基于注入锁定技术的非接触式免校准脉搏检测传感器

Non-Contact Free Calibration Pulse Detection Sensor Based on Injection Locking Technique

为了实现手腕脉搏检测系统的免校准脉冲检测,提出了一种基于注入锁定原理的邻近耦合射频传感器。该传感器由两个主要部分组成,包括谐波振荡器和具有压控振荡器的锁相回路(PLL)合成器。谐波振荡器由具有两个端口的微带谐振器(叉指电极机构)制成的,该微带谐振器可将桡动脉的膨胀或收缩转换为阻抗变化。然后,PLL合成器通过锁相振荡器将频率变化转换为直流电压内的变化。测量结果表明,由于桡动脉的变化,谐振器的阻抗变化会导致谐波振荡器产生高达0.68MHz的频率变化。在脉搏的一个周期内,测得的电压峰间值为10 m V^15 m V。证明了提出传感器可用于有效的非接触式手腕脉搏检测系统。

In order to realize the non-calibration pulse detection of the wrist pulse detection system, a proximity coupled radio frequency sensor based on injection locking principle is proposed. The sensor consists of two main parts,including a harmonic oscillator and a voltage controlled oscillator with a phase locked loop（PLL） synthesizer. The harmonic oscillator is made from a microstrip resonator with two ports, which can convert the expansion or contraction of the radial artery to the impedance change ~ Then, the frequency variation of the PLL synthesizer is converted to the DC voltage by the phase locked oscillator. The measurement results show that, due to the change of the radial artery, the impedance variation of the resonator can lead to the change of the frequency of the harmonic oscillator as high as 0.68 MHz. In one cycle of the pulse,the measured peak value is 10 mV~ 15 mV. It is proved that the proposed sensor can be used to effectively detect the non-contact wrist pulse detection system.