【正文】
在這個(gè)實(shí)驗(yàn)中,比較熱能性問題取得較好的結(jié)果。這種大直徑光斑的應(yīng)用導(dǎo)致了反射的輻射減小和一個(gè)更高的穿透程度。這種吸收隨著激光光斑直徑表面增加導(dǎo)致更多的光子數(shù)和油墨層散射的光斑直徑的增大。這種吸收由高斯光束入射組織時(shí)被繪制出來(lái)。這一觀察表明,應(yīng)該謹(jǐn)慎使用作為量化的熱變性在組織范圍內(nèi)的雙折射。但前期的量化數(shù)據(jù)可以得到。然而在手術(shù)中,在焊接現(xiàn)場(chǎng)周圍組織開始變紅,變白,并最終燒毀。一個(gè)較大的光斑直徑,因此使用不僅造成了更深,也更均勻的焊縫。 在附近的表皮熱變性外側(cè)區(qū)測(cè)量類似為2mm直徑的實(shí)地考察測(cè)量(p)。增加光斑直徑4mm,導(dǎo)致在焊接用的(n=7),或皮膚厚度平均深度的80%。熱變性擴(kuò)展到(n=7)(p)或皮膚厚度平均深度的 50%。形象的一個(gè)焊接用1mm直徑點(diǎn)創(chuàng)建。熱變性,觀察到570100(.,n=7)或30%的平均厚度為1900200真皮%的深度。模擬是運(yùn)行在一臺(tái)Pentium133MHz的PC計(jì)算機(jī)上運(yùn)行微軟的Windows95(微軟,微軟,WA)(美光,南帕,ID)III。在組織網(wǎng)格單元尺寸定為100m,及組織(長(zhǎng)寬深), 。請(qǐng)注意,在輻照實(shí)驗(yàn),輻照度舉行了127不變。從幾個(gè)來(lái)源匯編。他的假設(shè),避免了完整的光熱模型,將導(dǎo)致對(duì)真皮層的光子在穿透深度略有低估。三,皮膚被塑造為一個(gè)單一的假設(shè)真皮組織層,表皮和皮下組織有類似真皮的光學(xué)特性。第二,垂直油墨層建模為一個(gè)無(wú)限延伸,從皮膚表面下100m厚度的真皮作為吸收基礎(chǔ)。首先,因?yàn)樵诮M織垂直油墨層打亂了圓柱形對(duì)稱假設(shè)在原程序,數(shù)據(jù)存儲(chǔ)在直角坐標(biāo),而不是圓柱和卷積程序,不用于產(chǎn)生激光光束。所有模擬均可以運(yùn)行使用公共領(lǐng)域的代碼。用方差來(lái)確定激光光斑大小群體之間的熱變性測(cè)量統(tǒng)計(jì)學(xué)意義。測(cè)量研究組織的熱變性,觀察點(diǎn)。熱變性是指從縫合中心在三個(gè)不同深度的方向延伸:乳突狀真皮,中真皮,以及真皮基地。6mm直徑的光斑用于實(shí)驗(yàn),發(fā)現(xiàn)傷口部位有非常明顯的燒傷,因而停止實(shí)驗(yàn)。每個(gè)激光光斑直徑和光束最少進(jìn)行七次實(shí)驗(yàn)。背側(cè)皮膚,包括表皮和真皮,是用手術(shù)刀切除,然后切片??偨Y(jié)了這項(xiàng)研究的激光參數(shù)。傳遞到每塊肌肉組織的能量與功率計(jì)(MolectronPOWERMAX5100,波特蘭,OR)連接。W [在全最大(FWHM)全寬]。實(shí)驗(yàn)是在恒定光照下(127掃描每個(gè)縫合點(diǎn),光束在縫合點(diǎn)每次掃描10s停止一次??p合的進(jìn)行是用連續(xù)波(CW),Nd:YAG激光(李激光,型號(hào)703T)(托爾實(shí)驗(yàn)室,牛頓,新澤西州)。將試驗(yàn)品俯臥放置在實(shí)驗(yàn)臺(tái),為手術(shù)準(zhǔn)備。用15號(hào)手術(shù)刀在平行的脊柱進(jìn)行了2cm長(zhǎng)的全層切口。每個(gè)豚鼠被麻醉用阿托品( mg/kg),氯胺酮(30 mg/kg),甲苯噻嗪(2 mg/kg)腹腔注射給藥。材料和方法A實(shí)驗(yàn)在表面切口內(nèi)部縫合是在不斷進(jìn)行輻照,調(diào)查在縫合時(shí)各種激光光斑尺寸效應(yīng)的熱變性程度(1,2,4,6mm直徑的半高寬)。蒙特卡羅模擬表明,光子吸收最均勻分布是通過(guò)使用大口徑雙平頂光束。4實(shí)驗(yàn)結(jié)果表明,1激光光斑直徑是不同的,從1到6mm。本文對(duì)蒙特卡洛模擬也不斷進(jìn)行研究。W。1,2,4和6將實(shí)驗(yàn)白鼠背部去毛切開2cm長(zhǎng)的全層切口,用夾子在切口邊緣附近固定。 a large number of photons was used to create the desired beam pro?le. Second, the vertical ink layer was modeled as an in?nite absorber extending from the skin surface to the base of the dermis with a uniform thickness of 100 m. The experimentally measured absorption coef?cient for the ink, was 3500 cm. Even though histologic analysis of the welds showed variable staining of the tissue with a lateral thickness varying from 40 to 100 m, since the ink layer thickness was much greater than the probability that a photon could cross the ink layer was negligible, and the assumption that was in?nite is reasonable. Third, the skin was modeled as a single dermal tissue layer with the assumption that the epidermis and subcutaneous tissue have optical properties similar to that of the dermis. Finally, even though the optical properties of tissue are known to be temperaturedependent, with the dermal scattering coef?cient initially increasing with temperature for temperatures less than 60 C then decreasing sharply at higher temperatures and the dermal absorption coef?cient decreasing with increasing temperature , the optical properties in this model were assumed to be static. This assumption, which avoided a plete opticalthermal model, will result in a slight underestimation of the penetration depth of the photons in the dermis. The optical properties of guinea pig skin at a wavelength of have not been well characterized. The optical properties for human, pig, and rat dermis were therefore. piled from several sources. The optical properties used in the Monte Carlo simulations are listed in Table II. Note that in the experimental irradiations, the irradiance