Patent Publication Number: US-2004049852-A1

Title: Head immobilizer

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates generally to an improved head immobilization apparatus that is attachable to, and detachable from, a spine board of the type employed by emergency medical personnel for transporting injured persons.  
       BACKGROUND OF THE INVENTION  
       [0002] Spine boards have been used by physicians and emergency medical personnel for a number of years in the transport of injured or incapacitated persons. Particular care and attention is needed for the immobilization of the head and neck of an injured person being transported. Head and cervical spine immobilization is necessary to prevent possible neck (cervical spine) injuries from being exacerbated during transport. It is desirable that such immobilization be performed quickly and properly after an injured person has otherwise been properly secured on a spine board. Thus, a head immobilization apparatus should provide high level of motion restriction with an intuitive design allowing for simple and proper application. The apparatus should be fully adjustable to fit the injured person. Given the limited space in an ambulance, the apparatus should also be compact for easy storage.  
       [0003] After the injured person has been properly immobilized for transport, emergency medical personnel should have good visual and tactile access to the eyes, ears, mouth, nose, and neck of the injured person to properly diagnose the nature and extent of the injuries. Hence, a head immobilization apparatus should provide such access to the injured person. The injured person may need to be x-rayed while still on a spine board. Thus, the head immobilizer should have a high level of x-ray transparency.  
       [0004] With respect to head immobilization apparatuses, reference is made to the following:  
       [0005] Bodman, U.S. Pat. No. 5,265,625, relates to a device for immobilizing the head to prevent further injuries, such as neck injuries, including left and right complimentary blocks. Each block has a skull-supporting surface. The blocks contact the skull with the skull supporting surfaces diverging outwardly and upwardly to provide a wedging action to immobilize the skull against left and right movement as well as to position the height of the skull so that alignment of the neck is achieved. The skull-supporting surface surrounds but does not cover the ear so that assessment may be made easily. The left and right blocks may be disposable for one time use or permanently mounted on a carrier for reuse.  
       [0006] McReynolds et al, U.S. Pat. No. 5,207,716, relates to an apparatus for supporting and immobilizing a head during surgery or examination by a treating physician. A headrest is secured to a base support. The headrest has open sides and is shaped to engage a patient&#39;s head. A pair of immobilizing jaws engages the head from the side to hold the head in place. Repositionable arm platforms are provided for steadying the physician&#39;s arms.  
       [0007] Park, U.S. Pat. No. 4,771,493, relates to an adjustable therapeutic pillow apparatus for applying a gentle traction force to the head, neck, and shoulder region of a user. The apparatus includes a base, first and second pillow members having spaced-apart convex pillow surfaces for engagement with the user, and means for fastening the pillow members to the base. The apparatus is adjustable in that both the lateral spacing of the pillow members and the overall length of the pillow members may be adjusted.  
       [0008] Laurin et al., U.S. Pat. No. 5,154,186, provides an apparatus for restraining a patient having a suspected spinal injury in the form of a spinal restraint including a rigid board, a plurality of restraining straps, a head support, a foot support, and carrying handles. The restraining straps extend laterally across the board from side portions thereof, the straps being longitudinally removable and laterally retractable. The head support is adapted for immobilizing the head of a patient and comprises a center support for supporting the back of the head of a patient and two side supports, one on each side of the central support, each one for supporting the side of the head of a patient and being movable between a support configuration and a loading and storing configuration in which the side support lies substantially flush with the center support.  
       [0009] Durham, U.S. Pat. No. 5,657,766, relates to a head immobilizing apparatus including a main board having a central portion and spaced apart side edge portions. Positioned along the side edge portions are apertures to accommodate backboard engaging straps and head immobilizing straps. The backboard engaging straps are provided to secure the main board to a backboard in an emergency medical situation. The head immobilizing straps can be operably positioned in a variety of locations depending upon the apertures for positioning the head immobilizing straps. A pair of removable head supports is operably attached to the central portion of the main board through a hook and loop material. A head cushion is positioned at the central most portion of the main board. The main board of the head immobilizer is constructed of a high strength corrugated disposable material and the upright cushions and head pillow are constructed of an open cell foam to absorb blood and bodily fluids during trauma of the head of the patient.  
