For determination of breath-alcohol concentration (BrAC) the examined subject has to perform a breath test with forced expiration. During this test essential physical quantities change continuously. Ethanol concentration, breath temperature, and breath flow are such important quantities. Significant results can only be obtained if concentration (BrAC) and temperature have reached final values a...

In order to assess the relationship between methane (CH4) producing status and the breath excretion of hydrogen (H2) in healthy subjects, breath CH4 and H2 were simultaneously measured for 14 hours after oral ingestion of 10 g lactulose in 65 young volunteers. Forty were breath CH4 producers and 25 were not. Statistically significant differences were observed between both groups, with lower val...

BACKGROUND Several modifications of the 13C-urea breath test have been published. For reasons of cost efficiency and practicability, the urea dose and measurement duration should be reduced while still maintaining excellent diagnostic accuracy. AIMS To establish a validated simple protocol for the urea breath test with 50 mg 13C-urea and to compare this protocol with the conventional urea bre...

There have been a considerable number of cases litigating the validity of the forensic breath alcohol test and the potentials for a false positive ethanol reading. Recently, a claim asserted that the prior use of an over-the-counter (OTC) “oral care strip” normally used to suppress halitosis of the oral cavity, produced a false positive result when a subject was given a breath alcohol test duri...

Background Cardiac magnetic resonance (CMR) can be used to quantify cardiac mechanics from images that are generally acquired during an end-expiratory breath-hold. Unfortunately, it is difficult for subjects to hold their breath at the exact same position when undergoing a series of breath-holds during a typical CMR study. The effect of patient-specific variability in breath-hold positions on m...