Introduction to embedded systems

Real-time Patient monitoring system

CHAPTER - 1

PREAMBLE1.1 Introduction

In todays healthcare practice, physicians have a need to monitor more than one medical parameter for patients that are either hospitalized or leading their normal daily activities at home or at work but in need of constant medical care. Telemedicine (health-care delivery where physicians examine distant patients using mobile communication technologies) has been heralded as one of several possible solutions to some of the medical dilemmas that face many developing countries. The traditional way of providing Telemedicine services is to transmit biomedical signals from a patient to a hospital using landlines, such as the PSTN and integrated services digital network. While examining the current state of telemedicine in developing country India, telemedicine has brought a plethora of benefits to the populace of India, especially those living in rural and remote areas (constituting about 70% of Indias population) [1]. Objective of this project is to propose a wireless stand-alone a novel approach to patient monitoring is introduced.1.2 Scope of the studyIn a country like India, with an exponentially high population growth rate and a historically poor health-care delivery system with few medical facilities exist to serve the large population that resides in the villages. India has 80% of its main health-care centers located in cities that host only 30% of the population. These percentages reveal a dismal health-care scenario where only 20% of Indias quality health-care facilities cater to 70% of Indians confined to rural communities. According to survey [1], Indias rural population is more vulnerable than its urban counterpart based on three particular reasons: late discovery of ailment, transport time to urban health care facilities, and inexperienced primary healthcare providers in rural areas. The rapid growth of mobile communication technologies in India offers the potential to address these concerns and to save the patient extra cost associated with treatment, such as travel and other living expenses. The main objective of the study is to develop an efficient system that monitors and reports the data in real-time. This relieves incapable patients from needing to go in-person to the physicians. It also gives the healthcare professionals, the ability to react promptly to life-threatening situations, in a proactive way that involves the patients themselves.1.3 Problem FormulationThis is a project that aims to designing a system that will help doctors to monitor crucial parameters of patients like heart beat, body temperature and blood pressure using GSM communication technology. Also demonstrate how the reliability of the system can be enhanced using different design methodologies. The goal of this work is to build a compact and cost-effective monitoring system. The device is developed and implemented based on the existing industry standard communication network and patient monitoring software application is developed to store data that can be used for real time monitoring and later downloaded to a physicians workstation for analysis and diagnosis. It specifically targets assisted-living residents and others who may be benefited from continuous remote health monitoring and decision support system.1.4 Methodology

