Researchers at the University of California, Berkeley, have developed an ultrasound-powered implantable sensor that measures oxygen levels in the body’s deep tissues and transmits that data to an external device. The technology could be useful in controlling the viability of transplantation or exposure to oxygen in premature babies. It can also be adapted to measure other biochemical markers, such as carbon dioxide concentrations or pH levels.
Oxygen is crucial for living tissues and poor oxygenation leads to cell death. This process forms the basis of various pathological phenomena, but doctors may struggle to measure the oxygenation of tissues, at least in tissues that are not close to the surface of the body. Current methods for assessing tissue oxygenation involve the use of infrared light, but they can only penetrate a few centimeters.
“It’s very difficult to measure things inside the body,” Michel Maharbiz, a researcher involved in the study, said in a Berkeley ad. “The device demonstrates how, using ultrasound technology along with a very intelligent integrated circuit design, you can create sophisticated implants that go deep into tissues to take data from organs.”
New implants are fed by ultrasonic waves, which can travel long distances through the body. An external probe transmits ultrasonic vibrations through the body, which feed the small device implanted inside it. Data is relayed reflecting these ultrasonic waves as data packets on tissue oxygenation levels are incorporated. This technique allows bidirectional data to be exchanged with devices located at the bottom of the body.
Oxygen detection occurs through an optical LED and an optical detector inside the tax. The device itself is small and researchers describe it as smaller than a ladybug. So far, they have tested the device by tracking muscle oxygen levels in live sheep.
“A potential application of this device is to control organ transplants, as in the months following organ transplantation vascular complications can occur and these complications can lead to graft dysfunction,” Soner Sonmezoglu said. another researcher involved in the project. “It could also be used to measure tumor hypoxia, which may help doctors guide cancer radiation therapy.”
An important potential application of the new technology is to use it to help control oxygen levels in premature babies. “In premature babies, for example, we often need to provide supplemental oxygen, but we don’t have a reliable reading of the oxygen concentration in the tissues,” said Emin Maltepe, the project’s third researcher. “Other miniaturized versions of this device could help us better manage the oxygen exposure of our preterm infants in intensive care homes and help minimize some of the negative consequences of excessive exposure to oxygen, such as retinopathy of prematurity or chronic lung disease “.
Study a Nature’s biotechnology: Monitoring of deep tissue oxygenation with a millimeter-scale ultrasound implant