Method and system for calibrating a surgical tool and adapter therefor
A method for easily calibrating both the position of the tip of a surgical tool and the orientation of that tool includes attaching a tracking device capable of communication with the surgical navigation system to the surgical tool using an adapter, where the adapter has a known relation between the tracking device and the axis of the surgical tool. The method then performs a calibration process to calculate the position of the tip of the surgical tool and the position of the tracking device and orientation data for the surgical tool from the known relation between the tracking device and the axis of the surgical tool and from the tool tip position. Lastly, the method stores the position of the tool tip for the surgical tool and the orientation data within memory of the surgical navigation system so the position and the orientation of the surgical tool can be tracked by the surgical navigation system. The adapter has a body with an interior surface that defines an opening through which a surgical tool can be inserted, the opening having an axis. The adapter also has a docking structure for a tracking device such that there is a known relation between the tracking device and the axis of the opening and the axis of a tool that is inserted in the opening.
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This application is a divisional of U.S. patent application Ser. No. 10/246,599, filed Sep. 18, 2002.
FIELD OF THE INVENTIONThis invention generally relates to calibrating surgical tools for use with a surgical navigation system. More particularly this invention relates to the calibration of a combination of a universal tracking device and the surgical tool so that the position and orientation of the surgical tool can be determined by the surgical navigation system.
BACKGROUND OF THE INVENTIONThe use of image guided surgical navigation systems for assisting surgeons in performing delicate surgery has become more common. Typical surgical navigation systems utilize specially developed tools that include built in tracking devices so that the surgeon can see the position of the surgical tool overlaid on a monitor that shows a preoperative image or an intraoperative image. The preoperative images are typically prepared using well-known preoperative scanning techniques, such as MRI or CT scans. The intraoperative images can be prepared using flouroscope, low level x-ray and similar devices. The tracking devices typically include multiple optical emitters, such as LED's, that can be detected by the surgical navigation system. From the position of the emitters, the surgical navigation system can determine the position and/or orientation of the surgical tool.
As used in this specification, the term position means the coordinates of the tip of the surgical tool in three-dimensional space, the x, y, z or Cartesian coordinates, relative to the surgical navigation system. The term orientation means the pitch, roll, and yaw of the surgical tool. When both the position and the orientation of a surgical tool are defined, the absolute position of that surgical tool is known to the surgical navigation system.
In order for a surgeon to use a surgical tool without a built in tracking device with a surgical navigation system, a universal tracking device must be attached to the surgical tool. The universal tracking device and the surgical tool combination must be calibrated so that the surgical navigation system knows the relation between tip of the surgical tool and the position of the tracking device. Surgical tools with the attached universal tracking device can be calibrated and then tracked. If the tracking device and surgical tool have been calibrated relative to the surgical navigation system so that only the position of the tip of the surgical tool is known to the surgical navigation system, then only the position of the tip but not the orientation of the surgical tool can be tracked by the system. Because the exact path the surgeon will take during a particular surgical procedure is very important, it is preferable to know both the position and orientation of the surgical tools used during that procedure so that the surgical tools can be completely represented on the monitor of typical surgical navigation systems.
In order to provide both position and orientation data for the combination of the surgical tool and the attached universal tracking device, both the position and orientation for each surgical tool and tracking device combination must be calibrated. Typical prior calibration devices have been described in U.S. Pat. Nos. 5,987,960, 5,921,992 and 6,306,126. Each of these calibration devices utilizes the principal of constraining the axis of the surgical tool in a plane perpendicular to a base of the calibration device. Because the position of the base of the calibration device and the position of the axis of the surgical tool are known relative to optical tracking elements contained on the calibration device, the surgical navigation system can calculate the position and the orientation for the particular surgical tool and the tracking device combination. Thereafter, that surgical tool and tracking device combination can be completely tracked by the surgical navigation system.
