WO2016162741A1

WO2016162741A1 - Apparatus for non-invasive mechanical ventilation and relative method

Info

Publication number: WO2016162741A1
Application number: PCT/IB2016/000420
Authority: WO
Inventors: Paolo Licciulli; Diego MARTINENGO; Marco Fiore
Original assignee: Medical Products Research S.R.L.
Priority date: 2015-04-07
Filing date: 2016-04-04
Publication date: 2016-10-13

Abstract

An apparatus is described for non-invasive mechanical ventilation essentially comprising a turbine or fan (16) which generates an air flow towards a flexible tube (12) connected to a nose mask or similar (13) worn by a patient, wherein at least one flow and/or pressure detector (14) is associated with and connected upstream of the flexible tube (12) to reveal flow and/or pressure values inside the flexible tube (12) in a cycle of pressures comprising inspiration phases, or IPAP, alternating with expiration phases, or EPAP, passing from an initial pressure of an IPAP phase P2 to a final pressure of an IPAP phase PI, wherein P1 is greater than P2, and from an initial pressure of an EPAP phase P1 to a final pressure of an EPAP phase P2, wherein, in a first part of each IPAP inspiration phase, the pressure P2 is kept constant for a time ta- tb before activating the turbine (16) in the remaining inspiration phase, to pass from the initial pressure P2 to the final pressure P1 of the IPAP phase, and the relative non-invasive ventilation method.

Description

APPARATUS FOR NON-INVASIVE MECHANICAL VENTILATION AND RELATIVE METHOD

The present invention relates to an apparatus for non-invasive mechanical ventilation and the relative method.

There are currently many patients suffering from respiratory failure due to conditions affecting the lungs and rib cage. There are also patients whose functioning of the respiratory system is affected by insufficient ventilation caused by an excessive amount of carbon dioxide in the blood.

To act on these patients, the natural ventilation must be improved and pressurized air is generally supplied to the air ducts and lungs ^' of the patient by means of specific equipment destined for this purpose.

With this action, a non-invasive mechanical ventilation is provided to facilitate and improve the patient's breathing, by decreasing and improving the work of the muscles dedicated to breathing, and also avoiding specialized interventions on the patient.

Consequently there is generally simple equipment for non-invasive mechanical ventilation, comprising a fan which supplies air at a certain pressure or volume, and a nose or oronasal mask for its connection to the patient. A monitoring is then effected to ensure that there is a correct pressure or volume of air supplied in relation to the patient's breathing. A ventilation is therefore generally provided with a positive pressure at two pressure levels.

In particular, patent US 8240307 has, as set limit values, the positive air inspiration pressure (IPAP) and the positive air expiration pressure (EPAP) and specific devices are envisaged (flexible balloon tanks or bellows calibrated valves, pneumatic systems, etc.) which selectively intervene in relation to the positive pressure of the above-mentioned IPAP or EPAP phases.

The presence of devices makes the equipment complex in both construction and functioning, as the same must be present in the equipment and must intervene in relation to the respiratory phase of the patient.

The purpose of all of this is to effect, in the functioning of the equipment, the phase in which there is a subtraction of a prefixed quantity of air from the flow at the beginning of the inspiration phase with a pressure drop.

This is shown in figure 4 of patent US 8240307 and is effected in the time space indicated in 30, as illustrated in figure 1 of the present description which reproduces this figure.

In general however the machines currently used are aimed at minimizing the dead times between the IPAP and EPAP phases .

The general objective of the present invention is to develop an apparatus that can simplify and improve ventilation and supply pressurized air into the patient's air ducts and lungs according to the IPAP and EPAP phases sequentially in a simple and functional way .

A further objective of the present invention is to provide an apparatus capable of solving the drawbacks of the known art described above in an extremely simple and economical way, avoiding complex construction and functional characteristics of the apparatus.

The structural and functional characteristics of the present invention and its advantages with respect to the known art will appear even more evident from the following description, also referring to the enclosed schematic graph, which shows how the apparatus according to the present invention operates. In the drawings: figure 1 is a view that schematically shows the pressure trend in relation to the time in the apparatus of the prior patent US 8240307 indicating the various indexes which demonstrate the difference of said known art from the present invention in a cycle of pressures comprising inspiration phases or IPAP, alternating with expiration phases or EPAP;

figure 2 schematically shows an apparatus according to the present invention;

- figure 3 shows, in a diagram, the fans of the apparatus according to the present invention; and

figure 4 is a schematic view showing the pressure trend in relation to the time in the apparatus according to the present invention and in accordance with the non-invasive ventilation method according to the present invention.

With reference to what is specified above and as shown in figure 3, an apparatus for non-invasive mechanical ventilation essentially comprises a fan 11 which generates a flow of air towards a flexible tube 12 connected for example to a nose mask or the like 13 worn by a patient.

At least one flow and/or pressure detector 14 present in an electronic card is envisaged for revealing flow and/or pressure values downstream of a channel 15 during the cycle of pressures comprising inspiration phases or IPAP, alternating with expiration phases or EPAP. The channel 15 connects a turbine 16 to a hollow connector 17 connected to the flexible tube 12.

Both the turbine 16 and the at least one flow and/or pressure detector 14 are in turn associated and connected, by means of lines 18 and 19, to a central processing unit or central processor (CPU) 20.

Said central processing unit 20 centrally coordinates both the turbine 16 and the data received by the detector 14 following the instructions of a program present in the central memory (RAM) 21.

