Fixed camera device, system, and method for facilitating image-guided surgery

Abstract

Apparatus, system, and method for providing a rigid connection between a localization camera and a patient's head for image-guided surgery. The fixed camera head clamp includes a camera mount for rigidly securing the localization camera to the head clamp. In one embodiment, a proximal end of the camera mount is selectively secured to a receiving portion on a frame of the head clamp, and a distal end of the camera mount includes a camera receiver configured to receive the localization camera. The fixed camera head clamp system includes a head clamp and a localization camera. The camera mount system includes a camera mount secured to the patient's head and a localization camera secured to the camera receiver on the camera mount.

Description

Background Art

[0001] (Cross - reference to related applications) This application claims the benefit of priority of U.S. Application No. 17 / 132,268, filed on Dec. 23, 2020, which claims the benefit of priority of U.S. Provisional Patent Application No. 62 / 985,673, filed on Mar. 5, 2020, and both of them are incorporated herein by reference in their entirety.

[0002] (Background) In the field of image - guided cranial surgery, a localization camera in the operating room tracks the position of surgical instruments in three - dimensional space. This position information is transmitted from the localization camera to a computer. A computer monitor displays multi - sectional three - dimensional radiographic images of the patient's head and brain that are uploaded into the computer. The cranial anatomical structure of the patient positioned in the operating room is aligned with the radiographic image data using a probe tracked by the localization camera. In image - guided surgery, alignment is the process of transforming a three - dimensional radiographic data set (imaging space) such that it correlates with the three - dimensional coordinates of the corresponding patient's anatomical structure (surgical space). Following the alignment of the cranial anatomical structure, a navigation system can display the position of the tracked surgical instruments relative to the displayed radiographic anatomical structure. For this process to be accurate, the three - dimensional spatial relationship between the localization camera and the patient's head must be understood and maintained. If the localization camera moves during surgery, or if the patient's head moves, the accuracy of the navigation system deteriorates. To compensate for this problem, a tracked instrument grasped as a dynamic reference frame is fixed in relation to the patient's head. When the patient's head and the localization camera move relative to each other, their three - dimensional relationship is recalculated by the navigation system computer and the alignment solution is updated. Typically, the dynamic reference frame is fixed to a clamp that holds the patient's head in a stationary position for surgery.

[0003] The above measurements can play a role in maintaining the accuracy of image-guided cranial surgery, but they have limitations. To track a dynamic reference frame, a localization camera measures the spatial coordinates of markers on the reference frame along the x-axis, y-axis, and z-axis. The accuracy of these measurements varies as the viewing angle changes between the camera and the markers. To position the dynamic reference frame to accommodate items such as a microscope entering the surgical field, various instruments, and additional operating room personnel, it is common practice to move the camera to maintain its line of sight. Similarly, the patient's head is often repositioned during neurosurgery, which occurs when raising the head of the operating table, rotating the table, and raising or lowering the table. In these cases, when the camera moves relative to the markers on the dynamic reference frame, navigation errors are inadvertently induced.

[0004] Conventional head clamps include loose joints that allow the patient's head to move within the head clamp. When a localization camera is tracking a dynamic reference frame, the navigation system assumes that there is no movement of the head relative to the reference frame. However, in actual use, head movements as large as about 4 mm relative to the head clamp (and thus relative to the dynamic reference frame fixed to the head clamp) can exist. The errors caused by this relative movement are not detected by the navigation system and do not provide the optimal accuracy required in cranial surgery.

[0005] In addition, the head clamp is non-sterile and requires a sterile drape to maintain a sterile field during cranial surgery. In typical image-guided cranial surgery, the alignment process is performed prior to the application of the sterile drape because the drape needs to conceal portions of the patient's cranial anatomy that need to be visible and accessible during alignment. During this process, a non-sterile dynamic reference frame is used. Following alignment, the non-sterile dynamic reference frame is removed, the patient's head is prepared in a sterile manner, draped, and a sterile dynamic reference frame is attached to the head clamp through the drape. When the non-sterile dynamic reference frame is removed and replaced with a sterile one, errors are inadvertently introduced.