       [0010] Henley, Jr., U.S. Pat. No. 4,794,656, relates to a backboard for immobilizing and transporting injured persons and a head restraining device for employment with such a backboard. The backboard includes a rigid support member, two head engaging members which are slidably received in a track attached to the rigid support member and latching assemblies to hold the head support members in a fixed position relative to the rigid support board. The head support members are designed to be positioned adjacent the head of an injured person who has been placed on the backboard, one head support member on each side of the head. The head support members may be completely removed from the track when not in use. The latching assemblies include a spring-biased member which engages the track, due to the spring bias, and holds the head-engaging member in a fixed position. The backboard may include body-strapping members which include a cloth strap, a ring slidably and rotatably retained by one end of the strap and a snap hook swivelly connected to each ring. The snap hooks are connectable to rods embedded in the handholds of the support board or to the rings of other strapping members. The backboards may include a foot support assembly which includes a footplate and two extension members. The footplate is rotatably attached to two extension members which in turn are slidably attached to the support board.  
       [0011] Klippel, U.S. Pat. No. 3,566,422, relates to a spine board apparatus with a short upper board member that is secured behind a patient&#39;s back and neck.  
       [0012] Gregory et al. U.S. Pat. No. 4,221,213, relates to a headpiece which is provided for the head end of a table on which a patient lies on a side to have bottom side of the head engage the headpiece. A plurality of pads are adjustable by the headpiece support so that the head is retained in a fixed position while a chiropractor makes a vertible adjustment.  
       [0013] Patil et al., U.S. Pat. No. 4,463,758, provides a frame having a platform or support including an area thereon for supporting a patient&#39;s head and for maintaining the patient&#39;s head in position.  
       [0014] Brock, U.S. Pat. No. 3,449,776, provides a collapsible telescoping head support mounted on a stretcher and has adjustable torso members mounted thereon. Straps extend through the head support and torso members for immobilizing a broken neck.  
       [0015] Darby, Jr., U.S. Pat. No. 3,650,523, relates to a restraining assembly for children including a rigid support board having a head portion at one end adapted to underlie the head of the patient and laterally adjustable head holding pads provided on the head portion.  
       [0016] Rankin, U.S. Pat. No. 3,672,364, relates to an anatomical, compressible weight immobilizer, having orthopedic strap tension weights which are adapted to immobilize a portion of an injured patient&#39;s anatomy against disposition or dislocation, while the patient is reclining. To the portable orthopedic strap tension weighted components is secured a cervical chin strap supplement, in one embodiment. The unit with attachments is applicable to a stretcher or hospital bed or operating table and may be used alternately in the transport of the patient or in the retention of the patient in position for examination, operation or ambulatory movement.  
       [0017] Each of these patents provides spinal and cervical immobilization apparatuses with various features. None of these patents, however, discloses or suggests an immobilization apparatus that provides for ease of adjustability without removal of parts, integrated parts, accommodation for a wide range of sizes, consideration for x-rays, symmetrical parts for easy manufacturing, safety locks, etc. It has therefore been found desirable to design a head immobilizer with the advantages as noted below.  
       [0018] Thus, it is believed that heretofore the present invention has not been taught or suggested.  
       OBJECTS OF THE INVENTION  
       [0019] It is therefore an object of this invention to provide a head immobilizer with a high level of motion restriction to the head and neck of a patient.  
       [0020] It is also an object of this invention to provide a head immobilizer with intuitive design with minimal product training needed.  
       [0021] It is another object of this invention to provide a head immobilizer with good visual and tactile access to eyes, ears, mouth, nose, and neck.  
       [0022] It is a further object of this invention to provide a head immobilizer with high level of x-ray transparency.  
       [0023] It is yet another object of this invention to provide a head immobilizer with durable components that can be cleaned and reused multiple times.  
       [0024] It is yet also an object of this invention to provide a head immobilizer that is fully adjustable to fit a large range of patients.  
       [0025] It is yet a further object of this invention to provide a head immobilizer that allows for quick application and readjustment.  
       [0026] It is still another object of this invention to provide a head immobilizer that promotes proper immobilization technique.  
       [0027] It is another object of this invention to provide a head immobilizer that has a small and compact design for easy storage.  
       [0028] It is yet another object of this invention to provide a head immobilizer with low cost compared to other head immobilization systems.  
       [0029] It is also an object of this invention to provide a head immobilizer where all straps are permanently attached to eliminate lost parts.  
       [0030] It is still another object of this invention to provide a head immobilizer that is easily attachable to and detachable from a spine board and is adaptable to fit a broad variety of board types.  
       [0031] Various other objects, advantages and features of the present invention will become readily apparent from the ensuing detailed description and the novel features will be particularly pointed out in the appended claims.  
