Maxim Integrated MAXREFDES103 User manual

Maxim Integrated Page 1 of 42
MAXREFDES103# Health Sensor Band
User Guide
UG7145; Rev 1; 1/20
Abstract
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.

Maxim Integrated Page 2 of 42
Table of Contents
Detailed Hardware Description .....................................................................................................5
Required Equipment .....................................................................................................................5
System Diagram ...........................................................................................................................7
Operating the Health Sensor Band ...............................................................................................8
Power On/Off.............................................................................................................................8
Button Functionality...................................................................................................................9
Color Definitions for LED Status................................................................................................9
How to Position the Device on the Wrist .................................................................................10
Software Updates .......................................................................................................................11
Installing the PC GUI...............................................................................................................11
Updating the Micro Board Firmware (.bin) on the MAXREFDES103# ....................................12
Updating the MAX32664 Sensor Hub Algorithm Firmware (.msbl) .........................................13
Evaluation GUIs ..........................................................................................................................17
Using the DeviceStudio PC GUI..............................................................................................17
Installing the Windows 7 Driver for the PC GUI...................................................................17
USB Connection ..................................................................................................................19
Bluetooth LE Connection for Windows 10 ...........................................................................22
Starting the PPG Measurement...........................................................................................24
Data Format of the Log File .................................................................................................26
Flash Logging of Data..........................................................................................................27
Downloading the Log File ....................................................................................................27
Maxim Health Sensor Platform App for Android......................................................................30
Installing the App .................................................................................................................30
Optical Heart-Rate Monitoring .............................................................................................31
Pulse Oximetry ....................................................................................................................33
Heart-Rate Variability...........................................................................................................36
Respiration Rate ..................................................................................................................38
Notes on the Enclosure...............................................................................................................40
Time-Alignment Method for Comparing PPG Data to ECG Data ...............................................40
SpO2Calibration.........................................................................................................................41
Revision History ..........................................................................................................................42

Maxim Integrated Page 3 of 42
List of Figures
Figure 1. MAXREFDES103# wearable form factor in detail. ........................................................5
Figure 2. MAXREFDES103# system diagram. .............................................................................7
Figure 3. USB Type-C cable (left) and MAXDAP Pico Adapter board (right). ..............................8
Figure 4. PPG measurement. .....................................................................................................10
Figure 5. Install the .msi file. .......................................................................................................11
Figure 6. MAXDAP Pico Adapter .bin firmware updates port connected to the PC....................12
Figure 7. DAPLINK drive on the PC............................................................................................12
Figure 8. Reset button on the MAXDAP-TYPE-C Pico Adapter board. ......................................13
Figure 9. MAXDAP Pico Adapter board device port connected to the PC..................................13
Figure 10. Maxim DeviceStudio scan options.............................................................................14
Figure 11. Maxim DeviceStudio connected devices. ..................................................................14
Figure 12. Device tab to update the MAX32664 .msbl. ..............................................................15
Figure 13. Warning message......................................................................................................15
Figure 14. Upload the embedded heart-rate algorithm to the MAX32664. .................................16
Figure 15. .msbl file flashed successfully....................................................................................16
Figure 16. CDC DEVICE in Device Manager..............................................................................17
Figure 17. Locate and install the driver manually. ......................................................................18
Figure 18. Browse to the extracted release package..................................................................18
Figure 19. Select Install this driver software anyway. .................................................................19
Figure 20. Mbed Serial Port in Device Manager. ........................................................................19
Figure 21. USB connection to PC using a USB Type-C cable (left) and MAXDAP Pico Adapter
board device port (right)..............................................................................................................19
Figure 22. Scan for available devices. ........................................................................................20
Figure 23. Successful connection over USB...............................................................................21
Figure 24. Scan for available Windows BLE devices..................................................................22
Figure 25. Bluetooth LE device selection....................................................................................23
Figure 26. Successful connection over Bluetooth LE. ................................................................24
Figure 27. Configure for Algorithm mode....................................................................................25
Figure 28. Measurement data displayed.....................................................................................25

