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The project website: www.homeicu.ca
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firmware: github.com/hellozed/homeicu
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base station: github.com/hellozed/mychart
HomeICU is an open-source patient monitor that uses the wearable sensor to measure the patient's vital signs and enable doctors to diagnose and treat a patient remotely over the Internet.
Since the pandemic started, many DIY makers, engineers, and medical professionals have been collaborating over the Internet to make open-source medical devices to fight with COVID-19, such as ventilators. Now, you can use this design to replicate a medical-grade patient monitoring system to help home recovering COVID-19 patients.
Please feel free to use this design to build your version applications, and contribute to this development.
COVID-19 pandemics cause hundreds of thousands of deaths, it overwhelms the healthcare system and leads to a severe lack of hospital beds and intensive care units (ICUs) in many countries. 80% of COVID-19 patients would only have mild symptoms and are not require being admitted into the hospital, they can stay at home to recover, but COVID-19 has fatal consequences for people with underlying cardiovascular disease and causes cardiac injury even in patients without underlying heart conditions, the symptoms may develop into a very dangerous situation quickly without being monitored by medical professionals. To recover at home as a COVID-19 patient must be very scary and painful because patients worry about they could suddenly lose their life. It is crucial to use a smart monitor system to track the patient’s vital signs and alert the remote medical team to take action if it is necessary.
The remote patient monitor offers a way to ease the burden on clinics and hospitals while also preventing more patients from getting infected by visiting the hospital. Our ultimate goal is to move as many patients as possible out of the clinic that doesn’t need immediate, critical care.
During the COVID-19 outbreak, people are advised to practice social distancing and limit going out. Telehealth allows patients to communicate with doctors from the comfort of their homes, and serve patients who cannot visit the hospitals regularly for routine checkups. These include patients suffering from chronic ailments, undergoing the transition from hospital to home, or those living in remote areas. Telehealth is mostly done by video or phone if the patient has an HomeICU device at home, they can receive ICU type of support from their doctors.
HomeICU project is to build a medical-grade patient monitoring system similar to what is used in the hospital ICU settings. A wireless sensor tag will be attached to the patient's body, and the battery life can sustain for the whole recovering period without recharging, and the patient does not need to take the tag off while asleep or taking a shower.
The following vital signs will be measured and the doctor can view these parameters over the Internet.
Phase I - development completed:
- body temperature
- peripheral capillary oxygen saturation (SpO2/pulse oximetry)
- heart rate and heart-rate variability (HRV)
- respiration rate (based on impedance pneumography)
- electrocardiography (ECG)
- motion occurrence and cough intensity
Phase II - under development:
- blood pressure (by the 3rd party meter)
- GPS for guiding ambulance (by the base station)
- wearable device plastic
- continual blood pressure monitoring
- no base station version (sensor communicates with the server by MQTT, no need base station app)
- MQTT server and Firebase features.
The HomeICU app (base station) communicates with sensor hardware through the BLE and can display all vital signs on a single screen.
To reduce the cost to an extremely low level, we replaced the traditional base station with a cell phone app. The sensor tag communicates with the base station through low-energy Bluetooth (BLE). The patients can use their own tablet devices such as the iPhone, iPad, or Android phone work as a base station, just need to download and install an application.
The base station displays the patient’s vital signs similar to a normal ICU setting equipment. In the meantime, the patient’s vital signs data will be sent to a cloud IoT server and enable the doctor to access it over the internet. They also can set up the threshold to let software trigger an alert and notify the doctor to take action when patients developed into severe symptoms.
The software is developed with Flutter/Dart and one source code support both Android and iOS.
If the patient does not have a smartphone, the sensor tag can work independently mode, it means the vital signs and ECG measurement will be sent directly to the cloud server through MQTT, no base station is required.
- /firmware - sensor tag software.
- the code is hosted at https://github.com/hellozed/homeicu
- /GUI - "MyChart" project, the GUI app software for iPhone, iPad, and Android (Developed with Flutter/Dart Language)
- the code is hosted at https://github.com/hellozed/mychart
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/hardware - printed circuit board design .brd, .sch, designed with Autodesk Eagle tool)
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/datasheet- component manuals and reference design
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/docs - additional documentation
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/tools - tools for developing the project
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../homeicu-build - directory for building binary file, no backup needed.
- microprocessor: ESP32 The microprocessor decides the major development platform. The main reason for choosing the esp32 microprocessor is cost because the COVID-19 pandemic spread too fast and infects a large population, and the hardware solution must be very low to serve as many people as possible. The hardware will be used only for 2 weeks, then be disposed of. ESP32 has great price and usability, but it requires a Uart2USB chip and difficult to run debug.
NRF52 is also an ideal microprocessor for this development, which has much less power consumption and has a Jlink for debugging. NRF52 uses Keil MDK IDE, which provides a great development toolchain and library stack, but it is expensive and only support Windows OS. The alternative is SES IDE, free, and support Win, Mac, and Linux.
- IDE The firmware of the sensor tag is written with C/C++, and we use the Arduino IDE + Visual Studio Code (vscode) as the main developing tool, because the cost of them is zero, and support all operating system, this could encourage more developer to join.
The Arduino Software (IDE) allows you to write firmware codes and upload them to your sensor board, and it has a great amount of open-source library to use. VScode is the code editing tool and has great usability.
