RU2355432C2 - Method of heating aerosol in compression inhalers - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: in dispersion chamber operating from action of compressed gas supplied through nozzle of connecting pipe, and in which medicinal liquid is sucked into nozzle zone through narrow passages, aerosol heating is carried out directly in zone of medicinal liquid passing, and chink passages themselves are formed by connecting pipe which is an element of heater, and a cap placed outside. When heater temperature increases higher than definite level, heating is stopped until temperature does not reach set level due to heater cooling.

EFFECT: increase of electric safety, ensuring chamber sterilisation and reduction of time necessary to attain set mode of aerosol heating.

2 cl, 4 dwg

Description

The invention relates to medical equipment, namely to inhalation therapy (aerosol therapy) and can be used in pulmonology, otorhinolaryngology, phthisiology and other medical fields where compressor inhalers are used.

Compressor inhalers are the most common type of medical inhaler for aerosol therapy. In order to create an aerosol, they use a compressor to compress gas. Compressed gas is supplied through a flexible hose to a spray chamber consisting of a closed cup, fitting, cap, reflector and mouthpiece. Compressed gas (most often air), under pressure entering the nozzle, enters the narrow hole (nozzle) of the nozzle. As a result, at the nozzle exit, the air outflow rate increases sharply, which leads to a local drop in air pressure. Under the influence of rarefaction, the liquid drug solution through narrow supply channels formed between the outer surface of the nozzle and the cap worn on the nozzle enters the nozzle exit, where it mixes with the air stream and breaks up into individual particles. At the exit, a reflector is installed, which can be part of the cap; the purpose of the reflector is to break up large particles into smaller ones, which are fed to the patient with an air stream in the form of an aerosol through a mouthpiece.

The main disadvantage of compressor inhalers is that in the process of creating an aerosol, it cools and the temperature decreases compared to the ambient temperature due to the Joule-Thomson throttle effect. The indicated decrease in temperature reaches a value of 4 ÷ 5 deg, which leads to undesirable consequences for patients, because The chilled aerosol inhalation procedure is uncomfortable. Aerosol heating increases the comfort of the procedure and is fundamentally necessary for patients with severe bronchoid anaphylaxis (increased sensitivity) to cold stimuli.

Known methods and devices for heating medicinal aerosol in compressor inhalers (L. Osipov "Individual ultrasonic and compressor inhalers." M: IzoMed, 2003, p. 32-33).

A feature of the known methods is the use of electric heaters, which provide heating directly of the aerosol after its formation in the spray chamber (nebulizer) of the inhaler.

In the method used in Paris Therm compressor inhalers (1998 by Pan GmbH, Spezialisten fur effective Inhalation O41DO110 2/99), the aerosol is heated using a corrugated surface heating element, which is placed in the spray chamber and connected to the supply voltage using a cable extending through the top of the spray chamber next to the mouthpiece.

The disadvantages of this method of heating the aerosol are the following:

1. The presence of the power cable of the heating element near the mouthpiece, inserted into the patient's mouth. This requires the adoption of special measures to ensure electrical safety and is inconvenient during the inhalation procedure.

2. The inability to sterilize or fully disinfect the heating element, which is located inside the spray chamber and on which infected patient expiratory products may settle.

3. The need for a sufficiently long time to reach a steady temperature due to the fact that heating is carried out through a gaseous medium that does not conduct heat well.

4. Reducing the accuracy of dosing of the drug received in the form of an aerosol to the patient due to the uncontrolled deposition of drops of the drug solution on the surface of the heating element during the passage of the aerosol past it.

The technical result achieved by using the present invention is to ensure electrical safety, increase the convenience of carrying out the inhalation procedure, ensure sterilization of the spray chamber with the heating element, as well as reduce the time it takes to reach the steady state heating of the aerosol and increase the accuracy of the dosage of the drug.

