Clinically-used 12-Lead ECG
The 12-lead Electrocardiography (ECG) is one of the most frequently applied diagnostic tools in clinical cardiac medicine. A 12-lead ECG instrument records electrical activities of the heart from the frontal and the horizontal views by attaching 10 electrodes on the surfaces of limbs and the chest and therefore generates 12 groups of signals, called 12-lead ECG. Traditionally, a 12-lead ECG instrument stores ECG waveform data with vendor-specific formats whose ECG data are compressed or encrypted with vendor-specific algorithms in the instrument and then generates a hard-copy of the 12-lead ECG report. Recently, ECG instruments are equipped with vendor-specific computerized ECG viewers, which can be used only on desktop computers. In Taiwan, most hospitals adopt paper-ECG, which is due to the expenses of vender-specific ECG instruments and ECG viewers, as well as the management problems of 12-lead ECG records stored in different systems provided by various 12-lead ECG manufactures.
From paper-ECG to computerized ECG
In 2002, Open-ECG, an international academic organization, promoted the development of computerized 12-lead ECG by providing researchers with technical references of 12-lead ECG data formats, including International Organization for Standardization (ISO) approved Standard Communication Protocol–ECG (SCP-ECG), Food and Drug Administration (FDA) proposed Extensible Markup Language based ECG (XML-ECG), and National Electrical Manufactures Association (NEMA) recommended Digital Imaging and Communications in Medicine based ECG (DICOM-ECG) [1–4]. However, several ECG manufactures do not completely adopt the open protocol standards. Instead, they develop vendor-specific ECG data formats and ECG waveform encoding rules. Consequently, 12-lead ECG data formats are heterogeneous and vendor-dependent in clinical practice. With the help of OPEN-ECG, hospitals can develop 12-lead ECG e-diagnosis instead of paper-ECG by extracting the waveform data from several ECG instruments [5, 6].
The integration of heterogeneous 12-lead ECG
When a hospital purchases various ECG products from different manufactures, not only do clinicians encounter huge difficulty in retrieving ECG records, but information technicians (ITs) also have great difficulty in managing ECG information systems due to the heterogeneous ECG data formats and incompatible ECG information database provided by 12-lead ECG manufactures. To provide clinicians and ITs with easier ECG management by unifying heterogeneous ECG data formats, researchers converted clinically-used SCP-ECG and XML-ECG to DICOM-ECG that can be integrated in the Picture Archiving and Communication Systems (PACS) with medical images [7].
12-lead ECG telemedicine and pervasive health
The development of mobile computing-based medical applications is crucial, because it proves to enhance medical service quality [8, 9]. European M-Health Alliance (EuMHA) is a non-profit organization established in Finland in 2010. The goals of EuMHA are to promote the current health IT and to enhance the health service quality with various m-health applications and products [10]. To date, several mobile based single-lead or three-lead ECG products have been successfully developed to monitor heart rhythms remotely [11, 12]. A pioneer ECG telemedicine project, “Enhanced Personal, Intelligent, and Mobile system for Early Detection and Interpretation of Cardiac Syndromes (EPI-MEDICS)”, was created to change the traditional hospital-based cardiac care services to the personalized and non-hospital-based cardiac telecare services [13, 14]. In this European project, a self-developed ECG device, Personal Electrocardiogram Monitor (PEM), has the following functions: (a) synthesizing 12-lead ECG from the measured 3-lead ECG, (b) storing serial ECGs in the standard SCP-ECG format, (c) storing personal health record (PHR) in the XML format, (d) containing artificial intelligence based ECG interpretation, and (e) transmitting ECGs with PHR to remote care providers via Global System for Mobile Communication (GSM). This device greatly helped enhance the quality of cardiac telecare services because remote cardiologists can therefore offer timely diagnosis and treatment order for patients with heart diseases. Additionally, the integration of serial SCP-ECGs allows the cardiologists to access patients’ past and current ECG records, as well as PHR, which greatly facilitate the process of performing diagnosis and treatment with more comprehensive references to patients’ medical records [15, 16].
However, clinically used 12-lead ECG instruments are limited to the use in the hospital and consequently, they do not generate ECG reports outside the hospital. Due to the great variability of 12-lead ECG instruments and medical specialists’ interpretation skills, it remains a challenge to deliver rapid and accurate 12-lead ECG reports with senior cardiologists’ decision making support [17]. In fact, most 12-lead ECG telemedicine devices lack the ability to integrate with clinically-used 12-lead ECG instruments which generate reports and Hospital Information System (HIS) containing patients’ medication information and lab test reports. To enable 12-lead ECG transmission, a hospital has to purchase an additional ECG telemedicine station to receive ECG transmitted from ambulances, and a cardiologist has to be present at the station to interpret the transmitted ECG reports. Nevertheless, it is not always the case that a senior cardiologist stays in the hospital. When a patient needs immediate treatment and medical staff needs to consult a cardiologist who is physically away from the hospital, current 12-lead ECG telemedicine system cannot provide this cardiologist with patients’ historic ECG records, lab test results, or medication records. Consequently, medial services are greatly compromised.
