STMicroelectronics Announces Compact Motion Sensor to Improve Comfort and Measurement Accuracy for Medical Wearables and Implantables

STMicroelectronics (NYSE: STM, hereafter ST) has announced the MIS2DU12, a MEMS accelerometer that combines ultra-low power consumption, signal processing capabilities, and an ultra-compact size, making it ideal for medical wearables and implantable devices.

Produced using biocompatible materials and manufacturing processes, the MIS2DU12 features current consumption of just 20nA in power-down mode and less than 1µA in active mode, enabling long operating lives for implantable devices such as heart monitors and pacemakers. With a thickness of only 0.74mm and a 2 x 2mm footprint, it also enables ultra-thin, lightweight patch sensors with improved wearer comfort.

In patch sensors like glucose monitors and other vital parameter sensors, the MIS2DU12's sensor fusion maintains high accuracy even under macroscopic movement or environmental stress. These applications benefit from high sensitivity to micro-movements and high power efficiency. It features a dedicated built-in motion processing engine capable of detecting free-fall, wake-up, single/double taps, and active/inactive states, as well as 6-axis/4-axis orientation. It also includes self-test functionality and a temperature sensor.

Integrating motion processing circuitry for event detection and wake-up, the MIS2DU12 includes an anti-aliasing filter to maximize output data quality. By removing out-of-band vibration sources, the filter reduces the load on the host application processor and decreases overall system power consumption. The sensor's current consumption is a mere 0.47µA in ultra-low-power active mode with a 1.6Hz output data rate, and is kept to 5.6µA even when operating in normal mode with the anti-aliasing filter enabled.

The MIS2DU12 offers a selectable full-scale range of ±2g, ±4g, ±8g, or ±16g, an output data rate of 1.6Hz to 800Hz, and a wide operating temperature range of -40°C to +85°C. It integrates a 128-level FIFO buffer, providing large data storage and excellent flexibility while contributing to reduced system power consumption.

The STEVAL-MKI255A adapter board is also available for quick evaluation. This board, featuring the MIS2DU12 sensor, has a standard DIL24 pin layout, allowing it to be used in combination with the STEVAL-MKI109D evaluation board. The evaluation board is equipped with a high-performance 32-bit microcontroller and supports ST's "MEMS Studio" GUI...