March 2009

Insight into telemedicine instruments : Lieutenant Colonel Salil Garg, Cardiologist, Command Hospital, Pune and Squadron Leader Mudit Mathur, DD Space Ops, DSCC, Bhopal

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This is the second in a series of three articles on Telemedicine contributed by the authors.

Telemedicine has the potential to significantly change the delivery of healthcare. Today doctor-to-doctor or doctor-to-patient interaction through mobile telephony is routine, and with the advent of 3G networking even transmission of heavy images to handheld devices are possible.

However, the most accurate diagnosis and carefully planned treatment may fail, if there is a breakdown in the interpersonal skills necessary for communication. Therefore, patient satisfaction constitutes a crucial aspect of quality care. If clinicians are not comfortable with the technology or find that technology decreases their control over patient care, they may avoid using it, thereby precluding other benefits of telehealth. Clinical acceptance of a telehealth application may depend on the degree of confidence the clinician has in his or her clinical findings as well as the clinician’s satisfaction with the encounter in the absence of proximate, tactile interaction with the patient. Most doctors are most comfortable dealing with patients upfront. This maybe a habit of training and it is expected that younger doctors are more comfortable than their peers when dealing with faceless patients.

Telemedicine Instruments

From a rudimentary beginning with telegraphic or telephonic consultations to more advanced information and communication technologies (ICT) tools of today, telemedicine has been trying to keep pace with technology, which has consistently been outpacing its usage. By the time a technology can be adopted, it gets outdated.

Telemedicine and health information networks allow healthcare providers, payers, employers, pharmacies, laboratories, and other organisations to share patient data, financial data, and clinical data. Real time interactive audio and video connections may be essential in some situations, whereas telephonic consultations may prove satisfactory for others.

In most cases, the needs, options and cost of the service provided play a major role in deciding the technology to be adopted. Two different sites of an organisation may need two different technologies. For example, a consulting radiologist or dermatologist may need a very sophisticated and expensive display unit that is capable of showing fine high-resolution images, but for an attending physician lower resolution may be sufficient to support discussions of an image with a consultant or with a patient. A central consulting site will need significant radiographic storage capacity while the remote site may need very little. Hence, different telemedicine applications may involve quite different combination of technological configurations according to the organisational objectives in terms of equipment use and space requirement. Since the technology changes at a rapid pace, these complex issues of advanced technology usage make formidable demands on selecting the proper hardware and software options. The need to develop a variety of communication links with other organisations differs in the capacities and configurations of their systems.

A classical telemedicine clinical consultation would have the following four components:

  • Initial history taking – accomplished through an interactive audio video consultation and data exchange.
  • Physical examination – done directly with or without consulting over the media using audio capability and followed by additional data transfer related to the exam. Different medical peripherals may be used to acquire signals from auscultations. These are transferred in waveforms or as stills.
  • Investigations – radiological and pathological examinations done and images transferred – evaluation of the acquired data images is carried out.
  • Analysis and management – depending on the analysis of the data, a diagnosis is reached and a treatment plan devised and followed.

The core equipment traditionally needed for a telemedicine services are:

  • Integrating Platform – a powerful computer
  • CODEC – a technology that is required for transmission of video images. A CODEC compresses and decompresses the images transmitted.
  • MUX – a multiplexor to combine the communication lines to get the higher bandwidth.
  • Net Terminator – a device required at the point of termination of the ISDN lines.
  • Higher bandwidth providing lines are preferred, as the files of enriched medium that need to be transmitted is very large e.g. ISDN.
  • INPUT devices are such as camera, scanners, and other medical peripherals that enable the system to capture information during the clinical encounter.
  • An application software to integrate the data from the different sources
  • Robust operating system.


Devices are required which can capture and manipulate data so that it can be transmitted over the communication channel. These devices differ according to the necessities of the examination, and the consultant site but may not be absolutely sacrosanct as enumerated in the tables.

