Computer-assisted microsurgery methods and equipment

• US 5,755,725 A
• Filed: 09/10/1996
• Issued: 05/26/1998
• Est. Priority Date: 09/07/1993
• Status: Expired due to Term

• Current Assignee: Sarif Biomedical LLC (Marathon Patent Group, Inc.)
• Original Assignee: Deemed International, S.A.
• Inventors: Druais, Herve
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Woo, Julian W.
• Application Number:
  US08/612,932
• Time in Patent Office: 623 Days
• Field of Search: 606/130
• US Class Current: 606/130
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 90/10 for stereotaxic surgery, e.g. frame-based stereotaxis
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for

Abstract

Computer-assisted microsurgery equipment, of the type including an articulated tool support, with one of the ends being integral with a fixed reference system R_c. The system comprises cameras for determining the tool coordinates in said fixed reference system R_c, and an image data base wherein are recorded images from an imaging system in the image reference system R_i. The inventions characterized by having at least two sensors integral with the fixed reference system R_c supplying an electrical signal depending on the patient reference position R_p in the fixed reference system R_c, and a computer for matching the tool reference system R_o with the patient reference system R_p and the image reference system R_i according to data from the bidimensional sensor, cameras for determining the coordinates of the tool in the fixed reference system R_c and data from the image base. The computer supplies a signal for displaying the position of the tool in the image reference system R_i on a monitor and for controlling the position and shifting of said tool as a function of the control signals from the control unit.

Claims

1. A computer-assisted microsurgery installation, comprising:

(a) an articulated tool support, one end of which is integral with a fixed reference frame R_c ;

(b) an image data base comprising images in an image reference frame R_i ;

(c) at least two sensors, integral with the fixed reference frame R_c, supplying a signal that is a function of the position of a reference frame R_p of a patient in the fixed reference frame R_c ;

(d) a computer adapted to;

(1) determine correspondence of a reference frame R_o of the tool with the patient reference frame R_p and the image reference frame R_i as a function of the signal from the at least two sensors;

(2) output a display signal for visualization of position of the tool in the image reference frame R_i on a control screen; and

(3) control position and displacements of the tool as a function of control signals originating from a control unit, wherein the fixed reference frame R_c is independent of the patient reference frame R_p and of the image reference frame R_i ; and

(e) means for determining coordinates of the tool in the fixed reference system R_c based on data from the image data base.

2. The installation of claim 1, wherein the at least two sensors comprise at least two acquisition cameras integral with the fixed reference system R_c and positioned such that their field of observation includes a surgical intervention zone.

3. The installation of claim 2, further comprising a first geometrically defined trihedron, presenting at least four non-coplanar punctiform light sources integral with the tool, with the mobility space of the first trihedron being contained in the fields of vision of the acquisition cameras.

4. The installation of claim 3, further comprising a second geometrically defined trihedron, presenting at least four non-coplanar punctiform light sources integral with the patient, with the mobility space of the second trihedron being contained in the fields of vision of the acquisition cameras during an entire operative phase.

5. The installation of claim 1, wherein the means for determining coordinates of the tool in the fixed reference system R_c comprises at least two acquisition cameras integral with the fixed reference system R_c and positioned such that their field of observation includes the mobility space of the tool.

6. The installation of claim 5, further comprising a first geometrically defined trihedron, presenting at least four non-coplanar punctiform light sources integral with the tool, with the mobility space of the first trihedron being contained in the fields of vision of the acquisition cameras.

7. The installation of claim 6, further comprising a second geometrically defined trihedron presenting at least four non-coplanar punctiform light sources integral with the patient, with the mobility space of the second trihedron being contained in the fields of vision of the acquisition cameras during an entire operative phase.

8. The installation of claim 1, further comprising an additional sensor comprising a pointing end and at least two light points, the positions of which in relation to the pointing end are determined geometrically by placing the additional sensor within the fields of vision of the at least two sensors.

9. The installation of claim 1, wherein:

the at least two sensors comprise at least two acquisition cameras integral with the fixed reference system R_c and positioned such that their field of observation includes a surgical intervention zone and the mobility space of the tool; and

further comprising;

a first geometrically defined trihedron, presenting at least four non-coplanar punctiform light sources integral with the tool, with the mobility space of the first trihedron being contained in the fields of vision of the acquisition cameras;

a second geometrically defined trihedron, presenting at least four non-coplanar punctiform light sources integral with the patient, with the mobility space of the second trihedron being contained in the fields of vision of the acquisition cameras during an entire operative phase; and

an additional sensor comprising a pointing end and at least two light points, the positions of which in relation to the pointing end are determined geometrically by placing the additional sensor within the fields of vision of the acquisition cameras.

10. A method for performing microsurgery using a microsurgery tool, comprising the steps of:

(a) determining the position of the tool in a reference frame R_c of a camera by a transformation ^m1 T_c, giving the relation between a reference frame R_o of the tool and a fixed reference frame R_m1, and a transformation ^c T_m1It), giving the relation between the camera reference frame R_c and the fixed reference frame R_m1 determined in real time by optical measurement;

(b) determining a transformation ⁱ T_m2 giving the relation between an image reference frame R_i and a fixed reference frame R_m2 ;

(c) determining the position of the fixed reference frame R_m2 in relation to the camera reference frame R_c by a transformation ^m2 T_c(t) determined in real time by optical measurement;

(d) calculating a transformation ⁱ T_o(t)=ⁱ T_m2^m2 T_o(t)^c T_m1(t)^m1 T_o, giving the relation between the image reference frame R_i and the tool reference frame R_o, to display in real time a section corresponding to a point of interest indicating the position of the tool in relation to a prerecorded image; and

(e) performing the microsurgery based on the real-time display of the section.

11. A method for controlling a microsurgery tool in relation to an image data base, comprising the steps of:

(a) determining the position of the tool in a reference frame R_c of a camera by a transformation ^m1 T_o, giving the relation between a reference frame R_o of the tool and a fixed reference frame R_m1, and a transformation ^c T_m1(t), giving the relation between the reference flame R_c and the fixed reference frame R_m1 determined in real time by optical measurement;

(b) determining a transformation ⁱ T_m2 giving the relation between an image reference frame R_i and a fixed reference frame R_m2 ;

(c) determining the position of the fixed reference frame R_m2 in relation to the reference frame R_c by a transformation ^m2 T_c(t) determined in real time by optical measurement;

(d) calculating a transformation ⁱ T_o(t)=ⁱ T_m2^m2 T_c(t)^c T_m11(t)^m1 T_o, giving the relation between the image reference frame R_i and the tool reference frame R_o ;

(e) calculating a transformation ^o T_i(t), which is an inverse of the transformation ⁱ T_o(t) ; and

(f) automatically controlling the tool in real time in relation to a target defined in the image data base using the transformation ^o T_i(t).