[0006] There remains a need for instruments and techniques that minimize or eliminate relative movement between a localization camera and a dynamic reference frame during image-guided cranial surgery. Further, there remains a need to minimize line-of-sight issues during these surgeries. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0007] (Summary) Devices, systems, and methods are provided that are designed to minimize relative movement between a localization camera and a patient's head during cranial surgery. An improved head clamp is provided that minimizes relative movement between the clamp and the patient's head. A small localization camera is provided that can be rigidly mounted to the improved head clamp such that relative movement between the clamp and the localization camera is eliminated, the need for a dynamic reference frame is eliminated, and line-of-sight issues are minimized during image-guided surgery. A camera mounting system is provided that is designed to be directly affixed to a patient's head. A method is provided for improving the accuracy of image-guided surgery by utilizing the improved head clamp and the rigidly mountable localization camera, as well as by using the camera mounting system. The present invention provides, for example, the following items. (Item 1) A head clamp for facilitating image-guided surgery, the head clamp comprising a camera mounting portion for firmly fixing a position-specifying camera to the head clamp. (Item 2) A base support portion, A frame fixed to an upper end portion of the base support portion, the frame including a first upper end portion and a second upper end portion, a receiving portion being disposed at the first upper end portion, the frame defining a central space sized to receive a patient's head, the frame; A first pin assembly fixed to the first upper end portion of the frame, A second pin assembly fixed to the second upper end portion of the frame The head clamp according to item 1, further comprising, wherein the camera mounting portion extends from a proximal end to a distal end, the proximal end of the camera mounting portion being selectively fixed to the receiving portion of the frame, the distal end of the camera mounting portion including a camera receiving portion configured to receive a position-specifying camera. (Item 3) The head clamp according to item 2, wherein the frame includes a fixed frame portion and a movable frame portion, and the movable frame portion is selectively movable relative to the fixed frame portion and the base support portion. (Item 4) The head clamp according to item 3, wherein the fixed frame portion extends from the base support portion to the first upper end portion, and the movable frame portion extends from the fixed frame portion to the second upper end portion. (Item 5) The head clamp according to item 4, wherein the first pin assembly includes two pins and the second pin assembly includes one pin. (Item 6) The head clamp according to item 5, wherein the first pin assembly further includes a rotary base and a rotary locking portion, the two pins of the first pin assembly being fixed to the rotary base so as to selectively rotate the two pins, and in an engaged position, the rotary locking portion prevents rotation of the rotary base. (Item 7) The head clamp according to item 4, wherein the proximal end of the camera mounting portion includes a receiving portion locking portion, the receiving portion locking portion engaging with the receiving portion of the frame and configured to prevent rotation of the camera mounting portion relative to the fixed frame portion of the frame. (Item 8) The receiving portion of the frame includes a series of protrusions and a series of receiving portion spaces disposed between the protrusions, the head clamp according to item 7. (Item 9) The receiving portion locking portion at the proximal end of the camera mounting portion includes one or more locking protrusions sized to fit into one or more of the receiving portion spaces, the head clamp according to item 8. (Item 10) The head clamp according to item 9 further includes a fastener including a bolt and a knob configured to secure the proximal end of the camera mounting portion to the receiving portion of the frame. (Item 11) The bolt of the fastener extends through a bore in the proximal end of the camera mounting portion and is configured to engage a bore in the receiving portion of the frame, the head clamp according to item 10. (Item 12) The camera receiving portion at the distal end of the camera mounting portion includes an upper surface having a plurality of ridges, the head clamp according to item 4. (Item 13) The camera receiving portion further includes a threaded bolt and a knob, the threaded bolt extending upwardly beyond the plurality of ridges, the head clamp according to item 12. (Item 14) The receiving portion of the frame is removably secured to the first upper end portion of the frame, the head clamp according to item 4. (Item 15) A fixed camera head clamp system for facilitating image-guided surgery, a base support portion, a frame secured to the upper end portion of the base support portion, the frame including a first upper end portion and a second upper end portion, a receiving portion being disposed at the first upper end portion, the frame defining a central space sized to receive a patient's head, the frame, a first pin assembly secured to the first upper end portion of the frame, a second pin assembly secured to the second upper end portion of the frame, a camera mounting portion extending from a proximal end to a distal end, the proximal end of the camera mounting portion being selectively secured to the receiving portion of the frame, the distal end of the camera mounting portion including a camera receiving portion, the camera mounting portion, a positioning camera selectively attached to the camera receiving portion A fixed camera head clamp system comprising. (Item 16) The fixed camera head clamp system according to item 15, further comprising a drape configured to cover the position - specifying camera while the position - specifying camera is attached to the camera receiving portion. (Item 17) The fixed camera head clamp system according to item 15, wherein the position - specifying camera has a field of view of at least approximately 120 degrees. (Item 18) The fixed camera head clamp system according to item 15, wherein the position - specifying camera has a field of view of approximately 1 cm to 75 cm. (Item 19) The fixed camera head clamp system according to item 15, wherein the position - specifying camera is positioned at approximately 15 cm or less from the first pin assembly when attached to the camera receiving portion. (Item 20) A method for immobilizing a patient's head to facilitate image - guided surgery, comprising: a) placing the patient's head within an immobilization device; b) attaching a position - specifying camera to the immobilization device. (Item 21) The method according to item 20, wherein the immobilization device comprises a head clamp including a camera - mounting portion, and step (b) further comprises attaching the position - specifying camera to the camera - mounting portion and firmly securing the position - specifying camera to the head clamp. (Item 22) The head clamp comprises a base support portion and a frame fixed to the upper end of the base support portion, the frame including a first upper end and a second upper end, a receiving portion being disposed at the first upper end, the frame defining a central space sized to receive the patient's head, a first pin assembly fixed to the first upper end of the frame, and a second pin assembly fixed to the second upper end of the frame. The camera - mounting portion extends from a proximal end to a distal end, the proximal end of the camera - mounting portion being selectively fixed to the receiving portion of the frame, and the distal end of the camera - mounting portion including a camera receiving portion. (Item 23) Step (a) comprises: ii) attaching the base support portion and the frame to the surgical table; iii) positioning the patient on the surgical table with the patient's head positioned within the central space of the frame. (iv) using the first pin assembly and the second pin assembly to clamp and fix the patient's head within the head clamp; (v) attaching the camera mounting portion to the frame by securing the proximal end of the camera mounting portion to the receiving portion of the frame The method according to item 22, further comprising. (Item 24) Step (b) is (vi) attaching the position - specifying camera to the camera receiving portion at the distal end of the camera mounting portion; (vii) positioning a drape over the position - specifying camera and the camera mounting portion The method according to item 23, further comprising. (Item 25) The frame includes a fixed frame portion and a movable frame portion, the movable frame portion is selectively movable relative to the fixed frame portion and the base support portion, and the method includes before the patient's head is positioned within the central space, sliding the movable frame portion away from the fixed frame portion to expand the central space; when the patient's head is positioned within the central space, sliding the movable frame portion toward the fixed frame portion to adjust the size of the central space The method according to item 24, further comprising. (Item 26) The proximal end of the camera mounting portion includes a receiving portion locking portion, and step (e) further includes engaging the receiving portion of the frame with the receiving portion locking portion at the proximal end of the camera mounting portion to prevent rotation of the camera mounting portion relative to the frame. The method according to item 24. (Item 27) A camera mounting system for facilitating image - guided surgery, comprising a camera mounting portion extending from a proximal end to a distal end, the proximal end of the camera mounting portion being configured for selective attachment to a patient's head, the distal end of the camera mounting portion including a camera receiving portion, a camera mounting portion; a position - specifying camera selectively attachable to the camera receiving portion A camera mounting system comprising. (Item 28) The proximal end of the camera mounting portion is selectively attachable to the patient's head through a pin assembly. The camera mounting system according to item 27. (Item 29) The pin assembly includes two or more pins for direct attachment to the patient's head. The camera mounting system according to item 28. (Item 30) The camera receiving part of the camera mounting part includes an upper surface having a plurality of ridges, and the camera mounting system according to item 27. (Item 31) A method of using a position-specifying camera to facilitate image-guided surgery, the method including fixing the position-specifying camera at a position fixed to the patient's head. (Item 32) a) attaching the proximal end of the camera mounting part to the patient's head; and b) attaching the position-specifying camera to the distal end of the camera mounting part The method according to item 31, further including. (Item 33) Step (b) further includes attaching the position-specifying camera to a camera receiving part at the distal end of the camera mounting part, the camera receiving part being configured to attach the position-specifying camera to the camera mounting part in two or more directions. The method according to item 32. (Item 34) The camera receiving part includes an upper surface having a plurality of ridges, and the method according to item 33.

