Rocker arm assembly for head fixation device

Abstract

To provide a head fixation device relating to stabilization of a head and a neck.SOLUTION: A head fixation device includes a rocker arm assembly 300 with two or more contact members. The assembly includes arms that are non-curved in some embodiments. In some embodiments, the arms 12 and 14 of the assembly define a degree of curvature that is less than 40 degrees, and more preferably less than 30 degrees. In at least some embodiments, the assembly provides that at least two of the two or more contact members define a contact angle with the skull of about 90 degrees when contacting a generally or substantially planar portion or region of the skull.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 790,785, filed on January 10, 2019, and entitled "ROCKER ARM ASSEMBLY FOR HEAD FIXATION DEVICE," and to U.S. Provisional Patent Application No. 62 / 799,425, filed on January 31, 2019, and entitled "ROCKER ARM ASSEMBLY FOR HEAD FIXATION DEVICE," the disclosures of which are incorporated herein by reference. [Background technology]

[0002] The devices and methods disclosed herein relate to patient stabilization, and in particular to head and neck stabilization using stabilization devices known as head stabilization devices, also referred to as head fixation devices (hereinafter "HFDs" or, in the singular, "HFD"). Head fixation devices (HFDs) are used in a variety of surgical and medical procedures, such as in head or neck surgeries or examinations where it is desirable to securely hold the patient's head. Head fixation devices (HFDs) may include a variety of components configured to contact the patient's head, some of which include skull pins or pads held in pin or pad holder assemblies. The devices and methods disclosed herein relate to a variety of pin or pad holder assemblies. While a variety of stabilization devices and components of such devices have been made and used, it is believed that no one of ordinary skill in the art would have made and used the invention described herein prior to the present inventors. [Brief description of the drawings]

[0003] While the specification concludes with claims which particularly and distinctly define the invention, it is believed that the invention will be better understood from the following description of specific embodiments taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which: [Figure 1] FIG. 1 is a perspective view of an exemplary head fixation device (HFD) in the form of a skull clamp having an exemplary pin holder assembly configured with a curved rocker arm assembly having two pins on one side. [Diagram 2] 2 is a front cross-sectional view of the curved arm of the two pin rocker arm assembly of FIG. 1. [Diagram 3] FIG. 3 illustrates the stabilization configuration of the HFD of FIG. 1 for use with an oval-shaped patient's head, showing exemplary penetration angles for three-pin fixation. [Figure 4] FIG. 4 is an enlarged perspective view of an exemplary stable configuration showing a single pin and its penetration angle. [Diagram 5] FIG. 5 is a partial front view of an exemplary head fixation device (HFD) stable configuration showing an exemplary penetration angle formed by two pins of a two-pin curved rocker arm assembly when used against a flat surface of the skull of a patient's head. [Figure 6] FIG. 6 is a partial front view of an exemplary head fixation device (HFD) in a stable configuration, illustrating an exemplary penetration angle formed by two pins of another exemplary curved rocker arm assembly having two pins when used against a flat portion of the skull of a patient's head. [Figure 7] FIG. 7 is a partial front cross-sectional view of the stable configuration of the head fixation device (HFD) of FIG. 5 showing an exemplary penetration angle formed by the two holes of the curved rocker arm assembly with two pins when used against a flat surface of the skull of a patient's head (skull pins omitted in FIG. 7 ). [Figure 8]FIG. 8 is a partial front cross-sectional view of the stable configuration of the head fixation device (HFD) of FIG. 6 , illustrating an exemplary penetration angle formed by the two holes when used against a flat surface of the skull of a patient's head (skull pins omitted in FIG. 8 ). [Figure 9] FIG. 9 is a perspective view of an exemplary head fixation device (HFD) in the form of a skull clamp having an exemplary pin holder assembly configured with a rocker arm assembly having two pins on one side and configured to contact a flat area of ​​a patient's head.

