Validity of the Nasometer Measuring the Temporal Characteristics of Nasalization

Objective:

To examine the validity of the Nasometer (KayPENTAX, Lincoln Park, NJ) in measuring the temporal characteristics of nasalization by comparing the Nasometer measures to the measures from an external criterion procedure.

Design:

Speech samples consisted of three rate-controlled nonsense syllables, which varied in their vowel compositions: /izinizi/, /azanaza/, and /uzunuzu/. Acoustic data were recorded simultaneously through the Nasometer and an external criterion procedure (a specialized microphone set that collected acoustic signals separately for the nasal and oral channels). Speech segment durations measured from the two instrumental conditions were compared on the Nasometer display and the Computerized Speech Lab (KayPENTAX, Lincoln Park, NJ) display. Five durational variables were measured: total utterance duration, nasal onset interval, nasal consonant duration, nasal offset interval, and total nasalization duration.

Participants:

Fourteen normal adults who speak American English as their first language participated in the study.

Results:

No significant differences were found between the measures from the Nasometer and those from an external criterion procedure in all the durational variables pertinent to nasalization. Different vowels, however, yielded significantly different patterns in these durational variables, in which the low vowel /a/ context revealed significantly longer total nasalization duration than did the high vowel /i/ and /u/ contexts.

Conclusions:

The results suggest that the Nasometer can be used as a valid tool to measure the temporal characteristics underlying nasalization and confirm significant vowel effects on the temporal patterns of nasalization.

Evaluation of nasal obstruction with Odiosoft-Rhino in nasal septal deviation

BACKGROUND

Evaluation of a recently developed method for measuring nasal obstruction.

OBJECTIVE

To investigate the reliability of a new software program called Odiosoft-Rhino (OR) as a presumptive diagnostic method to evaluate the nasal airflow of patients who have nasal septal deviation and to compare OR results with the acoustic rhinometry (AR) results and visual analogue scale (VAS) of nasal obstruction.

SETTING

Referral centre, institutional practice.

METHODS

OR uses a software program to analyze the original sounds of nasal airflow and evaluate the sounds of both nasal inspiration and expiration and then performs spectral and frequency analysis. OR and AR were performed on 56 patients with nasal septal deviations and 52 healthy controls. Their VAS, minimal cross-sectional area (MCA)1, and MCA2 measurements and nasal expiratory sound analysis between 200 to 500, 500 to 1000, 1000 to 2000, 2000 to 4000, and 4000 to 6000 Hz frequencies were noted for the left and right nasal cavities.

MAIN OUTCOME MEASURE

Assessment and comparison of nasal obstruction with OR and AR methods.

RESULTS

There was a significant difference between the MCA1 and MCA2 values and the nasal expiratory sound intensity of the deviated patients at 200 to 500, 500 to 1000, 1000 to 2000, and 2000 to 4000 Hz of the patient group and the control group (p < .001). There was a correlation between the OR results of 2000 to 4000 and 4000 to 6000 Hz intervals and the MCA1 results of the deviated sides. From the receiver operating characteristic curve analysis, the pooled results showed that 81.8% of deviated patients in the 2000 to 4000 Hz frequency range were found under the curve (p < .001). Related to this, 83.4% sensitivity and 82.1% specificity with a 14.5 dB cutoff point were determined.

CONCLUSION

The OR test is noninvasive and requires little cooperation. The sensitivity and specificity of the OR test are reliable, so we could propose to use OR as a new diagnostic method to evaluate the nasal airflow in clinical practice. However, more studies with wider series and some technical modification are needed.

Rhinometry: an important clinical index for evaluation of the nose before and after rhinoplasty

BACKGROUND

Preoperative planning and postoperative outcome assessment in rhinoplasty are important. For preoperative planning, some standard relationships are defined and evaluated primarily with standard photographs, but photographs do not necessarily reflect reality. Outcome assessment, on the other hand, is mostly subjective, and again, even photographic analyses may not address real changes after rhinoplasty.

METHODS

"Rhinometry" is introduced as a clinical method for preoperative evaluations and postoperative judgments, and rhinometric parameters are defined. Measurements of these parameters were performed for 300 patients before rhinoplasty and in the follow-up visits 3 months postoperatively.

