System and method for positioning a tracking device

Disclosed is a system and method for tracking an instrument. The instrument may be tracked with one or more trackable members. The trackable members may be held relative to a handle to which the instrument is attached.

FIELD

The present disclosure relates to a device holder, and particularly to a holder to position a trackable member.

BACKGROUND

In a selected procedure an instrument may be moved relative to a subject. The subject may include an external cover or shell portion and internal members or portions. The instrument may be operated to perform a procedure on the internal components while only minimally disturbing the outer shell.

In performing a procedure, therefore, an instrument may be tracked with a tracking system. The tracked position of the instrument may be displayed on a display device for viewing a determined position of the instrument. The user may view the display device to determine or understand the position of the instrument relative to the subject. It may be selected, to track more than one instrument during a selected procedure.

SUMMARY

According to various embodiments, a system for tracking an instrument is disclosed. The system includes a plurality of trackable members and a tracking member holder. The tracking member holder includes a chassis portion, an instrument guiding portion having an internal wall defining an instrument passage, a trackable member engagement portion configured to hold at least one trackable member of the plurality of trackable members relative to the chassis portion, and a handle engageable portion configured to hold the chassis portion relative to a handle.

A system for tracking an instrument is disclosed, according to various embodiments. The system includes a tracking member holder, including (i) a chassis portion, (ii) a trackable member engagement portion, and (iii) a handle engaging portion. The system may further include an instrument handle. In various embodiments, an instrument may also be configured to be held relative to the instrument handle and moved with the instrument handle.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings. Although the following is disclosed regarding an exemplary surgical procedure on a human subject, it is understood that the subject disclosure and the following claims may be directed for non-human surgical procedures and non-surgical procedure.

With initial reference toFIGS. 1, 2 and 3, a holder10is illustrated. The holder10may alone, or in combination with trackable members, form a tracking device that is trackable, as discussed herein. The holder10may also be referred to as a tracking device holding assembly, a tracking device holder, a tracking member holder, trackable member holder, or guide assembly. The holder10may allow the use of a driver or handle54with multiple instruments, as discussed herein, with only one or a single registration or calibration.

The holder10may include a body or chassis portion14. The body14may include various features or sections. The sections may include a motor or handle assembly engaging region16that may be generally annular or selectively shaped to engage a driver or handle. An extension or open region or member20may extend from the handle assembly engaging region16. The extension region may be generally U-shaped. A guide or passage portion24may extend from the extension region20. The guide portion24may include a central bore of cannula24′ that may allow passage of an instrument, as discussed herein. The guide portion24may have buttresses25on one or more sides extending from the extension region20to assist in supporting the guide24.

The holder10may be formed as one piece (i.e. a single and/or unitary piece) or plurality of pieces. As discussed herein, the holder10may be selected to be formed of a rigid material. The rigid material may have a selected rigidity such that the holder10does not vary in shape or dimension during use. For example, the holder10maintains an initial shape during use of the holder10to hold tracking members30during use of an instrument52(FIG. 4).

In various embodiments, the holder10may be molded as a single piece of polyethylene, such as ultra-high molecular weight polyethylene, such as that used for bearing members. The material of the holder10may be a selected bearing material and/or a bearing material (e.g. a metal sleeve) may be provided in the bore24′. The holder10may also be formed of more than one material and/or members that are fixed together. The holder10may be formed entirely or partially of metal, metal alloys, polymers, filled polymers (e.g. glass filled nylon), or other appropriate materials.

The material selected for the holder10may further include additional properties. For example, the holder10may have a selected anti-slip or gripping property. The holder10may also be selectively reusable and sterilizable (e.g. with gas sterilization, radiation sterilization, etc.). Also, or alternatively, the holder10may be disposable and only single use.

