ES2860999A1 - MECHANICAL INTUBATION RESPIRATOR (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Intubation mechanical ventilator. The intubation mechanical ventilator comprises connections (20, 30, 130) to at least one source of gas and to at least one endotracheal tube intended to be introduced into a patient, a unit for regulating the flow of gas to the patient, and a programmable controller (200), characterized in that the flow regulation unit (70) comprises at least four calibrated branches (71 to 78) connected in parallel with each other, each of which comprises a bypass valve, and the programmable controller (200) is arranged to control the opening and closing of the bypass valve of each of the calibrated branches (71 to 78). This configuration makes it possible to produce respirators easily and quickly, without the need for complex and specialized elements. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

MECHANICAL INTUBATION RESPIRATOR

The present invention relates to a respirator, and more particularly a mechanical intubation or invasive respirator (IMV), of the type used in hospitals for patients with respiratory pathologies.

STATE OF THE PRIOR ART

Mechanical ventilation is an artificial respiration procedure that uses a mechanical device to supply, at least in part, the respiratory function of a patient. The respirator or ventilator is a system capable of supplying the lungs with a gas, or a mixture of gases (air, oxygen, etc.).

In some cases of pandemics, such as the COVID-19 pandemic, one of the critical items that hospitals claim are ventilators or mechanical intubation ventilators (IMVs) for patients with breathing difficulties. However, most of these devices incorporate sophisticated elements, for example very low pressure proportional valves (for example below 80 mbar) for the control of gas flow to the patient, which must be calibrated with great precision, and whose conditions of production do not allow a fast, massive and delocalized manufacturing, in case of need.

It would therefore be desirable to be able to have VMI devices that can be manufactured anywhere, easily and in a short time, in order to provide a solution to the intensive care units (ICU) of hospitals in emergency situations.

EXPLANATION OF THE INVENTION

According to one aspect, the present invention refers to a mechanical intubation ventilator, comprising connections to at least one gas source and to at least one endotracheal tube intended to be introduced into a patient, a flow regulation unit of gas to the patient, and a programmable controller, characterized in that the flow regulation unit comprises at least four calibrated branches connected in parallel with each other, each of which comprises a bypass valve, and the controller programmable is arranged to control the opening and closing of the bypass valve of each of the calibrated branches.

This configuration constitutes an alternative to that of proportional valve respirators, and allows respirators to be produced easily and quickly, without the need for complex and specialized elements whose supply can constitute a bottleneck that prevents the necessary production from being achieved. Furthermore, the provision of a plurality of branches in parallel, with shut-off valves controlled for example by a PLC (programmable logic controller) or an electronic board, allows to obtain high precision in flow control, at a reduced cost.

In some embodiments, each calibrated limb comprises a flow regulator that is set at a predetermined flow rate or passage section.

In some embodiments, the flow regulators on the calibrated legs are set to a flow rate or a through section that is different from one calibrated leg to another.

In some embodiments, the flow regulators for the calibrated legs are needle valves.

In some embodiments, the bypass valves for the calibrated legs are solenoid valves.

In some embodiments, the programmable controller is configured to open and close the various solenoid valves on the calibrated legs to control the predetermined gas flow rate and inspiration time.

In some embodiments, the flow regulating unit comprises at least six calibrated branches.

In some embodiments, the flow regulating unit comprises eight calibrated branches.

In some embodiments, the respirator comprises a connection to an air source, a connection to an oxygen source, and two dosage units, each connected to a of said connections and connected between them at the outlet, to mix air and oxygen in a predetermined ratio, the outlet of the two dosage units being arranged upstream with respect to the flow regulation unit.

In some embodiments, the respirator comprises a gas quality control unit connected to the dosage units.

In some embodiments, the programmable controller comprises a PLC.

Other objects, advantages, and features of embodiments of the invention will become apparent to the person skilled in the art from the description, or can be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular embodiments of the present invention will now be described by way of non-limiting example, with reference to the attached drawings, in which:

Figure 1 is a schematic of a ventilator or mechanical intubation ventilator (IMV) in accordance with one embodiment of the present invention.

