Measurement Of Nasal Airflow Research Articles

An investigation on airflow in pathological nasal airway by PIV

Understanding of airflow characteristics in nasal cavity is closely related with the physiological functions, like air-conditioning and smelling, and pathological aspects in nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. The next step on this topic is naturally studies for disordered nasal airways and this is the main purpose of this article. Airflows in the pathological nasal airways, including nasal cavity and upper pharynx, of Korean adults are investigated experimentally by PIV measurement technique and air resistance measurements. Quantitative data for normal and pathological nasal airway are obtained. Average and RMS velocity distributions are obtained for inspirational and expirational nasal airflows. The CBC PIV algorithm with window offset is used for PIV flow analysis. PIV measurements of nasal airflow for nasal cavities with 50% and 70% adenoid vegetation are conducted for the first time. The asymmetric nasal cavities, due to either congenital deformity or injury, are also investigated. Comparisons in nasal airflows for both normal and abnormal cases are also appreciated and airflow characteristics that are related with the abnormalities in nasal cavity are proposed.

Nasal Dyspnea: The Place of Rhinomanometry in its Objective Assessment

"Nasal dyspnea" describes the common symptom of nasal airway obstruction, which usually is assessed subjectively. Objective, quantitative methods are needed to assess the nasal airway adequately. Rhinomanometry, in use for >30 years, was reviewed. No other symptom of rhinitis can be measured as objectively and accurately as that of nasal obstruction. Determinations by rhinomanometry are precise, usually better than 5%. Most rhinomanometers meet the published requirements of standardization by the International Rhinologic Society. An improved system for scoring symptoms of nasal dyspnea is suggested. Rhinomanometry, potentially a gold standard for the objective measurement of obstructed nasal airflow, has a proven place in the selection of patients for septal and nasal valve reconstruction. Recommendations are given for extension of the standards to account for the near universal computerization of equipment. Miniaturization of equipment will increase its application to trials of drugs for rhinitis.

Simultaneous real-time measurements of mastication, swallowing, nasal airflow, and aroma release.

Mastication, swallowing, breath flow, and aroma release were measured simultaneously in vivo using electromyography, electroglottography, a turbine air flow meter, and the MS-Nose, respectively. Signals were synchronized either electronically or by aligning the nasal airflow data with the breath by breath release of acetone. Chewing affected nasal airflow, with the flow fluctuations following the mastication pattern. Data analysis suggested that air was pumped out of the mouth into the throat with each chew, and the mean volume was 26 mL. Aroma release was associated with the pulses of air pumped from the mouth with each chew. During swallowing, there was no nasal airflow, but after swallowing, aroma release was evident. The volume of the retronasal route was estimated at 48 mL when swallowing and 72 mL when samples were chewed. The combination of techniques shows the effects of physiological processes on aroma release.

아데노이드 비대증에 의한 비정상 비강 내 유동의 PIV해석

Airflow in the nasal cavity of Korean adults is investigated experimentally by PIV measurement. Quantitative data for normal and abnormal nasal cavities with adenoid vegetation are obtained. The CBC PIV algorithm with window offset is used for PIV flow analysis. Average and RMS distributions are obtained for inspirational and expirational nasal airflows. Comparisons between western and Korean nasal airflows are appreciated. Due to the difference in geometry of the frontal pan of nasal cavity, the flow near nares shows the difference. For the joint research on nasal deceases. PIV measurements of nasal airflow for nasal cavities with 50% and 70% adenoid vegetation are conducted for the first time. Comparisons in nasal airflows for both normal and abnormal cases are also appreciated.br/

Nasal Airflow Measurement During Quiet Respiration In Normal Subject Using Nasal Anemometer

Nasal Airflow Measurement During Quiet Respiration In Normal Subject Using Nasal Anemometer

Nasal Airflow Measurement During Quiet Respiration In Normal Subject Using Nasal Anemometer

Nasal Airflow Measurement During Quiet Respiration In Normal Subject Using Nasal Anemometer

Nasal Airflow in Health and Disease

This review examines our present understanding of the physiology, pathophysiology and pharmacology of nasal airflow. The main aim of the review is to discuss the basic scientific and clinical knowledge that is essential for a proper understanding of the usefulness of measurements of nasal airflow in the clinical practice of rhinology. The review concludes with a discussion of the measurement of nasal airflow to assess the efficacy of surgery in the treatment of nasal obstruction. Areas covered by the review include: influence of nasal blood vessels on nasal airflow; nasal valve and control of nasal airflow; autonomic control of nasal airflow; normal nasal airflow; nasal cycle; central control of nasal airflow; effect of changes in posture on nasal airflow; effect of exercise on nasal airflow; effect of hyperventilation and rebreathing on nasal airflow; nasal airflow in animals; cerebral effects of nasal airflow; sensation of nasal airflow; sympathomimetics and sympatholytics; histamine and antihistamines; bradykinin; and corticosteroids.

