CA2224888A1

CA2224888A1 - Spine board

Info

Publication number: CA2224888A1
Application number: CA002224888A
Authority: CA
Inventors: Richard Sunderland; Russell Ralph Mohberg; Michael Thomas Bologovsky; John Cline
Original assignee: Individual
Current assignee: Laerdal Medical Corp
Priority date: 1996-12-24
Filing date: 1997-12-17
Publication date: 1998-06-24
Also published as: HK1014335A1; GB9727291D0; GB2320685B; US5950627A; GB2320685A

Abstract

A spine board having internal stiffening elements mechanically connected to an outer shell via a number of speed pins. A quantity of urethane foam fills the spaces between the stiffening elements and the shell. The speed pins permit the rotational molding of the shell about a pair of graphite reinforcing tubes, which better distributes the loads to be born among the outer shell, urethane filler, and stiffening elements, thereby increasing the life span of the board.

Description

SPINE soARD
Field of the Invention The present invention relates gsnerally to an improved soine board of the type employed by paramedics for transporting injured individuals.

-Backqround of the Invention Spine boards have been used by ?hysicians and emergencymedical technicians for a numb-r of years in the trans?ort o' 1~ injured or incapacitated individuals. In g-neral terms, spin-boards typically are rectangular boards on which the injured individual is placed. A serapping system is used to secure th- individual to the board. The primary purpose of the spine board is to enable the transoort of an injured ?erson without ~- injury to his s?inal column. Th- grea~ u~ility of the s?ine boa-d has led to it becomir.g one o_ .h- standard pi-ces of e?~ipment typically found in an a.~bulanca (where the scarcity o- space ?-rmits only the most useful piec~s of eauipment).

A principal functional requirem3nt o_ a spine boa-~ is that it enable the transport of an injured ~erson with~ut injury to his spinal colu~n. Therefore, th~ spinal boa-d must be rigid, even when used to trans?ort heavy patients, for e~cessive flexion of the spine board can exacerbate spinal injuries. On the other hand, it is desirable that such boards be as light as possible, since they often must be carried in unpredictable and challenging settings.
One approach to meeting these basic design criteria has i0 been to use internal stiffening elements to impart extra rigidity to the spine board. For example, one commercially available spine board employs a plastic outer shell tha~ is filled with foam. Suspended within the foa~ are reinfo-cing rods to impart some greater stiffness to the board. These , rods are free-floating within the foam, in that they are inserted into the spine board after format on of the shell and prior to addition of foaLm. Durirg use, this (and similar) s?ine boards is subjected to irregular cyclical loading as patients of varying shape and weight are placed o~, car-ied, and removed from the spine board. These loading patterrs can cause the foam adjacent the stiffening rods to compress with time, the~eby creating voids in which the stiffening elements are not properly supported. This in turn, leads to fu..her co~?ression and deformation of th3 foam du-ing loading, which

2, further compromises the struc~ural integrity of th- boa-d.
Hen_-, ther- is a n-ed .or a s?in- bca-d that is as -igid aft-r many cyclic loadinsa as it is when first loaded w th a patient, yet which also is lightweight.
Other deficiencies that other approac;~es have presented lie in the placement of stiffening elements within the central portion of the board. This can be troubleaome since pa.ients may have to be x-rayed while still on the board, and materials that are suitable for use as stiffening elements generally block x-rays. Hence, the presence of stiffening elemen~s within the x-ray field of interest may occlude the desired field of interest.

,~ .