DETAILED EXHIBITION OF IMPLEMENTATION MODES

According to some embodiments, a mechanical ventilator or ventilator is presented, to assist the patient in breathing in an invasive manner, comprising an electrical, electronic and software part for controlling the process variables, which actuates and controls a pneumatic part. composed of valves, regulators and instrumentation necessary to monitor and control the gas supplied, and the patient himself.

The parameter adjustments and changes in the operation of the equipment or its manipulation are made from a screen provided on the surface of a rigid structure that houses the components, and the equipment also includes a monitoring screen and visual and audible alarms.

As is known, the medical personnel set in each case some operating parameters of the device, such as the proportion of air and oxygen to be supplied, as well as the tidal volume that must be introduced in each inspiration in the patient's lungs, the frequency of respiration, the inspiration to expiration ratio (I: E), or the positive pressure at the end of expiration (PEEP, Positive End-Expiratory Pressure), among others.

From these parameters entered by medical personnel, the device controller first determines the inspiration time and flow rate that the device must deliver to inflate the predetermined tidal volume during this calculated inspiration time.

For example, if the doctor establishes for a patient and a specific situation:

• 350 ml tidal volume

• I: E ratio of 1: 2 (ie expiration time is twice the inspiration time), • respiration rate of 20 breaths / minute (ie each full breath lasts 3 seconds),

then the inspiration time will be 1 second, and the gas flow required to deliver the tidal volume to the lungs will be 350 ml / second.

In general, in practice, the calculation of the inspiration time and the flow rate will be carried out by including an inspiration pause in the cycle, for example 10% of the total breathing time, in which case the inspiration time will be slightly less, and the flow rate will be slightly higher.

For the inspiration phase, the device controller regulates the various components of the pneumatic system, and in particular a flow control unit, so that they provide this predetermined gas flow rate, during the predetermined inspiration time.

According to embodiments of the present invention, the device controller can comprise a programmable logic controller (PLC) or the like, which regulates the opening and closing of a series of bypass valves, for example solenoid valves, of corresponding branches of the pneumatic circuit , connected in parallel with each other and inserted in the circuit pneumatic gas supply to the lungs, and that form the flow regulation unit: depending on the valve or solenoid valves open in each case, the gas flow that is provided to the patient varies. The branches can be equal to each other or, more preferably, they can be set at different flow rates.

The device controller can determine the combination of parallel branches and corresponding solenoid valves that is suitable to provide the predetermined flow rate (the branches whose sum of individual flows, at the circuit pressure, provides the predetermined flow) and can control the solenoid valves of the selected branches to open to start the inspiration phase and close again after the predetermined inspiration time has elapsed.

In practice, the flow rate at each instant during inspiration will depend on the flow rate that the branches of the open solenoid valves provide, at the gas pressure upstream of the solenoid valves; but it will also depend on the pressure in the patient's lungs, which will increase throughout inspiration. Through pressure sensors and / or flow meters in the pneumatic circuit, the controller can monitor and take into account, for the calculation of the predetermined flow, the increase in pressure in the lungs and / or the decrease in flow due to this back pressure, thus adjusting the predetermined flow rate, and the combination of solenoid valves to open, after each inspiration, to more precisely adjust the delivered volume to the desired tidal volume.

It can also be contemplated in some embodiments that the controller, determining or monitoring the flow rate directly or indirectly, for example in real time, modifies the combination of open solenoid valves during each inspiration, if necessary, in order to adjust flow in the most appropriate way.

In order to corroborate the volume actually delivered to the patient's lungs, a measurement of the instantaneous flow rate (Q) can be made, in real time, and integrated in the time between an initial moment (te) and a final moment (tf), with any known numerical method, thus determining the delivered gas volume (V):

C ^{QM = V}

The precision in the gas flow rate delivered to the patient's lungs depends on the number of branches in parallel with solenoid valves used: for example, with eight branches in parallel, each set at a different individual flow rate, the number of possible combinations is 8! (factorial of 8), that is to say up to 40,320 different combinations, which offer an accuracy comparable, or even higher, than that of a proportional valve with which known respirators are provided.

