CSAIL wireless system suggests future where doctors could implant sensors to track tumors or even dispense drugs.
Investigating inside the human body often requires cutting open a patient or swallowing long tubes with built-in cameras. But what if physicians could get a better glimpse in a less expensive, invasive, and time-consuming manner?
A team from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) led by Professor Dina Katabi is working on doing exactly that with an “in-body GPS” system dubbed ReMix. The new method can pinpoint the location of ingestible implants inside the body using low-power wireless signals. These implants could be used as tiny tracking devices on shifting tumors to help monitor their slight movements.
In animal tests, the team demonstrated that they can track the implants with centimeter-level accuracy. The team says that, one day, similar implants could be used to deliver drugs to specific regions in the body.
ReMix was developed in collaboration with researchers from Massachusetts General Hospital (MGH). The team describes the system in a paper that’s being presented at this week’s Association for Computing Machinery’s Special Interest Group on Data Communications (SIGCOMM) conference in Budapest, Hungary.
Tracking inside the body
To test ReMix, Katabi’s group first implanted a small marker in animal tissues. To track its movement, the researchers used a wireless device that reflects radio signals off the patient. This was based on a wireless technology that the researchers previously demonstrated to detect heart rate, breathing, and movement. A special algorithm then uses that signal to pinpoint the exact location of the marker.
Interestingly, the marker inside the body does not need to transmit any wireless signal. It simply reflects the signal transmitted by the wireless device outside the body. Therefore, it doesn’t need a battery or any other external source of energy.
A key challenge in using wireless signals in this way is the many competing reflections that bounce off a person’s body. In fact, the signals that reflect off a person’s skin are actually 100 million times more powerful than the signals of the metal marker itself.
To overcome this, the team designed an approach that essentially separates the interfering skin signals from the ones they’re trying to measure. They did this using a small semiconductor device, called a “diode,” that mixes signals together so the team can then filter out the skin-related signals. For example, if the skin reflects at frequencies of F1 and F2, the diode creates new combinations of those frequencies, such as F1-F2 and F1+F2. When all of the signals reflect back to the system, the system only picks up the combined frequencies, filtering out the original frequencies that came from the patient’s skin.
One potential application for ReMix is in proton therapy, a type of cancer treatment that involves bombarding tumors with beams of magnet-controlled protons. The approach allows doctors to prescribe higher doses of radiation, but requires a very high degree of precision, which means that it’s usually limited to only certain cancers.
Its success hinges on something that’s actually quite unreliable: a tumor staying exactly where it is during the radiation process. If a tumor moves, then healthy areas could be exposed to the radiation. But with a small marker like ReMix’s, doctors could better determine the location of a tumor in real-time and either pause the treatment or steer the beam into the right position. (To be clear, ReMix is not yet accurate enough to be used in clinical settings. Katabi says a margin of error closer to a couple of millimeters would be necessary for actual implementation.)
“The ability to continuously sense inside the human body has largely been a distant dream,” says Romit Roy Choudhury, a professor of electrical engineering and computer science at the University of Illinois, who was not involved in the research. “One of the roadblocks has been wireless communication to a device and its continuous localization. ReMix makes a leap in this direction by showing that the wireless component of implantable devices may no longer be the bottleneck.”
There are still many ongoing challenges for improving ReMix. The team next hopes to combine the wireless data with medical data, such as that from magnetic resonance imaging (MRI) scans, to further improve the system’s accuracy. In addition, the team will continue to reassess the algorithm and the various tradeoffs needed to account for the complexity of different bodies.
“We want a model that’s technically feasible, while still complex enough to accurately represent the human body,” says MIT PhD student Deepak Vasisht, lead author on the new paper. “If we want to use this technology on actual cancer patients one day, it will have to come from better modeling a person’s physical structure.”
The researchers say that such systems could help enable more widespread adoption of proton therapy centers. Today, there are only about 100 centers globally.
“One reason that [proton therapy] is so expensive is because of the cost of installing the hardware,” Vasisht says. “If these systems can encourage more applications of the technology, there will be more demand, which will mean more therapy centers, and lower prices for patients.”
Learn more: A “GPS for inside your body”
The Latest on: In-body GPS
via Google News
The Latest on: In-body GPS
- The TEMA-HF 1 (Telemonitoring in the Management of Heart Failure) Studyon November 23, 2020 at 4:00 pm
The GP's attention was focused only on those patients with suspicious changes in body weight ... by representatives of the participating GPs, as it allowed them to change medication more ...
- Benitez explains why Klopp’s five-subs idea does not workon November 19, 2020 at 2:03 am
After the initial medical exam, he tests players throughout the season in body composition ... “Now, we have GPS units. Expressed in a simple way, we measure the training effort (quantity ...
- Rafa Benitez disagrees with Liverpool boss Jurgen Klopp in five subs argumenton November 18, 2020 at 8:35 am
After the initial medical exam, he tests players throughout the season in body composition, stamina and strength ... way to control the load of the training sessions. "Now, we have GPS units.
- How technology is trying to address bias in policing — and why experts say it won’t be enoughon November 16, 2020 at 7:54 pm
Despite inconclusive data, there is renewed interest in body cameras this year as police ... like computer-generated police reports and in-vehicle GPS, have made modest improvements in ...
- Jeffrey Epstein's chilling 'smile of enjoyment' gave his sex crime guilt awayon November 16, 2020 at 4:32 am
In the one-hour special, experts in body language, linguistics and forensic psychology analyse video footage of Epstein’s pre-hearing deposition for a series of alleged sex crimes, and pinpoint ...
- 2020 Mercedes-AMG CLA45 S reviewon November 9, 2020 at 4:27 am
You’re not going to be unfashionably late in the Mercedes-AMG CLA45 S – the fastest version of the German brand’s most style-focused compact car. The CLA45 ...
- 2020 Mercedes-AMG CLA45 S reviewon November 8, 2020 at 11:22 pm
An increase in body length from 4630mm to 4688mm makes the CLA fractionally longer than some versions of the current Mercedes C-Class – a fact that might help buyers digest news that this CLA45 ...
- Hytera Launched Latest Ultra-thin, Smart Bodycam VM580Don November 5, 2020 at 10:00 pm
Global positioning, rapid indoor and outdoor positioning, and real-time tracking of frontline personnel VM580D supports global positioning configuration, such as GPS ... log data in body worn ...
- FFS, My Camera Should Be Better Than My Phone…on November 5, 2020 at 8:17 am
IBIS (in-body image stabilization), because most of ... There is no excuse to not include GPS — according to Alibaba you can buy a GPS chip for under $1, and a Sony CXD5603GF Ultra-Low-Power ...
- Mazda’s New Test Strategy Could Save 'Hundreds of Millions of Yen' Per Yearon November 4, 2020 at 4:00 pm
Taking a cue from the defense and consumer electronics industries, Mazda Motor Corp. has built an automated system for virtual validation test of vehicle electronics in body, chassis ... system to ...
via Bing News