RESULTS

Preoperatively, the nasal length and tip projection for most patients were more than ideal. There was moderate reduction in nasal length (mean, 9.21 mm) and a decrease in tip projection (mean, 3.34 mm) for the majority of the patients after rhinoplasty. Reductions in nasal length, tip projection, bony base width, alar base width, and alar base width during a smile were statistically significant. Patients who underwent surgery using the closed approach had significantly more reduction in nasal length and less reduction in tip projection. All the patients were satisfied with these pre- and postoperative data. Rhinometry changed the ideas of the authors about some changes that their operative approaches produce.

CONCLUSIONS

Rhinometry can change the ideas of plastic surgeons about the changes their operative approaches accomplish and can be a very useful guide for patients. It is recommended as a part of the pre- and postoperative physical examination of patients undergoing rhinoplasty.

Acoustic rhinometry in preschool children

OBJECTIVE

The aim of this study was to measure nasal cavity volume (NV) in preschool children with the use of acoustic rhinometry (AR).

STUDY DESIGN AND SETTING

Prospective study: 1) Nasal cavity models were used to test the correlations between NV, minimal cross-sectional area (MCA), and nasal resistance; 2) 97 four-year-olds (48 boys, 49 girls) and 137 five-year-olds (68 boys, 69 girls) children were selected to undergo AR.

RESULTS

1. Model tests showed that the resistance correlated better with the changes of the volume than the MCA. 2. The average bilateral NV in preschool children was 2.03 +/- 0.4 mL. There was no significant difference in either gender (P = 0.2) or age (P = 0.197).

CONCLUSIONS

Volume measurement appears more sensitive and reliable than the MCA in assessing nasal patency. AR was easily performed on preschool children, and normative NV values were achieved.

SIGNIFICANCE

The results and conclusions can be used to establish a standardized technique for AR measurement and interpretation.

Comparison of Optical Rhinometry and Active Anterior Rhinomanometry Using Nasal Provocation Testing

OBJECTIVE

To investigate whether there is a correlation between active anterior rhinomanometry (RMM) and optical rhinometry (ORM) data in the detection of changes in nasal congestion.

DESIGN

In 70 subjects both ORM and RMM were performed. Changes in nasal congestion were induced by nasal provocation with histamine, allergens, solvent, and xylometazoline hydrochloride, 0.1%. Using visual analog scales, subjects rated the degree of nasal congestion and how comfortable each of the 2 measures was. In total, 136 measurements were evaluated.

SUBJECTS

Seventy subjects were included in the study. All had a normal otorhinolaryngologic status with no acute or chronic infections.

INTERVENTIONS

Nasal provocation tests with allergens, histamine, control solution, or xylometazoline were performed.

MAIN OUTCOME MEASURES

Congestion or decongestion of the nasal mucosa was measured via nasal resistance (RMM), changes in light absorption of the nasal tissue (ORM), and visual analog scale.

RESULTS

When comparing the relative change in light extinction in ORM with nasal airflow in RMM, we found correlation coefficients up to r = -0.69. Results from RMM were correlated with the subjects' ratings of nasal congestion (r = -0.63). In comparison, the correlation coefficient between these ratings and ORM was r = 0.84. In addition, ORM was rated to be more comfortable than RMM.

CONCLUSIONS

The subjects' ratings of nasal congestion correlated to a higher degree with the results from ORM than with those from RMM. In addition, ORM was rated as more comfortable than RMM. Overall, ORM appeared to be a valid technique for the assessment of changes in nasal congestion.

Acoustic rhinometry in small children

OBJECTIVES

To study how acoustic rhinometry succeeds in a sample of small children of one to six years of age and to evaluate reasons for failed recordings.

METHODS

Twenty-six healthy children one to six years of age were invited to the Helsinki University Hospital, Department of Otorhinolaryngology for clinical examination and measurements with acoustic rhinometry.

RESULTS

Three children of ten refused recordings in the age group of one to two years. The children's nose adaptor was too small for three of seven children in the age group of three to four years. The anatomical nose adaptor and the adult nose tube were suitable for children between five to six years of age.

CONCLUSIONS

Acoustic rhinometry is well tolerated and usually well accepted in small children. The recordings succeeded in most children. However, lack of adequate equipment hinders measurements in part of the children.

