An MD&DI June 1997 Column
Although telemedicine was first envisioned as an aid for the general practitioner, it has so far been successful only in bringing together medical specialists. What is the current state of this technology, and what can we expect in the future?
When it was in its infancy just a few years ago, telemedicine was envisioned as a revolution in health-care information delivery for general practitioners. Yet its promise for general medicine has yet to be realized. Instead, this technology has been used so far in the medical specialties only, where there is a need to bring together a relatively few qualified doctors, who may be separated by large distances.
Maureen Ryan of VTEL (Austin, TX) says telemedicine is now used in specialties where it makes "financial sense."Photo courtesy of VTEL
For example, videos of patient skin, inner ears, and internal tissues obtained through endoscopes are sent out among specialists for consultation. Even the telemedicine systems that are currently installed in patients' homes send data only to specialists. Electrocardiographs are sent to be examined by cardiologists and the vital signs of low-birthweight infants are sent to neonatologists.
"As we move from a fee-for-service environment to managed care, it is all about productivity and preventive medicine and keeping the patient out of the hospital," says Maureen Ryan, health-care program manager for VTEL (Austin, TX). "The specialties where telemedicine is being applied are those that make the most financial sense," she adds.
THE TECHNOLOGY TODAY
VTEL, which recently bought competitor CLI (San Jose), is one of several commercial companies that are now jockeying for position in the telemedicine market. These companies include PictureTel (Andover, MA), Mystech Associates (Manassas, VA), and Multimedia Medical Systems (MMS; Charlottesville, VA), which recently bought competitor md/tv. The academic institutions in the forefront of telemedicine research are the University of Washington (Seattle) and Pacific Northwest Laboratory (Richland, WA), which is a national laboratory operated by the Batelle Memorial Institute for the U.S. Department of Energy.
There are two types of telemedicine technologies: real-time interactive systems and store-and-forward systems, which first record and then send patient data to a remote site for interpretation. Interactive systems provide instantaneous consultation by physicians across the state or across the globe. But this means physicians must be available at the same time. In the increasingly hectic world of health care, coordinating schedules for such consultation is difficult. This difficulty has led some developers to choose store-and-forward systems, which can be thought of as very sophisticated E-mail systems whose messages are electronic folders or directories that contain patient data. This data can include demographics, video and audio clips, and medical images such as magnetic resonance, computed tomography, and x-rays. The folders' contents can be examined at the convenience of the recipient.
MMS offers both types of telemedicine systems. CareLink is the company's interactive system, which delivers separate but simultaneous medical images and data, as well as videoconferencing to desktop computers. CaseReview captures, annotates, stores, and then forwards medical information in an electronic patient record.
These and similar products are finding their places in today's health-care system. MMS products, for example, are being used to support such specialty applications as renal dialysis and ophthalmology.
Companies typically are customizing their general-purpose telemedicine systems. For example, CLI offers videoconferencing systems that have been tailored to be used in a wide range of specialties. The systems have been developed to address cardiology; dermatology; ear, nose, and throat medicine; emergency or trauma medicine; internal medicine; nephrology; neurology; gynecology; oncology; orthopedics; pathology; pediatrics; psychiatry or psychology; radiology; surgery; and urology. The company has installed these systems in medical centers across the United States, including at the Bowman Gray School of Medicine, Kansas University Medical Center System, and the Medical College of Georgia.
Aside from using medical instruments such as endoscopes and electronic stethoscopes, these customized systems employ the same components that mainstream videoconferencing products use. The TeleProvider telemedicine workstation by Mystech, for example, uses a Pentium PC; a Windows NT or Windows 95 operating system; a high-speed communication line such as ISDN, T1, T3, or ATM; and Netscape, hypertext, and Java applets. These components, along with a video camera and an endoscope or electronic stethoscope, are tailored to meet the client's requirements. "We have to search for and test components to make sure they will meet the clinical requirements," says Mike Daconta, chief developer for TeleProvider. Which component is appropriate in a given situation "is very subjective, depending on the specialty and the ailments being addressed."
TeleProvider, like many other such products, does not have characteristic packaging. Its components are simply spread out over a desktop or table.
Some equipment developers have packaged their products for medical use. FRED (Friendly Rollabout Engineered for Doctors) from VTEL, for example, is packed into a cart that rides on casters and is encased in "scrubbable" stainless steel. Data and video ports interface with endoscopes, Dolby stethoscopes, otoscopes, ophthalmoscopes, and ECG machines. "The idea was to integrate these components into a whole product and run it from a simple interface," says Ryan. "FRED allows physicians to use their clinical tools in an environment that is merged with videoconferencing," she adds.
Because virtually all vendors of telemedicine equipment depend heavily on off-the-shelf hardware, the main challenge of building telemedicine systems is integrating the components and making them work in a cost-effective way.
Another major engineering challenge is making the information accessible. Early telemedicine systems brought to market in the early 1990s were point-to-point systems, meaning that each physician had to view the information without the advantage of viewing it in groups. Today, engineers are increasingly adapting technology to practitioners' need for group participation. Data sent from one point are being channeled into networks. In July, MMS plans to release a Windows NT server that will disperse data throughout a medical institution to allow access from many different sites.
