of position and orientation, by the tracking system when the tracking system is within a range of visibility of at least one tracking pattern of the tool guide tracker.

The camera is adequately positioned before surgery, so that the whole area in which the surgical robotic system is likely to move during the surgical intervention is encompassed in the field of view of the camera. The camera detects and localizes the tool guide tracker, by detecting and localizing the reflective markers of the tracking pattern located in the field of view of the camera.

The tool <NUM> may comprise a tracker, also called tool tracker, adapted to be detected by a tracking system in order to determine a position and orientation of the tool <NUM> relative to the tool guide <NUM> and/or relative to the surgical target <NUM>.

The tool tracker is mounted in a fixed relationship relative to the tool <NUM>, for example mounted to the tool <NUM>. Thus, a position and/or an orientation of the tool tracker relative to the tool <NUM> is known.

The tool tracker may be of a same or different nature to that of the tool guide tracker which is mounted on the tool guide <NUM>, that is to say may be an optical, electromagnetic, ultrasonic, or inertial tracker. When the tool tracker and the tool guide tracker are optical trackers, a tracking pattern of the tool tracker is different from the tracking pattern of the tool guide tracker, so that the optical tracking system may differentiate the tool tracker from the tool guide tracker. The tracking system is thus adapted to detect, in terms of position and/or orientation, the tool guide tracker and the tool tracker.

For example, when the tool <NUM> is a screwdriver, the tool tracker may be mounted on the screwdriver, for example on the screwdriver shaft <NUM>, in addition to the tool guide tracker which is mounted on the tool guide <NUM>. The position and orientation of the tool tracker mounted on the screwdriver, for example the position and orientation of the tool tracker relative to the tip of the screwdriver shaft <NUM>, is known. Thus, the position and/or orientation of the screwdriver relative to the surgical target <NUM> may be known when the tracking system acquires the tool tracker position.

The tool tracker mounted on the tool <NUM> may also serve to detect a misalignment between the tool <NUM> and the tool guide <NUM> before transitioning the guiding system from the second guiding configuration to the first guiding configuration. Thus, if such a misalignment is detected, it may be corrected, either manually by the user of the guiding system or automatically by the guiding system, so that the transition of the guiding system from the second guiding configuration to the first guiding configuration is not hindered or prevented by such a misalignment.

The guiding system may further comprise a patient tracker adapted to be positioned and/or oriented in a fixed relationship relative to a surgical target <NUM>. The patient tracker is mounted in a fixed relationship relative to the surgical target <NUM>. Thus, a position and/or an orientation of the patient tracker relative to the surgical target <NUM> is known.

The patient tracker may be of a same or different nature to that of the tool guide tracker which is mounted on the tool guide <NUM>, that is to say may be an optical, electromagnetic, ultrasonic, or inertial tracker. When the patient tracker, the tool tracker if present, and the tool guide tracker are optical trackers, a tracking pattern of the patient tracker is different from the tracking patterns of the tool tracker and of the tool guide tracker, so that the optical tracking system may differentiate the patient tracker from the tool tracker and the tool guide tracker. The tracking system is thus adapted to detect, in terms of position and/or orientation, the patient tracker, the tool tracker if present, and the tool guide tracker.

Localizing the tool guide tracker and/or the tool tracker relative to the patient tracker allows the localization of the tool guide <NUM> and/or the tool <NUM> relative to the surgical target <NUM>.

The patient tracker may be attached to an anatomical structure, for example to the skin or to a bone of the patient <NUM>, and may be placed next to the surgical target <NUM>.

When the patient tracker comprises one or more tracking patterns, each tracking pattern comprising at least one reflective marker, preferably at least four reflective markers, the patient tracker is positioned so that the localization system is within a range of visibility of at least one tracking pattern of the patient tracker. For example, the patient tracker may be positioned on the patient <NUM> before the surgical act. Thus, the patient tracker may be detected and localized at all times during surgery by the localization system.

A surgical robotic system, as illustrated by way of a non-limiting example in <FIG>, may comprise a robotic arm <NUM> comprising the guiding system as disclosed above, a tracking system configured to determine a position and/or orientation of the tool guide <NUM> and/or the tool <NUM> relative to a surgical target <NUM>, a control unit coupled to the tracking system and configured to control the robotic arm <NUM> to align the tool <NUM> with the surgical target <NUM>, and a display unit <NUM> adapted to configure a guiding of the tool guide <NUM> and/or the tool <NUM>.

