Arterial Pulse Signal Monitoring During the Valsalva Maneuver via a Flexible Microfluidic-Based Sensor

In light of the need to diagnose and monitor the heart condition of a heart failure patient, this paper presents a preliminary investigation on the application of a flexible microfluidic-based sensor for measuring the arterial pulse signal during the Valsalva Maneuver (VM), which allows assessment of the patient’s volume status. The core of the sensor is a polydimethylsiloxane (PDMS) microstructure embedded with a 5x1 electrolyte-enabled resistive transducer array. As a time-varying load, an arterial pulse signal acting on the microstructure gives rise to the distributed sensor deflection along the microstructure length and further registers as the resistance changes by the transducer array. The radial pulse signals of four healthy subjects during the VM are measured and are further expressed in terms of the absolute resistance and the sensor deflection. The pulse amplitude change in absolute resistance captures the expected hemodynamic response of a healthy subject to the VM, but the sensor deflection does not manifest such response, due to baseline drift. The corresponding pulse signals of the four subjects at-rest are also measured, verifying that the pulse amplitude change in absolute resistance does not arise from baseline drift. In the future, this sensor will be used to measure the arterial pulse signals of heart failure patients during the VM.