Make With Mouser IoT Design Contest

Introduction:

Connected health concept provides an infrastructure to virtually connect a patient with hospital.It basically uploads patient's meta-data to hospital server so that doctors can have their analysis based upon data on hospital cloud.Patient's without physically presence in hospital, doctor can monitor the health status prescribe medicine, and recommend some test(Outside connected health's reach).

Here we will concentrate only on HEART related issue.This infrastructure design mainly focused on to accumulate meta-data related to heart.Heart meta-data includes below data points

1.Heart beat per second
2.Spo2 Level on blood
3.Body temperature
4.ECG data

Connected health infra provides sensor Eco-system to gather all above meta-data info and push those data to could for storage.This whole connected health infrastructure can be converted as a wearable form factor.Hospitals just need to register the device and allocate a patent ID.All meta-data related to that particular patent will be stored on mapped patent ID.If patent feel any health related complication through that device he/she post
an emergency alert and may seek for immediate attention of Doctor.


HIGH LEVEL DESIGN:

1618688974684.png


(Img 1.0)
Here Micro-controller block uses ARM cortexM4 arch based evaluation board by TI-TIVA-C(TM4C1234GH).On Micro-controller a RTOS called QP is ported to manager various thread and different peripherals like SPI,I 2C,ADC and GPIO. Also QP provide tracing mechanism i.e logging and all logs are steamed over UART.

MAX31000 is a PPG sensor which is manufactured by Maxim.This sensor has I2C as peripheral for both configuration and streaming below meta data
1.Heart rate (Beats per second)
2.Spo2 percentage(value 0-100%)
3.Body Temperature(In Celcious)

AD8232 is an ECG sensor by Analog Device.Sensor has a 3.5mm connector where we can insert connector for electrode.It provides 3 wire based connector one connector needs to be connected on (Yellow :left arm,green: right leg, red: right arm).
Sensor provide 2 GPIO which will indicate the state of electrode (LO-,LO+).
LO-
LO− is high when the electrode to −IN is disconnected, and it is low when connected
LO+
LO+ is high when the +IN electrode is disconnected, and it is low when connected

OUTPUT pin has Operational Amplifier Output. The fully conditioned heart rate signal is present at this output. OUT can be connected to the input of an ADC in Micro-controller.

Once Micro-controller booted up.its started collecting meta-data samples from MAX3100 sensor.Meta data includes Spo2,heart rate.If heart rate drops below or goes up by setted threshold(Note:These threshold values are hard-coded randomly.Its not calibrated medically) QP(RTOS) will post a signal to start ECG operation.As per current implemaenation ECG connect warning will come as Terminal log.Once all electrodes are connected Micro-controller will receive a GPIO interrupt.On ISR of that GPIO interrupt.Micro-controller initialize the ADC module and started sampling the Analog signal from Output pin of AD8232.Those digital signal data are stored on Micro-controller RAM and whenever the buffer is full it will push those samples to cloud.Since we have collecting sample on fixed period (i.e 25 Hz) transmitted signals are reconstructed on web App logic.

Technical Details
  1. ECG
AD8232 provide 2 gpio called L0 and L1 which will indicate state of electrode
1.If pin is HIGH electrode is not connected
2.If pin is LOW electrode is connected

1618776070466.jpeg


(Img 1.1)
While transition from high-to-low happen for both pin happens,it will generate interrupts to Micro-controller.When Micro-controller get both interrupt GPIO ISR post a signal(Exclusive feature of QP) called


1618776067908.png

(Img 1.2)
On reception of ECG start signal,Micro-controller completes all required configuration and ready to receive analog signal from sensor.
ECG senor output pin data looks like below

1618776393942.png


(Img 1.3)
These signals are sampled in ADC Corresponding logs are streamed on Micro-controller.

1618776804456.png


(Img 1.4)


Above analog samples are stored on RAM buffer, once buffer reached the threshold these values are posted to cloud to re-construct the (img 1.3) on web App.

PPG:
  1. Here we uses MAX30100 as a PPG.It will stream all required meta data.PPG senor has I2C interface having slave ID 0xAE.(8 bit address mode).On very first stage Software will query for major and minor version.If it is success,then Micro-controller sends all required configuration.

1618948583961.png



After completion of all configuration,we need to send buffer address to get respective data.For example buffer address 0x06 for Heart beat and 0x04 for Spo2 data.
All these sensor samples are stored on Micro-controller RAM and if it hit the upper threshold, QP rtos send a signal to start ECG.ECG output is sampled by ADC and ADC data on .txt file is parsed and post it to a web App for reconstruction of original wavefom.

Web APP Usage:
This web app is hosted on local host i.e local PC. the snippet of UI looks like below.
1618949473667.png



On Clicking "View live heart rate" it will be navigated to below UI which will so ECG data.

1618949598587.png

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robotedmanmath
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