A Wrist-Worn Strap with an Array of Electrodes for Robust Physiological Sensing

Abstract

Robust sensing is one of the main challenges for wearable physiological monitoring because of the high dependency on the placement of electrodes on the body, retaining suitable contact between electrodes and skin, and the effect of motion artifacts. In this paper, we present a wrist-worn strap that includes a 2-D array of 48 miniature electrodes covering the bottom side of the wrist with good contact with the skin. Good skin contact directly impacts the sensing robustness. The array provides local measurements between adjacent electrodes that span the whole bottom side of the wrist with an area of 6.25×4.60 cm for robust sensing. The array allows for the automatic selection of the correct electrodes at the right location regardless of changes in the device placement on the wrist. In addition, using a large number of electrodes over a large area on the wrist ensures continuous contact of some electrodes with the skin during motion since all of the electrodes will not lose contact with the skin at the same time. We measured the electrode-skin impedance of the fabricated electrodes versus frequency and compared to other types of electrodes. We demonstrated good contact between all electrodes of the array and the skin by measuring electrode-skin impedance less than 10 kΩ at 16 kHz for all locations on the wrist strap. We also conducted measurements of impedance while the wearer was bending the wrist to validate the continuous contact of at least a subset of electrodes with the skin during such movements.

Multipurpose and Reusable Ultrathin Electronic Tattoos Based on PtSe2and PtTe2

“…The frequency sweep is usually performed three times, with each sweep taking approximately 90 s and 10 s delay between sweeps. The measured values correspond to the electrode–skin impedance as the tissue’s bioimpedance is much smaller when compared to the typical electrode–skin impedance . During the measurements, the skin moisture was not specifically monitored, neither was it manually induced or changed during the experiments.…”

“…The measured values correspond to the electrode− skin impedance as the tissue's bioimpedance is much smaller when compared to the typical electrode−skin impedance. 52 During the measurements, the skin moisture was not specifically monitored, neither was it manually induced or changed during the experiments. The characterization experiments were performed on one subject; hence any subject-to-subject performance variability is diminished.…”

“…The frequency sweep is usually performed three times, each sweep taking approximately 90 seconds, and 10 seconds delay between sweeps. The measured values correspond to the electrode-skin impedance since the tissue's bio-impedance is much smaller when compared to the typical electrode-skin impedance 48.…”

A Comparative Study on the Suitability and Treatment Compliance of an Improved Wristband Wearing Method Compared with the Traditional Method

“…On the one hand, the length of the wristband is the perimeter of the wrist plus the little finger, but there will still be wristband fall, rash, and other phenomena. On the other hand, the traditional wristband is made of soft PVC plastic material, which has poor air permeability, delicate skin of infants and young children, and is easy to be allergic to the QR code wristband of these materials, resulting in skin damage, resulting in adverse events caused by infants and young children unwilling to wear wristbands and parents do not put them at will [7][8][9][10]. In addition, as a special group, children with loose wristbands will lose their identity due to frequent physical activities [11].…”

Developing Personalized Models of Blood Pressure Estimation from Wearable Sensors Data Using Minimally-trained Domain Adversarial Neural Networks

“…There are a variety of techniques that have recently been investigated for their potential application to cuffless blood pressure estimation. Chief among those techniques include photoplethysmography (PPG) in conjunction with electrocardiography (ECG) (Thomas et al, 2016), dual PPGs (Nabeel et al, 2018;Wang et al, 2018), Doppler radar technology (Shay and Dai, 2017), or bioimpedance (Ibrahim et al, 2018). Each of these techniques attempt to measure the pulse transit time (PTT) or pulse wave velocity (PWV), both of which are known surrogates for blood pressure (Luo et al, 2016;Ibrahim and Jafari, 2019;Zheng et al, 2014).…”