       SUMMARY OF THE INVENTION  
       [0032] An embodiment of the present invention includes a base headboard (or “headboard” or “base board”) for providing a surface/interface for mounting one or more side blocks, which are adaptable for supporting one or more sides of a body part (e.g., the head). A soft material, such as a foam pad, is attached to the center portion of the headboard for providing comfortable support to the injured person&#39;s head. An elongated slot with teeth racks is disposed in the headboard on both sides of the injured person&#39;s head. The headboard also comprises straps for attaching to a spine board.  
       [0033] Two side head blocks are each removably attached to the headboard using a plunger-type lock that engages an elongated slot on a respective side of the headboard. These locks are engaged to the slots of the headboard through separate elongated slots in the head blocks, which may be aligned perpendicularly to the slots of the headboard. Advantageously, the head blocks may be adjusted by moving the engagement of the locks along a set of slots in the headboard and a set of slots in the head blocks, respectively. In addition, the head blocks may be rotated around the locks. Consequently, the present invention allows the blocks to be located at any point on the base within a predetermined limit of motion. The head blocks are, thus, adjustable so as to accommodate the various size features of a particular patient while promoting proper immobilization technique by minimizing movement of, and possible trauma to, the cervical spine of the patient.  
       [0034] Each head block has a universal configuration such that there is no difference between a left and a right head block. When attached to the headboard, each head block includes an upright planar portion with a soft material (foam pad) attached thereto for fitting a side of the injured person&#39;s head and a horizontal portion that includes the aforementioned slot for engaging the headboard. The upright planar portion includes an arch opening that exposes the side of the injured person&#39;s head so as to allow access thereto for injury diagnosis by emergency medical personnel. The arch opening also improves the x-ray transparency of the injured person&#39;s head, thus allowing emergency medical personnel to take x-ray of an injured person&#39;s head while it is immobilized. The upright planar portion further includes a curvilinear (bell-shaped) cross section for improving x-ray transparency. For easy storage, these portions of the head block may be removed from the base and disengaged to a flat position when not in use.  
       [0035] The preferred soft material for the headboard and head blocks (foam pads) is readily removable from the headboard and head blocks for easy replacement.  
       [0036] The head immobilizing apparatus may be adjusted with ease to fit a patient of any size/age (or at least two years old) without removing any of its parts. This integration of parts prevents parts from being lost or misplaced, and allows for quick immobilization of a patient without the need to locate individual parts. The locks for locking the head blocks include at least two locking stages, whereby individual directions of adjustment for the head blocks may be locked in place thus allowing for a better fit on a patient.  
       [0037] Attachment straps are incorporated to the headboard for attaching to a spine board. Head immobilizing straps may be extended across the forehead and chin of the injured person between the head blocks. According to an embodiment of the invention, the head immobilizing straps are angled such that the pressures thereof are oriented toward the mandible joint, which reduces discomfort while enabling emergency medical personnel to open the mouth of the injured person.  
       [0038] The cooperating attachment straps may further comprise cooperating hook or loop material or an adhesive double sided tape attached to a bottom surface of the bead pad means for attaching the head pad means to the headboard.  
       [0039] The headboard is preferably constructed of a molded plastic material and configured such that an elongated slot extends axially across the headboard perpendicular to the side edges on either side of a center portion thereof, and may further include a spineboard strap enabling the headboard to be attached to the spineboard.  
       [0040] The head pad means may further comprise a pair of universally configured pads, each pad having spaced apart upright side surfaces extending perpendicularly from a bottom and merging at a pair of ends. The head pad means and the head support means are preferably constructed with foam of a color dissimilar to the color of human blood.  
       [0041] The immobilizing strap means may further comprise a buckle enabling a free end of the immobilizing strap means to be inserted therethrough and folded over to attach to its length.  
       [0042] In accordance with another embodiment, the features of the headboard may be directly incorporated to a spineboard, thereby allowing head blocks to be attached thereto without the need of a separate headboard.  