SUMMARY OF THE INVENTIONThe present invention is directed to an improved method of calibrating both the position and orientation of a surgical tool for use with a surgical navigation system. This method includes the steps of attaching a tracking device capable of communicating with the surgical navigation system to the surgical tool using an adapter, wherein the surgical tool has both a tool axis and a tool tip and the adapter has a known relation between the tracking device and the tool axis. The method further includes the step of touching the tool tip to a calibration device capable of communicating with the surgical navigation system and capable of determining the position of the tool tip relative to the position of the tracking device. The method further includes the step of calculating the position of the tool tip and then calculating orientation data for the surgical tool from the known relation between the tracking device and the tool axis. Lastly, the method includes the step of storing the position of the tool tip and the orientation data for the surgical tool within memory of the surgical navigation system so that when the surgical tool is used with the surgical navigation system, the position and the orientation of the surgical tool can be tracked by the surgical navigation system.
A further method of the present invention for calibrating the position and the orientation of the surgical tool for use with the surgical navigation system comprises the following steps. The first step is attaching a tracking device capable of communicating with the surgical navigation system to the surgical tool using an adapter wherein the surgical tool has a tool axis and a tool tip and the adapter has a known relation between the tracking device and the tool axis. The second step in the method is touching the tool tip to a calibration device capable of communicating with the surgical navigation system and capable of determining a position of the tip of the surgical tool relative to a position of the tracking device. The method further includes the step of calculating the position of tool tip and the step of storing the position of the tool tip within memory of the surgical navigation system. Lastly, the method includes the step of determining orientation data for the surgical tool from the position of the tool tip and from a database of stored relations of the tracking device to the tool axis and from the position of the tool tip such that the position of the tool tip intersects an axis of the surgical tool from the database so that when the surgical tool is used with the surgical navigation system, the position and orientation of the surgical tool can be tracked by the surgical navigation system.
The present invention also is directed to an adapter to attach a tracking device to a surgical tool having axis, which comprises a body having an exterior surface, and an interior surface. The adapter also includes a docking structure for the tracking device attached to the exterior surface. Lastly, the adapter includes the interior surface that defines an opening extending through the body, the opening having an axis and the opening having a shape to engage the surgical tool such that there is identity between the axis of the opening and the tool axis.
The present invention further includes a system for the calibration of a surgical tool for use with a surgical navigation system. The system comprises a memory unit, an adapter that can be attached to a surgical tool having a tool tip and a tool axis, and a tracking device attached to the adapter, the tracking device capable of being tracked by the surgical navigation system, wherein the adapter has a known relation between the tracking device and the tool axis. The system further includes a calibration device capable of determining the position of the tool tip relative to the position of the tracking device and capable of communicating with the surgical navigation system. The system also includes a first circuit operative to calculate the position of the tool tip relative to a position of the tracking device and an orientation of the surgical tool from the known relation between the tracking device and the tool axis and from the position of the tool tip, and a second circuit operative to store the position of the tool tip and the orientation of the tool in the memory unit.
A further system of the present invention for calibrating a position and an orientation of a surgical tool for use with a surgical navigation system comprises means for attaching a tracking device capable of communication with the surgical navigation system to the surgical tool using an adapter, the surgical tool having a tool axis and a tool tip, and the adapter having a known relation between the tracking device and the tool axis. The system also includes means for calculating a position of the tool tip by touching the tool tip to a calibration device capable of communication with the surgical navigation system and capable of determining the position of the tool tip relative to a position of the tracking device and means for calculating orientation data for the surgical tool from the known relation between the tracking device and the tool axis and from the position of the tool tip. In addition, the system includes means for storing the position of the tool tip for the surgical tool and the orientation data for the surgical tool within memory of the surgical navigation system so that when the surgical tool is used with the surgical navigation system, the position and the orientation of the surgical tool can be tracked by the surgical navigation system.
A still further system of the present invention for calibrating a surgical tool for use with a surgical navigation system comprises a memory unit and means for attaching an adapter to a surgical tool having a tool tip and a tool axis. The system also includes means for tracking the surgical tool attached to the adapter, the tracking means capable of being tracked by the surgical navigation system, wherein the adapter has a known relation between the tracking device and the tool axis and means for calibrating capable of determining a position of the tool tip relative to the position of the tracking means and capable of communicating with the surgical navigation system. The system further includes means for calculating the position of the tool tip; and an orientation of the surgical tool from the known relation between the tracking device and the tool axis and from the position of the tool tip, and means for storing the position of the tool tip and the orientation of the surgical tool in the memory unit.
