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In this paper, we illustrate the development of a Wireless Stethoscope coupled with Bluetooth technology. The system will serve the purpose of transmitting heart sounds wirelessly to a Bluetooth receiver module, which can either be a Bluetooth speaker or a headset. This wireless technique will allow real-time transmission of heart sounds to students for better understanding. This product can serve as a teaching aid in medical institutions as multiple students can receive the transmitted sounds through earpieces, via a wireless connection.

Asthma is a disease of air flow obstruction. Transmitted sounds can be analyzed in detail and may shed light upon the physiology of asthma and how it changes over time. The goals of this study were to use a computerized analytic acoustic tool to evaluate respiratory sound patterns in asthmatic patients during acute attacks and after clinical improvement and to compare asthmatic profiles with those of normal individuals.Respiratory sound analysis throughout the respiratory cycle was performed on 22 symptomatic asthma patients at the time of presentation to the emergency department (ED) and after clinical improvement. Fifteen healthy volunteers were analyzed as a control group. Vibrations patterns were plotted. Right and left lungs were analyzed separately.Asthmatic attacks were found to be correlated with asynchrony between lungs. In normal subjects, the inspiratory and expiratory vibration energy peaks (VEPs) occurred almost simultaneously in both lungs; the time interval between right and left expiratory VEPs was 0.006 +/- 0.012 seconds. In symptomatic asthmatic patients on admission, the time interval between right and left expiratory VEPs was 0.14 +/- 0.09 seconds and after clinical improvement the interval decreased to 0.04 +/- 0.04 seconds. Compared to healthy volunteers, asynchrony between two lungs was increased in asthmatics (p0.05). The asynchrony was significantly reduced after clinical improvement (p0.05).Respiratory sound analysis demonstrated significant asynchrony between right and left lungs in asthma exacerbations, a finding which, to our knowledge, has never been reported to date. The asynchrony is significantly reduced with clinical improvement following treatment.

Objective.Develop and test methods for representing and classifying breath sounds in an intensive care setting. Methods.Breath sounds were recorded over the bronchial regions of the chest. The breath sounds were represented by their averaged power spectral density, summed into feature vectors across the frequency spectrum from 0 to 800 Hertz. The sounds were segmented by individual breath and each breath was divided into inspiratory and expiratory segments. Sounds were classified as normal or abnormal. Different back-propagation neural network configurations were evaluated. The number of input features, hidden units, and hidden layers were varied.Results.2127 individual breath sounds from the ICU patients and 321breaths from training tapes were obtained. Best overall classification rate for the ICU breath sounds was 73% with 62% sensitivity and 85% specificity. Best overall classification rate for the training tapes was 91% with 87%sensitivity and 95% specificity. Conclusions.Long term monitoring of lung sounds is not feasible unless several barriers can be overcome. Several choices in signal representation and neural network design greatly improved the classification rates of breath sounds. The analysis of transmitted sounds from the trachea to the lung is suggested as an area for future study.

The results of the study indicate that the head tissues act as a band pass filter that is far from flat. Instead there seems to be strong frequency variations in attenuation of transmitted sounds. The sounds are subject to phase shift and time delay, which can be used to decide from which TMJ the sound comes. Bilateral electronic recording with high sampling rate (>> 44 kHz) is needed to accurately and consistently identify the origin of a TMJ sound. Further studies on autopsy specimens and large subject groups are motivated.

In order to build the system which enables voice training interactively between the user and system, it is required to output the singing voice with rich sound as a teacher sound. Since the user listen to his own bone-transmitted sound as well as his air- transmitted sound when he utters, it is ideal to mix and output the bone-transmitted sounds with the air transmitted sounds of the teacher sound at the same mixing rate where the user actually listens to his singing voice. Here we present the result of investigation what rate of the air- transmitted and bone-transmitted sounds matches the natural situation of listening in utterance.

Adult individuals often show an area of decreased acuity for air transmitted sounds in the range between 2400 and 3000 pps. in the auditory field of frequency. Such ranges of decreased acuity are often sharply defined and may require a stimulus up to 500 or 1000 times the normal minimum to elicit response. This finding might be explained by almost any of the numerous theories of end organ behavior on the basis of a local defect in the basilar or tectorial membranes.The first subject of the series of the present investigation showed a bilateral defect in this frequency range which is known to have been constant for the past four years. When tested with the bone activating telephone receiver, this individual showed a decreased bone acuity through the same range of frequency. The second subject has had a unilateral defect in air acuity for at least five years, and on testing with the bone activating telephone it was found that he also showed a refect in bone acuity. The third subject displayed no lowered air...