Specialised medical equipment for telemedicine application

Bandwidth Demands: Both audio and video transmissions require high bandwidth usages, which are as under.
Audio Signals: Voice – normal 64kb/s (16-32kb/s), Hi – fi – 1.4Mb/s (192kb/s)

Thus voice and low-resolution images need lower bandwidth from 10 KBPS to 100 KBPS, whereas high definition images, audio-video conferencing and VCD, SVCD, DVD quality video require higher bandwidth between 100 KBPS to 10 MBPS. Multimedia file transfer, broadcast video HDTV and visualisation requirements may go up to even 1 GBPS.

One of the suggested methods is restructuring or manipulating information before it is sent on transmission media. Compressing data by ‘loss less’ compression technology increase communication capacity and reduce bandwidth. Digital data packet switching technologies can also be used for fast transfer of large data. Integrated Service Digital Network (ISDN) protocol can be used for standardised high-speed digital transmission of integrated audio, video, and data signals. The major benefit of ISDN is that it brings high bandwidth into homes and offices without the high expense of rewiring them to connect with the rest of the  telephone system that is mostly digital. It has been amply proved that by appropriate installation, it is possible to improve interaction and provide quality healthcare.  The entire scenario is about to undergo a big change. There could be wireless microwave technologies such as wireless local loop, communications satellite systems, stratospheric floating communications platforms, fiber-optic cables, cable modems, coaxial cables, or digital subscriber lines, smart antenna technology and software-programmable radio technology. All of these may substantially improve system performance.

Broadband communications and open source

Nowadays most of the emergency equipment has started incorporating broadband communications. There is now greater emphasis on implementing operating systems in all types of devices, from portable monitors to complex, life critical equipment. However, as far as more complex or critical equipment is concerned, the use of commercial off-the-shelf (COTS) components, including software components such as operating systems is less well defined than in the military or aerospace industries. Proprietary operating systems are still widely used in high end or patient critical equipment, presenting barriers to future improvements in cost, time to market, functionality and interoperability.

A set of operating systems based on the UNIX framework and enabling easy migration and design reuse by conforming to the POSIX API standards provides a scalable platform for developers. In addition to saving time in software development, application reuse also eases certification. The POSIX standards define an open operating interface that promotes code portability between systems. Only systems that are POSIX Conformant � thereby meeting all of
the profiles can guarantee code portability without modification. LynuxWorks’ LynxOS families of operating systems are POSIX Conformant and feature a native POSIX API, enabling portability of open standard Linux applications across all systems. This also gives engineering teams the flexibility to develop applications on a low cost Linux system, then migrate the application to the optimum OS for the end product.Ultimately, the target may be a hard real time system, such as LynxOS, or a security partitioned system such as LynxOS-SE that allows multiple real time applications to run concurrently. While taking advantage of established Windows and Linux media capabilities to stream video across a network connection, other systems running in separate partitions will manage secure access to patient records or patient critical aspects such as control of surgical instruments. A separation kernel, such as the LynxSecure hypervisor, achieves this by allowing virtualisation of several guest systems to operate in separate partitions. Multiple dissimilar systems, including BlueCat Linux systems or ordinary desktop systems such as Windows XP, can operate alongside more robust systems such as LynxOS or LynxOS-SE.

As the medical community adopts reference standards from the aerospace and military sectors to promote the use of COTS components, including software, certified operating systems that also support open standards will allow developers to deliver increasingly robust and feature rich products to market quickly and cost effectively


Benefits Fewer bugs. Open-source software tends to be more reliable. Just as medical discoveries prove their value through peer review, open source software is validated by thorough inspection by programmers outside the medical software’s development team.

Reduced overall cost. The overall cost tends to be lower because development is distributed among many users.

Improved evaluation. Measurements of quality applied to proprietary software are not exact because evaluators do not have access to the source code. With open-source software, outside reviewers can determine not only whether a particular piece of software works, but also the difficulty of the problem it attempts to solve.

