An Exploration of Behind-the-Ear ECG Signals From a Single Ear Using Inkjet Printed Conformal Tattoo Electrodes

Abstract

An exploration of behind-the-ear ECG signals from a single ear using inkjet printed conformal tattoo electrodes. In IEEE EMBC

Health-Related Indicators Measured Using Earable Devices: Systematic Review

“…Reported uses of earable devices were diet-related activity monitoring (9/51, 18% of the articles) [ 19 , 32 - 39 ]; brain status monitoring (7/51, 14% of the articles) [ 40 - 45 , 78 ]; cardiovascular disease (CVD) monitoring (5/51, 10% of the articles) [ 46 - 50 ]; central nervous system (CNS) disease monitoring and diagnosis (5/51, 10% articles) [ 51 - 54 , 79 ]; head injury monitoring (4/51, 8% of the articles) [ 55 - 58 ]; and monitoring of heart status [ 59 - 61 ], respiration [ 20 , 62 ], and sleep disorders [ 63 , 64 ] (7/51, 14% of the articles). Earable devices were used to monitor multiple diseases and health conditions in 16% (8/51) of the studies, namely, brain, cardiac, and respiratory functions [ 65 ]; cardiovascular status, sweating, and motion [ 66 ]; HR and breathing rate [ 67 ]; respiration and posture [ 21 ]; metabolic functions in relation to fever, insomnia, fatigue, and depression [ 22 ]; gait classification [ 68 ]; cardiovascular, metabolic, and mental disorders, including stress and pain response [ 69 ]; and chronic stress, cognitive dysfunctions, depression, and CVD [ 70 ].…”

“…EEG was used for monitoring in 22% (11/51) of the studies [ 40 , 41 , 43 - 45 , 51 - 54 , 63 , 78 ], body movements were monitored in 12% (6/51) of the studies [ 18 - 21 , 33 , 75 ], and body temperature was monitored in 10% (5/51) of the studies [ 22 , 64 , 71 - 73 ]. Photoplethysmography (PPG) was used for monitoring in 8% (4/51) of the studies [ 32 , 48 , 60 , 69 ], acceleration stress was monitored in 8% (4/51) of the studies [ 55 - 58 ], and ECG was used for monitoring in 6% (3/51) of the studies [ 49 , 50 , 59 ]. A total of 25% (13/51) of the articles reported the monitoring of multiple exposure- and disease-related biomarkers (ie, EEG outputs, breathing signals, and mechanical plethysmography [MPG] outputs [ 65 ]; ECG outputs, lactate levels, and head acceleration [ 66 ]; ECG, ballistocardiography, and PPG outputs [ 46 ]; PPG and bioacoustics outputs and vibrations [ 36 ]; PPG and bioacoustics outputs [ 34 ]; ear canal shape, electromyography [EMG] outputs, and occlusal force [ 39 ]; acceleration stress, body temperature, and HR variability [HRV] [ 68 ]; EEG, electro-oculography, and EMG outputs [ 42 ]; EEG and ECG outputs [ 70 ]; ear canal shape, muscle movement, and acoustic signals [ 35 ]; EMG outputs, ear canal pressure, and muscle movement [ 38 ]; PPG outputs and air pressure [ 61 ]; and body potential, EMG outputs, and capacitance [ 74 ]).…”

Wearable EEG and beyond

“…Examples of these are shown in Fig. 11 which have emerged from a number of labs [89][90][91]. Complete flexible systems, including using flexible transistors to form the data collection electronics have also been demonstrated [92].…”

“…b On the ear monitoring from [90]. c Behind the ear monitoring from [91] Unlike wearable devices, conformal temporary tattoo based devices use very flexible, non-permanent, substrates similar to those given to children as rub on tattoos. These have in-built adhesive to connect directly to the skin without requiring a gel, cap or similar, and the result is that the tattoos maintain a high quality connection to the body for many days at a time.…”

“…Removing the need to set up electrodes each time a person wants to use a BCI system could have a drastic impact on the use of such systems. Moreover, the behind the ear electrodes presented in [91] are based upon inkjet printing and so some of the personalisation elements introduced in Sect. 3 can potentially be maintained (although different as the electrodes are now essentially 2D).…”