RU2498823C1 - Liquid anaesthetic dispenser - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment. A liquid anaesthetic dispenser comprises a vertical tube, a tube pressure sensor and an electronic control unit. The tube is connected through a hydraulic circuit with a liquid anaesthetic container by an inlet solenoid pass-stop valve, and with a mixing evaporator by an outlet solenoid pass-stop valve. The above solenoid valves and the tube pressure sensor are electrically connected to the electronic control unit. An upper end of the tube is connected through a hydraulic circuit by a solenoid pass-stop valve with the mixing evaporator of breathing gases. The solenoid valve is electrically connected with the electronic control unit. The tube is made of an infrared transmitting material An infrared optolectronic sensor connected with the electronic control unit and fixed in relation to the tube body at the level exceeding the liquid yield level into the mixing evaporator is provided from the side of the tube.

EFFECT: using the invention enables more accurate adjustment of the liquid anaesthetic vapour concentration.

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Description

The present invention relates to medical equipment and can be used to create anesthesia-respiratory equipment.

Known anesthesia-breathing apparatus containing a block for the formation of liquid anesthetics, for example, the ventilator "Phase-5H" with the anesthetic prefix "Phase-PN", as well as the anesthetic complex "Phase-23" (manufacturer - OJSC "Ural Instrument-Making Plant", Yekaterinburg). In these devices, the method of dispensing anesthetics and a device for implementing this method are described in patent RU No. 2332242, IPC A61M 16/01, with priority dated 23.03.2006. According to this patent, a device for dispensing liquid anesthetics includes the separation of the main stream of carrier gas into two streams, one of which periodically passes through a bubbler evaporator, is saturated to a maximum concentration and then mixed with the second stream, thus providing the desired concentration.

The disadvantage of this technical solution is the insufficiently high and unstable accuracy of providing a given concentration of anesthetic, since it largely depends on many external changing parameters (temperature, level of anesthetic in the evaporation chamber, etc.).

It is also known "Device for inhalation anesthesia" (patent RU No. 2197999 with priority from 07.26.2001, as well as the published application for invention RU No. 2007146608 with priority from January 15, 2008), implemented in the apparatus "Xena-010" - ANALOGUE. According to these patents, the inhalation device comprises a syringe dispenser and a stepper motor, which provides the piston movement of this syringe according to a given program. The disadvantage of this device is the difficulty of ensuring the required accuracy of the concentration of anesthetic in the entire concentration range with a widely changing flow of respiratory carrier gas, as well as providing the necessary stock of liquid anesthetic for a long operation.

Anesthesia-respiratory apparatus is also known according to the patent for utility model No. 99707, IPC А61Н 31/02, with a priority of 06.16.2010 - PROTOTYPE. The liquid anesthetics dispenser of this apparatus is made in the form of a vertically arranged metering tube of small diameter, to the upper end of which an electronic pressure sensor is connected, and to the lower end is connected via an output electromagnetic shut-off-through valve a line connected to the mixing-evaporation chamber, as well as through an input electromagnetic shut-off valve - a line associated with a container for liquid anesthetic. The disadvantage of this technical solution is the possible instability of ensuring the required accuracy of the concentration of the anesthetic due to the initial level of anesthetic in the dosing tube changing during operation due to a possible violation of the tightness of the upper part of the dosing tube, and also because of the saturation of this container with liquid anesthetic vapors during prolonged operation , and also due to the fact that the initial vapor pressure in this part of the tube is not synchronized with the constantly changing pressure in the respiratory circuit (in mixing to the test chamber).

The aim of the present invention is to provide accurate and stable adjustment of the concentration of vapor of liquid anesthetics in a wide range of concentrations and flows of the carrier gas.

This goal is achieved by the fact that in the dosing device, the upper end of the tube of the liquid anesthetic dispenser is additionally connected by a pneumatic line through an electromagnetic shut-off valve with a mixing and evaporation chamber of respiratory gases, the electromagnetic valve itself is electrically connected to the electronic control unit, and the liquid anesthetics dispenser tube is made infrared optoelectronic is installed from a material transparent to infrared radiation and from the outside of this tube th sensor, fixed relative to the housing at a level exceeding the level of exit of liquid anesthetic into the mixing chamber.

Figure 1 shows a block diagram of the invention.

