Bioacoustics in Medical Sciences

Bioacoustics in Medical Sciences

• Human body organs and mechanisms produce acoustic signals, including sounds and vibrations. These signals propagate through tissues and reach the body surface.
• These signals contain information about the normal or abnormal activity of the sources that generated them (e.g., organs or mechanisms).
• Bioacoustics in medicine investigates how sound and acoustics are applied to medical diagnosis, treatment, and research. It integrates biology, physics, and engineering to solve medical challenges.
• Cardiovascular and respiratory sounds can be monitored using a stethoscope.

Acoustics

• Acoustics is the study of acoustic oscillations and waves.
• It analyzes the excitation, propagation, and interaction of these waves with matter.

Types of Waves

• Electromagnetic waves: These include gamma, X, optical, and radio waves.
• Mechanical waves: These include:
  • Liquid surface waves
  • Elastic waves
  • Acoustic waves
  • Seismic waves

Acoustic Waves

• Acoustic waves are mechanical waves that travel through a medium. The medium can be gas, liquid, or solid.
• The propagation of acoustic waves involves alterations in the medium’s regions leading to compression and rarefaction.

Wave Characteristics

• Wavelength: The shortest distance between two points on a wave with the same oscillation phases. Calculated as (speed/frequency).
• Frequency: The number of oscillations per unit time, measured in Hertz (Hz).
• Period: The time taken to complete one oscillation, measured in seconds. Related to frequency via (1/frequency).
• Propagation velocity: The velocity at which energy is transferred by a wave. Velocity differs in different media.

Types of Acoustic Waves

• Longitudinal: The direction of particle oscillation coincides with the direction of wave propagation.
• Transverse: The direction of particle oscillation is perpendicular to the direction of wave propagation.
• Commonly, acoustic waves in liquids and gases are longitudinal, while in solids they can have both longitudinal and transverse components.

Acoustic Wave Ranges

• Acoustic waves cover a broad frequency range (0 Hz to 10¹² - 10¹³ Hz).
• This range is divided for practical purposes into categories:
  • Infrasound (0 to 16 Hz)
  • Sound (16 to 20,000 Hz)
  • Ultrasound (20,000 to 10⁹ Hz)
  • Hypersound (10⁹ to 10¹³ Hz)

Sound Characteristics

• Objective (physical): Measured by instruments, independent of a person’s feelings.

• Subjective (physiological): Evaluated by a person, disregarding instrument readings.

• Sound Characteristics of the Sound: Includes acoustic pressure, oscillation amplitude, sound intensity, level of intensity, frequency, oscillation period, wavelength, propagation velocity, and harmonic (acoustic) spectrum.

Diagnostic Applications of Bioacoustics

• Imaging (using ultrasound): High-frequency sound waves create images of internal body structures. (e.g. Obstetrics, cardiology, abdominal imaging, 3D/4D ultrasound, Doppler imaging).
• Non-invasive Diagnostics:
  • Phonocardiography: Recording heart sounds for detecting murmurs or valve issues.
  • Lung sound analysis: Diagnosing respiratory diseases.
  • Voice analysis: Early detection of neurological conditions.

Therapeutic Applications of Bioacoustics

• High-Intensity Focused Ultrasound (HIFU): Non-invasive treatment using focused sound waves for destroying tumors or tissues.
• Lithotripsy: Using acoustic waves to break kidney stones into smaller pieces.
• Therapeutic ultrasound: Provides pain relief, reduces inflammation, and promotes tissue healing.

Wearable and Assistive Bioacoustics

• Hearing Aids and Cochlear Implants: Amplify or simulate sound for the hearing impaired.
• Wearable Monitors: Devices use bioacoustics to monitor vital signs (respiratory rate, heart sounds).
• Speech Generating Devices: Bioacoustics aids in voice synthesis for individuals with speech impairments.

Explore the intersection of bioacoustics and medical sciences. This quiz covers how acoustic signals from human organs are used for diagnosis and treatment. Delve into the principles of acoustics and the various types of waves involved in medical applications.