The program present in the memory 21 has been generated in relation to predetermined standard values of an initial pressure of an IPAP phase P2 and a final pressure of an IPAP phase PI, wherein PI is greater than P2. The values of both an initial pressure of an EPAP phase and a final pressure of an EPAP phase have also been taken into account: in particular, it is assumed that said values are respectively PI and P2 identical to the values PI and P2 previously indicated.

It can therefore be seen that according to the present invention there are identical initial pressure values of an IPAP phase P2 and final pressure values of an EPAP phase P2.

According to the invention, it has been found that it is sufficient for the apparatus to operate in a first part of each inspiration phase IPAP keeping the pressure P2 constant for a time ta-tb before activating the turbine 16 in the remaining inspiration phase for passing from the initial pressure P2 to the final pressure PI of the IPAP phase.

The apparatus according to the present invention therefore implements a cycle of pressures passing from the EPAP phase to the IPAP phase with a time delay ta- tb of the air supply in this phase with respect to the beginning of the IPAP phase according to the known art which is indicated by the dashed line of figure 4.

The apparatus of the invention therefore operates unexpectedly with respect to the known . art, delaying the air supply time in the first part of the inspiration phase (IPAP) for a time ta-tb, preferably ranging from 0.01 to 2 seconds, keeping the previous final EPAP pressure P2 constant.

The solution according to the present invention is based on a delay determined and established on the basis of selectable regulations. This delay is therefore completely different from the intrinsic delay of a ventilation system, whether it be electronic or mechanical, which in any case has a duration that can be measured in a few milliseconds, whereas the apparatus, object of the present invention, regulates the delay in tenths of a second.

It is specifically the determination and regulation of this delay (which is much greater than the intrinsic delay) that favours a better air perfusion at an alveolar level in some lung diseases.

The non-invasive mechanical ventilation according to the present invention comprises an alternation of phases i) and phases ii) , wherein in phases i) , an air flow passes from an initial pressure P2 to a final pressure PI and in phases ii) , the air flow passes from an initial pressure Pi to a final pressure P2, wherein PI is greater than P2, wherein in each phase i) , the pressure P2 is kept constant for a time ta-tb before passing from the initial pressure P2 to the final pressure PI.

The central processing unit 20, in fact, operates to also keep the number of revs of the turbine 16 for the time ta-tb of the first part of the inspiration phase so as to also keep the pressure P2 in this first part of the phase.

After this time ta-tb, it increases the number of revs of the turbine 16, bringing the air flow to the pressure PI.

This takes place with the apparatus according to the invention for each first part of the IPAP phase. It can therefore be seen that it is not necessary to have any particular equipment, such as the above- mentioned flexible balloon tanks or bellows, calibrated valves, pneumatic systems, etc. of the known art.

It is consequently not necessary to resort to any pressure drop with respect to the pressure existing at the end of the EPAP phase in order to optimally initiate the subsequent IPAP phase.

The apparatus according to the present invention is constructively simpler and easier to manage even by a technically more inexperienced user as it operates completely automatically. This is due to the fact that it is totally assigned to an electronic card which, through management software, controls, in the most appropriate way, the turbine 16 which generates the air flow in relation to the phases of the method that are being implemented for a non-invasive mechanical ventilation.

The objective mentioned in the preamble of the description has therefore been achieved.

The protection scope of the present invention is defined by the enclosed claims.

Claims

1) An apparatus for non-invasive mechanical ventilation essentially comprising a turbine or fan (16) which generates an air flow towards a flexible tube (12) connected to a nose mask or similar (13) worn by a patient, wherein at least one flow and/or pressure detector (14) is associated with and connected upstream of the flexible tube (12) to reveal flow and/or pressure values inside the flexible tube (12) in a cycle of pressures comprising inspiration phases, or IPAP, alternating with expiration phases, or EPAP, passing from an initial pressure of an IPAP phase P2 to a final pressure of an IPAP phase PI, wherein PI is greater than P2, and from an initial pressure of an EPAP phase PI to a final pressure of an EPAP phase P2, wherein, in a first part of each IPAP inspiration phase, the pressure P2 is kept constant for a time ta- tb before activating the turbine (16) in the remaining inspiration phase, to pass from the initial pressure P2 to the final pressure PI of the IPAP phase.

2) The apparatus according to claim 1, characterized in that said time ta-tb ranges from 0.01 to 2 seconds.

3) The apparatus according to claim 1 or 2, characterized in that both the turbine (16) and the detector (14) are, in turn, associated with and connected by means of lines (18,19) to a central processing unit or central processor (CPU) (20) which follows the instructions of a program present in a central memory (RAM) (21) .

4) The apparatus according to one or more of the previous claims, characterized in that said at least one flow and/or pressure detector (14) is connected to an end downstream of a channel (15) during a cycle of pressures comprising inspiration phases or IPAP, alternating with expiration phases or EPAP, wherein said channel (15) connects said turbine (16) to a hollow connector (17) connected to the flexible tube (12).

5) A method for non-invasive mechanical ventilation which comprises an alternation of phases i) and phases ii) , wherein in phases i) , an air flow passes from an initial pressure P2 to a final pressure PI and in phases ii) , the air flow passes from an initial pressure PI to a final pressure P2, wherein PI is greater than P2, wherein in each phase i) , the pressure P2 is kept constant for a time ta-tb before passing from the initial pressure P2 to the final pressure PI.

6) The method according to claim 5, characterized in that said time ta-tb ranges from 0.01 to 2 seconds.