Suppressing physiological interferences and physical noises in functional diffuse optical tomography via tandem inversion filtering and LSTM classification.

For performance enhancement of functional diffuse optical tomography (fDOT), we propose a tandem method that takes advantage of the inversion filtering and the long short term memory (LSTM) classification to simultaneously suppress the physiological interferences and physical noises in fDOT. In the former phase, the absorption perturbation maps over the scalp-skull (SS) and cerebral-cortex (CC) layers are firstly pre-reconstructed using a two-layer topography scheme. Then, the recovered SS-map is inversed into measurement space by the forward calculation to estimate the intensity changes associated with the physiological interferences. Finally, the raw measurements are adaptively filtered with reference to the estimated intensity changes for accomplishing the model-based full three-dimension (3D) reconstruction. In the later phase, for further removing the randomly distributed physical noises, mainly instrumental noise, a LSTM network based fusion strategy is applied, where a pixel-wise binary mask of "activated" or "inactive" state is generated by performing LSTM classification and then fused with the 3D reconstruction. The results of the simulative investigation and in-vivo experiment show the proposed tandem scheme achieves improved performance in fDOT using a cost-effective and physically explicable way. Thus, the proposed method can be promisingly applied in real-time neuroimaging to acquire cortical neural activation information with improved reliability, quantification and resolution.

A basic investigation into the optimization of cylindrical tubes used as acoustic stethoscopes for auscultation in COVID-19 diagnosis.

During the COVID-19 outbreak, the auscultation of heart and lung sounds has played an important role in the comprehensive diagnosis and real-time monitoring of confirmed cases. With clinicians wearing protective clothing in isolation wards, a potato chip tube stethoscope, which is a secure and flexible substitute for a conventional stethoscope, has been used by Chinese medical workers in the first-line treatment of COVID-19. In this study, an optimal design for this simple cylindrical stethoscope is proposed based on the fundamental theory of acoustic waveguides. Analyses of the cutoff frequency, sound power transmission coefficient, and sound wave propagation in the uniform lossless tube provide theoretical guidance for selecting the geometric parameters for this simple cylindrical stethoscope. A basic investigation into the auscultatory performances of the original tube and the optimal tube with proposed dimensions was conducted both in a semi-anechoic chamber and in a quiet laboratory. Both experimental results and front-line doctors' clinical feedback endorse the proposed theoretical optimization.

Increased advanced glycation end product and meat consumption is associated with childhood wheeze: analysis of the National Health and Nutrition Examination Survey.

We examined 4388 children from the 2003 to 2006 National Health and Nutrition Examination Survey and used survey-design-adjusted multivariable logistic regression to evaluate associations between dietary advanced glycation end product (AGE) and meat consumption frequencies and respiratory symptoms. Higher AGE intake was significantly associated with increased odds of wheezing (adjusted OR 1.18; 95% CI 1.02 to 1.36), wheeze-disrupted sleep (1.26; 95% CI 1.05 to 1.51) and exercise (1.34; 95% CI 1.08 to 1.67) and wheezing requiring prescription medication (1.35; 95% CI 1.13 to 1.63). Higher intake of non-seafood meats was associated with wheeze-disrupted sleep (2.32; 95% CI 1.11 to 4.82) and wheezing requiring prescription medication (2.23; 95% CI 1.10 to 4.54).

Low gestational vitamin D level and childhood asthma are related to impaired lung function in high-risk children.