The robotic arm <NUM> may comprise an end effector <NUM>. The tool guide <NUM> is adapted to be mounted on the end effector <NUM>. The robotic arm <NUM> may further comprise an end grip allowing manipulation of the robotic arm <NUM> by a user.

The display unit <NUM> may be configured so as to allow the user to plan the surgical intervention and/or to select a guiding configuration of the guiding system. The guiding system may be configured to automatically move the tool guide <NUM> and/or the tool <NUM> in order to achieve the desired configuration selected by the user. The display unit <NUM> may further be adapted to display information relative to the guiding of the tool <NUM> by the guiding system during the surgical intervention.

The surgical robotic system may comprise a base <NUM>. The robotic arm <NUM> of the surgical robotic system is fixed to the base <NUM>. The base <NUM> may be mobile on the ground, so that the user can move the base <NUM> in the operation room.

The surgical robotic system may comprise an imaging system <NUM>, such as an X-ray imaging system comprising a C-arm. The imaging system <NUM> acquires 2D or 3D images of the patient <NUM> during the surgical procedure, so as to provide the surgeon with information about the anatomical situation of the patient <NUM> and/or the position and orientation of the tool <NUM> during surgery. The surgical robotic system comprising the imaging system <NUM> also comprises the tracking system configured to determine the position and orientation of the tool guide <NUM> and/or the tool <NUM> relative to a surgical target.

A non-claimed method for guiding a tool <NUM> with a surgical robotic system as disclosed above relative to a surgical target <NUM>, wherein the surgical target <NUM> comprises a surgical target channel <NUM> directed along a surgical target axis S, comprises the following steps:.

This method offers both a rigid guiding and a more flexible guiding of the surgical robotic system by the guiding system, thus presents substantially similar advantages to those described above concerning the guiding system. In particular, the method allows to minimize the workload of the surgeon while efficiently assisting the surgeon, in order to optimize the guiding and the final result of the surgical procedure.

Transitioning the surgical robotic system from the first guiding configuration to the second guiding configuration may be performed by translating along the tool guide axis X the first and second coupling links <NUM>, <NUM> relative to the tool guide <NUM> along a predetermined transition length L4. In other words, the predetermined transition length L4 corresponds to the distance along the tool guide axis X that the first and second coupling links <NUM>, <NUM> have to be moved so as to transition the guiding system from the first guiding configuration to the second guiding configuration. The predetermined transition length L4 may correspond to a few millimeters, or to a few centimeters.

The step S1 may comprise a step of detecting and localizing the tool guide tracker relative to the patient tracker. As the position and/or orientation of the tool guide <NUM> relative to the tool guide tracker is known and the position and/or orientation of the surgical target <NUM> relative to the patient tracker is known, the position and/or orientation of the tool <NUM> relative to the surgical target <NUM> can correspondingly be deduced.

The step S2 may be performed manually by a user of the surgical robotic system, or automatically by the surgical robotic system. During the positioning, the guiding system may be in the first guiding configuration. The tool <NUM> may be positioned so as to face the surgical target channel <NUM>, a tip of the tool <NUM> being located on the surgical target axis S, the tool <NUM> being separated from the surgical target channel <NUM> by the predetermined distance. More specifically, the predetermined distance may be a distance in a direction of the surgical target axis S between the surgical target channel <NUM> and the tip of the tool <NUM>.

The predetermined distance is such that a position of a tip of the tool <NUM>, for example a tip of the drill or a tip of the screw <NUM> mounted on the screwdriver, corresponds substantially to a position of the first end of the surgical target channel <NUM>. For example, the tip of the screw <NUM> may be positioned substantially at the entry point into the bone <NUM> when the tool <NUM> is positioned at the predetermined distance from the surgical target channel <NUM>. <FIG> illustrates a non-limiting example of a guiding system wherein the tool <NUM> is positioned at the predetermined distance from the surgical target channel <NUM>, the tip of the screw <NUM> being positioned substantially at the entry point into the bone <NUM>.

The step S22 may be performed manually by a user of the surgical robotic system, or automatically by the surgical robotic system. In the non-limiting example of <FIG>, the tool <NUM>, the intermediate part <NUM> and the tool guide <NUM> are substantially parallel to each other, the tool guide axis X and the tool axis T being parallel, and the tool axis T is aligned with, that is to say substantially coincides with, the surgical target axis S.