The expiration is carried out in a similar way to other known respirators.

As can be seen schematically in the diagram of figure 1, in one embodiment the respirator 10 according to the invention comprises a pneumatic circuit, in which the directions of flow of the gases have been indicated with arrows. The circuit comprises an oxygen line with a connector 20 for an external oxygen gas (O2) source, and an air line with a connector 30 for an external air source.

The oxygen line comprises an oxygen dosing unit 40, and the air line comprises an air dosing unit 50.

respectivamente.The oxygen dosing unit 40 comprises, as visible in the figure: a pressure sensor, a pressure regulator with a manometric indicator, and two parallel lines, in each of which there is a manually adjustable flow regulator, for example a needle valve, and a gate valve, for example a solenoid valve. The flow regulator for each branch is factory-adjusted, so that the two branches are set at different flow values: therefore, a higher oxygen flow passes through one of the two branches, and a higher flow passes through the other branch. lower oxygen, as indicated on the figure with signs

respectively.

By opening the shut-off valves of one or the other branch of the oxygen dosing unit 40, or of both branches, different oxygen flow rates can be dosed.

respectivamente.Similarly, the air-oxygen dosing unit 50 comprises, as can be seen in the figure: a pressure sensor, a pressure regulator with a manometric indicator, and two lines in parallel, in each of which there is a regulator. manually adjustable flow rate, for example a needle valve, and a bypass valve, for example a solenoid valve. The flow regulator for each branch is factory-set, so that the two branches are set at different flow values: therefore, a higher air flow passes through one of the two branches, and a lower air flow passes through the other branch, as indicated on the figure with signs

respectively.

By opening the shut-off valves of one or the other branch of the air dosing unit 50, or of both branches, different air flow rates can be dosed.

The oxygen and air lines are joined downstream of the respective dosage units 40 and 50, with the interposition of both non-return valves, so that from the point of union the oxygen and air are mixed forming the gas that will be supplied to the patient, in proportions that can be adjusted by properly opening or closing the shut-off valves of each of the branches of the dosing units 40 and 50: for example, the mixture will be very rich in oxygen if the shut-off valves of both are opened branches of unit 40, and the valve in branch "-" of unit 50.

In other embodiments, different numbers of branches can be provided, in order to increase the number of different dosable proportions. Embodiments of the respirator in which the mixing of air and oxygen is performed with other devices or solutions for mixing gases can also be contemplated.

Returning to figure 1, at the point in the circuit where the air and oxygen lines meet and the mixture of both occurs, a branch (towards the left in the figure) is connected to a quality control unit of gas 60. Unit 60 comprises a gas quality QT sensor, a purge valve to protect the circuit, and a pressure regulator. In other variants of the respirator, the gas quality control could be carried out in another known way, and / or at another point or section of the circuit.

The gas made up of the air-oxygen mixture to be supplied to the patient flows through a branch (in the figure, to the right from the junction point between the oxygen and air lines) in which there is a flow regulation unit 70, by means of which it is possible to adjust or regulate, for each patient and at each moment, the gas flow that is supplied to the patient's lungs.

Unit 70 comprises a plurality of calibrated branches 71,72, 73 .... 78 in parallel (eight in the case of this example, but which could be another number), each of which allows the passage of a predetermined gas flow, set at the factory. For this, each calibrated branch 71 to 78 comprises, for example, a solenoid valve (or another type of valve) to open or close the passage of gas through the branch and a flow regulator, for example a needle valve: needle valves or any other type of flow regulator or limiter are set (for example, at the factory) to a predetermined flow section, and therefore to a predetermined flow rate, as a function of pressure. In the present specification we will generally speak of setting "at a predetermined flow", as it is the current expression, although what is physically adjusted may be the through section. As can be seen in the figure, each branch 71 to 78 can further comprise a non-return valve.