Another system of the present invention for calibrating a position and an orientation of a surgical tool for use with a surgical navigation system comprises means for attaching a tracking device capable of communication with the surgical navigation system to the surgical tool using an adapter, the surgical tool having a tool axis and a tool tip, and the adapter having a known relation between the tracking device and the tool axis. The system also includes means for calculating a position of the tool tip by touching the tool tip to a calibration device capable of communicating with the surgical navigation system and capable of determining the position of the tool tip relative to a position of the tracking device, and means for storing the position of tool tip within memory of the surgical navigation system. In addition the system has means for determining orientation data for the surgical tool from the position of the tool tip and from a database of stored relations of the tracking device to the tool axis and from the position of the tool tip, such that the position of the tool tip intersects an axis of the surgical tool from the database, so that when the surgical tool is used with the surgical navigation system the position and the orientation of the surgical tool can be tracked by the surgical navigation system.
Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
With reference to
Multiple docking pins 114 are mounted on docking pin bridge 104. In the embodiment as shown in
The opening 112 passes completely through the body 102 and is formed such that when a surgical tool 52 is placed through the opening 112, a tool axis 120 of the surgical tool 52 will be identical to the axis 110 of opening 112. This identity ofthe axis 110 and the tool axis 120 is an important aspect of the adapter 56. It enables the adapter 56 to be used with the reference tracking device 78 to calibrate not only the position of a tool tip 126 of surgical tool 52 but also calibrate the tool axis 120 such that surgical navigation system 50 can track both the position and the orientation of the surgical tool 52. The opening 112 and its axis 110 can be off set from the center of the body 102 if the surgical tool 52 is to be nonrotably held by the adapter 56.
Once the adapter 56 is placed on the surgical tool 52, it is important that the position of the adapter 56 relative to the tool tip 126 and the tool axis 120 remain undisturbed. While it is possible that the adapter 56 may be configured to rotate in place about the tool axis 120, so long as the distance from the tool tip 126 to the location of the universal tracking device 54 remains unchanged and so as long as the relation between the universal tracking device 54 and the tool axis 120 of the tool remains unchained, the position and orientation of the surgical tool 52 can be calibrated and tracked by the surgical navigation system 50.
In order to maintain the adapter 56 in a fixed location relative to the tool tip 126, spring-loaded balls 122 are provided within the interior of opening 112 and the interior surface 108 of body 102. These balls 122 are biased outwardly by springs 124 and cooperate to firmly engage the surgical tool 52 so that the relationship between the adapter 56 and the surgical tool 52 is maintained. For instance, the surgical tool 52 may have a small channel (not shown) within which balls 122 rest thereby holding the adapter 56 in a fixed relation with regard to the tool tip 126. Other means of firmly attaching the adapter 56 to the surgical tool 52 can also be used.
As shown in
As shown in
Turning now to
In addition, the universal tracking device 54 also includes a calibration point 200. The calibration point 200 is in a known relation to LED's 84 and has a center point that is easily identified so that the universal tracking device 54 can be used also as a reference tracking device 78, as shown in
As shown in
The tool tip position from the calculation block 305 is then stored and the stored tool tip position is passed to a calculation block 306 that calculates the orientation data for the surgical tool 156. In addition to the tool tip position from the block 305, surgical navigation system 50 has the database 96 of possible axes for the opening 152 relative to location of the universal tracking device 54 stored in memory 58b in the database 96. The database 96 is shown as a data block 306 and contains data previously stored in memory 58b relative to the relative position of the universal tracking device 54 relative to the possible axes of the opening for various adapters, such as axis 110 or axis 168. Since the adapter 56 and the adapter 150 can have a number of different docking pins 114, each of these docking pins is in a different position and orientation relative to the axis 110 and axis 168, respectively. The relative position of the universal tracking device 54 to either the axis 110 or the axis 168 for each docking pin 114 can be calculated by methods well known in the art. The result of this calculation for the location each docking pin 114 for each possible adapter that can be used with the surgical navigation system 50 is stored in the database 96 which has been previously loaded into in the memory of computer 58b on initialization of the program.
