原标题：Maxim MAX32664+ MAX86141智能手环健康平台解决方案

　　Maxim公司的智能手环健康平台MAXREFDES103#是基于超低功耗生物传感器集线器MAX32664和超低功耗光学数据采集系统MAX86140/MAX86141,采用高灵敏度PPG生物传感器,功率管理IC(PMIC)和Maxim公司的健康测量微控制器,能收集对健康有用的生物信息.该平台还包括用来计算基于生物传感器测量的心脏健康的算法.主要特性包括采用光电容积脉搏波描记法原理(PPG),基于手环的嵌入心律,血氧饱和度(SpO2)算法,心率变异性(HRV),呼吸速率, 睡眠质量库算法,可穿戴健康手环外形, MAX32664传感器集线器, MAX86141 PPG模拟前端(AFE),3轴加速度计, Windows®和Android 图形用户接口.主要用在可穿戴运动手表,健康跟踪器,心脏信号数据跟踪器.本文介绍了智能手环MAXREFDES103#主要特性,系统框图以及系统部件图,以及所用的主要元件包括超低功耗生物传感器集线器MAX32664主要特性和应用案例以及超低功耗光学数据采集系统MAX86140/MAX86141主要特性和典型应用电路.

　　This user guide provides information about preparing and running the MAXREFDES103# health sensor band. This platform uses a high-sensitivity PPG biosensor, power-management IC (PMIC), and microcontrollers from Maxim Integrated® in a wrist-worn design that allows the capture of biometric signals important to healthcare. The platform also contains algorithms for calculating heart health based on the biosensor measurements.

　　The MAXREFDES103# is a wrist-worn wearable form factor that demonstrates the high sensitivity and algorithm processing functions for health-sensing applications. This health sensor band platform includes an enclosure and a biometric sensor hub with an embedded algorithm for heart rate and SpO2 (MAX32664C) which processes PPG signals from the analog-front-end (AFE) sensor (MAX86141). Algorithm output and raw data can be streamed through Bluetooth® to an Android® app or PC GUI for demonstration, evaluation, and customized development.

　　Design files, firmware, and software can be found on the Design Resources tab. The board is also available for purchase.

　　智能手环MAXREFDES103#主要特性:

　　Photoplethysmography (PPG)

　　Wrist-based embedded heart rate, blood oxygen saturation (SpO2) algorithm

　　Heart rate variability (HRV), respiration rate, sleep quality library algorithm

　　Wearable health band form factor

　　MAX32664 sensor hub

　　MAX86141 PPG analog front-end

　　3-axis accelerometer

　　Windows® and Android GUIs

　　智能手环MAXREFDES103#应用:

　　Wearable sports watch

　　Healthcare tracker

　　Heart signal data tracker

　　图1. 智能手环MAXREFDES103#系统框图

　　图2. 智能手环MAXREFDES103#系统外形图

　　图3. 智能手环MAXREFDES103#系统部件图

　　The MAXREFDES103# contains enables quick evaluation of our hardware and embedded firmware for heart-rate and SpO2 monitoring on a wrist-based platform to significantly shorten development time for custom fitness, health, and clinical applications.

　　The MAXREFDES103# platform includes the following key components:

　　Micro board, which includes the MAX32630 microcontroller, MAX20303 power-management IC (PMIC), dual-mode Bluetooth, and 6-axis accelerometer and gyroscope

　　Sensor board, which includes the MAX86141 AFE, optical heart-rate sensor with one green LED, one red LED, one IR LED, two photodiodes, and MAX32664C biometric sensor hub with an embedded algorithm for heart rate and SpO2 monitoring

　　MAXDAP Pico Adapter board for use during a firmware upgrade for the micro board

　　Health sensor band enclosure and straps

　　Hardware design files, firmware, and software

　　超低功耗生物传感器集线器MAX32664

　　The MAX32664 is part of a sensor hub family with embed­ded firmware and algorithms for wearables. It seamlessly enables customer-desired sensor functionality, which includes communicating with Maxim’s optical sensor solu­tions and delivering raw or calculated data to the outside world. This is achieved while keeping overall system power consumption in check. The device family interfaces to a microcontroller host through a fast-mode slave I2C interface for field updates as well as access to raw and processed sensor data.

