Designing health/wellness and personal fitness devices, especially "wearables," presents a unique set of challenges: not only must they be very compact and extremely low power, but they must also interface with a set of diverse sensors, such as LEDs/photo-sensors (for blood-oxygen SpO2 readings), chest straps and patches for low-level cardiac signals (for EKGs), thermometers/temperature sensors, moisture sensors, and pressure transducers (for weight), to cite a few possibilities. Engineers striving to devise a viable approach and packaging for a product in this area often must resort to "cobbling together" a prototype and evaluation setup, which is a time-consuming, frustrating, fault-prone task—one which often has hardware and software incompatibilities that impede progress.
Analog/mixed-signal IC vendors are responding to the problem, as an integrated yet flexible and versatile development platform can ease the task, while also highlighting an array of their high-performance ICs at the same time. The hSensor Platform Maxim Integrated (formally called the MAXREFDES100# reference design) is a recent and powerful example: it includes its hSensor board, complete firmware with drivers, a debugger board and a graphical user interface (GUI). The hardware includes a broad range of sensors and interfaces:
MAX30003: Ultra-low power, single-channel integrated biopotential AFE
MAX30101: High-sensitivity pulse oximeter (SpO2) and heart-rate sensor
MAX30205: Industry’s only clinical-grade temperature sensor
MAX32620: Ultra-low power ARM® Cortex®-M4F microcontroller optimized for wearables
MAX14720: Industry’s lowest quiescent-current power-management integrated circuit (PMIC)
Additional components: Inertial sensors (three-axis accelerometer, six-axis accelerometer/gyroscope), barometric pressure sensor, flash memory and BLE radio.
However a set of just the sensors and their signal conditioning is necessary but not sufficient to fully relieve the designer's product-development pressures. Recognizing this, users of the Maxim hSensor platform have access to firmware source codes on Maxim’s website which, when combined with the platform, allows designers to load algorithms for different scenarios and adapt them to their specific applications. The firmware helps quickly test, validate and optimize designs, enabling faster evaluations and thus significantly reducing time to market.
The platform also includes support for the widely used ARM® mbed™ Internet of Things (IoT) Device Platform for writing software that controls hardware which can then connect to the cloud, simplifying creation of embedded, connected products. The mbed environment offers a high level of abstraction to eliminate maintenance of software tools and provide an extensive library of open-source software, supporting efficient evaluation and rapid prototyping of the application.