Brief Description of the Drawings

[0008] (Brief Description of the Drawings)

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Mode for Carrying Out the Invention

[0018] (Detailed Description of the Preferred Embodiment) Devices, systems, and methods are disclosed herein for providing a rigid connection between a position - specific camera and a patient's head to facilitate image - guided surgery. A fixed - camera head clamp includes a camera - mounting portion rigidly connected to the head clamp. The camera - mounting portion includes a camera - receiving portion configured to rigidly secure a position - specific camera thereto, whereby the position - specific camera is in a fixed position in the vicinity of the patient's head. The position - specific camera may have a close viewing range, for example, from 1 cm to 75 cm, and a wide field of view, for example, at least 120 degrees. The joints of the fixed - camera head clamp provide a rigid connection to reduce movement or backlash when the patient's head or body is moved or when the head clamp is adjusted. The fixed - camera system eliminates the need to move the position - specific camera around the operating room. The fixed - camera system also eliminates the need for a dynamic reference frame. The fixed - camera head - clamp system also includes a drape configured to conform over the position - specific camera, whereby the camera does not need to be removed and replaced after the patient is aligned with the position - specific camera. Thus, the fixed - camera system minimizes errors in conventional systems by reducing relative movement between the camera and the patient, eliminating the dynamic reference frame, and improving the draping process. This results in an improved accuracy of the navigation system. The camera - mounting system includes a camera - mounting portion secured to the patient's head and a position - specific camera secured to a camera - receiving portion on the camera - mounting portion. The camera - mounting portion may be secured to the patient's head using a pin assembly. The camera - mounting system can be used to facilitate image - guided surgery in which the patient's head is movable. FIGS. 1 - 8 and 10 illustrate exemplary embodiments of the fixed - camera head clamp and system, and the camera - mounting system, and numerous alternative embodiments of these devices and systems will be apparent to those skilled in the art after reviewing the present disclosure.

