Medical Manipulator And Method For Controlling A Medical Manipulator

Abstract

A medical manipulator includes a manipulator arm, an end effector secured to the manipulator arm and having at least one tool with a changing mass and/or mass distribution, and a manipulator controller for controlling the medical manipulator. In each control step, the manipulator controller uses a current load data matrix including the changing mass and/or mass distribution of the tool to prevent deviations from a target position or target path of the tool.

Claims

1. Medical manipulator (1), comprising: a. a manipulator arm (10); b. an end effector (20) mounted on the manipulator arm (10) and comprising at least one tool (21, 22, 23) with a varying mass and/or mass distribution (46); c. a manipulator control (30) for the controlling of the medical manipulator (1); wherein d. the manipulator control (30) uses a current load data matrix (40) with the varying mass and/or mass distribution (46) of the tool (21, 22, 23) in each regulation step in order to prevent deviations from a target posture or target path of the tool (21, 22, 23).

2-14. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.

[0026] FIG. 1 is a schematic construction of a medical manipulator according to the principles of the present disclosure.

DETAILED DESCRIPTION

[0027] In the following, preferred embodiments of the present invention are described in detail with reference to the attached figure.

[0028] FIG. 1 shows an embodiment of a medical manipulator 1. A manipulator arm 10 is mounted on a base mounting surface B. In the illustrated embodiment, the manipulator arm 10 consists of three arm parts A and two joints G. However, the kinematic chain of the manipulator arm 10 can also comprise a different number of arm parts A and joints G, as desired. The manipulator arm 10 can be freely moved all spatial directions.

[0029] An end effector 20 comprising at least one tool 21, 22, 23 and a varying mass and/or mass distribution is mounted on the manipulator arm 10. Normally, the tools 21, 22, 23 are movable with respect to the manipulator arm 10 and upon such movements change their respective mass distribution relative to the manipulator arm 10. The tools 21, 22, 23 can, for example, be moved via mechanical elements 52 independently of the posture or movement of the manipulator arm 10. In the illustrated embodiment, the end effector 20 comprises three tools 21, 22, 23, which are moved individually via the mechanical elements 52, for example further into or out of the body of the patient. The mechanical elements 52 can be, for example, linear axes 52 with which the tools 21, 22, 23 can be individually operated in a linear fashion. However, the end effector 20 can also comprise a different number of tools 21, 22, 23, as desired. If the tools 21, 22, 23, in particular the medical instruments, are, for example, maximally inserted into the body of the patient, then the mass distribution of the tool is maximally towards the front. If all tools or instruments 21, 22, 23 are maximally extracted from the body of the patient, then the mass distribution is maximally towards the rear.

[0030] The mechanical elements 52 of the tools 21, 22, 23 are controlled by an electronic control unit 50. Via data links 60, the electronic control unit 50 preferably transmits information regarding the position of the mechanical elements 52 to the manipulator control 30.

[0031] The manipulator control 30 comprises a current load data matrix 40, which is preferably calculated by the control 30 from the current mass distributions as well as the masses of the tools 21, 22, 23. The current mass distributions as well as masses of the tools 21, 22, 23 can be stored as data 46 in the control 30. Based upon the use of the current load data matrix, the movement of the medical manipulator 1 is performed exactly according to the specifications of a user or a program. The current load data matrix 40 is also determined with the assistance of a dynamic model 42 of the tool(s) 21, 22, 23. The data 46 regarding the mass distribution and mass of the tool 21, 22, 23 can be fed from the medical manipulator 1 via the data link 60 in each regulation step to the manipulator control 30 and is calculated from the dynamic model 42 in each regulation step. The dynamic model of the tool 42 can also be integrated in the dynamic model of the manipulator 44. In particular, future changes in the mass distribution and the mass of the tool can be taken into account during the control of the manipulator 1.

[0032] In a method for the control of a medical manipulator 1, the load data matrix 40 is updated in each regulation step. By taking into account the current mass distribution and the mass 46, the manipulator control 30 can determine the forces and torques appearing on the tool 21, 22, 23 and correct the posture or path of the tool such that a deviation from an original target posture or target path is prevented.

[0033] In particular, the dynamic model 42, 44 can be extrapolated into the future in order to determine future values for the mass distribution 46. However, information regarding planned changes in the mechanical elements 52 can also be transmitted from the electronic control unit 50 to the manipulator control unit 30. This information can then be directly taken into account in the subsequent time step in the manipulator control.

[0034] As a result, the current control commands that take into account the change in the mass and mass distribution of the tool 21, 22, 23 are then transmitted in each regulation step via the data link 60 to the medical manipulator 1. A movement or posture of the tool 21, 22, 23 without a deviation from the target path or target posture can hereby be enabled, although the mass or mass distribution of the tool 21, 22, 23 varies.

[0035] 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 NUMBERS

[0036] 1 Medical manipulator [0037] 10 Manipulator arm [0038] 20 End effector [0039] 21 Tool [0040] 22 Tool [0041] 23 Tool [0042] 24 Mounting surface [0043] 30 Manipulator control [0044] 40 Load data matrix [0045] 42 Dynamic model of the tool [0046] 44 Dynamic model of the manipulator [0047] 46 Mass distribution and mass of the tool [0048] 50 Electronic control unit [0049] 52 Mechanical elements [0050] 60 Data links [0051] A Arm part [0052] B Base mounting surface [0053] G Joint