Effect of exercise and nasal splinting on static and dynamic measures of nasal airflow

The main aim of this study was to assess the separate and combined effects of exercise and nasal splinting on static and dynamic measures of nasal airflow. In a randomized crossover design, 12 healthy participants (6 men, 6 women) performed static and dynamic spirometric nasal airflow assessment tests, with or without nasal splinting (Breathe-Right™), before and after a maximal oxygen uptake (VO 2max ) treadmill test. At least 7 days later, the V O 2max and nasal airflow tests were repeated. The results showed that the measured variables were not significantly different with and without nasal splinting. We conclude that the absence of significantly enhanced nasal patency observed for nasal splinting and after exercise suggest that these factors have a minimal impact on nasal airflow volume and rate.

The Use of Low Cost Dual Nostril Airflow Anemometer for the Measurement of Nasal airflow In Normal Subjects

The Use of Low Cost Dual Nostril Airflow Anemometer for the Measurement of Nasal airflow In Normal Subjects

Effect of Submucosal Diathermy to the Inferior Turbinates on Unilateral and Total Nasal Airflow in Patients with Rhinitis

The efficacy of the controversial treatment of submucosal diathermy to the inferior turbinates (SMDIT) was evaluated objectively. Twenty-seven patients with chronic rhinitis were investigated by hourly posterior rhinomanometry to assess changes in total and minimum (Fmin) and maximum (Fmax) unilateral nasal airflow over 5 h, before and 2-3 months after standardized SMDIT treatment. Nasal airflow was recorded at a sample pressure of 75 Pa and the results are reported as medians with interquartile range. Whilst SMDIT caused a significant 51% increase (p<0.0001) in total nasal airflow from 246 cm3/s (131) to 371 cm3/s (133) the changes in unilateral airflow provided further evidence which strongly supported the benefits of this operation. Unilateral Fmin significantly increased by 136% (p<0.0001) from 69 cm3/s (82) to 163 cm3/s (74) and Fmax significantly increased by 23% (p<0.0001) from 171 cm3/s (74) to 211 cm3/s (59). The effect of surgery was to ?splint? to the turbinate in a state of relative vasoconstriction. Our findings therefore provide functional evidence of submucosal fibrosis following SMDIT. The greater percentage change in unilateral Fmin suggests that this parameter is a more sensitive index of the effect of nasal surgery than total nasal airflow measurements. The importance of considering the nose as two separate airways in the evaluation of nasal treatments is emphasized.

Temporal Characteristics of Velopharyngeal Function in Children

This investigation was designed to examine the performance of children with normal speech on temporal aspects of aerodynamic tasks related to velopharyngeal closure.The investigation was a descriptive evaluation of variability in aerodynamic features related to velopharyngeal function during multiple repetitions of the word "hamper."Children without speech or velopharyngeal difficulties were seen in an experimental laboratory setting for the evaluation procedures.Twenty-seven subjects were recruited for the experiment. Three subjects were rejected because of behavioral difficulties, and the remaining 24 subjects were subdivided into 4 groups of 6 children (3 males and 3 females) aged 3, 6, 9, and 12 years. The children, who were from local schools and day care centers, volunteered to participate in the experiment. All of the children had age-appropriate speech, language, and hearing abilities, as determined by screening tests administered by one of the examiners (L.T.).Mean and variability of pressure-flow measures of peak intraoral air pressure and peak nasal airflow and the temporal measures accompanying each air pressure or airflow pulse were evaluated for the age groups of children examined in the experiment.The aerodynamic procedures employed to evaluate velopharyngeal closure during speech were reliable for use with young children. There was a numerical trend toward decreased duration of the temporal parameters with increasing age. Thus, children demonstrated durational values similar to those previously reported for normal-speaking adults. In general, peak oral air pressure and nasal airflow values were like those of previous investigations and demonstrated low variability across all age groups of children tested.The data from the present investigation provide a preliminary base for comparison of temporal features of velopharyngeal closure for the aerodynamic evaluation of children with impaired velopharyngeal function.

