WO2018219881A1

WO2018219881A1 - Assistive system for surgery

Info

Publication number: WO2018219881A1
Application number: PCT/EP2018/063964
Authority: WO
Inventors: Andy GIJBELS; Jonas SMITS
Original assignee: Katholieke Universiteit Leuven
Priority date: 2017-05-29
Filing date: 2018-05-28
Publication date: 2018-12-06

Abstract

A system (1) for assisting in surgery comprising a surgical system (3); support means (2) configured for supporting and positioning a body member when provided on the support means; a first alignment system (4), said first alignment system configured to support and position the surgical system with respect to the support means and configured to couple the support means and surgical system; a second alignment system (5), said second alignment system configured to support and position the support means, the first alignment system and surgical system.

Description

ASSISTIVE SYSTEM FOR SURGERY

Technical field

[0001] Embodiments of the present invention relate to an assistive system and method for surgery, which may be cooperative surgery, telesurgery or autonomous surgery. Some embodiments of the present invention provide methods and systems for eye surgery.

[0002] The present application is generally directed to medical devices, systems, and methods. In a particular embodiment, the invention provides surgical robotic systems and methods that make use of separate and/or independently positionable assemblies for manipulating a plurality of surgical end effectors at a surgical worksite.

Background art

[0003] Complex surgical procedures and methods require skill and precision on the part of the surgeon. State-of-the-art procedures often require such high levels of skill and precision that even the best surgeons at the peak of their performance are confronted with significant complication rates. Progression through high learning curves is required in order to master the increasingly complex and rapidly evolving surgical therapies. Numerous procedures do not make it to clinical practice due to the super-human skills required to perform them in a safe and successful way. As a result, people suffering from severe diseases are left untreated, despite the therapeutic potential of these novel procedures if adequately performed.

[0004] Advances in minimally invasive surgical technology could dramatically increase the number of surgeries performed in a minimally invasive manner. Minimally invasive medical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. The average length of a hospital stay for a standard surgery may also be shortened significantly using minimally invasive surgical techniques. Thus, an increased adoption of minimally invasive techniques could save millions of hospital days, and millions of dollars annually in hospital residency costs alone. Patient recovery times, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally invasive surgery (MIS). However, there are many disadvantages relating to MIS technology, for example, existing MIS instruments deny the surgeon the flexibility of tool placement found in open surgery. [0005] Furthermore, especially in the field of microsurgery, human limitations such as hand tremor, the application of excessive forces on the surgical entry port, and the inability of prolonged tool immobilization prohibit the safe execution of new high-precision surgical methods. Surgical assistive technology offers a way to surpass these limitations, thus allowing for new treatment methods to be safely and successfully performed.

[0006] Therefore there is a need for improved assistive systems for surgery.

Summary of the invention

[00027] It is an object of the invention to provide an improved assistive system for surgery able to overcome the above drawbacks of existing MIS systems. It is an object of the present invention to provide an assistive system for surgery which allows improved positioning accuracy and precision of a surgical instrument with respect to a body member undergoing surgical treatment.

[0008] According to a first aspect of the present invention there is provided a system for assisting in surgery as set out in the appended claims. The system houses a surgical system; support means configured for supporting and positioning a body member when provided on the support means; a first alignment system, said first alignment system configured to support and move/position the surgical system with respect to the support means and configured to couple the support means and surgical system; and a second alignment system, said second alignment system configured to support and move/position the support means, the first alignment system and surgical system.

[0009] The first alignment system may comprise three translational stages configured for motion along three mutually orthogonal axes of translation (Χ,Υ,Ζ), wherein each stage advantageously comprises positioning means configured to control the position of the respective stage. The translational stages are advantageously linear motion stages.

[0010] The first alignment system may further comprise a rotational stage advantageously configured for rotational motion (R) about one of the three axes of translation, the rotational stage advantageously comprising positioning means configured to control the position of the rotational stage (R).

[0011] The rotational stage (R) may be configured to rotate the surgical system in a plane defined by the axes of translation (X,Y) of two of the three translational stages. [000312] The second alignment system advantageously comprises three translational degrees of freedom. The second alignment system may comprise first, second, and third positioning means, each positioning means being configured to control the position of the second alignment system in a respective direction (Χ', Υ', Ζ').

[0013] The second alignment system may further comprise a rotational stage advantageously configured for rotational motion (R') comprising rotational positioning means configured to control the position of the rotational stage.

[0014] At least one of the positioning means may be configured to at least position the support means.

