Mobile Medicine

Stephen DeAngelis

July 08, 2010

In a previous post entitled Healthcare in the Developing World, I reported the significant difference that even basic healthcare facilities and programs can make in developing countries. New mobile devices are now being added to the kit of medical teams that could one day improve diagnosis and treatment in developing countries as well. For now, however, those devices (even the cheapest of them) remain too costly for use in most impoverished countries. One reason that mobile devices are important for healthcare in the developing world is that the poor often have a difficult time traveling to places where diagnostic medical care is available. Being able to bring healthcare to them can make a difference — sometimes a lifesaving difference. Let’s look at a few of the mobile devices being developed.

“A team of BYU engineers and chemists has created an inexpensive silicon microchip that reliably detects viruses, even at low concentrations” [“‘Lab on a Chip’ that Detects Viruses Developed by BYU Researchers,” Meridian Magazine, 17 February 2010]. The article continues:

“It’s another step toward the goal of enabling physicians and lab technicians to use small chips to test their patients’ samples for specific proteins or viruses. The researchers report their progress in Lab on a Chip, the top scientific journal devoted to the creation of chip-based biological tests. Aaron Hawkins, professor of electrical and computer engineering at BYU and supervisor of the chip design, said that currently, ‘Most of the tests that you’re given are fairly inaccurate unless you have a really high concentration of the virus.’ But because Hawkins’ chip screens for particles purely by size, it could accumulate many particles over time that otherwise might be missed by other tests. The hope is that, if such chip tests achieve widespread use, early detection in the doctor’s office rather than a lab could allow doctors to respond before symptoms arise and damage sets in.”

The article reports that the “chips work like coin sorters” in that “liquids flow until they hit a wall where big particles get stuck and small particles pass through a super-thin slot at the bottom.” When you are talking about viruses, you are, of course, talking about very, very small slots. The article continues:

“Each chip’s slot is set a little smaller than the size of the particle to be detected. After the particles get trapped against the wall, they form a line visible with a special camera. ‘One of the goals in the “lab on a chip” community is to try to measure down to single particles flowing through a tube or a channel,’ said Hawkins. … Capturing single particles has important applications besides simply knowing if a particular virus or protein is present. ‘One of the things I hope to see is for these chips to become a tool for virus purification,’ said David Belnap, an assistant professor of chemistry and co-author on the paper. He explained that a tool like the BYU chip would advance the pace of his research, allowing him and other researchers to consistently obtain pure samples essential for close inspection of viruses.”

The article referred to the “lab on a chip” as “inexpensive.” Cost has been a “huge barrier to making chips that can detect viruses” in the past. For example, it costs about $100 million to build “machinery precise enough to make chips with nano-sized parts necessary for medical and biological applications.” To reduce costs, “the BYU group developed an innovative solution” that dramatically reduced costs.

“First they used a simpler machine to form two dimensions in micrometers — 1,000 times larger than a nanometer. They formed the third dimension by placing a 50 nanometer-thin layer of metal onto the chip, then topping that with glass deposited by gasses. Finally they used an acid to wash away the thin metal, leaving the narrow gap in the glass as a virus trap. So far, the chips have one slot size. Hawkins says his team will make chips soon with progressively smaller slots, allowing a single channel to screen for particles of multiple sizes. Someone ‘reading’ such a chip would easily be able to determine which proteins or viruses are present based on which walls have particles stacked against them. After perfecting the chips’ capabilities, the next step, Hawkins says, is to engineer an easy-to-use way for a lab technician to introduce the test sample into the chip.”

As a headline in the Financial Times declares, “Instant mobile medical testing could save lives” [by Joia Shillingford, 16 June 2010]. Shillingford isn’t referring to the BYU lab-on-a-chip; rather, she is reporting on “an extraordinary new technology” that runs “all kinds of blood and saliva tests … instantly – without having to be sent off to a laboratory.” In this case, “instantly” means “less than 10 minutes.” Shillingford continues:

“Early, accurate diagnosis could … prolong the lives of people having heart attacks by making it easier to come up with a correct diagnosis and treatment in the first hour. How does it work? A device the size of a fat iPhone uses nanotechnology to analyse blood or saliva samples. A clear plastic slide, half the size of a business card contains a little dent, into which a pin prick of blood can be dropped. The blood flows down a tiny tube and interacts with chemicals. The slide is then inserted into the device and after an incubation period lasting minutes, a result is available on the digital display. It is possible to get as many as nine types of blood test from a single blood sample. For saliva tests, the user will probably spit into a tube fixed to the slide, which will be broken off after use. Swabs for viruses can be analysed too, but must be mixed with a liquid.”

Shillingford reports that everyone from paramedics to doctors to sports coaches are interested in the technology. She indicates that “people with long-term illnesses, who want to reduce hospital visits” could also use the device. She continues:

“The device has attracted interest from some big, global diagnostic businesses. It could be used to monitor pandemics. Results can be transmitted to a medical expert using third-generation mobile, GPRS (2.5G), or Wi-Fi wireless networking. Why so portable? The device contains powerful software but size and power consumption are kept low by the use of silver nanoparticles in the measurement process. Inside the slide, magnetic beads are bound to antibodies, which form clusters with the blood ingredient sought – for example, troponin (in the case of a heart attack). Using magnetism, the cluster is moved from the right to the left of the slide and its impact on the silver nanoparticles, which become silver ions, can be measured precisely.”

