The influence of dilution on the offline measurement of exhaled nitric oxide.


OBJECTIVE:Measurement of fractional exhaled nitric oxide (FeNO) is used to determine the presence and severity of eosinophilic airway inflammation in asthma and other wheezing illnesses. The gold standard of online measurement during a single prolonged exhalation is not suitable for use in young children. The international guidelines for offline measurements recommend collection of exhaled gas in an appropriate reservoir for later analysis in young children. The apparatus required for gas collection, however, creates dead space within the system, which may result in sample dilution and hence inaccuracy. Our objective was to investigate the effect such dilution might have on the accuracy of offline FeNO by comparing the results to online results. APPROACH:Thirty-five adult subjects without respiratory disease underwent online measurement of FeNO and, thereafter, undertook offline FeNO measurements via exhalation into a collection reservoir using one, five or ten inhalation-exhalation cycles. Fifteen of the subjects also exhaled using the five-breath technique via apparatus with additional dead space. An equation incorporating dead space volume and the number of breaths was used to predict the degree of dilution; the predicted results were compared to the measured results. MAIN RESULTS:The median (IQR) FeNO from a one-breath technique (22 (15-28) ppb was not significantly different to online values (19 (12-27) ppb, p  =  1.00), but the results from the five-breath technique (11 (4-19) ppb, p  <  0.0001), the ten-breath technique (6 (4-15) ppb, p  <  0.0001) and the additional dead space experiment (6 (3-8) ppb, p  =  0.0006) were significantly lower than online FeNO. Measured values were consistently significantly different to those predicted by the dilution equation, even when incorporating the exact exhaled volume of gas. SIGNIFICANCE:Offline FeNO results may be inaccurate when subjects are unable to fill the collection reservoir with a single exhalation, thus the technique may not be suitable for preschool children.


Physiol Meas


MacBean V,Pooranampillai D,Howard C,Lunt A,Greenough A




Has Abstract


2018-02-26 00:00:00












  • A comparison of methods for measurement of spatial resolution in two-dimensional circular EIT images.

    abstract::The literature concerning measurement of spatial resolution in electrical impedance tomography (EIT) is vague. Different groups often use their own method or a modified version of a better known method, thus hindering a generalized resolution measurement which could be useful for gauging the performance of one system ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Wheeler JL,Wang W,Tang M

    更新日期:2002-02-01 00:00:00

  • A finite element model of needle electrode spatial sensitivity.

    abstract::We used the finite element (FE) method to estimate the spatial sensitivity of a needle electrode for bioimpedance measurements. This current conducting needle with an insulated shaft was inserted in a saline solution and the current was measured at the neutral electrode. Model resistance and reactance were calculated ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Høyum P,Kalvøy H,Martinsen ØG,Grimnes S

    更新日期:2010-10-01 00:00:00

  • Cardio-respiratory signal extraction from video camera data for continuous non-contact vital sign monitoring using deep learning.

    abstract::Non-contact vital sign monitoring enables the estimation of vital signs, such as heart rate, respiratory rate and oxygen saturation (SpO2), by measuring subtle color changes on the skin surface using a video camera. For patients in a hospital ward, the main challenges in the development of continuous and robust non-co...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Chaichulee S,Villarroel M,Jorge J,Arteta C,McCormick K,Zisserman A,Tarassenko L

    更新日期:2019-12-02 00:00:00

  • The influence of cardiac preload and positive end-expiratory pressure on the pre-ejection period.

    abstract::The pre-ejection period (PEP) has recently been described as a potential parameter for monitoring cardiac preload. This study further investigated the influence of changes in intravascular volume status and the application of positive end-expiratory pressure (PEEP) on the pre-ejection period. In ten pigs, ECG, arteria...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Kubitz JC,Kemming GI,Schultheib G,Starke J,Podtschaske A,Goetz AE,Reuter DA

    更新日期:2005-12-01 00:00:00

  • Evaluation of an algorithm based on single-condition decision rules for binary classification of 12-lead ambulatory ECG recording quality.

    abstract::A new algorithm for classifying ECG recording quality based on the detection of commonly observed ECG contaminants which often render the ECG unusable for diagnostic purposes was evaluated. Contaminants (baseline drift, flat line, QRS-artefact, spurious spikes, amplitude stepwise changes, noise) were detected on indiv...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Di Marco LY,Duan W,Bojarnejad M,Zheng D,King S,Murray A,Langley P

