热释电效应与超声衰减结合的离体温度估计

针对不规则介质引起的超声信号方向改变对超声测温的影响，提出结合热释电传感器和衰减系数温变性的超声测温方法. 构建并论证由超声、待测体和热释电传感器组成的测温模型. 设计制作具有高吸声特性的传感器，评价该传感器的超声信号的响应性能. 结果显示，传感器的输出电压与到达的超声功率成正比，功率灵敏度为3.117 mV/W，测量误差小于2.5%. 通过估计离体猪肉组织温度验证测温方法的准确性，传感器的输出信号时域能量与组织温度的相关性达到0.975 5，该方法估计的温度与热电偶测量值基本一致，估计误差小于3.95 °C. 实验结果表明，利用热释电传感器与超声能够测量出组织的温度的变化.

Ex vivo estimation of temperature combined with pyroelectric effect and ultrasound attenuation

An ultrasonic temperature measurement method combining pyroelectric sensor and temperature-dependent attenuation coefficient was proposed aiming at the influence of the change of ultrasonic signal direction on ultrasonic temperature measurement caused by inhomogeneous medium. A temperature measurement model consisting of ultrasound, test object and pyroelectric sensor was constructed and demonstrated. A sensor with high sound absorption characteristics was designed and fabricated in order to evaluate its response to the ultrasonic signal. Results showed that the output voltage of the sensor was proportional to the reached ultrasonic power. The power sensitivity was 3.117 mV/W, and the measurement error was less than 2.5%. The accuracy of the temperature measurement method was evaluated by estimating the temperature of the pork. The correlation between the sensor output signal time domain energy and the tissue temperature was 0.975 5. The estimated temperature value of the method was basically the same as that of the thermocouple, and the estimated error was less than 3.95 °C. The experimental results show that the pyroelectric sensor and ultrasound can measure the temperature change of the tissue.