Acoustic Rhinometry and Paranasal Sinuses: A Systematic Study in Models, Anatomic Specimens, and In Vivo

OBJECTIVE/HYPOTHESIS

Acoustic rhinometry (AR) evaluates the cross-sectional areas (CSA) of the nasal cavity through acoustic reflections. The aim of this study was to test whether the paranasal sinuses are a cause for the measurement of increased CSA in the posterior cavum of the nose.

STUDY DESIGN

: Experimental study to evaluate the influence of paranasal sinus volume on AR measurements in two anatomic nose models, an anatomic specimen, and seven individuals.

METHODS

The paranasal sinus volume was systematically reduced by filling of the maxillary sinus with saline. The paranasal sinus ostia were enlarged in the models and the anatomic specimen by infundibulotomy and supraturbinal fenestration, with AR repeated thereafter.

RESULTS

No modification of the posterior area-distance curve was found in the models, the specimen, and the individuals after changing the volume of the maxillary sinus with unmodified anatomy of the paranasal sinus ostia. The apparent CSA measured in the posterior cavum after infundibulotomy and supraturbinate fenestration in the models and the specimen increased with the volume of the paranasal sinuses.

CONCLUSION

Regular anatomy provided, AR reveals reproducible measurements that correspond with the actual CSA up to the ostia of the paranasal sinuses. Untypical large openings to the paranasal sinuses (e.g., after paranasal sinus surgery) appear to contribute to the inaccuracy of AR by overlapping paranasal sinus CSA with the posterior part of the area distance curve.

Effects of anatomical variations of the nasal cavity on acoustic rhinometry measurements: a model study

BACKGROUND

The goal of this study was to assess how anatomic variations of the nasal cavity affect the accuracy of acoustic rhinometry (AR) measurements.

METHODS

A cast model of a human nasal cavity was used to investigate the effects of the nasal valve and paranasal sinuses on AR measurements. A luminal impression of a cadaver nasal cavity was made, and a cast model was created from this impression. To simulate the nasal valve, inserts of varying inner diameter were placed in the model nasal passage. To simulate the paranasal sinuses, side branches with varying neck diameters and cavity volumes were attached to the model.

RESULTS

The AR measurements of the anterior nasal passage were reasonably precise when the passage area of the insert was within the normal range. When the passage area of the insert was reduced, AR measurements significantly underestimated the cross-sectional areas beyond the insert. The volume of the paranasal sinus had limited effect on AR measurements when the sinus ostium was small. However, when the ostium size was large, increasing the volume of the sinus led to significant overestimation of AR-derived areas beyond the ostium.

CONCLUSION

The pathologies that narrow the anterior nasal passage result in the most significant AR error by causing area underestimation beyond the constriction. It also appears that increased paranasal sinus volume causes overestimation of areas posterior to the sinus ostium when the ostium size is large. If these physical effects are not considered, the results obtained during clinical examination with AR may be misinterpreted.

[Optical Rhinometry. Continuous, direct measurement of swelling of the nasal mucosa with allergen provocation. Real-time monitoring of the nasal provocation test using optical rhinometry]

BACKGROUND

Various methods exist for measuring swelling of the nasal mucosa. This is necessary in order to make the nasal provocation test objective. With the new method of optical rhinometry, it is possible to measure swelling of the mucosa directly from outside of the nose in real-time. The measurement is carried out with monochromatic near-infrared light of different wavelengths, the intensity change of which are recorded and displayed during the swelling.

MATERIALS AND METHODS

With the help of a specially developed prototype of an optical rhinometer, we carried out measurements on 15 subjects having positive nasal provocation tests with histamine and allergens, negative provocation tests with allergens in non-allergics, negative provocation tests with control solution, and decongestion with xylometazoline.

RESULTS

We found significant differences between positive and negative provocation tests ( P<0.01). Decongestion was different from all other groups ( P<0.01). Nasal congestion subjectively reported by the subject always correlated with the optical rhinometry findings.

CONCLUSION

The objective assessment of nasal swelling using optical rhinometry seems reliable. The course of the endonasal swelling can thereby be monitored in real-time. The measurement is largely independent of the cooperation of the patient. The swelling is measured directly and not indirectly via air flow resistance.