Maxim Integrated Page 4 of 42
Figure 29. Example log file PPG_.csv. .......................................................................................27
Figure 30. Power button on the MAXREFDES103#. ..................................................................28
Figure 31. MSD connection to PC using USB Type-C cable. .....................................................28
Figure 32. Flash Log Parser. ......................................................................................................29
Figure 33. Install the .apk............................................................................................................30
Figure 34. Run the .apk. .............................................................................................................30
Figure 35. Grant permissions and allow access. ........................................................................30
Figure 36. Click on the device named HSPSP02…....................................................................31
Figure 37. Main menu of the Maxim Health Sensor Platform app. .............................................31
Figure 38. Start heart-rate measurement....................................................................................32
Figure 39. Heart-rate measurement............................................................................................32
Figure 40. Positioning the health sensor band............................................................................33
Figure 41. Start SpO2measurement. .........................................................................................33
Figure 42. IR and Red signals displayed during SpO2measurement. .......................................34
Figure 43. SpO2measurement...................................................................................................34
Figure 44. Motion has turned red to indicate excessive motion..................................................35
Figure 45. Stop monitoring icon. .................................................................................................35
Figure 46. Retrieving the .csv log file from the Android device...................................................36
Figure 47. Start heart-rate variability measurement....................................................................37
Figure 48. Heart-rate variability measurement............................................................................37
Figure 49. Start the respiration rate measurement. ....................................................................38
Figure 50. Respiration rate measurement. .................................................................................38
Figure 51. Sleep quality assessment. .........................................................................................39
Figure 52. PPG and ECG data sets that have been time-aligned. .............................................40
List of Tables
Table 1. Button Functionality ........................................................................................................9
Table 2. Color Definitions for LED Status .....................................................................................9
Table 3. Data Table Column Definitions for the Log File (PPG_*.csv) .......................................26

Maxim Integrated Page 5 of 42
Detailed Hardware Description
Figure 1. MAXREFDES103# wearable form factor in detail.
Required Equipment
The MAXREFDES103# platform includes the following components:
•Micro board
•MAX32630 microcontroller
•MAX20303 power-management IC (PMIC)
•Dual-mode Bluetooth®connection
•Tri-color status LED
•Sensor board
•MAX86141 analog front-end and optical heart rate sensor with one green LED, one
red LED, one IR LED, and two photodiodes
The Bluetooth word mark and logos are registered trademarks owned by Bluetooth SIG, Inc. and any use of such marks by
Maxim is under license.
Top View
Left Right
Bottom View
Button F
USB Type-C
Power Button
LEDsPhotodiodes
Status LED
Serial Number
MAC Address
(Last Four Digits)

Maxim Integrated Page 6 of 42
•MAX32664 microcontroller with embedded heart-rate algorithm
•Three-axis accelerometer
•MAX4740 quad SPDT switch which, in combination with the MAX86140/41, enables
different LED and PD configurations
•One green LED, two combination RGB LEDs (One of these RGB LEDs is currently not
used by the algorithm. The extra LED is reserved for future use: To simplify the design,
the extra LED and the MAX4740 may be removed for the heart rate, SpO2use case.)
•MAXDAP Pico Adapter board to be used during a firmware upgrade for the micro board
•Two USB Micro-B cables for firmware upgrade of the micro board or for PC communication
with the micro board or charging of the health sensor band
•Health sensor band enclosure
•Battery
•One USB Type-C™cable for PC communication with the micro board (Windows®7 or
Windows 10) or charging of the health sensor band
Additional requirements:
•PC (Windows 10 only) with Bluetooth connection for data streaming and logging
•Android®device with Bluetooth connection for data streaming and logging
Android is a registered trademark of Google Inc.
USB Type-C is a trademark of Universal Serial Bus Implementers Forum, Inc.
Windows is a registered trademark of Microsoft Corporation.

Maxim Integrated Page 7 of 42
System Diagram
Figure 2. MAXREFDES103# system diagram.
Arm and Cortex are registered trademarks of Arm Limited.
MAX32630
Arm® Cortex®
M4F MCU
MAX20303
POWER-MANAGEMENT IC
PAN1326B
BLUETOOTH/BLE
BMI160
HOST ACCELEROMETER
I
2
C
QSPI
MX25U51245GZ4I54
64MB FLASH MEMORY
MAX32664
Arm Cortex M4F MCU
MAX86141
OPTICAL SENSOR
SENSOR BOARD
SENSOR HUB
I
2
C
UART
BOOTLOADER
MICROCONTROLLER BOARD
HR, SpO
2
ALGORITHM
KX122
3-AXIS ACCEL
(OPTIONAL)
SPI1
USB-C CONNECTOR
I
2
C
MAX4740
QUAD SPDT SWITCH
LED1
DRV
LED2
DRV
GPIO1
LED4 LED1 LE D5 LED2 LED6 LED3
LED3
DRV