[0015] The rotational stage of the second alignment system may be configured to tilt or rotate the support means about a first axis substantially parallel to a plane defined by the translational degrees of freedom of the second alignment system.

[0016] The system may be a portable and/or movable system.

[0017] The system may be a trolley system.

[0018] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims.

[0019] A method of performing assistive surgery is also described herein. Brief description of the figures

[000420] Further features of the present invention will become apparent from the examples and figures, wherein:

[000521] FIG. 1 schematically illustrates an assistive system for surgery in use according to embodiments of the present invention.

[000622] FIG. 2 schematically illustrates a detailed view of the assistive system for surgery illustrated in FIG. 1.

[0023] FIG. 3 schematically illustrates the surgical system and the first alignment system, that is, an intra-operative alignment system according to embodiments of the present invention.

[0024] FIG. 4 schematically illustrates the surgical system and first alignment system and part of the second alignment system according to embodiments of the present invention.

[0025] FIG. 5 schematically illustrates the second alignment system, that is, a pre-operative alignment system according to embodiments of the present invention. Description of embodiments [000726] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non- limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated. The term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B. Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein. In the drawings, like reference numerals indicate like features; and, a reference numeral appearing in more than one figure refers to the same element.

[0027] The drawings and the following detailed descriptions show specific embodiments of assistive systems for surgery. Assistive systems according to embodiments of the present invention may be used in any suitable kind of surgery. Some embodiments of the present invention are particularly suited to eye surgery.

[0028] In embodiments the present invention provides an assistive system for surgery which is illustrated in FIG. 1 and FIG. 2. The assistive system 1 , which may be for example a telesurgery system, a co-operative surgery system, or an autonomous system, comprises a support means 2, a surgical system 3, a first alignment system or intra-operative alignment system 4, and a second alignment system or pre-operative alignment system 5. The first alignment system 4 is preferably used to position the surgical system 3 in a precise way (e.g. in the mm range), relative to the patient, by the surgeon. On the other hand, the second alignment system 5 is preferably used to position the support and position the support means 2, the first alignment system 4 and surgical system 3 in a more robust way (e.g. in the cm range), for example by the nurse prepping the patient before surgery. Optionally the assistive system for surgery 1 according to embodiments of the present invention may comprise control means, e.g. a control pedal 6 and/or a control unit 7.

[0029] Generally when in surgery the patient's body, except for the patient's head, is placed on a surgical bed 9 (table or chair). A surgical microscope 10 is optionally provided for improving visualisation of the body member to be operated on. The patient's body member, which may be the patient's head 8 in the case of eye surgery, is placed on the support means 2 of the assistive system 1 according to embodiments of the present invention. In this way, advantageously the relative position of the patient's body member, for example the patient's head 8, and the assistive system 1 is maintained in the event of unintended motions of the assistive system 1 . The first alignment system 4 allows precise positioning of the surgical system 3 with respect to the body member to be operated upon, for example the head in the case of eye surgery. In use, the body member is supported by the support means 2 or support system, and so the first alignment system 4 allows precise positioning of the surgical system 3 with respect to the support system 2. The second alignment system 5 allows positioning of the support means 2, the first alignment system 4 and surgical system 3 with respect to the surgical bed or chair. As a result, the attainable surgical precision is higher compared to the case where the patient's body member, e.g. patient's head 8, is placed on the surgical bed and the assistive system 1 could move independently from the patient's head. Further, this layout is compatible with the majority of the commercially available surgical beds as opposed to assistive systems which need to be fixed to the surgical bed with the aid of bed specific mounts. Finally, the described assistive system according to embodiments of the present invention in most cases does not require the available surgical bed to be replaced as is the case for assistive systems which are mounted on a custom surgical bed.

[0030] In preferred embodiments the surgical system 3 used in an assistive system 1 according to embodiments of the present invention implements key functionalities of the assistive system as illustrated in FIG. 3. The key functionalities and the means to implement these functionalities may be elucidated as follows for the case of eye surgery: (a) stabilization of the eye with the aid of a remote-centre-of-motion (RCM) mechanism, for example an RCM mechanism as described WO 2014108545 A1 , as described in US5397323 A, or any other suitable RCM mechanism (b) enhancement of the precision of the motion of instrument 12 with aid of actuators (e.g. electrical motors) and an algorithm generating damping-like behaviour (force opposing the velocity, the force amplitude rises with the speed), active damping elements (e.g. using back-EMF of electrical motors, eddy current brakes, magnetorheological brakes, electrorheological brakes) or passive damping (e.g. two surfaces moving with respect to one another which are partly or fully immersed in a fluid) which are connected directly or indirectly with the different degrees of freedom of the surgical system, or (c) prolonged tool immobilization with the aid of active braking elements (e.g. electrical motors, or an electromagnetic brake), and/or passive braking elements ( e.g. a brake cable system or a pressurized fluid pushing two plates against each other).