The holder10may further include one or more positions, such as posts or projections28, for holding the tracking devices or trackable members30. For example, the tracking member30may include a recess or depression that engages (e.g. frictionally engages) the projection or post28that extends from a wing or portion29of the holder10. The wing may extend from an arm or portion of the extension portion24. In various embodiments, the trackable members30may snap to the posts28. The tracking member30, therefore, may be removably fixed to the holder10. The tracking member30may include one or more tracking members, such as a first trackable member30a, a second track trackable member30b, a third trackable member30c, and a fourth trackable member30d(referred to herein collectively of tracking or trackable members or devices30, unless specifically referred to individually). It is understood that more or less than four of the trackable members30may be provided with the holder10. Further, the trackable members30may be formed as one piece with the chassis14.

With additional reference toFIG. 4, the tracking members30may be any appropriate tracking members that may be tracked by a tracking system34. The tracking devices30may be tracked by the tracking system34, which may be incorporated or included with a navigation system36. In tracking the holder10with the tracking members30, a position (including a three dimension location and orientation (e.g. 1 or more degree of freedom, e.g. six degrees of freedom)) of the holder10an item to which it is attached may be determined.

In various embodiments, the tracking devices30may include members that are viewable by one or more cameras of the optical or camera localizer38. In various embodiments, therefore, the tracking system32may be an optical or light tracking system. In an optical tracking system the tracking members30may reflect (e.g. passive) or emit (e.g. active or LEDs) wavelengths of light that are visible or invisible (e.g. infrared wavelengths) that are detected by the cameras38a,38b. The tracking devices30may also or alternatively include one or more coils that may be trackable with an electromagnetic (EM) tracking system localizer. The EM localizer may include one or more coils or antennas42of a tracking coil array46that may generate a field in a navigation volume48.

Regardless of the specific configuration or type, the tracking devices30may be positioned on the holder10to assist in tracking an instrument or tool52, as illustrated inFIG. 3. Generally, the instrument52is able to rotate. For example, the driver54may include a motor that rotates the instrument52or the handle54is able to be used by the user56to rotate the instrument52. The holder10, however, generally holds the trackable members30at a selected single position relative to the handle54during use and for tracking.

In various embodiments, the holder10, including the trackable members30, may be referred to as a tracking device. The instrument52may be assembled or connected to a handle or drive assembly54. The handle, as a drive assembly,54may include a motor for rotating the instrument52. The motor in the handle54may be any appropriate motor such as pneumatic motor, an electrical motor, or the like. Generally, a user56may hold a selected portion of the handle54, such as a grasping handle58. If the handle54is powered, the user56may depress or engage one or more control mechanisms, such as a button60, to cause the motor included within the driver54to move a chuck assembly64, such as rotating the chuck assembly64that is generally within the extension region20. Rotating the chuck assembly64may rotate the instrument52.

In various embodiments, the instrument52may include an elongated shaft66and a working end68. The working end68may be any appropriate working end such as a tap, a screw, an awl, or any appropriate working end. Further, the working end68may include a distal or terminal end or portion68a. Regardless, the user56may engage the driver54to cause the working end68to engage a selected portion, such as a portion of a patient70.

The instrument52, as discussed above, can be any appropriate instrument. In various embodiments, the instrument52may include the working end68to include a tap, such as a tap to form a thread in a bore in a bone. Further, the working end68may include a terminal or distal end68a. The position of the working end68may be selected to be precisely known and/or determined. Thus, the tap at the working end68may be selected to be precisely and/or knowingly positioned relative to the patient70. For example, for forming and tapping a bore at a precise and/or preselected position for a bone screw. Further, an instrument52′ may include a screw at the working end68′. It is understood, however, that any appropriate number of instruments may be provided with different or the same working end.

In various embodiments, the selected position of the instrument52may be selected to be substantially precise, such as for positioning a pedicle screw, implant, deep brain simulation probe, or the like. Accordingly, a determined position of the instrument52with the tracking system32may assist in navigation of the instrument52with the navigation system34. As discussed further herein, the position of the instrument52may be determined with the tracking system32and illustrated on a display device72, such as with an icon52i. The icon52imay illustrate the position of the instrument52relative to the patient70represented by an image74. The image74may also be displayed on the display device72and the icon52imay be superimposed thereon. The user56may, therefore, view the display device72to determine or view a representation of the instrument52relative to the patient70by viewing the icon52irelative to the image74.