To resolve the aforementioned problems, we developed a series studies in 2009 and 2010 as illustrated in Figure 1. In these studies, we improved the traditional 12-lead ECG telemedicine through the use of mobile computing [6, 7, 18]. In these studies, the off-site cardiologists can ubiquitously use their cell phones implemented with mobile database to connect with hospitals’ database and to access patients’ ECG e-reports and medication records stored in HIS, so that they can offer timely assistance to the on-site Emergency Department (ED) physicians to deliver the most appropriate intervention. The clinically-used 12-lead ECG instrument is also transformed into a portable device that can be installed in an ambulance. The emergency medical technician (EMT) in the ambulance can use a cell phone equipped with Wi-Fi and 3G wireless telecommunication modules to deliver ECG to the hospital and the cell phones of off-site senior cardiologists in real time. It should be noted that the transmitted ECG report from an ambulance is then integrated in PACS and HIS system, so that off-site cardiologist can rapidly perform pre-hospital diagnosis with sufficient references and reduce the “door-to-balloon” time, which means the time elapses starting from the patient’s arrival in hospital and ending when a catheter crosses the blocked coronary artery. The mobile computing based 12-lead ECG telemedicine as compared to the traditional ECG telemedicine has great advantages because it is mobile and easy to use. More importantly, this system ensures rapid transmission between devices outside and inside the hospital, and it enables off-site senior cardiologist to ubiquitously access 12-lead ECG reports and offer timely decision making support.
Based on recent investigation in 2011 [19, 20], there are three major challenges in 12-lead ECG telemedicine, including (1) How can a patient’s 12-lead ECG measured in a moving ambulance or obtained at home be transmitted to the admitting hospital with rapid and effective pre-hospital diagnosis ? (2) How can the medical staff in rural areas use an open and public tele-cardiology system to consult experienced cardiologists in real time to improve treatment in emergency situations? (3) How to set up an open platform for researchers to perform large-scale 12-lead ECG clinical trials? In addition, 12-lead ECG interoperability is crucial to emergency telemedicine, especially if a patient with acute myocardial infarction is referred from one hospital to another hospital. When the cardiologist can interpret both current and past ECG from the previous hospital via shared medical system, repeated ECG examinations can be reduced and the patient’s treatment plan can be established appropriately and efficiently. However, 12-lead ECG interoperability is difficult to establish because of the heterogeneous HIS and ECG data formats [21].
The present challenges of 12-lead ECG telemedicine include not only to improve the services of a single clinic but also to strengthen the collaboration among clinics such as inter-hospital ECG interpretation. A promising method to develop inter-hospital 12-lead ECG telemedicine is to use cloud computing technology providing hospitals with a common platform with easily accessible computing resources and storage space on demand via internet and a low-cost pay-per-use model without long-term commitment.
Cloud computing, pervasive computing, and telemedicine
Cloud computing refers to the software application delivery service via web access among different computers with heterogeneous O.S. [22]. The cloud providers, who own large datacenters composed of a large amount of computers with internet link, provide users with the environment of data storage and software development with abstract management of computing resources in the datacenters. The user-developed applications in the cloud can be registered as services to the public. An individual or an organization can subscribe the cloud services to use the applications via web access without any hardware or software installation on-premise computers. Many applications, such as web hosting, data archiving, large-scale simulations, and social networking, can benefit from its features, including easily accessible computing resources and storage space on demand, networking, and high performance computing. Recent studies indicated that cloud computing can improve healthcare services and benefit biomedical research. For instance, a cloud computing based Voice over IP (VoIP) service for diabetic patients’ self-care management is created in 2010 by Piette and his colleagues [23]. The patients subscribing the cloud service received VoIP calls with pre-recorded voice messages as self-care reminders. In this study, the participants obtained better glycemic control than the patients without subscribing the service. The advantages of this cloud computing based healthcare service are cost effective, and it can be extended globally with ease. Recent studies also indicated that cloud computing can facilitate the biomedical informatics research communities, which need large-scale shared data and computational tools. Fusaro and his colleagues (2011) used high performance computing of Amazon Web Service to facilitate genomic findings [24]. There was other research proposing concept framework to improve healthcare services through the collaboration of cloud computing and mobile computing. For example, Nkosi and his colleagues (2010) proposed cloud computing based framework to improve deficient mobile devices used for healthcare services, including computing capacity, memory, and power consumption [25]. In this study, the mobile devices were used to acquire physiological signals, which were processed with massive computing resources. To relieve heavy execution and avoid power loss of mobile devices, the acquired physiological signals were redirected to a cloud service performing signal processing. The mobile devices then automatically received the results if the cloud service finished the job of massive computing of signal processing. This technology can benefit patients living at home whose physiological signals need to be monitored continuously, as their cell phones can transmit their physiological signals to a cloud service, which is responsible for signal processing, and remote physicians can access the results via web with a desktop computer or a cell phone. An industrial project of cloud computing based tele-homecare service is setting up by IBM, several European academic, research organizations, and hospitals. In this project, the patient’s vital signals can be monitored at home, and patients’ medication records are stored in a centralized cloud database. The physician can use the cloud platform to diagnose patients at home, the patients can access their medical records via this cloud service, and pharmacy administers can monitor and control the use of drugs [26].
The objectives of this study
This study aims to develop an effective model of 12-lead ECG telemedicine to overcome the challenges of 12-lead ECG telemedicine described in Sec. of 12-lead ECG telemedicine and pervasive health. The objectives of this study are as follows, (a) to facilitate inter-hospital 12-lead ECG tele-consultation, (b) to practice pre-hospital diagnosis, and (c) to enhance the interoperability of 12-lead ECG records among urban hospitals and rural clinics without the costly installation of additional 12-lead ECG telemedicine equipment.