Method and apparatus for alerting a user to sensed lateral forces upon a guide-sleeve in a robot surgical system

Abstract

Methods and apparatus for detecting or predicting surgical tool-bone skiving are disclosed. In some embodiments, the surgical tool is movably and/or snugly disposed within a guide-sleeve. In some embodiments, a magnitude of a lateral force between the surgical tool and the guide-sleeve is measured (e.g. by a force sensor or strain sensor). The present or future skiving may be detected or predicted according to the magnitude of the lateral force. In some embodiments, an alert signal is generated in response to the detecting or predicting of the skiving.

Claims

1. A system for performing a surgical procedure at a surgical site, the system comprising: a. a guide-sleeve defining axial and lateral directions; b. a surgical tool movably and/or snugly disposed within the guide-sleeve so that an alignment direction of the surgical tool is determined by that of the guide-sleeve; c. a skiving-detector configured to detect current and potential tool-bone skiving by the surgical tool, according to a magnitude of a lateral force between the surgical tool and the guide-sleeve or according to an indication of the lateral force magnitude; d. a position/orientation controller configured to use a comparison of any said detection to a threshold to predict skiving, wherein said threshold is selected to indicate an elevated risk of skiving; and e. an alerter configured to generate an alert signal upon a positive current detecting of skiving, or a positive predicting of skiving.

2. A method of preventing misalignment of a surgical instrument during its operation, said surgical instrument used to perform a surgical procedure at a surgical site, the method comprising: a. orienting and/or positioning a guide sleeve in a target orientation, said surgical instrument movably and/or snugly disposed within said guide-sleeve so that an alignment direction of said surgical tool is determined by that of said guide-sleeve; b. at a time when the surgical instrument is disposed within the guide sleeve, measuring, using a skiving-detector configured to detect current and potential tool-bone skiving by said surgical instrument, a magnitude of a lateral force between said surgical instrument and said guide sleeve or an indication of the lateral force magnitude; c. contingent upon the results of the measuring indicating that the lateral force magnitude or said indication thereof exceeds a threshold selected to indicate an elevated risk of skiving, generating an alert signal to indicate a positive current detecting of skiving, or a positive predicting of skiving; and d. if said alert signal is generated, refraining from operation of said surgical instrument.

3. The method of claim 2 wherein the orienting and/or positioning of the guide sleeve is performed robotically.

4. The method of claim 2 wherein the magnitude of the lateral force is indicative of at least one of a (i) a degree of bone flexibility; and (ii) a degree of flexibility by of the mounted object upon which the surgical robot is mounted on the bone.

5. The method of claim 2 wherein the surgical instrument is a surgical cannula.

6. The method of claim 2 wherein the surgical instrument comprises at least one of: (i) a plurality of teeth at a distal end thereof and (ii) a knurled knob at a proximal end thereof.

7. The method of claim 2 wherein the surgical tool instrument is selected from the group consisting of a drill, a reamer, a biopsy needle, forceps and an endoscope.

8. The method of claim 2 wherein the lateral force is at least partially caused by, or is primarily caused by, soft tissue pressure upon an inner sleeve within the guide sleeve.

9. The method of claim 8 wherein the inner sleeve is a surgical cannula.

10. The method of claim 2 wherein the measurement of the lateral force is performed by a force-meter deployed in an annular region outside of the inner sleeve and within the outer sleeve.

11. The method of claim 2 wherein the measurement of the indication of the lateral force is performed by a strain-meter configured to sense a strain upon the guide-sleeve.

12. The system of claim 1 wherein the skiving-detector comprises a strain-meter configured to sense a strain upon the guide-sleeve.

13. The system of claim 12, wherein said strain-meter is disposed on the outer surface of said guide-sleeve, and wherein said indication of said lateral force is a measurement of strain upon said outer surface of said guide-sleeve.