Configure Arduino for ESP32 board support: Installing ESP32 Platform in Boards Manager, and select the "ESP32 Dev Module".
- Autodesk Eagle for PCB design The cost is zero, and with great functionality.
HomeICU hardware is powered by the ESP32 SoC module, which supports pairing with smartphones through BLE and Wi-Fi.
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Microprocessor: ESP32, in WROOM32 module, Dual-core Xtensa 32-bit CPU, 4 MB of onboard SPI flash, 520 KB RAM.
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Wireless Connectivity: Wi-Fi and BLE (Bluetooth Low Energy).
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Sensors: ECG and respiration: TI ADS1292RR Pulse oximetry: MAX30102/MAXM86161 or TI AFE4400 Temperature sensor: Maxim MAX30205 Accelerometer: MMA8452Q
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Battery: Rechargeable 1000 mAh Lithium Polymer (LiPo) battery.
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USB: On-board battery charging
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Power Supply Isolated, medical-grade (5 V, 2.5 A) USB wall power adapter (100-240 VAC) with snap-on plugs for the following regions: US, EU, CA
This project has referenced codes from many different open-source projects and several different programming languages such as Arduino, C/C++, Flutter/Dart, and Python.
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It’s better to throw coding standards out and allow free expression.
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To build a prototype ASAP is more urgent than spending time on tidy up coding standards and make source code stylish and beautiful.
You need a breakout board bridges USB to UART for Arduino. This board brings out the DTR pin as opposed to the RTS pin of the FTDI cable. The DTR pin allows an Arduino target to auto-reset when a new Sketch is downloaded. This is a nice feature to have and allows a sketch to be downloaded without having to hit the reset button.
You can build this breakout board or just purchase one "SparkFun FT231X" from their website.
The initial prototype of the sensor board uses a 3-electrode ECG cable along with a standard stereo jack and a SpO2 finger probe. The formal version will replace them with a wearable sensor tag, no cable or probe is required.
It would be best NOT to connect the ECG front end to a human while it is also connected to:
- An ordinary wall wart
- A line-powered PC/Laptop
- A line-powered oscilloscope.
Do NOT connect it to yourself when any line-powered devices are connected to the circuit. Please battery or medical degree wall wart, which provides a higher level of isolation between input and output.
The HomeICU hardware, firmware, and MyChart base station software are open-source and licensed under the following licenses:
MIT License(http://opensource.org/licenses/MIT)
This application uses many Open Source components. You can find the source code of their open-source projects along with the license information below. We acknowledge and are grateful to these developers for their contributions to open source.
- Project: Arduino Library for Healthypi-v4 Copyright (c) 2019 ProtoCentral.
License: MIT
- Project: SparkFun Copyright (c), SparkFun.
License: MIT
Beerware: If you see me (or any other SparkFun employee) at the local, and you've found our code helpful, please buy us one round!
Attention: HomeICU project is in the developing stage and all the code and design shared here are the draft version and have not been formally released yet.
Please do NOT use the current code and design on the real human body until it receives medical device approval in your country.
Unless we receive the medical device approval, please only use this project under the following conditions:
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The HomeICU is intended only for electrical evaluation of the features in a laboratory, simulation, or development environment. It is intended for development purposes ONLY and is not intended to be used as all or part of an end-equipment application.
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The HomeICU should be used only by qualified engineers and technicians who are familiar with the risks associated with handling electrical and mechanical components, systems, and subsystems.
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The user is responsible for the safety of themselves, fellow employees and contractors, and coworkers when using or handling the HomeICU.
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The user is fully responsible for the contact interface between the human body and electronics; consequently, the user is responsible for preventing electrical hazards such as shock, electrostatic discharge, and electrical overstress of electric circuit components.
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You MUST NOT power the device from a non-isolated power source.
So far, HomeICU has NOT received any medical device certifications (FDA, CE, etc.) This device is NOT for consumer usage. It is not intended for direct interface with a patient, or patient diagnostics.
- CE / FCC / CSA safety and radio certification
- USFDA, EU CE medical device, Health Canada clearance
FDA, on March 20, 2020, issued updated guidance that allows for quicker entry into the market for digital remote monitoring equipment. Link
CPT Code 99453: Remote monitoring of physiologic parameter(s) (e.g., weight, blood pressure, pulse oximetry, respiratory flow rate), initial; set-up and patient education on the use of equipment. (Initial set-up and patient education of monitoring equipment)
CPT Code 99454: Device(s) supply with daily recording(s) or programmed alert(s) transmission, every 30 days. (Initial collection, transmission, and report/summary services to the clinician managing the patient)
CPT Code 99457: Remote physiologic monitoring treatment management services, clinical staff/physician/other qualified health care professional time in a calendar month requiring interactive communication with the patient/caregiver during the month; first 20 minutes
CPT Code 99458: Every additional 20 minutes (List separately in addition to code for primary procedure)
CPT Code 99091: Collection and interpretation of physiologic data (e.g., ECG, blood pressure, glucose monitoring) digitally stored and/or transmitted by the patient and/or caregiver to the physician or other qualified health care professional, qualified by education, training, licensure/ regulation (when applicable) requiring a minimum of 30 minutes, every 30 days.
Further reading: https://www.cms.gov