[0031] In a preferred embodiment, the surgical system 3 comprises at least four degrees of freedom, i.e. it allows for moving a surgical instrument 12 attached to it according to four (or more) degrees of freedom: two rotations A and B about a pivot point P, a rotation C about an axis of the instrument 12 and a (linear) translation T through pivot point P, in particular parallel to the axis of instrument 12. The pivot point P may be a remote centre of motion (RCM).

[0032] In preferred embodiments the first alignment system 4, e.g. the intra-operative alignment system, carries the surgical system 3 as illustrated in FIG. 4. The first alignment system 4 is advantageously used by the surgeon during the procedure. For example, the first alignment system 4 is operable for providing one or a combination of the following four motions:

(1 ) to orientate the surgical system 3 with respect to the operation site (e.g., the eye in case of eye surgery) in an XY-plane such that the region of interest (e.g., inside the eye) can be reached with the instrument 12 with the desired angle of approach,

(2) to align pivot point P of the surgical system 3 with the incision point through the patient, e.g. in the patient's eye (Figure 4). Aligning these two points enables the surgical system 3, e.g. when implementing a RCM mechanism, to keep the eye from rotating when the instrument is being manoeuvred inside the eye,

(3) when a certain targeted area inside the patient (e.g. inside the eye) cannot be reached, the eye can be moderately tilted intra-operatively by altering the location of the pivot point P with respect to the incision point, and/or

(4) the first alignment system 4 can allow for moving the surgical system 3 away from the operating scene in order to switch to manual surgery or to safely remove and/or insert a surgical instrument 12 into a tool holder 13 of the surgical system 3.

[0033] In orderto implement these functionalities, the first alignment means

4, e.g. the intra-operative alignment system, is advantageously equipped with at least three, advantageously four degrees of freedom: at least three (orthogonal) translational degrees of freedom X, Y, Z, and optionally at least one rotational degree of freedom R. These degrees of freedom can be implemented with the aid of at least three translational (linear motion) stages 41 , 42 and 43 respectively, and optionally at least one rotational stage 44. Each stage is advantageously equipped with an actuator (such as an electrical motor), a combination of a damping and braking element (such as a viscous damper and an electromagnetic brake) and/or a manual positioning element (such as a leadscrew positioner) to control the position of the stage. The stages do not necessarily need to be stacked in the depicted order (R-X-Y-Z). Rotational stage 44 can be omitted, but such design is believed to be suboptimal. In alternative embodiments the XYZ motion is not implemented by means of translational stages, but other designs are believed to be suboptimal.

[0034] In embodiments the second alignment system 5, e.g. pre-operative alignment system, carries the support means 2, the first alignment means 4 e.g. the intra- operative alignment system and the surgical system 3 as illustrated in FIG. 5. It is advantageously used by a member of the clinical team, e.g. a nurse, to correctly position the support means 2 with respect to the surgical bed such that the patient's body member, e.g. head, can be placed on the support means 2 in the desired posture with respect to the patient's body. Once the support means 2 is properly positioned, the reachable workspace of the first alignment system 4, i.e. intra-operative alignment system, and surgical system 3 will cover the regions of interest for the procedure. In order to implement desired functionalities of the second alignment system 5, i.e. preoperative alignment system, the second alignment system preferably comprises at least three, preferably at least four degrees of freedom: at least three (orthogonal) translational degrees of freedom X', Y' and Z' and optionally at least one rotational degree of freedom R'. Degrees of freedom X' and Y' may be implemented with the aid of advantageously pivoting wheels 51 placed at the bottom of the assistive system. This allows the operator to correctly position the assistive system 1 with respect to the surgical bed or chair on the floor. The assistive system may also include one or more brakes or motion- preventing elements which allow the wheels 51 , and the assistive system 1 , to be prevented from moving once the correct position of the assistive system 1 is achieved. In embodiments these wheels 51 may be provided in the form of the assistive system 1 being a trolley housing the surgical system 3, the first and second alignment systems 4, 5 and the support means 2. In other embodiments a combination of moving and fixed parts may be provided, fixing the assistive system 1 at one side while enabling two translational movements (in Χ',Υ') at the other side. The (linear) translational degree of freedom Z' is advantageously implemented in a central column 52 of the assistive system with the aid of e.g. an actuated (e.g. electrical motor) or manually movable (e.g. hydraulically, manually driven leadscrew system or other conventional mechanical means) translational joint. It is used to vertically level the support means 2 with the surface of the surgical table or chair within a certain range. Rotational degree of freedom R' is advantageously implemented in correspondence of the support means 2 with the aid of an actuated or manually movable rotational joint. It is used to place the support means 2 in the desired angle relative to the surface of the surgical bed. Axis of rotation of rotational degree of freedom R' is advantageously substantially parallel to a plane defined by translational degrees of freedom X and Y of the intra-operative alignment system 4.