The essence of the claimed invention lies in the fact that in a method of heating an aerosol in a compressor inhaler, which includes compressing gas in a compressor, supplying compressed gas through a flexible hose to the nozzle of the spray chamber and creating a vacuum at the outlet of the narrow nozzle of the nozzle for the injection of a drug solution poured into a spray chamber, through narrow channels to the outlet of the nozzle of the nozzle, where, as a result of mixing with the outgoing gas stream, the drug solution is turned into an aerosol stream, which is directed to azhatel and then fed through a mouthpiece to the patient, according to the present invention, the drug solution in the course of its passage through narrow channels to the exit nozzle of the nozzle is heated by an electric heater, heats the outer surface of the disposable nozzle and bottom spray chamber.

The invention provides that when the temperature of the heater rises above a certain level, the heating is stopped until the temperature reaches the set level due to the cooling of the heater.

The technical result is achieved by pre-heating a thin layer of the drug solution in the process of entering the solution to the nozzle outlet before converting the drug solution into a drug aerosol.

This allows:

- improve the usability of the inhaler and provide the necessary level of electrical safety requirements due to the location of the electric heater and power cable at the bottom of the spray chamber;

- to provide the possibility of sterilization or disinfection of the spray chamber after heating;

- reduce the time it takes to reach a mode that provides an increased temperature of the aerosol due to the rapid heating of a thin layer of the drug solution in the narrow channels between the heated surface of the nozzle and the cap;

- increase the accuracy of the dosage of the drug received in the form of the drug to the patient due to the lack of additional surfaces inside the spray chamber, on which an uncontrolled amount of aerosol can be deposited.

The essence of the present invention is illustrated by an example implementation of a patented method for heating an aerosol and drawings, which show:

Figure 1 is a drawing of the spray chamber, including a variant of the heater that implements the proposed method.

FIG. 2 is a drawing of another embodiment of a heater for the spray chamber shown in FIG.

Figure 3 is a photograph of an experimental sample of the device depicted in Figure 1.

Figure 4 - graphs of changes in temperature of the aerosol versus time for experimental samples of the options shown in figure 1 and figure 2 (obtained as a result of technical tests).

The heating method is carried out using the device (Figure 1), which is part of a compressor inhaler, consisting of a housing of the spray chamber 1, fitting 2 with a narrow outlet 3 (nozzle) in the upper part, cap 4 with a reflector 5 near the exit of the nozzle, mouthpiece 6 and the flexible hose 13. For the operation of the inhaler, the flexible hose 13 is connected to the compressor and the drug solution 7 is poured into the spray chamber, after which the compressor is turned on. As a compressor inhaler, any commercially available device can be used, for example, the Elisir device manufactured by Flaem Nuova (Italy).

Instead of the plastic nozzle commonly used in mass-produced inhalers, a metal nozzle is used, the lower end of which extends beyond the spray chamber and has a conical shape, which allows you to put on and remove from it a heating device. The heating device includes a metal coil 8, the inner hole of which is conical inverse to the conical shape of the lower part of the nozzle, to ensure good surface contact in order to reduce heat loss during heat transfer from coil 8 to the nozzle 2. A wire is wound on the metal coil 8 from above 10, the ends of which are connected to a power cable 11 connected to a voltage source. To reduce the heat radiation from the coil 8 with the wire 10 into the air, the coil is placed in a cup 9, which is made of a material with good heat-insulating properties.

Additionally, a heat-sensitive element 12 is fixed on the coil 8, which is connected to a power-off circuit, which is placed together with a source of supply voltage.

The proposed method for heating the aerosol is implemented as follows.

The required amount of drug solution 7 is poured into the spray chamber 1 of the compressor inhaler, after which the compressor is turned on and at the same time an electric voltage is applied to the heater wire 10. The wire is heated by electric current, heat is transferred to the coil 8 and through it the lower part of the fitting 2 in contact with it, as a result of which the entire fitting is heated.

