Chronic wounds affect around 2% of the world population with an annual multi-billion dollar cost to the healthcare system. This background pushes the development of new therapies and procedures for wound healing and its assessment. Among them, the potential of hydrogen (pH) assessment is an important indicator of the wound healing stage and condition. This paper presents the development of the first optical fiber-embedded smart wound dressing for pH assessment. An intrinsically pH-sensitive optical fiber is fabricated using a polydimethylsiloxane (PDMS) precursor doped with rhodamine B dye. Raman and Fourier transform infrared (FTIR) spectroscopies are performed in order to verify the presence of rhodamine B and PDMS in the fiber samples. Then, the fiber is embedded in gauze fabric and hydrocolloid wound dressing. In addition, such low Young’s modulus of PDMS fiber enables its use as a highly sensitive pressure sensor, where the results show that the fiber-embedded bandage can measure pressures as low as 0.1 kPa with a high linearity in the range of 0 to 0.3 kPa. The smart bandage is subjected to different pH, which resulted in a wavelength shift of 0.67 nm/pH when the absorption peak at 515 nm was analyzed. Furthermore, pH increase leads to linear decrease of the transmitted optical power ($R^2$ of 0.998), with rise and fall times below 20 s and 30 s, respectively. Therefore, the proposed optical fiber-embedded smart bandage enables the simultaneous assessment of pressure and pH on the wound region.

中文翻译：

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光子智能绷带用于伤口愈合评估

慢性伤口影响着全球约2％的人口，每年给医疗保健系统造成数十亿美元的损失。这种背景推动了伤口愈合及其评估的新疗法和方法的发展。其中，氢（pH）评估的潜力是伤口愈合阶段和状况的重要指标。本文介绍了用于pH评估的首个嵌入光纤的智能伤口敷料的开发。使用掺杂了若丹明B染料的聚二甲基硅氧烷（PDMS）前驱体来制造本质上对pH敏感的光纤。进行拉曼光谱和傅立叶变换红外光谱（FTIR），以验证纤维样品中若丹明B和PDMS的存在。然后，将纤维包埋在纱布和水胶体伤口敷料中。此外，如此低的PDMS纤维杨氏模量使其可用作高度灵敏的压力传感器，结果表明，包埋纤维的绷带可在0至0.3 kPa的范围内以高线性度测量低至0.1 kPa的压力。智能绷带受到不同的pH值，当分析515 nm处的吸收峰时，波长偏移为0.67 nm / pH。此外，pH值的增加会导致传输光功率的线性下降（${\mathrm{[R}}^{\mathrm{2个}}$（0.998），上升和下降时间分别低于20 s和30 s。因此，所提出的嵌入光纤的智能绷带使得能够同时评估伤口区域上的压力和pH。