The step S3 of guiding the surgical robotic system in the first guiding configuration allows a rigid guiding of the tool <NUM> relative to the surgical target <NUM>, the guiding system being in the first guiding configuration. The guiding may be performed in step S3 so as to reduce a distance between the tool <NUM> and the surgical target channel <NUM> and/or so as to partially insert the tool <NUM> inside the surgical target channel <NUM>.

More specifically, the step S3 may correspond to a translation of the tool <NUM> along the tool guide axis X of a distance corresponding substantially to the predetermined transition length L4 and may further include a rotation of the tool <NUM> around the tool axis T. Thus, if the tip of the tool <NUM> is positioned substantially at the first end of the surgical target channel <NUM> in step S2, then during step S3, the tool <NUM> is inserted inside the surgical target channel <NUM> along a distance which corresponds to the predetermined transition length L4. For example, the drill is inserted inside the bone <NUM>, or the screw <NUM> is inserted inside the drilled hole, along a distance which corresponds to the predetermined transition length L4. At the end of step S3, the tool <NUM> is partially inserted in the surgical target channel <NUM>, and the guiding system transitions from the first guiding configuration to the second guiding configuration.

The surgical target channel <NUM> may present a length along the surgical target axis S which is greater than the predetermined transition length L4. Thus, a transition between the first guiding configuration and the second guiding configuration of the guiding system occurs when the tool <NUM>, such as the screw <NUM> mounted on the screwdriver, or the drill, is inserted inside the surgical target channel <NUM> along the predetermined transition length L4, the screw <NUM> or drill being partially inserted inside the surgical target channel <NUM>.

<FIG> illustrates a non-limiting example of a guiding system having just transitioned to the second guiding configuration, the guiding system comprising a screw <NUM> which is partially inserted in the surgical target channel <NUM>.

The step S4 of guiding the surgical robotic system in the second guiding configuration allows a more flexible guiding of the tool <NUM> relative to the surgical target <NUM>, in order to insert the tool <NUM> deeper inside the surgical target channel <NUM>. <FIG> illustrates a non-limiting example of a surgical robotic system in a configuration where the screw <NUM> is partially inserted in the surgical target channel <NUM> and the guiding system is in the second guiding configuration, the second guiding configuration allowing a translation of the tool <NUM> relative the tool guide <NUM> along the tool guide axis X and an inclination of the tool <NUM> relative the tool guide axis X, as well as the rotation of the tool <NUM> around the tool axis T. <FIG> illustrates a surgical target channel <NUM> into which a screw <NUM> is fully inserted.

The step S4 of guiding the surgical robotic system in the second guiding configuration may comprise a step S41 of adjusting a relative position and/or orientation of the tool <NUM> with respect to the surgical target <NUM> in the at least one additional degree of freedom, wherein said step S41 is performed manually by a user of the surgical robotic system.

The predetermined distance from the surgical target channel <NUM> at which the tool <NUM> is positioned in step S2 may correspond to a distance L3 between the tool guide <NUM> and the surgical target channel <NUM>, more specifically to a distance L3 between the distal end of the tool guide <NUM> and the first end of the surgical target channel <NUM> during said step S2.

The predetermined distance at which the tool <NUM> is positioned in step S2 may be determined depending at least on a length of the tool L1+L2. The length of the tool L1+L2 corresponds to a distance between a tip of the tool <NUM> and a proximal end of the first coupling link <NUM>, <NUM>, more specifically to a distance between the tip of the tool <NUM> and the additional coupling link of the first coupling link <NUM>, <NUM>. A position of the proximal end of the first coupling link <NUM>, <NUM> may substantially correspond to a proximal position of the connecting section <NUM>, the connecting section <NUM> extending radially outwardly from the shaft <NUM> to mechanically connect the first and second coupling links <NUM>, <NUM> to the tool <NUM>.

The length of the tool L1+L2 may be known, or may be determined based on the acquisition of the tool guide tracker and/or the tool tracker by the tracking system.

