Meets Class-II regulations · Can be embedded in smartphones and wearable devices


Maxim Integrated Korea has launched a semiconductor-based blood pressure monitoring solution to facilitate the measurement of blood pressure, an important health indicator.
Considering the disadvantage of the large size of existing mechanical cuff-based devices, Maxim developed the MAXREFDES220# optical blood pressure measurement solution, which consists of a fully integrated optical sensor module, a microcontroller sensor hub, and a sensor algorithm.

This solution is embedded in smartphones or wearables, allowing users to measure their blood pressure anytime, anywhere by simply placing their finger on the device for 30 to 45 seconds in a comfortable position.

In addition, it meets Class II medical device regulatory limits and boasts the industry's highest accuracy while measuring blood pressure changes without a cuff. Under resting measurement conditions, it demonstrates accuracy with ▲systolic error (average 1.7 mmHg, standard deviation = 7.4 mmHg) and ▲diastolic error (average 0.1 mmHg, standard deviation = 7.6 mmHg), satisfying the Class II regulatory limits of average error 5 mmHg or less and standard deviation 8 mmHg or less.

To maintain accuracy, the MAXREFDES220# solution must be calibrated every four weeks, based on independent tests and a limited number of study subjects under rest conditions.

Because the algorithm code runs on small, ultra-low-power dedicated sensor hubs and microcontrollers, there is no need to integrate the new code into existing application processors. The reference design includes the MAX30101 or MAX30102 high-sensitivity photosensors as well as the MAX32664D sensor hub IC with the algorithm embedded.

The MAX30101 (using 3 LEDs) and MAX30102 (using 2 LEDs) pulse oximeters and heart rate optical sensor modules combine a photodetector, LED, and AFE (Analog Front-End) electronic device with an integrated cover glass.

The integrated optical design and lenses-on-top configuration enable an optimal signal-to-noise ratio (SNR) for small, low-cost, power-efficient modules, and is provided in a small 0.6mm x 3.3mm 14-pin optical package with an I2C interface to the sensor hub IC.

The MAX32664D sensor hub IC includes firmware for sensor control and execution of algorithms to measure blood pressure, heart rate, and blood oxygen levels without a cuff. In addition, with an ultra-small size of only 1.6mm x 1.6mm, it can be easily connected to the host microcontroller of the device without interruption.

Kris Ardis, Senior Director of Micro Security Software at Maxim, stated, “Although blood pressure is a critical vital sign, convenient and accurate monitoring has been difficult until now,” adding, “We are providing a variety of compact reference design products to enable system designers to develop accurate blood pressure monitors based on patient testing, even without a cuff.”