Development of Biomedical Transducer by Use of Optical Fiber Sensor and Actuator

光纤传感器在许多应用领域具有优势，特别是在医疗领域。设计了一种光学馈电系统，用于向高压电力系统等危险和噪声环境中使用的设备供电。然而，早先报道的系统的可用功率约为150MUW，对于传统设备的供电来说太低了。这项工作的目的是开发一种光学馈电系统，以便为传统的传感器元件(如温度监测器)提供足够的功率。激光传输到太阳能电池，在那里积累能量。光源为半导体激光器(SLD304XT，波长813 mm，最大光功率800 mW)。激光二极管采用渐变折射率光纤(芯径230微米)。8个串联的太阳能电池组装在光纤端周围。每个太阳能电池(S-4V，联合探测器技术)的有效面积为0.5x0.27厘米。在渐变折射率光纤尖端测得的最大光功率为800 mW。对采用IC温度传感器的温度测量电路进行了测试。光发射电路将输出信号转换为数字化的编码信号。数字化的信号通过另一根光纤传输到测光仪。光信号传输采用光路二极管(SFH 751，西门子)，8个太阳电池的开路电压约为4V，短路约6 mA。传感器电路的总电流消耗约为3 mA。数字化信号可由馈电小于2 mA的光路二极管传输。结果表明，该系统可以作为常规传感元件的电源，特别是具有传输距离长、抗电磁干扰能力强的特点。

Fiber optic sensors have advantages in a number of application, especially in the medical field. An optical power-feed system has been designed to supply power to devices which can be used in hazardous and noisy environment such as high voltage power systems. However, the available power of the earlier reported system was around 150 muW and was too low for the power supply to conventional devices. The aim of this work is to develop an optical power-feed system in order to sypply enough power to a conventional sensor element such as temperature monitors.Laser light was transmitted to solar cells where the energy is accumulated. A laser diode (SLD304XT, the wave length 813 mm, maximum optical power 800 mW) was used as a light source. A laser diode with graded-index fiber (230mum in core diameter) was used. Eight solar cells connected in series are assembled around the fiber end. Each solar cell (S-4V, United Detector Technology) had an active area was 0.5 x 0.27 cm. The maximum optical power measured in the tip of a graded-index optical fiber was 800 mW. The temperature measurement circuit with IC temperature sensor was tested. The output signal was converted into a digitized, coded signal by the optical transmitting circuit. The digitized signal was transmitted along another optical fiber to the light-measuring instrument. A light link diode (SFH 751, Siemens) was used for optical signal transmission.The open-circuit voltage of the eight solar cell was about 4 V and the short-circuit was about 6 mA. Total current consumption of the sensor circuit was about 3 mA. The digitized signal could be trans-mitted by a light-link diode feeded with less than 2 mA. The result indicates that the system can be used as power supply for conventional sensor elements, especially with potentially long transmission distance and immunity to electromagnetic interference.