UC Berkeley Swarm Lab
Smart Mattress: Wireless Sleep Tracking with MIMSYs
Sponsored by the Berkeley Sensor & Actuator Center and BASF (multi-national German chemical manufacturing company)
Advisor: Professor Kristofer Pister
Summer 2018
*All images courtesy of the Berkeley Sensor & Actuator Center (BSAC) unless otherwise specified
MIMSY: The Micro-Inertial Measurement System for the Internet of Things
My first project at the Ubiquitous Swarm Lab in the early summer of 2018: measuring & visualizing sleep activity from a wireless sensor network embedded in mattress foam.
I wrote firmware for each MIMSY, allowing them to communicate 9-axis IMU data over an OpenWSN 6-TiSCH mesh network to an OpenMote acting as a DAG root connected to my laptop. The wireless sensor node’s orientation is rendered in real-time using the OpenGL-based visualization software I wrote in Python.
Embedding BASF mattress foam with an array of MIMSYs allows them to form a OpenWSN 6TiSCH network routing orientation data back to a central computer to visualize and track sleep data at 0.2Hz (roughly 6000 samples over one night of sleep).
Future experiments include sampling & data-throughput optimization through the 6TiSCH network scheduling function, battery life optimization, and sleep studies with basic sleep pattern classification from time-series mattress deformation data.
Heatmap visualization of body position on a mattress [1]:
t1: person is not on the mattress
t2: person lays on the right side of the mattress
t3: person lays on the left side of the mattress
t4: person sits at the bottom left of the mattress
t5: person gets off the mattress.
The MIMSY smart mattress project was published in the 2019 IEEE World Forum on the Internet of Things and led to a paid contract with BASF through the rest of my time at Swarm to update & maintain the wireless sensing firmware & visualization software I built for their “smart foam” research for shoes, mattresses, and more.
I’d be lying if I said I didn’t spend a couple nights sleeping on the mattress at the lab.
List of Publications
1. Craig B. Schindler, Daniel S. Drew, Brian G. Kilberg, Felipe M. R. Campos, Soichiro Yanase, and Kristofer S. J. Pister. "MIMSY: The Micro Inertial Measurement System for the Internet of Things." IEEE 5th World Forum on Internet of Things (WF-IoT). Limerick, Ireland: IEEE, Apr. 2019. (link)
The Micro Inertial Measurement System (MIMSY) is an open source wireless sensor node for Internet of Things applications, specifically designed for a small system volume while maintaining functionality and extensibility. MIMSY is a 16mm × 16mm node with an Arm Cortex-M3 microprocessor, 802.15.4 wireless transceiver, and a 9-axis IMU. The system is fully compatible with the OpenWSN wireless sensor networking stack, which enables the straightforward implementation of standards compliant 6TiSCH mesh networks using MIMSY motes. While the application space of MIMSY is quite vast, we present three sample implementations showcasing the opportunities afforded by a small and relatively low-cost mote with mesh networking and inertial measurement capabilities, including: high granularity areal sensing for sleep monitoring with motes embedded in a foam mattress; high reliability, low latency communication for industrial process automation and control; and long lifetime physical event detection and activity monitoring with minimal setup time.
