DEVICES AND METHODS FOR AUTOMATICALLY VERIFYING, CALIBRATING AND SURVEYING INSTRUMENTS FOR COMPUTER-ASSISTED SURGERY

• US 20060264742A1
• Filed: 05/04/2006
• Published: 11/23/2006
• Est. Priority Date: 05/04/2005
• Status: Active Grant

• Current Assignee: Brainlab AG
• Original Assignee: Brainlab AG
• Inventors: NEUBAUER, Timo, PLASSKY, Norman
• Granted Patent: US 7,809,184 B2
• Time in Patent Office: Days
• US Class Current: 600/424
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2034/102 Modelling of surgical devices, implants or prosthesis
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• 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 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/98 using electromagnetic means, e.g. transponders

Abstract

A device and method for automatically verifying, calibrating and surveying a navigable surgical instrument, wherein by means of a scanning device, the geometry of the instrument, in particular the shape of the functional elements (e.g., tips) and their spatial position with respect to an attachable reference system, are detected. By means of a data processing unit, a three-dimensional model of the instrument is calculated from the detected information concerning the geometry of the instrument including the reference system, wherein verification, calibration or surveying is performed with the aid of the ascertained information concerning the geometry of the instrument.

Claims

1. A method for automatically verifying, calibrating or surveying an instrument, comprising:

detecting a geometry of the instrument and a reference system mountable to said instrument based on a scan of the instrument and reference system;

calculating a three-dimensional model of the instrument based on the detected geometry, wherein based on the geometry of the three-dimensional model, the instrument is verified, calibrated or surveyed.

2. The method of claim 1, wherein said reference system is formed by at least two active or passive markers.

3. The method of claim 1, wherein calculating includes using a data processing unit to perform the calculations.

4. The method of claim 1, further comprising:

recording emission characteristics and/or reflection characteristics of the reference system from different angles of observation via a camera unit;

ascertaining from the emission characteristics and/or reflection characteristics a quality, condition or shape of the reference system or of individual markers based on the angle of observation;

calculating an optical outline of the reference system from the quality, condition or shape; and

combining the optical outline of the reference system with the ascertained quality, condition or shape information related to the geometric outline of the reference system.

5. The method of claim 1, wherein verifying or calibrating comprises:

recognizing the geometry of the reference system or the geometry of a functional element of the instrument;

comparing the recognized geometries with geometries of functional elements and/or reference systems of other instruments stored in memory; and

automatically retrieving information stored in memory for the instrument based on the comparison.

6. The method of claim 1, further comprising:

detecting a surface of the instrument via the scan; and

representing the detected information on a display device as a three-dimensional model of the instrument, such that a functional element and the reference system of the instrument can be selected by a user via a user interface unit.

7. The method of claim 6, wherein detecting includes detecting the reference system and a functional element of the instrument.

8. The method of claim 1, wherein detecting comprises:

obtaining a first scan of the instrument at a first resolution;

ascertaining a first geometric structure of the of the instrument based on the first scan;

comparing the first geometric structure with geometric data stored in memory; and

retrieving information stored in memory for the instrument based on the comparison.

9. The method of claim 8, further comprising verifying or calibrating the instrument after the instrument has been identified, wherein verifying or calibrating comprises:

obtaining a second scan of functional elements of the instrument and the reference system at a second resolution, wherein the second resolution is higher than the first resolution;

comparing data from the second scan with geometric data stored in memory, said geometric data relating to the instrument.

10. The method of claim 9, wherein obtaining a second scan includes scanning the shape and position of the functional elements and the reference system with respect to one another.

11. The method of claim 9, wherein calibration comprises correcting geometric instrument data stored in memory when a deviation between the detected instrument geometry and the geometric instrument data stored in memory is greater than a predetermined tolerance level, wherein said correction is based on the ascertained geometry of the instrument, or the instrument is newly scanned in areas of the instrument that are not within the predetermined tolerance and data from the second scan is transferred into memory.

12. The method of claim 1, wherein if a deviation between the detected geometry of the instrument and geometric data stored in memory is less than or equal to a predetermined tolerance level, the instrument being examined and the geometric data stored in memory are assumed to match and a positive verification result is transmitted to a navigation system, whereupon the instrument is activated for a subsequent application.