[0004] The drawings are not intended to be limiting, and it is understood that various embodiments of the invention may be practiced in other ways, including ways not necessarily depicted in the drawings. The accompanying drawings, which are incorporated in and form a part of this specification, illustrate some aspects of the invention and, together with the associated description, explain the principles of the invention. However, the invention is not limited to the arrangements depicted in the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] The following description of a specific embodiment of the present invention does not limit the scope of the present invention. Other embodiments, features, aspects, embodiments, and advantages of the present invention will be apparent to those skilled in the art from the following exemplary description of one of the best modes for carrying out the present invention. It is understood that the present invention has other different and obvious aspects without departing from the present invention. Thus, the drawings and description are illustrative in nature and should not be interpreted as limiting.

[0006] I. Exemplary Rocker Arm Assembly Configured for Planar Area Contact FIG. 1 illustrates an exemplary head fixation device (HFD) in the form of a skull clamp (10) that uses three fixation points. The skull clamp (10) has a pair of arms (12, 14), each of which has a side portion (16, 18) and an upright portion (20, 22). The arms (12, 14) are laterally adjustable relative to one another to allow the skull clamp (10) to accommodate patient heads of various sizes. The skull clamp (10) includes a rocker arm assembly (100) that holds two pins (102) on one side of the skull clamp. In this embodiment, the rocker arm assembly (100) is connected to the skull clamp (10) at one end of the upright portion (20). At the end of the upright portion (22) opposite the rocker arm assembly (100) is a single pin holder (104) that holds a single pin (102).

[0007] 2 shows a cross-sectional view of arm (106) of rocker arm assembly (100). In this embodiment, arm (106) has a curvilinear shape and includes a pair of holes (108) therein. As such, holes (108) are configured to hold a pin (102) at each end of arm (106). Arm (106) is also angled inwardly such that longitudinal axes (A1, A2) defined by holes (108) of arm (106) extend in a manner that converges as shown.

[0008] FIG. 3 illustrates a stable configuration for an elliptical shaped patient's head using the skull clamp (10). In this embodiment, the contact angles formed by the pins and the contact points on the patient's head are shown as diagonally extending lines (L1, L2) forming a triangle. It is to be understood that the term "contact angle" as used herein also includes a penetration angle when the pins or contact members penetrate the skull during stabilization as opposed to simply contacting the skull without penetrating it. Thus, it is to be understood that the term "contact angle" includes both a contact angle and a penetration angle depending on the stable configuration. In this embodiment, the arm (106) of the rocker arm assembly (100) is configured with a curved shape designed to fit and provide the desired contact angle against the elliptical shaped patient's head. In some embodiments where the patient's skull is elliptical, i.e., the head shape resembles an ellipsoid, the overall placement of the three pins forms an isosceles triangle. This distributes the load across the three pins, which are configured to have a contact angle of 90 degrees or approximately 90 degrees, in other words, the pins contact or penetrate the skull at or approximately 90 degrees, or perpendicular or substantially perpendicular to the skull.

[0009] 4 shows a stable configuration in which the skull pin (102) defines a longitudinal axis (A3) and is placed in contact with an elliptical portion of the patient's head. A tangent line (T1) is shown at the point of contact where the skull pin (102) contacts the head. A contact angle (θ1), defined as the angle between the longitudinal axis (A3) of the skull pin (102) and the tangent line (T1), is shown as 90 degrees or approximately 90 degrees. In such a vertical or substantially vertical position, the skull pin (102) forms a secure and stable connection to the head.

[0010] In certain neurosurgical procedures, pins are secured to flat areas of the patient's skull rather than the oval-shaped areas described above. The skull has flat, nearly flat, or substantially flat areas over a given length of its bony structure. For the avoidance of doubt, it is to be understood that the term "flat area" as used herein encompasses not only flat areas, but also nearly flat areas, pseudo-flat areas, and / or other variations of these terms, as would be understood by one of ordinary skill in the art from the teachings herein. By way of example only and not by way of limitation, pins may be secured to flat areas of the skull in procedures in which the patient is placed in a prone (prone) position. For example, pins are placed in flat areas of the temporal and parietal bones in at least some cases to perform surgery on the occipital region, the posterior fossa, or the cervical spine.

