RU2456915C1 - Device for scull measurement - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: device for scull measurement relates to measuring instruments in field of medicine and can be used in anatomy, anthropology, forensic medicine, criminalistics for human scull study. Device contains mechanism of automatic object rotation, made in form of support disk with replaceable screw rests, which have possibility of correcting their height and position with respect to axis of rotation, which is brought into motion by stepper motor, unit of stepper motor control, ensuring automatic supply of preliminarily specified number of pulses corresponding to angular step of object rotation, laser rangefinder, ensuring measurement of distance to object surface, mechanism of vertical and horizontal travel of laser rangefinder.

EFFECT: mechanism of rotation and orientation with support disk and screw rests makes it possible to fix object in required position, stepper motor ensures automatic rotation of object around axis on 360° with specified angular step; mechanism of vertical and horizontal travel of laser rangefinder makes it possible to carry out layer-by-layer scanning of object surface with specified interval, as well as carry out measurements in separate points.

6 dwg

Description

The device for measuring the skull belongs to the field of biology and medicine and can be used for craniological research in anatomy, medical and historical anthropology, forensic medicine, biology.

Known cubus craniophore, designed to secure the skull in the desired position, and a graph that allows you to circle the skull with a pencil on a piece of paper (Alekseev V.P., Debets G.F. Craniometry. Methodology of anthropological research. - M .: Nauka, 1964. - S.96-100). Craniophore cube consists of a system of slats, limiting the space in the form of a cube, in which a skull is installed and fixed using a system of screws. The chart consists of a stand for a vertical bar with a millimeter graduation and a top bar with a curved needle and a lower bar with a pencil mounted on it. To obtain a contour of the skull, the graph is moved around the craniophore, touching the surface of the skull with a needle, while the pencil leaves a contour on a sheet of paper placed under the craniophore.

The disadvantage is that in order to obtain a graphic contour, the contact of the diaphragm needle with the surface of the skull is necessary, which can damage the object in case of poor preservation, as well as a mechanical way to obtain the result.

Of the known closest in technical essence is a Gokhman craniometer (Alekseev VP, Debets GF Kraniometriya. Methodology of anthropological research. - M .: Nauka, 1964. - P.101-105) containing a craniophore mounted on a movable a bar placed in the center of a rectangular stand, and a metal circle graduated with an interval of 1 °, on which a freely moving carriage with a movable ruler perpendicular to the tangent circle and graduated with an accuracy of 1 mm is mounted. The circle rotates around its axis by 90 °. The necessary parameters are removed by measuring the distance from the circle to the surface of the skull at intervals determined by the researcher.

The disadvantage also lies in the need for mechanical contact with the surface of the skull and a mechanical method of obtaining data.

The present invention is aimed at eliminating mechanical contact with the surface of the skull, the most gentle way to install and fix the skull in the right position, reducing measurement errors, eliminating the influence of subjective factors in the angular positioning of the object (operator errors).

The technical result is to obtain craniograms (contours of the surface of the skull) in any projection of interest to objects of any preservation, with the possibility of comparing the data with the results of studies conducted using traditional mechanical equipment.

This is achieved by the fact that in the device for measuring the skull, containing the unit for fixing the object (skull) and a measuring device,

according to the invention, a mechanism is automatically introduced for turning the object, made in the form of a support disk with interchangeable screw stops, which have the ability to correct their height and position relative to the axis of rotation, driven by a stepper motor, a stepper motor control unit that automatically feeds a preset number of pulses, corresponding to the angular step of rotation of the object, a laser range finder, providing a measurement of distance to the surface object, a mechanism of the vertical and horizontal movement of the laser rangefinder.

In this case, the rotation mechanism with a support disk and screw stops allows you to fix the object in the required position, the stepper motor provides automatic rotation of the object around the axis by 360 ° with an angular step from 0.9 ° (400 measurement points) to 13.5 ° (27 measurement points ), which eliminates subjective errors in the angular positioning of the object.

The use of a laser rangefinder allows measurements to be made in a gentle manner, eliminating mechanical contact with the object, which is especially important when examining objects of poor preservation. The mechanism of vertical and horizontal movement of the laser rangefinder makes it possible to layer-by-layer scan the surface of an object with a specified interval, as well as measure individual points. The measurement data are entered into computer spreadsheets, where the geometric parameters of the object are calculated by subtracting from the result of each measurement the distance from the reference base of the laser range finder to the axis of rotation of the object (constant for this craniometer).

