Portable electrocardiogram

Serious Statement

1: This work is protected by an open source agreement. Any form of online reselling of finished products or materials without permission is strictly prohibited.

2: Reprinting without permission is strictly prohibited. Please indicate the original author when reprinting. Any changes to the information are not allowed during the dissemination process.

3: This work has participated in the ** City Small Toys/Teaching Aids Production Competition and the ** City Youth Science and Technology Innovation Competition (30th). It is strictly prohibited to use this work to participate in any competition again (including but not limited to innovation competitions, inter-school/inter-provincial competitions) Electronic Design Competition)

4: The project publisher does not assume any responsibility for personal injury caused by changing the circuit due to improper operation (especially allergies to the *electrode pads)

5: If the use of data violates the spirit of open source and infringes upon intellectual property rights , we reserve the right to pursue legal liability.

Project Introduction

• This project miniaturizes and simplifies the traditional electrocardiogram device. It is not as bulky as the electrocardiogram monitor in the hospital. It is also not like the Bluetooth electrocardiogram sold on the market that relies on mobile phones to view data. It has many unstable factors, single functions and difficult operation. Cumbersome and excessive pursuit of new technologies such as Bluetooth and WIFI are counterproductive.

• At the same time, an optional switch anti-accidental touch function is added. Add other useful features: Satellite clock and room temperature meter included. Among them, the satellite clock is freed from the dependence on the network and manual time input. It only needs one-to-one time adjustment. It can be used in the wild and remote areas, expanding the scope of application. Equipped with 2500mAh lithium battery that can run for 24 hours.

• This project uses a 3.5-inch touch screen with a built-in touch menu, which can record electrocardiograms, set alarm thresholds, and turn on and off the alarm sound. When the time is inaccurate, the time can be set manually, and the timing module can be turned off to reduce power consumption and extend battery life. . The secondary menu is concise and easy to use, allowing you to quickly learn how to operate it.

*Note: This project is not designed with a defibrillator protection circuit, which may cause damage to the ECG detection circuit when using a defibrillator.

Please note that the ECG detection circuit is sensitive to static electricity. Static electricity will destroy the signal and interfere with signal collection .

Please pay attention to the allergy to the electrode pads during monitoring. If you are allergic to the electrode pads, please replace them in time. Use (3M) liquid dressing to spray 3~4 layers on the sticking area to protect the skin from allergies (other liquid dressings have not been tested for anti-allergic effects)

Module Composition

Main control: ESP32-WROOM32

ECG front end: AD8232-ACPZ-R7

Room temperature: BMP280

Charging management: TP4056

Battery: 2500mAh (LCSC C5289758)

Screen: ILI9488 [3.5-inch resistive touch]

*During assembly, the SD card slot on ILI9488 needs to be removed to make room for the battery.

Assembly drawing:

*When using a 2500mAh battery, the battery should be placed on the left side, the wire ends need to be protected with hot melt glue, and the boat switch (C2885782)

Electrode Placement

* Use RA LA RL when placing. RL can be changed to LL. If conditions do not allow, it can be connected above the joints of the limbs, as close to the proximal end as possible. What you see in others is opposite to what you see in yourself. Do not connect it reversely, otherwise II will lead It becomes a III guide.

For more instructions, playback software (Java), and hardware code (PlatformIO.Arduino), please see the attachment.

The playback software is available on Github Release 1.0 · hc5-github/Pocket-ECG