[0035] In embodiments the translational movement Z' of the second alignment system 5 is configured to move, e.g. lift, the support means 2, the first alignment system 4, and the surgical system 3 together, whereas the translation movement Z of the first alignment means 4 is configured to only move the surgical system 3. Therefore in preferred embodiments two separate, independent of each other, translational stages are provided. In alternative embodiments a translational stage Z' may be provided on the second alignment system 5 dedicated to displacing solely the support means 2 and a translational stage Z on the first alignment system 4 for displacing the surgical system 3.

[0036] Referring again to Fig. 4, the assistive system 1 advantageously comprises a mounting platform 53, on which the support means 2 and the stages 41 -44 of the first alignment system 4 are separately mounted. By so doing, the surgical system 3 can be moved irrespective of the supporting means 2, in particular to precisely position the surgical instrument 12 relative to the patient's body member. The mounting platform 53 is advantageously configured to move according to the three translational degrees of freedom X', Y', Z' of the second alignment system 5. In other words, mounting platform 53 is mounted on the wheels 51 and the column 52. The three translational stages 41 - 43 and the rotational stage 44 of the first alignment system are advantageously mounted between the mounting platform 53 and the surgical system 3 but advantageously not between the mounting platform and the support means 2.

[0037] The mounting platform 53 advantageously couples the support means 2 and the surgical system 3. The support means 2 is advantageously mounted on platform 53 through a rotational joint 54 implementing the rotational movement R'.

[0038] Advantageously, the rotational movement R' of the second alignment system 5 is configured to tilt the support means 2 about a first axis substantially parallel to a plane defined by the translational movements X and Y, and/or a plane defined by the translational movements X' and Y', advantageously without affecting the position and/or orientation of the surgical system 3, nor the first alignment system 4. The rotational movement R of the first alignment system 4 is configured to rotate the surgical system 3 left to right in a plane substantially parallel to plane defined by the translational movements of the first and second alignment systems 4, 5 (X,Y or Χ',Υ'), advantageously without affecting the position and/or orientation of the support means 2. As a result, the rotational movement R of the first alignment system 4 is in a direction substantially perpendicular to the rotational movement R' of the second alignment system 5. In other words, the rotational movements R and R' have rotation axes which are substantially orthogonal to one another. In further embodiments, further degrees of freedom can be provided to the support means 2 by adapting the second alignment means 5 (and enabling additional movement besides the rotational movement R'). In further specific embodiments, the rotational movements R, R' of the first and second alignment system 4, 5 respectively may be omitted still enabling a functional assistive system according the embodiments of the present invention.

[0039] As a result, the assistive system 1 allows on the one hand to position the support means 2 and the surgical system 3 integrally by way of the second alignment system 5, and on the other hand to move/position the surgical system 3, and hence the surgical instrument 12 relative to the support means 2 by way of the first alignment system 4.

[0040] In further embodiments, control means may be provided. Said control means may comprise a control unit 7 configured to receive information from a control pedal 6, sensors and/or screen and preferably ensures that the assistive system 1 behaves as commanded by the operator. In embodiments the control unit 7 may be integrated in the central column 52 of the assistive system 1 or provided as an external device. The control unit 7 is optional for the operation of the assistive system 1 according to embodiments of the present invention. In this case, the second alignment system 5, i.e. pre-operative alignment system, the first alignment system 4, i.e. intra-operative alignment system, and the surgical system 3 are manually controlled based on passive dampers, mechanical brakes, leadscrew systems, hydraulic systems and/or other conventional mechanical means to move and brake the different degrees of freedom of the assistive system 1. In further embodiments the control means may comprise a control pedal 6 (or a combination of the control pedal 6 and control unit 7). In these specific embodiments the control pedal 6 may comprise a number of input elements (buttons, levers, switches and/or alike) that are used by the operator to control the second alignment system 5, i.e. the pre-operative alignment system, the first alignment system 4, i.e. intra-operative alignment system and/or the surgical system 3. In some embodiments, the control pedal 6 can be simplified to a pedal where maximum one input element is foreseen for every one of these subsystems. In these embodiments, the subsystems are constructed to be partly or fully back-drivable. Passive dampers can be used to increase the positioning precision of the surgeon in the different degrees of freedom. Active or passive brakes can be coupled to one or more of the degrees of freedom of the subsystems. The input element on the control pedal 6 is then used to lock/unlock the related subsystem in part or in full. When the subsystem is unlocked, the surgeon can manually move the subsystem to the desired pose by hand.