The methodology includes consideration of a combination of wireless techniques, particularly the exploitation of cellular networks, types of clinical data for transmission and system memory storage. The system presented here contains GSM/GPRS modem for remote wireless communication and customized E-med software application designed using Microsoft Visual Studio for process the data in management unit. The patient monitoring device is connected to processing unit (computer) using RS232 serial communication, GSM for communication from base station to other mobile telephones and central monitoring unit, LAN to clinicians. This project makes use of health sensors as input to the system is simulated inputs, since actual sensors are costly and the main aim of the project is to bring out the idea that how the control system can be designed to monitor the patient health status. Many sequences of events that take place in development and implementation are explained throughout this report 1.5 Outcome and LimitationsThe adoption of mobile technology has led to new applications in health-care provision. There are medical cases that can be managed more efficiently by adopting wireless Telemedicine, such as Emergency and rescue situations etc... Thus medical services can be delivered to any location within the coverage of cellular networks. In this system design we used GSM technology, but the adoption of GPRS is relatively new which allow much more data to be transmitted, like high-resolution digital radiographic images, large volume MR/ CT images, audio and video signals.1.6 Literature SurveyLiterature survey was carried out on available previous published literatures, which lays the foundation and basis for the work in this project. An extensive study has been carried out to understand the Telemedicine Diffusion and Intelligent Healthcare.Thorough study has been made on the Real-time remote system for patient monitoring. Some of the basic concepts has been learnt before going through the telemedicine, they are: remote accessing, cellular networks, wireless technologies, telemedicine Diffusion in India, digital hospital, health care informatics, WAP-Based telemedicine, GPRS based systems(e.g. PDA-Based physiological monitoring) etc. Some of the updates and recent changes are learnt from internet download.Amrita Pal has presented a paper on Telemedicine Diffusion in developing Country: The Case of India (March 2004), explains the current state of telemedicine in a developing country, India. Also explains need for Telemedicine in India [1].Y. Lin and I-C. Jan has presented an IEEE paper on PDA-Based Patient Monitoring, in this paper proposes a wireless physiological monitoring system for patient transport and telemonitoring data management techniques [2].Andreas Hein and Oliver Nee propose a system called SAPHIRE-Intelligent Healthcare Monitoring based on Semantic Interoperability Platform-The Homecare Scenario [3]. In this system an intelligent healthcare monitoring and decision support system on a platform integrating the wireless medical sensor data with hospital information systems. In the SAPHIRE system, patient monitoring will be achieved by using agent technology where the "agent behavior" will be supported by intelligent clinical decision support systems which will be based on computerized clinical practice guidelines, and will access the patient medical history stored in medical information systems through semantically enriched Web services to tackle the interoperability problem.There are two main issues of interest to deal with monitoring heart patients. Firstly, the heart patients should be monitored in more natural environment, in their real daily lives, while they are using their heart medicine for a better test and evaluation of the treatment efficiency. Secondly, the hospitalization should be reduced in order to lower the expenses of the health care system and reduce the patients waiting time. Y.Jasemian, E.Toft and L.Arendt-Nielsen was designed a real-time monitoring cardiac patients at distance using GSM network [4].G. Virone and A. Wood has presented a paper on An Assisted Living Oriented Information System Based on a Residential Wireless Sensor Network for health monitoring explains system architecture for smart healthcare based on an advanced Wireless Sensor Network (WSN) [5]-[6]. It specifically targets assisted-living residents and others who may benefit from continuous, remote health monitoring. Many patient remote monitoring devices were reported in the literature [7]. A wireless telemedicine procedure was reported in [1], [8]. The unit helps physician to perform a computer-aided bedside patient monitoring is applied in areas where real-time vital function analysis takes place. Modern bedside monitoring requires not only the networking of bedside monitors with a central monitor but also other standard communication interfaces, to monitor the medical condition of a large number of patients. A protocol receives the temperature and pressure of a patient using a mobile device that is attached to the patients body via short messaging system (SMS) message [9]-[10]. The mobile device does not have data logging capabilities, nor does it have download and diagnosis features. The clinical usefulness of a wireless personal digital assistant (PDA) based on a GPRS-capable cellular phone and an Internet application for remote monitoring of real-time vital signs was discussed in [2], [11]-[12]. A wireless PDA-based physiological monitoring system for patient transport that uses wireless local area network (WLAN) technology to transmit patients biosignals in real-time to a remote central management unit was presented in [13]-[28]. Apart from the above mentioned papers and books there are some websites and documents which have gone though and are mentioned in the references (chapter 9). Some of the updates and recent changes are learnt from internet download. Most of the above systems do not have real-time logging capabilities, and automatic handling of emergency and rescue situations. The medical cases that can be managed more efficiently by adopting wireless Telemedicine.The proposed work is to communicating with their physician and biomedical signals are transmitted in real-time to the physician or hospital network. New technologies are also coming up and research in the above field is still going on. Some noted recent developments and research work are in progress. 1.7 Report OrganizationChapter 1 is used as an introduction on the scope, organization and aim of the thesis. Also reviews the previous published literature, which lays the foundation and basis for the work in this project. The remainder of the thesis is organized as follows. Chapter 2 gives an overview of various wireless telemedicine technologies. Chapter 3 gives the information about which are the methods we follow in our work. Introduction to the GSM communication compared with other communication technique and embedded device design, selection of software language etc..Chapter 4 explains the design and implementation of the Remote monitoring system. In that first unit (acquisition unit) of our system is explained. Chapter 5 explains the other two units (management and monitoring unit) with software design. The results of it are shown in chapter 6. Chapter 6 named RESULTS covers the verification and test plan, snapshots of the customized E-med software with results. Finally conclusion and future work are summarized in Chapter 7 and at the end references are listed.CHAPTER - 2WIRELESS TELEMEDICINE2.1 Introduction