The device was developed by “Dr Robert Porter of the National Physical Laboratory, a UK state-owned institute concerned with the accuracy of scientific measurement.” Although the device is not yet on the market, it should be available “in September or October this year” from a spin-off company from the NPL called Argento Diagnostics. In addition to running medical tests, the device could also be used to help keep the food supply chain healthier. Argento Diagnostics is “talking to a huge food producer which wants to be able to screen food preparation staff for bugs such as swine flu.” According to Shillingford, the “device will cost £100-£120, with specific slides, such as heart or sports, costing between £5 and £45 each.” As reasonable as that sounds, such tests will still remain outside of the financial reach of many of the world’s poorest people.

Another interesting mobile device under development is one that can turn a mobile phone into a microscope [“Far From a Lab? Turn a Cellphone Into a Microscope,” by Anne Eisenberg, New York Times, 7 November 2009]. Eisenberg reports:

“Microscopes are invaluable tools to identify blood and other cells when screening for diseases like anemia, tuberculosis and malaria. But they are also bulky and expensive. Now an engineer, using software that he developed and about $10 worth of off-the-shelf hardware, has adapted cellphones to substitute for microscopes. ‘We convert cellphones into devices that diagnose diseases,’ said Aydogan Ozcan, an assistant professor of electrical engineering and member of the California NanoSystems Institute at the University of California, Los Angeles, who created the devices. He has formed a company, Microskia, to commercialize the technology. The adapted phones may be used for screening in places far from hospitals, technicians or diagnostic laboratories, Dr. Ozcan said.”

No technology, except maybe radio, is more globally ubiquitous than the mobile phone. That is why Ozcan’s mobile phone microscope could be so important in the developing world. Eisenberg continues:

“In one prototype, a slide holding a finger prick of blood can be inserted over the phone’s camera sensor. The sensor detects the slide’s contents and sends the information wirelessly to a hospital or regional health center. For instance, the phones can detect the asymmetric shape of diseased blood cells or other abnormal cells, or note an increase of white blood cells, a sign of infection, he said. Dr. Ozcan’s devices provide a simple solution to a complex problem, said Ahmet Yildiz, an assistant professor of physics and molecular cell biology at the University of California, Berkeley. ‘This is an inexpensive way to eliminate a microscope and sample Mobile phone microscope biological images with a basic cellphone camera instead,’ he said. ‘If you are in a place where getting to a microscope or medical facility is not straightforward, this is a really smart solution.’ Neven Karlovac, the chief executive of Microskia in Los Angeles, said that some of the company’s products would be adaptations of regular cellphones. For phones without cameras, or phones too compact to modify, the company has different designs, including a simple box with a sensing chip that can be plugged into a cellphone or laptop with a USB cord, he said. ‘The idea is to commercialize this low-cost cell imaging and diagnostic platform and apply it to a number of different products,’ Dr. Karlovac said. The price of the devices has not been set.”

Because Ozcan’s devices use mobile phone digital camera technology rather than lenses, they are compact and can transmit data quickly and cheaply. According to Eisenberg, Dr. Ozcan’s system may someday prove “particularly helpful in screening for malaria,” one of the diseases that especially affects people in the developing world.

“‘Right now you need a microscope, and you need trained people,’ [notes Dr. Yvonne Bryson, a professor and chief of the pediatric infectious diseases division at the David Geffen School of Medicine at U.C.L.A.]. ‘But this device would allow you to work without either in a remote area.’ M. Fatih Yanik, an assistant professor of electrical engineering and computer science at the Massachusetts Institute of Technology, said, ‘This makes it possible for ordinary people to gather medical information in the field just by using a cellphone adapted with cheap parts.'”

One final innovation I’d like to discuss is a small sensor that could lead to test kits that could be used at home to detect cancer [“Small liquid sensor could lead to home cancer detection kits,” by Darren Quick, Gizmag, 18 February 2010]. Quick reports:

“Just as home tests revolutionized the detection of pregnancy, a tiny sensor being developed at the University of Missouri (MU) could bring the benefits of home testing to the diagnosis a variety of diseases, including breast and prostate cancers. The sensor, known as an acoustic resonant sensor, is smaller than a human hair and could one day be used in home testing kits for the easy, rapid and accurate diagnosis of a range of diseases. The real-time, special acoustic resonant sensor being developed by Jae Kwon, assistant professor of electrical and computer engineering at MU, uses micro/nanoelectromechanical systems (M/NEMS) to directly detect diseases in body fluids. Since the M/NEMS are tiny devices smaller than the diameter of a human hair and the sensor doesn’t require bulky data reading or analyzing equipment they can be integrated with equally small circuits, creating the potential for small stand-alone disease-screening systems. ‘Many disease-related substances in liquids are not easily tracked,’ said Kwon, ‘in a liquid environment, most sensors experience a significant loss of signal quality, but by using highly sensitive, low-signal-loss acoustic resonant sensors in a liquid, these substances can be effectively and quickly detected — a brand-new concept that will result in a noninvasive approach for breast cancer detection.’ As an added benefit Kwon’s sensor also produces rapid, almost immediate results that could reduce patient anxiety often felt after waiting for other detection methods, such as biopsies, which can take several days or weeks before results are known.”

Although the research looks promising, more work needs to be done before the technology is commercialized.

“‘Our ultimate goal is to produce a device that will simply and quickly diagnose multiple specific diseases, and eventually be used to create “point of care” systems, which are services provided to patients at their bedsides,’ Kwon said. Kwon believes the sensor has strong commercial potential as part of simple home kits for the easy, fast and accurate diagnosis of a range of diseases and he was awarded a US$400,000, five year National Science Foundation CAREER Award to continue his efforts to develop the sensor.”

Taken together, the technologies discussed above point to a growing trend that involves making medical devices smaller and, hopefully, more affordable. Affordability is important in both the developed and developing worlds. These technologies are also aimed at making diagnoses earlier so that treatments can be started before a disease becomes a medical crisis. That, too, should help reduce the costs of medical treatments and save lives.