In use, the patient is secured to the s?ine board with strapping. The manner in which an injured individual is strapped to a spine board may vary, depenaing on such divergent factors as the condition of the individual, the pref2rences of the supplier or the board, ard the economics o-various strapping approaches. There are many different types o strap?ing systems available. Unfortunatcly, some s?ine boards offer only "closed architecturen strapping systems, in that the board can not readily be modified to accept other strapping systems. There is a further need for a spine board that permits the use of a broad array of strapping elements.
consideration in the use of s?ine boards is the risk presented by microbial contamination. Injured irdividuals who ar-transported on spine boards a-e often both the source a-d 2_ re_i?ient of significant mic~obial cross cont~mination (as th-ough o?-n wounds). Such cross cont~mination may be patient to ?atient as noted, or patient to ca-e p~ovider. The-e is a need for a spine board that is resistant to micro~ial growths and that is easy to disinfect.
Summarv and Objects of the Invention It is an object of this invention to ?rovide a spine board that is rigid.
It is an object of this invention to provide a spine board that is light weight.
It is an object of this invention to ?rovide a spine board that is both light weight and sufficiently rigid to ~3 transport patients.
It is an object of this invention to ?rovide a spine board that is long-lasting in use.
It is an object of this invention to ?rovide a spine board that can be used with x-ray apparatus.
It is an object of this invention to ?rovide a spine board that permits the use of a wide arrav of stra?ping schemes.
It is an object of this invention to ?rovide a spin-board that is resistant to microbial growth.
These and other objects are met with a spine board having a rotationally molded outer polymer shell that contains both filler and discrete stiffening elements. The spine board of the present invention thus has both inner and oute~ structural elements, linked in a struc.u-ally integra~ed manr.e- during 2, th- moldirg process.
Located within the spine boa~d and in _lose p-o~imity to its outer shell are two carbon gra?hite tubes that act as stiffening elements, running approximat31y ~he leng.h of the spine boa-d. The materials of t:re s?ina board are X-ray transparent, with the exception of th- high ?roton density stiffening elements. Therefo-e, in o~der to provide an x-ray S field likely to permit visualization of most patients, the stiffening components are widely spaced apart. Mounted on each of the tubes are a series of location ?ins commonly referred to as speed pins, which are plastic elements that can be clipped or slidably mounted onto the tub3s with sufficient force so as to permit the sus?ension o th3 tubes in a mold ca~ity. The location of the speed pins is d-termined both by mechanical considerations and in consideration of the locations at which the user of the board may wish to attach strapping.
lS Each of the s?eed pins has two erds, on3 of which is connected to one of th3 reinforcing tube a-d the cther of which is connected to a rotationally molded sh311 made of high density polyethylene or other suitable material. The speed pins and r3inforcing tubes are inse-ted into a rotational mold prior to the formation of the shell, so that they are ins2rted-molded in place.
A quantity of catalyzed urethane foam fills the spaces betw3en the outer shell, spead pins, and tub3s (except for spac3s fo- hand-holds and areas wh--3 the s?e3d ?ins are ex~osed to acce~t stra~ing).
The s?in3 board affords two buil.-in ~o-ms o p~o?hylaxis against microb3s. Fi-st, as .he mat3_ial o_ the shell cools CA 02224888 l997-l2-l7 and asolidifies, it contracts about the s?ee~ pins, ?reventing th~ formation of open pockets where bacter~a can b-come established. Second, the material of the shell, s?eed pins and strapping may optionally be provided wi.h a quantity of S antimicrobial agent, added to the polymer mi~ prior to molding.
The spine board of this design thus links the outer shell, speed pins, and reinforcing tubes in a tightly integrated package that affords g-eat stif-r.ess wi~h little weisht penalty, and also is inherently resis~ant to microbial in-srowths. By insert molding the reinforcir.g elem~nts into the interior of the outer shell prior to the introduction of the urethane filler, one obtains a better distribution of the loading forces encountered during use, and tnus a ?roduct that ~5 of_ers greater longevity.

3ri ~f Descri~tion of the Fi~ur~s For a more complete understanding o,~ .his inv-ntion, re_erence should now be made to the e~-m?la-y embodiment illustrated in greater detail in the accom?anying drawings and described below. In the drawings:
Fig. lA. Is a top plan view of a s?ir.e board constructed acco-ding to the principles of the invention;
Fig. 13. IS a bottorn plan view of a s?ine boa~d 2, conatruct-d according to th- ?rinci?1-s o- ~r- invention;
Fig. 2. Is a side-elevatio?. l vi-w o- -h- spin- board of FIG. 1;

Fig. 3. Is a view of the spine board similar to th t presented in FIG. l, but further showing, in phantom, carbon fiber reinforcing tubes.
Figs. 4 - 7 are sectional views of the spine boarc of FIG. 3, taken along sections I-I, II-II, III-III, and TV-IV
respectively, in which the speed pins are not shown.
Fig. ~ is a sectional view of the spine board take~ along line IV-IV of FIG. 3, further showing the use of speed ?ins and differentiating between the outer shell and urethar.- core 1~ of the spine board.
Fig. 9 is a perspective view of the speed ?in and its connection to the graphite reinforcing tube.
Fig. 10 is a sectional ~iew of an embodiment of the spine board, taken along line III-III of FIG. 1, in which the ~, reinforcir.g tubes are mechanically linked to the outer shell by webbing.