By "calibrated branch" is understood here a branch of the pneumatic circuit configured so that it has a predetermined passage section, for example by means of a needle valve preset at the factory, so that the flow through the branch is predetermined, at a preset pressure, when its gate valve is open.

In relatively simple embodiments, the flow regulators of the calibrated branches 71 to 78 can all be set to the same flow value. In this case, by opening a greater or lesser number of calibrated branches 71 to 78 of the flow regulation unit 70, the flow or flow of gas supplied to the patient can be adjusted.

In other embodiments, each of the flow regulators of the calibrated branches 71 to 78 can be set to a different value of section or flow: in this case, the gas flow through the unit 70 as a whole depends on the combination of calibrated branches 71 to 78 that is open (that is, in which the corresponding bypass valve is open), and there are a very large number of possible combinations. In this way, a very fine adjustment of the gas flow to the patient can be made.

Downstream of the flow regulation unit 70 the gas flows through a general valve 80 which opens at the beginning of the operation, together with the valves of the unit 70; a flow meter or flow sensor 90; a pressure regulator or limiter 100 designed to prevent the admissible pressure for the patient from being exceeded; and a pressure sensor 110, which provides a measure of the pressure in the line in the vicinity of the outlet to the patient; and a safety valve 120. Next there is a connector 130, to which is attached, for example, a corrugated tube of those commonly used for tubing, which will conduct the gas to the patient's lungs.

In the inspiration phase, first the air and oxygen are received through the separate connections 20 and 30, the pressure is regulated to 2 bar-g by means of the pressure regulators, and the mixture of air and oxygen that the The doctor has previously programmed, using the dosage units 40 and 50. The concentration can then be measured to corroborate the action previously carried out. The mixture can then be directed to an automatic pressure regulator that can give the necessary pressure to cover the pressure losses in the circuit, and give the pressure required and necessary to bring the gas to the patient.

The gas flow is directed to the flow regulating unit 70, where the predetermined flow rate and the inspiration time are regulated. Gas exits the respirator into the usual vent tubes through connector 130.

As also shown in the figure, the respirator 10 further comprises an expiration line between a connector 140, to which is attached the corresponding tube from the patient's lungs, and one or more expiration or purge valves 170 (three in the example shown), through which the air expired by the patient is expelled to the environment, and which are controlled to open and close to allow the expiration of the patient and to maintain the desired PEEP. The expiration line further comprises a filter 150, for example a 0.01 µm superfine filter, and a flow sensor 160.

In the expiration phase, as in known respirators, the equipment stops supplying gas and waits for the patient to expire. Air leaves the patient and passes through the expiratory valve and filter and is pulled outside. The expiration time is set according to the selected inspiration time and I: E ratio.

Also schematically depicted in FIG. 1 are a programmable controller 200 and a data entry and display unit 210. The programmable controller 200 may comprise a PLC.

The controller 200 is connected to the unit 210 and to the sensors, valves and other elements of the pneumatic circuit, in order to make the necessary determinations from the inputs that the medical personnel make in the unit 210 and the readings of the sensors, control the process by acting on the valves and other elements of the circuit, and provide readings of the process variables through the unit 210.

In particular, the programmable controller 200 is arranged to determine and adjust the flow rate to be delivered to the patient, as explained above, and control the solenoid valves of the branches 71 to 78 of the flow regulation unit 70 in order to establish the determined flow rate.

The equipment can be planned and prepared to receive two plastic tubes with an internal diameter of 4 mm in two quick connections located in the structure of the equipment. These connections can be led to a differential pressure meter which can then be sent to the PLC to calculate the flow in real time, in order to carry out the flow measurements that may be necessary and for the correct operation and monitoring of the equipment. .

The equipment may require all those elements that are consumable in a conventional respirator. Mentioned, by way of example: expiration HEPA filter, expiration valve, fixed orifice flushometer, corrugated tube, humidifier, check valve (non-return), connection between the service gases and the equipment, and the necessary connections between the patient and equipment.

