30 Years of Medical Technology

NASA Tech Briefs, Apr 2006

In celebration of the 30th Anniversary of NASA Tech Briefs, our features in 2006 highlight a different technology category each month, tracing the past 30 years of the technology, and continuing with a glimpse into the future of where the technology is headed. Along the way, we include insights from industry leaders on the past, present, and future of each technology. This month, we take a look at the past 30 years of Medical Technology.

Many of today's most advanced medical technologies actually had their roots in inventions that date back much farther than 30 years ago. But these technologies only came to practical and widespread use after years of development, testing, and in some cases, approval by the U.S. Food and Drug Administration (FDA). So while medical breakthroughs such as the CAT scan, MRI, and laser vision correction seem to be recent advances, the technology behind them was founded more than 30 years ago. We've included here only a handful of the countless medical breakthroughs that have occurred since 1976.

Medical Imaging

Invented by Allan Cormack in the early 1960s, computed axial tomography (CAT) scanning received little interest until British engineer Godfrey Hounsfield and his team introduced the first CAT scan machine in 1972.

In the past 30 years, the CAT scan has transformed medical diagnostics by offering two-dimensional cross-sectional images, or slices, of the body. The CT scan machine is a round, rotating frame with an x-ray tube mounted on one side and a detector on the other side. A beam of x-rays is created as the rotating frame spins the tube and the detector around the patient. Each complete rotation creates a cross-sectional slice of the body. The slices are analyzed by computer.

The 1990s saw new spiral CT scanners that could image entire regions of the body, such as the lungs or abdomen, in about 30 seconds. The scanner rotates continuously, meaning that there are no gaps between slices. The data can be reconstructed to form 3D images, including blood vessels.

The next generation of medical imaging was developed in the late 1970s by Dr. Raymond Damadian and his colleagues, who used magnetic resonance imaging (MRI) to study the structure of chemicals. The first MRI exam performed on a human being took place on July 3, 1977. It took almost five hours to produce one image.

As late as 1982, there were only a few MRI scanners in the United States. Today, there are thousands, and images that used to take hours now take seconds. Subsequent improvements in the technique have resulted in the ability to obtain an unparalleled view inside the human body. The level of detail obtained from an MRI is greater than that achieved with any other type of imaging, making MRIs the method of choice for diagnosing many types of injuries or diseases. Advances such as functional MRI (fMRI) also enable imaging of blood flow, allowing doctors to see which areas of the brain are active during certain tasks. As a result, the fMRI shows potential for helping to detect and diagnose psychiatric disorders.

Another innovation in medical imaging is the Positron Emission Tomography (PET) scan, a noninvasive procedure that provides information about the body's chemistry, cell function, and exact location of a disease that is not achievable with CT or MRI scans.

The most common uses for PET scans are for cancer diagnostics, cardiology, and neurology. In neurology, for example, the PET scan can help to localize areas of the brain that cause epileptic seizures, dementia, Alzheimer's, Parkinson's, and Down's syndrome. The PET scan today is one of the most accurate diagnostic tools for identifying if a tumor is malignant, the extent of the cancer and if it has spread to other organs, and monitoring recurrences and the effectiveness of cancer treatments.

Although mammography was invented in the 1920s, it also has significantly improved and developed in the past 30 years. The imaging technique used to examine breast tissue for abnormalities, mammography has morphed into one of the most commonly used medical imaging techniques.

Film mammography is currently the most-used method, with images recorded on film similar to x-rays. Digital mammography, which has been approved by the FDA, records and stores the images in a computer database instead of on film. The image on the monitor can be enlarged, brightened, or contrasted to more accurately identify abnormalities, and past and current images can be superimposed for comparison.

Cochlear Implants

From the 1950s through the 1970s, various teams of researchers began working to create devices that could help restore hearing function. But in 1977, Adam Kissiah, a NASA engineer with no medical background, designed and patented the cochlear implant, a surgically implantable device that provides hearing sensation to persons with severe to profound hearing loss who receive little or no help from hearing aids. The concept of Kissiah's implant was not based on theories of medicine, but instead, on technical expertise he learned working as an electronics instrumentation engineer at NASA's Kennedy Space Center.