“Smart pills” that are able to diagnose and treat diseases in a way that is unimaginable to us today are just around the corner. However, in order for them to be effective, they will need a way of relaying their location in the body to medical personnel. Because of the tiny microscale of such smart pills, that’s easier said than done — although researchers at the California Institute of Technology think they may well have cracked it.
What they developed is a unique creation called ATOMS, standing for Addressable Transmitters Operated as Magnetic Spins. ATOMS is a silicon chip that relies on the same principles as magnetic resonance imaging (MRI) to determine where in the body it is located at any given time.
“To solve the problem of localizing microscale devices in the body, we borrowed some principles from nuclear magnetic resonance and embodied them in a silicon integrated circuit,” Mikhail Shapiro, an assistant professor of chemical engineering at Caltech, told Digital Trends. “Nuclear spins in atoms resonate at certain frequencies, which scale linearly with the strength of the magnetic field to which they are exposed. MRI is based on the idea of applying a magnetic field gradient, so that spins at two different locations resonate at two different frequencies. We can look at these frequencies and determine the locations of these spins, all at the same time. In our device, we have the same principle, but instead of a natural atom, we have a silicon chip that mimics its behavior by sensing the magnetic field and changing its resonance frequency. This allows us to figure out the chip’s location just by applying a magnetic field gradient and looking at the frequency that comes out.”
The research is still at a preliminary stage, but one day the hope is that the device could be deployed in settings like patients’ gastrointestinal tract, blood, or even their brain. Once there, it could measure for information such as pH levels, temperature, pressure, or sugar concentrations, and wirelessly transmit this data to doctors. At present, a final prototype chip — measuring just 1.4 square millimeters — has been demonstrated in mice.
“Ultimately, we envision a flotilla of tiny microchips circulating inside our bodies, taking measurements for diagnosis or releasing energy or drugs for therapy,” Shapiro continued. “The ATOMS technology will be integrated into these chips so we can see where they are and what they’re doing, and tell them what to do.”
A paper describing the work was recently published in the journal Biomedical Engineering.