14. The method of claim 11, wherein said strain-meter is disposed on the outer surface of said guide-sleeve and wherein said indication of said lateral force is a measurement of strain upon said outer surface of said guide-sleeve.

15. The method of claim 2, wherein said elevated risk of skiving is an elevated risk that the orientation of said surgical instrument does not match said target orientation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1A-1B, 2-8, 9A-9D, 10A-10C, 11A-11B and 12 illustrate prior surgical tools.

(2) FIGS. 13A-13D, and 14A-14C schematically illustrate surgical tools and systems according to some embodiments of the invention.

(3) FIGS. 15-16 are flow charts of methods according to some embodiments of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(4) The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the exemplary system only and are presented in the cause of providing what is believed to be a useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how several forms of the invention may be embodied in practice and how to make and use the embodiments.

(5) It should be understood that not every feature of the presently disclosed methods, apparatuses, and computer readable media having stored thereon is necessary in every implementation. It should also be understood that throughout this disclosure, where a process or method is shown or described, the steps of the method may be performed in any order or simultaneously, unless it is clear from the context that one step depends on another being performed first. As used throughout this application, the word may is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e. meaning must).

(6) Embodiments of the present invention relate to robotic surgical systems providing any feature or combination of features described above or in any of the figures.

(7) In some embodiments, although the surgical robot computes the correct position and orientation for sleeve 60, in fact, sleeve 60 may be slightly misoriented when a lateral force is exerted upon sleeve 60. For example, the force exerted on the surgical tool 70 and/or the inner sleeve 160 may be transferred to sleeve 60. Alternatively or additionally, this force may cause (i) the support element (e.g. clamp 40 or clamping portion 42 and clamp adaptor 45) and/or (ii) the sleeve 60 and/or inner sleeve 160 or surgical instrument 70 to bend.

(8) It is now disclosed that when sleeve 60 and/or inner sleeve 160 (e.g. canulla) and/or instrument 70 are improperly aligned, this may cause or be caused by a lateral force (i.e. in a direction perpendicular sleeve axis 62 and/or perpendicular to a direction of a planned trajectory 74 of surgical instrument). As such, a magnitude of such lateral force may be used as a marker/indicator describing a degree of misalignment between instrument 70 and sleeve 60i.e. smaller lateral forces are indicative that sleeve 60 (or inner sleeve 160 or instrument 70) is better aligned while larger lateral forces are indicative that sleeve (or inner sleeve 160 or instrument 70) is misaligned.

(9) When surgical tool 70 is laterally diverted from the planned trajectory by an external lateral force upon tool 70 and/or sleeve 60, this indicates that a lateral force is acting on the instrumentfor example, due to skiving on the bone or by soft tissue pressure. Hence minimizing this force means that the instrument is directed along the planned trajectory.

(10) By measuring the magnitude of the lateral force upon sleeve 60 (or an indicator thereof), it is possible to generate an alert signal if a magnitude of the lateral force exceeds a threshold value, to warn the user (e.g. a surgeon) to cease operation of instrument 70 or to refrain from operating instrument 70 due to an elevated risk that an orientation of 74 does not match the intended direction computed by the surgical robot.

(11) It is noted that sleeve 60 and/or instrument 70 may be subject to axial forces along sleeve axis 62e.g. a magnitude of the axial forces may significantly exceed that of the lateral forces. Thus, in some embodiments, it is desired to measure a magnitude of the lateral forces upon (or by) sleeve 60 in a manner that is substantially completely insensitive to a magnitude of a axial force along sleeve axis 62 of the guide-sleeve 60.

(12) Many examples in the present disclosure relate to orthopedicsthis is not a limitation. The presently-disclosed techniques and apparatus relate to any type of surgery including but not limited to orthopedics, neurosurgery, biopsy procedures, traditional procedures, minimally invasive procedures, laparoscopy or any other type of surgery.

