Operation Manual

MyotonPRO User Manual

Page 22 of 108

The acceleration curve with at least three positive peaks is characteristic of adequate natural

oscillation of the measured tissue (see Figure 1). If the tissue oscillation was not sufficient, the

time of mechanical impulse should be changed (Tap time) depending on the properties of the

measured tissue.

COMMENT Despite setting up the mechanical impulse time, the achieving of the third oscillation period in the

case of the standard diameter of the Probe (d = 3 mm) can be complicated if measuring thin

tissues (e.g. < 5 mm) and/or tissues of great stiffness (e.g. >700 N/m). In such cases, depending on

the Subject, tissue type and properties, a wider diameter Probe cap (of d = 10 mm) or smaller

diameter Probe (d = 1.5 mm) can be used

. The latter allows for more concentrated impulse

energy to generate the oscillation of tissue (e.g. for measuring the tendon of contracted muscle).

At the same time, all the rules of measuring (see chapter 2.2) must still be followed.

2.3.2 Short-term plastic deformation

If elastic deformation is not achieved the characteristic curve will show a double hump on the

first positive peak - this characterises unwanted plastic deformation as illustrated in Figure 2).

Figure 2: Tongue tip, Male 30, Central, Relaxed (Tap time 15ms)

Plastic deformation of the measured tissue occurs if the mechanical impulse that the Device

exerts overcomes the Limit of Strength of the measured tissue and the Probe bounces off the

supporting surface under the tissue (bone or artificial support). This leads to incorrect co-

oscillation and therefore to incorrect measurement results. Short-term plastic deformation can

occur when measuring thin (<5 mm thickness) and/or Tissues with low stiffness (e.g. tongue).

The main reason for short-term plastic deformation can be an overly strong mechanical impulse

to and/or too small contact surface (7mm

) of the standard Probe (d=3mm). To avoid this the

To order non-standard Probes, contact the sales representative or the manufacturer.