Optics and Photonics Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Sensors (Basel). 2020 Mar 3;20(5):1388. doi: 10.3390/s20051388.
The widely applied capillary refill time (CRT) measurement is currently performed by manually applying pressure and using a stopwatch to record the time taken for the skin to recover its normal colour after a blanching pressure is applied. This method is highly subjective and observer-dependent. This paper presents a new, integrated optical sensor probe, combining monitoring of the capillary refilling process with the blanching pressure applied. The sensor consists of an optical fibre-based reflectance photoplethysmography (PPG) sensor to measure the reflected light signal, as well as a fibre Bragg grating (FBG) to measure the applied blanching pressure and to indicate the time when pressure is released. This sensor was applied to calculate the CRT (1.38 ± 0.66 s) of 10 healthy adult volunteers with (55.2 ± 21.8 kPa) blanching pressures. The form of the capillary refilling data was investigated by fitting using an exponential regression model (R > 0.96). The integrated probe has the potential to improve the reliability of CRT measurements by standardising the optimum duration and magnitude of the pressure.
目前，广泛应用的毛细血管再充盈时间（CRT）测量是通过手动施加压力并用秒表记录皮肤在施加苍白压力后恢复正常颜色所需的时间来完成的。这种方法高度主观且依赖于观察者。本文提出了一种新的集成光学传感器探头，将毛细血管再充盈过程的监测与施加的苍白压力结合在一起。该传感器由基于光纤的反射光体积描记法（PPG）传感器组成，用于测量反射光信号，以及光纤布拉格光栅（FBG），用于测量施加的苍白压力并指示释放压力的时间。该传感器用于计算 10 名健康成年志愿者的 CRT（1.38±0.66s），施加的苍白压力为（55.2±21.8kPa）。通过使用指数回归模型（R>0.96）进行拟合来研究毛细血管再充盈数据的形式。集成探头有可能通过标准化压力的最佳持续时间和幅度来提高 CRT 测量的可靠性。
