UBC’s $100 ultrasound sensor heralds cheap, wearable diagnostic device
Canadian researchers say their low-power, flexible PolyCMUT transducer could be woven into a wearable ultrasound device and powered by a cell phone.
As the most widely used medical imaging technologies, ultrasound creates sonogram images by emitting high-frequency sound waves. The echoes that bounce back are detected by the transducer to form sonograms, a real-time view of internal soft tissues and organs.
“Transducer drums have typically been made out of rigid silicon materials that require costly, environment-controlled manufacturing processes, and this has hampered their use in ultrasound,” said Carlos Gerardo, a PhD candidate in electrical and computer engineering at UBC and the lead author of the Nature article detailing the transducer’s design. “By using polymer resin, we were able to produce polyCMUTs in fewer fabrication steps, using a minimum amount of equipment, resulting in significant cost savings.”
While CMUTs (capacitive micromachined ultrasound transducers) aren’t new and provide superior bandwidth and sensitivity, they typically do have limitations, the researchers say, in that they can be susceptible to acoustic crosstalk and limited tissue penetration depth.
However, by employing photopolymer materials and a simplified manufacturing technique, the UBC engineers say their polyCMUT prototype eliminates these problems and cost only $100 to manufacture. In addition, the sonograms produced by their device are as sharp as or even more detailed than those produced by traditional piezoelectric transducers.
“Since our transducer needs just 10 volts to operate, it can be powered by a smartphone, making it suitable for use in remote or low-power locations,” said co-author Edmond Cretu, UBC professor of electrical and computer engineering. “And unlike rigid ultrasound probes, our transducer has the potential to be built into a flexible material that can be wrapped around the body for easier scanning and more detailed views–without dramatically increasing costs.”
Co-author Robert Rohling, also a UBC professor of electrical and computer engineering, said the next step in the research is to develop a wide range of prototypes and eventually test their device in clinical applications.
“You could miniaturize these transducers and use them to look inside your arteries and veins. You could stick them on your chest and do live continuous monitoring of your heart in your daily life. It opens up so many different possibilities,” said Rohling.