MAXREFDES117#: HEART-RATE AND PULSE-OXIMETRY
MONITOR
The MAXREFDES117# reference design is a low power, optical heart-rate module complete
with integrated red and IR LEDs, and a power supply. This tiny board, perfect for wearable
projects, may be placed on a finger or earlobe to accurately detect heart rate. This versatile
module works with both Arduino and mbed platforms for quick testing, development and
system integration. A basic, open-source heart-rate and SpO algorithm is included in the
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example firmware.
The board features 8 sewing tap pads for attachment and quick electrical connection to a
development platform.
As with all Maxim reference designs, the BOM, schematics, layout files, and Gerber files are
all available from the Design Resources tab. In addition, boards are available for purchase.
Features
Optical Heart-Rate Monitor and Pulse Oximetry Solution
Tiny 12.7mm x 12.7mm (0.5in x 0.5in) Board Size
Low Power
Device Drivers
Free Algorithm
Example C Source Code For Arduino And mbed Platforms
Test Data
Competitive Advantages
Highly-integrated, small-size sensor
Non-chest based heart-rate/SpO detection
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Ultra-low power consumption
Applications
Wearables
Heart-rate monitor
Pulse oximeter
MAXREFDES117# System Board
Introduction
Wearable devices hold the potential to transform health and medical monitoring. Heart rate,
specifically, provides tremendous insight into heart function and health, during both activity
and rest. Innovation and development of both optical semiconductors and lower-power
integrated circuits makes the transition to wearables possible. Until now, only large
organizations, with deep development budgets, could deliver such advanced products.
MAXREFDES117# delivers the promise of wearable devices to all developers. This unique
design measures both heart rate and pulse oximetry. MAXREFDES117# features the
MAX30102 with integrated red and IR LEDs for heart-rate and SpO detection. This
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configuration ideally detects heart rate and pulse ox on a persons fingertip, earlobe, or other
fleshy extremity. The small board size of 12.7mm x 12.7mm (0.5in x 0.5in) is ideal for
wearable applications and may be stitched into fabric for immediate prototyping. Firmware is
available for both Arduino and mbed platforms, enabling users to develop with virtually any
platform. User needs to provide a 2V to 5.5V supply at the power input, perfect for virtually
any battery or Arduino and mbed form-factor board.
The MAXREFDES117# design utilizes the heart-rate/SpO sensor (MAX30102), an efficient,
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low-power step-down converter (MAX1921), and an accurate level translator (MAX14595).
The entire design typically operates at less than 5.5mW when using with the example
firmware. A block diagram of the system is shown in Figure 1.