Nasal Air Research Articles

Why the Wittenberg anatomist and scientist Konrad Victor Schneider (1614-1680) is also important for pneumologists

The Wittenberg physician Konrad Victor Schneider (1614-1680) was the first to prove that mucus is not formed in the brain, nor is it secreted into the nasal cavity via the ethmoid bone. He recognised that there is no open anatomical connection between the brain and the nasal air space. Schneider discovered the sinonasal mucosa as the production site of mucus and thus refuted the hypothesis of cerebral mucus production and secretion by Hippocrates, Galen and Vesal. The nasal mucosa was named "membrana Schneideria" in honour of Schneider.

A Noninvasive Method for Monitoring Breathing Patterns in Nonhuman Primates Using a Nasal Thermosensor.

Respiration is strongly linked to internal states such as arousal, emotion, and even cognitive processes and provides objective biological information to estimate these states in humans and animals. However, the measurement of respiration has not been established in macaque monkeys, which have been widely used as model animals for understanding various higher brain functions. In the present study, we developed a method to monitor the respiration of behaving monkeys. We first measured the temperature of their nasal breathing, which changes between inspiration and expiration phases, in an anesthetized condition and estimated the respiration pattern. We compared the estimated pattern with that obtained by a conventional chest band method that has been used in humans and applied to anesthetized, but not behaving, monkeys. These respiration patterns matched well, suggesting that the measurement of nasal air temperature can be used to monitor the respiration of monkeys. Furthermore, we confirmed that the respiration frequency in behaving monkeys monitored by the measurement of nasal air temperature was not affected by the orofacial movement of licking to obtain the liquid reward. We next examined the frequency of respiration when they listened to music or white noise. The respiratory frequency was higher when the monkeys listened to music than the noise. This result is consistent with a phenomenon in humans and indicates the accuracy of our monitoring method. These data suggest that the measurement of nasal air temperature enables us to monitor the respiration of behaving monkeys and thereby estimate their internal states.

Long- and short-term fluctuations compared for several organ systems across sleep stages.

Some details of cardiovascular and cardio-respiratory regulation and their changes during different sleep stages remain still unknown. In this paper we compared the fluctuations of heart rate, pulse rate, respiration frequency, and pulse transit times as well as EEG alpha-band power on time scales from 6 to 200s during different sleep stages in order to better understand regulatory pathways. The five considered time series were derived from ECG, photoplethysmogram, nasal air flow, and central electrode EEG measurements from full-night polysomnography recordings of 246 subjects with suspected sleep disorders. We applied detrended fluctuation analysis, distinguishing between short-term (6-16s) and long-term (50-200s) correlations, i.e., scaling behavior characterized by the fluctuation exponents α 1 and α 2 related with parasympathetic and sympathetic control, respectively. While heart rate (and pulse rate) are characterized by sex and age-dependent short-term correlations, their long-term correlations exhibit the well-known sleep stage dependence: weak long-term correlations during non-REM sleep and pronounced long-term correlations during REM sleep and wakefulness. In contrast, pulse transit times, which are believed to be mainly affected by blood pressure and arterial stiffness, do not show differences between short-term and long-term exponents. This is in constrast to previous results for blood pressure time series, where α 1 was much larger than α 2, and therefore questions a very close relation between pulse transit times and blood pressure values. Nevertheless, very similar sleep-stage dependent differences are observed for the long-term fluctuation exponent α 2 in all considered signals including EEG alpha-band power. In conclusion, we found that the observed fluctuation exponents are very robust and hardly modified by body mass index, alcohol consumption, smoking, or sleep disorders. The long-term fluctuations of all observed systems seem to be modulated by patterns following sleep stages generated in the brain and thus regulated in a similar manner, while short-term regulations differ between the organ systems. Deviations from the reported dependence in any of the signals should be indicative of problems in the function of the particular organ system or its control mechanisms.

Characterization of Retronasal Airflow Patterns during Intraoral Fluid Discrimination Using a Low-Cost, Open-Source Biosensing Platform.

