The human organism as a source of information

The human organism is an open dynamic system, able of receiving, processing, and giving information. The information given by an organism can be used in diagnosis.

A diagnosis is the description of a set of functional and morphological disfunctions (a disease) of an organism. “Diagnosis is the process of determining by examination the nature and circumstances of a diseased condition (”

Biosignals and their classification:

Any material manifestation of information about the biological system under study is a biological signal, or a biosignal. There are two types of biosignals:

  1. Proper Biosignals – Are body-generated signals. E.g. Electric discharges in the axon of a neuron.
  2. Mediated Biosignals – Are body modulated signals, i.e. they do not originate from within the organism.

Biosignals can also be sorted according to their physical nature.

  • electrical
  • non-electrical

Electrical signals are easily processed by electronic devices, however for non-electric signals suitable transducers are required.

A transducer is a device that receives a signal as a type of energy and converts in to another type of energy. In our case, transducers will have to convert either mechanical, thermal, light or radio energy into electric energy.

Biosignal Processing: consists of several steps

  1. Processing of biosignals – this is done by inert sensors and transducers
  2. Amplification and electronic treatment – the signals are amplified to a level high enough to give an eligible reading. Also, during this step unwanted noise is removed – selective band filters are used.
  3. Recording – the data is recorded and stored as: images, text or digital format. The advantage of storing the date in digital format is the rapidity with which it can be shared, and its longevity.


Notes compiled by Andrei Cociug.