Evaluation of Printed P(VDF-TrFE) Pressure Sensor Signal Quality in Arterial Pulse Wave Measurement

Abstract

In this contribution, we evaluate the performance of an additively fabricated piezoelectric poly(vinylidenefluoride-cotrifluoroethylene) (P(VDF-TrFE)) based dynamic pressure sensor in non-invasive arterial pulse wave (PW) measurement. Additively fabricated piezoelectric sensors have high potential for the realization of affordable and unobtrusive PW measurement systems which could enable the long-term monitoring of patients with cardiovascular diseases (CVDs). However, the accuracy and reliability of such sensors have not been extensively studied before. We propose an additive fabrication process for a P(VDF-TrFE) PW-sensor, measure PW from the radial artery at the wrist from 22 healthy volunteer subjects, calculate clinically relevant parameters based on the PW waveform and compare their values to the values obtained from concurrent measurement with an electromechanical film (EMFi) based reference sensor, used earlier in several clinical studies. We show that the signals recorded with the two sensors, as well as the radial augmentation index (rAIx) and the stiffness index (SI) calculated from them, are in good agreement with each other. These results demonstrate that the additively fabricated P(VDF-TrFE) PW sensors can reach a suitable level of accuracy and reliability for clinical use.Index Terms-Printed electronics, pulse wave measurement, radial artery, piezoelectric dynamic pressure sensor, P(VDF-TrFE), electret material, EMFi Korkeakoulunkatu 3, 33720, Tampere, Finland. M.-M. Laurila is the

Self-Powered, Ultrathin, and Transparent Printed Pressure Sensor for Biosignal Monitoring

“…54 The broken finger electrodes are not able to participate in charge collection when pressure is applied, and this will lead to a lower measured sensitivity. It is also possible an ≈7 times higher value (MIM ≈ 26.9 pC/N vs IDE ≈ 3.8 pC/N) in normal mode as shown previously by Laurila et al 39 At the same time, however, it had up to 33 times higher capacitance compared to a similar thickness IDE structure (MIM ≈ 1.57 nF vs IDE ≈ 51.10 pF). As the output voltage of the sensor is determined by the equation V = Q/C, this will result in higher voltage sensitivity for the IDE-based structure as shown in Figure 3a.…”

“…Furthermore, the piezoelectric and voltage sensitivity of three different P­(VDF-TrFE) thickness IDE sensors were compared to a conventional piezoelectric pressure sensor based on MIM structure. The piezoelectric sensitivity of a MIM structure based on the same P­(VDF-TrFE) material had an ≈7 times higher value (MIM ≈ 26.9 pC/N vs IDE ≈ 3.8 pC/N) in normal mode as shown previously by Laurila et al At the same time, however, it had up to 33 times higher capacitance compared to a similar thickness IDE structure (MIM ≈ 1.57 nF vs IDE ≈ 51.10 pF). As the output voltage of the sensor is determined by the equation V = Q / C , this will result in higher voltage sensitivity for the IDE-based structure as shown in Figure a.…”

“…Recently, the piezoelectric polymer poly­(vinylidene fluoride) (PVDF) and its copolymer poly­(vinylidene fluoride-trifluoroethylene) (P­(VDF-TrFE)) have been widely studied as active materials for sensing applications (e.g., electronic skin (e-skin), skin-conformable pressure sensors, and health monitoring patches) owing to their biocompatibility, high flexibility, cost-effectiveness, and simple and large-area processability. ,,,− In particular, these materials are also compatible with additive manufacturing technologies, such as printed electronics fabrication technologies (e.g., inkjet printing, screen printing, and bar coating). ,− Printing technologies can considerably simplify the fabrication steps and reduce material consumption, and therefore decrease the fabrication costs. Additionally, their inherently simple patterning makes them an excellent alternative to prototype and develop cost-effective flexible sensing devices .…”

Highly Sensitive Capacitive Pressure Sensors over a Wide Pressure Range Enabled by the Hybrid Responses of a Highly Porous Nanocomposite

“…Figure 5d exhibits the location of the carotid artery and the temporal artery with benchmark arterial pulse waveforms obtained by medical gold standards, such as invasive arterial lines. [ 84–88 ] For the carotid arterial pulse (CAP), a HRPS was placed on the neck over the carotid artery packaged between two medical tapes (3M Tegaderm), which induced a preload of around 1.5 kPa over the HRPS as shown in Figure 5e. While the human subject held his breath, the CAP was clearly visible without any amplification or signal processing (Figure 5f).…”

Flexible ferroelectric wearable devices for medical applications

“…Screen printed wearable piezoelectric devices have been developed for monitoring physiological signals ( Fares et al., 2020 ; Gonçalves et al., 2019 ; Laurila et al., 2019 ; Sato et al., 2019 ). Sekine et al.…”