(13) For brevity, some explicit combinations of various features are not explicitly illustrated in the figures and/or described. It is now disclosed that any combination of the method or device features disclosed herein can be combined in any mannerincluding any combination of featuresand any combination of features can be included in any embodiment and/or omitted from any embodiments.

Definitions

(14) For convenience, in the context of the description herein, various terms are presented here. To the extent that definitions are provided, explicitly or implicitly, here or elsewhere in this application, such definitions are understood to be consistent with the usage of the defined terms by those of skill in the pertinent art(s). Furthermore, such definitions are to be construed in the broadest possible sense consistent with such usage.

(15) The term skiving refers to slipping by any object (e.g. a distal end of the element) in contact with a bone. The object may be a sleeve or a canulla (e.g. having teeth at a distal end thereofe.g. as disclosed in U.S. Pat. No. 8,469,963 incorporated herein by reference) or a drill or any other object or surgical tool 70.

(16) Some embodiments relate to measuring a force or an indication thereof. Any time the term measuring a force is used it may refer to mechanical measuring of a forcee.g. using a force meter or a strain meter or any other instrument for measuring force. The mechanical measuring of a force may optionally employ optical means (e.g. strain gauge based on photoelasticity) and electrical circuitry.

(17) In the present disclosure electrical circuitry or electronic circuitry is intended broadly to describe any combination of hardware, software and/or firmware.

(18) Electronic circuitry may include may include any executable code module (i.e. stored on a computer-readable medium) and/or firmware and/or hardware element(s) including but not limited to field programmable logic array (FPLA) element(s), hard-wired logic element(s), field programmable gate array (FPGA) element(s), and application-specific integrated circuit (ASIC) element(s). Any instruction set architecture may be used including but not limited to reduced instruction set computer (RISC) architecture and/or complex instruction set computer (CISC) architecture. Electronic circuitry may be located in a single location or distributed among a plurality of locations where various circuitry elements may be in wired or wireless electronic communication with each other.

(19) A position/orientation controller is a device configured to determine or regulate changes in at least one of (i) a position of guide-sleeve 60 and/or (ii) an orientation of guide-sleeve 60for example, to a target portion and/or orientation. The position/orientation controller may by automated (e.g. a surgical robotfor example, including one or more motors) or may be a manual or passive guidance system where the mechanical force for moving and/or orienting the guide-sleeve is supplied manually. One example of a manual or passive guidance system is a frame-based or track-based system such as a stereotactic-based system comprising a stereotactic frame where the guide-sleeve moves along a frame or track.

(20) A robot may include a robot controller and/or electronic circuitryfor example, to compute any quantitye.g. a position and/or orientation of sleeve 60 or any other quantity. A robot is an example of a position/orientation controller.

(21) A guide-sleeve is any sleeve where it is intended to deploy an inner sleeve or a surgical instrument therein. The guide sleeve may define axial and lateral directions according to sleeve axis 62.

(22) A force between objects A and B (e.g. a lateral force) is any one of (i) a force applied by A upon object B; and (ii) a force applied by object B upon object A. A force between objects A and B may be applied directly or indirectly via one or more additional object(s).

(23) In some embodiments, substantially completely insensitive to a magnitude of a axial force means that the measured value of the lateral force (or indication thereof) increases by at most 10% (or at most 5% or at most 1%) in response to a 100% increase in a magnitude of axial forces upon sleeve 60 or sleeve 160 or instrument 70.

(24) One example of a device that may be used to measure a magnitude of lateral force applied upon sleeve 60 by instrument 70 (or by sleeve 60 upon instrument 70) is a force meter 155 deployed in annular region 68see FIGS. 13A-13B. In another example, it is possible to utilize the fact that the lateral force exerted by the inner sleeve upon the outer sleeve deforms the outer sleeve. Thus, in a second example and referring to FIGS. 13C-13D, it is possible utilize strain-meter 165 to measure the strain upon the outer sleeve 60 as an indicator of a magnitude of the lateral force by or upon sleeve 60. In this case the sensor can be located either on the inner surface or outer surface of the sleeve.