　　The MAX32664 Version A supports the MAX30101/MAX30102 high-sensitivity pulse oximeter and heart-rate sensor for wearable health for finger-based applications. A master mode I2C interface for communication with sen­sors is provided.

　　The MAX32664 Version B supports the MAX86140/MAX86141 for wrist-based applications. A master mode SPI interface for communication with sensors is provided.

　　The MAX32664 Version C supports the MAX86140/MAX86141 for wrist-based applications. A master mode SPI interface for communication with sensors is provided.

　　The MAX32664 Version D supports the MAX30101/MAX30102 high-sensitivity pulse oximeter and heart-rate sensor for wearable health for finger-based applications. A master mode I2C interface for communication with sensors is provided.

　　The tiny form factor (1.6mm x 1.6mm WLP or 3mm x 3mm TQFN) allows for integration into extremely small applica­tion devices.

　　MAX32664主要特性和优势:

　　Biometric Sensor Hub Enables Faster Time to Market

　　Finger-Based (Version A) Algorithms Measure:Pulse Heart Rate

　　Pulse Blood Oxygen Saturation (SpO2)

　　Wrist-Based (Version B) Algorithm Measures:Pulse Heart Rate

　　Wrist-Based (Version C) Algorithms Measure:Pulse Heart Rate

　　Pulse Blood Oxygen Saturation (SpO2)

　　Finger-Based (Version D) Algorithms Measure:Pulse Heart Rate

　　Pulse Blood Oxygen Saturation (SpO2)

　　Estimated Blood Pressure

　　Both Raw and Processed Data Are Available

　　Basic Peripheral Mix Optimizes Size and PerformanceOne Slave I2C for Communication with a Host Microcontroller

　　One Master I2C for Communication with Sensors (Version A)

　　One Master SPI for Communication with Sensors (Version B)

　　32.768kHz RTC

　　FIFO Provides Minimal Host Interaction

　　Bootloader Facilitates Secure, AuthenticatedFirmware Upgrades

　　MAX32664应用:

　　Wearable Fitness

　　Hearables

　　Wearable Medical

　　Portable Medical

　　Mobile Devices

　　图4. MAX32664简化框图

　　图5. MAX32664 Version A:心律和SpO2监视器

　　图6. MAX32664 Version B:心律监视器

　　图7. MAX32664 Version C:心律和SpO2监视器

　　图8. MAX32664 Version D:心律,SpO2和血压监视器

　　基于MAX32664传感器集线器参考设计平台接口指引

　　A number of reference design platforms, including the MAXREFDES101, MAXREFDES103, and MAXREFDES220, are available for Maxim customers to evaluate and develop a wide range of Maxim products for health-sensing applications. These platforms include biosensors, power-management ICs (PMIC), and microcontrollers that allow the capture of bio signals important to healthcare. Different embedded algorithm firmware is available for this platform to calculate heart rate, SpO2, or blood pressure. This document describes the commands and settings needed for communication with these platforms.

　　The sensor hub-based reference designs provide unique evaluation and development platforms in a wearable form factor. Each reference design include a biosensor (e.g., the MAX86141 or MAX30101), a variant of the MAX32664 that runs the algorithm firmware (e.g., the MAX32664A, B, C, or D, depending on the algorithm), a 6-axis accelerometer/gyroscope, a PMIC, and a host microcontroller (the MAX32630) that communicates with the MAX32664 sensor hub through an I2C interface. The host microcontroller firmware has a set of commands accessible by the user through the serial port or Bluetooth® LE1 to configure the MAX32664 and sensors, start/stop the algorithm, and stream data. The same interface commands are used by the Maxim DeviceStudio PC GUI to communicate with the platform.