As there can be number of different adapter configurations, the distance from the universal tracking device 54 to the axis of each particular adapter will vary. Each type of adapter can be encoded with a specific identifier that can be entered into the surgical navigation system 50. This can be done manually using the keyboard 66 or the mouse 64 to indicate which adapter is being used or automatically using a smart adapter 500 as shown in
Once the surgical navigation system 50 knows the identity of the particular adapter, the database 96 is queried for the potential axis for the particular adapter being used, such as the adapter 150, and the subset of the data is placed in memory as indicated by the data block 306 along with the tool tip position from the block 305. The subset of data stored in the data block 306 from database 96 is then used to calculate the orientation data. The program proceeds to a block 307, which calculates the orientation data by comparing the tool tip position with the data subset that has been taken from database 96 stored in the data block 306 for that particular adapter. If the tool tip position is located along any of the potential axes from the data block 306 and if the deviation of the tool tip position from the chosen potential axis is within acceptable limits, then the program branches, as shown in a block 308, to the validation process. If the position of the tool tip is not on one of the axes within acceptable limits, the program branches to block 309 that displays an error message as shown in
At the beginning of the validation process, a block 310 displays a message as shown in
If the calibration is concluded, the block 406 stores the tool tip position in memory, the program precedes to a block 407 that displays the validation message that is similar to that shown in
A block 412 determines axis calibration by taking the stored validated tool tip position from the block 410 and determining whether or not this tool tip position lies on any of the available axes stored in a block 413 from the axis database. The axis database is similar to that described relative to
Turning now to
The present invention is useful to quickly and easily calibrate both the position and orientation of a particular surgical tool without the need for complicated calibration devices that must be separately sterilized to be used within a surgical environment.
Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.
Claims
1.-20. (canceled)
21. A system for calibrating a surgical tool for use with a surgical navigation system comprising:
- a memory unit;
- an adapter that can be attached to a surgical tool having a tool tip and a tool axis;
- a tracking device attached to the adapter, the tracking device capable of being tracked by the surgical navigation system, wherein the adapter has a known relation between the tracking device and the tool axis;
- a calibration device capable of determining a position of the tool tip relative to the position of the tracking device and capable of communicating with the surgical navigation system;
- a first circuit operative to calculate the position of the tool tip; and an orientation of the surgical tool from the known relation between the tracking device and the tool axis and from the position of the tool tip, and
- a second circuit operative to store the position of the tool tip and the orientation of the surgical tool in the memory unit.
22. The system of claim 21 wherein the tracking device is attached to the adapter by a docking structure.
23. The system of claim 22 wherein the docking structure locks the tracking device into a specified position with respect to the adapter.
24. The system of claim 21 wherein the adapter is a body having an interior surface and an exterior surface.
25. The system of claim 24 wherein the interior surface defines an opening that has an axis and wherein the interior surface has a shape to engage the surgical tool, wherein the tool axis of the surgical tool inserted within the opening and the axis of the opening are identical.
26. The system of claim 21 wherein the tracking device is an optical tracking device.
27. The system of claim 26 wherein the optical tracking device includes infrared LED's.
28. The system of claim 21 wherein the system further includes a database of known relations of the tracking device to the tool axis and the first circuit calculates the orientation of the surgical tool from the database of known relations of the tracking device to the tool axis and from the position of the tool tip.
29-38. (canceled)
39. A system for calibrating a position and an orientation of a surgical tool for use with a surgical navigation system comprising:
- means for attaching a tracking device capable of communication with the surgical navigation system to the surgical tool using an adapter, the surgical tool having a tool axis and a tool tip, and the adapter having a known relation between the tracking device and the tool axis;
- means for calculating a position of the tool tip by touching the tool tip to a calibration device capable of communication with the surgical navigation system and capable of determining the position of the tool tip relative to a position of the tracking device;
- means for calculating orientation data for the surgical tool from the known relation between the tracking device and the tool axis and from the position of the tool tip; and
- means for storing the position of the tool tip for the surgical tool and the orientation data for the surgical tool within memory of the surgical navigation system so that when the surgical tool is used with the surgical navigation system, the position and the orientation of the surgical tool can be tracked by the surgical navigation system.
40. The system of claim 39 wherein the tracking device is attached to the adapter by a means for docking.
41. The system of claim 40 wherein the means for docking locks the tracking device into a specified position with respect to the adapter.
