A text message a day might just keep the doctor away.
With more than 2 billion cellphones already in pockets across the world and wireless networks growing faster and more capable each year, mobile technology offers a powerful new platform to deliver healthcare.
Researchers are finding ways to turn the mobile phone, known as a medium for trivial interactions, into a serious tool. There are text messages that remind people to take medicine and measure compliance; cellphone snapshots that could help diagnose disease; and wireless technology that can create a live two-way video link, streaming the scene in an ambulance to a trauma team.
"A key to this is how do you deliver information, which is what a diagnosis is - at the lowest possible cost," said George Whitesides, a Harvard University chemist who coauthored a paper in the journal Analytical Chemistry this month in which the simple camera phone turns diagnostic tool. "The problem, particularly in the developing world and at rural clinics in the United States, is you don't have enough people - you can't have a trained doctor travel 200 miles to do a simple test."
Whitesides envisions the cellphone as a catalyst, helping bring expert medical opinions and tools usually avail able only at well-equipped hospitals and doctor's offices into the field.
Special strips of paper could test for disease or contamination in people, livestock, and plants and then be photographed with a simple cellphone camera to replace more complex equipment. Minimally trained people in the field could collect samples and send results to experts who could use a pattern of colors to diagnose a disease and prescribe a treatment from afar.
In Whitesides' study, researchers at Harvard and in Brazil proved the concept was viable, creating a strip of paper sensitive to levels of glucose and protein commonly used to diagnose kidney diseases, which they successfully evaluated by cellphone photo.
But the wireless infrastructure that cellphone companies have spent billions to build and maintain offers other opportunities, too. At the Massachusetts Institute of Technology and the Nokia Research Center Cambridge, researchers are using existing wireless networks to create technology that could link specialists and emergency responders.
Building a network to carry high-quality, two-way video would require extensive investment for a hospital, said John Guttag, an electrical engineering and computer science professor at MIT working on the technology. But the problem with using existing wireless networks is already familiar to anyone with a cellphone: Individual networks have dead spots, and may be too slow.
The researchers devised software that sends a video much like what people see on television, but using infrastructure that already exists in a typical urban environment - a slew of different wireless providers. The software scans nearby wireless services and sends the data through a combination of the channels to overcome the limitations of a single network.
The researchers hope to deploy the technology in a field trial this year. A trauma team could use the technology to tell emergency responders to begin a course of treatment en route, or simply have a team of specialists ready when the ambulance arrives.
Already, some medical centers use two-way video feeds to connect stroke patients at a remote hospital with specialists; but the technology could bring that expertise directly to the ambulance, which could be crucial for a condition where time is of the essence.
"The notion was could we do it just using the infrastructure that was already there," Guttag said. "I don't have to maintain those networks, the hospital doesn't have to maintain those networks, and furthermore we know those networks are only going to get better" as technology and demand continue to progress.
Another team of researchers last month published a paper in the online journal, Public Library of Science ONE, showing that a Palm Treo 700W could be used with other equipment to image simulated breast cancer tumors.
The cellphone was used to transmit raw data from a biosensor to a processing facility and then display the results on a screen, opening the possibility of bringing medical imaging to people without access now.
Cellphone telemedicine offers the tantalizing possibility of expanding the immediacy, range, and efficacy of medicine in new ways, but business models will have to shift before such systems take off, according to Steve Tobin, a senior industry analyst at Frost and Sullivan.
Ultimately, he said, the challenge to new technologies will not be technological limitations, but the current healthcare infrastructure.
"The big thing that's always plagued the telemedicine industry is reimbursement - the ability to get reimbursed and paid for service," he said. "You're looking at a new way to grab data in what's really been an insular environment - inside the hospital."
Even so, cellphones are already beginning to eke out a niche next to the stethoscope.
Partners Home Care began a pilot program using digital images to help diagnose wounds in 2002. Home care nurses took a digital camera on visits and nurses who had been specially trained in wound care could examine images of wounds.
But even with digital images, the process wasn't efficient and could take days, according to Doug McClure, corporate manager for operations and technology for Partners HealthCare's Center for Connected Health. The group began to experiment with phones.
"The mobile phone is really intriguing to us, just from an ease of use kind of handle. The way we've been able to deal with the mobile phone is all-in-one. Snap a photo, you can send it automatically, you don't have to hook a cable into anything," McClure said.
But ultimately phones carried by hundreds of millions of healthy people may offer a bigger opportunity.
Verizon Wireless last month said it would offer Pill Phone, a service that allows people to look up drug interaction over their phone, as well as schedule pill reminders.
SexInfo, a sexual health hotline aimed at teens in San Francisco, allows teens to find clinics and basic information just by sending text messages. Other researchers are eyeing text messages as an ideal way to send reminders to diabetic patients.
Researchers at the Center for Connected Health and local hospitals experimented with text messages to remind dermatology patients to apply topical medicine and test their compliance. To monitor patient behavior, they developed a special monitoring cap for sunscreen that sent a time-stamped text message to a server every time the tube was opened. Patients also received daily text messages informing them of the weather and reminding them to apply the lotion.
"An incredible set of services and connectivity are enabled by [cellphones], and we all are married to them now," McClure said. "The opportunities for mobile phones are beyond imaging - it really moves to how do you get people to do a better job of taking better care of themselves."
Carolyn Y. Johnson can be reached at firstname.lastname@example.org.