The instrument52, which may be a first instrument, may be substituted or changed to a different instrument, such as an instrument52′, also referred to as a second instrument52′. The instrument52′ may include a working end68′ that may be different than the working end68, and may include a screw which may be placed in the bore tapped with the tap68. In various embodiments, the working end68may include a tap which is formed and configured to tap a portion of the patient70, such as a vertebra, and the screw68′ may be positioned in the tapped opening or bore. During a selected procedure, the instrument52, including the shaft66, may be removed from the handle54including the chuck64. A shaft66′ of the instrument52′ may then be positioned within the chuck64for driving the screw68′ into the subject or patient70.

The holder10may remain fixed to the handle54, with the connections as discussed herein, while the instrument52and/or52′ is positioned or repositioned (e.g. passed through the holder10) to the handle54. For example, in various embodiments, the shaft66of the instrument52may be first connected to the handle54. At a selected time, such as after using the instrument52(e.g. to tap a bore), the shaft66may be withdrawn or removed through the extension or guide portion24of the holder10while the holder10remained attached to the handle54. Once the instrument52is removed, and the shaft66′ of the instrument52′ may be passed through the guide or shaft holder24into the chuck64in a reverse manner. While the instrument52is removed from the tool54and the instrument52′ engaged therewith, the tracking device holder10may be maintained on the tool54. Accordingly, the instrument52need be the only portion or member removed from the tool54and the instrument52′ positioned into the tool54without moving or changing the tracking device holder10. This can reduce the time of a procedure by, for example, eliminating calibration or recalibration of the holder10with the trackable members relative to the handle54after changing an instrument relative to the handle54.

To assist in holding or to maintain fixation of the holder10to the handle54, in various embodiments, the holder10may include a tool or handle engagement mechanism at the tool engagement portion16. For example, a friction engagement or holding member80is positioned within a receiving groove or portion82of the tracking device holder10. The friction member80may include an O-ring formed of a selected material, such as a butyl rubber or other synthetic or natural rubber material. The ring80may extend or project from the groove82and engage an external surface or a portion of the tool54. The engagement of the holding member80with the tool54, such as the friction engagement, may not be overcome by movement of the instrument52,52′ through the guide portion24.

The tracking device holder10may be positioned at selected and fixed positions relative to the tool54through engagement of one or more indents90formed as depressions or passages in an end wall92and having an internal wall94. The internal wall94of the indent or groove90may engage a holding pin98that extends from the tool54. The holder10may then be positioned at a selected rotational position around an axis100extending through the tool54. As illustrated inFIG. 1, the tracking device holder10may include six indents or positions90at the tool engaging portion16. It is understood that more or fewer indents or positional members may be provided with the tracking device holder10. Regardless, the holder10may be oriented such that when pressed on the handle54the pin98will be received within the indent90to rotational fix the holder10relative to the handle54. It is understood, however, that the handle54may include one or more depressions that receives a pin or projection of the holder10.

The tracking members30may be placed generally on a plane102or on a selected side of the plane102. The plane102may be defined by at least a portion of the holder10. Thus, the holder10may rotate to rotate the plane around the axis100and be held in the selected position relative to the handle54. The plane102, therefore, may be positioned in a selected, e.g. optimal view or line of sight of the localizer38.

The engagement feature or mechanism80may include alternative and/or additional engagement features. For example, the tool engagement portion16may include an internal thread that engages an external thread defined or formed by the tool54. The holder10may then be threaded onto the tool54. Further, or alternatively thereto, a quick connect mechanism may be provided to engage the tracking device holder10with the tool54. For example, a holding member or ball may be retracted into the tool54when engaged by the tracking device holder10and then rebound or be biased into the holding portion or groove82in the tracking device holder10when the tracking device holder10is positioned at a selected position relative to the tool54. Accordingly, it is understood, that the tracking device holder10may be held relative to the tool54in any appropriate manner. Further, the tracking device holder10may be positioned at a selected rotational position relative to the tool54and held at the selected position.

