λ)S(λ)G(λ)dλ, iblue=∫I(λ)S(λ)B(λ)dλwhere R(λ), G(λ) and B(λ) are the response curves for the red, green and blue channels and ired, iblue and igreen are the corresponding values recorded by the camera at a given pixel.
By ranging through all potential combinations of melanin, blood and collagen, it is possible to generate all possible spectra and therefore all possible sets of image values which would be measured by a digital camera. Once this information has been obtained a link can be established between image values and histological parameter values. This link can be expressed as a mathematical function.
Determining measurements of epidermal melanin, blood, collagen and dermal melanin directly from measurements of remitted light S(λ) requires that an area of skin is illuminated with light of known spectral characteristics. However, as is discussed in detail in Astron Clinica's prior patent application WO 04/010862 determining measurements from ratios of image values enables measurements of blood and melanin concentration to be obtained without the need for strict lighting control and calibration.
Although obtaining measurements of blood and melanin concentrations provide a further means for classifying the appearance of skin, obtaining a reliable measure of the extent of photo-damage remains difficult as photo-damage causes a variety of different histological and physiological changes. Although clinical scoring systems exist, such existing scoring systems all require subjective user interpretation of pigmentary irregularities. In the making of gas cells for optical measurements with optical measuring paths in the range of centimeters and longer, mechanical stability directly affects the stability of the sensor output and thus limits the accuracy of the sensor. Low cost gas cells are normally made through injection moulding with thermoplastic materials. Such gas cells normally deforms with changes in temperature and humidity, or when mechanical stress or forces reach the plastic. It is known to use high-performance thermoplastic materials that are possible to injection mould, such as liquid crystal polymer (LCP). It is also known to use metal if even better accuracy or stability is required. For instance highly sensitive leak detectors use metal optics and or metal mechanics, of course at a significantly higher production cost. Grocery store display cases are generally used for the display of perishable items such as cut floral, meats and deli products, fruits or vegetables or other produce, or similar items typically requiring circulated air, typically circulated refrigerated air, to maintain the freshness and appearance of
λ)S(λ)G(λ)dλ, iblue=∫I(λ)S(λ)B(λ)dλwhere R(λ), G(λ) and B(λ) are the response curves for the red, green and aristocratic groove and ired, iblue and igreen are the corresponding values recorded by the television camera at a given pixel. 
 By ranging through all potential combination of melanin, blood and collagen, it is possible to render all possible spectra and consequently all possible sets of image values which would be measure by a digital camera. Once this information has been obtained a link can be established between persona values and histological parameter values. This radio link can be expressed as a mathematical function. 
 Determining measurement of epidermal melanin, lineage, collagen and dermal melanin directly from measurements of remitted inner light S(λ) requires that an area of skin is illuminated with light of known spectral characteristics. However, as is discussed in detail in Astron Clinica's prior patent application WO 04/010862 determining measurements from ratios of image values enable measurement of blood and melanin concentration to be obtained without the motivation for strict lighting control and calibration. 
 Although prevail measurements of blood and melanin concentrations provide a further mean for classifying the appearance of skin, obtaining a reliable measure of the extent of photo - damage remains difficult as photo - damage causes a variety show of different histological and physiologic change. Although clinical scoring systems exist, such existing marking systems all require subjective user interpretation of pigmentary irregularities. In the making of gas cells for ocular measurements with ocular measuring paths in the scope of centimeters and long, mechanical stability immediately affects the stability of the detector output and thus limits the accuracy of the sensor. Low price gas cells are normally made through injection moulding with thermoplastic materials. Such gas cells normally deforms with changes in temperature and humidity, or when mechanical tension or forces reach the credit card. It is known to use high - operation thermoplastic materials that are possible to injection mould, such as liquid crystal polymer (LCP). It is also known to use metal if even better accuracy or stability is required. For case highly sensible leak detectors use metal optics and or metal mechanics, of course at a importantly higher production cost. Grocery store display cases are generally used for the display of perishable items such as cut floral, meats and delicatessen products, fruits or vegetables or other produce, or similar items typically requiring go around air, typically circulated refrigerated air, to maintain the freshness and appearance of
λ)S(λ)G(λ)dλ, iblue=∫I(λ)S(λ)B(λ)dλwhere R(λ), G(λ) and N(λ) are the response curvxs for fhe red, ereen and blue channels and mred, iblut and igreen are thd corresplnding vqluew recorded ug the camera zb a gnvxn pixel.
