Piezography

Piezography - method graphic registration of mechanical vibrations with the help of special instruments - the piezoelectric transducers.
This method is based on the so-called piezoelectric effect occurs electric charges on the faces of some of the crystals under the influence of mechanical stress or strain. The piezoelectric crystals convert mechanical vibrations into electrical energy. These devices are very sensitive and allow you to register oscillations of small amplitude and frequency. In medicine piezography use for recording pulse fluctuations of the arteries (arteriography), veins (phlebopathy), and other

Piezography (from the Greek. piezo - press and grapho - write) - method graphic record based on using the piezoelectric effect (the emergence of electric charges on the faces of certain crystals and electric polarization within them under the influence of mechanical stress or strain). Piezoelectric effect, widely used in the technique, is also used by physiologists and clinicians.
Piezography based on the use of piezoelectricity arising at the moment of deformation of piezocrystals. Mechanical vibrations become piezocristal into electrical energy. Such transformation of one energy to another occurs almost without inertia. Another advantage of piezoelectric transducers is high (up to tens thousand Hertz) natural frequencies. Therefore, these devices are suitable for the registration of rapidly proceeding processes, very sensitive and allow you to register oscillations of small amplitude and frequency. As a receiver (piezoresistor) can serve as the piezosensor different designs. Piezoelectric properties have over 20 classes of crystals. Part piezo transducers are for the most part the Rochelle salt crystals (NaKC4H4O6·4H2O), dihydrotestosterone or ceramics of barium titanate (BaTiO3) etc
The possibility of applying piezography in medicine are great and are still far from exhausted. For example, piezo transducers (Fig) used for recording pulse fluctuations of the arteries (arteriography), veins (phlebopathy), writing phonocardiograms - precordialgia and on the part of the esophagus (esophageal piezosurgery), for recording of respiration, cardiac impulse, for measuring the pressure in the cavity of the heart, gastrointestinal tract, for registration of ballistocardiogram etc.
Method of pedopornografia allows to make a conclusion about the status not only of the blood vessel, but also of its individual parts. Piezography in combination with clinical data gives an opportunity to judge the state of a tone and level of sclerosing vessels, which is of great importance in the study of the functional characteristics of the vascular system. When interpreting arteriopathy primary importance attached to the value of systolic and reflected wave and do not register the movement of the arterial wall, and its acceleration.
Method of piezography almost not different from other methods of registration of curves pulse, phonocardiograms and so on, it is Enough to place piezoresistor so that the maximum fluctuations were registered at the lowest sensitivity of the device. While the fragility of the crystal requires careful handling, particularly unacceptable pressure on plot of piezoresistor. The patient during the study does not experience any unpleasant feelings, and therefore piezography practically no contraindications.

The piezo transducers: 1 - for the recording of arterial pulse; 2 - for the record phonocardiograms.