       [0043] The invention accordingly comprises the apparatus embodying features of construction, combination(s) of elements and arrangement of parts, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0044] For a more complete understanding of the invention, reference is made to the following description and accompanying drawings(s), wherein like reference numerals denote like elements and parts, in which:  
     [0045]FIG. 1 depicts a head immobilization apparatus assembled for attaching to a spine board in accordance with an embodiment of the present invention;  
     [0046]FIGS. 2A and 2B illustrate attaching a head block of the head immobilization apparatus to a base part and three ways for adjusting the head block before locking in accordance with an embodiment of the present invention;  
     [0047]FIG. 3 illustrates a locking device for attaching a head block of the head immobilization apparatus in accordance with an embodiment of the present invention;  
     [0048]FIG. 4A illustrates the underside of a locking device for attaching a head block of the head immobilization apparatus in accordance with an embodiment of the present invention;  
     [0049]FIG. 4B shows a view of the locking device and head block in accordance with an embodiment of the invention;  
     [0050]FIG. 5 illustrates an interaction between a locking device and a head block of the head immobilization apparatus in accordance with an embodiment of the present invention;  
     [0051]FIG. 6A depicts a base part of the head immobilization apparatus attached to a spine board in accordance with an embodiment of the present invention;  
     [0052]FIG. 6B shows a view of an interaction between a locking device and a head block of the head immobilization apparatus in accordance with an embodiment of the present invention;  
     [0053] FIGS.  7  to  11  illustrate the steps for applying the head immobilization apparatus to an injured person loaded on a spine board in accordance with an embodiment of the present invention;  
     [0054]FIG. 12 is a view of the head immobilization apparatus as attached to a spine board in accordance with an embodiment of the present invention;  
     [0055]FIGS. 13A, 13B, and  13 C illustrate storage and deployment positions of a head block of the head immobilization apparatus in accordance with an embodiment of the present invention;  
     [0056]FIG. 14 depicts an assembled head immobilization apparatus on a spine board in accordance with an embodiment of the present invention;  
     [0057]FIG. 15 depicts a head immobilizer mounting portion of a spine board of FIG. 14 in accordance with an embodiment of the present invention;  
     [0058]FIG. 16 illustrates the attachment of a head block to a spine board using an attachment device in accordance with an embodiment of the present invention;  
     [0059]FIG. 17 illustrates applying a head immobilization apparatus to an injured person loaded on a spine board in accordance with an embodiment of the present invention;  
     [0060]FIGS. 18A and 18B is a cross-sectional view of the attachment of a head block to a spine board using an attachment device in accordance with an embodiment of the present invention;  
     [0061]FIGS. 19A, 19B, and  19 C illustrate the x-ray transparent structure of a head block in accordance with an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0062]FIG. 1 depicts an assembled head immobilization apparatus  100  for attaching a spine board  102  in accordance with an embodiment of the invention. As illustrated in FIG. 1, head immobilization apparatus  100  comprises two head blocks  105  and  110  placed on either side of an injured person&#39;s head (see FIG. 11). It is noted that, in accordance with an embodiment of the inventions blocks  105  and  110  are of a uniform design so that they may be interchanged with each other on either side of the injured person&#39;s head. It is, thus, noted that the following description and corresponding Figures regarding either block  105  and  110  may be applied to other, and that duplicate description may be omitted.  
     [0063] Blocks  105  and  110  are fixed to a headboard (or base)  115  for supporting the back of the injured person&#39;s head by pressing down on plunger-type locks  120  and  125 . Blocks  105  and  110  can be released for readjustment or removal by depressing a respective lever on lock members  120  and  125 , which will be described in further detail below. Additional head motion restraint is achieved by connecting a strap  130 , which is attached to block  110  by a rivet  135 , to block  105  by a releasable fastener  140  across the forehead of the injured person (see FIG. 11), and connecting a corresponding strap  145 , which is attached to block  105  by a rivet  150 , across the chin back to block  110  by a releasable fastener  155  (see FIG. 11). In accordance with the invention, rivets  135  and  150  and fasteners  140  and  155  may be rotatable or disposed at a predetermined angle so that straps  130  and  145  connected across the forehead and chin of the injured person may be angled to accommodate a wider range of head sizes. In addition, the angles of straps  130  and  145  orient the pressures thereof toward the mandible joint, which reduces discomfort while enabling emergency medical personnel to open the mouth of the injured person. Blocks  105  and  110  also include arch openings  157  and  158 , respectively, for providing access to the sides of the injured person&#39;s head, including the ears. The arch opening also improves the x-ray transparency of the injured person&#39;s head, thus allowing emergency medical personnel to take x-ray of an injured person&#39;s head while it is immobilized. In the illustrative embodiment, fasteners  140  and  155  are hook and loop fabric tape-style fasteners that are attached to blocks  110  and  105 , respectively, for fastening straps  130  and  145 . It is noted that any fasteners, such as buttons, additional straps, etc., may be used.  