BACKGROUND: Lung function impairment in early life often persists into adulthood. Therefore, identifying risk factors for low childhood lung function is crucial. OBJECTIVE: We examined the effect of 25-hydroxyvitamin D (25[OH]D) level and childhood asthma phenotype on childhood lung function in the Vitamin D Antenatal Asthma Reduction Trial (VDAART). METHODS: The 25(OH)D level was measured at set time points in mothers during pregnancy and in children during early life. On the basis of parental reports, children were categorized into 3 clinical phenotypes: asymptomatic/infrequent wheeze, early transient wheeze, and asthma at age 6 years. Lung function was assessed with impulse oscillometry at ages 4, 5, and 6 years and with spirometry at ages 5 and 6 years. RESULTS: A total of 570 mother-child pairs were included in this post hoc analysis. Mean gestational 25(OH)D-level quartiles were negatively associated with child respiratory resistance at 5 Hz (R5) from age 4 to 6 years (ß, -0.021 kPa/L/s; 95% CI, -0.035 to -0.007; P = .003) and positively associated with FEV1 (ß, 0.018 L; 95% CI, 0.005-0.031; P = .008) and forced vital capacity (ß, 0.022 L; 95% CI, 0.009-0.036; P = .002) from age 5 to 6 years. Children with asthma at age 6 years had lower lung function from age 4 to 6 years than the asymptomatic/infrequent wheeze group (ß, 0.065 kPa/L/s; 95% CI, 0.028 to 0.102; P < .001 for R5 and ß, -0.063 L; 95% CI, -0.099 to -0.028; P < .001 for FEV1). CONCLUSIONS: Low gestational 25(OH)D level and childhood asthma are important risk factors for decreased lung function in early childhood.

When they stop drinking-examining end-of-life hydration practices and death rattle occurrence.

PURPOSE: To characterize the practice of subcutaneous hydration provision in the Beer-Sheva home care hospice unit. We also explore the potential connection between the provision of subcutaneous hydration and the incidence of death rattle. METHODS: This was a prospective observational study involving 120 hospice patients. During the 6 days before death, hospice staff recorded whether or not fluids were administered orally and/or subcutaneously; the duration, timing, and quantity of fluid administration; the incidence, timing, and duration of death rattle; and whether medications that can affect death rattle were given. RESULT: Fifty-three percent of the patients received subcutaneous hydration. The mean daily volume administered in the hydration group was 434 ml. There was a significant association between the duration of treatment in the hospice unit and provision of subcutaneous hydration (mean of 51 days in hydration group vs. 31 days in non-hydration group, p = 0.03). Although not statistically significant, males were more likely to receive subcutaneous hydration than females (62% of males vs. 46% of females, p = 0.09). There was a higher incidence of death rattle in men compared to women (54.7% in men vs. 32.8% in women, p = 0.025). A statistically significant association between death rattle and the provision of subcutaneous hydration wasn't demonstrated. CONCLUSION: The decision of whether to provide subcutaneous hydration is individualized taking into consideration the values of the patients and their families. The provision of 500 ml per day of subcutaneous saline during the last 6 days of life does not significantly increase the incidence of death rattle.

Efectos de una sesión de fisioterapia respiratoria en la obstrucción de la vía aérea en niños/as menores de 3 años / Effects of a single chest physical therapy session on bronchial obstruction in children younger than 3 years old

ANTECEDENTES Y OBJETIVO: La fisioterapia respiratoria (FR) es ampliamente utilizada para el manejo de disfunciones respiratorias infantiles, sin embargo, estudios dirigidos a objetivar este efecto son escasos. Por tanto, el objetivo de este estudio fue evaluar el efecto de una sesión de FR sobre la obstrucción bronquial en niños/as menores de 3 años. MATERIALES Y MÉTODOS: Estudio exploratorio. Fueron incluidos un total de 39 menores de 3 años (26 niños y 13 niñas) con diagnóstico de síndrome bronquial obstructivo (SBO). El nivel de obstrucción bronquial fue valorado mediante el score de Tal modificado antes y después de una sesión de FR. Mediante la prueba de Wilcoxon se compararon los niveles de obstrucción bronquial pre y postintervención en todo el grupo, según género y edad. RESULTADOS: Se observó una reducción significativa del grado de obstrucción bronquial en todo el grupo, varones, mujeres, menores y mayores de 9 meses (p < 0,05) posterior a una sesión de FR. CONCLUSIÓN: Una sesión de FR fue efectiva en disminuir el grado de obstrucción bronquial en niños/as con diagnóstico de SBO menores de 3 años

