Nordic-powered wireless ECG provides customizable measurements for remote healthcare monitoring

Finnish medical device manufacturer Movesense has launched a compact and lightweight wearable electrocardiogram (ECG) sensor for remote patient monitoring and telehealth applications. The ‘Movesense Medical’ sensor is registered as a Class IIa device under the European Union (EU) Medical Device Regulation (MDR), and is designed for use by remote healthcare providers, medical device manufacturers and integrators, hospitals, or by companies developing their own commercialized medical device.

Wealth of sensor data

Movesense Medical provides ECG, heart rate (HR), heart rate variability (HRV), and movement data via the integrated nine-axis inertial measurement unit (IMU). It employs Nordic Semiconductor’s nRF52832 SoC to supervise the Movesense firmware stack and record the sensor data using its powerful 64 MHz, 32-bit Arm® Cortex® M4 processor with floating point unit (FPU). This data is then transmitted via Bluetooth® LE wireless connectivity to the wearer’s smartphone. 

“Movesense Medical sensor is a ready-to-go solution for medtech innovators as it can be integrated into existing health applications or used to develop new wearable health solutions that improve patient outcome and save costs,” says Jussi Kaasinen, CEO and Founder at Movesense. “It also enables health operators and researchers running clinical trials the ability to access medically certified raw data.”

The Movesense Showcase app (available for iOS) can be used to test hardware functionality including ECG registration at various sampling rates, HR and HRV recording, and sensor signal collection at various dynamic ranges. The app source code and sample apps are also available to developers to use as a starting point for their own projects and to accelerate product development.

Ultra low power operation

Using a CR2025 coin cell battery, the Movesense Medical sensor can function for up to seven days – assuming continuous real time ECG streaming at a 256 Hz sample rate. Depending on the use case and amount of data being transmitted, the device can function for up to several weeks before the battery needs to be replaced. The ultra low power consumption is thanks in part to the nRF52832 SoC, which has been engineered to minimize power consumption with features such as the 2.4 GHz radio’s 5.5 mA peak RX/TX currents and a fully-automatic power management system.

“Battery life optimization is crucial to this application, to ensure the wearer’s medical data is collected and transmitted with no gaps,” says Kaasinen. “The ultra low power characteristics of the Nordic SoC helped make this possible. We also selected the chip due to the wide range of available hardware building blocks, and the generous 256/512 KB Flash memory and 32/64 KB RAM.

“In addition, Nordic provided us with access to excellent technical information, reference designs and brilliant application engineers.”

• About Movesense
• About nRF52832
• About Nordic Semiconductor