     [0064] To ensure comfort, foam pads  160  and  165  are riveted to blocks  105  and  110  on their surfaces that come in contact with the patient. An additional foam pad  170  is attached to headboard  115  via double-sided tape to cushion the back of the head and to prevent sliding. Pads  160 ,  165 , and  170  may be made with foam of a color dissimilar to the color of human blood. Advantageously, a used pad ( 160 ,  165 , or  170 ) may be easily identified and removed to be decontaminated and/or replaced.  
     [0065] As shown in FIG. 1, headboard  115  may be attached to a spine board  102  by means of 3 straps  175 ,  180 , and  185  (see also FIGS. 6, 7, and  12 ).  
     [0066]FIGS. 2A and 2B depict blocks  110  and  105 , respectively, being attached to headboard  115  using lock members  125  and  120 , and illustrate the three ways that blocks  110  and  105  may be adjusted to fit the head of an injured person. Illustratively, as shown in FIG. 2B, block  105  is attached to headboard  115  by engaging lock member  120  to slot  205  in headboard  115  through a slot  210  in block  105 . Block  105  may be slid laterally (to and from the center of headboard  115 ) along slot  205 , longitudinally along slot  210 , and rotated relative to headboard  115  in 5 degree increments (∓10 degree range) around lock member  120 . Correspondingly, as shown in FIG. 2A, block  110  may be operated in a similar manner on the opposite side of foam pad  170  along slot  215  of headboard  115  and slot  220  of block  110 . Thus, blocks  105  and  110  are respectively slid within a respective single slot  205  and  215  provided on both sides of foam pad  170  of headboard  115 .  
     [0067]FIGS. 3, 4A, and  4 B illustrate the two-part construction of lock member  120 , which enables a fit adjustment stage and a locking stage. By pushing lock member  120  down to a fit adjustment stage while in the configuration illustrated in FIG. 2, block  105  is physically connected to headboard  115  but can still be longitudinally and laterally adjusted along slot  210  and rotationally adjusted around lock member  120 . The locking stage, enabled by further pushing down on lock member  120 , fixes block  105  in place.  
     [0068]FIGS. 5, 6A, and  6 B illustrate parts of block  105  and headboard  115 , respectively, that interact with lock member  120  for locking block  105  to headboard  115 .  
     [0069] With reference to FIGS. 4A, 4B,  6 A, and  6 B, the fit adjustment stage is engaged with two flexible fingers  405  and  410  on the lower half of lock member  120  each engaging slot  205  of headboard  115 , thus locking block  105  vertically in place. In the fit adjustment stage, block  105  may still be rotated around lock member  120  and slid longitudinally along slot  210  of block  105  and laterally along slot  205  of headboard  115 .  
     [0070] Referring now to FIGS. 3, 5, and  6 B, the locking stage is engaged with rows of teeth  305  and  310  on the upper part of lock member  120  each locking into a respective rack of teeth  505  and  510  on block  105 , thus fixing block  105  longitudinally and rotationally. Lateral motion is also fixed by further deflecting flexible fingers  405  and  410  respective racks of teeth  605  and  610  in slot  205  of headboard  115 .  
     [0071] In the locking stage, block  105  can be unlocked for removal or for readjustment (in the adjustment stage) by pressing an unlock lever  515 , as shown in FIG. 5, on the upper lock part of lock member  120  and lifting up. Pressing lever  515  disengages it from a locking tab  615  (shown in FIG. 6B) in lock member  120  and disengages each set of teeth  305 ,  310 ,  405 , and  410  from their respective rack  505 ,  510 ,  605 ,  610  by simply lifting lock member  120 , thus allowing block  105  to once again ratchet along the surface of headboard  115  with three degrees of freedom, as illustrated by FIGS. 2A and 2B. In the unlocked state, block  105  can also be disconnected from headboard  115  by pulling up on it. Correspondingly, the operation of block  110  is the same as that of block  105  described above.  
     [0072] FIGS.  7  to  11  illustrate, step-by-step, the immobilization of a patient using head immobilization apparatus  100  according to the above-described embodiment of the invention. As shown in FIG. 7, the first step is to attach base headboard  115  to one end of spine board  102 . Straps  175  and  180 , which are riveted to headboard  115  on one side, loop around and under spine board  102  and fasten back to headboard  115  via clips  705  and  710  on the other side.  
     [0073] With headboard  115  in place, spine board  102  can be easily stored with no need to remove headboard  115  until cleaning is required. As shown in FIG. 8, the patient is placed onto spine board  102  with his head centered on foam pad  170 . Each block ( 105  and  110 ) and lock member ( 120  and  125 ) assembly is then placed into headboard  115  on either side of the head. Block adjustments are then made in an effort to restrict head motion and to center the ear in arch opening  157 , as shown in FIG. 9. Once the desired position of a block ( 105 ) is established, the user pushes down on the lock member ( 120 ), fixing the block ( 105 ) in place, as illustrated in FIG. 10. Preferably, an audible sound and/or visual cues may be provided to notify the user when the lock member ( 120 ) is fully engaged.  
