Telemedicine Delivered by WiMAX

By: Nirupam Mishra, Ratna Dileep Kumar, and Yugandhar. G., Ordyn Technologies Pvt Ltd
( 1 Jan 2009 )

In the past few years, telemedicine, or the use of communications networks in the exchange of healthcare information to enable clinical care, has become an important tool in providing efficient healthcare. The availability of an efficient and modern broadband telecommunications infrastructure has driven the growth of real time telemedicine applications.

In developed countries, telemedicine applications serve as "virtual transportation", which enables the ability to keep a patient where he is, yet being able to provide the appropriate medical care remotely. In critical situations, this can be vital to the patient's survival and quality of life. In resource poor countries, telemedicine improves care and enhances access to healthcare by linking patients, doctors and hospitals using communication technologies like ISDN and POTS lines. Such connections enable an easy exchange of clinical information. In doing so, telemedicine is able to make a profound impact on the healthcare situation in developing countries.

Healthcare services in developing countries like India remain a challenge. Factors that impede efficient delivery of healthcare services include: inadequate health infrastructure and clinical services, the outflow of doctors to the developed world, and the lack of training facilities.

Over 80 percent of India's main healthcare centers are located in cities that host only 30 percent of the population. This leaves just 20 percent of India's healthcare facilities to cater to almost 70 percent of the population. Furthermore, there is a limited number of qualified doctors and an almost non-availability of specialists and specialist care in these regions. Hence, India's rural population is more vulnerable than its urban counterpart.

HOW DOES TELEMEDICINE WORK?
When the patient and doctor require a second opinion, they use a software to consolidate the clinical information (on the patient) into an Electronic Patient Record (EPR), which they will use to refer to when they make the tele-consultation with the specialist. Once the connection to the specialist is established, the electronic patient record is uploaded. Using the software, the specialist then examines the clinical information, and suggests a course of action. If necessary, the doctors on both ends may arrange for a video conference to arrive at a diagnosis in a collaborative manner and decide upon the course of treatment. This advice is then formalized after the specialist sends back his opinion to the patient and doctor. The information transferred in a telemedicine exchange may include live bidirectional audio or video, recorded audio or video sent after the encounter ("store and forward" technology), medical records, medical images, sounds, or output from medical devices such as pulmonary function instruments, electrocardiographs, and ultrasonography devices.

Certain services seem well adapted to telemedicine, including:
• Radiology
Radiology reports can be forwarded by using secure, low bandwidth messaging systems
• Mental Health
Providing remote psychiatric counselling to mentally-ill patients using videoconference
• Cardiology
Cardiology has already widely embraced telemedicine. Electronic stethoscopes can facilitate the transmission of heart sounds with excellent fidelity. Echocardiograms, ultrasonographic images, electrocardiograms, and other images can readily be transmitted electronically and evaluated accurately as part of established telecardiology programs.
• Emergency and Transport Services
Teleconferencing provides a way by which practitioners in a remote area can receive real time emergency consultations with acceptable diagnostic sensitivity and specificity
• Hospital Care and Family Communications
Families separated from their infants can keep updated on their infants' condition and view images of their infants while they are in the neo-natal intensive care unit
• Patient Education & Chronic Disease
Patient education via teleconferencing to teach the proper use of asthma medications, childhood diabetes, etc
• School Health
Some school systems are experimenting with telemedicine links to extend the range of services in school clinics and decrease absenteeism for illness or disease management encounters
• Home Health/Telemonitoring
Health care professionals can remotely monitor a patient's vital signs, pulmonary function, or glucose concentration and then communicate with the patient to direct care by telephone, computer, or television monitor

UBIQUITOUS COMPUTING TELECARDIOLOGY
New wireless technologies for tele-cardiology give new possibilities for monitoring vital parameters with wearable biomedical sensors, giving the patient the freedom to be mobile while being under continuous monitoring. The implications and potential of wearable cardiac monitoring technologies are significant, since they can do the following:
• Detect early signs of health deterioration
• Notify healthcare providers in critical situations
• Find correlations between lifestyle and health
• Bring sports conditioning into a new dimension by providing detailed information about physiological signal under various exercise conditions
• Provide doctors with multi-sourced, real-time physiological dataThe major design requirements of a mobile unit include the following:
• portable and lightweight
• power autonomy of a few hours
• user-friendly interface
• collection and display of critical bio signals
• very low failure rate and highly accurate alarm triggers, especially if used for diagnostic purposes
• reliable real-time wireless data transmission anytime anywhere in any form