[0019] Referring to FIG. 1, the fixed camera head clamp 10 includes a base support portion 12, a frame 14, and a camera mounting portion 16. The base support portion 12 is configured for connection to one or more support members that are directly or indirectly fixed to the surgical table on which the patient is positioned. The frame 14 may have any shape, such as a C-shaped, H-shaped, U-shaped, V-shaped, W-shaped, or any other shape, that provides a central space sized to receive the patient's head. In one embodiment, the frame 14 is U-shaped. The frame 14 may include a first upper end portion 18 on a fixed frame portion 20 and a second upper end portion 22 on a movable frame portion 24. The fixed frame portion 20 extends from the base support portion 12 to the first upper end portion 18. The fixed frame portion 20 is rigidly connected to the base support portion 12. The movable frame portion 24 extends from the fixed frame portion 20 to the second upper end portion 22. The position of the movable frame portion 24 is selectively adjustable relative to the fixed frame portion 20 and the base support portion 12. In one embodiment, the movable frame portion 24 slidably engages the fixed frame portion 20. In a further embodiment, the movable frame portion 24 may include steel bearings to allow for tight tolerances, eliminate vibration and backlash, and extend the life of the system. The frame 14 defines a central space 26 between the fixed frame portion 20 and the movable frame portion 24.

[0020] A first pin assembly 28 is fixed to the first upper end portion 18, and a second pin assembly 30 is fixed to the second upper end portion 22 of the frame 14. The second pin assembly 30 may include one or more pins that extend into the central space 26. For example, the second pin assembly 30 may include a single pin 32. The first pin assembly 28 may include one or more pins that extend into the central space 26. For example, the first pin assembly 28 may include two pins 34. The first pin assembly 28 and the pins 34 are separated from the second pin assembly 30 and the pin 32 by the central space 26.

[0021] The first pin assembly 28 may include a rotating base 36 and a rotary locking portion 38. The pin 34 may be fixed to the rotating base 36 so as to selectively rotate the pin 34. When in the engaged position, the rotary locking portion 38 may prevent the rotation of the rotating base 36, thereby locking the position of each pin 34. In one embodiment, the rotary locking portion 38 completely prevents the rotation of the rotating base 36 in the engaged position. In another embodiment, the rotary locking portion 38 prevents the rotation of the pin 34 with zero backlash.

[0022] Referring to FIGS. 1-3, the receiving portion 40 is positioned at the first upper end portion 18 of the frame 14. In one embodiment, the receiving portion 40 is removably fixed to the first upper end portion 18 using bolts 42, screws, or another connection mechanism. The bolt 42 extends through an opening 44 in the receiving portion 40 and engages a threaded inner surface in an opening 46 within the first upper end portion 18 to fix the receiving portion 40 to the first upper end portion 18. The bottom surface 48 of the receiving portion 40 may have a shape that is complementary to the shape of the upper surface of the first upper end portion 18. For example, the first upper end portion 18 may have a rounded upper surface, and the bottom surface 48 of the receiving portion 40 may have a complementary concave shape. In an alternative embodiment, the receiving portion 40 may be integrally formed with the first upper end portion 18 of the frame 14.

[0023] Referring now to FIG. 3, the upper surface of the receiving portion 40 may include a series of protrusions 50 separated by a series of receiving spaces 52. In other words, the receiving spaces 52 are disposed between the protrusions 50. In one embodiment, the protrusions 50 form a dovetail design to ensure that the camera mounting portion 16 is firmly connected to the fixed frame portion 20. The receiving portion 40 may further include a bore 54 having a threaded inner surface 56.

[0024] Referring now to FIGS. 1, 2, and 4, the camera mounting portion 16 extends from the proximal end 60 to the distal end 62. The proximal end 60 of the camera mounting portion 16 is selectively secured to the receiving portion 40. The proximal end 60 of the camera mounting portion 16 may include a receiving portion locking portion, which is configured to engage the receiving portion 40 and prevent rotation of the camera mounting portion 16 relative to the frame 14. In one embodiment, the receiving portion locking portion of the proximal end 60 of the camera mounting portion 16 may include one or more locking protrusions 66 configured to engage a receiving portion space 52 on the upper surface of the receiving portion 40. The configuration of the series of protrusions 50 on the receiving portion 40 may allow connection of the camera mounting portion 16 at a plurality of angles relative to the frame 14 by positioning the locking protrusions 66 within different receiving portion spaces 52. The proximal end 60 may further include a bore 68, which is configured to align with the bore 54 of the receiving portion 40 when the proximal end 60 engages the receiving portion 40 at all angles. The shape, length, and angle of the camera mounting portion may vary in other embodiments.

