玻璃封装医用小型光纤光栅温度传感探头

针对体内测温、特别是肿瘤热疗体内温度实时监测对温度传感探头的体积、韧性和抗电磁干扰能力的要求,对医用小型光纤光栅温度传感探头进行了研究。提出了利用玻璃管封装短光纤布拉格光栅来有效避免应力引起的误差以及金属封装对电磁场分布的影响,同时提出用医用聚氨酯套管包裹探头及光纤来有效地保护探头及光纤并使其具备很好的韧性。封装后,探头截面直径为1mm、长度约为4mm。实验测量了稳定温度源在不同温度下探头的反射波长响应和温度变化时探头的响应时间,并测量了医用热疗机加热猪肉时肉内部的温度变化过程。结果表明,体温范围内探头反射波长与温度的线性相关系数可达0.999 95,温度传感精度为0.2℃,探头最大响应时间约为4s,并能实时监测医用热疗机加热猪肉时其内部的温度变化。

Medical miniature fiber grating temperature sensing probe encapsulated with glass

For body inner temperature measurement, especially for tumor hyperthermia temperature real-time monitoring, temperature sensing probes should have smaller volume, good toughness and resistance to electromagnetic interference ability. This paper focuses on a medical small optical fiber grating temperature sensing probe. The glass tube was used to encapsulate short fiber Bragg gratings to allow the probes to effectively avoid the error caused by stress and to eliminate the influence of metal packages on the distribution of electromagnetic field. Meanwhile, the probe and fiber were wrapped in medical polyurethane sleeve to effectively protect the probe and fiber and make them be good toughness. After packaging, the cross-section diameter and the length of the probe are 1 mm and about 4 mm, respectively. The reflection wavelengths of the probe at different temperatures, the response time of the probe at changed temperature and the internal temperature change process of the pork heated by the medical radiofrequency hyperthermia machine were measured experimentally. The results show that the linear correlation coefficient between the reflection wavelength of the probe and the temperature is 0.999 95 in the body temperature range. The temperature sensing accuracy and the maximum response time of the probe is 0.2℃ and about 4 s, respectively. Moreover, the probe can be used to monitor the internal temperature change of the pork heated by the medical radiofrequency hyperthermia machine in real-time.