AS FIVE-YEAR-OLD Thejas lay in bed in the consulting room at the Aragonda Apollo Hospital in the remote village of Aragonda, India about 170 km from Chennai, India, doctors first diagnosed a murmur in the heart and he was put on a color Doppler. As the color Doppler images were transmitted to the hospital in Chennai using special electronic communication. Pediatric Cardiologist Prem Shekhar diagnosed the case as Sallots Tetrology (multiple congenital defect of the heart). After a few hours of consultation with the surgeons and the hospital chairman. Dr.Pratap C.reddy, the child was transfferd to the Chenni Apollo Hospital for surgery. Dr.Reddy commented, this facility has heralded telemedicine in India and that as a special case, Thejas would be operated free of cost and all the expenses borne by the hospital.1This real-life example reflects one of many success stories like Online Telemedicine Research Institute (OTRI, Gujarat) has made a great impact on the lives of people living in the western part of India. On January 27, 2001 an earthquake devastated the western city of Bhuj and left thousands dead and many more homeless. Within a day, the OTRI in Ahmedabad, about 300 km from Bhuj, established satellite telephone links and set up all the equipment necessary to provide emergency medical care through telemedicine. The telemedicine diffusion in India, where patients in remote areas are diagnosed and treated for numerous medical conditions. Telemedicine is defined as the use of telecommunication technology (involving audio, video, and graphic data) to deliver health-care services, health education, and administrative services to sites that are physically distant from the host or educator. This chapter gives present condition how telemedicine is changing the delivery of medical services in India and then stat-of-art technologies for wireless telemedicine.1 This real story is selected from telemedicine diffusion case study in India [1].

2.2 Overview of Indias wireless telemedicine infrastructure

A country with an exponentially high population growth rate. Low teledensity (number of telephone landlines per 100 people), and a historically poor health-care delivery system. Indias telemedicine infrastructure is largely government owned; telemedicine initiatives are constrained by existing state-sponsored networks, varying only in terms of equipment and software applications. Until recently, telemedicine remained contingent upon Indias meager high-bandwidth landline telecommunications infrastructure. The popularity of wireless and Indias home-grown satellite technologies developed by Indian Space Research Organization (ISRO) offers critical infrastructure to support teleapplications. The satellite system having 130 C-band transponders linking many hundred earth stations in remote and rural areas along with thousands on very small aperture terminals (VSAT). This infrastructure enables the country to reach over 65% of the Indian landmass and 80% of its population. The technical infrastructure for typical telemedicine projects in India is shown in figure 2.1. [1].

2.3 Industry Standard-Based Monitoring Systems

Patient monitors are the most important diagnostic devices in the critical care units (CCUs) of hospitals, providing continuous display and interpretation of the patients vital functions. The rapid evolution of electronics and information technology is resulting in more powerful bedside patient monitors capable of complex biosignals processing and interpretation and usually equipped with some specialized communication interface.

During the last decade, centralized patient monitoring systems were installed in the majority of critical care facilities. Centralized patient monitoring provides the networking of several bedside patient monitors with a central monitoring station.2.3.1 Intelligent Decision Support System (DSS)As the world's population ages, those suffering from diseases of the elderly will increase. In-home and nursing-home pervasive networks may assist residents and their caregivers by providing continuous medical monitoring, control of home appliances, medical data access, and emergency communication.An intelligent decision support system (DSS) based on established clinical guidelines is a key component of the most recent idea of monitoring system. This DSS uses agent technology and provides clinicians as well as patients and their relatives with relevant medical information. Its suggestions are based on medical knowledge embedded into the guidelines, on input from the treating physician, on the patients history that is retrieved from the electronic healthcare record. Vital parameters gathered from sensors and transmitted wirelessly, as well as patient feedback are both also used as input for the DSS, If the patients state is identified as a potentially critical one, an alert is generated and propagated, triggering local reactions [3]-[5].2.3.2 Homecare ScenarioAim of the homecare scenario is the implementation of the infrastructure for homecare and individual patients by closing the gap between the IT infrastructure of health care institutions and the local infrastructure of the patients home. This is done by integrating the respective hardware and software on the so-called user-friendly multi-services home platform. Within the scope of the project, the multi-services home platform will be used as a residential gateway between the patients home and the clinic.