As discussed further herein tracking the tool54and/or the instrument52,52′ may require that the tracking devices30be positioned at a fixed and known position relative to the tool54and/or the instrument52,52′. Accordingly, the tracking device holder10may hold the tracking devices30at a fixed and selected position relative to the tool54during a procedure. Prior to tracking the instrument52,52′ (e.g. during a procedure), the tracking devices30may be calibrated or registered relative to a portion of the instrument52(e.g. the working end68and/or the terminal end68a) and/or the tool54. In various embodiments, calibration may occur with a fiducial or fixed/known point registration procedure as is generally understood in the art.

For example, calibration may occur by tracking the holder10, including the tracking devices30, positioned on the tool54. With or without the instrument52,52′ positioned within the tool54, the positions of the tracking devices30relative to the tool54may be determined. For example, the holder10may engage a selected feature, such as a divot, at a known position relative to the localizer38. The navigation system34may then determine the position of the tracking devices30relative to the tool54. The instrument52,52′ may then be engaged with the tool54and the navigation system34may recall from a navigation memory110a geometry of the instrument52,52′. The navigation system34may then, knowing the geometry of the instrument52,52′ and the position of the tracking devices30relative to the tool54, determine the position of the working end68,68′ based upon the known geometry of the respective tools52,52′. It is further understood that the user56may enter a geometry of the instruments52,52′ rather than having them recalled from the navigation memory110.

Regardless, the tracking device holder10is used to fixedly hold the tracking devices30relative to the tool54and/or the instrument52,52′. Thus, the user56need not directly engage the holder10. Further, the geometry of the tracking device holder10allows for the instrument52to be engaged and disengaged from the tool54and the instrument52′ to be engaged and disengaged from the tool54without removing the tracking device holder10or moving the tracking device holder10relative to the tool54. Therefore, once the tracking device holder10and the tracking devices30positioned therewith are registered or calibrated relative to the tool54the instrument may be changed relative to the tool54without requiring recalibration of the position of the tracking devices relative to the tool and/or with the respective instruments52,52′.

The selected instrument52,52′ (or other appropriate instrument), therefore, may be used to perform a procedure on the subject70. In various embodiments, with reference toFIG. 4, therefore, the tracking device holder10is used by the user56to position and/or navigate the instrument52relative to the subject70. For example, the instrument may include a tap at the working end68to tap (e.g. form threads in a bore) in a selected portion of the subject70including a vertebrae120. The image74may include an image of the vertebrae120as a vertebrae image124. The icon52imay be illustrated on the display device72relative to the image124.

The navigation system34may be used for various purposes or procedures by one or more users, such as the user56. The navigation system56may be used to determine or track a position of the instrument52in a volume, such as the navigation or tracking volume48. Tracking the position of the instrument52may assist the user56in determining a position of the instrument162even if the instrument52is not directly viewable by the user56. Various procedures may block the view of the user56, such as performing a repair or assembling an inanimate system, such as a robotic system, assembling portions of an airframe or an automobile, or the like. Various other procedures may include a surgical procedure, such as performing a spinal procedure, neurological procedure, positioning a deep brain simulation probe, or other surgical procedures on a living subject. In various embodiments, for example, the living subject may be a human subject70and the procedure may be performed on the human subject70. It is understood, however, that the instrument52may be tracked and/or navigated relative to any subject for any appropriate procedure.

Nevertheless, in various embodiments, the surgical navigation system34, as discussed further herein, may incorporate various portions such as those disclosed in U.S. Pat. Nos. RE44,305; 7,697,972; 8,644,907; and 8,842,893; and U.S. Pat. App. Pub. Nos. 2004/0199072, all incorporated herein by reference. Various components that may be used with or as a component of the surgical navigation system34may include an imaging system130that is operable to image the subject70, such as an O-Arm® imaging system, magnetic resonance imaging (MRI) system, computed tomography system, etc. A subject support132may be used to support or hold the subject70during imaging and/or during a procedure. The same or different supports may be used for different portions of a procedure.

