System With A Medical Instrument And A Recording Means

Abstract

A method for automatically predetermining an intended movement of a manipulator arrangement of a medical system having a medical instrument and a recording means for generating images, wherein the recording means and/or the instrument is guided by the manipulator arrangement. The method includes establishing an intended transformation between a reference stationary in relation to the recording means and a reference stationary in relation to the instrument; monitoring a deviation between the intended transformation and a current transformation between the reference stationary in relation to the recording means and the reference stationary in relation to the instrument; and determining a reset movement of the manipulator arrangement for returning the current transformation to the intended transformation when the deviation satisfies a predetermined condition.

Claims

1-11. (canceled)

12. A method for automatically predetermining a desired movement of a manipulator arrangement of a medical system, the medical system comprising a medical instrument and a recording means for creating images, wherein at least one of the recording means or the instrument are guided by the manipulator arrangement, the method comprising: determining an intended transformation between a recording means-side reference and an instrument-side reference; monitoring a deviation between the intended transformation and a current transformation between the recording means-side reference and the instrument-side reference; and determining a reset movement of the manipulator arrangement to return the current transformation to the intended transformation when the deviation satisfies a predetermined condition.

13. The method of claim 12, wherein the predetermined condition is a variable predetermined condition.

14. The method of claim 12, wherein the reset movement is at least one of: predetermined based on the deviation; or predetermined independently of a relative movement between the instrument and the recording means after the condition is satisfied.

15. The method of claim 14, wherein the reset movement is predetermined on the basis of the deviation when the condition is satisfied.

16. The method of claim 12, wherein the reset movement is predetermined with a velocity that is at least twice, or at most half, of a velocity of a relative movement between the instrument and the recording means.

17. The method of claim 16, wherein the velocity with which the reset movement is predetermined is at least one of a maximum velocity or a constant velocity.

18. The method of claim 12, wherein the intended transformation is predetermined based on an identified transformation between the recording means-side reference and the instrument-side reference.

19. The method of claim 18, wherein the transformation is variably predetermined.

20. The method of claim 12, wherein the intended transformation and the current transformation comprise at least one of a translation or a rotation between the recording means-side reference and the instrument-side reference.

21. The method of claim 12, wherein at least one of: the translation is a one-, two-, or three-dimensional translation; or the rotation is a one-, two-, or three-dimensional rotation.

22. The method of claim 12, wherein the deviation comprises at least one of a mathematical norm or a difference.

23. The method of claim 22, wherein at least one of: the norm is a one-dimensional norm; or the difference is a multi-dimensional difference.

24. The method of claim 12, wherein the condition is satisfied when an image of the instrument generated by the recording means satisfies a predetermined criterion.

25. The method of claim 24, wherein the predetermined criterion is variable.

26. The method of claim 12, wherein: the recording means is configured for at least one of: a) intracorporeal transmission, b) intracorporeal reception, c) extracorporeal transmission, or d) extracorporeal reception; and the at least one transmission or reception comprises at least one of: i) transmission or reception of visible electromagnetic radiation, ii) transmission or reception of invisible electromagnetic radiation, or iii) transmission or reception of ultrasound.

27. The method of claim 12, wherein at least one of the recording means or the instrument is at least one of: configured for minimally invasive use; or comprises a shaft that is movable by the manipulator arrangement to be inserted through a body orifice, and an end actuator.

28. A medical system, comprising: a manipulator arrangement; a medical instrument; a recording means for creating images; and a controller; wherein at least one of the recording means or the instrument is guided by the manipulator arrangement; and wherein the controller includes program code stored in a non-transitory, computer-readable storage medium, and the program code, when executed by the controller, implements the method of claim 12.

29. A computer program product including program code stored on a non-transitory, computer readable medium, wherein the program code, when executed by a computer implements the method of claim 12.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Further advantages and features of the invention will be apparent from the accompanying drawings and the description of the exemplary embodiments. For this purpose, partially in schematic form, the figures show:

[0041] FIG. 1: part of a medical system with a manipulator arrangement according to one embodiment of the present Invention; and

[0042] FIG. 2: a method for automatically predetermining an intended movement of the manipulator arrangement according to one embodiment of the present Invention.

DETAILED DESCRIPTION

[0043] FIG. 1 shows a part of a medical system according to one embodiment of the present invention.

[0044] The medical system comprises a manipulator arrangement with two manipulators, of which only one end flange 30 or 40, and a part of an arm 31 and 41 connected to said end flange via a pivot joint with a rotation angle q.sub.1 or q.sub.n, is respectively indicated in FIG. 1.

[0045] The medical system further comprises a medical instrument designed for minimally invasive use with an instrument shaft 20, which is inserted into a patient through a body orifice 62, and an end actuator 21 for clamping or the like, which can be moved in an actuated manner relative to the instrument shaft. The instrument shaft 20 is connected to the end flange 40 in a detachable manner and can thus be moved or guided by means of the manipulator arrangement.

[0046] The medical system further comprises a recording means for generating images that is designed for minimally invasive use and has a shaft 10, which is inserted into a patient through a body orifice 61, and an end actuator 11 in the form of a micro camera, which is stationary in relation to the shaft and intracorporeally receives visible electromagnetic radiation that is further processed by the recording means to generate images 5 of the end actuator 21 and its operational surroundings. The shaft 10 is connected to the end flange 30 in a detachable manner and can thus be moved or guided by means of the manipulator arrangement.

