外文翻譯---激光的組織接合激光束光斑尺寸和研究概況

1、<p><b>　　附錄A 英文原文</b></p><p>　　Laser Tissue Welding: Laser Spot Size and Beam Pro?le Studies</p><p><b>　　Abstract：</b></p><p>　　This paper evaluates the

2、 effect of laser spot diameter and beam pro?le on the shape of the thermal denaturation zone produced during laser tissue welding. 2-cm-long full-thickness incisions were made on the epilated backs of guinea pigs in vivo

3、. India ink was used as an absorber and clamps were used to appose the incision edges. Welding was performed using continuous-wave 1.06-m, Nd:YAG laser radiation scanned over the incisions to produce 100-ms pulses. Laser

4、 spot diameters of 1, 2, 4, and 6 mm</p><p>　　Index Terms— Denaturation, laser biomedical applications, laser materials-processing applications, laser welding, Monte Carlo methods, optical propagation.</p

5、><p>　　MATERIALS AND METHODS</p><p>　　Experiments</p><p>　　In vivo welding of skin incisions was performed at constant irradiance to investigate the effect of various laser spot sizes

6、(1-, 2-, 4-, and 6-mm-diameter FWHM) on the extent of thermal denaturation at the weld site. Adult female albino guinea pigs (Hartley, age 7–8 weeks, weight 400–500 grams) were shaved then epilated with a chemical depila

7、tor (Nair,Carter-Wallace, Inc., New York, NY). Each guinea pig was anesthetized with atropine (0.05 mg/kg), ketamine (30 mg/kg), and xylazine (2 mg/kg) adm</p><p>　　Welding was performed with a continuous-wa

8、ve (CW), Nd:YAG laser (Lee Laser, Model 703T) emitting 1.06 radiation that was coupled into a 600 -core diameter optical ?ber (Thor Labs, Newton, NJ). A stepper-motor-driven translation stage (Newport, Irvine, CA) scanne

9、d the laser beam along the axis of the weld site at speeds that effectively produced 100-ms-long pulses. Seventy scans were made along each weld; the beam stopped at the end of the weld site for 10 s after each scan. To

10、minimize thermal d</p><p>　　After welding, the anesthetized guinea pig was euthanized with an intracardiac overdose of sodium pentobarbitol (Nembutal, Abbott Laboratories, North Chicago, IL). The dorsal skin

11、, including epidermis and dermis, was excised with a scalpel and then sectioned. Samples were processed using standard histological techniques, including storage in 10% formalin, processing with graded alcohols and xylen

12、es, para?n embedding, sectioning, and hemotoxylin and eosin staining. A minimum of seven samples was </p><p>　　Thermal denaturation measurements were made using a transmission light microscope (Nikon, Japan)

13、 ?t with crossed linear polarizers (Prinz, Japan). Thermal denaturation was measured laterally from the center of the weld site at three different depths: the papillary dermis, mid-dermis, and base of the dermis. The dep

14、th to which one observed denaturation was recorded and divided by the skin thickness to obtain the fraction of a full-thickness weld that was achieved. Measurements were made consisten</p><p>　　Statistical a

15、nalyzes were conducted on the histological data. ANOVA was used to determine statistical signi?cance of thermal denaturation measurements between laser spot size groups.</p><p>　　Monte Carlo Simulation</p

16、><p>　　Monte Carlo simulations were run to investigate the effect of various spot sizes (1–6-mm diameters) and beam pro?les (Gaussian versus ?at-top and single versus dual beam) on the distribution of absorbed

17、radiation. All simulations were run using code available over the public domain . Several changes were made in the Monte Carlo code to adapt it for use with the geometry of this application. First, because the vertical i

18、nk layer in the tissue disrupted the cylindrical symmetry assumed in the Orig</p><p>　　Third, the skin was modeled as a single dermal tissue layer with the assumption that the epidermis and subcutaneous tiss

19、ue have optical properties similar to that of the dermis. Finally, even though the optical properties of tissue are known to be temperature-dependent, with the dermal scattering coef?cient initially increasing with tempe

20、rature for temperatures less than 60 C then decreasing sharply at higher temperatures and the dermal absorption coef?cient decreasing with increasing temperatur</p><p>　　III. RESULTS</p><p>　　A.

21、 Experiments</p><p>　　Histologic analysis showed that only shallow welds were achieved using a 1-mm-diameter laser irradiation area. Thermal denaturation was observed only to a depth of 570100 (meanS.D.,n=7)

22、 or 30% of the average dermal thickness of 1900200 , see Table III. Thermal denaturation lateral to the incision was limited to near the tissue surface. An image of a weld created with a 1-mm-diameter spot is shown in.&l

23、t;/p><p>　　When the laser spot diameter was increased to 2 mm, thermal denaturation was observed down to the middle layers of the dermis, as show. The thermal denaturation extended to an average depth of (n=7)(

24、p<0.001) or 50% of the dermal thickness. This depth was signi?cantly greater than achieved with a 1-mm-diameter spot Signi?cantly more lateral thermal denaturation was also measured at the surface of the skin, m, than

