OverviewROHM, a globally renowned semiconductor manufacturer, has developed an optical pulse sensor “BH1792GLC” for wearable devices such as smartwatches and smart bands, achieving a high-speed sampling rate of 1024Hz and supporting pressure measurement and vascular age measurement. The “BH1792GLC” is the second-generation product of ROHM’s pulse sensors, praised for its “high accuracy” and “low power consumption.” Its low power performance achieves the industry’s smallest power consumption of 0.44mA (when measuring pulse rate), helping applications to operate for longer periods. Additionally, it supports high-speed sampling at 1024Hz. Compared to previous products, the pulse measurement speed is up to 32 times faster, meeting the demand for high-speed sampling in vital sign sensing such as pressure measurement and vascular age measurement. The production base for the preliminary processes is ROHM Apollo Co., Ltd. (Fukuoka Prefecture, Japan), and the production base for the later processes is ROHM Electronics Philippines Inc. (Philippines). Furthermore, the pulse sensor evaluation board “BH1792GLC-EVK-001” for the general-purpose microcontroller development board “Arduino Uno” has been available for sale on the AMEYA360 and RightIC online platforms since March 2018. In the future, ROHM will continue to develop products that contribute to achieving a safe and comfortable society in the increasingly popular field of wearable devices.BackgroundIn recent years, as people’s health awareness has increased, the demand for wearable devices has risen not only for pulse rate measurement but also for measuring various vital signs, including pressure and vascular age. To measure complex vital signs, it is necessary to increase the sampling frequency and the number of measurements per unit time, but this leads to increased power consumption and shorter application drive times. ROHM has developed a low-power pulse sensor that can measure with high precision even in environments with strong infrared light, such as during significant movements and sunlight, utilizing its unique infrared removal technology and years of accumulated technical experience in the field of optical sensors. This time, ROHM further optimized these technologies to develop a high-speed sampling pulse sensor that meets the demands of the times.

Feature Details1. Supports vital sign measurement, meeting the demands of the times Achieves 1024Hz high-speed sampling, thereby meeting the complex vital sign measurement needs such as pressure and vascular age measurement. Additionally, this product also includes an infrared sensor for installation determination, providing all necessary sensors for wearable devices, which greatly helps simplify the system.

2. Utilizes ROHM’s unique optical filter for high-precision detection The photosensitive part consists of an infrared cutoff filter and a green filter, using ROHM’s unique optical filter that only allows green wavelengths to pass through, successfully reducing the interference of infrared and red light to less than one-tenth of that of general products. This enables high-precision pulse measurement even in environments with strong infrared light, such as during vigorous movements and sunlight.3. Achieves the industry’s smallest level of low power consumption, aiding in long-term application operation By selecting an external green LED (ROHM’s “SMLMN2ECT”) that is very suitable for the photosensitive characteristics of pulse sensors and optimizing the optical design, it achieves the industry’s smallest level of 0.44mA low consumption current (when measuring pulse rate). Additionally, compared to previous products, a FIFO (First in First out) function has been newly added to reduce the power consumption of the HOST (microcontroller), helping applications achieve long-term operation by reducing the power consumption of both the pulse sensor and the microcontroller.

4. Highly popular evaluation board for sensor expansion is also available for simpler and easier integration Alongside the sale of this product’s samples, the pulse sensor evaluation board “BH1792GLC-EVK-001” for the sensor expansion board “SensorShield-EVK-001” that connects to the widely used general-purpose microcontroller development board “Arduino Uno” has started selling on the AMEYA360 and RightIC online platforms.

At the same time, various documents and software necessary to prove vital sign sensing using the evaluation board can be downloaded from the webpage.Application Cases● Wearable devices such as smart bands and smartwatches● Smartphones● Other devices requiring vital sign data

Further Reading:

“Maxim Optical Heart Rate Sensor: MAX30102”

Recommended Training: From May 25 to May 27, 2018, a “MEMS Packaging and Testing Training Course” hosted by MEMS Consulting will be held in Wuxi. The training content includes: (1) MEMS discrete device packaging technologies (metal packaging, ceramic packaging, plastic packaging, etc.); (2) MEMS wafer-level packaging technologies (wafer-level bonding, wafer-level micro-caps, wafer-level sealing, TSV, etc.); (3) MEMS system-level packaging technologies and device failure case analysis; (4) Typical MEMS device packaging and testing technologies: MEMS microphones, optical sensors, magnetic sensors, fingerprint recognition sensors, RF filters, image sensors, gas sensors, etc.; (5) MEMS packaging bonding design; (6) Elective course: MEMS design tools Tanner software and applications (MEMS design – modeling and simulation methods).

MEMS Consulting Contact: Peng Lin Phone: 17368357393 E-mail: [email protected]