SU1367940A2 - Method of measuring elastic inertial parameters of manъs motor apparatus - Google Patents

Description

one

The invention relates to medicine, can be used to measure the mechanical parameters of the human musculoskeletal system in diagnostic studies, and is an improvement of the invention according to the author. No. 1176888.

The aim of the invention is to improve the accuracy and reduce the measurement time.

The method is carried out as follows.

A biomechanical link, such as a human arm, is fixed on a rigid support at a given angle and with the help of elastic elements, for example calibrated springs, give a static load that can vary in the range of 10 - 10 N / m.

On the biomechanical link, an additional weight of up to 40 kg is strengthened with a cuff.

The frequency of self-oscillations of a biomechanical link under load is measured, for example, using a frequency meter connected to a strain gauge attached to a link.

The additional mass is changed by reinforcing another known mass, and the stiffness of the elastic element is changed, for example, by replacing the calibrated spring so that the total load remains constant.

Extra weight is chosen. herewith, in such a way as to obtain a noticeable change in frequency, for example, 2-2.5 times, and after the change, the frequency of self-oscillations is also measured.

Prior to measurement, stable generation of mechanical vibrations of the studied human biomechanical link is excited by a static load, creating elastic elements with total stiffness not exceeding 200 N / m, measuring the frequency of the maximum of the spectrum of these oscillations and the value of the static load, estimate the results of these measurements moments of inertia of the biomechanical link, and

also frequency u). mechanical oscillations of the system during the subsequent repetition of measurements, during which the dynamic stimulating effect on the human motor apparatus with a frequency of stimulating pulses located

0

five

five

with a simple rational relationship with the frequency of oscillations of the biomechanical system, synchronize the stimulating pulses with the oscillations of the studied biomechanical link, filter and regulate the phase, providing a mode of maximum amplitude and monochromaticity of oscillations of the biomechanical link, and changing the amplitude of the stimulating effects, as well as reducing the bandwidth of the filter, set a given amount of monochromaticity 5 of the oscillatory process, the moment of inertia and the average frequency of the filter a ratio of

fn, - M

Q

five

40

J 1 - 41

where f is the oscillation frequency of the biomechanical link, Hz; M is the moment of static forces, Nm, created by elastic elements with a total stiffness of not more than 200 N / m;

 the maximum frequency of oscillation of the biomechanical level when exposed to a static load created by elastic elements with a stiffness not exceeding 200 N / m;

I is the moment of inertia of the biomechanical link, KG M. Tso. To another variant of the method implementation, the stiffness of the elastic element is first changed and the additional mass is replaced according to the constant load condition.

The final determination of the moment of inertia and stiffness is carried out according to the formulas

1 41 (- -4 ™

W, W

- -a, - I.);

45

50 X you D1, + I,) Ij),

if at first the additional mass is changed, and according to the formulas

51 1 1

-2- (x1-e ;,)

W, + U) i

, - (X, -,).

S - U)

U), and

.Ij and z, if the stiffness of the elastic element is changed.

Here 1 and about the required moment

inertia and rigidity;

frequency measurement before and after the change in mass and stiffness; respectively, the moments of inertia and rigidity of additional masses and elastic elements in each dimension.

Measuring at different positions of the test subject and different angles in the joints of the studied biomechanical link allows one to study the properties of the human motor apparatus.

Claims (1)

Invention Formula The method of measuring the elastic inertial parameters of the human motor apparatus according to author. No. 1176888, characterized in that, in order to improve accuracy and reduce measurement time, prior to measurement, a stable generation of mechanical vibrations of the human biomechanical link under investigation is excited by applying a static load created by elastic elements with a total stiffness not exceeding 200 N / m the frequency of the maximum of the spectrum of these oscillations and the magnitude of the static load are measured, and the inertia moment of the biomechanical link as well as the frequency UJ are estimated from the results of these measurements. mechanical vibrations systems with subsequent repetition of measurements, during which they perform a dynamic stimulating effect on the human motor apparatus with a frequency of stimulating impulses, which are in a simple rational relation with the frequency of oscillations of the biomechanical system S (synchronize the stimulating impulses with the oscillations of the biomechanical link under study, filter and regulate the phase, providing a mode of maximum amplitude and monochromatic vibrations of the biomechanical link, and, changing the amplitude of the stimulus uyuschih impacts, as well as reducing the filter bandwidth is set a predetermined value of monochromaticity of oscillation process, the moment of inertia and the center frequency of the filter is determined from the relationship f b „M, 41 M where f is the oscillation frequency of the biomechanical link, Hz; the moment of static forces, Nm, generated by elastic elements with a total hardness of not more than 200 N / m; - the maximum frequency of oscillation of the biomechanical element when exposed to a static load created by elastic elements with a stiffness not exceeding 200 N / m; -the moment of inertia of the biomechanical level, kg-m.