Trumpf VCSEL sources assess glucose in blood

10 Jan 2023

Partnership with RSP Systems aims to develop miniaturized wearable sensor.

A collaboration between Trumpf and RSP Systems aims to develop a wearable sensor for glucose that could simplify monitoring of diabetes.

The German laser vendor and the Danish medical device company will partner on the design of a system in which RSP Systems's current non-invasive blood monitoring technology can be miniaturized into a wearable platform.

On Trumpf's side this will involve the company's VCSEL diode technology, to meet the requirements for suitably compact laser sources able to be integrated into the device architecture.

"With our knowledge of the mechanisms of photonics, we can soon enable people with diabetes to measure their blood glucose levels more easily, more cheaply and entirely without pain," commented Berthold Schmidt of Trumpf Photonic Components.

Optical measurement of blood glucose has been the subject of intensive research in recent years. In 2018 the prototype of the GlucoSenz device combined near-infrared spectroscopy and chemometric techniques to measure absorbance characteristics through a person's thumb.

In 2020 MIT demonstrated how direct observation of the glucose fingerprint could be achieved using in vivo Raman spectroscopy in an off-axis non-contact spectroscopy architecture, in which the illuminating laser was orientated at an oblique angle of around 60 degrees and the subsequent Raman signal was collected vertically.

Innovation built on VCSEL laser sources

Thanks to the technique's glucose specificity, a confocal Raman spectrometer is at the heart of RSP System's existing sensor device. The noninvasive GlucoBeam platform is said to be the "first touch glucose monitoring technology," and involves a patient touching their thumb to the device. Scattered light from a 830-nanometer source is collected and processed using artificial intelligence.

In particular the device makes use of critical-depth Raman spectroscopy, according to RSP data, such that the Raman signal is spatially filtered to select signals from about 300 microns deep in an area of the thumb, which may include vascular, interstitial, and intracellular compartments.

The existing GlucoBeam is portable, but still the size of a paperback book. The partnership with Trumpf intends to create a smaller wearable device that can fit on a patient's wrist and carry out the analysis there.

"Touch Glucose Monitoring has been an ambition for device developers over the last three decades due to the vast implications for people needing to keep an eye on their glucose levels," said Anders Weber of RSP Systems. "Together with Trumpf, we will realize a wrist-worn device, aimed to cover all uses from people on insulin therapy to people at risk for developing diabetes."

Berthold Schmidt of Trumpf commented that the partnership was evidence of the innovation potential of VCSEL technology. "VCSEL lasers are clearing the way for a glucose sensor for your wrist, so people with diabetes can thus keep an eye on their glucose levels at all times. If we are successful together, we will improve the lives of hundreds of millions of people."