Nasal airflow plays a critical role in olfactory processes, and both retronasal and orthonasal olfaction involve sensorimotor processes that facilitate the delivery of volatiles to the olfactory epithelium during odor sampling. Although methods are readily available for monitoring nasal airflow characteristics in laboratory and clinical settings, our understanding of odor sampling behavior would be enhanced by the development of inexpensive wearable technologies. Thus, we developed a method of monitoring nasal air pressure using a lightweight, open-source brain–computer interface (BCI) system and used the system to characterize patterns of retronasal airflow in human participants performing an oral fluid discrimination task. Participants exhibited relatively sustained low-rate retronasal airflow during sampling punctuated by higher-rate pulses often associated with deglutition. Although characteristics of post-deglutitive pulses did not differ across fluid conditions, the cumulative duration, probability, and estimated volume of retronasal airflow were greater during discrimination of perceptually similar solutions. These findings demonstrate the utility of a consumer-grade BCI system in assessing human olfactory behavior. They suggest further that sensorimotor processes regulate retronasal airflow to optimize the delivery of volatiles to the olfactory epithelium and that discrimination of perceptually similar oral fluids may be accomplished by varying the duration of optimal airflow rate.

Characterization of nasal aerodynamics and air conditioning ability using CFD and its application to improve the empty nose syndrome (ENS) submucosal floor implant surgery – Part I methodology

BackgroundCFD simulation allows the visualization of airflow in nasal airways, but the predictions are rarely referenced in real surgeries. The limitations include having a reliable nasal geometry with reasonable boundary conditions and how the predictions corresponding to the symptoms. MethodsThe computational domain is developed from the computed tomography images and face profile of an empty nose syndrome patient with inferior turbinate reduction subtype before and after the submucosal floor implant surgery. The aerodynamics and the ability of conditioning the breathing air of the nasal cavities before and after the surgery are predicted using different breathing air conditions. Significant findingsThe surgery redistributes the airflow and improves the symptoms by having higher airflow fraction in sensor-rich inferior turbinate and shear stresses on superior turbinate olfactory region. The surgery enhances heat and water vapor fluxes from the mucus rich interior turbinate. After the surgery, the surface area on disease side with heat flux greater than the threshold 50 W/m2 increases at both anterior and turbinate, where receptors are rich to elevate the sense of the inhaled air. In summer and winter time, both the air temperature and relative humidity at choanae increases after the surgery by the enhanced nasal air conditioning ability.

Technical note: a nose ring sensor system to monitor dairy cow cardiovascular and respiratory metrics.

Monitoring cardiovascular and respiratory measurements corresponds to the precision livestock farming (PLF) objective to continuously monitor and assess dairy cows' welfare and health. Changes in heart rate, breathing rate, and oxygen saturation (SpO2) are valuable metrics in human and veterinary medicine to assess stress, pain, illness, and detect critical conditions. The common way to measure heart rate is either manually or with a stethoscope. Under research conditions, heart rate is usually measured with a sports watch chest belt. Breathing rate is obtained by counting the cow's flank movements which is a time-consuming and labor-intensive method that requires training and is prone to human error. No devices are available on the market that enable practical and easy pulse oximetry in farm animals. This study presents a wireless nose ring sensor system (NoRS) composed of thermal and photoplothysmography sensors that attach to the nostrils of four Holstein dairy cows. The NoRS's thermocouple measured the cow's nasal cavity air temperature; an optic sensor measured the IR (660 nm) and RED (660 nm) signals reflected from the cow's nasal septum. Breathing was calculated from the thermocouple signal's center frequency with a fast Fourier transformation or the signal peak count (i.e., oscillations). The breathing rate was compared to breathing observed by concurrently counting the flank movements. Heart rate and SpO2 were measured by integrated pulse oximetry and heart rate monitor module (MAX30101 TinyCircuit) assembled on the NoRS circuit. Heart rate was also measured with FFT and by counting the number of peaks from the optic sensor's raw IR and RED signals. These measures were compared to an off-the-shelf hand-held pulse oximeter's heart rate and SpO2 readings during the same time. The comparisons revealed highly significant correlations for the heart rate readings where the strength of the correlation was sensitive to the method. The correlation between breathing rate and the veterinarian's visual observations was low, albeit significant. Thus, inhale-exhale cycle counting constitutes a more precise approach than flank movement counts. The hand-held device's 96% SpO2 is compatible with near-saturation values expected in healthy cows. The mean NoRS SpO2 reading was 3% less. After further piloting under field conditions, the NoRS will require no animal restraining to automatically and continuously record cows' breathing rate, heart rate, and SpO2.

Furlow Palatoplasty and Tonsillectomy for Treating Patients With Submucous Cleft Palate and Tonsillar Hypertrophy: A One-Stage Procedure.

