Research Article BLOOD PRESSURE AND ECG MONITORING SYSTEM BASED ON INTERNET Swati Y.Gaikwad, Prof. Ms. Revati Shriram

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1 Research Article BLOOD PRESSURE AND ECG MONITORING SYSTEM BASED ON INTERNET Swati Y.Gaikwad, Prof. Ms. Revati Shriram Address for Correspondence ME II Year Bio.Instrumentation, Cummins college of Engg.Pune,Maharshtra,India Assistant Professor,Department of Instrumentation,Cummins college of Engg. Pune, Maharashtra, India ABSTRACT The objective of the work is to make a simple wireless ECG and BP transmission system for ambulance use. A Wireless electrocardiogram (ECG) / blood pressure (BP) telemonitor system focused on integration of biopotential amplifiers, oscillometric measurement of blood pressure, microcontroller devices, programming methods, wireless transmission, signal filtering and analysis, interfacing, and long term memory devices (24 hours) to develop a ECG/BP telemonitor. A long-term monitoring facilitates the capturing of sporadic events and therefore is an important contribution for the improvement of the therapy and, consequently, for the health of the patients. The task has been accomplished by Internet technology, ECG detector, NIBP module and personal computer as monitor. The specific objective of this device is to facilitate the long term continuous monitoring and recording of ECG and blood pressure signals. This device is able to acquire ECG/BP, transmit them wirelessly to a PC. It is also capable of calculating the heart rate (HR) in beats per minute, and providing systolic, diastolic and mean blood pressure values. Incorporation of GPRS technology allows wireless transmission to health or control centers. KEYWORDS: ECG detector, NIBP module, Microcontroller, VC++, Internet technology (TCP/IP), and personal computer. I. INTRODUCTION Telemedicine generally refers to the use of communications and information technologies for the delivery of clinical care. It is practiced on the basis of two concepts: real time (synchronous) and store-andforward (asynchronous). A term defining an expansion of telemedicine is telehealth deals with transmission of medical data for diagnosis or disease management (sometimes referred to as remote monitoring), as well as on advice on prevention of diseases and promotion of good health by patient monitoring and follow-ups. In store-and-forward telehealth, digital images, video, audio and clinical data are captured and "stored" on the client computer; then at a convenient time transmitted securely ("forwarded") to a clinic at another location where they are studied by relevant specialists. The opinion of the specialist is then transmitted back. Based on the requirements of the participating healthcare entities, this roundtrip could take between 2 to 48 hours. In many store-and forward specialties, such as teleradiology, an immediate response is not critical. However, telecardiology requires an immediate response. Thus, devices like holter, event recorder or continuous loop recorder can be replaced completely by a wireless monitor. The main objective of this project consists in the development of a biomedical instrumentation prototype for acquisition, processing and transmission of biomedical signals. These biomedical signals are acquired and then processed with a microcontroller. After processing, all data are sent to a communication interface that can send this information to a personal computer or a cell phone. The prototype developed, which is a NIBP module & an ECG module is intended to allow remote monitoring of patients living in areas with limited access to medical assistance or scarce clinical resources. [4] With the development of electronics and its application in medicine it is possible to transmit and process many vital parameters of the human body. The most important, and in this moment the most interesting signal for monitoring and analyzing is the electrocardiography (ECG) signal. For the patient suffering from the cardiac disease it is very important to perform accurate and quick diagnosis. For this purpose a continuous monitoring of the ECG signal, patient s current heart rate and BP are necessary. In this medical field, a big progress has been achieved in last few years. Telemedicine has been an active area of research for over 30 years. In the past, several telemedicine applications using wired communications were presented whereas nowadays the evolution of wireless communication means enables telemedicine systems to operate everywhere in the world thus expanding telemedicine benefits, applications, and services. This study covers the description of wireless telemedicine applications, how these applications are used in health care delivery and what are the technologies used. [6] Telemedicine is to improve the quality, increase the efficiency, and expand access of the healthcare delivery system to the under-staffed, remote, hard-toaccess, or under-privileged areas where there is a paucity of medical practitioners and facilities. It seems reasonable to envision that a telemedicine facility could significantly impact areas where there are needs for uniform healthcare access such as under-served populations of rural areas, developing countries, space flights, remote military bases, combat zones, and security health-care facilities. Mobile patient telemonitoring (i.e., emergency medicine), posthospital patient monitoring, home care monitoring, patient education and continuing medical education all are going to benefit from telemedicine. [4] A compact,