     [0074] As shown in FIG. 11, with both blocks ( 105  and  110 ) fixed snuggly against the patient&#39;s head, the two head-straps ( 130  and  145 ), made of loop material, are pulled taut across the chin and the forehead and fastened to the adjacent block ( 105  and  110 ) where a patch of fastening material ( 140  and  155 ) is provided. In this condition, the patient&#39;s head is fully immobilized.  
     [0075]FIG. 12 is an exploded view of head immobilization apparatus  100  in accordance with an embodiment of the invention. For clarity of illustration, block  110  and lock member  125  have been omitted from FIG. 12 with the understanding that they correspond to block  105  and lock member  120 , respectively. As shown in FIG. 12, block  105  is attached to headboard  115  by engaging lock member  120  to slot  205  in headboard  115  through slot  210  in block  105 .  
     [0076]FIGS. 13A, 13B, and  13 C illustrate a flat storage position of head block  105  (and  110 ) (FIG. 13A) and an upright deployment position thereof (FIG. 13B) in accordance with an embodiment of the invention. As shown in FIG. 13A, head block  105  comprises a hinge portion  1305  that allows an upper portion  1310  of block  105  to rotate 90 degrees to the upright deployment position shown in FIG. 13B. Corresponding snap hooks  1315  and  1320  and snap holes  1325  and  1330  snap into engagement and lock head block  105  in the upright deployment position of FIG. 13B. It is noted that the snap engagement of hooks  1315  and  1320  to holes  1325  and  1330  can be disengaged to restore block  105  to the flat position of FIG. 13A for storage. Referring back to FIG. 1, it is further noted that strap  145 , rivet  150 , and releasable fastener  140  are arranged on block  105  in an identical manner as strap  130 , rivet  135 , and releasable fastener  155  of block  110 . Alternatively, as illustrated by FIGS. 12, 13A, and  13 B, head block  105  may comprise strap bridges  1205  and  1210  for accommodating the equivalent of straps  130  and  145  described above. As described before, blocks  105  and  110  may be interchanged on either side of the injured person&#39;s head. In other words, head blocks  105  and  110 , according to an embodiment of the present invention, are identical with no differentiation between left and right head blocks. Furthermore, blocks  105  and  110  may be molded flat, as shown in FIG. 13A, and snapped into place upon deployment, as illustrated by FIG. 13B. Consequently, the manufacture of head blocks  105  and  110  is simplified. FIG. 13C illustrates an alternative embodiment for a detachable snap feature  1335  (which operates in a similar manner as snap hooks  1315  and  1320  and snap holes  1325  and  1330  shown in FIG. 13A) and hinge mechanism  1340  (which corresponds to hinge portion  1305  shown in FIG. 13A) for the above-described rotating engagement of upper portion  1310  of head block  105  from the flat storage position (shown in FIGS. 13A and 13C) to the upright deployment position (shown in FIG. 13B).  
     [0077] In accordance with an embodiment of the invention, upper portion  1310  of head block  105  (and  110 ) is taper-walled, having a bell-shaped cross section, with an arch opening  157  (and  158 , as shown in FIG. 1 and described above). The shape of upper portion  1310 , in accordance with the invention, allows x-rays be taken on the cervical spine region of a patient with minimal artifacts, and unimpeded through arch opening  157  (and opening  158  of corresponding head block  110  shown in FIG. 1). Details of the bell-shaped cross section of upper portion  1310  and its reduction of x-ray artifacts will be further described below with reference to FIGS. 19A, 19B, and  19 C.  
     [0078] As described above, according to one embodiment of the invention, blocks  105  and  110  are attached and locked to separate base headboard  115 , which can be attached to spine board  102  using straps  175 ,  180 , and  185  as shown in FIGS. 1 and 6. Advantageously, straps  175 ,  180 , and  185  are disposed in such a manner that headboard  115  may be attached to a spine board ( 102 ) of any design or manufacture.  