Aerodynamic Assessment of Velopharyngeal Function during Normal Speech Containing Different Places of Articulation

The aim of this study was to describe the aerodynamics related to velopharyngeal function during speech in bilabial, dental, and velar articulatory positions in Swedish speakers. Repeated syllables including voiceless stop consonants and sentences including combinations of voiceless stops and nasal consonants were uttered by 11 normal adults. Oropharyngeal pressure was assessed with a miniature pressure transducer positioned transnasally, in combination with measurement of nasal pressure and nasal airflow. The corresponding velopharyngeal opening area was estimated. The results suggest that the velopharyngeal function during stop consonants is similar in different articulatory positions. Differences in oropharyngeal pressure and nasal airflow between bilabial versus dental and velar positions were found, presumably due to differences in volume and compliance of the vocal tract.

Physiological versus Pharmacological Decongestion of the Nose in Healthy Human Subjects

In the present study we were interested to determine whether the maximum unilateral nasal airflow associated with the nasal cycle (Fmax physiol) was equivalent to the maximum unilateral nasal airflow that could be achieved by the application of a topical nasal decongestant (Fmax pharmacol). Eight healthy subjects (three male and five female, aged between 19-28 years) were recruited for this study. Unilateral nasal airflow was measured using posterior rhinomanometry at the inspiratory reference pressure of 75 Pa by alternately occluding each nostril with surgical tape. The study was run over 2 consecutive days. On day one, measurements of unilateral nasal airflow were performed every hour for 8 h in each subject and Fmax physiol was found to be 265 cm3/sec (147) (median and interquartile range). On day 2 the median unilateral nasal airflow before application of the nasal decongestant was 171 cm3/sec (140) and this increased to 251 cm3/sec (127) (p=0.046) at 15 min and to 278 cm3/sec (134) (p=0.005) at 45 min after application of the decongestant (Fmax pharmacol). A paired comparison of Fmax physiol and Fmax pharmacol showed that these nasal airflow measurements were not significantly different (p>0.999). The results show that there was no difference between the maximum physiological decongestion produced during the course of the nasal cycle and that produced pharmacologically by a topical nasal decongestant. This indicates that the point of maximal sympathetic vasoconstrictor tone occurring during the nasal cycle causes a constriction of the nasal venous sinuses that is equal to the constrictor response that can be achieved by applying a topical sympathomimetic medication.

Spontaneous Changes of Unilateral Nasal Airflow in Man. A Re-examination of the ‘Nasal Cycle’

It is now over 100 years since Kayser (Archiv Fur Laryngol Rhinol 1895; 3; 101-120) first reported in the scientific literature that the human nasal passages exhibit spontaneous changes in unilateral nasal airway resistance, yet our understanding of this unusual phenomenon is still very confused. Spontaneous, reciprocal changes in unilateral nasal resistance are often referred to as a “nasal cycle” and although this term is now commonly used to describe spontaneous changes in nasal resistance in man and animals, there is little evidence for any true periodicity. A major problem in increasing our knowledge and understanding of the so-called “nasal cycle” is that most studies have relied on simple descriptions of the changes in nasal resistance and have not developed any numerical parameters to quantify the changes in resistance over time. This lack of definition of what actually constitutes a nasal cycle has meant that the literature of the present day generally accepts the views put forward by Heetderks (Am J Med Sci 1927; 174: 231-244) and Stoksted (Acta Otolaryngol (Stockh) 1953; Suppl 109: 159-175) that around 80% of the healthy population exhibit a regular cycle. In order to define the characteristics of the spontaneous changes in nasal airway resistance we have used numerical measures of reciprocity and also developed a measurement of the division of airflow between the nasal passages over time. With these two parameters it is possible to describe the nature of the spontaneous changes in airflow in numerical terms and to define what exactly constitutes a nasal cycle. Fifty-two volunteers underwent hourly measurement of unilateral nasal airflow for 8 h. For each volunteer, two values were derived from the graph of unilateral nasal airflows against time: the correlation coefficient between unilateral airflows (r) and the airflow distribution ratio between the two nasal airways (ADR). The spread of different types of airflow pattern (nasal cycle) throughout the population was illustrated by plotting r against ADR for each subject. A nasal cycle was defined as having an r value between –0.6 and -1.0, and an ADR value between 0.7 and 1.0. Only 21% (11 of the 52 volunteers) exhibited airflow patterns that could be defined as a nasal cycle in these terms. This finding contradicts the generally accepted, but undefined, view that around 80% of the population exhibit a regular nasal cycle. The numerical definition of a nasal cycle in terms of both reciprocity and airflow distribution, as described in this paper may help to clarify our understanding of this interesting phenomenon and allow rhinologists to describe the spontaneous changes in nasal airflow in more exact terms than have been used previously in the literature.

