IISc Bengaluru Introduces Alternative Blood Glucose Monitoring Technique

Using photoacoustic sensing, the Department of Instrumentation and Applied Physics team employed polarized light and sound waves to detect glucose concentrations without breaking the skin.

Researchers at the Indian Institute of Science (IISc), Bengaluru, have devised a noninvasive method to measure blood glucose levels. This method offers a potential alternative to conventional needle-based testing.

Using photoacoustic sensing, the Department of Instrumentation and Applied Physics team employed polarized light and sound waves to detect glucose concentrations without breaking the skin.

How Does the Glucose Monitoring Technique Work?

This method involves shining a laser beam onto tissue, causing a slight heating (less than 1°C), which generates ultrasonic sound waves through vibrations. Sensitive detectors then measure these waves, with different molecules creating distinctive "fingerprints" based on their light absorption properties at various wavelengths.

The researchers focused on glucose's chiral nature, which leads to the rotation of polarized light during interaction. By altering the orientation of polarized light in glucose solutions, they observed changes in the intensity of emitted sound waves.

Jaya Prakash, assistant professor at IAP and the corresponding author of the study in Science Advances, noted, "We don't actually know why the acoustic signal changes when we change the polarisation state. But we can establish a relationship between glucose concentration and the intensity of acoustic signal at a particular wavelength."

Their experiments achieved near-clinical accuracy in estimating glucose concentrations in water, serum solutions, and slices of animal tissue, with precise measurements at varying depths in the tissue. A pilot study also tracked the blood glucose levels of a healthy participant before and after meals over three days.

Swathi Padmanabhan, a PhD student and the paper's first author, said, "Currently, the laser source we use has to generate very small nanosecond pulses, so it is expensive and bulky. We need to make it more compact."

She added that sound waves behave more predictably than light within the body, enabling clearer and more accurate measurements from deeper tissue layers.

The researchers believe this approach could detect other chiral molecules by adjusting the wavelength of light used. For example, they successfully estimated the concentration of naproxen, a common pain medication, in an ethanol solution, suggesting broader applications in diagnostics and healthcare.

Although promising, the technology needs further refinement to become clinically viable. The current setup requires a laser capable of generating extremely short nanosecond pulses, which makes it expensive and cumbersome.

Recently, ZEISS India collaborated with the Indian Institute of Science (IISc), Bengaluru, to drive research in AI for eye care. As part of this initiative, ZEISS established a research facility dedicated to developing high-fidelity AI solutions to improve vision care and training students in AI technologies.

Stay tuned for more such updates on Digital Health News.