Cuffless BP monitor meets Class-II regulatory accuracy
Blood pressure (BP) monitoring is conventionally achieved with bulky and mechanical cuff-based medical devices. Maxim Integrated Products believes it can help developers do away with the bulky arm cuff for a solid-state BP monitoring solution using a patient’s finger.
Design engineers can develop BP trending products with the MAXREFDES220# reference design from Maxim. It has a complete integrated optical sensor module, a microcontroller sensor hub and a sensing algorithm, to be embedded into smartphones or wearables. It enables users to place their finger on a device for 30 to 45 seconds while resting to measure blood pressure anywhere and anytime. The reference design includes the MAX30101 or MAX30102 high-sensitivity optical sensor, as well as the MAX32664D sensor hub IC with built-in algorithms.
The MAX30101 (using three LEDs) and MAX30102 (using two LEDs) pulse-oximeter and heart-rate optical sensor modules combine photodetectors, LEDs and analogue front-end (AFE) electronics with an integrated cover glass. This integrated optical design and lenses-on-top approach enables optimal signal-to-noise ratio (SNR) for a small, lower cost and power-efficient module, explains Maxim. It is supplied in a tiny 5.6 x 3.3mm 14-pin optical package with an I2C interface to the sensor hub IC.
The MAX32664D sensor hub IC includes firmware which controls the sensor and executes the algorithms which measure cuffless blood pressure, heart rate and blood-oxygen levels. At 1.6 x 1.6mm, it can easily fit into small devices to seamlessly and effortlessly connect to a device’s host microcontroller.
According to Maxim, the MAXREFDES220# provides industry-best accuracy that meets Class-II regulatory limits. Calibration is required every four weeks to maintain above accuracies. The integrated optical modules and ready-to-use algorithms in the sensor hub IC, together with complete optical system design guidance, enable customers to easily embed the finger-based BP solution into devices. The algorithm code runs on a small, ultra-low-power dedicated sensor hub microcontroller, eliminating the need to integrate new code into an existing application processor, to accelerate time to market.
The MAXREFDES220# reference design, MAX32664D in WLP, MAX30101 and MAX30102 are available now.