[0011] When the above-described rocker arm assembly and pin are used to fixate a pin in a flat area of ​​the skull, the pin contact angle is different than when the same rocker arm assembly and pin are used to fixate a pin in an oval-shaped area of ​​the skull. Thus, when the same rocker arm assembly and pin are used to fixate a pin in such a different bone shape area, it is impossible to achieve a pin contact angle of about 90 degrees. For example, when the same rocker arm assembly and pin are used to fixate a pin, such as the rocker arm assembly (100) having the pin (102) shown in Figures 1-4, which is configured to provide a pin contact angle of about 90 degrees when used with an oval-shaped head, it may be impossible to achieve a contact angle of 90 degrees or close to 90 degrees. As a result, stability and reliable stabilization may be compromised.

[0012] As an example, Figure 5 shows a portion of the rocker arm assembly (100) of Figures 1-3 when used against a flat portion of the skull (30) of a patient's head. In this embodiment, the contact angles are greater than 90 degrees when the pins are secured to the flat area of ​​the skull shown in Figure 5. Specifically, the contact angles (α1, α2) are defined as the angles between the longitudinal axis (A4, A5) and the tangent (T2) of each skull pin (102).

[0013] As a further example, Figure 7 shows a portion of the rocker arm assembly (100) of Figure 5 without the pins (102), again in use against a flat portion of the skull (30) of a patient's head. In this embodiment, the contact angles are greater than 90 degrees when the pins are secured to the flat area of ​​the skull shown in Figure 7. Specifically, the contact angles (α3, α4) are defined as the angles between the longitudinal axis (A6, A7) of each hole (108) and the tangent (T2).

[0014] As discussed above in connection with Figures 5 and 7, the contact angle can be defined by the orientation of the hole (108) or the pin (102). In some embodiments where the pin (102) is straight and the hole (108) is formed with a concentric receiver for receiving the pin (102), the longitudinal axis defined by the hole (108) and the pin (102) is the same. In such embodiments, the contact angle is the same whether defined by the orientation of the hole (108) or the orientation of the pin (102). However, in other embodiments, the hole (108) is omitted and the pin (102) can be formed with or as part of the arm (106). In such embodiments, the contact angle is defined by the orientation of the pin (102). In yet another embodiment, the hole (108) and the pin (102) may be shaped or configured such that they do not have the same or common longitudinal axis, thereby defining different contact angles, as defined herein. By way of example only and not by way of limitation, such an embodiment may be contemplated where the pin (102) is angled or curved rather than straight. In light of the teachings herein, other configurations of the rocker arm assembly (100) having the pin (102) and hole (108) where the pin (102) and hole (108) have different longitudinal axes, thereby defining different contact angles, as defined herein, will be obvious to one of ordinary skill in the art. In applications where the contact angle formed by the hole and the contact angle formed by the pin are different, it is the contacting member or pin that contacts the patient's head, and therefore the contact angle formed by the contacting member or pin is a significant factor in considering the stabilization of the patient.

[0015] FIG. 9 shows an exemplary head fixation device (HFD) in the form of a skull clamp (50) that uses three fixation points. The skull clamp (50) has a pair of arms (12, 14), each of which has a side portion (16, 18) and an upright portion (20, 22). The arms (12, 14) are laterally adjustable relative to one another to allow the skull clamp (50) to fit patient heads of various sizes. The skull clamp (50) includes a rocker arm assembly (300) that holds two pins (302) on one side of the skull clamp. In this embodiment, the rocker arm assembly (300) is connected to the skull clamp (50) at one end of the upright portion (20). At the end of the upright portion (22) opposite the rocker arm assembly (300) is a single pin holder (304) that holds a single pin (302).

[0016] Reference is now made to Figures 6 and 8. Figure 6 illustrates an exemplary two pin rocker arm assembly (300) configured for use with a skull clamp (50) as shown in Figure 9, but may be configured to replace the rocker arm assembly (100) of the skull clamp (10) shown in Figures 1-3 and for use with other types of head fixation devices (HFDs). In the embodiment of Figure 6, the two pin rocker arm assembly (300) is used against a flat portion of the skull (30) of the patient's head. In this embodiment, the contact angle is 90 degrees or about 90 degrees. This is an embodiment in which both pins (302) are used with the two pin rocker arm assembly (300). Specifically, the contact angles on each side of the arm (306), (α5, α6), are defined as the angles between the longitudinal axis (A8, A9) of each pin (302) and the tangent (T2).