(25) The skilled artisan will appreciate that although the sleeve 60 and tool 70 are illustrated as being cylindrical in shape, this is not a requirement, and other shapes may be used.

(26) A skiving detector comprises any combination of mechanical or electrical or optical or other components configured to detect at least one of a presence or absence or skiving between an (i) object (e.g. guide-sleeve 60 or instrument 70 such as an inner sleeve) and (ii) a bone of the patient.

(27) An alert-signal-generator comprises any of mechanical or electrical or optical or other components for generating a contingent alert signale.g. a visual alert signal or an audio alert signal or any other alert signal.

(28) The skilled artisan will appreciate that various elements in FIGS. 13A-13D and in FIGS. 14A-14C are illustrated schematicallyfor example, there is no requirement for a force meter 155 or strain mater 165 to have oval or diamond shapes. These are merely schematic symbols.

(29) FIGS. 14A-14C refer to the devices for directly or indirectly sensing lateral force by or upon sleeve 60 in the system described above with reference to FIGS. 10-11. For brevity, only top views are shown.

(30) In FIG. 14A a force sensor 155 is deployed in annular region 88for example, to sense a force applied by instrument 70 upon sleeve 60 via inner sleeve (e.g. canulla) 160.

(31) In FIG. 14B a force sensor 155 is deployed in annular region 88for example, to sense a force applied by sleeve 160 upon sleeve 60 and/or applied by instrument 70 upon sleeve 60 via inner sleeve (e.g. canulla) 160. For example, a distal end of sleeve 160 (e.g. canulla) may be in contact with the bone and may be skiving.

(32) FIG. 14C includes strain sensor 165 and is analogous to FIG. 13D.

(33) FIGS. 15-16 are flow charts of methods according to some embodiments of the invention.

(34) FIG. 15 is a flow-chart of a method for responding to lateral forces applied by or upon sleeve 60. FIG. 16 relates to responding to detected or predicted skiving.

(35) For both figures, in step S101, a surgical robot orients sleeve 60 in accordance with (i) medical imaging data (e.g. CT data) and/or (ii) a surgical objectivee.g. to drill into a target bone. In step S105, the user deploys (e.g. by manual insertion or automatically) a surgical tool 70 (or an inner sleeve 160) into guide-sleeve 60e.g. so that the tool 70 is deployed snugly and/or movably within guide-sleeve 60.

(36) In step S109, lateral-force by or upon guide-sleeve 60 is measured. In the event that a magnitude of the lateral force exceeds some sort of threshold value S113 (e.g. indicative of present or future skiving by canulla 160 or surgical instrument 70see step S125 of FIG. 16), then an alert signal is generated S117e.g. an audio or a visual alert signal or any other kind of alert signal. In this case, the user may elect remove and re-deploy surgical tool 70 within guide sleeve 60.

(37) In the absence of any alert signal, this may indicate that an orientation of axes 62, 72 and operation direction 74 is according to the planned direction assuming that relevant elements (robot, registration algorithm etc.) established when orienting sleeve 60 by the surgical robot. In this case, the user may elect, in the absence of the alert signal, to operate tool 70 in step S121.

(38) In the description and claims of the present application, each of the verbs, comprise include and have, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.

(39) All references cited herein are incorporated by reference in their entirety. Citation of a reference does not constitute an admission that the reference is prior art.

(40) The articles a and an are used herein to refer to one or to more than one. (i.e., to at least one) of the grammatical object of the article. By way of example, an element means one element or more than one element.

(41) The term including is used herein to mean, and is used interchangeably with, the phrase including but not limited to.

(42) The term or is used herein to mean, and is used interchangeably with, the term and/or, unless context clearly indicates otherwise.

(43) The term such as is used herein to mean, and is used interchangeably, with the phrase such as but not limited to.

(44) The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons skilled in the art.