Image Credits: Nixx Photography
In ancient times, physicians used a patient's breath and body odor as signals of disease and illness. While this method may seem crude, there is in fact science to support it. Diabetes, cancer of the stomach, lung, breast, and pancreas, asthma and Parkinson’s disease, as well as other illnesses, are linked with specific scent compounds that are emitted through the breath and skin.
While some of these smells may be potent, like scrofula for example which is associated with strong beer smells, and yellow fever which is associated with smells that would be familiar to a butcher’s shop, most of these odors are too low to be detected by the human nose.
Challenges Involved in the Detection of Volatile Organic Compounds
Scent profiles related to illness are related to the emittance of volatile organic compounds (VOCs) through the human body. VOCs are generally a reflection on the metabolic status of a person, so as disease changes the metabolic processes, it indirectly impacts the scents emitted by the person.
Creating a system sophisticated enough to accurately detect VOCs in breath and body odor is a challenge because the analysis is made complicated through variable factors such as sex and body mass. In addition, VOCs that marker disease are found in low levels so the system must be powerful.
As knowledge about the links between scent and illness has been known in the field of medicine for centuries, several attempts at creating systems to make a diagnosis based on scent have already been developed. For example, there is currently a system to detect the metabolite ethanol, which gives an indication of glucose levels. However, these systems require large and costly equipment along with experts to use it. They don’t solve the problem of providing a quick, easy to use the system to detect disease ahead of more complex physical tests.
Sniff-Cam—A Revolutionary Technology
This year, a paper has been published which details the development of a “sniff-cam”, constructed with ultraviolet ring light, filters, and a camera, and with 25 times greater sensitivity and broader dynamic range compared with any previously created systems. The Japanese team put together the prototype which has been proven to be successful in measuring extremely low concentration distribution of ethanol (EtOH) being emitted via the breath to give an indication of bacterial flora in the gut and mouth. They achieved this through using an ultraviolet-light-emitting diode mounted to a camera as an excitation light source, allowing for simultaneous excitation and imaging of the fluorescence, produced by EtOH reacting with oxidized nicotinamide adenine dinucleotide (NAD). The concentration of EtOH in the sample is visually represented by the expressed fluorescence, the distribution of which is measured, to calculate the level of EtOH present.
Plans are to refine the “sniff-cam” in order to use it to detect biomarkers at diagnostic levels. More development is needed in order to expand its capabilities to read emissions of a range of VOCs. In theory, the technology could be progressed to visually represent levels of VOCs related to a myriad of illnesses, test their levels, and report on where a diagnosis is indicated and further tests are required. With the advent of technology able to detect disease through scent, a whole new area of diagnosis is opening up.
Given the way the “sniff-cam” is made and functions, it is relatively cheap and easy to use by a medical practitioner. The result of the evolution of technology like the “sniff-cam” could realistically provide a simple process for screening people from diseases, improving on outcomes by alerting patients and medical practitioners to illness before symptoms have become salient.
Sources and Further Reading