ROHM offers an optical heart rate sensor for smartwatches and bands, which can be used to determine stress and vascular age thanks to its high sampling rate of 1024Hz.The BH1792GLC is the second pulse wave sensor developed by ROHM. It features high detection accuracy and low current consumption of only 0.44 mA during measurement. With a sampling rate of 1024 Hz, heart rate can be measured up to 32 times faster than with conventional solutions.
The BH1792GLC measures only 2.8 mm x 2.8 mm x 0.9 mm (width x depth x height).
In addition to heart rate measurement, an infrared sensor enables user recognition. An integrated FIFO (First In First Out) memory helps reduce power consumption by the host (MCU), thus lowering the sensor's current draw and extending its operating time. The heart rate sensor operates on supply voltages from 2.5 V to 3.6 V. Its operating temperature range is -20°C to +85°C. The BH1792GLC is the ideal solution for smart bands, watches, smartphones, and other wearable devices that require vital sign monitoring. The BH1792GLC has been available as a sample and in OEM quantities since December 2017.
An evaluation board (BH1792GLC-EVK-001) for the heart rate sensor is available through online distributors Chip One Stop, Zyco Store (Core Staff) and RS Components, which can be connected to open platform MCU boards such as Arduino Uno via ROHM's sensor display.
Basic information
In order to monitor and manage patient health, the demand for wearable devices that can measure not only heart rate but also vital signs such as stress and vascular age has increased in recent years. However, measuring complex vital signs requires a higher sampling frequency and a greater number of measurements per unit of time. This can increase energy consumption and reduce battery life.
In response to this development, ROHM has leveraged its extensive experience with optical sensors to develop a low-power heart rate sensor that enables highly accurate measurements even under intense infrared conditions such as direct sunlight or during strenuous activity. Thanks to its high sampling rate, the new sensor meets the evolving demands of the IoT and wearable product markets.
ROHM will continue to develop solutions for enhanced safety and comfort in wearables and other portable applications.
Essential features
1. Meets the growing demand for vital signs sensors.
Thanks to its high sampling rate of 1024Hz, more complex vital signs such as stress and vascular age can be determined. Furthermore, an integrated infrared sensor detects whether the device is being worn and simplifies system setup by integrating the necessary components.
2. The optical filter achieves high detection accuracy.
An optimized optical filter structure with integrated IR and green filters, which only allow light with a green wavelength to pass through, reduces susceptibility to external noise such as infrared and red light by a factor of ten compared to conventional solutions. This enables high-precision detection even under intense infrared conditions.
3. Low Power Consumption for Long Battery Life:
In combination with ROHM's green LED (SMLMN2ECT), which has been optimized for the light reception characteristics of the heart rate sensor, the improved optical design enables a reduced current consumption of 0.44 mA (during pulse measurement).
Furthermore, the module features a new FIFO (First In First Out) function that reduces power consumption by the host (MCU), decreases power consumption by the pulse sensor, and extends battery life.
4. The optional evaluation card makes it easier to use
Online retailers such as Chip One Stop, Zyco Store (Core Staff), and RS Components offer an evaluation board for the pulse sensor (BH1792GLC-EVK-001). This board can be connected to open-platform MCUs such as the Arduino Uno via ROHM's SensorShield (EVK-001).
All the necessary documents and software for using the vital signs sensor assessment card are available and can be downloaded from the following URL: http://www.rohm.com/web/eu/sensor-shield-support/heart-rate-sensor2