[0025] Referring to FIG. 2, the fastener 64 may include a bolt 70 and a knob 72. The knob 72 is configured to rotate the bolt 70. The bolt 70 of the fastener 64 extends through a bore 68 in the proximal end 60 of the camera mounting portion 16 and is configured to engage a threaded inner surface 56 of the bore 54 in the receiving portion 40. In this way, the fastener 64 may secure the proximal end 60 of the camera mounting portion 16 to the receiving portion 40 and prevent rotation of the camera mounting portion 16 relative to the fixed frame portion 20.

[0026] FIG. 5 illustrates the connection of the proximal end 60 of the camera mounting portion 16 to the receiving portion 40. Specifically, each of the locking protrusions 66 of the proximal end 60 is disposed, at least partially, within one of the receiving spaces 52 of the receiving portion space 52 on the upper surface of the receiving portion 40. The interaction between the locking protrusion 66 and the protrusion 50 adjacent to the receiving space 52 in which the locking protrusion 66 is disposed prevents rotation of the camera mounting portion 16 relative to the receiving portion 40, and thus prevents rotation of the camera mounting portion 16 relative to the frame 14. FIG. 5 also illustrates the bolt 70 of the fastener 64 disposed within the bore 54 of the receiving portion 40 to secure the proximal end 60 of the camera mounting portion 16 to the receiving portion 40.

[0027] Referring now to FIGS. 1, 2, and 6, the distal end 62 of the camera mounting portion 16 includes a camera receiving portion 80. The upper surface of the camera receiving portion 80 may include a plurality of ridges 82 configured to lock the camera in place. In one embodiment, the plurality of ridges 82 may be formed from a star pattern, such as a deep serrated star pattern. The plurality of ridges 82 may be disposed along an outer portion of the upper surface of the camera receiving portion 80. The camera receiving portion 80 may also include a threaded bolt 84 and a knob 86. The knob 86 is configured to rotate the threaded bolt 84. The threaded bolt 84 may extend upwardly from a central portion of the upper surface of the camera receiving portion 80. The threaded bolt 86 may extend upwardly beyond the plurality of ridges 82.

[0028] Referring now to FIG. 7, the fixed camera head clamp system 100 includes a head clamp 10 and a camera 102. The camera 102 may include a camera base 104. The camera base 104 may be fixed to the camera receiving portion 80 of the camera mounting portion 16 to fix the camera 102 to the camera mounting portion 16. In one embodiment, the plurality of ridges 82 of the camera receiving portion 80 have a shape that is complementary to the shape of the lower surface of the camera base 104. Alternatively, each of the camera base 104 and the camera receiving portion 80 may have any other complementary shape. For example, the lower surface of the camera base 104 may include one or more protrusions, and the upper surface of the camera receiving portion 80 may include one or more depressions configured to receive the protrusions of the camera base 104. Numerous other complementary arrangements for the camera base 104 and the camera receiving portion 80 will be readily apparent to those skilled in the art. Using the knob 86 (shown in FIG. 6), a threaded bolt 84 may be fixed within the bore of the camera 102, and the camera 102 may be fixed to the camera receiving portion 80 using the plurality of ridges 82, preventing rotation of the camera 102 relative to the camera receiving portion 80.

[0029] The camera 102 may be a positioning camera. In one embodiment, the camera 102 may have an integrated accelerometer and gravitometer. The camera 102 may have a wide field of view. For example, the camera 102 may have a field of view of at least approximately 120 degrees. The camera 102 may also have a close range. For example, the camera 102 may have a range of approximately 1 cm to 75 cm. In one embodiment, the camera 102 may be a Mini Optical 3D, USB camera sold by Intellijoint Surgical.

[0030] In one embodiment, the camera mounting portion 16 is formed from an I-shaped beam and may eliminate or reduce the deflection of the camera mounting portion 16 when the camera 102 is attached to the camera receiving portion 80. Since the camera 102 is rigidly fixed to the camera mounting portion 16, which in turn is rigidly fixed to the fixed frame portion 20, a reduced relative movement exists between the camera 102 and the patient's head positioned within the central space 26 between the pins 32 and 34. In some embodiments, the rigid connection of the fixed camera head clamp system 100 results in no relative movement between the camera 102 and the patient's head positioned within the central space 26.