When the tool <NUM> is a drill, the length of the tool L1+L2 corresponds to a distance between a tip of the drill and a proximal end of the first coupling link <NUM>, <NUM>. When the tool <NUM> is a screwdriver having a handle <NUM> and a shaft <NUM> extending from the handle <NUM>, the tool <NUM> is considered to include the screw <NUM> mounted to the tip of the shaft <NUM> of the screwdriver. The length of the tool L1+L2 corresponds to a distance between the tip of the screw <NUM> mounted on the screwdriver and the proximal end of the first coupling link <NUM>, <NUM>. The length of the tool L1+L2 thus corresponds to a sum of a distance between the proximal end of the first coupling link <NUM>, <NUM> to the tip of the shaft <NUM> of the screwdriver L1, and a length of the screw L2.

The predetermined distance from the surgical target channel <NUM> at which the tool <NUM> is positioned in step S2 is thus further determined depending on the length of the screw L2. The length of the screw L2 may correspond to a distance between the tip of the screwdriver and a tip of the screw <NUM> when the screw <NUM> is mounted on the screwdriver. The length of the screw L2 may be known, for example may be retrieved from a planning of the surgical procedure. The length L1 of the screwdriver may be fixed.

The tool <NUM> may be positioned in step S2 so that a tip of the screw <NUM>, or so that a tip of the drill, substantially coincides with the first end of the surgical target channel <NUM>, as illustrated for example in <FIG>. A position of the first end of the surgical target channel <NUM>, which corresponds to the position of the surgical target channel <NUM>, may be known, for example may be retrieved from the planning of the surgical procedure.

The tool <NUM> is thus moved towards the first end of the surgical target <NUM>, so that the tip of the tool <NUM> coincides with the first end of the surgical target channel <NUM> at the end of step S2. The tool <NUM> can then be inserted in the surgical target channel <NUM> in steps S3 and S4, towards the second end of the surgical target channel <NUM>.

The distance between the tool guide <NUM> and the surgical target channel <NUM> may be determined during the surgical procedure based on the acquisition of the tool guide tracker and/or the patient tracker by the tracking system, and may be controlled by the command of the surgical robotic system.

A length of guiding in first guiding configuration corresponds substantially to the predetermined transition length L4.

The predetermined transition length L4 corresponds to a distance between the distal end of the tool guide <NUM> and the first coupling link <NUM>, <NUM>, more specifically between the distal end of the tool guide <NUM> and the proximal end of the additional coupling link of the first coupling link <NUM>, <NUM>, when the tool <NUM> and tool guide <NUM> are positioned at the beginning of the surgical procedure.

The predetermined transition length L4 may be equal to <NUM>, in order to begin the surgical procedure with a system in the second guiding configuration. During the surgical procedure, the system may punctually transition from the second guiding configuration to the first guiding configuration.

The predetermined transition length L4 may be inputted by the user of the surgical robotic system before the surgery. The input of the predetermined transition length L4 may be done through a main interface of the surgical robotic system, typically a touch screen interface that allows the surgeon to plan the surgical procedure, follow the navigation and set up other parameters of the surgical systems. In the case of the predetermined transition length L4, it may be inputted during the planning phase.

The predetermined distance at which the tool <NUM> is positioned in step S2 may also be inputted by the user of the surgical robotic system before the surgery, for example during the planning phase.

Claim 1:
Guiding system for a surgical robotic system, comprising a tool guide (<NUM>) extending substantially around a tool guide axis (X), a tool (<NUM>) extending substantially around a tool axis (T), an intermediate part (<NUM>) mounted on the tool (<NUM>) so that the tool (<NUM>) and the intermediate part (<NUM>) are integral in translation and so that the tool (<NUM>) is mobile relative to the intermediate part (<NUM>) in rotation around the tool axis (T), and a first coupling link (<NUM>, <NUM>) adapted to couple the intermediate part (<NUM>) and the tool guide (<NUM>), wherein the guiding system presents a first guiding configuration in which the first coupling link (<NUM>, <NUM>) couples the intermediate part (<NUM>) and the tool guide (<NUM>) so that the intermediate part (<NUM>) and the tool guide (<NUM>) are mobile relative to each other according to a unique first degree of freedom, the first degree of freedom corresponding to a translation along the tool guide axis (X), characterized in that the guiding system further comprises a second coupling link (<NUM>) adapted to couple the intermediate part (<NUM>) and the tool guide (<NUM>), and in that the guiding system presents a second guiding configuration in which the second coupling link (<NUM>) couples the intermediate part (<NUM>) and the tool guide (<NUM>) so that the intermediate part (<NUM>) and the tool guide (<NUM>) are mobile relative to each other according to the first degree of freedom and according to at least one additional degree of freedom.