DE9003317U1 - Device for introducing an aerosol into an air stream - Google Patents

Description

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Thomas Sausen

The invention relates to a device for injecting an aerosol into an air stream, in particular for injecting an aerosol into an air stream to be inject.

It is known to inject a person with a !.-«ftstrc» charged with an aerosol via a nebulizer in order to read the person's reactions from which

' * a person's strength and the necessary medication are to be obtained. With the known method, it is not possible to achieve an exact fine dosage of the aerosol content in the air. It is therefore not possible to obtain an exact indication of the current state of an illness, e.g. asthma, in order to then determine the correct dosage of a medication. The object of the invention is therefore to give an air stream,

_f controlled by the flow of this air stream , to supply an aerosol in a predetermined quantity in a fine and precise dose. In particular, when used to introduce an allergen into an inhaled air stream, the precisely dosed addition of the allergen is intended to bring about a certain state of illness in the person, which allows an accurate diagnosis to be made and the appropriate medication to be administered in the optimal dosage of the medication. On the other hand, a test option for the suitability of a particular medication is also to be achieved.

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The allergens used include: histamine, acetylcholine, pollen suspensions, spore suspensions or the like; as medication, cortisone derivatives, beta-sympathomimetics

- The stated problem is solved by the features mentioned in claim 1. The subclaims name embodiments of the invention.

The amount of allergen to be added per breath, i.e. per activation of a nebulizer, should be between 100 and 200 micrograms. The amount of allergen to be added is approximately 100 micrograms in 0.6 seconds. If breathing is interrupted unexpectedly, the maximum difference in quantity is between 0 and 10%. This means that a high level of accuracy is achieved. The drawing shows an embodiment of the new device for the dosed addition of an aerosol to an air stream using the example of an air stream to be inhaled, in Fig. 1 as a block diagram of the individual components of the device , in

Fig. 2 is a schematic representation of a mouthpiece with

Connections for supply air and exhaust air as well as a

Nebulizer and an air flow sensor, in Fig. 3 a/b a valve in cross section and in view, Fig. 4 a circuit diagram of a control unit for the nebulizer

and the mouthpiece and in
Fig. 5 a circuit diagram of the front panel connections of the

Control unit

The iigur 1 shows the mouthpiece 1, the individual parts of which are shown in Fig. 2. It also shows the nebulizer 2, a compressor 3, a directional valve 4 and a control unit 5 for the nebulizer 2 and the mouthpiece 1. 6 designates an IR remote control device for the control unit and 7 designates a silencer on the directional valve 4 for the back ventilation of the nebulizer 2. A connection leads from the control unit 5

. cable 8 to the mouthpiece 1 and a connecting cable 9 to the Directional control valve 4. This is connected to the compressor 3 via a compressed air hose 10 and to the nebulizer 2 via another compressed air hose 11 with an intermediate plug-in coupling. The nebulizer 2 is connected to the mouthpiece 1 via a connecting flange 12 with an intermediate plug-in coupling. The mouthpiece 1 has openings 13 for supply air or fresh air and an opening for exhaust air and has the inductive sensor 15 referred to as the breathing sensor as well as a valve unit 16.

(In Figure 2, the latter parts are shown as a unit with the mouthpiece. The mouthpiece 1 has, in addition to the flange 12 for the nebulizer, a connection piece la for the supply air and a connection piece Ib for the exhaust air. In the connection piece la there is the supply air opening 13 in the form of holes for the inhaled air as well as an inductive sensor 15 as an air flow sensor. The valve unit 16 consists of a valve 16a for inhalation in the connection piece la and a valve 16b for exhalation in the connection piece Ib.

The valves 16a and 16b each consist of a valve plate 18 in the form of a plastic disk with a metal coating, held between stop pieces 17 via a spring 19. The valve 16a for supply air has a square valve plate 18, as shown in Fig. 3b. Perpendicular to the upper stop piece 17 is a retaining ring 17a for the spring 19, which also serves as a stop for the valve plate 18 and has drill holes 17b for the passage of air. A bacterial filter 20 for aerosol residues with a pack of filter cotton 21 is arranged in front of the exhaust air opening 14. Some components of the device are commercially available and therefore do not require any further explanation. The nebulizer 2 can be the De Vilbis No. 1-4101 or Kendall No. 00952, the inductive sensor 15 can be the Klöckner-Möller ATI 08 DD 2, the valve 4 can be the Euromatic 80200750.02010000 from Herion, and the bacterial filter 20 can be the De Vilbis No. 1-2100.

