For several decades, medical devices have been growing smaller, cheaper, and more portable. Point-of-care tests, performed outside the traditional laboratory, are now widely used for pregnancy testing, monitoring blood glucose in diabetes, and for many other applications.
Today, medical testing is undergoing another revolution. Recent technological advances are enabling the development of tests that make medical screening, diagnosis, and monitoring less invasive, more affordable, and more patient-focused. Some of these devices are next-generation point-of-care devices while others provide individuals with unprecedented genetic information.
"So much innovation and so many technological advances have occurred in recent times," wrote Eric Topol, MD, Medscape Editor-in-Chief in a recent online article, that these advances "are changing or soon will change the face of medicine."
New and emerging medical tests have the potential to deliver the kind of patient-centered, evidence-based medicine that consumers and healthcare professionals have been anticipating. Here are a few examples of those tests:
DNA blood tests for prenatal screening
Researchers have developed a test that works by analyzing fragments of fetal DNA that have been shed into the mother's blood to screen for genetic abnormalities like Down syndrome. Because this is a screening test, the results cannot be used alone. Positive results require pregnant women to have follow-up diagnostic testing, such as chorionic villus sampling (CVS) or amniocentesis.
About 800,000 U.S. women have used the cell-free fetal DNA test since it first came on the market in 2011. The test is also called non-invasive prenatal testing because it only requires a blood draw from the mother.
While cell-free fetal DNA screening seems to benefit many women, it's also raised some concerns. The test is not diagnostic and it can lead to false-positive or false-negative results. In some cases, a lack of knowledge about the need to follow up with diagnostic amniotic fluid testing has led women to terminate healthy pregnancies.
This highlights the need for both healthcare practitioners and patients to proceed with caution when encountering new medical testing technologies.
DNA blood tests for cancer screening
There are emerging cancer testing methods that rely on principles similar to cell-free fetal DNA screens. Researchers are now able to detect the DNA that cancer tumors shed into the blood of cancer patients. The technology is promising, but it will need to be part of additional, large clinical trials before it becomes a routine part of cancer evaluations.
These "liquid biopsies" could be done more frequently to monitor cancer and guide treatment changes in real time and with less risk than a traditional tissue biopsy or CT scan. They are less invasive as they rely only on a blood sample. So far, liquid biopsies have been studied for monitoring lung, colon, and blood cancers.
This technology could also eventually allow for non-invasive, early stage cancer screening. Some innovators are probing the possibility of developing a single blood test that would screen for a variety of cancers before symptoms appear and when cancer is easier to treat. While this proposal is exciting, years of research into such a test's reliability and usefulness are required before it would become a reality.
Glucose monitoring smart watch
For people with diabetes, having to prick their fingers to draw blood and then test the blood in a glucose monitoring machine can be an irksome process. Sometimes that means diabetics don't test their glucose as often as they should. Plus, the method doesn't provide the big picture of how an individual’s glucose levels change throughout the day and night.
Continuous glucose monitoring (CGM) offers a solution for replacing the finger prick method. These systems rely on a small sensor placed under the skin and a data receiver. One company is taking that concept a step further by offering streamlined CGM that is compatible with a smart watch. A major benefit of the device is that people can graph their glucose data. Parents and caregivers can keep an eye on their loved ones from afar.
Smartphone-based medical testing
Research on smartphone-based testing devices is flourishing. In 2015, researchers at Columbia University published a paper describing a device that attaches to a smartphone and performs an ELISA test for HIV and syphilis. The group hopes the test will help people in developing countries where laboratory access is limited.
Last year, researchers at Johns Hopkins University presented a smartphone-based device for chlamydia testing. It performed well alongside the gold standard test for the sexually transmitted infection and is more affordable. Smartphone tests for other infectious diseases, as well as for pregnancy, are in the works, plus a mobile device-based EKG is already on the market.
This is an exciting time for medical testing, but there are also many considerations as these technologies evolve. Data privacy is a concern as consumers and their healthcare providers become more awash in personal medical information.
Individuals also need to consider how they will navigate their newfound access to personal medical data, and when to seek out professional help. For example, DNA testing can raise unexpected questions. So if you choose to undergo DNA testing, whether it's with a lab test like cell-free fetal DNA, or a direct-to-consumer genetic test offered by some companies, you may wish to talk to a genetic counselor.
New testing devices are best used along with professional consultation to ensure you aren't making decisions that compromise your health. Many new testing technologies are still complimentary to traditional laboratory testing, not replacements for it. While many of the tests discussed here are in their infancy, they show the promise of moving us closer to fully personalized, less invasive, patient-focused medicine.