Maxim Integrated Page 8 of 42
Operating the Health Sensor Band
Power On/Off
The MAXREDES103# can be powered on by pressing and holding the power button for at least
one second.
Alternatively, the device powers on when connected to a PC using a USB Type-C cable or when
connected to a MAXDAP Pico Adapter board.
Figure 3. USB Type-C cable (left) and MAXDAP Pico Adapter board (right).
The MAXDAP Pico Adapter board has two USB Micro-B connectors. The bottom connector next
to the pushbutton is used for updating the .bin firmware of the micro board. The right connector
next to the “Device” label is used for the serial connection between the MAXREFDES103# and
the PC. Both connectors provide power to the MAXREFDES103#.
To power off, press and hold the power button on the MAXREFDES103# for at least 15 seconds.
Note: If the device becomes unresponsive, a hard reset to the device may be performed by using
the power-off and power-on procedures.
.bin
Firmware
Updates

Maxim Integrated Page 9 of 42
Button Functionality
Table 1 describes the functionality of the two buttons.
Table 1. Button Functionality
Button Short Press Long Press (3s)
Extra Long
Press (15s)
Power Button Turn off/on status LED; to
power on, press for 1s
To power off, press and hold the
power button on the
MAXREFDES103# until the LED
status turns magenta and blinks fast
Power off
Button F Start/stop data collection
(flash logging) N/A N/A
Color Definitions for LED Status
Table 2 describes the state of the device for a given color and blinking status.
Table 2. Color Definitions for LED Status
LED Color Solid (No Blinking) Fast Blink Slow Blink
Red
Failure detected – needs
system reset
Communications with the
MAX32664 failed
Battery critically low
(<10%)
Green
USB connected (no data
streaming)
Streaming USB data
Device is ready (no USB
connection)
Blue Reserved Streaming Bluetooth LE data
Bluetooth Low Energy
(Bluetooth LE or BLE)
connected (no data
streaming)
Magenta Reserved
To power off, press and hold
the power button on the
MAXREFDES103# until the
LED status turns magenta and
blinks fast
Reserved
Cyan Reserved Flash logging active
5 blinks indicate that
flash logging is complete
Yellow System is initializing
After the MAX32664
programming is complete, the
LED status flashes yellow for 2s
Battery low (10% to
25%)
White Reserved Reserved MSD mode
Off LEDs have been turned off N/A N/A

Maxim Integrated Page 10 of 42
How to Position the Device on the Wrist
Position the health sensor band approximately one finger width up the arm from the wrist bone. If
possible, wear the health sensor band on the non-dominant hand, as this improves the quality of
the data. The health sensor band should fit tightly but comfortably around the wrist. Make sure
the skin has direct contact with the openings for the LED/photodiodes at the center of the back of
the health sensor band.
Figure 4. PPG measurement.

Maxim Integrated Page 11 of 42
Software Updates
The MAXREFDES103# has been pre-loaded with the firmware that was available during
production. A firmware upgrade is strongly recommended to ensure that the most recent set of
firmware is loaded. To update the firmware, perform the following steps in this exact order:
1. Install the PC GUI using the .msi file
2. Flash the micro board .bin file
3. Flash the algorithm .msbl file
Installing the PC GUI
1. Uninstall any previously installed versions of the DeviceStudio GUI.
2. Download and extract the Eval Package for either Windows 10 (supports USB and
Bluetooth) or Windows 7 (supports only USB) from the Maxim website for the
MAXREFDES103#.
Note: The software package includes the latest firmware .bin, algorithm .msbl, and the
corresponding Windows application .msi. All three must be updated to ensure
compatibility.
3. Double click on the .msi file. Check the box for “I accept the terms in the License
Agreement.” Click Install, and then click Finish.
Figure 5. Install the .msi file.
Maxim is a registered trademark of Maxim Integrated Products, Inc.

Maxim Integrated Page 12 of 42
Updating the Micro Board Firmware (.bin) on the MAXREFDES103#
Firmware upgrades to the MAX32630 may be performed using the provided MAXDAP Pico
Adapter board per the following steps.
Note: The software package includes the latest .bin firmware, .msbl algorithm, and the
corresponding .msi Windows application. All three components must be updated to ensure
compatibility.
1. Connect the MAXDAP Pico Adapter board .bin firmware updates port to the PC using the
USB Micro-B cable.
Figure 6. MAXDAP Pico Adapter .bin firmware updates port connected to the PC.
2. Wait for the Windows drivers to install. After the drivers have installed, the PC recognizes
the device, which shows up as a drive named DAPLINK on the PC.
Figure 7. DAPLINK drive on the PC.
3. To flash the host firmware to the MAX32630, drag and drop the .bin binary file into the
DAPLINK drive on your PC.
4. The MAXREFDES103# does not automatically reset after flashing the micro board with
the new firmware. Press and release the reset button on the MAXDAP Pico Adapter board
to restart the health band. The button is located below the top USB Micro-B connector.
.bin
Firmware
Updates