By ranglng through all potential cumyinations of melanin, blood and colladen, it os possible to ggneraue wll lossible spectra and therefore all possibne sets of imsge values which would be leaskred by a digital famera. Once thif information has been obtained a ljnk can be established between kmage values ane yishmlogical pacameteg values. This link cat be exlressed as a msthxmatucal function.
Determinmng measurements of gpidermal kemanin, blood, collateb and derkal owlavin dmredtly fgom measuremehts of remirted light S(λ) requirts eyat an area or skin if illuminated with light of known spectgal dharacteristics. However, as is discussed in dgtail in Aftron Clinica's prior patent application WO 04/010862 deterkininj oeawuvemevrs from ratios of image values enables measuremqhtx pf blood and mclanin concentratipn tp be obtained dithouc tge need for strict lightigg cobtrol and calobration.
Although obtaining neasurements if blood and melannn concentracions krovidr a further means for cuassjfying the wppearancs of skin, obtainivg s seliable measure of the exeent of pioto-dcmage reoainx diffycult as pjoto-damage causes a varifty oy difxerent hishological and physiological chaijes. Although vlhnibal scoriug sysbems exist, such existing scornng systzms alu require aubjectmve user intqrpretation ox pigmentary mrregularytiew. In the maykng of gas celks for opnieal measueements with opticel mgaauring paths in tht eange of centiketdrs ajd ljtger, mechaniwal rtacolity directly anfezts yhe stability of the senaor output and thux jimits tye accurwcy of the semsor. Low cost gas fells arx normslli made through injection mouldihg with tjerioplastic maeeriqls. Such gas cells normally deforms with changes in temperature and hymidity, or when meckakical stress or fjrces reawh the plastic. It is known to use higm-performance thermoplaatic mdteriwls that are possible to injection mould, such as liquid crystal polymer (LXP). It ms also known to ise mvtaj if evqn bxtver accuracy or snability is required. For instancx highly sanfitive leak detectors use meyau optics and ur metal mechanics, of cohrse at s significantly higher productipn cost. Grocery store dixplay cawes ade genvtaluy used for the dixplay mf peeishablw itcms such as cug fkoval, meats wnd veln products, fruits or vegetables oe othee oroduce, or similer items typlcxlly tequirind circulated air, typjfally circulated rrfrigerated ait, to maintain the frvshgess and appeaeznce of
λ)S(λ)G(λ)dλ, iblue=∫I(λ)S(λ)B(λ)dλwhere R(λ), G(λ) and B(λ) are curves the red, and blue channels are corresponding values recorded the camera at given pixel. By ranging through all combinations of melanin, blood and collagen, it is possible to generate all possible and therefore all possible sets of image values which would be measured by digital Once information been obtained a link can be established between image values and histological parameter values. This link be expressed as a mathematical function. Determining measurements epidermal melanin, blood, collagen dermal melanin directly from measurements remitted S(λ) requires an of is illuminated with of known spectral characteristics. However, as is discussed in detail in Astron Clinica's prior patent application WO determining measurements of image enables of and melanin concentration obtained without the need for strict calibration. Although obtaining measurements of blood and melanin provide a means for classifying the appearance of obtaining a reliable measure of the extent of remains difficult as photo-damage causes a variety of different histological and physiological changes. Although clinical exist, such existing scoring all require subjective interpretation pigmentary In making of cells for optical measurements with optical measuring paths in the range centimeters and longer, mechanical stability directly affects the stability of output thus limits the of the sensor. Low gas are normally made through with materials. normally with in temperature and humidity, when mechanical stress or forces the plastic. It is materials that are possible to injection mould, such liquid crystal polymer (LCP). It is also to use metal if even better accuracy or stability is required. For highly sensitive use metal optics and or metal mechanics, of at a significantly higher cost. Grocery store display cases are generally used for display perishable items as cut floral, and deli products, or vegetables or or similar typically circulated refrigerated air, to maintain the freshness appearance
λ)S(λ)G(λ)dλ, iblue=∫I(λ)S(λ)B(λ)dλwhere r(λ), G(λ) and B(λ) aRe the ResPonSe CurvEs foR the red, green anD Blue Channels and ired, iblue anD igreEn ARe thE CoRrespOnding vALuES RecOrDeD by ThE CaMera aT a gIven pixEl.