BACKGROUND AND OBJECTIVE: Chest physical therapy (CPT) is widely used for the management of childhood respiratory disorders, however, studies that quantify this effect are scarce. Therefore, the aim of this study was to assess the effect of a single chest physical therapy (CPT) session on the bronchial obstruction of children younger than three years old. MATERIAL AND METHODS: This is an exploratory study. Thirty nine children younger than three years old (26 males and 13 females) with syndrome of bronchial obstruction (SBO) were included. The level of bronchial obstruction was measured with the modified Score of Tal before and after a single CPT session. Through the Wilcoxon test, comparisons of the bronchial obstruction levels were made of the whole group, males, females, and in those younger and older than 9 months as well. RESULTS: Significant reductions in bronchial obstruction levels were seen in all the children, an effect that was also seen in the males, females, and in those younger and older than 9 months (p<.05) after a single CPT session. CONCLUSION: A single CPT session was effective in reducing the bronchial obstruction levels in children with SBO, younger than three years old

A wheeze recognition algorithm for practical implementation in children.

BACKGROUND: The detection of wheezes as an exacerbation sign is important in certain respiratory diseases. However, few highly accurate clinical methods are available for automatic detection of wheezes in children. This study aimed to develop a wheeze detection algorithm for practical implementation in children. METHODS: A wheeze recognition algorithm was developed based on wheezes features following the Computerized Respiratory Sound Analysis guidelines. Wheezes can be detected by auscultation with a stethoscope and using an automatic computerized lung sound analysis. Lung sounds were recorded for 30 s in 214 children aged 2 months to 12 years and 11 months in a pediatric consultation room. Files containing recorded lung sounds were assessed by two specialist physicians and divided into two groups: 65 were designated as "wheeze" files, and 149 were designated as "no-wheeze" files. All lung sound judgments were agreed between two specialist physicians. We compared wheeze recognition between the specialist physicians and using the wheeze recognition algorithm and calculated the sensitivity, specificity, positive predictive value, and negative predictive value for all recorded sound files to evaluate the influence of age on the wheeze detection sensitivity. RESULTS: The detection of wheezes was not influenced by age. In all files, wheezes were differentiated from noise using the wheeze recognition algorithm. The sensitivity, specificity, positive predictive value, and negative predictive value of the wheeze recognition algorithm were 100%, 95.7%, 90.3%, and 100%, respectively. CONCLUSIONS: The wheeze recognition algorithm could identify wheezes in sound files and therefore may be useful in the practical implementation of respiratory illness management at home using properly developed devices.

Artificial intelligence accuracy in detecting pathological breath sounds in children using digital stethoscopes.

BACKGROUND: Manual auscultation to detect abnormal breath sounds has poor inter-observer reliability. Digital stethoscopes with artificial intelligence (AI) could improve reliable detection of these sounds. We aimed to independently test the abilities of AI developed for this purpose. METHODS: One hundred and ninety two auscultation recordings collected from children using two different digital stethoscopes (Clinicloud™ and Littman™) were each tagged as containing wheezes, crackles or neither by a pediatric respiratory physician, based on audio playback and careful spectrogram and waveform analysis, with a subset validated by a blinded second clinician. These recordings were submitted for analysis by a blinded AI algorithm (StethoMe AI) specifically trained to detect pathologic pediatric breath sounds. RESULTS: With optimized AI detection thresholds, crackle detection positive percent agreement (PPA) was 0.95 and negative percent agreement (NPA) was 0.99 for Clinicloud recordings; for Littman-collected sounds PPA was 0.82 and NPA was 0.96. Wheeze detection PPA and NPA were 0.90 and 0.97 respectively (Clinicloud auscultation), with PPA 0.80 and NPA 0.95 for Littman recordings. CONCLUSIONS: AI can detect crackles and wheeze with a reasonably high degree of accuracy from breath sounds obtained from different digital stethoscope devices, although some device-dependent differences do exist.

