Researchers from Jinan University in China have developed a smart photoacoustic imaging approach by using a combination of laser light and ultrasound.
The new technique is believed to have the potential for application in medical diagnostics, wearable devices and instrumentation.
By leveraging optical fibre technology, the researchers devised new sensors for photoacoustic imaging.
The technique uses fibre-optic ultrasound detection to assess the acoustic effects on laser pulses through temperature changes that occur due to the elastic strain.
According to lead researcher Long Jin, traditional fibre optic sensors identify extremely weak signals of acoustic waves but do not work ‘well’ for ultrasound waves used during medical imaging.
Jin added that the new sensors were specifically designed for medical imaging, with better sensitivity compared to existing piezoelectric transducers.
The researchers developed a unique ultrasound sensor comprising a compact laser built within the 8µ diameter core of a single-mode optical fibre, which is doped with ytterbium and erbium to get necessary optical gain.
It is expected that the fibre laser-based ultrasound sensors will be helpful in photoacoustic microscopy.
Jin noted: “By raster scanning the laser spot, we can obtain a photoacoustic image of the vessels and capillaries of a mouse’s ear.
“This method can also be used to structurally image other tissues and functionally image oxygen distribution by using other excitation wavelengths – which takes advantage of the characteristic absorption spectra of different target tissues.”
The laser sensor could also be used for endoscopes and has wearable applications. As it has an 8µ diameter, the new sensor may offer an alternative for current commercial endoscopic products with larger dimensions.