The main elements of this scheme are:

1. Capacity for liquid anesthetic

2. Tube for liquid anesthetics dispenser

3. Inlet check-pass solenoid valve

4. The output shut-off and solenoid valve

5. Mixing and evaporation chamber

6. Pressure sensor

7. Calibration solenoid valve

8. The electronic control unit

9. Opto-electronic sensor

In the present invention, the container for anesthetic 1 is connected by a hydraulic line to the dispenser tube 2 (through the inlet solenoid valve 3), the lower part of the dispenser tube is also connected through the outlet shut-off valve 4 to the mixing-evaporation chamber 5, and the upper part of the dispenser tube is connected to the pressure sensor 6 .

In addition, the upper part of the dispenser tube is additionally connected by a pneumatic line through a calibration electromagnetic shut-off valve 7 with a mixing and evaporation chamber of respiratory gases 5, and the electromagnetic valves 3, 4, 7, as well as the pressure sensor 6 are electrically connected to the electronic control unit 8. In this case, the tube of the liquid anesthetic dispenser is made of a material transparent to infrared radiation, and an infrared optoelectronic sensor 9, 3 fixed relative to the tube body at the level exceeding the output level of the anesthetic liquid in the mixing chamber.

The claimed invention operates as follows.

The principle of operation of the dispenser itself is carried out in the same manner as described in the prototype patent (No. 99707), namely:

the electronic unit according to a given algorithm (based on the use of the well-known physical law of Mendeleev-Clapeyron for evaporating liquids) carries out command control of valves 3 and 4 as follows: first, valve 3 opens (while valve 4 is closed), and the liquid anesthetic flows from the tank 1 into the tube 2 dispensers, compressing the gas contained in the tube 2, to a certain pressure, recorded by the pressure sensor 6, forming an "air cushion". At a given signal level from the sensor 6, at the command of the associated electronic unit 8, the valve 3 closes and the valve 4 opens, and the liquid anesthetic from the tube 2 under pressure from the air compressed in the air cushion at the top of the tube 2 begins to be squeezed out into the mixing and evaporation chamber 5 (where it evaporates in a stream of respiratory gas). In this case, the air pressure in the upper part of the tube 2 in the air cushion begins to decrease, which is detected by the pressure sensor 6 and enters the electronic control unit 8. And the decrease in pressure in the air cushion in the upper part of the tube 2 is proportional to the liquid flow rate from the lower part according to the Mendeleev-Clapeyron law tube 2, and therefore, when the airbag pressure decreases to a level that determines the required volume of displaced fluid (necessary to ensure evaporation of the anesthetic with a given concentration), valve 4 closes , and valve 3 opens and the whole process repeats.

However, in the process of operation of the device due to imperfect tightness of the upper part of the tube of the dispenser 2, the initial "zero" overpressure may be gradually violated. Therefore, periodically, for example, after every 6th functional cycle of the device’s operation, a calibration cycle is performed, in which the control unit 8 transmits a command to simultaneously open valves 7 and 4, and valve 3 remains closed. In this case, the anesthetic, under its own weight, starts to flow out of the tube 2 into the mixing container 5, and when the anesthetic reaches the level of the optoelectronic sensor 9 (for infrared radiation of which the anesthetic is opaque and the material of the tube 2 itself is transparent), the sensor is activated and gives a command (via the electronic unit 8) to close valves 7 and 4, and thus, the system status is automatically recorded again at the initial (“zero”) level.

Then, the operation of the device continues according to the algorithm described above.

The proposed technical solution will allow the formation of a respiratory gas flow with the required characteristics for the accuracy of maintaining a given concentration of evaporating anesthetics in a wide range of changes in the mechanical ventilation parameters.

Claims (1)

A liquid anesthetic dispenser comprising a vertical tube connected by a hydraulic line to a liquid anesthetic container through an inlet electromagnetic shut-off valve and to a mixing and evaporation chamber through an outlet electromagnetic shut-off valve, a tube pressure sensor, an electronic control unit to which are electrically connected the specified electromagnetic valves and the pressure sensor in the tube, characterized in that the upper end of the tube dispenser liquid anesthetics it is completely connected by a pneumatic line through an electromagnetic shut-off valve with a mixing and evaporation chamber of respiratory gases, the electromagnetic valve itself is electrically connected to the electronic control unit, the tube of the liquid anesthetic dispenser is made of material transparent to infrared radiation, and an infrared optoelectronic tube is installed on the outside of this tube the sensor associated with the electronic control unit and fixed relative to the tube body at a level exceed it output level of the liquid anesthetic in the mixing and vaporization chamber.

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