CROSS REFERENCE TO RELATED APPLICATIONSThis application is a continuation in part of application Ser. No. 06/943,655, filed Dec. 17, 1986 now abandoned.
BACKGROUND OF THE INVENTIONThis invention relates to cervical collars worn to immobilize or restrict the movement of the head.
Cervical collars are generally of two types, either stock ("off-the-shelf") in various sizes, or customized ("made-to-fit") for the individual patient. Because of the additional time, equipment and labor involved, the customized collar is less popular than the stock collar which can be made available in different standard sizes to accommodate various heights and circumferences of the neck.
The desirable qualities of a stock cervical collar include comfort, support and durability. Comfort requires that all portions of the collar in contact with the neck be soft and flexible, and also that the collar be lightweight. Support requires a certain amount of rigidity to immobilize the head and neck, with respect to both forward-backward and side-to-side movement. Durability requires that the collar not tear or lose its qualities of comfort and support, or otherwise wear out during a period of use exceeding several weeks or months.
In addition to the foregoing, the ideal cervical collar would be simple and economical to manufacture.
Heretofore, stock cervical collars have failed to meet one or more of these requirements. Exemplary of such prior art collars is that described in U.S. Pat. No. 3,756,226 which is commonly known as the Philadelphia collar. While perhaps the most popular of stock collars, the Philadelphia collar has several drawbacks. The Philadelphia collar has front and back halves made of a foam polymeric material which are held in place by an adjustable strap secured to each half by rivets extending through the foam material. Rigid reinforcing members are positioned vertically at the bight of each half, i.e. under the chin and along the spine at the base of the head. The foam polymeric material does not support the head so that side-to-side movement thereof is not adequately inhibited by the reinforcement added only at the bights. Moreover, the foam material tears easily, especially adjacent the strap. The reinforcement under the chin is uncomfortable because the support of the chin is concentrated on the relatively small area of the reinforcing member in contact with the chest, and also because the reinforcement is secured tightly to the neck against the trachea or Adam's apple.
Other types of prior art cervical collars are seen in U.S. Pat. Nos. 4,205,667; 3,662,057; 3,504,667; 3,042,027; and 2,818,063.
SUMMARY OF THE INVENTIONThe present invention is a cervical collar having preformed front and back halves and an adjustable strap for holding the halves in position to encircle the neck. The front and back halves are preformed from a laminate comprising outer layers or sheets of foam polymeric material and an inner layer or sheet of solid or non-foamed thermoplastic material. The foam outer layers provide comfort, while the solid insert provides reinforcement for support and durability. The strap may be secured to the front half of the collar by stitching at ends of the front half, and to the back half by looping through parallel slots formed in the rearmost portion thereof. In this manner, no protrusions or rivets are made to contact the wearer, and all portions of the collar in contact with the wearer are soft and flexible for complete comfort.
In a preferred embodiment, a large hole is formed in the front most portion of the front half to correspond to and accommodate the trachea or Adam's apple.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a perspective view of the collar in place on a person's neck;
FIG. 2 is a perspective view of the front and back halves of the collar disassembled;
FIG. 3 is a perspective view of the front half of the collar as viewed from the front;
FIG. 4 is a perspective view of the back half of the collar as viewed from the back;
FIG. 5 is a sectional view of the back half of the collar along the lines 5--5 in FIG. 4;
FIG. 6 is a sectional view of a portion of the strap as secured to the front half of the collar along the lines 6--6 in FIG. 3;
FIG. 6A is a sectional view of a portion of the front half of a modified collar securing strap;
FIG. 7 is a sectional view of the front half of the collar along lines 7--7 of FIG. 3; and
FIG. 8 is a sectional view of the back half of the collar as seen along thelines 8--8 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTSWith reference to the drawings, thecervical collar 10 includes afront half 12, aback half 14 and a releasable strap means 16. The front andback halves 12, 14, are provided in a laminate or sandwich construction including theouter layers 20, 22 and theinner layer 24 as best seen in FIGS. 5, 6, 7 and 8. The material of theouter layers 20, 20', 22, 22' is a foam polymeric material such as, for example, polyethylene or polyurethane. The foam material is preferably soft and pliable for comfort, yet tear resistant for durability. A suitable commercially available foam material is foam polyethylene sheet sold by Voltex under the trade designation Volara 4E3/16.
The material of theinner layer 24 is a semirigid or rigid sheet of a solid thermoplastic material such as, for example, a LDPE or LLDPE polyethylene or high density polypropylene. A suitable commercially available solid material is 100 mil LDPE sheet sold by Bisby Co., Portsmouth, NH.
Theinner layer 24 is substantially coextensive with theouter layers 20, 22 except for theedges 26, 28, 26', 28' of eachhalf 12, 14 respectively, of thecollar 10. This results in an unreinforced or padded periphery of about 5-20 mm along theedges 26, 26', 28, 28' of eachhalf 12, 14 for comfort at the points of contact with the head, neck, shoulders, etc. As seen from FIG. 6, reinforcinglayer 24 also stops short of the ends of the collar halves, such that the ends are flexible and in the case of the front half, short of thestitching 56 fastening the straps to the collar half.