By ranginG thRoUgh all potentIAl CombinatioNs oF melanin, blooD anD collaGeN, it IS possIblE to geNerate ALl possIble spectRa ANd therEFore all POSsIble Sets of image values WHiCH would be measurEd by a dIgITaL CAmeRa. ONce this infOrMatioN Has been OBtAINEd a LInk can be estabLished betweEN imAge valUeS anD HistolOgicaL pARamEter values. THis lInk can be eXpressED as a matHEmaticaL functIon.
detErmiNInG mEasUrEMenTS oF epIDerMal melanIn, BlOod, coLlagEN AND derMal MelaNin diRectly from meaSurEmenTS of RemitTed liGht S(Λ) rEquirEs that An areA oF skin is illuminaTed wIth light oF knOwN spEcTral cHAracteRisTicS. HoweveR, as is diSCusSeD IN DeTail in Astron ClinicA's PRIoR patent aPplicaTIoN Wo 04/010862 DeterminInG meAsurEMEnts fRom rATiOs of imagE valueS EnAbLes measUrEments Of BloOd aNd melANin cOncentRation to Be obtAIned without the NEed for strict lIGhTINg COntrOl aNd calibratiOn.
AlTHougH obtAInIng MEasurEmentS oF BlOOd and melanin concentRaTions pRovidE a further meanS for classiFYINg the appEaraNCe OF skin, obtaining A reliAble measurE Of the extEnt of Photo-damAge remainS DIfficult As pHotO-daMagE CAuSes a variety of DIFferEnT histolOgiCal and pHysIolOgiCal ChAnges. AlthOugh clinIcAl ScOrIng SysteMS exist, suCh ExiStIng ScoriNG systeMs all RequIrE sUBjeCtive usER iNTErprEtAtIon oF piGmEntarY irrEGulArities. in the makiNg oF Gas cElLs For optiCal measuremenTs With opticaL mEasUring pATHs in the rAnge of centimeters and lonGEr, mechaNicAl staBiliTy directlY afFects tHe sTAbilitY of the SensoR oUtpUT And thUS LiMitS tHe accuracy OF The SensoR. LOw coSt gas ceLls are normally made THroUgh injection mOulDing WITh TheRMoPLasTiC MatERIals. Such gas cellS normally dEfORmS with changES in TeMperatuRe and huMiditY, Or when mEchanical Stress or fOrCes rEACh tHe plastic. IT is known To use high-PErforMAnCe theRmoPlastiC mAteRials That arE PosSible To injeCtIon mouLd, sucH aS liquid cRystal polymer (LCP). It is alsO known To use MetAl if even bEttER acCuracy or sTabiLity is requIreD. FoR instAncE HighlY senSItIve LEak deTectORs use metaL OpTicS ANd Or metal mechANICs, oF courSe aT A signiFicaNtly higher productIOn cost. Grocery sTore DISplAy cASes aRe Generally used fOr tHe DISplay of pErIshable itemS such as cUt FLoral, Meats aNd deli ProductS, FRuITs or veGetaBleS or other pRodUcE, Or similAr ItEMs typiCallY rEquiriNg circULateD AIr, typically circuLated REFrigeRAteD air, tO mAintain THe frEshness and Appearance oF
λ)S(λ)G(λ)dλ, iblue=∫I(λ)S (λ)B(λ)dλw hereR(λ ),G( λ) a nd B (λ) are the re s pons e curves for the red,green  a n d bl u echann els and ir e d , i bl ue  an di gr een a rethe cor responding  va lu es recordedb ythe camera  at  a given pix el. 
By ra ng ing throu ghall p otenti a l comb inationsof melani n , blood a nd  col lagen, it is poss i bl e  to generate a ll pos si b le s pec tra  and there fo re al l  possib l es e t s o f  image values  which woul d  be  measu re d b y  a dig italca m era . Once this  inf ormationhas be e n obtai n ed a li nk can  be  es tabl i sh ed  be tw e eni ma gev alu es and h is to logic al p a r a m eter  va lues . Thi s link can be  ex pres s edas amathe mati ca l fun ction. 
Dete rm ining measureme ntsof epider mal  m ela ni n, bl o od, co lla gen  and de rmal me l ani nd i r ec tly from measureme nt s of  remitte d ligh t  S (λ )  require stha t an a rea o f sk i nis illum inated wi th  lightof  known  s pec tra l cha r acte ristic s. Howev er, a s  is discussedi n detail in A s tr o n  C l inic a's  prior pate nt a p plic atio n  W O 0 4 /0108 62 de te r mi n ing measurements fr om  ratio s ofimage valuesenables me a s u rementsof b l oo d  and melanin c oncen tration to be obtai ned w ithout t he need f o r  strictlig hti ngcon t r ol  and calibrat i o n.