25、 for the 1-mm-diameter spot.</p><p>　　Increasing the spot diameter to 4 mm resulted in welds with an average depth of (n=7) , or 80% of the dermal thickness。The depth of these welds was signi?cantly greater

26、than that produced in both the 1-mm- and 2-mm-diameter spot studies(p<0.001).The lateral zone of thermal denaturation near the epidermis measured similar to that measured for the 2-mm-diameter spot study Signi?cantly

27、more thermal denaturation was measured in the middle layers of the dermis for the 4-mm-diameter spot(,n=7), than f</p><p>　　Experiments performed with a 6-mm-diameter spot resulted in full-thickness welds of

28、 in depth. During surgery, however, the tissue surrounding the weld site began to redden,blanch, and eventually burn. Due to concerns over the welfare of the animals, these experiments were terminated before statisticall

29、y signi?cant quantitative data could be obtained.</p><p>　　It should be noted that in some places where there were signi?cant tinctoral and textural changes to the collagen ?bers that made the tissue appeare

30、d completely denatured, signi?cant collagen birefringence was often still present. In such cases,we measured to the edge of the region of tinctoral and textural change. This observation suggests that one should be carefu

31、l when using birefringence as a tool for quantifying the extent of thermal denaturation in tissue.</p><p>　　B. Monte Carlo Simulations</p><p>　　It shows the effect of laser spot diameter on the

32、absorption pro?le. absorption is plotted as a function of the depth into the tissue along the ink layer for an incident beam with a Gaussian beam pro?le. The absorption at the surface(d=0.0mm) is due to direct absorption

33、 of the incident radiation by the ink layer as well as absorption of backscattered radiation. The absorption immediately beneath the surface increases with increasing laser spot diameter because a larger number of photon

34、s are back</p><p><b>　　附錄B 中文譯文</b></p><p>　　激光的組織接合：激光束光斑尺寸和研究概況</p><p><b>　　摘要：</b></p><p>　　本文主要研究在激光縫合肌肉組織時(shí)激光光斑的熱變性對(duì)縫合效果的評(píng)估。將實(shí)驗(yàn)白鼠背部去毛切開2cm長(zhǎng)的

35、全層切口，用夾子在切口邊緣附近固定。進(jìn)行縫合的是采用連續(xù)波1.06 Nd：YAG激光器掃描輻射對(duì)切口產(chǎn)生100ms脈沖。1，2，4和6 mm激光光斑直徑進(jìn)行了研究，其能量分別為1，4，16，36 W。輻照度維持為127。本文對(duì)蒙特卡洛模擬也不斷進(jìn)行研究。激光光斑的大小以及光束中光子的分布在內(nèi)部被吸收。激光光斑直徑是不同的，從1到6mm。高斯，平頂，雙高斯，雙平頂光束剖面進(jìn)行了研究。實(shí)驗(yàn)結(jié)果表明，1 ，2&#

36、160;，4 和6mm直徑的斑點(diǎn)產(chǎn)生的熱變性的平均深度分別為570，970，1470和1900m。蒙特卡羅模擬表明，光子吸收最均勻分布是通過使用大口徑雙平頂光束。</p><p>　　關(guān)鍵詞：激光生物醫(yī)學(xué)應(yīng)用，激光材料加工應(yīng)用，激光縫合，蒙特卡羅方法，光的傳播。</p><p><b>　　材料和方法</b></p><p><

37、b>　　A實(shí)驗(yàn)</b></p><p>　　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）。把成年白鼠（哈特利，年齡7-8周，體重400-500g）用化學(xué)脫毛劑脫毛（奈爾，卡特 - 華萊士公司，紐約，NY）。每個(gè)豚鼠被麻醉用阿托品（0.05 mg/kg），氯胺酮（30 mg/kg），甲苯噻嗪（2 mg/kg）

38、腹腔注射給藥。把1％利多卡因與1:10萬腎上腺素作為局部麻醉用在每個(gè)切口部位。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。拿微吸管將大約2-5升墨汁（印度Rapidograph黑色油墨，3080- F，100納米顆粒的直徑，酸值INoor，Bloomsbury區(qū)，新澤西州）分別適用于傷口邊緣。將試驗(yàn)品俯臥放置在實(shí)驗(yàn)臺(tái)，為手術(shù)準(zhǔn)備。夾子被用來在縫合時(shí)放在附近的切口邊緣固定?？p合的進(jìn)行是用連續(xù)波（CW），Nd：YAG激光（李激光，型

39、號(hào)703T）發(fā)光1.06輻射成600芯徑光纖（托爾實(shí)驗(yàn)室，牛頓，新澤西州）。用電機(jī)驅(qū)動(dòng)（新港，爾灣，加利福尼亞州）沿傷口控制縫合速度，有效地生產(chǎn)的100ms長(zhǎng)的脈沖激光束的軸。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><p>　　接合后，實(shí)驗(yàn)白鼠是安樂死于過量的鈉pentobarbitol（戊巴比妥，雅培公司，北芝加哥，IL）。背側(cè)皮膚，包括表皮和真皮，是用手術(shù)刀切除，然后切片。樣品處理采用標(biāo)準(zhǔn)