An instrument for the non-invasive objective assessment of velar function during speech

This paper describes the development of a non-invasive, computer-based, clinical instrument that infers velar function by way of the measurement of nasal and oral airflow. The design criteria of the instrument were based upon a wide ranging review of current practice and available techniques. The instrument measures and displays both nasal and oral airflow, along with the envelope of the speech sound waveform. This allows the clinician to determine whether airflow is associated with oral or nasal airflow and, hence, to infer the position of the velum. Preliminary clinical trials suggest that the instrument provides valuable objective information about the movement of the soft palate, particularly within the time domain. Hence, it is believed that the device provides additional information for the assessment of velar function, complementing those techniques currently employed.

Objective and subjective nasal airflow

Purpose: This study was designed to assess whether a correlation exists between the rhinomanometric measurement of nasal resistance, nasal airflow, and the subjective sensation of airflow. Materials and Methods: Sixteen patients with recurrent maxillary sinusitis were examined before and after uncinectomy during functional endoscopic sinus surgery. Subjective nasal sensation of airflow was assessed by means of a visual scale before and after uncinectomy. Rhinomanometry was performed three times for every patient: before anesthesia, and before and after uncinectomy. The subjective nasal sensation of airflow was compared with the nasal airflow and resistance to flow as measured by rhinomanometry. Results: Rhinomanometric measurements were almost the same before and after uncinectomy, with no significant difference, whereas patients reported a significant improvement in nasal airflow. Conclusion: Rhinomanometric measurements of nasal airflow and resistance often have no correlation to the patient's sensation of airflow. However, because it is the patients' ultimate concern to breathe more comfortably, the rhinomanometer has little clinical value.

Age and velopharyngeal function during speech production.

This investigation was designed to determine if velopharyngeal function during speech production, as reflected in measures of nasal air flow, differs with age in adults. Eighty subjects were studied, 40 women and 40 men, representing four age groups (20-30, 40-50, 60-70, and 80 + years). Results showed no age-related differences in nasal air flow. Sex-related differences in flow were found on productions of nasal consonants only. These findings do not support the suggestion of Hutchinson, Robinson, and Nerbonne (1978) that velopharyngeal function deteriorates with age.

Timing and magnitudes of oral and nasal flow in cochlear implant patients and normals

Vowel nasalization was assessed in cochlear implant patients pre- and post-implant, and in normal-hearing speakers, using measures of oral, nasal, and total airflow. Speech materials consisted of the utterance /taC/, (where C=/n/, /m/, or /d/, embedded in a carrier phrase. Airflow was transduced with a two-chamber Rothenberg mask. Measures included the relative timing of the onsets of nasal and oral airflow, and the ratios of peak oral and nasal flow to total flow following the /t/ release. Pre- to post-implant differences may reflect an adjustment of the control of the velum, possibly in response to a perceived difference in nasalization and/or as a consequence of concomitant changes in other speech parameters. Preliminary ratio data from one cochlear implant patient indicate a possible enhancement of the nasal/non-nasal contrast post-implant. Further, in the /tad/ utterance, the oral flow pulse at consonant release was accompanied by a small pulse of nasal flow: velar closure during the consonant may have been assisted by the oral pressure increase, thus the pressure drop at consonant release would result in a small passive velar opening movement. These observations and additional measures are being explored further. [Work supported by NIH.]

Resection of Obstructing Inferior Turbinates Following Rhinoplasty

Total inferior turbinectomy was carried out in 38 patients who complained of nasal obstruction following rhinoplasty or rhinoseptoplasty and in whom hypertrophied inferior turbinates were found to be the cause of obstruction. Postoperatively, relief of nasal obstruction was reported by 84 percent of patients, while rhinoscopy showed wide, clean nasal airways in 92 percent. Nasal airflow measurements in 32 tested patients showed increased patency in all of them, including 3 who still complained of nasal obstruction postoperatively. The follow-up period ranged from 1 to 7 years (mean 2.8 years). Atrophic changes of the nasal mucosa or chronic purulent infection was not observed in any of the patients. Because the results of partial procedures on the inferior turbinates are often unsatisfactory, I suggest performing total inferior turbinectomy in patients with obstructing inferior turbinates following rhinoplasty.

Nasal airflow measurement using a compensated thermistor anemometer

A nasal anemometer is a useful tool for speech therapists in their assessment of treatment effectiveness. This work is the second part of a research scheme which describes how the system is compatible with the use of an IBM PC-AT microcomputer using a suitable analogue-to-digital convertor. This enables the system to perform signal processing and to display, draw, and calculate a numerical 'figure of merit' using Kendall's tau nonparametric correlation.