Detailed Descri~tion Refe-ring now to the drawings, wherein like numerals indicate like parts throughout, the principal components of a preferred embodiment of a spine board 10 are illustrated in Figs. 1 - 3. The spine board comprises an outer shell 12, a pair of reinforcing tubes 50 (shown in phantom in FIG. 3), and a series o speed pins 40 tha. link the reinforcing tubes 50 2, to the sh~ll 12. The s?ace betweer. the outer shell and the rein_orci-.g tubes and sp--d ?irs is filled with a foam material 30 of uniform distribution and density.

The shell 12 has an upper surface 12a or bearing a patient, an underside 12b that can be ?laced to rest either o-.
ground or on a gurney, a head portion 12c and a foot portion 12d. The head portion 12c is provided with an attachment means (such as a hole 16) for facilitating attachment of certain cervical immobilization devices. Such devices are often used with spine boards to help prevent injury to the spinal column, particularly the cervical region or neck, during patient trans-er to a medlcal acility. For ex~m?le, O the cervical region of the patient's s?ine (which is especially vulnerable) is typically secured and immobilized using a cervical collar, such as that disclosed in U.S. Reissue Patent No. 32,219 to Garth.
Other head and neck securing devices can be used with ~~ this spine board in addition to or in ?lace of a cervical collar. These vary in design, and th- ins.ant spine board 10 is designed to acco~modate thes-. On- ex~mple of an immobilization devic- that can be used with this board in conjunction with a ce-vical collar is set forth in U.S. Patent No. 5,360,393 to Garth et al. This patent discloses a disposable cardboard, plastic film and adhesive system which attaches to spine boards by m-ans of an adh-sive-backed tape.
This device is used to minimize rotational movement of the ?atient's s?inal col~mn during patient tr~ns?ortation.
2, The und-rside 123 of the spine board outer sh-ll 12 is ?rovided with a se-ies of g-ound contact s-ctions 20 (see Fig.
2) on which the s?in- board can rcst when ?laced on the ground. These contact points 20 are fo~led in the outer shell about the reinforcing tubes 50 (which are furth-~ discussed below).
The peripheral portions of the s?ine board 10 are provided with a series of hand holes 22A-F and lifting handles 23A-F, spaced along the perimeter of the s?ine board. The spine board 10 can be hand-carried by two or more paramedics lifting the spine board 10 by these handles 23. Generally speaking, at least two individuals are em?loyed to effectively ~C ca.ry a patient strapped to the s?ine board 10. ~owever, the spine board can, under certain circumstances, be dragged by a single paramedic. If necessary, a lone paramedic can lift the spine board 10 via the handles 23A located at the head of the board, and drag it along the sround on detachable wear skids 1, 26 optionally located at the underside of the foot region 12d or head region 12c to protect th- spine board from abrasion.
Of course, the spine board lO can b- dragg-d along its other end as well.
The patient will generally be secured to the s?ine board by means of straps crossing the ?atient's abdomen, extremities (legs and feet), and thoracic region. Such straps are ty?ically adjustable in order that the required degree of tightness may be achieved as is dic~ated by the patient's condition. Certain trauma condi; ons may cic_a,e varying 2, d-g~ees ol~ unrestricted access to th- pati-nt. ~s r.oted, such st-a?ping may b- ?rovided in a r~-.~-r of ways. Therefor3, the spine board is d-signed to allow as much flexibility in selection of strapping as is reasonably pOSa ble without compromising the structural and mechanical as?ects of the product's design. The spine board iO provideas an open a-c:~itecture with respect to the strapping it will S accommodate, in that it can accommodate a wide array of straps and strapping systems.
For example, the periphery 14 of the s?ine board 10 is curvillnear or undulating, so as to allow the use of cer.ain "Wra?-Around" techniques of patient securement. "Wrap-Around"
~O describes the application of a single stra? to the spin- board 10. The undulating edges 14 of th- spine board 10 caus- the stra?â to tighten as the patient shifts, th--eby preven.ing th- patient from slipping longitudinally on the spine board 10. In certain circumstances, as when a pa.ient must be moved with his head elevated above the level of his feet (this can occur when he is being moved down a staircas_), such s-~urement is ?articularly useful in ?reven~ing longitudinal sli?page of the strapping. This feature is of particular im?ortance to air lift paramedics.
In addition to the use of the single-s~rap wrap around method, multiple straps may be em?loyed. These are attached to the spine board 10 via standard clips hooked to one or more of the speed pins 40 located i-, the s?eed pin holes 28 on the la~eral sides of the board. The stra?s em?loyed may be 2, dis?osable or non-disposable, ar.~ can vary i- ler.gth o- width, as well as in the ?articular hardw~-e by which th-y are at.ached to the s?ine board. (~xam?les of s.-a??irg a?proaches are set forth in U.S. Patent No. 5,211,186 to Shoemaker et al. and U.S. Patent No. ~,79~,o56 to Henley, th~