The device works as follows: As soon as the air flow in the mouthpiece starts towards the front end, e.g. by inhaling, the valve plate 18 of the valve 16a moves downwards and opens the air supply path to the mouthpiece 1 via the openings 13. If the distance between the plate 18 and the inductive sensor is greater than 1 mm, the latter switches its output to 0 volts and thereby releases the control unit 5 via line 8 (inverted logic), so that the latter switches the directional valve 4 to the compressed air passage from the

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Compressor 3 can switch to the nebulizer 2 via the hoses 10, 11. The aerosol thus formed in a venturi nozzle of the nebulizer can then enter the mouthpiece 1. As soon as the amount of aerosol determined over the specified time unit is reached, the control unit 5 switches the directional valve 4 off again based on a target opening time comparison circuit 22. The required valve opening time is preset in the control unit via BCD coding switch 30. It compares the preset time with the target time in a comparator 22 and switches the directional valve 4 on or off via a gate circuit 23. As soon as the air flow in the mouthpiece 1 stops or flows towards the valve 16b for exhalation during exhalation, the valve plate 18 in the valve 16a returns to its closed position. Its distance from the inductive sensor 15 is then less than 1 mm. The sensor 15 then switches off the time generator 25 in the control unit via its connection 31. After an interruption of the flow in the mouthpiece before the target quantity determined by the target time is reached, when the flow in the air pipe resumes, the control unit is switched on again by the inductive sensor 15 as described above and switches the directional control valve 4 on again for the remaining time of the target time that has not yet elapsed. The control unit sends control pulses of between 0 and 9999 ms to the directional control valve 4, which is designed as a solenoid valve. This enables the very sensitive

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The exact setting of the respective target quantity is possible. A further circuit in the control unit counts all the nebulisations that have been completed and blocks a start button when a previously set number in the range of 1 to 9 nebulisations Fig. 5/35 is reached. The device can be returned to its basic state by pressing a "Reset counter" button. A zero can also be set for the number of nebulisations, so that any number of nebulisations can be triggered one after the other. The number of nebulisations that have been completed is shown by a seven-segment display (one digit) on the control unit. It is connected to a connector strip 29. The elapsed time is also shown in the control unit by a seven-segment display (four digits). It is connected to a connector strip 28. The IR remote control can be used to start and stop and reset the number of nebulisations. A commercially available remote control can be used as a remote control and as a J receiver 26 in the control unit.

A Siemens parts kit consisting of the ICs SLB 3801, TDA 4054 and SLB 3802 must be used.

The compressor 3 or a compressed air bottle with pressure stabilization and activated carbon filter to be used must meet the following conditions:

In order to compensate for system tolerances, an output pressure of at least 2 bar i 0.5 bar must be adjustable. Its output must reach 15 liters of air per minute. Its output air must

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be free of condensation and 01. f

A fast-switching, back-vented pneumatic valve is preferably used as directional control valve 4. This ensures

when switching off the pressure between nebulizer and valve *

This results in a more precise compressed air pulse (higher edge steepness) and dripping of the nebulizer is avoided. In addition, the influence of the length of the compressed air hose 11 is reduced. The control unit has a digital circuit with a quartz oscillator 25a as a time base.

Through this and the partial chain 25, a pulse of a precisely specified length, 1 ms, is generated. In addition to this time generator 25, 25a, the control unit has the following essential components: the comparator 22, the gate circuit 23, the circuit part 26 for counting the elapsed nebulizations, the connector strip 28 for displaying the

elapsed time, the connector block 29 for the display of the ;

Number of foggings completed as well as part 24 for counting the 1 ms time cycles (actual time generation and storage) and part 27 for decoding the BCD code into the 7 segment code of the time display.

The pulses from part 25 are counted in part 24 and result in the elapsed actual time (BCD code). In part 27 this code is decoded and translated into the 7 segment code for the display. The comparator 22 compares the BCD code of the actual time with the BCD code of the target time from the switch block 30. ...8

The gate circuit 23 controls the entire process. It evaluates the pulses from the comparator, the control unit and the counter for the number of nebulizations and passes the pulse on to the valve.

