RU1821175C - Device for determining tooth channel length - Google Patents

Description

The invention relates to medical equipment and can be used in medicine when the differences in resistance of living tissues are determined.

The aim of the invention is to increase the accuracy of determining the length of the tooth canal by the fact that in a known device comprising a voltage stabilizer and an active electrode connected in series, mechanically connected to a position indicator, as well as a passive electrode, and. a tissue resistance measuring unit, a tissue resistance measuring unit is introduced comprising a series-connected alternating generator, a trigger, a key, a first driver, a threshold recorder, a stop unit, a trigger unit, the first output of which is connected to a second input of the threshold value recorder, and the second - to the second input of the trigger and the input of the adjustable generator, as well as the converter, the second driver and inverter, the output of which is connected to the second input of the key, and the input to the third input of the key, the output the house of the regulated generator and the input of the second driver, the output of which is connected to the third input of the threshold recorder

a value, the fourth input of which is connected to the output of the converter, the input of which is connected to a passive electrode, and the threshold value recorder comprises in series a first memory element, a comparison element and an indicator, as well as a second memory element, the output of which is connected to the second input of the comparison element; and the first input is to the output of the first memory element, the second input is to the first input of the threshold recorder, the second input of which is connected to the third input of the comparison element, the third input is from the second input of the first memory element, the fourth input - to the first input of the first memory element, and an output - with a comparison output element.

In FIG. 1 shows a block diagram of a device: in FIG. 2 shows a threshold logger.

A device for determining the length of a tooth canal comprises an active electrode 1, an indicator of the position of the active electrode; 2, passive electrode 3, voltage stabilizer 4, tissue resistance measuring unit 5, consisting of a transducer b, the input of which is connected to the passive electrode 3, and the output is connected to the recorder

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threshold value 7, the output of which is connected through the stop unit 8, to the start block 9, the outputs of which are connected respectively to the second input of the threshold value recorder 7 to the inputs of the regulated generator 10 and trigger 11, while the output of the controlled generator 10 is connected to the trigger 11 connected in series , key 12, the first driver 13. whose output is connected to the first input of the threshold value recorder 7, and the output of the adjustable generator 10 is connected through the second driver 14 to the third input of the recorder 7, and is also connected to the third input of the key 12 and through an inverter to the second input of the key 12, while the threshold logger contains a first connected memory element 16, a comparison element 17 with a threshold regulator, an indicator 18, and also a second memory element nineteen.

The device operates as follows.:. . .-.

Depending on the skills of the doctor (the rate of introduction of the active electrode 1), the regulator sets the desired sampling frequency within 2-200 Hz at the output of the generator 10 and then allows the operation of the regulated generator 10, trigger 11 sec. Of the launch unit 9, while trigger 11 through the key 12 connects the pulse shaper 13 to the input of the pulse shaper 14, which ensures that the same signals from the transducer 6 are recorded in the memory elements 16.19, which is necessary to prevent false triggering of the comparison element 17 at the initial time because a different signal at its inputs. Then, with the next pulse, trigger 11 connects the input of the pulse former 13 through the key 12 to the output of the adjustable generator 10 through the inverter 15 and in this state it freezes. The active electrode 1 is inserted into the tooth canal, and the resistance between the active 1 and passive 3 electrodes changes. The change occurs smoothly until the active electrode 1 extends beyond the tooth canal, then there is a jump in the change in resistance, which is determined by the recorder 7 as follows. Signals proportional to the change in Resistance between active 1 and passive 3 electrodes from converter 6 are first written to memory block 16, compared in comparison element 17 with the value recorded previously in memory block 19, and if the mismatch does not exceed the threshold value set by the controller threshold / value of the signal value in the block

the memory 16 is written to the memory unit 19. This is ensured by the fact that the pulse shapers 13-, 14 operate on different pulse edges from the output of the generator 10.

The threshold value, which determines the sensitivity of the device, can be set both before the study and can be adjusted depending on the individual characteristics of the patient during the study.

The mismatch signal from the comparison element 17 is fed to the detector 18, which provides either sound or light signals, and also in the case of open

a stop unit 8 to a start unit 9, which stops the operation of the generator 10 and prepares for a new start of the device. Work with the device is simple, does not require special education and can

carried out both in stationary and field conditions.

Formula of the invention

Claims (2)

1. Device for determining the length a tooth channel containing a voltage stabilizer connected in series and an active electrode mechanically connected to a position indicator, as well as a passive electrode, and a measurement unit tissue resistance, characterized in that, in order to increase the accuracy of determining the length of the tooth tooth, the tissue resistance measuring unit comprises a series-regulated oscillator, trigger, key, first shaper, the first output of which is connected to the second input of the threshold value recorder, and the second to the second trigger input and adjustable generator input, and a converter, a second driver and an inverter, the output of which is connected to the second input of the key, and the input to the third input of the key, the output of the adjustable generator and the input of the second driver, the output of which is connected to the third input of the threshold value recorder,. the fourth input of which is connected to the output of the converter, the input of which is connected to a passive electrode. 2. The device according to claim 1, wherein the threshold value recorder comprises in series a first memory element, a comparison element and an indicator, as well as a second memory element, the output of which is connected to the second input of the comparison element, and the first input to the output of the first memory element, the second input to the first input of the threshold recorder, the second the input of which is connected to the third input of the comparison element, the fourth input to the first input of the first memory element, and the output with the output of the comparison element. F.ig.1