Fabricating a Portable ECG Device Using AD823X Analog Front-End Microchips and Open-Source Development Validation

Abstract

Relevant to mobile health, the design of a portable electrocardiograph (ECG) device using AD823X microchips as the analog front-end is presented. Starting with the evaluation board of the chip, open-source hardware and software components were integrated into a breadboard prototype. This required modifying the microchip with the breadboard-friendly Arduino Nano board in addition to a data logger and a Bluetooth breakout board. The digitized ECG signal can be transmitted by serial cable, via Bluetooth to a PC, or to an Android smartphone system for visualization. The data logging shield provides gigabytes of storage, as the signal is recorded to a microSD card adapter. A menu incorporates the device’s several operating modes. Simulation and testing assessed the system stability and performance parameters in terms of not losing any sample data throughout the length of the recording and finding the maximum sampling frequency; and validation determined and resolved problems that arose in open-source development. Ultimately, a custom printed circuit board was produced requiring advanced manufacturing options of 2.5 mils trace widths for the small package components. The fabricated device did not degrade the AD823X noise performance, and an ECG waveform with negligible distortion was obtained. The maximum number of samples/second was 2380 Hz in serial cable transmission, whereas in microSD recording mode, a continuous ECG signal for up to 36 h at 500 Hz was verified. A low-cost, high-quality portable ECG for long-term monitoring prototype that reasonably complies with electrical safety regulations and medical equipment design was realized.

A novel methodology for the synchronous collection and multimodal visualisation of continuous neurocardiovascular and neuromuscular physiological data in adults with long COVID

“…Therefore, the EMG data used in this study were extracted from the Secure Digital (SD) cards that were embedded into the SHIMMER® devices. However, due to the hardware architecture of these EMG devices, which use serial peripheral interface as the means for data communication between the microcontroller and the SD card, the characteristics of the data logging process set certain limits to the sampling frequency of the recorded analog signal to avoid excess packet drops [75]. This leads to a trade-off between sampling frequency, which dictates the details of the signals captured, and packet transmission, which governs the quality of the data received in the recording [76].…”

A Real-Time Wearable Physiological Monitoring System for Home-Based Healthcare Applications

“…Various forms of physiological monitoring devices are commercially available but most of them are designed for recreational purposes. Most of recently developed monitoring devices lack the compactness [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ] and wireless connectivity [ 22 ] which is essential for everyday wearable application. Other monitoring devices are limited to a single ECG or EMG channel [ 15 , 17 , 23 , 24 ] and a long-term stability test including the interference study is left out [ 15 , 17 , 18 , 24 ].…”

“…Other monitoring devices are limited to a single ECG or EMG channel [ 15 , 17 , 23 , 24 ] and a long-term stability test including the interference study is left out [ 15 , 17 , 18 , 24 ]. Furthermore, smart sensor networks that utilize a cloud network environment and machine learning have been proposed by various research groups [ 25 , 26 , 27 ] but existing personal healthcare monitoring devices fail to demonstrate the wearable monitoring platform with user-friendly personal smartphone connectivity features for real-time monitoring [ 18 ] and cloud networking for further data processing [ 15 , 16 , 17 , 22 , 23 , 24 ].…”

A comparative study between single lead AD8232 heart rate monitor and standard electrocardiograh to acquire electrocardiographic data for cardiac autonomic function testing

“…Many improvements were made to make it more portable especially using the latest software programming languages (5,6) . There are many significant portable devices are also developed with the AD823X module using Arduino platform however they required 2 to 3 PCB boards to operate and special python program to execute signal acquiring code (7) . The current device was a low cost implementation which is an improved version with single PCB and quite portable compared to the other single lead ECG devices.…”