Thefront half 12 is generally U-shaped, is wider at the frontmost portion 30 and tapers both in height and in thickness toward theends 32, 34 which correspond to the respective sides of the head and neck. The frontmost portion 30 has adepression 36 formed in the top edge thereof to receive and support the chin. If desired, additional padding may be provided in thechin depression 36 in the form of moleskin orflannel pad 38 which may be glued or otherwise secured in thedepression 36. The front most portion extends downwardly from the top edge to abottom edge 28 that engages the chest of the user.
Theback half 14 is generally U-shaped, is widest at the rearmost portion 40 and tapers both in height and in thickness toward theends 42, 44 which correspond to the respective sides of the head and neck. The rearmost portion 40 is curved in the vertical direction to correspond to the shape of the base of the head and neck along the spine.
The front andback halves 12, 14 are secured in place on the neck by releasable strap means 16. Theends 32, 34 of thefront half 12 overlap therespective ends 42, 44 of theback half 14 to provide continuous encircling support around the entire neck inhibiting side-to-side movement of the head. Forward motion of the head is restricted by the frontmost portion 30 of thefront half 12 which prevents downward movement of the chin by transmitting force from thechin depression 36 to the bottom of the frontmost portion 30 in contact with the upper portion of the chest along the clavicles and the sternal notch. Rearward movement of the head is restricted by the rearmost portion 40 of theback half 14 which transmits force from the base of the head at the top of the rearmost portion 40 to the bottom of the rear portion 40 in contact with the upper part of the back and shoulders along the trapezius muscles and the spine.
Releasable strap means 16 is preferably a hook and loop fabric fastener comprisinghook attachment material 50 andloop receiving material 51 sold under the trademark Velcro but alternatively and less preferably could be buckles, snaps, buttons, or the like. In the preferred embodiment, thestrap 16portion 52 spans the outer perimeter of thefront half 12 and is securely fastened thereto at theends 32, 34 by stitching 54, 56 or other suitable fastening means. Asecond portion 58 spans the outer perimeter of theback half 14, being looped throughparallel slots 60, 62. Thesecond portion 58 is generally of uniform width exceeding the length of theslots 60, 62 and has anarrow portion 64 corresponding to theslots 60, 62. Thenarrow portion 64 has a width equal to or less than the length of theslots 60, 62. The second portion of thestrap 16 is prevented from slipping with respect to theback portion 14 by means of its generally uniform width exceeding the length of theparallel slots 60, 62 through which it is looped.
Preferably, aloop fabric 51 is affixed to thestrap portion 52 and thestrap portion 58 has terminal ends withhook fabric 50. Alternately, buckles 64, 66 (see FIG. 6A) may be attached to each end of thefirst strap portion 52 by looping the ends of theportion 52 through the respective buckles 64, 66 and doubling them over at thestitching 54, 56. The ends of thesecond strap portion 58 can then be looped through the respective buckles 64, 66 and doubled over to mate the surfaces such as 50, 51, thereby securing the collar in place.
A plurality ofperforations 70 may be formed in the front and back halves 12, 14 to permit ventilation. In addition, alarge hole 72 may be formed in thefront half 12 at thefront portion 30 to correspond to and accommodate the enlarged portion of the trachea at the base of the neck for added comfort. This is a distinct advantage over the collar of U.S. Pat. No. 3,756,226 because the external reinforcement of that collar at the bight prevents any such accommodation of the Adam's apple and instead presses tightly against it.
The manufacture of the present collar is simple and economical. The layers, 20, 22, 24 are cut to shape from a sheet of the respective materials for the front and back halves 12, 14. The sheets are then placed in their respective positions and heated sufficiently to form the laminate by bonding or fusing of the opposing surfaces of theinner layer 24 to the adjacent surfaces of the opposing surfaces of theinner layer 24 to the adjacent surfaces of theouter layers 20, 22 and by bonding or fusing of the opposing surfaces of theouter layer 20 and theouter layer 22 at theedges 26, 28. Theparallel slots 60, 62, and if desired, the air holes 70 and thetrachea hole 72, are then cut in the laminate. The laminate is then heated above its glass transition temperature and formed into the appropriate shape by compression molding, cooled in the mold and then removed. The edges are then trimmed and thestrap 16 attached by stitching to thefront half 12 and looping through theparallel slots 60, 62 on theback half 14.
The collar may be made available in various sizes of height and diameter to accommodate varying sizes of necks, ranging from heights of 3 to 6 inches and internal diameters 31/4, 41/4 and 51/4 inches and diameters 91/2, 10, 1/2, and 121/2 inches will provide 9 standard sizes which will comfortable and supportively fit most any neck.