2 cost-effective, and easy to use wireless ECG/BP telemonitor could assist patients and clinicians in telemedicine applications. In a lot of critical care situations, to obtain a more accurate description of a patient s status, various vital signs (electrocardiogram, blood pressure, temperature, oxygen saturation, etc) are necessary to provide a comprehensive index of the patient s health. To achieve this objective, healthcare providers need to monitor the patient for long periods of time in the hospital. Such systems could provide a more practical and convenient alternative for both the patients and the healthcare team. A. Need of Wireless Transmission: An ECG/BP signal is useful for a doctor to evaluate a patient s heart condition relating to: - Whether a heart attack has occurred - What parts of the heart is damaged - Irregular heart beats - Whether the heart is not receiving enough blood or oxygen It has been demonstrated, an ECG/BP signal is extremely valuable, making it a conventional mechanism used in hospitals by both doctors and nurses. The aim of this project is to develop a wireless system to provide a more user-friendly device for ambulatory application. Similarly it provides the doctor or nurse with a trouble-free approach to the patient s ECG/BP signal. In fact, for patients in rural and regional areas an ECG report could be sent to a doctor for examination. Thus, this is a system in which the doctors at his/her house can treat the patient in the emergency condition in the hospital. [11] II. WIRELESS COMMUNICATION Incorporation of technologies such as Bluetooth, GPRS, GSM or Wi-Fi in these systems allows wireless transmission to health or control centers. This system describes a low-cost, portable system with wireless transmission capabilities for the acquisition, processing, storing and visualization in real time of the electrical activity of the heart to a Personal Computer. The data acquisition unit, built here transmits ECG and BP signals using stream-oriented TCP interface program.tcp/ip was at one time just one of many different sets of protocols that could be used to provide network-layer and transport-layer functionality. ICP allows for both TCP and UDP connections. TCP/IP sockets were used in the system for reliable communication. Today there are still other options for internetworking protocol suites, but TCP/IP is the universally-accepted world-wide standard. Its growth in popularity has been due to a number of important factors. Some of these are historical, such as the fact that it is tied to the Internet as described above, while others are related to the characteristics of the protocol suite itself. III. WIRELESS TRANSMISSION OF ECG/BP Fig.1 shows the concept of proposed ECG/BP wireless transmission system. Here we collect the ECG from the patient from the surface electrodes and give it to the ECG circuit, which enables the signal conditioning process. After that the ECG is seen on the Digital Storage Oscilloscope (DSO), from which it is interfaced with the computer, which in turn transfers the ECG waves to the mobile by any wireless protocol. Then finally this ECG waves is sent to the doctors computer, who diagnose the disorder and in reply gives the technician necessary guidance in the hospital to help patient recover from the life threatening condition. Same for the BP signal. The ECG signals acquired from different points of the body (wrist, ankle and chest area) are of very low amplitude (0.05 mv 10 mv). Furthermore, this signal includes some noises resulting from 50 Hz power electricity lines and other environmental effects. To be able to process this signal, filtering and amplifying of the signal is required. The main block scheme of the system is sketched in Fig.1. The analog signal acquired from the ECG-electrodes is amplified and then handled by the ADC. Then the Microcontroller (MCU) makes analog to digital conversion of the signal and sends the digital signal via RS-232 to PC for monitoring. PC runs simple software that controls received data from serial port and plots the ECG signal on the screen. [7] Fig.1 ECG/BP wireless transmission system The Data acquisition module contains some local intelligence to handle data acquisition, conversion, and serial transmission to the patient s workstation. This subsystem is designed taking into consideration the requirements of a nonclinical situation. The device should be easily connected to the remote computer, should not have any adjustments to be made by the patient, and should be controlled from the server for any sampling frequency or gain adjustments. [3] A block diagram of the system is shown in Fig. 1.The front-end amplifier was built around the instrumentation amplifier, with high-pass filtering, driven right leg, and guard driving circuits, controlled gain, and filtering. The digital section comprises the data-conversion section and the control unit. A 12-bit serial A/D converter is employed. The sampling frequency is governed by the control unit, and it can be switched between samples per second. The control unit also implements the bidirectional communication protocol to the PC, through a proper RS-232 interface provided in the system Commands for gain control in the front-end amplifier and for sampling frequency changes in the A/D are provided in this fashion. The circuit uses, for isolation purposes, capacitive isolation in the case of the ECG channel and transformer isolation for the power supply, which can be either an ac/dc wall adaptor or rechargeable batteries. The control unit is built around the Microchip dspic30f5011 with a 40-