Infinitely supportable/customisable. When the source code is available, the problem of ‘vendor lock’ disappears. As long as programmers can be hired, the software can be customised and supported.

Despite the many advantages of the open source development model, there are challenges to overcome. First, there are few medical open source projects that are beyond the prototype stage. This lack of large scale, open source medical implementation introduces doubt as to open source’s feasibility in the medical arena. Another problem with open source projects is that implementation often requires a great deal of technical expertise.


A recent editorial in the BMJ discussed the future of free medical software. It gave the staggering statistic that the government in the United Kingdom spent �7.1bn on information systems in 1998-9, of which �1bn was in healthcare. It concluded that ‘free software concepts make particular sense in medicine: … medical knowledge is becoming more open, not less, and the idea of locking it up in proprietary systems is untenable.’

This article generated a large number of responses and much debate.

The common software that is used today for telemedicine application is the Picture Archiving and Communication System (PACS). In some places the software is purpose built and designed by the service providers. Some COTS software packages are also available and are designed specifically for telemedicine application. This kind of software is basically used in applications such as teleradiology, teledermatology, telepathology and monitoring of vital signs.

Our current method of producing medical software requires revolutionary change in order to meet the needs of today’s patients, providers, and healthcare administrators. The open source software development model has the potential to deliver inexpensive software of higher quality than can be provided by proprietary vendors. There are several ways in which the open source software development model addresses the needs of the medical community most adequately.

Medical Linux operating system designed exclusively for medical networked applications

There is now growing awareness that taking this technology into the healthcare environment can contribute to disease prevention and speedier diagnosis, while improving patient comfort and convenience. Improvements in software design are central to delivery of these advances. Developers need more flexible and robust platforms on which to build sophisticated features, such as graphical user interfaces to promote ease of use. Scalability is also growing in importance as vendors seek to extend their product ranges, leveraging existing applications, and core competencies. Increased use of networking technologies to access patient records is also focusing developers’ attention on data security capabilities, as well as greater reliability and robustness to deliver devices that can simultaneously perform patient critical functions such as monitoring vital signs or supporting respiration. There is also a growing awareness of the benefits of ‘plug and play’ interoperability between instruments, as user communities seek to create systems based on standards to improve patient care and boost efficiency.

Telemedicine pre-purchase evaluation

While purchasing equipment/software/telecom services, a thorough assessment of the following is desired:

  • Does it meet all current and emerging standards for interoperability/data exchange?
  • Does the design optimise the available telecommunications infrastructure?
  • System appropriateness – Have all technological options been considered?
  • Does the system allow for upgrades and can it communicate with other networks? (Stay away from proprietary hardware and software, use “open systems”)
  • Can it be operated and maintained with available resources? (In house versus outside technical support)
  • Can it be easily used by clinicians and patients?
  • Can it generate sufficient revenue or achieve sufficient cost savings to cover telecommunications charges, equipment depreciation, maintenance and other system-related costs?
  • Is it proven to work in the project setting? (i.e., space, lighting, acoustics, ease of use)
  • Vendor and telecommunications service contracts, extended warranties, where appropriate. What is the maximum “down-time” when a system malfunctions?

Measure of physician satisfaction with telemedicine technology is important and one needs to answer questions such as the following:

  • How would this situation have been handled without telemedicine?
  • How was the patient’s care affected by this encounter?
  • What is the next step for the patient in terms of future care for this problem (e.g., continue with current care, referral, and admission)?
  • Did current experience make it more or less likely that you would use telemedicine in the future?


All in all the application and success of telemedicine broadly depends on end users – the patients and physicians. There is a strong need for educating and familiarising physicians with the new medium, since it is up to them to see that the patients are made comfortable in such an environment. The technical team who maintain the systems and application software too must be dedicated towards keeping everything in order.

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