40、組織學(xué)技術(shù)，包括10％的福爾馬林存儲(chǔ)，與分級(jí)醇，二甲苯，石蠟包埋，切片，HE染色和hemotoxylin和處理。每個(gè)激光光斑直徑和光束最少進(jìn)行七次實(shí)驗(yàn)。 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)。熱變性測(cè)量是用透射光顯微鏡（Nikon，日本）配合（普林茨，日本）線性偏光片。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。深度觀察每一個(gè)變化的記錄和皮膚的厚度為獲得一個(gè)完

41、全縫合后接合處最小的部分。測(cè)量研究組織的熱變性，觀察點(diǎn)。統(tǒng)計(jì)分析是進(jìn)行實(shí)驗(yàn)的數(shù)據(jù)。用方差來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。</p><p><b>　　B.蒙特卡羅模擬</b></p><p>　　蒙特卡羅模擬是調(diào)查各種斑的大?。? – 6mm直徑）和光束剖面（高斯與平頂，單與雙光束）對(duì)吸收的輻射分布的影響。所有模擬均可以運(yùn)行使用公共領(lǐng)域的代碼。一些變

42、化的蒙特卡洛代碼，用來適應(yīng)與此應(yīng)用程序使用它的幾何形狀。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。光束剖面，而是創(chuàng)建使用一個(gè)隨機(jī)數(shù)發(fā)生器，大量的光子被用來創(chuàng)建所需的光束。第二，垂直油墨層建模為一個(gè)無限延伸，從皮膚表面下100m厚度的真皮作為吸收基礎(chǔ)。為實(shí)驗(yàn)測(cè)量油墨的吸收系數(shù)，被3500cm，即使對(duì)焊縫組織學(xué)分析表明有橫向從40到100米不等厚度組織變量染色，由于

43、油墨層厚度比越大概率是一個(gè)光子可以穿過油墨層可以忽略不計(jì)，并假設(shè)是無限的，是合理的。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。最后，即使組織的光學(xué)特性是已知的溫度依賴性，與最初的真皮散射系數(shù)隨溫度的增加溫度低于60℃，然后在較高的溫度急劇下降和皮膚吸收系數(shù)隨著溫度的降低，在這個(gè)模型的光學(xué)性能均假定是靜態(tài)的。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</p><p&

44、gt;<b>　　III。結(jié)果</b></p><p><b>　　A.實(shí)驗(yàn)</b></p><p>　　組織學(xué)分析表明，只有淺焊縫均達(dá)到使用1毫米直徑的激光照射面積。熱變性，觀察到570100（平均S.D.，n=7）或30%的平均厚度為1900200真皮％的深度。熱變性外側(cè)切口被限制在附近的組織表面。形象的一個(gè)焊接用1mm直徑點(diǎn)創(chuàng)建。</

45、p><p>　　當(dāng)激光光斑直徑增加2毫米，熱變性，觀察到了真皮層，中間層。熱變性擴(kuò)展到（n=7）（p<0.001）或皮膚厚度平均深度的 50%。這個(gè)深度顯著大于顯著的橫向熱變性（n=7）（p<0,001），也是在皮膚面測(cè)量比為1mm直徑當(dāng)場(chǎng)1mm直徑的現(xiàn)場(chǎng)實(shí)現(xiàn)。</p><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%。研究表示這些接合處深度均顯

46、著高于1mm和2mm直徑的。 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<0.001）。在附近的表皮熱變性外側(cè)區(qū)測(cè)量類似于為2mm直徑的點(diǎn)，顯著更多的熱變性測(cè)定為4mm直徑的真皮斑在中間層（,N =7）但是，當(dāng)移動(dòng)從上層為4mm直徑點(diǎn)的真皮層中比為2mm直徑的位置，測(cè)量的研究比為2mm直徑點(diǎn)（,N =7）（P<0.001）熱變性梯度較小。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。<

47、/p><p>　　在1900深度全層接合造成6mm直徑的點(diǎn)進(jìn)行實(shí)驗(yàn)。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。由于對(duì)動(dòng)物福利的關(guān)注，這些實(shí)驗(yàn)被終止。但前期的量化數(shù)據(jù)可以得到。</p><p>　　應(yīng)當(dāng)指出，在一些地方存在顯著tinctoral和結(jié)構(gòu)變化的膠原纖維，使組織出現(xiàn)了完全變性，顯著的膠原蛋白往往是仍然存在雙折射. 在這種情況下，我們測(cè)到的tinctoral和結(jié)構(gòu)變化區(qū)

48、域的邊緣。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。</p><p><b>　　B.蒙特卡羅模擬</b></p><p>　　顯示了激光光斑直徑對(duì)吸收輪廓的效果。這種吸收由高斯光束入射組織時(shí)被繪制出來。在表面（d=0.0mm）的這一輻射吸收是由直接輻射吸收油墨層以及反向散射輻射構(gòu)成。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