How Science Uses Lasers for Your Health

This is the effect of lasers in diagnosis of common disease.

This study from 2018 shows how lasers can help with the diagnosis of a few common diseases. The study focuses on the possible replacement of current diagnosis methods which utilize breath analysis. Breath analysis is a common mode of diagnosis for some common disease such as type 1 diabetes, lung cancer, obesity and much more; and with new upcoming laser technologies, experts expect breath analysis to get way more accessible and easier than it already is.

11.3% of the American population (approximately 38 million people) had type 1 diabetes back in 2019, according to official government reports. Obesity and lung cancer also show high diagnose rates, so developing new, faster and more accurate methods to diagnose these diseases will certainly do good. According to CDC, even though millions of cases for these diseases get diagnosed each year, statists estimate that about quarter of the total cases go unnoticed and thus undiagnosed. New techniques for breath analysis are expected to also grant a reduction in the number of undiagnosed cases.

Breath analysis currently utilizes a few different kinds of chemical ionization mass spectrometry, which is basically a process of vapour analysis where the gas that is being analyzed is ionized through electron ionization and therefore reacts to create the mass to charge ratio that the experts need. To put it on simpler terms, think of a village where the villagers (analyte gas) live their lives completely ordinarily. Let’s say a band of rebels come to the village to turn them against their king (electron ionization). The villager then rebel(ionize) and come together rebel against the king. However, some families in the village seem more rebellious than others.

Mass spectrometry basically inspects how many villagers there are and how “rebellious” they are, and give us how many villagers from each family there are in the rebellion in total. Now, imagine the same situation where the rebels use more advanced propaganda techniques and LASERS!

That is where optical absorption spectroscopy, beware the difference from spectrometry. Spectrometry uses electrons to break molecules apart whereas spectroscopy uses electromagnetic radiation. This new technique uses lasers to pinpoint not from which family each villager is, but who each villager is. Even though currently the use of lasers is not as available and accurate as mass spectrometry optical frequency combs proves that the future has plans for optical absorption spectroscopy.

Optical frequency combs, or OFC for short, is a mid-infrared laser technology which made lasers relevant in the breath analysis industry once more, after lasers were proved to be less efficient than its competitors in early 2010s. Development of OFC showed a great boost in the accuracy and availability of laser-based breath analysis methods, particularly optical absorption spectroscopy. With OFC lasers, the whole method upgraded from what casual lasers offered.

A casual laser emits light in a narrow wavelength (region) whereas OFC lasers are equally distant and accurate with the ability to cover a wider wavelength range in the spectrum. This is what allows us to distinguish villagers as their own self instead of what family they belong to (which is not as discrete).

OFC is not only used for breath analysis; it is also useful in areas like astronomy and quantum observation. It is utilized in astronomy as an astro-comb, which is a type of frequency comb that is specialized for astronomy. It can also be found in atomic clocks, the standard for time, which measure time by the different energy levels of atom.

Researchers suggest that if with such little advancement in OFC, we get this much of a major upgrade to the laser-based breath analysis industry, then only time will show how much more can be accomplished with further advances in OFC technology.

Citation:

Metsälä, M. (2018). Optical techniques for breath analysis: from single to multi-species detection. Journal of Breath Research, 12(2), [027104]. https://doi.org/10.1088/1752-7163/aa8a31

Author:

Egemen TÜRKER