24-hour monitoring possible with enhanced battery life and HRM

Silicon Labs announced a family of optical biometric sensors that provide electrocardiogram (ECG) and advanced heart rate monitoring (HRM) capabilities for the design of a wide range of wearable healthcare and fitness products.

The Si117x sensor module combines ultra-low power consumption, high sensitivity, and high integration, making it ideal for the design of smartwatches, wrist patch-type devices, and other wearable devices that require long battery life and enhanced HRM accuracy. To enable developers to streamline product development and accelerate time-to-market, Silicon Labs provides a complete end-to-end sensing solution consisting of the Si117x sensor module, HRM algorithms, the Wireless Gecko SoC for Bluetooth connectivity, and an easy-to-use wrist-based development kit supported by sample code and example projects.

24-hour HRM is a key requirement for health and fitness wearable devices. Through 24-hour heart rate monitoring, end users and healthcare professionals can analyze physiological patterns, track health abnormalities early before they worsen into disease, and correct lifestyle habits.

To meet market demands for power efficiency, the Si117x sensor continuously performs HRM operations while consuming less than 50µA of current (integrated current consumption of the sensor + LED). The synchronization function of the built-in buffer and accelerometer further reduces system-level power consumption.

Because this sensor is highly power-efficient, developers can design wearable devices that can perform continuous monitoring tasks without significantly affecting battery life, even when using smaller batteries.

The Si117x sensor further enhances the end-user experience by providing enhanced HRM accuracy. This sensor offers a fast sampling rate, a high signal-to-noise ratio (SNR) of over 100 dB, and the ability to eliminate ambient noise and erroneous data. This enables the detection of high-quality signals that facilitate heart rate monitoring, despite various physiological constraints that impede accurate sensing, such as varying skin tones or tattoos. More accurate observation of the HR waveform enables biometrics beyond conventional HRM, such as heart rate variability (HRV), stress analysis, and pulse volume.

The Si117x module has a very high level of integration, which not only simplifies wearable design but also allows for easy synchronization of measurement results from various sensors without significantly increasing system costs or board area. Each module can support up to 4 LEDs (all 4 can be driven simultaneously), and these 4 LED drivers can each be programmed independently (1.7 to 310mA).

Tom Pannell, Senior Director of IoT Product Marketing at Silicon Labs, stated, “As the health and fitness wearable market continues to grow, developers want complete biometric sensing solutions that operate flawlessly without complex integration tasks. Silicon Labs is the only supplier capable of providing a total HRM sensing solution in-house, ranging from sensor modules and algorithms to wireless SoCs that can transmit measurement results via Bluetooth LE. Silicon Labs’ example HRM project handles the interfaces between these components, and centralizing contact points in this way significantly simplifies customer support and debugging.”