　　This document describes the protocol and commands to interface the host microcontroller firmware on the Maxim reference design platform, including:

　　• Generic commands common to all MAX32664 variants

　　• MAX32664 variant-specific commands and settings

　　图9.基于MAX32664传感器集线器参考设计平台架构图

　　超低功耗光学数据采集系统MAX86140/MAX86141

　　The MAX86140/MAX86141 are ultra-low-power, com­pletely integrated, optical data acquisition systems. On the transmitter side, the MAX86140/MAX86141 have three programmable high-current LED drivers that can be configured to drive up to six LEDs. With two MAX86140/MAX86141 devices working in master-slave mode, the LED drivers can drive up to twelve LEDs. On the receiver side, MAX86140 consists of a single optical readout channels, while the MAX86141 has two opti­cal readout channels that can operate simultaneously. The devices have low-noise signal conditioning analog front-end (AFE) including 19-bit ADC, an industry-lead ambient light cancellation (ALC) circuit, and a picket fence detect and replace algorithm. Due to the low power consumption, compact size, easy/flexible-to-use and industry-lead ambient light rejection capability of MAX86140/MAX86141, the devices are ideal for a wide variety of optical-sensing applications, such as pulse oximetry and heart rate detection.

　　The MAX86140/MAX86141 operate on a 1.8V main supply voltage and a 3.1~5.5V LED driver supply voltage. Both devices support a standard SPI compatible interface and fully autonomous operation. Each device has a large 128-word built-in FIFO. The MAX86140/MAX86141 is available in compact wafer-level package (WLP) (2.048 x 1.848mm) with 0.4mm ball pitch.

　　MAX86140/MAX86141主要特性和优势:

　　Complete Single and Dual-Channel Optical Data Acquisition System

　　Built-in Algorithm Further Enhances Rejection of Fast Ambient Transients

　　Optimized Architecture for Transmissive and Reflective Heart Rate or SpO2 Monitoring

　　Low Dark Current Noise of < 50pA RMS (Sample to Sample Variance)

　　Lower Effective Dark Current Noise Achievable Through Multiple Sample Modes and On-Chip Averaging

　　High-Resolution, 19-Bit Charge Integrating ADC

　　Three Low-Noise, 8-Bit LED Current DACs

　　Excellent Dynamic Range > 90dB in White Card Loop-Back Test (Sample-to-Sample Variance)

　　Dynamic Range Extendable to > 104dB for SpO2 and > 110dB for HRM with Multiple Sample Modes and On-Chip Averaging

　　Excellent Ambient Range and Rejection Capability> 100μA Ambient Photodetector Current

　　> 70dB Ambient Rejection at 120Hz

　　Ultra-Low-Power Operation for Body Wearable DevicesLow-Power Operation, Optical Readout Channel< 10μA (typ) at 25sps

　　Short Exposure Integration Period of 14.8μs, 29.4μs, 58.7μs, 117.3μs

　　Low Shutdown Current = 20μW (typ)

　　Built-in Algorithm Further Enhances Rejection of Fast Ambient Transients

　　Miniature 2.048 x 1.848mm, 5 x 4 0.4mm Ball Pitch WLP

　　-40°C to +85°C Operating Temperature Range

　　MAX86140/MAX86141应用:

　　Wearable Devices for Fitness, Wellness and Medical Applications

　　Optimized for Wrist, Finger, Ear, and Other Locations

　　Optimized Performance to DetectOptical Heart Rate

　　Oxygen Saturation (SpO2)

　　Muscle Oxygen Saturation (SmO2 and StO2)

　　图10. MAX86140/MAX86141简化框图

　　图11. MAX86140/MAX86141无外接复接器的GPIO CTRL[3:0] 0010框图

　　图12. MAX86140/MAX86141带外接复接器的GPIO CTRL[3:0] 0010框图

　　图13. MAX86140/MAX86141无外接复接器的GPIO CTRL[3:0] 0100框图

　　图14. MAX86140/MAX86141带外接复接器的GPIO CTRL[3:0] 0100框图

　　图15. MAX86140/MAX86141 GPIO CTRL[3:0] 0101框图

　　图15. MAX86140/MAX86141带单个外接复接器的GPIO CTRL[3:0] 0110和0111框图

　　图16. MAX86140/MAX86141带两个外接复接器的GPIO CTRL[3:0] 0110和0111框图

　　图17. MAX86140/MAX86141无外接复接器的GPIO CTRL[3:0] 0110和1000框图

　　图18. MAX86140/MAX86141带外接复接器的GPIO CTRL[3:0] 0110和1000框图

　　图19. MAX86140/MAX86141典型应用电路