Engineers create a tiny wireless implant that measures tissue oxygen levels

Shane McGlaun - Apr 15, 2021, 7:59am CDT
Engineers create a tiny wireless implant that measures tissue oxygen levels

Engineers from the University of California, Berkeley have announced the creation of a very small wireless implantable to provide real-time measurements of tissue oxygen levels deep within the body. The device is very small at approximately the size of a ladybug, and is powered by ultrasound waves. Researchers believe the device could help medical professionals monitor the health of transplanted organs or tissue and provide them with early warning signs of tissue failure or organ rejection.

The technology was created with help from physicians at the University of California, San Francisco, and helps pave the way for other miniaturized sensors to track other biochemical markers in the body, including pH and carbon dioxide. Researchers hope the sensor might one day provide doctors with minimally invasive methods for monitoring biochemistry inside functioning organs and tissues. Engineers on the project say it’s very difficult to measure things deep inside the body.

The new sensor demonstrates how ultrasound technology coupled with integrated circuit design allows the creation of implants embedded inside the body and gathers data from organs. Oxygen is particularly important to the body as it’s a key component in the ability for cells to harness energy from food people eat. Tissue requires a steady supply of oxygen to survive, and if deprived of oxygen tissue quickly dies.

Typical methods for measuring tissue oxygen can only provide information on what is happening near the body’s surface. Those typical methods use electromagnetic waves such as infrared light able to penetrate only a few centimeters into the skin or organ tissue. There are other methods using magnetic resonance imaging to provide information about deep tissue oxygenation, but they require long scan times and can’t provide real-time data.

The new sensors use ultrasonic waves to wirelessly communicate outside the body, which are also able to travel through the body at longer distances than electromagnetic waves. The sensors the team created measure 4.5mm by 3mm and use an oxygen-sensing film, optical fiber, and integrated circuit. A Paisano-Crystal converts the electronic signal from the integrated circuit into ultrasonic waves that can be transmitted through living tissue. Researchers are currently working to improve the technology to allow the sensor to survive for longer periods inside the body.

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