SU1276335A1 - Apparatus for diagnosis of vitality of limbs - Google Patents

Abstract

The invention relates to medical technology. The purpose of the invention is to improve the accuracy and reduce the time of diagnosis of post-traumatic changes. The device contains a temperature meter, the first and second temperature sensor. In addition, the device has a cooling chamber, a switch, a control unit, a calculator. The temperature meter contains a constant voltage source, a capacitor connected in series an adder, a comparator, an And element, a counter. The ratio of the rates of temperature change in healthy and damaged tissue of the segments of symmetrical extremities is measured when exposed to a hypothermic shock. Based on this ratio, a prediction is made about the viability of the damaged segment relative to the healthy symmetric segment. When the values of this ratio are in the range from 1 to 0.25 (b segment is viable. 1 c. Nfl, 3 pictures. (L

Description

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The invention relates to medical technology, in particular to diagnostic devices investigating the thermodynamic properties of biological tissues, and can be used as devices for indirectly investigating regional blood circulation in limb injuries in order to predict the viability of the tissue of a segment or the entire limb.

The purpose of the invention is to increase the accuracy and reduce the time of diagnosis of post-traumatic changes.

FIG. 1 is a block diagram of the device; in fig. 2 - diagrams explaining the operation of the temperature meter unit; in fig. 3 - diagrams explaining the operation of the control unit.

A device for diagnosing the viability of the extremities contains a temperature meter 1, a first temperature sensor 2, a second temperature sensor 3 connected by inputs to the first input of the temperature meter 1 and placed respectively on the damaged 4 and healthy 5 tissue segments of symmetrical limbs.

The device also comprises a cooling chamber 6, a switch 7, a control unit 8, a calculator 9, the cooling chamber 6 being adapted to place the extremities in it. The outputs of the first and second sensors 2 and 3 are connected respectively to the first and second inputs of the switch 7, the output of which is connected to the first input of the temperature meter 1, the second input of which is connected to the first input of the control unit 8, and the second output to the first input of the calculator 9, the second the input of which is connected to the second output of the control unit 8, the third output of which is connected to the third input of the switch 7.

The temperature meter contains a source of constant voltage 10, a capacitor 11 connected in series adder 12, comparator 13, element 14, a counter 15 whose output is connected to the second output of temperature meter 1, the first output of which is connected to the first output of constant source 10 and the first input of the switch 12, the second input with the second input of the element I, the first input with the total thickness, the second input of the adder 12, the second input of the comparator 13 and the first plate of the capacitor 11, the second plate of which is connected to The other input of the adder 12 and the second input of the source 10 of constant voltage.

The essence of the invention is that measuring the rate of temperature change in healthy and damaged tissue of the segments of symmetrical limbs when exposed to a hypothermic shock. In terms of this ratio, a prediction is made about the viability of the damaged segment relative to the healthy symmetric segment. With a ratio of 1-0.25, the segment is viable.

A device for diagnosing tissue viability in injuries of limbs works as follows.

In the cooling chamber 6, a temperature of 10-15 ° C below ambient temperature is created. Sensors 2 and 3 are attached respectively to healthy and damaged tissue of the segments of symmetrical limbs 4 and 5. The operator from control device 8 initiates the reset signal of the binary counter 15 to zero and the connection signal of the discharge circuit to the capacitor 1 1 in order to discharge it.

Both limbs 4 and 5 are subjected to a hypothermic impact, for which they are connected to the cooling device chamber 6. The operator from the control device 8 initiates the launch of this device. In this case, with the repetition period Tp (Fig. 3), two sets of control signals Tf are sequentially output, during which two measurements of the resistance values of sensors 2 and 3, made on thermistors, are inserted into the microcalculator. With the arrival of the “Start” signal during the time interval T „(Fig. 3), the measurement information is processed according to a given algorithm and the coefficient K is calculated:

The temperature meter 1 operates as follows.

When the switch 7 connects to 5, its first input of one of the temperature sensors (thermistor), for example sensor 2, starts charging the capacitor 11 from the constant voltage source 10. The voltage plots of the capacitor 1 1 and thermistor 2 relative to the housing are shown in FIG. 2a

The algebraic addition of the voltages on the thermistor 2 and the capacitor 11 is carried out in the adder 12, the shape of the voltage at the output of which is shown in FIG. 26

The voltage shape at the output of the comparator 13 is shown in FIG. 2c. The pulse duration at the output of the comparator 13 is equal to the time interval by the value of ti and is proportional to the value of the thermistor Q of the resistor R. From the output of the comparator 13 a pulse arrives at the first input of the element 14, the second input of which receives pulses of frequency F.

By the end of the time interval ti, a code is formed at the output of the binary counter 16, which is proportional to the resistance value of the thermistor 2.

After the formation of the pulse at the output of the comparator 13, the device

The control generates in succession a signal for the opening of the control of the VOX of the switch 7 and a signal for the connection of the discharge circuit of the capacitor 11 to the latter. The discharge of the capacitor 11 occurs in the interval between the switching of the controlled keys. By the time the second thermistor 3 is connected to the input of the temperature measurement unit 1, the voltage on the capacitor 11 is zero.

The process of generating a binary code proportional to the resistance value of thermistor 3 is similar to the one indicated above.

FIG. Figure 3 shows the timing diagrams of the issuance of control signals by the control unit: a is the interval Gf with a repetition period Tn for generating a binary code proportional to the resistance value of the thermistor 2 and entering this code into the micro calculator 9; b - interval Gf with a repetition period Tn to form a binary code proportional to the resistance value of the thermistor 3 and enter this code into the microcalculator 9, c - the signal "Start of execution of the microcalculator 9 program; g - the structure of the interval Gf, which consists of the interval Gpr converting the resistance of the thermistor into a binary code, the interval Tz of writing the binary code to the first general register of the microcalculator 9, the interval Gf resetting the binary counter 15 to zero and the capacitor 11.

Reducing the time of diagnosis from 6 hours to 10-15 minutes allows you to establish the viability of the limb on the operating table and at the time of primary surgical treatment to perform reconstructive surgery, which will save the limb or cut it in order to avoid the development of traumatic toxicosis.

Improving the accuracy of diagnosing tissue viability is achieved through a hypothermic effect on both limbs, which removes the effect of local a)

pallet processes, carries out the functional load on the vessels of the limb, which makes it possible to establish the response of the vascular system and judge from it the accuracy of the viability of the limb with a greater degree.

Claims (2)

1. A device for diagnosing limb viability, containing a temperature meter, first and second sensors connected by inputs to the first output of a temperature meter, characterized in that, in order to improve accuracy and reduce the time for diagnosing post-traumatic changes, it contains a cooling chamber, a switch, a unit control computer, the cooling chamber is made with the possibility of placing the examined limbs in it, the outputs of the first and second sensors are connected respectively to the first and the second inputs of the switch, the output of which is connected to the first input of the temperature meter, the second input of which is connected to the first output of the control unit, and the second output to the first input of the calculator, 5, the second input of which is connected to the second output of the control unit, the third output of which is connected to the third input of the switch. 2. A device according to claim 1, characterized in that the temperature meter contains a constant voltage source, a capacitor connected in series an adder, a comparator, an AND element, a counter, the output of which is the second temperature meter output, the first output of which is connected to the first output source of constant voltage and the first input of the adder, the second input - with the second input of the element I, the first input - with the total length, the second input of the adder, the second input of the comparator and the first capacitor plate, the second facing of which It is connected to the third input of the adder and the second input of a constant voltage source. uc 7b Td b) &) about T d) TPR / TC c / e 3