An Integrated Wearable Sensor for Unobtrusive Continuous Measurement of Autonomic Nervous System

Advancements in miniaturized electronics and smart sensors combined with a broad platform of smart phones, big data, cloud service, and wireless communication have not only empowered wearable technology, they have also increased users life expectancy. For example, a wearable system provides unobtrusive ambulatory, continuous, ubiquitous health measurement, and real-time solution for patients physical without hampering the natural movement of the wearer. However, the ability to measure one's Autonomic Nervous System (ANS) using wearable biosensors in healthcare applications has been limited due to several challenges related to a lack in wearability, accuracy, reliability, and low-power consumption. In this paper, we presented a novel wearable ring sensor for the continuous measurement of four ANS activities: 1) electrodermal activity; 2) heart rate; 3) skin temperature; and 4) locomotion. Detailed information is given regarding the development of the proposed ring sensor followed by a discussion of the evaluation that was done utilizing the wearable sensor on volunteers to gather data. Specifically, volunteers wore the ring sensor while being simultaneously monitored with real-time telemetry, the sensor values are processed and analyzed. This paper is a continuation and extension of earlier work by the authors. New validation, experimental results, and development of the mobile application have been added to improve the previous system. The experiment demonstrated accurate results, and data were collected from 43 participants of diverse age, body mass, height, and race. Additionally, to evaluate the performance of the developed ring sensor, we compared the results with a state-of-the-art open source device. This paper aims to improve the worn biomedical sensor market, specifically when it comes to size and accuracy of worn sensors.