Hearables: Multimodal physiological in-ear sensing

Abstract

Future health systems require the means to assess and track the neural and physiological function of a user over long periods of time, and in the community. Human body responses are manifested through multiple, interacting modalities – the mechanical, electrical and chemical; yet, current physiological monitors (e.g. actigraphy, heart rate) largely lack in cross-modal ability, are inconvenient and/or stigmatizing. We address these challenges through an inconspicuous earpiece, which benefits from the relatively stable position of the ear canal with respect to vital organs. Equipped with miniature multimodal sensors, it robustly measures the brain, cardiac and respiratory functions. Comprehensive experiments validate each modality within the proposed earpiece, while its potential in wearable health monitoring is illustrated through case studies spanning these three functions. We further demonstrate how combining data from multiple sensors within such an integrated wearable device improves both the accuracy of measurements and the ability to deal with artifacts in real-world scenarios.

In-Ear EEG Biometrics for Feasible and Readily Collectable Real-World Person Authentication

“…In a recent effort to enable collectable EEG, the in-ear sensing technology [12] was introduced into the research community. The ear-EEG has been proven to provide on-par signal quality, compared to conventional scalp-EEG, in terms of steady state responses [12,24], monitoring sleep stages [25,26], and also for monitoring cardiac activity [27,28]. The advantages of the in-ear EEG sensing for a potential biometrics application in the real-world are:…”

“…The latest 'off-the-shelf' generic viscoelastic EEG sensor is made from affordable/consumable standard earplugs [29], • Robustness: The viscoelastic substrate expands after the insertion, so the electrodes fit firmly inside the ear canal [27], where the position of electrodes remains the same in different recording sessions, • User-friendliness: The sensor can be applied straightforwardly by the user, without the need for a trained person. Therefore, biometrics with ear-EEG offers a high degree of collectability, a critical issue in real-world applications.…”

A Survey on the Affordances of “Hearables”

“…Bio-acoustic recordings may also be useful within applications that use audio solely as an input device, such as user authentication, which is especially important for wearable devices that might be shared by different users [44,45]. Bio-acoustic recordings have been used to monitor cardiac activity and respiration rate [11]. The affordances of monitoring user respiration rate include stress/exertion levels, triggers based on punctuated exhaling (such as laughter or sobbing), the detection of sleep apnea, etc.…”

“…While hearables have a number of affordances for ubiquitous computing, many of these affordances are particularly relevant for affective computing, in which computers have the ability "to recognize, express, and "have" emotions" [9]. Hearables are particularly useful for recording affective data input, as the ear is a rich source for collecting many types of biological signals pertaining to our emotional states; ear-mounted sensors can potentially monitor cardiovascular, respiratory, perspiration, and brain states [10,11]. This type of data has been utilized in a variety of different applications, including fitness tracking, health monitoring, improved computer interfaces, and various context-aware/"smart" systems.…”

“…While many of these systems have been focused on applications for the disabled, able-bodied persons will also be able to benefit from similar applications [36]. Further, single channel EEG measurements can also be used to monitor a user's general sleep patterns [11].…”