Children with cleft palate are more liable to have obstructive sleep apnea than children with normal palate due to narrow airways. Tonsillar hypertrophy is a common cause of pediatric obstructive sleep apnea; hence, it is not surprising to be encountered during cleft palate repair. The aim of this study was to evaluate the feasibility of tonsillectomy and Furlow palatoplasty performed as a 1-stage operation in patients presenting with submucous cleft palate (SMCP) and tonsillar hypertrophy. Eleven pediatric patients with SMCP and hypertrophied tonsils were included in this case series study. Furlow palatoplasty and tonsillectomy were performed for the patients in 1 sitting. The evaluation of velopharyngeal function was done preoperatively and postoperatively via auditory-perceptual-assessment, nasometry, and flexible nasopharyngoscopy. In addition, the Epworth sleepiness scale for children/adolescents was administered to the parents to assess daytime sleepiness of their children. The speech improved postoperatively. Auditory-perceptual-assessment showed significant reductions in hypernasal speech, nasal air escape, and weak pressure consonants. In addition, nasometry revealed significantly decreased nasalance scores for nasal and oral sentences. A postoperative increased velar movement was observed with a significant improvement in velopharyngeal closure. The preoperative Epworth sleepiness scale for children/adolescents assessment revealed excessive daytime sleepiness in 8 patients, with significant improvement of scores postoperatively. Removal of hypertrophied tonsils during the repair of SMCP with Furlow palatoplasty did not negatively affect speech outcome or velar movement postoperatively. It is logical to perform both procedures simultaneously in 1 sitting to avoid postoperative sleep-related breathing disorder, which may necessitate a second stage operation.

PRE & POST OPERATIVE ASSESSMENT OF NASAL AIRFLOW BY ACTIVE ANTERIOR RHINOMANOMETRY IN OBSTRUCTIVE NASAL PATHOLOGIES

Nasal obstruction is a common symptom seen across various nasal pathologies, the objective way of measuring nasal obstruction is active rhinomanometry. To measure the difference in the nasal airow of cases of nasal pathology with nasal obstruction, a prospective study was undertaken to compare the pre and post-operative rhinomanometry ndings in cases presenting with nasal obstruction.

Identifying chronic rhinosinusitis without nasal polyps by analyzing aspirated nasal air with an electronic nose based on differential mobility spectrometry

Background The diagnosis of chronic rhinosinusitis (CRS) is a complicated procedure. An electronic nose (eNose) is a novel method that detects disease from gas-phase mixtures, such as human breath. Aims/Objectives To determine whether an eNose based on differential mobility spectrometry (DMS) can detect chronic rhinosinusitis without nasal polyps (CRSsNP) by analyzing aspirated nasal air. Materials and methods Adult patients with CRSsNP were examined. The control group consisted of patients with septal deviation. Nasal air was aspirated into a collection bag and analyzed with DMS. The DMS data were classified using regularized linear discriminant analysis (LDA) models with 10-fold cross-validation. Results The accuracy of the DMS to distinguish CRSsNP from patients with septal deviation was 69%. Sensitivity and specificity were 67 and 70%, respectively. Bonferroni-corrected statistical differences were clearly noted. When a subgroup with more severe inflammatory disease was compared to controls, the classification accuracy increased to 82%. Conclusions The results of this feasibility study demonstrate that CRSsNP can potentially be differentiated distinguished from patients with similar nasal symptoms by analyzing the aspirated nasal air using DMS. Further research is warranted to evaluate the ability of this novel method in the differential diagnostics of CRS.

Computational assessment of the nasal air conditioning and paranasal sinus ventilation from nasal assisted breathing therapy

Nasal cannula oxygen therapy is a common treatment option for patients with respiratory failure but needs further investigation to understand its potential for use for assisted breathing. Air with a high oxygen level is introduced into the nasal cavity using a nasal cannula during assisted breathing via oxygen therapy. The treatment impacts the nasal airflow dynamics and air-conditioning function. This study aims to investigate the nasal heat and mass transfer and sinus ventilation during assisted breathing at different operating conditions using computational fluid dynamics simulations. The nasal geometry was reconstructed from high-resolution computed tomography scans of a healthy subject. A constant inhalation flow rate of 15 LPM (liters per minute) was used, and the nasal cannula flow rate was set to between 5 and 15 LPM. The results demonstrated that assisted breathing at a high flow rate impacted sinus ventilation. It also changed the mucosal surface heat and mass transfer, thus inhaled air temperature and humidity. The high flow assisted breathing at 36 °C affected the nasal heat flux the most compared with other breathing conditions, while the low flow assisted breathing had minimal effect and, therefore, could be considered ineffective for any relevant treatment.

Assessment of Functional Outcomes of an Autospreader Flap and Spreader Graft in Rhinoplasty.