Image data may be acquired during a surgical procedure or acquired prior to a surgical procedure for displaying the image74on the display device72. The instrument52may be tracked in the trackable volume or the navigational volume48that is defined by the tracking system, including the localizer38,40. The position of the instrument52may be tracked in the tracking volume relative to the subject70and then illustrated as the icon52iwith the display device72. In various embodiments, the icon52imay be superimposed on the image74and/or adjacent to the image74. As discussed herein, the navigation system34may incorporate the display device72and operate to render the image74from selected image data, display the image74, determine the position of the instrument52, determine the location of the icon52i, etc.

In various embodiments, the localizer46may be an electro-magnetic (EM) localizer that is operable to generate electro-magnetic fields with a transmitting coil array (TCA)42which is incorporated into the localizer46. The TCA42may include one or more coil groupings or arrays. In various embodiments, more than one group is included and each of the groupings may include three coils, also referred to as trios or triplets. The coils may be powered to generate or form an electro-magnetic field by driving current through the coils of the coil groupings. As the current is driven through the coils, the electro-magnetic fields generated will extend away from the coils42and form the navigation domain or volume48, such as encompassing all or a portion of the subject70, including spinal vertebrae120, or other appropriate portion. The coils may be powered through a TCA controller and/or power supply136.

The navigation domain or volume48may also be defined by a volume or area that is viewable by cameras of the localizer38. In various embodiments a selected number of cameras (e.g. two cameras38a,38b) may view the volume48. The volume viewable by the localizer38may include the navigation volume48. The position of the tracking device or trackable members30may be determined relative to a patient tracker140, that is also viewable, or relative to the localizer38(e.g. if the localizer38is fixed relative to the subject70).

The navigation domain or volume48generally defines a navigation space or patient space. As is generally understood in the art, the instrument52, such as discussed above, may include a drill, lead, etc., may be tracked in the navigation domain relative to a patient or subject70with the tracking assembly10including the trackable members30. For example, the instrument52may be freely moveable, such as by the user56, relative to the dynamic preference frame (DRF) or reference frame tracker140that is fixed relative to the subject70. Both the tracking devices10,140may include trackable members30and/or tracking or sensing coils (e.g. conductive material formed as a coil) that sense and are used to measure a magnetic field strength, etc. Due to the tracking device10connected or associated with the instrument52, relative to the DRF140, the navigation system30may be used to determine the position of the instrument52relative to the DRF140.

The navigation volume or patient space may be registered to an image space of the patient and the icon52irepresenting the instrument52may be illustrated at a known and tracked location with the display device, such as superimposed on the image74. Registration of the patient space to the image space and determining a location of a tracking device, such as with the tracking device10relative to the DRF140, may be performed as generally known in the art, including as disclosed in U.S. Pat. Nos. RE44,305; 7,697,972; 8,644,907; and 8,842,893; and U.S. Pat. App. Pub. Nos. 2004/0199072, all incorporated herein by reference.

The navigation system34may further include a navigation processor system146. The navigation processor system146may include the display device72, one or more of the localizers38,40, the TCA controller136, and other portions and/or connections thereto. For example, a wire connection may be provided between the TCA controller136and a navigation processing unit148. Further, the navigation processor system146may have one or more inputs, such as a keyboard150, and have and/or be in communication with one or more memory systems110, either integrated or via a communication system. The navigation processor system146may, according to various embodiments, include those disclosed in U.S. Pat. Nos. RE44,305; 7,697,972; 8,644,907; and 8,842,893; and U.S. Pat. App. Pub. Nos. 2004/0199072, all incorporated herein by reference, or may also include the commercially available StealthStation® or Fusion™ surgical navigation systems sold by Medtronic Navigation, Inc. having a place of business in Louisville, Co.