3 MHz clock 16-bit microcontroller. It does allow a sampling frequency of 400 samples per seconds while establishing a 56-kb/s bidirectional serial communication with the PC. The actual patient device has a one channel three-electrode-bioamplifier bandwidth of Hz, gain of 1000, and commonmode rejection ratio (CMRR) of 120 db at 60 Hz. [3] Medical equipment uses sensors to monitor body condition that transform physical signals into electrical signals that will be converted to the digital world. The signal-path design in medical applications is critical due to the low magnitude of the signals and the presence of many sources of noise. This article will discuss, through the example of an ECG (Electrocardiogram) and BP (Blood pressure), how to build the sensor interface with a suitable amplifier in order to increase battery life and patient security. IV. ECG & BP ACQUISITION SYSTEM A. ECG Acquisition: The ECG signal is an electrical signal generated by the heart s beating, which can be used as a diagnostic tool for examining some of the functions of the heart. It has a principal measurement range of 1 to 3 mv and signal frequency range of 0.05 to 140 Hz. According to the technical requirements, the proposed system is composed of two main parts: ECG acquisition platform and analog to digital signal processing. Fig.2 shows the block diagram of ECG module. ECG signals were acquired through a low power consumption ECG amplifier. The input to this circuit was provided by three 10-inch long patient wires (packaged inside a patient cable). The patient cable has low-noise, well-shielded, and equipped with snap-on connectors. These wires are connected to disposable Ag/AgCl snap-on skin electrodes. The ECG amplifier can construct with a gain of 1000, a CMRR of 80dB and a frequency bandwidth of Hz.[1] These signals are both amplified and filtered to the required specifications. The duration between peaks of the QRS waves (R-R intervals) can be used to calculate the beat-to-beat heart rate (HR). The output waveform from the ECG amplifier is then fed to the rest of the system. Proper ECG signal acquisition is carried out using filters for noise suppression and amplifiers to enlarge the signal amplitude as much as possible, while keeping it within the input voltage range of the analogdigital converter (ADC). The task of the ADC is then to digitize the analog voltage with a resolution high enough to represent the original signal. These values can then be collected by a microcontroller (MCU) which maintains the connection with the wireless transmitter. [1] Block Diagram Description: Leads: Electrodes are used for sensing bio-electric potentials as caused by muscle and nerve cells. ECG electrodes are generally of the direct-contact type. They work as transducers converting ionic flow from the body through an electrolyte into electron current and consequentially an electric potential measurable by the front end of the ECG system.[1] Fig.2 Block diagram of ECG signal acquisition Instrumentation Amplifiers: The instrumentation amplifier is basically a differential amplifier that amplifies the difference between the two input signals. Hence the common mode signal is effectively eliminated. Two buffer amplifiers at the input of each signal, is provided to offer very high input impedance. The gain of the instrumentation amplifier is set around 1000[1]. Analog to Digital Converter: The Analog to Digital Converter (ADC) encodes the ECG signal into an 8-bit binary code, by taking rapid samples of the processed ECG signal. Since the ADC input should be constant when a conversion is in progress, the Sample and Hold amplifier is used to store the sampled ECG signal and provide the instantaneous value of the sample to the ADC. The sampling rate must conform to Nyquist sampling theorem which states: For a band-limited (Finite Bandwidth) signal with maximum frequency fmax, the equally spaced sampling frequency fs must be greater than twice of the maximum frequency fmax. In order for the signal be uniquely reconstructed without aliasing. The frequency 2 fmax is called the Nyquist sampling rate. fmax is commonly referred to as the Nyquist frequency. For the ECG system fmax = 250Hz. The sampling frequency therefore needs to be set to a minimum of 500Hz. [1] Fig.3 shows the snapshot of ECG module. Fig.3 ECG Module B. BP Acquisition: Blood pressure is the pressure that the heart and arteries apply to squeeze blood around the body. It is expressed in millimeters of mercury (mmhg). Two figures are recorded, systolic and diastolic pressures. Systolic pressure refers to the highest pressure in the arteries that the heart produces when it contracts, and diastolic refers to the lowest pressure when the heart relaxes between beats. For example, a normal blood pressure may be around 130/78. Blood pressure is variable throughout the day and is affected by many factors.