    更新日期:2012-09-01 00:00:00

  • Monitoring nasal conductance by bilateral nasal cannula pressure transducers.

    abstract::Nasal obstruction is common and may disturb well-being during daytime and sleep. Its objective assessment by standard methods requires patient cooperation and inconvenient instrumentation. Therefore, the purpose of this study was to develop a novel, unobtrusive technique for continuous monitoring of changes in nasal c...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Thurnheer R,Bloch KE

    更新日期:2004-04-01 00:00:00

  • Cardiorespiratory coupling in young healthy subjects.

    abstract:OBJECTIVE:To quantify the presence of cardiorespiratory interaction in a group of 41 healthy subjects performing a subset of the Ewing test battery. APPROACH:We measure the empirical distribution of the cardiorespiratory coupling time (RI), defined as the time from inspiration onset to R peaks in the ECG. The study pr...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Sobiech T,Buchner T,Krzesiński P,Gielerak G

    更新日期:2017-11-30 00:00:00

  • Multi-frequency parameter mapping of electrical impedance scanning using two kinds of circuit model.

    abstract::Electrical impedance scanning (EIS) is a kind of potential bio-impedance measurement technology, especially aiding the diagnosis of breast cancer in women. By changing the frequency of the driving signal in turn while keeping the other conditions stable, multi-frequency measurement results on the object can be obtaine...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Liu R,Dong X,Fu F,You F,Shi X,Ji Z,Wang K

    更新日期:2007-07-01 00:00:00

  • Fetal beat detection in abdominal ECG recordings: global and time adaptive approaches.

    abstract::We present a method for location of fetal QRS in maternal abdominal ECG recordings. This method's initial, global approach was proposed in the context of the 2013 PhysioNet/Computing in Cardiology Challenge where it was tested on the 447 four channel one-minute recordings.The first step is filtering to eliminate basel...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Rodrigues R

    更新日期:2014-08-01 00:00:00

  • Photoplethysmography detection of lower limb peripheral arterial occlusive disease: a comparison of pulse timing, amplitude and shape characteristics.

    abstract::The assessment and diagnosis of lower limb peripheral arterial occlusive disease (PAOD) is important since it can lead progressively to disabling claudication, ischaemic rest pain and gangrene. Historically, the first assessment has been palpation of the peripheral pulse since it can become damped, delayed and diminis...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Allen J,Oates CP,Lees TA,Murray A

    更新日期:2005-10-01 00:00:00

  • Fractal analysis of foetal heart rate variability.

    abstract::Current methods for analysing foetal heart rate (FHR) patterns have yet to meet their full potential in the recognition of hypoxia in the foetus. Following the recent suggestion that fractal analysis can be applied to FHR recordings, the current paper describes a method for distinguishing two simultaneous fractal dime...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Gough NA

    更新日期:1993-08-01 00:00:00

  • Time variation of ammonia, acetone, isoprene and ethanol in breath: a quantitative SIFT-MS study over 30 days.

    abstract::A study of the concentrations of the common breath metabolites ammonia, acetone, isoprene, ethanol and acetaldehyde in the breath of five subjects over a period of 30 days has been carried out. Breath samples were taken and analysed in the early morning on arrival at the laboratory. The real time analyses of three con...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Diskin AM,Spanel P,Smith D

    更新日期:2003-02-01 00:00:00

  • Association between RR interval and high-frequency heart rate variability acquired during short-term, resting recordings with free and paced breathing.

    abstract::High-frequency (HF) oscillations in RR interval from 0.15-0.40 Hz are widely accepted as a measure of cardiac vagal outflow but the HF/RR relationship appears complex, particularly with longer RR intervals. The aim of this study was to evaluate the HF/RR interval relationship during free and paced breathing. HF power ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Sandercock G,Gladwell V,Dawson S,Nunan D,Brodie D,Beneke R

    更新日期:2008-07-01 00:00:00

  • The effect of ambient air temperature on whole-body bioelectrical impedance.