Tracking information, including regarding the viewed and/or triangulated position of the tracking devices10,140may be delivered via a communication system, such as the TCA controller, which also may be a tracking device controller136, to the navigation processor system146including the navigation processor148. Navigation processor148may be a part of the work station or computer system146that includes the display device72to display the image74. Various other memory and processing systems may also be provided with and/or in communication with the processor system148such as an imaging processing unit154. The image processing unit154may be incorporated into the imaging system130, such as the O-Arm® imaging system, as discussed above. The imaging system130may, therefore, include various portions such as a source and a x-ray detector that are moveable within a gantry160. The imaging system130may also be tracked with a tracking device166. It is understood, however, that the imaging system130need not be present while tracking the tracking devices, including the instrument tracking device10. Also, the imaging system130may be any appropriate imaging system including a MRI, CT, etc.

Information regarding all of the tracking devices may be communicated to the navigation processor148for determining a position of the tracked portions relative to each other and/or for localizing the instrument52relative to the image74. The imaging system130may be used to acquire image data to generate or produce the image74of the subject70. It is understood, however, that other appropriate imaging systems may also be used. The TCA controller136may be used to operate and power the TCA46and or the localizer38, as discussed above.

In various embodiments, therefore, and with continuing reference toFIGS. 1-4, the holder10, also referred to as the tracking device or assembly, may be tracked with the tracking system32, such as with the localizer38, to determine a position of the instrument52with the navigation system34. As discussed above, tracking may occur due to the tracking members30that are held by the holder10relative to the handle54. During a procedure, however, the instrument52and/or52′ may be removed and replaced with the other of the instrument52,52′ without removing the holder10. Thus, only the instrument52,52′; may be removed from the handle54. It is understood, however, that other additional instruments may also be positioned relative to the handle54after removing the exemplary disclosed instruments.

As discussed above, the holder10including the trackable members30may be a registered and/or calibrated relative to the handle54prior to tracking any instruments and/or performing a procedure on the subject70. In various embodiments, therefore, the holder10may be fitted to the handle54, as discussed above, and then calibrated or registered. The calibration may include predetermining (e.g. during a manufacture) a geometry of the holder10and/or the members30relative to the handle54and saving the predetermined geometry. The predetermined geometry may then be recalled, such as by the user56, once assembling the holder10to the handle54. The navigation processing unit148may recall from the navigation memory110the predetermined geometry and use the recalled predetermined geometry for calibration of the holder10relative to the handle54. The geometry of the instrument, such as the instrument52, can also then be calibrated and/or recalled from the navigation memory110to be able to track the position of the instrument52, including the working end68.

Alternatively, or in addition to a lookup table or recalling from memory, the tracking system32may be calibrated during use. For example, the holder10may be positioned or fit to the handle54in a selected manner, as discussed above. A portion of the holder10, once fitted to the handle54, may then be touched to a known or registerable portion, such as a divot formed by the DRF140. For example, a distal end of the holder or selected portion thereof, such as a projection10cmay engage a divot (e.g. shaped indent in the DRF140). Once the distal end, for example the projection10c, engages the divot of the DRF140the tracking system32may be operated to calibrate or determine a position of the projection10cin the navigation volume70. Therefore during a procedure the geometry or position of at least a portion of the holder10may be determined during a procedure. Then the instrument52fixed to the handle54may also be touched to the divot of the DRF140to know the distal end of the working end68relative to the end or projection10cof the holder10.

Upon removal of the instrument52and insertion of the instrument52′, the calibration of the holder10relative to the handle54need not be repeated, especially if and/or only if the holder10is not removed from the handle54during removal of the instrument52and/or insertion of the instrument52′. The instrument52may be removed through the holder10and the instrument52′ may be inserted into the handle54through the holder10.

Accordingly, the holder10, including the trackable members30, may be calibrated relative to the handle54at a single time and only one time, such as prior to a procedure or during a procedure. After the calibration, instruments may be removed and inserted, such as serially or sequentially, with the handle54without requiring recalibration of the holder10including the trackable members30. Thus, the user56may select different instruments and attach the different instruments at selected different times to the handle54without requiring recalibration of the holder and the trackable members30to continue tracking and navigation of the selected instrument52. Therefore the position (i.e. including a three dimensional location and selected degrees of freedom of orientation (three degrees of freedom)) may be made with the tracking system32to allow for navigation of the instrument52with the navigation system34.