13. The method of claim 1, wherein detecting a geometry comprises:

calculating a distance between a functional element of the instrument and the reference system;

transmitting the calculated distance to a navigation system.

14. The method of claim 1, wherein surveying the instrument comprises:

obtaining a first scan of the instrument and reference system at a first resolution;

calculating a three-dimensional model of the instrument from the first scan;

providing the model on a display device;

locating characteristic shapes forming the model;

ascertaining a scan area based on the characteristic shapes; and

obtaining a second scan of the ascertained scan area at a second resolution, wherein the second resolution is higher than the first resolution

15. The method of claim 14, wherein locating characteristic shapes includes locating geometric shapes of the reference system or a functional element of the instrument.

16. The method of claim 1, further comprising detecting a surface of the instrument as the instrument is rotated about a scanning unit, wherein the three dimensional model of the instrument is calculated using the detected surface and rotation data.

17. A method for navigating an instrument, comprising:

verifying, calibrating or surveying the instrument according to claim 1;

detecting a spatial position of the reference system;

determining a spatial position of a functional element of the instrument based on geometric data regarding the reference system, said data stored in computer memory; and

providing on a display the spatial position of the functional element relative to an anatomical structure to be treated.

18. A computer program which, when running on a computer or loaded onto a computer, carries out the methods according to claim 1.

19. A program storage medium or computer program product comprising the computer program according to claim 18.

20. A device for automatically verifying, calibrating or surveying an instrument, comprising:

a scanning unit configured to detect a geometry of the instrument, a geometry of a reference system attachable on the instrument, and the geometry of the reference system relative to the geometry of the instrument, wherein the instrument can be rotated relative to the scanning unit; and

a data processing unit configured to calculate a three-dimensional model of the instrument and ascertain a position of a functional element of the instrument, said calculation based on a characteristic arrangement of the reference system.

21. The device of claim 20, further comprising an infrared camera unit, wherein a spatial position of the camera unit with respect to the scanning unit is known or can be determined, wherein the camera unit enables emission characteristics or reflection characteristics of markers and of the reference system formed by the markers to be determined, from the emission or reflection characteristics information concerning a condition or quality or a shape of the markers can be ascertained from various directions of view onto the reference system and combined with the information concerning the geometry of the reference system, said geometrical information being stored in a database.

22. The device of claim 21, further comprising a database, wherein at least one of the detected information concerning the geometry of the instrument and the reference system, information concerning the condition, quality or shape of the markers, information concerning the geometry of other instruments and their reference systems, or information concerning the condition, quality or shape of the markers of other instruments can be saved in the database.

23. The device of claim 22, wherein information concerning the reference system includes a distance from the reference system to a functional element of the instrument.

24. The device of claim 20, further comprising:

a display device on which the ascertained three-dimensional model of the instrument can be represented; and

a user interface unit configured for selecting a functional element of the instrument or the markers forming the reference system.

25. The device of claim 24, wherein the display device is a touch screen, and the user interface is arranged on the touch screen.

26. The device of claim 20, further comprising a navigation system linked wirelessly or via a wired connection to the data processing unit, wherein the ascertained information concerning the instrument can be transmitted to the navigation system, and on the basis of the transferred information concerning the arrangement of the markers forming the reference system, a navigation procedure can be carried out using the navigation system and incorporating and/or compensating for ascertained errors of the markers.

27. The device of claim 20, further comprising a communication device for communicating with an instrument equipped with a mobile, read-only or readable and writeable data memory, wherein identifying features of the instrument are provided to the data processing unit and/or the scanning unit via the communication link.

28. The device of claim 27, wherein the communication device uses wireless transfer technologies.

29. A program embodied in a computer-readable medium for automatically verifying, calibrating or surveying an instrument, comprising:

code that directs the detection of a geometry of the instrument and a reference system mountable to said instrument based on a scan of the instrument and reference system;

code that calculates a three-dimensional model of the instrument based on the detected geometry, wherein based on the geometry of the three-dimensional model, the instrument is verified, calibrated or surveyed.