The upper part of Figure 5 shows the connection parts on the front DC plate of the control unit. 30 is the switch block for setting the target time. 32 is the button for operation, 33 is the connection for the nebulizer 2, 34 is the connection for the inductive sensor 15. 35 is the switch block for setting the number of nebulizations. The lower part of Figure 5 shows the associated power supply part 36. Instead of the inductive sensor 15, a spirometer with its tubular measuring cell can be used as an air flow sensor at the point marked A in Figure 2, which switches the control unit (5).

Instead of the inductive sensor, the measuring cell of a body plethysmograph can also be connected to the mouthpiece at the point marked A, whose tmd measuring electronics switches the control unit. In this case, the valves 16a and 16b and the filters 20, 21 are omitted.

Thomas Sausen

The process to be carried out with the new device can be carried out in such a way that the flow in the pipe is registered by an air flow sensor 15 which switches the nebulizer Z on or off via an electronically digitally adjustable control device 5.

It can also be done in such a way that the supply of aerosol into the tube is initiated immediately at the start of the flow in the tube, e.g. when inhalation begins, or after a delay time, so that until the flow in the tube is interrupted, e.g. when inhalation is interrupted by coughing, the supply of aerosol from the nebulizer is interrupted and after a stable flow in the tube has been restored, e.g. a stable breathing position when breathing in again, the supply of aerosol is resumed until a set amount is reached. In this method, the amount of aerosol supplied can be adjustable by the nebulization time.

Claims (11)

C-: &bull;■&bull;■&bull;■■&igr;·)· ^ ^f 4 H)I It« ·* Il ».-.If Thomas Sausen ■ Protection claims "* 1. Device for introducing a substance into an air stream, in particular an allergen into an inhaled air flow, characterized in that:■ an air tube open at one end, eg a mouthpiece IM, a ;.; open connection to an electrical, digitally adjustable control unit (5) to be switched on and an air supply connection (la) with an inlet valve (16a) and an inductive sensor (15) as an air flow sensor that switches the control unit (5). 2. Device according to claim 1, characterized in that the air pipe has an exhaust air connection (1b) with an outlet valve (16b) at its end opposite the front open end. 3. Device according to claim 2, characterized by a pack of filter wool (21) and a bacterial filter (20) for aerosol residues in front of the exhaust air opening (14) of the exhaust air connection (1b). 4. Device according to one of claims 1 to 3, characterized by a directional control valve (4) (2/2 or 2/3 ways) to be switched by the control unit (5) between a compressor (3) or a compressed air connection and the nebulizer (2). &bull; ti &diams; · I ti · · < 2— 5. Device according to claim 4, characterized by a silencer (7) on the directional control valve (4) for back ventilation of the nebulizer (2). 6. Device according to claim 4 or 5, characterized by a compressed air coupling between the directional control valve (4) and the nebulizer (2), the actuating part of which has an actuating disc which projects approximately one finger's width beyond the circumference of the coupling. 7. Device according to one of claims 1 to 6, characterized by a valve (16a) for supply air consisting of a square valve plate (18) held between stop pieces (17) by a spring (19) and a retaining ring (17a) arranged perpendicular to the upper stop piece (17) for the spring (19) with drill holes {17b} for the air supply. 8. Device according to one of claims 4 to 7, characterized in that the mouthpiece (1) is provided with inductive ( sensor (15) with the nebulizer (2) and the directional control valve (4) is combined into one component by means of plug-in couplings. 9. Device according to one of claims 1 to 8, characterized by an electronically digitally adjustable control device (5) with the parts: quartz oscillator (25a) and chain of parts (25) as time generator (25/25a), comparator (22), gate circuit (23), counter of the time pulses (24), number counter (26) and decoder (27). 10. Device according to one of claims 1 to 9, characterized in that a spirometer is also used on the mouthpiece as an air flow sensor, the electronics of which are switched by the control device (5). 11. Device according to one of claims 1 to 9, characterized in that the pneumotachograph©*« of a body plethysmograph can be used as the air flow sensor, the measuring electronics of which are switched by the control device (5).