42. The system of claim 39 wherein the adapter is a body having an interior surface and an exterior surface.
43. The system of claim 42 wherein the interior surface defines an opening that has an axis and wherein the interior surface has a shape to engage the surgical tool, wherein the tool axis of the surgical tool inserted within the opening and the axis of the opening are identical.
44. The system of claim 39 wherein the tracking device is an optical tracking device.
45. The system of claim 44 wherein the optical tracking device includes infrared LED's.
46. The system of claim 39 wherein the system further includes a database of known relations of the tracking device to the tool axis and the first circuit calculates the orientation of the surgical tool from the database of known relations of the tracking device to the tool axis and from the position of the tool tip.
47. A system for calibrating a surgical tool for use with a surgical navigation system comprising:
- a memory unit;
- means for attaching an adapter to a surgical tool having a tool tip and a tool axis;
- means for tracking the surgical tool attached to the adapter, the tracking means capable of being tracked by the surgical navigation system, wherein the adapter has a known relation between the tracking device and the tool axis;
- means for calibrating capable of determining a position of the tool tip relative to the position of the tracking means and capable of communicating with the surgical navigation system;
- means for calculating the position of the tool tip; and an orientation of the surgical tool from the known relation between the tracking device and the tool axis and from the position of the tool tip, and
- means for storing the position of the tool tip and the orientation of the surgical tool in the memory unit.
48. The system of claim 47 wherein the tracking means is attached to the adapter by a means for docking.
49. The system of claim 48 wherein the docking means locks the tracking device into a specified position with respect to the adapter.
50. The system of claim 49 wherein the adapter is a body having an interior surface and an exterior surface.
51. The system of claim 50 wherein the interior surface defines an opening that has an axis and wherein the interior surface has a shape to engage the surgical tool, wherein the tool axis of the surgical tool inserted within the opening and the axis of the opening are identical.
52. The system of claim 47 wherein the tracking means is an optical tracking device.
53. The system of claim 52 wherein the optical tracking device includes infrared LED's.
54. The system of claim 47 wherein the system further includes a database of known relations of the tracking device to the tool axis and the first circuit calculates the orientation of the surgical tool from the database of known relations of the tracking device to the tool axis and from the position of the tool tip.
55. A system for calibrating a position and an orientation of a surgical tool for use with a surgical navigation system comprising:
- means for attaching a tracking device capable of communication with the surgical navigation system to the surgical tool using an adapter, the surgical tool having a tool axis and a tool tip, and the adapter having a known relation between the tracking device and the tool axis;
- means for calculating a position of the tool tip by touching the tool tip to a calibration device capable of communicating with the surgical navigation system and capable of determining the position of the tool tip relative to a position of the tracking device;
- means for storing the position of tool tip within memory of the surgical navigation system; and
- means for determining orientation data for the surgical tool from the position of the tool tip and from a database of stored relations of the tracking device to the tool axis and from the position of the tool tip, such that the position of the tool tip intersects an axis of the surgical tool from the database, so that when the surgical tool is used with the surgical navigation system the position and the orientation of the surgical tool can be tracked by the surgical navigation system.
56. The system of claim 55 wherein the tracking device is attached to the adapter by a means for docking.
57. The system of claim 56 wherein the means for docking locks the tracking device into a specified position with respect to the adapter.
58. The system of claim 55 wherein the adapter is a body having an interior surface and an exterior surface.
59. The system of claim 58 wherein the interior surface defines an opening that has an axis and wherein the interior surface has a shape to engage the surgical tool, wherein the tool axis of the surgical tool inserted within the opening and the axis of the opening are identical.
60. The system of claim 55 wherein the tracking device is an optical tracking device.
61. The system of claim 60 wherein the optical tracking device includes infrared LED's.
62. The system of claim 55 wherein the system further includes a database of known relations of the tracking device to the tool axis and the first circuit calculates the orientation of the surgical tool from the database of known relations of the tracking device to the tool axis and from the position of the tool tip.
Type: Application
Filed: Dec 28, 2006
Publication Date: Jul 26, 2007
Applicant:
Inventors: Jose Luis Moctezuma De La Barrera (Freiburg), Amir Sarvestini (Freiburg)
Application Number: 11/646,960
International Classification: A61B 17/00 (20060101);