Frequency responses of conventional and amplified stethoscopes for measuring heart sounds

Alanazi, Ahmad A.; Atcherson, Samuel R.; Franklin, Clifford; Bryan, Melinda Freyaldenhoven

doi:10.4103/sjmms.sjmms_118_19

Cited by 9 publications

(4 citation statements)

References 11 publications

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“…As can be seen the dominant frequency is well within the 120 Hz threshold of stethoscopes. As the frequency does not exceed 55 Hz in this study, we recommend selecting an amplified stethoscope [32] . Based on this data, a continuous correlation between the degree of stenosis and the dominant auscultated frequency of vortex shedding (Strouhal number) is constructed; see Fig.…”

Section: Resultsmentioning

confidence: 98%

“…A break frequency is obtained by solving for the spectrum of acoustic frequencies generated by the bruits and post-processing for an observed frequency where the slope of the spectrum changes significantly. This frequency has been reported to arise in a range that may be better suited for phonoangiography, e.g., [18] , but not for stethoscopes (< 120 Hz), cf., [32] , which motivates our research to identify another frequency that can be stethoscopically associated with bruits.…”

Section: Introductionmentioning

confidence: 98%

“…While bruits have been known to relate to vortex shedding and have been long understood to correlate with the degree of stenosis, previous correlations have been identified via the concept of a break frequency, as originally identified via phonoangiograms [18] , and computational studies have remained true to this concept, e.g., [52] . The limitation of the break frequency is that it lies beyond the best range for stethoscope-based clinical diagnoses of critical heart sounds (70-120 Hz) [32] , rendering its identification reliant on sophisticated sensors and computer-assisted devices. Our paper introduces an alternative frequency definition that restricts the acoustic spectrum to the formation of the von Karman vortex street, identifying this phase of flow automatically by means of the Q-criterion.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A CFD-FFT approach to hemoacoustics that enables degree of stenosis prediction from stethoscopic signals

Ali

Hafez

Elkhodary

et al. 2023

Heliyon

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Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A CFD-FFT approach to hemoacoustics that enables degree of stenosis prediction from stethoscopic signals

Ali

Hafez

Elkhodary

et al. 2023

Heliyon

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“…The second filter, intended for respiratory sounds, covers the range of 50 Hz to 1000 Hz (Fig. 8) [34]. These filters help to enhance the clarity of the relevant audio frequencies, further improving the usability of the digital stethoscope.…”

Section: B Android Applicationmentioning

confidence: 99%

Clinical IoT in Practice: A Novel Design and Implementation of a Multi-functional Digital Stethoscope for Remote Health Monitoring

Baraeinejad,

Shams,

Saberi Hamedani

et al. 2023

Preprint

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<p>This study introduces a cutting-edge digital stethoscope optimized for remote health monitoring. Integrating Micro-Electromechanical Systems (MEMS) microphones with Bluetooth Low Energy (BLE) 5, the device ensures high-fidelity, real-time audio transmission. It seamlessly connects to an Internet of Things (IoT) platform through an embedded system, highlighting its potential in remote healthcare scenarios, especially during global health emergencies. Advanced features encompass Active Noise Cancellation, extended battery life, and intricate internal sound filtration. Paired with a dedicated Android application, the stethoscope streamlines the capture, storage, and visualization of auscultation data. Crucially, its integration with Electronic Health Records (EHRs) and its capability to generate vast datasets can significantly advance diagnostic precision, leveraging Digital Signal Processing and Artificial Intelligence methodologies. </p>

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Low‐Intensity Sensitive and High Stability Flexible Heart Sound Sensor Enabled by Hybrid Near‐Field/Far‐Field Electrospinning

Huang

Zhao

2023

Adv Funct Materials

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Low-cost and wearable heart sound sensors can facilitate early detection and monitoring of cardiovascular and respiratory diseases. Such sensors are currently limited by either the complexity of fabrication processes or low sensitivity and reliability for weak signal detection. Here, a hybrid near-field/ far-field electrospinning approach is demonstrated that enables low-cost fabrication and optimization of triboelectric heterostructures for heart sound sensing. Specifically, by combining the far-field produced highly polarized and porous polyvinylidene difluoride network for triboelectric electrification and near-field patterned polyurethane grid spacers for vibration enhancement and charge trapping, the greatly improved sensor output at the heart sound frequency (50-150 Hz) and intensity (<80 dB) range, demonstrating record high sensitivity of 7027 mV Pa −1 and low detection limit of 47 dB. The sensor exhibits excellent stability under both sudden physical disturbance and longterm cycling stress, showing no degradation during 7 h of continuous operation. It is demonstrated that the sensor can be integrated with apparel and capture high-quality heart sound signals at all five diagnostic auscultation points and distinguish characteristic heart sound patterns caused by different cardiovascular diseases.

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Frequency responses of conventional and amplified stethoscopes for measuring heart sounds

Cited by 9 publications

References 11 publications

A CFD-FFT approach to hemoacoustics that enables degree of stenosis prediction from stethoscopic signals

A CFD-FFT approach to hemoacoustics that enables degree of stenosis prediction from stethoscopic signals

Clinical IoT in Practice: A Novel Design and Implementation of a Multi-functional Digital Stethoscope for Remote Health Monitoring

Low‐Intensity Sensitive and High Stability Flexible Heart Sound Sensor Enabled by Hybrid Near‐Field/Far‐Field Electrospinning

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