contents of which are incorporated herein for this purpose.) The s?eed pins 0, hand holes 22, and periphery of the board afford a wide array of strapping options for most patients. However, some patients may be of such small stature (e.g., children) that it may be desirable to provide a narrower wrap than the outer periphery of the board can provide. To that end, more medially located pediatric C strapping slots are provided to facilitate the immobilization of children, for whom the outer strap?ing areas may be tOO fa~
a?art for proper securement.
A series of flattened recessed areas '9 is located an th~
underside 12B of the outer shell (see Fig. 13), intermediate 1- the hand holes 22 and pediatric holes 24. These recesses 19 hel? guide the placement of the straps about the board.
One of the fundamental d-sign conside-ations of a s?ine board is that it be rigid, particularly in the sense of resisting ,lexion about its midline axis (s-e Fig. 1), where bending under the weight of a patient is most likely to arise.
On the other hand, it is desirable to make the spine board as light as possible, so as to facilitate its use in what are often haza-dous and unpredictable circumstances. Prior a??roaches to these design corsiderations have often led to 2, one consid=ration being ?ermittQd to domir.at- the o.her.
The ?--sent spine board 10 provid-s both s-eat rigidity and light weight - the s?ire board weighs a??roximately il -16 pounds. This is accomplished via a sys em of reinfo-cing tubes 50 that impart rigidity to the shell 12 of the s?ine board 10 ~ia a link provided by the s?eed pins 40. The interlocking nature of these elements is established both through their particular design and by the manner in which the board is manufactured, which shall now be discussed.
Briefly, the skeletal elements of th- spine board are first assembled and placed within the cavity of a rotational mold. The skeletal elements comprise the graphite tubes 50 and the s?eed pirs 40. The outer shell 12 is then rotationally molded about the skeletal elements, causing the outer shell 12 to surround and encase the interior elements.
The interior spaces are then filled with a semi-rigid foam 30.
~ Two pultruded graphite tubes 50, mad- of a unidirectional ~inyl ester/carbon fiber material, are em?loyed as the primary skeletal stiffening elements. While other materials can be used for the stiffening elements (e.g., glass reinforced plastics, phenolic and fabric composites, e?oxy glass reinforced materials etc.), th- use o gra?hite tubes is preferred as this material and shape ?ro~ides great rigidity with little penalty for weight.
The tubes 50 are each connected to a series of speed pins ~0 (see Figs. 8 and 9). Th~se speed pins ~0 are made of a material which is sufficiently the-m~ally s.able that it can 2, make contact with the hot mold surfaces of a rotational r..old without de'eriorating, r"-lting or breaking down. In general, the material employed r.,~st be able to withs.an.d tem?eratur-s in excess of 400 degrees Fahrenheic. They must also offer a high degree of mechanical integrity ir. use when subjected to the kinds of stresses which the se_urement of a patient to the soine board will likely impose on them, and be cost-effective.
~aterials suitable for this purpose include vinylester with carbon fiber strands, polyphenylene sulfide, polysulfone, polyester, polyetherimide, polyetheretherketone, phenolic, urea formaldehyde, melamine, various thermosetting injection moldable plastics, cast and machine aluminum, monel, and other lG metals. Additionally, wire forms, ?ressure stamped sheet metal materials and investment cas~ings can be emoloyed, although a polymer such as vinyl ester carbon fiber is preferred due to its superior strength to weight ratio.
In the illustrated embodiment, six s?-ed pins 40 are 1~ connected to each tube 50, although a fewe- or greater number of speed pins 40 can be used. The n~mbe~ and location of the s?-ed pins 40 em?loy~d is driven by two considerations.
~irat, in the finished board 10, their expcsed central po-tions 41 (the only portion visible as it projects through th- wall of the rotationally mold-d outer shell 12) provide locations along which straps can be attach-d via quick-action cli?s - hence the term "speed pin". (Alterratively, the clip ?o-tion of the speed pin can b- a co~?lete ring of material tha; is then slid onto th- reir.-orc ng tu~-.) Second, the 2, s?--d ?ins 40 also serve as locatior.al el-~-nts durirg th-fo-mation of the out-- shell 12, c -ir.s wn.i_h .hey hold the reinforcins tubes 50 in plac- withir. the cavity o- the rotational mold prior to and during moldiny. The~eafte- they continue to provide a measure of mechanical linkaye betwecn the tubes 50 and the outer shell 12.
The speed pins 40 are snap-fitted to the reinLorciny 5 tubes S0 via curved, snap-on portions 42 located a~ the medial ends of the speed pins 40 (see Figs. ~ and 9). At thei-lateral extremities 46, the speed pins 40 terminate with a locating tab 44A which, in conjunction with the locatins tab 44~ on the medial end of the speed pin, enable the mold