The equipment will be able to monitor, among others, the following parameters: inlet pressure of the two gases (air and O2), O2 concentration, equipment outlet pressure, inspiration pressure, inspiration and expiration flow, tidal volume, volume of inspiration, expiratory volume, PEEP, respiration rate, and inspiration-expiration ratio.

Also described herein is a method of applying mechanical respiration to a patient, which may comprise the steps of:

- providing a pneumatic circuit comprising at least one connection to a source of gas to be supplied to the patient, and a set of branches arranged in parallel, which can be the same or different from each other and each one provided with a solenoid valve; - depending on a predetermined inspiration time and a predetermined tidal volume to be applied to a patient, determining a flow rate to be delivered to the patient;

- determining a subset of branches such that the sum of the flow rates of the branches of the subset is the flow rate to be supplied to the patient; and

- opening said solenoid valves of said subset of branches for at least a part of the predetermined inspiration time.

The same subset of branches and corresponding solenoid valves can be open for the entire predetermined inspiration time; alternatively, it is possible to recalculate and determine in real time, throughout inspiration, the subset of branches and solenoid valves to open and close during inspiration.

Embodiments of the method can be implemented for example by a device according to one of the embodiments described or claimed herein.

Although only some particular embodiments and examples of the invention have been described herein, the skilled person will understand that other alternative embodiments and / or uses of the invention are possible, as well as obvious modifications and equivalent elements. Furthermore, the present invention encompasses all possible combinations of the specific embodiments that have been described. The numerical signs relative to the drawings and placed in parentheses in a claim are only to attempt to increase the understanding of the claim, and should not be construed as limiting the scope of protection of the claim. The scope of the present invention should not be limited to specific embodiments, but should be determined solely by a proper reading of the appended claims.

Claims (11)

1. Intubation mechanical respirator, comprising connections (20, 30, 130) to at least one source of gas and to at least one endotracheal tube intended to be introduced into a patient, a unit for regulating the flow of gas to the patient, and a programmable controller (200), characterized in that the flow regulation unit (70) comprises at least four calibrated branches (71 to 78) connected in parallel with each other, each of which comprises a bypass valve, and The programmable controller (200) is arranged to control the opening and closing of the bypass valve of each of the calibrated branches (71 to 78). Respirator according to claim 1, characterized in that each calibrated branch comprises a flow regulator that is set at a predetermined flow or passage section. Respirator according to claim 2, characterized in that the flow regulators of the calibrated branches (71 to 78) are set at a flow rate or a passage section that is different from one calibrated branch to another. Respirator according to any one of claims 2 or 3, characterized in that the flow regulators of the calibrated branches (71 to 78) are needle valves. Respirator according to any one of the preceding claims, characterized in that the passage valves of the calibrated branches (71 to 78) are solenoid valves. 6. Respirator according to any one of the preceding claims, characterized in that the programmable controller (200) is configured to open and close the different solenoid valves of the calibrated branches (71 to 78) to control the gas flow and the time of predetermined inspiration. Respirator according to any one of the preceding claims, characterized in that the flow regulation unit (70) comprises at least six calibrated branches (71 to 78). Respirator according to claim 7, characterized in that the flow regulation unit (70) comprises eight calibrated branches (71 to 78). Respirator according to any one of the preceding claims, characterized in that it comprises a connection (30) to an air source, a connection (20) to an oxygen source, and two dosage units (40, 50), each one connected to one of said connections (20, 30) and connected between them at the outlet, to mix air and oxygen in a predetermined ratio, the outlet of the two dosage units (40, 50) being arranged upstream with respect to the flow control unit (70). Respirator according to any one of the preceding claims, characterized in that it comprises a gas quality control unit (60) connected to the dosage units (40, 50). Respirator according to any one of the preceding claims, characterized in that the programmable controller (200) comprises a PLC.