Monitoring the Cardiovascular Changes of a Rabbit Caused by Phenylephrine via a Microfluidic-Based Tactile Sensor

In this work, a microfluidic-based tactile sensor was investigated for monitoring changes in the cardiovascular (CV) system of a rabbit caused by phenylephrine. The sensor was fixed on the front right leg of an anesthetized rabbit to measure the arterial pulse signal. Phenylephrine, as a vasoconstrictor, was used to introduce CV changes of the rabbit. Two sensors, one with high sensitivity and the other with low sensitivity, were tested on their suitability for measuring the pulse signals of the rabbit. The sensor with low sensitivity generated clear pulse signals and was further used to monitor the CV changes of the rabbit caused by phenylephrine. An automated sphygmomanometer and an ECG were used to record blood pressure and heart rate for comparison. Three low-dose injections of phenylephrine were sequentially performed on the rabbit. Through model-based analysis of the measured pulse signals, arterial elastic modulus, arterial radius and pulse wave velocity (PWV) were obtained. As compared with the baseline values measured before injection, injections of phenylephrine caused an increase in mean blood pressure (MAP) recorded by the medical instruments, and a decrease in arterial radius (increase in peripheral vascular resistance (PVR)) and an increase in arterial elastic modulus and PWV captured by the tactile sensor. Thus, the tactile sensor was proven to be feasible for monitoring the changes in the CV system caused by phenylephrine.