3 o?-rator to locate and fix the speed pins 0 in s~ace within the rotational molding tool employed. Hence, th- initial ste?
in the manufacture of the spine board calls for establishing a framework of speed pins 40 and reinforcing tubes S0 that are held in place within a rotational mold prior to the i, introduction of any molding material. By insert moldir.g the r-inforcing tubes 50 and speed pins ~0 in ?lace, they can be pOâi tioned very close to where the outer shell 12 is fo~ed, in the region between the hand holes 22 ar.d the pediatric holes 24 (see Figs. 4 - 7, which further illustrate the location of the reinforcement tubes 50).
Providing such close proximity of th- tubes 50 to the outer shell 12 offers several advantages over prio-ap~roaches. First, it facilitates the for~ation of webb ng of tr.- material of the shell onto th- r-inforcing tub-s 50 durir.s th- rotational molding of th- shell. Such conn-ctions s-rve to further lin~ the tubes with the shell. (This as?ect c- th-inv-ntion is utiliz-d in the embodiment discuss-c furtr.--below with respect to FIG. 10.) Second, by locating the reinforcing tubes 50 near the lateral peri~hery of the board, they leave the central portion of the board clear of stiffening elements that could interfere with the x-ray visualization the patient.
Once the speed pins 40 and reinforcing tubes 50 are in place within the mold, the mold is rotated and filled with a ~uantity of molten polymer, such as high density polyethylene.
The rotation of the mold tool causes the molten polymer to i0 flow to the inner walls of the mold, thereby forming the rotationally molded shell 12. This process is approximately twenty minutes in length.
The rotational mold will reach temperatures of up to 500 Degrees Fahrenheit. However, the most uniform ambient temperatu~e will likely be in the region of 350 to 400 Degrees Fahrenheit. The graphite tubes 50 are held in place using plastic molded components, i.e., the speed ?ins 40 (now serving as localization d-vices) positioned along the 13ngth of the reinforcing tubes 50. The reinforcing tubes 50 do not make direct contact with the surface of the rotational mold at any time during this process. During this process the molten material of the shell adhe~_s to the outer (lateral) ends of the speed pins, providing both a firm mechanical connection and a he~.,.-tic seal of th- sh-ll 12 againa-~ th- speed pins.
2, The thickness of the shell varies, frcm a maximum thickness of .15 inches in th- r-gions of th- handles (wh3r3 stresses a_e a t to be hish-s~), to .09 inches elsewhere.