Maxim Integrated Page 13 of 42
Figure 8. Reset button on the MAXDAP-TYPE-C Pico Adapter board.
Updating the MAX32664 Sensor Hub Algorithm Firmware (.msbl)
After the host firmware binary is updated to the micro board, the .msbl Biometric Sensor Hub
algorithm must be updated with the PC GUI by performing the following steps.
Note: The software package includes the latest .bin firmware, .msbl algorithm, and the
corresponding .msi Windows application. All three components must be updated to ensure
compatibility.
1. Open the Maxim DeviceStudio Windows application.
2. Connect the MAXDAP Pico Adapter board device port to the PC using the USB Micro-B
cable. Wait five seconds.
Figure 9. MAXDAP Pico Adapter board device port connected to the PC.
3. Select the Serial over USB/Bluetooth scan option, then click Scan.
Reset
Device

Maxim Integrated Page 14 of 42
Figure 10. Maxim DeviceStudio scan options.
4. Verify that the Devices list in the Connected Devices section shows PPG.
Figure 11. Maxim DeviceStudio connected devices.

Maxim Integrated Page 15 of 42
5. Go to the Device tab and select Update SmartSensor_MAX32664 Software. Then
select Update Firmware and select the *.msbl file from the extracted Eval Package and
click Open.
Figure 12. Device tab to update the MAX32664 .msbl.
6. Click OK on the Warning!pop-up window.
Figure 13. Warning message.
The embedded algorithm for heart-rate and SpO2measurement is uploaded to the
MAX32664 microcontroller on the sensor board.

Maxim Integrated Page 16 of 42
Figure 14. Upload the embedded heart-rate algorithm to the MAX32664.
Figure 15. .msbl file flashed successfully.

Maxim Integrated Page 17 of 42
Evaluation GUIs
The MAXREFDES103# is compatible with two evaluation GUIs: the DeviceStudio PC GUI and
the Maxim Health Sensor Platform GUI App for Android.
The DeviceStudio PC GUI provides the ability to configure the algorithm, as well as to view and
log the processed/raw data. In raw data mode, the algorithm is disabled and the AFE settings
may be configured. In algorithm mode, the embedded Maxim-supplied algorithm is configured
and processed, and raw data for heart rate and SpO2are displayed. DeviceStudio also has a
parser utility that converts the logged data in flash memory to .csv format.
The Maxim Health Sensor Platform GUI allows the display of processed data and the logging of
data through an Android app. The app displays the processed data from the embedded algorithm
for:
•Heart Rate
•SpO2
In addition to displaying the data from the embedded algorithm, the app includes additional
algorithms:
•Heart Rate Variability
•Respiration Rate
•Sleep Quality
Using the DeviceStudio PC GUI
The Windows 10 PC GUI currently supports connection to the MAXREFDES103# through USB
or Bluetooth LE. The Windows 7 PC GUI only supports connection to the MAXREFDES103#
through USB.
Installing the Windows 7 Driver for the PC GUI
To use the PC GUI on a Windows 7 PC, installing the driver manually might be required. To
manually install the USB serial driver, perform the following steps:
1. Uninstall any previously installed versions of the DeviceStudio GUI.
2. Download the Windows 7 Eval Package from the Maxim website for the
MAXREFDES103#.
3. Extract the .zip file to a known location.
4. Open Device Manager, which can be found in the Windows Control Panel.
5. If manual driver installation is needed, the MAXREFDES103# appears under Other
devices as CDC DEVICE. Right-click CDC DEVICE and select Properties.
Figure 16. CDC DEVICE in Device Manager.
6. If Update Driver… is grayed out, click Change Settings, and then click Update Driver…

Maxim Integrated Page 18 of 42
7. Select Browse my computer for driver software.
Figure 17. Locate and install the driver manually.
8. Navigate to the location of the.zip file that was extracted in step 3, then click Next.
Figure 18. Browse to the extracted release package.

Maxim Integrated Page 19 of 42
9. When prompted by the Windows Security window, click Install this driver software
anyway.
Figure 19. Select Install this driver software anyway.
10. After the driver is installed successfully, the MAXREFDES103# appears as an Mbed®
Serial Port. (The COM port number used may be different from COM4.)
Figure 20. Mbed Serial Port in Device Manager.
USB Connection
1. Connect the health sensor band to the PC with a USB Type-C cable (or with the MAXDAP
Pico Adapter board using a USB Micro-B cable).
Figure 21. USB connection to PC using a USB Type-C cable (left) and MAXDAP Pico
Adapter board device port (right).
Mbed is a registered trademark of Arm Limited.

Maxim Integrated Page 20 of 42
2. Under Scan Mode, select Serial over USB/Bluetooth, then click Scan.
Figure 22. Scan for available devices.