大功率LED灯在X线机模拟光源中的应用

目前国内外所生产的X线机缩光器内的模拟光源,均采用卤素灯作为X线机模拟光源的方法,由于卤素灯不是冷光源灯,使用功率较高、电流大,在缩光器狭小的空间内升温快,在此工作状态下容易损毁卤素灯灯座和灯开关,使X线机无法正常工作,此类故障时常发生。为了彻底解决缩光器内的模拟光源用卤素灯易损等问题,笔者采用大功率白光LED(light emitingdiode,LED,发光二极管)灯,替代卤素灯彻底解决上述问题。1材料与方法1.1材料1W/LED灯、卤素灯、1W20Ω半可变电阻、TES-1335型照度计。1.2方法用TES-1335型照度计对原X线机缩光器模拟光源进行测试。靶片距1m时工作面照度为150(Lux),改用1W/LED灯后,靶片距不变工作面照度为300(Lux),因为各种类型X线机缩光器模拟光源的供电电压不同,分别有交流与直流12V两种电压,只需根据电压不同加以改进即可。2结果卤素灯和白光大功率1W/LED灯寿命、工作照度、功率、价格情况见表1。用大功率1W白光LED灯代替卤素灯,在X线机缩光器模拟光源中应用是可行的,提高了照明度,1W白光LED灯的电流小约700mA以下,LED灯属冷光源灯不易升温、小电流也...     

Platelet concentrates and ultraviolet light

Platelet concentrates (PCs) may be irradiated with ultraviolet light (UVL) to abolish mixed lymphocyte reactions (MLR) whilst retaining adequate function and this might therefore prevent recipient alloimmunization (AI). However, conventional platelet storage containers are relatively impermeable to UVL. We have undertaken studies of in vitro platelet storage using different plastic containers and also measured in vivo platelet recovery and survival after storage in DuPont Stericell bags which were found to be both UV-permeable and biocompatible. PCs irradiated with 3000 Joules/m² (J/m²) of UVL and then stored for 5 days appear suitable for transfusion and may prove to be non-immunogenic. Further in vivo studies of haemostatic efficacy and recipient alloimmunization are now warranted.     

光亮胆道造影法在腹腔镜胆囊切除术中的应用研究

目的在腹腔镜胆囊切除术(Laparoscopic cholecystectomy，LC)中利用光亮胆道造影法(light cholangiography，LCP)显示胆管走向，预防胆道损伤。方法在LC中分别经十二指肠乳头向胆总管置入光导纤维(light cholangiography through duodenum，LCPD)及经胆囊管置入光导纤维(light cholangiography through cysstic duct，LCPC)，导入冷光源，在腹腔镜电视图像中直接观看从胆管内透出的光亮，从而判断胆管的解剖位置。结果两种途径置入光导纤维行光亮胆道造影法均能在LC中提供直视胆道图像。LCPD操作复杂，但能提供全面的胆道图像。LCPC主要提供胆囊管及胆囊的胆道图像，与LCPD相比操作极为方便。结论光亮胆道造影法能清楚、直接地显示胆管走向。在解剖不清的LC中，能有效地帮助术者进行解剖，提高手术安全性，具有很高的实用价值。     

Characterization of light penetration in rat tissues

OBJECTIVE: The goal of this study is to determine the optical properties of different rat tissues with respect to spatial intensity variation and light distribution. We are interested mainly in the wavelength of 630 nm. Nevertheless, for liver tissue we have used 514 nm and 670 nm as well. BACKGROUND DATA: In the past, many articles have been written about the interaction of lasers with rat tissues. However, the technique of imaging the light distribution allows us to obtain the spatial scattering as well as an effective attenuation coefficient for the light intensity. METHODS: Slices of different rat tissues were placed between two microscope slide mounts (spaced by 3 mm). A laser beam was irradiated on the sandwiched tissue. A CCD camera placed on the side, orthogonal to the beam path, recorded the intensity distribution of the scattered light. Analysis of this spatial intensity profile allowed determining the variation of the intensity as the light penetrates the tissue. RESULTS: We have found that abdominal wall fat presents the lowest exponential decay when compared with liver, muscle, and kidney. The obtained values provided good data about the light distribution in those tissues when irradiated with a nondiffuse laser beam. For all tissues, we observed a spherical light distribution and exponential decay. Cirrhotic liver shows much stronger decay than healthy liver. These results are useful for several applications of laser for biostimulation a phototherapy.