     [0079] In accordance with another embodiment, the aforementioned features of headboard  115  may be incorporated directly to spine board  102 , whereby head blocks  105  and  110  may be attached directly to spine board  102 . FIG. 14 illustrates blocks  105  and  110  attached directly to a spine board  1400  using lock member  120  and lock member  125  (not shown), thus omitting base headboard  115 . FIG. 15 depicts spine board  1400  without blocks  105  and  110  attached thereto. As shown in FIG. 15, spine board  1400  includes a single slot  1405  and  1410  to engage a respective head block, which are functional equivalents of slots  205  and  215  of headboard  115 . Block  105  may be attached to spine board  1400  by engaging lock member  120  to a slot  1405  in spine board  1400  through a slot  210  in block  105 . Block  105  may be slid laterally (to and from the center of spine board  1400 ) along slot  1405 , longitudinally along slot  210 , and rotated relative to spine board  1400  in 5 degree increments (∓10 degree range) around lock member  120 . Correspondingly, block  110  may be operated in a similar manner along slot  1410 . Thus, blocks  105  and  110  may be respectively slid within a respective single slot  1405  and  1410  provided on both sides of a center portion of spine board  1400 . By decreasing the total number of parts (base headboard  115 ) and attachments thereof (straps  175 ,  180 , and  185 ), this embodiment reduces the storage space required, and improves x-ray clarity and patient immobilization.  
     [0080] The lock member ( 120  and  125 ) for engaging a head block ( 105  and  110 ) to a base board ( 115  or  1400 ) described thus far is based on the positive engagement of meshes of gear teeth. When a head block ( 105  and  110 ) is connected to the base board ( 115  or  1400 ) using the lock member ( 120  and  125 )(where a bottom portion of the lock member may include a mechanism for movably attaching to a slot in the base board through a slot in the head block), the head block may be adjusted longitudinally (along the long axis of the backboard), laterally (towards the centerline of the board), and rotationally around a locking mechanism ( 120  and  125 ). By pushing down on the locking mechanism ( 120  and  125 ), the user may lock the three adjustment components into place. This locking step causes two locking fingers to deflect into the gaps between rows of teeth in the base, holding the head block ( 105  and  110 ) in position laterally. This user action is also simultaneously meshing two sets of teeth on the handle with teeth on the head block ( 105  and  110 ), effectively fixing the head block ( 105  and  110 ) longitudinally and rotationally. A lock member ( 120  and  125 ) based on mechanical engagement is very strong and can consistently perform its function in wet, hot, and cold environments.  
     [0081] In accordance with an alternative embodiment, a head block ( 105  and  110 ) may be locked in position by friction. Instead of relying on the interference of teeth to restrict motion, high friction planar surfaces that have enough pressure exerted normal to the surfaces thereof may be used to eliminate motion between them. This alternative locking mechanism may be used particularly for the locking of a head block ( 105  and  110 ) laterally on a base board ( 115  or  1400 ). When the user pushes down on a handle, as will be described in detail below, instead of deflecting teeth into the spaces between other teeth, one flat surface is pushed against another with enough force to eliminate the possibility of slip. The contact surface may be roughened to provide a high-friction interface or a compressible material such as synthetic rubber or other elastomer could be employed to ensure a solid grip. On a microscopic level, frictional locking is very similar to the large teeth rack system: miniature “teeth” are interlocking on the adjacent surfaces thereby restricting motion. It is the high force normal to the contact surfaces that is the major difference between the two techniques. For this alternative embodiment, the part complexity is greatly reduced because rows of teeth are no longer needed.  
     [0082]FIG. 16 depicts a head block  1600 , an interfacing block  1605 , and a spine board  1610  in accordance with an illustrative embodiment of the above-described friction-based locking mechanism. As shown in FIG. 16, head block  1600  includes detachable foam pad  1607  (which is an equivalent of foam pad  160 ), a tape guiding surfaces  1612  and  1613  a tape receiving holder  1615 , a cam lock  1620 , and a notch  1625  for slidably accommodating interfacing block  1605 . A tape dispenser (not shown) is disposed under tape guiding surface  1612 . According to the invention, interfacing block  1605  may be permanently mounted on head block  1600 . As further illustrated in FIG. 16, head block  1600  is attached to spine board  1610  by sliding interfacing block  1605  into a track  1635  of spine board  1610 . Head block  1600  may be adjusted laterally (to and from center of spine board  1610 ), longitudinally (by sliding head block  1600  on interfacing block  1605  along notch  1625 ), and rotationally (by rotating around interfacing block  1605 ) before being locked into place on spine board  1610  by lowering cam lock  1620 . Head block  1600  also comprises slanted surface  1637 , which is the functional equivalent of arch opening  157 , for providing emergency medical personnel access to the side of the injured person&#39;s head, including the ear. Spine board  1610  includes a removable head pad  1640 , which is similar to head pad  170 . It is noted that head block  1600  is attached directly to spine board  1610 , corresponding to the embodiment shown in FIGS. 14 and 15.  
