Identification > Measurements > Measuring paradigm

At statement of a problem of identification we are limited to measurements of periodic movements [25]. As an interval of time of measurements one warm cycle is accepted. It is made for following practical reasons:

• The majority of existing methods of measurements on blood circulation system are limited to a time interval of one cardiac cycle. Naturally there is an identification problem under the information only about one cardiac cycle in the assumption of identity of all cardiac cycles which follow the measured.



• Dependence of an estimation of the identified parametres on an initial condition of object that is important at practical interpretation of results of identification is eliminated.

There are various methods of measurement of physiological sizes. The most essential features of these methods at statement of a problem of identification in [25] have been named by a measuring paradigm. Three basic measuring paradigms are allocated.

Paradigm C. Paradigm of continuous measurements. The vector of measurements is defined as analytical function from a vector of a condition and a vector of parametres during any moment of time on an interval of time of supervision according to the formula:

(75)

For example, according to this paradigm the curve of a blood pressure by means of an analogue sensor of pressure and the analogue-digital converter is measured.

Paradigm D. Paradigm of measurements during the chosen moments of a cardiac cycle. Vectors of measurements are defined as analytical functions from a vector of a condition and a vector of parametres during the chosen moments of time on an interval of time of supervision according to the formula:

(76)

For example, according to this paradigm haemodynamics parametres during the moments of change of phases of a cardiac cycle are measured: end-diastolic and end-systolic ventricular volumes and others.

Paradigm I. Paradigm of integrated measurements. The haemodynamic sizes integrated on all interval of time of supervision are measured. The vector of measurements is defined as functional from a trajectory on an interval of time of supervision and a vector of parametres according to the formula:

(77)

As an example it is possible to result a classical way of measurement of arterial pressure on Korotkov. Systolic pressure is defined as its maximum value on a cardiac cycle, and diastolic pressure is defined as its minimum value.