Wolfgang Neuberger

Infrared cables and catheters for medical applications

New medical applications of IR lasers are possible with flexible cables and catheters for laser power delivery. Optical parameters of fibers for Er; CO- and CO2-lasers along with design of special optical connectors, efficient coupling units, and optics at distal end are reviewed. Applications of cables and catheters for laser therapy and medical diagnostics are analyzed.

Diffusing fiber tips for high-power medical laser applications

For most applications in laser medicine suitable delivery systems are required. We developed fiber optic based diffusing tips especially for photodynamic therapy (PDT) and laser induced thermotherapy (LITT). To realize an adequate emitting cylindrical diffuser the fiber core was abraded by a precision cutter. Hence, the use of scattering media such as TiO2-doped polymers is avoided. Because the diffuser size is mainly determined by the manipulated fiber and a surrounding glass capillary, one can realize small diameters ((phi) approximately equals 3 mm). The laser light is distributed mainly by surface scattering and total reflection at the fiber air boundary. Because the use of absorbing media is avoided, it is possible to apply high laser power as necessary in LITT and pulsed PDT. We produced diffusing tips with lengths of several centimeters and typical diameters of 3 mm. By controlling the fiber-shaping process, a homogeneous intensity profile or even special designs can be achieved. The control is done by either on-line camera surveillance or calculated predictions. A delivery system especially for the photodynamical treatment of female cervix dysplasia has been designed.

MIR fiber tools for CO2 laser medicine

Silver halide polycrystalline MIR-fibers are coming to practical exploitation in CO-laser medicine through the development of core/clad fibers technology and design of suitable flexible delivery systems, convenient and reliable for operations. Recent results of such development and useful exploitation features are presented.

Applications of MIR fibers for medical diagnostics

In this work only first steps in blood glucose measurements were made and possibilities of tissue analysis were demonstrated with a MIR fiber probe. Spectroscopic measurements with the same objects by ATR (attenuated total reflectance) elements were made before, but advantages make fiber use more attractive.