Additionally, the development of reliable communication protocols according to data privacy requirements, the semantically enriched patient data and their integration into the hospital information system and the electronic healthcare record.

The emergence of internet technologies and telemedicine also opens new scales and makes new demands on patient monitoring. Home-care monitoring offers faster, more effective and cost-saving rehabilitation and mobilization of patients. Telecare monitors can provide both halter and on-line, noninvasive monitoring of vital functions.

Wireless patient monitoring systems not only increase the mobility of patients and medical personnel but also improve the quality of health care. With respect to the remote monitoring of patients, many groups have demonstrated the transmission of vital biosignals using various wireless technologies. In some methods cellular phones used to transmit vital signs from the ambulance to the hospital, either in store-and-forward mode or in real-time mode. 2.3.3 Real-time and Always-onWith the recent advances of Internet and wireless technology it becomes possible for physicians and care givers to remotely access patient data from anywhere and anytime. Wireless access to the patients vital parameters and signals could greatly benefit the daily routine of caregivers, thus providing around the clock continuous care. This physiological and environmental data can be monitored continuously, allowing real-time response by emergency or healthcare workers. 2.4 State-of-the-Art

Most of existing systems patient monitors belong to the so-called first generation systems with traditional and quit reliable signal interpretation capabilities. Decision support and interactivity as a higher level of signal interpretation are the features of the second and third-generation monitors. These systems provide more advanced, usually knowledge based signal interpretation.

From architectural point of view, many existing systems support the networking of bedside monitors to a central monitor via a vendor-specific communication interface. The signal interpretation features of the central monitoring are usually more advanced than the bedside monitors. However, there are several standards for transmitting various types of medical information. The medical information bus (single communication channel) is the only existing standard that deals with the low level communication technology between bedside medical devices. Although the medical information bus specifies all the seven open system interconnection protocol layers. The medical information sharing was designed in an object-oriented way, considering the most important requirements on bedside networks: plug-and-play and fast reconfiguration, ease-of-use, reliable fault diagnostic and patient safety. 2.4.1 Mobile TechnologyThe adoption of mobile technology has led to new m-Health applications in health-care provision [7], a sample healthcare network shown in figure 2.2. Although face-to-face consultations between a clinician and a patient will never be replaced, there are medical cases that can be managed more efficiently by adopting wireless Telemedicine. Emergency and rescue situations, and sport science physiological measurements. Medical services can now be delivered to any location within the coverage of cellular networks. Wireless Telemedicine can be categorized in terms of the technology, namely 1)Satellite link, 2)Short-range networks and links, and 3)Mobile cellular networks (e.g.,GSM,GPRS,3G). The use of satellite communications requires expensive equipment, dedicated links, and skilled operators. Wireless local area networks (LANs) [5], [9] and short-rang radio-frequency (RF) Transceivers, as used in hospitals [6],[13], Cannot be used for truly mobile applications, unlike GSM cellular network, which is adopted hear [7],[11]. To allow world-wide connection, a mobile cellular network is also needed; initially this is GSM, while in the future it could be 3G.A comparison of security and encryption for wireless technologies is shown in table 2.1 [8] - [16].

TechnologySecurity/Encryption

Bluetooth128-bit authentication key and 8-128 bit encryption key [8].

WLANWired equivalent privacy (WEP) protocol with RC4 Encryption algorithm [2], [15]-[16].

GPRSThree tier security with A3 algorithm for user authentication, A8 Ciphering Key Generating Algorithm and A5 Ciphering Algorithm for Data Encryption [2], [12].

3Gf8 UMTS Confidentiality Algorithm and f9 UMTS integrity algorithm [8].

Some applications of wireless telemedicine have involved the transmission of data using down-link channels. i.e., from hospital to clinician. There is probably a greater need for uplink channels, e.g., sending signals from a patient during emergency situations or nonemergency situations, in many systems, the implementation principles have been demonstrated earlier but there are limitations that merit further research, including the replacement of an infrared link with a Bluetooth link between the patients monitor unit and the mobile telephone. Most previous wireless telemedicine projects have focussed on the use of GSM, but the adoption of GPRS is relatively new. Its major advantage is that it enables the transmission of both data and speech.