[0031] Referring to FIG. 8, the fixed camera head clamp system 100 may further include a drape 108, which is configured to cover the camera 102 and the camera mounting portion 16 and provide a sterile field for the surgical procedure. The system 100 may also include a clip 110 configured to provide a smooth and secure fit of the drape 108 over the lens of the camera 102. After positioning the drape 108 over the camera 102, the clip 110 may be secured over the drape 108 at the front end of the camera 102 to hold the drape 108 flat over the lens of the camera 102. The clip 110 may be autoclavable. The camera 102 may be positioned 15 cm or less from the patient's head 112.

[0032] Referring now to FIGS. 1, 7, and 8, the fixed camera head clamping system 100 can be used to immobilize a patient's head for image-guided neurosurgery. In other embodiments, the head clamp 10 and the head clamping system 100 can be used to immobilize a patient's head for image-guided ENT surgery, dental surgery, plastic surgery, cranial surgery, or any other surgical procedure, for which the patient's head is immobilized. The head clamp 10 may be attached to a surgical table in an operating room by securing the base support 12 to the table. The user may slide the movable frame portion 24 away from the fixed frame portion 20 such that the first upper end 18 and the second upper end 22 move apart and the central space 26 expands. The patient may then be positioned on the surgical table with the patient's head 112 positioned within the central space 26 of the head clamp 10. The user may then slide the movable frame portion 24 towards the fixed frame portion 20 and move the second upper end 22 closer to the first upper end 18 until the pins 34 and 32 engage the patient's head 112. The first pin assembly 28 may be adjusted to set the desired rotational position of the pin 34. The pins 34 and 32 may then be secured to the patient's head 112 to clamp the patient's head 112 within the head clamp 10.

[0033] The camera mounting portion 16 may then be connected to the receiving portion 40 at a desired angle relative to the fixed frame portion 20. The locking protrusion 66 (shown in FIG. 4) at the proximal end 60 of the camera mounting portion 16 may engage the receiving space 52 (shown in FIG. 3) of the receiving portion 40 that accommodates the desired angle. Bolts 70 may then be secured through the bores 68 and 54 to secure the camera mounting portion 16 to the receiving portion 40 and the fixed frame portion 20.

[0034] Next, the camera 102 may be attached to the camera mounting portion 16. The camera base 104 may be fixed to the camera receiving portion 80 on the camera mounting portion 16 as described above. The camera 102 may be positioned such that the lens of the camera 102 faces in a direction substantially parallel to the camera mounting portion 16. Next, the drape 108 may be positioned over the camera 102 and the camera mounting portion 16. Next, the patient's anatomical structure may be aligned by the camera 102 using a standard alignment method employed by the surgical navigation system. Next, the patient may be draped and the surgery may be performed.

[0035] During the surgery, the camera 102 may transmit information to a surgical navigation system that generates and displays on a monitor in the operating room three-dimensional images of multiple cross-sections of the patient's anatomical structure and the position of the surgeon's instruments. This system enables craniotomy navigation without dynamic referencing because it provides a rigid connection between the patient's head 112 and the camera 102. Since there is no need to move the camera 102 around the operating room and the camera 102 remains fixed in position relative to the patient's head, errors and inaccuracies are reduced or eliminated by the system 100.

[0036] While the sterile drape 108 is being applied over the camera 102, the camera 102 remains rigidly fixed to the head clamp rather than removing and reattaching the dynamic reference frame in a conventional system, so the fixed camera head clamp system 100 eliminates this additional step that introduces error or inaccuracy into conventional systems. The patient can be aligned either before or after the sterile drape is applied over the camera 102.

[0037] Referring now to FIG. 9, a test was conducted to determine the accuracy loss resulting from certain activities in the operating room using the fixed camera head clamp 10 and system 100 in comparison to a conventional head clamp. The process of applying a sterile drape to the patient and the clamp system resulted in an accuracy loss of 0.5 mm when using a conventional head clamp, but only 0.1 mm of accuracy loss when using the fixed camera head clamp 10. Similarly, the process of retracting the drape resulted in an accuracy loss of 0.8 mm when using a conventional head clamp, but only 0.25 mm of accuracy loss when using the fixed camera head clamp 10. The use of a scalp retractor resulted in an accuracy loss of 1.4 mm when using a conventional head clamp, but only 0.35 mm of accuracy loss when using the fixed camera head clamp 10. Tilting the patient's head resulted in an accuracy loss of 2.6 mm when using a conventional head clamp, but only 0.75 mm of accuracy loss when using the fixed camera head clamp 10. Moving the camera resulted in an accuracy loss of 2.9 mm when using a conventional head clamp, but only 0.75 mm of accuracy loss when using the fixed camera head clamp 10. These tests demonstrated the improved accuracy of the head clamp 10 and system 100 over the conventional head clamp.

