Title: Neonatal Jaundice Phototherapy
By: sunnyiut
Design Challenge: Bluetooth Unleashed
Blog number: 02
| Blog List | |
|---|---|
| 01 : Introduction | 02: Project Plan |
This is my second blog post in the Bluetooth Unleashed and I'll present my project plan. It's basically a Hardware Overview which includes the basic modules i'll be using in this project and how these modules will be placed and interconnected.
Modules:
- Phototherapy unit [Blue LED light source with driver circuitry]
- Interfacing and control unit to control the LED light intensity
- Wearable health monitor which will collect and send health parameters to the control unit
The first two modules will be mounted on the baby cradle.
The third one [wearable health monitor] will be placed on the baby's body.
The communication between module 2 and 3 will be based on BLE.
There will be other modules like Power Supply and Battery Backup.
There will be eye mask to protect the baby's eyes from phtototherapy lights.
Module 1 & 2 - Phototherapy Unit and Control Unit:
Phototherapy Unit -
The Phototherapy Unit includes a LED panel consists of 27-45 LEDs. This is the base of the treatment - BLUE LED.
Design criteria:
- Max Intensity - > 30 μW/cm2/nm
- Min Intensity - > 12 μW/cm2/nm
- LED Wavelength - 458 nm [i am using ~460nm]
- Center point indication
ASMT-QBB3-NBD0EASMT-QBB3-NBD0E
This is the LED I have selected to use in my project.
It's a high brightness 460nm Blue LED
luminous flux - 11500 with max If = 150mA
It has a forward voltage of 3.5v with 500mW power dissipation.
The Phototherapy Unit will also have necessary mounting pole and brackets to place the device on the baby cradle.
Interfacing and Control Unit -
The Interfacing and Control Unit will be based on MSP432P401 MCU. It will control the LED panel with the help of a DC-DC converter module, display the health parameter of the baby and interface with the wearable health monitor module using BLE.
TPS56C215EVM-762TPS56C215EVM-762
To power up the driving circuit of the LEDs. It's a synchronous step down converter.
I already have this module with me.
It has current drive upto 12A with fast switching 1.2MHz.
It contains DCAP2 technology, which will be helpful to vary the LOAD [LED intensity] very fast.
The output voltage is set to 1.2v, but it can be varied externally.
Texas Instruments - CC2640R2 LaunchPad
the hero......
It will be used to collect data using BLE from the wearable health monitoring device.
It will send the physiological and environmental data to the MSP432 MCU and generate notifications if necessary.
Connect EVE
FT-800 graphic controller board will be used as display module.
- monitor the basic health parameters of the baby
- Heart rate
- Body temperatur
- monitor the ambient environment of the treatment area
- ambient temperature
- humidity
- light intensity
The interface and control unit will control the LED panel intensity based on the light intensity sensor.
MAX30100 heart rate sensor will be used to get baby's heart rate through PPG [photoplethysmograph]
However, the challenge will be 'signal to noise ratio' as photoplethysmography method is generally applied on finger tip or wrist joint or ear lobe. For babies we can go for the Foot. But mounting it on chest will provide very low signal with high DC offset [due to skin and tissue] and ambient noise [50/60 Hz].
For adult we don't have a chance. But for babies I can give it a try as because -
The LEDs have a max driving current of 50mA [I don't know the luminescence] and ADC resolution is 16 bit. Hope it will be good enough to reconstruct the signal.
Sensors Booster Pack
The Sensors Booster Pack will be used to collect environmental data -
- ambient light and temperature
- humidity
- the infrared temperature sensor can be used to measure baby's body temperature
MSP432P401R
The MSP-EXP432P401R LaunchPad will
- collect the environmental information from the 'Sensors Booster Pack'
- collect heart rate from MAX30100
- send it to control unit through BLE
BOOSTXLCC2650MA
BLE module to send data
That's the end of this blog post.
I have already received the Hero Kit - CC2640R2 Launchpad. I am waiting for the LEDs I have ordered from the 150$ shopping cart.
However, I am ready to move on with the bluetooth communication part. It will be interesting and challenging to me as I am new to Simplelink Wireless MCUs.
So, my next blog post will be on my 'out of the box' experience of the CC2640R2 launchpad.
I'll try out some demo/sample programs.
And after that I'll move on to CC2650 module.
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