It is essential that a patients received data are archived and accessible to clinicians when required. The data includes the international mobile subscriber identification number, which is unique to the subscriber identity model card in the telephone. By using a password, a clinician can log on to access that patients database. GSM is a wireless platform that uses radio frequencies, since the radio medium can be accessed by anyone, authentication of users to prove that they are who they claim to be, is a very important element of a mobile network. Authentication involves two functional entities, the SIM card in the mobile, and the Authentication Centre (AuC). Each subscriber is given a secret key, one copy of which is stored in the SIM card and the other in the AuC. 2.4.2 The Internet

The use of the internet by health care provides, and certainly their patients, has seen dramatic increases in past few years. The dramatic increase in the popularity of the internet means that health care providers are left with the decision to either capitalize on the new e-world, or being left behind. For those that choose to integrate the internet into their suite of services, the internet offers several key benefits. These benefits include allowing physicians and specialists from across the globe to share vital health care information. Also, the internet has the capability of allowing patients to self-select themselves to view information on the internet, and apply their own diseases management and prevention. In addition, internet technology allows patients and physicians to communicate with each other with greater flexibility and convenience, via e-mail. A third primary benefit that the internet has to offer the health care industry is its unique ability to enable telemedicine, which brings health care to an entire new level [11],[14].CHAPTER - 3SYSTEM ARCHITECTURE AND REQUIREMENTSThe chapter includes Overview of the implemented system, GSM communication and consideration of a combination of wireless techniques, particularly the exploitation of cellular networks, types of clinical data transmission and system memory storage and lastly software design.3.1 Overview of the Implemented System

The aim of this project is to design and implement a mobile system for monitoring vital signs, and to facilitate the continuous monitoring of patients during transport. The telemedicine system consists mainly of two parts:

1. The mobile unit, which is set up around the patient to acquire the patients physiological data, and 2. The management unit, which enables the medical staffs to telemonitoring the patients condition in real-time. The management unit is from either a fixed computer within an existing hospital network or a mobile laptop via LAN.

The major design requirements of the mobile unit are follows: 1. It should be portable and lightweight, which means easy to carry.2. It should have power autonomy of more than 60 min to support patient transport.3. It should have a user-friendly interface.4. It should collect and display critical biosignals, including three-lead BT (Body temperature), HR (Heart Rate), and BP (Blood Pressure). 5. It should record patient information and data; and 6. It supports wireless communication. On the other hand, the design requirements of the management unit are as follows: 1. It must have an easy-to-use interface. 2. It must display critical biosignals and analysis of data. 3. It must record, retrieve, and manage patient information and data (local database).

4. It must be connectable to the internet to transmit data and distribute information with authorisation.Furthermore, at the consultation terminals such as wireless PDAs or laptops, the medical staffs can use them either to monitor the physiological parameters and waveforms of a remote patient online or to access his or her case history through the wireless connection to the management unit.Connection in the studied hospital scenario has been established by LAN technology with speed up to 10Mb/s. An access point acts as a bridge for the network data to be transmitted to and received from the existing wired hospital network; it allows efficient sharing network resources throughout an entire building. The transition of data between a mobile unit and a management unit is serves as the client server architecture. In the propose design, the mobile unit, central monitoring unit serves as the client end and the management unit serves as the server end. Communication depends on the transmit ion control protocol for error-free medical data transmission. All users are required to enter a user name and password to the system via a remote authentication dial-in user service server. In addition, a robust algorithm is implemented in the designed C#.Net program, permitting both central unit and management unit to perform end-to-end encryption.3.2 Wireless Technology

The principal sketch of telemedicine system is as shown in figure 3.1.The system is designed after a careful consideration. in this progress, the technical, data security, practical and economical aspects were taken into consideration to achieve a suitable system design and set-up.in order to select the most appropriate technology for the system realization, properties of the existing modern technologies such as Bluetooth, Short-rang radio-frequency (RF), GSM and GPRS have been investigated [3], [7]-[8], [17], as shown in table 3.1.

TechnologyData RateFrequencyMax. Range

IrDA (Infrared)4MbpsIR Spectrum2m

HomeRF (Home Radio Frequency)1Mbps2.4GHz