6th International Electronic Conference on Sensors and Applications “Portable ECG system design using the AD8232 microchip and open-source platform” Miguel Bravo-Zanoguera, Daniel Cuevas-González, Juan Pablo García-Vázquez, Roberto López- Avitia, Marco Reyna-Carranza UNIV IVERSID IDAD A AUTÓNOMA D DE E BAJA C CALIF LIFORNIA IA Facultad de Ingeniería 15/Nov/2019 Mexicali, Baja California, México 1
CONTENTS Problem Statement Background General and Specifics Objetives Materials and Methods Results and Discussion Conclusions 2
PROBLEM STATEMENT Cardiovascular diseases (CVD) are one of the leading causes of death worldwide. World Health Organization (WHO) reports indicate that 31% of deaths are due to CVD. In the last decades there has been an alarming increase in the population that presents cardiovascular problems, being one of the main causes of death worldwide, which due to lack of knowledge or identification of the problem tend to end up in death due to heart attack or heart conditions [1]. A trend that helps to address this problem is the development of medical devices for personal use, known as “mobile health”, with the use of technology such as: smartphones, monitoring sensors, and software applications that register , transmit or store user data to access their health condition at all times [2]. Mobile health wearables market is extremely fast-moving, and consumers demand more accurate battery- powered mobile devices. Figur ure 1 1. Mo Mobile bile He Health th Schem heme. 3
JUSTIFICATION ECG ANYWHERE. Iwatch series 4. Alivecor, Kardia. SPYDERDOCTOR. Qardiocore. Figure 2 2. Current nt Mo Mobile bile Health Systems. . This project proposes the development of an ECG system with the AD8232 chip for long time recording and real-time ECG monitoring (online) in a low cost system based on an open source platform. The proposed prototype offers the following advantages: Long time ECG recordings Real-time transmission on smart devices ECG records with .txt format for easy information management. 3 communication protocols for connectivity with smart devices The portable monitoring equipment allows to register the vital signs while the user performs his daily activities, and to capture events that occur infrequently or specific circumstances, and thus be able to make a more precise diagnosis. 4
BACKGOUND Electrocardio diograph po portabili lity Currently portable devices, “mobile health” for personal monitoring and Norman Holter in 1949 - backpack, about 37 Kg, with ECG registration health care. and transmission. Figure 4 4. Mobile Health Scheme. Figure 3 3. First portable electrocardiograph. The need to develop miniature equipment is considered by semiconductor companies that develop microchips. Semiconductor companies IMEC • Texas Instruments • Analog Devices • (Developing microchips for the development of miniature and “wearable” equipment ) Figur ure 5 5. Semic icond nduc uctor companies es. 5
BACKGOUND - RELATED WORK Table 1. Ta 1. Current mHealth single channel ECG devices. Modelo Mo CMRR RR Bandwith Sampling Recording Re Cost st Data displa lay Data stora rage (Hz Hz) frequency dur duration (US USD) Iwa watch apple [ [3]. NA NA NA 30 s 499-699 IPhone, Ipad. Memoria dispositivo Alivec vecor, Kardi dia [4]. 76dB 0.5-40 300 Hz 30 s 249 Smartphone Memoria dispositivo Qardiocore [5]. NA 0.05-40 600 Hz. 24h 500 Smartphone Memoria dispositivo. ECG Any Anywhere [6]. ≥ 105 NA 500 Hz. NA 400 Tablet, Smartphone Memoria dispositivo Spyde der wirel eles ess ECG [7] 7] >100 0.5-25 125 Hz 72 h 500 Smartphone Nube internet Cardi dioSecur ur [8] 8] NA 0.5-40 250-500 Hz. 30 m 130 +120 LCD Screen and microSD card subscription. software PC Table 2. Ta 2. Documents related to application of the AD8232 chip in mHealth portable systems. Document Re Reference Ye Year Descrip iptio ion type Un electrocardiógrafo inteligente de bajo coste [9]. Thesis 2014 AD8232 chip and Arduino for portable ECG application. Wireless Hybrid Bio-Sensing with Mobile based Monitoring System [10]. Thesis 2013 AD8232 chip and Arduino for portable ECG application. A Health Shirt with ECG Real-time Display on Android Platform [11]. Article 2014 AD8232 chip and Arduino for portable ECG application. A Portable ECG Monitor with Low Power Consumption and Small Size Based on AD8232 Chip [12]. Article 2014 AD8232 chip and Arduino for portable ECG application. Design of ECG Homecare:12-Lead ECG Acquisition using Single Channel ECG Device Developed on Article 2015 AD8232 chip and Arduino for portable ECG application. AD8232 Analog Front End [13]. Designing a low-cost real-time group heart rate monitoring system [14]. Article 2018 AD8232 chip and Arduino for portable ECG application. Simple fabrication method of an ultrasensitive gold microstructured dry skin sensor for Dry microelectrode development, with the AD8232 chip and Article 2018 biopotential recording [15]. Arduino. ECG T-shirt for exercise with AD8232 chip, App interface on A wearable H-shirt for exercise ECG monitoring and individual lactate threshold computing [16]. Article 2017 Smartphone with classification algorithms. 6