The introduction of new elements and the relationships between them provides a solution to the problem.

Figure 1 shows a General view of the craniometric laser complex.

Figure 2 shows the rotation and orientation mechanism.

Figure 3 - site horizontal and vertical movement of the laser rangefinder.

Figure 4 - structural diagram of the complex.

Figure 5 is a General view of the block of electronic components.

The device consists of (figure 1):

1 - rotation and orientation mechanism (MPO),

2 - laser range finder (LD) mounted on

3 - node vertical and horizontal movement (UVGP),

4 - control circuit (SU),

5 - power source (IP),

6 - computer

7 - grounds.

The object of study (OI) 8 is installed on the MPO.

The rotation and orientation mechanism (MPO) (Fig. 2) is made on the basis of a DUNASUN stepper motor (9) of type 4SHG-023A 39S with a pitch of 1.8 ° and a gearbox ½, as a result of which the angular pitch of the support disk (10) is 0, 9 °, by means of a stepper motor (BH), it ensures the rotation of the optical axis by a given angle at the command of the control system. Orientation of the OI in space is carried out using the VU (11) lockable screw stops equipped with disk pads rotating on bearings, the surface of which is glued with soft rubber for better adhesion to the OI. This design of the VU allows you to leave it stationary when orienting the OI with respect to the vertical axis.

The vertical position of the OI can be changed by screwing the VU into the radially located holes of the support disk mounted on the axis of the ШД gearbox.

LD brand DISTO ^TM D3 installed on UVGP (figure 3) and allows you to measure the distance from a given base to the OI (8) by command SU. The vertical and horizontal positions of the LD can be changed using vertical screws (12) and horizontal movement (13) with a resolution of 0.1 mm according to nonius scales. The operating modes of the LD are programmed according to the instructions attached to it by the manufacturer.

According to the manufacturer’s description on an LD, the diameter of the laser measuring beam is 6 mm, while the spot area on the OI would not allow measurements of small fragments with sufficient accuracy. To reduce the measurement error caused by such a large spot area, a diaphragm is installed on the output optical system of the LD, which reduces this area by 16 times compared to the factory one.

IP provides appropriate nutrition for all components of the complex: SU, MPO, LD.

The computer (6) can be anything with the corresponding software tasks.

All nodes and elements of the complex are mounted on the basis of 7 (figure 1).

The control circuit (SU) (Fig. 4) contains: a controlled generator (UG) (14), the pulse repetition rate from which is controlled by the tuning resistor R1 (15); register (16); control keys SH (17); control unit (BU) (18); binary counters (SI1 (19), SI2 (20)); match pattern (=) (21); decoder 2/7 (D) (22); seven-segment indicator (I) (23); transistor switch (TC) (24); three control buttons (K1 (25), K2 (26), K3 (27)).

The components of the control circuit work as follows.

The UG generates pulses with a frequency regulated by the resistor R1, which ensures the angular movement of the SH shaft within its mechanical capabilities. Pulses from the UG are fed to the input of the register R, which operates in the Johnson code.

At the same time, pulses from the UG arrive at the inputs SI1, SI2 and a transistor switch (TC).

TC with the arrival of each pulse sends a signal to the indicator And, the comma of which gives a light signal indicating the operation of the UG and the arrival of these pulses to P, SI1 and SI2.

Counter SI1 counts the number of pulses received from the UG to the input of register R.

SI2 counter is required to set the number of pulses that provide rotation by a given angle of the MPO support disk. The state of SI2 through a decoder and indicator allows you to visually control the number of pulses set by the researcher to rotate the OI by a given angle.

If the codes of the SI1 and SI2 counters coincide, the matching circuit (=), executed according to the “Exclusive OR” scheme, sends a signal to the control unit, which prohibits the supply of pulses from the UG to P, SI1 and SI2.

The decoder D converts the binary code of the SI2 counter into the code of the seven-segment indicator And, showing the number of pulses entered into this counter during installation.

The indicator readings corresponding to the number of pulses introduced in SI2 are shown in table 1.

Register P controls the stepper motor control keys, made according to the Darlington circuit and supplying current pulses to the stepper motor windings, which, in turn, are shunted by diodes that compensate for the occurrence of the counter-emf that occurs when the stepper motor control keys are closed. When a signal prohibiting the supply of pulses to P appears on the control unit with (=), the latter remains in a state corresponding to the arrival of the last pulse. In this case, the corresponding control key for the stepper motor remains open, thereby fixing the position of the OI necessary for making an LD measurement.