Predicting the outcome of respiratory disease in wheezing infants using tidal flow-volume loop shape

INTRODUCTION AND OBJECTIVES: Wheezing (RW) infants with a positive asthma predictive index (API+) have a lower lung function as measured by forced expiratory techniques. Tidal flow-volume loops (TFVL) are easy to perform in infants, and sedation is not necessary. MATERIALS AND METHODS: A total of 216 wheezing infants were successfully measured, and 183 of them were followed for over a year. TFVL loops were classified into one of three categories depending of their geometric shape (symmetric, convex, and concave). Respiratory rate (Rr), presence of API+, and the number of exacerbations during the following year were also recorded. RESULTS: Children with concave loops had more exacerbations in the following year (OR = 6.8 [IC95% 3.33;13.91]). Infants API + were also significantly more related to concave loops (OR = 10.02 [IC 95% 4.53; 22.15]). Rr was higher in infants with concave loops (44+/−15.5 vs. 36.6 +/−12.6; p < 0.01). CONCLUSION: Infants with a concave TFVL have a higher probability of experiencing exacerbations in the following year, and are at a higher risk of suffering asthma

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[Evaluation of the use of a simulation software in the learning of cardiopulmonary auscultation in undergraduate medical students]. / Evaluation de l'utilisation d'un logiciel de simulation dans l'apprentissage de l'auscultation cardio-pulmonaire chez les étudiants en premier cycle d'études médicales.

INTRODUCTION: Medsounds™ software allows to create an auscultation learning platform, by providing real pre-recorded cardiopulmonary sounds on virtual chests. The study aimed at comparing the skills in cardiopulmonary auscultation between students who benefited from this platform and students who did not have access to it. METHODS: A controlled trial was conducted with 2nd year medical students randomised into three groups. Groups A, B and C received 10 h of cardiopulmonary clinical training. In addition, group B benefited from an online access to the educative platform, and group C had a demonstration of the platform during their clinical training, then an online access. The main outcome was a 3-point multiple-choice questionnaire based on 2 original case vignettes about the description of cardiopulmonary sounds. The secondary outcome was the faculty exam on high-fidelity cardiopulmonary simulator. RESULTS: Groups A and B included 127 students, and group C 117. Students in group C had a significantly higher score than those in group A (1.72/3 versus 1.48/3; p = 0.02), without difference between the groups B and C. Students who actually had a demonstration of the platform and used it at home had a higher score than those who did not use it (1.87 versus 1.51; p = 0.01). Students who had a demonstration of the platform before using it performed a better pulmonary examination on high-fidelity simulators. CONCLUSION: The supervised use of an online auscultation simulation software in addition to the traditional clinical training seems to improve the auscultation performances of undergraduated medical students.

Smartphone-Based Self-Testing of COVID-19 Using Breathing Sounds.

Telemedicine could be a key to control the world-wide disruptive and spreading novel coronavirus disease (COVID-19) pandemic. The COVID-19 virus directly targets the lungs, leading to pneumonia-like symptoms and shortness of breath with life-threatening consequences. Despite the fact that self-quarantine and social distancing are indispensable during the pandemic, the procedure for testing COVID-19 contraction is conventionally available through nasal swabs, saliva test kits, and blood work at healthcare settings. Therefore, devising personalized self-testing kits for COVID-19 virus and other similar viruses is heavily admired. Many e-health initiatives have been made possible by the advent of smartphones with embedded software, hardware, high-performance computing, and connectivity capabilities. A careful review of breathing sounds and their implications in identifying breathing complications suggests that the breathing sounds of COVID-19 contracted users may reveal certain acoustic signal patterns, which is worth investigating. To this end, acquiring respiratory data solely from breathing sounds fed to the smartphone's microphone strikes as a very appealing resolution. The acquired breathing sounds can be analyzed using advanced signal processing and analysis in tandem with new deep/machine learning and pattern recognition techniques to separate the breathing phases, estimate the lung volume, oxygenation, and to further classify the breathing data input into healthy or unhealthy cases. The ideas presented have the potential to be deployed as self-test breathing monitoring apps for the ongoing global COVID-19 pandemic, where users can check their breathing sound pattern frequently through the app.

