ECG plot using PCA10004/5

[Shrijit Mukherjee]

Hi, I was wondering if anyone has done this seemingly doable job of producing continuous ECG trace using PCA1004 and PCA10005 devices. My intended use case is this: Use one of PCA10004 or PCA10005 as Master and other as slave (GATT server and client). Use the Analogue input of the slave to connect to a ECG simulator (www.ms-gmbh.de/.../phantom_start.htm) and transmit data continuously to a PC , connected with the other device. Or, the PC may be connected to PCA10000 dongle as GATT client.

It may also be fine to use only one of the boards to transmit data (GATT server) and see it on a iOS device.

Has anyone done a similar task?

I see this post to be closely relevant but doesn't end successfully.

[cocoa]

Hi,

you need a specific ECG ADC, nRF51822 ADC has not the precision required for such task. ECG analog front end requires simultaneous sampling, 16-bit (minimum) delta-sigma ADC, gain amplifier with high common mode rejection and very low offset and drift, input bias current around 200 pA.

Sampling rate starts from 125 SPS to 8000 SPS

Use nRF51822 only as data transmitter and not as analog converter.

-c

PS: if used differently from an hobby device , FDA approval is required as medical device.

[Shrijit Mukherjee]

Yes, I agree. I have the front end solution for picking up the ECG but that's not I am concerned about in this post. If you see my post, I have said, at this stage I want to use a ECG simulator, nothing too medically sophisticated. Consider this as a simple problem: Transmit a 20 Hz sine wave using BLE nRF51822. Can I get some help? :)

I am not worried about any of the other concerns that you have raised, although they are valid. At this stage, I must have a proof-of-principle BLE based wireless link working.

I have worked quite a lot with analogue stuff and bench data converters but not so much this (digital/ wireless stuff). If I can interface nRF51822 with LabVIEW, even that is a start for me (I know some people have done it with other BLE modules).

[cocoa]

Hi, I thought you wanted to use the ADC port of nRF51 to convert analog signal.

If you are using a commercial AFE you should have some communication port (SPI and GPIO).

Use these to communicate the ADC conversions to nRF SPI or GPIO.

If you haven't comm ports, you can calculate the ADC sample rate that's fits with nRF51 data rate of your ble custom service.

-c