[0041] While specific embodiments of the subject invention have been discussed, the above specification is illustrative and not restrictive. Many variations of the invention will become apparent to those skilled in the art upon review of this specification and the claims below. The full scope of the invention should be determined by reference to the claims, along with their full scope of equivalents, and the specification, along with such variations.

Claims

1. A system (1 ) for assisting in surgery of a patient, comprising: a surgical system (3);

support means (2) configured for supporting and positioning a body member (8) of the patient relative to the support means;

a first alignment system (4), said first alignment system configured to support and position the surgical system (3) with respect to the support means (2) and configured to couple the support means and the surgical system;

a second alignment system (5), said second alignment system configured to support and position the support means (2), the first alignment system (4) and the surgical system (3).

2. The system for assisting in surgery of claim 1 , wherein the first alignment system (4) comprises three translational degrees of freedom (X, Y, Z), wherein each of the three degrees of freedom is coupled to positioning means configured to control a position of the first alignment system along the respective degree of freedom.

3. The system for assisting in surgery of claim 2, wherein the first alignment system (4) further comprises a rotational stage (44) comprising positioning means configured to control the position of the rotational stage (44).

4. The system for assisting in surgery according to claim 3, wherein the rotational stage (44) is configured to rotate the surgical system (3) in a plane defined by two of the three translational stages (41 , 42).

5. The system for assisting in surgery according to any one of the claims 2 to 4, wherein the first alignment system is operable to effect motion of the surgical system (3) relative to the support means (2).

6. The system for assisting in surgery according to any one of the preceding claims, wherein the second alignment system (5) comprises three translational degrees of freedom.

7. The system for assisting in surgery according to claim 6, comprising a mounting platform (53) on which the support means (2) and the first alignment system (4) are mounted, and wherein the mounting platform is configured to be moved according to at least one of the three translational degrees of freedom (Ζ') of the second alignment system (5).

8. The system for assisting in surgery according to claim 7, wherein the three translational stages (41 , 42, 43) and optionally the rotational stage (44) connect the mounting platform (53) and the surgical system (3) to provide motion of the surgical system (3) independently of the support means (2).

9. The system for assisting in surgery according to any one of the claims 6 to 8, wherein the second alignment system (5) further comprises a rotational stage (54) implementing a rotational degree of freedom (R'), the rotational stage comprising positioning means configured to control the rotational position of the rotational stage.

10. The system for assisting in surgery according to claim 9, wherein the rotational stage (54) of the second alignment system is configured to tilt or rotate the support means (2) about a first axis substantially parallel to a plane defined by two of the three translational stages (41 , 42).

11. The system for assisting in surgery according to claim 9 or 10 in conjunction with claim 8, wherein the rotational stage (54) of the second alignment system (5) connects the mounting platform and the support means (2) to allow for tilting the support means relative to the mounting platform.

12. The system for assisting in surgery according to claim 1 1 , wherein the rotational stage (54) and the first alignment system (4) are mounted on the mounting platform independently of one another.

13. The system for assisting in surgery according to any one of the preceding claims, wherein the system is a portable and/or movable system.

14. The system for assisting in surgery according to any one of the preceding claims, wherein the system is a trolley system.

15. The system for assisting in surgery according to any one of the preceding claims, comprising a control pedal (6) comprising at least one input element for controlling operation of a respective one or more of: the first alignment system (4), the second alignment system (5), and the surgical system (3).

16. The system for assisting in surgery according to claim 15, wherein one or more of: the first alignment system (4), the second alignment system (5), and the surgical system (3) comprises one or more back-drivable actuators.

17. The system for assisting in surgery according to claim 15 or 16, comprising a damping element coupled to a degree of freedom of one or more of: the first alignment system, the second alignment system, and the surgical system.

18. The system for assisting in surgery according to any one of the claims 15 to 17, wherein at least one of the plurality of input elements is operable to lock or to unlock at least one degree of freedom of a respective one or more of: the first alignment system (4), the second alignment system (5), and the surgical system (3).