Breath diagnostics

HWG based gas sensing such as in breath diagnostics or process monitoring have the required breakthrough potential to bring the advantages of HWG based sensing concepts to bear. 

Future prospects of breath diagnostics using laser techniques... 

Miirtz M. 2005. Breath diagnostics using laser spectroscopy . Opt. Photon. News 16(1) 30-35. 

Breath diagnostics involve the analysis of a human breath sample to monitor, diagnose, and detect diseases and conditions. Exhaled breath contains a complex mixture of nitrogen, oxygen, carbon dioxide, water, and trace amounts of various volatile organic compounds hke NO, acetone, isoprene, and ammonia. Many of these species are formed as the by-products of metabohc processes and can be used as biomarkers for various diseases. Examples of such biomarkers are acetone for diabetes mellitus (type I), ammonia for renal disease, NO for asthma, etc. 

A breath test, used to determine the presence of Helicobacter pylori, associated with stomach ulcers, is an example of a diagnostic product involving separate drug and device components. To perform the test, a patient swallows some isotopically (e.g. 

Ketogenesis occurs in mitochondria of hepatocytes when excess acetyl CoA accumulates in the fasting state. HMG CoA synthase forms HMG-CoA, and HMG-CoA lyase breaks HMG-CoA into acetoacetate, which can subsequently be reduced to 3-hydroxybutyrate. Acetone is a minor side product formed nonenzymatically but is not used as a fuel in tissues. It does, however, impart a strong odor (sweet or fruity) to the breath, which is almost diagnostic for ketoacidosis. 

A variety of factors can trigger insomnia. Medications, medical illness, pain, stress, schedule changes, depression, anxiety, and nighttime breathing problems all can produce insomnia. When insomnia has no clear cause, that is, it is not secondary to another condition, it is termed primary insomnia. The diagnostic criteria for primary insomnia are shown in Table 9.1. 

Breathing-Reiated Sieep Disorders. The breathing-related sleep disorders include obstructive sleep apnea, central sleep apnea, and alveolar hypoventilation. Of these three, obstructive sleep apnea is by far the most common. The patient with sleep apnea usually breathes normally when awake and only stops breathing while asleep. Occasional episodes of apnea are normal, but five or more episodes of apnea per hour are usually considered diagnostic of the disorder. 

Panic disorder is characterized by the repeated and often unpredictable occurrence of panic attacks. According to the Diagnostic and Statistical Manual of Mental Disorders, panic attacks have an abrupt onset, reach their peak in 10 minutes, and are accompanied by at least 4 of 13 listed symptoms, which include shortness of breath, increased heart rate, chest pain, dizziness, choking sensations, numbness or tingling, hot/cold flashes, sweating, trembling, and nausea. Victims of these episodes feel an intense fear that can be better characterized as terror, often of losing control of their body and/or... 

Sensors for Breath Analysis An Advanced Approach to Express Diagnostics and Monitoring of Human Diseases... 

This study demonstrates high efficacy and expediency of the TCNQ derivative-based point-contact multistracture as a prospective asset for development of new sensors. The complex character of the sensors response curve and correlation of some response characteristics with different pathological manifestations in human breath, may be further used as a noninvasive diagnostic method alternative to some invasive approaches currently routinely used in clinic. The need for reliable and feasible gas analysis methods functional in presence of atmospheric air, opens opportunities for application of the proposed sensor technique in other spheres of human activity. High sensitivity of the point-contact multistructure enabling analysis of composite gas mixtures, opens up wide possibilities to apply the demonstrated approach for environment and health protection, such as detection of trace amounts... 

Abnormal respiratory breathing patterns are of limited practical value, since a comatose patient due to cerebrovascular disease often requires immediate airway protection and mechanical ventilation. Urgent diagnostic imaging will provide the appro-... 

The hydrogen (H2) breath test is generally considered the diagnostic method of choice because it is sensitive, noninvasive, and relatively inexpensive. Normally, humans exhale very little H2 gas as H2 is not a product of human metabolism. However, H2 and other gases are produced when undigested lactose in the colon is fermented by bacteria. The H2 is absorbed and carried through the bloodstream to the lungs, where it is exhaled and can be detected. Raised H2 levels in exhaled air indicate insuffi-... 

Blake, R.S., Whyte, C., Monks, P.S., Ellis, A.M. Proton transfer reaction time-of-flight mass spectrometry a good prospect for diagnostic breath analysis. In Amann, A., Smith, D. (eds.) Breath analysis for clinical diagnosis and therapeutic monitoring, p. 45. World Scientific, Toh Tuck Link, Singapore (2005)... 

Miekisch, W., Schubert, J.K. From highly sophisticated analytical techniques to life-saving diagnostics technical developments in breath analysis. Trends Anal. Chem. 25, 665-673 (2006)... 

Type 1 question regarding diagnostic accuracy of a test In patients coming to the emergency department with shortness of breath, how well does B-type natriuretic peptide (BNP) or N-terminal pro-BNP predict (identify the presence of) heart failure as assessed by the cardiac ejection fraction measured by echocardiography ... 

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