生物医学工程-医用激光技术
Laser
激光的特点:
3. 高能量密度 4. 短脉冲
典 型 固体 激 光 光 路 及 电 路 示 意 图
Red to Green Converter Shutter #2 Power Meter
Power Controller
脉冲电源 连续电源 及相应 控 制电路
(220V/8A)
Shutter #1 Flash lamp Q-Switched
by Pulse Duration Selection
500-600nm Or >2300nm 600- 700nm 700- 1000nm 1064nm
Degree of Activity: by Fluence Selection
Material and Method
Animal model Depilated Kuming t Modalities
QS 1064nm (5ns)
LP 1064nm (0.35ms)
Youthful skin contains a predominance of collagen type Ⅲ, a tensile, flexible, and less fibrous form of collagen. During the aging process, collagen type Ⅲ is gradually replaced by collagen type Ⅰ.
Peng Xi and Qiushi Ren*
Institute for Laser Medicine & Bio-Photonics Department of Biomedical Engineering Shanghai Jiaotong University
Clinical Responses of the Skin to the Narrow Band UVB Treatment
T-Cell Apoptosis: Local Immunosuppression Vitamin D Production: Melanocyte Stimulation: Reaches Basal Layer Mast Cell Apoptosis: Relieves Itching Antibacterial: Kills Exposed Bacteria
光机械作用
在泌尿外科中的应用:激光碎石
1983: 第一台激光碎石系统: 脉冲染料激光碎石 系统
532nm/1064nm 双波长碎石系统 钬激光碎石系统
Video
泌尿系结石的腔内治 疗(URS)的优点:
直接接触结石。 直视下手术。 直接快速地清除结石碎 粒。 碎石效果好于体外冲击 波碎石(ESWL),尤 其是膀胱结石和输尿管
7
8
Selective and Targeted Photo-Therapy for Skin Cancer Using Dendrimer-Coated Gold Nano-Rods Conjugated By RGD peptide
Conclusion:
All laser treated areas show marked increases in fibroblast and collagen genesis Photo-Mechanical effect using Q-switched Nd:YAG laser promotes more effectively the synthesis of collagen type III Photo-thermal effect favored more the formation of collagen type I.
HPD+hv → 3(HPD) 3(HPD)+3-O2 → 1O2+HPD 1O2+A →AOX+3O2
有待研究的课题:
效率高, 避光要求低 注射光敏剂后最佳的激光照射时间 最佳的治疗波长和治疗参数
光机械作用
产生的机理:
激光的脉宽(与组织的作用 时间)小于组织吸收激光能 量后的传导时间
Q-Switch Nd:YAG Pulse Laser: 激光波长: 1064 nm 激光能量: 6mJ 激光脉宽: 5ns
In 1905, Albert Einstein published the theory of the photoelectric effect.
激光发展历史
激光的产生机理由爱因斯坦在1917年预言 L A S E R Light Amplificati on Stimulated Emission Radiation
Non-Invasive Multi-Modality Cellulite Reduction
Extra-Cellulite Accumulation under the Skin
Multi-Modality Non-Invasive Cellulite Reduction Probe
5 9 1 6
激光发展历史
1960年: Maiman 发明第一台红宝石 激光, 获得诺贝尔物理学奖
Maiman,T.H.: 1960, Nature, 187, 493.
激光的特点:
1. 单色性
激光的产生原理
光子放大 光子 Ordinary Light Laser Light
普通光的产生原理
激光的特点
2. 方向性
极易弯曲的软镜配合插入 W.O.M. 的特细光纤,使得深部结石的治疗 变得更加容易。
尿路结石– 新的 治疗方法
膀 胱 结 石 输 尿 管 结 石 肾 结 石
体 外 冲 击 波 碎 石 腔 内 碎 石
W.O.M. U100 激光碎石机
光热作用
产生的机理:
激光与组织的作用时间(激光脉宽)大 于组织吸收激光能量后的传导时间
主要特 点: 柔韧
通过内窥镜接近结石: 可以使用硬镜, 半硬镜或软镜。
W.O.M. U100 激光碎石机可以治疗尿道任何位置的结石,包括肾脏。
柔韧性:W.O.M. U100 激光碎石机的光纤 W.O.M. GF100 的光纤直径:280/730 µm
钬激光的光纤直径: 400/800 µm
(Wolf 9F纤维 输尿管镜)
Effect
Thermal Effect Thermal Effect Thermal Effect Non-Thermal (Mechanical)
Material and Method
Laser Parameters
determined by skin reaction of mice
80% of the Fluence that induces skin erythema
303nm is the superior wavelength for Psoriasis Treatment
T-Cell Apoptosis D3 Production
Excimer Laser
303nm 303nm
Portable LED Device for Home Treatment of Psoriasis and Vertilago
散射
靶组织 透射
生物组织中各种“靶组织” (色基)的吸收光谱
Pure Scattering
软组织的吸收特点:
水的吸收系数从最大到最小相差 1000万倍 (3.0 µm) ————— = 10.000.000 (0.5 µm)
532nm (绿光)不被无血管的软组织所吸收,并且散射 较强, 易造成周边组织损伤!
595-nm pulsed dye laser (10 ms) 1320-nm Nd:YAG laser (0.35 ms) 1064-nm Nd:YAG lasers long-pulsed (0.3 ms) 1064-nm Nd:YAG lasers Q-switched (5 ns)
Material and Method
Skin samples were taken and analyzed post-operatively at:
1 hr, 1 day, 1 wk, 3 wk, 4wk and 8wk Histological changes
H-E Stain ( Thickness of Dermis and No. of Fibroblast) Sirius Red Stain (Collagen Type I and III)
Y. Dang et. al.: Experimental Dermatology 14 (12), 876-882, 2006 H. Liu, et. al: : Lasers in Surgery and Medicine 40:13-19, 2008
Portable Narrow-Band High Intensity LED System for Psoriasis and Vertilago
光热作用
激光与光子生物医学研究小组 的研究工作
Non-ablative Collagen Remodeling Initiated by Different Laser Effects:
A Comparative Study on Mouse Model
Goal for Anti-Aging Treatment
Hydroxyproline Content Assay: Amount of New Collagen Formation at 4 wk and 8 wk
Results
Relative Increase Percentages of Type I and III
Conclusion:
QS 1064-nm laser promotes most synthesis of collagen type Ⅲ