ST launches tiny motion sensor for wearable and implantable medical applications
STMicroelectronics’ MIS2DU12 MEMS accelerometer combines ultra-low power, signal processing, and an ultra-low profile suitable for wearable and implantable medical applications.
Produced using biocompatible materials and manufacturing processes, the MIS2DU12 has a 20nA power-down and sub-1µA active mode to extend the operating envelope of implantables such as cardiac monitors and pacemakers. At only 0.74mm high, and 2mm x 2mm, it enables skin patches to become extremely slim, lightweight, and comfortable to wear.
In skin patches such as glucose monitors and other bio-parameter sensors, the MIS2DU12’s sensor fusion ensures precision even during macroscopic motion and environmental stress. The applications benefit from high micro-motion sensitivity, power efficiency. The dedicated internal engine for motion processing detects free-fall, wake-up, single/double-tap, activity/inactivity, and calculates 6D/4D orientation. There are also built-in self-test and an embedded temperature sensor.
With integrated motion processing for event detection and wake-up, the MIS2DU12 contains an anti-alias filter to maximize output-data quality. By removing out-of-band vibration sources, this filter offloads the main application processor to help cut system power consumption. The sensor draws just 0.47μA in ultra-low-power active mode with 1.6Hz output data rate, and 5.6µA in normal operation with the anti-alias filter enabled.
The MIS2DU12 has user-selectable full scales of ±2g/±4g/±8g/±16g, output data rates from 1.6Hz to 800Hz, and operates over the extended temperature range from -40°C to +85°C. An integrated 128-level FIFO buffer provides generous data storage and extra flexibility to save system power consumption.
For rapid evaluation, the STEVAL-MKI255A adapter board contains a MIS2DU12 sensor and has a standard DIL24 pin arrangement for use with the STEVAL-MKI109D evaluation board. The board includes a high-performance 32-bit microcontroller and is ready to use with ST’s MEMS Studio GUI.
