Soft Iontronic Capacitive Sensor for Beat‐to‐Beat Blood Pressure Measurements

Abstract

Continuous beat‐to‐beat blood pressure (BP) monitoring provides hemodynamic information such as BP changes and waveforms over time, providing abundant information to more accurately diagnose a person's cardiovascular health compared to static cuff‐based measurements. To overcome the shortcomings of current techniques, a highly sensitive (S = 108.52 kPa−1 for 0–5 kPa range) soft capacitive sensor that can be worn like a Band‐Aid is developed such that continuous beat‐to‐beat BP monitoring can be sustainably achieved after an initial calibration. The sensor leverages iontronic material with air gaps for the dielectric combined with highly wrinkled, stretchable electrodes; the resulting average sensitivity of this device is demonstrated to be higher than that of other comparable sensors in literature. For the hemodynamic capture, the operating frequency of 300 kHz is chosen to achieve higher temporal resolution in continuous BP monitoring. Further, the multi‐island design in this work allows for rapid placement of the sensor without needing to accurately align with the underlying artery. Because of the improved sensitivity, the sensors can be adhered to the pulse points without an applanator. Finally, this sensor demonstrates sustained beat‐to‐beat blood pressure recordings that show excellent systolic, diastolic, and mean arterial pressure correlation with an FDA‐cleared device, the Caretaker.

Flexible, Breathable, and Hydrophobic Iontronic Tactile Sensors Based on a Nonwoven Fabric Platform for Permeable and Waterproof Wearable Sensing Applications

“…Figure g shows the outstanding repeatability and superior stability when loading/unloading for up to 10,000 cycles. In the end, Figure h compares the sensitivity, detection range, and response time between the fabric tactile sensor developed in this work and those reported in the literature − (Table S1), indicating that the high-level sensing performance is achieved in the field. The high sensitivity, wide detection range, fast response time, low detection limit, good dynamic response, and excellent stability give the developed fabric tactile sensor the potential to be used for practical high-accuracy and long-term wearable sensing applications.…”

Reliable and Scalable Piezoresistive Sensors with an MXene/MoS2 Hierarchical Nanostructure for Health Signals Monitoring

“…Each cycle consists of a percussion wave (P-wave), tidal wave (T-wave), and diastolic wave (D-wave). The time interval between P- and the T-wave peaks is defined as Δ T DVP , and the radial artery augmentation index (AIr) depends on the ratio between the T- and P-wave intensities. ,− Elderly individuals may have a pulse waveform without an inflection point or T peak due to the increased stiffness and decreased elasticity of their blood vessels, which leads to a high AIr and a shortened Δ T DVP . Conversely, healthy and elastic arteries typically have a smaller AIr and a longer Δ T DVP .…”

Blood pressure measurement techniques, standards, technologies, and the latest futuristic wearable cuff-less know-how

“…Modern flexible pressure sensors based on different mechanisms, such as a piezocapacitive, piezoresistive, piezoelectric, triboelectric, and organic photodetector, and integration with digital health ecosystems are just a few examples of technological advancements in BP monitoring. [15][16][17][18][19][20] Moreover, integration with the 'internet of things' can strengthen the future of the 'internet of medical things'. 21 Several studies emphasize this area's significance and suggest that a timely assessment is required.…”