[0017] By using the two pin rocker arm assembly (300), each pin is held by the rocker arm assembly (300) to achieve a contact angle of 90 degrees or close to 90 degrees when the pin is fixed and stabilized on a flat area of ​​the skull of the patient's head. That is, in the arrangement shown in Fig. 6, the pin (302) is fixed perpendicular to the flat area of ​​the skull. In other words, even when the flat area of ​​the skull is fixed or used as a fixation location by the pin, the rocker arm assembly (300) allows the surgeon or user to contact or penetrate the bone perpendicularly with the pin (302) of the rocker arm assembly.

[0018] As a further example, Figure 8 shows a portion of the rocker arm assembly (300) of Figure 6 without the pin (302). In this embodiment, the rocker arm assembly (300) with arms (306) and holes (308) is configured for use in fixing a pin against a flat portion of the skull. Thus, when the pin is fixed against the flat area of ​​the skull shown in Figure 8, the contact angle is 90 degrees or approximately 90 degrees. Specifically, the contact angles (α7, α8) on each side of the arms (306) are defined as the angles between the longitudinal axis (A10, A11) and the tangent (T2) of each hole (308).

[0019] As discussed above in connection with Figures 6 and 8, the contact angle can be defined by the orientation of the hole (308) or the pin (302). In some embodiments where the pin (302) is straight and the hole (308) is formed with a concentric receiver for receiving the pin (302), the longitudinal axis defined by the hole (308) and the pin (302) is the same. In such embodiments, the contact angle is the same whether defined by the orientation of the hole (308) or the orientation of the pin (302). However, in other embodiments, the hole (308) is omitted and the pin (302) can be formed with or as part of the arm (306). In such embodiments, the contact angle is defined by the orientation of the pin (302). In yet another embodiment, the hole (308) and the pin (302) may be shaped or configured such that they do not have the same or common longitudinal axis, thereby defining different contact angles, as defined herein. By way of example only and not by way of limitation, such an embodiment may be where the pin (302) is angled or curved rather than straight. In light of the teachings herein, other configurations of the rocker arm assembly (300) having the pin (302) and hole (308) where the pin (302) and hole (308) have different longitudinal axes, thereby defining different contact angles, as defined herein, will be obvious to one of ordinary skill in the art. In applications where the contact angle formed by the hole and the contact angle formed by the pin are different, it is the contact member or pin that contacts the patient's head, and therefore the contact angle formed by the contact member or pin is a significant factor in considering the patient's stabilization.

[0020] In one embodiment of the exemplary two pin rocker arm assembly (300), the arm (306) is approximately 9mm x 9mm x 70mm-110mm and has two perpendicular pin receivers or holes (308) at either end of the arm (306) spaced 50mm-90mm apart. In another embodiment of the exemplary two pin rocker arm assembly (300), the arm (306) is smaller, approximately 9mm x 9mm x 40mm-70mm and has two perpendicular pin receivers or holes (308) at either end of the arm (306) spaced 20mm-55mm apart. This smaller two pin rocker arm assembly (300) is configured for use with pediatric patients or patients with smaller sized heads.

[0021] Comparing rocker arm assembly (100) and rocker arm assembly (300), in each assembly, each pin (102, 302) defines a longitudinal axis or centerline, as shown in Figures 5 and 6. In some embodiments, the centerlines of a pair of pins in rocker arm assembly (100) intersect to form an angle, such as β1 in Figure 5. The angle defines an arc angle, which may also be referred to herein as the radius of the arm or the curvature of the arm. In the illustrated rocker arm assembly (100), β1 is 40 degrees.