[0047] The medical system further comprises a control means 7 in the form of a computer.

[0048] This control means implements a method according to one embodiment of the present invention, which will be explained in the following with reference to FIG. 2:

[0049] First, in Step S10, an intended transformation T.sub.s=T.sub.KW(t.sub.0) between a recording means fixed reference and an instrument fixed reference is determined.

[0050] As indicated in FIG. 1, the recording means fixed reference example may, for example be a coordinate system K, which is stationary relative to the camera 11. Similarly, the recording means fixed reference may, for example, also be a coordinate system B, which is stationary relative to the image 5 generated by the camera.

[0051] In an analogous manner, the instrument fixed reference may for example, as indicated in FIG. 1, be a coordinate system W, which is stationary relative to the end actuator 21 or the instrument shaft 20. Similarly, the instrument fixed reference may, for example, also be a coordinate system W′, which is stationary relative to the depiction of the instrument in the image 5 generated by the camera.

[0052] The transformation is suggested as an example in FIG. 1 by the image T.sub.KW between the coordinate systems K and W or the image T.sub.W′B between the coordinate systems W′ and B. It describes the relative position and orientation of the camera 11 and the instrument shaft 20 or end actuator 21, or of the generated image 5 and the depiction of the instrument therein.

[0053] In each case the transformation T.sub.KW is determined by means of forward kinematics on the basis of the measured joint angle q=(q.sub.1, . . . q.sub.n) or an identified pose of the manipulator arrangement.

[0054] The transformation T.sub.W′B can likewise always be determined on the basis of the measured joint angle q while taking into account a field of view of the camera 11. Similarly, the transformation T.sub.W′B, which conveys a relative position and/or orientation of the depiction of the end actuator 21 of the instrument in the image 5 generated by the recording means 11, can also be determined by means of image recognition.

[0055] The intended transformation is predetermined in Step S10 on the basis of a current transformation between the recording means fixed reference and the instrument fixed reference identified at time t.sub.0. As an example, this is indicated by T.sub.s=T.sub.KW(t.sub.0) in the embodiment of FIG. 2.

[0056] A mathematical norm of a difference between the intended and a continuously identified current transformation T.sub.a(q(t)), which is expressed as “∥ . . . ∥” and determined from the joint angles q=(q.sub.1, . . . q.sub.n) of the manipulator arrangement, is then periodically or continuously determined in Step S20 as a deviation Δ between the intended transformation, and the respective current transformation between the recording means fixed reference and the instrument fixed reference. This is then monitored in Step S30, to see whether this deviation Δ exceeds a predetermined threshold value Δ.sub.0, i.e. to see whether, in particular, a relative position and/or orientation between the recording means and the instrument has changed excessively.

[0057] As soon as the deviation Δ exceeds the predetermined threshold value Δ.sub.0 (S30: “Y”), which is indicated as an example in FIG. 1 by a dotted line illustrating a deflected position of the medical instrument, a predetermined condition is satisfied, and in a Step S40 the control means 7 determines a reset movement d of the manipulator arrangement to return the current transformation to the intended transformation, which for illustration is indicated in FIG. 1 with a dash-dotted line.

[0058] In the exemplary embodiment, this condition is predetermined in such a way that it is satisfied if the depiction of the instrument in the image 5 generated by the recording means is outside a predetermined area of the image.

[0059] In Step S40, when the condition (S30 “Y”) is satisfied, the reset movement d is determined on the basis of the deviation Δ in such a way that this deviation decreases, preferably to zero, (Δ(d)=0), for example by solving a minimization problem “d so that Δ(d)=minimum!” or something similar.

[0060] The control means can subsequently implement this predetermined intended or reset movement by means of appropriate actuation of the joints of the manipulator arrangement (not shown in FIG. 2).

[0061] In the embodiment, the reset movement can optionally be predetermined with a velocity dd/dt, which is at least twice or at most one half a velocity of a relative movement between the instrument and the recording means.

[0062] In Step S40, the reset movement of the manipulator arrangement to return the current transformation to the intended transformation is determined in such a way that a position and/or orientation of the end actuator 21 of the instrument does not change. The above-mentioned minimization problem is accordingly solved only by varying the joint angles of the manipulator 30, 31, which guides the camera 11.

[0063] Even though exemplary embodiments have been outlined in the foregoing description, it should be noted that a variety of modifications are possible. In addition, it should be noted that the exemplary embodiments are merely examples that are by no means intended to limit the scope of protection, the applications and the structure in any way. Rather, with the foregoing description, the skilled person is provided with a guide for implementation of at least one exemplary embodiment, whereby a variety of changes, in particular with respect to the function and arrangement of the described components may be made without departing from the scope of protection as it is emerges from the claims and the equivalent combinations of features.

[0064] While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.

LIST OF REFERENCE SIGNS

[0065] 10 Shaft (recording means)

[0066] 11 Camera (recording means)

[0067] 20 Instrument shaft

[0068] 21 End actuator

[0069] 30, 40 End flange (manipulator)

[0070] 31, 41 Arm (manipulator)

[0071] 5 Image

[0072] 61, 62 Body orifice

[0073] 7 Control means

[0074] d Reset movement

[0075] B Recording means image fixed reference

[0076] K Recording means component fixed reference

[0077] q.sub.1, q.sub.n,

[0078] q Joint angle

[0079] T Transformation

[0080] W Instrument component fixed reference

[0081] W′ Instrument image fixed reference

[0082] Δ Deviation