AFE4490 vs MSP430FG439 dev board

Kelvsu,

MSP430FG439 based heart rate and EKG monitor is a bio-potential based approach to measure the heart rate using the EKG signal.

The AFE4490 is a high performance analog front end for high end clinical pulse oximeter and optical heart rate monitoring applications. It is more robust and performs much better under non-ideal conditions such as high ambient light and motion artifact.

You may want to consider your system's heart rate accuracy requirements to decide which solution will be suitable for your application.

Regards

Praveen.

Praveen,

I was refering to "A Single-Chip Pulsoximeter Design Using the MSP430", which uses MSP430FG439, a design kit is also provided here https://www.olimex.com/Products/Modules/Biofeedback/MOD-PULSE/

http://www.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=slaa274&fileType=pdf

It is based on Pulse oximeter design, I was comparing this to AFE4490 design " AFE4490SPO2EVM", both are based on pulse oximeter,  It seems not clearto me  why AFE4490 is even introduced later by TI, maybe accuracy is a consideration. 

However I am looking for reference design and PCB files, BOM for a quick turn key solution, could find one. 

Appreciate if you can point me to those files

thanks

Kelvsu

Kelvshu,

We have developed reference design that has smaller form factor than the evaluation module (AFE4490SPO2EVM).

Here is the link for the pulse oximeter reference design using AFE4490.

http://www.ti.com/tool/tida-00010

Thanks Praveen,

Just to clarify few things:

1) Can I interpret that "the single chip solution for pulse oximeter" is not recommended by TI, I ask this because this is a really compact/simple design if it works, MPS430 plus LEDs will give you pulse oximeter. 

2) if pick AFE4490, can it be converted to reflective pulse oximeter? any suggestion on using what RED/IFED leds and photodiode to design reflective one.

thanks

Kelvshu

Kelvshu,

1. Unfortunately I cannot comment if single chip solution (discrete + MCU) or dual chip solution (integrated AFE + MCU) is better mainly due to the fact that it totally depends on the trade-off benefits of price, area, power and performance requirements of the application.

But I can certainly point out the benefits of having a fully integrated AFE for pulse oximeter applications.

Integrated AFE signal chain offers several knobs that can be adjusted to achieve the SNR requirements needed for high end clinical pulse oximeter applications as well as the low power demands of battery-powered optical HRM applications. Also the AFE integrates a completely configurable timer module. The advantage of the timer module is that it completely offloads the pulse sequencing and timing control usage of the timers from the host processor to synchronize the LED turn on, sampling and data conversions. This reduces the load on the microcontroller allowing it to perform algorithm and other application related activities. The quality and the performance of the AFE44xx solution has been validated by top clinical pulse oximeter customers in Europe and Asia. 

2. AFE4490 works with both transmissive and reflective sensors. Below are some of the reflective sensors we have evaluated:

DCM03 - Integrated dual emitter and photodiode

DLED-660/940-LLS-3 Integrated dual emitter

QSB34CGR - Photodiode