Fu-Lher control over the thickness of any ~art of the sh~ll can b2 ex3rcised by varying the tem?~-a~u-~ of th~ facing por~ion of the mold (the material terds to build up most eff2ctiv21y when the temperatu,e is great2st).
As is conventional in molding ?~ocess2s, the outer shell 12 is formed with limited number of entry and venting ports 60. These ports are used for the purpose of filling the product with stiffening foam 30, and for venting air or other gases from the product when the foam is introduc2d into the G system.
Once the shell is formed, both it and its internal framewor.~ are removed from the rotational mold and permitted to cool, during which time the material of the shell contracts so~;e so as to form a hermetic seal against the s?eed pins. At , this poi~t, the reinforcement tubes 50 are connected to the outer shell by the speed pins ~0. This m~_nanical link can be ausmented with webbing betw~2n insid2 wall of th~ outer shell 12 and the reinforcement tubes 50.
In standard rotational molding ?roceà~.es, care must be taken that facing interior walls not be too close to one another, lest the material of the walls "we2" across the gap during the molding process. This can be used to positive effect in the manufacture of the s?ine boa-d 10, as is illustrated in the embodim2nt sho~r. i? FI~. 10. 'ier2, 2, s~l~cted ?ortions of the reinfo-cing el~.m2?.~s 50 are fu-ther bou?d to .he shell 12 via a w2b o- ma-2-ial that e~terds from facing ~a-ts of th- outer shell to ~r_i.cl~ and bound the reinforcing elements 50. In effect, the ~e~bing acts as a conrector element, linking the reinforcing elements to .he outer shell 12. The degree to which this occurs is depen.dent u?on the spacing between these elements, and further va-ies along the longitudinal extent of the reinforcing tubes 50, being complete in the cross-section shown in FIG. 10, but less complete at other locations (so as to penmit the subsequent flow of filler 30 into the periphery of the spine board 10).
This connection further integrat~s the reir~orcing elem~nts ~0 and spine board shell together into a mechanically unitary structure.
Once the rotationally molded outer shell 12 has been formed, it is filled with a ~uantity of liquid foam, which im?arts additional strength and rigidity to the s?ine board as ', it solidifies. One foam which may be employed is catalyzed urethane foam. A n~bsr of filling p-ocesses may be em?loyed, ir-luding reaction injection molding (~ I), in which a single or multi-component chemical system is injected in such a marner as to utilize the rotationally mold-d component of the spine board as a mold in its own right.
The foam 30 is injected into the shell 12 by means of the ent-y ports 60 located in the back of the s?ir,e boa-d (see FIG. lB). (Alternatively or additionally, the reinforcing tubes 50 ~..ay be provided with holes s~ tha. they car. b~ used 2, as conduits to channel the cataly7ed u--than- foam to th-e;ct_emities of the s?ine boa.d 10.) ~- th s manr.e-, th-ro.a_ionally molded component of the s?ire board outer shell 12 is u.ilized as a mold for rec~iving th~ urethan~ foam 30.
During this operation the spine board is ~eld in form-followirg wooden jigs to prevent the s?in~ board from distorting under the injection and ex?ansion pressures of the urethane foam.
Once the foam has set, the s?ine board is released from the jigs. At this stage circular injection molded closures, in the form of caps, are placed into the filling and venting ~orts on the back of the spine board. These circular caps are ~' "Spln-Welded" into ?osition in the conventional manner in order co hermetically seal off the interio- of the spine board from its exterior. Such sealing greatly reduces the likelihood that the interior of the board will b-come a source of infection, and also simplifies the ste?s that must be taken to cl-an and disinfect the board b-tw-en uses.
A further pro?hylaxis against bacteria and other microb-s can be ?rovided by th- material o- the boa-d itself. A time-release antimicrobial additiv- may be placed within the material of the spin- board. In g-neral t-rms, the additive 23 must be sufficiently stable so as to withstand the thermal stresses presented by the rotational molding process without significant reduction in efficacy, ard must be suitable for contact with a ?atient's skin. Such additives are commercially available, as for exaLm?le, ar ad~i~iv- manufactured by 2, ~Iicroban ~rodu~ts Co~?any, o~ Yu-.e-sville, North Carolina ~ha. is sold und-r the trad- name ~Iic~ob2r.3. The additiv- ca?.
be com?ounded ir.to the -aw mol~ir.c m2t--ia's em?loy-d fo~ the 1~