Problems have likewise emerged in ubiquitous computing, specifically in the following areas.
1. Embedded systems
• Both vital sensors and base stations have to be wearable to ensure mobility and attention
• Attention has to be paid to the body placement, human movement, weight, size, and other constraints
• Reduction of power consumption relative to the increase in the performance of processors, memories, and other components

2. Networking
• Providing ubiquitous access to central information services
• Lower power consumption, ensuring high level of security
• Extensive interoperability features
• Integrated functionality such as service discovery, self configuration, encryption, and authentication
• Protection of privacy and communication security considering mobile Internet connections

3. Context awareness
• Personal identification, personalized health monitoring systems provide functions such as reminder services or medication support, depending on measured vital signs and individual disease patterns. The data should travel reliably to the remote nurse or physician.
• Time: Timing synchronization of distributed sensors

There are also a number of limitations in some of today's existing wireless technologies like general packet radio service (GPRS) in deploying telemedicine applications. These relate to the following: the lack of an existing flexible and integrated "m-health-on-demand" linkage of the different mobile telecommunication options and standards for e-health services. This lack of linkage and compatibility for telemedical services exists due to the difficulty of achieving operational compatibility between the telecommunication services, terminals, and devices standards, and "mhealth protocols".
• The high cost of communication links, especially between satellites and global mobile devices, and the limitation of existing wireless data rates especially for the globally available 2.5G and third generation (3G) services for some e-health services. The availability of secure mobile Internet connectivity and information access especially for e-health systems is likewise another concern.
• Healthcare is a very complex industry that is difficult to change. Organizational changes are very often required for healthcare institutions to benefit from e-health and m-health services.
• The short term and long term economic consequences and working conditions for physicians and healthcare experts using these technologies are not yet fully understood or properly investigated. The methods of payment and reimbursement issues for e-health and m-health services are not yet fully developed and standardized.
• There is a lack of integration between existing e-health services and other information systems (e.g., referral and ordering systems, medical records, etc.).
• The demonstration projects so far have failed to show that m-health services result in real savings and have cost effective potential.

QOS REQUIREMENTS IN MOBILE TELECOMPUTING APPLICATIONS
Based on its delay tolerance, telemedicine data can be classified as stream (e.g., ambient video and audio), conversational (videoconferencing), near real-time, and not realtime. In a medical environment, different data traffic with different classes of quality of service (QoS) requirements have to be transmitted simultaneously.

One of the critical issues that will be discussed is how to optimize network performance to provide medical services with other multimedia services simultaneously. The telehealth data from different patients, who may be widely scattered, will consist of various physiological parameters, text, voice as well as video for diverse chronic diseases. These data must coexist together as well as with other commercial data such as voice, video (streaming or real), multimedia, and Internet. QoS provisioning for the future advanced telehealth monitoring technologies and systems is therefore a difficult proposition as the communication infrastructure must satisfy QoS requirements of different classes of applications.

WIMAX AS A SOLUTION FOR TELEMEDICINE
WiMAX (Worldwide Interoperability for Microwave Access) is proposed as the solution for the delivery of voice, real time video, ECG signals, and medical scans information from an ambulance to a hospital. The QoS constraints for different services are being investigated and the feasibility of using WiMAX technology is being demonstrated.

WiMAX is a technology that provides broadband wireless access with the services having different QoS. It allows the wireless transmission of data in a variety of ways, ranging from point-to-point links to point-to-multipoint and full mobile cellular type access. The technology is based on the IEEE 802.16 standard (also called Wireless MAN). There are two types of mode supported by IEEE 802.16. These are Point-to-Multipoint and Mesh mode.

The Point-to-Multipoint is easier to implement and is cost effective. Hence, people in developing countries like India are focusing on the Point-to-Multipoint mode of implementation. The IEEE 802.16e has the Point-to-Multipoint capability in the 2GHz to 11Ghz band. It has a Non-Line-of- Site (NLOS) capability also, and the PHY used by IEEE 802.16e is Orthogonal Frequency Division Multiple Access (OFDMA), which includes Orthogonal Frequency Division Multiplex (OFDM). With OFDMA, a Subscriber Station or user can simultaneously receive and transmit data, which is one of the basic requirements of Telemonitoring and Telemedicine. The differences between WiMAX, Wi-Fi and 3G are shown in Table 1.

The different QoS service types provided by WiMAX are:
1. Unsolicited Grant Service (UGS)
UGS is designed to support real time uplink flows that transports fixed size data packets on a periodic basis, such as T1/E1 and Voice over IP. The service offers fixed size grants on a real time periodic basis, which eliminates the overhead and latency of the Subscriber Station request and assures that grants are available.