The use of spectrograms improves the classification of wheezes and crackles in an educational setting.

Chest auscultation is a widely used method in the diagnosis of lung diseases. However, the interpretation of lung sounds is a subjective task and disagreements arise. New technological developments like the use of visSual representation of sounds through spectrograms could improve the agreement when classifying lung sounds, but this is not yet known. In this study, we tested if the use of spectrograms improves the agreement when classifying wheezes and crackles. To do this, we asked twenty-three medical students at UiT the Arctic University of Norway to classify 30 lung sounds recordings for the presence of wheezes and crackles. The sample contained 15 normal recordings and 15 with wheezes or crackles. The students classified the recordings in a random order twice. First sound only, then sound with spectrograms. We calculated kappa values for the agreement between each student and the expert classification with and without display of spectrograms and tested for significant improvement between these two coefficients. We also calculated Fleiss kappa for the 23 observers with and without the spectrogram. In an individual analysis comparing each student to an expert annotated reference standard we found that 13 out of 23 students had a positive change in kappa when classifying wheezes with the help of spectrograms. When classifying crackles 16 out of 23 showed improvement when spectrograms were used. In a group analysis we observed that Fleiss kappa values were k = 0.51 and k = 0.56 (p = 0.63) for classifying wheezes without and with spectrograms. For crackles, these values were k = 0.22 and k = 0.40 (p = <0.01) in the same order. Thus, we conclude that the use of spectrograms had a positive impact on the inter-rater agreement and the agreement with experts. We observed a higher improvement in the classification of crackles compared to wheezes.

Validation of a Body-Conducted Sound Sensor for Respiratory Sound Monitoring and a Comparison with Several Sensors.

The ideal respiratory sound sensor exhibits high sensitivity, wide-band frequency characteristics, and excellent anti-noise properties. We investigated the body-conducted sound sensor (BCS) and verified its usefulness in respiratory sound monitoring through comparison with an air-coupled microphone (ACM) and acceleration sensor (B & K: 8001). We conducted four experiments for comparison: 1) estimation by equivalent circuit model of sensors and measurement by a sensitivity evaluation system; 2) measurement of tissue-borne sensitivity-to-air-noise sensitivity ratio (SRTA); 3) respiratory sound measurement through a simulator; and 4) actual respiratory sound measurement using human subjects. For 1), the simulation and measured values of all the sensors showed good agreement; BCS demonstrated sensitivity ~10 dB higher than ACM and higher sensitivity in the high-frequency segments compared with 8001. In 2), BCS showed high SRTA in the 600-1000 and 1200-2000-Hz frequency segments. In 3), BCS detected wheezes in the high-frequency segments of the respiratory sound. Finally, in 4), the sensors showed similar characteristics and features in the high-frequency segments as the simulators, where typical breathing sound detection was possible. BCS displayed a higher sensitivity and anti-noise property in high-frequency segments compared with the other sensors and is a useful respiratory sound sensor.

Wearable Cardiopulmonary Function Evaluation System for Six-Minute Walking Test.

As a submaximal exercise test, a 6-min walking test (6MWT) can be considered a suitable index for the exercise capacity of patients with a respiratory problem. Traditionally, medical staff manually collect cardiopulmonary information using different devices. However, no integrated monitoring system is currently available to simultaneously record the real-time breathing sound, heart rhythm, and precise walking information (i.e., walking distance, speed, and acceleration) during the 6MWT. In this study, a wearable and wireless multiparameter monitoring system is proposed to simultaneously monitor the breathing sound, oxygen saturation (SpO2), electrocardiograph (ECG) signals, and precise walking information during the 6MWT. Here, a wearable mechanical design was successfully used to reduce the effect of motion artifacts on the breathing sound and ECG signal. A multiparameter detection algorithm was designed to effectively estimate heart and breathing rates. Finally, the cardiopulmonary function of smokers was evaluated using the proposed system. The evaluation indicated that this system could reveal dynamic changes and differences in the breathing rate, heart rate, SpO2, walking speed, and acceleration during the 6MWT. The proposed system can serve as a more integrated approach to monitor cardiopulmonary parameters and obtain precise walking information simultaneously during the 6MWT.