Effects of the nasal valve on acoustic rhinometry measurements: a model study

The influence of nasal valve on acoustic rhinometry (AR) measurements was evaluated by using simple nasal cavity models. Each model consisted of a cylindrical pipe with an insert simulating the nasal valve. The AR-determined cross-sectional areas beyond the insert were consistently underestimated, and the corresponding area-distance curves showed pronounced oscillations. The area underestimation was more pronounced in models with inserts of small passage area. The experimental results are discussed in terms of theoretically calculated "sound-power reflection coefficients" for the pipe models. The reason for area underestimation is reflection of most of the incident sound power from the barrier at the front junction between the pipe and the insert. It was also demonstrated that the oscillations are due to low-frequency acoustic resonances in the portion of the pipe beyond the insert. The results suggest that AR does not provide reliable information about the cross-sectional areas of the nasal cavity posterior to a significant constriction, such as pathologies narrowing the nasal valve area. When the passage area of the nasal valve is decreased, the role of AR as a diagnostic tool for the entire nasal cavity becomes limited.

Available techniques for objective assessment of upper airway narrowing in snoring and sleep apnea

A number of techniques are available to determine the level of obstructive predominance in snoring and in the obstructive sleep apnea hypopnea syndrome (OSAHS): lateral cephalography, awake endoscopy, awake endoscopy with the Müller maneuver, endoscopy during sleep, endoscopy with nasal continuous positive airway pressure during sleep, fluoroscopy, CT scanning, MR scanning, manometry, and acoustic reflections. Data from different studies using various methods suggest that different patients have different patterns of narrowing or collapse of the pharynx. No reference standard exists for the determination of the predominant obstructive level during obstructive events, so further investigations are necessary to improve and validate existing methods and develop new techniques. These would improve our understanding of the pathophysiology of OSAHS and snoring and help to select the correct treatment option for different patients. This article lists criteria that must be used to assess the available techniques for diagnosis of obstruction level in snoring and OSAHS. The advantages and limitations of each diagnostic technique are summarized, with emphasis on the acoustic reflectometry technique.

Evaluation of the importance of head and probe stabilisation in acoustic rhinometry

As yet there is no established procedure to ensure the repeatability of acoustic rhinometry measurements although anecdotal evidence suggests that instrument fixation improves repeatability. The aim of this study is to validate the methodology of acoustic rhinometry and determine whether instrument fixation and head stabilisation is necessary. Four methods were compared in fifteen healthy volunteers, after nasal decongestion: A) Patient holding the probe (patient-held), B) Probe fixed in a probe stand (probe-stand), C) Probe fixed in stand and head stabilised in head rest (head-rest), D) Examiner holding the probe (examiner-performed). The two minimum cross-sectional areas and volume between 0 and 5 cm were recorded. The examiner-performed and probe-stand methods were consistently less variable than the other methods. With examiner-performed method, this was significant (p < 0.05) versus head-rest and patient-held methods for both measures of minimum cross-sectional area. For nasal volume the examiner-performed method was significantly (p < 0.05) less variable than the head-rest method. In conclusion, examiner-performed acoustic rhinometry is more repeatable than combined head stabilisation and instrument fixation and therefore the use of a head-rest may be unnecessary. Instrument fixation or examiner performed test is also preferable to allowing the patient to position the probe. The repeatability of the probe-stand method was similar to the examiner-performed method.

Effect of the external nasal dilator on nasal minimal cross-sectional area in orientals as assessed by acoustic rhinometry

OBJECTIVE

This study aimed to evaluate the effect of the external nasal dilator on the dimension of the nasal valve in Orientals.

DESIGN

A cohort study of normal subjects.

SETTING

Academic institution.

METHODS

The nasal fossae of normal subjects were assessed by acoustic rhinometry before and after application of the external nasal dilator.

MAIN OUTCOME MEASURES

The minimal cross-sectional area of the nasal fossae and the total cross-sectional area of the nose.

RESULTS

Nasal fossae of 25 normal subjects were evaluated. There was a significant increase of 0.10 cm2 (SD = 0.16) or a 17% increase in the minimal cross-sectional area of the 50 nasal cavities after application of the external nasal dilator (Wilcoxon's matched-pairs signed rank test, p = .0001). A significant increase in the total minimal cross-sectional area for the whole nose after application was also present (0.19 cm2, SD = .27, or 16%; Wilcoxon's matched-pairs signed rank test, p = .0032).

CONCLUSIONS

The external nasal dilator results in an increase in the minimal cross-sectional area of the nasal airway in Orientals.