Technical Research Centre of Finland (VTT) has developed its first prototype to quickly and painlessly diagnose illness by the optical analysis of isotopes contained in exhaled air.
With the device, it is possible to determine with absolute certainty during the appointment whether the patient’s stomach troubles are caused by Helicobacter, according to the researchers. The certainty is based on its ability to measure not only carbon13 but also oxygen18 in exhaled air.
The device is based on a technology developed by VTT’s MIKES Metrology, optical absorption spectroscopy in a multipass chamber with the sample volume reduced to just 40 microliters, which is less than ten millionths of an adult’s lung capacity.
Due to the extremely small sample volume, the gas inside the chamber can rapidly be exchanged. This, in turn, enables the entire breathing cycle of the patient to be analyzed rapidly by the same device.
VTT’s painless, quick and reliable method for diagnosing Helicobacter from exhaled air. (Credit: Technical Research Centre of Finland)
Carbon dioxide is formed of carbon atoms with different masses. The origin of the gas can be determined by measuring these carbon isotopes. Helicobacter can be detected in exhaled air, when the carbon12 of a urea molecule is artificially replaced by carbon13.
This replacement is done by means of a harmless pill containing the urea chemical and swallowed by the patient. If there are Helicobacteria in the stomach, they will break down the urea molecules into carbon dioxide molecules that will then enter the patient’s system, finally traveling via the lungs into the exhaled air.
The device analyzes the ratio between carbon13 and carbon12 in exhaled air. When the carbon13 ratio in exhaled air increases after taking the pill, it has been shown that with a 97 percent certainty that the patient is suffering from Helicobacter that can be treated with drugs. The difference in VTT’s device is that it also analyzes the ratio of oxygen18 in the exhaled air, which guarantees a 100 percent certainty for the diagnosis.
Spectrometry based on the analysis of isotopes has thus far been widely applied in medical analysis, because carbon13 is relatively easy to measure with a nondispersive optical device. Detecting oxygen18 is more difficult due to its significantly weaker absorption, and spectrally, it is located between the main isotope and carbon13. Its detection requires mid-infrared lasers that did not enter the market until recent years.
The Helicobacter pylori or Helicobacter is connected to several problems in the upper gastrointestinal tract, such as ulcers and gastritis. According to estimates, 30-40 percent of the population in developed countries has the infection.
Traditional diagnosis of the bacteria can be unpleasant for the patient, as it requires a biopsy using gastroscopy, which currently means that the patient has to swallow a tube that is then used to take a sample from the stomach. The accuracy of the procedure depends on the skills of the person performing the procedure, and getting a diagnosis may take several days.
Current commercial devices based on exhaled air analysis give a result with a 95 to 98 percent reliability, which means that the results must often be confirmed with gastroscopy. Those units only perform the analysis on carbon13.
VTT says its device has the benefit of eliminating false positives from the analysis. According to a study published in 2014 (Abhijit Maity et. al. J. Anal. At. Spectom. 29, 2014), a 100 percent analysis accuracy can be achieved when oxygen18 is analyzed from exhaled air in addition to carbon13.
Meanwhile, diagnosis methods based on respiratory air are a growing trend. In addition to Helicobacter, respiratory air can be used to analyze a person’s energy consumption and weight loss, early-stage Type 2 diabetes and blood poisoning or sepsis, a main cause of mortality after surgical operations.
VTT reported that it also plans follow-up projects intended to develop the device for diagnosing other illnesses, as well as analyzing proteins and various chemicals, and measuring Oxygen17. Because the device measures completely safe and stable isotopes, it can also be utilized by the food industry, according to the researchers.
The analyzer has possible other applications in the monitoring of surgery patients and unconscious patients, because it can operate next to the patient around the clock. Accurate and specific data can be obtained from each breathing cycle.
VTT’s prototype includes a computer, a pump and optics, and it is operated with a single button. It communicates wirelessly with tablets and smartphones. The result of the measurement is displayed immediately.