Automated sleep stage classification based on tracheal body sound and actigraphy.

The current gold standard for assessment of most sleep disorders is the in-laboratory polysomnography (PSG). This approach produces high costs and inconveniences for the patients. An accessible and simple preliminary screening method to diagnose the most common sleep disorders and to decide whether a PSG is necessary or not is therefore desirable. A minimalistic type-4 monitoring system which utilized tracheal body sound and actigraphy to accurately diagnose the obstructive sleep apnea syndrome was previously developed. To further improve the diagnostic ability of said system, this study aims to examine if it is possible to perform automated sleep staging utilizing body sound to extract cardiorespiratory features and actigraphy to extract movement features. A linear discriminant classifier based on those features was used for automated sleep staging using the type-4 sleep monitor. For validation 53 subjects underwent a full-night screening at Ulm University Hospital using the developed sleep monitor in addition to polysomnography. To assess sleep stages from PSG, a trained technician manually evaluated EEG, EOG, and EMG recordings. The classifier reached 86.9% accuracy and a Kappa of 0.69 for sleep/wake classification, 76.3% accuracy and a Kappa of 0.42 for Wake/REM/NREM classification, and 56.5% accuracy and a Kappa of 0.36 for Wake/REM/light sleep/deep sleep classification. For the calculation of sleep efficiency (SE), a coefficient of determination r2 of 0.78 is reached. Additionally, subjects were classified into groups of SEs (SE≥40%, SE≥60% and SE≥80%). A Cohen's Kappa >0.61 was reached for all groups, which is considered as substantial agreement. The presented method provides satisfactory performance in sleep/wake and wake/REM/NREM sleep staging while maintaining a simple setup and offering high comfort. This minimalistic approach may address the need for a simple yet reliable preliminary sleep screening in an ambulatory setting.

Association between overweight or obesity and the risk for childhood asthma and wheeze: An updated meta-analysis on 18 articles and 73 252 children.

BACKGROUND: Overweight or obesity is increasingly recognized as a possible risk factor for childhood asthma. OBJECTIVES: We aimed to meta-analyse the association between overweight or obesity and the risk for childhood asthma and wheeze and meanwhile explore potential causes of between-study heterogeneity. METHODS: Literature search, study selection, and data extraction were performed independently and in duplicate. Data were analysed by STATA software. RESULTS: Eighteen articles and 73 252 children were analysed. In overall analyses, there was a significant association between overweight or obesity and the risk for childhood asthma (odds ratio [OR] = 1.30; 95% confidence interval [CI], 1.23-1.39; P < 0.001) and wheeze (OR = 1.90; 95% CI, 1.38-2.63; P < 0.001), with none/marginal publication bias as revealed by the Egger test (P = 0.938/0.038), respectively. Subgroup analyses showed that children with obesity (OR = 1.40; 95% CI, 1.29-1.52) were more likely to have asthma than children with overweight (OR = 1.22; 95% CI, 1.14-1.31), and in children with overweight or obesity, girls (OR = 1.34; 95% CI, 1.16-1.56) were more likely to have asthma than boys (OR = 1.27; 95% CI, 1.15-1.40). CONCLUSIONS: Our findings indicate that overweight or obesity is a significant risk factor for childhood asthma and wheeze and in children with overweight or obesity, the risk is more evident in girls than in boys.

Tidal breathing flow volume profiles during sleep in wheezing infants measured by impedance pneumography.