During the operation of the compressor inhaler, the drug solution 7 under the action of rarefaction enters from below to the upper part of the nozzle 2 through narrow channels formed between the outer surface of the nozzle 2 and the inner surface of the cap 4 worn on the nozzle. In contact with the heated surface of the nozzle, a thin layer of the drug solution 7 quickly heats up and enters the nozzle 3 of the nozzle 2 in a heated form. When an aerosol is formed, it cools down compared to the temperature of the supplied drug solution, however, due to the fact that it was preheated, the outlet temperature of the mouthpiece 6 connected to the spray chamber 1 will be higher than the ambient temperature. So at the heating temperature of the layer of the drug solution 7 in the narrow channels between the fitting 2 and the cap 4, reaching 40-45 degrees. Celsius, the temperature of the aerosol at the outlet of the mouthpiece 6 is 30-35 degrees. Celsius, which provides comfortable inhalation of the aerosol by the patient.

The invention provides that when the heating temperature rises above a certain value, the heater is disconnected from the supply voltage. This is achieved by the fact that when the temperature rises above the specified value, a signal for switching off the supply voltage is triggered by a signal from the thermosensitive element 12, as a result of which the heating stops, and the heater temperature decreases due to the natural cooling process. The need to turn off the supply voltage arises in the case when the drug solution ends in the spray chamber, as well as in the case when the user turns on the compressor inhaler, having forgotten to pour the drug solution 7 into the spray chamber 1 first.

Figure 2 shows another embodiment of a device that implements the proposed method for heating an aerosol.

The embodiment in FIG. 2 differs from the previously described embodiment shown in FIG. 1 in that instead of a metal fitting 2 and a heating element including a coil 8, a wire 10 and a cup 9, a fitting 2 is used, mounted in a spray chamber with a wire 10 reinforced in the body of the nozzle 2 and located close to the outer surface of the nozzle 2. The wire 10 is connected to the power cable 11 through a sealed connector 14. A cap similar to cap 4 with a reflector 5 shown in Fig. 1 is put on the nozzle 2 (in Fig. 2 not shown).

For the manufacture of the nozzle, in this embodiment, a material with good electrical and heat-insulating properties is used and only for the outer surface of the nozzle a material with good thermal conductivity or metallization is used to provide better heat transfer from the heated wire 10 to a thin layer of the drug solution 7 in contact with the surface of the nozzle 2.

The applicant has made experimental samples of devices that implement the proposed heating method and are depicted in figure 1 and figure 2. Figure 3 shows a photograph of an experimental sample of the device, a drawing of which is given in figure 1.

Figure 4 shows graphs of changes in temperature of the aerosol at the mouthpiece outlet as a function of time after turning on the compressor inhaler. Graphs obtained during the technical testing of experimental samples of the devices shown in figure 1 and figure 2. The solid line shows a graph of temperature changes for a variant of the device shown in FIG. 1, the dotted line shows a graph for a variant of the device shown in FIG. 2. In both cases, a high heating rate and a short time to reach the steady state are ensured.

Claims (2)

1. A method of heating an aerosol in a compressor inhaler by compressing gas in a compressor, supplying compressed gas through a flexible hose to the nozzle of the spray chamber and creating a vacuum at the outlet of the nozzle of the nozzle to enter under the influence of rarefaction to the exit of the nozzle of the nozzle through narrow channels between the nozzle and the cap worn on the nozzle of the drug solution, poured into the spray chamber, mixing the drug solution with an outgoing gas stream over the heating device with the formation of an aerosol, characterized in that it is heated noe device heats fitting and through the thin layer of the drug solution flowing through the narrow channels between the nipple and the cap to a temperature of 40-45 ° C and the formation of aerosol in the spray chamber, its temperature at the outlet of the mouthpiece is 30-35 ° C. 2. The method according to claim 1, characterized in that when the temperature of the heater rises above a certain level, the heating is stopped until the temperature reaches the set level due to the cooling of the heater.

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