[0022] In the rocker arm assembly (300) shown in FIG. 6, the centerlines or longitudinal axes of the pins (302) are parallel and therefore do not intersect and form a predetermined angle. In another embodiment where the centerlines or longitudinal axes of the pins (302) are close to parallel, but not perfectly parallel, the centerlines or longitudinal axes intersect and form a predetermined angle, as described above. In cases where the axes are close to parallel, but not perfectly parallel, the angle formed is less than 40 degrees. Thus, in the rocker arm assembly (300), the angle represented by β2 is greater than or equal to about 0 degrees and less than 40 degrees (as formed by β2 in FIG. 6). It should be understood that, for the purposes of this specification, β2 is defined to be 0 degrees when the axes defined by the pins (302) are parallel.

[0023] Thus, a rocker arm assembly configured to secure a pin to a flat area of ​​a skull can have an arm curvature defined by an angle formed by the longitudinal axes or centerlines of the pair of pins that is greater than or equal to 0 degrees and less than 40 degrees. For example, when β2 is equal to 0 degrees, the arm (306) of the rocker arm assembly (300) has a straight and non-curved shape. When β2 is greater than 0 degrees and less than 40 degrees, the arm (106) of the rocker arm assembly (100) has a slight curvature. Thus, it should be understood that in some embodiments, the arm (306) is straight, while in other embodiments, the arm (306) has a curvature that is less than that of a rocker arm assembly designed to secure a pin to an oval shaped skull. Furthermore, in other embodiments, the angle may be between about 0 degrees and about 30 degrees, or between about 0 degrees and about 20 degrees, or between about 0 degrees and about 10 degrees. Other angle ranges will be apparent to one of ordinary skill in the art in light of the teachings herein.

[0024] In another comparison of rocker arm assembly (100) and rocker arm assembly (300), the holes (108, 308) of each assembly define a longitudinal axis or centerline as shown in Figures 7 and 8. In some embodiments, the centerlines of a pair of holes (108, 308) intersect to form an angle, such as β3 in Figure 7. The angle defines an angle of arc, which may also be referred to herein as the radius of arm (106) or the curvature of the arm. In rocker arm assembly (100), β3 is 40 degrees.

[0025] In the rocker arm assembly (300) shown in FIG. 8, the centerlines or longitudinal axes of the holes (308) are parallel and therefore do not intersect and form a predetermined angle. In another embodiment where the centerlines or longitudinal axes of the holes (308) are close to parallel, but not perfectly parallel, the centerlines or longitudinal axes intersect and form a predetermined angle, as described above. In cases where the axes are close to parallel, but not perfectly parallel, the angle formed is less than 40 degrees. Thus, in the rocker arm assembly (300), the angle represented by β4 is greater than or equal to about 0 degrees and less than 40 degrees (as formed by β4 in FIG. 8). It should be understood that, for the purposes of this specification, β4 is defined to be 0 degrees when the axes defined by the holes (308) are parallel.

[0026] Thus, a rocker arm assembly configured to secure a pin to a flat area of ​​a skull can have an arm curvature defined by an angle formed by the longitudinal axes or centerlines of the pair of pins that is greater than or equal to 0 degrees and less than 40 degrees. For example, when β4 is equal to 0 degrees, the arm (306) of the rocker arm assembly (300) has a straight and non-curved shape. When β4 is greater than 0 degrees and less than 40 degrees, the arm (106) of the rocker arm assembly (100) has a slight curvature. Thus, it should be understood that while in some embodiments the arm (306) is straight, in other embodiments it has a curvature that is less than that of a rocker arm assembly designed to secure a pin to an oval shaped skull. Furthermore, in other embodiments, the angle may be between about 0 degrees and about 30 degrees, or between about 0 degrees and about 20 degrees, or between about 0 degrees and about 10 degrees. Other ranges of angles will be apparent to one of ordinary skill in the art in light of the teachings herein.

[0027] As described above, rocker arm assemblies such as the rocker arm assembly (100) are configured to be used with an oval-shaped skull. Such rocker arm assemblies have a predetermined angle of 40 degrees or greater, formed by either a pair of holes or a pair of pins in the arms of the rocker arm. If such rocker arm assemblies are used to secure a pin within a flat area of ​​the skull, the contact angle may deviate significantly from the penetration angle, thereby compromising stability and reliable stabilization. However, as shown and described in connection with the rocker arm assembly (300), by using a stable configuration in which the angle formed by either a pair of holes or a pair of pins in the arms of the rocker arm is less than 40 degrees, the contact angle can be maintained at or close to 90 degrees, thereby achieving stability and / or reliable stabilization of the patient in a procedure involving the securing of a pin to a flat area of ​​the skull of the head.