2. Extended Real Time Polling Services (ertPS)
The Extended rtPS is a scheduling mechanism which builds on the efficiency of both UGS and rtPS. The Base Station shall provide unicast grants in an unsolicited manner like in UGS, thus saving the latency of a bandwidth request. However, while a UGS allocation is fixed in size, an ertPS allocation is dynamic.

3. Real Time Polling Services (rtPS)
The rtPS is designed to support realtime uplink service flows that transport variable size data packets on a periodic basis, such as MPEG video.

4. Non Real Time Polling Services (nrtPS)
Delay tolerant data streams comprising variable sized data packets for which minimum data rate is required.

5. Best effort Service (BE)
Data streams for which no minimum service level is required and therefore may only be handled on a space available basis.

Meanwhile, a Telemedicine Network requires the following:
1. Interoperability
Telemedicine networks must interface together and create an open environment that enables the sharing of applications on different participating systems in real time or provides for the seamless interface between several applications.

2. Compatibility
Equipment/systems of different vendors and different versions of the same system must be able to inter-connect.

3. Scalability
Equipment/systems must be able to be augmented with additional features and functions as modular add on options.

4. Portability
The data generated by an application that runs on one system can be easily ported to different platforms with minimum effort.

5. Reliability
Telemedicine systems must follow relevant reliability standards for equipment/systems of similar category to ensure the availability of service with minimum system downtime.

All the requirements of a telemedicine network can be fulfilled by WiMAX, because its high bandwidth, various class of services, wireless connectivity with fixed, nomadic and mobile Subscriber Station Interoperability and Reliability features.

Conclusions from a number of telemedicine studies have demonstrated that expert guided treatment have made nurses use more advanced wound care remedies with better healing outcomes and this has led to increased patient satisfaction as a result of a decrease in patient travel and reduced waiting time. Furthermore studies have concluded that it is possible for experts at a hospital to conduct clinical examinations and decision-making at a distance, in close cooperation with the visiting nurse and the patient, all done through telemedicine applications.

In order for a telemedical consultation to be characterized as a viable alternative to a visit to an outpatient clinic, participants must experience the telemedical treatment as satisfactory in terms of:
• how the clinicians/doctors are provided with sufficient and accurate clinical information for clinical assessments so they could come out with the best possible decisions;
• how visiting nurses feel supported and secured during the sessions, and the patient is satisfied with the consultations

Wireless technologies such as WiMAX can promote the wider use and access of Telemedicine especially in developing countries. For telemonitoring and telecardiology applications, hardware used must be reliable as they will be worn for long periods of time in various environments. We have seen that the QoS requirement for various telemedicine applications can be fulfilled by the services provided by WiMAX. Using video conferencing with reliable communication systems can best provide medical services in rural areas of the developing countries like India.REFERENCES
[1] IEEE Std 802.16 2004. "IEEE Standard for Local and Metropolitan Area Networks, Part 16: Air Interface for Fixed Broadband Wireless Access System". 2004.

[2] IEEE LAN/MAN Standard Committee, "IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems". IEEE Std 802.16e 2005.

[3] Jane Clemensen, Simon B. Larsen, Marit Kirkevold, and Niels Ejskjaer. "Treatment of Diabetic Foot Ulcers in the Home: Video Consultations as an Alternative to Outpatient Hospital Care". Hindawi Publishing Corp. International Journal of Telemedicine and Applications Volume 2008. Article ID 132890, 6 pages doi:10.1155/2008/132890.

[4] J. Zhou, X. Shen, and N. D. Georganas. "Haptic Telesurgery Simulation". Proceedings of the 3rd IEEE International Work Shop on Haptic, Audio and Visual Environments and their Applications (HAVE '04). pp. 99¨C104, Ottawa, Canada, October 2004.

[5] A.L. Lage, J. Martins, J. Oliveira, and W. Cunha. "A Quality of Service Approach for Managing Telemedicine Multimedia Applications Requirements". Proceedings of the 4th IEEE International Workshop on IP Operations and Management (IPOM '04). pp. 186¨C190. Beijing, China. October 2004.

[6] C. LeRouge, M. J. Garfield, and A. R. Hevner. "Quality Attributes in Telemedicine Video Conferencing". Proceedings of the 35th Annual Hawaii International Conference on System Sciences (HICSS '02). pp. 2050¨C2059. Big Island, Hawaii, USA. January 2002.

[7] J.C. Lin, "Applying Telecommunication Technology to Health Care Delivery". IEEE Engineering in Medicine and Biology Magazine. Vol. 18, No. 4, pp. 28¨C31. 1999.


CAPTIONS
Figure 1: WiMAX network with telecardiology and telemonitoring systems.
Table 1: Differences between WiMAX, Wi-Fi and 3G.

Click here for the illustrations:

Figure 1, Table 1