     [0083]FIG. 17 illustrates head block  1600  and a corresponding head block  1700  attached to spine board  1610  using a headboard  1705  (similar to headboard  115 ) so as to immobilize an injured person&#39;s head in accordance with an alternative embodiment of the invention. As shown in FIG. 17, head block  1700  comprises a tape dispenser  1710  that is similar to the dispenser under tape guiding surface  1612 . A tape receiving holder similar to holder  1615  is disposed under tape guiding surface  1715  of head block  1700 . As illustrated by FIG. 17, a tape  1720  from the dispenser under guiding surface  1612  is extended across the forehead of the patient and removably attached to the receiving holder under guiding surface  1715  of head block  1700 . Similarly, tape  1725  from dispenser  1710  may be extended across the chin of the patient and removably attached to receiving holder  1615 . Thus, tapes  1720  and  1725  perform the function of fitting head blocks  1600  and  1700  to the sides of the patient&#39;s head, which is similar to that of straps  130  and  145 . Similar to rivets  135  and  150  and fasteners  140  and  155 , the tape dispensers and receivers may be rotatable or disposed at a predetermined angle so that tapes  1720  and  1725  connected across the forehead and chin of the injured person may be angled to accommodate a wider range of head sizes. Tapes  1720  and  1725 , integrated in blocks  1600  and  1700 , allow for easy strapping of the patient&#39;s head. As described before, cam lock  1620  is used to lock block  1600  into position, and may be disengaged by lifting in the direction of arrow  1730 . As further illustrated by FIG. 17, slanted surface  1637  and a corresponding slanted surface  1735  of head block  1700  provide emergency medical personnel with access to the sides of the patient&#39;s head, including the ears.  
     [0084]FIGS. 18A and 18B illustrate an alternative embodiment of a friction-based locking mechanism for holding a head block ( 105 ) in place on a base ( 115 ). By pushing down on a handle  1805  of a lock mechanism that is similar to lock mechanism  120  (shown in FIG. 6B), an internal lock feature of the lock mechanism causes a lock section  1810  to deflect out against base slot walls  1815  of base board  115  with sufficient normal pressure to hold head block  105  in place. The friction-based locking mechanism shown in FIGS. 18A and 18B is significantly simpler than lock mechanism  120  shown in FIG. 6B, thus simplifying a manufacturing process therefor.  
     [0085] As described before, head blocks  105  and  110  may be taper-walled, having bell-shaped cross sections for minimizing x-ray artifacts. In further consideration of minimizing x-ray artifacts, head blocks  105  and  110  are preferably made from a relatively x-ray transparent material (and a disposable, cleanable, and rigid material)(e.g., a non-metallic material). FIGS. 19A, 19B, and  19 C illustrate the x-ray transparent cross-sectional structure of upper portion  1310  (of head blocks  105  and  110 ) shown in FIGS. 13A, 13B, and  13 C.  
     [0086] In order to provide sturdy head immobilization, head blocks  105  and  110  are preferably shaped so that they are sufficiently rigid. However, abrupt density (or thickness) changes of an object between an x-ray source and an image pickup, e.g., x-ray film or slide, causes x-ray artifacts. As shown in FIG. 19A, a curvilinear shape with tapered/feathered ends (or bell shape) causes significantly less x-ray artifacts than other rigid shapes, such as U-channel sections (with vertical walls) and ribbings. Therefore, as shown in FIGS. 19B and 19C, it is preferable that upper portion  1310  (of head blocks  105  and  110 ) have a cross section that is curvilinear with tapered/feathered ends (or bell shaped), and without any ribs or vertical walls.  
     [0087] As described before, arch openings  157  and  158  of head blocks  105  and  110  (as shown in FIG. 1) are provided so that the injured person&#39;s head, particularly the cervical spine area, is x-ray transparent. It is further noted that all fasteners (e.g.,  140  and  155 ) and mechanisms (e.g.,  120  and  125 ) for head blocks  105  and  110  are arranged away from the cervical spine area for similar reasons.  
     [0088] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, because certain changes may be made in carrying out the above method(s) and in the construction(s) set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. For example, the described embodiments apply to immobilizing an injured person&#39;s head. However, the invention may be applied to immobilizing other parts of the body, such as an injured person&#39;s knee, pelvis, etc.  
     [0089] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.