Nasal obstruction after rhinoplasty occurs due to narrowing of the internal nasal valve. Narrowing is due to osteotomy performed to close the open roof of nose after dorsum hump resection. Spreader grafts and autospreader flaps are used to prevent such narrowing. in this study, we aimed to compare the effects of these 2 rhinoplasty techniques on olfactory function, nasal air passage opening, quality of life, and patient satisfaction. In this prospective study, 48 rhinoplasty patients were randomly divided into 2 groups according to graft technique used, either spreader graft or autospreader flap. These 2 groups were compared for patient satisfaction. The sinonasal outcome test-22, peak nasal flowmetry, and Connecticut Chemosensory Clinical Research Center test were applied to all patients before and 8 weeks after surgery. The study enrolled 48 patients. Nasal airflow increased in both groups postoperatively. in the preoperative and postoperative comparison of odor functions, postoperative odor functions were similar in both groups. In the autospreader flap group, the preoperative rhinoplasty outcome evaluation questionnaire score was 4.1 ± 2.2 versus 21.3 ± 2.6 in the third postoperative month. The preoperative rhinoplasty outcome evaluation score was 3.9 ± 2.1 in the spreader graft group and 19.7 ± 1.9 in the third postoperative month. In the present study, postoperative nasal airflow improved in the patients in both the spreader graft and autospreader flap groups. in the patient satisfaction surveys after rhinoplasty, the satisfaction of the patients in the autospreader flap group was higher than that of the patients in the spreader graft group.

The vomeronasal system in semiaquatic beavers.

In contrast to the main olfactory system that detects volatile chemicals in the nasal air, the vomeronasal system can detect nonvolatile chemicals as well as volatiles. In the vomeronasal system, chemicals are perceived by the vomeronasal organ (VNO) projecting axons to the accessory olfactory bulb (AOB). Beavers (Castor spp.) are semiaquatic mammals that have developed chemical communication. It is possible that the beaver's anal gland secretions, nonvolatile and insoluble substances, may work as a messenger in the water and that beavers may detect the nonvolatile chemicals floating on the water surface via the VNO. The present study aimed to clarify the specificities of the beaver vomeronasal system by histologically and immunohistochemically analyzing the VNO and AOB of 12 Eurasian beavers (C. fiber). The VNO directly opened to the nasal cavity and was independent of a narrow nasopalatine duct connecting the oral and nasal cavities. The VNO comprised soft tissues including sensory and nonsensory epithelium, glands, a venous sinus, an artery, as well as cartilage inner, and bone outer enclosures. The AOB had distinct six layers, and anti-G protein α-i2 and α-o subunits were, respectively, immunoreactive in rostral and caudal glomeruli layers indicating expressions of V1Rs and V2Rs. According to gene repertories analysis, the beavers had 23 and six intact V1R and V2R genes respectively. These findings suggested that beavers recognize volatile odorants and nonvolatile substances using the vomeronasal system. The beaver VNO was developed as well as in other rodents, and it had two specific morphological features, namely, disadvantaged contact with the oral cavity because of a tiny nasopalatine duct, and a double bone and cartilage envelope. Our results highlight the importance of the vomeronasal system in beaver chemical communication and support the possibility that beavers can detect chemicals floating on the water surface via the VNO.

The application of polyethylene glycol-coated collagen patches in nasal surgery.

Nasal packing is a significant factor of postoperative morbidity that affects quality of recovery following nasal surgery. The polyethylene glycol-coated (PEG) collagen patch (Hemopatch® ) is a synthetic hemostatic agent with a dual mechanism of action, but whether it can be applied in nasal surgery remains unexplored. The postoperative symptoms of thick nasal discharge, loss of smell, headache, postnasal discharge, ear fullness and lack of good night's sleep in patients with Hemopatch are minimal after surgery. The total nasal resistance at postoperative day 1 (0.224 Pa/cm3) is lower than the preoperative total nasal resistance (0.412 Pa/cm3), indicating that the nasal air flow increases after surgery in patients using Hemopatch at postoperative day 1. This is the first report to demonstrate that Hemopatch is an alternative nasal packing to reduce the postoperative morbidity after nasal surgery.

DNMTs Are Involved in TGF-β1-Induced Epithelial-Mesenchymal Transitions in Airway Epithelial Cells.