[0028] II. Exemplary Combinations The following examples relate to non-exhaustive aspects in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to limit the scope of any claims presented at any time in this application or any subsequent application of this application. In addition, the following examples are provided for illustrative purposes only. It is believed that the various teachings herein can be configured and applied in many different other aspects. It is also believed that certain configurations mentioned in the following examples may be omitted in some of the variant embodiments. EXAMPLES

[0029] A device for use with a head immobilization device for stabilizing a patient's head, the device having two or more contact members configured to contact the patient's head, the device being configured such that each of the two or more contact members defines a longitudinal axis extending through a distal end of the contact member configured to contact the patient's head, the angle formed by the two longitudinal axes being less than about 30 degrees. EXAMPLES

[0030] In the device described in Example 1, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull, the contact angle being approximately 90 degrees. EXAMPLES

[0031] In the device of Example 1, the angle formed by the two longitudinal axes is preferably less than about 20 degrees. EXAMPLES

[0032] In the device described in Example 3, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull, the contact angle being approximately 90 degrees. EXAMPLES

[0033] In the device described in Example 1, the angle formed by the two longitudinal axes is preferably less than about 10 degrees. EXAMPLES

[0034] In the device described in Example 5, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull, the contact angle being approximately 90 degrees. EXAMPLES

[0035] In the device described in Example 1, the angle formed by the two longitudinal axes is preferably about 0 degrees. EXAMPLES

[0036] In the device described in Example 7, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull, the contact angle being approximately 90 degrees. EXAMPLES

[0037] In the device described in any one or more of Examples 1 to 8, at least two of the two or more contact members are configured to contact a substantially planar portion of the patient's skull. EXAMPLES

[0038] The device according to any one or more of the first to ninth embodiments, wherein the two or more contact members are selectively retained by the device. EXAMPLES

[0039] The device according to any one or more of Examples 1-10, wherein the two or more contact members are formed as a unitary structure with the device. EXAMPLES

[0040] The device according to any one or more of Examples 1-11, wherein the device comprises an arm configured to carry or hold the two or more contact members. EXAMPLES

[0041] The device according to any one or more of Examples 1-12, wherein the two or more contact members comprise skull pins. EXAMPLES

[0042] The device according to any one or more of Examples 1-12, wherein the two or more contact members comprise pads. EXAMPLES

[0043] In the device described in any one or more of Examples 1-14, each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull, the contact angle being approximately 90 degrees, and the contact angle being a penetration angle. EXAMPLES

[0044] The device according to any one or more of Examples 1-15, wherein the device comprises a rocker arm assembly including an arm configured to carry or hold the two or more contact members. EXAMPLES

[0045] 17. The apparatus of embodiment 16, wherein the arm of the rocker arm assembly is non-curved. EXAMPLES

[0046] The device according to one or more of Examples 16-17, wherein the arm has two or more holes configured to hold one of the two or more contact members. EXAMPLES

[0047] In the device according to any one or more of Examples 1 to 18, at least two of the two or more contact members are spaced apart by a distance of about 50 mm to about 90 mm. EXAMPLES

[0048] In the device according to any one or more of Examples 1 to 18, at least two of the two or more contact members are spaced apart by about 20 mm to about 50 mm. EXAMPLES

[0049] A rocker arm assembly for use with a head immobilization device for stabilizing a patient's head, the rocker arm assembly having an arm with two or more holes, each of the holes configured to selectively retain a contact member configured to contact the patient's head, each of the holes defining a longitudinal axis, an angle formed between two of the longitudinal axes being less than about 30 degrees. EXAMPLES

[0050] In the rocker arm assembly of Example 21, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole portion forms a predetermined contact angle with a substantially flat portion of the skull, the contact angle being approximately 90 degrees. EXAMPLES