[0038] In an alternative embodiment, the camera mounting portion 16 can be attached to any existing head clamp. In this embodiment, the proximal end 60 of the camera mounting portion 16 may be configured to be secured to a joint on the existing head clamp. For example, the joint of the existing head clamp may include protrusions and depressions identical to the upper surface of the receiving portion 40 described herein. In another example, the proximal end 60 may include a plurality of ridges such as a star configuration configured to be secured to the receiving portion of the existing head clamp. In other embodiments, without limitation, any attachment mechanism including, but not limited to, clamps, vice grips, adhesives, tapes may be used to directly attach the small position - specific camera to any immobilization device such as a head frame (including existing head frames). In yet another embodiment, the position - specific camera may be directly fixed to the patient's head.

[0039] Referring now to FIG. 10, the camera mounting system 120 may include a camera mounting portion 122 that extends from a proximal end 124 to a distal end 126. The proximal end 124 of the camera mounting portion 122 may be attached to a pin assembly 128 that is directly attached to the patient's head 130. The pin assembly 128 includes two or more pins for preventing rotation of the camera mounting portion 122 relative to the patient's head 130. Alternatively, the proximal end 124 of the camera mounting portion 122 may be attached to the patient's head 130 using any fixation mechanism configured to support the weight of the camera mounting portion 122 and prevent its rotation. The camera receiving portion 132 may be attached to the distal end 126 of the camera mounting portion 122. The position - specific camera 134 may be attached to the camera receiving portion 132. In an alternative embodiment, the camera receiving portion may be integrally formed with the distal end 126 of the camera mounting portion 122 and may include a plurality of ridges similar to the plurality of ridges 82 of the camera receiving portion 80 shown in FIG. 6. The camera mounting system 120 reduces relative movement between the camera 134 and the patient's head 130 for image - guided surgery in which the patient's head is not immobilized, i.e., no head clamp is used. The camera mounting system 120 provides a rigid connection between the camera 134 and the patient's head 130. The camera mounting system 120 can be used by attaching the proximal end 124 of the camera mounting portion 122 to the pin assembly 128 and then attaching the pin assembly 128 to the patient's head 130. Alternatively, first, the pin assembly 128 may be attached to the patient's head 130, and then the proximal end 124 of the camera mounting portion 122 may be attached to the pin assembly 128. Finally, the position - specific camera 134 may be attached to the camera receiving portion 132.

[0040] Except as otherwise described or illustrated, each of the components within the device can be formed from aluminum, steel, another metal, plastic, or any other durable material. Each device described in this disclosure can include any combination of the described components, features, and / or functions of each individual device embodiment. Each method described in this disclosure can include any combination of the described steps in any order, including the absence of a described step and any combination of steps used in separate embodiments. Any numerical range disclosed herein includes any subrange therein. "Plurality" means "two or more."

[0041] Preferred embodiments have been described, but it should be understood that the embodiments are illustrative only and that the scope of the invention should be defined only by the appended claims, at which time all equivalents, numerous variations, and modifications that come naturally to those skilled in the art from a review of this specification are embraced.

Claims

1. A head clamp for facilitating image-guided surgery, a camera mounting portion for firmly fixing a position-specific camera to the head clamp, a base support portion, a frame fixed to the base support portion, the frame including a fixed frame portion and a movable frame portion, the movable frame portion being selectively movable relative to the fixed frame portion, the frame defining a central space sized to receive a patient's head, a first pin assembly fixed to a first upper end portion of the fixed frame portion, a second pin assembly fixed to a second upper end portion of the movable frame portion and comprising, the camera mounting portion extending from a proximal end to a distal end, the proximal end of the camera mounting portion being selectively fixed to the first upper end portion of the frame, the distal end of the camera mounting portion including a camera receiving portion configured to receive the position-specific camera.

2. The head clamp according to claim 1, further comprising a receiving portion disposed at the first upper end portion, the proximal end of the camera mounting portion being selectively fixed to the receiving portion of the frame.

3. The head clamp according to claim 2, wherein the fixed frame portion extends from the base support portion to the first upper end portion, and the movable frame portion extends from the fixed frame portion to the second upper end portion.

4. The head clamp according to claim 3, wherein the first pin assembly includes two pins, and the second pin assembly includes one pin.

5. The head clamp according to claim 4, wherein the first pin assembly further includes a rotating base and a rotary locking portion, the two pins of the first pin assembly being fixed to the rotating base so as to selectively rotate the two pins, and in the engaged position, the rotary locking portion prevents rotation of the rotating base.

6. The head clamp according to claim 3, wherein the proximal end of the camera mounting portion includes a receiving portion locking portion, the receiving portion locking portion engaging the receiving portion of the frame and configured to prevent rotation of the camera mounting portion relative to the fixed frame portion of the frame.

7. The head clamp according to claim 6, wherein the receiving portion of the frame includes a series of protrusions and a series of receiving portion spaces disposed between the protrusions.