    abstract::It has previously been shown that extreme changes in ambient air temperature can affect whole-body bioelectrical impedance. The purpose of this study was to determine if more moderate changes in ambient air temperature, such as those experienced in most laboratory settings, would also affect bioelectric impedance anal...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Buono MJ,Burke S,Endemann S,Graham H,Gressard C,Griswold L,Michalewicz B

    更新日期:2004-02-01 00:00:00

  • In vivo neutron activation analysis of bone manganese in workers.

    abstract:OBJECTIVE:Manganese (Mn) is a neurotoxin. However, the impact of elevated, chronic Mn exposure is not well understood, partially due to the lack of a cumulative exposure biomarker. To address this gap, our group developed a compact in vivo neutron activation analysis (IVNAA) system to quantify Mn concentration in bone ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Liu Y,Rolle-McFarland D,Mostafaei F,Zhou Y,Li Y,Zheng W,Wells E,Nie LH

    更新日期:2018-03-23 00:00:00

  • Daily physical activity patterns from hip- and wrist-worn accelerometers.

    abstract::Accelerometer wear location may influence physical activity estimates. This study investigates this relationship through the examination of activity patterns throughout the day. Participants from the aging research evaluating accelerometry (AREA) study (n men  =  37, n women  =  47, mean age (SD)  =  78.9 (5.5) years)...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Shiroma EJ,Schepps MA,Harezlak J,Chen KY,Matthews CE,Koster A,Caserotti P,Glynn NW,Harris TB

    更新日期:2016-10-01 00:00:00

  • The measurement of sedentary patterns and behaviors using the activPAL™ Professional physical activity monitor.

    abstract::Epidemiological studies have associated the negative effects of sedentary time and sedentary patterns on health indices. However, these studies have used methodologies that do not directly measure the sedentary state. Recent technological developments in the area of motion sensors have incorporated inclinometers, whic...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Dowd KP,Harrington DM,Bourke AK,Nelson J,Donnelly AE

    更新日期:2012-11-01 00:00:00

  • Prediction of sustained harmonic walking in the free-living environment using raw accelerometry data.

    abstract:OBJECTIVE:Using raw, sub-second-level accelerometry data, we propose and validate a method for identifying and characterizing walking in the free-living environment. We focus on sustained harmonic walking (SHW), which we define as walking for at least 10 s with low variability of step frequency. APPROACH:We utilize th...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Urbanek JK,Zipunnikov V,Harris T,Fadel W,Glynn N,Koster A,Caserotti P,Crainiceanu C,Harezlak J

    更新日期:2018-02-28 00:00:00

  • Reference intervals for the evoked tympanic membrane displacement measurement: a non-invasive measure of intracranial pressure.

    abstract:OBJECTIVE:Evoked tympanic membrane displacement (TMD) is a non-invasive technique for assessing intracranial pressure (ICP). The aim of this study was to define reference intervals (RIs) in the healthy population. APPROACH:Measurements were made in 154 healthy adults. Results were quantified by V m, which is the most ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Campbell-Bell CM,Birch AA,Vignali D,Bulters D,Marchbanks RJ

    更新日期:2018-01-31 00:00:00

  • Chronodiagnostic acquisition of recovery speed of heart rate under bathing stress.

    abstract::Cycling on an ergometer is one effective means of measuring cardiovascular function while applying stress on the heart. Bathing in a hot water bath applies a low stress to the heart. The electrocardiograms of a healthy adult male (aged 35 at the start of study) were recorded while taking a hot water bath with no elect...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章


    authors: Ishijima M,Togawa T

    更新日期:1999-11-01 00:00:00

  • Circuit modeling of the electrical impedance: II. Normal subjects and system reproducibility.

    abstract::Part I of this series showed that the five-element circuit model accurately mimics impedances measured using multi-frequency electrical impedance myography (MFEIM), focusing on changes brought on by disease. This paper addresses two requirements which must be met if the method is to qualify for clinical use. First, th...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Shiffman CA,Rutkove SB

    更新日期:2013-02-01 00:00:00

  • Ischemic small intestine-in vivo versus ex vivo bioimpedance measurements.

    abstract:OBJECTIVE:Bioimpedance has been used to investigate changes in electrical parameters during ischemia in various tissues. The small intestine is a multi-layered structure, with several distinct tissue types, and ischemia related changes occur at different times in the different intestinal layers. When investigating how ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Strand-Amundsen RJ,Reims HM,Tronstad C,Kalvøy H,Martinsen ØG,Høgetveit JO,Ruud TE,Tønnessen TI

