Bordvik Daniel Huseby, Haslerud Sturla, Naterstad Ingvill Fjell, Lopes-Martins Rodrigo Alvaro Brandão, Leal Junior Ernesto Cesar Pinto, Bjordal Jan Magnus, Joensen Jon
1 NorPhyPain Research Group, Faculty of Health and Social Sciences, Centre for Evidence Based Practice, Bergen University College , Bergen, Norway .
2 Physiotherapy Research Group, Department of Global Public Health and Primary Care, University of Bergen , Bergen, Norway .
Photomed Laser Surg. 2017 Oct;35(10):546-554. doi: 10.1089/pho.2016.4257. Epub 2017 Apr 21.
The majority of studies investigating penetration of laser light are performed in vitro on skin flaps, with measures of immediate penetration depth and energy loss. The aim of this study was to investigate the penetration time profiles for two different lasers used in low-level laser therapy, during 150 sec of exposure both in stretched and relaxed human Achilles in situ.
Thirty-four Achilles tendons from 17 healthy volunteers were irradiated by an 810 nm, 200 mW, continuous- and a 904 nm, 60 mW, super-pulsed laser. Irradiation was performed with the Achilles tendons in relaxed and stretched condition. The energy penetrating skin-skin was measured every 30 sec using an optical power meter.
The 810 nm laser penetration ability did not differ significantly in relaxed and stretched condition with 0.17% [standard error of the mean (SEM) 0.02] of mean output power (MOP) and 0.02% (SEM 0.004) of MOP, respectively. The 904 nm laser demonstrated a statistical significant (p < 0.05) and almost linear increasing penetration ability both in relaxed and stretched Achilles from 0.25% (SEM 0.03) to 0.38% (SEM 0.04) of MOP and from 0.05% (SEM 0.01) to 0.13% (SEM 0.01) of MOP, respectively. The penetrated ability differed between lasers and tissue conditions at all measure points (p < 0.05).
The 904 nm laser penetrates relatively more energy than the 810 nm laser in in situ human Achilles. Moreover, penetration from the super-pulsed 904 nm laser increased during exposure time, whereas penetration from the 810 nm laser was constant. In addition, stretching the Achilles causes a higher energy attenuation by the tissue.
大多数关于激光穿透的研究是在体外对皮瓣进行的，测量的是即时穿透深度和能量损失。本研究的目的是调查在低强度激光治疗中使用的两种不同激光在原位拉伸和松弛的人体跟腱中暴露150秒期间的穿透时间曲线。
对17名健康志愿者的34条跟腱分别用810nm、200mW连续激光和904nm、60mW超脉冲激光进行照射。在跟腱处于松弛和拉伸状态下进行照射。每隔30秒使用光功率计测量穿透皮肤的能量。
810nm激光在松弛和拉伸状态下的穿透能力无显著差异，平均输出功率（MOP）分别为0.17%[平均标准误差（SEM）0.02]和0.02%（SEM 0.004）。904nm激光在松弛和拉伸的跟腱中均表现出统计学显著差异（p<0.05）且穿透能力几乎呈线性增加，MOP分别从0.25%（SEM 0.03）增加到0.38%（SEM 0.04）以及从0.05%（SEM 0.01）增加到0.13%（SEM 0.01）。在所有测量点，激光和组织条件之间的穿透能力均存在差异（p<0.05）。
在原位人体跟腱中，904nm激光比810nm激光穿透的能量相对更多。此外，超脉冲904nm激光的穿透在暴露时间内增加，而810nm激光的穿透保持恒定。此外，拉伸跟腱会导致组织对能量的更高衰减。
