Biophysics

Fundamental concepts of Physics of Waves. Knowledge of Math at the 12th grade.

– 1 lecture of 2 hours per week where the professor summarily exposes the syllabus content;

– 1 theoretical-practice lesson of 1 hour a week where the professor applies the physics concepts, presented in the previous lecture, to understand practical examples related to the field of Audiology, showing to the student how to apply these concepts in problem solving;

– 1 theoretical-practice lesson of 1 hour a week, where students are invited to solve practical exercises with the support of their teacher. These exercises are intended to be related with the field of Audiology, so that physics concepts can be used to clarify these phenomena from a scientific view. They are also important to develop effective analysis and problem solving skills.

This curricular unit aims to provide Audiology students with a solid base in fundamental biophysics concepts necessary to achieve the overall objectives of the training course of Audiology at Coimbra Health School, with an emphasis on the aspects related with the perception of sound intensity and pitch, and the acoustic and bioelectric behavior of the auditory, vestibular and phonatory systems,  while transmitting the intellectual understanding of mechanisms underlying the scientific method and rigor that so clearly are reflected in the field of Physics.

1. Physical and physiological aspects of the human auditory perception (15 hours)
Logarithmic scales – definition; the decibel (dB) and references; calculations on scales dB
Sound pressure level – Webner-Fechner law; definition of sound intensity level and sound pressure level; weighted scales; auditory perception of intensity: hearing thresholds, minimum discernible difference, curves of constant sensitivity, hearing level and range of headphones
Sense of pitch – relationship between pitch and frequency; scales Mel and Bark; critical bands and masking.

2. Fluid Mechanics (15 hours)
Hydrostatic – cohesive forces and states of matter; density; hydrostatic pressure; fundamental law of hydrostatics; applications; Archimedes principle; hydrostatic potential energy
Hydrodynamic (non-viscous flow) – fluid flow: stationary and turbulent, non-viscous and viscous fluids; the continuity equation, flow rate; Bernoulli’s equation; Venturi principle; aerodynamic effect of fluttering and sound production
Viscous flow – dissipation of mechanical energy and viscosity; velocity profile; Poiseuille’s law; hydrodynamic resistance, hydrodynamic circuits; Stokes law

3. Bioelectricity and nerve receptors (15 hours)
Diffusion phenomena – current density of solute; Fick’s laws for diffusion; membrane permeability; strength of diffusion, chemical potential; molecular mobility
Ion diffusion – electric charge, charge density; electrostatic force and electrostatic energy; electric field and electrostatic potential; electric mobility; electrochemical potential; ion current density; Nernst equation and the Nernst-Planck
Bioelectricity and nerve receptors – resting potential; action potential and nerve impulses; nerve conduction; nerve receptors

4. Biophysics and bioacoustics of the auditory, vestibular and speech (15 hours)
Auditory system – biophysical processes of auditory detection, and its anatomical and physiological correlation; external ear, acoustic behavior, the transfer function; middle ear: mechanical-acoustic behavior; inner ear: the basilar membrane mechanical, frequency discrimination, theories of hearing, masking, discrimination in amplitude, sensory-neural aspects, nonlinear behavior behaviors; bone conduction
Vestibular system – Vestibular biophysical processes of detection, and their anatomical and physiological correlation; otoliths; sensory-neural aspects
Phonatory system – biophysical processes of sound training, and their anatomical and physiological correlation; acoustic-mechanical behavior of the vocal cords; acoustic behavior of the larynx and oral cavity, resonance and formants.

NAO

Main Bibliography:

DURÁN, Biofísica – Fundamentos e Aplicações

Editora: Makron Books / Prentice Hall

Ano de Edição: 2003

PEDROSO DE LIMA, Biofísica Médica

Editora: Imprensa da Universidade de Coimbra

Ano de Edição: 2002

PEDROSO DE LIMA, Ouvido, Ondas e Vibrações

Editora: Imprensa da Universidade de Coimbra

Ano de Edição: 2013

Secondary bibliography:

HAUGHTON, Acoustics for Audiologists

Editora: Academic Press

Ano de Edição: 2002