4 Fig 4 ECG along with Blood Pressure waveform [9] Thus, the pressure of blood against the walls of arteries is recorded as two numbers the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats). The standard ECG along with Blood Pressure waveform is shown in Fig.4. [8] The oscillometric method of blood pressure measurement is a non-invasive method that monitors the amplitude of cuff pressure changes during cuff deflation to determine arterial blood pressure. The cuff pressure is first elevated above the patient systolic blood pressure level and the cuff begins to deflate at a certain rate. The initial rise in amplitude of these pressure fluctuations during cuff deflation corresponds closely to the systolic blood pressure. As the cuff is further deflated, these pressure fluctuations increases in amplitude until a peak is reached which is usually referred to as the mean arterial pressure (MAP). As cuff deflation continues, the diastolic pressure can be determined based upon the rapidly diminishing amplitude of the pressure fluctuations. Thus systolic, MAP and diastolic blood pressures can be accurately obtained by supervising the pressure fluctuations while controlling the cuff deflation rate. [9] Fig.5 shows the snapshot of NIBP module. This NIBP Module is an oscillometric blood pressure system. The module is controlled via software commands issued from a host system through an asynchronous serial data port (factory configurable to Logic Level or RS- 232). All Module operations must be initiated by the Host system (Device which holds and communicates with the NIBP module). The module is designed to take blood pressure measurements on demand. After each blood pressure measurement, the Module will discard the previous blood pressure results. Serial communications baud rate is 9600, with 1 start bit, 8- bit data, no parity, and 1 stop bit. Fig.5 NIBP Module Inputs to the Module consist of: - Cuff Pressure - Serial Data Port - Power - Outputs from the Module consist of: - Serial Data Port Operating Procedure The Module is designed to operate on a demand basis. After a power-on reset, the Host system will initialize the operating parameters for the module. Typical operation of the Module consists of using only four commands, the START BP (patient specific), ABORT BP,GET_BP_DATAand the GET_CUFF_PRESSURE commands. The following is a typical sequence of operations for using the Module: 1. Module goes through a power-on reset (ROM, RAM, A/D, and Calibration Tests) 2. Host system issues START BP command. 3. Module begins a blood pressure measurement. 4. Host system repeatedly sends the GET_CUFF_PRESSURE command (Module will reply with actual cuff pressure) while the BP reading is in progress. 5. Module notifies the Host system that the BP measurement is finished. 6. Host system issues GET_BP_DATA command. 7. Module responds with BP data values (systolic, diastolic, etc.). Repeat Step 2 through Step 7 every time a new BP is needed.[9] After digitization of the oscillometric signal by the analog to digital converter (ADC) contained in the main microprocessor, the signal is further filtered (using software filtering techniques) before being used by the main algorithm to determine the systolic and diastolic points in the waveform. Simultaneously, the cuff pressure is measured directly from the transducer output by a different channel of the ADC. By combining the information provided by the oscillometric waveform and the cuff pressure, the systolic, mean arterial and diastolic blood pressures are determined. Analysis of the oscillometric waveform also provides information on the pulse rate, which is reported and stored in the microprocessor nonvolatile memory, together with the blood pressure results. [9] V. SYSTEM SETUP The client server architecture shown in Fig.6 is defined as follows: the client application provides visualization, archiving, transmission, and chat facilities to the remote user (i.e., the patient). The server, which is located at the physician s end, takes care of the incoming data, provides control of the remote acquisition module, and organizes patient sessions according to the number and requirements of the patients connected to the server. Both applications have been designed and developed in VC++, using the object-oriented methodology. [3]