[0051] In the rocker arm assembly of Example 21, the angle formed by the two longitudinal axes is preferably less than about 20 degrees. EXAMPLES

[0052] In the rocker arm assembly of Example 23, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole portion forms a predetermined contact angle with a substantially flat portion of the skull, the contact angle being approximately 90 degrees. EXAMPLES

[0053] In the rocker arm assembly of Example 21, the angle formed by the two longitudinal axes is preferably less than about 10 degrees. EXAMPLES

[0054] In the rocker arm assembly of Example 25, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole portions forms a predetermined contact angle with a substantially planar portion of the skull, the contact angle being approximately 90 degrees. EXAMPLES

[0055] In the rocker arm assembly according to Example 21, the angle formed by the two longitudinal axes is preferably about 0 degrees. EXAMPLES

[0056] In the rocker arm assembly described in Example 27, the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole portion forms a predetermined contact angle with a substantially flat portion of the skull, the contact angle being approximately 90 degrees. EXAMPLES

[0057] In the rocker arm assembly described in any one or more of Examples 21 to 28, the two contact members configured to be held in corresponding holes are configured to contact a substantially flat portion of the patient's skull. EXAMPLES

[0058] In a rocker arm assembly described in any one or more of Examples 21-29, each of the holes defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull, the contact angle being approximately 90 degrees, and the contact angle being a penetration angle. EXAMPLES

[0059] The rocker arm assembly of any one or more of Examples 21-30, wherein the arm is non-curved. EXAMPLES

[0060] In the rocker arm assembly according to any one or more of Examples 21 to 31, at least two of the two or more holes are spaced apart from each other by about 50 mm to about 90 mm. EXAMPLES

[0061] In the rocker arm assembly according to any one or more of Examples 21 to 31, at least two of the two or more holes are spaced apart from each other by about 20 mm to about 55 mm. EXAMPLES

[0062] A head immobilization device for stabilizing a patient's head having a rocker arm assembly having an arm configured to selectively retain two or more contact members configured to contact a generally planar portion of the patient's head, at least two of the contact members forming a contact angle of approximately 90 degrees with the generally planar portion of the patient's head.

[0063] III. Miscellaneous Any one or more of the teachings, expressions, embodiments, and examples described herein may be combined with any one or more of the other teachings, expressions, embodiments, and examples described herein. Thus, the teachings, expressions, embodiments, and examples described below should not be considered as being independent of each other. In view of the teachings of this specification, it will be apparent to those skilled in the art that various suitable combinations of the teachings are possible. Such modifications and variations are intended to be included within the scope of the claims.

[0064] Although various embodiments of the present invention have been shown and described, those skilled in the art can make appropriate modifications to further improve the methods and systems described herein without departing from the scope of the present invention. Some of such possible modifications have been described, but other modifications will be obvious to those skilled in the art. For example, the examples, embodiments, geometrical characteristics, materials, dimensions, ratios, steps, etc. described above are illustrative and not required. Therefore, it should be understood that the scope of the present invention should be considered based on the following claims and is not limited to the details of structure and operation described and illustrated in the specification and drawings.

Claims

1. 1. An apparatus for use with a head immobilization device for stabilizing a patient's head, comprising: two or more contact members configured to contact the patient's head; the device being configured such that each of the two or more contact members defines a longitudinal axis extending through a distal end of the contact member configured to contact the patient's head; the angle formed by the two longitudinal axes is less than about 30 degrees; Device.

2. 2. The device of claim 1, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull; The contact angle is about 90 degrees.

3. 2. The apparatus of claim 1, wherein the angle formed by the two longitudinal axes is preferably less than about 20 degrees.

4. 4. The device of claim 3, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull; The contact angle is about 90 degrees.

5. 2. The apparatus of claim 1, wherein the angle formed by the two longitudinal axes is preferably less than about 10 degrees.

6. 6. The device of claim 5, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull; The contact angle is about 90 degrees.

7. 2. The apparatus of claim 1, wherein the angle formed by the two longitudinal axes is preferably about 0 degrees.

