Presenter: Shirrish Naganter Ramesh

Faculty Sponsor: Nikhil Saxena

School: UMass Amherst

Research Area: Electrical and Computer Engineering

Session: Poster Session 4, 2:15 PM - 3:00 PM, Auditorium, A20

ABSTRACT

Long-duration environmental and physiological monitoring in remote environments requires sensing systems that are compact, energy-efficient, and capable of operating without terrestrial communication infrastructure. This project presents the design and prototype implementation of ResQOS, a dual-device wearable platform that integrates physiological sensing, environmental monitoring, and satellite communication for autonomous emergency detection and remote alert transmission.

The system consists of a Physical Sensing Unit (PSU) worn by the user and an Environmental Sensing Unit (ESU) carried externally. Both devices are built around Nordic nRF52840 microcontrollers and communicate via Bluetooth Low Energy (BLE). The PSU measures physiological parameters including heart rate and blood oxygen saturation (MAX30102), body motion (LIS3DH accelerometer), hydration through bioimpedance sensing, and body temperature. The ESU collects environmental data including temperature, humidity, pressure, and gas concentration (BME688), carbon monoxide (MQ-7), and ambient oxygen (ME2-O2). It also integrates GPS positioning (PA1616D) and a RockBLOCK 9704 modem using the Iridium satellite network for off-grid emergency communication.

Embedded firmware evaluates combined environmental and physiological data to detect hazards such as hypoxia, hypothermia, heat stroke, and dangerous falls. The ESU operates on a 60 s duty cycle, averaging 65 mA and achieving 4–5 days of runtime with a 7500 mAh battery, while the PSU averages 12 mA, enabling 48 hours of operation with a 700 mAh battery. Satellite messages of up to 340 bytes are transmitted with typical 5–20 s latency.

Prototype testing demonstrated stable BLE communication, successful sensor integration, and reliable end-to-end satellite message transmission.