Development and evaluation of phototherapy device made of luminous polymer optical fiber fabrics

Abstract

This thesis presents a systematic study of luminous polymer optical fiber (POF) fabrics, which exhibit high performance and can be applied in phototherapy. Based on a comprehensive literature review, smart textiles integrated with POF and phototherapy, this research includes investigating the light side-emitting properties of POF, designing and fabricating POF fabric prototype that meets the requirements of selected phototherapy application. It further includes a study of the effectiveness of luminous POF fabrics system via in vitro experiments. Laser ablation method was explored to create surface patterns on the POF for provoking light side-emitting. Infrared CO₂ laser made various V shaped grooves on POF, whose morphology depended on the processing parameters, that is, resolution, laser intensity and pixel time. The transmission and side emission behavior of the POFs with V-grooves at various bending conditions were investigated experimentally and theoretically. The results illustrated that the transmission power decreased with decreasing bending radius because most of light coming to the notch face was reflected back. Hence, the side emission was stable when POF was bent. Theoretical analysis was performed on the relationship between the side-emitting light power and the various V-groove patterns on POF. The conditions of POFs with single V-groove pattern and multiple V-groove patterns were quantitatively calculated respectively. The simulation results revealed that the side-emission power mainly depended on the depth and the opening angle of V-groove on POF. A deeper V-groove was favored for side emission. The relationship between the V-groove angle and side-emission power was more complex than that between the depth and side-emission power. Extremely large or small opening angle of V-groove would be obstructive to side-emitting light. An optimal half-angle, about 33°, was identified for the largest side emission. Based on the simulation results, optimal V-groove patterns were created by a mechanical method. The measured side-emission parameters were comparable with the simulation results. Luminous POF fabrics were designed and fabricated. The wavelength of emitting light can be easily varied for different phototherapy purposes. Luminous POF fabrics were woven by using POFs as weft and cotton yarns as warp yarns. 625 nm wavelength was selected to use for photorejuvenation. The fabric prototype was characterized including surface temperature, light intensity and stability of light intensity during long-time irradiation. Luminous POF fabric system exhibited good performance. In addition, intensity-adjustable light emitting diode (LED) array system was also produced to study, in parallel, with the fabric system, the effect of light irradiation on human skin cell. Safety of light radiation and POF fabric contacted with skin was evaluated according to international standards IEC 62471:2006 Photobiological safety of lamps and lamp systems and ISO 10993: 2009 Biological evaluation of medical devices. Experimental results confirmed that the POF fabric system was safe for human. In vitro study on the effect of low-level light irradiation on human fibroblast cells was preliminarily conducted. The experiment results demonstrated that the low-level red light irradiation from LED promoted cell proliferation and collagen synthesis. The combination of red light irradiation and epidermal growth factor (EGF) application had more beneficial effects on cell proliferation and collagen synthesis. The further experiment result testified the effectiveness of POF fabric system, which also promoted the collagen synthesis from human fibroblasts.