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

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.

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Portable ECG System Design Using the AD8232 Microchip and Open-Source Platform

Proceedings ◽

10.3390/ecsa-6-06584 ◽

2019 ◽

Vol 42 (1) ◽

pp. 49

Author(s):

Miguel Bravo-Zanoguera ◽

Daniel Cuevas-González ◽

Juan P. García-Vázquez ◽

Roberto L. Avitia ◽

M. A. Reyna

Keyword(s):

Open Source ◽

Printed Circuit Board ◽

Analog Circuit ◽

Circuit Board ◽

System Stability ◽

Electrical Safety ◽

Analog Filters ◽

Ecg Signal ◽

Data Logging ◽

Data Logger

This paper presents the design of a portable electrocardiograph (ECG) device using the AD8232 microchip as the analog front-end (AFE). Starting with the manufacturer’s evaluation board of the AFE chip for testing circuit configurations, open-source hardware and software components were integrated into a breadboard prototype. Ultimately, a custom printed circuit board (PCB) was produced. The prototype required to accommodate the microchip on a SMD-to-DIP adapter for testing with the breadboard-friendly Arduino microcontroller alongside a data logger and a Bluetooth breakout board. The analog ECG signal from the AFE output was digitized using one channel of the 10-bit analog-to-digital Converter (ADC) of the ATmega328 microcontroller contained in the Arduino Nano board. The digitized ECG signal can be transmitted not only by serial cable using the Arduino functions, but also via Bluetooth to a PC or to an Android smartphone system when the HC-06 shield is used. The data logging shield provides gigabytes of storage, and the signal is recorded to a micro SD card adapter along with the date and time stamp data of the sample capture (real-time clock provided). In addition to hardware and software development, a simulation was used in the analog circuit design with SPICE Multisim software and the related macromodel library to assess system stability. Besides the analog filters in the AFE stage, digital filtering by means of simple difference equations was investigated. A menu was incorporated to choose from the several modes of operation of the device. The ECG test signals were obtained from a patient simulator (SimCube) and real patients. A portable ECG system for monitoring applications that complies with electrical safety regulations and medical equipment design was realized.

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Development of Analog Front-end for Capacitive ECG Signal Acquisition

10.1109/et52713.2021.9579902 ◽

2021 ◽

Author(s):

Dimiter H. Badarov ◽

Georgy S. Mihov ◽

Ivo Ts. Iliev

Keyword(s):

Signal Acquisition ◽

Ecg Signal ◽

Front End ◽

Analog Front End

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A 0.5 V 68 nW ECG Monitoring Analog Front-End for Arrhythmia Diagnosis

Journal of Low Power Electronics and Applications ◽

10.3390/jlpea8030027 ◽

2018 ◽

Vol 8 (3) ◽

pp. 27 ◽

Cited By ~ 2

Author(s):

Avish Kosari ◽

Jacob Breiholz ◽

NingXi Liu ◽

Benton Calhoun ◽

David Wentzloff

Keyword(s):

Low Power ◽

Power Efficiency ◽

Low Noise ◽

Signal Acquisition ◽

Cmos Process ◽

Ecg Signal ◽

Ecg Monitoring ◽

Power Circuit ◽

Front End ◽

Analog Front End

This paper presents a power efficient analog front-end (AFE) for electrocardiogram (ECG) signal monitoring and arrhythmia diagnosis. The AFE uses low-noise and low-power circuit design methodologies and aggressive voltage scaling to satisfy both the low power consumption and low input-referred noise requirements of ECG signal acquisition systems. The AFE was realized with a three-stage fully differential AC-coupled amplifier, and it provides bio-signal acquisition with programmable gain and bandwidth. The AFE was implemented in a 130 nm CMOS process, and it has a measured tunable mid-band gain from 31 to 52 dB with tunable low-pass and high-pass corner frequencies. Under only 0.5 V supply voltage, it consumes 68 nW of power with an input-referred noise of 2.8 µVrms and a power efficiency factor (PEF) of 3.9, which makes it very suitable for energy-harvesting applications. The low-noise 68nW AFE was also integrated on a self-powered physiological monitoring System on Chip (SoC) that is used to capture ECG bio-signals. Heart rate extraction (R-R) detection algorithms were implemented and utilized to analyze the ECG data received by the AFE, showing the feasibility of <100 nW AFE for continuous ECG monitoring applications.

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A low-cost, open-source autonomous surface vehicle as a multipurpose waste stabilization pond monitoring platform

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2018.110 ◽

2018 ◽

Vol 9 (1) ◽

pp. 172-180

Author(s):

A. Cuppens ◽

G. Menesse ◽

E. Caligaris ◽

O. Marecos ◽

G. Wyseure

Keyword(s):

Open Source ◽

Autonomous Navigation ◽

Low Cost ◽

Construction Materials ◽

Working Environment ◽

Monitoring Data ◽

Data Logging ◽

Data Logger ◽

Autonomous Surface Vehicle ◽

Waste Stabilization

Abstract Although waste stabilization ponds (WSPs) are widely used in developing countries, monitoring data on their operational performance are scarce. Traditional methods for monitoring in-pond conditions, i.e. conducting hand held measurements from a small boat or installing fixed sensor networks, are not straightforward to realize and create an unhealthy working environment for field workers. A promising technology for the safe and efficient collection of monitoring data is a compact autonomous surface vehicle (ASV), capable of autonomous navigation along a predefined trajectory based on geographic coordinates and measurements in different places and depths. In this practical paper, the development process, technical details and functional testing results of a low-cost ASV for WSP monitoring are presented. Commonly available construction materials and electronic components were used to ensure affordability and reparability. The access to online tutorials and peer-support was crucial for assembling the open-source autopilot and data logger. The ASV demonstrated satisfactory performance for both the autonomous navigation as well as the georeferenced data logging of measurements at a real-scale WSP in Paraguay. This study demonstrates how the adoption of open-source hardware and software offers the flexibility for the wastewater professionals to develop customized DIY solutions for specific monitoring applications and working environments.

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Computers for data, control and simulation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106661 ◽

1988 ◽

Vol 46 ◽

pp. 920-921

Author(s):

David C. Joy

Keyword(s):

Personal Computers ◽

Monitoring And Control ◽

Data Logging ◽

Data Logger ◽

Operational Conditions ◽

Data Control ◽

The Many ◽

And Control

Personal computers (PCs) are a powerful resource in the EM Laboratory, both as a means of automating the monitoring and control of microscopes, and as a tool for quantifying the interpretation of data. Not only is a PC more versatile than a piece of dedicated data logging equipment, but it is also substantially cheaper. In this tutorial the practical principles of using a PC for these types of activities will be discussed.The PC can form the basis of a system to measure, display, record and store the many parameters which characterize the operational conditions of the EM. In this mode it is operating as a data logger. The necessary first step is to find a suitable source from which to measure each of the items of interest. It is usually possible to do this without having to make permanent corrections or modifications to the EM.

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