Overnight analysis of tidal breathing flow volume (TBFV) loops, recorded by impedance pneumography (IP), has been successfully applied in the home monitoring of children with wheezing disorders. However, little is known on how sleep physiology modifies the relationship between TBFV profiles and wheeze. We studied such interactions in wheezing infants. Forty-three infants recruited because of recurrent lower airway symptoms were divided into three groups based on their risk of asthma: high (HR), intermediate (IR), or low (LR). Sedated patients underwent infant lung function testing including assessment of airway responsiveness to methacholine at the hospital and a full-night recording of TBFV profiles at home with IP during natural sleep. Overnight TBFV indexes were estimated from periods of higher and lower respiration variability, presumably belonging to active [rapid eye movement (REM)] and quiet [non-REM (NREM)] sleep, respectively. From 35 valid recordings, absolute time indexes showed intrasubject sleep phase differences. Peak flow relative to time and volume was lower in HR compared with LR only during REM, suggesting altered expiratory control. Indexes estimating the concavity/convexity of flow decrease during exhalation suggested limited flow during passive exhale in HR compared with IR and LR, similarly during NREM and REM. Moreover, during REM convexity was negatively correlated with maximal flow at functional residual capacity and methacholine responsiveness. We conclude that TBFV profiles determined from overnight IP recordings vary because of sleep phase and asthma risk. Physiological changes during REM, most likely decrease in respiratory muscle tone, accentuate the changes in TBFV profiles caused by airway obstruction. NEW & NOTEWORTHY Impedance pneumography was used to investigate overnight tidal breathing flow volume (TBFV) indexes and their interactions with sleep phase [rapid eye movement (REM) vs. non-REM] at home in wheezing infants. The study shows that TBFV indexes vary significantly because of sleep phase and asthma risk of the infant and that during REM the changes in TBFV indexes caused by airway obstruction are accentuated and better associated with lung function of the infant.

A Lung Sound Category Recognition Method Based on Wavelet Decomposition and BP Neural Network.

In this paper, a method of characteristic extraction and recognition on lung sounds is given. Wavelet de-noised method is adopted to reduce noise of collected lung sounds and extract wavelet characteristic coefficients of the de-noised lung sounds by wavelet decomposition. Considering the problem that lung sounds characteristic vectors are of high dimensions after wavelet decomposition and reconstruction, a new method is proposed to transform the characteristic vectors from reconstructed signals into reconstructed signal energy. In addition, we use linear discriminant analysis (LDA) to reduce the dimension of characteristic vectors for comparison in order to obtain a more efficient way for recognition. Finally, we use BP neural network to carry out lung sounds recognition where comparatively high-dimensional characteristic vectors and low- dimensional vectors are set as input and lung sounds categories as output with a recognition accuracy of 82.5% and 92.5%.

Comparison of a Novel Handheld Telehealth Device with Stand-Alone Examination Tools in a Clinic Setting.

Background and Objective: Research demonstrates that telemedicine is effective in pediatric settings but little is published to validate the quality of the data acquired by remote peripheral examination devices to accurately inform clinical decision-making.Introduction: The primary aim was to compare a novel Food and Drug Administration (FDA)-cleared multifunctional remote examination device (Tyto) with other stand-alone digital examination devices. The secondary aim was to ascertain whether either device produced images or sounds better able to provide clinical information to clinicians caring for children.Materials and Methods: Otoscopic images and heart and lung sounds from 50 patients of ages 2-18 years were acquired using the novel device and a stand-alone digital otoscope and stethoscope. Data were stored on a secure server for review by physicians (two pulmonary faculty, two general faculty, two cardiology faculty, and two cardiology fellows). Reviewers were blinded and they reviewed images and audio files in a randomized manner. Images and sounds were scored in terms of quality using a Likert scale. Means and standard deviations (and t-tests to compare those means) were calculated. Individual (heart sounds, lung sounds, and otoscopic images) and aggregate scores were compared.Results: The novel device provided higher sound and image quality with less chance of an inability to make a diagnosis than the stand-alone devices. The novel device had a superior mean comparative diagnostic score with a high intra- and inter-reliability of cardiac, pulmonary, and otoscopic diagnosis.Discussion and Conclusions: The novel device outperformed the stand-alone digital stethoscope and otoscope and was better able to provide usable data to support a clinical encounter.