8. 8. The device of claim 7, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull; The contact angle is about 90 degrees.

9. 10. The device of claim 1, wherein at least two of the two or more contact members are configured to contact a substantially planar portion of the patient's skull.

10. 2. The apparatus of claim 1, wherein the two or more contact members are selectively retained by the apparatus.

11. 10. The device of claim 1, wherein the two or more contact members are formed as a unitary structure with the device.

12. 10. The device of claim 1, wherein the device comprises an arm configured to carry or hold the two or more contact members.

13. 10. The device of claim 1, wherein the two or more contact members comprise skull pins.

14. 2. The apparatus of claim 1, wherein the two or more contact members comprise pads.

15. 2. The device of claim 1, wherein each of the contact members defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull; The contact angle is about 90 degrees, the contact angle being the penetration angle. Device.

16. 10. The apparatus of claim 1, further comprising a rocker arm assembly including an arm configured to carry or hold the two or more contact members.

17. 17. The apparatus of claim 16, wherein the arms of the rocker arm assembly are non-curved.

18. 17. The device of claim 16, wherein the arm has two or more holes configured to hold one of the two or more contact members.

19. 10. The apparatus of claim 1, wherein at least two of the two or more contact members are spaced apart by about 50 mm to about 90 mm.

20. 10. The apparatus of claim 1, wherein at least two of the two or more contact members are spaced apart by about 20 mm to about 50 mm.

21. 1. A rocker arm assembly for use with a head immobilization device for stabilizing a patient's head, comprising: an arm having two or more holes, each of the holes configured to selectively retain a contact member configured to contact the patient's head; each of the holes defines a longitudinal axis, and an angle formed between two of the longitudinal axes is less than about 30 degrees; Rocker arm assembly.

22. 22. The rocker arm assembly of claim 21, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole forms a predetermined contact angle with a substantially planar portion of the skull; The contact angle is approximately 90 degrees.

23. 22. The rocker arm assembly of claim 21, wherein the angle formed by the two longitudinal axes is preferably less than about 20 degrees.

24. 24. The rocker arm assembly of claim 23, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole forms a predetermined contact angle with a substantially planar portion of the skull; The contact angle is approximately 90 degrees.

25. 22. The rocker arm assembly of claim 21, wherein the angle formed by the two longitudinal axes is preferably less than about 10 degrees.

26. 26. The rocker arm assembly of claim 25, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole forms a predetermined contact angle with a substantially planar portion of the skull; The contact angle is approximately 90 degrees.

27. 22. The rocker arm assembly of claim 21, wherein the angle formed by the two longitudinal axes is preferably approximately 0 degrees.

28. 28. The rocker arm assembly of claim 27, wherein the angle formed between the two longitudinal axes is determined by an arrangement in which each of the two contact members configured to be retained in the corresponding hole forms a predetermined contact angle with a substantially planar portion of the skull; The contact angle is approximately 90 degrees.

29. 22. The rocker arm assembly of claim 21, wherein the two contact members configured to be retained in the corresponding holes are configured to contact a substantially planar portion of the patient's skull.

30. 22. The rocker arm assembly of claim 21, wherein each of the holes defining the two longitudinal axes forms a predetermined contact angle with a substantially planar portion of the patient's skull; The contact angle is about 90 degrees, the contact angle being the penetration angle. Rocker arm assembly.

31. The rocker arm assembly of claim 21 , wherein the arm is non-curved.

32. 22. The rocker arm assembly of claim 21, wherein at least two of the two or more holes are spaced apart by between about 50 mm and about 90 mm.

33. 22. The rocker arm assembly of claim 21, wherein at least two of the two or more holes are spaced apart from each other by between about 20 mm and about 55 mm.

34. A head immobilization device for stabilizing a patient's head, comprising: A rocker arm assembly, The rocker arm assembly includes an arm configured to selectively retain two or more contact members; the two or more contact members are configured to contact a substantially planar portion of the patient's head; At least two of the contact members form a contact angle of approximately 90 degrees with a generally planar portion of the patient's head. Head immobilization device.

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