All electronic components, except for the power source and laser range finder, are located in the housing (figure 5) (28).

The controls are: the resistor R1 (“Speed”) is made under the slot, the button for setting the automatic rotation angle “Installation” (on the K1 block diagram), the start button “Start” (on the K2 block diagram), the control button for the range finder “Measurement” (on block diagram K3).

An indicator (29) is also displayed on the external panel of the case.

Work with the complex

We turn on the power source, while the supply voltage is supplied to the electronic unit and the LD. To activate the LD, press the K3 button. In this case, the LD display is illuminated and a laser beam appears at the output of the LD.

To clarify the reference base, we establish a rectangular standard with plane-parallel faces on the MPO support disk. The face facing the LD is combined with the center of the axis of rotation of the support disk and measure.

Before starting work on the SHU, we install the OI and use the screw stops to orient it relative to the LD, turning the latter on to the laser radiation without measurement.

We set the LD horizontally and to the height of the scan using the vertical movement screws.

We program the LD for the corresponding measurement mode.

The LD can be programmed into two measurement modes:

- sequential measurement mode;

- continuous measurement mode.

Then, using the K1 button, we set the number of pulses corresponding to the selected angular step of rotation of the OI, checking it by the indicator and table 1.

After all the preparatory operations, we proceed to the measurements.

For measurements in the sequential measurement mode, press the K2 button. The holding time of the K2 button does not affect the operation of the MPO, it affects only the number of clicks (there must be one click!). In this case, the OI rotates by an angle corresponding to the number of pulses set by the K1 button in SI2, and is fixed in this position. During the rotation, the OI flashes a comma on the indicator, signaling the supply of pulses to the stepper motor. After the rotation of the OI is stopped, press the K3 button to turn on the LD to measure the distance to the OI, read the result from the LD display and enter it in the corresponding cell of the Excel computer table.

For the following measurements, repeat pressing the K2 button, then the K3 button and read the measurement result from the LD display, sequentially entering them into the cells of the Excel computer table.

To take measurements in the continuous measurement mode, set the LD to the continuous measurement mode by pressing the shortcut button and holding it for several seconds.

After the LD has switched to the selected mode by pressing the K2 button, we give a signal to turn the OI to the set angle and after the next turn of the OI, we read the measurement readings from the LD display, entering them into the cells of the Excel computer table.

To make measurements, the K3 button should not be pressed, i.e. all rotation and measurement operations are performed with one K2 button. At the same time, the measurement of LD increases to 1 ... 2 seconds and the readings are displayed on the scoreboard continuously. The first LD reading may be incorrect (from the previous measurement), so several repeated readings should be considered.

For local measurements (small fragments of OI), we translate the LD into the continuous measurement mode and, moving the LD with the screws for horizontal and vertical movement of the UHF, we make the necessary measurements, entering them in the table.

Calculation of the parameters of the OI and the construction of the contours of the cross-sections of the scan is performed automatically in the tables Excel PC, according to the formulas and selected diagrams of the construction of dependency graphs introduced by the researcher.

An example of such a calculation from measurements and the construction of a diagram are presented in Fig.6.

The angle of rotation of the OI between measurements is 9 ° (10 pulses set in SI2, the corresponding indicator reading is ⊏).

The graphs in Table 2 show: No. — number of the measurement point, “Angle” —the angle of rotation of the OI in degrees, “Measurement” —distance from the OI to the base, “Radius” —distance from the surface of the OI to its rotation axis.

In addition, the calculation of the distances between points 28-33 and 9-13 at the OI is presented.

All measurement values are given in mm.

The proposed device allows to perform craniometric studies of skulls of any safety in a non-contact manner with fixing the object in the most gentle way, to obtain bypass craniograms in any plane with the ability to compare the results with research results using traditional mechanical equipment. In addition, the error associated with the subjective determination of measurement points in the mechanical method of taking craniometric parameters is eliminated. The device allows to obtain the dimensional characteristics of the sections of the skull inaccessible to mechanical devices: eye sockets, pterygo-palatine fossa, external auditory meatus, and also to obtain dimensional characteristics of the inner base of the skull.

Claims (1)

A device for measuring the skull, comprising a skull fixation unit and a measuring device, characterized in that the fixation unit is additionally equipped with interchangeable screw stops with the ability to correct their height and location, a mechanism for rotating the skull around a vertical axis, a control unit that allows you to change the angle of rotation of the skull and laser rangefinder mounted on the mechanism of translational vertical and horizontal movement.

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