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Background Current techniques for measuring absolute lung volumes rely on bulky and expensive equipment and are complicated to use for the operator and the patient. A novel method for measurement of absolute lung volumes, the MiniBox method, is presented. Research Question Across a population of patients and healthy participants, do values for total lung capacity (TLC) determined by the novel compact device (MiniBox, PulmOne Advanced Medical Devices, Ltd.) compare favorably with measurements determined by traditional whole body plethysmography? Study Design and Methods A total of 266 participants (130 men) and respiratory patients were recruited from five global centers (three in Europe and two in the United States). The study population comprised individuals with obstructive (n = 197) and restrictive (n = 33) disorders as well as healthy participants (n = 36). TLC measured by conventional plethysmography (TLCPleth) was compared with TLC measured by the MiniBox (TLCMB). Results TLC values ranged between 2.7 and 10.9 L. The normalized root mean square difference (NSD) between TLCPleth and TLCMB was 7.0% in healthy participants. In obstructed patients, the NSD was 7.9% in mild obstruction and 9.1% in severe obstruction. In restricted patients, the NSD was 7.8% in mild restriction and 13.9% in moderate and severe restriction. No significant differences were found between TLC values obtained by the two measurement techniques. Also no significant differences were found in results obtained among the five centers. Interpretation TLC as measured by the novel MiniBox system is not significantly different from TLC measured by conventional whole body plethysmography, thus validating the MiniBox method as a reliable method to measure absolute lung volumes.

BackgroundAmong the most basic measures of respiratory function is the total lung capacity (TLC). TLC is the pulmonary gas volume at maximal lung inflation, which is the sum of the volume of gas that can be exhaled –the vital capacity (VC)– and the volume of gas that cannot –the residual volume (RV). Determination of VC requires only spirometry whereas determination of RV or TLC requires body plethysmography, gas dilution or washout, or thoracic imaging, each of which is more complex than spirometry, and none of which is suited to routine office practice, population screening, or community medicine. To fill this gap, we describe here a new approach to determine TLC without plethysmography.MethodsIn a heterogeneous population of 434 volunteers (265 male, 169 female; 201 healthy, 170 with airflow obstruction, and 63 with ventilatory restriction), we determined TLC in the standard fashion using conventional body plethysmography (TLCpleth). In the same individuals, we also determined TLC in a novel fashion using the MiniBox ™ (TLCMB). To obtain TLCMB, population-based data from traditional spirometry together with flow-interruption transients were subjected to data mining and machine-learning to create for each individual subject an unbiased statistical determination of TLC.ResultsFor the combined heterogeneous population, we found TLCpleth = 1.02TLCMB −0.091 L, adjusted r2=0.824. For the heterogeneous population as a whole, and for each subpopulation, TLCMB closely tracked TLCpleth. For 26 healthy subjects measured on different days, the coefficient of variation for repeated measurements in was 3.3% for TLCpleth versus 1.6% for TLCMB.ConclusionsThese results establish the validity and potential utility of a new method for rapid, accurate, and repeatable determination of TLC in a heterogeneous patient population, but without the need of a plethysmograph.

Using Triumf's neutral atom trap, Trinat, for nuclear $\ensuremath{\beta}$ decay, we have measured the $\ensuremath{\beta}$ asymmetry with respect to the initial nuclear spin in $^{37}\mathrm{K}$ to be ${A}_{\ensuremath{\beta}}=\ensuremath{-}0.5707{(13)}_{\mathrm{syst}}{(13)}_{\mathrm{stat}}{(5)}_{\mathrm{pol}}$, a 0.3% measurement. This is the best relative accuracy of any $\ensuremath{\beta}$-asymmetry measurement in a nucleus or the neutron, and is in agreement with the standard model prediction $\ensuremath{-}0.5706(7)$. We compare constraints on physics beyond the standard model with other $\ensuremath{\beta}$-decay measurements, and improve the value of ${V}_{\mathrm{ud}}$ measured in this mirror nucleus by a factor of 4.