speed pins 0, outer shell 12, or sc-ap?i ng The antimicrobial additive resides, a-.er molding of the plastic material, within the inters~itial s?aces o_ the polymer. The apparent relatively higr va?or ?resau e of some anti-microbial additives causes the additive to ~-lease slowly over time.
Therefore, the spine board has "Antimicrobial Time Release"
properties, providing an additional measure of protection against bacteria.
It is often desirable to provide molded-in graphics in a spine board, often using block le~tering. However, such block lettering may be incompatible wieh the us- of an antimicrobial agent in the shell, as it may present a r-gion where the agent is ineffective. This problem can be avoid-d by using a molded-in g-aphic system utilizing s?ecially designed "outline i5 lettering". Such lettering is selected to be of a thickness and type and style suitable to allow ~eliznce on the efficacy of an ".~-~imicrobial Zon- o_ Inhibition", 2S this is defined by the Kirby-Bauer Test Methodolosy. Drovided that no ?oint contained within th- two dimensional gra?hic symbols used is further away from th- outer boundary of the graphic symbology than twice the effective "Zone of Inhibition" of the ~ntimicrobial Spine board, the agent will still be effective in use. This ensu-es that bact-ria are ~e?t to a minimum across the whole S?ine boa-d, and that th--- a-e no regions of the gra?hics which lack e~~f--tiv- a-..imic-o~ial activity.
Thus, the ?-esent inv-n.ion ?~OViC'a a hygienic, ligh.
w-ight spin- boa~d that r-mains risic th-ough many uses.

Claims

What is claimed is:

1. A spine board comprising:
an outer shell;
at least one stiffening element located within the space defined by the outer shell;
at least one connector linking the stiffening member to the outer shell; and a filler between the stiffening member and the outer shell.

2. A spine board as set forth in claim 1, wherein the connector has two ends, one of which is attached to the stiffening element and the other of which is connected directly to the outer shell.

3. A spine board as set forth in claim 1, wherein the stiffening elements are elongated rods.

4. A spine board as set forth in claim 1, wherein the stiffening elements are tubes.

5. A spine board as set forth in claim 4, wherein there are two stiffening elements.

6. A spine board as set forth in claim 5, wherein the stiffening elements comprise graphite.

7. A spine board as set forth in claim 6, wherein the stiffening elements are pultruded.

8. A spine board as set forth in claim 6, wherein the stiffening elements comprise a vinyl ester-carbon fiber material.

9. A spine board as set forth in claim 1, wherein the are two stiffening elements and a plurality of connectors linking each of the reinforcing elements with the outer shell.

10. A spine board as set forth in claim 9, wherein the outer shell is made of a polymer.

11. A spine board as set forth in claim 10, where the outer shell is made of high density polyethylene.

12. A spine board as set forth in claim 10, wherein the outer shell forms a hermetic seal with the connectors.

13. A spine board as set forth in claim 10, further comprising handles along the periphery of the board.

14. A spine board as set forth in claim 10, further comprising an antimicrobial material that is an integral part of the outer shell.

15. A spine board as set forth in claim 10, further comprising a series of webs of material extending from the shell to the stiffening elements.

16. A spine board as set forth in claim 10, wherein the proximity of the connectors and reinforcing elements to the outer shell is such as to encourage the formation of webbing from the inside surface of the outer shell to the connectors and the reinforcing elements.

17. A spine board comprising:
a polymeric outer shell defining an interior space and having an upper surface, a lower surface, and a peripheral surface linking the upper surface to the lower surface, said outer shell having a length and a width;
at least two stiffening members located within the outer shell, said stiffening members extending approximately the length of the outer shell of the spine board; and connectors linking the stiffening members to the outer shell.

13. A spine board as set forth in claim 17, further comprising an antimicrobial material that is an integral part of the outer shell.

19. A spine board as set forth in claim 17, further comprising a series of webs of material extending from the shell to the stiffening members.

20. A spine board as set forth in claim 17, wherein the proximity of the connectors and stiffening members to the outer shell is such that it encourages the formation of webbing from the inside surface of the outer shell to the stiffening members and connectors.

21. A spine board as set forth in claim 17, wherein the stiffening elements comprise granite.

22. A spine board as set forth in claim 21, wherein the stiffening elements are tubular.

23. A spine board as set forth in claim 17, wherein the stiffening elements are located rear the periphery of the spine board.

24. A spine board as set forth in claim 17, wherein the spine board comprises a series of handles located along the periphery of the spine board.

25. A spine board as set forth in claim 24, wherein the handles each comprise a hole that passes through the spine board.