Chronic rhinosinusitis (CRS) pathogenesis is closely related to tissue remodeling, including epithelial–mesenchymal transition (EMT). Epigenetic mechanisms play key roles in EMT. DNA methylation, mediated by DNA methyltransferases (DNMTs), is an epigenetic marker that is critical to EMT. The goal of this study was to determine whether DNMTs were involved in TGF-β1-induced EMT and elucidate the underlying mechanisms in nasal epithelial cells and air–liquid interface cultures. Global DNA methylation and DNMT activity were quantified. DNMT expression was measured using real-time PCR (qRT–PCR) in human CRS tissues. mRNA and protein levels of DNMTs, E-cadherin, vimentin, α-SMA, and fibronectin were determined using RT–PCR and Western blotting, respectively. DNMT1, DNMT3A, and DNMT3B gene expression were knocked down using siRNA transfection. MAPK phosphorylation and EMT-related transcription factor levels were determined using Western blotting. Signaling pathways were analyzed using specific inhibitors of MAPK. We demonstrated these data in primary nasal epithelial cells and air–liquid interface cultures. Global DNA methylation, DNMT activity, and DNMT expression increased in CRS tissues. DNMT expression was positively correlated with Lund–McKay CT scores. TGF-β1 dose-dependently induced DNMT expression. Further, 5-Aza inhibited TGF-β1-induced DNMT, Snail, and Slug expression related to EMT, as well as p38 and JNK phosphorylation in A549 cells and TGF-β1-induced DNMT expression and EMT in primary nasal epithelial cells and air–liquid interface cultures. TGF-β1-induced DNMT expression leads to DNA methylation and EMT via p38, JNK, Snail, and Slug signaling pathways. Inhibition of DNMT suppressed the EMT process and therefore is potentially a CRS therapeutic strategy.

Nasal Air Puff Promotes Default Mode Network Activity in Mechanically Ventilated Comatose Patients: A Noninvasive Brain Stimulation Approach

ObjectivesComa state and loss of consciousness are associated with impaired brain activity, particularly gamma oscillations, that integrate functional connectivity in neural networks, including the default mode network (DMN). Mechanical ventilation (MV) in comatose patients can aggravate brain activity, which has decreased in coma, presumably because of diminished nasal airflow. Nasal airflow, known to drive functional neural oscillations, synchronizing distant brain networks activity, is eliminated by tracheal intubation and MV. Hence, we proposed that rhythmic nasal air puffing in mechanically ventilated comatose patients may promote brain activity and improve network connectivity. Materials and MethodsWe recorded electroencephalography (EEG) from 15 comatose patients (seven women) admitted to the intensive care unit because of opium poisoning and assessed the activity, complexity, and connectivity of the DMN before and during the nasal air-puff stimulation. Nasal cavity air puffing was done through a nasal cannula controlled by an electrical valve (open duration of 630 ms) with a frequency of 0.2 Hz (ie, 12 puff/min). ResultsOur analyses demonstrated that nasal air puffing enhanced the power of gamma oscillations (30–100 Hz) in the DMN. In addition, we found that the coherence and synchrony between DMN regions were increased during nasal air puffing. Recurrence quantification and fractal dimension analyses revealed that EEG global complexity and irregularity, typically seen in wakefulness and conscious state, increased during rhythmic nasal air puffing. ConclusionsRhythmic nasal air puffing, as a noninvasive brain stimulation method, opens a new window to modifying the brain connectivity integration in comatose patients. This approach may potentially influence comatose patients’ outcomes by increasing brain reactivity and network connectivity.

Septocolumellar Suture Technique for Correction of Septal Caudal Dislocation

Objective: To describe this technique for treatment of caudal septal dislocation and to evaluate the effectiveness of this technique in terms of correction of cosmetic deformity and relief of nasal obstruction.Methods: This was a descriptive case series study performed at ENT department of Services Institute of Medical Sciences (SIMS), Services Hospital, Jail Road, Lahore. 30 Cases of mild to moderate degree of septal caudal dislocation were selected and operated. The septum was fixed by sutures to the anterior nasal spine. Columellar pocket was made and septum was sutured in the pocket by two sutures at upper and lower levels to increase the stability of corrected septum.Results: We performed this suturing technique on 30 septoplasty cases during 3 years from Jan-2016 to Jan-2019. Among them 12 (40%) were male and 18 (60%) were female. Total follow up period ranged between 3 to 6 months. Anterior rhinoscopy showed no persistence of deviation or dislocation in 25 patients. 5 cases had mild deviation of septum on non-operated side.Conclusion: Two level septocolomellar suture technique is very effective, easy to learn & perform and shows long term reliability in correction of caudal septal dislocation. This is effective in improving cosmesis and nasal air flow.

