Vital Care - 01 Introduction

Title: Vital Care

By: Md. Kamrul Hussain

Project Category: Design Challenge

Project Name: Design For A Cause 2021

Blog post: 01

Covid-19 has changed the way we live, it’s a new normal limiting our activities. As vaccines are reaching out, we are getting ready to move on again. However, those who have been critically effected already are facing difficulties after recovering from the virus. It effects different body parts. Post recovery after care is needed where a continuous vital monitoring device can ease the process. I would like to develop a basic prototype of a vital monitoring device as a part of after care for those who have recovered from Covid-19. This device will send the health parameter into the cloud for telemedicine.

Points of interest

Organs that may be affected by COVID-19 include:

• Heart

Imaging tests taken months after recovery from COVID-19 have shown lasting damage to the heart muscle, even in people who experienced only mild COVID-19 symptoms. This may increase the risk of heart failure or other heart complications in the future.

• Lungs

The type of pneumonia often associated with COVID-19 can cause long-standing damage to the tiny air sacs (alveoli) in the lungs. The resulting scar tissue can lead to long-term breathing problems.

• Brain

Even in young people, COVID-19 can cause strokes, seizures and Guillain-Barre syndrome — a condition that causes temporary paralysis. COVID-19 may also increase the risk of developing Parkinson's disease and Alzheimer's disease.

Recently published guidance by the NHS lays out the likely aftercare needs of patients recovering from covid-19 and identifies potential respiratory problems including chronic cough, fibrotic lung disease, bronchiectasis, and pulmonary vascular disease.

Reference:  https://www.bmj.com/content/370/bmj.m3001

Post-infection COVID-19 patients showed impaired lung function; the most important of the pulmonary function tests affected was the diffusion capacity.

Reference: https://www.journalpulmonology.org/en-respiratory-function-in-patients-post-infection-avance-S2531043720302452

Many studies have shown that most common abnormality of lung function in discharged survivors with COVID-19 is impairment of diffusion capacity, followed by restrictive ventilatory defects.

My focus will be mainly on the sectors those I have experience to deal with before. Like ECG, SPO2, Impedance measurement to get the Respiration Rate.

Project description-

So, the features I would like to implement in this design challenge are

• Plethysmograph
• Single lead ECG with motion artifact rejection, fast recovery and lead off detection
• Temperature
• Respiration
• Wireless monitoring system and notification through IOT and Android smart phone

Primary objective-

System model

Module 01

AD8232 will be used for single lead ECG data acquisition.

Impedance measuring topology can be used for respiration rate detection. However, respiration can be detected by the R-R period from ECG signal too.

Another way could be use of ADAS1000 series AFEs for both ECG and respiration all together.

I have both AD8232 and ADAS1000 in my hand which I got from ELEMENT14 for another design challenge. I have used the AD8232 for the 'sudden impact design challenge' and posted several blogs on that earlier.

The monitoring device will send data to module 2 through BLE.

Module 02

Photoplethysmograph signal will be taken using MAX30102 for oxygen saturation in blood.

A temperature sensor will be used to measure body temperature simultaneously.  MAX30102 has on chip temperature sensor, which can be calibrated and used for this purpose.

Arduino NANO 33 IOT will capture the data and process it. It will also receive the data from module 1.

It will communicate with the cloud platform using the wifi. In the absence of the IOT, it can send data to a smart phone app to store the body parameters. The App will push the data into the cloud when it gets online.

NANO 33 IOT comes with an onboard 6 axis IMU [LSM6DS3] which can be used for detecting rapid movement. The PPG signals from MAX30102 can be distorted and SPO2 calculations may give errors due to this rapid movement. The IMU chip can be useful to get rid of this kind of motion artifact.

Module 03

A smart phone android app can be used to monitor and store offline data. The cloud platform will be used to store data online, which can be examined by the doctor later on.

Design Considerations

The main challenge for this event, will be the time limit. Integrating all the features in one platform will be really hard to achieve within the time limit. So, it’s better to go for a prototype design at first.

Another hard part will be arranging the electrodes and prepare the modules for experimental setup. The evaluation kits will not be suitable to implement in the final experiment. So, some backup budget should be maintained for single chips and components if customized boards are designed.

An efficient way to integrate all these parameters will be using ADPD4100 multimodal analog front end. There is an evaluation board available, it can be used in future for a final design to make it compact and wearable.