20. A spine board as set forth in claim 15, further comprising a plurality of pediatric holes for facilitating the securement of children to the spine board with strapping.

27. A spine board as set forth in claim 15, further comprising:
a plurality of hand holes along the periphery of the spine board; and a plurality of pediatric holes inwardly located from the hand holes for facilitating the securement of children to the spine board;
wherein the stiffening elements are positioned within the outer shell between the hand holes and the pediatric holes.

28. A spine board as set forth in claim 17, wherein the periphery of the spine board is curvilinear.

29. A spine board as set forth in claim 17, wherein the lower surface of the spine board has a plurality of protrusion for serving as ground contact locations.

30. A spine board as set forth in claim 17 further comprising wear skids.

31. A spine board as set forth in claim 30, wherein the wear skids are detachable from the spine board.

32. A spine board as set forth in claim 17, wherein the connectors are made of a material that can maintain its mechanical integrity after being heated to 400 °F.

33. A spine board as set forth in claim 17, wherein the connectors are made of plastic.

34. A spine board as set forth in claim 19, wherein the connectors have first and second end portions and a central, pin-like portion.

35. A spine board as set forth in claim 29, wherein one of the end potions of the connectors is imbedded within the material of the outer shell and the other of the end portions of the connectors is directly connected to one of the stiffenings elements.

36. A spine board as set forth in claim 35, further comprising locating tabs for facilitating the location of the connectors within a mold.

37. A spine board as set forth in claim 35, wherein the spine board is manufactured by rotationally molding the outer shell about the connectors and stiffness members so as to bring about the bridging of liquefied material from the inside surface of the outer shell to the connectors and the stiffening elements.

38. A spine board as set forth in claim 30, wherein the end of the connectors that is connected to the stifffening element clips onto the stiffening element.

39. A spine board set forth in claim 30, wherein the connectors are configured so that they can be slid onto the stiffening elements.

40. A spine board as set forth in claim 30, wherein the spine board has a plurality of holes near the periphery of the spine board, and the connectors project through the walls of the outer shell at these holes, thereby exposing the central pin-like portion of the connectors.

41. A spine board as set forth in claim 32, wherein the central pin-like portion of the connector is configured to receive the attachment hardware of a strap.

2. A spine board as set forth in claim, 32, wherein the material of the outer shell seals against the connectors where they penetrate the outer shell of the spine board.

43. A spine board as set forth in claim 17, further comprising foam between the outer shell and the stiffening elements.

44. A spine board as set forth in claim 43, wherein the foam is of the urethane type.

45. A spine board as set forth in claim 4, wherein the foam is catalyzed urethane foam.

46. A method for manufacturing a spine board, comprising the steps of:
affixing a plurality of speed localization elements having two ends to two carbon graphite reinforcing tubes;
mounting the free ends of the localization elements to the inner wall of a rotational mold;
closing the mold;
charging the rotational mold cavity with a quantity of liquid polymer; and rotating the mold so as to foam the outer shell of the spine board.

47. The method of claim 45, wherein during the step of forming the outer shell liquefied polymer bridges from the inner wall of the mold to the reinforcing tubes, thereby forming the outer shell liquefied polymer bridges from the inner wall of the mold to the reinforcing tubes, thereby further connecting the reinforcing tubes to the outer shell.

48. The method of claim 46, further comprising the steps of:
removing the outer shell from the mold; and charging the cavity within the outer shell with foam.

49. The method of claim 6, wherein the polymer material from which the outer shell is formed contains an antimicrobial additive.

50. A spine board comprising:
a polymeric outer shell defining an interior space and having an upper surface, a lower surface, and a curvilinear peripheral surface linking the upper surface to the lower surface, said curvilinear peripheral surface facilitating the use self-tightening strapping systems with the spine board;
and speed pins for facilitating the attachment of strapping to the spine board, said speed pins being hermetically sealed along selected portions with the respect to the shell.

51. A spine board as set forth in claim 50, further comprising a quantity of antimicrobial additive in the outer shell, said antimicrobial additive in the spine board having a zone of inhibition.

52. A spine board as set forth in claim 51, further comprising graphics on the outer shell in the form of outline graphics, the thickness of the outline of such graphics being such that no point contained within the graphics is further away from the outer boundary of the graphic than twice the effective zone of inhibition of the antimicrobial additive in the spine board.