    更新日期:2017-05-01 00:00:00

  • Comparison of self-reported measure of sitting time (IPAQ) with objective measurement (activPAL).

    abstract::This study compared sitting time measured by a questionnaire (International Physical Activity Questionnaire; IPAQ) with concurrently measured objective sitting time from an accelerometer-based measure of thigh inclination (activPAL).Adults (n = 69), wore an activPAL for a week, and then completed the long-form 7 d rec...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Chastin SF,Culhane B,Dall PM

    更新日期:2014-11-01 00:00:00

  • A phantom for evaluating bone mineral density of the hand by dual-energy x-ray absorptiometry.

    abstract::Dual-energy x-ray absorptiometry (DXA) is a precise, widely used method for measuring bone mineral density (BMD), usually of the lumbar spine and femoral neck. Recent developments, such as a lower x-ray tube current and pixel by pixel analysis, enable smaller bones and thinner tissues volumes, as in the hand, to be me...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Steel SA,Swann P,Langley G,Langton CM

    更新日期:1997-08-01 00:00:00

  • Value of simulated body surface potential maps as templates in localizing sites of ectopic activation for radiofrequency ablation.

    abstract::Body surface potential maps recorded during catheter pace mapping can facilitate the localization of the site of origin of ventricular tachycardia. In this study, we investigated the value of a realistic computer model of the human ventricular myocardium in generating body surface potential maps as templates for ident...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Hren R,Horácek BM

    更新日期:1997-11-01 00:00:00

  • Characteristic impedance: frequency or time domain approach?

    abstract:OBJECTIVE:Characteristic impedance (Zc) is an important component in the theory of hemodynamics. It is a commonly used metric of proximal arterial stiffness and pulse wave velocity. Calculated using simultaneously measured dynamic pressure and flow data, estimates of characteristic impedance can be obtained using metho...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Qureshi MU,Colebank MJ,Schreier DA,Tabima DM,Haider MA,Chesler NC,Olufsen MS

    更新日期:2018-01-31 00:00:00

  • Restoration of the electrocardiogram during mechanical cardiopulmonary resuscitation.

    abstract:OBJECTIVE:An artefact-free electrocardiogram (ECG) is essential during cardiac arrest to decide therapy such as defibrillation. Mechanical cardiopulmonary resuscitation (CPR) devices cause movement artefacts that alter the ECG. This study analyzes the effectiveness of mechanical CPR artefact suppression filters to rest...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Isasi I,Irusta U,Aramendi E,Idris AH,Sörnmo L

    更新日期:2020-11-06 00:00:00

  • Life-threatening false alarm rejection in ICU: using the rule-based and multi-channel information fusion method.

    abstract::False alarm (FA) rates as high as 86% have been reported in intensive care unit monitors. High FA rates decrease quality of care by slowing staff response times while increasing patient burdens and stresses. In this study, we proposed a rule-based and multi-channel information fusion method for accurately classifying ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Liu C,Zhao L,Tang H,Li Q,Wei S,Li J

    更新日期:2016-08-01 00:00:00

  • Endocardial center motion for quantification of left ventricular discoordination in heart failure using cine MRI.

    abstract:OBJECTIVE:To compare a novel cardiovascular magnetic resonance technique for the assessment of left ventricular (LV) mechanical discoordination by characterizing the endocardial center motion (ECM) in short-axis cine MRI in healthy volunteers and heart failure patients with left bundle branch block (HF-LBBB). APPROACH...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Saporito S,Houthuizen P,Aben JMM,Westenberg JJM,van Den Bosch HCM,van Assen HC,Mischi M

    更新日期:2018-02-28 00:00:00

  • Assessment of 1-lead and 2-lead electrode patterns in electrical impedance endotomography.

    abstract::Electrical impedance endotomography (EIE) is a modality of impedance imaging where the electrodes are located on an insulating core placed at the centre of the region of interest. The absence of a physical limit to the medium surrounding the probe enables the use of remote electrodes. The present study compares the fe...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Fournier-Desseux A,Jossinet J

    更新日期:2005-08-01 00:00:00