Wearable autonomous microsystem with electrochemical gas sensor array for real-time health and safety monitoring


Airborne pollution and explosive gases threaten human health and occupational safety, therefore generating high demand for a wearable autonomous multi-analyte gas sensor system for real-time environmental monitoring. This paper presents a system level solution through synergistic integration of sensors, electronics, and data analysis algorithms. Electrochemical sensors featuring ionic liquids were chosen to provide low-power room-temperature operation, rapid response, high sensitivity, good selectivity, and a long operating life with low maintenance. The system utilizes a multi-mode electrochemical instrumentation circuit that combines all signal condition functions within a single microelectronics chip to minimize system cost, size and power consumption. Embedded sensor array signal processing algorithms enable gas classification and concentration estimation within a real-world mixture of analytes. System design and integration methodologies are described, and preliminary results are shown for a first generation SO(2) sensor and a thumb-drive sized prototype system.

Download full-text


Available from: Haitao Li, Aug 30, 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a real-time, electrochemical gas sensor array system featuring room temperature ionic-liquid interfaces and targeting safety monitoring in underground mines. A prototype system was constructed using a custom ionic-liquid sensor array, a custom multi-mode electrochemical sensor readout board, and a commercial low power microcontroller board. Gas sensors for multiple mine gases were implemented in a 2 by 2 miniaturized array. A novel resource-sharing circuit tailored to our gas sensor array was utilized to significantly decrease power, cost and size while implementing two electrochemical detection modes. The system achieves a resolution as high as 0.01% vol in amperometry mode and 0.06% vol in impedance spectroscopy mode for oxygen as an example target gas.
    Full-text · Conference Paper · Nov 2013
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Hemorrhagic shock (HS) is the leading cause of death for people with traumatic injuries. The onset of HS is correlated with marked changes in the plasma vasopressin levels and some studies indicate that administrating vasopressin in the bloodstream can help stabilize the situation. This situation calls naturally for the use of implantable devices for both the monitoring and treatment of HS. In this work, we present a self-powered hemorrhagic-shock autonomous integrated device (hemoAID) that continuously monitors vasopressin levels and releases vasopressin automatically when levels drop below a certain threshold. We demonstrate that the device can operate at physiological concentrations of vasopressin, in sheep serum, thus paving the way towards the development of an autonomous implantable device for HS prevention.
    Full-text · Article · Feb 2014 · PLoS ONE