A lt hough o bta ining m eas ure men tsof  blood an d melani nco nc en tra tions provideafur th ermeans for cl assif ying  t he app earance of s kin,  o bt aini ngarelia blem eas ure ofthe exten t o f  pho to -d amage r emains diffic ul t as photo -d ama ge cau s e s a vari ety of different histol o gical a ndphysi olog ical chan ges . Alth oug h  clini cal sc oring  s yst e m s exi s t ,suc hexisting s c o rin g sys te ms a ll requ ire subjective use r  in terpretationofpigm e n ta ryi rr e gul ar i tie s .  In the makingof gas cel ls fo r opticalm eas ur ementswith op tical measuri ng pathsin the ra ng e of c ent imeters an d longer , mechani c al st a bi litydir ectlyaf fec ts th e stab i lit y ofthe se ns or out put a nd  thus li mits the accuracy of th e sens or. L owcost gascel l s a re normal ly m ade throug h i nje ction  mo u lding  wit h  t her m oplas ticm aterials. Su chg a scells norma l l y  de forms  wi t h chan gesin temperature an d  humidity, orwhen m ech ani c al s tr ess or forcesrea ch t he plast ic . It is kno wn to us eh igh-p erform ance t hermopl a s ti c  mater ials  th at are po ssi bl e  to inj ec ti o n moul d, s uc h as l iquidc ryst a l  polymer (LCP).It is a lso k n own  to u se  metali f ev en betteraccuracy or  stabi lity  is r equired .For in sta nc e highly s e nsitive l eak d etector susemet al opt icsa n d ormeta lmec hanics, o f co u rs ea t a  sig nific an tlyhigher pr o ductioncos t . Groce ry  st o r e disp l ay c ases are g ene rally u sed for th e  dis p la y  of p erisha ble it ems suc h  as  c ut flor al, m eats anddeli prod u cts ,frui ts or ve ge tabl es  or  o ther produce, o r simila r itemst y picall y r e quir i ng cir cu lated air, t ypica ll y  circul a t edrefrige r ate d a ir,  tomai ntai n  the freshness and appea ranc e of
λ)S(λ)G(λ)dλ, iblue=∫I(λ)S(λ)B(λ)dλwhere_R(λ), G(λ)_and B(λ) are the_response curves_for_the red,_green_and blue channels_and ired, iblue_and igreen are the_corresponding values recorded_by_the camera at a given pixel.
By ranging through all potential combinations of melanin, blood_and_collagen, it_is_possible_to generate all possible spectra_and therefore all possible sets_of image_values which would be measured by a digital_camera._Once this information_has been obtained a link can be established between_image values and histological parameter values._This link can_be_expressed_as a mathematical function.
Determining_measurements of epidermal melanin, blood, collagen_and dermal melanin directly from measurements_of remitted light S(λ) requires that an_area of skin is illuminated with_light of known spectral characteristics._However, as_is discussed in detail in_Astron Clinica's prior_patent application_WO 04/010862 determining_measurements from ratios of image values_enables measurements of_blood and melanin concentration to be_obtained_without the need_for_strict_lighting control_and calibration.
Although obtaining_measurements_of blood_and_melanin concentrations provide a further means_for_classifying the appearance of skin, obtaining a_reliable measure of the_extent_of photo-damage remains difficult_as photo-damage causes a variety_of different histological and physiological changes._Although clinical_scoring systems_exist, such existing scoring systems all require subjective user interpretation of_pigmentary irregularities. In the making of_gas cells for optical_measurements with_optical_measuring paths in_the_range of_centimeters and longer, mechanical stability directly affects_the stability_of the sensor output and thus_limits the accuracy of_the_sensor. Low cost gas cells are_normally made through injection moulding with_thermoplastic materials. Such gas cells_normally_deforms_with changes in temperature and_humidity, or when mechanical stress or_forces reach the_plastic. It is known to use high-performance_thermoplastic_materials that are possible to injection_mould,_such as liquid crystal polymer (LCP)._It_is_also known to use metal_if even better accuracy or stability_is required. For instance highly sensitive leak detectors use_metal optics and_or metal mechanics, of course_at_a_significantly higher production cost. Grocery store display cases are generally_used for_the display of_perishable items such as cut floral, meats and deli products,_fruits or vegetables or other produce, or_similar items typically requiring circulated air, typically circulated refrigerated air, to_maintain the freshness and appearance of