Bioinformation Engineering

Origin of BiosignalsFajar Purnama 152-D8713

Computer Science and Electrical EngineeringKumamoto University

What is Biosignal?

● It is any signal that can be found in any living being.

● Though today modern technologies represent biosignals in sinusoid forms.

Where does it come from?● It came from within our body > travels to

the skin > captured by an instrument > perceived by us

Where does it origins?

● It origins from major organs within our body like brain, heart, kidneys, liver, and lungs.

● Today we can see what’s wrong with the body by observing the biosignal.

https://upload.wikimedia.org/wikipedia/commons/8/8e/2701_Water_Content_in_the_Body-01.jpg

How deep the origin● As deep as the substance that structured the major

organs = cells, the smallest unit in life.

How does cells produce biosignals?● When the cells of living things are stimulated, sodium (Na+) and potassium (K+) ions move rapidly

through the cell membrane’s ion channel, creating difference in electric potential.

● Sodium is usually found outside in form of salt NaCl while Potassium is usually found inside the cell.

● Electricity itself is defined as the flow of electric charge.

https://media.giphy.com/media/11rQETQPpbTiJW/source.gif

Contents of Cell Membrane● Before discussing about bioelectricity, let’s look at the

cell membrane. The cell membrane consists if lipid bilayer and proteins. There are many kind of channels for the bellow illustration.

https://upload.wikimedia.org/wikipedia/commons/thumb/9/91/Scheme_facilitated_diffusion_in_cell_membrane-en.svg/2000px-Scheme_facilitated_diffusion_in_cell_membrane-en.svg.png

Passive Channel

● It is a passive way where ions flows from higher concentration to lower concentration.

https://media.giphy.com/media/2gscv6A65oHqU/giphy.gif

Active Channel● The active channel also called the transport channel activates when the concentration reaches equilibrium.● It functions to create difference in concentration again in order for the flow in the previous slide to flow again.

potassium (K+) is returned to the cell and sodium (Na+) is released.

https://media.giphy.com/media/suHCaPseJhib6/giphy.gif

Enzymes

● Not to forget that attraction between positive and negative charge contributes to the flow i.e. potassium (K+) attracted to chloride (Cl-). Enzymes helps or accelerates the bonding.

Resting and Action Potential

● The resting potential is a state where the flow of ion in and out of the cell is stable (looping from slide 8 - 10).

● While action potential is a state where the cell is excited, enabling more ions flow, thus generating more bioelectricity or biosignal.

Cell Stimulation

● The cell can be stimulated artificially or naturally from the brain > neuron > cells. This will turn into action potential.

Bioelectricity or Biosignalhttps://upload.wikimedia.org/wikipedia/commons/2/2f/Action_potential_propagation_animation.gif

Gated Channel● The channels responsible for action potential is voltage gated channel and

transmitter gated channel. Think of them as transistors.● Voltage gated channel activates when an applied voltage around certain level

and transmitter gated channel activates when substances locks onto a channel.

Circuit Equivalent Model

● With enough understanding the phenomena can be modeled