Other companies are focusing on the Internet and institution-specific intranets to disperse information. Mystech engineer Daconta notes that TeleProvider packages data using Java, which is rapidly becoming a standard for Web-based products. As a result, TeleProvider data can be accessed using common Web browsers such as Netscape or Microsoft Explorer. "The point-to-point model is not practical," Daconta says. "Telemedicine won't work until it is ubiquitous and easy for the doctor. Using Java, we can get data onto many of the desktops within an organization."
Resolution is another major concern in telemedicine, particularly when diagnosis relies heavily on images. The use of video for diagnostic purposes, as in the case of dermatologic and endoscopic images, presents special concerns.
Building on software developed to improve the quality of images from space probes, the NASA Ames Research Center (Moffett Field, CA) has a software package that promises to improve both the spatial and gray scale resolution of video images by using images of the same area from slightly different perspectives. "If the camera moves even just a fraction of a pixel, it's an independent sample of the same area," says Peter Cheeseman, an Ames research scientist. "And it's the combination of all those independent samples that allows you to get the super resolution."
Audio technology also presents a challenge for telemedicine. Current systems are typically monaural rather than stereo. If telemedicine is to achieve its potential for providing expert advice in complex environments such as busy operating suites and emergency rooms, a more realistic conveyance of sound will be necessary. In the modern operating room, for example, there is a cacophony of auditory cues from many different diagnostic and monitoring systems. Surgeons and nurses depend on these cues to monitor a patient's status. Remote physicians will need to identify the origin of each sound.
The solution to audio limitation may already be in hand, as an outgrowth of work that is currently being conducted at the Spatial Auditory Displays Laboratory at NASA Ames.
Durand R. Bequalt, PhD, a research scientist at the laboratory, has developed a system for localizing noises by providing three-dimensional sound over headphones. "Various things have different alarms, but a lot of them sound very similar; the sound of a heart machine might seem the same as the sound of another machine," Bequalt says. This technology may also be useful for patient consultations by spatially separating the voices to determine who is speaking. Standards that define which types of alarms are used on specific types of machines would also help remote physicians identify sounds.
TELEMEDICINE OF THE FUTURE
Although hearing and sight are the only senses used in telemedicine today, they may not be the only ones used in the future. Odors can sometimes play an important role in diagnosing conditions such as infection, a perforated bowel, or a nicked bile duct.
Engineers at the Pacific Northwest Laboratory have developed TeleSmell, a prototypical system that would use an electronic nose to capture the essence of odors, encode and transmit the data to the telemedicine site, and then use a decoder to reconstruct the odor for the consulting expert to smell.
Alternatively, a neural network might be introduced to analyze the odor for the operator, negating the need to reconstruct it remotely. Such systems are still in their infancy, however.
Federal laboratories, such as Pacific Northwest, tend to address the most sophisticated technologies. That is especially true when national security is involved. The Defense Department and NASA are backing a number of initiatives that could provide a quantum leap in the definition of telemedicine.
ATL (Bothell, WA), in collaboration with the University of Washington, is leading an effort to develop a telemedi-cine system that would relay video and diagnostic ultrasound images from a trauma scene to a remote medical command post where emergency-care specialists would guide the examination. "Patients could be triaged quickly, and a decision could be made about whether they should be transported for interventional therapy such as controlling hemorrhage or dealing with injured organs," says William Shuman, MD, a clinical professor who specializes in trauma care at the University of Washington.
The ultrasound scanner for this system would fit in the palm of a medic's hand. Its development is being sponsored by the Defense Department and a consortium that includes ATL, the University of Washington, Harris Semiconductor (Melbourne, FL), and VLSI Technology (San Jose). A commercial product may be in hand by 2000.
Similarly advanced and potentially useful research is under way at NASA. The space agency was arguably the first organization to embrace telemedicine. "Ever since the beginning of manned spaceflight, we have monitored the health of our crew members," says Roger Billica, MD, chief of medical operations for NASA at the Johnson Space Flight Center in Houston.
Besides daily private medical videoconferences between the crew surgeon and shuttle crew members, ground crew members are also monitored on video. Parameters monitored include ECG, heart rate, oxygen consumption, heat production, and suit carbon dioxide levels.
Extended stays in orbit, such as those anticipated onboard the international space station, require a more sophisticated system for rapid diagnosis of illness. NASA has developed a suitcase-sized package, called the telemedicine instrumentation pack. It contains an endoscope, ophthalmoscope, dermatology macroimaging lens, ECG, automatic blood pressure sensor, electronic stethoscope, pulse oximeter, and a computer with a two-way voice and video control. The telemedicine pack is scheduled to be placed on the shuttle soon.
Efforts aimed at the battlefield and exotic environments such as space might be adapted to civilian use. University of Washington researchers and their colleagues at ATL already envision a battlefield triage system for use by paramedics aiding accident victims. And NASA is looking for commercial companies that might license its telemedicine kit for down-to-earth applications. "You could carry it anywhere, like a suitcase," Billica says. "Just plug it in, do an exam, hook it into a network, and have the physician on the other end participate in a basic physical examination."