BACKGOUND - AFES (Analog Front End) microchips Advances in the area of microelectronics have allowed the development of multifunction integrated circuits for the acquisition of biopotentials, developed by companies: IMEC, Texas Instrument s, Maxim Integrated y Analog Devices, enabling the development of portable medical instruments and wearables [17-19]. These new specialized integrated circuits, known as AFE ("Analog Front-End") are aimed at conditioning biosignals for digital stethoscope, electrocardiogram (ECG), electromyography (EMG), pulse oximeter (SpO2) and bioimpedance. Reduce component cost by over 50% of a discrete design , a single-chip solution increases system reliability and patient mobility Reduce components and board size by 80% and also reduce noise pick-up, have low energy consumption allowing the development of long-life portable equipment and lightweight [21, 22]. Since 2011, Analog Devices and Texas Instruments companies introduced AFE integrated circuits for ECG application [20]. In 2012, the Analog Devices AD8232 microchip won the award for best electronic design of AFE single-lead heart-rate monitor, in the category of medical innovation [21]. Figure 6. A) Microchip AFE AD8232. B) Diagram of the internal structure of the AD8232 microchip. C) AD8232 microchip footprint .AD8232 estructura LFCSP. 7
PROJECT OBJECTIVES Gener eral Ob Objetive: Manufacture a prototype of a portable ECG system with data logging and wireless data transmission, using the AD8232 chip as an initial analog stage, and open source development platform. Specif ific ic Objet etives es: Evaluate and validate the operation, scope and limitations of the AD8232 microchip, for monitoring the ECG signal. Characterize the Arduino open source platform with C programming, to increase its performance in the application of a data acquisition system and application of digital filters in real time. Design the circuit of a portable ECG system with the following modes of operation: serial transmission, microSD card recording, and Bluetooth transmission. 8
MATERIALS AND METHODS Open- Open- AFE AD8232, Circuit Buffer Data ouput source source adapter and implementation overrun modes hardware software simulation and testing problem 9
AD8232 CIRCUIT SIMULATION Multisim simulation* Component development * Macromodel * Circuit design Circuit Specs: *Gain *Cutoff frequencies *Filters evaluation System robustness: *Montecarlo *Temperature Analysis *Worst Case *Fourier Analysis Figure 7 7. Circuit with S SPICE c componen ent i in Mu Mult ltis isim im soft oftware . . 10
OPEN-SOURCE HARDWARE Bluetooth HC-06 Data Logger Shield Arduino Nano CH340 *ATmega328 Microcontroller *16 MHz oscillator *AT commands * RTC1307 *CH340 USB interface *Integrated antenna and *MicroSD reader RF transceivers *Coin battery *115,200 bauds operation *Level 5V to 3.3V regulator Figure 8 8. Open en-source b boards ds a and f d featur ures es. 11
OPEN-SOURCE HARDWARE Open-source hardware is one whose design specifications and schematic diagrams are public access, either under some kind of payment or for free. The designation of open-source hardware refers to the freedom to use the device and its documentation in a design, but still you need to buy the integrated circuits. Disadvantages: Advantages: Designs are specific and unique. Technological independence The availability of components is difficult in developing Promotes hardware quality and open standards. countries. Collaborative work between designs allows their reuse Hardware manufacturing involves the design, simulation, and adaptation. production and implementation infrastructure. Reduce costs and design times in projects. 12
OPEN-SOURCE SOFTWARE IDE Arduino Arduino libraries • Serial Communication: Use of UART port. • SD Library: write the information to micro SD Timer One: Interrupt programming • Software Serial: Virtual UART port configuration. • Bluetooth Graphics Theremino Figure 9 9. Open en-source software a e and d libr brarie ies. 13
Recommend
More recommend