5 Fig.6 An Internet-based telemedical system.[3] V. DESIGN OF SYSTEM SOFTWARE In this paper, we have built a software platform by using VC++ program, and the platform can realize ECG real-time transmission. Fig.7 shows the software block diagram. On the terminal of monitoring system, medical care person will be able to see and analyze the real-time ECG from the client, and finally make recommendations in time to achieve the purpose of long-distance medical care. Through the VC++ programming, a client/server model is built and the family and medical centers are connected. On the basis of the remote diagnosis, the family side of the program and monitoring equipment can be connected, and the data from the serial port can be real-time read. The medical center pre-treats the received data and saves them in the database. In addition the software of the medical center links the central database, in order to find client s history information and to make a more accurate diagnosis. Fig.7 Design of system software Fig.8 and Fig.9 shows monitor and server side flowchart respectively. Fig.9 Server side flowchart RESULT Execution of the client s application generates the GUI shown in Fig. 10. The interface can be divided in three main sections. At the bottom are shown the three elements that allow the control of the DAM, as well as the Internet connection. In the middle, the ECG visualization is contained. While the server is running), it is waiting for service requests in a predefined transport control protocol/internet protocol (TCP/IP) port. Clients can start a session from anywhere in the Internet by accessing the server s connection port. The port used by the client to contact the server is released so that the server can accept new requests, and the assigned ports are configured. For each new session, different instances of the server s objects are created, generating a new window for each client, allowing independent data flow, and DAM control. Before any interconnection has been accomplished, the DAM is totally under the control of the client. Once the connection is reached, the server receives full control of the DAM s parameters (gain and sampling frequency). The ECG can be stored in a file. These files can be later visualized at the client or transferred to the server by . In order to establish the client server sessions, the computer can be connected to the Internet using any access mode. If telephonic medium is used via modem, a minimal transfer rate of 28.8 kb/s is required. Fig.8 Monitor side flowchart Fig.10 Server and Client Interface CONCLUSION A wireless ECG/BP transmission system is able to accurately and reliably acquire, transmit, record and real-time display the ECG/BP signal. The specific

6 characteristic of this system is it only transmits ECG signal but don t process the raw data in order to avoid possible false diagnose caused by data distortion induced by data process. Compact, portable and costeffective telemonitors could assist patients and clinicians in telemedicine applications. This article introduces the wireless communication electrocardiogram detection system which applies the dspic30f5011 processor and the communication modules. This system has many features including convenient manipulation, low-power, high performance, real-time transport and so on. This system is not only can realize the long distance moving for the ECG, but also can transmit the ECG & BP to the local computer, which can make the local monitoring possible. In the meanwhile, with the developing of the monitoring technique and network communication, the long-distance moving and monitoring for the ECG will be improved and completed gradually, it would be of great help to the patients and doctors. Work is currently ongoing for improving aspects of the system in both hardware and software. ACKNOWLEDGEMENT We would like to acknowledge with thanks, the assistance provided by departmental staff of the Cummins College of engineering.we would also like to acknowledge Mr. Suhas Patil & Mrs. Vrinda Savargaonkar, Manager, Concept Integration, Pune for their continuous guidance and encouragement and assistance. REFERENCES 1. A. Istanbullu, P.A. Oner, I. Kocaturk, I. Ozcan Low Cost ECG Monitoring Experiment Set- Up for Nonclinical Applications OPTIM /08/$ IEEE. 2. A. L. F. Sparenberg1, T. Russomano1, D.F.G. de Azevedo, Transmission of Digital Electrocardiogram (ECG) via Modem Connection, in Southern Brazil 3. Alfredo I. Hernández, Fernando Mora, uillermo Villegas, Gianfranco Passariello, and Guy Carrault Real-Time ECG Transmission via Internet for Nonclinical Applications. 4. Dina Simunic, Slaven Tomac, Ivan Vrdoljak Wireless ECG Monitoring System University of Zagreb, Faculty of Electrical Engineering and Computing,Unska 3, Zagreb, Croatia. 5. Haroon Mustafa Khan Wireless ECG Design University of Queensland Thesis. 6. Marcos Bolaños, Homayoun Nazeran, Izzac Gonzalez, Ricardo Parra, and Christopher Martinez A PDA based Electrocardiogram/Blood Pressure Telemonitor for Telemedicine Proceedings of the 26th Annual International Conference of the IEEE EMBS San Francisco. 7. Nilton Serigioli1, Rodrigo Reina Muñoz and Edgar Charry Rodriguez Biomedical Signals Monitoring Based in Mobile Computing 32nd Annual International Conference of the IEEE EMBS. 8. Nivedita Daimiwal, Asmita Wakankar, Dipali Ramdasi and Mrunal Chandratreya Microcontroller Based ECG and Blood Pressure Simulator J. Instrum. Soc. India 37(4) Operating manual of NIBP Concept Integration. 10. Wun-Jin Li, Yuan-Long Luo, Yao-Shun Chang, and Yuan-Hsiang Lin, Member, IEEE A Wireless Blood Pressure Monitoring System for Personal Health Management.