Plethysmography System to Monitor the Jugular Venous Pulse: A Feasibility Study

Abstract

Cerebral venous outflow is investigated in the diagnosis of heart failure through the monitoring of jugular venous pulse, an indicator to assess cardiovascular diseases. The jugular venous pulse is a weak signal stemming from the lying internal jugular vein and often invasive methodologies requiring surgery are mandatory to detect it. Jugular venous pulse can also be extrapolated via the ultrasound technique, but it requires a qualified healthcare operator to perform the examination. In this work, a wireless, user-friendly, wearable device for plethysmography is developed to investigate the possibility of monitoring the jugular venous pulse non-invasively. The proposed device can monitor the jugular venous pulse and the electrocardiogram synchronously. To study the feasibility of using the proposed device to detect physiological variables, several measurements were carried out on healthy subjects by considering three different postures: supine, sitting, and upright. Data acquired in the experiment were properly filtered to highlight the cardiac oscillation and remove the breathing contribution, which causes a considerable shift in the amplitude of signals. To evaluate the proper functioning of the wearable device for plethysmography, a comparison with the ultrasound technique was carried out. As a satisfactory result, the acquired signals resemble the typical jugular venous pulse waveforms found in literature.

Keywords: capacitive strain gauge; electrocardiography; internal jugular vein; jugular venous pulse; plethysmography; wearable device.

Figure 1

Typical Jugular Venous Pulse wave pattern with the respective sound and electrical synchronization waves.

Figure 2

Design and outline dimensions of the capacitive strain gauge sensor.

Figure 3

Wearable device for plethysmography.

Figure 4

US machine used in this work: My-LabAlpha console (a); US probe (b).

Figure 5

Calibration curve for the capacitive strain gauge sensor. Horizontal axis reports the length of the sensor in mm, vertical axis reports the correlated response of the device in counts, together with its standard deviation.

Figure 6

Characterization of strain gauge sensor: for the sensor extended and in contact with air (a); for the sensor wrapped around the arm (b).

Figure 7

JVP waveform with the corresponding ECG trace for the subject 2 in supine position (a); sitting position (b); upright position (c).

Figure 8

Comparison for the same heartbeats between the JVP waveform (blue) with the corresponding ECG markers (red) and the IJV-CSA signal (orange) with the corresponding ECG markers (black).

Figure 9

Temporal distances between the peaks ‘a-a’, ‘v-v’, and ‘ECG markers’ of the two different signals, for all the considered heartbeats.