Differentiation of aspirated nasal air from room air using analysis with a differential mobility spectrometry-based electronic nose: a proof-of-concept study

Over the last few decades, breath analysis using electronic nose (eNose) technology has become a topic of intense research, as it is both non-invasive and painless, and is suitable for point-of-care use. To date, however, only a few studies have examined nasal air. As the air in the oral cavity and the lungs differs from the air in the nasal cavity, it is unknown whether aspirated nasal air could be exploited with eNose technology. Compared to traditional eNoses, differential mobility spectrometry uses an alternating electrical field to discriminate the different molecules of gas mixtures, providing analogous information. This study reports the collection of nasal air by aspiration and the subsequent analysis of the collected air using a differential mobility spectrometer. We collected nasal air from ten volunteers into breath collecting bags and compared them to bags of room air and the air aspirated through the device. Distance and dissimilarity metrics between the sample types were calculated and statistical significance evaluated with Kolmogorov-Smirnov test. After leave-one-day-out cross-validation, a shrinkage linear discriminant classifier was able to correctly classify 100% of the samples. The nasal air differed (p < 0.05) from the other sample types. The results show the feasibility of collecting nasal air by aspiration and subsequent analysis using differential mobility spectrometry, and thus increases the potential of the method to be used in disease detection studies.

Effect of maxillary surgical movement on nasal cavity and maxillary sinus dimensions and function after Le Fort I osteotomy

This study was designed to evaluate the effects of different maxillary movements performed in Le Fort I surgery on the anatomy of the nasal cavity and maxillary sinus, occurrence of rhinosinusitis, and nasal airflow. Patients were divided into three groups: group I underwent pure advancement, group II underwent advancement with yaw rotation, and group III underwent advancement with impaction movements. All evaluations were performed using pre- and postoperative computed tomography images and surveys. Twenty-eight patients were enrolled. The mean pre- and postoperative nasal air volumes in group I were 22.74 ± 6.32 cm3 and 25.17 ± 6.19 cm3, respectively, showing a significant increase (P = 0.041). The mean pre- and postoperative maxillary sinus air volumes were 33.94 ± 13.72 cm3 and 26.28 ± 14.12 cm3 in group II and 35.29 ± 9.58 cm3 and 28.65 ± 8.42 cm3 in group III, respectively, showing significant reductions (P = 0.028 and P = 0.007, respectively). For all movements, the occurrence of septum deviation and nasal airflow impairment was not statistically significant. Pure maxillary advancement movement enhanced nasal cavity air volume. The yaw rotation movement significantly increased quantitative clinical rhinosinusitis symptoms. The risk of airflow impairment following Le Fort I surgery is low.

Classification of Sleep Apnea Events Using Nasal Air Flow (NAF) Signals. (Dept. E)

Detecting and diagnosing different types of Sleep Apnea (Obstructive, Central and Hypopneaisone of the major tasks in sleep medicine. Clinically, analyzing Nasal Airflow (NAF) signal is the most sufficient and direct reliably effective method for the automatic detection of Sleep Apnea events by checking the airflow amplitude reduction. This paper investigates and compares the performance of three classifiers: a kohen self-organizing map (SOM), Adaptive Neuro Fuzzy Inference System ?(ANFIS) AND Hidden Markov Model (HMM) for the classification of Sleep apnea events. The results have shown that the highest correct classification rate is 95.7% when using HMM with order 13.

Effect of antibiotic pack on hard palate after fistula closure on nasal airflow and reoccurrence rate

This parallel blocked randomized controlled trial was done in two groups of 30 patients each to determine if placement of an antibiotic oral pack on the hard palate after hard palatal fistula repair reduces nasal air emission and fistula re-occurrence. Group A had an oral pack on the hard palate for 5 days post-operatively while group B did not. In group A, percentage of nasal air emission was tested using nasometry with and without pack. Paired t-tests were performed to compare nasal emissions for patients with and without pack. Recurrence of fistulas after 6 months between group A and B was tested using odds ratio. Effect of nasal air emission on fistula rates was tested using paired t-tests. There was a significant increase (p < 0.0001) in nasal emission after removal of the pack in group A. Fistula re-occurrence tended to be higher in group B (no pack) than group A but this was not significant (p = 0.242). There was no correlation between nasal air emission and fistula rates. In patients with recurrent fistulae, placement of an oral pack after fistula repair diminishes nasal air emission. Whether this has an impact on re-occurrence of fistulae needs to be investigated further.