8. The receiving portion locking portion at the proximal end of the camera mounting portion includes one or more locking protrusions sized to fit into one or more of the receiving portion spaces, the head clamp according to claim 7.

9. The head clamp according to claim 8, further comprising a fastener including a bolt and a knob configured to fix the proximal end of the camera mounting portion to the receiving portion of the frame.

10. The bolt of the fastener extends through a bore in the proximal end of the camera mounting portion and is configured to engage a bore in the receiving portion of the frame, the head clamp according to claim 9.

11. The camera receiving portion at the distal end of the camera mounting portion includes an upper surface having a plurality of ridges, the head clamp according to claim 3.

12. The camera receiving portion further includes a threaded bolt and a knob, the threaded bolt extending upwardly beyond the plurality of ridges, the head clamp according to claim 11.

13. The receiving portion of the frame is removably fixed to the first upper end portion of the frame, the head clamp according to claim 3.

14. A fixed camera head clamp system for facilitating image-guided surgery, a base support portion, a frame fixed to the upper end portion of the base support portion, the frame comprising a first arm and a second arm, the first arm comprising a first upper end portion, the second arm comprising a second upper end portion, a receiving portion being disposed at the first upper end portion, the frame defining a central space sized to receive a patient's head, a frame, a first pin assembly fixed to the first upper end portion of the frame, a second pin assembly fixed to the second upper end portion of the frame, a camera mounting portion extending from a proximal end to a distal end, the proximal end of the camera mounting portion being selectively fixed to the receiving portion of the frame, the distal end of the camera mounting portion including a camera receiving portion, a camera mounting portion, a position-specific camera selectively attached to the camera receiving portion A fixed camera head clamp system comprising.

15. The fixed camera head clamp system according to claim 14, further comprising a drape configured to cover the position - specifying camera while the position - specifying camera is attached to the camera receiving portion.

16. The fixed camera head clamp system according to claim 14, wherein the position - specifying camera has a field of view of at least approximately 120 degrees.

17. The fixed camera head clamp system according to claim 14, wherein the position - specifying camera has a field of view of approximately 1 cm to 75 cm.

18. The fixed camera head clamp system according to claim 14, wherein the position - specifying camera is positioned at approximately 15 cm or less from the first pin assembly when attached to the camera receiving portion.

19. An immobilization device for immobilizing a patient's head to facilitate image - guided surgery, the immobilization device comprising: a head clamp including a camera - mounting portion; a base support portion; a frame fixed to the base support portion, the frame including a fixed frame portion and a movable frame portion; a first pin assembly fixed to a first upper end portion of the fixed frame portion; a second pin assembly fixed to a second upper end portion of the movable frame portion and being provided with; the immobilization device is configured such that a patient's head can be placed within the immobilization device; a position - specifying camera is configured to be attached to the immobilization device; the camera - mounting portion extends from a proximal end to a distal end, and the proximal end of the camera - mounting portion is selectively fixed to the first upper end portion of the frame. The immobilization device.

20. The immobilization device according to claim 19, wherein the position - specifying camera is attached to the camera - mounting portion to firmly fix the position - specifying camera to the head clamp.

21. Further comprising a first pin assembly and a second pin assembly, a receiving portion is disposed at the first upper end portion, the frame defines a central space sized to receive a patient's head, the proximal end of the camera - mounting portion is selectively fixed to the receiving portion of the frame, and the distal end of the camera - mounting portion includes a camera receiving portion. The immobilization device according to claim 20.

22. The base support portion and the frame are attached to a surgical table. The patient is positioned on the operating table with the patient's head positioned within the central space of the frame. The patient's head is clamped within the head clamp using the first pin assembly and the second pin assembly. The camera mounting portion is attached to the frame by fixing the proximal end of the camera mounting portion to the receiving portion of the frame, the immobilization device according to claim 21. **Claim 23**: Further comprising a drape. The position-specifying camera is attached to the camera receiving portion at the distal end of the camera mounting portion. The drape is positioned across the position-specifying camera and the camera mounting portion, the immobilization device according to claim 22. **Claim 24** The frame includes a fixed frame portion and a movable frame portion, the movable frame portion being selectively movable relative to the fixed frame portion and the base support portion. Before the patient's head is positioned within the central space, the movable frame portion is configured to expand the central space by being slid away from the fixed frame portion. When the patient's head is positioned within the central space, the movable frame portion is configured to adjust the size of the central space by being slid toward the fixed frame portion, the immobilization device according to claim 23. **Claim 25** The proximal end of the camera mounting portion includes a receiving portion locking portion, and the receiving portion of the frame is configured to engage with the receiving portion locking portion of the proximal end of the camera mounting portion to prevent rotation of the camera mounting portion relative to the frame, the immobilization device according to claim 23.

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